r365382 - [Sema] Resolve placeholder types before type deduction to silence
Akira Hatanaka via cfe-commits
cfe-commits at lists.llvm.org
Mon Jul 8 13:04:40 PDT 2019
Author: ahatanak
Date: Mon Jul 8 13:04:39 2019
New Revision: 365382
URL: http://llvm.org/viewvc/llvm-project?rev=365382&view=rev
Log:
[Sema] Resolve placeholder types before type deduction to silence
spurious `-Warc-repeated-use-of-weak` warnings
The spurious -Warc-repeated-use-of-weak warnings are issued when an
initializer expression uses a weak ObjC pointer.
My first attempt to silence the warnings (r350917) caused clang to
reject code that is legal in C++17. The patch is based on the feedback I
received from Richard when the patch was reverted.
http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20190422/268945.html
http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20190422/268943.html
Differential Revision: https://reviews.llvm.org/D62645
Modified:
cfe/trunk/include/clang/AST/Expr.h
cfe/trunk/include/clang/Basic/Attr.td
cfe/trunk/lib/Sema/SemaDecl.cpp
cfe/trunk/lib/Sema/SemaExpr.cpp
cfe/trunk/lib/Sema/SemaExprCXX.cpp
cfe/trunk/test/SemaObjC/arc-repeated-weak.mm
Modified: cfe/trunk/include/clang/AST/Expr.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/Expr.h?rev=365382&r1=365381&r2=365382&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/Expr.h (original)
+++ cfe/trunk/include/clang/AST/Expr.h Mon Jul 8 13:04:39 2019
@@ -490,6 +490,15 @@ public:
return false;
}
+ /// Returns whether this expression has a placeholder type that isn't
+ /// Overload.
+ bool hasNonOverloadPlaceholderType() const {
+ if (auto *PlaceholderType = getType()->getAsPlaceholderType())
+ if (PlaceholderType->isNonOverloadPlaceholderType())
+ return true;
+ return false;
+ }
+
/// isKnownToHaveBooleanValue - Return true if this is an integer expression
/// that is known to return 0 or 1. This happens for _Bool/bool expressions
/// but also int expressions which are produced by things like comparisons in
Modified: cfe/trunk/include/clang/Basic/Attr.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/Attr.td?rev=365382&r1=365381&r2=365382&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/Attr.td (original)
+++ cfe/trunk/include/clang/Basic/Attr.td Mon Jul 8 13:04:39 2019
@@ -1844,6 +1844,16 @@ def ObjCBoxable : Attr {
let Documentation = [ObjCBoxableDocs];
}
+
+// This is used to indicate that the type of the annotated variable's
+// initializer was changed from UnknownAny to 'id'.
+def ObjCDefaultedAnyToId : Attr {
+ // This attribute has no spellings as it is only ever created implicitly.
+ let Spellings = [];
+ let Subjects = SubjectList<[Var]>;
+ let Documentation = [Undocumented];
+}
+
def OptimizeNone : InheritableAttr {
let Spellings = [Clang<"optnone">];
let Subjects = SubjectList<[Function, ObjCMethod]>;
Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=365382&r1=365381&r2=365382&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDecl.cpp Mon Jul 8 13:04:39 2019
@@ -10985,18 +10985,6 @@ QualType Sema::deduceVarTypeFromInitiali
return QualType();
}
- // Expressions default to 'id' when we're in a debugger.
- bool DefaultedAnyToId = false;
- if (getLangOpts().DebuggerCastResultToId &&
- Init->getType() == Context.UnknownAnyTy && !IsInitCapture) {
- ExprResult Result = forceUnknownAnyToType(Init, Context.getObjCIdType());
- if (Result.isInvalid()) {
- return QualType();
- }
- Init = Result.get();
- DefaultedAnyToId = true;
- }
-
// C++ [dcl.decomp]p1:
// If the assignment-expression [...] has array type A and no ref-qualifier
// is present, e has type cv A
@@ -11030,6 +11018,7 @@ QualType Sema::deduceVarTypeFromInitiali
// checks.
// We only want to warn outside of template instantiations, though:
// inside a template, the 'id' could have come from a parameter.
+ bool DefaultedAnyToId = VDecl && VDecl->hasAttr<ObjCDefaultedAnyToIdAttr>();
if (!inTemplateInstantiation() && !DefaultedAnyToId && !IsInitCapture &&
!DeducedType.isNull() && DeducedType->isObjCIdType()) {
SourceLocation Loc = TSI->getTypeLoc().getBeginLoc();
@@ -11108,6 +11097,27 @@ void Sema::AddInitializerToDecl(Decl *Re
}
Init = Res.get();
+ // Expressions default to 'id' when we're in a debugger
+ // and we are assigning it to a variable of Objective-C pointer type.
