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[sxemacs] / src / lread.c

/* Lisp parsing and input streams.
   Copyright (C) 1985-1989, 1992-1995 Free Software Foundation, Inc.
   Copyright (C) 1995 Tinker Systems.
   Copyright (C) 1996 Ben Wing.
   Copyright (C) 2004 Steve Youngs.

This file is part of SXEmacs

SXEmacs is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

SXEmacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>. */


/* Synched up with: Mule 2.0, FSF 19.30. */

/* This file has been Mule-ized. */

#include <config.h>
#include "lisp.h"

#include "buffer.h"
#include "bytecode.h"
#include "elhash.h"
#include "lstream.h"
#include "opaque.h"
#ifdef FILE_CODING
#include "mule/file-coding.h"
#endif
#include "ent/ent.h"

#include "sysfile.h"

Lisp_Object Qread_char, Qstandard_input;
Lisp_Object Qvariable_documentation;
#define LISP_BACKQUOTES
#ifdef LISP_BACKQUOTES
/*
   Nonzero means inside a new-style backquote
   with no surrounding parentheses.
   Fread initializes this to zero, so we need not specbind it
   or worry about what happens to it when there is an error.

SXEmacs:
   Nested backquotes are perfectly legal and fail utterly with
   this silliness. */
static int new_backquote_flag, old_backquote_flag;
Lisp_Object Qbackquote, Qbacktick, Qcomma, Qcomma_at, Qcomma_dot;
#endif
Lisp_Object Qvariable_domain;   /* I18N3 */
Lisp_Object Vvalues, Vstandard_input, Vafter_load_alist;
Lisp_Object Qcurrent_load_list;
Lisp_Object Qload, Qload_file_name;
Lisp_Object Qfset;
Lisp_Object Vload_suppress_alist;

/* Hash-table that maps directory names to hashes of their contents.  */
static Lisp_Object Vlocate_file_hash_table;

Lisp_Object Qexists, Qreadable, Qwritable, Qexecutable;

Lisp_Object Vureaders;

/* See read_escape() for an explanation of this.  */
#if 0
int fail_on_bucky_bit_character_escapes;
#endif

/* This symbol is also used in fns.c */
#define FEATUREP_SYNTAX

#ifdef FEATUREP_SYNTAX
Lisp_Object Qfeaturep;
#endif

/* non-zero if inside `load' */
int load_in_progress;

/* Whether Fload_internal() should check whether the .el is newer
   when loading .elc */
int load_warn_when_source_newer;
/* Whether Fload_internal() should check whether the .elc doesn't exist */
int load_warn_when_source_only;
/* Whether Fload_internal() should ignore .elc files when no suffix is given */
int load_ignore_elc_files;

/* Search path for files to be loaded. */
Lisp_Object Vload_path;

/* Search path for files when dumping. */
/* Lisp_Object Vdump_load_path; */

/* This is the user-visible association list that maps features to
   lists of defs in their load files. */
Lisp_Object Vload_history;

/* This is used to build the load history.  */
Lisp_Object Vcurrent_load_list;

/* Name of file actually being read by `load'.  */
Lisp_Object Vload_file_name;

/* Same as Vload_file_name but not Lisp-accessible.  This ensures that
   our #$ checks are reliable. */
Lisp_Object Vload_file_name_internal;

Lisp_Object Vload_file_name_internal_the_purecopy;

/* Function to use for reading, in `load' and friends.  */
Lisp_Object Vload_read_function;

/* The association list of objects read with the #n=object form.
   Each member of the list has the form (n . object), and is used to
   look up the object for the corresponding #n# construct.
   It must be set to nil before all top-level calls to read0.  */
Lisp_Object Vread_objects;

/* Nonzero means load should forcibly load all dynamic doc strings.  */
/* Note that this always happens (with some special behavior) when
   purify_flag is set. */
static int load_force_doc_strings;

/* List of descriptors now open for Fload_internal.  */
static Lisp_Object Vload_descriptor_list;

/* In order to implement "load_force_doc_strings", we keep
   a list of all the compiled-function objects and such
   that we have created in the process of loading this file.
   See the rant below.

   We specbind this just like Vload_file_name, so there's no
   problems with recursive loading. */
static Lisp_Object Vload_force_doc_string_list;

/* A resizing-buffer stream used to temporarily hold data while reading */
static Lisp_Object Vread_buffer_stream;

#ifdef COMPILED_FUNCTION_ANNOTATION_HACK
Lisp_Object Vcurrent_compiled_function_annotation;
#endif

static int load_byte_code_version;

/* An array describing all known built-in structure types */
static structure_type_dynarr *the_structure_type_dynarr;

#if 0                           /* FSF defun hack */
/* When nonzero, read conses in pure space */
static int read_pure;
#endif

#if 0                           /* FSF stuff */
/* For use within read-from-string (this reader is non-reentrant!!)  */
static int read_from_string_index;
static int read_from_string_limit;
#endif

/* parser hook for resclass objects */
int(*ase_resc_rng_pred_f)(const char *cp) = NULL;
int(*ase_resc_elm_pred_f)(const char *cp) = NULL;
Lisp_Object(*ase_resc_rng_f)(char *cp) = NULL;
Lisp_Object(*ase_resc_elm_f)(char *cp) = NULL;
/* parser hook for perms */
Lisp_Object(*ase_permutation_f)(Lisp_Object);


#if 0                           /* More FSF implementation kludges. */
/* In order to implement load-force-doc-string, FSF saves the
   #@-quoted string when it's seen, and goes back and retrieves
   it later.

   This approach is not only kludgy, but it in general won't work
   correctly because there's no stack of remembered #@-quoted-strings
   and those strings don't generally appear in the file in the same
   order as their #$ references. (Yes, that is amazingly stupid too.

   It would be trivially easy to always encode the #@ string
   [which is a comment, anyway] in the middle of the (#$ . INT) cons
   reference.  That way, it would be really easy to implement
   load-force-doc-string in a non-kludgy way by just retrieving the
   string immediately, because it's delivered on a silver platter.)

   And finally, this stupid approach doesn't work under Mule, or
   under MS-DOS or Windows NT, or under VMS, or any other place
   where you either can't do an ftell() or don't get back a byte
   count.

   Oh, and one more lossage in this approach: If you attempt to
   dump any ELC files that were compiled with `byte-compile-dynamic'
   (as opposed to just `byte-compile-dynamic-docstring'), you
   get hosed.  FMH! (as the illustrious JWZ was prone to utter)

   The approach we use is clean, solves all of these problems, and is
   probably easier to implement anyway.  We just save a list of all
   the containing objects that have (#$ . INT) conses in them (this
   will only be compiled-function objects and lists), and when the
   file is finished loading, we go through and fill in all the
   doc strings at once. */

 /* This contains the last string skipped with #@.  */
static char *saved_doc_string;
/* Length of buffer allocated in saved_doc_string.  */
static int saved_doc_string_size;
/* Length of actual data in saved_doc_string.  */
static int saved_doc_string_length;
/* This is the file position that string came from.  */
static int saved_doc_string_position;
#endif

EXFUN(Fread_from_string, 3);

/* When errors are signaled, the actual readcharfun should not be used
   as an argument if it is an lstream, so that lstreams don't escape
   to the Lisp level.  */
#define READCHARFUN_MAYBE(x) (LSTREAMP (x)                                      \
                              ? (build_string ("internal input stream"))        \
                              : (x))
\f
static DOESNT_RETURN read_syntax_error(const char *string)
{
        signal_error(Qinvalid_read_syntax,
                     list1(build_translated_string(string)));
}

static Lisp_Object continuable_read_syntax_error(const char *string)
{
        return Fsignal(Qinvalid_read_syntax,
                       list1(build_translated_string(string)));
}
\f
/* Handle unreading and rereading of characters. */
static Emchar readchar(Lisp_Object readcharfun)
{
        /* This function can GC */

        if (BUFFERP(readcharfun)) {
                Emchar c;
                struct buffer *b = XBUFFER(readcharfun);

                if (!BUFFER_LIVE_P(b))
                        error("Reading from killed buffer");

                if (BUF_PT(b) >= BUF_ZV(b))
                        return -1;
                c = BUF_FETCH_CHAR(b, BUF_PT(b));
                BUF_SET_PT(b, BUF_PT(b) + 1);

                return c;
        } else if (LSTREAMP(readcharfun)) {
                Emchar c = Lstream_get_emchar(XLSTREAM(readcharfun));
#ifdef DEBUG_SXEMACS            /* testing Mule */
                static int testing_mule = 0;    /* Change via debugger */
                if (testing_mule) {
                        if (c >= 0x20 && c <= 0x7E)
                                stderr_out("%c", c);
                        else if (c == '\n')
                                stderr_out("\\n\n");
                        else
                                stderr_out("\\%o ", c);
                }
#endif                          /* testing Mule */
                return c;
        } else if (MARKERP(readcharfun)) {
                Emchar c;
                Bufpos mpos = marker_position(readcharfun);
                struct buffer *inbuffer = XMARKER(readcharfun)->buffer;

                if (mpos >= BUF_ZV(inbuffer))
                        return -1;
                c = BUF_FETCH_CHAR(inbuffer, mpos);
                set_marker_position(readcharfun, mpos + 1);
                return c;
        } else {
                Lisp_Object tem = call0(readcharfun);

                if (!CHAR_OR_CHAR_INTP(tem))
                        return -1;
                return XCHAR_OR_CHAR_INT(tem);
        }
}

/* Unread the character C in the way appropriate for the stream READCHARFUN.
   If the stream is a user function, call it with the char as argument.  */

static void unreadchar(Lisp_Object readcharfun, Emchar c)
{
        if (c == -1)
                /* Don't back up the pointer if we're unreading the end-of-input mark,
                   since readchar didn't advance it when we read it.  */
                ;
        else if (BUFFERP(readcharfun))
                BUF_SET_PT(XBUFFER(readcharfun),
                           BUF_PT(XBUFFER(readcharfun)) - 1);
        else if (LSTREAMP(readcharfun)) {
                Lstream_unget_emchar(XLSTREAM(readcharfun), c);
#ifdef DEBUG_SXEMACS            /* testing Mule */
                {
                        static int testing_mule = 0;    /* Set this using debugger */
                        if (testing_mule)
                                fprintf(stderr,
                                        (c >= 0x20 && c <= 0x7E) ? "UU%c" :
                                        ((c == '\n') ? "UU\\n\n" : "UU\\%o"),
                                        c);
                }
#endif
        } else if (MARKERP(readcharfun))
                set_marker_position(readcharfun,
                                    marker_position(readcharfun) - 1);
        else
                call1(readcharfun, make_char(c));
}

static Lisp_Object read0(Lisp_Object readcharfun);
static Lisp_Object read1(Lisp_Object readcharfun);
/* allow_dotted_lists means that something like (foo bar . baz)
   is acceptable.  If -1, means check for starting with defun
   and make structure pure. (not implemented, probably for very
   good reasons)
*/
/*
   If check_for_doc_references, look for (#$ . INT) doc references
   in the list and record if load_force_doc_strings is non-zero.
   (Such doc references will be destroyed during the loadup phase
   by replacing with Qzero, because Snarf-documentation will fill
   them in again.)

   WARNING: If you set this, you sure as hell better not call
   free_list() on the returned list here. */

static Lisp_Object read_list(Lisp_Object readcharfun,
                             Emchar terminator,
                             int allow_dotted_lists,
                             int check_for_doc_references);
\f
static void readevalloop(Lisp_Object readcharfun,
                         Lisp_Object sourcefile,
                         Lisp_Object(*evalfun) (Lisp_Object), int printflag);

static Lisp_Object load_unwind(Lisp_Object stream)
{                               /* used as unwind-protect function in load */
        Lstream_close(XLSTREAM(stream));
        if (--load_in_progress < 0)
                load_in_progress = 0;
        return Qnil;
}

static Lisp_Object load_descriptor_unwind(Lisp_Object oldlist)
{
        Vload_descriptor_list = oldlist;
        return Qnil;
}

static Lisp_Object load_file_name_internal_unwind(Lisp_Object oldval)
{
        Vload_file_name_internal = oldval;
        return Qnil;
}

static Lisp_Object
load_file_name_internal_the_purecopy_unwind(Lisp_Object oldval)
{
        Vload_file_name_internal_the_purecopy = oldval;
        return Qnil;
}

static Lisp_Object load_byte_code_version_unwind(Lisp_Object oldval)
{
        load_byte_code_version = XINT(oldval);
        return Qnil;
}

static inline int
suppressedp_loop(int len, char *nonreloc, Lisp_Object reloc)
{
        EXTERNAL_LIST_LOOP_2(_acons_, Vload_suppress_alist) {
                if (CONSP(_acons_) && STRINGP(XCAR(_acons_))) {
                        Lisp_Object name = XCAR(_acons_);
                        if (XSTRING_LENGTH(name) == len &&
                            !memcmp(XSTRING_DATA(name), nonreloc, len)) {
                                struct gcpro gcpro1;
                                Lisp_Object val;

                                GCPRO1(reloc);
                                val = Feval(XCDR(_acons_));
                                UNGCPRO;

                                if (!NILP(val))
                                        return 1;
                        }
                }
        }
        return 0;
}

static int
suppressedp(char *nonreloc, Lisp_Object reloc)
{
/* Check if NONRELOC/RELOC (an absolute filename) is suppressed according
   to load-suppress-alist. */
        int len;

        if (!NILP (reloc)) {
                nonreloc = (char*)XSTRING_DATA(reloc);
                len = XSTRING_LENGTH(reloc);
        } else {
                len = strlen(nonreloc);
        }
        if (len >= 4 && !strcmp(nonreloc + len - 4, ".elc"))
                len -= 4;
        else if (len >= 3 && !strcmp(nonreloc + len - 3, ".el"))
                len -= 3;

        return suppressedp_loop(len, nonreloc, reloc);
}

/* The plague is coming.

