[clang] eaf725b - [Clang] Add captures to the instantiation scope of lambda call operators
Corentin Jabot via cfe-commits
cfe-commits at lists.llvm.org
Wed Sep 6 12:59:51 PDT 2023
Author: Corentin Jabot
Date: 2023-09-06T21:59:45+02:00
New Revision: eaf725bc9371a6699902d67d97662caaa3332799
URL: https://github.com/llvm/llvm-project/commit/eaf725bc9371a6699902d67d97662caaa3332799
DIFF: https://github.com/llvm/llvm-project/commit/eaf725bc9371a6699902d67d97662caaa3332799.diff
LOG: [Clang] Add captures to the instantiation scope of lambda call operators
Like concepts checking, a trailing return type of a lambda
in a dependent context may refer to captures in which case
they may need to be rebuilt, so the map of local decl
should include captures.
This patch reveal a pre-existing issue.
`this` is always recomputed by TreeTransform.
`*this` (like all captures) only become `const`
after the parameter list.
However, if try to recompute the value of `this` (in a parameter)
during template instantiation while determining the type of the call operator,
we will determine it to be const (unless the lambda is mutable).
There is no good way to know at that point that we are in a parameter
or not, the easiest/best solution is to transform the type of this.
Note that doing so break a handful of HLSL tests.
So this is a prototype at this point.
Fixes #65067
Fixes #63675
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D159126
Added:
Modified:
clang/docs/ReleaseNotes.rst
clang/include/clang/Sema/Sema.h
clang/lib/Sema/SemaConcept.cpp
clang/lib/Sema/SemaDecl.cpp
clang/lib/Sema/SemaLambda.cpp
clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
clang/lib/Sema/TreeTransform.h
clang/test/SemaCXX/lambda-capture-type-deduction.cpp
Removed:
################################################################################
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 73b0ad39ecbf4b..fe3e9f778b5292 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -263,9 +263,14 @@ Bug Fixes to C++ Support
(`#64172 <https://github.com/llvm/llvm-project/issues/64172>`_) and
(`#64723 <https://github.com/llvm/llvm-project/issues/64723>`_).
- Fix crash when parsing the requires clause of some generic lambdas.
+- Fix crash when parsing the requires clause of some generic lambdas.
(`#64689 <https://github.com/llvm/llvm-project/issues/64689>`_`)
+- Fix crash when the trailing return type of a generic and dependent
+ lambda refers to an init-capture.
+ (`#65067 <https://github.com/llvm/llvm-project/issues/65067>`_` and
+ `#63675 <https://github.com/llvm/llvm-project/issues/63675>`_`)
+
Bug Fixes to AST Handling
^^^^^^^^^^^^^^^^^^^^^^^^^
- Fixed an import failure of recursive friend class template.
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 5fdca93c66ab5c..4fd0e6bd5982a7 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -7352,6 +7352,14 @@ class Sema final {
sema::LambdaScopeInfo *RebuildLambdaScopeInfo(CXXMethodDecl *CallOperator);
+ class LambdaScopeForCallOperatorInstantiationRAII
+ : private FunctionScopeRAII {
+ public:
+ LambdaScopeForCallOperatorInstantiationRAII(
+ Sema &SemasRef, FunctionDecl *FD, MultiLevelTemplateArgumentList MLTAL,
+ LocalInstantiationScope &Scope);
+ };
+
/// Check whether the given expression is a valid constraint expression.
/// A diagnostic is emitted if it is not, false is returned, and
/// PossibleNonPrimary will be set to true if the failure might be due to a
diff --git a/clang/lib/Sema/SemaConcept.cpp b/clang/lib/Sema/SemaConcept.cpp
index fa3dadf68229ee..d1fa8e7831225b 100644
--- a/clang/lib/Sema/SemaConcept.cpp
+++ b/clang/lib/Sema/SemaConcept.cpp
@@ -600,11 +600,6 @@ bool Sema::SetupConstraintScope(
if (addInstantiatedParametersToScope(FD, FromMemTempl->getTemplatedDecl(),
Scope, MLTAL))
return true;
- // Make sure the captures are also added to the instantiation scope.
