[clang] [CIR] Add support for array constructors (PR #149142)
via cfe-commits
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Wed Jul 16 10:05:34 PDT 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-clang
Author: Morris Hafner (mmha)
<details>
<summary>Changes</summary>
This patch upstreams support for creating arrays of classes that require calling a constructor.
* Adds the ArrayCtor operation
* New lowering pass for lowering ArrayCtor to a loop
---
Patch is 24.31 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/149142.diff
9 Files Affected:
- (modified) clang/include/clang/CIR/Dialect/IR/CIROps.td (+37-1)
- (modified) clang/include/clang/CIR/Dialect/IR/CIRTypeConstraints.td (+8)
- (modified) clang/lib/CIR/CodeGen/CIRGenClass.cpp (+110)
- (modified) clang/lib/CIR/CodeGen/CIRGenExpr.cpp (+30-29)
- (modified) clang/lib/CIR/CodeGen/CIRGenFunction.cpp (+45)
- (modified) clang/lib/CIR/CodeGen/CIRGenFunction.h (+12)
- (modified) clang/lib/CIR/Dialect/Transforms/LoweringPrepare.cpp (+85-1)
- (added) clang/test/CIR/CodeGen/array-ctor.cpp (+70)
- (added) clang/test/CIR/IR/array-ctor.cir (+29)
``````````diff
diff --git a/clang/include/clang/CIR/Dialect/IR/CIROps.td b/clang/include/clang/CIR/Dialect/IR/CIROps.td
index d19cd83d78b40..4c30a54bc650f 100644
--- a/clang/include/clang/CIR/Dialect/IR/CIROps.td
+++ b/clang/include/clang/CIR/Dialect/IR/CIROps.td
@@ -607,7 +607,7 @@ def CIR_ConditionOp : CIR_Op<"condition", [
//===----------------------------------------------------------------------===//
defvar CIR_YieldableScopes = [
- "CaseOp", "DoWhileOp", "ForOp", "IfOp", "ScopeOp", "SwitchOp",
+ "ArrayCtor", "CaseOp", "DoWhileOp", "ForOp", "IfOp", "ScopeOp", "SwitchOp",
"TernaryOp", "WhileOp"
];
@@ -2219,6 +2219,42 @@ def CIR_TrapOp : CIR_Op<"trap", [Terminator]> {
let assemblyFormat = "attr-dict";
}
+//===----------------------------------------------------------------------===//
+// ArrayCtor
+//===----------------------------------------------------------------------===//
+
+class CIR_ArrayInitDestroy<string mnemonic> : CIR_Op<mnemonic> {
+ let arguments = (ins
+ Arg<CIR_PtrToArray, "array address", [MemWrite, MemRead]>:$addr
+ );
+
+ let regions = (region SizedRegion<1>:$body);
+ let assemblyFormat = [{
+ `(` $addr `:` qualified(type($addr)) `)` $body attr-dict
+ }];
+
+ let builders = [
+ OpBuilder<(ins "mlir::Value":$addr,
+ "llvm::function_ref<void(mlir::OpBuilder &, mlir::Location)>":$regionBuilder), [{
+ assert(regionBuilder && "builder callback expected");
+ mlir::OpBuilder::InsertionGuard guard($_builder);
+ mlir::Region *r = $_state.addRegion();
+ $_state.addOperands(ValueRange{addr});
+ $_builder.createBlock(r);
+ regionBuilder($_builder, $_state.location);
+ }]>
+ ];
+}
+
+def CIR_ArrayCtor : CIR_ArrayInitDestroy<"array.ctor"> {
+ let summary = "Initialize array elements with C++ constructors";
+ let description = [{
+ Initialize each array element using the same C++ constructor. This
+ operation has one region, with one single block. The block has an
+ incoming argument for the current array index to initialize.