   Ring around the rosy, pocket full of posy,
   Ashes ashes, they all fall down.
   */
void ebolify_bytecode_constants(Lisp_Object vector)
{
        int len = XVECTOR_LENGTH(vector);
        int i;

        for (i = 0; i < len; i++) {
                Lisp_Object el = XVECTOR_DATA(vector)[i];

                /* We don't check for `eq', `equal', and the others that have
                   bytecode opcodes.  This might lose if someone passes #'eq or
                   something to `funcall', but who would really do that?  As
                   they say in law, we've made a "good-faith effort" to
                   unfuckify ourselves.  And doing it this way avoids screwing
                   up args to `make-hash-table' and such.  As it is, we have to
                   add an extra Ebola check in decode_weak_list_type(). --ben */
                if (EQ(el, Qassoc))
                        el = Qold_assoc;
                else if (EQ(el, Qdelq))
                        el = Qold_delq;
#if 0
                /* I think this is a bad idea because it will probably mess
                   with keymap code. */
                else if (EQ(el, Qdelete))
                        el = Qold_delete;
#endif
                else if (EQ(el, Qrassq))
                        el = Qold_rassq;
                else if (EQ(el, Qrassoc))
                        el = Qold_rassoc;

                XVECTOR_DATA(vector)[i] = el;
        }
}

static Lisp_Object pas_de_lache_ici(int fd, Lisp_Object victim)
{
        Lisp_Object tem;
        EMACS_INT pos;

        if (!INTP(XCDR(victim)))
                signal_simple_error("Bogus doc string reference", victim);
        pos = XINT(XCDR(victim));
        if (pos < 0)
                pos = -pos;     /* kludge to mark a user variable */
        tem = unparesseuxify_doc_string(fd, pos, 0, Vload_file_name_internal);
        if (!STRINGP(tem))
                signal_error(Qerror, tem);
        return tem;
}

static Lisp_Object load_force_doc_string_unwind(Lisp_Object oldlist)
{
        struct gcpro gcpro1;
        Lisp_Object list = Vload_force_doc_string_list;
        Lisp_Object tail;
        int fd = XINT(XCAR(Vload_descriptor_list));

        GCPRO1(list);
        /* restore the old value first just in case an error occurs. */
        Vload_force_doc_string_list = oldlist;

        LIST_LOOP(tail, list) {
                Lisp_Object john = Fcar(tail);
                if (CONSP(john)) {
                        assert(CONSP(XCAR(john)));
                        assert(!purify_flag);   /* should have been handled in read_list() */
                        XCAR(john) = pas_de_lache_ici(fd, XCAR(john));
                } else {
                        Lisp_Object doc;

                        assert(COMPILED_FUNCTIONP(john));
                        if (CONSP(XCOMPILED_FUNCTION(john)->instructions)) {
                                struct gcpro ngcpro1;
                                Lisp_Object juan = (pas_de_lache_ici
                                                    (fd,
                                                     XCOMPILED_FUNCTION(john)->
                                                     instructions));
                                Lisp_Object ivan;

                                NGCPRO1(juan);
                                ivan = Fread(juan);
                                if (!CONSP(ivan))
                                        signal_simple_error
                                            ("invalid lazy-loaded byte code",
                                             ivan);
                                XCOMPILED_FUNCTION(john)->instructions =
                                    XCAR(ivan);
                                /* v18 or v19 bytecode file.  Need to Ebolify. */
                                if (XCOMPILED_FUNCTION(john)->flags.ebolified
                                    && VECTORP(XCDR(ivan)))
                                        ebolify_bytecode_constants(XCDR(ivan));
                                XCOMPILED_FUNCTION(john)->constants =
                                    XCDR(ivan);
                                NUNGCPRO;
                        }
                        doc =
                            compiled_function_documentation(XCOMPILED_FUNCTION
                                                            (john));
                        if (CONSP(doc)) {
                                assert(!purify_flag);   /* should have been handled in
                                                           read_compiled_function() */
                                doc = pas_de_lache_ici(fd, doc);
                                set_compiled_function_documentation
                                    (XCOMPILED_FUNCTION(john), doc);
                        }
                }
        }

        if (!NILP(list))
                free_list(list);

        UNGCPRO;
        return Qnil;
}

/* Close all descriptors in use for Fload_internal.
   This is used when starting a subprocess.  */

void close_load_descs(void)
{
        Lisp_Object tail;
        LIST_LOOP(tail, Vload_descriptor_list)
            close(XINT(XCAR(tail)));
}

#ifdef I18N3
Lisp_Object Vfile_domain;

Lisp_Object restore_file_domain(Lisp_Object val)
{
        Vfile_domain = val;
        return Qnil;
}
#endif                          /* I18N3 */

DEFUN("load-internal", Fload_internal, 1, 6, 0, /*
Execute a file of Lisp code named FILE; no coding-system frobbing.
This function is identical to `load' except for the handling of the
CODESYS and USED-CODESYS arguments under SXEmacs/Mule. (When Mule
support is not present, both functions are identical and ignore the
CODESYS and USED-CODESYS arguments.)

If support for Mule exists in this Emacs, the file is decoded
according to CODESYS; if omitted, no conversion happens.  If
USED-CODESYS is non-nil, it should be a symbol, and the actual coding
system that was used for the decoding is stored into it.  It will in
general be different from CODESYS if CODESYS specifies automatic
encoding detection or end-of-line detection.
*/
      (file, noerror, nomessage, nosuffix, codesys, used_codesys))
{
        /* This function can GC */
        int fd = -1;
        int speccount = specpdl_depth();
        int source_only = 0;
        Lisp_Object newer = Qnil;
        Lisp_Object handler = Qnil;
        Lisp_Object found = Qnil;
        struct gcpro gcpro1, gcpro2, gcpro3;
        int reading_elc = 0;
        int message_p = NILP(nomessage);
/*#ifdef DEBUG_SXEMACS*/
        static Lisp_Object last_file_loaded;
/*#endif*/
        struct stat s1, s2;
        GCPRO3(file, newer, found);

        CHECK_STRING(file);

/*#ifdef DEBUG_SXEMACS*/
        if (purify_flag && noninteractive) {
                message_p = 1;
                last_file_loaded = file;
        }
/*#endif / * DEBUG_SXEMACS */

        /* If file name is magic, call the handler.  */
        handler = Ffind_file_name_handler(file, Qload);
        if (!NILP(handler))
                RETURN_UNGCPRO(call5(handler, Qload, file, noerror,
                                     nomessage, nosuffix));

        /* Do this after the handler to avoid
           the need to gcpro noerror, nomessage and nosuffix.
           (Below here, we care only whether they are nil or not.)  */
        file = Fsubstitute_in_file_name(file);
#ifdef FILE_CODING
        if (!NILP(used_codesys))
                CHECK_SYMBOL(used_codesys);
#endif

        /* Avoid weird lossage with null string as arg,
           since it would try to load a directory as a Lisp file.
           Unix truly sucks. */
        if (XSTRING_LENGTH(file) > 0) {
                char *foundstr;
                int foundlen;

                fd = locate_file(Vload_path, file,
                                 ((!NILP(nosuffix))
                                  ? Qnil
                                  : build_string(load_ignore_elc_files
                                                 ? ".el:"
                                                 : ".elc:.el:")), &found, -1);

                if (fd < 0) {
                        if (NILP(noerror)) {
                                signal_file_error("Cannot open load file",
                                                  file);
                        } else {
                                UNGCPRO;
                                return Qnil;
                        }
                }

                foundlen = XSTRING_LENGTH(found);
                foundstr = (char *)alloca( foundlen+ 1);
                strncpy(foundstr, (char *)XSTRING_DATA(found), foundlen+1);


                /* The omniscient JWZ thinks this is worthless, but I beg to
                   differ. --ben */
                if (load_ignore_elc_files) {
                        newer = Ffile_name_nondirectory(found);
                } else if (load_warn_when_source_newer &&
                           !memcmp(".elc", foundstr + foundlen - 4, 4)) {
                        if (!fstat(fd, &s1)) {  /* can't fail, right? */
                                int result;
                                /* temporarily hack the 'c' off the end of the
                                   filename */
                                foundstr[foundlen - 1] = '\0';
                                result = sxemacs_stat(foundstr, &s2);
                                if (result >= 0 &&
                                    (unsigned)s1.st_mtime <
                                    (unsigned)s2.st_mtime) {
                                        Lisp_Object newer_name =
                                                make_string((Bufbyte*)foundstr,
                                                            foundlen - 1);
                                        struct gcpro nngcpro1;
                                        NNGCPRO1(newer_name);
                                        newer = Ffile_name_nondirectory(
                                                newer_name);
                                        NNUNGCPRO;
                                }
                                /* put the 'c' back on (kludge-o-rama) */
                                foundstr[foundlen - 1] = 'c';
                        }
                } else if (load_warn_when_source_only &&
                           /* `found' ends in ".el" */
                           !memcmp(".el", foundstr + foundlen - 3, 3) &&
                           /* `file' does not end in ".el" */
                           memcmp(".el",
                                  XSTRING_DATA(file) + XSTRING_LENGTH(file) - 3,
                                  3)) {
                        source_only = 1;
                }

                if (!memcmp(".elc", foundstr + foundlen - 4, 4))
                        reading_elc = 1;
        }
#define PRINT_LOADING_MESSAGE(done)                                     \
        do {                                                            \
                if (load_ignore_elc_files) {                            \
                        if (message_p) {                                \
                                message("Loading %s..." done,           \
                                        XSTRING_DATA(newer));           \
                        }                                               \
                } else if (!NILP(newer)) {                              \
                        message("Loading %s..." done " (file %s is newer)", \
                                XSTRING_DATA(file),                     \
                                XSTRING_DATA(newer));                   \
                } else if (source_only) {                               \
                        Lisp_Object tmp = Ffile_name_nondirectory(file); \
                        message("Loading %s..." done                    \
                                " (file %s.elc does not exist)",        \
                                XSTRING_DATA(file),                     \
                                XSTRING_DATA(tmp)); \
                } else if (message_p) {                                 \
                        message("Loading %s..." done,                   \
                                XSTRING_DATA(file));                    \
                }                                                       \
        } while (0)

        PRINT_LOADING_MESSAGE("");

        {
                /* Lisp_Object's must be malloc'ed, not stack-allocated */
                Lisp_Object lstrm = Qnil;
                const int block_size = 8192;
                struct gcpro ngcpro1;

                NGCPRO1(lstrm);
               if (fd < 0)
                      signal_file_error("Cannot open load file", file);

                lstrm = make_filedesc_input_stream(fd, 0, -1, LSTR_CLOSING);
                /* 64K is used for normal files; 8K should be OK here because
                 * Lisp files aren't really all that big. */
                Lstream_set_buffering(XLSTREAM(lstrm),
                                      LSTREAM_BLOCKN_BUFFERED, block_size);
#ifdef FILE_CODING
                lstrm = make_decoding_input_stream(
                        XLSTREAM(lstrm), Fget_coding_system(codesys));
                Lstream_set_buffering(XLSTREAM(lstrm),
                                      LSTREAM_BLOCKN_BUFFERED, block_size);
#endif
                /* NOTE: Order of these is very important.
                 * Don't rearrange them. */
                record_unwind_protect(load_unwind, lstrm);
                record_unwind_protect(load_descriptor_unwind,
                                      Vload_descriptor_list);
                record_unwind_protect(load_file_name_internal_unwind,
                                      Vload_file_name_internal);
                record_unwind_protect(
                        load_file_name_internal_the_purecopy_unwind,
                        Vload_file_name_internal_the_purecopy);
                record_unwind_protect(load_force_doc_string_unwind,
                                      Vload_force_doc_string_list);
                Vload_file_name_internal = found;
                Vload_file_name_internal_the_purecopy = Qnil;
                specbind(Qload_file_name, found);
                Vload_descriptor_list =
                        Fcons(make_int(fd), Vload_descriptor_list);
                Vload_force_doc_string_list = Qnil;
#ifdef I18N3
                record_unwind_protect(restore_file_domain, Vfile_domain);
                /* set it to nil; a call to #'domain will set it. */
                Vfile_domain = Qnil;
#endif
                load_in_progress++;

                /* Now determine what sort of ELC file we're reading in. */
                record_unwind_protect(load_byte_code_version_unwind,
                                      make_int(load_byte_code_version));
                if (reading_elc) {
                        char elc_header[8];
                        int num_read;

                        num_read = Lstream_read(XLSTREAM(lstrm), elc_header, 8);
                        if (num_read < 8 || strncmp(elc_header, ";ELC", 4)) {
                                /* Huh?  Probably not a valid ELC file. */
                                /* no Ebolification needed */
                                load_byte_code_version = 100;
                                Lstream_unread(XLSTREAM(lstrm), elc_header,
                                               num_read);
                        } else {
                                load_byte_code_version = elc_header[4];
                        }
                } else {
                        /* no Ebolification needed */
                        load_byte_code_version = 100;
                }

                readevalloop(lstrm, file, Feval, 0);
#ifdef FILE_CODING
                if (!NILP(used_codesys)) {
                        Lisp_Object tmp =
                                decoding_stream_coding_system(XLSTREAM(lstrm));
                        Fset(used_codesys, XCODING_SYSTEM_NAME(tmp));
                }
#endif
                unbind_to(speccount, Qnil);

                NUNGCPRO;
        }

        {
                Lisp_Object tem;
                /* #### Disgusting kludge */
                /* Run any load-hooks for this file.  */
                /* #### An even more disgusting kludge.  There is horrible code */
                /* that is relying on the fact that dumped lisp files are found */
                /* via `load-path' search. */
                Lisp_Object name = file;

                if (!NILP(Ffile_name_absolute_p(file))) {
                        name = Ffile_name_nondirectory(file);
                }

                {
                        struct gcpro ngcpro1;

                        NGCPRO1(name);
                        tem = Fassoc(name, Vafter_load_alist);
                        NUNGCPRO;
                }
                if (!NILP(tem)) {
                        struct gcpro ngcpro1;

                        NGCPRO1(tem);
                        /* Use eval so that errors give a semi-meaningful
                         * backtrace.  --Stig */
                        tem = Fcons(Qprogn, Fcdr(tem));
                        Feval(tem);
                        NUNGCPRO;
                }
        }

/*#ifdef DEBUG_SXEMACS*/
        if (purify_flag && noninteractive) {
                if (!EQ(last_file_loaded, file)) {
                        message("Loading %s ...done", XSTRING_DATA(file));
                }
        }
/*#endif / * DEBUG_SXEMACS */

        if (!noninteractive) {
                PRINT_LOADING_MESSAGE("done");
        }
        UNGCPRO;
        return Qt;
}
\f
/* ------------------------------- */
/*          locate_file            */
/* ------------------------------- */

static int decode_mode_1(Lisp_Object mode)
{
        if (EQ(mode, Qexists))
                return F_OK;
        else if (EQ(mode, Qexecutable))
                return X_OK;
        else if (EQ(mode, Qwritable))
                return W_OK;
        else if (EQ(mode, Qreadable))
                return R_OK;
        else if (INTP(mode)) {
                check_int_range(XINT(mode), 0, 7);
                return XINT(mode);
        } else
                signal_simple_error("Invalid value", mode);
        return 0;               /* unreached */
}

static int decode_mode(Lisp_Object mode)
{
        if (NILP(mode))
                return R_OK;
        else if (CONSP(mode)) {
                Lisp_Object tail;
                int mask = 0;
                EXTERNAL_LIST_LOOP(tail, mode)
                    mask |= decode_mode_1(XCAR(tail));
                return mask;
        } else
                return decode_mode_1(mode);
}

DEFUN("locate-file", Flocate_file, 2, 4, 0,     /*
Search for FILENAME through PATH-LIST.
If SUFFIXES is non-nil, it should be a list of suffixes to append to
file name when searching.

If MODE is non-nil, it should be a symbol or a list of symbol representing
requirements.  Allowed symbols are `exists', `executable', `writable', and
`readable'.  If MODE is nil, it defaults to `readable'.

Filenames are checked against `load-suppress-alist' to determine if they
should be ignored.

