1 //===-- HostInfoLinux.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 "lldb/Host/linux/HostInfoLinux.h"
11 #include "lldb/Host/Config.h"
12 #include "lldb/Host/FileSystem.h"
13 #include "lldb/Utility/Log.h"
14 
15 #include "llvm/Support/Threading.h"
16 
17 #include <limits.h>
18 #include <stdio.h>
19 #include <string.h>
20 #include <sys/utsname.h>
21 #include <unistd.h>
22 
23 #include <algorithm>
24 #include <mutex>
25 
26 using namespace lldb_private;
27 
28 namespace {
29 struct HostInfoLinuxFields {
30   std::string m_distribution_id;
31   llvm::VersionTuple m_os_version;
32 };
33 
34 HostInfoLinuxFields *g_fields = nullptr;
35 }
36 
37 void HostInfoLinux::Initialize() {
38   HostInfoPosix::Initialize();
39 
40   g_fields = new HostInfoLinuxFields();
41 }
42 
43 llvm::VersionTuple HostInfoLinux::GetOSVersion() {
44   static llvm::once_flag g_once_flag;
45   llvm::call_once(g_once_flag, []() {
46     struct utsname un;
47     if (uname(&un) != 0)
48       return;
49 
50     llvm::StringRef release = un.release;
51     // The kernel release string can include a lot of stuff (e.g.
52     // 4.9.0-6-amd64). We're only interested in the numbered prefix.
53     release = release.substr(0, release.find_first_not_of("0123456789."));
54     g_fields->m_os_version.tryParse(release);
55   });
56 
57   return g_fields->m_os_version;
58 }
59 
60 bool HostInfoLinux::GetOSBuildString(std::string &s) {
61   struct utsname un;
62   ::memset(&un, 0, sizeof(utsname));
63   s.clear();
64 
65   if (uname(&un) < 0)
66     return false;
67 
68   s.assign(un.release);
69   return true;
70 }
71 
72 bool HostInfoLinux::GetOSKernelDescription(std::string &s) {
73   struct utsname un;
74 
75   ::memset(&un, 0, sizeof(utsname));
76   s.clear();
77 
78   if (uname(&un) < 0)
79     return false;
80 
81   s.assign(un.version);
82   return true;
83 }
84 
85 llvm::StringRef HostInfoLinux::GetDistributionId() {
86   // Try to run 'lbs_release -i', and use that response for the distribution
87   // id.
88   static llvm::once_flag g_once_flag;
89   llvm::call_once(g_once_flag, []() {
90 
91     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST));
92     if (log)
93       log->Printf("attempting to determine Linux distribution...");
94 
95     // check if the lsb_release command exists at one of the following paths
96     const char *const exe_paths[] = {"/bin/lsb_release",
97                                      "/usr/bin/lsb_release"};
98 
99     for (size_t exe_index = 0;
100          exe_index < sizeof(exe_paths) / sizeof(exe_paths[0]); ++exe_index) {
101       const char *const get_distribution_info_exe = exe_paths[exe_index];
102       if (access(get_distribution_info_exe, F_OK)) {
103         // this exe doesn't exist, move on to next exe
104         if (log)
105           log->Printf("executable doesn't exist: %s",
106                       get_distribution_info_exe);
107         continue;
108       }
109 
110       // execute the distribution-retrieval command, read output
111       std::string get_distribution_id_command(get_distribution_info_exe);
112       get_distribution_id_command += " -i";
113 
114       FILE *file = popen(get_distribution_id_command.c_str(), "r");
115       if (!file) {
116         if (log)
117           log->Printf("failed to run command: \"%s\", cannot retrieve "
118                       "platform information",
119                       get_distribution_id_command.c_str());
120         break;
121       }
122 
123       // retrieve the distribution id string.
