1 //===--- Tooling.cpp - Running clang standalone tools ---------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 //  This file implements functions to run clang tools standalone instead
11 //  of running them as a plugin.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "clang/Tooling/Tooling.h"
16 #include "clang/Driver/Compilation.h"
17 #include "clang/Driver/Driver.h"
18 #include "clang/Driver/Tool.h"
19 #include "clang/Frontend/CompilerInstance.h"
20 #include "clang/Frontend/FrontendDiagnostic.h"
21 #include "clang/Frontend/TextDiagnosticPrinter.h"
22 #include "clang/Tooling/ArgumentsAdjusters.h"
23 #include "clang/Tooling/CompilationDatabase.h"
24 #include "llvm/ADT/STLExtras.h"
25 #include "llvm/Option/Option.h"
26 #include "llvm/Support/Debug.h"
27 #include "llvm/Support/FileSystem.h"
28 #include "llvm/Support/Host.h"
29 #include "llvm/Support/PathV1.h"
30 #include "llvm/Support/raw_ostream.h"
31 
32 // For chdir, see the comment in ClangTool::run for more information.
33 #ifdef _WIN32
34 #  include <direct.h>
35 #else
36 #  include <unistd.h>
37 #endif
38 
39 namespace clang {
40 namespace tooling {
41 
42 FrontendActionFactory::~FrontendActionFactory() {}
43 
44 // FIXME: This file contains structural duplication with other parts of the
45 // code that sets up a compiler to run tools on it, and we should refactor
46 // it to be based on the same framework.
47 
48 /// \brief Builds a clang driver initialized for running clang tools.
49 static clang::driver::Driver *newDriver(clang::DiagnosticsEngine *Diagnostics,
50                                         const char *BinaryName) {
51   const std::string DefaultOutputName = "a.out";
52   clang::driver::Driver *CompilerDriver = new clang::driver::Driver(
53     BinaryName, llvm::sys::getDefaultTargetTriple(),
54     DefaultOutputName, *Diagnostics);
55   CompilerDriver->setTitle("clang_based_tool");
56   return CompilerDriver;
57 }
58 
59 /// \brief Retrieves the clang CC1 specific flags out of the compilation's jobs.
60 ///
61 /// Returns NULL on error.
62 static const llvm::opt::ArgStringList *getCC1Arguments(
63     clang::DiagnosticsEngine *Diagnostics,
64     clang::driver::Compilation *Compilation) {
65   // We expect to get back exactly one Command job, if we didn't something
66   // failed. Extract that job from the Compilation.
67   const clang::driver::JobList &Jobs = Compilation->getJobs();
68   if (Jobs.size() != 1 || !isa<clang::driver::Command>(*Jobs.begin())) {
69     SmallString<256> error_msg;
70     llvm::raw_svector_ostream error_stream(error_msg);
71     Compilation->PrintJob(error_stream, Compilation->getJobs(), "; ", true);
72     Diagnostics->Report(clang::diag::err_fe_expected_compiler_job)
73         << error_stream.str();
74     return NULL;
75   }
76 
77   // The one job we find should be to invoke clang again.
78   const clang::driver::Command *Cmd =
79       cast<clang::driver::Command>(*Jobs.begin());
80   if (StringRef(Cmd->getCreator().getName()) != "clang") {
81     Diagnostics->Report(clang::diag::err_fe_expected_clang_command);
82     return NULL;
83   }
84 
85   return &Cmd->getArguments();
86 }
87 
88 /// \brief Returns a clang build invocation initialized from the CC1 flags.
89 static clang::CompilerInvocation *newInvocation(
90     clang::DiagnosticsEngine *Diagnostics,
91     const llvm::opt::ArgStringList &CC1Args) {
92   assert(!CC1Args.empty() && "Must at least contain the program name!");
93   clang::CompilerInvocation *Invocation = new clang::CompilerInvocation;
94   clang::CompilerInvocation::CreateFromArgs(
95       *Invocation, CC1Args.data() + 1, CC1Args.data() + CC1Args.size(),
96       *Diagnostics);
97   Invocation->getFrontendOpts().DisableFree = false;
98   return Invocation;
99 }
100 
101 bool runToolOnCode(clang::FrontendAction *ToolAction, const Twine &Code,
102                    const Twine &FileName) {
103   return runToolOnCodeWithArgs(
104       ToolAction, Code, std::vector<std::string>(), FileName);
105 }
106 
107 bool runToolOnCodeWithArgs(clang::FrontendAction *ToolAction, const Twine &Code,
108                            const std::vector<std::string> &Args,
109                            const Twine &FileName) {
110   SmallString<16> FileNameStorage;
111   StringRef FileNameRef = FileName.toNullTerminatedStringRef(FileNameStorage);
112   std::vector<std::string> Commands;
113   Commands.push_back("clang-tool");
114   Commands.push_back("-fsyntax-only");
115   Commands.insert(Commands.end(), Args.begin(), Args.end());
116   Commands.push_back(FileNameRef.data());
117   FileManager Files((FileSystemOptions()));
118   ToolInvocation Invocation(Commands, ToolAction, &Files);
119 
120   SmallString<1024> CodeStorage;
121   Invocation.mapVirtualFile(FileNameRef,
122                             Code.toNullTerminatedStringRef(CodeStorage));
123   return Invocation.run();
124 }
125 
126 std::string getAbsolutePath(StringRef File) {
127   SmallString<1024> BaseDirectory;
128   if (const char *PWD = ::getenv("PWD"))
129     BaseDirectory = PWD;
130   else
131     llvm::sys::fs::current_path(BaseDirectory);
132   SmallString<1024> PathStorage;
133   if (llvm::sys::path::is_absolute(File)) {
134     llvm::sys::path::native(File, PathStorage);
135     return PathStorage.str();
136   }
137   StringRef RelativePath(File);
138   // FIXME: Should '.\\' be accepted on Win32?
