Enable Linux distribution in vendor portion of host triple.

This change does the following:

* enables building lldb-gdbserver on linux_x86-64 platforms.

  Note - it builds but it has several run-time issues where many gdb
  remote protocol features are not properly implemented yet. I'm
  working on these one at a time.

* lldb-gdbserver: does not enable the eLaunchFlagDebug launch flag on
  Linux. Currently the POSIX launch routine will assert if that flag
  is passed in, presumably because that launch mode is not yet
  available.  This prevents lldb-gdbserver from asserting the moment
  it launches the debuggee process.

* Adds ConstString& Host::GetDistributionId ()

  This method is defined to return an empty result on all platforms
  except for Linux.  On Linux, it makes one attempt to execute
  'lsb_release -i' (both /usr/bin/lsb_release, where it appears
  on ubuntu, and /bin/lsb_release, where it appears on fedora
  if the redhat-lsb package is installed).  If lsb_release is not
  found in either of those locations, or if 'lsb_release -i' does
  not return the first line starting with "Distributor ID:\t",
  then the distribution id is empty.  The method will lower-case
  the id and replace whitespace with underscores.

* Modify Host::GetArchitecture () so that linux replaces an unknown
  vendor portion with the results of GetDistributionId () if that
  is non-empty.  This shows up now in qHostInfo remote packet
  responses and on the lldb host side.  Tested with ubuntu and
  fedora (the latter both with the default of not having lsb_release
  installed, and with having lsb_release installed via the redhat-lsb
  package).

  Examples of triples on Linux after this change:

    # x86_64 Unbuntu 12.04 LTS:
    x86_64-ubuntu-linux-gnu

    # x86_64 Fedora 20 Desktop with redhat-lsb package installed
    x86_64-fedora-linux-gnu

    # x86_64 Fedora 20 Desktop without redhat-lsb-core installed
    # (i.e. no /bin/lsb_release available)
    # same as before the change
    x86_64--linux-gnu

  Note I intend to have Android respond with:

    {arch}-android-linux

  when I get to implementing Android lldb-gdbserver support.

llvm-svn: 199510

lldb/include/lldb/Host/Host.h

@@ -201,6 +201,23 @@ public:
     static const ConstString &
     GetTargetTriple ();
 
+    //------------------------------------------------------------------
+    /// Gets the name of the distribution (i.e. distributor id).
+    ///
+    /// On Linux, this will return the equivalent of lsb_release -i.
+    /// Android will return 'android'.  Other systems may return
+    /// nothing.
+    ///
+    /// @return
+    ///     A ConstString reference containing the OS distribution id.
+    ///     The return string will be all lower case, with whitespace
+    ///     replaced with underscores.  The return string will be
+    ///     empty (result.AsCString() will return NULL) if the distribution
+    ///     cannot be obtained.
+    //------------------------------------------------------------------
+    static const ConstString &
+    GetDistributionId ();
+
     //------------------------------------------------------------------
     /// Get the process ID for the calling process.
     ///

lldb/source/Host/common/Host.cpp

@@ -368,7 +368,13 @@ Host::GetArchitecture (SystemDefaultArchitecture arch_kind)
         // If the OS is Linux, "unknown" in the vendor slot isn't what we want
         // for the default triple.  It's probably an artifact of config.guess.
         if (triple.getOS() == llvm::Triple::Linux && triple.getVendor() == llvm::Triple::UnknownVendor)
+        {
+            const char *const dist_c_str = GetDistributionId ().AsCString ();
+            if (dist_c_str)
+                triple.setVendorName (dist_c_str);
+            else
                 triple.setVendorName ("");
+        }
 
         switch (triple.getArch())
         {
@@ -446,6 +452,19 @@ Host::GetTargetTriple()
     return g_host_triple;
 }
 
+// See linux/Host.cpp for Linux-based implementations of this.
+// Add your platform-specific implementation to the appropriate host file.
+#if !defined(__linux__)
+
+const ConstString &
+    Host::GetDistributionId ()
+{
+    static ConstString s_distribution_id;
+    return s_distribution_id;
+}
+
+#endif // #if !defined(__linux__)
+
 lldb::pid_t
 Host::GetCurrentProcessID()
 {

lldb/source/Host/linux/Host.cpp

@@ -20,6 +20,7 @@
 // Other libraries and framework includes
 // Project includes
 #include "lldb/Core/Error.h"
+#include "lldb/Core/Log.h"
 #include "lldb/Target/Process.h"
 
