[clang] 5ea1580 - Revert "Reland [Modules] Remove unnecessary check when generating name lookup table in ASTWriter"
Ilya Biryukov via cfe-commits
cfe-commits at lists.llvm.org
Fri Apr 21 05:08:52 PDT 2023
Author: Ilya Biryukov
Date: 2023-04-21T14:08:18+02:00
New Revision: 5ea158077ec9ca50857ede5cbb0b27c61663fd55
URL: https://github.com/llvm/llvm-project/commit/5ea158077ec9ca50857ede5cbb0b27c61663fd55
DIFF: https://github.com/llvm/llvm-project/commit/5ea158077ec9ca50857ede5cbb0b27c61663fd55.diff
LOG: Revert "Reland [Modules] Remove unnecessary check when generating name lookup table in ASTWriter"
This reverts commit 67b298f6d82e0b4bb648ac0dabe895e816a77ef1.
We got linker errors with undefined symbols during a compiler release
and tracked it down to this change. I am in the process of understanding
what is happening and getting a reproducer.
Sorry for reverting this again.
I will reopen #61065 until we fix this.
Added:
Modified:
clang/include/clang/Serialization/ASTWriter.h
clang/lib/Serialization/ASTWriter.cpp
clang/test/Modules/pr61065.cppm
Removed:
################################################################################
diff --git a/clang/include/clang/Serialization/ASTWriter.h b/clang/include/clang/Serialization/ASTWriter.h
index d31fa38b9382..09ee1744e894 100644
--- a/clang/include/clang/Serialization/ASTWriter.h
+++ b/clang/include/clang/Serialization/ASTWriter.h
@@ -514,6 +514,7 @@ class ASTWriter : public ASTDeserializationListener,
void WriteTypeAbbrevs();
void WriteType(QualType T);
+ bool isLookupResultExternal(StoredDeclsList &Result, DeclContext *DC);
bool isLookupResultEntirelyExternal(StoredDeclsList &Result, DeclContext *DC);
void GenerateNameLookupTable(const DeclContext *DC,
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index 029f30416d61..245304254811 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -3849,6 +3849,12 @@ class ASTDeclContextNameLookupTrait {
} // namespace
+bool ASTWriter::isLookupResultExternal(StoredDeclsList &Result,
+ DeclContext *DC) {
+ return Result.hasExternalDecls() &&
+ DC->hasNeedToReconcileExternalVisibleStorage();
+}
+
bool ASTWriter::isLookupResultEntirelyExternal(StoredDeclsList &Result,
DeclContext *DC) {
for (auto *D : Result.getLookupResult())
@@ -3879,17 +3885,20 @@ ASTWriter::GenerateNameLookupTable(const DeclContext *ConstDC,
// order.
SmallVector<DeclarationName, 16> Names;
- // We also track whether we're writing out the DeclarationNameKey for
- // constructors or conversion functions.
- bool IncludeConstructorNames = false;
- bool IncludeConversionNames = false;
+ // We also build up small sets of the constructor and conversion function
+ // names which are visible.
+ llvm::SmallPtrSet<DeclarationName, 8> ConstructorNameSet, ConversionNameSet;
+
+ for (auto &Lookup : *DC->buildLookup()) {
+ auto &Name = Lookup.first;
+ auto &Result = Lookup.second;
- for (auto &[Name, Result] : *DC->buildLookup()) {
// If there are no local declarations in our lookup result, we
// don't need to write an entry for the name at all. If we can't
// write out a lookup set without performing more deserialization,
// just skip this entry.
- if (isLookupResultEntirelyExternal(Result, DC))
+ if (isLookupResultExternal(Result, DC) &&
+ isLookupResultEntirelyExternal(Result, DC))
continue;
// We also skip empty results. If any of the results could be external and
@@ -3906,20 +3915,24 @@ ASTWriter::GenerateNameLookupTable(const DeclContext *ConstDC,
// results for them. This in almost certainly a bug in Clang's name lookup,
// but that is likely to be hard or impossible to fix and so we tolerate it
// here by omitting lookups with empty results.
- if (Result.getLookupResult().empty())
+ if (Lookup.second.getLookupResult().empty())
continue;
- switch (Name.getNameKind()) {
+ switch (Lookup.first.getNameKind()) {
default:
- Names.push_back(Name);
+ Names.push_back(Lookup.first);
break;
case DeclarationName::CXXConstructorName:
- IncludeConstructorNames = true;
+ assert(isa<CXXRecordDecl>(DC) &&
+ "Cannot have a constructor name outside of a class!");
+ ConstructorNameSet.insert(Name);
break;
case DeclarationName::CXXConversionFunctionName:
- IncludeConversionNames = true;
+ assert(isa<CXXRecordDecl>(DC) &&
+ "Cannot have a conversion function name outside of a class!");
+ ConversionNameSet.insert(Name);
break;
}
}
@@ -3927,34 +3940,55 @@ ASTWriter::GenerateNameLookupTable(const DeclContext *ConstDC,
// Sort the names into a stable order.
llvm::sort(Names);
- if (IncludeConstructorNames || IncludeConversionNames) {
+ if (auto *D = dyn_cast<CXXRecordDecl>(DC)) {
// We need to establish an ordering of constructor and conversion function
- // names, and they don't have an intrinsic ordering. We also need to write
- // out all constructor and conversion function results if we write out any
- // of them, because they're all tracked under the same lookup key.
