e87f889e31
After making no progress on this for a very long time, let's acknowledge it's not going anywhere and remove it from the codebase.
975 lines
42 KiB
C++
975 lines
42 KiB
C++
/*
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* Copyright (c) 2024, Matthew Olsson <mattco@serenityos.org>
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* Copyright (c) 2025, Idan Horowitz <idan.horowitz@serenityos.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include "LibJSGCPluginAction.h"
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#include <clang/ASTMatchers/ASTMatchFinder.h>
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#include <clang/ASTMatchers/ASTMatchers.h>
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#include <clang/Basic/SourceManager.h>
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#include <clang/Frontend/CompilerInstance.h>
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#include <clang/Frontend/FrontendPluginRegistry.h>
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#include <clang/Lex/MacroArgs.h>
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#include <map>
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#include <set>
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#include <unordered_map>
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#include <unordered_set>
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template<typename T>
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class SimpleCollectMatchesCallback : public clang::ast_matchers::MatchFinder::MatchCallback {
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public:
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explicit SimpleCollectMatchesCallback(std::string name)
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: m_name(std::move(name))
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{
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}
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void run(clang::ast_matchers::MatchFinder::MatchResult const& result) override
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{
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if (auto const* node = result.Nodes.getNodeAs<T>(m_name))
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m_matches.push_back(node);
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}
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auto const& matches() const { return m_matches; }
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private:
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std::string m_name;
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std::vector<T const*> m_matches;
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};
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static bool record_inherits_from_cell(clang::CXXRecordDecl const& record)
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{
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if (!record.isCompleteDefinition())
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return false;
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bool inherits_from_cell = record.getQualifiedNameAsString() == "GC::Cell";
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record.forallBases([&](clang::CXXRecordDecl const* base) -> bool {
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if (base->getQualifiedNameAsString() == "GC::Cell") {
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inherits_from_cell = true;
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return false;
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}
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return true;
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});
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return inherits_from_cell;
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}
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// Check if a type has a visit_edges method that takes GC::Cell::Visitor&
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static bool type_has_visit_edges_method(clang::CXXRecordDecl const* record)
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{
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if (!record || !record->isCompleteDefinition())
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return false;
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for (auto const* method : record->methods()) {
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if (method->getNameAsString() != "visit_edges")
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continue;
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if (method->getNumParams() != 1)
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continue;
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// Check that the parameter is a reference to Visitor (GC::Cell::Visitor)
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auto param_type = method->getParamDecl(0)->getType();
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if (!param_type->isReferenceType())
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continue;
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return true;
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}
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return false;
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}
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enum class ContainsGCPtrResult {
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No,
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Yes,
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YesRequiresVisitEdges, // Contains GC pointers and the type needs its own visit_edges
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};
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static std::map<clang::CXXRecordDecl const*, ContainsGCPtrResult> s_contains_gc_ptr_cache;
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// Forward declaration
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static ContainsGCPtrResult type_contains_gc_ptr(clang::QualType const& type, std::set<clang::CXXRecordDecl const*>& visited);
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static ContainsGCPtrResult record_contains_gc_ptr(clang::CXXRecordDecl const* record, std::set<clang::CXXRecordDecl const*>& visited)
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{
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if (!record || !record->isCompleteDefinition())
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return ContainsGCPtrResult::No;
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// Avoid infinite recursion
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if (visited.contains(record))
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return ContainsGCPtrResult::No;
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visited.insert(record);
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// Check cache
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auto cache_it = s_contains_gc_ptr_cache.find(record);
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if (cache_it != s_contains_gc_ptr_cache.end())
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return cache_it->second;
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// Cell types are visited directly via GC::Ptr/GC::Ref, not through substruct visiting
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if (record_inherits_from_cell(*record)) {
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s_contains_gc_ptr_cache[record] = ContainsGCPtrResult::No;
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return ContainsGCPtrResult::No;
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}
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// Skip GC infrastructure types that handle their own visiting
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auto qualified_name = record->getQualifiedNameAsString();
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static std::set<std::string> gc_infrastructure_types {
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"GC::Root",
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"GC::RootImpl",
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"GC::HeapBlock",
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"GC::CellAllocator",
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"GC::TypeIsolatingCellAllocator",
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"GC::RootVector",
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"GC::Heap",
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"GC::MarkedVector",
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"GC::ConservativeVector",
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};
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if (gc_infrastructure_types.contains(qualified_name)) {
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s_contains_gc_ptr_cache[record] = ContainsGCPtrResult::No;
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return ContainsGCPtrResult::No;
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}
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// Skip AK types - they're library types that don't need visit_edges
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if (qualified_name.starts_with("AK::") || qualified_name.starts_with("Optional<")) {
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s_contains_gc_ptr_cache[record] = ContainsGCPtrResult::No;
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return ContainsGCPtrResult::No;
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}
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ContainsGCPtrResult result = ContainsGCPtrResult::No;
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for (auto const* field : record->fields()) {
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auto field_result = type_contains_gc_ptr(field->getType(), visited);
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if (field_result == ContainsGCPtrResult::YesRequiresVisitEdges) {
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result = ContainsGCPtrResult::YesRequiresVisitEdges;
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break;
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}
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if (field_result == ContainsGCPtrResult::Yes) {
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result = ContainsGCPtrResult::YesRequiresVisitEdges;
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}
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}
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s_contains_gc_ptr_cache[record] = result;
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return result;
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}
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static ContainsGCPtrResult type_contains_gc_ptr(clang::QualType const& type, std::set<clang::CXXRecordDecl const*>& visited)
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{
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// Handle elaborated types
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clang::QualType actual_type = type;
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if (auto const* elaborated = llvm::dyn_cast<clang::ElaboratedType>(type.getTypePtr()))
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actual_type = elaborated->desugar();
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// Check for JS::Value directly
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if (auto const* record = actual_type->getAsCXXRecordDecl()) {
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if (record->getQualifiedNameAsString() == "JS::Value")
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return ContainsGCPtrResult::Yes;
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}
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// Check for raw pointers to Cell types (these should use GC::Ptr instead)
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if (auto const* pointer_type = actual_type->getAs<clang::PointerType>()) {
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if (auto const* pointee = pointer_type->getPointeeCXXRecordDecl()) {
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if (pointee->hasDefinition() && record_inherits_from_cell(*pointee))
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return ContainsGCPtrResult::Yes;
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}
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}
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// Check for raw references to Cell types (these should use GC::Ref instead)
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if (auto const* reference_type = actual_type->getAs<clang::ReferenceType>()) {
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if (auto const* pointee = reference_type->getPointeeCXXRecordDecl()) {
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if (pointee->hasDefinition() && record_inherits_from_cell(*pointee))
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return ContainsGCPtrResult::Yes;
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}
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}
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// Check for template specializations (GC::Ptr, GC::Ref, Vector, HashMap, etc.)
