1 //===--- GlobalCompilationDatabase.cpp --------------------------*- C++-*-===//
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 #include "GlobalCompilationDatabase.h"
11 #include "clang/Tooling/CompilationDatabase.h"
12 #include "llvm/Support/FileSystem.h"
13 #include "llvm/Support/Path.h"
14 
15 namespace clang {
16 namespace clangd {
17 
18 static void addExtraFlags(tooling::CompileCommand &Command,
19                           const std::vector<std::string> &ExtraFlags) {
20   if (ExtraFlags.empty())
21     return;
22   assert(Command.CommandLine.size() >= 2 &&
23          "Expected a command line containing at least 2 arguments, the "
24          "compiler binary and the output file");
25   // The last argument of CommandLine is the name of the input file.
26   // Add ExtraFlags before it.
27   auto It = Command.CommandLine.end();
28   --It;
29   Command.CommandLine.insert(It, ExtraFlags.begin(), ExtraFlags.end());
30 }
31 
32 tooling::CompileCommand getDefaultCompileCommand(PathRef File) {
33   std::vector<std::string> CommandLine{"clang", "-fsyntax-only", File.str()};
34   return tooling::CompileCommand(llvm::sys::path::parent_path(File),
35                                  llvm::sys::path::filename(File), CommandLine,
36                                  /*Output=*/"");
37 }
38 
39 std::vector<tooling::CompileCommand>
40 DirectoryBasedGlobalCompilationDatabase::getCompileCommands(PathRef File) {
41   std::vector<tooling::CompileCommand> Commands;
42 
43   auto CDB = getCompilationDatabase(File);
44   if (CDB)
45     Commands = CDB->getCompileCommands(File);
46   if (Commands.empty())
47     Commands.push_back(getDefaultCompileCommand(File));
48 
49   auto It = ExtraFlagsForFile.find(File);
50   if (It != ExtraFlagsForFile.end()) {
51     // Append the user-specified flags to the compile commands.
52     for (tooling::CompileCommand &Command : Commands)
53       addExtraFlags(Command, It->second);
54   }
55 
56   return Commands;
57 }
58 
59 void DirectoryBasedGlobalCompilationDatabase::setExtraFlagsForFile(
60     PathRef File, std::vector<std::string> ExtraFlags) {
61   ExtraFlagsForFile[File] = std::move(ExtraFlags);
62 }
63 
64 tooling::CompilationDatabase *
65 DirectoryBasedGlobalCompilationDatabase::getCompilationDatabase(PathRef File) {
66   std::lock_guard<std::mutex> Lock(Mutex);
67 
68   namespace path = llvm::sys::path;
69 
70   assert((path::is_absolute(File, path::Style::posix) ||
71           path::is_absolute(File, path::Style::windows)) &&
72          "path must be absolute");
73 
74   for (auto Path = path::parent_path(File); !Path.empty();
75        Path = path::parent_path(Path)) {
76 
77     auto CachedIt = CompilationDatabases.find(Path);
78     if (CachedIt != CompilationDatabases.end())
79       return CachedIt->second.get();
80     std::string Error;
81     auto CDB = tooling::CompilationDatabase::loadFromDirectory(Path, Error);
82     if (!CDB) {
83       if (!Error.empty()) {
84         // FIXME(ibiryukov): logging
85         // Output.log("Error when trying to load compilation database from " +
86         //            Twine(Path) + ": " + Twine(Error) + "\n");
87       }
88       continue;
89     }
90 
91     // FIXME(ibiryukov): Invalidate cached compilation databases on changes
92     auto result = CDB.get();
93     CompilationDatabases.insert(std::make_pair(Path, std::move(CDB)));
94     return result;
95   }
96 
97   // FIXME(ibiryukov): logging
98   // Output.log("Failed to find compilation database for " + Twine(File) +
99   // "\n");
100   return nullptr;
101 }
102 
103 } // namespace clangd
104 } // namespace clang
105