llvm-project/clang-tools-extra/clangd/ParsedAST.cpp

531 lines
21 KiB
C++

//===--- ParsedAST.cpp -------------------------------------------*- C++-*-===//
//
// 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 "ParsedAST.h"
#include "../clang-tidy/ClangTidyDiagnosticConsumer.h"
#include "../clang-tidy/ClangTidyModuleRegistry.h"
#include "AST.h"
#include "Compiler.h"
#include "Diagnostics.h"
#include "Headers.h"
#include "IncludeFixer.h"
#include "Logger.h"
#include "SourceCode.h"
#include "Trace.h"
#include "index/CanonicalIncludes.h"
#include "index/Index.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TokenKinds.h"
#include "clang/Frontend/CompilerInstance.h"
#include "clang/Frontend/CompilerInvocation.h"
#include "clang/Frontend/FrontendActions.h"
#include "clang/Frontend/Utils.h"
#include "clang/Index/IndexDataConsumer.h"
#include "clang/Index/IndexingAction.h"
#include "clang/Lex/Lexer.h"
#include "clang/Lex/MacroInfo.h"
#include "clang/Lex/PPCallbacks.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Lex/PreprocessorOptions.h"
#include "clang/Sema/Sema.h"
#include "clang/Serialization/ASTWriter.h"
#include "clang/Serialization/PCHContainerOperations.h"
#include "clang/Tooling/CompilationDatabase.h"
#include "clang/Tooling/Syntax/Tokens.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <memory>
// Force the linker to link in Clang-tidy modules.
// clangd doesn't support the static analyzer.
#define CLANG_TIDY_DISABLE_STATIC_ANALYZER_CHECKS
#include "../clang-tidy/ClangTidyForceLinker.h"
namespace clang {
namespace clangd {
namespace {
template <class T> std::size_t getUsedBytes(const std::vector<T> &Vec) {
return Vec.capacity() * sizeof(T);
}
class DeclTrackingASTConsumer : public ASTConsumer {
public:
DeclTrackingASTConsumer(std::vector<Decl *> &TopLevelDecls)
: TopLevelDecls(TopLevelDecls) {}
bool HandleTopLevelDecl(DeclGroupRef DG) override {
for (Decl *D : DG) {
auto &SM = D->getASTContext().getSourceManager();
if (!isInsideMainFile(D->getLocation(), SM))
continue;
if (const NamedDecl *ND = dyn_cast<NamedDecl>(D))
if (isImplicitTemplateInstantiation(ND))
continue;
// ObjCMethodDecl are not actually top-level decls.
if (isa<ObjCMethodDecl>(D))
continue;
TopLevelDecls.push_back(D);
}
return true;
}
private:
std::vector<Decl *> &TopLevelDecls;
};
class ClangdFrontendAction : public SyntaxOnlyAction {
public:
std::vector<Decl *> takeTopLevelDecls() { return std::move(TopLevelDecls); }
protected:
std::unique_ptr<ASTConsumer>
CreateASTConsumer(CompilerInstance &CI, llvm::StringRef InFile) override {
return std::make_unique<DeclTrackingASTConsumer>(/*ref*/ TopLevelDecls);
}
private:
std::vector<Decl *> TopLevelDecls;
};
// When using a preamble, only preprocessor events outside its bounds are seen.
// This is almost what we want: replaying transitive preprocessing wastes time.
// However this confuses clang-tidy checks: they don't see any #includes!
// So we replay the *non-transitive* #includes that appear in the main-file.
// It would be nice to replay other events (macro definitions, ifdefs etc) but
// this addresses the most common cases fairly cheaply.
class ReplayPreamble : private PPCallbacks {
public:
// Attach preprocessor hooks such that preamble events will be injected at
// the appropriate time.
// Events will be delivered to the *currently registered* PP callbacks.
static void attach(const IncludeStructure &Includes,
CompilerInstance &Clang) {
auto &PP = Clang.getPreprocessor();
auto *ExistingCallbacks = PP.getPPCallbacks();
// No need to replay events if nobody is listening.
if (!ExistingCallbacks)
return;
PP.addPPCallbacks(std::unique_ptr<PPCallbacks>(
new ReplayPreamble(Includes, ExistingCallbacks,
Clang.getSourceManager(), PP, Clang.getLangOpts())));
// We're relying on the fact that addPPCallbacks keeps the old PPCallbacks
// around, creating a chaining wrapper. Guard against other implementations.
assert(PP.getPPCallbacks() != ExistingCallbacks &&
"Expected chaining implementation");
}
private:
ReplayPreamble(const IncludeStructure &Includes, PPCallbacks *Delegate,
const SourceManager &SM, Preprocessor &PP,
const LangOptions &LangOpts)
: Includes(Includes), Delegate(Delegate), SM(SM), PP(PP),
LangOpts(LangOpts) {}
// In a normal compile, the preamble traverses the following structure:
//
// mainfile.cpp
// <built-in>
// ... macro definitions like __cplusplus ...
