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-rw-r--r--contrib/llvm/lib/MC/MCWin64EH.cpp252
1 files changed, 252 insertions, 0 deletions
diff --git a/contrib/llvm/lib/MC/MCWin64EH.cpp b/contrib/llvm/lib/MC/MCWin64EH.cpp
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+++ b/contrib/llvm/lib/MC/MCWin64EH.cpp
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+//===- lib/MC/MCWin64EH.cpp - MCWin64EH implementation --------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#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/MCSectionCOFF.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/Support/Win64EH.h"
+
+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)) {
+ 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)) {
+ 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);
+ }
+}
+
+namespace Win64EH {
+void UnwindEmitter::Emit(MCStreamer &Streamer) const {
+ MCContext &Context = Streamer.getContext();
+
+ // Emit the unwind info structs first.
+ for (const auto &CFI : Streamer.getWinFrameInfos()) {
+ MCSection *XData = getXDataSection(CFI->Function, Context);
+ Streamer.SwitchSection(XData);
+ EmitUnwindInfo(Streamer, CFI);
+ }
+
+ // Now emit RUNTIME_FUNCTION entries.
+ for (const auto &CFI : Streamer.getWinFrameInfos()) {
+ MCSection *PData = getPDataSection(CFI->Function, Context);
+ Streamer.SwitchSection(PData);
+ EmitRuntimeFunction(Streamer, CFI);
+ }
+}
+
+void UnwindEmitter::EmitUnwindInfo(MCStreamer &Streamer,
+ WinEH::FrameInfo *info) const {
+ // Switch sections (the static function above is meant to be called from
+ // here and from Emit().
+ MCContext &context = Streamer.getContext();
+ MCSection *xdataSect = getXDataSection(info->Function, context);
+ Streamer.SwitchSection(xdataSect);
+
+ llvm::EmitUnwindInfo(Streamer, info);
+}
+}
+} // End of namespace llvm
+
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