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/Config.h"
11 #include "lldb/Host/linux/HostInfoLinux.h"
12 #include "lldb/Utility/Log.h"
13 
14 #include "llvm/Support/Threading.h"
15 
16 #include <limits.h>
17 #include <stdio.h>
18 #include <string.h>
19 #include <sys/utsname.h>
20 #include <unistd.h>
21 
22 #include <algorithm>
23 #include <mutex> // std::once
24 
25 using namespace lldb_private;
26 
27 namespace {
28 struct HostInfoLinuxFields {
29   HostInfoLinuxFields() : m_os_major(0), m_os_minor(0), m_os_update(0) {}
30 
31   std::string m_distribution_id;
32   uint32_t m_os_major;
33   uint32_t m_os_minor;
34   uint32_t m_os_update;
35 };
36 
37 HostInfoLinuxFields *g_fields = nullptr;
38 }
39 
40 void HostInfoLinux::Initialize() {
41   HostInfoPosix::Initialize();
42 
43   g_fields = new HostInfoLinuxFields();
44 }
45 
46 bool HostInfoLinux::GetOSVersion(uint32_t &major, uint32_t &minor,
47                                  uint32_t &update) {
48   static bool success = false;
49   static llvm::once_flag g_once_flag;
50   llvm::call_once(g_once_flag, []() {
51 
52     struct utsname un;
53     if (uname(&un) == 0) {
54       int status = sscanf(un.release, "%u.%u.%u", &g_fields->m_os_major,
55                           &g_fields->m_os_minor, &g_fields->m_os_update);
56       if (status == 3)
57         success = true;
58       else {
59         // Some kernels omit the update version, so try looking for just "X.Y"
60         // and set update to 0.
61         g_fields->m_os_update = 0;
62         status = sscanf(un.release, "%u.%u", &g_fields->m_os_major,
63                         &g_fields->m_os_minor);
64         if (status == 2)
65           success = true;
66       }
67     }
68   });
69 
70   major = g_fields->m_os_major;
71   minor = g_fields->m_os_minor;
72   update = g_fields->m_os_update;
73   return success;
74 }
75 
76 bool HostInfoLinux::GetOSBuildString(std::string &s) {
77   struct utsname un;
78   ::memset(&un, 0, sizeof(utsname));
79   s.clear();
80 
81   if (uname(&un) < 0)
82     return false;
83 
84   s.assign(un.release);
85   return true;
86 }
87 
88 bool HostInfoLinux::GetOSKernelDescription(std::string &s) {
89   struct utsname un;
90 
91   ::memset(&un, 0, sizeof(utsname));
92   s.clear();
93 
94   if (uname(&un) < 0)
95     return false;
96 
97   s.assign(un.version);
98   return true;
99 }
100 
101 llvm::StringRef HostInfoLinux::GetDistributionId() {
102   // Try to run 'lbs_release -i', and use that response for the distribution
103   // id.
104   static llvm::once_flag g_once_flag;
105   llvm::call_once(g_once_flag, []() {
106 
107     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST));
108     if (log)
109       log->Printf("attempting to determine Linux distribution...");
110 
111     // check if the lsb_release command exists at one of the following paths
112     const char *const exe_paths[] = {"/bin/lsb_release",
113                                      "/usr/bin/lsb_release"};
114 
115     for (size_t exe_index = 0;
116          exe_index < sizeof(exe_paths) / sizeof(exe_paths[0]); ++exe_index) {
117       const char *const get_distribution_info_exe = exe_paths[exe_index];
118       if (access(get_distribution_info_exe, F_OK)) {
119         // this exe doesn't exist, move on to next exe
120         if (log)
121           log->Printf("executable doesn't exist: %s",
122                       get_distribution_info_exe);
123         continue;
124       }
125 
126       // execute the distribution-retrieval command, read output
127       std::string get_distribution_id_command(get_distribution_info_exe);
128       get_distribution_id_command += " -i";
129 
130       FILE *file = popen(get_distribution_id_command.c_str(), "r");
131       if (!file) {
132         if (log)
133           log->Printf("failed to run command: \"%s\", cannot retrieve "
134                       "platform information",
135                       get_distribution_id_command.c_str());
136         break;
137       }
138 
139       // retrieve the distribution id string.
