llvm-project/llvm/lib/MC/MCSymbol.cpp
Fangrui Song 190778a8ba MCSymbol: Rename SymContents to kind
The names "SymbolContents" and "SymContents*" members are confusing.
Rename to kind and Kind::XXX similar to lld/ELF/Symbols.h

Rename SymContentsVariable to Kind::Equated as the former term is
"equated symbol", not "variable".
2025-08-16 15:10:35 -07:00

91 lines
3.0 KiB
C++

//===- lib/MC/MCSymbol.cpp - MCSymbol implementation ----------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCSymbol.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Config/llvm-config.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include <cassert>
#include <cstddef>
using namespace llvm;
// There are numerous MCSymbol objects, so keeping sizeof(MCSymbol) small is
// crucial for minimizing peak memory usage.
static_assert(sizeof(MCSymbol) <= 24, "Keep the base symbol small");
// Only the address of this fragment is ever actually used.
static MCFragment SentinelFragment;
// Sentinel value for the absolute pseudo fragment.
MCFragment *MCSymbol::AbsolutePseudoFragment = &SentinelFragment;
void *MCSymbol::operator new(size_t s, const MCSymbolTableEntry *Name,
MCContext &Ctx) {
// We may need more space for a Name to account for alignment. So allocate
// space for the storage type and not the name pointer.
size_t Size = s + (Name ? sizeof(NameEntryStorageTy) : 0);
// For safety, ensure that the alignment of a pointer is enough for an
// MCSymbol. This also ensures we don't need padding between the name and
// symbol.
static_assert((unsigned)alignof(MCSymbol) <= alignof(NameEntryStorageTy),
"Bad alignment of MCSymbol");
void *Storage = Ctx.allocate(Size, alignof(NameEntryStorageTy));
NameEntryStorageTy *Start = static_cast<NameEntryStorageTy*>(Storage);
NameEntryStorageTy *End = Start + (Name ? 1 : 0);
return End;
}
void MCSymbol::setVariableValue(const MCExpr *Value) {
assert(Value && "Invalid equated expression");
assert((kind == Kind::Regular || kind == Kind::Equated) &&
"Cannot equate a common symbol");
this->Value = Value;
kind = Kind::Equated;
setUndefined();
}
void MCSymbol::print(raw_ostream &OS, const MCAsmInfo *MAI) const {
// The name for this MCSymbol is required to be a valid target name. However,
// some targets support quoting names with funny characters. If the name
// contains a funny character, then print it quoted.
StringRef Name = getName();
if (!MAI || MAI->isValidUnquotedName(Name)) {
OS << Name;
return;
}
if (MAI && !MAI->supportsNameQuoting())
report_fatal_error("Symbol name with unsupported characters");
OS << '"';
for (char C : Name) {
if (C == '\n')
OS << "\\n";
else if (C == '"')
OS << "\\\"";
else if (C == '\\')
OS << "\\\\";
else
OS << C;
}
OS << '"';
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
LLVM_DUMP_METHOD void MCSymbol::dump() const {
dbgs() << *this;
}
#endif