1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <err.h>
18 #include <fcntl.h>
19 #include <fts.h>
20 #include <sys/stat.h>
21 #include <sys/types.h>
22 #include <unistd.h>
23 
24 #include <memory>
25 #include <string>
26 
27 #include <android-base/unique_fd.h>
28 #include <clang/Basic/VirtualFileSystem.h>
29 #include <llvm/ADT/IntrusiveRefCntPtr.h>
30 #include <llvm/Support/MemoryBuffer.h>
31 
32 #include "Utils.h"
33 
34 using android::base::unique_fd;
35 using namespace clang::vfs;
36 
addDirectoryToVFS(InMemoryFileSystem * vfs,const std::string & path)37 static void addDirectoryToVFS(InMemoryFileSystem* vfs, const std::string& path) {
38   char* paths[] = { const_cast<char*>(path.c_str()), nullptr };
39   std::unique_ptr<FTS, decltype(&fts_close)> fts(
40       fts_open(paths, FTS_COMFOLLOW | FTS_LOGICAL | FTS_NOCHDIR, nullptr), fts_close);
41 
42   if (!fts) {
43     err(1, "failed to open directory %s", path.c_str());
44   }
45 
46   while (FTSENT* ent = fts_read(fts.get())) {
47     if ((ent->fts_info & FTS_F) == 0) {
48       continue;
49     }
50 
51     const char* file_path = ent->fts_accpath;
52     unique_fd fd(open(file_path, O_RDONLY | O_CLOEXEC));
53     if (fd == -1) {
54       err(1, "failed to open header '%s'", file_path);
55     }
56 
57     auto buffer_opt = llvm::MemoryBuffer::getOpenFile(fd, file_path, -1, false, false);
58     if (!buffer_opt) {
59       errx(1, "failed to map header '%s'", file_path);
60     }
61 
62     if (!vfs->addFile(file_path, ent->fts_statp->st_mtime, std::move(buffer_opt.get()))) {
63       errx(1, "failed to add file '%s'", file_path);
64     }
65   }
66 }
67 
createCommonVFS(const std::string & header_dir,const std::string & dependency_dir,bool add_versioning_header)68 llvm::IntrusiveRefCntPtr<FileSystem> createCommonVFS(const std::string& header_dir,
69                                                      const std::string& dependency_dir,
70                                                      bool add_versioning_header) {
71   auto vfs = std::make_unique<InMemoryFileSystem>();
72   addDirectoryToVFS(vfs.get(), header_dir);
73   if (!dependency_dir.empty()) {
74     addDirectoryToVFS(vfs.get(), dependency_dir);
75   }
76 
77   if (add_versioning_header) {
78     const char* top = getenv("ANDROID_BUILD_TOP");
79     if (!top) {
80       errx(1, "-i passed, but ANDROID_BUILD_TOP is unset");
81     }
82 
83     std::string header_path = std::string(top) + "/bionic/libc/include/android/versioning.h";
84     auto buffer_opt = llvm::MemoryBuffer::getFile(header_path);
85     if (!buffer_opt) {
86       err(1, "failed to open %s", header_path.c_str());
87     }
88     vfs->addFile("android/versioning.h", 0, std::move(buffer_opt.get()));
89   }
90 
91   return llvm::IntrusiveRefCntPtr<FileSystem>(vfs.release());
92 }
93