1 //===--- tools/pp-trace/PPTrace.cpp - Clang preprocessor tracer -----------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements pp-trace, a tool for displaying a textual trace
10 // of the Clang preprocessor activity. It's based on a derivation of the
11 // PPCallbacks class, that once registerd with Clang, receives callback calls
12 // to its virtual members, and outputs the information passed to the callbacks
13 // in a high-level YAML format.
14 //
15 // The pp-trace tool also serves as the basis for a test of the PPCallbacks
16 // mechanism.
17 //
18 // The pp-trace tool supports the following general command line format:
19 //
20 // pp-trace [options] file... [-- compiler options]
21 //
22 // Basically you put the pp-trace options first, then the source file or files,
23 // and then -- followed by any options you want to pass to the compiler.
24 //
25 //===----------------------------------------------------------------------===//
26
27 #include "PPCallbacksTracker.h"
28 #include "clang/AST/ASTConsumer.h"
29 #include "clang/AST/ASTContext.h"
30 #include "clang/Basic/SourceManager.h"
31 #include "clang/Driver/Options.h"
32 #include "clang/Frontend/CompilerInstance.h"
33 #include "clang/Frontend/FrontendAction.h"
34 #include "clang/Frontend/FrontendActions.h"
35 #include "clang/Lex/Preprocessor.h"
36 #include "clang/Tooling/Execution.h"
37 #include "clang/Tooling/Tooling.h"
38 #include "llvm/Option/Arg.h"
39 #include "llvm/Option/ArgList.h"
40 #include "llvm/Option/OptTable.h"
41 #include "llvm/Option/Option.h"
42 #include "llvm/Support/CommandLine.h"
43 #include "llvm/Support/FileSystem.h"
44 #include "llvm/Support/GlobPattern.h"
45 #include "llvm/Support/InitLLVM.h"
46 #include "llvm/Support/Path.h"
47 #include "llvm/Support/ToolOutputFile.h"
48 #include "llvm/Support/WithColor.h"
49 #include <string>
50 #include <vector>
51
52 using namespace llvm;
53
54 namespace clang {
55 namespace pp_trace {
56
57 static cl::OptionCategory Cat("pp-trace options");
58
59 static cl::opt<std::string> Callbacks(
60 "callbacks", cl::init("*"),
61 cl::desc("Comma-separated list of globs describing the list of callbacks "
62 "to output. Globs are processed in order of appearance. Globs "
63 "with the '-' prefix remove callbacks from the set. e.g. "
64 "'*,-Macro*'."),
65 cl::cat(Cat));
66
67 static cl::opt<std::string> OutputFileName(
68 "output", cl::init("-"),
69 cl::desc("Output trace to the given file name or '-' for stdout."),
70 cl::cat(Cat));
71
error(Twine Message)72 LLVM_ATTRIBUTE_NORETURN static void error(Twine Message) {
73 WithColor::error() << Message << '\n';
74 exit(1);
75 }
76
77 namespace {
78
79 class PPTraceAction : public ASTFrontendAction {
80 public:
PPTraceAction(const FilterType & Filters,raw_ostream & OS)81 PPTraceAction(const FilterType &Filters, raw_ostream &OS)
82 : Filters(Filters), OS(OS) {}
83
84 protected:
CreateASTConsumer(CompilerInstance & CI,StringRef InFile)85 std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
86 StringRef InFile) override {
87 Preprocessor &PP = CI.getPreprocessor();
88 PP.addPPCallbacks(
89 std::make_unique<PPCallbacksTracker>(Filters, CallbackCalls, PP));
90 return std::make_unique<ASTConsumer>();
91 }
92
EndSourceFileAction()93 void EndSourceFileAction() override {
94 OS << "---\n";
95 for (const CallbackCall &Callback : CallbackCalls) {
96 OS << "- Callback: " << Callback.Name << "\n";
97 for (const Argument &Arg : Callback.Arguments)
98 OS << " " << Arg.Name << ": " << Arg.Value << "\n";
99 }
100 OS << "...\n";
101
102 CallbackCalls.clear();
103 }
104
105 private:
106 const FilterType &Filters;
107 raw_ostream &OS;
108 std::vector<CallbackCall> CallbackCalls;
109 };
110
111 class PPTraceFrontendActionFactory : public tooling::FrontendActionFactory {
112 public:
PPTraceFrontendActionFactory(const FilterType & Filters,raw_ostream & OS)113 PPTraceFrontendActionFactory(const FilterType &Filters, raw_ostream &OS)
114 : Filters(Filters), OS(OS) {}
115
create()116 std::unique_ptr<FrontendAction> create() override {
117 return std::make_unique<PPTraceAction>(Filters, OS);
118 }
119
120 private:
121 const FilterType &Filters;
122 raw_ostream &OS;
123 };
124 } // namespace
125 } // namespace pp_trace
126 } // namespace clang
127
main(int argc,const char ** argv)128 int main(int argc, const char **argv) {
129 using namespace clang::pp_trace;
130 InitLLVM X(argc, argv);
131 auto OptionsParser = clang::tooling::CommonOptionsParser::create(
132 argc, argv, Cat, llvm::cl::ZeroOrMore);
133 if (!OptionsParser)
134 error(toString(OptionsParser.takeError()));
135 // Parse the IgnoreCallbacks list into strings.
136 SmallVector<StringRef, 32> Patterns;
137 FilterType Filters;
138 StringRef(Callbacks).split(Patterns, ",",
139 /*MaxSplit=*/-1, /*KeepEmpty=*/false);
140 for (StringRef Pattern : Patterns) {
141 Pattern = Pattern.trim();
142 bool Enabled = !Pattern.consume_front("-");
143 Expected<GlobPattern> Pat = GlobPattern::create(Pattern);
144 if (Pat)
145 Filters.emplace_back(std::move(*Pat), Enabled);
146 else
147 error(toString(Pat.takeError()));
148 }
149
150 // Create the tool and run the compilation.
151 clang::tooling::ClangTool Tool(OptionsParser->getCompilations(),
152 OptionsParser->getSourcePathList());
153
154 std::error_code EC;
155 llvm::ToolOutputFile Out(OutputFileName, EC, llvm::sys::fs::OF_Text);
156 if (EC)
157 error(EC.message());
158 PPTraceFrontendActionFactory Factory(Filters, Out.os());
159 int HadErrors = Tool.run(&Factory);
160
161 // If we had errors, exit early.
162 if (HadErrors)
163 return HadErrors;
164
165 Out.keep();
166
167 return 0;
168 }
169