// <command-line>
// ... macro definitions for args like -Dfoo=bar ...
// "header1.h"
// ... header file contents ...
// "header2.h"
// ... header file contents ...
// ... main file contents ...
//
// When using a preamble, the "header1" and "header2" subtrees get skipped.
// We insert them right after the built-in header, which still appears.
void FileChanged(SourceLocation Loc, FileChangeReason Reason,
SrcMgr::CharacteristicKind Kind, FileID PrevFID) override {
// It'd be nice if there was a better way to identify built-in headers...
if (Reason == FileChangeReason::ExitFile &&
SM.getBuffer(PrevFID)->getBufferIdentifier() == "<built-in>")
replay();
}
void replay() {
for (const auto &Inc : Includes.MainFileIncludes) {
const FileEntry *File = nullptr;
if (Inc.Resolved != "")
if (auto FE = SM.getFileManager().getFile(Inc.Resolved))
File = *FE;
llvm::StringRef WrittenFilename =
llvm::StringRef(Inc.Written).drop_front().drop_back();
bool Angled = llvm::StringRef(Inc.Written).startswith("<");
// Re-lex the #include directive to find its interesting parts.
llvm::StringRef Src = SM.getBufferData(SM.getMainFileID());
Lexer RawLexer(SM.getLocForStartOfFile(SM.getMainFileID()), LangOpts,
Src.begin(), Src.begin() + Inc.HashOffset, Src.end());
Token HashTok, IncludeTok, FilenameTok;
RawLexer.LexFromRawLexer(HashTok);
assert(HashTok.getKind() == tok::hash);
RawLexer.setParsingPreprocessorDirective(true);
RawLexer.LexFromRawLexer(IncludeTok);
IdentifierInfo *II = PP.getIdentifierInfo(IncludeTok.getRawIdentifier());
IncludeTok.setIdentifierInfo(II);
IncludeTok.setKind(II->getTokenID());
RawLexer.LexIncludeFilename(FilenameTok);
Delegate->InclusionDirective(
HashTok.getLocation(), IncludeTok, WrittenFilename, Angled,
CharSourceRange::getCharRange(FilenameTok.getLocation(),
FilenameTok.getEndLoc()),
File, "SearchPath", "RelPath", /*Imported=*/nullptr, Inc.FileKind);
if (File)
// FIXME: Use correctly named FileEntryRef.
Delegate->FileSkipped(FileEntryRef(File->getName(), *File), FilenameTok,
Inc.FileKind);
else {
llvm::SmallString<1> UnusedRecovery;
Delegate->FileNotFound(WrittenFilename, UnusedRecovery);
}
}
}
const IncludeStructure &Includes;
PPCallbacks *Delegate;
const SourceManager &SM;
Preprocessor &PP;
const LangOptions &LangOpts;
};
} // namespace
void dumpAST(ParsedAST &AST, llvm::raw_ostream &OS) {
AST.getASTContext().getTranslationUnitDecl()->dump(OS, true);
}
llvm::Optional<ParsedAST>
ParsedAST::build(std::unique_ptr<clang::CompilerInvocation> CI,
llvm::ArrayRef<Diag> CompilerInvocationDiags,
std::shared_ptr<const PreambleData> Preamble,
std::unique_ptr<llvm::MemoryBuffer> Buffer,
llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,
const SymbolIndex *Index, const ParseOptions &Opts) {
assert(CI);
// Command-line parsing sets DisableFree to true by default, but we don't want
// to leak memory in clangd.
