[clang] [Clang] C++ Templates: Refactor and fix `TransformLambdaExpr`'s mishandling of TypeLocs (PR #78801)
Yuxuan Chen via cfe-commits
cfe-commits at lists.llvm.org
Sun Jan 21 19:33:52 PST 2024
https://github.com/yuxuanchen1997 updated https://github.com/llvm/llvm-project/pull/78801
>From 2f95a8ff5f79221c568d9793fcbbd664a22e23df Mon Sep 17 00:00:00 2001
From: Yuxuan Chen <ych at meta.com>
Date: Fri, 19 Jan 2024 13:42:46 -0800
Subject: [PATCH] Refactor and fix Lambda prototype instantiation when it's
attributed or macro qualified
---
clang/lib/Sema/SemaTemplateInstantiate.cpp | 19 +++--
clang/lib/Sema/TreeTransform.h | 70 +++++++------------
clang/test/SemaCXX/template-instantiation.cpp | 16 ++++-
3 files changed, 56 insertions(+), 49 deletions(-)
diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index e12186d7d82f8d0..8a053e34a577120 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -1203,6 +1203,9 @@ namespace {
// Whether to evaluate the C++20 constraints or simply substitute into them.
bool EvaluateConstraints = true;
+ // Whether we are in the middle of transforming a lambda expression.
+ bool TransformingLambda = false;
+
public:
typedef TreeTransform<TemplateInstantiator> inherited;
@@ -1454,8 +1457,9 @@ namespace {
ExprResult TransformLambdaExpr(LambdaExpr *E) {
LocalInstantiationScope Scope(SemaRef, /*CombineWithOuterScope=*/true);
Sema::ConstraintEvalRAII<TemplateInstantiator> RAII(*this);
-
+ TransformingLambda = true;
ExprResult Result = inherited::TransformLambdaExpr(E);
+ TransformingLambda = false;
if (Result.isInvalid())
return Result;
@@ -2178,10 +2182,15 @@ QualType TemplateInstantiator::TransformFunctionProtoType(TypeLocBuilder &TLB,
CXXRecordDecl *ThisContext,
Qualifiers ThisTypeQuals,
Fn TransformExceptionSpec) {
- // We need a local instantiation scope for this function prototype.
- LocalInstantiationScope Scope(SemaRef, /*CombineWithOuterScope=*/true);
- return inherited::TransformFunctionProtoType(
- TLB, TL, ThisContext, ThisTypeQuals, TransformExceptionSpec);
+ if (TransformingLambda)
+ return inherited::TransformFunctionProtoType(
+ TLB, TL, ThisContext, ThisTypeQuals, TransformExceptionSpec);
+ else {
+ // We need a local instantiation scope for this function prototype.
+ LocalInstantiationScope Scope(SemaRef, /*CombineWithOuterScope=*/true);
+ return inherited::TransformFunctionProtoType(
+ TLB, TL, ThisContext, ThisTypeQuals, TransformExceptionSpec);
+ }
}
ParmVarDecl *TemplateInstantiator::TransformFunctionTypeParam(
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index e55e752b9cc354c..80e2d6da9fcf416 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -13636,58 +13636,42 @@ TreeTransform<Derived>::TransformLambdaExpr(LambdaExpr *E) {
// The transformation MUST be done in the CurrentInstantiationScope since
// it introduces a mapping of the original to the newly created
// transformed parameters.
