[clang] 2e1ad93 - [clang] fix broken canonicalization of DeducedTemplateSpecializationType (#95202)
via cfe-commits
cfe-commits at lists.llvm.org
Wed Jun 12 18:40:43 PDT 2024
Author: Matheus Izvekov
Date: 2024-06-12T22:40:39-03:00
New Revision: 2e1ad93961a3f444659c5d02d800e3144acccdb4
URL: https://github.com/llvm/llvm-project/commit/2e1ad93961a3f444659c5d02d800e3144acccdb4
DIFF: https://github.com/llvm/llvm-project/commit/2e1ad93961a3f444659c5d02d800e3144acccdb4.diff
LOG: [clang] fix broken canonicalization of DeducedTemplateSpecializationType (#95202)
This reverts the functional elements of commit
3e78fa860235431323aaf08c8fa922d75a7cfffa and redoes it, by fixing the
true root cause of #61317.
A TemplateName can be non-canonical; profiling it based on the canonical
name would result in inconsistent preservation of as-written information
in the AST.
The true problem in #61317 is that we would not consider the methods
with requirements expression which contain DTSTs as the same in relation
to merging of declarations when importing modules.
The expressions would never match because they contained DTSTs pointing
to different redeclarations of the same class template, but since
canonicalization for them was broken, their canonical types would not
match either.
---
No changelog entry because #61317 was already claimed as fixed in
previous release.
Added:
clang/unittests/AST/ProfilingTest.cpp
Modified:
clang/include/clang/AST/ASTContext.h
clang/include/clang/AST/TemplateName.h
clang/include/clang/AST/Type.h
clang/lib/AST/ASTContext.cpp
clang/lib/AST/TemplateName.cpp
clang/unittests/AST/CMakeLists.txt
Removed:
################################################################################
diff --git a/clang/include/clang/AST/ASTContext.h b/clang/include/clang/AST/ASTContext.h
index 8bce4812f0d48..f1f20fca477a4 100644
--- a/clang/include/clang/AST/ASTContext.h
+++ b/clang/include/clang/AST/ASTContext.h
@@ -1771,6 +1771,13 @@ class ASTContext : public RefCountedBase<ASTContext> {
QualType DeducedType,
bool IsDependent) const;
+private:
+ QualType getDeducedTemplateSpecializationTypeInternal(TemplateName Template,
+ QualType DeducedType,
+ bool IsDependent,
+ QualType Canon) const;
+
+public:
/// Return the unique reference to the type for the specified TagDecl
/// (struct/union/class/enum) decl.
QualType getTagDeclType(const TagDecl *Decl) const;
diff --git a/clang/include/clang/AST/TemplateName.h b/clang/include/clang/AST/TemplateName.h
index 988a55acd2252..24a7fde76195d 100644
--- a/clang/include/clang/AST/TemplateName.h
+++ b/clang/include/clang/AST/TemplateName.h
@@ -346,7 +346,9 @@ class TemplateName {
/// error.
void dump() const;
- void Profile(llvm::FoldingSetNodeID &ID);
+ void Profile(llvm::FoldingSetNodeID &ID) {
+ ID.AddPointer(Storage.getOpaqueValue());
+ }
/// Retrieve the template name as a void pointer.
void *getAsVoidPointer() const { return Storage.getOpaqueValue(); }
diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 9eb3f6c09e3d3..fab233b62d8d1 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -6050,30 +6050,27 @@ class DeducedTemplateSpecializationType : public DeducedType,
DeducedTemplateSpecializationType(TemplateName Template,
QualType DeducedAsType,
- bool IsDeducedAsDependent)
+ bool IsDeducedAsDependent, QualType Canon)
: DeducedType(DeducedTemplateSpecialization, DeducedAsType,
toTypeDependence(Template.getDependence()) |
(IsDeducedAsDependent
? TypeDependence::DependentInstantiation
: TypeDependence::None),
- DeducedAsType.isNull() ? QualType(this, 0)
- : DeducedAsType.getCanonicalType()),
+ Canon),
Template(Template) {}
public:
/// Retrieve the name of the template that we are deducing.
