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Diffstat (limited to 'contrib/llvm/lib/MC/MCWin64EH.cpp')
| -rw-r--r-- | contrib/llvm/lib/MC/MCWin64EH.cpp | 680 |
1 files changed, 0 insertions, 680 deletions
diff --git a/contrib/llvm/lib/MC/MCWin64EH.cpp b/contrib/llvm/lib/MC/MCWin64EH.cpp deleted file mode 100644 index 4e9a29667097..000000000000 --- a/contrib/llvm/lib/MC/MCWin64EH.cpp +++ /dev/null @@ -1,680 +0,0 @@ -//===- lib/MC/MCWin64EH.cpp - MCWin64EH 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/MCWin64EH.h" -#include "llvm/ADT/Twine.h" -#include "llvm/MC/MCContext.h" -#include "llvm/MC/MCExpr.h" -#include "llvm/MC/MCObjectFileInfo.h" -#include "llvm/MC/MCObjectStreamer.h" -#include "llvm/MC/MCSectionCOFF.h" -#include "llvm/MC/MCStreamer.h" -#include "llvm/MC/MCSymbol.h" -#include "llvm/Support/Win64EH.h" - -using namespace llvm; - -// NOTE: All relocations generated here are 4-byte image-relative. - -static uint8_t CountOfUnwindCodes(std::vector<WinEH::Instruction> &Insns) { - uint8_t Count = 0; - for (const auto &I : Insns) { - switch (static_cast<Win64EH::UnwindOpcodes>(I.Operation)) { - default: - llvm_unreachable("Unsupported unwind code"); - case Win64EH::UOP_PushNonVol: - case Win64EH::UOP_AllocSmall: - case Win64EH::UOP_SetFPReg: - case Win64EH::UOP_PushMachFrame: - Count += 1; - break; - case Win64EH::UOP_SaveNonVol: - case Win64EH::UOP_SaveXMM128: - Count += 2; - break; - case Win64EH::UOP_SaveNonVolBig: - case Win64EH::UOP_SaveXMM128Big: - Count += 3; - break; - case Win64EH::UOP_AllocLarge: - Count += (I.Offset > 512 * 1024 - 8) ? 3 : 2; - break; - } - } - return Count; -} - -static void EmitAbsDifference(MCStreamer &Streamer, const MCSymbol *LHS, - const MCSymbol *RHS) { - MCContext &Context = Streamer.getContext(); - const MCExpr *Diff = - MCBinaryExpr::createSub(MCSymbolRefExpr::create(LHS, Context), - MCSymbolRefExpr::create(RHS, Context), Context); - Streamer.EmitValue(Diff, 1); -} - -static void EmitUnwindCode(MCStreamer &streamer, const MCSymbol *begin, - WinEH::Instruction &inst) { - uint8_t b2; - uint16_t w; - b2 = (inst.Operation & 0x0F); - switch (static_cast<Win64EH::UnwindOpcodes>(inst.Operation)) { - default: - llvm_unreachable("Unsupported unwind code"); - case Win64EH::UOP_PushNonVol: - EmitAbsDifference(streamer, inst.Label, begin); - b2 |= (inst.Register & 0x0F) << 4; - streamer.EmitIntValue(b2, 1); - break; - case Win64EH::UOP_AllocLarge: - EmitAbsDifference(streamer, inst.Label, begin); - if (inst.Offset > 512 * 1024 - 8) { - b2 |= 0x10; - streamer.EmitIntValue(b2, 1); - w = inst.Offset & 0xFFF8; - streamer.EmitIntValue(w, 2); - w = inst.Offset >> 16; - } else { - streamer.EmitIntValue(b2, 1); - w = inst.Offset >> 3; - } - streamer.EmitIntValue(w, 2); - break; - case Win64EH::UOP_AllocSmall: - b2 |= (((inst.Offset - 8) >> 3) & 0x0F) << 4; - EmitAbsDifference(streamer, inst.Label, begin); - streamer.EmitIntValue(b2, 1); - break; - case Win64EH::UOP_SetFPReg: - EmitAbsDifference(streamer, inst.Label, begin); - streamer.EmitIntValue(b2, 1); - break; - case Win64EH::UOP_SaveNonVol: - case Win64EH::UOP_SaveXMM128: - b2 |= (inst.Register & 0x0F) << 