@@ -39,6 +39,7 @@ static inline void*
aligned_alloc (std::size_t al, std::size_t sz)
{
void *ptr;
+ // posix_memalign has additional requirement, not present on aligned_alloc:
// The value of alignment shall be a power of two multiple of sizeof(void *).
if (al < sizeof(void*))
al = sizeof(void*);
@@ -53,20 +54,24 @@ aligned_alloc (std::size_t al, std::size_t sz)
#else
extern "C" void *memalign(std::size_t boundary, std::size_t size);
#endif
-#define aligned_alloc memalign
-#else
+static inline void*
+aligned_alloc (std::size_t al, std::size_t sz)
+{
+#ifdef __sun
+ // Solaris 10 memalign requires that alignment is greater than or equal to
+ // the size of a word.
+ if (al < sizeof(int))
+ al = sizeof(int);
+#endif
+ return memalign (al, sz);
+}
+#else // !HAVE__ALIGNED_MALLOC && !HAVE_POSIX_MEMALIGN && !HAVE_MEMALIGN
#include <stdint.h>
// The C library doesn't provide any aligned allocation functions, define one.
// This is a modified version of code from gcc/config/i386/gmm_malloc.h
static inline void*
aligned_alloc (std::size_t al, std::size_t sz)
{
- // Alignment must be a power of two.
- if (al & (al - 1))
- return nullptr;
- else if (!sz)
- return nullptr;
-
// We need extra bytes to store the original value returned by malloc.
if (al < sizeof(void*))
al = sizeof(void*);
@@ -90,8 +95,13 @@ operator new (std::size_t sz, std::align_val_t al)
void *p;
std::size_t align = (std::size_t)al;
+ /* Alignment must be a power of two. */
+ /* XXX This should be checked by the compiler (PR 86878). */
+ if (__builtin_expect (align & (align - 1), false))
+ _GLIBCXX_THROW_OR_ABORT(bad_alloc());
+
/* malloc (0) is unpredictable; avoid it. */
- if (sz == 0)
+ if (__builtin_expect (sz == 0, false))
sz = 1;
#if _GLIBCXX_HAVE_ALIGNED_ALLOC
Solaris memalign requires alignment to be at least sizeof(int), so increase it as needed. Also move the check for valid alignments from the fallback implementation of aligned_alloc into operator new, as it's required for all of aligned_alloc, memalign, posix_memalign and __aligned_malloc. This adds a branch to check for undefined behaviour which we could just ignore, so the check could just be removed. It should certainly be removed if PR 86878 is implemented to issue a warning about calls with invalid alignments. PR libstdc++/86861 * libsupc++/new_opa.cc [_GLIBCXX_HAVE_MEMALIGN] (aligned_alloc): Replace macro with inline function. [__sun]: Increase alignment to meet memalign precondition. [!HAVE__ALIGNED_MALLOC && !HAVE_POSIX_MEMALIGN && !HAVE_MEMALIGN] (aligned_alloc): Move check for valid alignment to operator new. Remove redundant check for non-zero size, it's enforced by the caller. (operator new): Move check for valid alignment here. Use __builtin_expect on check for zero size. Tested powerpc64le-linux, committed to trunk. commit 926a15251b85d0b1a8b6bd08a138ad90ec9c83df Author: Jonathan Wakely <jwakely@redhat.com> Date: Mon Aug 6 15:43:43 2018 +0100 PR libstdc++/86861 Meet precondition for Solaris memalign Solaris memalign requires alignment to be at least sizeof(int), so increase it as needed. Also move the check for valid alignments from the fallback implementation of aligned_alloc into operator new, as it's required for all of aligned_alloc, memalign, posix_memalign and __aligned_malloc. This adds a branch to check for undefined behaviour which we could just ignore, so the check could just be removed. It should certainly be removed if PR 86878 is implemented to issue a warning about calls with invalid alignments. PR libstdc++/86861 * libsupc++/new_opa.cc [_GLIBCXX_HAVE_MEMALIGN] (aligned_alloc): Replace macro with inline function. [__sun]: Increase alignment to meet memalign precondition. [!HAVE__ALIGNED_MALLOC && !HAVE_POSIX_MEMALIGN && !HAVE_MEMALIGN] (aligned_alloc): Move check for valid alignment to operator new. Remove redundant check for non-zero size, it's enforced by the caller. (operator new): Move check for valid alignment here. Use __builtin_expect on check for zero size.