Emit the TLS intialization functions into a list.
Add the TLS initialization functions to a list of initialization functions. The
back-end takes this list and places the function pointers into the correct
section. This way they're called before `main().'
<rdar://problem/13733006>
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180739 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGDeclCXX.cpp b/lib/CodeGen/CGDeclCXX.cpp
index 9ffcff2..4d78ea8 100644
--- a/lib/CodeGen/CGDeclCXX.cpp
+++ b/lib/CodeGen/CGDeclCXX.cpp
@@ -304,6 +304,7 @@
Guard->setThreadLocal(true);
CodeGenFunction(*this)
.GenerateCXXGlobalInitFunc(InitFn, CXXThreadLocalInits, Guard);
+ AddTLSInitFunc(InitFn);
}
getCXXABI().EmitThreadLocalInitFuncs(CXXThreadLocals, InitFn);
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index bf67bd1..6247b15 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -182,6 +182,7 @@
AddGlobalCtor(ObjCInitFunction);
EmitCtorList(GlobalCtors, "llvm.global_ctors");
EmitCtorList(GlobalDtors, "llvm.global_dtors");
+ EmitTLSList(TLSInitFuncs);
EmitGlobalAnnotations();
EmitStaticExternCAliases();
EmitLLVMUsed();
@@ -479,6 +480,12 @@
GlobalDtors.push_back(std::make_pair(Dtor, Priority));
}
+/// AddTLSInitFunc - Add a function to the list that will initialize TLS
+/// variables before main() runs.
+void CodeGenModule::AddTLSInitFunc(llvm::Function *Init) {
+ TLSInitFuncs.push_back(Init);
+}
+
void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) {
// Ctor function type is void()*.
llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false);
@@ -507,6 +514,25 @@
}
}
+void CodeGenModule::EmitTLSList(ArrayRef<llvm::Constant*> Fns) {
+ if (Fns.empty()) return;
+
+ // TLS init function types are void()*.
+ llvm::FunctionType* TLSFTy = llvm::FunctionType::get(VoidTy, false);
+ llvm::Type *TLSPFTy = llvm::PointerType::getUnqual(TLSFTy);
+
+ SmallVector<llvm::Constant*, 8> Inits;
+ for (ArrayRef<llvm::Constant*>::iterator I = Fns.begin(),
+ E = Fns.end(); I != E; ++I)
+ Inits.push_back(llvm::ConstantExpr::getBitCast(*I, TLSPFTy));
+
+ llvm::ArrayType *AT = llvm::ArrayType::get(TLSPFTy, Inits.size());
+ new llvm::GlobalVariable(TheModule, AT, false,
+ llvm::GlobalValue::AppendingLinkage,
+ llvm::ConstantArray::get(AT, Inits),
+ "llvm.tls_init_funcs");
+}
+
llvm::GlobalValue::LinkageTypes
CodeGenModule::getFunctionLinkage(const FunctionDecl *D) {
GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
diff --git a/lib/CodeGen/CodeGenModule.h b/lib/CodeGen/CodeGenModule.h
index 0f4fe8a..ca30096 100644
--- a/lib/CodeGen/CodeGenModule.h
+++ b/lib/CodeGen/CodeGenModule.h
@@ -293,6 +293,10 @@
/// priorities to be emitted when the translation unit is complete.
CtorList GlobalDtors;
+ /// TLSInitFuncs - Store the list of TLS initialization functions toe be
+ /// emitted with the translation unit is complete.
+ std::vector<llvm::Constant*> TLSInitFuncs;
+
/// MangledDeclNames - A map of canonical GlobalDecls to their mangled names.
llvm::DenseMap<GlobalDecl, StringRef> MangledDeclNames;
llvm::BumpPtrAllocator MangledNamesAllocator;
@@ -1053,11 +1057,18 @@
void AddGlobalCtor(llvm::Function *Ctor, int Priority=65535);
void AddGlobalDtor(llvm::Function *Dtor, int Priority=65535);
+ void AddTLSInitFunc(llvm::Function *Init);
+
/// EmitCtorList - Generates a global array of functions and priorities using
/// the given list and name. This array will have appending linkage and is
/// suitable for use as a LLVM constructor or destructor array.
void EmitCtorList(const CtorList &Fns, const char *GlobalName);
+ /// EmitTLSList - Generates a global array of functions with the name
+ /// `llvm.tls_init_funcs'. This array will have appending linkage and is meant
+ /// to hold initialization functions for TLS variables.
+ void EmitTLSList(ArrayRef<llvm::Constant*> Fns);
+
/// EmitFundamentalRTTIDescriptor - Emit the RTTI descriptors for the
/// given type.
void EmitFundamentalRTTIDescriptor(QualType Type);