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if (auto const* specialization = actual_type->getAs<clang::TemplateSpecializationType>()) {
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auto template_name = specialization->getTemplateName().getAsTemplateDecl()->getQualifiedNameAsString();
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// Direct GC pointer types
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if (template_name == "GC::Ptr" || template_name == "GC::Ref")
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return ContainsGCPtrResult::Yes;
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// Raw pointers don't need visiting
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if (template_name == "GC::RawPtr" || template_name == "GC::RawRef")
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return ContainsGCPtrResult::No;
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// Root types handle their own visiting
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if (template_name == "GC::Root" || template_name == "GC::RootVector")
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return ContainsGCPtrResult::No;
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// Check template arguments recursively for containers
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for (auto const& arg : specialization->template_arguments()) {
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if (arg.getKind() == clang::TemplateArgument::Type) {
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auto arg_result = type_contains_gc_ptr(arg.getAsType(), visited);
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if (arg_result != ContainsGCPtrResult::No)
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return arg_result;
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}
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}
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}
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// Check for record types (structs/classes) that might contain GC pointers
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if (auto const* record = actual_type->getAsCXXRecordDecl()) {
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return record_contains_gc_ptr(record, visited);
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}
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return ContainsGCPtrResult::No;
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}
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static ContainsGCPtrResult type_contains_gc_ptr(clang::QualType const& type)
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{
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std::set<clang::CXXRecordDecl const*> visited;
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return type_contains_gc_ptr(type, visited);
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}
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static std::vector<clang::QualType> get_all_qualified_types(clang::QualType const& type)
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{
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std::vector<clang::QualType> qualified_types;
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if (auto const* template_specialization = type->getAs<clang::TemplateSpecializationType>()) {
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auto specialization_name = template_specialization->getTemplateName().getAsTemplateDecl()->getQualifiedNameAsString();
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// Do not unwrap GCPtr/NonnullGCPtr/RootVector
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static std::unordered_set<std::string> gc_relevant_type_names {
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"GC::Ptr",
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"GC::Ref",
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"GC::RawPtr",
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"GC::RawRef",
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"GC::RootVector",
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"GC::Root",
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};
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if (gc_relevant_type_names.contains(specialization_name)) {
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qualified_types.push_back(type);
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} else {
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auto const template_arguments = template_specialization->template_arguments();
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for (size_t i = 0; i < template_arguments.size(); i++) {
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auto const& template_arg = template_arguments[i];
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if (template_arg.getKind() == clang::TemplateArgument::Type) {
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auto template_qualified_types = get_all_qualified_types(template_arg.getAsType());
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std::move(template_qualified_types.begin(), template_qualified_types.end(), std::back_inserter(qualified_types));
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}
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}
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}
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} else {
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qualified_types.push_back(type);
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}
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return qualified_types;
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}
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enum class OuterType {
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GCPtr,
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RawPtr,
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Root,
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Ptr,
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Ref,
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Value,
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};
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struct QualTypeGCInfo {
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std::optional<OuterType> outer_type { {} };
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bool base_type_inherits_from_cell { false };
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};
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static std::optional<QualTypeGCInfo> validate_qualified_type(clang::QualType const& type)
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{
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if (auto const* pointer_decl = type->getAs<clang::PointerType>()) {
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if (auto const* pointee = pointer_decl->getPointeeCXXRecordDecl())
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return QualTypeGCInfo { OuterType::Ptr, record_inherits_from_cell(*pointee) };
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} else if (auto const* reference_decl = type->getAs<clang::ReferenceType>()) {
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if (auto const* pointee = reference_decl->getPointeeCXXRecordDecl())
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return QualTypeGCInfo { OuterType::Ref, record_inherits_from_cell(*pointee) };
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} else if (auto const* specialization = type->getAs<clang::TemplateSpecializationType>()) {
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auto template_type_name = specialization->getTemplateName().getAsTemplateDecl()->getQualifiedNameAsString();
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OuterType outer_type;
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if (template_type_name == "GC::Ptr" || template_type_name == "GC::Ref") {
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outer_type = OuterType::GCPtr;
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} else if (template_type_name == "GC::RawPtr" || template_type_name == "GC::RawRef") {
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outer_type = OuterType::RawPtr;
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} else if (template_type_name == "GC::Root") {
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outer_type = OuterType::Root;
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} else {
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return {};
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}
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auto template_args = specialization->template_arguments();
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if (template_args.size() != 1)
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return {}; // Not really valid, but will produce a compilation error anyway
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auto const& type_arg = template_args[0];
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auto const* record_type = type_arg.getAsType()->getAs<clang::RecordType>();
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if (!record_type)
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return {};
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auto const* record_decl = record_type->getAsCXXRecordDecl();
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if (!record_decl->hasDefinition()) {
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// If we don't have a definition (this is a forward declaration), assume that the type inherits from
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// GC::Cell instead of not checking it at all. If it does inherit from GC:Cell, this will make sure it's
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// visited. If it does not, any attempt to visit it will fail compilation on the visit call itself,
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// ensuring it's no longer wrapped in a GC::Ptr.
