Fix for clang memcpyizer bugs 23911 and 23924 (patch by Denis Zobnin)

The fix is to remove duplicate copy-initialization of the only memcpy-able struct member and to correct the address of aggregately initialized members in destructors' calls during stack unwinding (in order to obtain address of struct member by using GEP instead of 'bitcast').
Differential Revision: http://reviews.llvm.org/D10990

llvm-svn: 242127

1 files changed, 23 insertions, 13 deletions

diff --git a/clang/lib/CodeGen/CGClass.cpp b/clang/lib/CodeGen/CGClass.cpp
index b977824..c49f182 100644
--- a/clang/lib/CodeGen/CGClass.cpp
+++ b/clang/lib/CodeGen/CGClass.cpp
@@ -554,6 +554,20 @@ static bool isMemcpyEquivalentSpecialMember(const CXXMethodDecl *D) {
   return false;
 }
 
+static void EmitLValueForAnyFieldInitialization(CodeGenFunction &CGF,
+                                                CXXCtorInitializer *MemberInit,
+                                                LValue &LHS) {
+  FieldDecl *Field = MemberInit->getAnyMember();
+  if (MemberInit->isIndirectMemberInitializer()) {
+    // If we are initializing an anonymous union field, drill down to the field.
+    IndirectFieldDecl *IndirectField = MemberInit->getIndirectMember();
+    for (const auto *I : IndirectField->chain())
+      LHS = CGF.EmitLValueForFieldInitialization(LHS, cast<FieldDecl>(I));
+  } else {
+    LHS = CGF.EmitLValueForFieldInitialization(LHS, Field);
+  }
+}
+
 static void EmitMemberInitializer(CodeGenFunction &CGF,
                                   const CXXRecordDecl *ClassDecl,
                                   CXXCtorInitializer *MemberInit,
@@ -572,16 +586,7 @@ static void EmitMemberInitializer(CodeGenFunction &CGF,
   QualType RecordTy = CGF.getContext().getTypeDeclType(ClassDecl);
   LValue LHS = CGF.MakeNaturalAlignAddrLValue(ThisPtr, RecordTy);
 
-  if (MemberInit->isIndirectMemberInitializer()) {
-    // If we are initializing an anonymous union field, drill down to
-    // the field.
-    IndirectFieldDecl *IndirectField = MemberInit->getIndirectMember();
-    for (const auto *I : IndirectField->chain())
-      LHS = CGF.EmitLValueForFieldInitialization(LHS, cast<FieldDecl>(I));
-    FieldType = MemberInit->getIndirectMember()->getAnonField()->getType();
-  } else {
-    LHS = CGF.EmitLValueForFieldInitialization(LHS, Field);
-  }
+  EmitLValueForAnyFieldInitialization(CGF, MemberInit, LHS);
 
   // Special case: if we are in a copy or move constructor, and we are copying
   // an array of PODs or classes with trivial copy constructors, ignore the
@@ -1072,6 +1077,7 @@ namespace {
           CopyingValueRepresentation CVR(CGF);
           EmitMemberInitializer(CGF, ConstructorDecl->getParent(),
                                 AggregatedInits[0], ConstructorDecl, Args);
+          AggregatedInits.clear();
         }
         reset();
         return;
@@ -1088,10 +1094,14 @@ namespace {
       LValue LHS = CGF.MakeNaturalAlignAddrLValue(ThisPtr, RecordTy);
 
       for (unsigned i = 0; i < AggregatedInits.size(); ++i) {
-        QualType FieldType = AggregatedInits[i]->getMember()->getType();
+        CXXCtorInitializer *MemberInit = AggregatedInits[i];
+        QualType FieldType = MemberInit->getAnyMember()->getType();
         QualType::DestructionKind dtorKind = FieldType.isDestructedType();
-        if (CGF.needsEHCleanup(dtorKind))
-          CGF.pushEHDestroy(dtorKind, LHS.getAddress(), FieldType);
+        if (!CGF.needsEHCleanup(dtorKind))
+          continue;
+        LValue FieldLHS = LHS;
+        EmitLValueForAnyFieldInitialization(CGF, MemberInit, FieldLHS);
+        CGF.pushEHDestroy(dtorKind, FieldLHS.getAddress(), FieldType);
       }
     }