xref: /freebsd/contrib/llvm-project/llvm/tools/llvm-diff/llvm-diff.cpp (revision 5c65a0a9163cc00389d8527ee12c4e69df07ea42)
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 "lib/DiffLog.h"
14  #include "lib/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 "llvm/Support/WithColor.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    Name.consume_front("@");
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  cl::OptionCategory DiffCategory("Diff Options");
60  
61  static cl::opt<std::string> LeftFilename(cl::Positional,
62                                           cl::desc("<first file>"), cl::Required,
63                                           cl::cat(DiffCategory));
64  static cl::opt<std::string> RightFilename(cl::Positional,
65                                            cl::desc("<second file>"),
66                                            cl::Required, cl::cat(DiffCategory));
67  static cl::list<std::string> GlobalsToCompare(cl::Positional,
68                                                cl::desc("<globals to compare>"),
69                                                cl::cat(DiffCategory));
70  
71  int main(int argc, char **argv) {
72    cl::HideUnrelatedOptions({&DiffCategory, &getColorCategory()});
73    cl::ParseCommandLineOptions(argc, argv);
74  
75    LLVMContext Context;
76  
77    // Load both modules.  Die if that fails.
78    std::unique_ptr<Module> LModule = readModule(Context, LeftFilename);
79    std::unique_ptr<Module> RModule = readModule(Context, RightFilename);
80    if (!LModule || !RModule) return 1;
81  
82    DiffConsumer Consumer;
83    DifferenceEngine Engine(Consumer);
84  
85    // If any global names were given, just diff those.
86    if (!GlobalsToCompare.empty()) {
87      for (unsigned I = 0, E = GlobalsToCompare.size(); I != E; ++I)
88        diffGlobal(Engine, *LModule, *RModule, GlobalsToCompare[I]);
89  
90    // Otherwise, diff everything in the module.
91    } else {
92      Engine.diff(LModule.get(), RModule.get());
93    }
94  
95    return Consumer.hadDifferences();
96  }
97