commit 0a8485643114f0dcb0b1cd037d18872b43464888
author Akira Hatanaka <ahatanaka@apple.com> Thu Jan 10 20:12:16 2019 +0000
committer Akira Hatanaka <ahatanaka@apple.com> Thu Jan 10 20:12:16 2019 +0000
tree 0bc4034cd8f4f49055bd972dbf99d26f680b0781
parent 0f36e2354001754807c670ab9d562551a8a2175b

[Sema] Call CheckPlaceholderExpr to resolve typeof or decltype
placeholder expressions while an unevaluated context is still on the
expression evaluation context stack.

This prevents recordUseOfWeek from being called when a weak variable is
used as an operand of a decltype or a typeof expression and fixes
spurious -Warc-repeated-use-of-weak warnings.

rdar://problem/45742525

Differential Revision: https://reviews.llvm.org/D55662

llvm-svn: 350887

clang/lib/Sema/SemaExpr.cpp

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index eddf901..f65e97e 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -14557,6 +14557,10 @@
 }
 
 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);

clang/lib/Sema/SemaExprCXX.cpp

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index e963058..04f77a8 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -6543,6 +6543,11 @@
              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

clang/lib/Sema/SemaExprObjC.cpp

diff --git a/clang/lib/Sema/SemaExprObjC.cpp b/clang/lib/Sema/SemaExprObjC.cpp
index ce80db7..ed780ef 100644
--- a/clang/lib/Sema/SemaExprObjC.cpp
+++ b/clang/lib/Sema/SemaExprObjC.cpp
@@ -3161,7 +3161,7 @@
           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);
       }

clang/lib/Sema/SemaTemplateDeduction.cpp

diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp
index 155d842..f2f989c 100644
--- a/clang/lib/Sema/SemaTemplateDeduction.cpp
+++ b/clang/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;

clang/lib/Sema/SemaType.cpp

diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index bf2bfda..bf1b9c6 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -8055,9 +8055,7 @@
 }
 
 QualType Sema::BuildTypeofExprType(Expr *E, SourceLocation Loc) {
-  ExprResult ER = CheckPlaceholderExpr(E);
-  if (ER.isInvalid()) return QualType();
-  E = ER.get();
+  assert(!E->hasPlaceholderType() && "unexpected placeholder");
 
   if (!getLangOpts().CPlusPlus && E->refersToBitField())
     Diag(E->getExprLoc(), diag::err_sizeof_alignof_typeof_bitfield) << 2;
@@ -8142,9 +8140,7 @@
 
 QualType Sema::BuildDecltypeType(Expr *E, SourceLocation Loc,
                                  bool AsUnevaluated) {
-  ExprResult ER = CheckPlaceholderExpr(E);
-  if (ER.isInvalid()) return QualType();
-  E = ER.get();
+  assert(!E->hasPlaceholderType() && "unexpected placeholder");
 
   if (AsUnevaluated && CodeSynthesisContexts.empty() &&
       E->HasSideEffects(Context, false)) {