Line data Source code
1 : //===- lib/MC/MCWasmStreamer.cpp - Wasm Object Output ---------------------===//
2 : //
3 : // The LLVM Compiler Infrastructure
4 : //
5 : // This file is distributed under the University of Illinois Open Source
6 : // License. See LICENSE.TXT for details.
7 : //
8 : //===----------------------------------------------------------------------===//
9 : //
10 : // This file assembles .s files and emits Wasm .o object files.
11 : //
12 : //===----------------------------------------------------------------------===//
13 :
14 : #include "llvm/MC/MCWasmStreamer.h"
15 : #include "llvm/ADT/STLExtras.h"
16 : #include "llvm/ADT/SmallPtrSet.h"
17 : #include "llvm/MC/MCAsmBackend.h"
18 : #include "llvm/MC/MCAsmLayout.h"
19 : #include "llvm/MC/MCAssembler.h"
20 : #include "llvm/MC/MCCodeEmitter.h"
21 : #include "llvm/MC/MCContext.h"
22 : #include "llvm/MC/MCExpr.h"
23 : #include "llvm/MC/MCInst.h"
24 : #include "llvm/MC/MCObjectStreamer.h"
25 : #include "llvm/MC/MCSection.h"
26 : #include "llvm/MC/MCSectionWasm.h"
27 : #include "llvm/MC/MCSymbol.h"
28 : #include "llvm/MC/MCSymbolWasm.h"
29 : #include "llvm/MC/MCValue.h"
30 : #include "llvm/Support/Casting.h"
31 : #include "llvm/Support/Debug.h"
32 : #include "llvm/Support/ErrorHandling.h"
33 : #include "llvm/Support/TargetRegistry.h"
34 : #include "llvm/Support/raw_ostream.h"
35 :
36 : using namespace llvm;
37 :
38 298 : MCWasmStreamer::~MCWasmStreamer() {}
39 :
40 0 : void MCWasmStreamer::mergeFragment(MCDataFragment *DF, MCDataFragment *EF) {
41 0 : flushPendingLabels(DF, DF->getContents().size());
42 :
43 0 : for (unsigned i = 0, e = EF->getFixups().size(); i != e; ++i) {
44 0 : EF->getFixups()[i].setOffset(EF->getFixups()[i].getOffset() +
45 0 : DF->getContents().size());
46 0 : DF->getFixups().push_back(EF->getFixups()[i]);
47 : }
48 0 : if (DF->getSubtargetInfo() == nullptr && EF->getSubtargetInfo())
49 : DF->setHasInstructions(*EF->getSubtargetInfo());
50 0 : DF->getContents().append(EF->getContents().begin(), EF->getContents().end());
51 0 : }
52 :
53 0 : void MCWasmStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
54 : // Let the target do whatever target specific stuff it needs to do.
55 0 : getAssembler().getBackend().handleAssemblerFlag(Flag);
56 :
57 : // Do any generic stuff we need to do.
58 0 : llvm_unreachable("invalid assembler flag!");
59 : }
60 :
61 656 : void MCWasmStreamer::ChangeSection(MCSection *Section,
62 : const MCExpr *Subsection) {
63 : MCAssembler &Asm = getAssembler();
64 : auto *SectionWasm = static_cast<const MCSectionWasm *>(Section);
65 656 : const MCSymbol *Grp = SectionWasm->getGroup();
66 656 : if (Grp)
67 9 : Asm.registerSymbol(*Grp);
68 :
69 656 : this->MCObjectStreamer::ChangeSection(Section, Subsection);
70 656 : Asm.registerSymbol(*Section->getBeginSymbol());
71 656 : }
72 :
73 0 : void MCWasmStreamer::EmitWeakReference(MCSymbol *Alias,
74 : const MCSymbol *Symbol) {
75 0 : getAssembler().registerSymbol(*Symbol);
76 0 : const MCExpr *Value = MCSymbolRefExpr::create(
77 0 : Symbol, MCSymbolRefExpr::VK_WEAKREF, getContext());
78 0 : Alias->setVariableValue(Value);
79 0 : }
80 :
81 953 : bool MCWasmStreamer::EmitSymbolAttribute(MCSymbol *S, MCSymbolAttr Attribute) {
82 : assert(Attribute != MCSA_IndirectSymbol && "indirect symbols not supported");
83 :
84 : auto *Symbol = cast<MCSymbolWasm>(S);
85 :
86 : // Adding a symbol attribute always introduces the symbol; note that an
87 : // important side effect of calling registerSymbol here is to register the
88 : // symbol with the assembler.
