[PATCH] D32410: change the way objcboxedexpr is handled

[Nick Lewycky via Phabricator via cfe-commits]

nlewycky created this revision.

Make ObjCBoxedExpr less of a special case, teach the expression evaluator to handle it in general, sometimes descending through to its subexpr. Remove the code that called CheckForIntOverflow from outside BuildObjCBoxedExpr, leaving its only caller CheckCompletedExpr.

To make the existing tests continue to work, we also need to whitelist ObjCBoxedExpr as a top-level expression in CheckForIntOverflow. Ultimately that we shouldn't need to whitelist, but one piece at a time.


https://reviews.llvm.org/D32410

Files:
  lib/AST/ExprConstant.cpp
  lib/Sema/SemaChecking.cpp
  lib/Sema/SemaExprObjC.cpp


Index: lib/Sema/SemaExprObjC.cpp
===================================================================
--- lib/Sema/SemaExprObjC.cpp
+++ lib/Sema/SemaExprObjC.cpp
@@ -595,7 +595,6 @@
         break;
       }
     }
-    CheckForIntOverflow(ValueExpr);
     // FIXME:  Do I need to do anything special with BoolTy expressions?
     
     // Look for the appropriate method within NSNumber.
Index: lib/Sema/SemaChecking.cpp
===================================================================
--- lib/Sema/SemaChecking.cpp
+++ lib/Sema/SemaChecking.cpp
@@ -9882,6 +9882,9 @@
 
     if (auto InitList = dyn_cast<InitListExpr>(E))
       Exprs.append(InitList->inits().begin(), InitList->inits().end());
+
+    if (isa<ObjCBoxedExpr>(E))
+      E->IgnoreParenCasts()->EvaluateForOverflow(Context);
   } while (!Exprs.empty());
 }
 
Index: lib/AST/ExprConstant.cpp
===================================================================
--- lib/AST/ExprConstant.cpp
+++ lib/AST/ExprConstant.cpp
@@ -4466,6 +4466,8 @@
     { return StmtVisitorTy::Visit(E->getSubExpr()); }
   bool VisitUnaryPlus(const UnaryOperator *E)
     { return StmtVisitorTy::Visit(E->getSubExpr()); }
+  bool VisitObjCBoxedExpr(const ObjCBoxedExpr *E)
+    { return StmtVisitorTy::Visit(E->getSubExpr()); }
   bool VisitChooseExpr(const ChooseExpr *E)
     { return StmtVisitorTy::Visit(E->getChosenSubExpr()); }
   bool VisitGenericSelectionExpr(const GenericSelectionExpr *E)
@@ -5471,7 +5473,26 @@
   bool VisitObjCStringLiteral(const ObjCStringLiteral *E)
       { return Success(E); }
   bool VisitObjCBoxedExpr(const ObjCBoxedExpr *E)
-      { return Success(E); }
+      {
+        // Should we continue evaluation after determining the result value?
+        switch (Info.EvalMode) {
+        case EvalInfo::EM_PotentialConstantExpression:
+        case EvalInfo::EM_PotentialConstantExpressionUnevaluated:
+        case EvalInfo::EM_EvaluateForOverflow:
+        case EvalInfo::EM_IgnoreSideEffects:
+          if (!E->getSubExpr()->isValueDependent()) {
+            APValue Discard;
+            Evaluate(Discard, Info, E->getSubExpr());
+          }
+
+        case EvalInfo::EM_ConstantExpression:
+        case EvalInfo::EM_ConstantExpressionUnevaluated:
+        case EvalInfo::EM_ConstantFold:
+        case EvalInfo::EM_OffsetFold:
+          return Success(E);
+        }
+      llvm_unreachable("Missed EvalMode case");
+      }
   bool VisitAddrLabelExpr(const AddrLabelExpr *E)
       { return Success(E); }
   bool VisitCallExpr(const CallExpr *E);


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