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