================
@@ -420,6 +420,118 @@ AST_MATCHER(CXXConstructExpr,
isSafeSpanTwoParamConstruct) {
return false;
}
+class MaxValueEval : public RecursiveASTVisitor<MaxValueEval> {
+
+ std::vector<llvm::APInt> val;
+ ASTContext &Context;
+ llvm::APInt Max;
+ unsigned bit_width;
+
+public:
+ typedef RecursiveASTVisitor<MaxValueEval> VisitorBase;
+
+ explicit MaxValueEval(ASTContext &Ctx, const Expr *exp) : Context(Ctx) {
+ bit_width = Ctx.getIntWidth(exp->getType());
+ Max = llvm::APInt::getSignedMaxValue(bit_width);
+ val.clear();
+ }
+
+ bool findMatch(Expr *exp) {
+ TraverseStmt(exp);
+ return true;
+ }
+
+ bool VisitDeclRefExpr(DeclRefExpr *dre) {
+ val.push_back(Max);
+ return false;
+ }
+
+ bool VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
+ val.push_back(Max);
+ return false;
+ }
+
+ bool EvaluateExpression(Expr *exp) {
+ Expr::EvalResult EVResult;
+ if (exp->EvaluateAsInt(EVResult, Context)) {
+ llvm::APSInt Result = EVResult.Val.getInt();
+ val.push_back(Result);
+ return true;
+ }
+ return false;
+ }
+
+ bool VisitBinaryOperator(BinaryOperator *E) {
----------------
malavikasamak wrote:
Well.. This is a bit tricky and we actually don't always depend on the LHS and
RHS evaluation. Here, I am first checking if the expr evaluates to a constant
value. If yes, we store the result and don't traverse any further. If it does
not, only then we process the LHS and RHS to extract their limits.
https://github.com/llvm/llvm-project/pull/112284
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