Remove custom handling of array copies in lambda by-value array capture and
copy constructors of classes with array members, instead using
ArrayInitLoopExpr to represent the initialization loop.
This exposed a bug in the static analyzer where it was unable to differentiate
between zero-initialized and unknown array values, which has also been fixed
here.
llvm-svn: 289618
diff --git a/clang/lib/CodeGen/CGClass.cpp b/clang/lib/CodeGen/CGClass.cpp
index 709c4af..05d0567 100644
--- a/clang/lib/CodeGen/CGClass.cpp
+++ b/clang/lib/CodeGen/CGClass.cpp
@@ -562,140 +562,6 @@
isBaseVirtual);
}
-/// Initialize a member of aggregate type using the given expression
-/// as an initializer.
-///
-/// The member may be an array. If so:
-/// - the destination l-value will be a pointer of the *base* element type,
-/// - ArrayIndexVar will be a pointer to a variable containing the current
-/// index within the destination array, and
-/// - ArrayIndexes will be an array of index variables, one for each level
-/// of array nesting, which will need to be updated as appropriate for the
-/// array structure.
-///
-/// On an array, this function will invoke itself recursively. Each time,
-/// it drills into one nesting level of the member type and sets up a
-/// loop updating the appropriate array index variable.
-static void EmitAggMemberInitializer(CodeGenFunction &CGF,
- LValue LHS,
- Expr *Init,
- Address ArrayIndexVar,
- QualType T,
- ArrayRef<VarDecl *> ArrayIndexes,
- unsigned Index) {
- assert(ArrayIndexVar.isValid() == (ArrayIndexes.size() != 0));
-
- if (Index == ArrayIndexes.size()) {
- LValue LV = LHS;
-
- Optional<CodeGenFunction::RunCleanupsScope> Scope;
-
- if (ArrayIndexVar.isValid()) {
- // When we're processing an array, the temporaries from each
- // element's construction are destroyed immediately.
- Scope.emplace(CGF);
-
- // If we have an array index variable, load it and use it as an offset.
- // Then, increment the value.
- llvm::Value *Dest = LHS.getPointer();
- llvm::Value *ArrayIndex = CGF.Builder.CreateLoad(ArrayIndexVar);
- Dest = CGF.Builder.CreateInBoundsGEP(Dest, ArrayIndex, "destaddress");
- llvm::Value *Next = llvm::ConstantInt::get(ArrayIndex->getType(), 1);
- Next = CGF.Builder.CreateAdd(ArrayIndex, Next, "inc");
- CGF.Builder.CreateStore(Next, ArrayIndexVar);
-
- // Update the LValue.
- CharUnits EltSize = CGF.getContext().getTypeSizeInChars(T);
- CharUnits Align = LV.getAlignment().alignmentOfArrayElement(EltSize);
- LV.setAddress(Address(Dest, Align));
-
- // Enter a partial-array EH cleanup to destroy previous members
- // of the array if this initialization throws.
- if (CGF.CGM.getLangOpts().Exceptions) {
- if (auto DtorKind = T.isDestructedType()) {
- if (CGF.needsEHCleanup(DtorKind)) {
- CGF.pushRegularPartialArrayCleanup(LHS.getPointer(),
- LV.getPointer(), T,
- LV.getAlignment(),
- CGF.getDestroyer(DtorKind));
- }
- }
- }
- }
-
- switch (CGF.getEvaluationKind(T)) {
- case TEK_Scalar:
- CGF.EmitScalarInit(Init, /*decl*/ nullptr, LV, false);
- break;
- case TEK_Complex:
- CGF.EmitComplexExprIntoLValue(Init, LV, /*isInit*/ true);
- break;
- case TEK_Aggregate: {
- AggValueSlot Slot =
- AggValueSlot::forLValue(LV,
- AggValueSlot::IsDestructed,
- AggValueSlot::DoesNotNeedGCBarriers,
- AggValueSlot::IsNotAliased);
-
- CGF.EmitAggExpr(Init, Slot);
- break;
- }
- }
-
- return;
- }
-
- const ConstantArrayType *Array = CGF.getContext().getAsConstantArrayType(T);
- assert(Array && "Array initialization without the array type?");
- Address IndexVar = CGF.GetAddrOfLocalVar(ArrayIndexes[Index]);
-
- // Initialize this index variable to zero.
- llvm::Value* Zero
- = llvm::Constant::getNullValue(IndexVar.getElementType());
- CGF.Builder.CreateStore(Zero, IndexVar);
-
- // Start the loop with a block that tests the condition.
- llvm::BasicBlock *CondBlock = CGF.createBasicBlock("for.cond");
- llvm::BasicBlock *AfterFor = CGF.createBasicBlock("for.end");
-
- CGF.EmitBlock(CondBlock);
-
- llvm::BasicBlock *ForBody = CGF.createBasicBlock("for.body");
- // Generate: if (loop-index < number-of-elements) fall to the loop body,
- // otherwise, go to the block after the for-loop.
