1//===- RecordStreamer.h - Record asm defined and used symbols ---*- 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#ifndef LLVM_LIB_OBJECT_RECORDSTREAMER_H
10#define LLVM_LIB_OBJECT_RECORDSTREAMER_H
11
12#include "llvm/ADT/DenseMap.h"
13#include "llvm/ADT/MapVector.h"
14#include "llvm/ADT/StringMap.h"
15#include "llvm/MC/MCDirectives.h"
16#include "llvm/MC/MCStreamer.h"
17#include "llvm/Support/SMLoc.h"
18#include <vector>
19
20namespace llvm {
21
22class MCSymbol;
23class Module;
24
25class RecordStreamer : public MCStreamer {
26public:
27 enum State { NeverSeen, Global, Defined, DefinedGlobal, DefinedWeak, Used,
28 UndefinedWeak};
29
30private:
31 const Module &M;
32 StringMap<State> Symbols;
33 // Map of aliases created by .symver directives, saved so we can update
34 // their symbol binding after parsing complete. This maps from each
35 // aliasee to its list of aliases.
36 MapVector<const MCSymbol *, std::vector<StringRef>> SymverAliasMap;
37
38 /// Get the state recorded for the given symbol.
39 State getSymbolState(const MCSymbol *Sym);
40
41 void markDefined(const MCSymbol &Symbol);
42 void markGlobal(const MCSymbol &Symbol, MCSymbolAttr Attribute);
43 void markUsed(const MCSymbol &Symbol);
44 void visitUsedSymbol(const MCSymbol &Sym) override;
45
46public:
47 RecordStreamer(MCContext &Context, const Module &M);
48
49 void emitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
50 void emitAssignment(MCSymbol *Symbol, const MCExpr *Value) override;
51 bool emitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) override;
52 void emitZerofill(MCSection *Section, MCSymbol *Symbol, uint64_t Size,
53 Align ByteAlignment, SMLoc Loc = SMLoc()) override;
54 void emitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
55 Align ByteAlignment) override;
56
57 // Ignore format-specific directives; we do not need any information from
58 // them, but the default implementation of these methods crashes, so we
59 // override them with versions that do nothing.
60 void emitSubsectionsViaSymbols() override {};
61 void beginCOFFSymbolDef(const MCSymbol *Symbol) override {}
62 void emitCOFFSymbolStorageClass(int StorageClass) override {}
63 void emitCOFFSymbolType(int Type) override {}
64 void endCOFFSymbolDef() override {}
65
66 /// Record .symver aliases for later processing.
67 void emitELFSymverDirective(const MCSymbol *OriginalSym, StringRef Name,
68 bool KeepOriginalSym) override;
69
70 // Emit ELF .symver aliases and ensure they have the same binding as the
71 // defined symbol they alias with.
72 void flushSymverDirectives();
73
74 // Symbols iterators
75 using const_iterator = StringMap<State>::const_iterator;
76 const_iterator begin();
77 const_iterator end();
78
79 // SymverAliasMap iterators
80 using const_symver_iterator = decltype(SymverAliasMap)::const_iterator;
81 iterator_range<const_symver_iterator> symverAliases();
82};
83
84} // end namespace llvm
85
86#endif // LLVM_LIB_OBJECT_RECORDSTREAMER_H
87