Revert adding hostname to module hash

I didn't realize how easily the hostname could change - for example just
changing wireless networks seems to prompt it in some cases.

Users can always set their own local module cache path to avoid this.

This reverts commits r228592, 228594, 228601 and 228613.
rdar://19287368

llvm-svn: 229815

1 files changed, 0 insertions, 17 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 7413ae2601d..edfee213994 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -39,9 +39,6 @@
 #include <memory>
 #include <sys/stat.h>
 #include <system_error>
-#if LLVM_ON_UNIX
-#include <unistd.h> // for gethostname()
-#endif
 using namespace clang;
 
 //===----------------------------------------------------------------------===//
@@ -2028,20 +2025,6 @@ std::string CompilerInvocation::getModuleHash() const {
     }
   }
 
-#if LLVM_ON_UNIX
-  // 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[0] = 0;
-  if (gethostname(hostname, 255) == 0) {
-    // Forcibly null-terminate the result, since POSIX doesn't require that
-    // truncation result in an error or that truncated names be null-terminated.
-    hostname[sizeof(hostname)-1] = 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);
 }