Export of internal Abseil changes

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3e60f355db5afd7a864591d81a6c383b6c0a0780 by Samuel Benzaquen <sbenza@google.com>:

Internal change

PiperOrigin-RevId: 272531442

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6d189240b8cebe3a390c730de491156d03049229 by Andy Getzendanner <durandal@google.com>:

Fix AtomicHook init-order fiasco under MSVC 2019.

On this platform, constexpr static init sometimes happens after dynamic init =/.  When it does, we should not zero hook_ (overwriting the value written there by dynamic init); instead we should leave it alone.  This works even when constexpr static init goes first since all uses of AtomicHook should have static storage duration and be zero-initialized.

https://developercommunity.visualstudio.com/content/problem/336946/class-with-constexpr-constructor-not-using-static.html

PiperOrigin-RevId: 272525226

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d01b14fc06bc75b41c51976ed32e7c304ea1aab7 by Abseil Team <absl-team@google.com>:

exclude emscripten from running tests involving long doubles

PiperOrigin-RevId: 272497628
GitOrigin-RevId: 3e60f355db5afd7a864591d81a6c383b6c0a0780
Change-Id: I3c8a8f5acaf7652a06ef40cf028ef5d2e142f81b
This commit is contained in:
Abseil Team 2019-10-02 15:20:57 -07:00 committed by CJ Johnson
parent aad33fefaa
commit 25597bdfc1
12 changed files with 166 additions and 12 deletions

View file

@ -14,11 +14,15 @@
#include "absl/base/internal/atomic_hook.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "absl/base/attributes.h"
#include "absl/base/internal/atomic_hook_test_helper.h"
namespace {
using ::testing::Eq;
int value = 0;
void TestHook(int x) { value = x; }
@ -67,4 +71,24 @@ TEST(AtomicHookTest, WithDefaultFunction) {
EXPECT_EQ(value, 2);
}
ABSL_CONST_INIT int override_func_calls = 0;
void OverrideFunc() { override_func_calls++; }
static struct OverrideInstaller {
OverrideInstaller() { absl::atomic_hook_internal::func.Store(OverrideFunc); }
} override_installer;
TEST(AtomicHookTest, DynamicInitFromAnotherTU) {
// MSVC 14.2 doesn't do constexpr static init correctly; in particular it
// tends to sequence static init (i.e. defaults) of `AtomicHook` objects
// after their dynamic init (i.e. overrides), overwriting whatever value was
// written during dynamic init. This regression test validates the fix.
// https://developercommunity.visualstudio.com/content/problem/336946/class-with-constexpr-constructor-not-using-static.html
EXPECT_THAT(absl::atomic_hook_internal::default_func_calls, Eq(0));
EXPECT_THAT(override_func_calls, Eq(0));
absl::atomic_hook_internal::func();
EXPECT_THAT(absl::atomic_hook_internal::default_func_calls, Eq(0));
EXPECT_THAT(override_func_calls, Eq(1));
EXPECT_THAT(absl::atomic_hook_internal::func.Load(), Eq(OverrideFunc));
}
} // namespace