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return QualTypeGCInfo { outer_type, true };
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}
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return QualTypeGCInfo { outer_type, record_inherits_from_cell(*record_decl) };
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} else if (auto const* record = type->getAsCXXRecordDecl()) {
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if (record->getQualifiedNameAsString() == "JS::Value")
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return QualTypeGCInfo { OuterType::Value, true };
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}
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return {};
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}
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static std::optional<QualTypeGCInfo> validate_field_qualified_type(clang::FieldDecl const* field_decl)
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{
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auto type = field_decl->getType();
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if (auto const* elaborated_type = llvm::dyn_cast<clang::ElaboratedType>(type.getTypePtr()))
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type = elaborated_type->desugar();
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for (auto const& qualified_type : get_all_qualified_types(type)) {
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if (auto error = validate_qualified_type(qualified_type))
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return error;
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}
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return {};
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}
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static bool decl_has_annotation(clang::Decl const* decl, std::string name)
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{
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for (auto const* attr : decl->attrs()) {
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if (auto const* annotate_attr = llvm::dyn_cast<clang::AnnotateAttr>(attr)) {
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if (annotate_attr->getAnnotation() == name)
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return true;
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}
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}
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return false;
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}
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bool LibJSGCVisitor::VisitCXXRecordDecl(clang::CXXRecordDecl* record)
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{
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using namespace clang::ast_matchers;
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if (!record || !record->isCompleteDefinition() || (!record->isClass() && !record->isStruct()))
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return true;
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// Cell triggers a bunch of warnings for its empty visit_edges implementation, but
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// it doesn't have any members anyways so it's fine to just ignore.
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auto qualified_name = record->getQualifiedNameAsString();
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if (qualified_name == "GC::Cell")
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return true;
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auto& diag_engine = m_context.getDiagnostics();
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std::vector<clang::FieldDecl const*> fields_that_need_visiting;
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std::vector<clang::FieldDecl const*> substruct_fields_that_need_visiting;
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auto record_is_cell = record_inherits_from_cell(*record);
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for (clang::FieldDecl const* field : record->fields()) {
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if (decl_has_annotation(field, "serenity::ignore_gc"))
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continue;
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// Skip anonymous structs/unions - their members are accessed indirectly
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// and may be handled specially (e.g., tagged unions with type checks)
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if (field->isAnonymousStructOrUnion())
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continue;
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auto validation_results = validate_field_qualified_type(field);
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if (validation_results) {
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auto [outer_type, base_type_inherits_from_cell] = *validation_results;
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if (outer_type == OuterType::Ptr || outer_type == OuterType::Ref) {
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if (base_type_inherits_from_cell) {
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auto diag_id = diag_engine.getCustomDiagID(clang::DiagnosticsEngine::Error, "%0 to GC::Cell type should be wrapped in %1");
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auto builder = diag_engine.Report(field->getLocation(), diag_id);
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if (outer_type == OuterType::Ref) {
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builder << "reference"
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<< "GC::Ref";
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} else {
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builder << "pointer"
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<< "GC::Ptr";
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}
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}
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} else if (outer_type == OuterType::GCPtr || outer_type == OuterType::RawPtr || outer_type == OuterType::Value) {
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if (!base_type_inherits_from_cell) {
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auto diag_id = diag_engine.getCustomDiagID(clang::DiagnosticsEngine::Error, "Specialization type must inherit from GC::Cell");
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diag_engine.Report(field->getLocation(), diag_id);
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} else if (outer_type != OuterType::RawPtr) {
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fields_that_need_visiting.push_back(field);
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}
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} else if (outer_type == OuterType::Root) {
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if (record_is_cell && m_detect_invalid_function_members) {
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// FIXME: Change this to an Error when all of the use cases get addressed and remove the plugin argument
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auto diag_id = diag_engine.getCustomDiagID(clang::DiagnosticsEngine::Warning, "Types inheriting from GC::Cell should not have %0 fields");
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auto builder = diag_engine.Report(field->getLocation(), diag_id);
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builder << "GC::Root";
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}
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}
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// Field is a direct GC type, don't also check for substruct
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continue;
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}
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// Check if this field is a substruct (non-Cell type) containing GC pointers
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auto contains_result = type_contains_gc_ptr(field->getType());
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if (contains_result == ContainsGCPtrResult::YesRequiresVisitEdges) {
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substruct_fields_that_need_visiting.push_back(field);
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}
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}
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// Non-Cell types don't need visit_edges just for existing - they only need it
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// when used as a member of a Cell (checked below for Cell types).
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// However, if they DO have visit_edges, verify it visits all GC members.