TemplateName getTemplateName() const { return Template;}
- void Profile(llvm::FoldingSetNodeID &ID) {
+ void Profile(llvm::FoldingSetNodeID &ID) const {
Profile(ID, getTemplateName(), getDeducedType(), isDependentType());
}
static void Profile(llvm::FoldingSetNodeID &ID, TemplateName Template,
QualType Deduced, bool IsDependent) {
Template.Profile(ID);
- QualType CanonicalType =
- Deduced.isNull() ? Deduced : Deduced.getCanonicalType();
- ID.AddPointer(CanonicalType.getAsOpaquePtr());
+ Deduced.Profile(ID);
ID.AddBoolean(IsDependent || Template.isDependent());
}
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index cd76b8aa271da..aa22825602a40 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -5926,11 +5926,9 @@ QualType ASTContext::getUnconstrainedType(QualType T) const {
return T;
}
-/// Return the uniqued reference to the deduced template specialization type
-/// which has been deduced to the given type, or to the canonical undeduced
-/// such type, or the canonical deduced-but-dependent such type.
-QualType ASTContext::getDeducedTemplateSpecializationType(
- TemplateName Template, QualType DeducedType, bool IsDependent) const {
+QualType ASTContext::getDeducedTemplateSpecializationTypeInternal(
+ TemplateName Template, QualType DeducedType, bool IsDependent,
+ QualType Canon) const {
// Look in the folding set for an existing type.
void *InsertPos = nullptr;
llvm::FoldingSetNodeID ID;
@@ -5941,7 +5939,8 @@ QualType ASTContext::getDeducedTemplateSpecializationType(
return QualType(DTST, 0);
auto *DTST = new (*this, alignof(DeducedTemplateSpecializationType))
- DeducedTemplateSpecializationType(Template, DeducedType, IsDependent);
+ DeducedTemplateSpecializationType(Template, DeducedType, IsDependent,
+ Canon);
llvm::FoldingSetNodeID TempID;
DTST->Profile(TempID);
assert(ID == TempID && "ID does not match");
@@ -5950,6 +5949,20 @@ QualType ASTContext::getDeducedTemplateSpecializationType(
return QualType(DTST, 0);
}
+/// Return the uniqued reference to the deduced template specialization type
+/// which has been deduced to the given type, or to the canonical undeduced
+/// such type, or the canonical deduced-but-dependent such type.
+QualType ASTContext::getDeducedTemplateSpecializationType(
+ TemplateName Template, QualType DeducedType, bool IsDependent) const {
+ QualType Canon = DeducedType.isNull()
+ ? getDeducedTemplateSpecializationTypeInternal(
+ getCanonicalTemplateName(Template), QualType(),
+ IsDependent, QualType())
+ : DeducedType.getCanonicalType();
+ return getDeducedTemplateSpecializationTypeInternal(Template, DeducedType,
+ IsDependent, Canon);
+}
+
/// getAtomicType - Return the uniqued reference to the atomic type for
/// the given value type.
