Make the COFF streamer emit unwind info when processing a .seh_handlerdata
directive.
Implement emission of Win64 EH unwind info.
Pull in <cassert> 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
diff --git a/lib/MC/MCWin64EH.cpp b/lib/MC/MCWin64EH.cpp
new file mode 100644
index 0000000..9884f66
--- /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<MCWin64EHInstruction> &instArray){
+ uint8_t count = 0;
+ for (std::vector<MCWin64EHInstruction>::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
+