Implement the initial part of C++0x [expr.const]p2, which specifies
that the unevaluated subexpressions of &&, ||, and ? : are not
considered when determining whether the expression is a constant
expression. Also, turn the "used in its own initializer" warning into
a runtime-behavior warning, so that it doesn't fire when a variable is
used as part of an unevaluated subexpression of its own initializer.
Fixes PR9999.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@131968 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index 1126289..1206fe7 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -2957,6 +2957,21 @@
case BO_LAnd:
case BO_LOr: {
ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx);
+
+ // C++0x [expr.const]p2:
+ // [...] subexpressions of logical AND (5.14), logical OR
+ // (5.15), and condi- tional (5.16) operations that are not
+ // evaluated are not considered.
+ if (Ctx.getLangOptions().CPlusPlus0x && LHSResult.Val == 0) {
+ if (Exp->getOpcode() == BO_LAnd &&
+ Exp->getLHS()->EvaluateAsInt(Ctx) == 0)
+ return LHSResult;
+
+ if (Exp->getOpcode() == BO_LOr &&
+ Exp->getLHS()->EvaluateAsInt(Ctx) != 0)
+ return LHSResult;
+ }
+
ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx);
if (LHSResult.Val == 0 && RHSResult.Val == 1) {
// Rare case where the RHS has a comma "side-effect"; we need
@@ -3015,10 +3030,22 @@
return NoDiag();
}
ICEDiag CondResult = CheckICE(Exp->getCond(), Ctx);
- ICEDiag TrueResult = CheckICE(Exp->getTrueExpr(), Ctx);
- ICEDiag FalseResult = CheckICE(Exp->getFalseExpr(), Ctx);
if (CondResult.Val == 2)
return CondResult;
+
+ // C++0x [expr.const]p2:
+ // subexpressions of [...] conditional (5.16) operations that
+ // are not evaluated are not considered
+ bool TrueBranch = Ctx.getLangOptions().CPlusPlus0x
+ ? Exp->getCond()->EvaluateAsInt(Ctx) != 0
+ : false;
+ ICEDiag TrueResult = NoDiag();
+ if (!Ctx.getLangOptions().CPlusPlus0x || TrueBranch)
+ TrueResult = CheckICE(Exp->getTrueExpr(), Ctx);
+ ICEDiag FalseResult = NoDiag();
+ if (!Ctx.getLangOptions().CPlusPlus0x || !TrueBranch)
+ FalseResult = CheckICE(Exp->getFalseExpr(), Ctx);
+
if (TrueResult.Val == 2)
return TrueResult;
if (FalseResult.Val == 2)