reference, declarationdefinition
definition → references, declarations, derived classes, virtual overrides
reference to multiple definitions → definitions
unreferenced
    1
    2
    3
    4
    5
    6
    7
    8
    9
   10
   11
   12
   13
   14
   15
   16
   17
   18
   19
   20
   21
   22
   23
   24
   25
   26
   27
   28
   29
   30
   31
   32
   33
   34
   35
   36
   37
   38
   39
   40
   41
   42
   43
   44
   45
   46
   47
   48
   49
   50
   51
   52
   53
   54
   55
   56
   57
   58
   59
   60
   61
   62
   63
   64
   65
   66
   67
   68
   69
   70
   71
   72
   73
   74
   75
   76
   77
   78
   79
   80
   81
   82
   83
   84
   85
   86
   87
   88
   89
   90
   91
   92
   93
   94
   95
   96
   97
   98
   99
  100
  101
  102
  103
  104
  105
  106
  107
  108
  109
  110
  111
  112
  113
  114
  115
  116
  117
  118
  119
  120
  121
  122
  123
  124
  125
  126
  127
  128
  129
  130
  131
  132
  133
  134
  135
  136
  137
  138
  139
  140
  141
  142
  143
  144
  145
  146
  147
  148
  149
  150
  151
  152
  153
  154
  155
  156
  157
  158
  159
  160
  161
  162
  163
  164
  165
  166
  167
  168
//===--- tools/pp-trace/PPTrace.cpp - Clang preprocessor tracer -----------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file implements pp-trace, a tool for displaying a textual trace
// of the Clang preprocessor activity.  It's based on a derivation of the
// PPCallbacks class, that once registerd with Clang, receives callback calls
// to its virtual members, and outputs the information passed to the callbacks
// in a high-level YAML format.
//
// The pp-trace tool also serves as the basis for a test of the PPCallbacks
// mechanism.
//
// The pp-trace tool supports the following general command line format:
//
//    pp-trace [options] file... [-- compiler options]
//
// Basically you put the pp-trace options first, then the source file or files,
// and then -- followed by any options you want to pass to the compiler.
//
//===----------------------------------------------------------------------===//

#include "PPCallbacksTracker.h"
#include "clang/AST/ASTConsumer.h"
#include "clang/AST/ASTContext.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Driver/Options.h"
#include "clang/Frontend/CompilerInstance.h"
#include "clang/Frontend/FrontendAction.h"
#include "clang/Frontend/FrontendActions.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Tooling/Execution.h"
#include "clang/Tooling/Tooling.h"
#include "llvm/Option/Arg.h"
#include "llvm/Option/ArgList.h"
#include "llvm/Option/OptTable.h"
#include "llvm/Option/Option.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/GlobPattern.h"
#include "llvm/Support/InitLLVM.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/ToolOutputFile.h"
#include "llvm/Support/WithColor.h"
#include <string>
#include <vector>

using namespace llvm;

namespace clang {
namespace pp_trace {

static cl::OptionCategory Cat("pp-trace options");

static cl::opt<std::string> Callbacks(
    "callbacks", cl::init("*"),
    cl::desc("Comma-separated list of globs describing the list of callbacks "
             "to output. Globs are processed in order of appearance. Globs "
             "with the '-' prefix remove callbacks from the set. e.g. "
             "'*,-Macro*'."),
    cl::cat(Cat));

static cl::opt<std::string> OutputFileName(
    "output", cl::init("-"),
    cl::desc("Output trace to the given file name or '-' for stdout."),
    cl::cat(Cat));

LLVM_ATTRIBUTE_NORETURN static void error(Twine Message) {
  WithColor::error() << Message << '\n';
  exit(1);
}

namespace {

class PPTraceAction : public ASTFrontendAction {
public:
  PPTraceAction(const FilterType &Filters, raw_ostream &OS)
      : Filters(Filters), OS(OS) {}

protected:
  std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
                                                 StringRef InFile) override {
    Preprocessor &PP = CI.getPreprocessor();
    PP.addPPCallbacks(
        std::make_unique<PPCallbacksTracker>(Filters, CallbackCalls, PP));
    return std::make_unique<ASTConsumer>();
  }

  void EndSourceFileAction() override {
    OS << "---\n";
    for (const CallbackCall &Callback : CallbackCalls) {
      OS << "- Callback: " << Callback.Name << "\n";
      for (const Argument &Arg : Callback.Arguments)
        OS << "  " << Arg.Name << ": " << Arg.Value << "\n";
    }
    OS << "...\n";

    CallbackCalls.clear();
  }

private:
  const FilterType &Filters;
  raw_ostream &OS;
  std::vector<CallbackCall> CallbackCalls;
};

class PPTraceFrontendActionFactory : public tooling::FrontendActionFactory {
public:
  PPTraceFrontendActionFactory(const FilterType &Filters, raw_ostream &OS)
      : Filters(Filters), OS(OS) {}

  std::unique_ptr<FrontendAction> create() override {
    return std::make_unique<PPTraceAction>(Filters, OS);
  }

private:
  const FilterType &Filters;
  raw_ostream &OS;
};
} // namespace
} // namespace pp_trace
} // namespace clang

int main(int argc, const char **argv) {
  using namespace clang::pp_trace;
  InitLLVM X(argc, argv);
  auto OptionsParser = clang::tooling::CommonOptionsParser::create(
      argc, argv, Cat, llvm::cl::ZeroOrMore);
  if (!OptionsParser)
    error(toString(OptionsParser.takeError()));
  // Parse the IgnoreCallbacks list into strings.
  SmallVector<StringRef, 32> Patterns;
  FilterType Filters;
  StringRef(Callbacks).split(Patterns, ",",
                             /*MaxSplit=*/-1, /*KeepEmpty=*/false);
  for (StringRef Pattern : Patterns) {
    Pattern = Pattern.trim();
    bool Enabled = !Pattern.consume_front("-");
    Expected<GlobPattern> Pat = GlobPattern::create(Pattern);
    if (Pat)
      Filters.emplace_back(std::move(*Pat), Enabled);
    else
      error(toString(Pat.takeError()));
  }

  // Create the tool and run the compilation.
  clang::tooling::ClangTool Tool(OptionsParser->getCompilations(),
                                 OptionsParser->getSourcePathList());

  std::error_code EC;
  llvm::ToolOutputFile Out(OutputFileName, EC, llvm::sys::fs::OF_Text);
  if (EC)
    error(EC.message());
  PPTraceFrontendActionFactory Factory(Filters, Out.os());
  int HadErrors = Tool.run(&Factory);

  // If we had errors, exit early.
  if (HadErrors)
    return HadErrors;

  Out.keep();

  return 0;
}