1 //===- lib/MC/MCXCOFFStreamer.cpp - XCOFF Object Output -------------------===//
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 assembles .s files and emits XCOFF .o object files.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "llvm/MC/MCXCOFFStreamer.h"
14 #include "llvm/BinaryFormat/XCOFF.h"
15 #include "llvm/MC/MCAsmBackend.h"
16 #include "llvm/MC/MCAssembler.h"
17 #include "llvm/MC/MCCodeEmitter.h"
18 #include "llvm/MC/MCDirectives.h"
19 #include "llvm/MC/MCObjectWriter.h"
20 #include "llvm/MC/MCSectionXCOFF.h"
21 #include "llvm/MC/MCSymbolXCOFF.h"
22 #include "llvm/MC/TargetRegistry.h"
23 #include "llvm/Support/Casting.h"
24
25 using namespace llvm;
26
MCXCOFFStreamer(MCContext & Context,std::unique_ptr<MCAsmBackend> MAB,std::unique_ptr<MCObjectWriter> OW,std::unique_ptr<MCCodeEmitter> Emitter)27 MCXCOFFStreamer::MCXCOFFStreamer(MCContext &Context,
28 std::unique_ptr<MCAsmBackend> MAB,
29 std::unique_ptr<MCObjectWriter> OW,
30 std::unique_ptr<MCCodeEmitter> Emitter)
31 : MCObjectStreamer(Context, std::move(MAB), std::move(OW),
32 std::move(Emitter)) {}
33
emitSymbolAttribute(MCSymbol * Sym,MCSymbolAttr Attribute)34 bool MCXCOFFStreamer::emitSymbolAttribute(MCSymbol *Sym,
35 MCSymbolAttr Attribute) {
36 auto *Symbol = cast<MCSymbolXCOFF>(Sym);
37 getAssembler().registerSymbol(*Symbol);
38
39 switch (Attribute) {
40 // XCOFF doesn't support the cold feature.
41 case MCSA_Cold:
42 return false;
43
44 case MCSA_Global:
45 case MCSA_Extern:
46 Symbol->setStorageClass(XCOFF::C_EXT);
47 Symbol->setExternal(true);
48 break;
49 case MCSA_LGlobal:
50 Symbol->setStorageClass(XCOFF::C_HIDEXT);
51 Symbol->setExternal(true);
52 break;
53 case llvm::MCSA_Weak:
54 Symbol->setStorageClass(XCOFF::C_WEAKEXT);
55 Symbol->setExternal(true);
56 break;
57 case llvm::MCSA_Hidden:
58 Symbol->setVisibilityType(XCOFF::SYM_V_HIDDEN);
59 break;
60 case llvm::MCSA_Protected:
61 Symbol->setVisibilityType(XCOFF::SYM_V_PROTECTED);
62 break;
63 case llvm::MCSA_Exported:
64 Symbol->setVisibilityType(XCOFF::SYM_V_EXPORTED);
65 break;
66 default:
67 report_fatal_error("Not implemented yet.");
68 }
69 return true;
70 }
71
emitXCOFFSymbolLinkageWithVisibility(MCSymbol * Symbol,MCSymbolAttr Linkage,MCSymbolAttr Visibility)72 void MCXCOFFStreamer::emitXCOFFSymbolLinkageWithVisibility(
73 MCSymbol *Symbol, MCSymbolAttr Linkage, MCSymbolAttr Visibility) {
74
75 emitSymbolAttribute(Symbol, Linkage);
76
77 // When the caller passes `MCSA_Invalid` for the visibility, do not emit one.
