teemperor created this revision.
teemperor added a reviewer: shafik.
Herald added subscribers: lldb-commits, JDevlieghere, aprantl.
Herald added a project: LLDB.
CXXRecordDecls that have a move constructor but no copy constructor need to
have their implicit copy constructor marked as deleted (see C++11
[class.copy]p7, p18)
Currently we don't do that when building an AST with ClangASTContext which
causes
Sema to realise that the AST is malformed and asserting when trying to create
an implicit
copy constructor for us in the expression:
Assertion failed: ((data().DefaultedCopyConstructorIsDeleted ||
needsOverloadResolutionForCopyConstructor())
&& "Copy constructor should not be deleted"), function
setImplicitCopyConstructorIsDeleted, file include/clang/AST/DeclCXX.h, line 828.
In the test case there is a class `NoCopyCstr` that should have its copy
constructor marked as
deleted (as it has a move constructor). When we end up trying to tab complete
in the
`IndirectlyDeletedCopyCstr` constructor, Sema realises that the
`IndirectlyDeletedCopyCstr`
has no implicit copy constructor and tries to create one for us. It then
realises that
`NoCopyCstr` also has no copy constructor it could find via lookup. However
because we
haven't marked the FieldDecl as having a deleted copy constructor the
`needsOverloadResolutionForCopyConstructor()` returns false and the assert
fails.
`needsOverloadResolutionForCopyConstructor()` would return true if during the
time we
added the `NoCopyCstr` FieldDecl to `IndirectlyDeletedCopyCstr` we would have
actually marked
it as having a deleted copy constructor (which would then mark the copy
constructor of
`IndirectlyDeletedCopyCstr ` as needing overload resolution and Sema is happy).
This patch sets the correct mark when we complete our CXXRecordDecls (which is
the time when
we know whether a copy constructor has been declared). In theory we don't have
to do this if
we had a Sema around when building our debug info AST but at the moment we
don't have this
so this has to do the job for now.
Repository:
rLLDB LLDB
https://reviews.llvm.org/D72694
Files:
lldb/packages/Python/lldbsuite/test/commands/expression/completion-crash1/TestCompletionCrash1.py
lldb/packages/Python/lldbsuite/test/commands/expression/completion-crash1/main.cpp
lldb/source/Symbol/ClangASTContext.cpp
lldb/unittests/Symbol/TestClangASTContext.cpp
Index: lldb/unittests/Symbol/TestClangASTContext.cpp
===================================================================
--- lldb/unittests/Symbol/TestClangASTContext.cpp
+++ lldb/unittests/Symbol/TestClangASTContext.cpp
@@ -523,3 +523,89 @@
EXPECT_EQ("foo", func_template->getName());
EXPECT_EQ(clang::AccessSpecifier::AS_public, func_template->getAccess());
}
+
+TEST_F(TestClangASTContext, TestDeletingImplicitCopyCstrDueToMoveCStr) {
+ // We need to simulate this behavior in our AST that we construct as we don't
+ // have a Sema instance that can do this for us:
+ // C++11 [class.copy]p7, p18:
+ // If the class definition declares a move constructor or move assignment
+ // operator, an implicitly declared copy constructor or copy assignment
+ // operator is defined as deleted.
+
+ // Create a record and start defining it.
+ llvm::StringRef class_name = "S";
+ CompilerType t = clang_utils::createRecord(*m_ast, class_name);
+ m_ast->StartTagDeclarationDefinition(t);
+
+ // Create a move constructor that will delete the implicit copy constructor.
+ CompilerType return_type = m_ast->GetBasicType(lldb::eBasicTypeVoid);
+ CompilerType param_type = t.GetRValueReferenceType();
+ CompilerType function_type =
+ m_ast->CreateFunctionType(return_type, ¶m_type, /*num_params*/ 1,
+ /*variadic=*/false, /*quals*/ 0U);
+ bool is_virtual = false;
+ bool is_static = false;
+ bool is_inline = false;
+ bool is_explicit = true;
+ bool is_attr_used = false;
+ bool is_artificial = false;
+ m_ast->AddMethodToCXXRecordType(
+ t.GetOpaqueQualType(), class_name.data(), nullptr, function_type,
+ lldb::AccessType::eAccessPublic, is_virtual, is_static, is_inline,
+ is_explicit, is_attr_used, is_artificial);
+
+ // Complete the definition and check the created record.
+ m_ast->CompleteTagDeclarationDefinition(t);
+ auto *record = llvm::cast<CXXRecordDecl>(ClangUtil::GetAsTagDecl(t));
+ // We can't call defaultedCopyConstructorIsDeleted() as this requires that
+ // the Decl passes through Sema which will actually compute this field.
+ // Instead we check that there is no copy constructor declared by the user
+ // which only leaves a non-deleted defaulted copy constructor as an option
+ // that our record will have no simple copy constructor.
+ EXPECT_FALSE(record->hasUserDeclaredCopyConstructor());
+ EXPECT_FALSE(record->hasSimpleCopyConstructor());
+}
+
+TEST_F(TestClangASTContext, TestNotDeletingUserCopyCstrDueToMoveCStr) {
+ // Tests that we don't delete the a user-defined copy constructor when
+ // a move constructor is provided.