`locate-file' keeps hash tables of the directories it searches through,
in order to speed things up.  It tries valiantly to not get confused in
the face of a changing and unpredictable environment, but can occasionally
get tripped up.  In this case, you will have to call
`locate-file-clear-hashing' to get it back on track.  See that function
for details.
*/
      (filename, path_list, suffixes, mode))
{
        /* This function can GC */
        Lisp_Object tp;

        CHECK_STRING(filename);

        if (LISTP(suffixes)) {
                Lisp_Object tail;
                EXTERNAL_LIST_LOOP(tail, suffixes)
                    CHECK_STRING(XCAR(tail));
        } else
                CHECK_STRING(suffixes);

        locate_file(path_list, filename, suffixes, &tp, decode_mode(mode));
        return tp;
}

/* Recalculate the hash table for the given string.  DIRECTORY should
   better have been through Fexpand_file_name() by now.  */

static Lisp_Object locate_file_refresh_hashing(Lisp_Object directory)
{
        Lisp_Object hash =
            make_directory_hash_table((char *)XSTRING_DATA(directory));

        if (!NILP(hash))
                Fputhash(directory, hash, Vlocate_file_hash_table);
        return hash;
}

/* find the hash table for the given directory, recalculating if necessary */

static Lisp_Object locate_file_find_directory_hash_table(Lisp_Object directory)
{
        Lisp_Object hash = Fgethash(directory, Vlocate_file_hash_table, Qnil);
        if (NILP(hash))
                return locate_file_refresh_hashing(directory);
        else
                return hash;
}

/* The SUFFIXES argument in any of the locate_file* functions can be
   nil, a list, or a string (for backward compatibility), with the
   following semantics:

   a) nil    - no suffix, just search for file name intact
               (semantically different from "empty suffix list", which
               would be meaningless.)
   b) list   - list of suffixes to append to file name.  Each of these
               must be a string.
   c) string - colon-separated suffixes to append to file name (backward
               compatibility).

   All of this got hairy, so I decided to use a mapper.  Calling a
   function for each suffix shouldn't slow things down, since
   locate_file is rarely called with enough suffixes for funcalls to
   make any difference.  */

/* Map FUN over SUFFIXES, as described above.  FUN will be called with a
   char * containing the current file name, and ARG.  Mapping stops when
   FUN returns non-zero. */
static void
locate_file_map_suffixes(Lisp_Object filename, Lisp_Object suffixes,
                         int (*fun) (char *, void *), void *arg)
{
        /* This function can GC */
        char *fn;
        int fn_len, max;

        /* Calculate maximum size of any filename made from
           this path element/specified file name and any possible suffix.  */
        if (CONSP(suffixes)) {
                /* We must traverse the list, so why not do it right. */
                Lisp_Object tail;
                max = 0;
                LIST_LOOP(tail, suffixes) {
                        if (XSTRING_LENGTH(XCAR(tail)) > max)
                                max = XSTRING_LENGTH(XCAR(tail));
                }
        } else if (NILP(suffixes))
                max = 0;
        else
                /* Just take the easy way out */
                max = XSTRING_LENGTH(suffixes);

        fn_len = XSTRING_LENGTH(filename);
        fn = (char *)alloca(max + fn_len + 1);
        memcpy(fn, (char *)XSTRING_DATA(filename), fn_len);

        /* Loop over suffixes.  */
        if (!STRINGP(suffixes)) {
                if (NILP(suffixes)) {
                        /* Case a) discussed in the comment above. */
                        fn[fn_len] = 0;
                        if ((*fun) (fn, arg))
                                return;
                } else {
                        /* Case b) */
                        Lisp_Object tail;
                        LIST_LOOP(tail, suffixes) {
                                memcpy(fn + fn_len, XSTRING_DATA(XCAR(tail)),
                                       XSTRING_LENGTH(XCAR(tail)));
                                fn[fn_len + XSTRING_LENGTH(XCAR(tail))] = 0;
                                if ((*fun) (fn, arg))
                                        return;
                        }
                }
        } else {
                /* Case c) */
                const char *nsuffix = (const char *)XSTRING_DATA(suffixes);

                while (1) {
                        char *esuffix = (char *)strchr(nsuffix, ':');
                        int lsuffix =
                            esuffix ? esuffix - nsuffix : (int)strlen(nsuffix);

                        /* Concatenate path element/specified name with the suffix.  */
                        strncpy(fn + fn_len, nsuffix, lsuffix);
                        fn[fn_len + lsuffix] = '\0';

                        if ((*fun) (fn, arg))
                                return;

                        /* Advance to next suffix.  */
                        if (esuffix == 0)
                                break;
                        nsuffix += lsuffix + 1;
                }
        }
}

struct locate_file_in_directory_mapper_closure {
        int fd;
        Lisp_Object *storeptr;
        int mode;
};

static int locate_file_in_directory_mapper(char *fn, void *arg)
{
        struct locate_file_in_directory_mapper_closure *closure =
            (struct locate_file_in_directory_mapper_closure *)arg;
        struct stat st;

        /* Ignore file if it's a directory.  */
        if (sxemacs_stat(fn, &st) >= 0 && (st.st_mode & S_IFMT) != S_IFDIR) {
                /* Check that we can access or open it.  */
                if (closure->mode >= 0)
                        closure->fd = access(fn, closure->mode);
                else
                        closure->fd = open(fn, O_RDONLY | OPEN_BINARY, 0);

                if (closure->fd >= 0) {
                        if (!suppressedp(fn, Qnil)) {
                                /* We succeeded; return this descriptor and
                                   filename.  */
                                if (closure->storeptr)
                                        *closure->storeptr = build_string(fn);

                                /* If we actually opened the file, set
                                   close-on-exec flag on the new descriptor so
                                   that subprocesses can't whack at it.  */
                                if (closure->mode < 0)
                                        (void)fcntl(closure->fd,
                                                    F_SETFD, FD_CLOEXEC);

                                return 1;
                        } else {
                                /* Avoid closing stdin upon success of
                                   access, where closure->fd would be
                                   0 but the file is not open on that
                                   descriptor
                                */
                                if(closure->fd > 0)
                                        close(closure->fd);
                                closure->fd=-1;
                        }
                }
        }
        /* Keep mapping. */
        return 0;
}

/* look for STR in PATH, optionally adding SUFFIXES.  DIRECTORY need
   not have been expanded.  */

static int
locate_file_in_directory(Lisp_Object directory, Lisp_Object str,
                         Lisp_Object suffixes, Lisp_Object * storeptr, int mode)
{
        /* This function can GC */
        struct locate_file_in_directory_mapper_closure closure;
        Lisp_Object filename = Qnil;
        struct gcpro gcpro1, gcpro2, gcpro3;

        GCPRO3(directory, str, filename);

        filename = Fexpand_file_name(str, directory);
        if (NILP(filename) || NILP(Ffile_name_absolute_p(filename)))
                /* If there are non-absolute elts in PATH (eg ".") */
                /* Of course, this could conceivably lose if luser sets
                   default-directory to be something non-absolute ... */
        {
                if (NILP(filename))
                        /* NIL means current directory */
                        filename = current_buffer->directory;
                else
                        filename = Fexpand_file_name(filename,
                                                     current_buffer->directory);
                if (NILP(Ffile_name_absolute_p(filename))) {
                        /* Give up on this directory! */
                        UNGCPRO;
                        return -1;
                }
        }

        closure.fd = -1;
        closure.storeptr = storeptr;
        closure.mode = mode;

        locate_file_map_suffixes(filename, suffixes,
                                 locate_file_in_directory_mapper, &closure);

        UNGCPRO;
        return closure.fd;
}

/* do the same as locate_file() but don't use any hash tables. */

static int
locate_file_without_hash(Lisp_Object path, Lisp_Object str,
                         Lisp_Object suffixes, Lisp_Object * storeptr, int mode)
{
        /* This function can GC */
        int absolute = !NILP(Ffile_name_absolute_p(str));

        EXTERNAL_LIST_LOOP(path, path) {
                int val =
                    locate_file_in_directory(XCAR(path), str, suffixes,
                                             storeptr,
                                             mode);
                if (val >= 0)
                        return val;
                if (absolute)
                        break;
        }
        return -1;
}

static int locate_file_construct_suffixed_files_mapper(char *fn, void *arg)
{
        Lisp_Object *tail = (Lisp_Object *) arg;
        *tail = Fcons(build_string(fn), *tail);
        return 0;
}

/* Construct a list of all files to search for.
   It makes sense to have this despite locate_file_map_suffixes()
   because we need Lisp strings to access the hash-table, and it would
   be inefficient to create them on the fly, again and again for each
   path component.  See locate_file(). */

static Lisp_Object
locate_file_construct_suffixed_files(Lisp_Object filename, Lisp_Object suffixes)
{
        Lisp_Object tail = Qnil;
        struct gcpro gcpro1;
        GCPRO1(tail);

        locate_file_map_suffixes(filename, suffixes,
                                 locate_file_construct_suffixed_files_mapper,
                                 &tail);

        UNGCPRO;
        return Fnreverse(tail);
}

DEFUN("locate-file-clear-hashing", Flocate_file_clear_hashing, 1, 1, 0, /*
Clear the hash records for the specified list of directories.
`locate-file' uses a hashing scheme to speed lookup, and will correctly
track the following environmental changes:

  -- changes of any sort to the list of directories to be searched.
  -- addition and deletion of non-shadowing files (see below) from the
     directories in the list.
  -- byte-compilation of a .el file into a .elc file.

`locate-file' will primarily get confused if you add a file that shadows
\(i.e. has the same name as) another file further down in the directory list.
In this case, you must call `locate-file-clear-hashing'.

If PATH is t, it means to fully clear all the accumulated hashes.  This
can be used if the internal tables grow too large, or when dumping.
*/
      (path))
{
        if (EQ(path, Qt))
                Fclrhash(Vlocate_file_hash_table);
        else {
                Lisp_Object pathtail;
                EXTERNAL_LIST_LOOP(pathtail, path) {
                        Lisp_Object pathel =
                            Fexpand_file_name(XCAR(pathtail), Qnil);
                        Fremhash(pathel, Vlocate_file_hash_table);
                }
        }
        return Qnil;
}

/* Search for a file whose name is STR, looking in directories
   in the Lisp list PATH, and trying suffixes from SUFFIXES.
   SUFFIXES is a list of possible suffixes, or (for backward
   compatibility) a string containing possible suffixes separated by
   colons.
   On success, returns a file descriptor.  On failure, returns -1.

   MODE nonnegative means don't open the files,
   just look for one for which access(file,MODE) succeeds.  In this case,
   returns a nonnegative value on success.  On failure, returns -1.

   If STOREPTR is nonzero, it points to a slot where the name of
   the file actually found should be stored as a Lisp string.
   Nil is stored there on failure.

   Called openp() in FSFmacs. */

int
locate_file(Lisp_Object path, Lisp_Object str, Lisp_Object suffixes,
            Lisp_Object * storeptr, int mode)
{
        /* This function can GC */
        Lisp_Object suffixtab = Qnil;
        Lisp_Object pathtail, pathel_expanded;
        int val;
        struct gcpro gcpro1, gcpro2, gcpro3, gcpro4;

        if (storeptr)
                *storeptr = Qnil;

        /* Is it really necessary to gcpro path and str?  It shouldn't be
           unless some caller has fucked up.  There are known instances that
           call us with build_string("foo:bar") as SUFFIXES, though. */
        GCPRO4(path, str, suffixes, suffixtab);

        /* if this filename has directory components, it's too complicated
           to try and use the hash tables. */
        if (!NILP(Ffile_name_directory(str))) {
                val =
                    locate_file_without_hash(path, str, suffixes, storeptr,
                                             mode);
                UNGCPRO;
                return val;
        }

        suffixtab = locate_file_construct_suffixed_files(str, suffixes);

        EXTERNAL_LIST_LOOP(pathtail, path) {
                Lisp_Object pathel = XCAR(pathtail);
                Lisp_Object hash_table;
                Lisp_Object tail;
                int found = 0;

                /* If this path element is relative, we have to look by hand. */
                if (NILP(pathel) || NILP(Ffile_name_absolute_p(pathel))) {
                        val =
                            locate_file_in_directory(pathel, str, suffixes,
                                                     storeptr, mode);
                        if (val >= 0) {
                                UNGCPRO;
                                return val;
                        }
                        continue;
                }

                pathel_expanded = Fexpand_file_name(pathel, Qnil);
                hash_table =
                    locate_file_find_directory_hash_table(pathel_expanded);

                if (!NILP(hash_table)) {
                        /* Loop over suffixes.  */
                        LIST_LOOP(tail, suffixtab)
                            if (!NILP(Fgethash(XCAR(tail), hash_table, Qnil))) {
                                found = 1;
                                break;
                        }
                }

                if (found) {
                        /* This is a likely candidate.  Look by hand in this directory
                           so we don't get thrown off if someone byte-compiles a file. */
                        val =
                            locate_file_in_directory(pathel, str, suffixes,
                                                     storeptr, mode);
                        if (val >= 0) {
                                UNGCPRO;
                                return val;
                        }

                        /* Hmm ...  the file isn't actually there. (Or possibly it's
                           a directory ...)  So refresh our hashing. */
                        locate_file_refresh_hashing(pathel_expanded);
                }
        }

        /* File is probably not there, but check the hard way just in case. */
        val = locate_file_without_hash(path, str, suffixes, storeptr, mode);
        if (val >= 0) {
                /* Sneaky user added a file without telling us. */
                Flocate_file_clear_hashing(path);
        }

        UNGCPRO;
        return val;
}
\f
#ifdef LOADHIST

/* Merge the list we've accumulated of globals from the current input source
   into the load_history variable.  The details depend on whether
   the source has an associated file name or not. */

static void build_load_history(int loading, Lisp_Object source)
{
        REGISTER Lisp_Object tail, prev, newelt;
        REGISTER Lisp_Object tem, tem2;
        int foundit;

#if !defined(LOADHIST_DUMPED)
        /* Don't bother recording anything for preloaded files.  */
        if (purify_flag)
                return;
#endif

        tail = Vload_history;
        prev = Qnil;
        foundit = 0;
        while (!NILP(tail)) {
                tem = Fcar(tail);

                /* Find the feature's previous assoc list... */
                if (internal_equal(source, Fcar(tem), 0)) {
                        foundit = 1;

                        /*  If we're loading, remove it. */
                        if (loading) {
                                if (NILP(prev))
                                        Vload_history = Fcdr(tail);
                                else
                                        Fsetcdr(prev, Fcdr(tail));
                        }

                        /*  Otherwise, cons on new symbols that are not already members.  */
                        else {
                                tem2 = Vcurrent_load_list;

                                while (CONSP(tem2)) {
                                        newelt = XCAR(tem2);

                                        if (NILP(Fmemq(newelt, tem)))
                                                Fsetcar(tail, Fcons(Fcar(tem),
                                                                    Fcons
                                                                    (newelt,
                                                                     Fcdr
                                                                     (tem))));

                                        tem2 = XCDR(tem2);
                                        QUIT;
                                }
                        }
                } else
                        prev = tail;
                tail = Fcdr(tail);
                QUIT;
        }

        /* If we're loading, cons the new assoc onto the front of load-history,
           the most-recently-loaded position.  Also do this if we didn't find
           an existing member for the current source.  */
        if (loading || !foundit)
                Vload_history = Fcons(Fnreverse(Vcurrent_load_list),
                                      Vload_history);
}