+ }];
+}
+
//===----------------------------------------------------------------------===//
// VecCreate
//===----------------------------------------------------------------------===//
diff --git a/clang/include/clang/CIR/Dialect/IR/CIRTypeConstraints.td b/clang/include/clang/CIR/Dialect/IR/CIRTypeConstraints.td
index 2bf77583465a6..d7d55dfbc0654 100644
--- a/clang/include/clang/CIR/Dialect/IR/CIRTypeConstraints.td
+++ b/clang/include/clang/CIR/Dialect/IR/CIRTypeConstraints.td
@@ -165,6 +165,12 @@ def CIR_AnyIntOrFloatType : AnyTypeOf<[CIR_AnyFloatType, CIR_AnyIntType],
def CIR_AnyComplexType : CIR_TypeBase<"::cir::ComplexType", "complex type">;
+//===----------------------------------------------------------------------===//
+// Array Type predicates
+//===----------------------------------------------------------------------===//
+
+def CIR_AnyArrayType : CIR_TypeBase<"::cir::ArrayType", "array type">;
+
//===----------------------------------------------------------------------===//
// Pointer Type predicates
//===----------------------------------------------------------------------===//
@@ -216,6 +222,8 @@ def CIR_PtrToIntOrFloatType : CIR_PtrToType<CIR_AnyIntOrFloatType>;
def CIR_PtrToComplexType : CIR_PtrToType<CIR_AnyComplexType>;
+def CIR_PtrToArray : CIR_PtrToType<CIR_AnyArrayType>;
+
//===----------------------------------------------------------------------===//
// Vector Type predicates
//===----------------------------------------------------------------------===//
diff --git a/clang/lib/CIR/CodeGen/CIRGenClass.cpp b/clang/lib/CIR/CodeGen/CIRGenClass.cpp
index 8667bb60d114e..26ace1c366780 100644
--- a/clang/lib/CIR/CodeGen/CIRGenClass.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenClass.cpp
@@ -12,6 +12,7 @@
#include "CIRGenCXXABI.h"
#include "CIRGenFunction.h"
+#include "CIRGenValue.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/RecordLayout.h"
@@ -311,6 +312,115 @@ void CIRGenFunction::emitInitializerForField(FieldDecl *field, LValue lhs,
assert(!cir::MissingFeatures::requiresCleanups());
}
+/// Emit a loop to call a particular constructor for each of several members
+/// of an array.
+///
+/// \param ctor the constructor to call for each element
+/// \param arrayType the type of the array to initialize
+/// \param arrayBegin an arrayType*
+/// \param zeroInitialize true if each element should be
+/// zero-initialized before it is constructed
+void CIRGenFunction::emitCXXAggrConstructorCall(
+ const CXXConstructorDecl *ctor, const clang::ArrayType *arrayType,
+ Address arrayBegin, const CXXConstructExpr *e, bool newPointerIsChecked,
+ bool zeroInitialize) {
+ QualType elementType;
+ mlir::Value numElements = emitArrayLength(arrayType, elementType, arrayBegin);
+ emitCXXAggrConstructorCall(ctor, numElements, arrayBegin, e,
+ newPointerIsChecked, zeroInitialize);
+}
+
+/// Emit a loop to call a particular constructor for each of several members
+/// of an array.
+///
+/// \param ctor the constructor to call for each element
+/// \param numElements the number of elements in the array;
+/// may be zero
+/// \param arrayBase a T*, where T is the type constructed by ctor
+/// \param zeroInitialize true if each element should be
+/// zero-initialized before it is constructed
+void CIRGenFunction::emitCXXAggrConstructorCall(
+ const CXXConstructorDecl *ctor, mlir::Value numElements, Address arrayBase,
+ const CXXConstructExpr *e, bool newPointerIsChecked, bool zeroInitialize) {
+ // It's legal for numElements to be zero. This can happen both
+ // dynamically, because x can be zero in 'new A[x]', and statically,
+ // because of GCC extensions that permit zero-length arrays. There
+ // are probably legitimate places where we could assume that this
+ // doesn't happen, but it's not clear that it's worth it.
+
+ // Optimize for a constant count.
+ auto constantCount = dyn_cast<cir::ConstantOp>(numElements.getDefiningOp());
+ if (constantCount) {
+ auto constIntAttr = mlir::dyn_cast<cir::IntAttr>(constantCount.getValue());
+ // Just skip out if the constant count is zero.
