From 4d733af3c7a6c51eb848cbeb0076458658ec2e8a Mon Sep 17 00:00:00 2001
From: Matt Pharr <matt.pharr@intel.com>
Date: Wed, 6 Jul 2011 11:33:33 +0100
Subject: [PATCH] Add check to make sure file exists before running
 preprocessor.

(If the file doesn't exist, clang ends up crashing, so we'd like to
avoid that.)
---
 module.cpp | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/module.cpp b/module.cpp
index b5927ab8..09db04fd 100644
--- a/module.cpp
+++ b/module.cpp
@@ -152,6 +152,17 @@ Module::CompileFile() {
     bool runPreprocessor = g->runCPP;
 
     if (runPreprocessor) {
+        if (filename != NULL) {
+            // Try to open the file first, since otherwise we crash in the
+            // preprocessor if the file doesn't exist.
+            FILE *f = fopen(filename, "r");
+            if (!f) {
+                perror(filename);
+                return 1;
+            }
+            fclose(f);
+        }
+
         std::string buffer;
         llvm::raw_string_ostream os(buffer);
         execPreprocessor((filename != NULL) ? filename : "-", &os);