+ if (getLangOpts().DebuggerCastResultToId &&
+ Init->getType() == Context.UnknownAnyTy) {
+ ExprResult Result = forceUnknownAnyToType(Init, Context.getObjCIdType());
+ if (Result.isInvalid()) {
+ VDecl->setInvalidDecl();
+ return;
+ }
+ Init = Result.get();
+ VDecl->addAttr(ObjCDefaultedAnyToIdAttr::CreateImplicit(Context));
+ } else if (!Init->getType().isNull() &&
+ Init->hasNonOverloadPlaceholderType()) {
+ Res = CheckPlaceholderExpr(Init).get();
+ if (!Res.isUsable()) {
+ VDecl->setInvalidDecl();
+ return;
+ }
+ Init = Res.get();
+ }
+
if (DeduceVariableDeclarationType(VDecl, DirectInit, Init))
return;
}
Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=365382&r1=365381&r2=365382&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExpr.cpp Mon Jul 8 13:04:39 2019
@@ -6678,6 +6678,14 @@ Sema::MaybeConvertParenListExprToParenEx
ExprResult Sema::ActOnParenListExpr(SourceLocation L,
SourceLocation R,
MultiExprArg Val) {
+ for (size_t I = 0, E = Val.size(); I != E; ++I)
+ if (Val[I]->hasNonOverloadPlaceholderType()) {
+ ExprResult Result = CheckPlaceholderExpr(Val[I]);
+ if (!Result.isUsable())
+ return ExprError();
+ Val[I] = Result.get();
+ }
+
return ParenListExpr::Create(Context, L, Val, R);
}
Modified: cfe/trunk/lib/Sema/SemaExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprCXX.cpp?rev=365382&r1=365381&r2=365382&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExprCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExprCXX.cpp Mon Jul 8 13:04:39 2019
@@ -1793,6 +1793,14 @@ Sema::BuildCXXNew(SourceRange Range, boo
NumInits = List->getNumExprs();
}
+ for (unsigned I = 0, E = NumInits; I != E; ++I)
+ if (Inits[I]->hasNonOverloadPlaceholderType()) {
+ ExprResult Result = CheckPlaceholderExpr(Inits[I]);
+ if (!Result.isUsable())
+ return ExprError();
+ Inits[I] = Result.get();
+ }
+
// C++11 [expr.new]p15:
// A new-expression that creates an object of type T initializes that
// object as follows:
Modified: cfe/trunk/test/SemaObjC/arc-repeated-weak.mm
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaObjC/arc-repeated-weak.mm?rev=365382&r1=365381&r2=365382&view=diff
==============================================================================
--- cfe/trunk/test/SemaObjC/arc-repeated-weak.mm (original)
+++ cfe/trunk/test/SemaObjC/arc-repeated-weak.mm Mon Jul 8 13:04:39 2019
@@ -1,5 +1,5 @@
-// RUN: %clang_cc1 -fsyntax-only -fobjc-runtime-has-weak -fobjc-arc -fblocks -Wno-objc-root-class -std=c++11 -Warc-repeated-use-of-weak -verify %s
-// RUN: %clang_cc1 -fsyntax-only -fobjc-runtime-has-weak -fobjc-weak -fblocks -Wno-objc-root-class -std=c++11 -Warc-repeated-use-of-weak -verify %s
+// RUN: %clang_cc1 -fsyntax-only -fobjc-runtime-has-weak -fobjc-arc -fblocks -Wno-objc-root-class -std=c++14 -Warc-repeated-use-of-weak -verify %s
+// RUN: %clang_cc1 -fsyntax-only -fobjc-runtime-has-weak -fobjc-weak -fblocks -Wno-objc-root-class -std=c++14 -Warc-repeated-use-of-weak -verify %s
@interface Test {
@public
@@ -467,6 +467,18 @@ void foo() {
__typeof__(NSBundle2.foo2.weakProp) t5;
}
+void testAuto() {
+ auto __weak wp = NSBundle2.foo2.weakProp;
+}
+
+void testLambdaCaptureInit() {
+ [capture(NSBundle2.foo2.weakProp)] {} ();
+}
+
+void testAutoNew() {
+ auto p = new auto(NSBundle2.foo2.weakProp);
+}
+
// This used to crash in the constructor of WeakObjectProfileTy when a
// DeclRefExpr was passed that didn't reference a VarDecl.
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