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
29using namespace llvm;
30
31/// Reads a module from a file. On error, messages are written to stderr
32/// and null is returned.
33static std::unique_ptr<Module> readModule(LLVMContext &Context,
34 StringRef Name) {
35 SMDiagnostic Diag;
36 std::unique_ptr<Module> M = parseIRFile(Filename: Name, Err&: Diag, Context);
37 if (!M)
38 Diag.print(ProgName: "llvm-diff", S&: errs());
39 return M;
40}
41
42static void diffGlobal(DifferenceEngine &Engine, Module &L, Module &R,
43 StringRef Name) {
44 // Drop leading sigils from the global name.
45 Name.consume_front(Prefix: "@");
46
47 Function *LFn = L.getFunction(Name);
48 Function *RFn = R.getFunction(Name);
49 if (LFn && RFn)
50 Engine.diff(L: LFn, R: 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
59static cl::OptionCategory DiffCategory("Diff Options");
60
61static cl::opt<std::string> LeftFilename(cl::Positional,
62 cl::desc("<first file>"), cl::Required,
63 cl::cat(DiffCategory));
64static cl::opt<std::string> RightFilename(cl::Positional,
65 cl::desc("<second file>"),
66 cl::Required, cl::cat(DiffCategory));
67static cl::list<std::string> GlobalsToCompare(cl::Positional,
68 cl::desc("<globals to compare>"),
69 cl::cat(DiffCategory));
70
71int main(int argc, char **argv) {
72 cl::HideUnrelatedOptions(Categories: {&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, Name: LeftFilename);
79 std::unique_ptr<Module> RModule = readModule(Context, Name: 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, L&: *LModule, R&: *RModule, Name: GlobalsToCompare[I]);
89
90 // Otherwise, diff everything in the module.
91 } else {
92 Engine.diff(L: LModule.get(), R: RModule.get());
93 }
94
95 return Consumer.hadDifferences();
96}
97