diff options
| author | Jonathan Wakely <jwakely@redhat.com> | 2018-10-12 00:21:11 +0100 |
|---|---|---|
| committer | Jonathan Wakely <redi@gcc.gnu.org> | 2018-10-12 00:21:11 +0100 |
| commit | 49cb790a4c7be09fbb3f2e57595379d0cbbd9e54 (patch) | |
| tree | 3edecd41269f5ea8a5db5ab7adca024655100032 | |
| parent | 47d31f1aa489dd5efca99747e377acc27a0cced2 (diff) | |
| download | gcc-49cb790a4c7be09fbb3f2e57595379d0cbbd9e54.zip gcc-49cb790a4c7be09fbb3f2e57595379d0cbbd9e54.tar.gz gcc-49cb790a4c7be09fbb3f2e57595379d0cbbd9e54.tar.bz2 | |
PR libstdc++/77691 increase allocation size to at least alignment
It's not safe to assume that malloc(n) returns memory aligned to more
than n, so when relying on the guaranteed alignment of malloc ensure
that the number of bytes allocated is at least as large as the
alignment.
PR libstdc++/77691
* include/experimental/memory_resource (__resource_adaptor_imp): Do
not allocate sizes smaller than alignment when relying on guaranteed
alignment.
* testsuite/experimental/memory_resource/new_delete_resource.cc:
Adjust expected number of bytes allocated for alignof(max_align_t).
From-SVN: r265068
| -rw-r--r-- | libstdc++-v3/ChangeLog | 9 | ||||
| -rw-r--r-- | libstdc++-v3/include/experimental/memory_resource | 9 | ||||
| -rw-r--r-- | libstdc++-v3/testsuite/experimental/memory_resource/new_delete_resource.cc | 10 |
3 files changed, 23 insertions, 5 deletions
diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index 93293c0..35be45e 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,12 @@ +2018-10-12 Jonathan Wakely <jwakely@redhat.com> + + PR libstdc++/77691 + * include/experimental/memory_resource (__resource_adaptor_imp): Do + not allocate sizes smaller than alignment when relying on guaranteed + alignment. + * testsuite/experimental/memory_resource/new_delete_resource.cc: + Adjust expected number of bytes allocated for alignof(max_align_t). + 2018-10-11 François Dumont <fdumont@gcc.gnu.org> * include/debug/forward_list diff --git a/libstdc++-v3/include/experimental/memory_resource b/libstdc++-v3/include/experimental/memory_resource index ccb45bf..fd40d2c 100644 --- a/libstdc++-v3/include/experimental/memory_resource +++ b/libstdc++-v3/include/experimental/memory_resource @@ -421,7 +421,12 @@ namespace pmr { do_allocate(size_t __bytes, size_t __alignment) override { if (__alignment <= __guaranteed_alignment<_Alloc>::value) - return _M_alloc.allocate(__bytes); + { + if (__bytes < __alignment) + __bytes = __alignment; + return _M_alloc.allocate(__bytes); + } + const _AlignMgr __mgr(__bytes, __alignment); // Assume _M_alloc returns 1-byte aligned memory, so allocate enough @@ -437,6 +442,8 @@ namespace pmr { auto __ptr = static_cast<char*>(__p); if (__alignment <= __guaranteed_alignment<_Alloc>::value) { + if (__bytes < __alignment) + __bytes = __alignment; _M_alloc.deallocate(__ptr, __bytes); return; } diff --git a/libstdc++-v3/testsuite/experimental/memory_resource/new_delete_resource.cc b/libstdc++-v3/testsuite/experimental/memory_resource/new_delete_resource.cc index 11667b1..3af3861 100644 --- a/libstdc++-v3/testsuite/experimental/memory_resource/new_delete_resource.cc +++ b/libstdc++-v3/testsuite/experimental/memory_resource/new_delete_resource.cc @@ -109,11 +109,13 @@ test03() using std::size_t; void* p = nullptr; + auto max = [](int n, int a) { return n > a ? n : a; }; + bytes_allocated = 0; memory_resource* r1 = new_delete_resource(); - p = r1->allocate(1); - VERIFY( bytes_allocated == 1 ); + p = r1->allocate(1); // uses alignment = alignof(max_align_t) + VERIFY( bytes_allocated <= alignof(max_align_t) ); VERIFY( aligned<max_align_t>(p) ); r1->deallocate(p, 1); VERIFY( bytes_allocated == 0 ); @@ -125,13 +127,13 @@ test03() VERIFY( bytes_allocated == 0 ); p = r1->allocate(3, alignof(short)); - VERIFY( bytes_allocated == 3 ); + VERIFY( bytes_allocated == max(3, alignof(short)) ); VERIFY( aligned<short>(p) ); r1->deallocate(p, 3, alignof(short)); VERIFY( bytes_allocated == 0 ); p = r1->allocate(4, alignof(long)); - VERIFY( bytes_allocated == 4 ); + VERIFY( bytes_allocated == max(4, alignof(long)) ); VERIFY( aligned<long>(p) ); r1->deallocate(p, 4, alignof(long)); VERIFY( bytes_allocated == 0 ); |