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if (!record_is_cell) {
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// Check if this non-Cell type has a visit_edges method
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clang::DeclarationName name = &m_context.Idents.get("visit_edges");
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auto const* visit_edges_method = record->lookup(name).find_first<clang::CXXMethodDecl>();
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if (visit_edges_method && visit_edges_method->getBody()) {
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// Verify that all GC pointer fields are visited
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if (!fields_that_need_visiting.empty() || !substruct_fields_that_need_visiting.empty()) {
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MatchFinder field_access_finder;
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SimpleCollectMatchesCallback<clang::MemberExpr> field_access_callback("member-expr");
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auto field_access_matcher = memberExpr(
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hasAncestor(cxxMethodDecl(hasName("visit_edges"))),
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hasObjectExpression(hasType(pointsTo(cxxRecordDecl(hasName(record->getName()))))))
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.bind("member-expr");
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field_access_finder.addMatcher(field_access_matcher, &field_access_callback);
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field_access_finder.matchAST(visit_edges_method->getASTContext());
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std::unordered_set<std::string> fields_that_are_visited;
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for (auto const* member_expr : field_access_callback.matches())
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fields_that_are_visited.insert(member_expr->getMemberNameInfo().getAsString());
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auto gc_member_diag_id = diag_engine.getCustomDiagID(clang::DiagnosticsEngine::Error,
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"GC-allocated member is not visited in %0::visit_edges");
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for (auto const* field : fields_that_need_visiting) {
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if (!fields_that_are_visited.contains(field->getNameAsString())) {
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auto builder = diag_engine.Report(field->getBeginLoc(), gc_member_diag_id);
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builder << record->getName();
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}
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}
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auto substruct_diag_id = diag_engine.getCustomDiagID(clang::DiagnosticsEngine::Error,
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"Member %0 contains GC pointers but is not visited in %1::visit_edges");
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for (auto const* field : substruct_fields_that_need_visiting) {
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if (!fields_that_are_visited.contains(field->getNameAsString())) {
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auto builder = diag_engine.Report(field->getBeginLoc(), substruct_diag_id);
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|
builder << field->getName() << record->getName();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
validate_record_macros(*record);
|
|
|
|
// Check that overrides of must_survive_garbage_collection() and finalize() have the
|
|
// corresponding static constexpr bool flags set
|
|
auto check_override_requires_flag = [&](char const* method_name, char const* flag_name) {
|
|
clang::DeclarationName decl_name = &m_context.Idents.get(method_name);
|
|
auto const* method = record->lookup(decl_name).find_first<clang::CXXMethodDecl>();
|
|
if (!method || !method->isVirtual() || !method->size_overridden_methods())
|
|
return;
|
|
|
|
// Check if the method is defined in this class (not just inherited)
|
|
if (method->getParent() != record)
|
|
return;
|
|
|
|
// Look for the static constexpr bool flag
|
|
clang::DeclarationName flag_decl_name = &m_context.Idents.get(flag_name);
|
|
auto const* flag_var = record->lookup(flag_decl_name).find_first<clang::VarDecl>();
|
|
|
|
bool flag_found = false;
|
|
if (flag_var && flag_var->isStaticDataMember() && flag_var->isConstexpr()) {
|
|
// Check if it's set to true
|
|
if (auto const* init = flag_var->getInit()) {
|
|
if (auto const* bool_literal = llvm::dyn_cast<clang::CXXBoolLiteralExpr>(init->IgnoreParenImpCasts())) {
|
|
flag_found = bool_literal->getValue();
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!flag_found) {
|
|
auto diag_id = diag_engine.getCustomDiagID(clang::DiagnosticsEngine::Error,
|
|
"Class %0 overrides %1 but does not set static constexpr bool %2 = true");
|
|
auto builder = diag_engine.Report(method->getBeginLoc(), diag_id);
|
|
builder << record->getName() << method_name << flag_name;
|
|
}
|
|
};
|
|
|
|
check_override_requires_flag("must_survive_garbage_collection", "OVERRIDES_MUST_SURVIVE_GARBAGE_COLLECTION");
|
|
check_override_requires_flag("finalize", "OVERRIDES_FINALIZE");
|
|
|
|
// Check that Cell subclasses (and all their base classes) don't have non-trivial destructors.
|
|
// They should override Cell::finalize() instead.
|
|
auto check_no_nontrivial_destructor = [&](clang::CXXRecordDecl const* check_record) {
|
|
if (!check_record || !check_record->isCompleteDefinition())
|
|
return;
|
|
if (check_record->getQualifiedNameAsString() == "GC::Cell")
|
|
return;
|
|
auto const* destructor = check_record->getDestructor();
|
|
if (!destructor || !destructor->isUserProvided())
|
|
return;
|
|
// Only flag destructors whose body we can see, that aren't defaulted,
|
|
// and that have a non-empty body. This way, out-of-line `= default` destructors
|
|
// and empty-body destructors `~Foo() {}` are fine.
|
|
if (!destructor->getBody() || destructor->isDefaulted())
|
|
return;
|
|
if (auto const* body = llvm::dyn_cast<clang::CompoundStmt>(destructor->getBody())) {
|
|
if (body->body_empty())
|
|
return;
|
|
}
|
|
if (decl_has_annotation(destructor, "ladybird::allow_cell_destructor"))
|
|
return;
|
|
auto diag_id = diag_engine.getCustomDiagID(clang::DiagnosticsEngine::Error,
|
|
"GC::Cell-inheriting class %0 has a non-trivial destructor; override Cell::finalize() instead (and set OVERRIDES_FINALIZE)");
|
|
auto builder = diag_engine.Report(destructor->getBeginLoc(), diag_id);
|
|
builder << check_record->getName();
|
|
};
|
|
|
|
check_no_nontrivial_destructor(record);
|
|
record->forallBases([&](clang::CXXRecordDecl const* base) -> bool {
|
|
if (base->getQualifiedNameAsString() == "GC::Cell")
|
|
return false;
|
|
// Only check bases that are themselves part of the Cell hierarchy.
