Support/MemoryBuffer: Replace all uses of std::string *ErrMsg with error_code &ec. And fix clients.

llvm-svn: 121379
diff --git a/llvm/lib/Linker/LinkItems.cpp b/llvm/lib/Linker/LinkItems.cpp
index cbbdd4b..7716b61 100644
--- a/llvm/lib/Linker/LinkItems.cpp
+++ b/llvm/lib/Linker/LinkItems.cpp
@@ -18,6 +18,7 @@
 #include "llvm/Support/Path.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/system_error.h"
 using namespace llvm;
 
 // LinkItems - This function is the main entry point into linking. It takes a
@@ -160,7 +161,8 @@
   // Check for a file of name "-", which means "read standard input"
   if (File.str() == "-") {
     std::auto_ptr<Module> M;
-    if (MemoryBuffer *Buffer = MemoryBuffer::getSTDIN(&Error)) {
+    error_code ec;
+    if (MemoryBuffer *Buffer = MemoryBuffer::getSTDIN(ec)) {
       if (!Buffer->getBufferSize()) {
         delete Buffer;
         Error = "standard input is empty";
@@ -172,7 +174,7 @@
             return false;
       }
     }
-    return error("Cannot link stdin: " + Error);
+    return error("Cannot link stdin: " + ec.message());
   }
 
   // Determine what variety of file it is.
diff --git a/llvm/lib/Linker/Linker.cpp b/llvm/lib/Linker/Linker.cpp
index 6e27fda..9606d06 100644
--- a/llvm/lib/Linker/Linker.cpp
+++ b/llvm/lib/Linker/Linker.cpp
@@ -18,6 +18,7 @@
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Config/config.h"
+#include "llvm/Support/system_error.h"
 using namespace llvm;
 
 Linker::Linker(StringRef progname, StringRef modname,
@@ -98,11 +99,14 @@
   std::string ParseErrorMessage;
   Module *Result = 0;
 
-  std::auto_ptr<MemoryBuffer> Buffer(MemoryBuffer::getFileOrSTDIN(FN.c_str()));
+  error_code ec;
+  std::auto_ptr<MemoryBuffer> Buffer(
+    MemoryBuffer::getFileOrSTDIN(FN.c_str(), ec));
   if (Buffer.get())
     Result = ParseBitcodeFile(Buffer.get(), Context, &ParseErrorMessage);
   else
-    ParseErrorMessage = "Error reading file '" + FN.str() + "'";
+    ParseErrorMessage = "Error reading file '" + FN.str() + "'" + ": "
+                      + ec.message();
 
   if (Result)
     return std::auto_ptr<Module>(Result);