- uint64_t NumElements = Array->getSize().getZExtValue();
- llvm::Value *Counter = CGF.Builder.CreateLoad(IndexVar);
- llvm::Value *NumElementsPtr =
- llvm::ConstantInt::get(Counter->getType(), NumElements);
- llvm::Value *IsLess = CGF.Builder.CreateICmpULT(Counter, NumElementsPtr,
- "isless");
-
- // If the condition is true, execute the body.
- CGF.Builder.CreateCondBr(IsLess, ForBody, AfterFor);
-
- CGF.EmitBlock(ForBody);
- llvm::BasicBlock *ContinueBlock = CGF.createBasicBlock("for.inc");
-
- // Inside the loop body recurse to emit the inner loop or, eventually, the
- // constructor call.
- EmitAggMemberInitializer(CGF, LHS, Init, ArrayIndexVar,
- Array->getElementType(), ArrayIndexes, Index + 1);
-
- CGF.EmitBlock(ContinueBlock);
-
- // Emit the increment of the loop counter.
- llvm::Value *NextVal = llvm::ConstantInt::get(Counter->getType(), 1);
- Counter = CGF.Builder.CreateLoad(IndexVar);
- NextVal = CGF.Builder.CreateAdd(Counter, NextVal, "inc");
- CGF.Builder.CreateStore(NextVal, IndexVar);
-
- // Finally, branch back up to the condition for the next iteration.
- CGF.EmitBranch(CondBlock);
-
- // Emit the fall-through block.
- CGF.EmitBlock(AfterFor, true);
-}
-
static bool isMemcpyEquivalentSpecialMember(const CXXMethodDecl *D) {
auto *CD = dyn_cast<CXXConstructorDecl>(D);
if (!(CD && CD->isCopyOrMoveConstructor()) &&
@@ -779,14 +645,11 @@
}
}
- ArrayRef<VarDecl *> ArrayIndexes;
- if (MemberInit->getNumArrayIndices())
- ArrayIndexes = MemberInit->getArrayIndices();
- CGF.EmitInitializerForField(Field, LHS, MemberInit->getInit(), ArrayIndexes);
+ CGF.EmitInitializerForField(Field, LHS, MemberInit->getInit());
}
void CodeGenFunction::EmitInitializerForField(FieldDecl *Field, LValue LHS,
- Expr *Init, ArrayRef<VarDecl *> ArrayIndexes) {
+ Expr *Init) {
QualType FieldType = Field->getType();
switch (getEvaluationKind(FieldType)) {
case TEK_Scalar:
@@ -801,30 +664,13 @@
EmitComplexExprIntoLValue(Init, LHS, /*isInit*/ true);
break;
case TEK_Aggregate: {
- Address ArrayIndexVar = Address::invalid();
- if (ArrayIndexes.size()) {
- // The LHS is a pointer to the first object we'll be constructing, as
- // a flat array.
- QualType BaseElementTy = getContext().getBaseElementType(FieldType);
- llvm::Type *BasePtr = ConvertType(BaseElementTy);
- BasePtr = llvm::PointerType::getUnqual(BasePtr);
- Address BaseAddrPtr = Builder.CreateBitCast(LHS.getAddress(), BasePtr);
- LHS = MakeAddrLValue(BaseAddrPtr, BaseElementTy);
-
- // Create an array index that will be used to walk over all of the
- // objects we're constructing.
- ArrayIndexVar = CreateMemTemp(getContext().getSizeType(), "object.index");
- llvm::Value *Zero =
- llvm::Constant::getNullValue(ArrayIndexVar.getElementType());
- Builder.CreateStore(Zero, ArrayIndexVar);
-
- // Emit the block variables for the array indices, if any.
- for (unsigned I = 0, N = ArrayIndexes.size(); I != N; ++I)
- EmitAutoVarDecl(*ArrayIndexes[I]);
- }
-
- EmitAggMemberInitializer(*this, LHS, Init, ArrayIndexVar, FieldType,
- ArrayIndexes, 0);
+ AggValueSlot Slot =
+ AggValueSlot::forLValue(LHS,
+ AggValueSlot::IsDestructed,
+ AggValueSlot::DoesNotNeedGCBarriers,
+ AggValueSlot::IsNotAliased);
+ EmitAggExpr(Init, Slot);
+ break;
}
}
diff --git a/clang/lib/CodeGen/CGExprAgg.cpp b/clang/lib/CodeGen/CGExprAgg.cpp
index d756eca..9ead6b8 100644
--- a/clang/lib/CodeGen/CGExprAgg.cpp
+++ b/clang/lib/CodeGen/CGExprAgg.cpp
@@ -1328,27 +1328,12 @@
llvm::Value *begin = Builder.CreateInBoundsGEP(destPtr.getPointer(), indices,
"arrayinit.begin");
- QualType elementType = E->getSubExpr()->getType();
+ QualType elementType =
+ CGF.getContext().getAsArrayType(E->getType())->getElementType();
CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType);
CharUnits elementAlign =
destPtr.getAlignment().alignmentOfArrayElement(elementSize);
- // Prepare for a cleanup.