89 953 : getAssembler().registerSymbol(*Symbol);
90 :
91 953 : switch (Attribute) {
92 : case MCSA_LazyReference:
93 : case MCSA_Reference:
94 : case MCSA_SymbolResolver:
95 : case MCSA_PrivateExtern:
96 : case MCSA_WeakDefinition:
97 : case MCSA_WeakDefAutoPrivate:
98 : case MCSA_Invalid:
99 : case MCSA_IndirectSymbol:
100 : case MCSA_Protected:
101 : return false;
102 :
103 : case MCSA_Hidden:
104 : Symbol->setHidden(true);
105 : break;
106 :
107 : case MCSA_Weak:
108 : case MCSA_WeakReference:
109 : Symbol->setWeak(true);
110 : Symbol->setExternal(true);
111 : break;
112 :
113 378 : case MCSA_Global:
114 : Symbol->setExternal(true);
115 : break;
116 :
117 352 : case MCSA_ELF_TypeFunction:
118 : Symbol->setType(wasm::WASM_SYMBOL_TYPE_FUNCTION);
119 : break;
120 :
121 : case MCSA_ELF_TypeObject:
122 : break;
123 :
124 0 : default:
125 : // unrecognized directive
126 0 : llvm_unreachable("unexpected MCSymbolAttr");
127 : return false;
128 : }
129 :
130 : return true;
131 : }
132 :
133 0 : void MCWasmStreamer::EmitCommonSymbol(MCSymbol *S, uint64_t Size,
134 : unsigned ByteAlignment) {
135 0 : llvm_unreachable("Common symbols are not yet implemented for Wasm");
136 : }
137 :
138 442 : void MCWasmStreamer::emitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
139 : cast<MCSymbolWasm>(Symbol)->setSize(Value);
140 442 : }
141 :
142 0 : void MCWasmStreamer::EmitLocalCommonSymbol(MCSymbol *S, uint64_t Size,
143 : unsigned ByteAlignment) {
144 0 : llvm_unreachable("Local common symbols are not yet implemented for Wasm");
145 : }
146 :
147 159 : void MCWasmStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
148 : SMLoc Loc) {
149 159 : MCObjectStreamer::EmitValueImpl(Value, Size, Loc);
150 159 : }
151 :
152 77 : void MCWasmStreamer::EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
153 : unsigned ValueSize,
154 : unsigned MaxBytesToEmit) {
155 77 : MCObjectStreamer::EmitValueToAlignment(ByteAlignment, Value, ValueSize,
156 : MaxBytesToEmit);
157 77 : }
158 :
159 5 : void MCWasmStreamer::EmitIdent(StringRef IdentString) {
160 : // TODO(sbc): Add the ident section once we support mergable strings
161 : // sections in the object format
162 5 : }
163 :
164 0 : void MCWasmStreamer::EmitInstToFragment(const MCInst &Inst,
165 : const MCSubtargetInfo &STI) {
166 0 : this->MCObjectStreamer::EmitInstToFragment(Inst, STI);
167 0 : }
168 :
169 1087 : void MCWasmStreamer::EmitInstToData(const MCInst &Inst,
170 : const MCSubtargetInfo &STI) {
171 : MCAssembler &Assembler = getAssembler();
172 : SmallVector<MCFixup, 4> Fixups;
173 : SmallString<256> Code;
174 : raw_svector_ostream VecOS(Code);
175 1087 : Assembler.getEmitter().encodeInstruction(Inst, VecOS, Fixups, STI);
176 :
177 : // Append the encoded instruction to the current data fragment (or create a
178 : // new such fragment if the current fragment is not a data fragment).
179 1087 : MCDataFragment *DF = getOrCreateDataFragment();
180 :
181 : // Add the fixups and data.
182 1403 : for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
183 632 : Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
184 316 : DF->getFixups().push_back(Fixups[i]);
185 : }
186 : DF->setHasInstructions(STI);
187 1087 : DF->getContents().append(Code.begin(), Code.end());
188 1087 : }
189 :
190 151 : void MCWasmStreamer::FinishImpl() {
191 151 : EmitFrames(nullptr);
192 :
193 151 : this->MCObjectStreamer::FinishImpl();
194 150 : }
195 :
196 150 : MCStreamer *llvm::createWasmStreamer(MCContext &Context,
197 : std::unique_ptr<MCAsmBackend> &&MAB,
198 : std::unique_ptr<MCObjectWriter> &&OW,
199 : std::unique_ptr<MCCodeEmitter> &&CE,
200 : bool RelaxAll) {
201 : MCWasmStreamer *S =
202 300 : new MCWasmStreamer(Context, std::move(MAB), std::move(OW), std::move(CE));
203 150 : if (RelaxAll)
204 : S->getAssembler().setRelaxAll(true);
205 150 : return S;
206 : }
207 :
208 0 : void MCWasmStreamer::EmitThumbFunc(MCSymbol *Func) {
209 0 : llvm_unreachable("Generic Wasm doesn't support this directive");
210 : }
211 :
212 0 : void MCWasmStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
213 0 : llvm_unreachable("Wasm doesn't support this directive");
214 : }
215 :
216 0 : void MCWasmStreamer::EmitZerofill(MCSection *Section, MCSymbol *Symbol,
217 : uint64_t Size, unsigned ByteAlignment,
218 : SMLoc Loc) {
219 0 : llvm_unreachable("Wasm doesn't support this directive");
220 : }
221 :
222 0 : void MCWasmStreamer::EmitTBSSSymbol(MCSection *Section, MCSymbol *Symbol,
223 : uint64_t Size, unsigned ByteAlignment) {
224 0 : llvm_unreachable("Wasm doesn't support this directive");
225 : }
|