- if (isLambdaCallOperator(FD) &&
- addInstantiatedCapturesToScope(FD, FromMemTempl->getTemplatedDecl(),
- Scope, MLTAL))
- return true;
}
return false;
@@ -629,11 +624,6 @@ bool Sema::SetupConstraintScope(
// child-function.
if (addInstantiatedParametersToScope(FD, InstantiatedFrom, Scope, MLTAL))
return true;
-
- // Make sure the captures are also added to the instantiation scope.
- if (isLambdaCallOperator(FD) &&
- addInstantiatedCapturesToScope(FD, InstantiatedFrom, Scope, MLTAL))
- return true;
}
return false;
@@ -712,20 +702,8 @@ bool Sema::CheckFunctionConstraints(const FunctionDecl *FD,
}
CXXThisScopeRAII ThisScope(*this, Record, ThisQuals, Record != nullptr);
- // When checking the constraints of a lambda, we need to restore a
- // LambdaScopeInfo populated with correct capture information so that the type
- // of a variable referring to a capture is correctly const-adjusted.
- FunctionScopeRAII FuncScope(*this);
- if (isLambdaCallOperator(FD)) {
- LambdaScopeInfo *LSI = RebuildLambdaScopeInfo(
- const_cast<CXXMethodDecl *>(cast<CXXMethodDecl>(FD)));
- // Constraints are checked from the parent context of the lambda, so we set
- // AfterParameterList to false, so that `tryCaptureVariable` finds
- // explicit captures in the appropriate context.
- LSI->AfterParameterList = false;
- } else {
- FuncScope.disable();
- }
+ LambdaScopeForCallOperatorInstantiationRAII LambdaScope(
+ *this, const_cast<FunctionDecl *>(FD), *MLTAL, Scope);
return CheckConstraintSatisfaction(
FD, {FD->getTrailingRequiresClause()}, *MLTAL,
@@ -913,15 +891,10 @@ bool Sema::CheckInstantiatedFunctionTemplateConstraints(
ThisQuals = Method->getMethodQualifiers();
Record = Method->getParent();
}
- CXXThisScopeRAII ThisScope(*this, Record, ThisQuals, Record != nullptr);
- FunctionScopeRAII FuncScope(*this);
- if (isLambdaCallOperator(Decl)) {
- LambdaScopeInfo *LSI = RebuildLambdaScopeInfo(cast<CXXMethodDecl>(Decl));
- LSI->AfterParameterList = false;
- } else {
- FuncScope.disable();
- }
+ CXXThisScopeRAII ThisScope(*this, Record, ThisQuals, Record != nullptr);
+ LambdaScopeForCallOperatorInstantiationRAII LambdaScope(
+ *this, const_cast<FunctionDecl *>(Decl), *MLTAL, Scope);
llvm::SmallVector<Expr *, 1> Converted;
return CheckConstraintSatisfaction(Template, TemplateAC, Converted, *MLTAL,
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index d94366dac102a2..d6e090ee496eb3 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -15380,6 +15380,10 @@ LambdaScopeInfo *Sema::RebuildLambdaScopeInfo(CXXMethodDecl *CallOperator) {
LSI->CallOperator = CallOperator;
LSI->Lambda = LambdaClass;
LSI->ReturnType = CallOperator->getReturnType();
+ // This function in calls in situation where the context of the call operator
+ // is not entered, so we set AfterParameterList to false, so that
+ // `tryCaptureVariable` finds explicit captures in the appropriate context.