78 if (Visibility == MCSA_Invalid)
79 return;
80
81 emitSymbolAttribute(Symbol, Visibility);
82 }
83
emitXCOFFExceptDirective(const MCSymbol * Symbol,const MCSymbol * Trap,unsigned Lang,unsigned Reason,unsigned FunctionSize,bool hasDebug)84 void MCXCOFFStreamer::emitXCOFFExceptDirective(const MCSymbol *Symbol,
85 const MCSymbol *Trap,
86 unsigned Lang, unsigned Reason,
87 unsigned FunctionSize,
88 bool hasDebug) {
89 getAssembler().getWriter().addExceptionEntry(Symbol, Trap, Lang, Reason,
90 FunctionSize, hasDebug);
91 }
92
emitCommonSymbol(MCSymbol * Symbol,uint64_t Size,Align ByteAlignment)93 void MCXCOFFStreamer::emitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
94 Align ByteAlignment) {
95 getAssembler().registerSymbol(*Symbol);
96 Symbol->setExternal(cast<MCSymbolXCOFF>(Symbol)->getStorageClass() !=
97 XCOFF::C_HIDEXT);
98 Symbol->setCommon(Size, ByteAlignment);
99
100 // Default csect align is 4, but common symbols have explicit alignment values
101 // and we should honor it.
102 cast<MCSymbolXCOFF>(Symbol)->getRepresentedCsect()->setAlignment(
103 ByteAlignment);
104
105 // Emit the alignment and storage for the variable to the section.
106 emitValueToAlignment(ByteAlignment);
107 emitZeros(Size);
108 }
109
emitZerofill(MCSection * Section,MCSymbol * Symbol,uint64_t Size,Align ByteAlignment,SMLoc Loc)110 void MCXCOFFStreamer::emitZerofill(MCSection *Section, MCSymbol *Symbol,
111 uint64_t Size, Align ByteAlignment,
112 SMLoc Loc) {
113 report_fatal_error("Zero fill not implemented for XCOFF.");
114 }
115
emitInstToData(const MCInst & Inst,const MCSubtargetInfo & STI)116 void MCXCOFFStreamer::emitInstToData(const MCInst &Inst,
117 const MCSubtargetInfo &STI) {
118 MCAssembler &Assembler = getAssembler();
119 SmallVector<MCFixup, 4> Fixups;
120 SmallString<256> Code;
121 raw_svector_ostream VecOS(Code);
122 Assembler.getEmitter().encodeInstruction(Inst, VecOS, Fixups, STI);
123
124 // Add the fixups and data.
125 MCDataFragment *DF = getOrCreateDataFragment(&STI);
126 const size_t ContentsSize = DF->getContents().size();
127 auto &DataFragmentFixups = DF->getFixups();
128 for (auto &Fixup : Fixups) {
129 Fixup.setOffset(Fixup.getOffset() + ContentsSize);
130 DataFragmentFixups.push_back(Fixup);
131 }
132
133 DF->setHasInstructions(STI);
134 DF->getContents().append(Code.begin(), Code.end());
135 }
136
createXCOFFStreamer(MCContext & Context,std::unique_ptr<MCAsmBackend> && MAB,std::unique_ptr<MCObjectWriter> && OW,std::unique_ptr<MCCodeEmitter> && CE,bool RelaxAll)137 MCStreamer *llvm::createXCOFFStreamer(MCContext &Context,
138 std::unique_ptr<MCAsmBackend> &&MAB,
139 std::unique_ptr<MCObjectWriter> &&OW,
140 std::unique_ptr<MCCodeEmitter> &&CE,
141 bool RelaxAll) {
142 MCXCOFFStreamer *S = new MCXCOFFStreamer(Context, std::move(MAB),
143 std::move(OW), std::move(CE));
144 if (RelaxAll)
145 S->getAssembler().setRelaxAll(true);
146 return S;
147 }
148
emitXCOFFLocalCommonSymbol(MCSymbol * LabelSym,uint64_t Size,MCSymbol * CsectSym,Align Alignment)149 void MCXCOFFStreamer::emitXCOFFLocalCommonSymbol(MCSymbol *LabelSym,
150 uint64_t Size,
151 MCSymbol *CsectSym,
152 Align Alignment) {
153 emitCommonSymbol(CsectSym, Size, Alignment);
154 }
155