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1 //===--- CompilationDatabase.cpp - ----------------------------------------===//
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 contains implementations of the CompilationDatabase base class
11 //  and the FixedCompilationDatabase.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "clang/Tooling/CompilationDatabase.h"
16 #include "clang/Basic/Diagnostic.h"
17 #include "clang/Basic/DiagnosticOptions.h"
18 #include "clang/Driver/Action.h"
19 #include "clang/Driver/Compilation.h"
20 #include "clang/Driver/Driver.h"
21 #include "clang/Driver/DriverDiagnostic.h"
22 #include "clang/Driver/Job.h"
23 #include "clang/Frontend/TextDiagnosticPrinter.h"
24 #include "clang/Tooling/CompilationDatabasePluginRegistry.h"
25 #include "clang/Tooling/Tooling.h"
26 #include "llvm/ADT/SmallString.h"
27 #include "llvm/Option/Arg.h"
28 #include "llvm/Support/Host.h"
29 #include "llvm/Support/Path.h"
30 #include <sstream>
31 #include <system_error>
32 using namespace clang;
33 using namespace tooling;
34 
~CompilationDatabase()35 CompilationDatabase::~CompilationDatabase() {}
36 
37 std::unique_ptr<CompilationDatabase>
loadFromDirectory(StringRef BuildDirectory,std::string & ErrorMessage)38 CompilationDatabase::loadFromDirectory(StringRef BuildDirectory,
39                                        std::string &ErrorMessage) {
40   std::stringstream ErrorStream;
41   for (CompilationDatabasePluginRegistry::iterator
42        It = CompilationDatabasePluginRegistry::begin(),
43        Ie = CompilationDatabasePluginRegistry::end();
44        It != Ie; ++It) {
45     std::string DatabaseErrorMessage;
46     std::unique_ptr<CompilationDatabasePlugin> Plugin(It->instantiate());
47     if (std::unique_ptr<CompilationDatabase> DB =
48             Plugin->loadFromDirectory(BuildDirectory, DatabaseErrorMessage))
49       return DB;
50     ErrorStream << It->getName() << ": " << DatabaseErrorMessage << "\n";
51   }
52   ErrorMessage = ErrorStream.str();
53   return nullptr;
54 }
55 
56 static std::unique_ptr<CompilationDatabase>
findCompilationDatabaseFromDirectory(StringRef Directory,std::string & ErrorMessage)57 findCompilationDatabaseFromDirectory(StringRef Directory,
58                                      std::string &ErrorMessage) {
59   std::stringstream ErrorStream;
60   bool HasErrorMessage = false;
61   while (!Directory.empty()) {
62     std::string LoadErrorMessage;
63 
64     if (std::unique_ptr<CompilationDatabase> DB =
65             CompilationDatabase::loadFromDirectory(Directory, LoadErrorMessage))
66       return DB;
67 
68     if (!HasErrorMessage) {
69       ErrorStream << "No compilation database found in " << Directory.str()
70                   << " or any parent directory\n" << LoadErrorMessage;
71       HasErrorMessage = true;
72     }
73 
74     Directory = llvm::sys::path::parent_path(Directory);
75   }
76   ErrorMessage = ErrorStream.str();
77   return nullptr;
78 }
79 
80 std::unique_ptr<CompilationDatabase>
autoDetectFromSource(StringRef SourceFile,std::string & ErrorMessage)81 CompilationDatabase::autoDetectFromSource(StringRef SourceFile,
82                                           std::string &ErrorMessage) {
83   SmallString<1024> AbsolutePath(getAbsolutePath(SourceFile));
84   StringRef Directory = llvm::sys::path::parent_path(AbsolutePath);
85 
86   std::unique_ptr<CompilationDatabase> DB =
87       findCompilationDatabaseFromDirectory(Directory, ErrorMessage);
88 
89   if (!DB)
90     ErrorMessage = ("Could not auto-detect compilation database for file \"" +
91                    SourceFile + "\"\n" + ErrorMessage).str();
92   return DB;
93 }
94 
95 std::unique_ptr<CompilationDatabase>
autoDetectFromDirectory(StringRef SourceDir,std::string & ErrorMessage)96 CompilationDatabase::autoDetectFromDirectory(StringRef SourceDir,
97                                              std::string &ErrorMessage) {
98   SmallString<1024> AbsolutePath(getAbsolutePath(SourceDir));
99 
100   std::unique_ptr<CompilationDatabase> DB =
101       findCompilationDatabaseFromDirectory(AbsolutePath, ErrorMessage);
102 
103   if (!DB)
104     ErrorMessage = ("Could not auto-detect compilation database from directory \"" +
105                    SourceDir + "\"\n" + ErrorMessage).str();
106   return DB;
107 }
108 
~CompilationDatabasePlugin()109 CompilationDatabasePlugin::~CompilationDatabasePlugin() {}
110 
111 namespace {
112 // Helper for recursively searching through a chain of actions and collecting
113 // all inputs, direct and indirect, of compile jobs.
