[LTO] Fix error reporting when a file passed to libLTO is invalid or non-existent

This addresses PR26060 where function lto_module_create() could return nullptr
but lto_get_error_message() returned an empty string.

The error() call after LTOModule::createFromFile() in llvm-lto is then removed
because any error from this function should go through the diagnostic handler in
llvm-lto which will exit the program. The error() call was added because this
previously did not happen when the file was non-existent. This is fixed by the
patch. (The situation that llvm-lto reports an error when the input file does
not exist is tested by llvm/tools/llvm-lto/error.ll).

Differential Revision: http://reviews.llvm.org/D16106

llvm-svn: 258298

1 files changed, 0 insertions, 2 deletions

diff --git a/llvm/tools/lto/lto.cpp b/llvm/tools/lto/lto.cpp
index d8f99c050a3..e7062b59d52 100644
--- a/llvm/tools/lto/lto.cpp
+++ b/llvm/tools/lto/lto.cpp
@@ -81,7 +81,6 @@ static void diagnosticHandler(const DiagnosticInfo &DI, void *Context) {
     DiagnosticPrinterRawOStream DP(Stream);
     DI.print(DP);
   }
-  sLastErrorString += '\n';
 }
 
 // Initialize the configured targets if they have not been initialized.
@@ -111,7 +110,6 @@ namespace {
 static void handleLibLTODiagnostic(lto_codegen_diagnostic_severity_t Severity,
                                    const char *Msg, void *) {
   sLastErrorString = Msg;
-  sLastErrorString += "\n";
 }
 
 // This derived class owns the native object file. This helps implement the