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/Core/Log.h"
11 #include "lldb/Host/linux/HostInfoLinux.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 {
25 struct HostInfoLinuxFields
26 {
27     HostInfoLinuxFields()
28         : m_os_major(0)
29         , m_os_minor(0)
30         , m_os_update(0)
31     {
32     }
33 
34     std::string m_distribution_id;
35     uint32_t m_os_major;
36     uint32_t m_os_minor;
37     uint32_t m_os_update;
38 };
39 
40 HostInfoLinuxFields *g_fields = nullptr;
41 }
42 
43 void
44 HostInfoLinux::Initialize()
45 {
46     HostInfoPosix::Initialize();
47 
48     g_fields = new HostInfoLinuxFields();
49 }
50 
51 uint32_t
52 HostInfoLinux::GetMaxThreadNameLength()
53 {
54     return 16;
55 }
56 
57 bool
58 HostInfoLinux::GetOSVersion(uint32_t &major, uint32_t &minor, uint32_t &update)
59 {
60     static bool success = false;
61     static std::once_flag g_once_flag;
62     std::call_once(g_once_flag,  []() {
63 
64         struct utsname un;
65         if (uname(&un) == 0)
66         {
67             int status = sscanf(un.release, "%u.%u.%u", &g_fields->m_os_major, &g_fields->m_os_minor, &g_fields->m_os_update);
68             if (status == 3)
69                 success = true;
70             else
71             {
72                 // Some kernels omit the update version, so try looking for just "X.Y" and
73                 // set update to 0.
74                 g_fields->m_os_update = 0;
75                 status = sscanf(un.release, "%u.%u", &g_fields->m_os_major, &g_fields->m_os_minor);
76                 if (status == 2)
77                     success = true;
78             }
79         }
80     });
81 
82 
83     major = g_fields->m_os_major;
84     minor = g_fields->m_os_minor;
85     update = g_fields->m_os_update;
86     return success;
87 }
88 
89 bool
90 HostInfoLinux::GetOSBuildString(std::string &s)
91 {
92     struct utsname un;
93     ::memset(&un, 0, sizeof(utsname));
94     s.clear();
95 
96     if (uname(&un) < 0)
97         return false;
98 
99     s.assign(un.release);
100     return true;
101 }
102 
103 bool
104 HostInfoLinux::GetOSKernelDescription(std::string &s)
105 {
106     struct utsname un;
107 
108     ::memset(&un, 0, sizeof(utsname));
109     s.clear();
110 
111     if (uname(&un) < 0)
112         return false;
113 
114     s.assign(un.version);
115     return true;
116 }
117 
118 llvm::StringRef
119 HostInfoLinux::GetDistributionId()
120 {
121     // Try to run 'lbs_release -i', and use that response
122     // for the distribution id.
123     static std::once_flag g_once_flag;
124     std::call_once(g_once_flag,  []() {
125 
126         Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST));
127         if (log)
128             log->Printf("attempting to determine Linux distribution...");
129 
130         // check if the lsb_release command exists at one of the
131         // following paths
132         const char *const exe_paths[] = {"/bin/lsb_release", "/usr/bin/lsb_release"};
133 
134         for (size_t exe_index = 0; exe_index < sizeof(exe_paths) / sizeof(exe_paths[0]); ++exe_index)
135         {
136             const char *const get_distribution_info_exe = exe_paths[exe_index];
137             if (access(get_distribution_info_exe, F_OK))
138             {
139                 // this exe doesn't exist, move on to next exe
140                 if (log)
141                     log->Printf("executable doesn't exist: %s", get_distribution_info_exe);
142                 continue;
143             }
144 
145             // execute the distribution-retrieval command, read output
146             std::string get_distribution_id_command(get_distribution_info_exe);
147             get_distribution_id_command += " -i";
148 
149             FILE *file = popen(get_distribution_id_command.c_str(), "r");
150             if (!file)
151             {
152                 if (log)
153                     log->Printf("failed to run command: \"%s\", cannot retrieve "
154                                 "platform information",
155                                 get_distribution_id_command.c_str());
156                 break;
157             }
158 
159             // retrieve the distribution id string.
