blob: 609ef096293042cd34476d0ed505606a3a70a70b [file] [log] [blame]
//===- lib/MC/MCSectionXCOFF.cpp - XCOFF 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/MCSectionXCOFF.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/raw_ostream.h"
namespace llvm {
class MCExpr;
class Triple;
} // namespace llvm
using namespace llvm;
MCSectionXCOFF::~MCSectionXCOFF() = default;
void MCSectionXCOFF::printCsectDirective(raw_ostream &OS) const {
OS << "\t.csect " << QualName->getName() << "," << Log2(getAlign()) << '\n';
}
void MCSectionXCOFF::printSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
raw_ostream &OS,
const MCExpr *Subsection) const {
if (getKind().isText()) {
if (getMappingClass() != XCOFF::XMC_PR)
report_fatal_error("Unhandled storage-mapping class for .text csect");
printCsectDirective(OS);
return;
}
if (getKind().isReadOnly()) {
if (getMappingClass() != XCOFF::XMC_RO &&
getMappingClass() != XCOFF::XMC_TD)
report_fatal_error("Unhandled storage-mapping class for .rodata csect.");
printCsectDirective(OS);
return;
}
if (getKind().isReadOnlyWithRel()) {
if (getMappingClass() != XCOFF::XMC_RW &&
getMappingClass() != XCOFF::XMC_RO &&
getMappingClass() != XCOFF::XMC_TD)
report_fatal_error(
"Unexepected storage-mapping class for ReadOnlyWithRel kind");
printCsectDirective(OS);
return;
}
// Initialized TLS data.
if (getKind().isThreadData()) {
// We only expect XMC_TL here for initialized TLS data.
if (getMappingClass() != XCOFF::XMC_TL)
report_fatal_error("Unhandled storage-mapping class for .tdata csect.");
printCsectDirective(OS);
return;
}
if (getKind().isData()) {
switch (getMappingClass()) {
case XCOFF::XMC_RW:
case XCOFF::XMC_DS:
case XCOFF::XMC_TD:
printCsectDirective(OS);
break;
case XCOFF::XMC_TC:
case XCOFF::XMC_TE:
break;
case XCOFF::XMC_TC0:
OS << "\t.toc\n";
break;
default:
report_fatal_error(
"Unhandled storage-mapping class for .data csect.");
}
return;
}
if (isCsect() && getMappingClass() == XCOFF::XMC_TD) {
// Common csect type (uninitialized storage) does not have to print csect
// directive for section switching unless it is local.
if (getKind().isCommon() && !getKind().isBSSLocal())
return;
assert(getKind().isBSS() && "Unexpected section kind for toc-data");
printCsectDirective(OS);
return;
}
// Common csect type (uninitialized storage) does not have to print csect
// directive for section switching.
if (isCsect() && getCSectType() == XCOFF::XTY_CM) {
assert((getMappingClass() == XCOFF::XMC_RW ||
getMappingClass() == XCOFF::XMC_BS ||
getMappingClass() == XCOFF::XMC_UL) &&
"Generated a storage-mapping class for a common/bss/tbss csect we "
"don't "
"understand how to switch to.");
// Common symbols and local zero-initialized symbols for TLS and Non-TLS are
// eligible for .bss/.tbss csect, getKind().isThreadBSS() is used to cover
// TLS common and zero-initialized local symbols since linkage type (in the
// GlobalVariable) is not accessible in this class.
assert((getKind().isBSSLocal() || getKind().isCommon() ||
getKind().isThreadBSS()) &&
"wrong symbol type for .bss/.tbss csect");
// Don't have to print a directive for switching to section for commons and
// zero-initialized TLS data. The '.comm' and '.lcomm' directives of the
// variable will create the needed csect.
return;
}
// Zero-initialized TLS data with weak or external linkage are not eligible to
// be put into common csect.
if (getKind().isThreadBSS()) {
printCsectDirective(OS);
return;
}
// XCOFF debug sections.
if (getKind().isMetadata() && isDwarfSect()) {
OS << "\n\t.dwsect " << format("0x%" PRIx32, *getDwarfSubtypeFlags())
<< '\n';
OS << MAI.getPrivateLabelPrefix() << getName() << ':' << '\n';
return;
}
report_fatal_error("Printing for this SectionKind is unimplemented.");
}
bool MCSectionXCOFF::useCodeAlign() const { return getKind().isText(); }
bool MCSectionXCOFF::isVirtualSection() const {
// DWARF sections are always not virtual.
if (isDwarfSect())
return false;
assert(isCsect() &&
"Handling for isVirtualSection not implemented for this section!");
// XTY_CM sections are virtual except for toc-data symbols.
return (XCOFF::XTY_CM == CsectProp->Type) &&
(getMappingClass() != XCOFF::XMC_TD);
}