139   if (RelativePath.startswith("./")) {
140     RelativePath = RelativePath.substr(strlen("./"));
141   }
142   SmallString<1024> AbsolutePath(BaseDirectory);
143   llvm::sys::path::append(AbsolutePath, RelativePath);
144   llvm::sys::path::native(Twine(AbsolutePath), PathStorage);
145   return PathStorage.str();
146 }
147 
148 ToolInvocation::ToolInvocation(
149     ArrayRef<std::string> CommandLine, FrontendAction *ToolAction,
150     FileManager *Files)
151     : CommandLine(CommandLine.vec()), ToolAction(ToolAction), Files(Files) {
152 }
153 
154 void ToolInvocation::mapVirtualFile(StringRef FilePath, StringRef Content) {
155   SmallString<1024> PathStorage;
156   llvm::sys::path::native(FilePath, PathStorage);
157   MappedFileContents[PathStorage] = Content;
158 }
159 
160 bool ToolInvocation::run() {
161   std::vector<const char*> Argv;
162   for (int I = 0, E = CommandLine.size(); I != E; ++I)
163     Argv.push_back(CommandLine[I].c_str());
164   const char *const BinaryName = Argv[0];
165   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
166   TextDiagnosticPrinter DiagnosticPrinter(
167       llvm::errs(), &*DiagOpts);
168   DiagnosticsEngine Diagnostics(
169     IntrusiveRefCntPtr<clang::DiagnosticIDs>(new DiagnosticIDs()),
170     &*DiagOpts, &DiagnosticPrinter, false);
171 
172   const OwningPtr<clang::driver::Driver> Driver(
173       newDriver(&Diagnostics, BinaryName));
174   // Since the input might only be virtual, don't check whether it exists.
175   Driver->setCheckInputsExist(false);
176   const OwningPtr<clang::driver::Compilation> Compilation(
177       Driver->BuildCompilation(llvm::makeArrayRef(Argv)));
178   const llvm::opt::ArgStringList *const CC1Args = getCC1Arguments(
179       &Diagnostics, Compilation.get());
180   if (CC1Args == NULL) {
181     return false;
182   }
183   OwningPtr<clang::CompilerInvocation> Invocation(
184       newInvocation(&Diagnostics, *CC1Args));
185   return runInvocation(BinaryName, Compilation.get(), Invocation.take());
186 }
187 
188 bool ToolInvocation::runInvocation(
189     const char *BinaryName,
190     clang::driver::Compilation *Compilation,
191     clang::CompilerInvocation *Invocation) {
192   // Show the invocation, with -v.
193   if (Invocation->getHeaderSearchOpts().Verbose) {
194     llvm::errs() << "clang Invocation:\n";
195     Compilation->PrintJob(llvm::errs(), Compilation->getJobs(), "\n", true);
196     llvm::errs() << "\n";
197   }
198 
199   // Create a compiler instance to handle the actual work.
200   clang::CompilerInstance Compiler;
201   Compiler.setInvocation(Invocation);
202   Compiler.setFileManager(Files);
203   // FIXME: What about LangOpts?
204 
205   // ToolAction can have lifetime requirements for Compiler or its members, and
206   // we need to ensure it's deleted earlier than Compiler. So we pass it to an
207   // OwningPtr declared after the Compiler variable.
208   OwningPtr<FrontendAction> ScopedToolAction(ToolAction.take());
209 
210   // Create the compilers actual diagnostics engine.
211   Compiler.createDiagnostics();
212   if (!Compiler.hasDiagnostics())
213     return false;
214 
215   Compiler.createSourceManager(*Files);
216   addFileMappingsTo(Compiler.getSourceManager());
217 
218   const bool Success = Compiler.ExecuteAction(*ScopedToolAction);
219 
220   Compiler.resetAndLeakFileManager();
221   Files->clearStatCaches();
222   return Success;
223 }
224 
225 void ToolInvocation::addFileMappingsTo(SourceManager &Sources) {
226   for (llvm::StringMap<StringRef>::const_iterator
227            It = MappedFileContents.begin(), End = MappedFileContents.end();
228        It != End; ++It) {
229     // Inject the code as the given file name into the preprocessor options.
