From c1760eaf3b575ad174fd88b252fd16bd525fa818 Mon Sep 17 00:00:00 2001 From: Martin Sebor Date: Sun, 16 May 2021 15:21:18 -0600 Subject: Enable support for GCC 11 -Wmismatched-dealloc. To help detect common kinds of memory (and other resource) management bugs, GCC 11 adds support for the detection of mismatched calls to allocation and deallocation functions. At each call site to a known deallocation function GCC checks the set of allocation functions the former can be paired with and, if the two don't match, issues a -Wmismatched-dealloc warning (something similar happens in C++ for mismatched calls to new and delete). GCC also uses the same mechanism to detect attempts to deallocate objects not allocated by any allocation function (or pointers past the first byte into allocated objects) by -Wfree-nonheap-object. This support is enabled for built-in functions like malloc and free. To extend it beyond those, GCC extends attribute malloc to designate a deallocation function to which pointers returned from the allocation function may be passed to deallocate the allocated objects. Another, optional argument designates the positional argument to which the pointer must be passed. This change is the first step in enabling this extended support for Glibc. --- wcsmbs/wchar.h | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) (limited to 'wcsmbs') diff --git a/wcsmbs/wchar.h b/wcsmbs/wchar.h index ce0acb1c28..075776890f 100644 --- a/wcsmbs/wchar.h +++ b/wcsmbs/wchar.h @@ -151,7 +151,8 @@ extern size_t wcsxfrm_l (wchar_t *__s1, const wchar_t *__s2, size_t __n, locale_t __loc) __THROW; /* Duplicate S, returning an identical malloc'd string. */ -extern wchar_t *wcsdup (const wchar_t *__s) __THROW __attribute_malloc__; +extern wchar_t *wcsdup (const wchar_t *__s) __THROW + __attribute_malloc__ __attr_dealloc_free; #endif /* Find the first occurrence of WC in WCS. */ @@ -562,9 +563,23 @@ extern wchar_t *wcpncpy (wchar_t *__restrict __dest, /* Wide character I/O functions. */ #if defined __USE_XOPEN2K8 || __GLIBC_USE (LIB_EXT2) +# ifndef __attr_dealloc_fclose +# if defined __has_builtin +# if __has_builtin (__builtin_fclose) +/* If the attribute macro hasn't been defined yet (by ) and + fclose is a built-in, use it. */ +# define __attr_dealloc_fclose __attr_dealloc (__builtin_fclose, 1) +# endif +# endif +# endif +# ifndef __attr_dealloc_fclose +# define __attr_dealloc_fclose /* empty */ +# endif + /* Like OPEN_MEMSTREAM, but the stream is wide oriented and produces a wide character string. */ -extern __FILE *open_wmemstream (wchar_t **__bufloc, size_t *__sizeloc) __THROW; +extern __FILE *open_wmemstream (wchar_t **__bufloc, size_t *__sizeloc) __THROW + __attribute_malloc__ __attr_dealloc_fclose; #endif #if defined __USE_ISOC95 || defined __USE_UNIX98 -- cgit 1.4.1