Change the representation of GNU ?: expressions to use a different expression

class and to bind the shared value using OpaqueValueExpr.  This fixes an
unnoticed problem with deserialization of these expressions where the
deserialized form would lose the vital pointer-equality trait;  or rather,
it fixes it because this patch also does the right thing for deserializing
OVEs.

Change OVEs to not be a "temporary object" in the sense that copy elision is
permitted.

This new representation is not totally unawkward to work with, but I think
that's really part and parcel with the semantics we're modelling here.  In
particular, it's much easier to fix things like the copy elision bug and to
make the CFG look right.

I've tried to update the analyzer to deal with this in at least some          
obvious cases, and I think we get a much better CFG out, but the printing
of OpaqueValueExprs probably needs some work.

llvm-svn: 125744

1 files changed, 11 insertions, 20 deletions

diff --git a/clang/lib/CodeGen/CGExprComplex.cpp b/clang/lib/CodeGen/CGExprComplex.cpp
index 15901eb..8b4ead8 100644
--- a/clang/lib/CodeGen/CGExprComplex.cpp
+++ b/clang/lib/CodeGen/CGExprComplex.cpp
@@ -130,12 +130,9 @@ public:
   ComplexPairTy VisitArraySubscriptExpr(Expr *E) { return EmitLoadOfLValue(E); }
   ComplexPairTy VisitMemberExpr(const Expr *E) { return EmitLoadOfLValue(E); }
   ComplexPairTy VisitOpaqueValueExpr(OpaqueValueExpr *E) {
-    if (E->isGLValue()) return EmitLoadOfLValue(E);
-
-    // Otherwise, the mapping is... what, exactly?  Probably a
-    // first-class aggregate, but it's really just not worthwhile.
-    CGF.ErrorUnsupported(E, "complex opaque r-value");
-    return ComplexPairTy();
+    if (E->isGLValue())
+      return EmitLoadOfLValue(CGF.getOpaqueLValueMapping(E));
+    return CGF.getOpaqueRValueMapping(E).getComplexVal();
   }
 
   // FIXME: CompoundLiteralExpr
@@ -260,7 +257,8 @@ public:
   ComplexPairTy VisitBinComma      (const BinaryOperator *E);
 
 
-  ComplexPairTy VisitConditionalOperator(const ConditionalOperator *CO);
+  ComplexPairTy
+  VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
   ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
 
   ComplexPairTy VisitInitListExpr(InitListExpr *E);
@@ -647,25 +645,18 @@ ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
 }
 
 ComplexPairTy ComplexExprEmitter::
-VisitConditionalOperator(const ConditionalOperator *E) {
+VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
   TestAndClearIgnoreReal();
   TestAndClearIgnoreImag();
   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
 
-  CodeGenFunction::ConditionalEvaluation eval(CGF);
+  // Bind the common expression if necessary.
+  CodeGenFunction::OpaqueValueMapping binding(CGF, E);
 
-  if (E->getLHS())
-    CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
-  else {
-    Expr *save = E->getSAVE();
-    assert(save && "VisitConditionalOperator - save is null");
-    // Intentionally not doing direct assignment to ConditionalSaveExprs[save] !!
-    ComplexPairTy SaveVal = Visit(save);
-    CGF.ConditionalSaveComplexExprs[save] = SaveVal;
-    CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
-  }
+  CodeGenFunction::ConditionalEvaluation eval(CGF);
+  CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
 
   eval.begin(CGF);
   CGF.EmitBlock(LHSBlock);
@@ -676,7 +667,7 @@ VisitConditionalOperator(const ConditionalOperator *E) {
 
   eval.begin(CGF);
   CGF.EmitBlock(RHSBlock);
-  ComplexPairTy RHS = Visit(E->getRHS());
+  ComplexPairTy RHS = Visit(E->getFalseExpr());
   RHSBlock = Builder.GetInsertBlock();
   CGF.EmitBlock(ContBlock);
   eval.end(CGF);