+ if (constIntAttr && constIntAttr.getUInt() == 0)
+ return;
+ // Otherwise, emit the check.
+ } else {
+ cgm.errorNYI(e->getSourceRange(), "dynamic-length array expression");
+ }
+
+ auto arrayTy = mlir::dyn_cast<cir::ArrayType>(arrayBase.getElementType());
+ assert(arrayTy && "expected array type");
+ mlir::Type elementType = arrayTy.getElementType();
+ cir::PointerType ptrToElmType = builder.getPointerTo(elementType);
+
+ // Tradional LLVM codegen emits a loop here. CIR lowers to a loop as part of
+ // LoweringPrepare.
+
+ // The alignment of the base, adjusted by the size of a single element,
+ // provides a conservative estimate of the alignment of every element.
+ // (This assumes we never start tracking offsetted alignments.)
+ //
+ // Note that these are complete objects and so we don't need to
+ // use the non-virtual size or alignment.
+ QualType type = getContext().getTypeDeclType(ctor->getParent());
+ CharUnits eltAlignment = arrayBase.getAlignment().alignmentOfArrayElement(
+ getContext().getTypeSizeInChars(type));
+
+ // Zero initialize the storage, if requested.
+ if (zeroInitialize)
+ emitNullInitialization(*currSrcLoc, arrayBase, type);
+
+ // C++ [class.temporary]p4:
+ // There are two contexts in which temporaries are destroyed at a different
+ // point than the end of the full-expression. The first context is when a
+ // default constructor is called to initialize an element of an array.
+ // If the constructor has one or more default arguments, the destruction of
+ // every temporary created in a default argument expression is sequenced
+ // before the construction of the next array element, if any.
+ {
+ assert(!cir::MissingFeatures::runCleanupsScope());
+
+ // Evaluate the constructor and its arguments in a regular
+ // partial-destroy cleanup.
+ if (getLangOpts().Exceptions &&
+ !ctor->getParent()->hasTrivialDestructor()) {
+ cgm.errorNYI(e->getSourceRange(), "partial array cleanups");
+ }
+
+ // Emit the constructor call that will execute for every array element.
+ auto arrayOp = builder.createPtrBitcast(arrayBase.getPointer(), arrayTy);
+ builder.create<cir::ArrayCtor>(
+ *currSrcLoc, arrayOp, [&](mlir::OpBuilder &b, mlir::Location loc) {
+ auto arg = b.getInsertionBlock()->addArgument(ptrToElmType, loc);
+ Address curAddr = Address(arg, elementType, eltAlignment);
+ assert(!cir::MissingFeatures::sanitizers());
+ auto currAVS = AggValueSlot::forAddr(
+ curAddr, type.getQualifiers(), AggValueSlot::IsDestructed,
+ AggValueSlot::IsNotAliased, AggValueSlot::DoesNotOverlap,
+ AggValueSlot::IsNotZeroed);
+ emitCXXConstructorCall(ctor, Ctor_Complete,
+ /*ForVirtualBase=*/false,
+ /*Delegating=*/false, currAVS, e);
+ builder.create<cir::YieldOp>(loc);
+ });
+ }
+
+ if (constantCount.use_empty())
+ constantCount.erase();
+}
+
void CIRGenFunction::emitDelegateCXXConstructorCall(
const CXXConstructorDecl *ctor, CXXCtorType ctorType,
const FunctionArgList &args, SourceLocation loc) {
diff --git a/clang/lib/CIR/CodeGen/CIRGenExpr.cpp b/clang/lib/CIR/CodeGen/CIRGenExpr.cpp
index 51da48d330f55..9f4d883066055 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExpr.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExpr.cpp
@@ -1594,37 +1594,38 @@ void CIRGenFunction::emitCXXConstructExpr(const CXXConstructExpr *e,
return;
}
- if (getContext().getAsArrayType(e->getType())) {
- cgm.errorNYI(e->getSourceRange(), "emitCXXConstructExpr: array type");
- return;
- }
+ if (const ArrayType *arrayType = getContext().getAsArrayType(e->getType())) {
+ assert(!cir::MissingFeatures::sanitizers());
+ emitCXXAggrConstructorCall(cd, arrayType, dest.getAddress(), e, false);
+ } else {
- clang::CXXCtorType type = Ctor_Complete;
- bool forVirtualBase = false;
- bool delegating = false;
-
- switch (e->getConstructionKind()) {
- case CXXConstructionKind::Complete:
- type = Ctor_Complete;
- break;
- case CXXConstructionKind::Delegating:
- // We should be emitting a constructor; GlobalDecl will assert this
- type = curGD.getCtorType();
- delegating = true;
- break;
- case CXXConstructionKind::VirtualBase:
- // This should just set 'forVirtualBase' to true and fall through, but
- // virtual base class support is otherwise missing, so this needs to wait
- // until it can be tested.
