forked from OSchip/llvm-project
78 lines
2.8 KiB
C++
78 lines
2.8 KiB
C++
//===- lib/MC/MCWinEH.cpp - Windows EH implementation ---------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/ADT/StringRef.h"
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#include "llvm/MC/MCContext.h"
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#include "llvm/MC/MCObjectFileInfo.h"
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#include "llvm/MC/MCSectionCOFF.h"
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#include "llvm/MC/MCSymbol.h"
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#include "llvm/MC/MCWinEH.h"
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#include "llvm/Support/COFF.h"
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namespace llvm {
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namespace WinEH {
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/// We can't have one section for all .pdata or .xdata because the Microsoft
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/// linker seems to want all code relocations to refer to the same object file
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/// section. If the code described is comdat, create a new comdat section
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/// associated with that comdat. If the code described is not in the main .text
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/// section, make a new section for it. Otherwise use the main unwind info
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/// section.
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static const MCSection *getUnwindInfoSection(
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StringRef SecName, const MCSectionCOFF *UnwindSec, const MCSymbol *Function,
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MCContext &Context) {
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if (Function && Function->isInSection()) {
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// If Function is in a COMDAT, get or create an unwind info section in that
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// COMDAT group.
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const MCSectionCOFF *FunctionSection =
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cast<MCSectionCOFF>(&Function->getSection());
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if (FunctionSection->getCharacteristics() & COFF::IMAGE_SCN_LNK_COMDAT) {
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return Context.getAssociativeCOFFSection(
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UnwindSec, FunctionSection->getCOMDATSymbol());
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}
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// If Function is in a section other than .text, create a new .pdata section.
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// Otherwise use the plain .pdata section.
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if (const auto *Section = dyn_cast<MCSectionCOFF>(FunctionSection)) {
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StringRef CodeSecName = Section->getSectionName();
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if (CodeSecName == ".text")
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return UnwindSec;
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if (CodeSecName.startswith(".text$"))
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CodeSecName = CodeSecName.substr(6);
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return Context.getCOFFSection(
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(SecName + Twine('$') + CodeSecName).str(),
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COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
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SectionKind::getDataRel());
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}
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}
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return UnwindSec;
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}
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const MCSection *UnwindEmitter::getPDataSection(const MCSymbol *Function,
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MCContext &Context) {
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const MCSectionCOFF *PData =
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cast<MCSectionCOFF>(Context.getObjectFileInfo()->getPDataSection());
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return getUnwindInfoSection(".pdata", PData, Function, Context);
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}
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const MCSection *UnwindEmitter::getXDataSection(const MCSymbol *Function,
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MCContext &Context) {
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const MCSectionCOFF *XData =
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cast<MCSectionCOFF>(Context.getObjectFileInfo()->getXDataSection());
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return getUnwindInfoSection(".xdata", XData, Function, Context);
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}
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}
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}
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