#else                           /* !LOADHIST */
#define build_load_history(x,y)
#endif                          /* !LOADHIST */
\f
#if 0                           /* FSFmacs defun hack */
Lisp_Object unreadpure(void)
{                               /* Used as unwind-protect function in readevalloop */
        read_pure = 0;
        return Qnil;
}
#endif                          /* 0 */

static void
readevalloop(Lisp_Object readcharfun,
             Lisp_Object sourcename,
             Lisp_Object(*evalfun) (Lisp_Object), int printflag)
{
        /* This function can GC */
        REGISTER Emchar c;
        REGISTER Lisp_Object val = Qnil;
        int speccount = specpdl_depth();
        struct gcpro gcpro1, gcpro2;
        struct buffer *b = 0;

        if (BUFFERP(readcharfun))
                b = XBUFFER(readcharfun);
        else if (MARKERP(readcharfun))
                b = XMARKER(readcharfun)->buffer;

        /* Don't do this.  It is not necessary, and it needlessly exposes
           READCHARFUN (which can be a stream) to Lisp.  --hniksic */
        /*specbind (Qstandard_input, readcharfun); */

        specbind(Qcurrent_load_list, Qnil);

#ifdef COMPILED_FUNCTION_ANNOTATION_HACK
        Vcurrent_compiled_function_annotation = Qnil;
#endif
        GCPRO2(val, sourcename);

        LOADHIST_ATTACH(sourcename);

        while (1) {
                QUIT;

                if (b != 0 && !BUFFER_LIVE_P(b))
                        error("Reading from killed buffer");

                c = readchar(readcharfun);
                if (c == ';') {
                        /* Skip comment */
                        while ((c = readchar(readcharfun)) != '\n' && c != -1)
                                QUIT;
                        continue;
                }
                if (c < 0)
                        break;

                /* Ignore whitespace here, so we can detect eof.  */
                if (c == ' ' || c == '\t' || c == '\n' || c == '\f'
                    || c == '\r')
                        continue;

#if 0                           /* FSFmacs defun hack */
                if (purify_flag && c == '(') {
                        int count1 = specpdl_depth();
                        record_unwind_protect(unreadpure, Qnil);
                        val = read_list(readcharfun, ')', -1, 1);
                        unbind_to(count1, Qnil);
                } else
#else                           /* No "defun hack" -- Emacs 19 uses read-time syntax for bytecodes */
                {
                        unreadchar(readcharfun, c);
                        Vread_objects = Qnil;
                        if (NILP(Vload_read_function))
                                val = read0(readcharfun);
                        else
                                val = call1(Vload_read_function, readcharfun);
                }
#endif
                val = (*evalfun) (val);
                if (printflag) {
                        Vvalues = Fcons(val, Vvalues);
                        if (EQ(Vstandard_output, Qt))
                                Fprin1(val, Qnil);
                        else
                                Fprint(val, Qnil);
                }
        }

        build_load_history(LSTREAMP(readcharfun) ||
                           /* This looks weird, but it's what's in FSFmacs */
                           (b ? BUF_NARROWED(b) : BUF_NARROWED(current_buffer)),
                           sourcename);
        UNGCPRO;

        unbind_to(speccount, Qnil);
}

DEFUN("eval-buffer", Feval_buffer, 0, 2, "bBuffer: ",   /*
Execute BUFFER as Lisp code.
Programs can pass two arguments, BUFFER and PRINTFLAG.
BUFFER is the buffer to evaluate (nil means use current buffer).
PRINTFLAG controls printing of output:
nil means discard it; anything else is a stream for printing.

If there is no error, point does not move.  If there is an error,
point remains at the end of the last character read from the buffer.
*/
      (buffer, printflag))
{
        /* This function can GC */
        int speccount = specpdl_depth();
        Lisp_Object tem, buf;

        if (NILP(buffer))
                buf = Fcurrent_buffer();
        else
                buf = Fget_buffer(buffer);
        if (NILP(buf))
                error("No such buffer.");

        if (NILP(printflag))
                tem = Qsymbolp; /* #### #@[]*&$#*[& SI:NULL-STREAM */
        else
                tem = printflag;
        specbind(Qstandard_output, tem);
        record_unwind_protect(save_excursion_restore, save_excursion_save());
        BUF_SET_PT(XBUFFER(buf), BUF_BEGV(XBUFFER(buf)));
        readevalloop(buf, XBUFFER(buf)->filename, Feval, !NILP(printflag));

        return unbind_to(speccount, Qnil);
}

#if 0
xxDEFUN("eval-current-buffer", Feval_current_buffer, 0, 1, "",  /*
Execute the current buffer as Lisp code.
Programs can pass argument PRINTFLAG which controls printing of output:
nil means discard it; anything else is stream for print.

If there is no error, point does not move.  If there is an error,
point remains at the end of the last character read from the buffer.
                                                                 */
        (printflag)) {
        code omitted;
}
#endif                          /* 0 */

DEFUN("eval-region", Feval_region, 2, 3, "r",   /*
Execute the region as Lisp code.
When called from programs, expects two arguments START and END
giving starting and ending indices in the current buffer
of the text to be executed.
Programs can pass third optional argument STREAM which controls output:
nil means discard it; anything else is stream for printing it.

If there is no error, point does not move.  If there is an error,
point remains at the end of the last character read from the buffer.

Note:  Before evaling the region, this function narrows the buffer to it.
If the code being eval'd should happen to trigger a redisplay you may
see some text temporarily disappear because of this.
*/
      (start, end, stream))
{
        /* This function can GC */
        int speccount = specpdl_depth();
        Lisp_Object tem;
        Lisp_Object cbuf = Fcurrent_buffer();

        if (NILP(stream))
                tem = Qsymbolp; /* #### #@[]*&$#*[& SI:NULL-STREAM */
        else
                tem = stream;
        specbind(Qstandard_output, tem);

        if (NILP(stream))
                record_unwind_protect(save_excursion_restore,
                                      save_excursion_save());
        record_unwind_protect(save_restriction_restore,
                              save_restriction_save());

        /* This both uses start and checks its type.  */
        Fgoto_char(start, cbuf);
        Fnarrow_to_region(make_int(BUF_BEGV(current_buffer)), end, cbuf);
        readevalloop(cbuf, XBUFFER(cbuf)->filename, Feval, !NILP(stream));

        return unbind_to(speccount, Qnil);
}
\f
DEFUN("read", Fread, 0, 1, 0,   /*
Read one Lisp expression as text from STREAM, return as Lisp object.
If STREAM is nil, use the value of `standard-input' (which see).
STREAM or the value of `standard-input' may be:
a buffer (read from point and advance it)
a marker (read from where it points and advance it)
a function (call it with no arguments for each character,
call it with a char as argument to push a char back)
a string (takes text from string, starting at the beginning)
t (read text line using minibuffer and use it).
*/
      (stream))
{
        if (NILP(stream))
                stream = Vstandard_input;
        if (EQ(stream, Qt))
                stream = Qread_char;

        Vread_objects = Qnil;

#ifdef COMPILED_FUNCTION_ANNOTATION_HACK
        Vcurrent_compiled_function_annotation = Qnil;
#endif
        if (EQ(stream, Qread_char)) {
                Lisp_Object val = call1(Qread_from_minibuffer,
                                        build_translated_string
                                        ("Lisp expression: "));
                return Fcar(Fread_from_string(val, Qnil, Qnil));
        }

        if (STRINGP(stream))
                return Fcar(Fread_from_string(stream, Qnil, Qnil));

        return read0(stream);
}

DEFUN("read-from-string", Fread_from_string, 1, 3, 0,   /*
Read one Lisp expression which is represented as text by STRING.
Returns a cons: (OBJECT-READ . FINAL-STRING-INDEX).
START and END optionally delimit a substring of STRING from which to read;
they default to 0 and (length STRING) respectively.
*/
      (string, start, end))
{
        Bytecount startval, endval;
        Lisp_Object tem;
        Lisp_Object lispstream = Qnil;
        struct gcpro gcpro1;

#ifdef COMPILED_FUNCTION_ANNOTATION_HACK
        Vcurrent_compiled_function_annotation = Qnil;
#endif
        GCPRO1(lispstream);
        CHECK_STRING(string);
        get_string_range_byte(string, start, end, &startval, &endval,
                              GB_HISTORICAL_STRING_BEHAVIOR);
        lispstream = make_lisp_string_input_stream(string, startval,
                                                   endval - startval);

        Vread_objects = Qnil;

        tem = read0(lispstream);
        /* Yeah, it's ugly.  Gonna make something of it?
           At least our reader is reentrant ... */
        tem =
            (Fcons(tem, make_int
                   (bytecount_to_charcount
                    (XSTRING_DATA(string),
                     startval + Lstream_byte_count(XLSTREAM(lispstream))))));
        Lstream_delete(XLSTREAM(lispstream));
        UNGCPRO;
        return tem;
}

static Lisp_Object
ureader_find(Lisp_Object name)
{
        return Fcdr(Fassoc(name, Vureaders));
}

/*
 * NOTE:
 *  ureader_read() assumes that input starts with < character and
 *  should finish on matching > character.
 */
static Lisp_Object
ureader_read(Lisp_Object ureader_fun, Lisp_Object readcharfun)
{
        Emchar c;
        unsigned int oparens = 0;
        struct gcpro gcpro1;
        Lisp_Object instr;

        Lstream_rewind(XLSTREAM(Vread_buffer_stream));
        while ((c = readchar(readcharfun)) >= 0) {
                if (c == '<')
                        oparens++;
                else if (c == '>') {
                        if (oparens == 0)
                                /* We got final closing paren */
                                break;
                        else
                                oparens--;
                }
                Lstream_put_emchar(XLSTREAM (Vread_buffer_stream), c);
                QUIT;
        }
        if (c < 0)
                return Fsignal(Qend_of_file,
                               list1(READCHARFUN_MAYBE(readcharfun)));

        Lstream_flush(XLSTREAM(Vread_buffer_stream));
        GCPRO1(instr);
        instr = make_string(resizing_buffer_stream_ptr
                            (XLSTREAM(Vread_buffer_stream)),
                            Lstream_byte_count(XLSTREAM(Vread_buffer_stream)));

        RETURN_UNGCPRO(call1(ureader_fun, instr));
}

\f
#ifdef LISP_BACKQUOTES

static Lisp_Object backquote_unwind(Lisp_Object ptr)
{                               /* used as unwind-protect function in read0() */
        int *counter = (int *)get_opaque_ptr(ptr);
        if (--*counter < 0)
                *counter = 0;
        free_opaque_ptr(ptr);
        return Qnil;
}

#endif

/* Use this for recursive reads, in contexts where internal tokens
   are not allowed.  See also read1(). */
static Lisp_Object read0(Lisp_Object readcharfun)
{
        Lisp_Object val = read1(readcharfun);

        if (CONSP(val) && UNBOUNDP(XCAR(val))) {
                Emchar c = XCHAR(XCDR(val));
                free_cons(XCONS(val));
                return Fsignal(Qinvalid_read_syntax,
                               list1(Fchar_to_string(make_char(c))));
        }

        return val;
}
\f
static Emchar read_escape(Lisp_Object readcharfun)
{
        /* This function can GC */
        Emchar c = readchar(readcharfun);

        if (c < 0)
                signal_error(Qend_of_file,
                             list1(READCHARFUN_MAYBE(readcharfun)));

        switch (c) {
        case 'a':
                return '\007';
        case 'b':
                return '\b';
        case 'd':
                return 0177;
        case 'e':
                return 033;
        case 'f':
                return '\f';
        case 'n':
                return '\n';
        case 'r':
                return '\r';
        case 't':
                return '\t';
        case 'v':
                return '\v';
        case '\n':
                return -1;

        case 'M':
                c = readchar(readcharfun);
                if (c < 0)
                        signal_error(Qend_of_file,
                                     list1(READCHARFUN_MAYBE(readcharfun)));
                if (c != '-')
                        error("Invalid escape character syntax");
                c = readchar(readcharfun);
                if (c < 0)
                        signal_error(Qend_of_file,
                                     list1(READCHARFUN_MAYBE(readcharfun)));
                if (c == '\\')
                        c = read_escape(readcharfun);
                return c | 0200;

                /* Originally, FSF_KEYS provided a degree of FSF Emacs
                   compatibility by defining character "modifiers" alt, super,
                   hyper and shift to infest the characters (i.e. integers).

                   However, this doesn't cut it for XEmacs 20, which
                   distinguishes characters from integers.  Without Mule, ?\H-a
                   simply returns ?a because every character is clipped into
                   0-255.  Under Mule it is much worse -- ?\H-a with FSF_KEYS
                   produces an illegal character, and moves us to crash-land.

                   For these reasons, FSF_KEYS hack is useless and without hope
                   of ever working under XEmacs 20.  */
#undef FSF_KEYS

#ifdef FSF_KEYS
#define alt_modifier   (0x040000)
#define super_modifier (0x080000)
#define hyper_modifier (0x100000)
#define shift_modifier (0x200000)
/* fsf uses a different modifiers for meta and control.  Possibly
   byte_compiled code will still work fsfmacs, though... --Stig

   #define ctl_modifier   (0x400000)
   #define meta_modifier  (0x800000)
*/
#define FSF_LOSSAGE(mask)                                                       \
      if (fail_on_bucky_bit_character_escapes ||                                \
          ((c = readchar (readcharfun)) != '-'))                                \
        error ("Invalid escape character syntax");                              \
      c = readchar (readcharfun);                                               \
      if (c < 0)                                                                \
        signal_error (Qend_of_file, list1 (READCHARFUN_MAYBE (readcharfun)));   \
      if (c == '\\')                                                            \
        c = read_escape (readcharfun);                                          \
      return c | mask

        case 'S':
                FSF_LOSSAGE(shift_modifier);
        case 'H':
                FSF_LOSSAGE(hyper_modifier);
        case 'A':
                FSF_LOSSAGE(alt_modifier);
        case 's':
                FSF_LOSSAGE(super_modifier);
#undef alt_modifier
#undef super_modifier
#undef hyper_modifier
#undef shift_modifier
#undef FSF_LOSSAGE