- cgm.errorNYI(e->getSourceRange(),
- "emitCXXConstructExpr: virtual base constructor");
- return;
- case CXXConstructionKind::NonVirtualBase:
- type = Ctor_Base;
- break;
- }
+ clang::CXXCtorType type = Ctor_Complete;
+ bool forVirtualBase = false;
+ bool delegating = false;
- emitCXXConstructorCall(cd, type, forVirtualBase, delegating, dest, e);
+ switch (e->getConstructionKind()) {
+ case CXXConstructionKind::Complete:
+ type = Ctor_Complete;
+ break;
+ case CXXConstructionKind::Delegating:
+ // We should be emitting a constructor; GlobalDecl will assert this
+ type = curGD.getCtorType();
+ delegating = true;
+ break;
+ case CXXConstructionKind::VirtualBase:
+ // This should just set 'forVirtualBase' to true and fall through, but
+ // virtual base class support is otherwise missing, so this needs to wait
+ // until it can be tested.
+ cgm.errorNYI(e->getSourceRange(),
+ "emitCXXConstructExpr: virtual base constructor");
+ return;
+ case CXXConstructionKind::NonVirtualBase:
+ type = Ctor_Base;
+ break;
+ }
+
+ emitCXXConstructorCall(cd, type, forVirtualBase, delegating, dest, e);
+ }
}
RValue CIRGenFunction::emitReferenceBindingToExpr(const Expr *e) {
diff --git a/clang/lib/CIR/CodeGen/CIRGenFunction.cpp b/clang/lib/CIR/CodeGen/CIRGenFunction.cpp
index e532b9d855843..bdc1df41c26e8 100644
--- a/clang/lib/CIR/CodeGen/CIRGenFunction.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenFunction.cpp
@@ -805,4 +805,49 @@ bool CIRGenFunction::shouldNullCheckClassCastValue(const CastExpr *ce) {
return true;
}
+/// Computes the length of an array in elements, as well as the base
+/// element type and a properly-typed first element pointer.
+mlir::Value
+CIRGenFunction::emitArrayLength(const clang::ArrayType *origArrayType,
+ QualType &baseType, Address &addr) {
+ const clang::ArrayType *arrayType = origArrayType;
+
+ // If it's a VLA, we have to load the stored size. Note that
+ // this is the size of the VLA in bytes, not its size in elements.
+ if (isa<VariableArrayType>(arrayType)) {
+ cgm.errorNYI(*currSrcLoc, "VLAs");
+ return builder.getConstInt(*currSrcLoc, SizeTy, 0);
+ }
+
+ uint64_t countFromCLAs = 1;
+ QualType eltType;
+
+ auto cirArrayType = mlir::dyn_cast<cir::ArrayType>(addr.getElementType());
+
+ while (cirArrayType) {
+ assert(isa<ConstantArrayType>(arrayType));
+ countFromCLAs *= cirArrayType.getSize();
+ eltType = arrayType->getElementType();
+
+ cirArrayType =
+ mlir::dyn_cast<cir::ArrayType>(cirArrayType.getElementType());
+
+ arrayType = getContext().getAsArrayType(arrayType->getElementType());
+ assert((!cirArrayType || arrayType) &&
+ "CIR and Clang types are out-of-sync");
+ }
+
+ if (arrayType) {
+ // From this point onwards, the Clang array type has been emitted
+ // as some other type (probably a packed struct). Compute the array
+ // size, and just emit the 'begin' expression as a bitcast.
