1 //===---- ClangQuery.cpp - clang-query tool -------------------------------===//
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 tool is for interactive exploration of the Clang AST using AST matchers.
10 // It currently allows the user to enter a matcher at an interactive prompt and
11 // view the resulting bindings as diagnostics, AST pretty prints or AST dumps.
12 // Example session:
13 //
14 // $ cat foo.c
15 // void foo(void) {}
16 // $ clang-query foo.c --
17 // clang-query> match functionDecl()
18 //
19 // Match #1:
20 //
21 // foo.c:1:1: note: "root" binds here
22 // void foo(void) {}
23 // ^~~~~~~~~~~~~~~~~
24 // 1 match.
25 //
26 //===----------------------------------------------------------------------===//
27 
28 #include "Query.h"
29 #include "QueryParser.h"
30 #include "QuerySession.h"
31 #include "clang/Frontend/ASTUnit.h"
32 #include "clang/Tooling/CommonOptionsParser.h"
33 #include "clang/Tooling/Tooling.h"
34 #include "llvm/LineEditor/LineEditor.h"
35 #include "llvm/Support/CommandLine.h"
36 #include "llvm/Support/Error.h"
37 #include "llvm/Support/MemoryBuffer.h"
38 #include "llvm/Support/Signals.h"
39 #include "llvm/Support/WithColor.h"
40 #include <string>
41 
42 using namespace clang;
43 using namespace clang::ast_matchers;
44 using namespace clang::ast_matchers::dynamic;
45 using namespace clang::query;
46 using namespace clang::tooling;
47 using namespace llvm;
48 
49 static cl::extrahelp CommonHelp(CommonOptionsParser::HelpMessage);
50 static cl::OptionCategory ClangQueryCategory("clang-query options");
51 
52 static cl::opt<bool>
53     UseColor("use-color",
54              cl::desc(
55                  R"(Use colors in detailed AST output. If not set, colors
56 will be used if the terminal connected to
57 standard output supports colors.)"),
58              cl::init(false), cl::cat(ClangQueryCategory));
59 
60 static cl::list<std::string> Commands("c", cl::desc("Specify command to run"),
61                                       cl::value_desc("command"),
62                                       cl::cat(ClangQueryCategory));
63 
64 static cl::list<std::string> CommandFiles("f",
65                                           cl::desc("Read commands from file"),
66                                           cl::value_desc("file"),
67                                           cl::cat(ClangQueryCategory));
68 
69 static cl::opt<std::string> PreloadFile(
70     "preload",
71     cl::desc("Preload commands from file and start interactive mode"),
72     cl::value_desc("file"), cl::cat(ClangQueryCategory));
73 
74 bool runCommandsInFile(const char *ExeName, std::string const &FileName,
75                        QuerySession &QS) {
76   auto Buffer = llvm::MemoryBuffer::getFile(FileName);
77   if (!Buffer) {
78     llvm::errs() << ExeName << ": cannot open " << FileName << ": "
79                  << Buffer.getError().message() << "\n";
80     return true;
81   }
82 
83   StringRef FileContentRef(Buffer.get()->getBuffer());
84 
85   while (!FileContentRef.empty()) {
86     QueryRef Q = QueryParser::parse(FileContentRef, QS);
87     if (!Q->run(llvm::outs(), QS))
88       return true;
89     FileContentRef = Q->RemainingContent;
90   }
91   return false;
92 }
93 
94 int main(int argc, const char **argv) {
95   llvm::sys::PrintStackTraceOnErrorSignal(argv[0]);
96 
97   llvm::Expected<CommonOptionsParser> OptionsParser =
98       CommonOptionsParser::create(argc, argv, ClangQueryCategory,
99                                   llvm::cl::OneOrMore);
100 
101   if (!OptionsParser) {
102     llvm::WithColor::error() << llvm::toString(OptionsParser.takeError());
103     return 1;
104   }
105 
106   if (!Commands.empty() && !CommandFiles.empty()) {
107     llvm::errs() << argv[0] << ": cannot specify both -c and -f\n";
108     return 1;
109   }
110 
111   if ((!Commands.empty() || !CommandFiles.empty()) && !PreloadFile.empty()) {
112     llvm::errs() << argv[0]
113                  << ": cannot specify both -c or -f with --preload\n";
114     return 1;
115   }
116 
117   ClangTool Tool(OptionsParser->getCompilations(),
118                  OptionsParser->getSourcePathList());
119 
120   if (UseColor.getNumOccurrences() > 0) {
121     ArgumentsAdjuster colorAdjustor = [](const CommandLineArguments &Args, StringRef /*unused*/) {
122       CommandLineArguments AdjustedArgs = Args;
123       if (UseColor)
124         AdjustedArgs.push_back("-fdiagnostics-color");
125       else
126         AdjustedArgs.push_back("-fno-diagnostics-color");
127       return AdjustedArgs;
128     };
129     Tool.appendArgumentsAdjuster(colorAdjustor);
130   }
131 
132   std::vector<std::unique_ptr<ASTUnit>> ASTs;
133   int ASTStatus = 0;
134   switch (Tool.buildASTs(ASTs)) {
135   case 0:
136     break;
137   case 1: // Building ASTs failed.
138     return 1;
139   case 2:
140     ASTStatus |= 1;
141     llvm::errs() << "Failed to build AST for some of the files, "
142                  << "results may be incomplete."
143                  << "\n";
144     break;
145   default:
146     llvm_unreachable("Unexpected status returned");
147   }
148 
149   QuerySession QS(ASTs);
150 
151   if (!Commands.empty()) {
152     for (auto &Command : Commands) {
153       QueryRef Q = QueryParser::parse(Command, QS);
154       if (!Q->run(llvm::outs(), QS))
155         return 1;
156     }
157   } else if (!CommandFiles.empty()) {
158     for (auto &CommandFile : CommandFiles) {
159       if (runCommandsInFile(argv[0], CommandFile, QS))
160         return 1;
161     }
162   } else {
163     if (!PreloadFile.empty()) {
164       if (runCommandsInFile(argv[0], PreloadFile, QS))
165         return 1;
166     }
167     LineEditor LE("clang-query");
168     LE.setListCompleter([&QS](StringRef Line, size_t Pos) {
169       return QueryParser::complete(Line, Pos, QS);
170     });
171     while (llvm::Optional<std::string> Line = LE.readLine()) {
172       QueryRef Q = QueryParser::parse(*Line, QS);
173       Q->run(llvm::outs(), QS);
174       llvm::outs().flush();
175       if (QS.Terminate)
176         break;
177     }
178   }
179 
180   return ASTStatus;
181 }
182