160             char distribution_id[256] = {'\0'};
161             if (fgets(distribution_id, sizeof(distribution_id) - 1, file) != NULL)
162             {
163                 if (log)
164                     log->Printf("distribution id command returned \"%s\"", distribution_id);
165 
166                 const char *const distributor_id_key = "Distributor ID:\t";
167                 if (strstr(distribution_id, distributor_id_key))
168                 {
169                     // strip newlines
170                     std::string id_string(distribution_id + strlen(distributor_id_key));
171                     id_string.erase(std::remove(id_string.begin(), id_string.end(), '\n'), id_string.end());
172 
173                     // lower case it and convert whitespace to underscores
174                     std::transform(id_string.begin(), id_string.end(), id_string.begin(), [](char ch)
175                                    {
176                         return tolower(isspace(ch) ? '_' : ch);
177                     });
178 
179                     g_fields->m_distribution_id = id_string;
180                     if (log)
181                         log->Printf("distribution id set to \"%s\"", g_fields->m_distribution_id.c_str());
182                 }
183                 else
184                 {
185                     if (log)
186                         log->Printf("failed to find \"%s\" field in \"%s\"", distributor_id_key, distribution_id);
187                 }
188             }
189             else
190             {
191                 if (log)
192                     log->Printf("failed to retrieve distribution id, \"%s\" returned no"
193                                 " lines",
194                                 get_distribution_id_command.c_str());
195             }
196 
197             // clean up the file
198             pclose(file);
199         }
200     });
201 
202     return g_fields->m_distribution_id.c_str();
203 }
204 
205 FileSpec
206 HostInfoLinux::GetProgramFileSpec()
207 {
208     static FileSpec g_program_filespec;
209 
210     if (!g_program_filespec)
211     {
212         char exe_path[PATH_MAX];
213         ssize_t len = readlink("/proc/self/exe", exe_path, sizeof(exe_path) - 1);
214         if (len > 0)
215         {
216             exe_path[len] = 0;
217             g_program_filespec.SetFile(exe_path, false);
218         }
219     }
220 
221     return g_program_filespec;
222 }
223 
224 bool
225 HostInfoLinux::ComputeSharedLibraryDirectory(FileSpec &file_spec)
226 {
227     if (HostInfoPosix::ComputeSharedLibraryDirectory(file_spec))
228         return true;
229     file_spec.GetDirectory() = GetProgramFileSpec().GetDirectory();
230     return (bool)file_spec.GetDirectory();
231 }
232 
233 bool
234 HostInfoLinux::ComputeSystemPluginsDirectory(FileSpec &file_spec)
235 {
236     FileSpec temp_file("/usr/lib/lldb", true);
237     file_spec.GetDirectory().SetCString(temp_file.GetPath().c_str());
238     return true;
239 }
240 
241 bool
242 HostInfoLinux::ComputeUserPluginsDirectory(FileSpec &file_spec)
243 {
244     // XDG Base Directory Specification
245     // http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
246     // If XDG_DATA_HOME exists, use that, otherwise use ~/.local/share/lldb.
247     const char *xdg_data_home = getenv("XDG_DATA_HOME");
248     if (xdg_data_home && xdg_data_home[0])
249     {
250         std::string user_plugin_dir(xdg_data_home);
251         user_plugin_dir += "/lldb";
252         file_spec.GetDirectory().SetCString(user_plugin_dir.c_str());
253     }
254     else
255         file_spec.GetDirectory().SetCString("~/.local/share/lldb");
256     return true;
257 }
258 
259 void
260 HostInfoLinux::ComputeHostArchitectureSupport(ArchSpec &arch_32, ArchSpec &arch_64)
261 {
262     HostInfoPosix::ComputeHostArchitectureSupport(arch_32, arch_64);
263 
264     const char *distribution_id = GetDistributionId().data();
265 
266     // On Linux, "unknown" in the vendor slot isn't what we want for the default
267     // triple.  It's probably an artifact of config.guess.
268     if (arch_32.IsValid())
269     {
270         arch_32.SetDistributionId(distribution_id);
271         if (arch_32.GetTriple().getVendor() == llvm::Triple::UnknownVendor)
272             arch_32.GetTriple().setVendorName("");
273     }
274     if (arch_64.IsValid())
275     {
276         arch_64.SetDistributionId(distribution_id);
277         if (arch_64.GetTriple().getVendor() == llvm::Triple::UnknownVendor)
278             arch_64.GetTriple().setVendorName("");
279     }
280 }
281