4; - EmitAbsDifference(streamer, inst.Label, begin); - streamer.EmitIntValue(b2, 1); - w = inst.Offset >> 3; - if (inst.Operation == Win64EH::UOP_SaveXMM128) - w >>= 1; - streamer.EmitIntValue(w, 2); - break; - case Win64EH::UOP_SaveNonVolBig: - case Win64EH::UOP_SaveXMM128Big: - b2 |= (inst.Register & 0x0F) << 4; - EmitAbsDifference(streamer, inst.Label, begin); - streamer.EmitIntValue(b2, 1); - if (inst.Operation == Win64EH::UOP_SaveXMM128Big) - w = inst.Offset & 0xFFF0; - else - w = inst.Offset & 0xFFF8; - streamer.EmitIntValue(w, 2); - w = inst.Offset >> 16; - streamer.EmitIntValue(w, 2); - break; - case Win64EH::UOP_PushMachFrame: - if (inst.Offset == 1) - b2 |= 0x10; - EmitAbsDifference(streamer, inst.Label, begin); - streamer.EmitIntValue(b2, 1); - break; - } -} - -static void EmitSymbolRefWithOfs(MCStreamer &streamer, - const MCSymbol *Base, - const MCSymbol *Other) { - MCContext &Context = streamer.getContext(); - const MCSymbolRefExpr *BaseRef = MCSymbolRefExpr::create(Base, Context); - const MCSymbolRefExpr *OtherRef = MCSymbolRefExpr::create(Other, Context); - const MCExpr *Ofs = MCBinaryExpr::createSub(OtherRef, BaseRef, Context); - const MCSymbolRefExpr *BaseRefRel = MCSymbolRefExpr::create(Base, - MCSymbolRefExpr::VK_COFF_IMGREL32, - Context); - streamer.EmitValue(MCBinaryExpr::createAdd(BaseRefRel, Ofs, Context), 4); -} - -static void EmitRuntimeFunction(MCStreamer &streamer, - const WinEH::FrameInfo *info) { - MCContext &context = streamer.getContext(); - - streamer.EmitValueToAlignment(4); - EmitSymbolRefWithOfs(streamer, info->Function, info->Begin); - EmitSymbolRefWithOfs(streamer, info->Function, info->End); - streamer.EmitValue(MCSymbolRefExpr::create(info->Symbol, - MCSymbolRefExpr::VK_COFF_IMGREL32, - context), 4); -} - -static void EmitUnwindInfo(MCStreamer &streamer, WinEH::FrameInfo *info) { - // If this UNWIND_INFO already has a symbol, it's already been emitted. - if (info->Symbol) - return; - - MCContext &context = streamer.getContext(); - MCSymbol *Label = context.createTempSymbol(); - - streamer.EmitValueToAlignment(4); - streamer.EmitLabel(Label); - info->Symbol = Label; - - // Upper 3 bits are the version number (currently 1). - uint8_t flags = 0x01; - if (info->ChainedParent) - flags |= Win64EH::UNW_ChainInfo << 3; - else { - if (info->HandlesUnwind) - flags |= Win64EH::UNW_TerminateHandler << 3; - if (info->HandlesExceptions) - flags |= Win64EH::UNW_ExceptionHandler << 3; - } - streamer.EmitIntValue(flags, 1); - - if (info->PrologEnd) - EmitAbsDifference(streamer, info->PrologEnd, info->Begin); - else - streamer.EmitIntValue(0, 1); - - uint8_t numCodes = CountOfUnwindCodes(info->Instructions); - streamer.EmitIntValue(numCodes, 1); - - uint8_t frame = 0; - if (info->LastFrameInst >= 0) { - WinEH::Instruction &frameInst = info->Instructions[info->LastFrameInst]; - assert(frameInst.Operation == Win64EH::UOP_SetFPReg); - frame = (frameInst.Register & 0x0F) | (frameInst.Offset & 0xF0); - } - streamer.EmitIntValue(frame, 1); - - // Emit unwind instructions (in reverse order). - uint8_t numInst = info->Instructions.size(); - for (uint8_t c = 0; c < numInst; ++c) { - WinEH::Instruction inst = info->Instructions.back(); - info->Instructions.pop_back(); - EmitUnwindCode(streamer, info->Begin, inst); - } - - // For alignment purposes, the instruction array will always have an even - // number of entries, with the final entry potentially unused (in which case - // the array will be one longer than indicated by the count of unwind codes - // field). - if (numCodes & 1) { - streamer.EmitIntValue(0, 2); - } - - if (flags & (Win64EH::UNW_ChainInfo << 3)) - EmitRuntimeFunction(streamer, info->ChainedParent); - else if (flags & - ((Win64EH::UNW_TerminateHandler|Win64EH::UNW_ExceptionHandler) << 3)) - streamer.EmitValue(MCSymbolRefExpr::create(info->ExceptionHandler, - MCSymbolRefExpr::VK_COFF_IMGREL32, - context), 4); - else if (numCodes == 0) { - // The minimum size of an UNWIND_INFO struct is 8 bytes. If we're not - // a chained unwind info, if there is no handler, and if there are fewer - // than 2 slots used in the unwind code array, we have to pad to 8 bytes. - streamer.EmitIntValue(0, 4); - } -} - -void llvm::Win64EH::UnwindEmitter::Emit(MCStreamer &Streamer) const { - // Emit the unwind info structs first. - for (const auto &CFI : Streamer.getWinFrameInfos()) { - MCSection *XData = Streamer.getAssociatedXDataSection(CFI->TextSection); - Streamer.SwitchSection(XData); - ::EmitUnwindInfo(Streamer, CFI.get()); - } - - // Now emit RUNTIME_FUNCTION entries. - for (const auto &CFI : Streamer.getWinFrameInfos()) { - MCSection *PData = Streamer.getAssociatedPDataSection(CFI->TextSection); - Streamer.SwitchSection(PData); - EmitRuntimeFunction(Streamer, CFI.get()); - } -} - -void llvm::Win64EH::UnwindEmitter::EmitUnwindInfo( - MCStreamer &Streamer, WinEH::FrameInfo *info) const { - // Switch sections (the static function above is meant to be called from - // here and from Emit(). - MCSection *XData = Streamer.getAssociatedXDataSection(info->TextSection); - Streamer.SwitchSection(XData); - - ::EmitUnwindInfo(Streamer, info); -} - -static int64_t GetAbsDifference(MCStreamer &Streamer, const MCSymbol *LHS, - const MCSymbol *RHS) { - MCContext &Context = Streamer.getContext(); - const MCExpr *Diff = - MCBinaryExpr::createSub(MCSymbolRefExpr::create(LHS, Context), - MCSymbolRefExpr::create(RHS, Context), Context); - MCObjectStreamer *OS = (MCObjectStreamer *)(&Streamer); - // It should normally be possible to calculate the length of a function - // at this point, but it might not be possible in the presence of certain - // unusual constructs, like an inline asm with an alignment directive. - int64_t value; - if (!Diff->evaluateAsAbsolute(value, OS->getAssembler())) - report_fatal_error("Failed to evaluate function length in SEH unwind info"); - return value; -} - -static uint32_t -ARM64CountOfUnwindCodes(const std::vector<WinEH::Instruction> &Insns) { - uint32_t Count = 0; - for (const auto &I : Insns) { - switch (static_cast<Win64EH::UnwindOpcodes>(I.Operation)) { - default: - llvm_unreachable("Unsupported ARM64 unwind code"); - case Win64EH::UOP_AllocSmall: - Count += 1; - break; - case Win64EH::UOP_AllocMedium: - Count += 2; - break; - case Win64EH::UOP_AllocLarge: - Count += 4; - break; - case Win64EH::UOP_SaveFPLRX: - Count += 1; - break; - case Win64EH::UOP_SaveFPLR: - Count += 1; - break; - case Win64EH::UOP_SaveReg: - Count += 2; - break; - case Win64EH::UOP_SaveRegP: - Count += 2; - break; - case Win64EH::UOP_SaveRegPX: - Count += 2; - break; - case Win64EH::UOP_SaveRegX: - Count += 2; - break; - case Win64EH::UOP_SaveFReg: - Count += 2; - break; - case Win64EH::UOP_SaveFRegP: - Count += 2; - break; - case Win64EH::UOP_SaveFRegX: - Count += 2; - break; - case Win64EH::UOP_SaveFRegPX: - Count += 2; - break; - case Win64EH::UOP_SetFP: - Count += 1; - break; - case Win64EH::UOP_AddFP: - Count += 2; - break; - case Win64EH::UOP_Nop: - Count += 1; - break; - case Win64EH::UOP_End: - Count += 1; - break; - } - } - return Count; -} - -// Unwind opcode encodings and restrictions are documented at -// https://docs.microsoft.com/en-us/cpp/build/arm64-exception-handling -static void ARM64EmitUnwindCode(MCStreamer &streamer, const MCSymbol *begin, - WinEH::Instruction &inst) { - uint8_t b, reg; - switch (static_cast<Win64EH::UnwindOpcodes>(inst.Operation)) { - default: - llvm_unreachable("Unsupported ARM64 unwind code"); - case Win64EH::UOP_AllocSmall: - b = (inst.Offset >> 4) & 0x1F; - streamer.EmitIntValue(b, 1); - break; - case Win64EH::UOP_AllocMedium: { - uint16_t hw = (inst.Offset >> 4) & 0x7FF; - b = 0xC0; - b |= (hw >> 8); - streamer.EmitIntValue(b, 1); - b = hw & 0xFF; - streamer.EmitIntValue(b, 1); - break; - } - case Win64EH::UOP_AllocLarge: { - uint32_t w; - b = 0xE0; - streamer.EmitIntValue(b, 1); - w = inst.Offset >> 4; - b = (w & 0x00FF0000) >> 16; - streamer.EmitIntValue(b, 1); - b = (w & 0x0000FF00) >> 8; - streamer.EmitIntValue(b, 1); - b = w & 0x000000FF; - streamer.EmitIntValue(b, 1); - break; - } - case Win64EH::UOP_SetFP: - b = 0xE1; - streamer.EmitIntValue(b, 1); - break; - case Win64EH::UOP_AddFP: - b = 0xE2; - streamer.EmitIntValue(b, 1); - b = (inst.Offset >> 3); - streamer.EmitIntValue(b, 1); - break; - case Win64EH::UOP_Nop: - b = 0xE3; - streamer.EmitIntValue(b, 1); - break; - case Win64EH::UOP_SaveFPLRX: - b = 0x80; - b |= ((inst.Offset - 1) >> 3) & 0x3F; - streamer.EmitIntValue(b, 1); - break; - case Win64EH::UOP_SaveFPLR: - b = 0x40; - b |= (inst.Offset >> 3) & 0x3F; - streamer.EmitIntValue(b, 1); - break; - case Win64EH::UOP_SaveReg: - assert(inst.Register >= 19 && "Saved reg must be >= 19"); - reg = inst.Register - 19; - b = 0xD0 | ((reg & 0xC) >> 2); - streamer.EmitIntValue(b, 1); - b = ((reg & 0x3) << 6) | (inst.Offset >> 3); - streamer.EmitIntValue(b, 1); - break; - case Win64EH::UOP_SaveRegX: - assert(inst.Register >= 19 && "Saved reg must be >= 19"); - reg = inst.Register - 19; - b = 0xD4 | ((reg & 0x8) >> 3); - streamer.EmitIntValue(b, 1); - b = ((reg & 0x7) << 5) | ((inst.Offset >> 3) - 1); - streamer.EmitIntValue(b, 1); - break; - case Win64EH::UOP_SaveRegP: - assert(inst.Register >= 19 && "Saved registers must be >= 19"); - reg = inst.Register - 19; - b = 0xC8 | ((reg & 0xC) >> 2); - streamer.EmitIntValue(b, 1); - b = ((reg & 0x3) << 6) | (inst.Offset >> 3); - streamer.EmitIntValue(b, 1); - break; - case Win64EH::UOP_SaveRegPX: - assert(inst.Register >= 19 && "Saved registers must be >= 19"); - reg = inst.Register - 19; - b = 0xCC | ((reg & 0xC) >> 2); - streamer.EmitIntValue(b, 