fi
])dnl SXE_CHECK_DIRNAME
-AC_DEFUN([_SXE_CHECK_DIRNAME_SIDE_EFFECT], [dnl
- ## defines sxe_func_dirname_side_effect
- ## and DIRNAME_SIDE_EFFECT
- pushdef([resvar], [sxe_func_dirname_side_effect])
-
- AC_MSG_CHECKING([whether dirname modifies its argument by side-effect])
- AC_RUN_IFELSE([AC_LANG_SOURCE([[
-#ifdef HAVE_LIBGEN_H
-# include <libgen.h>
-#endif
-
-int dirname_modifies_argument()
-{
- char p[11] = "somefile\000";
- dirname(p);
- return ((p[0] == '.' && p[1] == '\0') == 0);
-}
-
-int main()
-{
- return dirname_modifies_argument();
-}
- ]])],
- resvar[=yes],
- resvar[=no],
- resvar[=no])
- AC_MSG_RESULT([$]resvar)
-
- if test "$[]resvar[]" = "yes"; then
- AC_DEFINE([DIRNAME_SIDE_EFFECT], [1],
- [Whether dirname() operates by side effect])
- fi
-
- popdef([resvar])
-])dnl _SXE_CHECK_DIRNAME_SIDE_EFFECT
-
AC_DEFUN([_SXE_CHECK_DIRNAME_RETVAL], [dnl
## arg #1 is the return type, char* by default
## arg #2 is the final test,
popdef([rettest])
])dnl _SXE_CHECK_DIRNAME_RETVAL
-AC_DEFUN([_SXE_CHECK_DIRNAME_RETVAL_OWNER], [dnl
- ## defines sxe_func_dirname_retval_owner,
- ## values are either "sys" or "user"
- pushdef([resvar], [sxe_func_dirname_retval_owner])
-
- malloc_check=${MALLOC_CHECK_}
- ## Turn off the stupid glibc 2.5 stack trace check. We *know* we may
- ## do something bad here :-)
- MALLOC_CHECK_=0
- export MALLOC_CHECK_
- ## this test is especially critical, because some systems do not
- ## allocate memory for the user when the return value is "."
- ## instead they point to a static const char somewhere in their
- ## guts which, of course, must not be furtherly modified, free'd or
- ## anything ... took me fucking ages to find out what's going on
- ## so let's drink to the morons responsible for THAT!
- AC_MSG_CHECKING([to whom belongs the object returned by dirname])
- if test "$opsys" = "darwin" ; then
- resvar=sys
- else
- AC_RUN_IFELSE([AC_LANG_SOURCE([[
-#ifdef HAVE_LIBGEN_H
-# include <libgen.h>
-#endif
-
-#define FOLLOW_FREE_STRATEGY 1
-#define FOLLOW_REALLOC_STRATEGY 1
-
-int owner_of_object_returned_by_dirname()
-{
- void *r; /* any pointer is just fine */
- char p[11] = "./somefile\000";
-
- r = (void*)dirname(p);
-#if FOLLOW_REALLOC_STRATEGY
- /* reallocation would help already */
- r = realloc(r, 4096);
-#endif
-#if FOLLOW_FREE_STRATEGY
- /* if r was ours we should be able to free it */
- free(r);
-#endif
-#if FOLLOW_FREE_STRATEGY || FOLLOW_REALLOC_STRATEGY
- return 0;
-#else
- return 1;
-#endif
-}
-
-int main()
-{
- return owner_of_object_returned_by_dirname();
-}
- ]])],
- resvar[=user],
- resvar[=sys],
- resvar[=sys])
- fi
- if test "${malloc_check}" = "" ; then
- unset MALLOC_CHECK_
- else
- MALLOC_CHECK_=${malloc_check}
- fi
- AC_MSG_RESULT([$]resvar)
-
- if test "$[]resvar[]" = "user"; then
- AC_DEFINE([DIRNAME_USER_OWNS_RETVAL], [1],
- [Whether the user space owns the retval of dirname()])