114 struct CompileJobAnalyzer {
run__anon970dbca40111::CompileJobAnalyzer115   void run(const driver::Action *A) {
116     runImpl(A, false);
117   }
118 
119   SmallVector<std::string, 2> Inputs;
120 
121 private:
122 
runImpl__anon970dbca40111::CompileJobAnalyzer123   void runImpl(const driver::Action *A, bool Collect) {
124     bool CollectChildren = Collect;
125     switch (A->getKind()) {
126     case driver::Action::CompileJobClass:
127       CollectChildren = true;
128       break;
129 
130     case driver::Action::InputClass: {
131       if (Collect) {
132         const driver::InputAction *IA = cast<driver::InputAction>(A);
133         Inputs.push_back(IA->getInputArg().getSpelling());
134       }
135     } break;
136 
137     default:
138       // Don't care about others
139       ;
140     }
141 
142     for (const driver::Action *AI : A->inputs())
143       runImpl(AI, CollectChildren);
144   }
145 };
146 
147 // Special DiagnosticConsumer that looks for warn_drv_input_file_unused
148 // diagnostics from the driver and collects the option strings for those unused
149 // options.
150 class UnusedInputDiagConsumer : public DiagnosticConsumer {
151 public:
UnusedInputDiagConsumer()152   UnusedInputDiagConsumer() : Other(nullptr) {}
153 
154   // Useful for debugging, chain diagnostics to another consumer after
155   // recording for our own purposes.
UnusedInputDiagConsumer(DiagnosticConsumer * Other)156   UnusedInputDiagConsumer(DiagnosticConsumer *Other) : Other(Other) {}
157 
HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,const Diagnostic & Info)158   void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
159                         const Diagnostic &Info) override {
160     if (Info.getID() == clang::diag::warn_drv_input_file_unused) {
161       // Arg 1 for this diagnostic is the option that didn't get used.
162       UnusedInputs.push_back(Info.getArgStdStr(0));
163     }
164     if (Other)
165       Other->HandleDiagnostic(DiagLevel, Info);
166   }
167 
168   DiagnosticConsumer *Other;
169   SmallVector<std::string, 2> UnusedInputs;
170 };
171 
172 // Unary functor for asking "Given a StringRef S1, does there exist a string
173 // S2 in Arr where S1 == S2?"
174 struct MatchesAny {
MatchesAny__anon970dbca40111::MatchesAny175   MatchesAny(ArrayRef<std::string> Arr) : Arr(Arr) {}
operator ()__anon970dbca40111::MatchesAny176   bool operator() (StringRef S) {
177     for (const std::string *I = Arr.begin(), *E = Arr.end(); I != E; ++I)
178       if (*I == S)
179         return true;
180     return false;
181   }
182 private:
183   ArrayRef<std::string> Arr;
184 };
185 } // namespace
186 
187 /// \brief Strips any positional args and possible argv[0] from a command-line
188 /// provided by the user to construct a FixedCompilationDatabase.
189 ///
190 /// FixedCompilationDatabase requires a command line to be in this format as it
191 /// constructs the command line for each file by appending the name of the file
192 /// to be compiled. FixedCompilationDatabase also adds its own argv[0] to the
193 /// start of the command line although its value is not important as it's just
194 /// ignored by the Driver invoked by the ClangTool using the
195 /// FixedCompilationDatabase.
196 ///
197 /// FIXME: This functionality should probably be made available by
198 /// clang::driver::Driver although what the interface should look like is not
199 /// clear.
200 ///
201 /// \param[in] Args Args as provided by the user.
202 /// \return Resulting stripped command line.
203 ///          \li true if successful.
204 ///          \li false if \c Args cannot be used for compilation jobs (e.g.
205 ///          contains an option like -E or -version).
stripPositionalArgs(std::vector<const char * > Args,std::vector<std::string> & Result)206 static bool stripPositionalArgs(std::vector<const char *> Args,
207                                 std::vector<std::string> &Result) {
208   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
209   UnusedInputDiagConsumer DiagClient;
210   DiagnosticsEngine Diagnostics(
211       IntrusiveRefCntPtr<clang::DiagnosticIDs>(new DiagnosticIDs()),
212       &*DiagOpts, &DiagClient, false);
213 
214   // The clang executable path isn't required since the jobs the driver builds
215   // will not be executed.
216   std::unique_ptr<driver::Driver> NewDriver(new driver::Driver(
217       /* ClangExecutable= */ "", llvm::sys::getDefaultTargetTriple(),
218       Diagnostics));
219   NewDriver->setCheckInputsExist(false);
220 
221   // This becomes the new argv[0]. The value is actually not important as it
222   // isn't used for invoking Tools.
223   Args.insert(Args.begin(), "clang-tool");
224 
225   // By adding -c, we force the driver to treat compilation as the last phase.
