[CodeGen] Avoid destructing a callee-destructued struct type in a

function if a function delegates to another function.

Fix a bug introduced in r328731, which caused a struct with ObjC __weak
fields that was passed to a function to be destructed twice, once in the
callee function and once in another function the callee function
delegates to. To prevent this, keep track of the callee-destructed
structs passed to a function and disable their cleanups at the point of
the call to the delegated function.

This reapplies r331016, which was reverted in r331019 because it caused
an assertion to fail in EmitDelegateCallArg on a windows bot. I made
changes to EmitDelegateCallArg so that it doesn't try to deactivate
cleanups for structs that have trivial destructors (cleanups for those
structs are never pushed to the cleanup stack in EmitParmDecl).

rdar://problem/39194693

Differential Revision: https://reviews.llvm.org/D45382

llvm-svn: 331020

1 files changed, 13 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 091fdc7ab7a..7889d089074 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -587,7 +587,7 @@ public:
   /// \brief Enters a new scope for capturing cleanups, all of which
   /// will be executed once the scope is exited.
   class RunCleanupsScope {
-    EHScopeStack::stable_iterator CleanupStackDepth;
+    EHScopeStack::stable_iterator CleanupStackDepth, OldCleanupScopeDepth;
     size_t LifetimeExtendedCleanupStackSize;
     bool OldDidCallStackSave;
   protected:
@@ -610,6 +610,8 @@ public:
           CGF.LifetimeExtendedCleanupStack.size();
       OldDidCallStackSave = CGF.DidCallStackSave;
       CGF.DidCallStackSave = false;
+      OldCleanupScopeDepth = CGF.CurrentCleanupScopeDepth;
+      CGF.CurrentCleanupScopeDepth = CleanupStackDepth;
     }
 
     /// \brief Exit this cleanup scope, emitting any accumulated cleanups.
@@ -635,9 +637,14 @@ public:
       CGF.PopCleanupBlocks(CleanupStackDepth, LifetimeExtendedCleanupStackSize,
                            ValuesToReload);
       PerformCleanup = false;
+      CGF.CurrentCleanupScopeDepth = OldCleanupScopeDepth;
     }
   };
 
+  // Cleanup stack depth of the RunCleanupsScope that was pushed most recently.
+  EHScopeStack::stable_iterator CurrentCleanupScopeDepth =
+      EHScopeStack::stable_end();
+
   class LexicalScope : public RunCleanupsScope {
     SourceRange Range;
     SmallVector<const LabelDecl*, 4> Labels;
@@ -1095,6 +1102,11 @@ private:
   /// decls.
   DeclMapTy LocalDeclMap;
 
+  // Keep track of the cleanups for callee-destructed parameters pushed to the
+  // cleanup stack so that they can be deactivated later.
+  llvm::DenseMap<const ParmVarDecl *, EHScopeStack::stable_iterator>
+      CalleeDestructedParamCleanups;
+
   /// SizeArguments - If a ParmVarDecl had the pass_object_size attribute, this
   /// will contain a mapping from said ParmVarDecl to its implicit "object_size"
   /// parameter.