- elif test "$[]resvar[]" = "sys"; then
- AC_DEFINE([DIRNAME_SYS_OWNS_RETVAL], [1],
- [Whether the system owns the retval of dirname()])
- fi
-
- popdef([resvar])
-])dnl _SXE_CHECK_DIRNAME_RETVAL_OWNER
-
-AC_DEFUN([_SXE_CHECK_DIRNAME_ON_PROTECTED_MEMORY], [dnl
- ## defines sxe_func_dirname_accepts_protmem
- pushdef([resvar], [sxe_func_dirname_accepts_protmem])
-
- AC_MSG_CHECKING([whether dirname can operate on protected mem blocks])
- AC_RUN_IFELSE([AC_LANG_SOURCE([[
-#ifdef HAVE_LIBGEN_H
-# include <libgen.h>
-#endif
-
-int dirname_can_operate_on_protected_mem_blocks()
-{
- dirname("./somefile");
- return 0;
-}
-
-int main()
-{
- return dirname_can_operate_on_protected_mem_blocks();
-}
- ]])],
- resvar[=yes],
- resvar[=no],
- resvar[=no])
- AC_MSG_RESULT([$]resvar)
-
- if test "$[]resvar[]" = "yes"; then
- AC_DEFINE([DIRNAME_ACCEPTS_PROTMEM], [1],
- [Whether dirname() accepts protected memory blocks])
- fi
-
- popdef([resvar])
-])dnl _SXE_CHECK_DIRNAME_ON_PROTECTED_MEMORY
-
AC_DEFUN([_SXE_CHECK_DIRNAME_ON_C99_RESTRICT_MEMORY], [dnl
## defines sxe_func_dirname_accepts_restrmem
pushdef([resvar], [sxe_func_dirname_accepts_restrmem])
AC_DEFUN([SXE_CHECK_BROKEN_DIRNAME], [dnl
## defines 3 vars, look in the sub macros to see which ones
- _SXE_CHECK_DIRNAME_SIDE_EFFECT
- _SXE_CHECK_DIRNAME_ON_PROTECTED_MEMORY
_SXE_CHECK_DIRNAME_ON_C99_RESTRICT_MEMORY
_SXE_CHECK_DIRNAME_RETVAL
- _SXE_CHECK_DIRNAME_RETVAL_OWNER
])dnl SXE_CHECK_BROKEN_DIRNAME
extern_inline void
x__dirname(char *restrict res, const char *file, size_t len)
__attribute__((always_inline));
-#if defined(HAVE_DIRNAME) && defined(DIRNAME_SIDE_EFFECT)
+#if defined(HAVE_DIRNAME)
extern_inline void
x__dirname(char *restrict res, const char *file, size_t len)
{
- /* assumes res is malloc'd of size LEN */
- xstrncpy(res, file, len);
- dirname(res);
- return;
-}
-#elif defined(HAVE_DIRNAME) && !defined(DIRNAME_ACCEPTS_PROTMEM)
-extern_inline void
-x__dirname(char *restrict res, const char *file, size_t len)
-{
- /* assumes res is malloc'd of size LEN */
- char *result;
- xstrncpy(res, file, len);
- /* if we were using side effects we woulda matched the above cond */
- result = dirname(res);
- xstrncpy(res, result, len);
- return;
-}
-#elif defined(HAVE_DIRNAME)
-extern_inline void
-x__dirname(char *restrict res, const char *file, size_t len)
-{
- /* assumes res is malloc'd of size LEN */
- char *result = dirname(res);
- xstrncpy(res, result, len);
- return;
+ /* assumes res is malloc'd of size LEN */
+ char *result;
+ xstrncpy(res, file, len);
+ result = dirname(res);
+ if (res == result) {
+ return;
+ }
+ if (result < res || result >= (res+len)) {
+ xstrncpy(res, result, len);
+ } else {
+ /* Use memmove if result overlaps res */
+ memmove(res, result, strlen(result)+1);
+ }
+ return;
}
#endif
projects / sxemacs / commitdiff