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 "Logger.h"
12 #include "clang/Tooling/CompilationDatabase.h"
13 #include "llvm/Support/FileSystem.h"
14 #include "llvm/Support/Path.h"
15 
16 namespace clang {
17 namespace clangd {
18 
19 tooling::CompileCommand
20 GlobalCompilationDatabase::getFallbackCommand(PathRef File) const {
21   return tooling::CompileCommand(llvm::sys::path::parent_path(File),
22                                  llvm::sys::path::filename(File),
23                                  {"clang", File.str()},
24                                  /*Output=*/"");
25 }
26 
27 DirectoryBasedGlobalCompilationDatabase::
28     DirectoryBasedGlobalCompilationDatabase(
29         llvm::Optional<Path> CompileCommandsDir)
30     : CompileCommandsDir(std::move(CompileCommandsDir)) {}
31 
32 llvm::Optional<tooling::CompileCommand>
33 DirectoryBasedGlobalCompilationDatabase::getCompileCommand(PathRef File) const {
34   if (auto CDB = getCDBForFile(File)) {
35     auto Candidates = CDB->getCompileCommands(File);
36     if (!Candidates.empty()) {
37       addExtraFlags(File, Candidates.front());
38       return std::move(Candidates.front());
39     }
40   } else {
41     log(Context::empty(), // FIXME(ibiryukov): pass a proper Context here.
42         "Failed to find compilation database for " + Twine(File));
43   }
44   return llvm::None;
45 }
46 
47 tooling::CompileCommand
48 DirectoryBasedGlobalCompilationDatabase::getFallbackCommand(
49     PathRef File) const {
50   auto C = GlobalCompilationDatabase::getFallbackCommand(File);
51   addExtraFlags(File, C);
52   return C;
53 }
54 
55 void DirectoryBasedGlobalCompilationDatabase::setExtraFlagsForFile(
56     PathRef File, std::vector<std::string> ExtraFlags) {
57   std::lock_guard<std::mutex> Lock(Mutex);
58   ExtraFlagsForFile[File] = std::move(ExtraFlags);
59 }
60 
61 void DirectoryBasedGlobalCompilationDatabase::addExtraFlags(
62     PathRef File, tooling::CompileCommand &C) const {
63   std::lock_guard<std::mutex> Lock(Mutex);
64 
65   auto It = ExtraFlagsForFile.find(File);
66   if (It == ExtraFlagsForFile.end())
67     return;
68 
69   auto &Args = C.CommandLine;
70   assert(Args.size() >= 2 && "Expected at least [compiler, source file]");
71   // The last argument of CommandLine is the name of the input file.
72   // Add ExtraFlags before it.
73   Args.insert(Args.end() - 1, It->second.begin(), It->second.end());
74 }
75 
76 tooling::CompilationDatabase *
77 DirectoryBasedGlobalCompilationDatabase::getCDBInDirLocked(PathRef Dir) const {
78   // FIXME(ibiryukov): Invalidate cached compilation databases on changes
79   auto CachedIt = CompilationDatabases.find(Dir);
80   if (CachedIt != CompilationDatabases.end())
81     return CachedIt->second.get();
82   std::string Error = "";
83   auto CDB = tooling::CompilationDatabase::loadFromDirectory(Dir, Error);
84   auto Result = CDB.get();
85   CompilationDatabases.insert(std::make_pair(Dir, std::move(CDB)));
86   return Result;
87 }
88 
89 tooling::CompilationDatabase *
90 DirectoryBasedGlobalCompilationDatabase::getCDBForFile(PathRef File) const {
91   namespace path = llvm::sys::path;
92   assert((path::is_absolute(File, path::Style::posix) ||
93           path::is_absolute(File, path::Style::windows)) &&
94          "path must be absolute");
95 
96   std::lock_guard<std::mutex> Lock(Mutex);
97   if (CompileCommandsDir)
98     return getCDBInDirLocked(*CompileCommandsDir);
99   for (auto Path = path::parent_path(File); !Path.empty();
100        Path = path::parent_path(Path))
101     if (auto CDB = getCDBInDirLocked(Path))
102       return CDB;
103   return nullptr;
104 }
105 
106 } // namespace clangd
107 } // namespace clang
108