1 //===-- BitcodeWriterPass.h - Bitcode writing pass --------------*- 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 /// \file
9 ///
10 /// This file provides a bitcode writing pass.
11 ///
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_BITCODE_BITCODEWRITERPASS_H
15 #define LLVM_BITCODE_BITCODEWRITERPASS_H
16 
17 #include "llvm/IR/PassManager.h"
18 
19 namespace llvm {
20 class Module;
21 class ModulePass;
22 class Pass;
23 class raw_ostream;
24 
25 /// Create and return a pass that writes the module to the specified
26 /// ostream. Note that this pass is designed for use with the legacy pass
27 /// manager.
28 ///
29 /// If \c ShouldPreserveUseListOrder, encode use-list order so it can be
30 /// reproduced when deserialized.
31 ///
32 /// If \c EmitSummaryIndex, emit the summary index (currently for use in ThinLTO
33 /// optimization).
34 ///
35 /// If \c EmitModuleHash, compute and emit the module hash in the bitcode
36 /// (currently for use in ThinLTO incremental build).
37 ModulePass *createBitcodeWriterPass(raw_ostream &Str,
38                                     bool ShouldPreserveUseListOrder = false,
39                                     bool EmitSummaryIndex = false,
40                                     bool EmitModuleHash = false);
41 
42 /// Check whether a pass is a BitcodeWriterPass.
43 bool isBitcodeWriterPass(Pass *P);
44 
45 /// Pass for writing a module of IR out to a bitcode file.
46 ///
47 /// Note that this is intended for use with the new pass manager. To construct
48 /// a pass for the legacy pass manager, use the function above.
49 class BitcodeWriterPass : public PassInfoMixin<BitcodeWriterPass> {
50   raw_ostream &OS;
51   bool ShouldPreserveUseListOrder;
52   bool EmitSummaryIndex;
53   bool EmitModuleHash;
54 
55 public:
56   /// Construct a bitcode writer pass around a particular output stream.
57   ///
58   /// If \c ShouldPreserveUseListOrder, encode use-list order so it can be
59   /// reproduced when deserialized.
60   ///
61   /// If \c EmitSummaryIndex, emit the summary index (currently
62   /// for use in ThinLTO optimization).
63   explicit BitcodeWriterPass(raw_ostream &OS,
64                              bool ShouldPreserveUseListOrder = false,
65                              bool EmitSummaryIndex = false,
66                              bool EmitModuleHash = false)
OS(OS)67       : OS(OS), ShouldPreserveUseListOrder(ShouldPreserveUseListOrder),
68   EmitSummaryIndex(EmitSummaryIndex), EmitModuleHash(EmitModuleHash) {}
69 
70   /// Run the bitcode writer pass, and output the module to the selected
71   /// output stream.
72   PreservedAnalyses run(Module &M, ModuleAnalysisManager &);
73 
isRequired()74   static bool isRequired() { return true; }
75 };
76 
77 }
78 
79 #endif
80