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