1); - b = ((reg & 0x3) << 6) | ((inst.Offset >> 3) - 1); - streamer.EmitIntValue(b, 1); - break; - case Win64EH::UOP_SaveFReg: - assert(inst.Register >= 8 && "Saved dreg must be >= 8"); - reg = inst.Register - 8; - b = 0xDC | ((reg & 0x4) >> 2); - streamer.EmitIntValue(b, 1); - b = ((reg & 0x3) << 6) | (inst.Offset >> 3); - streamer.EmitIntValue(b, 1); - break; - case Win64EH::UOP_SaveFRegX: - assert(inst.Register >= 8 && "Saved dreg must be >= 8"); - reg = inst.Register - 8; - b = 0xDE; - streamer.EmitIntValue(b, 1); - b = ((reg & 0x7) << 5) | ((inst.Offset >> 3) - 1); - streamer.EmitIntValue(b, 1); - break; - case Win64EH::UOP_SaveFRegP: - assert(inst.Register >= 8 && "Saved dregs must be >= 8"); - reg = inst.Register - 8; - b = 0xD8 | ((reg & 0x4) >> 2); - streamer.EmitIntValue(b, 1); - b = ((reg & 0x3) << 6) | (inst.Offset >> 3); - streamer.EmitIntValue(b, 1); - break; - case Win64EH::UOP_SaveFRegPX: - assert(inst.Register >= 8 && "Saved dregs must be >= 8"); - reg = inst.Register - 8; - b = 0xDA | ((reg & 0x4) >> 2); - streamer.EmitIntValue(b, 1); - b = ((reg & 0x3) << 6) | ((inst.Offset >> 3) - 1); - streamer.EmitIntValue(b, 1); - break; - case Win64EH::UOP_End: - b = 0xE4; - streamer.EmitIntValue(b, 1); - break; - } -} - -// Returns the epilog symbol of an epilog with the exact same unwind code -// sequence, if it exists. Otherwise, returns nulltpr. -// EpilogInstrs - Unwind codes for the current epilog. -// Epilogs - Epilogs that potentialy match the current epilog. -static MCSymbol* -FindMatchingEpilog(const std::vector<WinEH::Instruction>& EpilogInstrs, - const std::vector<MCSymbol *>& Epilogs, - const WinEH::FrameInfo *info) { - for (auto *EpilogStart : Epilogs) { - auto InstrsIter = info->EpilogMap.find(EpilogStart); - assert(InstrsIter != info->EpilogMap.end() && - "Epilog not found in EpilogMap"); - const auto &Instrs = InstrsIter->second; - - if (Instrs.size() != EpilogInstrs.size()) - continue; - - bool Match = true; - for (unsigned i = 0; i < Instrs.size(); ++i) - if (Instrs[i].Operation != EpilogInstrs[i].Operation || - Instrs[i].Offset != EpilogInstrs[i].Offset || - Instrs[i].Register != EpilogInstrs[i].Register) { - Match = false; - break; - } - - if (Match) - return EpilogStart; - } - return nullptr; -} - -// Populate the .xdata section. The format of .xdata on ARM64 is documented at -// https://docs.microsoft.com/en-us/cpp/build/arm64-exception-handling -static void ARM64EmitUnwindInfo(MCStreamer &streamer, WinEH::FrameInfo *info) { - // If this UNWIND_INFO already has a symbol, it's already been emitted. - if (info->Symbol) - return; - - MCContext &context = streamer.getContext(); - MCSymbol *Label = context.createTempSymbol(); - - streamer.EmitValueToAlignment(4); - streamer.EmitLabel(Label); - info->Symbol = Label; - - int64_t RawFuncLength; - if (!info->FuncletOrFuncEnd) { - // FIXME: This is very wrong; we emit SEH data which covers zero bytes - // of code. But otherwise test/MC/AArch64/seh.s crashes. - RawFuncLength = 0; - } else { - // FIXME: GetAbsDifference tries to compute the length of the function - // immediately, before the whole file is emitted, but in general - // that's impossible: the size in bytes of certain assembler directives - // like .align and .fill is not known until the whole file is parsed and - // relaxations are applied. Currently, GetAbsDifference fails with a fatal - // error in that case. (We mostly don't hit this because inline assembly - // specifying those directives is rare, and we don't normally try to - // align loops on AArch64.) - // - // There are two potential approaches to delaying the computation. One, - // we could emit something like ".word (endfunc-beginfunc)/4+0x10800000", - // as long as we have some conservative estimate we could use to prove - // that we don't need to split the unwind data. Emitting the constant - // is straightforward, but there's no existing code for estimating the - // size of the function. - // - // The other approach would be to use a dedicated, relaxable fragment, - // which could grow to accommodate splitting the unwind data if - // necessary. This is more straightforward, since it automatically works - // without any new infrastructure, and it's consistent with how we handle - // relaxation in other contexts. But it would require some refactoring - // to move parts of the pdata/xdata emission into the implementation of - // a fragment. We could probably continue to encode the unwind codes - // here, but we'd have to emit the pdata, the xdata header, and the - // epilogue scopes later, since they depend on whether the we need to - // split the unwind data. - RawFuncLength = GetAbsDifference(streamer, info->FuncletOrFuncEnd, - info->Begin); - } - if (RawFuncLength > 0xFFFFF) - report_fatal_error("SEH unwind data splitting not yet implemented"); - uint32_t FuncLength = (uint32_t)RawFuncLength / 4; - uint32_t PrologCodeBytes = ARM64CountOfUnwindCodes(info->Instructions); - uint32_t TotalCodeBytes = PrologCodeBytes; - - // Process epilogs. - MapVector<MCSymbol *, uint32_t> EpilogInfo; - // Epilogs processed so far. - std::vector<MCSymbol *> AddedEpilogs; - - for (auto &I : info->EpilogMap) { - MCSymbol *EpilogStart = I.first; - auto &EpilogInstrs = I.second; - uint32_t CodeBytes = ARM64CountOfUnwindCodes(EpilogInstrs); - - MCSymbol* MatchingEpilog = - FindMatchingEpilog(EpilogInstrs, AddedEpilogs, info); - if (MatchingEpilog) { - assert(EpilogInfo.find(MatchingEpilog) != EpilogInfo.end() && - "Duplicate epilog not found"); - EpilogInfo[EpilogStart] = EpilogInfo.lookup(MatchingEpilog); - // Clear the unwind codes in the EpilogMap, so that they don't get output - // in the logic below. - EpilogInstrs.clear(); - } else { - EpilogInfo[EpilogStart] = TotalCodeBytes; - TotalCodeBytes += CodeBytes; - AddedEpilogs.push_back(EpilogStart); - } - } - - // Code Words, Epilog count, E, X, Vers, Function Length - uint32_t row1 = 0x0; - uint32_t CodeWords = TotalCodeBytes / 4; - uint32_t CodeWordsMod = TotalCodeBytes % 4; - if (CodeWordsMod) - CodeWords++; - uint32_t EpilogCount = info->EpilogMap.size(); - bool ExtensionWord = EpilogCount > 31 || TotalCodeBytes > 124; - if (!ExtensionWord) { - row1 |= (EpilogCount & 0x1F) << 22; - row1 |= (CodeWords & 0x1F) << 27; - } - // E is always 0 right now, TODO: packed epilog setup - if (info->HandlesExceptions) // X - row1 |= 