226   // It will then issue warnings via Diagnostics about un-used options that
227   // would have been used for linking. If the user provided a compiler name as
228   // the original argv[0], this will be treated as a linker input thanks to
229   // insertng a new argv[0] above. All un-used options get collected by
230   // UnusedInputdiagConsumer and get stripped out later.
231   Args.push_back("-c");
232 
233   // Put a dummy C++ file on to ensure there's at least one compile job for the
234   // driver to construct. If the user specified some other argument that
235   // prevents compilation, e.g. -E or something like -version, we may still end
236   // up with no jobs but then this is the user's fault.
237   Args.push_back("placeholder.cpp");
238 
239   // Remove -no-integrated-as; it's not used for syntax checking,
240   // and it confuses targets which don't support this option.
241   Args.erase(std::remove_if(Args.begin(), Args.end(),
242                             MatchesAny(std::string("-no-integrated-as"))),
243              Args.end());
244 
245   const std::unique_ptr<driver::Compilation> Compilation(
246       NewDriver->BuildCompilation(Args));
247 
248   const driver::JobList &Jobs = Compilation->getJobs();
249 
250   CompileJobAnalyzer CompileAnalyzer;
251 
252   for (const auto &Cmd : Jobs) {
253     // Collect only for Assemble jobs. If we do all jobs we get duplicates
254     // since Link jobs point to Assemble jobs as inputs.
255     if (Cmd.getSource().getKind() == driver::Action::AssembleJobClass)
256       CompileAnalyzer.run(&Cmd.getSource());
257   }
258 
259   if (CompileAnalyzer.Inputs.empty()) {
260     // No compile jobs found.
261     // FIXME: Emit a warning of some kind?
262     return false;
263   }
264 
265   // Remove all compilation input files from the command line. This is
266   // necessary so that getCompileCommands() can construct a command line for
267   // each file.
268   std::vector<const char *>::iterator End = std::remove_if(
269       Args.begin(), Args.end(), MatchesAny(CompileAnalyzer.Inputs));
270 
271   // Remove all inputs deemed unused for compilation.
272   End = std::remove_if(Args.begin(), End, MatchesAny(DiagClient.UnusedInputs));
273 
274   // Remove the -c add above as well. It will be at the end right now.
275   assert(strcmp(*(End - 1), "-c") == 0);
276   --End;
277 
278   Result = std::vector<std::string>(Args.begin() + 1, End);
279   return true;
280 }
281 
loadFromCommandLine(int & Argc,const char * const * Argv,Twine Directory)282 FixedCompilationDatabase *FixedCompilationDatabase::loadFromCommandLine(
283     int &Argc, const char *const *Argv, Twine Directory) {
284   const char *const *DoubleDash = std::find(Argv, Argv + Argc, StringRef("--"));
285   if (DoubleDash == Argv + Argc)
286     return nullptr;
287   std::vector<const char *> CommandLine(DoubleDash + 1, Argv + Argc);
288   Argc = DoubleDash - Argv;
289 
290   std::vector<std::string> StrippedArgs;
291   if (!stripPositionalArgs(CommandLine, StrippedArgs))
292     return nullptr;
293   return new FixedCompilationDatabase(Directory, StrippedArgs);
294 }
295 
296 FixedCompilationDatabase::
FixedCompilationDatabase(Twine Directory,ArrayRef<std::string> CommandLine)297 FixedCompilationDatabase(Twine Directory, ArrayRef<std::string> CommandLine) {
298   std::vector<std::string> ToolCommandLine(1, "clang-tool");
299   ToolCommandLine.insert(ToolCommandLine.end(),
300                          CommandLine.begin(), CommandLine.end());
301   CompileCommands.emplace_back(Directory, StringRef(),
302                                std::move(ToolCommandLine));
303 }
304 
305 std::vector<CompileCommand>
getCompileCommands(StringRef FilePath) const306 FixedCompilationDatabase::getCompileCommands(StringRef FilePath) const {
307   std::vector<CompileCommand> Result(CompileCommands);
308   Result[0].CommandLine.push_back(FilePath);
309   Result[0].Filename = FilePath;
310   return Result;
311 }
312 
313 std::vector<std::string>
getAllFiles() const314 FixedCompilationDatabase::getAllFiles() const {
315   return std::vector<std::string>();
316 }
317 
318 std::vector<CompileCommand>
getAllCompileCommands() const319 FixedCompilationDatabase::getAllCompileCommands() const {
320   return std::vector<CompileCommand>();
321 }
322 
323 namespace clang {
324 namespace tooling {
325 
326 // This anchor is used to force the linker to link in the generated object file
327 // and thus register the JSONCompilationDatabasePlugin.
328 extern volatile int JSONAnchorSource;
329 static int LLVM_ATTRIBUTE_UNUSED JSONAnchorDest = JSONAnchorSource;
330 
331 } // end namespace tooling
332 } // end namespace clang
333