- TypeSourceInfo *NewCallOpTSI = nullptr;
- {
- auto OldCallOpTypeLoc =
- E->getCallOperator()->getTypeSourceInfo()->getTypeLoc();
-
- auto TransformFunctionProtoTypeLoc =
- [this](TypeLocBuilder &TLB, FunctionProtoTypeLoc FPTL) -> QualType {
- SmallVector<QualType, 4> ExceptionStorage;
- return this->TransformFunctionProtoType(
- TLB, FPTL, nullptr, Qualifiers(),
- [&](FunctionProtoType::ExceptionSpecInfo &ESI, bool &Changed) {
- return TransformExceptionSpec(FPTL.getBeginLoc(), ESI,
- ExceptionStorage, Changed);
- });
- };
+ auto OldCallOpTypeLoc =
+ E->getCallOperator()->getTypeSourceInfo()->getTypeLoc();
- QualType NewCallOpType;
- TypeLocBuilder NewCallOpTLBuilder;
+ TypeLocBuilder NewCallOpTLBuilder;
+ QualType NewCallOpType =
+ getDerived().TransformType(NewCallOpTLBuilder, OldCallOpTypeLoc);
- if (auto ATL = OldCallOpTypeLoc.getAs<AttributedTypeLoc>()) {
- NewCallOpType = this->TransformAttributedType(
- NewCallOpTLBuilder, ATL,
- [&](TypeLocBuilder &TLB, TypeLoc TL) -> QualType {
- return TransformFunctionProtoTypeLoc(
- TLB, TL.castAs<FunctionProtoTypeLoc>());
- });
- } else {
- auto FPTL = OldCallOpTypeLoc.castAs<FunctionProtoTypeLoc>();
- NewCallOpType = TransformFunctionProtoTypeLoc(NewCallOpTLBuilder, FPTL);
- }
-
- if (NewCallOpType.isNull())
- return ExprError();
- NewCallOpTSI =
- NewCallOpTLBuilder.getTypeSourceInfo(getSema().Context, NewCallOpType);
- }
+ if (NewCallOpType.isNull())
+ return ExprError();
- ArrayRef<ParmVarDecl *> Params;
- if (auto ATL = NewCallOpTSI->getTypeLoc().getAs<AttributedTypeLoc>()) {
- Params = ATL.getModifiedLoc().castAs<FunctionProtoTypeLoc>().getParams();
- } else {
- auto FPTL = NewCallOpTSI->getTypeLoc().castAs<FunctionProtoTypeLoc>();
- Params = FPTL.getParams();
- }
+ TypeSourceInfo *NewCallOpTSI =
+ NewCallOpTLBuilder.getTypeSourceInfo(getSema().Context, NewCallOpType);
+
+ auto ExtractParams = [](TypeLoc TL) {
+ auto ExtractParamsImpl = [](auto Self,
+ TypeLoc TL) -> ArrayRef<ParmVarDecl *> {
+ if (auto FPTL = TL.getAs<FunctionProtoTypeLoc>()) {
+ return FPTL.getParams();
+ } else if (auto ATL = TL.getAs<AttributedTypeLoc>()) {
+ return Self(Self, ATL.getModifiedLoc());
+ } else if (auto MQTL = TL.getAs<MacroQualifiedTypeLoc>()) {
+ return Self(Self, MQTL.getInnerLoc());
+ } else {
+ llvm_unreachable("Unhandled TypeLoc");
+ }
+ };
+ return ExtractParamsImpl(ExtractParamsImpl, TL);
+ };
getSema().CompleteLambdaCallOperator(
NewCallOperator, E->getCallOperator()->getLocation(),
E->getCallOperator()->getInnerLocStart(),
E->getCallOperator()->getTrailingRequiresClause(), NewCallOpTSI,
E->getCallOperator()->getConstexprKind(),
- E->getCallOperator()->getStorageClass(), Params,
- E->hasExplicitResultType());
+ E->getCallOperator()->getStorageClass(),
+ ExtractParams(NewCallOpTSI->getTypeLoc()), E->hasExplicitResultType());
getDerived().transformAttrs(E->getCallOperator(), NewCallOperator);
getDerived().transformedLocalDecl(E->getCallOperator(), {NewCallOperator});
diff --git a/clang/test/SemaCXX/template-instantiation.cpp b/clang/test/SemaCXX/template-instantiation.cpp
index 8543af0d5428d03..42be88fef461eed 100644
--- a/clang/test/SemaCXX/template-instantiation.cpp
+++ b/clang/test/SemaCXX/template-instantiation.cpp
@@ -1,15 +1,29 @@
-// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -verify -fsyntax-only %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -ast-dump %s | FileCheck %s
// expected-no-diagnostics
namespace GH76521 {
+#define MYATTR __attribute__((preserve_most))
+
template <typename T>
void foo() {
+ // CHECK: FunctionDecl {{.*}} foo 'void ()'
auto l = []() __attribute__((preserve_most)) {};
+ // CHECK: CXXMethodDecl {{.*}} operator() 'auto () __attribute__((preserve_most)) const' inline
+ auto l2 = [](T t) __attribute__((preserve_most)) -> T { return t; };
+ // CHECK: CXXMethodDecl {{.*}} operator() 'auto (int) const -> int __attribute__((preserve_most))':'auto (int) __attribute__((preserve_most)) const -> int' implicit_instantiation inline instantiated_fro
}
+template <typename T>
void bar() {
+ // CHECK: FunctionDecl {{.*}} bar 'void ()'
+ auto l = []() MYATTR {};
+ // CHECK: CXXMethodDecl {{.*}} operator() 'auto () __attribute__((preserve_most)) const' inline
+}
+
+int main() {
foo<int>();
+ bar<int>();
}
}
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