Check in LLVM r95781.
diff --git a/lib/Linker/Linker.cpp b/lib/Linker/Linker.cpp
new file mode 100644
index 0000000..32aa0f9
--- /dev/null
+++ b/lib/Linker/Linker.cpp
@@ -0,0 +1,172 @@
+//===- lib/Linker/Linker.cpp - Basic Linker functionality ----------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains basic Linker functionality that all usages will need.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Linker.h"
+#include "llvm/Module.h"
+#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/System/Path.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Config/config.h"
+using namespace llvm;
+
+Linker::Linker(StringRef progname, StringRef modname,
+ LLVMContext& C, unsigned flags):
+ Context(C),
+ Composite(new Module(modname, C)),
+ LibPaths(),
+ Flags(flags),
+ Error(),
+ ProgramName(progname) { }
+
+Linker::Linker(StringRef progname, Module* aModule, unsigned flags) :
+ Context(aModule->getContext()),
+ Composite(aModule),
+ LibPaths(),
+ Flags(flags),
+ Error(),
+ ProgramName(progname) { }
+
+Linker::~Linker() {
+ delete Composite;
+}
+
+bool
+Linker::error(StringRef message) {
+ Error = message;
+ if (!(Flags&QuietErrors))
+ errs() << ProgramName << ": error: " << message << "\n";
+ return true;
+}
+
+bool
+Linker::warning(StringRef message) {
+ Error = message;
+ if (!(Flags&QuietWarnings))
+ errs() << ProgramName << ": warning: " << message << "\n";
+ return false;
+}
+
+void
+Linker::verbose(StringRef message) {
+ if (Flags&Verbose)
+ errs() << " " << message << "\n";
+}
+
+void
+Linker::addPath(const sys::Path& path) {
+ LibPaths.push_back(path);
+}
+
+void
+Linker::addPaths(const std::vector<std::string>& paths) {
+ for (unsigned i = 0, e = paths.size(); i != e; ++i)
+ LibPaths.push_back(sys::Path(paths[i]));
+}
+
+void
+Linker::addSystemPaths() {
+ sys::Path::GetBitcodeLibraryPaths(LibPaths);
+ LibPaths.insert(LibPaths.begin(),sys::Path("./"));
+}
+
+Module*
+Linker::releaseModule() {
+ Module* result = Composite;
+ LibPaths.clear();
+ Error.clear();
+ Composite = 0;
+ Flags = 0;
+ return result;
+}
+
+// LoadObject - Read in and parse the bitcode file named by FN and return the
+// module it contains (wrapped in an auto_ptr), or auto_ptr<Module>() and set
+// Error if an error occurs.
+std::auto_ptr<Module>
+Linker::LoadObject(const sys::Path &FN) {
+ std::string ParseErrorMessage;
+ Module *Result = 0;
+
+ std::auto_ptr<MemoryBuffer> Buffer(MemoryBuffer::getFileOrSTDIN(FN.c_str()));
+ if (Buffer.get())
+ Result = ParseBitcodeFile(Buffer.get(), Context, &ParseErrorMessage);
+ else
+ ParseErrorMessage = "Error reading file '" + FN.str() + "'";
+
+ if (Result)
+ return std::auto_ptr<Module>(Result);
+ Error = "Bitcode file '" + FN.str() + "' could not be loaded";
+ if (ParseErrorMessage.size())
+ Error += ": " + ParseErrorMessage;
+ return std::auto_ptr<Module>();
+}
+
+// IsLibrary - Determine if "Name" is a library in "Directory". Return
+// a non-empty sys::Path if its found, an empty one otherwise.
+static inline sys::Path IsLibrary(StringRef Name,
+ const sys::Path &Directory) {
+
+ sys::Path FullPath(Directory);
+
+ // Try the libX.a form
+ FullPath.appendComponent(("lib" + Name).str());
+ FullPath.appendSuffix("a");
+ if (FullPath.isArchive())
+ return FullPath;
+
+ // Try the libX.bca form
+ FullPath.eraseSuffix();
+ FullPath.appendSuffix("bca");
+ if (FullPath.isArchive())
+ return FullPath;
+
+ // Try the libX.so (or .dylib) form
+ FullPath.eraseSuffix();
+ FullPath.appendSuffix(&(LTDL_SHLIB_EXT[1]));
+ if (FullPath.isDynamicLibrary()) // Native shared library?
+ return FullPath;
+ if (FullPath.isBitcodeFile()) // .so file containing bitcode?
+ return FullPath;
+
+ // Not found .. fall through
+
+ // Indicate that the library was not found in the directory.
+ FullPath.clear();
+ return FullPath;
+}
+
+/// FindLib - Try to convert Filename into the name of a file that we can open,
+/// if it does not already name a file we can open, by first trying to open
+/// Filename, then libFilename.[suffix] for each of a set of several common
+/// library suffixes, in each of the directories in LibPaths. Returns an empty
+/// Path if no matching file can be found.
+///
+sys::Path
+Linker::FindLib(StringRef Filename) {
+ // Determine if the pathname can be found as it stands.
+ sys::Path FilePath(Filename);
+ if (FilePath.canRead() &&
+ (FilePath.isArchive() || FilePath.isDynamicLibrary()))
+ return FilePath;
+
+ // Iterate over the directories in Paths to see if we can find the library
+ // there.
+ for (unsigned Index = 0; Index != LibPaths.size(); ++Index) {
+ sys::Path Directory(LibPaths[Index]);
+ sys::Path FullPath = IsLibrary(Filename, Directory);
+ if (!FullPath.isEmpty())
+ return FullPath;
+ }
+ return sys::Path();
+}