ComputeSupportExeDirectory for Linux

Summary:
Fixes http://reviews.llvm.org/D8511

The original method of using dladdr() could return the incorrect relative
path if not dynamically linked against liblldb and the working directory
has changed. This is not a problem when built with python, since
ScriptInterpreterPython::InitializePrivate calls
HostInfo::GetLLDBPath(ePathTypeLLDBShlibDir, ...) and caches the
correct path before any changes to the working directory.

The /proc/self/exe approach fails if run using Python, but works for all other
cases (including for android, which doesn't have dladdr()).

So if we combine the two, we should reasonably cover all corner cases.

Reviewers: vharron, ovyalov, clayborg

Reviewed By: ovyalov, clayborg

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D8570

llvm-svn: 233129

lldb/include/lldb/Host/android/HostInfoAndroid.h

@@ -25,7 +25,6 @@ class HostInfoAndroid : public HostInfoLinux
 
   protected:
     static void ComputeHostArchitectureSupport(ArchSpec &arch_32, ArchSpec &arch_64);
-    static bool ComputeSupportExeDirectory(FileSpec &file_spec);
 };
 
 } // end of namespace lldb_private

lldb/include/lldb/Host/linux/HostInfoLinux.h

@@ -40,7 +40,7 @@ class HostInfoLinux : public HostInfoPosix
     static FileSpec GetProgramFileSpec();
 
   protected:
-    static bool ComputeSharedLibraryDirectory(FileSpec &file_spec);
+    static bool ComputeSupportExeDirectory(FileSpec &file_spec);
     static bool ComputeSystemPluginsDirectory(FileSpec &file_spec);
     static bool ComputeUserPluginsDirectory(FileSpec &file_spec);
     static void ComputeHostArchitectureSupport(ArchSpec &arch_32, ArchSpec &arch_64);

lldb/source/Host/android/HostInfoAndroid.cpp

@@ -30,13 +30,6 @@ HostInfoAndroid::ComputeHostArchitectureSupport(ArchSpec &arch_32, ArchSpec &arc
     }
 }
 
-bool
-HostInfoAndroid::ComputeSupportExeDirectory(FileSpec &file_spec)
-{
-    file_spec.GetDirectory() = HostInfoLinux::GetProgramFileSpec().GetDirectory();
-    return (bool)file_spec.GetDirectory();
-}
-
 FileSpec
 HostInfoAndroid::GetDefaultShell()
 {

lldb/source/Host/common/Host.cpp

@@ -487,8 +487,6 @@ Host::GetModuleFileSpecForHostAddress (const void *host_addr)
         if (info.dli_fname)
             module_filespec.SetFile(info.dli_fname, true);
     }
-#else
-    assert(false && "dladdr() not supported on Android");
 #endif
     return module_filespec;
 }

lldb/source/Host/linux/HostInfoLinux.cpp

@@ -222,12 +222,14 @@ HostInfoLinux::GetProgramFileSpec()
 }
 
 bool
-HostInfoLinux::ComputeSharedLibraryDirectory(FileSpec &file_spec)
+HostInfoLinux::ComputeSupportExeDirectory(FileSpec &file_spec)
 {
-    if (HostInfoPosix::ComputeSharedLibraryDirectory(file_spec))
+    if (HostInfoPosix::ComputeSupportExeDirectory(file_spec) &&
+            !file_spec.IsRelativeToCurrentWorkingDirectory() &&
+            file_spec.Exists())
         return true;
     file_spec.GetDirectory() = GetProgramFileSpec().GetDirectory();
-    return (bool)file_spec.GetDirectory();
+    return !file_spec.GetDirectory().IsEmpty();
 }
 
 bool