1//===-- ClangHost.cpp -----------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "ClangHost.h"
10
11#include "clang/Basic/Version.h"
12#include "clang/Config/config.h"
13#include "clang/Driver/Driver.h"
14
15#include "llvm/ADT/StringRef.h"
16#include "llvm/ADT/Twine.h"
17#include "llvm/Support/FileSystem.h"
18#include "llvm/Support/Threading.h"
19
20#include "lldb/Host/Config.h"
21#include "lldb/Host/FileSystem.h"
22#include "lldb/Host/HostInfo.h"
23#include "lldb/Utility/FileSpec.h"
24#include "lldb/Utility/LLDBLog.h"
25#include "lldb/Utility/Log.h"
26
27#include <string>
28
29using namespace lldb_private;
30
31static bool VerifyClangPath(const llvm::Twine &clang_path) {
32 if (FileSystem::Instance().IsDirectory(path: clang_path))
33 return true;
34 Log *log = GetLog(mask: LLDBLog::Host);
35 LLDB_LOGF(log,
36 "VerifyClangPath(): "
37 "failed to stat clang resource directory at \"%s\"",
38 clang_path.str().c_str());
39 return false;
40}
41
42///
43/// This will compute the clang resource directory assuming that clang was
44/// installed with the same prefix as lldb.
45///
46/// If verify is true, the first candidate resource directory will be returned.
47/// This mode is only used for testing.
48///
49static bool DefaultComputeClangResourceDirectory(FileSpec &lldb_shlib_spec,
50 FileSpec &file_spec,
51 bool verify) {
52 Log *log = GetLog(mask: LLDBLog::Host);
53 std::string raw_path = lldb_shlib_spec.GetPath();
54 llvm::StringRef parent_dir = llvm::sys::path::parent_path(path: raw_path);
55 static const std::string clang_resource_path =
56 clang::driver::Driver::GetResourcesPath(BinaryPath: "bin/lldb");
57
58 static const llvm::StringRef kResourceDirSuffixes[] = {
59 // LLVM.org's build of LLDB uses the clang resource directory placed
60 // in $install_dir/lib{,64}/clang/$clang_version or
61 // $install_dir/bin/$CLANG_RESOURCE_DIR
62 clang_resource_path,
63 // swift-lldb uses the clang resource directory copied from swift, which
64 // by default is placed in $install_dir/lib{,64}/lldb/clang. LLDB places
65 // it there, so we use LLDB_INSTALL_LIBDIR_BASENAME.
66 LLDB_INSTALL_LIBDIR_BASENAME "/lldb/clang",
67 };
68
69 for (const auto &Suffix : kResourceDirSuffixes) {
70 llvm::SmallString<256> clang_dir(parent_dir);
71 llvm::SmallString<32> relative_path(Suffix);
72 llvm::sys::path::native(path&: relative_path);
73 llvm::sys::path::append(path&: clang_dir, a: relative_path);
74 if (!verify || VerifyClangPath(clang_path: clang_dir)) {
75 LLDB_LOG(log,
76 "DefaultComputeClangResourceDir: Setting ClangResourceDir "
77 "to \"{0}\", verify = {1}",
78 clang_dir.str(), verify ? "true" : "false");
79 file_spec.SetDirectory(clang_dir);
80 FileSystem::Instance().Resolve(file_spec);
81 return true;
82 }
83 }
84
85 return false;
86}
87
88bool lldb_private::ComputeClangResourceDirectory(FileSpec &lldb_shlib_spec,
89 FileSpec &file_spec,
90 bool verify) {
91#if !defined(__APPLE__)
92 return DefaultComputeClangResourceDirectory(lldb_shlib_spec, file_spec,
93 verify);
94#else
95 std::string raw_path = lldb_shlib_spec.GetPath();
96
97 auto rev_it = llvm::sys::path::rbegin(raw_path);
98 auto r_end = llvm::sys::path::rend(raw_path);
99
100 // Check for a Posix-style build of LLDB.
101 while (rev_it != r_end) {
102 if (*rev_it == "LLDB.framework")
103 break;
104 ++rev_it;
105 }
106
107 // We found a non-framework build of LLDB
108 if (rev_it == r_end)
109 return DefaultComputeClangResourceDirectory(lldb_shlib_spec, file_spec,
110 verify);
111
112 // Inside Xcode and in Xcode toolchains LLDB is always in lockstep
113 // with the Swift compiler, so it can reuse its Clang resource
114 // directory. This allows LLDB and the Swift compiler to share the
115 // same Clang module cache.
116 llvm::SmallString<256> clang_path;
117 const char *swift_clang_resource_dir = "usr/lib/swift/clang";
118 auto parent = std::next(rev_it);
119 if (parent != r_end && *parent == "SharedFrameworks") {
120 // This is the top-level LLDB in the Xcode.app bundle.
121 // E.g., "Xcode.app/Contents/SharedFrameworks/LLDB.framework/Versions/A"
122 raw_path.resize(parent - r_end);
123 llvm::sys::path::append(clang_path, raw_path,
124 "Developer/Toolchains/XcodeDefault.xctoolchain",
125 swift_clang_resource_dir);
126 if (!verify || VerifyClangPath(clang_path)) {
127 file_spec.SetDirectory(clang_path);
128 FileSystem::Instance().Resolve(file_spec);
129 return true;
130 }
131 } else if (parent != r_end && *parent == "PrivateFrameworks" &&
132 std::distance(parent, r_end) > 2) {
133 ++parent;
134 ++parent;
135 if (*parent == "System") {
136 // This is LLDB inside an Xcode toolchain.
137 // E.g., "Xcode.app/Contents/Developer/Toolchains/" \
138 // "My.xctoolchain/System/Library/PrivateFrameworks/LLDB.framework"
139 raw_path.resize(parent - r_end);
140 llvm::sys::path::append(clang_path, raw_path, swift_clang_resource_dir);
141 if (!verify || VerifyClangPath(clang_path)) {
142 file_spec.SetDirectory(clang_path);
143 FileSystem::Instance().Resolve(file_spec);
144 return true;
145 }
146 }
147 }
148
149 // Fall back to the Clang resource directory inside the framework.
150 raw_path = lldb_shlib_spec.GetPath();
151 raw_path.resize(rev_it - r_end);
152 raw_path.append("LLDB.framework/Resources/Clang");
153 file_spec.SetDirectory(raw_path);
154 FileSystem::Instance().Resolve(file_spec);
155 return true;
156#endif // __APPLE__
157}
158
159FileSpec lldb_private::GetClangResourceDir() {
160 static FileSpec g_cached_resource_dir;
161 static llvm::once_flag g_once_flag;
162 llvm::call_once(flag&: g_once_flag, F: []() {
163 if (FileSpec lldb_file_spec = HostInfo::GetShlibDir())
164 ComputeClangResourceDirectory(lldb_shlib_spec&: lldb_file_spec, file_spec&: g_cached_resource_dir,
165 verify: true);
166 Log *log = GetLog(mask: LLDBLog::Host);
167 LLDB_LOGF(log, "GetClangResourceDir() => '%s'",
168 g_cached_resource_dir.GetPath().c_str());
169 });
170 return g_cached_resource_dir;
171}
172

source code of lldb/source/Plugins/ExpressionParser/Clang/ClangHost.cpp