+ // See also the TestDeletingImplicitCopyCstrDueToMoveCStr test.
+ llvm::StringRef class_name = "S";
+ CompilerType t = clang_utils::createRecord(*m_ast, class_name);
+ m_ast->StartTagDeclarationDefinition(t);
+
+ CompilerType return_type = m_ast->GetBasicType(lldb::eBasicTypeVoid);
+ bool is_virtual = false;
+ bool is_static = false;
+ bool is_inline = false;
+ bool is_explicit = true;
+ bool is_attr_used = false;
+ bool is_artificial = false;
+ // Create a move constructor.
+ {
+ CompilerType param_type = t.GetRValueReferenceType();
+ CompilerType function_type =
+ m_ast->CreateFunctionType(return_type, ¶m_type, /*num_params*/ 1,
+ /*variadic=*/false, /*quals*/ 0U);
+ m_ast->AddMethodToCXXRecordType(
+ t.GetOpaqueQualType(), class_name.data(), nullptr, function_type,
+ lldb::AccessType::eAccessPublic, is_virtual, is_static, is_inline,
+ is_explicit, is_attr_used, is_artificial);
+ }
+ // Create a copy constructor.
+ {
+ CompilerType param_type = t.GetLValueReferenceType().AddConstModifier();
+ CompilerType function_type =
+ m_ast->CreateFunctionType(return_type, ¶m_type, /*num_params*/ 1,
+ /*variadic=*/false, /*quals*/ 0U);
+ m_ast->AddMethodToCXXRecordType(
+ t.GetOpaqueQualType(), class_name.data(), nullptr, function_type,
+ lldb::AccessType::eAccessPublic, is_virtual, is_static, is_inline,
+ is_explicit, is_attr_used, is_artificial);
+ }
+
+ // Complete the definition and check the created record.
+ m_ast->CompleteTagDeclarationDefinition(t);
+ auto *record = llvm::cast<CXXRecordDecl>(ClangUtil::GetAsTagDecl(t));
+ EXPECT_TRUE(record->hasUserDeclaredCopyConstructor());
+}
Index: lldb/source/Symbol/ClangASTContext.cpp
===================================================================
--- lldb/source/Symbol/ClangASTContext.cpp
+++ lldb/source/Symbol/ClangASTContext.cpp
@@ -7784,6 +7784,19 @@
clang::TagDecl *tag_decl = tag_type->getDecl();
if (auto *cxx_record_decl = llvm::dyn_cast<CXXRecordDecl>(tag_decl)) {
+ // If we have a move constructor declared but no copy constructor we
+ // need to explicitly mark it as deleted. Usually Sema would do this for
+ // us in Sema::DeclareImplicitCopyConstructor but we don't have a Sema
+ // when building an AST from debug information.
+ // See also:
+ // C++11 [class.copy]p7, p18:
+ // If the class definition declares a move constructor or move assignment
+ // operator, an implicitly declared copy constructor or copy assignment
+ // operator is defined as deleted.
+ if (cxx_record_decl->hasUserDeclaredMoveConstructor() &&
+ cxx_record_decl->needsImplicitCopyConstructor())
+ cxx_record_decl->setImplicitCopyConstructorIsDeleted();
+
if (!cxx_record_decl->isCompleteDefinition())
cxx_record_decl->completeDefinition();
cxx_record_decl->setHasLoadedFieldsFromExternalStorage(true);
Index: lldb/packages/Python/lldbsuite/test/commands/expression/completion-crash1/main.cpp
===================================================================
--- lldb/packages/Python/lldbsuite/test/commands/expression/completion-crash1/main.cpp
+++ lldb/packages/Python/lldbsuite/test/commands/expression/completion-crash1/main.cpp
@@ -1,12 +1,12 @@
-namespace std {
struct a {
a() {}
a(a &&);
};
-template <class> struct au {
+struct au {
a ay;
- ~au() { //%self.dbg.GetCommandInterpreter().HandleCompletion("e ", len("e "), 0, -1, lldb.SBStringList())
+ au() { //%self.dbg.GetCommandInterpreter().HandleCompletion("e ", len("e "), 0, -1, lldb.SBStringList())
}
};
+int main() {
+ au{};
}
-int main() { std::au<int>{}; }
Index: lldb/packages/Python/lldbsuite/test/commands/expression/completion-crash1/TestCompletionCrash1.py
===================================================================
--- lldb/packages/Python/lldbsuite/test/commands/expression/completion-crash1/TestCompletionCrash1.py
+++ lldb/packages/Python/lldbsuite/test/commands/expression/completion-crash1/TestCompletionCrash1.py
@@ -1,4 +1,4 @@
from lldbsuite.test import lldbinline
from lldbsuite.test import decorators
-lldbinline.MakeInlineTest(__file__, globals(), [decorators.skipIf(bugnumber="rdar://53659341")])
+lldbinline.MakeInlineTest(__file__, globals())
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