#endif                          /* FSF_KEYS */

        case 'C':
                c = readchar(readcharfun);
                if (c < 0)
                        signal_error(Qend_of_file,
                                     list1(READCHARFUN_MAYBE(readcharfun)));
                if (c != '-')
                        error("Invalid escape character syntax");
        case '^':
                c = readchar(readcharfun);
                if (c < 0)
                        signal_error(Qend_of_file,
                                     list1(READCHARFUN_MAYBE(readcharfun)));
                if (c == '\\')
                        c = read_escape(readcharfun);
                /* FSFmacs junk for non-ASCII controls.
                   Not used here. */
                if (c == '?')
                        return 0177;
                else
                        return c & (0200 | 037);

        case '0':
        case '1':
        case '2':
        case '3':
        case '4':
        case '5':
        case '6':
        case '7':
                /* An octal escape, as in ANSI C.  */
                {
                        REGISTER Emchar i = c - '0';
                        REGISTER int count = 0;
                        while (++count < 3) {
                                if ((c = readchar(readcharfun)) >= '0'
                                    && c <= '7')
                                        i = (i << 3) + (c - '0');
                                else {
                                        unreadchar(readcharfun, c);
                                        break;
                                }
                        }
                        return i;
                }

        case 'x':
                /* A hex escape, as in ANSI C, except that we only allow latin-1
                   characters to be read this way.  What is "\x4e03" supposed to
                   mean, anyways, if the internal representation is hidden?
                   This is also consistent with the treatment of octal escapes. */
                {
                        REGISTER Emchar i = 0;
                        REGISTER int count = 0;
                        while (++count <= 2) {
                                c = readchar(readcharfun);
                                /* Remember, can't use isdigit(), isalpha() etc. on Emchars */
                                if (c >= '0' && c <= '9')
                                        i = (i << 4) + (c - '0');
                                else if (c >= 'a' && c <= 'f')
                                        i = (i << 4) + (c - 'a') + 10;
                                else if (c >= 'A' && c <= 'F')
                                        i = (i << 4) + (c - 'A') + 10;
                                else {
                                        unreadchar(readcharfun, c);
                                        break;
                                }
                        }
                        return i;
                }

#ifdef MULE
                /* #### need some way of reading an extended character with
                   an escape sequence. */
#endif

        default:
                return c;
        }
}
\f
/* read symbol-constituent stuff into `Vread_buffer_stream'. */
static Bytecount
read_atom_0(Lisp_Object readcharfun, Emchar firstchar, int *saw_a_backslash)
{
        /* This function can GC */
        Emchar c = ((firstchar) >= 0 ? firstchar : readchar(readcharfun));
        Lstream_rewind(XLSTREAM(Vread_buffer_stream));

        *saw_a_backslash = 0;

        while (c > 040          /* #### - comma should be here as should backquote */
               && !(c == '\"' || c == '\'' || c == ';' || c == '(' || c == ')'
#ifndef HAVE_FPFLOAT
                    /* If we have floating-point support, then we need
                       to allow <digits><dot><digits>.  */
                    || c == '.'
#endif                          /* not HAVE_FPFLOAT */
                    || c == '[' || c == ']' || c == '#')) {
                if (c == '\\') {
                        c = readchar(readcharfun);
                        if (c < 0)
                                signal_error(Qend_of_file,
                                             list1(READCHARFUN_MAYBE
                                                   (readcharfun)));
                        *saw_a_backslash = 1;
                }
                Lstream_put_emchar(XLSTREAM(Vread_buffer_stream), c);
                QUIT;
                c = readchar(readcharfun);
        }

        if (c >= 0)
                unreadchar(readcharfun, c);
        /* blasted terminating 0 */
        Lstream_put_emchar(XLSTREAM(Vread_buffer_stream), 0);
        Lstream_flush(XLSTREAM(Vread_buffer_stream));

        return Lstream_byte_count(XLSTREAM(Vread_buffer_stream)) - 1;
}

static Lisp_Object parse_integer(const Bufbyte * buf, Bytecount len, int base);

static Lisp_Object
read_atom(Lisp_Object readcharfun, Emchar firstchar, int uninterned_symbol)
{
        /* This function can GC */
        int saw_a_backslash;
        Bytecount len = read_atom_0(readcharfun, firstchar, &saw_a_backslash);
        char *read_ptr = (char *)
            resizing_buffer_stream_ptr(XLSTREAM(Vread_buffer_stream));

        /* Is it an integer? */
        if (!(saw_a_backslash || uninterned_symbol)) {
                /* If a token had any backslashes in it, it is disqualified from
                   being an integer or a float.  This means that 123\456 is a
                   symbol, as is \123 (which is the way (intern "123") prints).
                   Also, if token was preceded by #:, it's always a symbol.
                 */
                char *p = read_ptr + len;
                char *p1 = read_ptr;

                if (*p1 == '+' || *p1 == '-')
                        p1++;
                if (p1 != p) {
                        int c;

                        while (p1 != p && (c = *p1) >= '0' && c <= '9')
                                p1++;
#ifdef HAVE_FPFLOAT
                        /* Integers can have trailing decimal points.  */
                        if (p1 > read_ptr && p1 < p && *p1 == '.')
                                p1++;
#endif
                        if (p1 == p) {
                                /* It is an integer. */
#ifdef HAVE_FPFLOAT
                                if (p1[-1] == '.')
                                        p1[-1] = '\0';
#endif
                                return parse_integer((Bufbyte*)read_ptr, len,
                                                     10);
                        }
                }
#if defined HAVE_MPQ && defined WITH_GMP
                if (isbigq_string(read_ptr))
                        return read_bigq_string(read_ptr);
#endif
#if defined HAVE_MPFR && defined WITH_MPFR
                if (isfloat_string(read_ptr) && (Vread_real_as == Qbigfr))
                        return read_bigfr_string(read_ptr);
#endif  /* HAVE_MPFR */
#if defined HAVE_MPF && defined WITH_GMP
                if (isfloat_string(read_ptr) && (Vread_real_as == Qbigf))
                        return read_bigf_string(read_ptr);

#endif  /* HAVE_MPF */
#ifdef HAVE_FPFLOAT
                if (isfloat_string(read_ptr)) {
                        return make_float(str_to_fpfloat(read_ptr));
                }
#endif
#if defined HAVE_PSEUG && defined WITH_PSEUG
                if (isgaussian_string(read_ptr))
                        return read_bigg_string(read_ptr);
#endif
#if defined HAVE_MPC && defined WITH_MPC ||     \
        defined HAVE_PSEUC && defined WITH_PSEUC
                if (isbigc_string(read_ptr))
                        return read_bigc_string(read_ptr);
#endif  /* HAVE_MPC */
#if defined HAVE_QUATERN && defined WITH_QUATERN
                if (isquatern_string(read_ptr))
                        return read_quatern_string(read_ptr);
#endif
        }

        /* check for resclass syntax */
        if (ase_resc_rng_pred_f && ase_resc_rng_f &&
            ase_resc_rng_pred_f(read_ptr))
                return ase_resc_rng_f(read_ptr);
        if (ase_resc_elm_pred_f && ase_resc_elm_f &&
            ase_resc_elm_pred_f(read_ptr))
                return ase_resc_elm_f(read_ptr);

        {
                Lisp_Object sym;
                if (uninterned_symbol)
                        sym =
                            Fmake_symbol(make_string
                                         ((Bufbyte *) read_ptr, len));
                else {
                        Lisp_Object name =
                            make_string((Bufbyte *) read_ptr, len);
                        sym = Fintern(name, Qnil);
                }
                return sym;
        }
}

static Lisp_Object
parse_integer(const Bufbyte * buf, Bytecount len, int base)
{
        const Bufbyte *lim = buf + len;
        const Bufbyte *p = buf;
        EMACS_UINT num = 0;
        int negativland = 0;

        if (*p == '-') {
                negativland = 1;
                p++;
        } else if (*p == '+') {
                p++;
        }

        if (p == lim)
                goto loser;

        for (; (p < lim) && (*p != '\0'); p++) {
                int c = *p;
                EMACS_UINT onum;

                if (isdigit(c))
                        c = c - '0';
                else if (isupper(c))
                        c = c - 'A' + 10;
                else if (islower(c))
                        c = c - 'a' + 10;
                else
                        goto loser;

                if (c < 0 || c >= base)
                        goto loser;

                onum = num;
                num = num * base + c;
                if (num < onum)
                        goto overflow;
        }

        {
                EMACS_INT int_result =
                    negativland ? -(EMACS_INT) num : (EMACS_INT) num;
                Lisp_Object result = make_int(int_result);
                if (num && ((XINT(result) < 0) != negativland))
                        goto overflow;
                if (XINT(result) != int_result)
                        goto overflow;
                return result;
        }
      overflow:
#if defined HAVE_MPZ && (defined WITH_GMP || defined WITH_BSDMP)
        return read_bigz_string((const char*)buf, base);
#elif 0
        /* This is going to kill us!
         * Big integers cannot be used anywhere if the reader rewards
         * their occurence that harshly
         */
        return Fsignal(Qinvalid_read_syntax,
                       list3(build_translated_string
                             ("Integer constant overflow in reader"),
                             make_string(buf, len), make_int(base)));
#else
        warn_when_safe(Qinvalid_read_syntax, Qwarning,
                       "Integer constant overflow in reader: %s,"
                       "  proceeding nervously with 0.",
                       buf);
        return Qzero;
#endif /* HAVE_MPZ && WITH_GMP||WITH_BSDMP */
      loser:
        return Fsignal(Qinvalid_read_syntax,
                       list3(build_translated_string
                             ("Invalid integer constant in reader"),
                             make_string(buf, len), make_int(base)));
}

static Lisp_Object
read_integer(Lisp_Object readcharfun, int base)
{
        /* This function can GC */
        int saw_a_backslash;
        Bytecount len = read_atom_0(readcharfun, -1, &saw_a_backslash);
        return (parse_integer
                (resizing_buffer_stream_ptr(XLSTREAM(Vread_buffer_stream)),
                 ((saw_a_backslash)
                  ? 0           /* make parse_integer signal error */
                  : len), base));
}

static Lisp_Object
read_bit_vector(Lisp_Object readcharfun)
{
        unsigned_char_dynarr *dyn = Dynarr_new(unsigned_char);
        Lisp_Object val;

        while (1) {
                unsigned char bit;
                Emchar c = readchar(readcharfun);
                if (c == '0')
                        bit = 0;
                else if (c == '1')
                        bit = 1;
                else {
                        if (c >= 0)
                                unreadchar(readcharfun, c);
                        break;
                }
                Dynarr_add(dyn, bit);
        }

        val = make_bit_vector_from_byte_vector(Dynarr_atp(dyn, 0),
                                               Dynarr_length(dyn));
        Dynarr_free(dyn);

        return val;
}
\f
/* structures */

struct structure_type*
define_structure_type(Lisp_Object type,
                      int(*validate)(Lisp_Object data, Error_behavior errb),
                      Lisp_Object(*instantiate)(Lisp_Object data))
{
        struct structure_type st;

        st.type = type;
        st.keywords = Dynarr_new(structure_keyword_entry);
        st.validate = validate;
        st.instantiate = instantiate;
        Dynarr_add(the_structure_type_dynarr, st);

        return Dynarr_atp(the_structure_type_dynarr,
                          Dynarr_length(the_structure_type_dynarr) - 1);
}

void
define_structure_type_keyword(struct structure_type *st, Lisp_Object keyword,
                              int (*validate) (Lisp_Object keyword,
                                               Lisp_Object value,
                                               Error_behavior errb))
{
        struct structure_keyword_entry en;

        en.keyword = keyword;
        en.validate = validate;
        Dynarr_add(st->keywords, en);
}

static struct structure_type*
recognized_structure_type(Lisp_Object type)
{
        int i;

        for (i = 0; i < Dynarr_length(the_structure_type_dynarr); i++) {
                struct structure_type *st =
                    Dynarr_atp(the_structure_type_dynarr, i);
                if (EQ(st->type, type))
                        return st;
        }

        return 0;
}

static Lisp_Object
read_structure(Lisp_Object readcharfun)
{
        Emchar c = readchar(readcharfun);
        Lisp_Object list = Qnil;
        Lisp_Object orig_list = Qnil;
        Lisp_Object already_seen = Qnil;
        int keyword_count;
        struct structure_type *st;
        struct gcpro gcpro1, gcpro2;

        GCPRO2(orig_list, already_seen);
        if (c != '(')
                RETURN_UNGCPRO(continuable_read_syntax_error
                               ("#s not followed by paren"));
        list = read_list(readcharfun, ')', 0, 0);
        orig_list = list;
        {
                int len = XINT(Flength(list));
                if (len == 0)
                        RETURN_UNGCPRO(continuable_read_syntax_error
                                       ("structure type not specified"));
                if (!(len & 1))
                        RETURN_UNGCPRO
                            (continuable_read_syntax_error
                             ("structures must have alternating keyword/value pairs"));
        }

        st = recognized_structure_type(XCAR(list));
        if (!st)
                RETURN_UNGCPRO(Fsignal(Qinvalid_read_syntax,
                                       list2(build_translated_string
                                             ("unrecognized structure type"),
                                             XCAR(list))));

        list = Fcdr(list);
        keyword_count = Dynarr_length(st->keywords);
        while (!NILP(list)) {
                Lisp_Object keyword, value;
                int i;
                struct structure_keyword_entry *en = NULL;

                keyword = Fcar(list);
                list = Fcdr(list);
                value = Fcar(list);
                list = Fcdr(list);

                if (!NILP(memq_no_quit(keyword, already_seen)))
                        RETURN_UNGCPRO(Fsignal(Qinvalid_read_syntax,
                                               list2(build_translated_string
                                                     ("structure keyword already seen"),
                                                     keyword)));

                for (i = 0; i < keyword_count; i++) {
                        en = Dynarr_atp(st->keywords, i);
                        if (EQ(keyword, en->keyword))
                                break;
                }

                if (i == keyword_count)
                        RETURN_UNGCPRO(Fsignal(Qinvalid_read_syntax,
                                               list2(build_translated_string
                                                     ("unrecognized structure keyword"),
                                                     keyword)));

                if (en->validate && !(en->validate) (keyword, value, ERROR_ME))
                        RETURN_UNGCPRO
                            (Fsignal(Qinvalid_read_syntax,
                                     list3(build_translated_string
                                           ("invalid value for structure keyword"),
                                           keyword, value)));

                already_seen = Fcons(keyword, already_seen);
        }

        if (st->validate && !(st->validate) (orig_list, ERROR_ME))
                RETURN_UNGCPRO(Fsignal(Qinvalid_read_syntax,
                                       list2(build_translated_string
                                             ("invalid structure initializer"),
                                             orig_list)));

        RETURN_UNGCPRO((st->instantiate) (XCDR(orig_list)));
}
\f
static Lisp_Object read_compiled_function(Lisp_Object readcharfun, int);
static Lisp_Object read_vector(Lisp_Object readcharfun, int terminator);

/* Get the next character; filter out whitespace and comments */

static Emchar
reader_nextchar(Lisp_Object readcharfun)
{
        /* This function can GC */
        Emchar c;

      retry:
        QUIT;
        c = readchar(readcharfun);
        if (c < 0)
                signal_error(Qend_of_file,
                             list1(READCHARFUN_MAYBE(readcharfun)));

        switch (c) {
        default:
                {
                        /* Ignore whitespace and control characters */
                        if (c <= 040)
                                goto retry;
                        return c;
                }

        case ';':
                {
                        /* Comment */
                        while ((c = readchar(readcharfun)) >= 0 && c != '\n')
                                QUIT;
                        goto retry;
                }
        }
}

#if 0
static Lisp_Object list2_pure(int pure, Lisp_Object a, Lisp_Object b)
{
        return pure ? pure_cons(a, pure_cons(b, Qnil)) : list2(a, b);
}
#endif

