[Sema][ObjC] Don't warn about an implicitly retained self if the
retaining block and all of the enclosing blocks are non-escaping.
If the block implicitly retaining self doesn't escape, there is no risk
of creating retain cycles, so clang shouldn't diagnose it and force
users to add self-> to silence the diagnostic.
Also, fix a bug where clang was failing to diagnose an implicitly
retained self inside a c++ lambda nested inside a block.
rdar://problem/25059955
Differential Revision: https://reviews.llvm.org/D60736
llvm-svn: 358624
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index fbe258b..8e0badf 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -13150,6 +13150,35 @@
bool IsLambda = false;
};
+static void diagnoseImplicitlyRetainedSelf(Sema &S) {
+ llvm::DenseMap<const BlockDecl *, bool> EscapeInfo;
+
+ auto IsOrNestedInEscapingBlock = [&](const BlockDecl *BD) {
+ if (EscapeInfo.count(BD))
+ return EscapeInfo[BD];
+
+ bool R = false;
+ const BlockDecl *CurBD = BD;
+
+ do {
+ R = !CurBD->doesNotEscape();
+ if (R)
+ break;
+ CurBD = CurBD->getParent()->getInnermostBlockDecl();
+ } while (CurBD);
+
+ return EscapeInfo[BD] = R;
+ };
+
+ // If the location where 'self' is implicitly retained is inside a escaping
+ // block, emit a diagnostic.
+ for (const std::pair<SourceLocation, const BlockDecl *> &P :
+ S.ImplicitlyRetainedSelfLocs)
+ if (IsOrNestedInEscapingBlock(P.second))
+ S.Diag(P.first, diag::warn_implicitly_retains_self)
+ << FixItHint::CreateInsertion(P.first, "self->");
+}
+
Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body,
bool IsInstantiation) {
FunctionDecl *FD = dcl ? dcl->getAsFunction() : nullptr;
@@ -13361,6 +13390,8 @@
diag::warn_objc_secondary_init_missing_init_call);
getCurFunction()->ObjCWarnForNoInitDelegation = false;
}
+
+ diagnoseImplicitlyRetainedSelf(*this);
} else {
// Parsing the function declaration failed in some way. Pop the fake scope
// we pushed on.
diff --git a/clang/lib/Sema/SemaDeclObjC.cpp b/clang/lib/Sema/SemaDeclObjC.cpp
index d0674c6..430c2a2 100644
--- a/clang/lib/Sema/SemaDeclObjC.cpp
+++ b/clang/lib/Sema/SemaDeclObjC.cpp
@@ -359,6 +359,7 @@
/// ActOnStartOfObjCMethodDef - This routine sets up parameters; invisible
/// and user declared, in the method definition's AST.
void Sema::ActOnStartOfObjCMethodDef(Scope *FnBodyScope, Decl *D) {
+ ImplicitlyRetainedSelfLocs.clear();
assert((getCurMethodDecl() == nullptr) && "Methodparsing confused");
ObjCMethodDecl *MDecl = dyn_cast_or_null<ObjCMethodDecl>(D);
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index ef39092..e64eeec 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -2575,11 +2575,9 @@
!Diags.isIgnored(diag::warn_arc_repeated_use_of_weak, Loc))
getCurFunction()->recordUseOfWeak(Result);
}
- if (getLangOpts().ObjCAutoRefCount) {
- if (CurContext->isClosure())
- Diag(Loc, diag::warn_implicitly_retains_self)
- << FixItHint::CreateInsertion(Loc, "self->");
- }
+ if (getLangOpts().ObjCAutoRefCount)
+ if (const BlockDecl *BD = CurContext->getInnermostBlockDecl())
+ ImplicitlyRetainedSelfLocs.push_back({Loc, BD});
return Result;
}