Fix UB in string.bench.cpp.
The usage of aligned_storage failed to pass the alignment it wanted,
which caused it to have a larger size and alignment that the
std::string's it was intended to store.
This patch manually specifies the alignment, as well as cleaning up
type alias bugs.
llvm-svn: 346779
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 3bea50aeb35704798aefa9acbb8973c7864f3732
diff --git a/benchmarks/string.bench.cpp b/benchmarks/string.bench.cpp
index d7f919b..b8f97e6 100644
--- a/benchmarks/string.bench.cpp
+++ b/benchmarks/string.bench.cpp
@@ -195,21 +195,21 @@
struct StringMove {
static void run(benchmark::State& state) {
// Keep two object locations and move construct back and forth.
- std::aligned_storage<sizeof(std::string)>::type Storage[2];
+ std::aligned_storage<sizeof(std::string), alignof(std::string)>::type Storage[2];
using S = std::string;
- S* Data = reinterpret_cast<S*>(Storage);
size_t I = 0;
- new (static_cast<void*>(Data)) std::string(makeString(Length()));
+ S *newS = new (static_cast<void*>(Storage)) std::string(makeString(Length()));
for (auto _ : state) {
// Switch locations.
I ^= 1;
benchmark::DoNotOptimize(Storage);
// Move construct into the new location,
- new (static_cast<void*>(Storage + I)) S(std::move(Data[I ^ 1]));
+ S *tmpS = new (static_cast<void*>(Storage + I)) S(std::move(*newS));
// then destroy the old one.
- Data[I ^ 1].~S();
+ newS->~S();
+ newS = tmpS;
}
- Data[I].~S();
+ newS->~S();
}
static std::string name() { return "BM_StringMove" + Length::name(); }