xref: /llvm-project/llvm/tools/llvm-diff/llvm-diff.cpp (revision 586ecdf205aa8b3d162da6f955170a6736656615)
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   if (Name.starts_with("@"))
46     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 
60 cl::OptionCategory DiffCategory("Diff Options");
61 
62 static cl::opt<std::string> LeftFilename(cl::Positional,
63                                          cl::desc("<first file>"), cl::Required,
64                                          cl::cat(DiffCategory));
65 static cl::opt<std::string> RightFilename(cl::Positional,
66                                           cl::desc("<second file>"),
67                                           cl::Required, cl::cat(DiffCategory));
68 static cl::list<std::string> GlobalsToCompare(cl::Positional,
69                                               cl::desc("<globals to compare>"),
70                                               cl::cat(DiffCategory));
71 
72 int main(int argc, char **argv) {
73   cl::HideUnrelatedOptions({&DiffCategory, &getColorCategory()});
74   cl::ParseCommandLineOptions(argc, argv);
75 
76   LLVMContext Context;
77 
78   // Load both modules.  Die if that fails.
79   std::unique_ptr<Module> LModule = readModule(Context, LeftFilename);
80   std::unique_ptr<Module> RModule = readModule(Context, RightFilename);
81   if (!LModule || !RModule) return 1;
82 
83   DiffConsumer Consumer;
84   DifferenceEngine Engine(Consumer);
85 
86   // If any global names were given, just diff those.
87   if (!GlobalsToCompare.empty()) {
88     for (unsigned I = 0, E = GlobalsToCompare.size(); I != E; ++I)
89       diffGlobal(Engine, *LModule, *RModule, GlobalsToCompare[I]);
90 
91   // Otherwise, diff everything in the module.
92   } else {
93     Engine.diff(LModule.get(), RModule.get());
94   }
95 
96   return Consumer.hadDifferences();
97 }
98