CI->getFrontendOpts().DisableFree = false;
const PrecompiledPreamble *PreamblePCH =
Preamble ? &Preamble->Preamble : nullptr;
StoreDiags ASTDiags;
std::string Content = std::string(Buffer->getBuffer());
std::string Filename =
std::string(Buffer->getBufferIdentifier()); // Absolute.
auto Clang = prepareCompilerInstance(std::move(CI), PreamblePCH,
std::move(Buffer), VFS, ASTDiags);
if (!Clang)
return None;
auto Action = std::make_unique<ClangdFrontendAction>();
const FrontendInputFile &MainInput = Clang->getFrontendOpts().Inputs[0];
if (!Action->BeginSourceFile(*Clang, MainInput)) {
log("BeginSourceFile() failed when building AST for {0}",
MainInput.getFile());
return None;
}
// Set up ClangTidy. Must happen after BeginSourceFile() so ASTContext exists.
// Clang-tidy has some limitiations to ensure reasonable performance:
// - checks don't see all preprocessor events in the preamble
// - matchers run only over the main-file top-level decls (and can't see
// ancestors outside this scope).
// In practice almost all checks work well without modifications.
std::vector<std::unique_ptr<tidy::ClangTidyCheck>> CTChecks;
ast_matchers::MatchFinder CTFinder;
llvm::Optional<tidy::ClangTidyContext> CTContext;
{
trace::Span Tracer("ClangTidyInit");
dlog("ClangTidy configuration for file {0}: {1}", Filename,
tidy::configurationAsText(Opts.ClangTidyOpts));
tidy::ClangTidyCheckFactories CTFactories;
for (const auto &E : tidy::ClangTidyModuleRegistry::entries())
E.instantiate()->addCheckFactories(CTFactories);
CTContext.emplace(std::make_unique<tidy::DefaultOptionsProvider>(
tidy::ClangTidyGlobalOptions(), Opts.ClangTidyOpts));
CTContext->setDiagnosticsEngine(&Clang->getDiagnostics());
CTContext->setASTContext(&Clang->getASTContext());
CTContext->setCurrentFile(Filename);
CTChecks = CTFactories.createChecks(CTContext.getPointer());
ASTDiags.setLevelAdjuster([&CTContext](DiagnosticsEngine::Level DiagLevel,
const clang::Diagnostic &Info) {
if (CTContext) {
std::string CheckName = CTContext->getCheckName(Info.getID());
bool IsClangTidyDiag = !CheckName.empty();
if (IsClangTidyDiag) {
// Check for warning-as-error.
// We deliberately let this take precedence over suppression comments
// to match clang-tidy's behaviour.
if (DiagLevel == DiagnosticsEngine::Warning &&
CTContext->treatAsError(CheckName)) {
return DiagnosticsEngine::Error;
}
// Check for suppression comment. Skip the check for diagnostics not
// in the main file, because we don't want that function to query the
// source buffer for preamble files. For the same reason, we ask
// shouldSuppressDiagnostic not to follow macro expansions, since
// those might take us into a preamble file as well.
bool IsInsideMainFile =
Info.hasSourceManager() &&
isInsideMainFile(Info.getLocation(), Info.getSourceManager());
if (IsInsideMainFile && tidy::shouldSuppressDiagnostic(
DiagLevel, Info, *CTContext,
/* CheckMacroExpansion = */ false)) {
return DiagnosticsEngine::Ignored;
}
}
}
return DiagLevel;
});
Preprocessor *PP = &Clang->getPreprocessor();
for (const auto &Check : CTChecks) {
// FIXME: the PP callbacks skip the entire preamble.
// Checks that want to see #includes in the main file do not see them.
Check->registerPPCallbacks(Clang->getSourceManager(), PP, PP);
Check->registerMatchers(&CTFinder);
}
}
// Add IncludeFixer which can recover diagnostics caused by missing includes
// (e.g. incomplete type) and attach include insertion fixes to diagnostics.
llvm::Optional<IncludeFixer> FixIncludes;
auto BuildDir = VFS->getCurrentWorkingDirectory();
if (Opts.SuggestMissingIncludes && Index && !BuildDir.getError()) {
auto Style = getFormatStyleForFile(Filename, Content, VFS.get());
auto Inserter = std::make_shared<IncludeInserter>(
Filename, Content, Style, BuildDir.get(),
&Clang->getPreprocessor().getHeaderSearchInfo());
if (Preamble) {
for (const auto &Inc : Preamble->Includes.MainFileIncludes)
Inserter->addExisting(Inc);
}
FixIncludes.emplace(Filename, Inserter, *Index,
/*IndexRequestLimit=*/5);
ASTDiags.contributeFixes([&FixIncludes](DiagnosticsEngine::Level DiagLevl,
const clang::Diagnostic &Info) {
return FixIncludes->fix(DiagLevl, Info);
});
Clang->setExternalSemaSource(FixIncludes->unresolvedNameRecorder());
}
// Copy over the includes from the preamble, then combine with the
// non-preamble includes below.
auto Includes = Preamble ? Preamble->Includes : IncludeStructure{};
// Replay the preamble includes so that clang-tidy checks can see them.
if (Preamble)
ReplayPreamble::attach(Includes, *Clang);
// Important: collectIncludeStructure is registered *after* ReplayPreamble!
