| //===-- CodeGen/AsmPrinter/AIXException.cpp - AIX Exception Impl ----------===// |
| // |
| // 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 contains support for writing AIX exception info into asm files. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "DwarfException.h" |
| #include "llvm/CodeGen/AsmPrinter.h" |
| #include "llvm/CodeGen/MachineModuleInfo.h" |
| #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h" |
| #include "llvm/MC/MCSectionXCOFF.h" |
| #include "llvm/MC/MCStreamer.h" |
| #include "llvm/Target/TargetLoweringObjectFile.h" |
| #include "llvm/Target/TargetMachine.h" |
| |
| namespace llvm { |
| |
| AIXException::AIXException(AsmPrinter *A) : EHStreamer(A) {} |
| |
| void AIXException::emitExceptionInfoTable(const MCSymbol *LSDA, |
| const MCSymbol *PerSym) { |
| // Generate EH Info Table. |
| // The EH Info Table, aka, 'compat unwind section' on AIX, have the following |
| // format: struct eh_info_t { |
| // unsigned version; /* EH info verion 0 */ |
| // #if defined(__64BIT__) |
| // char _pad[4]; /* padding */ |
| // #endif |
| // unsigned long lsda; /* Pointer to LSDA */ |
| // unsigned long personality; /* Pointer to the personality routine */ |
| // } |
| |
| auto *EHInfo = |
| cast<MCSectionXCOFF>(Asm->getObjFileLowering().getCompactUnwindSection()); |
| if (Asm->TM.getFunctionSections()) { |
| // If option -ffunction-sections is on, append the function name to the |
| // name of EH Info Table csect so that each function has its own EH Info |
| // Table csect. This helps the linker to garbage-collect EH info of unused |
| // functions. |
| SmallString<128> NameStr = EHInfo->getName(); |
| raw_svector_ostream(NameStr) << '.' << Asm->MF->getFunction().getName(); |
| EHInfo = Asm->OutContext.getXCOFFSection(NameStr, EHInfo->getKind(), |
| EHInfo->getCsectProp()); |
| } |
| Asm->OutStreamer->switchSection(EHInfo); |
| MCSymbol *EHInfoLabel = |
| TargetLoweringObjectFileXCOFF::getEHInfoTableSymbol(Asm->MF); |
| Asm->OutStreamer->emitLabel(EHInfoLabel); |
| |
| // Version number. |
| Asm->emitInt32(0); |
| |
| const DataLayout &DL = MMI->getModule()->getDataLayout(); |
| const unsigned PointerSize = DL.getPointerSize(); |
| |
| // Add necessary paddings in 64 bit mode. |
| Asm->OutStreamer->emitValueToAlignment(Align(PointerSize)); |
| |
| // LSDA location. |
| Asm->OutStreamer->emitValue(MCSymbolRefExpr::create(LSDA, Asm->OutContext), |
| PointerSize); |
| |
| // Personality routine. |
| Asm->OutStreamer->emitValue(MCSymbolRefExpr::create(PerSym, Asm->OutContext), |
| PointerSize); |
| } |
| |
| void AIXException::endFunction(const MachineFunction *MF) { |
| // There is no easy way to access register information in `AIXException` |
| // class. when ShouldEmitEHBlock is false and VRs are saved, A dumy eh info |
| // table are emitted in PPCAIXAsmPrinter::emitFunctionBodyEnd. |
| if (!TargetLoweringObjectFileXCOFF::ShouldEmitEHBlock(MF)) |
| return; |
| |
| const MCSymbol *LSDALabel = emitExceptionTable(); |
| |
| const Function &F = MF->getFunction(); |
| assert(F.hasPersonalityFn() && |
| "Landingpads are presented, but no personality routine is found."); |
| const auto *Per = |
| cast<GlobalValue>(F.getPersonalityFn()->stripPointerCasts()); |
| const MCSymbol *PerSym = Asm->TM.getSymbol(Per); |
| |
| emitExceptionInfoTable(LSDALabel, PerSym); |
| } |
| |
| } // End of namespace llvm |