|
|
// Non-Cell mixins (e.g. Weakable) are not our concern here.
|
|
if (!record_inherits_from_cell(*base))
|
|
return true;
|
|
check_no_nontrivial_destructor(base);
|
|
return true;
|
|
});
|
|
|
|
clang::DeclarationName name = &m_context.Idents.get("visit_edges");
|
|
auto const* visit_edges_method = record->lookup(name).find_first<clang::CXXMethodDecl>();
|
|
if (!visit_edges_method && !fields_that_need_visiting.empty()) {
|
|
auto diag_id = diag_engine.getCustomDiagID(clang::DiagnosticsEngine::Error, "GC::Cell-inheriting class %0 contains a GC-allocated member %1 but has no visit_edges method");
|
|
auto builder = diag_engine.Report(record->getLocation(), diag_id);
|
|
builder << record->getName()
|
|
<< fields_that_need_visiting[0];
|
|
}
|
|
if (!visit_edges_method && !substruct_fields_that_need_visiting.empty()) {
|
|
auto diag_id = diag_engine.getCustomDiagID(clang::DiagnosticsEngine::Error, "GC::Cell-inheriting class %0 contains a member %1 that has GC pointers but has no visit_edges method");
|
|
auto builder = diag_engine.Report(record->getLocation(), diag_id);
|
|
builder << record->getName()
|
|
<< substruct_fields_that_need_visiting[0];
|
|
}
|
|
if (!visit_edges_method || !visit_edges_method->getBody())
|
|
return true;
|
|
|
|
// NOTE: The check for calling Base::visit_edges() is now handled by the general
|
|
// must_upcall attribute check in VisitCXXMethodDecl, since Cell::visit_edges()
|
|
// is annotated with MUST_UPCALL.
|
|
|
|
// Search for uses of all fields that need visiting. We don't ensure they are _actually_ visited
|
|
// with a call to visitor.visit(...), as that is too complex. Instead, we just assume that if the
|
|
// field is accessed at all, then it is visited.
|
|
|
|
if (fields_that_need_visiting.empty() && substruct_fields_that_need_visiting.empty())
|
|
return true;
|
|
|
|
MatchFinder field_access_finder;
|
|
SimpleCollectMatchesCallback<clang::MemberExpr> field_access_callback("member-expr");
|
|
|
|
auto field_access_matcher = memberExpr(
|
|
hasAncestor(cxxMethodDecl(hasName("visit_edges"))),
|
|
hasObjectExpression(hasType(pointsTo(cxxRecordDecl(hasName(record->getName()))))))
|
|
.bind("member-expr");
|
|
|
|
field_access_finder.addMatcher(field_access_matcher, &field_access_callback);
|
|
field_access_finder.matchAST(visit_edges_method->getASTContext());
|
|
|
|
std::unordered_set<std::string> fields_that_are_visited;
|
|
for (auto const* member_expr : field_access_callback.matches())
|
|
fields_that_are_visited.insert(member_expr->getMemberNameInfo().getAsString());
|
|
|
|
auto gc_member_diag_id = diag_engine.getCustomDiagID(clang::DiagnosticsEngine::Error, "GC-allocated member is not visited in %0::visit_edges");
|
|
|
|
for (auto const* field : fields_that_need_visiting) {
|
|
if (!fields_that_are_visited.contains(field->getNameAsString())) {
|
|
auto builder = diag_engine.Report(field->getBeginLoc(), gc_member_diag_id);
|
|
builder << record->getName();
|
|
}
|
|
}
|
|
|
|
auto substruct_not_visited_diag_id = diag_engine.getCustomDiagID(clang::DiagnosticsEngine::Error,
|
|
"Member %0 contains GC pointers but is not visited in %1::visit_edges");
|
|
auto substruct_needs_visit_edges_diag_id = diag_engine.getCustomDiagID(clang::DiagnosticsEngine::Error,
|
|
"Member %0 contains GC pointers but its type has no visit_edges method");
|
|
|
|
for (auto const* field : substruct_fields_that_need_visiting) {
|
|
if (!fields_that_are_visited.contains(field->getNameAsString())) {
|
|
// Check if the substruct type has a visit_edges method
|
|
auto field_type = field->getType();
|
|
if (auto const* elaborated = llvm::dyn_cast<clang::ElaboratedType>(field_type.getTypePtr()))
|
|
field_type = elaborated->desugar();
|
|
|
|
// For smart pointer types (OwnPtr, RefPtr, etc.), check the pointed-to type
|
|
clang::CXXRecordDecl const* type_to_check = nullptr;
|
|
if (auto const* specialization = field_type->getAs<clang::TemplateSpecializationType>()) {
|
|
auto template_name = specialization->getTemplateName().getAsTemplateDecl()->getQualifiedNameAsString();
|
|
static std::set<std::string> smart_pointer_types {
|
|
"OwnPtr", "NonnullOwnPtr", "RefPtr", "NonnullRefPtr",
|
|
"ValueComparingRefPtr", "ValueComparingNonnullRefPtr",
|
|
"AK::OwnPtr", "AK::NonnullOwnPtr", "AK::RefPtr", "AK::NonnullRefPtr",
|
|
"Web::CSS::ValueComparingRefPtr", "Web::CSS::ValueComparingNonnullRefPtr"
|
|
};
|
|
if (smart_pointer_types.contains(template_name)) {
|
|
auto const& args = specialization->template_arguments();
|
|
if (args.size() >= 1 && args[0].getKind() == clang::TemplateArgument::Type) {
|
|
type_to_check = args[0].getAsType()->getAsCXXRecordDecl();
|
|
}
|
|
}
|
|
}
|
|
if (!type_to_check)
|
|
type_to_check = field_type->getAsCXXRecordDecl();
|
|
|
|
if (type_to_check && !type_has_visit_edges_method(type_to_check)) {
|
|
auto builder = diag_engine.Report(field->getBeginLoc(), substruct_needs_visit_edges_diag_id);
|
|
builder << field->getName();
|
|
} else {
|
|
auto builder = diag_engine.Report(field->getBeginLoc(), substruct_not_visited_diag_id);
|
|
builder << field->getName() << record->getName();
|
|
}
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
