tools/llvm-diff/llvm-diff.cpp

   1 //===-- llvm-diff.cpp - Module comparator command-line driver ---*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file defines the command-line driver for the difference engine.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "DiffLog.h"
  15 #include "DifferenceEngine.h"
  16 #include "llvm/ADT/StringRef.h"
  17 #include "llvm/IR/LLVMContext.h"
  18 #include "llvm/IR/Module.h"
  19 #include "llvm/IR/Type.h"
  20 #include "llvm/IRReader/IRReader.h"
  21 #include "llvm/Support/CommandLine.h"
  22 #include "llvm/Support/MemoryBuffer.h"
  23 #include "llvm/Support/SourceMgr.h"
  24 #include "llvm/Support/raw_ostream.h"
  25 #include <string>
  26 #include <utility>
  27
  28
  29 using namespace llvm;
  30
  31 /// Reads a module from a file.  On error, messages are written to stderr
  32 /// and null is returned.
  33 static std::unique_ptr<Module> readModule(LLVMContext &Context,
  34                                           StringRef Name) {
  35   SMDiagnostic Diag;
  36   std::unique_ptr<Module> M = parseIRFile(Name, Diag, Context);
  37   if (!M)
  38     Diag.print("llvm-diff", errs());
  39   return M;
  40 }
  41
  42 static void diffGlobal(DifferenceEngine &Engine, Module &L, Module &R,
  43                        StringRef Name) {
  44   // Drop leading sigils from the global name.
  45   if (Name.startswith("@")) Name = Name.substr(1);
  46
  47   Function *LFn = L.getFunction(Name);
  48   Function *RFn = R.getFunction(Name);
  49   if (LFn && RFn)
  50     Engine.diff(LFn, RFn);
  51   else if (!LFn && !RFn)
  52     errs() << "No function named @" << Name << " in either module\n";
  53   else if (!LFn)
  54     errs() << "No function named @" << Name << " in left module\n";
  55   else
  56     errs() << "No function named @" << Name << " in right module\n";
  57 }
  58
  59 static cl::opt<std::string> LeftFilename(cl::Positional,
  60                                          cl::desc("<first file>"),
  61                                          cl::Required);
  62 static cl::opt<std::string> RightFilename(cl::Positional,
  63                                           cl::desc("<second file>"),
  64                                           cl::Required);
  65 static cl::list<std::string> GlobalsToCompare(cl::Positional,
  66                                               cl::desc("<globals to compare>"));
  67
  68 int main(int argc, char **argv) {
  69   cl::ParseCommandLineOptions(argc, argv);
  70
  71   LLVMContext Context;
  72
  73   // Load both modules.  Die if that fails.
  74   std::unique_ptr<Module> LModule = readModule(Context, LeftFilename);
  75   std::unique_ptr<Module> RModule = readModule(Context, RightFilename);
  76   if (!LModule || !RModule) return 1;
  77
  78   DiffConsumer Consumer;
  79   DifferenceEngine Engine(Consumer);
  80
  81   // If any global names were given, just diff those.
  82   if (!GlobalsToCompare.empty()) {
  83     for (unsigned I = 0, E = GlobalsToCompare.size(); I != E; ++I)
  84       diffGlobal(Engine, *LModule, *RModule, GlobalsToCompare[I]);
  85
  86   // Otherwise, diff everything in the module.
  87   } else {
  88     Engine.diff(LModule.get(), RModule.get());
  89   }
  90
  91   return Consumer.hadDifferences();
  92 }