Query.cpp

//===---- Query.cpp - clang-query query -----------------------------------===//
//
// 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 "Query.h"
#include "QueryParser.h"
#include "QuerySession.h"
#include "clang/AST/ASTDumper.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/Frontend/ASTUnit.h"
#include "clang/Frontend/TextDiagnostic.h"
#include "llvm/Support/raw_ostream.h"
#include <optional>

using namespace clang::ast_matchers;
using namespace clang::ast_matchers::dynamic;

namespace clang {
namespace query {

Query::~Query() {}

bool InvalidQuery::run(llvm::raw_ostream &OS, QuerySession &QS) const {
  OS << ErrStr << "\n";
  return false;
}

bool NoOpQuery::run(llvm::raw_ostream &OS, QuerySession &QS) const {
  return true;
}

bool HelpQuery::run(llvm::raw_ostream &OS, QuerySession &QS) const {
  OS << "Available commands:\n\n"
        "  match MATCHER, m MATCHER          "
        "Match the loaded ASTs against the given matcher.\n"
        "  let NAME MATCHER, l NAME MATCHER  "
        "Give a matcher expression a name, to be used later\n"
        "                                    "
        "as part of other expressions.\n"
        "  set bind-root (true|false)        "
        "Set whether to bind the root matcher to \"root\".\n"
        "  set print-matcher (true|false)    "
        "Set whether to print the current matcher.\n"
        "  set enable-profile (true|false)   "
        "Set whether to enable matcher profiling.\n"
        "  set traversal <kind>              "
        "Set traversal kind of clang-query session. Available kinds are:\n"
        "    AsIs                            "
        "Print and match the AST as clang sees it.  This mode is the "
        "default.\n"
        "    IgnoreUnlessSpelledInSource     "
        "Omit AST nodes unless spelled in the source.\n"
        "  set output <feature>              "
        "Set whether to output only <feature> content.\n"
        "  enable output <feature>           "
        "Enable <feature> content non-exclusively.\n"
        "  disable output <feature>          "
        "Disable <feature> content non-exclusively.\n"
        "  quit, q                           "
        "Terminates the query session.\n\n"
        "Several commands accept a <feature> parameter. The available features "
        "are:\n\n"
        "  print                             "
        "Pretty-print bound nodes.\n"
        "  diag                              "
        "Diagnostic location for bound nodes.\n"
        "  detailed-ast                      "
        "Detailed AST output for bound nodes.\n"
        "  dump                              "
        "Detailed AST output for bound nodes (alias of detailed-ast).\n\n";
  return true;
}

bool QuitQuery::run(llvm::raw_ostream &OS, QuerySession &QS) const {
  QS.Terminate = true;
  return true;
}

namespace {

struct CollectBoundNodes : MatchFinder::MatchCallback {
  std::vector<BoundNodes> &Bindings;
  StringRef Unit;
  CollectBoundNodes(std::vector<BoundNodes> &Bindings, StringRef Unit)
      : Bindings(Bindings), Unit(Unit) {}
  void run(const MatchFinder::MatchResult &Result) override {
    Bindings.push_back(Result.Nodes);
  }
  StringRef getID() const override { return Unit; }
};

struct QueryProfiler {
  llvm::StringMap<llvm::TimeRecord> Records;

  ~QueryProfiler() {
    llvm::TimerGroup TG("clang-query", "clang-query matcher profiling",
                        Records);
    TG.print(llvm::errs());
    llvm::errs().flush();
  }
};

} // namespace

bool MatchQuery::run(llvm::raw_ostream &OS, QuerySession &QS) const {
  unsigned MatchCount = 0;

  std::optional<QueryProfiler> Profiler;
  if (QS.EnableProfile)
    Profiler.emplace();

  for (auto &AST : QS.ASTs) {
    ast_matchers::MatchFinder::MatchFinderOptions FinderOptions;
    std::optional<llvm::StringMap<llvm::TimeRecord>> Records;
    if (QS.EnableProfile) {
      Records.emplace();
      FinderOptions.CheckProfiling.emplace(*Records);
    }