1 << 20; - row1 |= FuncLength & 0x3FFFF; - streamer.EmitIntValue(row1, 4); - - // Extended Code Words, Extended Epilog Count - if (ExtensionWord) { - // FIXME: We should be able to split unwind info into multiple sections. - // FIXME: We should share epilog codes across epilogs, where possible, - // which would make this issue show up less frequently. - if (CodeWords > 0xFF || EpilogCount > 0xFFFF) - report_fatal_error("SEH unwind data splitting not yet implemented"); - uint32_t row2 = 0x0; - row2 |= (CodeWords & 0xFF) << 16; - row2 |= (EpilogCount & 0xFFFF); - streamer.EmitIntValue(row2, 4); - } - - // Epilog Start Index, Epilog Start Offset - for (auto &I : EpilogInfo) { - MCSymbol *EpilogStart = I.first; - uint32_t EpilogIndex = I.second; - uint32_t EpilogOffset = - (uint32_t)GetAbsDifference(streamer, EpilogStart, info->Begin); - if (EpilogOffset) - EpilogOffset /= 4; - uint32_t row3 = EpilogOffset; - row3 |= (EpilogIndex & 0x3FF) << 22; - streamer.EmitIntValue(row3, 4); - } - - // Emit prolog unwind instructions (in reverse order). - uint8_t numInst = info->Instructions.size(); - for (uint8_t c = 0; c < numInst; ++c) { - WinEH::Instruction inst = info->Instructions.back(); - info->Instructions.pop_back(); - ARM64EmitUnwindCode(streamer, info->Begin, inst); - } - - // Emit epilog unwind instructions - for (auto &I : info->EpilogMap) { - auto &EpilogInstrs = I.second; - for (uint32_t i = 0; i < EpilogInstrs.size(); i++) { - WinEH::Instruction inst = EpilogInstrs[i]; - ARM64EmitUnwindCode(streamer, info->Begin, inst); - } - } - - int32_t BytesMod = CodeWords * 4 - TotalCodeBytes; - assert(BytesMod >= 0); - for (int i = 0; i < BytesMod; i++) - streamer.EmitIntValue(0xE3, 1); - - if (info->HandlesExceptions) - streamer.EmitValue( - MCSymbolRefExpr::create(info->ExceptionHandler, - MCSymbolRefExpr::VK_COFF_IMGREL32, context), - 4); -} - -static void ARM64EmitRuntimeFunction(MCStreamer &streamer, - const WinEH::FrameInfo *info) { - MCContext &context = streamer.getContext(); - - streamer.EmitValueToAlignment(4); - EmitSymbolRefWithOfs(streamer, info->Function, info->Begin); - streamer.EmitValue(MCSymbolRefExpr::create(info->Symbol, - MCSymbolRefExpr::VK_COFF_IMGREL32, - context), - 4); -} - -void llvm::Win64EH::ARM64UnwindEmitter::Emit(MCStreamer &Streamer) const { - // Emit the unwind info structs first. - for (const auto &CFI : Streamer.getWinFrameInfos()) { - MCSection *XData = Streamer.getAssociatedXDataSection(CFI->TextSection); - Streamer.SwitchSection(XData); - ARM64EmitUnwindInfo(Streamer, CFI.get()); - } - - // Now emit RUNTIME_FUNCTION entries. - for (const auto &CFI : Streamer.getWinFrameInfos()) { - MCSection *PData = Streamer.getAssociatedPDataSection(CFI->TextSection); - Streamer.SwitchSection(PData); - ARM64EmitRuntimeFunction(Streamer, CFI.get()); - } -} - -void llvm::Win64EH::ARM64UnwindEmitter::EmitUnwindInfo( - MCStreamer &Streamer, WinEH::FrameInfo *info) const { - // Switch sections (the static function above is meant to be called from - // here and from Emit(). - MCSection *XData = Streamer.getAssociatedXDataSection(info->TextSection); - Streamer.SwitchSection(XData); - ARM64EmitUnwindInfo(Streamer, info); -} |