[cfe-commits] r142866 - /cfe/trunk/lib/AST/ExprConstant.cpp
Richard Smith
richard-llvm at metafoo.co.uk
Mon Oct 24 15:35:48 PDT 2011
Author: rsmith
Date: Mon Oct 24 17:35:48 2011
New Revision: 142866
URL: http://llvm.org/viewvc/llvm-project?rev=142866&view=rev
Log:
Add explanatory comments for ICE checking in C99 mode.
Modified:
cfe/trunk/lib/AST/ExprConstant.cpp
Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=142866&r1=142865&r2=142866&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Mon Oct 24 17:35:48 2011
@@ -2974,6 +2974,9 @@
return NoDiag();
case Expr::CallExprClass:
case Expr::CXXOperatorCallExprClass: {
+ // C99 6.6/3 allows function calls within unevaluated subexpressions of
+ // constant expressions, but they can never be ICEs because an ICE cannot
+ // contain an operand of (pointer to) function type.
const CallExpr *CE = cast<CallExpr>(E);
if (CE->isBuiltinCall(Ctx))
return CheckEvalInICE(E, Ctx);
@@ -3034,6 +3037,9 @@
case UO_PreDec:
case UO_AddrOf:
case UO_Deref:
+ // C99 6.6/3 allows increment and decrement within unevaluated
+ // subexpressions of constant expressions, but they can never be ICEs
+ // because an ICE cannot contain an lvalue operand.
return ICEDiag(2, E->getLocStart());
case UO_Extension:
case UO_LNot:
@@ -3050,7 +3056,7 @@
case Expr::OffsetOfExprClass: {
// Note that per C99, offsetof must be an ICE. And AFAIK, using
// Evaluate matches the proposed gcc behavior for cases like
- // "offsetof(struct s{int x[4];}, x[!.0])". This doesn't affect
+ // "offsetof(struct s{int x[4];}, x[1.0])". This doesn't affect
// compliance: we should warn earlier for offsetof expressions with
// array subscripts that aren't ICEs, and if the array subscripts
// are ICEs, the value of the offsetof must be an integer constant.
@@ -3079,6 +3085,9 @@
case BO_AndAssign:
case BO_XorAssign:
case BO_OrAssign:
+ // C99 6.6/3 allows assignments within unevaluated subexpressions of
+ // constant expressions, but they can never be ICEs because an ICE cannot
+ // contain an lvalue operand.
return ICEDiag(2, E->getLocStart());
case BO_Mul:
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