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Remove short-circuit evaluation and the extension warnings. I'm 

pretty sure we want to keep constant expression verification outside of 
Evaluate. Because of that, the short-circuit evaluation doesn't 
generally make sense, and the comma warning doesn't make sense in its 
current form.

llvm-svn: 65525
This commit is contained in:
Eli Friedman 2009-02-26 10:19:36 +00:00
parent 98c56a4fe9
commit 9cb9ff4342
1 changed files with 6 additions and 43 deletions
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49
clang/lib/AST/ExprConstant.cpp
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@ -42,12 +42,8 @@ struct EvalInfo {
/// EvalResult - Contains information about the evaluation.
Expr::EvalResult &EvalResult;
/// ShortCircuit - will be greater than zero if the current subexpression has
/// will not be evaluated because it's short-circuited (according to C rules).
unsigned ShortCircuit;
EvalInfo(ASTContext &ctx, Expr::EvalResult& evalresult) : Ctx(ctx),
EvalResult(evalresult), ShortCircuit(0) {}
EvalResult(evalresult) {}
};
@ -559,13 +555,6 @@ public:
IntExprEvaluator(EvalInfo &info, APValue &result)
: Info(info), Result(result) {}
bool Extension(SourceLocation L, diag::kind D, const Expr *E) {
Info.EvalResult.DiagLoc = L;
Info.EvalResult.Diag = D;
Info.EvalResult.DiagExpr = E;
return true; // still a constant.
}
bool Success(const llvm::APSInt &SI, const Expr *E) {
assert(E->getType()->isIntegralType() && "Invalid evaluation result.");
assert(SI.isSigned() == E->getType()->isSignedIntegerType() &&
@ -592,18 +581,7 @@ public:
}
bool Error(SourceLocation L, diag::kind D, const Expr *E) {
// If this is in an unevaluated portion of the subexpression, ignore the
// error.
if (Info.ShortCircuit) {
// If error is ignored because the value isn't evaluated, get the real
// type at least to prevent errors downstream.
return Success(0, E);
}
// Take the first error.
// FIXME: This is wrong if we happen to have already emitted an
// extension diagnostic; in that case we should report this error.
if (Info.EvalResult.Diag == 0) {
Info.EvalResult.DiagLoc = L;
Info.EvalResult.Diag = D;
@ -792,14 +770,10 @@ bool IntExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
if (!Visit(E->getRHS()))
return false;
if (!Info.ShortCircuit) {
// If we can't evaluate the LHS, it must be because it has
// side effects.
if (!E->getLHS()->isEvaluatable(Info.Ctx))
Info.EvalResult.HasSideEffects = true;
return Extension(E->getOperatorLoc(), diag::note_comma_in_ice, E);
}
// If we can't evaluate the LHS, it might have side effects;
// conservatively mark it.
if (!E->getLHS()->isEvaluatable(Info.Ctx))
Info.EvalResult.HasSideEffects = true;
return true;
}
@ -812,19 +786,8 @@ bool IntExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
if (HandleConversionToBool(E->getLHS(), lhsResult, Info)) {
// We were able to evaluate the LHS, see if we can get away with not
// evaluating the RHS: 0 && X -> 0, 1 || X -> 1
if (lhsResult == (E->getOpcode() == BinaryOperator::LOr) ||
!lhsResult == (E->getOpcode() == BinaryOperator::LAnd)) {
Info.ShortCircuit++;
bool rhsEvaluated = HandleConversionToBool(E->getRHS(), rhsResult, Info);
Info.ShortCircuit--;
// FIXME: Return an extension warning saying that the RHS could not be
// evaluated.
// if (!rhsEvaluated) ...
(void) rhsEvaluated;
if (lhsResult == (E->getOpcode() == BinaryOperator::LOr))
return Success(lhsResult, E);
}
if (HandleConversionToBool(E->getRHS(), rhsResult, Info)) {
if (E->getOpcode() == BinaryOperator::LOr)