// Otherwise we would collect the replayed includes again...
// (We can't *just* use the replayed includes, they don't have Resolved path).
Clang->getPreprocessor().addPPCallbacks(
collectIncludeStructureCallback(Clang->getSourceManager(), &Includes));
// Copy over the macros in the preamble region of the main file, and combine
// with non-preamble macros below.
MainFileMacros Macros;
if (Preamble)
Macros = Preamble->Macros;
Clang->getPreprocessor().addPPCallbacks(
std::make_unique<CollectMainFileMacros>(Clang->getSourceManager(),
Clang->getLangOpts(), Macros));
// Copy over the includes from the preamble, then combine with the
// non-preamble includes below.
CanonicalIncludes CanonIncludes;
if (Preamble)
CanonIncludes = Preamble->CanonIncludes;
else
CanonIncludes.addSystemHeadersMapping(Clang->getLangOpts());
std::unique_ptr<CommentHandler> IWYUHandler =
collectIWYUHeaderMaps(&CanonIncludes);
Clang->getPreprocessor().addCommentHandler(IWYUHandler.get());
// Collect tokens of the main file.
syntax::TokenCollector CollectTokens(Clang->getPreprocessor());
if (llvm::Error Err = Action->Execute())
log("Execute() failed when building AST for {0}: {1}", MainInput.getFile(),
toString(std::move(Err)));
// We have to consume the tokens before running clang-tidy to avoid collecting
// tokens from running the preprocessor inside the checks (only
// modernize-use-trailing-return-type does that today).
syntax::TokenBuffer Tokens = std::move(CollectTokens).consume();
std::vector<Decl *> ParsedDecls = Action->takeTopLevelDecls();
// AST traversals should exclude the preamble, to avoid performance cliffs.
Clang->getASTContext().setTraversalScope(ParsedDecls);
{
// Run the AST-dependent part of the clang-tidy checks.
// (The preprocessor part ran already, via PPCallbacks).
trace::Span Tracer("ClangTidyMatch");
CTFinder.matchAST(Clang->getASTContext());
}
// UnitDiagsConsumer is local, we can not store it in CompilerInstance that
// has a longer lifetime.
Clang->getDiagnostics().setClient(new IgnoreDiagnostics);
// CompilerInstance won't run this callback, do it directly.
ASTDiags.EndSourceFile();
// XXX: This is messy: clang-tidy checks flush some diagnostics at EOF.
// However Action->EndSourceFile() would destroy the ASTContext!
// So just inform the preprocessor of EOF, while keeping everything alive.
Clang->getPreprocessor().EndSourceFile();
std::vector<Diag> Diags = CompilerInvocationDiags;
// Add diagnostics from the preamble, if any.
if (Preamble)
Diags.insert(Diags.end(), Preamble->Diags.begin(), Preamble->Diags.end());
// Finally, add diagnostics coming from the AST.
{
std::vector<Diag> D = ASTDiags.take(CTContext.getPointer());
Diags.insert(Diags.end(), D.begin(), D.end());
}
return ParsedAST(std::move(Preamble), std::move(Clang), std::move(Action),
std::move(Tokens), std::move(Macros), std::move(ParsedDecls),
std::move(Diags), std::move(Includes),
std::move(CanonIncludes));
}
ParsedAST::ParsedAST(ParsedAST &&Other) = default;
ParsedAST &ParsedAST::operator=(ParsedAST &&Other) = default;
ParsedAST::~ParsedAST() {
if (Action) {
// We already notified the PP of end-of-file earlier, so detach it first.
// We must keep it alive until after EndSourceFile(), Sema relies on this.
auto PP = Clang->getPreprocessorPtr(); // Keep PP alive for now.
Clang->setPreprocessor(nullptr); // Detach so we don't send EOF again.
Action->EndSourceFile(); // Destroy ASTContext and Sema.
// Now Sema is gone, it's safe for PP to go out of scope.