+ cgm.errorNYI(*currSrcLoc, "length for non-array underlying types");
+ }
+
+ baseType = eltType;
+ auto numElements = builder.getConstInt(*currSrcLoc, SizeTy, countFromCLAs);
+
+ return numElements;
+}
+
} // namespace clang::CIRGen
diff --git a/clang/lib/CIR/CodeGen/CIRGenFunction.h b/clang/lib/CIR/CodeGen/CIRGenFunction.h
index 3baabba5adfe1..b4f79338ae81e 100644
--- a/clang/lib/CIR/CodeGen/CIRGenFunction.h
+++ b/clang/lib/CIR/CodeGen/CIRGenFunction.h
@@ -761,6 +761,8 @@ class CIRGenFunction : public CIRGenTypeCache {
/// even if no aggregate location is provided.
RValue emitAnyExprToTemp(const clang::Expr *e);
+ mlir::Value emitArrayLength(const clang::ArrayType *arrayType,
+ QualType &baseType, Address &addr);
LValue emitArraySubscriptExpr(const clang::ArraySubscriptExpr *e);
Address emitArrayToPointerDecay(const Expr *array);
@@ -837,6 +839,16 @@ class CIRGenFunction : public CIRGenTypeCache {
void emitCXXConstructExpr(const clang::CXXConstructExpr *e,
AggValueSlot dest);
+ void emitCXXAggrConstructorCall(const CXXConstructorDecl *ctor,
+ const clang::ArrayType *arrayType,
+ Address arrayBegin, const CXXConstructExpr *e,
+ bool newPointerIsChecked,
+ bool zeroInitialize = false);
+ void emitCXXAggrConstructorCall(const CXXConstructorDecl *ctor,
+ mlir::Value numElements, Address arrayBase,
+ const CXXConstructExpr *e,
+ bool newPointerIsChecked,
+ bool zeroInitialize);
void emitCXXConstructorCall(const clang::CXXConstructorDecl *d,
clang::CXXCtorType type, bool forVirtualBase,
bool delegating, AggValueSlot thisAVS,
diff --git a/clang/lib/CIR/Dialect/Transforms/LoweringPrepare.cpp b/clang/lib/CIR/Dialect/Transforms/LoweringPrepare.cpp
index 5493b86a0a321..d32d47761b485 100644
--- a/clang/lib/CIR/Dialect/Transforms/LoweringPrepare.cpp
+++ b/clang/lib/CIR/Dialect/Transforms/LoweringPrepare.cpp
@@ -8,6 +8,8 @@
#include "PassDetail.h"
#include "clang/AST/ASTContext.h"
+#include "clang/AST/CharUnits.h"
+#include "clang/CIR/Dialect/Builder/CIRBaseBuilder.h"
#include "clang/CIR/Dialect/IR/CIRDialect.h"
#include "clang/CIR/Dialect/Passes.h"
@@ -22,15 +24,97 @@ struct LoweringPreparePass : public LoweringPrepareBase<LoweringPreparePass> {
void runOnOperation() override;
void runOnOp(Operation *op);
+ void lowerArrayCtor(ArrayCtor op);
};
} // namespace
-void LoweringPreparePass::runOnOp(Operation *op) {}
+void LoweringPreparePass::runOnOp(Operation *op) {
+ if (auto arrayCtor = dyn_cast<ArrayCtor>(op)) {
+ lowerArrayCtor(arrayCtor);
+ }
+}
+
+static void lowerArrayDtorCtorIntoLoop(CIRBaseBuilderTy &builder,
+ mlir::Operation *op, mlir::Type eltTy,
+ mlir::Value arrayAddr,
+ uint64_t arrayLen) {
+ // Generate loop to call into ctor/dtor for every element.
