On Mon, Mar 27, 2023 at 8:00 PM Xi Ruoyao via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > memmem is not POSIX so the system may lack it. Then libiberty will > provide an implementation, but it's a "supplemental function" and not > declared in libiberty.h. We need to declare the prototype to use it > then.
Was there a reason to use memmem over strstr in the first place? Otherwise looks reasonable. Richard. > See libiberty doc at > https://gcc.gnu.org/onlinedocs/libiberty/Supplemental-Functions.html. > > Tested by bootstrapping GCC in the following container environments on > x86_64-linux-gnu: > > 1. "Vanilla" system with memmem in Glibc. > 2. memmem removed from string.h. > 3. memmem removed from both string.h and libc.so. > > For 3, also verified that memmem from libiberty is linked into fixincl > executable. > > Ok for trunk? > > fixincludes/ChangeLog: > > PR other/109293 > * configure.ac (AC_CHECK_DECLS): Add memmem. > * configure: Regenerate. > * config.h.in: Regenerate. > * system.h (memmem): Declare if HAVE_DECL_MEMMEM is zero. > --- > fixincludes/config.h.in | 4 ++++ > fixincludes/configure | 10 ++++++++++ > fixincludes/configure.ac | 2 +- > fixincludes/system.h | 4 ++++ > 4 files changed, 19 insertions(+), 1 deletion(-) > > diff --git a/fixincludes/config.h.in b/fixincludes/config.h.in > index 69a67f5f116..0fd21b721b9 100644 > --- a/fixincludes/config.h.in > +++ b/fixincludes/config.h.in > @@ -78,6 +78,10 @@ > don't. */ > #undef HAVE_DECL_GETC_UNLOCKED > > +/* Define to 1 if you have the declaration of `memmem', and to 0 if you > don't. > + */ > +#undef HAVE_DECL_MEMMEM > + > /* Define to 1 if you have the declaration of `putchar_unlocked', and to 0 if > you don't. */ > #undef HAVE_DECL_PUTCHAR_UNLOCKED > diff --git a/fixincludes/configure b/fixincludes/configure > index b3bca666a4d..bdcc41f6ddc 100755 > --- a/fixincludes/configure > +++ b/fixincludes/configure > @@ -5043,6 +5043,16 @@ fi > cat >>confdefs.h <<_ACEOF > #define HAVE_DECL_VASPRINTF $ac_have_decl > _ACEOF > +ac_fn_c_check_decl "$LINENO" "memmem" "ac_cv_have_decl_memmem" > "$ac_includes_default" > +if test "x$ac_cv_have_decl_memmem" = xyes; then : > + ac_have_decl=1 > +else > + ac_have_decl=0 > +fi > + > +cat >>confdefs.h <<_ACEOF > +#define HAVE_DECL_MEMMEM $ac_have_decl > +_ACEOF > > ac_fn_c_check_decl "$LINENO" "clearerr_unlocked" > "ac_cv_have_decl_clearerr_unlocked" "$ac_includes_default" > if test "x$ac_cv_have_decl_clearerr_unlocked" = xyes; then : > diff --git a/fixincludes/configure.ac b/fixincludes/configure.ac > index 14813b910f1..ef2227e3c93 100644 > --- a/fixincludes/configure.ac > +++ b/fixincludes/configure.ac > @@ -88,7 +88,7 @@ define(fixincludes_UNLOCKED_FUNCS, clearerr_unlocked > feof_unlocked dnl > fread_unlocked fwrite_unlocked getchar_unlocked getc_unlocked dnl > putchar_unlocked putc_unlocked) > AC_CHECK_FUNCS(fixincludes_UNLOCKED_FUNCS) > -AC_CHECK_DECLS([abort, asprintf, basename(char *), errno, vasprintf]) > +AC_CHECK_DECLS([abort, asprintf, basename(char *), errno, vasprintf, memmem]) > AC_CHECK_DECLS(m4_split(m4_normalize(fixincludes_UNLOCKED_FUNCS))) > > # Checks for typedefs, structures, and compiler characteristics. > diff --git a/fixincludes/system.h b/fixincludes/system.h > index dca5d57b2e3..687fb2e2025 100644 > --- a/fixincludes/system.h > +++ b/fixincludes/system.h > @@ -209,6 +209,10 @@ extern int errno; > extern void abort (void); > #endif > > +#if defined (HAVE_DECL_MEMMEM) && !HAVE_DECL_MEMMEM > +extern void *memmem (const void *, size_t, const void *, size_t); > +#endif > + > #if HAVE_SYS_STAT_H > # include <sys/stat.h> > #endif > -- > 2.40.0 >
