[PATCH] D32410: change the way the expr evaluator handles objcboxedexpr

[Nick Lewycky via Phabricator via cfe-commits]

nlewycky updated this revision to Diff 97173.
nlewycky added a comment.

If the boxing method can't be constexpr then we can never evaluate it for a constant value, which means that we should unconditionally return Error, and use noteFailure to decide whether to visit the subexpr.


https://reviews.llvm.org/D32410

Files:
  lib/AST/ExprConstant.cpp
  lib/Sema/SemaChecking.cpp
  lib/Sema/SemaExprObjC.cpp
  test/CodeGenObjCXX/boxing.mm


Index: test/CodeGenObjCXX/boxing.mm
===================================================================
--- test/CodeGenObjCXX/boxing.mm
+++ test/CodeGenObjCXX/boxing.mm
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -emit-llvm -o - %s | FileCheck %s
+
+ at interface NSNumber
++ (id)numberWithInt:(int)n;
+ at end
+
+int n = 1;
+int m = (@(n++), 0);
+
+// CHECK: define {{.*}} @__cxx_global_var_init()
+// CHECK: load i32, i32* @n
+// CHECK: store i32 %{{.*}}, i32* @n
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
@@ -5481,8 +5481,11 @@
   bool VisitUnaryAddrOf(const UnaryOperator *E);
   bool VisitObjCStringLiteral(const ObjCStringLiteral *E)
       { return Success(E); }
-  bool VisitObjCBoxedExpr(const ObjCBoxedExpr *E)
-      { return Success(E); }
+  bool VisitObjCBoxedExpr(const ObjCBoxedExpr *E) {
+    if (Info.noteFailure())
+      EvaluateIgnoredValue(Info, E->getSubExpr());
+    return Error(E);
+  }
   bool VisitAddrLabelExpr(const AddrLabelExpr *E)
       { return Success(E); }
   bool VisitCallExpr(const CallExpr *E);


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D32410.97173.patch
Type: text/x-patch
Size: 1994 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20170428/8bd16567/attachment.bin>