// Check if a method (or any method it overrides) has the must_upcall annotation
|
|
static bool method_requires_upcall(clang::CXXMethodDecl const* method)
|
|
{
|
|
if (!method)
|
|
return false;
|
|
|
|
if (decl_has_annotation(method, "must_upcall"))
|
|
return true;
|
|
|
|
// Check overridden methods recursively
|
|
for (auto const* overridden : method->overridden_methods()) {
|
|
if (method_requires_upcall(overridden))
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
// Get the immediate parent class's method that this method overrides
|
|
static clang::CXXMethodDecl const* get_immediate_base_method(clang::CXXMethodDecl const* method)
|
|
{
|
|
if (!method->isVirtual() || method->overridden_methods().empty())
|
|
return nullptr;
|
|
|
|
// The overridden_methods() returns the immediate parent(s) that this method overrides
|
|
// For single inheritance, there's just one
|
|
for (auto const* overridden : method->overridden_methods())
|
|
return overridden;
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
bool LibJSGCVisitor::VisitCXXMethodDecl(clang::CXXMethodDecl* method)
|
|
{
|
|
if (!method || !method->isVirtual() || !method->doesThisDeclarationHaveABody())
|
|
return true;
|
|
|
|
// Skip if this method is not an override
|
|
if (!method->size_overridden_methods())
|
|
return true;
|
|
|
|
// Check if any method in the override chain has must_upcall annotation
|
|
if (!method_requires_upcall(method))
|
|
return true;
|
|
|
|
auto const* base_method = get_immediate_base_method(method);
|
|
if (!base_method)
|
|
return true;
|
|
|
|
auto const* parent_class = base_method->getParent();
|
|
if (!parent_class)
|
|
return true;
|
|
|
|
auto method_name = method->getNameAsString();
|
|
|
|
// Search for a call to Base::method_name or ParentClass::method_name
|
|
using namespace clang::ast_matchers;
|
|
|
|
MatchFinder upcall_finder;
|
|
SimpleCollectMatchesCallback<clang::MemberExpr> upcall_callback("member-call");
|
|
|
|
auto upcall_matcher = cxxMethodDecl(
|
|
equalsNode(method),
|
|
hasDescendant(memberExpr(member(hasName(method_name))).bind("member-call")));
|
|
|
|
upcall_finder.addMatcher(upcall_matcher, &upcall_callback);
|
|
upcall_finder.matchAST(m_context);
|
|
|
|
bool upcall_found = false;
|
|
|
|
for (auto const* member_expr : upcall_callback.matches()) {
|
|
// Check if this is a qualified call (e.g., Base::method or ParentClass::method)
|
|
if (!member_expr->hasQualifier())
|
|
continue;
|
|
|
|
// Get the record decl that the qualifier refers to
|
|
auto const* qualifier = member_expr->getQualifier();
|
|
if (!qualifier)
|
|
continue;
|
|
|
|
auto const* qualifier_type = qualifier->getAsType();
|
|
if (!qualifier_type)
|
|
continue;
|
|
|
|
auto const* qualifier_record = qualifier_type->getAsCXXRecordDecl();
|
|
if (!qualifier_record)
|
|
continue;
|
|
|
|
// Check if the qualifier refers to a base class of the current class
|
|
auto const* current_class = method->getParent();
|
|
if (!current_class)
|
|
continue;
|
|
|
|
// The qualifier should be the same as or a base of the parent class
|
|
if (qualifier_record == parent_class || current_class->isDerivedFrom(qualifier_record)) {
|
|
upcall_found = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!upcall_found) {
|
|
auto& diag_engine = m_context.getDiagnostics();
|
|
auto diag_id = diag_engine.getCustomDiagID(clang::DiagnosticsEngine::Error,
|
|
"Missing call to Base::%0 (required by must_upcall attribute)");
|
|
auto builder = diag_engine.Report(method->getBeginLoc(), diag_id);
|
|
builder << method_name;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
struct CellTypeWithOrigin {
|
|
clang::CXXRecordDecl const& base_origin;
|
|
LibJSCellMacro::Type type;
|
|
};
|
|
|
|
static std::optional<CellTypeWithOrigin> find_cell_type_with_origin(clang::CXXRecordDecl const& record)
|
|
{
|
|
for (auto const& base : record.bases()) {
|
|
if (auto const* base_record = base.getType()->getAsCXXRecordDecl()) {
|
|
auto base_name = base_record->getQualifiedNameAsString();
|
|
|
|
if (base_name == "GC::Cell")
|
|
return CellTypeWithOrigin { *base_record, LibJSCellMacro::Type::GCCell };
|
|
|
|
if (base_name == "JS::Object")
|
|
return CellTypeWithOrigin { *base_record, LibJSCellMacro::Type::JSObject };
|
|
|
|
if (base_name == "JS::Environment")
|
|
return CellTypeWithOrigin { *base_record, LibJSCellMacro::Type::JSEnvironment };
|
|
|
|
if (base_name == "JS::PrototypeObject")
|
|
return CellTypeWithOrigin { *base_record, LibJSCellMacro::Type::JSPrototypeObject };
|
|
|
|
if (base_name == "Web::Bindings::PlatformObject")
|
|
return CellTypeWithOrigin { *base_record, LibJSCellMacro::Type::WebPlatformObject };
|
|
|
|
if (auto origin = find_cell_type_with_origin(*base_record))
|
|
return CellTypeWithOrigin { *base_record, origin->type };
|
|
}
|
|
}
|
|
|
|
return {};
|
|
}
|
|
|
|
LibJSGCVisitor::CellMacroExpectation LibJSGCVisitor::get_record_cell_macro_expectation(clang::CXXRecordDecl const& record)
|
|
{
|
|
auto origin = find_cell_type_with_origin(record);
|
|
assert(origin.has_value());
|
|
|
|
// Need to iterate the bases again to turn the record into the exact text that the user used as
|
|
// the class base, since it doesn't have to be qualified (but might be).
