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