tools/llvm-diff/llvm-diff.cpp

   1 //===-- llvm-diff.cpp - Module comparator command-line driver ---*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file defines the command-line driver for the difference engine.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "DiffLog.h"
  14 #include "DifferenceEngine.h"
  15 #include "llvm/ADT/StringRef.h"
  16 #include "llvm/IR/LLVMContext.h"
  17 #include "llvm/IR/Module.h"
  18 #include "llvm/IR/Type.h"
  19 #include "llvm/IRReader/IRReader.h"
  20 #include "llvm/Support/CommandLine.h"
  21 #include "llvm/Support/MemoryBuffer.h"
  22 #include "llvm/Support/SourceMgr.h"
  23 #include "llvm/Support/raw_ostream.h"
  24 #include <string>
  25 #include <utility>
  26
  27
  28 using namespace llvm;
  29
  30 /// Reads a module from a file.  On error, messages are written to stderr
  31 /// and null is returned.
  32 static std::unique_ptr<Module> readModule(LLVMContext &Context,
  33                                           StringRef Name) {
  34   SMDiagnostic Diag;
  35   std::unique_ptr<Module> M = parseIRFile(Name, Diag, Context);
  36   if (!M)
  37     Diag.print("llvm-diff", errs());
  38   return M;
  39 }
  40
  41 static void diffGlobal(DifferenceEngine &Engine, Module &L, Module &R,
  42                        StringRef Name) {
  43   // Drop leading sigils from the global name.
  44   if (Name.startswith("@")) Name = Name.substr(1);
  45
  46   Function *LFn = L.getFunction(Name);
  47   Function *RFn = R.getFunction(Name);
  48   if (LFn && RFn)
  49     Engine.diff(LFn, RFn);
  50   else if (!LFn && !RFn)
  51     errs() << "No function named @" << Name << " in either module\n";
  52   else if (!LFn)
  53     errs() << "No function named @" << Name << " in left module\n";
  54   else
  55     errs() << "No function named @" << Name << " in right module\n";
  56 }
  57
  58 static cl::opt<std::string> LeftFilename(cl::Positional,
  59                                          cl::desc("<first file>"),
  60                                          cl::Required);
  61 static cl::opt<std::string> RightFilename(cl::Positional,
  62                                           cl::desc("<second file>"),
  63                                           cl::Required);
  64 static cl::list<std::string> GlobalsToCompare(cl::Positional,
  65                                               cl::desc("<globals to compare>"));
  66
  67 int main(int argc, char **argv) {
  68   cl::ParseCommandLineOptions(argc, argv);
  69
  70   LLVMContext Context;
  71
  72   // Load both modules.  Die if that fails.
  73   std::unique_ptr<Module> LModule = readModule(Context, LeftFilename);
  74   std::unique_ptr<Module> RModule = readModule(Context, RightFilename);
  75   if (!LModule || !RModule) return 1;
  76
  77   DiffConsumer Consumer;
  78   DifferenceEngine Engine(Consumer);
  79
  80   // If any global names were given, just diff those.
  81   if (!GlobalsToCompare.empty()) {
  82     for (unsigned I = 0, E = GlobalsToCompare.size(); I != E; ++I)
  83       diffGlobal(Engine, *LModule, *RModule, GlobalsToCompare[I]);
  84
  85   // Otherwise, diff everything in the module.
  86   } else {
  87     Engine.diff(LModule.get(), RModule.get());
  88   }
  89
  90   return Consumer.hadDifferences();
  91 }