xref: /freebsd/contrib/llvm-project/llvm/tools/llvm-diff/llvm-diff.cpp (revision 13ec1e3155c7e9bf037b12af186351b7fa9b9450)
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.
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 
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 
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