Extract IRGen's constant-emitter into its own helper class and clean up

the interface.

The ultimate goal here is to make it easier to do some more interesting
things in constant emission, like emit constant initializers that have
ignorable side-effects, or doing the majority of an initialization
in-place and then patching up the last few things with calls.  But for
now this is mostly just a refactoring.

llvm-svn: 310964

1 files changed, 6 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp
index 2351786..75a1350 100644
--- a/clang/lib/CodeGen/CGDecl.cpp
+++ b/clang/lib/CodeGen/CGDecl.cpp
@@ -19,6 +19,7 @@
 #include "CGOpenMPRuntime.h"
 #include "CodeGenFunction.h"
 #include "CodeGenModule.h"
+#include "ConstantEmitter.h"
 #include "TargetInfo.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/CharUnits.h"
@@ -307,7 +308,8 @@ static bool hasNontrivialDestruction(QualType T) {
 llvm::GlobalVariable *
 CodeGenFunction::AddInitializerToStaticVarDecl(const VarDecl &D,
                                                llvm::GlobalVariable *GV) {
-  llvm::Constant *Init = CGM.EmitConstantInit(D, this);
+  ConstantEmitter emitter(*this);
+  llvm::Constant *Init = emitter.tryEmitForInitializer(D);
 
   // If constant emission failed, then this should be a C++ static
   // initializer.
@@ -355,6 +357,8 @@ CodeGenFunction::AddInitializerToStaticVarDecl(const VarDecl &D,
   GV->setConstant(CGM.isTypeConstant(D.getType(), true));
   GV->setInitializer(Init);
 
+  emitter.finalize(GV);
+
   if (hasNontrivialDestruction(D.getType()) && HaveInsertPoint()) {
     // We have a constant initializer, but a nontrivial destructor. We still
     // need to perform a guarded "initialization" in order to register the
@@ -1236,7 +1240,7 @@ void CodeGenFunction::EmitAutoVarInit(const AutoVarEmission &emission) {
   llvm::Constant *constant = nullptr;
   if (emission.IsConstantAggregate || D.isConstexpr()) {
     assert(!capturedByInit && "constant init contains a capturing block?");
-    constant = CGM.EmitConstantInit(D, this);
+    constant = ConstantEmitter(*this).tryEmitAbstractForInitializer(D);
   }
 
   if (!constant) {