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/Utility/Log.h"
12 
13 #include "llvm/Support/Threading.h"
14 
15 #include <limits.h>
16 #include <stdio.h>
17 #include <string.h>
18 #include <sys/utsname.h>
19 #include <unistd.h>
20 
21 #include <algorithm>
22 #include <mutex> // std::once
23 
24 using namespace lldb_private;
25 
26 namespace {
27 struct HostInfoLinuxFields {
28   HostInfoLinuxFields() : m_os_major(0), m_os_minor(0), m_os_update(0) {}
29 
30   std::string m_distribution_id;
31   uint32_t m_os_major;
32   uint32_t m_os_minor;
33   uint32_t m_os_update;
34 };
35 
36 HostInfoLinuxFields *g_fields = nullptr;
37 }
38 
39 void HostInfoLinux::Initialize() {
40   HostInfoPosix::Initialize();
41 
42   g_fields = new HostInfoLinuxFields();
43 }
44 
45 bool HostInfoLinux::GetOSVersion(uint32_t &major, uint32_t &minor,
46                                  uint32_t &update) {
47   static bool success = false;
48   static llvm::once_flag g_once_flag;
49   llvm::call_once(g_once_flag, []() {
50 
51     struct utsname un;
52     if (uname(&un) == 0) {
53       int status = sscanf(un.release, "%u.%u.%u", &g_fields->m_os_major,
54                           &g_fields->m_os_minor, &g_fields->m_os_update);
55       if (status == 3)
56         success = true;
57       else {
58         // Some kernels omit the update version, so try looking for just "X.Y"
59         // and
60         // 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
103   // for the distribution 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
112     // following paths
113     const char *const exe_paths[] = {"/bin/lsb_release",
114                                      "/usr/bin/lsb_release"};
115 
116     for (size_t exe_index = 0;
117          exe_index < sizeof(exe_paths) / sizeof(exe_paths[0]); ++exe_index) {
118       const char *const get_distribution_info_exe = exe_paths[exe_index];
119       if (access(get_distribution_info_exe, F_OK)) {
120         // this exe doesn't exist, move on to next exe
121         if (log)
122           log->Printf("executable doesn't exist: %s",
123                       get_distribution_info_exe);
124         continue;
125       }
126 
127       // execute the distribution-retrieval command, read output
128       std::string get_distribution_id_command(get_distribution_info_exe);
129       get_distribution_id_command += " -i";
130 
131       FILE *file = popen(get_distribution_id_command.c_str(), "r");
132       if (!file) {
133         if (log)
134           log->Printf("failed to run command: \"%s\", cannot retrieve "
135                       "platform information",
136                       get_distribution_id_command.c_str());
137         break;
138       }
139 
140       // retrieve the distribution id string.
141       char distribution_id[256] = {'\0'};
142       if (fgets(distribution_id, sizeof(distribution_id) - 1, file) != NULL) {
143         if (log)
144           log->Printf("distribution id command returned \"%s\"",
145                       distribution_id);
146 
147         const char *const distributor_id_key = "Distributor ID:\t";
148         if (strstr(distribution_id, distributor_id_key)) {
149           // strip newlines
150           std::string id_string(distribution_id + strlen(distributor_id_key));
151           id_string.erase(std::remove(id_string.begin(), id_string.end(), '\n'),
152                           id_string.end());
153 
154           // lower case it and convert whitespace to underscores
155           std::transform(
156               id_string.begin(), id_string.end(), id_string.begin(),
157               [](char ch) { return tolower(isspace(ch) ? '_' : ch); });
158 
159           g_fields->m_distribution_id = id_string;
160           if (log)
161             log->Printf("distribution id set to \"%s\"",
162                         g_fields->m_distribution_id.c_str());
163         } else {
164           if (log)
165             log->Printf("failed to find \"%s\" field in \"%s\"",
166                         distributor_id_key, distribution_id);
167         }
168       } else {
169         if (log)
170           log->Printf("failed to retrieve distribution id, \"%s\" returned no"
171                       " lines",
172                       get_distribution_id_command.c_str());
173       }
174 
175       // clean up the file
176       pclose(file);
177     }
178   });
179 
180   return g_fields->m_distribution_id;
181 }
182 
183 FileSpec HostInfoLinux::GetProgramFileSpec() {
184   static FileSpec g_program_filespec;
185 
186   if (!g_program_filespec) {
187     char exe_path[PATH_MAX];
188     ssize_t len = readlink("/proc/self/exe", exe_path, sizeof(exe_path) - 1);
189     if (len > 0) {
190       exe_path[len] = 0;
191       g_program_filespec.SetFile(exe_path, false);
192     }
193   }
194 
195   return g_program_filespec;
196 }
197 
198 bool HostInfoLinux::ComputeSupportExeDirectory(FileSpec &file_spec) {
199   if (HostInfoPosix::ComputeSupportExeDirectory(file_spec) &&
200       file_spec.IsAbsolute() && file_spec.Exists())
201     return true;
202   file_spec.GetDirectory() = GetProgramFileSpec().GetDirectory();
203   return !file_spec.GetDirectory().IsEmpty();
204 }
205 
206 bool HostInfoLinux::ComputeSystemPluginsDirectory(FileSpec &file_spec) {
207   FileSpec temp_file("/usr/lib/lldb/plugins", true);
208   file_spec.GetDirectory().SetCString(temp_file.GetPath().c_str());
209   return true;
210 }
211 
212 bool HostInfoLinux::ComputeUserPluginsDirectory(FileSpec &file_spec) {
213   // XDG Base Directory Specification
214   // http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
215   // If XDG_DATA_HOME exists, use that, otherwise use ~/.local/share/lldb.
216   const char *xdg_data_home = getenv("XDG_DATA_HOME");
217   if (xdg_data_home && xdg_data_home[0]) {
218     std::string user_plugin_dir(xdg_data_home);
219     user_plugin_dir += "/lldb";
220     file_spec.GetDirectory().SetCString(user_plugin_dir.c_str());
221   } else
222     file_spec.GetDirectory().SetCString("~/.local/share/lldb");
223   return true;
224 }
225 
226 void HostInfoLinux::ComputeHostArchitectureSupport(ArchSpec &arch_32,
227                                                    ArchSpec &arch_64) {
228   HostInfoPosix::ComputeHostArchitectureSupport(arch_32, arch_64);
229 
230   const char *distribution_id = GetDistributionId().data();
231 
232   // On Linux, "unknown" in the vendor slot isn't what we want for the default
233   // triple.  It's probably an artifact of config.guess.
234   if (arch_32.IsValid()) {
235     arch_32.SetDistributionId(distribution_id);
236     if (arch_32.GetTriple().getVendor() == llvm::Triple::UnknownVendor)
237       arch_32.GetTriple().setVendorName(llvm::StringRef());
238   }
239   if (arch_64.IsValid()) {
240     arch_64.SetDistributionId(distribution_id);
241     if (arch_64.GetTriple().getVendor() == llvm::Triple::UnknownVendor)
242       arch_64.GetTriple().setVendorName(llvm::StringRef());
243   }
244 }
245