/* Read the next Lisp object from the stream READCHARFUN and return it.
   If the return value is a cons whose car is Qunbound, then read1()
   encountered a misplaced token (e.g. a right bracket, right paren,
   or dot followed by a non-number).  To filter this stuff out,
   use read0(). */

static Lisp_Object
read_string(Lisp_Object readcharfun, Emchar delim, int raw)
{
#ifdef I18N3
        /* #### If the input stream is translating, then the string
           should be marked as translatable by setting its
           `string-translatable' property to t.  .el and .elc files
           normally are translating input streams.  See Fgettext()
           and print_internal(). */
#endif
        Emchar c;
        int cancel = 0;

        Lstream_rewind(XLSTREAM(Vread_buffer_stream));
        while ((c = readchar(readcharfun)) >= 0 && c != delim) {
                if (c == '\\') {
                        if (raw) {
                                /* For raw strings, insert the
                                   backslash and the next char, */
                                Lstream_put_emchar(
                                        XLSTREAM(Vread_buffer_stream), c);
                                c = readchar(readcharfun);
                        } else {
                                /* otherwise, backslash escapes the next char */
                                c = read_escape(readcharfun);
                        }
                }
                /* c is -1 if \ newline has just been seen */
                if (c == -1) {
                        if (!Lstream_byte_count(XLSTREAM(Vread_buffer_stream))) {
                                cancel = 1;
                        }
                } else {
                        Lstream_put_emchar(XLSTREAM
                                           (Vread_buffer_stream),
                                           c);
                }
                QUIT;
        }
        if (c < 0) {
                return Fsignal(Qend_of_file,
                               list1(READCHARFUN_MAYBE(readcharfun)));
        }

        /* If purifying, and string starts with \ newline,
           return zero instead.  This is for doc strings
           that we are really going to find in lib-src/DOC.nn.nn  */
        if (purify_flag && NILP(Vinternal_doc_file_name) && cancel) {
                return Qzero;
        }

        Lstream_flush(XLSTREAM(Vread_buffer_stream));
        return make_string(resizing_buffer_stream_ptr
                           (XLSTREAM(Vread_buffer_stream)),
                           Lstream_byte_count(XLSTREAM(Vread_buffer_stream)));
}

static Lisp_Object
read_raw_string(Lisp_Object readcharfun)
{
        Emchar c;
        c = reader_nextchar(readcharfun);
        switch (c) {
                /* #r:engine"my sexy raw string" -- raw string w/ flags*/
        /* case ':': */
                /* #r"my raw string" -- raw string */
        case '\"':
                return read_string(readcharfun, '\"', 1);
                /* invalid syntax */
        default: {
                unreadchar(readcharfun, c);
                return Fsignal(Qinvalid_read_syntax,
                               list1(build_string
                                     ("unrecognized raw string syntax")));
        }
        }
}

static Lisp_Object
read1(Lisp_Object readcharfun)
{
        Emchar c;

retry:
        c = reader_nextchar(readcharfun);

        switch (c) {
        case '(': {
#ifdef LISP_BACKQUOTES          /* old backquote compatibility in lisp reader */
                /* if this is disabled, then other code in eval.c must be
                   enabled */
                Emchar ch = reader_nextchar(readcharfun);
                switch (ch) {
                case '`': {
                        Lisp_Object tem;
                        int speccount = specpdl_depth();
                        ++old_backquote_flag;
                        record_unwind_protect(backquote_unwind,
                                              make_opaque_ptr
                                              (&old_backquote_flag));
                        tem = read0(readcharfun);
                        unbind_to(speccount, Qnil);
                        ch = reader_nextchar(readcharfun);
                        if (ch != ')') {
                                unreadchar(readcharfun, ch);
                                return
                                        Fsignal
                                        (Qinvalid_read_syntax,
                                         list1(build_string
                                               ("Weird old-backquote syntax")));
                        }
                        return list2(Qbacktick, tem);
                }
                case ',': {
                        if (old_backquote_flag) {
                                Lisp_Object tem, comma_type;
                                ch = readchar(readcharfun);
                                if (ch == '@')
                                        comma_type = Qcomma_at;
                                else {
                                        if (ch >= 0)
                                                unreadchar
                                                        (readcharfun,
                                                         ch);
                                        comma_type = Qcomma;
                                }
                                tem = read0(readcharfun);
                                ch = reader_nextchar
                                        (readcharfun);
                                if (ch != ')') {
                                        unreadchar(readcharfun,
                                                   ch);
                                        return Fsignal(
                                                Qinvalid_read_syntax,
                                                list1(build_string
                                                      ("Weird old-backquote "
                                                       "syntax")));
                                }
                                return list2(comma_type, tem);
                        } else {
                                unreadchar(readcharfun, ch);
#if 0
                                return
                                        Fsignal
                                        (Qinvalid_read_syntax,
                                         list1(build_string
                                               ("Comma outside of backquote")));
#else
                                /* #### - yuck....but this is reverse
                                   ####   compatible. */
                                /* mostly this is required by edebug, which does
                                   its own annotated reading.  We need to have
                                   an annotated_read function that records (with
                                   markers) the buffer positions of the elements
                                   that make up lists, then that can be used in
                                   edebug and bytecomp and the check above can
                                   go back in. --Stig */
                                break;
#endif
                        }
                }
                default:
                        unreadchar(readcharfun, ch);
                }       /* switch(ch) */
#endif                          /* old backquote crap... */
                return read_list(readcharfun, ')', 1, 1);
        }
        case '[':
                return read_vector(readcharfun, ']');

        case ')':
        case ']':
                /* #### - huh? these don't do what they seem... */
                return noseeum_cons(Qunbound, make_char(c));
        case '.': {
#ifdef HAVE_FPFLOAT
                /* If a period is followed by a number, then we should read it
                   as a floating point number.  Otherwise, it denotes a dotted
                   pair.
                */
                c = readchar(readcharfun);
                unreadchar(readcharfun, c);

                /* Can't use isdigit on Emchars */
                if (c < '0' || c > '9')
                        return noseeum_cons(Qunbound, make_char('.'));

                /* Note that read_atom will loop
                   at least once, assuring that we will not try to UNREAD
                   two characters in a row.
                   (I think this doesn't matter anymore because there should
                   be no more danger in unreading multiple characters) */
                return read_atom(readcharfun, '.', 0);

#else                           /* ! HAVE_FPFLOAT */
                return noseeum_cons(Qunbound, make_char('.'));
#endif                          /* ! HAVE_FPFLOAT */
        }

        case '#': {
                c = readchar(readcharfun);
                switch (c) {
#if 0                           /* FSFmacs silly char-table syntax */
                case '^':
#endif
#if 0                           /* FSFmacs silly bool-vector syntax */
                case '&':
#endif
                        /* "#["-- byte-code constant syntax */
                        /* purecons #[...] syntax */
                case '[':
                        return read_compiled_function(readcharfun, ']'
                                                      /*, purify_flag */
                                );
                        /* "#:"-- gensym syntax */
                case ':':
                        return read_atom(readcharfun, -1, 1);
                        /* #'x => (function x) */
                case '\'':
                        return list2(Qfunction, read0(readcharfun));
#if 0
                        /* RMS uses this syntax for fat-strings.
                           If we use it for vectors, then obscure bugs happen.
                        */
                        /* "#(" -- Scheme/CL vector syntax */
                case '(':
                        return read_vector(readcharfun, ')');
#endif
#if 0                           /* FSFmacs */
/* When are we going to drop this crap??? -hroptatyr */
                case '(': {
                        Lisp_Object tmp;
                        struct gcpro gcpro1;

                        /* Read the string itself.  */
                        tmp = read1(readcharfun);
                        if (!STRINGP(tmp)) {
                                if (CONSP(tmp)
                                    && UNBOUNDP(XCAR(tmp)))
                                        free_cons(XCONS(tmp));
                                return
                                        Fsignal
                                        (Qinvalid_read_syntax,
                                         list1(build_string("#")));
                        }
                        GCPRO1(tmp);
                        /* Read the intervals and their properties.  */
                        while (1) {
                                Lisp_Object beg, end, plist;
                                Emchar ch;
                                int invalid = 0;

                                beg = read1(readcharfun);
                                if (CONSP(beg) && UNBOUNDP(XCAR(beg))) {
                                        ch = XCHAR(XCDR(beg));
                                        free_cons(XCONS(beg));
                                        if (ch == ')')
                                                break;
                                        else
                                                invalid = 1;
                                }
                                if (!invalid) {
                                        end =
                                                read1(readcharfun);
                                        if (CONSP(end)
                                            &&
                                            UNBOUNDP(XCAR(end)))
                                        {
                                                free_cons(XCONS
                                                          (end));
                                                invalid = 1;
                                        }
                                }
                                if (!invalid) {
                                        plist =
                                                read1(readcharfun);
                                        if (CONSP(plist)
                                            &&
                                            UNBOUNDP(XCAR
                                                     (plist))) {
                                                free_cons(XCONS
                                                          (plist));
                                                invalid = 1;
                                        }
                                }
                                if (invalid) {
                                        RETURN_UNGCPRO
                                                (Fsignal
                                                 (Qinvalid_read_syntax,
                                                  list2(build_string
                                                        ("invalid string "
                                                         "property list"),
                                                        XCDR(plist))));
                                }
                                Fset_text_properties(beg, end, plist, tmp);
                        }
                        UNGCPRO;
                        return tmp;
                }
#endif  /* 0 */
                case '@': {
                        /* #@NUMBER is used to skip NUMBER following characters.
                           That's used in .elc files to skip over doc strings
                           and function definitions.  */
                        int i, nskip = 0;

                        /* Read a decimal integer.  */
                        while ((c = readchar(readcharfun)) >= 0
                               && c >= '0' && c <= '9')
                                nskip =
                                        (10 * nskip) + (c - '0');
                        if (c >= 0)
                                unreadchar(readcharfun, c);

                        /* FSF has code here that maybe caches the skipped
                           string.  See above for why this is totally
                           losing.  We handle this differently. */

                        /* Skip that many characters.  */
                        for (i = 0; i < nskip && c >= 0; i++)
                                c = readchar(readcharfun);

                        goto retry;
                }
                case '$':
                        return Vload_file_name_internal;
                        /* bit vectors */
                case '*':
                        return read_bit_vector(readcharfun);
                        /* #o10 => 8 -- octal constant syntax */
                case 'o':
                        return read_integer(readcharfun, 8);
                        /* #xdead => 57005 -- hex constant syntax */
                case 'x':
                        return read_integer(readcharfun, 16);
                        /* #b010 => 2 -- binary constant syntax */
                case 'b':
                        return read_integer(readcharfun, 2);

                case 'p': {
                        Emchar _c_ = reader_nextchar(readcharfun);
                        /* check for permutation syntax */
                        if (_c_ == '[') {
                                Lisp_Object perm =
                                        read_vector(readcharfun, ']');
                                if (ase_permutation_f) {
                                        return ase_permutation_f(perm);
                                }
                                return perm;
                        } else {
                                Lisp_Object err;
                                unreadchar(readcharfun, _c_);
                                err = build_string(
                                        "unrecognised permutation syntax");
                                return Fsignal(
                                        Qinvalid_read_syntax, list1(err));
                        }
                }

                case 'r':
                        /* #r"raw\stringt" -- raw string syntax */
                        return read_raw_string(readcharfun);

                case 's':
                        /* #s(foobar key1 val1 key2 val2) --
                         * structure syntax */
                        return read_structure(readcharfun);
                case '<': {
                        /* Check user readers */
                        Lisp_Object uoname = read_string(readcharfun, ' ', 0);
                        Lisp_Object ureader = ureader_find(uoname);
                        if (!NILP(ureader))
                                return ureader_read(ureader, readcharfun);

                        unreadchar(readcharfun, c);
                        return Fsignal(Qinvalid_read_syntax,
                                       list2(build_string
                                             ("No ureader for"), uoname));
                }
#ifdef FEATUREP_SYNTAX
                case '+':
                case '-': {
                        Lisp_Object feature_exp, obj, tem;
                        struct gcpro gcpro1, gcpro2;

                        feature_exp = read0(readcharfun);
                        obj = read0(readcharfun);

                        /* the call to `featurep' may GC. */
                        GCPRO2(feature_exp, obj);
                        tem = call1(Qfeaturep, feature_exp);
                        UNGCPRO;

                        if (c == '+' && NILP(tem))
                                goto retry;
                        if (c == '-' && !NILP(tem))
                                goto retry;
                        return obj;
                }
#endif
                case '0':
                case '1':
                case '2':
                case '3':
                case '4':
                case '5':
                case '6':
                case '7':
                case '8':
                case '9': {
                        /* Reader forms that can reuse previously read
                           objects.  */
                        int n = 0;
                        Lisp_Object found;

                        /* Using read_integer() here is impossible, because it
                           chokes on `='.  Using parse_integer() is too hard.
                           So we simply read it in, and ignore overflows, which
                           is safe.  */
                        while (c >= '0' && c <= '9') {
                                n *= 10;
                                n += c - '0';
                                c = readchar(readcharfun);
                        }
                        found = assq_no_quit(make_int(n), Vread_objects);
                        if (c == '=') {
                                /* #n=object returns object, but associates it
                                   #with
                                   n for #n#.  */
                                Lisp_Object obj;
                                if (CONSP(found))
                                        return
                                                Fsignal
                                                (Qinvalid_read_syntax,
                                                 list2
                                                 (build_translated_string
                                                  ("Multiply defined symbol label"),
                                                  make_int(n)));
                                obj = read0(readcharfun);
                                Vread_objects =
                                        Fcons(Fcons
                                              (make_int(n), obj),
                                              Vread_objects);
                                return obj;
                        } else if (c == '#') {
                                /* #n# returns a previously read object.  */
                                if (CONSP(found))
                                        return XCDR(found);
                                else
                                        return
                                                Fsignal
                                                (Qinvalid_read_syntax,
                                                 list2
                                                 (build_translated_string
                                                  ("Undefined symbol label"),
                                                  make_int(n)));
                        }
                        return Fsignal(Qinvalid_read_syntax,
                                       list1(build_string
                                             ("#")));
                }
                default: {
                        unreadchar(readcharfun, c);
                        return Fsignal(Qinvalid_read_syntax,
                                       list1(build_string
                                             ("#")));
                }
                }
        }

        /* Quote */
        case '\'':
                return list2(Qquote, read0(readcharfun));

#ifdef LISP_BACKQUOTES
        case '`': {
                Lisp_Object tem;
                int speccount = specpdl_depth();
                ++new_backquote_flag;
                record_unwind_protect(backquote_unwind,
                                      make_opaque_ptr
                                      (&new_backquote_flag));
                tem = read0(readcharfun);
                unbind_to(speccount, Qnil);
                return list2(Qbackquote, tem);
        }

        case ',': {
                if (new_backquote_flag) {
                        Lisp_Object comma_type = Qnil;
                        int ch = readchar(readcharfun);

