From 0d5156018dd3d0d075cc14a0aa6078979c7a85d3 Mon Sep 17 00:00:00 2001 From: Abseil Team Date: Thu, 27 May 2021 10:22:20 -0700 Subject: Export of internal Abseil changes -- cbd86b318ce206d1fe9eb001979b8d2efe57e5fa by Derek Mauro : Stop inlining `CurrentThreadIdentityIfPresent()` on Apple platforms In some build configurations the Apple linker rejects thread_local variables exposed in headers Fixes #954 Fixes #965 PiperOrigin-RevId: 375930997 GitOrigin-RevId: e34600e09f748b686d20a4f729ae914ebfd9e7bf Change-Id: I9fcd2f02bd6abdea3ed412217e1be18f2c7bf762 --- absl/base/internal/thread_identity.cc | 8 ++++---- absl/base/internal/thread_identity.h | 17 +++++++++++------ 2 files changed, 15 insertions(+), 10 deletions(-) diff --git a/absl/base/internal/thread_identity.cc b/absl/base/internal/thread_identity.cc index 6ea010ed..9950e63a 100644 --- a/absl/base/internal/thread_identity.cc +++ b/absl/base/internal/thread_identity.cc @@ -120,10 +120,10 @@ void SetCurrentThreadIdentity( ABSL_THREAD_IDENTITY_MODE == ABSL_THREAD_IDENTITY_MODE_USE_CPP11 // Please see the comment on `CurrentThreadIdentityIfPresent` in -// thread_identity.h. Because DLLs cannot expose thread_local variables in -// headers, we opt for the correct-but-slower option of placing the definition -// of this function only in a translation unit inside DLL. -#if defined(ABSL_BUILD_DLL) || defined(ABSL_CONSUME_DLL) +// thread_identity.h. When we cannot expose thread_local variables in +// headers, we opt for the correct-but-slower option of not inlining this +// function. +#ifndef ABSL_INTERNAL_INLINE_CURRENT_THREAD_IDENTITY_IF_PRESENT ThreadIdentity* CurrentThreadIdentityIfPresent() { return thread_identity_ptr; } #endif #endif diff --git a/absl/base/internal/thread_identity.h b/absl/base/internal/thread_identity.h index 9ee651a3..6e25b92f 100644 --- a/absl/base/internal/thread_identity.h +++ b/absl/base/internal/thread_identity.h @@ -236,13 +236,18 @@ ABSL_CONST_INIT extern thread_local ThreadIdentity* thread_identity_ptr; #error Thread-local storage not detected on this platform #endif -// thread_local variables cannot be in headers exposed by DLLs. However, it is -// important for performance reasons in general that -// `CurrentThreadIdentityIfPresent` be inlined. This is not possible across a -// DLL boundary so, with DLLs, we opt to have the function not be inlined. Note +// thread_local variables cannot be in headers exposed by DLLs or in certain +// build configurations on Apple platforms. However, it is important for +// performance reasons in general that `CurrentThreadIdentityIfPresent` be +// inlined. In the other cases we opt to have the function not be inlined. Note // that `CurrentThreadIdentityIfPresent` is declared above so we can exclude -// this entire inline definition when compiling as a DLL. -#if !defined(ABSL_BUILD_DLL) && !defined(ABSL_CONSUME_DLL) +// this entire inline definition. +#if !defined(__APPLE__) && !defined(ABSL_BUILD_DLL) && \ + !defined(ABSL_CONSUME_DLL) +#define ABSL_INTERNAL_INLINE_CURRENT_THREAD_IDENTITY_IF_PRESENT 1 +#endif + +#ifdef ABSL_INTERNAL_INLINE_CURRENT_THREAD_IDENTITY_IF_PRESENT inline ThreadIdentity* CurrentThreadIdentityIfPresent() { return thread_identity_ptr; } -- cgit v1.2.3