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//===- lib/MC/MCSectionELF.cpp - ELF Code Section Representation ----------===//
//
// 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/MCSectionELF.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/TargetParser/Triple.h"
#include <cassert>
using namespace llvm;
// Decides whether a '.section' directive
// should be printed before the section name.
bool MCSectionELF::shouldOmitSectionDirective(StringRef Name,
const MCAsmInfo &MAI) const {
if (isUnique())
return false;
return MAI.shouldOmitSectionDirective(Name);
}
static void printName(raw_ostream &OS, StringRef Name) {
if (Name.find_first_not_of("0123456789_."
"abcdefghijklmnopqrstuvwxyz"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ") == Name.npos) {
OS << Name;
return;
}
OS << '"';
for (const char *B = Name.begin(), *E = Name.end(); B < E; ++B) {
if (*B == '"') // Unquoted "
OS << "\\\"";
else if (*B != '\\') // Neither " or backslash
OS << *B;
else if (B + 1 == E) // Trailing backslash
OS << "\\\\";
else {
OS << B[0] << B[1]; // Quoted character
++B;
}
}
OS << '"';
}
void MCSectionELF::printSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
raw_ostream &OS,
const MCExpr *Subsection) const {
if (shouldOmitSectionDirective(getName(), MAI)) {
OS << '\t' << getName();
if (Subsection) {
OS << '\t';
Subsection->print(OS, &MAI);
}
OS << '\n';
return;
}
OS << "\t.section\t";
printName(OS, getName());
// Handle the weird solaris syntax if desired.
if (MAI.usesSunStyleELFSectionSwitchSyntax() &&
!(Flags & ELF::SHF_MERGE)) {
if (Flags & ELF::SHF_ALLOC)
OS << ",#alloc";
if (Flags & ELF::SHF_EXECINSTR)
OS << ",#execinstr";
if (Flags & ELF::SHF_WRITE)
OS << ",#write";
if (Flags & ELF::SHF_EXCLUDE)
OS << ",#exclude";
if (Flags & ELF::SHF_TLS)
OS << ",#tls";
OS << '\n';
return;
}
OS << ",\"";
if (Flags & ELF::SHF_ALLOC)
OS << 'a';
if (Flags & ELF::SHF_EXCLUDE)
OS << 'e';
if (Flags & ELF::SHF_EXECINSTR)
OS << 'x';
if (Flags & ELF::SHF_WRITE)
OS << 'w';
if (Flags & ELF::SHF_MERGE)
OS << 'M';
if (Flags & ELF::SHF_STRINGS)
OS << 'S';
if (Flags & ELF::SHF_TLS)
OS << 'T';
if (Flags & ELF::SHF_LINK_ORDER)
OS << 'o';
if (Flags & ELF::SHF_GROUP)
OS << 'G';
if (Flags & ELF::SHF_GNU_RETAIN)
OS << 'R';
// If there are os-specific flags, print them.
if (T.isOSSolaris())
if (Flags & ELF::SHF_SUNW_NODISCARD)
OS << 'R';
// If there are target-specific flags, print them.
Triple::ArchType Arch = T.getArch();
if (Arch == Triple::xcore) {
if (Flags & ELF::XCORE_SHF_CP_SECTION)
OS << 'c';
if (Flags & ELF::XCORE_SHF_DP_SECTION)
OS << 'd';
} else if (T.isARM() || T.isThumb()) {
if (Flags & ELF::SHF_ARM_PURECODE)
OS << 'y';
} else if (Arch == Triple::hexagon) {
if (Flags & ELF::SHF_HEX_GPREL)
OS << 's';
} else if (Arch == Triple::x86_64) {
if (Flags & ELF::SHF_X86_64_LARGE)
OS << 'l';
}
OS << '"';
OS << ',';
// If comment string is '@', e.g. as on ARM - use '%' instead
if (MAI.getCommentString()[0] == '@')
OS << '%';
else
OS << '@';
if (Type == ELF::SHT_INIT_ARRAY)
OS << "init_array";
else if (Type == ELF::SHT_FINI_ARRAY)
OS << "fini_array";
else if (Type == ELF::SHT_PREINIT_ARRAY)
OS << "preinit_array";
else if (Type == ELF::SHT_NOBITS)
OS << "nobits";
else if (Type == ELF::SHT_NOTE)
OS << "note";
else if (Type == ELF::SHT_PROGBITS)
OS << "progbits";
else if (Type == ELF::SHT_X86_64_UNWIND)
OS << "unwind";
else if (Type == ELF::SHT_MIPS_DWARF)
// Print hex value of the flag while we do not have
// any standard symbolic representation of the flag.
OS << "0x7000001e";
else if (Type == ELF::SHT_LLVM_ODRTAB)
OS << "llvm_odrtab";
else if (Type == ELF::SHT_LLVM_LINKER_OPTIONS)
OS << "llvm_linker_options";
else if (Type == ELF::SHT_LLVM_CALL_GRAPH_PROFILE)
OS << "llvm_call_graph_profile";
else if (Type == ELF::SHT_LLVM_DEPENDENT_LIBRARIES)
OS << "llvm_dependent_libraries";
else if (Type == ELF::SHT_LLVM_SYMPART)
OS << "llvm_sympart";
else if (Type == ELF::SHT_LLVM_BB_ADDR_MAP)
OS << "llvm_bb_addr_map";
else if (Type == ELF::SHT_LLVM_BB_ADDR_MAP_V0)
OS << "llvm_bb_addr_map_v0";
else if (Type == ELF::SHT_LLVM_OFFLOADING)
OS << "llvm_offloading";
else if (Type == ELF::SHT_LLVM_LTO)
OS << "llvm_lto";
else
report_fatal_error("unsupported type 0x" + Twine::utohexstr(Type) +
" for section " + getName());
if (EntrySize) {
assert(Flags & ELF::SHF_MERGE);
OS << "," << EntrySize;
}
if (Flags & ELF::SHF_LINK_ORDER) {
OS << ",";
if (LinkedToSym)
printName(OS, LinkedToSym->getName());
else
OS << '0';
}
if (Flags & ELF::SHF_GROUP) {
OS << ",";
printName(OS, Group.getPointer()->getName());
if (isComdat())
OS << ",comdat";
}
if (isUnique())
OS << ",unique," << UniqueID;
OS << '\n';
if (Subsection) {
OS << "\t.subsection\t";
Subsection->print(OS, &MAI);
OS << '\n';
}
}
bool MCSectionELF::useCodeAlign() const {
return getFlags() & ELF::SHF_EXECINSTR;
}
bool MCSectionELF::isVirtualSection() const {
return getType() == ELF::SHT_NOBITS;
}
StringRef MCSectionELF::getVirtualSectionKind() const { return "SHT_NOBITS"; }