                        if (ch == '@')
                                comma_type = Qcomma_at;
                        else if (ch == '.')
                                comma_type = Qcomma_dot;
                        else {
                                if (ch >= 0)
                                        unreadchar(readcharfun, ch);
                                comma_type = Qcomma;
                        }
                        return list2(comma_type, read0(readcharfun));
                } else {
                        /* YUCK.  99.999% backwards compatibility.  The Right
                           Thing(tm) is to signal an error here, because it's
                           really invalid read syntax.  Instead, this permits
                           commas to begin symbols (unless they're inside
                           backquotes).  If an error is signalled here in the
                           future, then commas should be invalid read syntax
                           outside of backquotes anywhere they're found (i.e.
                           they must be quoted in symbols) -- Stig */
                        return read_atom(readcharfun, c, 0);
                }
        }
#endif

        case '?': {
                /* Evil GNU Emacs "character" (ie integer) syntax */
                c = readchar(readcharfun);
                if (c < 0)
                        return Fsignal(Qend_of_file,
                                       list1(READCHARFUN_MAYBE
                                             (readcharfun)));

                if (c == '\\')
                        c = read_escape(readcharfun);
                return make_char(c);
        }

        case '\"':
                /* String */
                return read_string(readcharfun, '\"', 0);

        default: {
                /* Ignore whitespace and control characters */
                if (c <= 040)
                        goto retry;
                return read_atom(readcharfun, c, 0);
        }
        }
}
\f
#ifdef HAVE_FPFLOAT

#define LEAD_INT 1
#define DOT_CHAR 2
#define TRAIL_INT 4
#define E_CHAR 8
#define EXP_INT 16
/* for complex numbers */
#define INTERMEDIATE_UNARY_SYMBOL 32
#define LEAD_INT2 64
#define DOT_CHAR2 128
#define TRAIL_INT2 256
#define E_CHAR2 512
#define EXP_INT2 1024
#define I_CHAR 2048
#define LEAD_Z 2
#define Z_CHAR 4096

int
isfloat_string(const char *cp)
{
        int state = 0;
        const Bufbyte *ucp = (const Bufbyte *)cp;

        if (*ucp == '+' || *ucp == '-')
                ucp++;

        if (*ucp >= '0' && *ucp <= '9') {
                state |= LEAD_INT;
                while (*ucp >= '0' && *ucp <= '9')
                        ucp++;
        }
        if (*ucp == '.') {
                state |= DOT_CHAR;
                ucp++;
        }
        if (*ucp >= '0' && *ucp <= '9') {
                state |= TRAIL_INT;
                while (*ucp >= '0' && *ucp <= '9')
                        ucp++;
        }
        if (*ucp == 'e' || *ucp == 'E') {
                state |= E_CHAR;
                ucp++;
                if ((*ucp == '+') || (*ucp == '-'))
                        ucp++;
        }

        if (*ucp >= '0' && *ucp <= '9') {
                state |= EXP_INT;
                while (*ucp >= '0' && *ucp <= '9')
                        ucp++;
        }
        return (((*ucp == 0) || (*ucp == ' ') || (*ucp == '\t')
                 || (*ucp == '\n')
                 || (*ucp == '\r') || (*ucp == '\f'))
                && (state == (LEAD_INT | DOT_CHAR | TRAIL_INT)
                    || state == (DOT_CHAR | TRAIL_INT)
                    || state == (LEAD_INT | E_CHAR | EXP_INT)
                    || state ==
                    (LEAD_INT | DOT_CHAR | TRAIL_INT | E_CHAR | EXP_INT)
                    || state == (DOT_CHAR | TRAIL_INT | E_CHAR | EXP_INT)));
}
#endif                          /* HAVE_FPFLOAT */
#if defined HAVE_MPC && defined WITH_MPC ||     \
        defined HAVE_PSEUC && defined WITH_PSEUC
int
isbigc_string (const char *cp)
{
        int state;
        const Bufbyte *ucp = (const Bufbyte *)cp;


/* parse the real part */
        state = 0;
        if (*ucp == '+' || *ucp == '-')
                ucp++;

        if (*ucp >= '0' && *ucp <= '9') {
                state |= LEAD_INT;
                while (*ucp >= '0' && *ucp <= '9')
                        ucp++;
        }
        if (*ucp == '.') {
                state |= DOT_CHAR;
                ucp++;
        }
        if (*ucp >= '0' && *ucp <= '9') {
                state |= TRAIL_INT;
                while (*ucp >= '0' && *ucp <= '9')
                        ucp++;
        }
        if (*ucp == 'e' || *ucp == 'E') {
                state |= E_CHAR;
                ucp++;
                if ((*ucp == '+') || (*ucp == '-'))
                        ucp++;
        }

        if (*ucp >= '0' && *ucp <= '9') {
                state |= EXP_INT;
                while (*ucp >= '0' && *ucp <= '9')
                        ucp++;
        }

        /* check if we had a real number until here */
        if (!(state == (LEAD_INT | DOT_CHAR | TRAIL_INT) ||
              state == (DOT_CHAR | TRAIL_INT) ||
              state == (LEAD_INT | E_CHAR | EXP_INT) ||
              state == (LEAD_INT | DOT_CHAR | TRAIL_INT | E_CHAR | EXP_INT) ||
              state == (DOT_CHAR | TRAIL_INT | E_CHAR | EXP_INT)))
                return 0;

/* now parse imaginary part */
        state = 0;
        if (*ucp == '+' || *ucp == '-') {
                state |= INTERMEDIATE_UNARY_SYMBOL;
                ucp++;
        }

        if (*ucp >= '0' && *ucp <= '9') {
                state |= LEAD_INT2;
                while (*ucp >= '0' && *ucp <= '9')
                        ucp++;
        }
        if (*ucp == '.') {
                state |= DOT_CHAR2;
                ucp++;
        }
        if (*ucp >= '0' && *ucp <= '9') {
                state |= TRAIL_INT2;
                while (*ucp >= '0' && *ucp <= '9')
                        ucp++;
        }
        if (*ucp == 'e' || *ucp == 'E') {
                state |= E_CHAR2;
                ucp++;
                if ((*ucp == '+') || (*ucp == '-'))
                        ucp++;
        }

        if (*ucp >= '0' && *ucp <= '9') {
                state |= EXP_INT2;
                while (*ucp >= '0' && *ucp <= '9')
                        ucp++;
        }
        if (*ucp == 'i' || *ucp == 'I') {
                state |= I_CHAR;
                ucp++;
        }
        return (((*ucp == 0) || (*ucp == ' ') || (*ucp == '\t') ||
                 (*ucp == '\n') || (*ucp == '\r') || (*ucp == '\f')) &&
                (state == (INTERMEDIATE_UNARY_SYMBOL | LEAD_INT2 | DOT_CHAR2 |
                           TRAIL_INT2 | I_CHAR) ||
                 state == (INTERMEDIATE_UNARY_SYMBOL | DOT_CHAR2 |
                           TRAIL_INT2 | I_CHAR) ||
                 state == (INTERMEDIATE_UNARY_SYMBOL | LEAD_INT2 |
                           E_CHAR2 | EXP_INT2 | I_CHAR) ||
                 state == (INTERMEDIATE_UNARY_SYMBOL | LEAD_INT2 | DOT_CHAR2 |
                           TRAIL_INT2 | E_CHAR2 | EXP_INT2 | I_CHAR) ||
                 state == (INTERMEDIATE_UNARY_SYMBOL | DOT_CHAR2 | TRAIL_INT2 |
                           E_CHAR2 | EXP_INT2 | I_CHAR) ||
                 state == (INTERMEDIATE_UNARY_SYMBOL | I_CHAR)));
}
#endif  /* HAVE_MPC */
#if defined WITH_PSEUG && defined HAVE_PSEUG
int
isgaussian_string (const char *cp)
{
        int state;
        const Bufbyte *ucp = (const Bufbyte *)cp;


/* parse the real part */
        state = 0;
        if (*ucp == '+' || *ucp == '-')
                ucp++;

        if (*ucp >= '0' && *ucp <= '9') {
                state |= LEAD_INT;
                while (*ucp >= '0' && *ucp <= '9')
                        ucp++;
        }

        /* check if we had a int number until here */
        if (!(state == (LEAD_INT)))
                return 0;

/* now parse imaginary part */
        state = 0;
        if (*ucp == '+' || *ucp == '-') {
                state |= INTERMEDIATE_UNARY_SYMBOL;
                ucp++;
        }

        if (*ucp >= '0' && *ucp <= '9') {
                state |= LEAD_INT2;
                while (*ucp >= '0' && *ucp <= '9')
                        ucp++;
        }
        if (*ucp == 'i' || *ucp == 'I') {
                state |= I_CHAR;
                ucp++;
        }
        return (((*ucp == 0) || (*ucp == ' ') || (*ucp == '\t') ||
                 (*ucp == '\n') || (*ucp == '\r') || (*ucp == '\f')) &&
                (state == (INTERMEDIATE_UNARY_SYMBOL | LEAD_INT2 | I_CHAR) ||
                 state == (INTERMEDIATE_UNARY_SYMBOL | I_CHAR)));
}
#endif  /* HAVE_PSEUG */
#if defined HAVE_MPQ && defined WITH_GMP
int
isbigq_string (const char *cp)
{
        /* Possible minus/plus sign */
        if (*cp == '-' || *cp == '+')
                cp++;

        /* Numerator */
        if (*cp < '0' || *cp > '9')
                return 0;

        do {
                cp++;
        } while (*cp >= '0' && *cp <= '9');

        /* Slash */
        if (*cp++ != '/')
                return 0;

        /* Denominator */
        if (*cp < '0' || *cp > '9')
                return 0;

        do {
                cp++;
        } while (*cp >= '0' && *cp <= '9');

        return *cp == '\0' || *cp == ' ' || *cp =='\t' || *cp == '\n' ||
                *cp == '\r' || *cp == '\f';
}
#endif  /* HAVE_MPQ */

\f
static void*
sequence_reader(Lisp_Object readcharfun,
                Emchar terminator,
                void *state,
                void*(*conser)(Lisp_Object, void*, Charcount))
{
        Charcount len;

        for (len = 0;; len++) {
                Emchar ch;

                QUIT;
                ch = reader_nextchar(readcharfun);

                if (ch == terminator)
                        return state;
                else
                        unreadchar(readcharfun, ch);
#ifdef FEATUREP_SYNTAX
                if (ch == ']')
                        read_syntax_error("\"]\" in a list");
                else if (ch == ')')
                        read_syntax_error("\")\" in a vector");
#endif
                state = ((conser) (readcharfun, state, len));
        }
}

struct read_list_state {
        Lisp_Object head;
        Lisp_Object tail;
        int length;
        int allow_dotted_lists;
        Emchar terminator;
};

static void*
read_list_conser(Lisp_Object readcharfun, void *state, Charcount len)
{
        struct read_list_state *s = (struct read_list_state *)state;
        Lisp_Object elt;

        elt = read1(readcharfun);

        if (CONSP(elt) && UNBOUNDP(XCAR(elt))) {
                Lisp_Object tem = elt;
                Emchar ch;

                elt = XCDR(elt);
                free_cons(XCONS(tem));
                tem = Qnil;
                ch = XCHAR(elt);
#ifdef FEATUREP_SYNTAX
                if (ch == s->terminator) {
                        /* deal with #+, #- reader macros */
                        unreadchar(readcharfun, s->terminator);
                        goto done;
                } else if (ch == ']')
                        read_syntax_error("']' in a list");
                else if (ch == ')')
                        read_syntax_error("')' in a vector");
                else
#endif
                if (ch != '.')
                        signal_simple_error("BUG! Internal reader error", elt);
                else if (!s->allow_dotted_lists)
                        read_syntax_error("\".\" in a vector");
                else {
                        if (!NILP(s->tail))
                                XCDR(s->tail) = read0(readcharfun);
                        else
                                s->head = read0(readcharfun);
                        elt = read1(readcharfun);
                        if (CONSP(elt) && UNBOUNDP(XCAR(elt))) {
                                ch = XCHAR(XCDR(elt));
                                free_cons(XCONS(elt));
                                if (ch == s->terminator) {
                                        unreadchar(readcharfun, s->terminator);
                                        goto done;
                                }
                        }
                        read_syntax_error(". in wrong context");
                }
        }
#if 0                           /* FSFmacs defun hack, or something ... */
        if (NILP(tail) && defun_hack && EQ(elt, Qdefun) && !read_pure) {
                record_unwind_protect(unreadpure, Qzero);
                read_pure = 1;
        }
#endif

#ifdef COMPILED_FUNCTION_ANNOTATION_HACK
        if (s->length == 1 && s->allow_dotted_lists && EQ(XCAR(s->head), Qfset)) {
                if (CONSP(elt) && EQ(XCAR(elt), Qquote) && CONSP(XCDR(elt)))
                        Vcurrent_compiled_function_annotation = XCAR(XCDR(elt));
                else
                        Vcurrent_compiled_function_annotation = elt;
        }
#endif

        elt = Fcons(elt, Qnil);
        if (!NILP(s->tail))
                XCDR(s->tail) = elt;
        else
                s->head = elt;
        s->tail = elt;
      done:
        s->length++;
        return s;
}
\f
#if 0                           /* FSFmacs defun hack */
/* -1 for allow_dotted_lists means allow_dotted_lists and check
   for starting with defun and make structure pure. */
#endif

static Lisp_Object
read_list(Lisp_Object readcharfun,
          Emchar terminator,
          int allow_dotted_lists, int check_for_doc_references)
{
        struct read_list_state s;
        struct gcpro gcpro1, gcpro2;
#ifdef COMPILED_FUNCTION_ANNOTATION_HACK
        Lisp_Object old_compiled_function_annotation =
            Vcurrent_compiled_function_annotation;
#endif

        s.head = Qnil;
        s.tail = Qnil;
        s.length = 0;
        s.allow_dotted_lists = allow_dotted_lists;
        s.terminator = terminator;
        GCPRO2(s.head, s.tail);

        sequence_reader(readcharfun, terminator, &s, read_list_conser);
#ifdef COMPILED_FUNCTION_ANNOTATION_HACK
        Vcurrent_compiled_function_annotation =
            old_compiled_function_annotation;
#endif

        if ((purify_flag || load_force_doc_strings) && check_for_doc_references) {
                /* check now for any doc string references and record them
                   for later. */
                Lisp_Object tail;

                /* We might be dealing with an imperfect list so don't
                   use LIST_LOOP */
                for (tail = s.head; CONSP(tail); tail = XCDR(tail)) {
                        Lisp_Object holding_cons = Qnil;

                        {
                                Lisp_Object elem = XCAR(tail);
                                /* elem might be (#$ . INT) ... */
                                if (CONSP(elem)
                                    && EQ(XCAR(elem), Vload_file_name_internal))
                                        holding_cons = tail;
                                /* or it might be (quote (#$ . INT)) i.e.
                                   (quote . ((#$ . INT) . nil)) in the case of
                                   `autoload' (autoload evaluates its arguments, while
                                   `defvar', `defun', etc. don't). */
                                if (CONSP(elem) && EQ(XCAR(elem), Qquote)
                                    && CONSP(XCDR(elem))) {
                                        elem = XCAR(XCDR(elem));
                                        if (CONSP(elem)
                                            && EQ(XCAR(elem),
                                                  Vload_file_name_internal))
                                                holding_cons = XCDR(XCAR(tail));
                                }
                        }

