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//===- lib/MC/MCWasmStreamer.cpp - Wasm Object Output ---------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file assembles .s files and emits Wasm .o object files.
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCWasmStreamer.h"
#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCFixup.h"
#include "llvm/MC/MCObjectStreamer.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSectionWasm.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCSymbolWasm.h"
#include "llvm/MC/TargetRegistry.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/ErrorHandling.h"
namespace llvm {
class MCContext;
class MCStreamer;
class MCSubtargetInfo;
} // namespace llvm
using namespace llvm;
MCWasmStreamer::~MCWasmStreamer() = default; // anchor.
void MCWasmStreamer::emitLabel(MCSymbol *S, SMLoc Loc) {
auto *Symbol = cast<MCSymbolWasm>(S);
MCObjectStreamer::emitLabel(Symbol, Loc);
const MCSectionWasm &Section =
static_cast<const MCSectionWasm &>(*getCurrentSectionOnly());
if (Section.getSegmentFlags() & wasm::WASM_SEG_FLAG_TLS)
Symbol->setTLS();
}
void MCWasmStreamer::emitLabelAtPos(MCSymbol *S, SMLoc Loc, MCDataFragment &F,
uint64_t Offset) {
auto *Symbol = cast<MCSymbolWasm>(S);
MCObjectStreamer::emitLabelAtPos(Symbol, Loc, F, Offset);
const MCSectionWasm &Section =
static_cast<const MCSectionWasm &>(*getCurrentSectionOnly());
if (Section.getSegmentFlags() & wasm::WASM_SEG_FLAG_TLS)
Symbol->setTLS();
}
void MCWasmStreamer::changeSection(MCSection *Section, uint32_t Subsection) {
MCAssembler &Asm = getAssembler();
auto *SectionWasm = cast<MCSectionWasm>(Section);
const MCSymbol *Grp = SectionWasm->getGroup();
if (Grp)
Asm.registerSymbol(*Grp);
this->MCObjectStreamer::changeSection(Section, Subsection);
Asm.registerSymbol(*Section->getBeginSymbol());
}
bool MCWasmStreamer::emitSymbolAttribute(MCSymbol *S, MCSymbolAttr Attribute) {
assert(Attribute != MCSA_IndirectSymbol && "indirect symbols not supported");
auto *Symbol = cast<MCSymbolWasm>(S);
// Adding a symbol attribute always introduces the symbol; note that an
// important side effect of calling registerSymbol here is to register the
// symbol with the assembler.
getAssembler().registerSymbol(*Symbol);
switch (Attribute) {
case MCSA_LazyReference:
case MCSA_Reference:
case MCSA_SymbolResolver:
case MCSA_PrivateExtern:
case MCSA_WeakDefinition:
case MCSA_WeakDefAutoPrivate:
case MCSA_Invalid:
case MCSA_IndirectSymbol:
case MCSA_Protected:
case MCSA_Exported:
return false;
case MCSA_Hidden:
Symbol->setHidden(true);
break;
case MCSA_Weak:
case MCSA_WeakReference:
Symbol->setWeak(true);
Symbol->setExternal(true);
break;
case MCSA_Global:
Symbol->setExternal(true);
break;
case MCSA_ELF_TypeFunction:
Symbol->setType(wasm::WASM_SYMBOL_TYPE_FUNCTION);
break;
case MCSA_ELF_TypeTLS:
Symbol->setTLS();
break;
case MCSA_ELF_TypeObject:
case MCSA_Cold:
break;
case MCSA_NoDeadStrip:
Symbol->setNoStrip();
break;
default:
// unrecognized directive
llvm_unreachable("unexpected MCSymbolAttr");
return false;
}
return true;
}
void MCWasmStreamer::emitCommonSymbol(MCSymbol *S, uint64_t Size,
Align ByteAlignment) {
llvm_unreachable("Common symbols are not yet implemented for Wasm");
}
void MCWasmStreamer::emitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
cast<MCSymbolWasm>(Symbol)->setSize(Value);
}
void MCWasmStreamer::emitLocalCommonSymbol(MCSymbol *S, uint64_t Size,
Align ByteAlignment) {
llvm_unreachable("Local common symbols are not yet implemented for Wasm");
}
void MCWasmStreamer::emitIdent(StringRef IdentString) {
// TODO(sbc): Add the ident section once we support mergable strings
// sections in the object format
}
void MCWasmStreamer::finishImpl() {
emitFrames(nullptr);
this->MCObjectStreamer::finishImpl();
}
MCStreamer *llvm::createWasmStreamer(MCContext &Context,
std::unique_ptr<MCAsmBackend> &&MAB,
std::unique_ptr<MCObjectWriter> &&OW,
std::unique_ptr<MCCodeEmitter> &&CE) {
MCWasmStreamer *S =
new MCWasmStreamer(Context, std::move(MAB), std::move(OW), std::move(CE));
return S;
}
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