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
  17 #include "llvm/LLVMContext.h"
  18 #include "llvm/Module.h"
  19 #include "llvm/Type.h"
  20 #include "llvm/ADT/DenseMap.h"
  21 #include "llvm/ADT/SmallVector.h"
  22 #include "llvm/ADT/StringRef.h"
  23 #include "llvm/Support/CommandLine.h"
  24 #include "llvm/Support/IRReader.h"
  25 #include "llvm/Support/MemoryBuffer.h"
  26 #include "llvm/Support/raw_ostream.h"
  27 #include "llvm/Support/SourceMgr.h"
  28
  29 #include <string>
  30 #include <utility>
  31
  32
  33 using namespace llvm;
  34
  35 /// Reads a module from a file.  On error, messages are written to stderr
  36 /// and null is returned.
  37 static Module *ReadModule(LLVMContext &Context, StringRef Name) {
  38   SMDiagnostic Diag;
  39   Module *M = ParseIRFile(Name, Diag, Context);
  40   if (!M)
  41     Diag.Print("llvmdiff", errs());
  42   return M;
  43 }
  44
  45 static void diffGlobal(DifferenceEngine &Engine, Module *L, Module *R,
  46                        StringRef Name) {
  47   // Drop leading sigils from the global name.
  48   if (Name.startswith("@")) Name = Name.substr(1);
  49
  50   Function *LFn = L->getFunction(Name);
  51   Function *RFn = R->getFunction(Name);
  52   if (LFn && RFn)
  53     Engine.diff(LFn, RFn);
  54   else if (!LFn && !RFn)
  55     errs() << "No function named @" << Name << " in either module\n";
  56   else if (!LFn)
  57     errs() << "No function named @" << Name << " in left module\n";
  58   else
  59     errs() << "No function named @" << Name << " in right module\n";
  60 }
  61
  62 static cl::opt<std::string> LeftFilename(cl::Positional,
  63                                          cl::desc("<first file>"),
  64                                          cl::Required);
  65 static cl::opt<std::string> RightFilename(cl::Positional,
  66                                           cl::desc("<second file>"),
  67                                           cl::Required);
  68 static cl::list<std::string> GlobalsToCompare(cl::Positional,
  69                                               cl::desc("<globals to compare>"));
  70
  71 int main(int argc, char **argv) {
  72   cl::ParseCommandLineOptions(argc, argv);
  73
  74   LLVMContext Context;
  75
  76   // Load both modules.  Die if that fails.
  77   Module *LModule = ReadModule(Context, LeftFilename);
  78   Module *RModule = ReadModule(Context, RightFilename);
  79   if (!LModule || !RModule) return 1;
  80
  81   DiffConsumer Consumer(LModule, RModule);
  82   DifferenceEngine Engine(Context, Consumer);
  83
  84   // If any global names were given, just diff those.
  85   if (!GlobalsToCompare.empty()) {
  86     for (unsigned I = 0, E = GlobalsToCompare.size(); I != E; ++I)
  87       diffGlobal(Engine, LModule, RModule, GlobalsToCompare[I]);
  88
  89   // Otherwise, diff everything in the module.
  90   } else {
  91     Engine.diff(LModule, RModule);
  92   }
  93
  94   delete LModule;
  95   delete RModule;
  96
  97   return Consumer.hadDifferences();
  98 }