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
33using namespace llvm;
34
35/// Reads a module from a file.  On error, messages are written to stderr
36/// and null is returned.
37static Module *ReadModule(LLVMContext &Context, StringRef Name) {
38  SMDiagnostic Diag;
39  Module *M = ParseIRFile(Name, Diag, Context);
40  if (!M)
41    Diag.print("llvm-diff", errs());
42  return M;
43}
44
45static 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
62static cl::opt<std::string> LeftFilename(cl::Positional,
63                                         cl::desc("<first file>"),
64                                         cl::Required);
65static cl::opt<std::string> RightFilename(cl::Positional,
66                                          cl::desc("<second file>"),
67                                          cl::Required);
68static cl::list<std::string> GlobalsToCompare(cl::Positional,
69                                              cl::desc("<globals to compare>"));
70
71int 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;
82  DifferenceEngine Engine(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}
99