r228601 - Update r228592 for when gethostname() returns an error

[Ben Langmuir]

Author: benlangmuir
Date: Mon Feb  9 14:13:11 2015
New Revision: 228601

URL: http://llvm.org/viewvc/llvm-project?rev=228601&view=rev
Log:
Update r228592 for when gethostname() returns an error

If gethostname() is not successful, just skip adding the hostname to the
module hash.  And don't bother setting hostname[255] = 0, since if
gethostname() is successful, it will be null-terminated already (and if
it's not successful we don't read the string now.

Modified:
    cfe/trunk/lib/Frontend/CompilerInvocation.cpp

Modified: cfe/trunk/lib/Frontend/CompilerInvocation.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/CompilerInvocation.cpp?rev=228601&r1=228600&r2=228601&view=diff
==============================================================================
--- cfe/trunk/lib/Frontend/CompilerInvocation.cpp (original)
+++ cfe/trunk/lib/Frontend/CompilerInvocation.cpp Mon Feb  9 14:13:11 2015
@@ -2028,10 +2028,10 @@ std::string CompilerInvocation::getModul
   // The LockFileManager cannot tell when processes from another host are
   // running, so mangle the hostname in to the module hash to separate them.
   char hostname[256];
-  hostname[255] = 0;
   hostname[0] = 0;
-  gethostname(hostname, 255);
-  code = hash_combine(code, StringRef(hostname));
+  if (gethostname(hostname, 255) == 0)
+    code = hash_combine(code, StringRef(hostname));
+  // Ignore failures in gethostname() by not including the hostname in the hash.
 #endif
 
   return llvm::APInt(64, code).toString(36, /*Signed=*/false);