QualType ASTContext::getAtomicType(QualType T) const {
diff --git a/clang/lib/AST/TemplateName.cpp b/clang/lib/AST/TemplateName.cpp
index 11544dbb56e31..d4e8a8971a971 100644
--- a/clang/lib/AST/TemplateName.cpp
+++ b/clang/lib/AST/TemplateName.cpp
@@ -264,15 +264,6 @@ bool TemplateName::containsUnexpandedParameterPack() const {
return getDependence() & TemplateNameDependence::UnexpandedPack;
}
-void TemplateName::Profile(llvm::FoldingSetNodeID &ID) {
- if (const auto* USD = getAsUsingShadowDecl())
- ID.AddPointer(USD->getCanonicalDecl());
- else if (const auto *TD = getAsTemplateDecl())
- ID.AddPointer(TD->getCanonicalDecl());
- else
- ID.AddPointer(Storage.getOpaqueValue());
-}
-
void TemplateName::print(raw_ostream &OS, const PrintingPolicy &Policy,
Qualified Qual) const {
auto handleAnonymousTTP = [](TemplateDecl *TD, raw_ostream &OS) {
diff --git a/clang/unittests/AST/CMakeLists.txt b/clang/unittests/AST/CMakeLists.txt
index 29d2b39cff8b1..dcc9bc0f39ac2 100644
--- a/clang/unittests/AST/CMakeLists.txt
+++ b/clang/unittests/AST/CMakeLists.txt
@@ -31,6 +31,7 @@ add_clang_unittest(ASTTests
EvaluateAsRValueTest.cpp
ExternalASTSourceTest.cpp
NamedDeclPrinterTest.cpp
+ ProfilingTest.cpp
RandstructTest.cpp
RecursiveASTVisitorTest.cpp
SizelessTypesTest.cpp
diff --git a/clang/unittests/AST/ProfilingTest.cpp b/clang/unittests/AST/ProfilingTest.cpp
new file mode 100644
index 0000000000000..ed81f4e1c5f2f
--- /dev/null
+++ b/clang/unittests/AST/ProfilingTest.cpp
@@ -0,0 +1,73 @@
+//===- unittests/AST/ProfilingTest.cpp --- Tests for Profiling ------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/Tooling/Tooling.h"
+#include "gtest/gtest.h"
+#include <utility>
+
+namespace clang {
+namespace {
+using namespace ast_matchers;
+
+static auto getClassTemplateRedecls() {
+ std::string Code = R"cpp(
+ template <class> struct A;
+ template <class> struct A;
+ template <class> struct A;
+ )cpp";
+ auto AST = tooling::buildASTFromCode(Code);
+ ASTContext &Ctx = AST->getASTContext();
+
+ auto MatchResults = match(classTemplateDecl().bind("id"), Ctx);
+ SmallVector<ClassTemplateDecl *, 3> Res;
+ for (BoundNodes &N : MatchResults) {
+ if (auto *CTD = const_cast<ClassTemplateDecl *>(
+ N.getNodeAs<ClassTemplateDecl>("id")))
+ Res.push_back(CTD);
+ }
+ assert(Res.size() == 3);
+ for (auto &&I : Res)
+ assert(I->getCanonicalDecl() == Res[0]);
+ return std::make_tuple(std::move(AST), Res[1], Res[2]);
+}
+
+template <class T> static void testTypeNode(const T *T1, const T *T2) {
+ {
+ llvm::FoldingSetNodeID ID1, ID2;
+ T1->Profile(ID1);
+ T2->Profile(ID2);
+ ASSERT_NE(ID1, ID2);
+ }
+ auto *CT1 = cast<T>(T1->getCanonicalTypeInternal());
+ auto *CT2 = cast<T>(T2->getCanonicalTypeInternal());
+ {
+ llvm::FoldingSetNodeID ID1, ID2;
+ CT1->Profile(ID1);
+ CT2->Profile(ID2);
+ ASSERT_EQ(ID1, ID2);
+ }
+}
+
+TEST(Profiling, DeducedTemplateSpecializationType_Name) {
+ auto [AST, CTD1, CTD2] = getClassTemplateRedecls();
+ ASTContext &Ctx = AST->getASTContext();
+
+ auto *T1 = cast<DeducedTemplateSpecializationType>(
+ Ctx.getDeducedTemplateSpecializationType(TemplateName(CTD1), QualType(),
+ false));
+ auto *T2 = cast<DeducedTemplateSpecializationType>(
+ Ctx.getDeducedTemplateSpecializationType(TemplateName(CTD2), QualType(),
+ false));
+ testTypeNode(T1, T2);
+}
+
+} // namespace
+} // namespace clang
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