1 //===- llvm/IR/Comdat.h - Comdat definitions --------------------*- 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 /// @file
10 /// This file contains the declaration of the Comdat class, which represents a
11 /// single COMDAT in LLVM.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_IR_COMDAT_H
16 #define LLVM_IR_COMDAT_H
17 
18 #include "llvm-c/Types.h"
19 #include "llvm/Support/CBindingWrapping.h"
20 
21 namespace llvm {
22 
23 class raw_ostream;
24 class StringRef;
25 template <typename ValueTy> class StringMapEntry;
26 
27 // This is a Name X SelectionKind pair. The reason for having this be an
28 // independent object instead of just adding the name and the SelectionKind
29 // to a GlobalObject is that it is invalid to have two Comdats with the same
30 // name but different SelectionKind. This structure makes that unrepresentable.
31 class Comdat {
32 public:
33   enum SelectionKind {
34     Any,          ///< The linker may choose any COMDAT.
35     ExactMatch,   ///< The data referenced by the COMDAT must be the same.
36     Largest,      ///< The linker will choose the largest COMDAT.
37     NoDuplicates, ///< No other Module may specify this COMDAT.
38     SameSize,     ///< The data referenced by the COMDAT must be the same size.
39   };
40 
41   Comdat(const Comdat &) = delete;
42   Comdat(Comdat &&C);
43 
44   SelectionKind getSelectionKind() const { return SK; }
45   void setSelectionKind(SelectionKind Val) { SK = Val; }
46   StringRef getName() const;
47   void print(raw_ostream &OS, bool IsForDebug = false) const;
48   void dump() const;
49 
50 private:
51   friend class Module;
52 
53   Comdat();
54 
55   // Points to the map in Module.
56   StringMapEntry<Comdat> *Name = nullptr;
57   SelectionKind SK = Any;
58 };
59 
60 // Create wrappers for C Binding types (see CBindingWrapping.h).
61 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(Comdat, LLVMComdatRef)
62 
63 inline raw_ostream &operator<<(raw_ostream &OS, const Comdat &C) {
64   C.print(OS);
65   return OS;
66 }
67 
68 } // end namespace llvm
69 
70 #endif // LLVM_IR_COMDAT_H
71