llvm-diff.cpp revision 263508 
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/DenseMap.h"
17#include "llvm/ADT/SmallVector.h"
18#include "llvm/ADT/StringRef.h"
19#include "llvm/IR/LLVMContext.h"
20#include "llvm/IR/Module.h"
21#include "llvm/IR/Type.h"
22#include "llvm/IRReader/IRReader.h"
23#include "llvm/Support/CommandLine.h"
24#include "llvm/Support/MemoryBuffer.h"
25#include "llvm/Support/SourceMgr.h"
26#include "llvm/Support/raw_ostream.h"
27#include <string>
28#include <utility>
29
30
31using namespace llvm;
32
33/// Reads a module from a file.  On error, messages are written to stderr
34/// and null is returned.
35static Module *ReadModule(LLVMContext &Context, StringRef Name) {
36  SMDiagnostic Diag;
37  Module *M = ParseIRFile(Name, Diag, Context);
38  if (!M)
39    Diag.print("llvm-diff", errs());
40  return M;
41}
42
43static void diffGlobal(DifferenceEngine &Engine, Module *L, Module *R,
44                       StringRef Name) {
45  // Drop leading sigils from the global name.
46  if (Name.startswith("@")) Name = Name.substr(1);
47
48  Function *LFn = L->getFunction(Name);
49  Function *RFn = R->getFunction(Name);
50  if (LFn && RFn)
51    Engine.diff(LFn, RFn);
52  else if (!LFn && !RFn)
53    errs() << "No function named @" << Name << " in either module\n";
54  else if (!LFn)
55    errs() << "No function named @" << Name << " in left module\n";
56  else
57    errs() << "No function named @" << Name << " in right module\n";
58}
59
60static cl::opt<std::string> LeftFilename(cl::Positional,
61                                         cl::desc("<first file>"),
62                                         cl::Required);
63static cl::opt<std::string> RightFilename(cl::Positional,
64                                          cl::desc("<second file>"),
65                                          cl::Required);
66static cl::list<std::string> GlobalsToCompare(cl::Positional,
67                                              cl::desc("<globals to compare>"));
68
69int main(int argc, char **argv) {
70  cl::ParseCommandLineOptions(argc, argv);
71
72  LLVMContext Context;
73
74  // Load both modules.  Die if that fails.
75  Module *LModule = ReadModule(Context, LeftFilename);
76  Module *RModule = ReadModule(Context, RightFilename);
77  if (!LModule || !RModule) return 1;
78
79  DiffConsumer Consumer;
80  DifferenceEngine Engine(Consumer);
81
82  // If any global names were given, just diff those.
83  if (!GlobalsToCompare.empty()) {
84    for (unsigned I = 0, E = GlobalsToCompare.size(); I != E; ++I)
85      diffGlobal(Engine, LModule, RModule, GlobalsToCompare[I]);
86
87  // Otherwise, diff everything in the module.
88  } else {
89    Engine.diff(LModule, RModule);
90  }
91
92  delete LModule;
93  delete RModule;
94
95  return Consumer.hadDifferences();
96}
97