+ Location loc = op->getLoc();
+
+ // TODO: instead of fixed integer size, create alias for PtrDiffTy and unify
+ // with CIRGen stuff.
+ auto ptrDiffTy =
+ cir::IntType::get(builder.getContext(), 64, /*isSigned=*/false);
+ auto numArrayElementsConst = builder.create<cir::ConstantOp>(
+ loc, ptrDiffTy, cir::IntAttr::get(ptrDiffTy, arrayLen));
+
+ auto begin = builder.create<cir::CastOp>(
+ loc, eltTy, cir::CastKind::array_to_ptrdecay, arrayAddr);
+ mlir::Value end = builder.create<cir::PtrStrideOp>(loc, eltTy, begin,
+ numArrayElementsConst);
+
+ mlir::Value tmpAddr = builder.createAlloca(
+ loc, /*addr type*/ builder.getPointerTo(eltTy),
+ /*var type*/ eltTy, "__array_idx", builder.getAlignmentAttr(1));
+ builder.createStore(loc, begin, tmpAddr);
+
+ cir::DoWhileOp loop = builder.createDoWhile(
+ loc,
+ /*condBuilder=*/
+ [&](mlir::OpBuilder &b, mlir::Location loc) {
+ auto currentElement = b.create<cir::LoadOp>(loc, eltTy, tmpAddr);
+ mlir::Type boolTy = cir::BoolType::get(b.getContext());
+ auto cmp = builder.create<cir::CmpOp>(loc, boolTy, cir::CmpOpKind::eq,
+ currentElement, end);
+ builder.createCondition(cmp);
+ },
+ /*bodyBuilder=*/
+ [&](mlir::OpBuilder &b, mlir::Location loc) {
+ auto currentElement = b.create<cir::LoadOp>(loc, eltTy, tmpAddr);
+
+ CallOp ctorCall;
+ op->walk([&](CallOp c) { ctorCall = c; });
+ assert(ctorCall && "expected ctor call");
+
+ auto one = builder.create<cir::ConstantOp>(
+ loc, ptrDiffTy, cir::IntAttr::get(ptrDiffTy, 1));
+
+ ctorCall->moveAfter(one);
+ ctorCall->setOperand(0, currentElement);
+
+ // Advance pointer and store them to temporary variable
+ auto nextElement =
+ builder.create<cir::PtrStrideOp>(loc, eltTy, currentElement, one);
+ builder.createStore(loc, nextElement, tmpAddr);
+ builder.createYield(loc);
+ });
+
+ op->replaceAllUsesWith(loop);
+ op->erase();
+}
+
+void LoweringPreparePass::lowerArrayCtor(ArrayCtor op) {
+ CIRBaseBuilderTy builder(getContext());
+ builder.setInsertionPointAfter(op.getOperation());
+
+ Type eltTy = op->getRegion(0).getArgument(0).getType();
+ auto arrayLen =
+ mlir::cast<cir::ArrayType>(op.getAddr().getType().getPointee()).getSize();
+ lowerArrayDtorCtorIntoLoop(builder, op, eltTy, op.getAddr(), arrayLen);
+}
void LoweringPreparePass::runOnOperation() {
+ Operation *op = getOperation();
+
llvm::SmallVector<Operation *> opsToTransform;
+ op->walk([&](Operation *op) {
+ if (isa<ArrayCtor>(op)) {
+ opsToTransform.push_back(op);
+ }
+ });
+
for (auto *o : opsToTransform)
runOnOp(o);
}
diff --git a/clang/test/CIR/CodeGen/array-ctor.cpp b/clang/test/CIR/CodeGen/array-ctor.cpp
new file mode 100644
index 0000000000000..0a2661248f908
--- /dev/null
+++ b/clang/test/CIR/CodeGen/array-ctor.cpp
@@ -0,0 +1,70 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -Wno-unused-value -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck --input-file=%t.cir %s -check-prefix=CIR
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -Wno-unused-value -fclangir -emit-llvm %s -o %t-cir.ll
+// RUN: FileCheck --input-f...
[truncated]
``````````
</details>
https://github.com/llvm/llvm-project/pull/149142
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