Refactor: split Uninitialized state on APValue into an "Absent" state

representing no such object, and an "Indeterminate" state representing
an uninitialized object. The latter is not yet used, but soon will be.

llvm-svn: 361328

3 files changed, 6 insertions, 4 deletions

diff --git a/clang/lib/CodeGen/CGExprConstant.cpp b/clang/lib/CodeGen/CGExprConstant.cpp
index 70904b192a3..caa327c19a4 100644
--- a/clang/lib/CodeGen/CGExprConstant.cpp
+++ b/clang/lib/CodeGen/CGExprConstant.cpp
@@ -1860,8 +1860,10 @@ ConstantLValueEmitter::VisitMaterializeTemporaryExpr(
 llvm::Constant *ConstantEmitter::tryEmitPrivate(const APValue &Value,
                                                 QualType DestType) {
   switch (Value.getKind()) {
-  case APValue::Uninitialized:
-    llvm_unreachable("Constant expressions should be initialized.");
+  case APValue::None:
+  case APValue::Indeterminate:
+    // Out-of-lifetime and indeterminate values can be modeled as 'undef'.
+    return llvm::UndefValue::get(CGM.getTypes().ConvertType(DestType));
   case APValue::LValue:
     return ConstantLValueEmitter(*this, Value, DestType).tryEmit();
   case APValue::Int:
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index a2d6d59800c..b9573f71a3a 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -1990,7 +1990,7 @@ Address CodeGenFunction::EmitMSVAListRef(const Expr *E) {
 
 void CodeGenFunction::EmitDeclRefExprDbgValue(const DeclRefExpr *E,
                                               const APValue &Init) {
-  assert(!Init.isUninit() && "Invalid DeclRefExpr initializer!");
+  assert(Init.hasValue() && "Invalid DeclRefExpr initializer!");
   if (CGDebugInfo *Dbg = getDebugInfo())
     if (CGM.getCodeGenOpts().getDebugInfo() >= codegenoptions::LimitedDebugInfo)
       Dbg->EmitGlobalVariable(E->getDecl(), Init);
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index a16e7ce47f9..6daea419281 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -4886,7 +4886,7 @@ ConstantAddress CodeGenModule::GetAddrOfGlobalTemporary(
     // evaluating the initializer if the surrounding constant expression
     // modifies the temporary.
     Value = getContext().getMaterializedTemporaryValue(E, false);
-    if (Value && Value->isUninit())
+    if (Value && Value->isAbsent())
       Value = nullptr;
   }