Update third_party/base/memory/aligned_memory.*.
Port the following CLs:
crrev.com/756778: Add IsAligned helpers, but not IsPageAligned() to
avoid dragging in more Chromium headers.
crrev.com/773784: GCC fix for IsAligned().
crrev.com/776967: Clean up CL.
Change-Id: If2138b0e1e0cd3465d55e069a4e6b0808fc4ce4e
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/70476
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
diff --git a/third_party/base/memory/aligned_memory.cc b/third_party/base/memory/aligned_memory.cc
index b4cd54f..3cacf3f 100644
--- a/third_party/base/memory/aligned_memory.cc
+++ b/third_party/base/memory/aligned_memory.cc
@@ -16,23 +16,25 @@
void* AlignedAlloc(size_t size, size_t alignment) {
DCHECK(size > 0U);
- DCHECK_EQ(alignment & (alignment - 1), 0U);
+ DCHECK(bits::IsPowerOfTwo(alignment));
DCHECK_EQ(alignment % sizeof(void*), 0U);
void* ptr = nullptr;
#if defined(COMPILER_MSVC)
ptr = _aligned_malloc(size, alignment);
-// Android technically supports posix_memalign(), but does not expose it in
-// the current version of the library headers used by Chrome. Luckily,
-// memalign() on Android returns pointers which can safely be used with
-// free(), so we can use it instead. Issue filed to document this:
-// http://code.google.com/p/android/issues/detail?id=35391
#elif defined(OS_ANDROID)
+ // Android technically supports posix_memalign(), but does not expose it in
+ // the current version of the library headers used by Chrome. Luckily,
+ // memalign() on Android returns pointers which can safely be used with
+ // free(), so we can use it instead. Issue filed to document this:
+ // http://code.google.com/p/android/issues/detail?id=35391
ptr = memalign(alignment, size);
#else
- if (int ret = posix_memalign(&ptr, alignment, size)) {
+ int ret = posix_memalign(&ptr, alignment, size);
+ if (ret != 0) {
ptr = nullptr;
}
#endif
+
// Since aligned allocations may fail for non-memory related reasons, force a
// crash if we encounter a failed allocation; maintaining consistent behavior
// with a normal allocation failure in Chrome.
@@ -40,7 +42,7 @@
CHECK(false);
}
// Sanity check alignment just to be safe.
- DCHECK_EQ(reinterpret_cast<uintptr_t>(ptr) & (alignment - 1), 0U);
+ DCHECK(IsAligned(ptr, alignment));
return ptr;
}
diff --git a/third_party/base/memory/aligned_memory.h b/third_party/base/memory/aligned_memory.h
index 59510e7..06241a5 100644
--- a/third_party/base/memory/aligned_memory.h
+++ b/third_party/base/memory/aligned_memory.h
@@ -12,7 +12,7 @@
#include "build/build_config.h"
#include "third_party/base/base_export.h"
-#include "third_party/base/compiler_specific.h"
+#include "third_party/base/bits.h"
#if defined(COMPILER_MSVC)
#include <malloc.h>
@@ -56,6 +56,28 @@
}
};
+#ifdef __has_builtin
+#define SUPPORTS_BUILTIN_IS_ALIGNED (__has_builtin(__builtin_is_aligned))
+#else
+#define SUPPORTS_BUILTIN_IS_ALIGNED 0
+#endif
+
+inline bool IsAligned(uintptr_t val, size_t alignment) {
+ // If the compiler supports builtin alignment checks prefer them.
+#if SUPPORTS_BUILTIN_IS_ALIGNED
+ return __builtin_is_aligned(val, alignment);
+#else
+ DCHECK(bits::IsPowerOfTwo(alignment));
+ return (val & (alignment - 1)) == 0;
+#endif
+}
+
+#undef SUPPORTS_BUILTIN_IS_ALIGNED
+
+inline bool IsAligned(void* val, size_t alignment) {
+ return IsAligned(reinterpret_cast<uintptr_t>(val), alignment);
+}
+
} // namespace base
} // namespace pdfium
