Supply a C interface to the "LinkModules" method.

Patch by Andrew Wilkins!

llvm-svn: 156469

include/llvm-c/Linker.h

@@ -0,0 +1,42 @@
+/*===-- llvm-c/Linker.h - Module Linker C Interface -------------*- C++ -*-===*\
+|*                                                                            *|
+|*                     The LLVM Compiler Infrastructure                       *|
+|*                                                                            *|
+|* This file is distributed under the University of Illinois Open Source      *|
+|* License. See LICENSE.TXT for details.                                      *|
+|*                                                                            *|
+|*===----------------------------------------------------------------------===*|
+|*                                                                            *|
+|* This file defines the C interface to the module/file/archive linker.       *|
+|*                                                                            *|
+\*===----------------------------------------------------------------------===*/
+
+#ifndef LLVM_C_LINKER_H
+#define LLVM_C_LINKER_H
+
+#include "llvm-c/Core.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+typedef enum {
+  LLVMLinkerDestroySource = 0, /* Allow source module to be destroyed. */
+  LLVMLinkerPreserveSource = 1 /* Preserve the source module. */
+} LLVMLinkerMode;
+
+
+/* Links the source module into the destination module, taking ownership
+ * of the source module away from the caller. Optionally returns a
+ * human-readable description of any errors that occurred in linking.
+ * OutMessage must be disposed with LLVMDisposeMessage. The return value
+ * is true if an error occurred, false otherwise. */
+LLVMBool LLVMLinkModules(LLVMModuleRef Dest, LLVMModuleRef Src,
+                         LLVMLinkerMode Mode, char **OutMessage);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

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 @@ bool Linker::LinkModules(Module *Dest, Module *Src, unsigned Mode,
 
   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;
+}