                        if (CONSP(holding_cons)) {
                                if (purify_flag) {
                                        if (NILP(Vinternal_doc_file_name))
                                                /* We have not yet called
                                                   Snarf-documentation, so
                                                   assume this file is described
                                                   in the DOC file and
                                                   Snarf-documentation will fill
                                                   in the right value later.
                                                   For now, replace the whole
                                                   list with 0.  */
                                                XCAR(holding_cons) = Qzero;
                                        else
                                                /* We have already called
                                                   Snarf-documentation, so make
                                                   a relative file name for this
                                                   file, so it can be found
                                                   properly in the installed
                                                   Lisp directory.  We don't use
                                                   Fexpand_file_name because
                                                   that would make the directory
                                                   absolute now.  */
                                                XCAR(XCAR(holding_cons)) =
                                                    concat2(build_string
                                                            ("../lisp/"),
                                                            Ffile_name_nondirectory
                                                            (Vload_file_name_internal));
                                } else
                                        /* Not pure.  Just add to
                                           Vload_force_doc_string_list, and the
                                           string will be filled in properly in
                                           load_force_doc_string_unwind(). */
                                        Vload_force_doc_string_list =
                                            /* We pass the cons that holds the
                                               (#$ . INT) so we can modify it
                                               in-place. */
                                            Fcons(holding_cons,
                                                  Vload_force_doc_string_list);
                        }
                }
        }

        UNGCPRO;
        return s.head;
}

static Lisp_Object
read_vector(Lisp_Object readcharfun, Emchar terminator)
{
        Lisp_Object tem;
        Lisp_Object *p;
        int len;
        int i;
        struct read_list_state s;
        struct gcpro gcpro1, gcpro2;

        s.head = Qnil;
        s.tail = Qnil;
        s.length = 0;
        s.allow_dotted_lists = 0;
        GCPRO2(s.head, s.tail);

        sequence_reader(readcharfun, terminator, &s, read_list_conser);

        UNGCPRO;
        tem = s.head;
        len = XINT(Flength(tem));

#if 0                           /* FSFmacs defun hack */
        if (read_pure)
                s.head = make_pure_vector(len, Qnil);
        else
#endif
                s.head = make_vector(len, Qnil);

        for (i = 0, p = &(XVECTOR_DATA(s.head)[0]); i < len; i++, p++) {
                Lisp_Cons *otem = XCONS(tem);
                tem = Fcar(tem);
                *p = tem;
                tem = otem->cdr;
                free_cons(otem);
        }
        return s.head;
}

static Lisp_Object
read_compiled_function(Lisp_Object readcharfun, Emchar terminator)
{
        /* Accept compiled functions at read-time so that we don't
           have to build them at load-time. */
        Lisp_Object stuff;
        Lisp_Object make_byte_code_args[COMPILED_DOMAIN + 1];
        struct gcpro gcpro1;
        int len;
        int iii;
        int saw_a_doc_ref = 0;

        /* Note: we tell read_list not to search for doc references
           because we need to handle the "doc reference" for the
           instructions and constants differently. */
        stuff = read_list(readcharfun, terminator, 0, 0);
        len = XINT(Flength(stuff));
        if (len < COMPILED_STACK_DEPTH + 1 || len > COMPILED_DOMAIN + 1)
                return
                    continuable_read_syntax_error
                    ("#[...] used with wrong number of elements");

        for (iii = 0; CONSP(stuff); iii++) {
                Lisp_Cons *victim = XCONS(stuff);
                make_byte_code_args[iii] = Fcar(stuff);
                if ((purify_flag || load_force_doc_strings)
                    && CONSP(make_byte_code_args[iii])
                    && EQ(XCAR(make_byte_code_args[iii]),
                          Vload_file_name_internal)) {
                        if (purify_flag && iii == COMPILED_DOC_STRING) {
                                /* same as in read_list(). */
                                if (NILP(Vinternal_doc_file_name))
                                        make_byte_code_args[iii] = Qzero;
                                else
                                        XCAR(make_byte_code_args[iii]) =
                                            concat2(build_string("../lisp/"),
                                                    Ffile_name_nondirectory
                                                    (Vload_file_name_internal));
                        } else
                                saw_a_doc_ref = 1;
                }
                stuff = Fcdr(stuff);
                free_cons(victim);
        }
        GCPROn(make_byte_code_args, len);

        /* v18 or v19 bytecode file.  Need to Ebolify. */
        if (load_byte_code_version < 20 && VECTORP(make_byte_code_args[2]))
                ebolify_bytecode_constants(make_byte_code_args[2]);

        /* make-byte-code looks at purify_flag, which should have the same
         *  value as our "read-pure" argument */
        stuff = Fmake_byte_code(len, make_byte_code_args);
        XCOMPILED_FUNCTION(stuff)->flags.ebolified =
            (load_byte_code_version < 20);
        if (saw_a_doc_ref)
                Vload_force_doc_string_list =
                    Fcons(stuff, Vload_force_doc_string_list);
        UNGCPRO;
        return stuff;
}
\f
void init_lread(void)
{
        char *stroot = NULL, *btroot = NULL;
        Vvalues = Qnil;

        load_in_progress = 0;

        Vload_descriptor_list = Qnil;

        /* kludge: locate-file does not work for a null load-path, even if
           the file name is absolute. */

        Vload_path = Fcons(build_string(""), Qnil);
        /* The following is intended for the build chain only */
        if ((stroot = getenv("SOURCE_TREE_ROOT")) && strlen(stroot)) {
                Lisp_Object lispsubdir = build_string("lisp");
                Lisp_Object strootdir = build_string(stroot);
                Lisp_Object stlispdir =
                        Fexpand_file_name(lispsubdir, strootdir);
                Vload_path = Fcons(stlispdir, Vload_path);
        }
        if ((btroot = getenv("BUILD_TREE_ROOT")) && strlen(btroot)) {
                Lisp_Object lispsubdir = build_string("lisp");
                Lisp_Object btrootdir = build_string(btroot);
                Lisp_Object btlispdir =
                        Fexpand_file_name(lispsubdir, btrootdir);
                Vload_path = Fcons(btlispdir, Vload_path);
        }

        /* This used to get initialized in init_lread because all streams
           got closed when dumping occurs.  This is no longer true --
           Vread_buffer_stream is a resizing output stream, and there is no
           reason to close it at dump-time.

           Vread_buffer_stream is set to Qnil in vars_of_lread, and this
           will initialize it only once, at dump-time.  */
        if (NILP(Vread_buffer_stream))
                Vread_buffer_stream = make_resizing_buffer_output_stream();

        Vload_force_doc_string_list = Qnil;
}

void syms_of_lread(void)
{
        DEFSUBR(Fread);
        DEFSUBR(Fread_from_string);
        DEFSUBR(Fload_internal);
        DEFSUBR(Flocate_file);
        DEFSUBR(Flocate_file_clear_hashing);
        DEFSUBR(Feval_buffer);
        DEFSUBR(Feval_region);

        defsymbol(&Qstandard_input, "standard-input");
        defsymbol(&Qread_char, "read-char");
        defsymbol(&Qcurrent_load_list, "current-load-list");
        defsymbol(&Qload, "load");
        defsymbol(&Qload_file_name, "load-file-name");
        defsymbol(&Qfset, "fset");

#ifdef LISP_BACKQUOTES
        defsymbol(&Qbackquote, "backquote");
        defsymbol(&Qbacktick, "`");
        defsymbol(&Qcomma, ",");
        defsymbol(&Qcomma_at, ",@");
        defsymbol(&Qcomma_dot, ",.");
#endif

        defsymbol(&Qexists, "exists");
        defsymbol(&Qreadable, "readable");
        defsymbol(&Qwritable, "writable");
        defsymbol(&Qexecutable, "executable");
}

void structure_type_create(void)
{
        the_structure_type_dynarr = Dynarr_new(structure_type);
}

void reinit_vars_of_lread(void)
{
        Vread_buffer_stream = Qnil;
        staticpro_nodump(&Vread_buffer_stream);
}

void vars_of_lread(void)
{
        reinit_vars_of_lread();

        DEFVAR_LISP("values", &Vvalues  /*
List of values of all expressions which were read, evaluated and printed.
Order is reverse chronological.
                                         */ );

        DEFVAR_LISP("standard-input", &Vstandard_input  /*
Stream for read to get input from.
See documentation of `read' for possible values.
                                                         */ );
        Vstandard_input = Qt;

        DEFVAR_LISP("load-path", &Vload_path    /*
*List of directories to search for files to load.
Each element is a string (directory name) or nil (try default directory).

Note that the elements of this list *may not* begin with "~", so you must
call `expand-file-name' on them before adding them to this list.

Initialized based on EMACSLOADPATH environment variable, if any,
otherwise to default specified in by file `paths.h' when SXEmacs was built.
If there were no paths specified in `paths.h', then SXEmacs chooses a default
value for this variable by looking around in the file-system near the
directory in which the SXEmacs executable resides.
                                                 */ );
        Vload_path = Qnil;

/*  xxxDEFVAR_LISP ("dump-load-path", &Vdump_load_path,
    "*Location of lisp files to be used when dumping ONLY."); */

        DEFVAR_BOOL("load-in-progress", &load_in_progress       /*
Non-nil iff inside of `load'.
                                                                 */ );
        DEFVAR_LISP ("load-suppress-alist", &Vload_suppress_alist /*
An alist of expressions controlling whether particular files can be loaded.
Each element looks like (FILENAME EXPR).
FILENAME should be a full pathname, but without the .el suffix.
When `load' is run and is about to load the specified file, it evaluates
the form to determine if the file can be loaded.
This variable is normally initialized automatically.
                                                                  */ );
        Vload_suppress_alist = Qnil;

        DEFVAR_LISP("after-load-alist", &Vafter_load_alist      /*
An alist of expressions to be evalled when particular files are loaded.
Each element looks like (FILENAME FORMS...).
When `load' is run and the file-name argument is FILENAME,
the FORMS in the corresponding element are executed at the end of loading.

FILENAME must match exactly!  Normally FILENAME is the name of a library,
with no directory specified, since that is how `load' is normally called.
An error in FORMS does not undo the load,
but does prevent execution of the rest of the FORMS.
                                                                 */ );
        Vafter_load_alist = Qnil;

        DEFVAR_BOOL("load-warn-when-source-newer", &load_warn_when_source_newer /*
*Whether `load' should check whether the source is newer than the binary.
If this variable is true, then when a `.elc' file is being loaded and the
corresponding `.el' is newer, a warning message will be printed.
                                                                                 */ );
        load_warn_when_source_newer = 0;

        DEFVAR_BOOL("load-warn-when-source-only", &load_warn_when_source_only   /*
*Whether `load' should warn when loading a `.el' file instead of an `.elc'.
If this variable is true, then when `load' is called with a filename without
an extension, and the `.elc' version doesn't exist but the `.el' version does,
then a message will be printed.  If an explicit extension is passed to `load',
no warning will be printed.
                                                                                 */ );
        load_warn_when_source_only = 0;

        DEFVAR_BOOL("load-ignore-elc-files", &load_ignore_elc_files     /*
*Whether `load' should ignore `.elc' files when a suffix is not given.
This is normally used only to bootstrap the `.elc' files when building SXEmacs.
                                                                         */ );
        load_ignore_elc_files = 0;

#ifdef LOADHIST
        DEFVAR_LISP("load-history", &Vload_history      /*
Alist mapping source file names to symbols and features.
Each alist element is a list that starts with a file name,
except for one element (optional) that starts with nil and describes
definitions evaluated from buffers not visiting files.
The remaining elements of each list are symbols defined as functions
or variables, and cons cells `(provide . FEATURE)' and `(require . FEATURE)'.
                                                         */ );
        Vload_history = Qnil;

        DEFVAR_LISP("current-load-list", &Vcurrent_load_list    /*
Used for internal purposes by `load'.
                                                                 */ );
        Vcurrent_load_list = Qnil;
#endif

        DEFVAR_LISP("load-file-name", &Vload_file_name  /*
Full name of file being loaded by `load'.
                                                         */ );
        Vload_file_name = Qnil;

        DEFVAR_LISP("load-read-function", &Vload_read_function  /*
Function used by `load' and `eval-region' for reading expressions.
The default is nil, which means use the function `read'.
                                                                 */ );
        Vload_read_function = Qnil;

        DEFVAR_BOOL("load-force-doc-strings", &load_force_doc_strings   /*
Non-nil means `load' should force-load all dynamic doc strings.
This is useful when the file being loaded is a temporary copy.
                                                                         */ );
        load_force_doc_strings = 0;

        /* See read_escape().  */
#if 0
        /* Used to be named `puke-on-fsf-keys' */
        DEFVAR_BOOL("fail-on-bucky-bit-character-escapes", &fail_on_bucky_bit_character_escapes /*
Whether `read' should signal an error when it encounters unsupported
character escape syntaxes or just read them incorrectly.
                                                                                                 */ );
        fail_on_bucky_bit_character_escapes = 0;
#endif

        /* This must be initialized in init_lread otherwise it may start out
           with values saved when the image is dumped. */
        staticpro(&Vload_descriptor_list);

        /* Initialized in init_lread. */
        staticpro(&Vload_force_doc_string_list);

        Vload_file_name_internal = Qnil;
        staticpro(&Vload_file_name_internal);

        Vload_file_name_internal_the_purecopy = Qnil;
        staticpro(&Vload_file_name_internal_the_purecopy);

#ifdef COMPILED_FUNCTION_ANNOTATION_HACK
        Vcurrent_compiled_function_annotation = Qnil;
        staticpro(&Vcurrent_compiled_function_annotation);
#endif

        /* So that early-early stuff will work */
        Ffset(Qload, intern("load-internal"));

#ifdef FEATUREP_SYNTAX
        defsymbol(&Qfeaturep, "featurep");
        Fprovide(intern("xemacs"));
        Fprovide(intern("sxemacs"));
        Fprovide(intern("raw-strings"));
#ifdef INFODOCK
        Fprovide(intern("infodock"));
#endif                          /* INFODOCK */
#endif                          /* FEATUREP_SYNTAX */

#ifdef LISP_BACKQUOTES
        old_backquote_flag = new_backquote_flag = 0;
#endif

#ifdef I18N3
        Vfile_domain = Qnil;
#endif

        Vread_objects = Qnil;
        staticpro(&Vread_objects);

        Vlocate_file_hash_table = make_lisp_hash_table(200,
                                                       HASH_TABLE_NON_WEAK,
                                                       HASH_TABLE_EQUAL);
        staticpro(&Vlocate_file_hash_table);
#ifdef DEBUG_SXEMACS
        {
                Lisp_Object tmp = intern("Vlocate-file-hash-table");
                symbol_value(XSYMBOL(tmp)) = Vlocate_file_hash_table;
        }
#endif

        /* User defined readers */
        DEFVAR_LISP("ureaders", &Vureaders /*
Alist of user defined readers.
Car is ureader NAME, represented by string to match against when reading
#<NAME bla-bla-bla>
Cdr is user function called with one arg - string.
Function must return lisp object or signal error.
                                           */
                );
}

/* lread.c ends here */