[PATCH] D55662: [Sema][ObjC] Do not warn about repeated uses of weak variables when the variables are accessed in an unevaluated context.

[Akira Hatanaka via Phabricator via cfe-commits]

ahatanak updated this revision to Diff 178957.
ahatanak added a comment.

Remove the call to `CheckPlaceholderExpr` in `Sema::BuildDecltypeType` and move it to `Sema::DeduceAutoType`. Assert that the expression that is passed to `Sema::BuildDecltypeType` isn't a placeholder.


Repository:
  rC Clang

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D55662/new/

https://reviews.llvm.org/D55662

Files:
  lib/Sema/SemaExpr.cpp
  lib/Sema/SemaExprCXX.cpp
  lib/Sema/SemaExprObjC.cpp
  lib/Sema/SemaTemplateDeduction.cpp
  lib/Sema/SemaType.cpp
  test/SemaObjC/arc-repeated-weak.mm


Index: test/SemaObjC/arc-repeated-weak.mm
===================================================================
--- test/SemaObjC/arc-repeated-weak.mm
+++ test/SemaObjC/arc-repeated-weak.mm
@@ -462,6 +462,9 @@
   NSString * t2 = NSBundle.foo2.prop;
   use(NSBundle.foo2.weakProp); // expected-warning{{weak property 'weakProp' may be accessed multiple times}}
   use(NSBundle2.foo2.weakProp); // expected-note{{also accessed here}}
+  decltype([NSBundle2.foo2 weakProp]) t3;
+  decltype(NSBundle2.foo2.weakProp) t4;
+  __typeof__(NSBundle2.foo2.weakProp) t5;
 }
 
 // This used to crash in the constructor of WeakObjectProfileTy when a
Index: lib/Sema/SemaType.cpp
===================================================================
--- lib/Sema/SemaType.cpp
+++ lib/Sema/SemaType.cpp
@@ -8040,9 +8040,7 @@
 }
 
 QualType Sema::BuildTypeofExprType(Expr *E, SourceLocation Loc) {
-  ExprResult ER = CheckPlaceholderExpr(E);
-  if (ER.isInvalid()) return QualType();
-  E = ER.get();
+  assert(!E->getType()->getAsPlaceholderType() && "unexpected placeholder");
 
   if (!getLangOpts().CPlusPlus && E->refersToBitField())
     Diag(E->getExprLoc(), diag::err_sizeof_alignof_typeof_bitfield) << 2;
@@ -8127,9 +8125,7 @@
 
 QualType Sema::BuildDecltypeType(Expr *E, SourceLocation Loc,
                                  bool AsUnevaluated) {
-  ExprResult ER = CheckPlaceholderExpr(E);
-  if (ER.isInvalid()) return QualType();
-  E = ER.get();
+  assert(!E->getType()->getAsPlaceholderType() && "unexpected placeholder");
 
   if (AsUnevaluated && CodeSynthesisContexts.empty() &&
       E->HasSideEffects(Context, false)) {
Index: lib/Sema/SemaTemplateDeduction.cpp
===================================================================
--- lib/Sema/SemaTemplateDeduction.cpp
+++ lib/Sema/SemaTemplateDeduction.cpp
@@ -4429,6 +4429,10 @@
         return DAR_FailedAlreadyDiagnosed;
       }
 
+      ExprResult ER = CheckPlaceholderExpr(Init);
+      if (ER.isInvalid())
+        return DAR_FailedAlreadyDiagnosed;
+      Init = ER.get();
       QualType Deduced = BuildDecltypeType(Init, Init->getBeginLoc(), false);
       if (Deduced.isNull())
         return DAR_FailedAlreadyDiagnosed;
Index: lib/Sema/SemaExprObjC.cpp
===================================================================
--- lib/Sema/SemaExprObjC.cpp
+++ lib/Sema/SemaExprObjC.cpp
@@ -3140,7 +3140,7 @@
           Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_weak;
         if (!IsWeak && Sel.isUnarySelector())
           IsWeak = ReturnType.getObjCLifetime() & Qualifiers::OCL_Weak;
-        if (IsWeak &&
+        if (IsWeak && !isUnevaluatedContext() &&
             !Diags.isIgnored(diag::warn_arc_repeated_use_of_weak, LBracLoc))
           getCurFunction()->recordUseOfWeak(Result, Prop);
       }
Index: lib/Sema/SemaExprCXX.cpp
===================================================================
--- lib/Sema/SemaExprCXX.cpp
+++ lib/Sema/SemaExprCXX.cpp
@@ -6539,6 +6539,11 @@
              ExpressionEvaluationContextRecord::EK_Decltype &&
          "not in a decltype expression");
 
+  ExprResult Result = CheckPlaceholderExpr(E);
+  if (Result.isInvalid())
+    return ExprError();
+  E = Result.get();
+
   // C++11 [expr.call]p11:
   //   If a function call is a prvalue of object type,
   // -- if the function call is either
Index: lib/Sema/SemaExpr.cpp
===================================================================
--- lib/Sema/SemaExpr.cpp
+++ lib/Sema/SemaExpr.cpp
@@ -14552,6 +14552,10 @@
 }
 
 ExprResult Sema::HandleExprEvaluationContextForTypeof(Expr *E) {
+  ExprResult Result = CheckPlaceholderExpr(E);
+  if (Result.isInvalid())
+    return ExprError();
+  E = Result.get();
   if (!E->getType()->isVariablyModifiedType())
     return E;
   return TransformToPotentiallyEvaluated(E);


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D55662.178957.patch
Type: text/x-patch
Size: 3794 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20181219/8a92f301/attachment-0001.bin>