xref: /freebsd/contrib/llvm-project/llvm/tools/llvm-diff/llvm-diff.cpp (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71)
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 static cl::opt<std::string> LeftFilename(cl::Positional,
59                                          cl::desc("<first file>"),
60                                          cl::Required);
61 static cl::opt<std::string> RightFilename(cl::Positional,
62                                           cl::desc("<second file>"),
63                                           cl::Required);
64 static cl::list<std::string> GlobalsToCompare(cl::Positional,
65                                               cl::desc("<globals to compare>"));
66 
67 int main(int argc, char **argv) {
68   cl::ParseCommandLineOptions(argc, argv);
69 
70   LLVMContext Context;
71 
72   // Load both modules.  Die if that fails.
73   std::unique_ptr<Module> LModule = readModule(Context, LeftFilename);
74   std::unique_ptr<Module> RModule = readModule(Context, RightFilename);
75   if (!LModule || !RModule) return 1;
76 
77   DiffConsumer Consumer;
78   DifferenceEngine Engine(Consumer);
79 
80   // If any global names were given, just diff those.
81   if (!GlobalsToCompare.empty()) {
82     for (unsigned I = 0, E = GlobalsToCompare.size(); I != E; ++I)
83       diffGlobal(Engine, *LModule, *RModule, GlobalsToCompare[I]);
84 
85   // Otherwise, diff everything in the module.
86   } else {
87     Engine.diff(LModule.get(), RModule.get());
88   }
89 
90   return Consumer.hadDifferences();
91 }
92