- llvm::SmallPtrSet<DeclarationName, 8> AddedNames;
- for (Decl *ChildD : cast<CXXRecordDecl>(DC)->decls()) {
- if (auto *ChildND = dyn_cast<NamedDecl>(ChildD)) {
- auto Name = ChildND->getDeclName();
- switch (Name.getNameKind()) {
- default:
- continue;
-
- case DeclarationName::CXXConstructorName:
- if (!IncludeConstructorNames)
+ // names, and they don't have an intrinsic ordering.
+
+ // First we try the easy case by forming the current context's constructor
+ // name and adding that name first. This is a very useful optimization to
+ // avoid walking the lexical declarations in many cases, and it also
+ // handles the only case where a constructor name can come from some other
+ // lexical context -- when that name is an implicit constructor merged from
+ // another declaration in the redecl chain. Any non-implicit constructor or
+ // conversion function which doesn't occur in all the lexical contexts
+ // would be an ODR violation.
+ auto ImplicitCtorName = Context->DeclarationNames.getCXXConstructorName(
+ Context->getCanonicalType(Context->getRecordType(D)));
+ if (ConstructorNameSet.erase(ImplicitCtorName))
+ Names.push_back(ImplicitCtorName);
+
+ // If we still have constructors or conversion functions, we walk all the
+ // names in the decl and add the constructors and conversion functions
+ // which are visible in the order they lexically occur within the context.
+ if (!ConstructorNameSet.empty() || !ConversionNameSet.empty())
+ for (Decl *ChildD : cast<CXXRecordDecl>(DC)->decls())
+ if (auto *ChildND = dyn_cast<NamedDecl>(ChildD)) {
+ auto Name = ChildND->getDeclName();
+ switch (Name.getNameKind()) {
+ default:
continue;
- break;
- case DeclarationName::CXXConversionFunctionName:
- if (!IncludeConversionNames)
- continue;
- break;
+ case DeclarationName::CXXConstructorName:
+ if (ConstructorNameSet.erase(Name))
+ Names.push_back(Name);
+ break;
+
+ case DeclarationName::CXXConversionFunctionName:
+ if (ConversionNameSet.erase(Name))
+ Names.push_back(Name);
+ break;
+ }
+
+ if (ConstructorNameSet.empty() && ConversionNameSet.empty())
+ break;
}
- // We should include lookup results for this name.
- if (AddedNames.insert(Name).second)
- Names.push_back(Name);
- }
- }
+
+ assert(ConstructorNameSet.empty() && "Failed to find all of the visible "
+ "constructors by walking all the "
+ "lexical members of the context.");
+ assert(ConversionNameSet.empty() && "Failed to find all of the visible "
+ "conversion functions by walking all "
+ "the lexical members of the context.");
}
// Next we need to do a lookup with each name into this decl context to fully
diff --git a/clang/test/Modules/pr61065.cppm b/clang/test/Modules/pr61065.cppm
index 44fa3679974a..cf6fcdda78cd 100644
--- a/clang/test/Modules/pr61065.cppm
+++ b/clang/test/Modules/pr61065.cppm
@@ -6,9 +6,9 @@
// RUN: %clang_cc1 -std=c++20 %t/a.cppm -emit-module-interface -o %t/a.pcm
// RUN: %clang_cc1 -std=c++20 %t/b.cppm -emit-module-interface -o %t/b.pcm \
// RUN: -fprebuilt-module-path=%t
-// RUN: %clang_cc1 -std=c++20 %t/c.cppm -emit-module-interface -o %t/c.pcm \
-// RUN: -fprebuilt-module-path=%t
-// RUN: %clang_cc1 -std=c++20 %t/d.cpp -fsyntax-only -verify -fprebuilt-module-path=%t
+// DISABLED: %clang_cc1 -std=c++20 %t/c.cppm -emit-module-interface -o %t/c.pcm \
+// DISABLED: -fprebuilt-module-path=%t
+// DISABLED: %clang_cc1 -std=c++20 %t/d.cpp -fsyntax-only -verify -fprebuilt-module-path=%t
//--- a.cppm
export module a;
More information about the cfe-commits
mailing list