Initially, it may seem like this function might not be needed in any form, since mingw-w64 lacks the main stpcpy function.
However, third party projects may contain their own implementation of the stpcpy function. When GCC sees a declaration of the stpcpy function, it assumes that it is legal to do optimizations on strcpy+strlen into stpcpy. When strcpy is wrapped with fortification wrappers, so that strcpy ends up calling __builtin___strcpy_chk (which then calls __strcpy_chk), GCC can also transform this into __builtin___stpcpy_chk, which can generate a call to __stpcpy_chk. GCC's libssp does provide an implementation of __stpcpy_chk, even if the platform itself lacks stpcpy. Therefore, mingw-w64-crt's implementation of the ssp routines also does need an implementation of __stpcpy_chk, even if it is hard to practically produce calls to it. This should fix one issue discussed at https://github.com/msys2/MINGW-packages/issues/5803#issuecomment-1276812143. Signed-off-by: Martin Storsjö <mar...@martin.st> --- mingw-w64-crt/Makefile.am | 2 +- mingw-w64-crt/ssp/stpcpy_chk.c | 19 +++++++++++++++++++ 2 files changed, 20 insertions(+), 1 deletion(-) create mode 100644 mingw-w64-crt/ssp/stpcpy_chk.c diff --git a/mingw-w64-crt/Makefile.am b/mingw-w64-crt/Makefile.am index 053eab3cf..1dff68409 100644 --- a/mingw-w64-crt/Makefile.am +++ b/mingw-w64-crt/Makefile.am @@ -566,7 +566,7 @@ src_libmingwex=\ \ ssp/chk_fail.c ssp/memcpy_chk.c ssp/memmove_chk.c ssp/mempcpy_chk.c \ ssp/memset_chk.c ssp/stack_chk_fail.c ssp/stack_chk_guard.c ssp/strcat_chk.c \ - ssp/strcpy_chk.c ssp/strncat_chk.c ssp/strncpy_chk.c \ + ssp/stpcpy_chk.c ssp/strcpy_chk.c ssp/strncat_chk.c ssp/strncpy_chk.c \ \ stdio/mingw_pformat.h \ stdio/scanf2-argcount-char.c stdio/scanf2-argcount-wchar.c \ diff --git a/mingw-w64-crt/ssp/stpcpy_chk.c b/mingw-w64-crt/ssp/stpcpy_chk.c new file mode 100644 index 000000000..aaa387680 --- /dev/null +++ b/mingw-w64-crt/ssp/stpcpy_chk.c @@ -0,0 +1,19 @@ +/** + * This file has no copyright assigned and is placed in the Public Domain. + * This file is part of the mingw-w64 runtime package. + * No warranty is given; refer to the file DISCLAIMER.PD within this package. + */ + +#include <string.h> + +void __cdecl __chk_fail(void) __attribute__((__noreturn__)); + +char *__cdecl __stpcpy_chk(char *dst, const char *src, size_t bufsize); + +char *__cdecl __stpcpy_chk(char *dst, const char *src, size_t bufsize) +{ + size_t n = strlen(src); + if (n >= bufsize) + __chk_fail(); + return memcpy(dst, src, n + 1) + n; +} -- 2.25.1 _______________________________________________ Mingw-w64-public mailing list Mingw-w64-public@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
