From 3185f5c35322cbd10040ab20f265042d477efe62 Mon Sep 17 00:00:00 2001 From: Charles Davis Date: Sun, 22 May 2011 03:01:05 +0000 Subject: [PATCH] Make the COFF streamer emit unwind info when processing a .seh_handlerdata directive. Implement emission of Win64 EH unwind info. Pull in in MCWin64EH.h so it can use the assert() macro. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131832 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/MC/MCStreamer.h | 2 + include/llvm/MC/MCWin64EH.h | 10 +- lib/MC/CMakeLists.txt | 1 + lib/MC/MCWin64EH.cpp | 189 +++++++++++++++++++++++++++++++++++ lib/MC/WinCOFFStreamer.cpp | 10 ++ 5 files changed, 208 insertions(+), 4 deletions(-) create mode 100644 lib/MC/MCWin64EH.cpp diff --git a/include/llvm/MC/MCStreamer.h b/include/llvm/MC/MCStreamer.h index 55f25e44a0a..bfcb4609aee 100644 --- a/include/llvm/MC/MCStreamer.h +++ b/include/llvm/MC/MCStreamer.h @@ -80,6 +80,8 @@ namespace llvm { void EmitFrames(bool usingCFI); + MCWin64EHUnwindInfo *getCurrentW64UnwindInfo(){return CurrentW64UnwindInfo;} + public: virtual ~MCStreamer(); diff --git a/include/llvm/MC/MCWin64EH.h b/include/llvm/MC/MCWin64EH.h index a88b5040b8b..39f30465466 100644 --- a/include/llvm/MC/MCWin64EH.h +++ b/include/llvm/MC/MCWin64EH.h @@ -16,6 +16,7 @@ #define LLVM_MC_MCWIN64EH_H #include "llvm/Support/Win64EH.h" +#include #include namespace llvm { @@ -59,20 +60,21 @@ namespace llvm { struct MCWin64EHUnwindInfo { MCWin64EHUnwindInfo() : Begin(0), End(0), ExceptionHandler(0), - Function(0), PrologEnd(0), HandlesUnwind(false), - HandlesExceptions(false), LastFrameInst(-1), - ChainedParent(0), Instructions(), Emitted(false) {} + Function(0), PrologEnd(0), Symbol(0), + HandlesUnwind(false), HandlesExceptions(false), + LastFrameInst(-1), ChainedParent(0), + Instructions() {} MCSymbol *Begin; MCSymbol *End; const MCSymbol *ExceptionHandler; const MCSymbol *Function; MCSymbol *PrologEnd; + MCSymbol *Symbol; bool HandlesUnwind; bool HandlesExceptions; int LastFrameInst; MCWin64EHUnwindInfo *ChainedParent; std::vector Instructions; - bool Emitted; }; class MCWin64EHUnwindEmitter { diff --git a/lib/MC/CMakeLists.txt b/lib/MC/CMakeLists.txt index 6aed059f0f4..a77ecd3bd8a 100644 --- a/lib/MC/CMakeLists.txt +++ b/lib/MC/CMakeLists.txt @@ -30,6 +30,7 @@ add_llvm_library(LLVMMC MCStreamer.cpp MCSymbol.cpp MCValue.cpp + MCWin64EH.cpp MachObjectWriter.cpp WinCOFFStreamer.cpp WinCOFFObjectWriter.cpp diff --git a/lib/MC/MCWin64EH.cpp b/lib/MC/MCWin64EH.cpp new file mode 100644 index 00000000000..9884f66e5fb --- /dev/null +++ b/lib/MC/MCWin64EH.cpp @@ -0,0 +1,189 @@ +//===- 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/MC/MCStreamer.h" +#include "llvm/MC/MCContext.h" +#include "llvm/MC/MCExpr.h" +#include "llvm/Target/TargetAsmInfo.h" + +namespace llvm { + +// NOTE: All relocations generated here are 4-byte image-relative. + +static uint8_t CountOfUnwindCodes(std::vector &instArray){ + uint8_t count = 0; + for (std::vector::const_iterator I = instArray.begin(), + E = instArray.end(); I != E; ++I) { + switch (I->getOperation()) { + case Win64EH::UOP_PushNonVol: + case Win64EH::UOP_AllocSmall: + case Win64EH::UOP_SetFPReg: + case Win64EH::UOP_PushMachFrame: + count += 1; + case Win64EH::UOP_SaveNonVol: + case Win64EH::UOP_SaveXMM128: + count += 2; + case Win64EH::UOP_SaveNonVolBig: + case Win64EH::UOP_SaveXMM128Big: + count += 3; + case Win64EH::UOP_AllocLarge: + if (I->getSize() > 512*1024-8) + count += 3; + else + count += 2; + } + } + return count; +} + +static void EmitUnwindCode(MCStreamer &streamer, MCWin64EHInstruction &inst) { + uint8_t b1, b2; + uint16_t w; + b2 = (inst.getOperation() & 0x0F) << 4; + switch (inst.getOperation()) { + case Win64EH::UOP_PushNonVol: + streamer.EmitIntValue(0, 1); + b2 |= inst.getRegister() & 0x0F; + streamer.EmitIntValue(b2, 1); + break; + case Win64EH::UOP_AllocLarge: + streamer.EmitIntValue(0, 1); + if (inst.getSize() > 512*1024-8) { + b2 |= 1; + streamer.EmitIntValue(b2, 1); + w = inst.getSize() & 0xFFF8; + streamer.EmitIntValue(w, 2); + w = inst.getSize() >> 16; + } else { + streamer.EmitIntValue(b2, 1); + w = inst.getSize() >> 3; + } + streamer.EmitIntValue(w, 2); + break; + case Win64EH::UOP_AllocSmall: + b2 |= (inst.getSize() >> 3) & 0x0F; + streamer.EmitIntValue(0, 1); + streamer.EmitIntValue(b2, 1); + break; + case Win64EH::UOP_SetFPReg: + b1 = inst.getOffset() & 0xF0; + streamer.EmitIntValue(b1, 1); + streamer.EmitIntValue(b2, 1); + break; + case Win64EH::UOP_SaveNonVol: + case Win64EH::UOP_SaveXMM128: + b2 |= inst.getRegister() & 0x0F; + streamer.EmitIntValue(0, 1); + streamer.EmitIntValue(b2, 1); + w = inst.getOffset() >> 3; + if (inst.getOperation() == Win64EH::UOP_SaveXMM128) + w >>= 1; + streamer.EmitIntValue(w, 2); + break; + case Win64EH::UOP_SaveNonVolBig: + case Win64EH::UOP_SaveXMM128Big: + b2 |= inst.getRegister() & 0x0F; + streamer.EmitIntValue(0, 1); + streamer.EmitIntValue(b2, 1); + if (inst.getOperation() == Win64EH::UOP_SaveXMM128Big) + w = inst.getOffset() & 0xFFF0; + else + w = inst.getOffset() & 0xFFF8; + streamer.EmitIntValue(w, 2); + w = inst.getOffset() >> 16; + streamer.EmitIntValue(w, 2); + break; + case Win64EH::UOP_PushMachFrame: + if (inst.isPushCodeFrame()) + b2 |= 1; + streamer.EmitIntValue(0, 1); + streamer.EmitIntValue(b2, 1); + break; + } +} + +static void EmitRuntimeFunction(MCStreamer &streamer, + MCWin64EHUnwindInfo *info) { + MCContext &context = streamer.getContext(); + + streamer.EmitValue(MCSymbolRefExpr::Create(info->Begin, context), 4); + streamer.EmitValue(MCSymbolRefExpr::Create(info->End, context), 4); + streamer.EmitValue(MCSymbolRefExpr::Create(info->Symbol, context), 4); +} + +static void EmitUnwindInfo(MCStreamer &streamer, MCWin64EHUnwindInfo *info) { + // If this UNWIND_INFO already has a symbol, it's already been emitted. + if (info->Symbol) return; + + MCContext &context = streamer.getContext(); + // Upper 3 bits are the version number (currently 1). + uint8_t flags = 0x20; + info->Symbol = context.CreateTempSymbol(); + streamer.EmitLabel(info->Symbol); + + if (info->ChainedParent) + flags |= Win64EH::UNW_ChainInfo; + else { + if (info->HandlesUnwind) + flags |= Win64EH::UNW_TerminateHandler; + if (info->HandlesExceptions) + flags |= Win64EH::UNW_ExceptionHandler; + } + streamer.EmitIntValue(flags, 1); + + // Build up the prolog size expression. + const MCExpr *prologSize = MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create( + info->PrologEnd, context), + MCSymbolRefExpr::Create( + info->Begin, context), + context); + streamer.EmitAbsValue(prologSize, 1); + + uint8_t numCodes = CountOfUnwindCodes(info->Instructions); + streamer.EmitIntValue(numCodes, 1); + + uint8_t frame = 0; + if (info->LastFrameInst >= 0) { + MCWin64EHInstruction &frameInst = info->Instructions[info->LastFrameInst]; + assert(frameInst.getOperation() == Win64EH::UOP_SetFPReg); + frame = ((frameInst.getRegister() & 0x0F) << 4) | + ((frameInst.getOffset() >> 4) & 0x0F); + } + streamer.EmitIntValue(frame, 1); + + // Emit unwind instructions (in reverse order). + uint8_t numInst = info->Instructions.size(); + for (uint8_t c = 0; c < numInst; ++c) { + MCWin64EHInstruction inst = info->Instructions.back(); + info->Instructions.pop_back(); + EmitUnwindCode(streamer, inst); + } + + if (flags & Win64EH::UNW_ChainInfo) + EmitRuntimeFunction(streamer, info->ChainedParent); + else if (flags &(Win64EH::UNW_TerminateHandler|Win64EH::UNW_ExceptionHandler)) + streamer.EmitValue(MCSymbolRefExpr::Create(info->ExceptionHandler, context), + 4); +} + +void MCWin64EHUnwindEmitter::EmitUnwindInfo(MCStreamer &streamer, + MCWin64EHUnwindInfo *info) { + // Switch sections (the static function above is meant to be called from + // here and from Emit(). + MCContext &context = streamer.getContext(); + const TargetAsmInfo &asmInfo = context.getTargetAsmInfo(); + const MCSection *xdataSect = asmInfo.getWin64EHTableSection(); + streamer.SwitchSection(xdataSect); + + llvm::EmitUnwindInfo(streamer, info); +} + +} // End of namespace llvm + diff --git a/lib/MC/WinCOFFStreamer.cpp b/lib/MC/WinCOFFStreamer.cpp index 46968e601be..8b0cfcbd62c 100644 --- a/lib/MC/WinCOFFStreamer.cpp +++ b/lib/MC/WinCOFFStreamer.cpp @@ -23,6 +23,7 @@ #include "llvm/MC/MCAsmLayout.h" #include "llvm/MC/MCCodeEmitter.h" #include "llvm/MC/MCSectionCOFF.h" +#include "llvm/MC/MCWin64EH.h" #include "llvm/Target/TargetRegistry.h" #include "llvm/Target/TargetAsmBackend.h" #include "llvm/ADT/StringMap.h" @@ -74,6 +75,7 @@ public: unsigned MaxBytesToEmit); virtual void EmitFileDirective(StringRef Filename); virtual void EmitInstruction(const MCInst &Instruction); + virtual void EmitWin64EHHandlerData(); virtual void Finish(); private: @@ -377,6 +379,14 @@ void WinCOFFStreamer::EmitInstruction(const MCInst &Instruction) { Fragment->getFixups()); } +void WinCOFFStreamer::EmitWin64EHHandlerData() { + MCStreamer::EmitWin64EHHandlerData(); + + // We have to emit the unwind info now, because this directive + // actually switches to the .xdata section! + MCWin64EHUnwindEmitter::EmitUnwindInfo(*this, getCurrentW64UnwindInfo()); +} + void WinCOFFStreamer::Finish() { MCObjectStreamer::Finish(); } -- 2.34.1