- QualType::DestructionKind dtorKind = elementType.isDestructedType();
- Address endOfInit = Address::invalid();
- EHScopeStack::stable_iterator cleanup;
- llvm::Instruction *cleanupDominator = nullptr;
- if (CGF.needsEHCleanup(dtorKind)) {
- endOfInit = CGF.CreateTempAlloca(begin->getType(), CGF.getPointerAlign(),
- "arrayinit.endOfInit");
- CGF.pushIrregularPartialArrayCleanup(begin, endOfInit, elementType,
- elementAlign,
- CGF.getDestroyer(dtorKind));
- cleanup = CGF.EHStack.stable_begin();
- } else {
- dtorKind = QualType::DK_none;
- }
-
llvm::BasicBlock *entryBB = Builder.GetInsertBlock();
llvm::BasicBlock *bodyBB = CGF.createBasicBlock("arrayinit.body");
@@ -1359,11 +1344,22 @@
index->addIncoming(zero, entryBB);
llvm::Value *element = Builder.CreateInBoundsGEP(begin, index);
- // Tell the EH cleanup that we finished with the last element.
- if (endOfInit.isValid()) Builder.CreateStore(element, endOfInit);
+ // Prepare for a cleanup.
+ QualType::DestructionKind dtorKind = elementType.isDestructedType();
+ EHScopeStack::stable_iterator cleanup;
+ if (CGF.needsEHCleanup(dtorKind)) {
+ CGF.pushRegularPartialArrayCleanup(
+ begin, element, elementType, elementAlign, CGF.getDestroyer(dtorKind));
+ cleanup = CGF.EHStack.stable_begin();
+ } else {
+ dtorKind = QualType::DK_none;
+ }
// Emit the actual filler expression.
{
+ // Temporaries created in an array initialization loop are destroyed
+ // at the end of each iteration.
+ CodeGenFunction::RunCleanupsScope CleanupsScope(CGF);
CodeGenFunction::ArrayInitLoopExprScope Scope(CGF, index);
LValue elementLV =
CGF.MakeAddrLValue(Address(element, elementAlign), elementType);
@@ -1385,7 +1381,8 @@
CGF.EmitBlock(endBB);
// Leave the partial-array cleanup if we entered one.
- if (dtorKind) CGF.DeactivateCleanupBlock(cleanup, cleanupDominator);
+ if (dtorKind)
+ CGF.DeactivateCleanupBlock(cleanup, index);
}
void AggExprEmitter::VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E) {
diff --git a/clang/lib/CodeGen/CGExprCXX.cpp b/clang/lib/CodeGen/CGExprCXX.cpp
index ab2468e..71c8fb8 100644
--- a/clang/lib/CodeGen/CGExprCXX.cpp
+++ b/clang/lib/CodeGen/CGExprCXX.cpp
@@ -2140,10 +2140,7 @@
auto VAT = CurField->getCapturedVLAType();
EmitStoreThroughLValue(RValue::get(VLASizeMap[VAT->getSizeExpr()]), LV);
} else {
- ArrayRef<VarDecl *> ArrayIndexes;
- if (CurField->getType()->isArrayType())
- ArrayIndexes = E->getCaptureInitIndexVars(i);
- EmitInitializerForField(*CurField, LV, *i, ArrayIndexes);
+ EmitInitializerForField(*CurField, LV, *i);
}
}
}
diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
index ba0064f..e4b1581 100644
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -2206,7 +2206,7 @@
auto VAT = CurField->getCapturedVLAType();
EmitStoreThroughLValue(RValue::get(VLASizeMap[VAT->getSizeExpr()]), LV);
} else {
- EmitInitializerForField(*CurField, LV, *I, None);
+ EmitInitializerForField(*CurField, LV, *I);
}
}
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index eddaf65..bc4efd3 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -1601,8 +1601,7 @@
void EmitCtorPrologue(const CXXConstructorDecl *CD, CXXCtorType Type,
FunctionArgList &Args);
- void EmitInitializerForField(FieldDecl *Field, LValue LHS, Expr *Init,
- ArrayRef<VarDecl *> ArrayIndexes);
+ void EmitInitializerForField(FieldDecl *Field, LValue LHS, Expr *Init);
/// Struct with all informations about dynamic [sub]class needed to set vptr.
struct VPtr {