Move some Host logic into HostInfo class.

This patch creates a HostInfo class, a static class used to answer
basic queries about the host platform.  As part of this change,
some functionality is moved from Host to HostInfo, and relevant
fixups are performed in the rest of the codebase.

This is part of a larger effort to isolate more code in the Host
layer into platform-specific groups, to make it easier to make
platform specific changes for a particular Host without breaking
other hosts.

Reviewed by: Greg Clayton

Differential Revision: http://reviews.llvm.org/D4963

llvm-svn: 215992

1 files changed, 149 insertions, 0 deletions

diff --git a/lldb/source/Host/linux/HostInfoLinux.cpp b/lldb/source/Host/linux/HostInfoLinux.cpp
new file mode 100644
index 00000000000..8e620f43ca6
--- /dev/null
+++ b/lldb/source/Host/linux/HostInfoLinux.cpp
@@ -0,0 +1,149 @@
+//===-- HostInfoLinux.cpp ---------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Core/Log.h"
+#include "lldb/Host/linux/HostInfoLinux.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <sys/utsname.h>
+
+#include <algorithm>
+
+using namespace lldb_private;
+
+std::string HostInfoLinux::m_distribution_id;
+uint32_t HostInfoLinux::m_os_major = 0;
+uint32_t HostInfoLinux::m_os_minor = 0;
+uint32_t HostInfoLinux::m_os_update = 0;
+
+bool
+HostInfoLinux::GetOSVersion(uint32_t &major, uint32_t &minor, uint32_t &update)
+{
+    static bool is_initialized = false;
+    static bool success = false;
+
+    if (!is_initialized)
+    {
+        is_initialized = true;
+        struct utsname un;
+
+        if (uname(&un))
+            goto finished;
+
+        int status = sscanf(un.release, "%u.%u.%u", &major, &minor, &update);
+        if (status == 3)
+        {
+            success = true;
+            goto finished;
+        }
+
+        // Some kernels omit the update version, so try looking for just "X.Y" and
+        // set update to 0.
+        update = 0;
+        status = sscanf(un.release, "%u.%u", &major, &minor);
+        success = !!(status == 2);
+    }
+
+finished:
+    major = m_os_major;
+    minor = m_os_minor;
+    update = m_os_update;
+    return success;
+}
+
+llvm::StringRef
+HostInfoLinux::GetDistributionId()
+{
+    static bool is_initialized = false;
+    // Try to run 'lbs_release -i', and use that response
+    // for the distribution id.
+
+    if (!is_initialized)
+    {
+        is_initialized = 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 (size_t 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());
+                break;
+            }
+
+            // 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);
+                    });
+
+                    m_distribution_id = id_string;
+                    if (log)
+                        log->Printf("distribution id set to \"%s\"", m_distribution_id.c_str());
+                }
+                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 m_distribution_id.c_str();
+}