|
|
for (auto const& base : record.bases()) {
|
|
if (auto const* base_record = base.getType()->getAsCXXRecordDecl()) {
|
|
if (base_record == &origin->base_origin) {
|
|
auto& source_manager = m_context.getSourceManager();
|
|
auto char_range = source_manager.getExpansionRange({ base.getBaseTypeLoc(), base.getEndLoc() });
|
|
auto exact_text = clang::Lexer::getSourceText(char_range, source_manager, m_context.getLangOpts());
|
|
return { origin->type, exact_text.str() };
|
|
}
|
|
}
|
|
}
|
|
|
|
assert(false);
|
|
__builtin_unreachable();
|
|
}
|
|
|
|
void LibJSGCVisitor::validate_record_macros(clang::CXXRecordDecl const& record)
|
|
{
|
|
auto& source_manager = m_context.getSourceManager();
|
|
auto record_range = record.getSourceRange();
|
|
|
|
// FIXME: The current macro detection doesn't recursively search through macro expansion,
|
|
// so if the record itself is defined in a macro, the GC_CELL/etc won't be found
|
|
if (source_manager.isMacroBodyExpansion(record_range.getBegin()))
|
|
return;
|
|
|
|
auto [expected_cell_macro_type, expected_base_name] = get_record_cell_macro_expectation(record);
|
|
auto file_id = m_context.getSourceManager().getFileID(record.getLocation());
|
|
auto it = m_macro_map.find(file_id.getHashValue());
|
|
auto& diag_engine = m_context.getDiagnostics();
|
|
|
|
auto report_missing_macro = [&] {
|
|
auto diag_id = diag_engine.getCustomDiagID(clang::DiagnosticsEngine::Error, "Expected record to have a %0 macro invocation");
|
|
auto builder = diag_engine.Report(record.getLocation(), diag_id);
|
|
builder << LibJSCellMacro::type_name(expected_cell_macro_type);
|
|
};
|
|
|
|
if (it == m_macro_map.end()) {
|
|
report_missing_macro();
|
|
return;
|
|
}
|
|
|
|
std::vector<clang::SourceRange> sub_ranges;
|
|
for (auto const& sub_decl : record.decls()) {
|
|
if (auto const* sub_record = llvm::dyn_cast<clang::CXXRecordDecl>(sub_decl))
|
|
sub_ranges.push_back(sub_record->getSourceRange());
|
|
}
|
|
|
|
bool found_macro = false;
|
|
|
|
auto record_name = record.getDeclName().getAsString();
|
|
if (record.getQualifier()) {
|
|
// FIXME: There has to be a better way to get this info. getQualifiedNameAsString() gets too much info
|
|
// (outer namespaces that aren't part of the class identifier), and getNameAsString() doesn't get
|
|
// enough info (doesn't include parts before the namespace specifier).
|
|
auto loc = record.getQualifierLoc();
|
|
auto& sm = m_context.getSourceManager();
|
|
auto begin_offset = sm.getFileOffset(loc.getBeginLoc());
|
|
auto end_offset = sm.getFileOffset(loc.getEndLoc());
|
|
auto const* file_buf = sm.getCharacterData(loc.getBeginLoc());
|
|
auto prefix = std::string { file_buf, end_offset - begin_offset };
|
|
record_name = prefix + "::" + record_name;
|
|
}
|
|
|
|
for (auto const& macro : it->second) {
|
|
if (record_range.fullyContains(macro.range)) {
|
|
bool macro_is_in_sub_decl = false;
|
|
for (auto const& sub_range : sub_ranges) {
|
|
if (sub_range.fullyContains(macro.range)) {
|
|
macro_is_in_sub_decl = true;
|
|
break;
|
|
}
|
|
}
|
|
if (macro_is_in_sub_decl)
|
|
continue;
|
|
|
|
if (found_macro) {
|
|
auto diag_id = diag_engine.getCustomDiagID(clang::DiagnosticsEngine::Error, "Record has multiple GC_CELL-like macro invocations");
|
|
diag_engine.Report(record_range.getBegin(), diag_id);
|
|
}
|
|
|
|
found_macro = true;
|
|
if (macro.type != expected_cell_macro_type) {
|
|
auto diag_id = diag_engine.getCustomDiagID(clang::DiagnosticsEngine::Error, "Invalid GC-CELL-like macro invocation; expected %0");
|
|
auto builder = diag_engine.Report(macro.range.getBegin(), diag_id);
|
|
builder << LibJSCellMacro::type_name(expected_cell_macro_type);
|
|
}
|
|
|
|
// This is a compile error, no diagnostic needed
|
|
if (macro.args.size() < 2)
|
|
return;
|
|
|
|
// NOTE: DOMURL is a special case since the C++ class is named differently than the IDL.