140       char distribution_id[256] = {'\0'};
141       if (fgets(distribution_id, sizeof(distribution_id) - 1, file) != NULL) {
142         if (log)
143           log->Printf("distribution id command returned \"%s\"",
144                       distribution_id);
145 
146         const char *const distributor_id_key = "Distributor ID:\t";
147         if (strstr(distribution_id, distributor_id_key)) {
148           // strip newlines
149           std::string id_string(distribution_id + strlen(distributor_id_key));
150           id_string.erase(std::remove(id_string.begin(), id_string.end(), '\n'),
151                           id_string.end());
152 
153           // lower case it and convert whitespace to underscores
154           std::transform(
155               id_string.begin(), id_string.end(), id_string.begin(),
156               [](char ch) { return tolower(isspace(ch) ? '_' : ch); });
157 
158           g_fields->m_distribution_id = id_string;
159           if (log)
160             log->Printf("distribution id set to \"%s\"",
161                         g_fields->m_distribution_id.c_str());
162         } else {
163           if (log)
164             log->Printf("failed to find \"%s\" field in \"%s\"",
165                         distributor_id_key, distribution_id);
166         }
167       } else {
168         if (log)
169           log->Printf("failed to retrieve distribution id, \"%s\" returned no"
170                       " lines",
171                       get_distribution_id_command.c_str());
172       }
173 
174       // clean up the file
175       pclose(file);
176     }
177   });
178 
179   return g_fields->m_distribution_id;
180 }
181 
182 FileSpec HostInfoLinux::GetProgramFileSpec() {
183   static FileSpec g_program_filespec;
184 
185   if (!g_program_filespec) {
186     char exe_path[PATH_MAX];
187     ssize_t len = readlink("/proc/self/exe", exe_path, sizeof(exe_path) - 1);
188     if (len > 0) {
189       exe_path[len] = 0;
190       g_program_filespec.SetFile(exe_path, false, FileSpec::Style::native);
191     }
192   }
193 
194   return g_program_filespec;
195 }
196 
197 bool HostInfoLinux::ComputeSupportExeDirectory(FileSpec &file_spec) {
198   if (HostInfoPosix::ComputeSupportExeDirectory(file_spec) &&
199       file_spec.IsAbsolute() && file_spec.Exists())
200     return true;
201   file_spec.GetDirectory() = GetProgramFileSpec().GetDirectory();
202   return !file_spec.GetDirectory().IsEmpty();
203 }
204 
205 bool HostInfoLinux::ComputeSystemPluginsDirectory(FileSpec &file_spec) {
206   FileSpec temp_file("/usr/lib" LLDB_LIBDIR_SUFFIX "/lldb/plugins", true);
207   file_spec.GetDirectory().SetCString(temp_file.GetPath().c_str());
208   return true;
209 }
210 
211 bool HostInfoLinux::ComputeUserPluginsDirectory(FileSpec &file_spec) {
212   // XDG Base Directory Specification
213   // http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html If
214   // XDG_DATA_HOME exists, use that, otherwise use ~/.local/share/lldb.
215   const char *xdg_data_home = getenv("XDG_DATA_HOME");
216   if (xdg_data_home && xdg_data_home[0]) {
217     std::string user_plugin_dir(xdg_data_home);
218     user_plugin_dir += "/lldb";
219     file_spec.GetDirectory().SetCString(user_plugin_dir.c_str());
220   } else
221     file_spec.GetDirectory().SetCString("~/.local/share/lldb");
222   return true;
223 }
224 
225 void HostInfoLinux::ComputeHostArchitectureSupport(ArchSpec &arch_32,
226                                                    ArchSpec &arch_64) {
227   HostInfoPosix::ComputeHostArchitectureSupport(arch_32, arch_64);
228 
229   const char *distribution_id = GetDistributionId().data();
230 
231   // On Linux, "unknown" in the vendor slot isn't what we want for the default
232   // triple.  It's probably an artifact of config.guess.
233   if (arch_32.IsValid()) {
234     arch_32.SetDistributionId(distribution_id);
235     if (arch_32.GetTriple().getVendor() == llvm::Triple::UnknownVendor)
236       arch_32.GetTriple().setVendorName(llvm::StringRef());
237   }
238   if (arch_64.IsValid()) {
239     arch_64.SetDistributionId(distribution_id);
240     if (arch_64.GetTriple().getVendor() == llvm::Triple::UnknownVendor)
241       arch_64.GetTriple().setVendorName(llvm::StringRef());
242   }
243 }
244