230     const llvm::MemoryBuffer *Input =
231         llvm::MemoryBuffer::getMemBuffer(It->getValue());
232     // FIXME: figure out what '0' stands for.
233     const FileEntry *FromFile = Files->getVirtualFile(
234         It->getKey(), Input->getBufferSize(), 0);
235     Sources.overrideFileContents(FromFile, Input);
236   }
237 }
238 
239 ClangTool::ClangTool(const CompilationDatabase &Compilations,
240                      ArrayRef<std::string> SourcePaths)
241     : Files((FileSystemOptions())) {
242   ArgsAdjusters.push_back(new ClangStripOutputAdjuster());
243   ArgsAdjusters.push_back(new ClangSyntaxOnlyAdjuster());
244   for (unsigned I = 0, E = SourcePaths.size(); I != E; ++I) {
245     SmallString<1024> File(getAbsolutePath(SourcePaths[I]));
246 
247     std::vector<CompileCommand> CompileCommandsForFile =
248       Compilations.getCompileCommands(File.str());
249     if (!CompileCommandsForFile.empty()) {
250       for (int I = 0, E = CompileCommandsForFile.size(); I != E; ++I) {
251         CompileCommands.push_back(std::make_pair(File.str(),
252                                   CompileCommandsForFile[I]));
253       }
254     } else {
255       // FIXME: There are two use cases here: doing a fuzzy
256       // "find . -name '*.cc' |xargs tool" match, where as a user I don't care
257       // about the .cc files that were not found, and the use case where I
258       // specify all files I want to run over explicitly, where this should
259       // be an error. We'll want to add an option for this.
260       llvm::outs() << "Skipping " << File << ". Command line not found.\n";
261     }
262   }
263 }
264 
265 void ClangTool::mapVirtualFile(StringRef FilePath, StringRef Content) {
266   MappedFileContents.push_back(std::make_pair(FilePath, Content));
267 }
268 
269 void ClangTool::setArgumentsAdjuster(ArgumentsAdjuster *Adjuster) {
270   clearArgumentsAdjusters();
271   appendArgumentsAdjuster(Adjuster);
272 }
273 
274 void ClangTool::appendArgumentsAdjuster(ArgumentsAdjuster *Adjuster) {
275   ArgsAdjusters.push_back(Adjuster);
276 }
277 
278 void ClangTool::clearArgumentsAdjusters() {
279   for (unsigned I = 0, E = ArgsAdjusters.size(); I != E; ++I)
280     delete ArgsAdjusters[I];
281   ArgsAdjusters.clear();
282 }
283 
284 int ClangTool::run(FrontendActionFactory *ActionFactory) {
285   // Exists solely for the purpose of lookup of the resource path.
286   // This just needs to be some symbol in the binary.
287   static int StaticSymbol;
288   // The driver detects the builtin header path based on the path of the
289   // executable.
290   // FIXME: On linux, GetMainExecutable is independent of the value of the
291   // first argument, thus allowing ClangTool and runToolOnCode to just
292   // pass in made-up names here. Make sure this works on other platforms.
293   std::string MainExecutable =
294     llvm::sys::Path::GetMainExecutable("clang_tool", &StaticSymbol).str();
295 
296   bool ProcessingFailed = false;
297   for (unsigned I = 0; I < CompileCommands.size(); ++I) {
298     std::string File = CompileCommands[I].first;
299     // FIXME: chdir is thread hostile; on the other hand, creating the same
300     // behavior as chdir is complex: chdir resolves the path once, thus
301     // guaranteeing that all subsequent relative path operations work
302     // on the same path the original chdir resulted in. This makes a difference
303     // for example on network filesystems, where symlinks might be switched
304     // during runtime of the tool. Fixing this depends on having a file system
305     // abstraction that allows openat() style interactions.
306     if (chdir(CompileCommands[I].second.Directory.c_str()))
307       llvm::report_fatal_error("Cannot chdir into \"" +
308                                CompileCommands[I].second.Directory + "\n!");
309     std::vector<std::string> CommandLine = CompileCommands[I].second.CommandLine;
310     for (unsigned I = 0, E = ArgsAdjusters.size(); I != E; ++I)
311       CommandLine = ArgsAdjusters[I]->Adjust(CommandLine);
312     assert(!CommandLine.empty());
313     CommandLine[0] = MainExecutable;
314     // FIXME: We need a callback mechanism for the tool writer to output a
315     // customized message for each file.
316     DEBUG({
317       llvm::dbgs() << "Processing: " << File << ".\n";
318     });
319     ToolInvocation Invocation(CommandLine, ActionFactory->create(), &Files);
320     for (int I = 0, E = MappedFileContents.size(); I != E; ++I) {
321       Invocation.mapVirtualFile(MappedFileContents[I].first,
322                                 MappedFileContents[I].second);
323     }
324     if (!Invocation.run()) {
325       // FIXME: Diagnostics should be used instead.
326       llvm::errs() << "Error while processing " << File << ".\n";
327       ProcessingFailed = true;
328     }
329   }
330   return ProcessingFailed ? 1 : 0;
331 }
332 
333 } // end namespace tooling
334 } // end namespace clang
335