    MatchFinder Finder(FinderOptions);
    std::vector<BoundNodes> Matches;
    DynTypedMatcher MaybeBoundMatcher = Matcher;
    if (QS.BindRoot) {
      std::optional<DynTypedMatcher> M = Matcher.tryBind("root");
      if (M)
        MaybeBoundMatcher = *M;
    }
    StringRef OrigSrcName = AST->getOriginalSourceFileName();
    CollectBoundNodes Collect(Matches, OrigSrcName);
    if (!Finder.addDynamicMatcher(MaybeBoundMatcher, &Collect)) {
      OS << "Not a valid top-level matcher.\n";
      return false;
    }

    ASTContext &Ctx = AST->getASTContext();
    Ctx.getParentMapContext().setTraversalKind(QS.TK);
    Finder.matchAST(Ctx);
    if (QS.EnableProfile)
      Profiler->Records[OrigSrcName] += (*Records)[OrigSrcName];

    if (QS.PrintMatcher) {
      SmallVector<StringRef, 4> Lines;
      Source.split(Lines, "\n");
      auto FirstLine = Lines[0];
      Lines.erase(Lines.begin(), Lines.begin() + 1);
      while (!Lines.empty() && Lines.back().empty()) {
        Lines.resize(Lines.size() - 1);
      }
      unsigned MaxLength = FirstLine.size();
      std::string PrefixText = "Matcher: ";
      OS << "\n  " << PrefixText << FirstLine;

      for (auto Line : Lines) {
        OS << "\n" << std::string(PrefixText.size() + 2, ' ') << Line;
        MaxLength = std::max<int>(MaxLength, Line.rtrim().size());
      }

      OS << "\n"
         << "  " << std::string(PrefixText.size() + MaxLength, '=') << "\n\n";
    }

    for (auto MI = Matches.begin(), ME = Matches.end(); MI != ME; ++MI) {
      OS << "\nMatch #" << ++MatchCount << ":\n\n";

      for (auto BI = MI->getMap().begin(), BE = MI->getMap().end(); BI != BE;
           ++BI) {
        if (QS.DiagOutput) {
          clang::SourceRange R = BI->second.getSourceRange();
          if (R.isValid()) {
            TextDiagnostic TD(OS, AST->getASTContext().getLangOpts(),
                              &AST->getDiagnostics().getDiagnosticOptions());
            TD.emitDiagnostic(
                FullSourceLoc(R.getBegin(), AST->getSourceManager()),
                DiagnosticsEngine::Note, "\"" + BI->first + "\" binds here",
                CharSourceRange::getTokenRange(R), {});
          }
        }
        if (QS.PrintOutput) {
          OS << "Binding for \"" << BI->first << "\":\n";
          BI->second.print(OS, AST->getASTContext().getPrintingPolicy());
          OS << "\n";
        }
        if (QS.DetailedASTOutput) {
          OS << "Binding for \"" << BI->first << "\":\n";
          ASTDumper Dumper(OS, Ctx, AST->getDiagnostics().getShowColors());
          Dumper.SetTraversalKind(QS.TK);
          Dumper.Visit(BI->second);
          OS << "\n";
        }
      }

      if (MI->getMap().empty())
        OS << "No bindings.\n";
    }
  }

  OS << MatchCount << (MatchCount == 1 ? " match.\n" : " matches.\n");
  return true;
}

bool LetQuery::run(llvm::raw_ostream &OS, QuerySession &QS) const {
  if (Value) {
    QS.NamedValues[Name] = Value;
  } else {
    QS.NamedValues.erase(Name);
  }
  return true;
}

#ifndef _MSC_VER
const QueryKind SetQueryKind<bool>::value;
const QueryKind SetQueryKind<OutputKind>::value;
#endif

bool FileQuery::run(llvm::raw_ostream &OS, QuerySession &QS) const {
  auto Buffer = llvm::MemoryBuffer::getFile(StringRef{File}.trim());
  if (!Buffer) {
    if (Prefix.has_value())
      llvm::errs() << *Prefix << ": ";
    llvm::errs() << "cannot open " << File << ": "
                 << Buffer.getError().message() << "\n";
    return false;
  }

  StringRef FileContentRef(Buffer.get()->getBuffer());

  while (!FileContentRef.empty()) {
    QueryRef Q = QueryParser::parse(FileContentRef, QS);
    if (!Q->run(llvm::outs(), QS))
      return false;
    FileContentRef = Q->RemainingContent;
  }
  return true;
}

} // namespace query
} // namespace clang