1 files changed, 91 insertions, 0 deletions
diff --git a/llvm/tools/llvm-diff/llvm-diff.cpp b/llvm/tools/llvm-diff/llvm-diff.cpp
new file mode 100644
index 000000000000..aaf7989e2e3d
--- /dev/null
+++ b/llvm/tools/llvm-diff/llvm-diff.cpp
@@ -0,0 +1,91 @@
+//===-- llvm-diff.cpp - Module comparator command-line driver ---*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the command-line driver for the difference engine.
+//
+//===----------------------------------------------------------------------===//
+
+#include "DiffLog.h"
+#include "DifferenceEngine.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Type.h"
+#include "llvm/IRReader/IRReader.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/SourceMgr.h"
+#include "llvm/Support/raw_ostream.h"
+#include <string>
+#include <utility>
+
+
+using namespace llvm;
+
+/// Reads a module from a file.  On error, messages are written to stderr
+/// and null is returned.
+static std::unique_ptr<Module> readModule(LLVMContext &Context,
+                                          StringRef Name) {
+  SMDiagnostic Diag;
+  std::unique_ptr<Module> M = parseIRFile(Name, Diag, Context);
+  if (!M)
+    Diag.print("llvm-diff", errs());
+  return M;
+}
+
+static void diffGlobal(DifferenceEngine &Engine, Module &L, Module &R,
+                       StringRef Name) {
+  // Drop leading sigils from the global name.
+  if (Name.startswith("@")) Name = Name.substr(1);
+
+  Function *LFn = L.getFunction(Name);
+  Function *RFn = R.getFunction(Name);
+  if (LFn && RFn)
+    Engine.diff(LFn, RFn);
+  else if (!LFn && !RFn)
+    errs() << "No function named @" << Name << " in either module\n";
+  else if (!LFn)
+    errs() << "No function named @" << Name << " in left module\n";
+  else
+    errs() << "No function named @" << Name << " in right module\n";
+}
+
+static cl::opt<std::string> LeftFilename(cl::Positional,
+                                         cl::desc("<first file>"),
+                                         cl::Required);
+static cl::opt<std::string> RightFilename(cl::Positional,
+                                          cl::desc("<second file>"),
+                                          cl::Required);
+static cl::list<std::string> GlobalsToCompare(cl::Positional,
+                                              cl::desc("<globals to compare>"));
+
+int main(int argc, char **argv) {
+  cl::ParseCommandLineOptions(argc, argv);
+
+  LLVMContext Context;
+
+  // Load both modules.  Die if that fails.
+  std::unique_ptr<Module> LModule = readModule(Context, LeftFilename);
+  std::unique_ptr<Module> RModule = readModule(Context, RightFilename);
+  if (!LModule || !RModule) return 1;
+
+  DiffConsumer Consumer;
+  DifferenceEngine Engine(Consumer);
+
+  // If any global names were given, just diff those.
+  if (!GlobalsToCompare.empty()) {
+    for (unsigned I = 0, E = GlobalsToCompare.size(); I != E; ++I)
+      diffGlobal(Engine, *LModule, *RModule, GlobalsToCompare[I]);
+
+  // Otherwise, diff everything in the module.
+  } else {
+    Engine.diff(LModule.get(), RModule.get());
+  }
+
+  return Consumer.hadDifferences();
+}