 #include "lldb/Host/Host.h"
@@ -494,3 +495,114 @@ Host::GetEnvironment (StringList &env)
         env.AppendString(env_entry);
     return i;
 }
+
+const ConstString &
+Host::GetDistributionId ()
+{
+    // Try to run 'lbs_release -i', and use that response
+    // for the distribution id.
+
+    static bool s_evaluated;
+    static ConstString s_distribution_id;
+
+    if (!s_evaluated)
+    {
+        s_evaluated = true;
+
+        Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_HOST));
+        if (log)
+            log->Printf ("attempting to determine Linux distribution...");
+
+        // check if the lsb_release command exists at one of the
+        // following paths
+        const char *const exe_paths[] = {
+            "/bin/lsb_release",
+            "/usr/bin/lsb_release"
+        };
+
+        for (int exe_index = 0;
+             exe_index < sizeof (exe_paths) / sizeof (exe_paths[0]);
+             ++exe_index)
+        {
+            const char *const get_distribution_info_exe = exe_paths[exe_index];
+            if (access (get_distribution_info_exe, F_OK))
+            {
+                // this exe doesn't exist, move on to next exe
+                if (log)
+                    log->Printf ("executable doesn't exist: %s",
+                            get_distribution_info_exe);
+                continue;
+            }
+
+            // execute the distribution-retrieval command, read output
+            std::string get_distribution_id_command (get_distribution_info_exe);
+            get_distribution_id_command += " -i";
+
+            FILE *file = popen (get_distribution_id_command.c_str (), "r");
+            if (!file)
+            {
+                if (log)
+                    log->Printf (
+                        "failed to run command: \"%s\", cannot retrieve "
+                        "platform information",
+                        get_distribution_id_command.c_str ());
+                return s_distribution_id;
+            }
+
+            // retrieve the distribution id string.
+            char distribution_id[256] = { '\0' };
+            if (fgets (distribution_id, sizeof (distribution_id) - 1, file)
+                    != NULL)
+            {
+                if (log)
+                    log->Printf ("distribution id command returned \"%s\"",
+                            distribution_id);
+
+                const char *const distributor_id_key = "Distributor ID:\t";
+                if (strstr (distribution_id, distributor_id_key))
+                {
+                    // strip newlines
+                    std::string id_string (distribution_id +
+                            strlen (distributor_id_key));
+                    id_string.erase(
+                        std::remove (
+                            id_string.begin (),
+                            id_string.end (),
+                            '\n'),
+                        id_string.end ());
+
+                    // lower case it and convert whitespace to underscores
+                    std::transform (
+                        id_string.begin(),
+                        id_string.end (),
+                        id_string.begin (),
+                        [] (char ch)
+                        { return tolower ( isspace (ch) ? '_' : ch ); });
+
+                    s_distribution_id.SetCString (id_string.c_str ());
+                    if (log)
+                        log->Printf ("distribion id set to \"%s\"",
+                                s_distribution_id.GetCString ());
+                }
+                else
+                {
+                    if (log)
+                        log->Printf ("failed to find \"%s\" field in \"%s\"",
+                                distributor_id_key, distribution_id);
+                }
+            }
+            else
+            {
+                if (log)
+                    log->Printf (
+                        "failed to retrieve distribution id, \"%s\" returned no"
+                        " lines", get_distribution_id_command.c_str ());
+            }
+
+            // clean up the file
+            pclose(file);
+        }
+    }
+
+    return s_distribution_id;
+}

lldb/tools/Makefile

@@ -10,9 +10,18 @@
 LLDB_LEVEL := ..
 include $(LLDB_LEVEL)/../../Makefile.config
 
-# tfiala test commit: will include lldb-gdbserver for linux x86_64 soon.
+# enable lldb-gdbserver for supported platforms
+DIRS :=
+ifneq (,$(strip $(filter $(HOST_OS), Linux)))
+ifneq (,$(strip $(filter $(HOST_ARCH), x86_64)))
+DIRS += lldb-gdbserver
+else
+endif
+else
+endif
+
 ifneq ($(HOST_OS),MingW)
-DIRS := driver lldb-platform
+DIRS += driver lldb-platform
 endif
 
 include $(LLDB_LEVEL)/Makefile

lldb/tools/lldb-gdbserver/lldb-gdbserver.cpp

@@ -199,7 +199,13 @@ main (int argc, char *argv[])
     {
         // Launch the program specified on the command line
         launch_info.SetArguments((const char **)argv, true);
-        launch_info.GetFlags().Set(eLaunchFlagDebug | eLaunchFlagStopAtEntry);
+
+        unsigned int launch_flags = eLaunchFlagStopAtEntry;
+#if !defined(__linux__)
+        // linux doesn't yet handle eLaunchFlagDebug
+        launch_flags |= eLaunchFlagDebug;
+#endif
+        launch_info.GetFlags ().Set (launch_flags);
         error = Host::LaunchProcess (launch_info);
 
         if (error.Success())