From 904098e80cfea900c7744ea00f15087baec9c598 Mon Sep 17 00:00:00 2001 From: Richard Smith Date: Wed, 5 Jun 2019 00:04:33 +0000 Subject: [PATCH] PR42111: Use guarded initialization for thread-local variables with unordered initialization and internal linkage. We'll run their initializers once on each reference, so we need a guard variable even though they only have a single definition. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@362562 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/CGDeclCXX.cpp | 8 +++++++- test/CodeGenCXX/cxx1y-variable-template.cpp | 17 +++++++++++++++++ 2 files changed, 24 insertions(+), 1 deletion(-) diff --git a/lib/CodeGen/CGDeclCXX.cpp b/lib/CodeGen/CGDeclCXX.cpp index ce0163723c..199e0ac99e 100644 --- a/lib/CodeGen/CGDeclCXX.cpp +++ b/lib/CodeGen/CGDeclCXX.cpp @@ -630,7 +630,13 @@ void CodeGenFunction::GenerateCXXGlobalVarDeclInitFunc(llvm::Function *Fn, // Use guarded initialization if the global variable is weak. This // occurs for, e.g., instantiated static data members and // definitions explicitly marked weak. - if (Addr->hasWeakLinkage() || Addr->hasLinkOnceLinkage()) { + // + // Also use guarded initialization for a variable with dynamic TLS and + // unordered initialization. (If the initialization is ordered, the ABI + // layer will guard the whole-TU initialization for us.) + if (Addr->hasWeakLinkage() || Addr->hasLinkOnceLinkage() || + (D->getTLSKind() == VarDecl::TLS_Dynamic && + isTemplateInstantiation(D->getTemplateSpecializationKind()))) { EmitCXXGuardedInit(*D, Addr, PerformInit); } else { EmitCXXGlobalVarDeclInit(*D, Addr, PerformInit); diff --git a/test/CodeGenCXX/cxx1y-variable-template.cpp b/test/CodeGenCXX/cxx1y-variable-template.cpp index dd8f28e429..51d1b54b37 100644 --- a/test/CodeGenCXX/cxx1y-variable-template.cpp +++ b/test/CodeGenCXX/cxx1y-variable-template.cpp @@ -27,4 +27,21 @@ int *p = &n<0>; // CHECK: @_ZN5OuterIA100_cE5InnerIA20_cE3arrIA3_cEE = linkonce_odr global [123 x i32] zeroinitializer // CHECK: @_ZGVN5OuterIA100_cE5InnerIA20_cE3arrIA3_cEE = linkonce_odr global +// CHECK: @_ZTHN7PR4211112_GLOBAL__N_11nILi0EEE = internal alias {{.*}} @[[PR42111_CTOR:.*]] + // CHECK: call {{.*}}@_Z8init_arrv + +// Ensure that we use guarded initialization for an instantiated thread_local +// variable with internal linkage. +namespace PR42111 { + int f(); + namespace { template thread_local int n = f(); } + // CHECK: define {{.*}}@[[PR42111_CTOR]]( + // CHECK: load {{.*}} @_ZGVN7PR4211112_GLOBAL__N_11nILi0EEE + // CHECK: icmp eq i8 {{.*}}, 0 + // CHECK: br i1 + // CHECK: call i32 @_ZN7PR421111fEv( + // CHECK: store i32 {{.*}}, i32* @_ZN7PR4211112_GLOBAL__N_11nILi0EEE + // CHECK: store i8 1, i8* @_ZGVN7PR4211112_GLOBAL__N_11nILi0EEE + int g() { return n<> + n<>; } +} -- 2.40.0