Supply a C interface to the "LinkModules" method.
Patch by Andrew Wilkins!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156469 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Linker/LinkModules.cpp b/lib/Linker/LinkModules.cpp
index 630289b..7293f3d 100644
--- a/lib/Linker/LinkModules.cpp
+++ b/lib/Linker/LinkModules.cpp
@@ -25,6 +25,7 @@
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Utils/Cloning.h"
 #include "llvm/Transforms/Utils/ValueMapper.h"
+#include "llvm-c/Linker.h"
 #include <cctype>
 using namespace llvm;
 
@@ -1335,3 +1336,17 @@
 
   return false;
 }
+
+//===----------------------------------------------------------------------===//
+// C API.
+//===----------------------------------------------------------------------===//
+
+LLVMBool LLVMLinkModules(LLVMModuleRef Dest, LLVMModuleRef Src,
+                         LLVMLinkerMode Mode, char **OutMessages) {
+  std::string Messages;
+  LLVMBool Result = Linker::LinkModules(unwrap(Dest), unwrap(Src),
+                                        Mode, OutMessages? &Messages : 0);
+  if (OutMessages)
+    *OutMessages = strdup(Messages.c_str());
+  return Result;
+}