}
}
ASTContext &ParsedAST::getASTContext() { return Clang->getASTContext(); }
const ASTContext &ParsedAST::getASTContext() const {
return Clang->getASTContext();
}
Preprocessor &ParsedAST::getPreprocessor() { return Clang->getPreprocessor(); }
std::shared_ptr<Preprocessor> ParsedAST::getPreprocessorPtr() {
return Clang->getPreprocessorPtr();
}
const Preprocessor &ParsedAST::getPreprocessor() const {
return Clang->getPreprocessor();
}
llvm::ArrayRef<Decl *> ParsedAST::getLocalTopLevelDecls() {
return LocalTopLevelDecls;
}
const MainFileMacros &ParsedAST::getMacros() const { return Macros; }
const std::vector<Diag> &ParsedAST::getDiagnostics() const { return Diags; }
std::size_t ParsedAST::getUsedBytes() const {
auto &AST = getASTContext();
// FIXME(ibiryukov): we do not account for the dynamically allocated part of
// Message and Fixes inside each diagnostic.
std::size_t Total =
clangd::getUsedBytes(LocalTopLevelDecls) + clangd::getUsedBytes(Diags);
// FIXME: the rest of the function is almost a direct copy-paste from
// libclang's clang_getCXTUResourceUsage. We could share the implementation.
// Sum up variaous allocators inside the ast context and the preprocessor.
Total += AST.getASTAllocatedMemory();
Total += AST.getSideTableAllocatedMemory();
Total += AST.Idents.getAllocator().getTotalMemory();
Total += AST.Selectors.getTotalMemory();
Total += AST.getSourceManager().getContentCacheSize();
Total += AST.getSourceManager().getDataStructureSizes();
Total += AST.getSourceManager().getMemoryBufferSizes().malloc_bytes;
if (ExternalASTSource *Ext = AST.getExternalSource())
Total += Ext->getMemoryBufferSizes().malloc_bytes;
const Preprocessor &PP = getPreprocessor();
Total += PP.getTotalMemory();
if (PreprocessingRecord *PRec = PP.getPreprocessingRecord())
Total += PRec->getTotalMemory();
Total += PP.getHeaderSearchInfo().getTotalMemory();
return Total;
}
const IncludeStructure &ParsedAST::getIncludeStructure() const {
return Includes;
}
const CanonicalIncludes &ParsedAST::getCanonicalIncludes() const {
return CanonIncludes;
}
ParsedAST::ParsedAST(std::shared_ptr<const PreambleData> Preamble,
std::unique_ptr<CompilerInstance> Clang,
std::unique_ptr<FrontendAction> Action,
syntax::TokenBuffer Tokens, MainFileMacros Macros,
std::vector<Decl *> LocalTopLevelDecls,
std::vector<Diag> Diags, IncludeStructure Includes,
CanonicalIncludes CanonIncludes)
: Preamble(std::move(Preamble)), Clang(std::move(Clang)),
Action(std::move(Action)), Tokens(std::move(Tokens)),
Macros(std::move(Macros)), Diags(std::move(Diags)),
LocalTopLevelDecls(std::move(LocalTopLevelDecls)),
Includes(std::move(Includes)), CanonIncludes(std::move(CanonIncludes)) {
assert(this->Clang);
assert(this->Action);
}
llvm::Optional<ParsedAST>
buildAST(PathRef FileName, std::unique_ptr<CompilerInvocation> Invocation,
llvm::ArrayRef<Diag> CompilerInvocationDiags,
const ParseInputs &Inputs,
std::shared_ptr<const PreambleData> Preamble) {
trace::Span Tracer("BuildAST");
SPAN_ATTACH(Tracer, "File", FileName);
auto VFS = Inputs.FS;
if (Preamble && Preamble->StatCache)
VFS = Preamble->StatCache->getConsumingFS(std::move(VFS));
if (VFS->setCurrentWorkingDirectory(Inputs.CompileCommand.Directory)) {
log("Couldn't set working directory when building the preamble.");
// We proceed anyway, our lit-tests rely on results for non-existing working
// dirs.
}
return ParsedAST::build(
std::make_unique<CompilerInvocation>(*Invocation),
CompilerInvocationDiags, Preamble,
llvm::MemoryBuffer::getMemBufferCopy(Inputs.Contents, FileName),
std::move(VFS), Inputs.Index, Inputs.Opts);
}
} // namespace clangd
} // namespace clang