Add preliminary (and probably broken) codegen support for C++ static initializers.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@55180 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGCXX.cpp b/lib/CodeGen/CGCXX.cpp
new file mode 100644
index 0000000..76e044b
--- /dev/null
+++ b/lib/CodeGen/CGCXX.cpp
@@ -0,0 +1,136 @@
+//===--- CGDecl.cpp - Emit LLVM Code for declarations ---------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This contains code dealing with C++ code generation.
+//
+//===----------------------------------------------------------------------===//
+
+// We might split this into multiple files if it gets too unwieldy
+
+#include "CodeGenFunction.h"
+#include "CodeGenModule.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Decl.h"
+#include "llvm/ADT/StringExtras.h"
+
+using namespace clang;
+using namespace CodeGen;
+
+using llvm::utostr;
+
+
+// FIXME: Name mangling should be moved to a separate class.
+
+static void mangleDeclContextInternal(const DeclContext *D, std::string &S)
+{
+ assert(isa<TranslationUnitDecl>(D->getParent()) &&
+ "Only one level of decl context mangling is currently supported!");
+
+ if (FunctionDecl* FD = dyn_cast<FunctionDecl>(D)) {
+ S += utostr(FD->getIdentifier()->getLength());
+ S += FD->getIdentifier()->getName();
+
+ if (FD->param_size() == 0)
+ S += 'v';
+ else
+ assert(0 && "mangling of types not supported yet!");
+ } else
+ assert(0 && "Unsupported decl type!");
+}
+
+static void mangleVarDeclInternal(const VarDecl &D, std::string &S)
+{
+ S += 'Z';
+ mangleDeclContextInternal(D.getDeclContext(), S);
+ S += 'E';
+
+ S += utostr(D.getIdentifier()->getLength());
+ S += D.getIdentifier()->getName();
+}
+
+static std::string mangleVarDecl(const VarDecl& D)
+{
+ std::string S = "_Z";
+
+ mangleVarDeclInternal(D, S);
+
+ return S;
+}
+
+static std::string mangleGuardVariable(const VarDecl& D)
+{
+ std::string S = "_ZGV";
+
+ mangleVarDeclInternal(D, S);
+
+ return S;
+}
+
+llvm::GlobalValue *
+CodeGenFunction::GenerateStaticCXXBlockVarDecl(const VarDecl &D)
+{
+ assert(!getContext().getLangOptions().ThreadsafeStatics &&
+ "thread safe statics are currently not supported!");
+ const llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(D.getType());
+
+ // FIXME: If the function is inline, the linkage should be weak.
+ llvm::GlobalValue::LinkageTypes linkage = llvm::GlobalValue::InternalLinkage;
+
+ // Create the guard variable.
+ llvm::GlobalValue *GuardV =
+ new llvm::GlobalVariable(llvm::Type::Int64Ty, false,
+ linkage,
+ llvm::Constant::getNullValue(llvm::Type::Int64Ty),
+ mangleGuardVariable(D),
+ &CGM.getModule());
+
+ // FIXME: Address space.
+ const llvm::Type *PtrTy = llvm::PointerType::get(llvm::Type::Int8Ty, 0);
+
+ // Load the first byte of the guard variable.
+ llvm::Value *V = Builder.CreateLoad(Builder.CreateBitCast(GuardV, PtrTy),
+ "tmp");
+
+ // Compare it against 0.
+ llvm::Value *nullValue = llvm::Constant::getNullValue(llvm::Type::Int8Ty);
+ llvm::Value *ICmp = Builder.CreateICmpEQ(V, nullValue , "tobool");
+
+ llvm::BasicBlock *InitBlock = llvm::BasicBlock::Create("init");
+ llvm::BasicBlock *EndBlock = llvm::BasicBlock::Create("initend");
+
+ // If the guard variable is 0, jump to the initializer code.
+ Builder.CreateCondBr(ICmp, InitBlock, EndBlock);
+
+ EmitBlock(InitBlock);
+
+ llvm::GlobalValue *GV =
+ new llvm::GlobalVariable(LTy, false,
+ llvm::GlobalValue::InternalLinkage,
+ llvm::Constant::getNullValue(LTy),
+ mangleVarDecl(D),
+ &CGM.getModule(), 0,
+ D.getType().getAddressSpace());
+
+ const Expr *Init = D.getInit();
+ if (!hasAggregateLLVMType(Init->getType())) {
+ llvm::Value *V = EmitScalarExpr(Init);
+ Builder.CreateStore(V, GV, D.getType().isVolatileQualified());
+ } else if (Init->getType()->isAnyComplexType()) {
+ EmitComplexExprIntoAddr(Init, GV, D.getType().isVolatileQualified());
+ } else {
+ EmitAggExpr(Init, GV, D.getType().isVolatileQualified());
+ }
+
+ Builder.CreateStore(llvm::ConstantInt::get(llvm::Type::Int8Ty, 1),
+ Builder.CreateBitCast(GuardV, PtrTy));
+
+ EmitBlock(EndBlock);
+ return GV;
+}
+
diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp
index 1d17210..b60e20f 100644
--- a/lib/CodeGen/CGDecl.cpp
+++ b/lib/CodeGen/CGDecl.cpp
@@ -86,7 +86,13 @@
if ((D.getInit() == 0) || NoInit) {
Init = llvm::Constant::getNullValue(LTy);
} else {
- Init = CGM.EmitConstantExpr(D.getInit(), this);
+ if (D.getInit()->isConstantExpr(getContext(), 0))
+ Init = CGM.EmitConstantExpr(D.getInit(), this);
+ else {
+ assert(getContext().getLangOptions().CPlusPlus &&
+ "only C++ supports non-constant static initializers!");
+ return GenerateStaticCXXBlockVarDecl(D);
+ }
}
assert(Init && "Unable to create initialiser for static decl");
diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index 8642c1b..cf057d8 100644
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -525,6 +525,10 @@
bool NoInit,
const char *Separator);
+ // GenerateStaticBlockVarDecl - return the static declaration of
+ // a local variable. Performs initialization of the variable if necessary.
+ llvm::GlobalValue *GenerateStaticCXXBlockVarDecl(const VarDecl &D);
+
//===--------------------------------------------------------------------===//
// Internal Helpers
//===--------------------------------------------------------------------===//