124       char distribution_id[256] = {'\0'};
125       if (fgets(distribution_id, sizeof(distribution_id) - 1, file) != NULL) {
126         if (log)
127           log->Printf("distribution id command returned \"%s\"",
128                       distribution_id);
129 
130         const char *const distributor_id_key = "Distributor ID:\t";
131         if (strstr(distribution_id, distributor_id_key)) {
132           // strip newlines
133           std::string id_string(distribution_id + strlen(distributor_id_key));
134           id_string.erase(std::remove(id_string.begin(), id_string.end(), '\n'),
135                           id_string.end());
136 
137           // lower case it and convert whitespace to underscores
138           std::transform(
139               id_string.begin(), id_string.end(), id_string.begin(),
140               [](char ch) { return tolower(isspace(ch) ? '_' : ch); });
141 
142           g_fields->m_distribution_id = id_string;
143           if (log)
144             log->Printf("distribution id set to \"%s\"",
145                         g_fields->m_distribution_id.c_str());
146         } else {
147           if (log)
148             log->Printf("failed to find \"%s\" field in \"%s\"",
149                         distributor_id_key, distribution_id);
150         }
151       } else {
152         if (log)
153           log->Printf("failed to retrieve distribution id, \"%s\" returned no"
154                       " lines",
155                       get_distribution_id_command.c_str());
156       }
157 
158       // clean up the file
159       pclose(file);
160     }
161   });
162 
163   return g_fields->m_distribution_id;
164 }
165 
166 FileSpec HostInfoLinux::GetProgramFileSpec() {
167   static FileSpec g_program_filespec;
168 
169   if (!g_program_filespec) {
170     char exe_path[PATH_MAX];
171     ssize_t len = readlink("/proc/self/exe", exe_path, sizeof(exe_path) - 1);
172     if (len > 0) {
173       exe_path[len] = 0;
174       g_program_filespec.SetFile(exe_path, FileSpec::Style::native);
175     }
176   }
177 
178   return g_program_filespec;
179 }
180 
181 bool HostInfoLinux::ComputeSupportExeDirectory(FileSpec &file_spec) {
182   if (HostInfoPosix::ComputeSupportExeDirectory(file_spec) &&
183       file_spec.IsAbsolute() && FileSystem::Instance().Exists(file_spec))
184     return true;
185   file_spec.GetDirectory() = GetProgramFileSpec().GetDirectory();
186   return !file_spec.GetDirectory().IsEmpty();
187 }
188 
189 bool HostInfoLinux::ComputeSystemPluginsDirectory(FileSpec &file_spec) {
190   FileSpec temp_file("/usr/lib" LLDB_LIBDIR_SUFFIX "/lldb/plugins");
191   FileSystem::Instance().Resolve(temp_file);
192   file_spec.GetDirectory().SetCString(temp_file.GetPath().c_str());
193   return true;
194 }
195 
196 bool HostInfoLinux::ComputeUserPluginsDirectory(FileSpec &file_spec) {
197   // XDG Base Directory Specification
198   // http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html If
199   // XDG_DATA_HOME exists, use that, otherwise use ~/.local/share/lldb.
200   const char *xdg_data_home = getenv("XDG_DATA_HOME");
201   if (xdg_data_home && xdg_data_home[0]) {
202     std::string user_plugin_dir(xdg_data_home);
203     user_plugin_dir += "/lldb";
204     file_spec.GetDirectory().SetCString(user_plugin_dir.c_str());
205   } else
206     file_spec.GetDirectory().SetCString("~/.local/share/lldb");
207   return true;
208 }
209 
210 void HostInfoLinux::ComputeHostArchitectureSupport(ArchSpec &arch_32,
211                                                    ArchSpec &arch_64) {
212   HostInfoPosix::ComputeHostArchitectureSupport(arch_32, arch_64);
213 
214   const char *distribution_id = GetDistributionId().data();
215 
216   // On Linux, "unknown" in the vendor slot isn't what we want for the default
217   // triple.  It's probably an artifact of config.guess.
218   if (arch_32.IsValid()) {
219     arch_32.SetDistributionId(distribution_id);
220     if (arch_32.GetTriple().getVendor() == llvm::Triple::UnknownVendor)
221       arch_32.GetTriple().setVendorName(llvm::StringRef());
222   }
223   if (arch_64.IsValid()) {
224     arch_64.SetDistributionId(distribution_id);
225     if (arch_64.GetTriple().getVendor() == llvm::Triple::UnknownVendor)
226       arch_64.GetTriple().setVendorName(llvm::StringRef());
227   }
228 }
229