Reverse Interop: Nested namespace support

This commit is contained in:
David Blaikie
2026-03-19 22:14:13 +00:00
parent 08148f3a3a
commit 38ae676da8
2 changed files with 30 additions and 32 deletions
+28 -17
View File
@@ -20,6 +20,7 @@
#include "clang/Sema/MultiplexExternalSemaSource.h"
#include "clang/Sema/Sema.h"
#include "common/check.h"
#include "common/map.h"
#include "common/raw_string_ostream.h"
#include "llvm/ADT/IntrusiveRefCntPtr.h"
#include "llvm/ADT/StringRef.h"
@@ -347,9 +348,12 @@ class CarbonExternalASTSource : public clang::ExternalASTSource {
auto StartTranslationUnit(clang::ASTConsumer* consumer) -> void override;
private:
auto MapInstIdToClangDecl(clang::DeclContext& decl_context,
LookupResult lookup) -> clang::NamedDecl*;
Check::Context* context_;
clang::ASTContext* ast_context_;
clang::NamespaceDecl* carbon_cpp_namespace_ = nullptr;
Map<clang::DeclContext*, SemIR::InstId> scope_mapping;
};
void CarbonExternalASTSource::StartTranslationUnit(
@@ -361,24 +365,27 @@ void CarbonExternalASTSource::StartTranslationUnit(
}
// Map a Carbon entity to a Clang NamedDecl.
static auto MapInstIdToClangDecl(Context& context,
clang::ASTContext& ast_context,
clang::DeclContext& decl_context,
LookupResult lookup) -> clang::NamedDecl* {
auto CarbonExternalASTSource::MapInstIdToClangDecl(
clang::DeclContext& decl_context, LookupResult lookup)
-> clang::NamedDecl* {
auto target_inst_id = lookup.scope_result.target_inst_id();
if (auto target_inst =
context.insts().TryGetAs<SemIR::Namespace>(target_inst_id)) {
auto& name_scope = context.name_scopes().Get(target_inst->name_scope_id);
context_->insts().TryGetAs<SemIR::Namespace>(target_inst_id)) {
auto& name_scope = context_->name_scopes().Get(target_inst->name_scope_id);
auto* identifier_info =
GetClangIdentifierInfo(context, name_scope.name_id());
GetClangIdentifierInfo(*context_, name_scope.name_id());
// TODO: Don't immediately use the decl_context - build any intermediate
// namespaces iteratively.
// Eventually add a mapping and use that/populate it/keep it up to date.
// decl_context could be prepopulated in that mapping and not passed
// explicitly to MapInstIdToClangDecl.
return clang::NamespaceDecl::Create(
ast_context, &decl_context, false, clang::SourceLocation(),
auto* namespace_decl = clang::NamespaceDecl::Create(
*ast_context_, &decl_context, false, clang::SourceLocation(),
clang::SourceLocation(), identifier_info, nullptr, false);
scope_mapping.Insert(static_cast<clang::DeclContext*>(namespace_decl),
target_inst_id);
namespace_decl->setHasExternalVisibleStorage();
return namespace_decl;
}
return nullptr;
}
@@ -386,7 +393,10 @@ static auto MapInstIdToClangDecl(Context& context,
auto CarbonExternalASTSource::FindExternalVisibleDeclsByName(
const clang::DeclContext* decl_context, clang::DeclarationName decl_name,
const clang::DeclContext* /*OriginalDC*/) -> bool {
if (decl_context != carbon_cpp_namespace_) {
auto decl_context_inst_id =
scope_mapping.Lookup(const_cast<clang::DeclContext*>(decl_context));
if (!decl_context_inst_id) {
if (decl_context->getDeclKind() != clang::Decl::Kind::TranslationUnit) {
return false;
}
@@ -400,13 +410,15 @@ auto CarbonExternalASTSource::FindExternalVisibleDeclsByName(
// Build the top level 'Carbon' namespace
auto& ast_context = decl_context->getParentASTContext();
auto& mutable_tu_decl_context = *ast_context.getTranslationUnitDecl();
carbon_cpp_namespace_ = clang::NamespaceDecl::Create(
auto* carbon_cpp_namespace = clang::NamespaceDecl::Create(
ast_context, &mutable_tu_decl_context, false, clang::SourceLocation(),
clang::SourceLocation(), &ast_context.Idents.get(carbon_namespace_name),
nullptr, false);
carbon_cpp_namespace_->setHasExternalVisibleStorage();
carbon_cpp_namespace->setHasExternalVisibleStorage();
scope_mapping.Insert(static_cast<clang::DeclContext*>(carbon_cpp_namespace),
SemIR::Namespace::PackageInstId);
SetExternalVisibleDeclsForName(decl_context, decl_name,
{carbon_cpp_namespace_});
{carbon_cpp_namespace});
return true;
}
@@ -418,7 +430,7 @@ auto CarbonExternalASTSource::FindExternalVisibleDeclsByName(
// here - completeness should've been checked by clang before this point.
if (!AppendLookupScopesForConstant(
*context_, SemIR::LocId::None,
context_->constant_values().Get(SemIR::Namespace::PackageInstId),
context_->constant_values().Get(decl_context_inst_id.value()),
SemIR::ConstantId::None, &lookup_scopes)) {
return false;
}
@@ -441,8 +453,7 @@ auto CarbonExternalASTSource::FindExternalVisibleDeclsByName(
}
// Map the found Carbon entity to a Clang NamedDecl.
auto* clang_decl = MapInstIdToClangDecl(*context_, *ast_context_,
*carbon_cpp_namespace_, result);
auto* clang_decl = MapInstIdToClangDecl(*decl_context_inst_id.key(), result);
if (!clang_decl) {
return false;
}