Don't crash when specifying a core file that isn't readable.

Fixes include:
1 - added new FileSpec method: bool FileSpec::Readable()
2 - detect when an executable is not readable and give an appropriate error for:
    (lldb) file /tmp/unreadablefile
3 - detect when a core file is not readable and give an appropriate error
4 - detect when a specified core file doesn't exist and give an appropriate error
    
<rdar://problem/17727734>

llvm-svn: 215741

1 files changed, 9 insertions, 0 deletions

diff --git a/lldb/source/Host/common/FileSpec.cpp b/lldb/source/Host/common/FileSpec.cpp
index 9ce4e99d769..56179a38f36 100644
--- a/lldb/source/Host/common/FileSpec.cpp
+++ b/lldb/source/Host/common/FileSpec.cpp
@@ -483,6 +483,15 @@ FileSpec::Exists () const
 }
 
 bool
+FileSpec::Readable () const
+{
+    const uint32_t permissions = GetPermissions();
+    if (permissions & eFilePermissionsEveryoneR)
+        return true;
+    return false;
+}
+
+bool
 FileSpec::ResolveExecutableLocation ()
 {
     if (!m_directory)