+ LSI->AfterParameterList = false;
const LambdaCaptureDefault LCD = LambdaClass->getLambdaCaptureDefault();
if (LCD == LCD_None)
diff --git a/clang/lib/Sema/SemaLambda.cpp b/clang/lib/Sema/SemaLambda.cpp
index 5256d91a19a0d0..1702ddb3ee0fbf 100644
--- a/clang/lib/Sema/SemaLambda.cpp
+++ b/clang/lib/Sema/SemaLambda.cpp
@@ -20,6 +20,7 @@
#include "clang/Sema/ScopeInfo.h"
#include "clang/Sema/SemaInternal.h"
#include "clang/Sema/SemaLambda.h"
+#include "clang/Sema/Template.h"
#include "llvm/ADT/STLExtras.h"
#include <optional>
using namespace clang;
@@ -2254,3 +2255,34 @@ ExprResult Sema::BuildBlockForLambdaConversion(SourceLocation CurrentLocation,
return BuildBlock;
}
+
+Sema::LambdaScopeForCallOperatorInstantiationRAII::
+ LambdaScopeForCallOperatorInstantiationRAII(
+ Sema &SemasRef, FunctionDecl *FD, MultiLevelTemplateArgumentList MLTAL,
+ LocalInstantiationScope &Scope)
+ : FunctionScopeRAII(SemasRef) {
+ if (!isLambdaCallOperator(FD)) {
+ FunctionScopeRAII::disable();
+ return;
+ }
+
+ if (FD->isTemplateInstantiation() && FD->getPrimaryTemplate()) {
+ FunctionTemplateDecl *PrimaryTemplate = FD->getPrimaryTemplate();
+ if (const auto *FromMemTempl =
+ PrimaryTemplate->getInstantiatedFromMemberTemplate()) {
+ SemasRef.addInstantiatedCapturesToScope(
+ FD, FromMemTempl->getTemplatedDecl(), Scope, MLTAL);
+ }
+ }
+
+ else if (FD->getTemplatedKind() == FunctionDecl::TK_MemberSpecialization ||
+ FD->getTemplatedKind() == FunctionDecl::TK_DependentNonTemplate) {
+ FunctionDecl *InstantiatedFrom =
+ FD->getTemplatedKind() == FunctionDecl::TK_MemberSpecialization
+ ? FD->getInstantiatedFromMemberFunction()
+ : FD->getInstantiatedFromDecl();
+ SemasRef.addInstantiatedCapturesToScope(FD, InstantiatedFrom, Scope, MLTAL);
+ }
+
+ SemasRef.RebuildLambdaScopeInfo(cast<CXXMethodDecl>(FD));
+}
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 63f022d5c2ff09..37a7d6204413a3 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -2426,6 +2426,9 @@ Decl *TemplateDeclInstantiator::VisitCXXMethodDecl(
cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
+ Sema::LambdaScopeForCallOperatorInstantiationRAII LambdaScope(
+ SemaRef, const_cast<CXXMethodDecl *>(D), TemplateArgs, Scope);
+
// Instantiate enclosing template arguments for friends.
SmallVector<TemplateParameterList *, 4> TempParamLists;
unsigned NumTempParamLists = 0;
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 7323140bc336bc..a075ade1adb7bb 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -12325,7 +12325,7 @@ TreeTransform<Derived>::TransformCXXNullPtrLiteralExpr(
template<typename Derived>
ExprResult
TreeTransform<Derived>::TransformCXXThisExpr(CXXThisExpr *E) {
- QualType T = getSema().getCurrentThisType();
+ QualType T = getDerived().TransformType(E->getType());
if (!getDerived().AlwaysRebuild() && T == E->getType()) {
// Mark it referenced in the new context regardless.
diff --git a/clang/test/SemaCXX/lambda-capture-type-deduction.cpp b/clang/test/SemaCXX/lambda-capture-type-deduction.cpp
index 9855122c962722..7bf36a6a9cab73 100644
--- a/clang/test/SemaCXX/lambda-capture-type-deduction.cpp
+++ b/clang/test/SemaCXX/lambda-capture-type-deduction.cpp
@@ -260,3 +260,40 @@ void f(int) {
void test() { f<int>(0); }
}
+
+namespace GH65067 {
+
+template <typename> class a {
+public:
+ template <typename b> void c(b f) { d<int>(f)(0); }
+ template <typename, typename b> auto d(b f) {
+ return [f = f](auto arg) -> a<decltype(f(arg))> { return {}; };
+ }
+};
+a<void> e;
+auto fn1() {
+ e.c([](int) {});
+}
+
+}
+
+namespace GH63675 {
+
+template <class _Tp> _Tp __declval();
+struct __get_tag {
+ template <class _Tag> void operator()(_Tag);
+};
+template <class _ImplFn> struct __basic_sender {
+ using __tag_t = decltype(__declval<_ImplFn>()(__declval<__get_tag>()));
+ _ImplFn __impl_;
+};
+auto __make_basic_sender = []<class... _Children>(
+ _Children... __children) {
+ return __basic_sender{[... __children = __children]<class _Fun>(
+ _Fun __fun) -> decltype(__fun(__children...)) {}};
+};
+void __trans_tmp_1() {
+ __make_basic_sender(__trans_tmp_1);
+}
+
+}
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