Print the tool name when an error comes from so that I can tell which
tool of a pipeline is having issues.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3166 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-dis/llvm-dis.cpp b/tools/llvm-dis/llvm-dis.cpp
index 13c4da3..bc0c55b 100644
--- a/tools/llvm-dis/llvm-dis.cpp
+++ b/tools/llvm-dis/llvm-dis.cpp
@@ -50,15 +50,15 @@
 
   Module *M = ParseBytecodeFile(InputFilename);
   if (M == 0) {
-    cerr << "bytecode didn't read correctly.\n";
+    cerr << argv[0] << ": bytecode didn't read correctly.\n";
     return 1;
   }
   
   if (OutputFilename != "") {   // Specified an output filename?
     if (!Force && std::ifstream(OutputFilename.c_str())) {
       // If force is not specified, make sure not to overwrite a file!
-      cerr << "Error opening '" << OutputFilename
-           << "': File exists! Sending to standard output.\n";
+      cerr << argv[0] << ": error opening '" << OutputFilename
+           << "': file exists! Sending to standard output.\n";
     } else {
       Out = new std::ofstream(OutputFilename.c_str());
     }
@@ -81,8 +81,8 @@
 
       if (!Force && std::ifstream(OutputFilename.c_str())) {
         // If force is not specified, make sure not to overwrite a file!
-        cerr << "Error opening '" << OutputFilename
-             << "': File exists! Sending to standard output.\n";
+        cerr << argv[0] << ": error opening '" << OutputFilename
+             << "': file exists! Sending to standard output.\n";
       } else {
         Out = new std::ofstream(OutputFilename.c_str());
 
@@ -94,7 +94,7 @@
   }
 
   if (!Out->good()) {
-    cerr << "Error opening " << OutputFilename
+    cerr << argv[0] << ": error opening " << OutputFilename
 	 << ": sending to stdout instead!\n";
     Out = &std::cout;
   }