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 "DiffLog.h"
14 #include "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 <string>
25 #include <utility>
26
27
28 using namespace llvm;
29
30 /// Reads a module from a file. On error, messages are written to stderr
31 /// and null is returned.
readModule(LLVMContext & Context,StringRef Name)32 static std::unique_ptr<Module> readModule(LLVMContext &Context,
33 StringRef Name) {
34 SMDiagnostic Diag;
35 std::unique_ptr<Module> M = parseIRFile(Name, Diag, Context);
36 if (!M)
37 Diag.print("llvm-diff", errs());
38 return M;
39 }
40
diffGlobal(DifferenceEngine & Engine,Module & L,Module & R,StringRef Name)41 static void diffGlobal(DifferenceEngine &Engine, Module &L, Module &R,
42 StringRef Name) {
43 // Drop leading sigils from the global name.
44 if (Name.startswith("@")) Name = Name.substr(1);
45
46 Function *LFn = L.getFunction(Name);
47 Function *RFn = R.getFunction(Name);
48 if (LFn && RFn)
49 Engine.diff(LFn, RFn);
50 else if (!LFn && !RFn)
51 errs() << "No function named @" << Name << " in either module\n";
52 else if (!LFn)
53 errs() << "No function named @" << Name << " in left module\n";
54 else
55 errs() << "No function named @" << Name << " in right module\n";
56 }
57
58 cl::OptionCategory DiffCategory("Diff Options");
59
60 static cl::opt<std::string> LeftFilename(cl::Positional,
61 cl::desc("<first file>"), cl::Required,
62 cl::cat(DiffCategory));
63 static cl::opt<std::string> RightFilename(cl::Positional,
64 cl::desc("<second file>"),
65 cl::Required, cl::cat(DiffCategory));
66 static cl::list<std::string> GlobalsToCompare(cl::Positional,
67 cl::desc("<globals to compare>"),
68 cl::cat(DiffCategory));
69
main(int argc,char ** argv)70 int main(int argc, char **argv) {
71 cl::HideUnrelatedOptions({&DiffCategory, &getColorCategory()});
72 cl::ParseCommandLineOptions(argc, argv);
73
74 LLVMContext Context;
75
76 // Load both modules. Die if that fails.
77 std::unique_ptr<Module> LModule = readModule(Context, LeftFilename);
78 std::unique_ptr<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.get(), RModule.get());
92 }
93
94 return Consumer.hadDifferences();
95 }
96