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/Core/Log.h"
12 
13 #include <limits.h>
14 #include <stdio.h>
15 #include <string.h>
16 #include <sys/utsname.h>
17 
18 #include <algorithm>
19 #include <mutex> // std::once
20 
21 using namespace lldb_private;
22 
23 namespace {
24 struct HostInfoLinuxFields {
25   HostInfoLinuxFields() : m_os_major(0), m_os_minor(0), m_os_update(0) {}
26 
27   std::string m_distribution_id;
28   uint32_t m_os_major;
29   uint32_t m_os_minor;
30   uint32_t m_os_update;
31 };
32 
33 HostInfoLinuxFields *g_fields = nullptr;
34 }
35 
36 void HostInfoLinux::Initialize() {
37   HostInfoPosix::Initialize();
38 
39   g_fields = new HostInfoLinuxFields();
40 }
41 
42 uint32_t HostInfoLinux::GetMaxThreadNameLength() { return 16; }
43 
44 bool HostInfoLinux::GetOSVersion(uint32_t &major, uint32_t &minor,
45                                  uint32_t &update) {
46   static bool success = false;
47   static std::once_flag g_once_flag;
48   std::call_once(g_once_flag, []() {
49 
50     struct utsname un;
51     if (uname(&un) == 0) {
52       int status = sscanf(un.release, "%u.%u.%u", &g_fields->m_os_major,
53                           &g_fields->m_os_minor, &g_fields->m_os_update);
54       if (status == 3)
55         success = true;
56       else {
57         // Some kernels omit the update version, so try looking for just "X.Y"
58         // and
59         // set update to 0.
60         g_fields->m_os_update = 0;
61         status = sscanf(un.release, "%u.%u", &g_fields->m_os_major,
62                         &g_fields->m_os_minor);
63         if (status == 2)
64           success = true;
65       }
66     }
67   });
68 
69   major = g_fields->m_os_major;
70   minor = g_fields->m_os_minor;
71   update = g_fields->m_os_update;
72   return success;
73 }
74 
75 bool HostInfoLinux::GetOSBuildString(std::string &s) {
76   struct utsname un;
77   ::memset(&un, 0, sizeof(utsname));
78   s.clear();
79 
80   if (uname(&un) < 0)
81     return false;
82 
83   s.assign(un.release);
84   return true;
85 }
86 
87 bool HostInfoLinux::GetOSKernelDescription(std::string &s) {
88   struct utsname un;
89 
90   ::memset(&un, 0, sizeof(utsname));
91   s.clear();
92 
93   if (uname(&un) < 0)
94     return false;
95 
96   s.assign(un.version);
97   return true;
98 }
99 
100 llvm::StringRef HostInfoLinux::GetDistributionId() {
101   // Try to run 'lbs_release -i', and use that response
102   // for the distribution id.
103   static std::once_flag g_once_flag;
104   std::call_once(g_once_flag, []() {
105 
106     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST));
107     if (log)
108       log->Printf("attempting to determine Linux distribution...");
109 
110     // check if the lsb_release command exists at one of the
111     // 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.c_str();
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);
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/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
214   // If 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