|
|
if (macro.args[0].text != record_name && record_name != "DOMURL") {
|
|
auto diag_id = diag_engine.getCustomDiagID(clang::DiagnosticsEngine::Error, "Expected first argument of %0 macro invocation to be %1");
|
|
auto builder = diag_engine.Report(macro.args[0].location, diag_id);
|
|
builder << LibJSCellMacro::type_name(expected_cell_macro_type) << record_name;
|
|
}
|
|
|
|
if (expected_cell_macro_type == LibJSCellMacro::Type::JSPrototypeObject) {
|
|
// FIXME: Validate the args for this macro
|
|
} else if (macro.args[1].text != expected_base_name) {
|
|
auto diag_id = diag_engine.getCustomDiagID(clang::DiagnosticsEngine::Error, "Expected second argument of %0 macro invocation to be %1");
|
|
auto builder = diag_engine.Report(macro.args[1].location, diag_id);
|
|
builder << LibJSCellMacro::type_name(expected_cell_macro_type) << expected_base_name;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!found_macro)
|
|
report_missing_macro();
|
|
}
|
|
|
|
LibJSGCASTConsumer::LibJSGCASTConsumer(clang::CompilerInstance& compiler, bool detect_invalid_function_members)
|
|
: m_compiler(compiler)
|
|
, m_detect_invalid_function_members(detect_invalid_function_members)
|
|
{
|
|
auto& preprocessor = compiler.getPreprocessor();
|
|
preprocessor.addPPCallbacks(std::make_unique<LibJSPPCallbacks>(preprocessor, m_macro_map));
|
|
}
|
|
|
|
void LibJSGCASTConsumer::HandleTranslationUnit(clang::ASTContext& context)
|
|
{
|
|
LibJSGCVisitor visitor { context, m_macro_map, m_detect_invalid_function_members };
|
|
visitor.TraverseDecl(context.getTranslationUnitDecl());
|
|
}
|
|
|
|
char const* LibJSCellMacro::type_name(Type type)
|
|
{
|
|
switch (type) {
|
|
case Type::GCCell:
|
|
return "GC_CELL";
|
|
case Type::JSObject:
|
|
return "JS_OBJECT";
|
|
case Type::JSEnvironment:
|
|
return "JS_ENVIRONMENT";
|
|
case Type::JSPrototypeObject:
|
|
return "JS_PROTOTYPE_OBJECT";
|
|
case Type::WebPlatformObject:
|
|
return "WEB_PLATFORM_OBJECT";
|
|
default:
|
|
__builtin_unreachable();
|
|
}
|
|
}
|
|
|
|
void LibJSPPCallbacks::LexedFileChanged(clang::FileID curr_fid, LexedFileChangeReason reason, clang::SrcMgr::CharacteristicKind, clang::FileID, clang::SourceLocation)
|
|
{
|
|
if (reason == LexedFileChangeReason::EnterFile) {
|
|
m_curr_fid_hash_stack.push_back(curr_fid.getHashValue());
|
|
} else {
|
|
assert(!m_curr_fid_hash_stack.empty());
|
|
m_curr_fid_hash_stack.pop_back();
|
|
}
|
|
}
|
|
|
|
void LibJSPPCallbacks::MacroExpands(clang::Token const& name_token, clang::MacroDefinition const&, clang::SourceRange range, clang::MacroArgs const* args)
|
|
{
|
|
if (auto* ident_info = name_token.getIdentifierInfo()) {
|
|
static llvm::StringMap<LibJSCellMacro::Type> libjs_macro_types {
|
|
{ "GC_CELL", LibJSCellMacro::Type::GCCell },
|
|
{ "JS_OBJECT", LibJSCellMacro::Type::JSObject },
|
|
{ "JS_ENVIRONMENT", LibJSCellMacro::Type::JSEnvironment },
|
|
{ "JS_PROTOTYPE_OBJECT", LibJSCellMacro::Type::JSPrototypeObject },
|
|
{ "WEB_PLATFORM_OBJECT", LibJSCellMacro::Type::WebPlatformObject },
|
|
{ "WEB_NON_IDL_PLATFORM_OBJECT", LibJSCellMacro::Type::WebPlatformObject },
|
|
};
|
|
|
|
auto name = ident_info->getName();
|
|
if (auto it = libjs_macro_types.find(name); it != libjs_macro_types.end()) {
|
|
LibJSCellMacro macro { range, it->second, {} };
|
|
|
|
for (size_t arg_index = 0; arg_index < args->getNumMacroArguments(); arg_index++) {
|
|
auto const* first_token = args->getUnexpArgument(arg_index);
|
|
auto stringified_token = clang::MacroArgs::StringifyArgument(first_token, m_preprocessor, false, range.getBegin(), range.getEnd());
|
|
// The token includes leading and trailing quotes
|
|
auto len = strlen(stringified_token.getLiteralData());
|
|
std::string arg_text { stringified_token.getLiteralData() + 1, len - 2 };
|
|
macro.args.push_back({ arg_text, first_token->getLocation() });
|
|
}
|
|
|
|
assert(!m_curr_fid_hash_stack.empty());
|
|
auto curr_fid_hash = m_curr_fid_hash_stack.back();
|
|
if (m_macro_map.find(curr_fid_hash) == m_macro_map.end())
|
|
m_macro_map[curr_fid_hash] = {};
|
|
m_macro_map[curr_fid_hash].push_back(macro);
|
|
}
|
|
}
|
|
}
|
|
|
|
static clang::FrontendPluginRegistry::Add<LibJSGCPluginAction> X("libjs_gc_scanner", "analyze LibJS GC usage");
|