| File: | build/source/llvm/lib/MC/MCWin64EH.cpp |
| Warning: | line 1979, column 7 Value stored to 'HasR11' is never read |
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| 1 | //===- lib/MC/MCWin64EH.cpp - MCWin64EH implementation --------------------===// |
| 2 | // |
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 4 | // See https://llvm.org/LICENSE.txt for license information. |
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | |
| 9 | #include "llvm/MC/MCWin64EH.h" |
| 10 | #include "llvm/ADT/Twine.h" |
| 11 | #include "llvm/MC/MCContext.h" |
| 12 | #include "llvm/MC/MCExpr.h" |
| 13 | #include "llvm/MC/MCObjectStreamer.h" |
| 14 | #include "llvm/MC/MCStreamer.h" |
| 15 | #include "llvm/MC/MCSymbol.h" |
| 16 | #include "llvm/Support/Win64EH.h" |
| 17 | namespace llvm { |
| 18 | class MCSection; |
| 19 | } |
| 20 | |
| 21 | using namespace llvm; |
| 22 | |
| 23 | // NOTE: All relocations generated here are 4-byte image-relative. |
| 24 | |
| 25 | static uint8_t CountOfUnwindCodes(std::vector<WinEH::Instruction> &Insns) { |
| 26 | uint8_t Count = 0; |
| 27 | for (const auto &I : Insns) { |
| 28 | switch (static_cast<Win64EH::UnwindOpcodes>(I.Operation)) { |
| 29 | default: |
| 30 | llvm_unreachable("Unsupported unwind code")::llvm::llvm_unreachable_internal("Unsupported unwind code", "llvm/lib/MC/MCWin64EH.cpp" , 30); |
| 31 | case Win64EH::UOP_PushNonVol: |
| 32 | case Win64EH::UOP_AllocSmall: |
| 33 | case Win64EH::UOP_SetFPReg: |
| 34 | case Win64EH::UOP_PushMachFrame: |
| 35 | Count += 1; |
| 36 | break; |
| 37 | case Win64EH::UOP_SaveNonVol: |
| 38 | case Win64EH::UOP_SaveXMM128: |
| 39 | Count += 2; |
| 40 | break; |
| 41 | case Win64EH::UOP_SaveNonVolBig: |
| 42 | case Win64EH::UOP_SaveXMM128Big: |
| 43 | Count += 3; |
| 44 | break; |
| 45 | case Win64EH::UOP_AllocLarge: |
| 46 | Count += (I.Offset > 512 * 1024 - 8) ? 3 : 2; |
| 47 | break; |
| 48 | } |
| 49 | } |
| 50 | return Count; |
| 51 | } |
| 52 | |
| 53 | static void EmitAbsDifference(MCStreamer &Streamer, const MCSymbol *LHS, |
| 54 | const MCSymbol *RHS) { |
| 55 | MCContext &Context = Streamer.getContext(); |
| 56 | const MCExpr *Diff = |
| 57 | MCBinaryExpr::createSub(MCSymbolRefExpr::create(LHS, Context), |
| 58 | MCSymbolRefExpr::create(RHS, Context), Context); |
| 59 | Streamer.emitValue(Diff, 1); |
| 60 | } |
| 61 | |
| 62 | static void EmitUnwindCode(MCStreamer &streamer, const MCSymbol *begin, |
| 63 | WinEH::Instruction &inst) { |
| 64 | uint8_t b2; |
| 65 | uint16_t w; |
| 66 | b2 = (inst.Operation & 0x0F); |
| 67 | switch (static_cast<Win64EH::UnwindOpcodes>(inst.Operation)) { |
| 68 | default: |
| 69 | llvm_unreachable("Unsupported unwind code")::llvm::llvm_unreachable_internal("Unsupported unwind code", "llvm/lib/MC/MCWin64EH.cpp" , 69); |
| 70 | case Win64EH::UOP_PushNonVol: |
| 71 | EmitAbsDifference(streamer, inst.Label, begin); |
| 72 | b2 |= (inst.Register & 0x0F) << 4; |
| 73 | streamer.emitInt8(b2); |
| 74 | break; |
| 75 | case Win64EH::UOP_AllocLarge: |
| 76 | EmitAbsDifference(streamer, inst.Label, begin); |
| 77 | if (inst.Offset > 512 * 1024 - 8) { |
| 78 | b2 |= 0x10; |
| 79 | streamer.emitInt8(b2); |
| 80 | w = inst.Offset & 0xFFF8; |
| 81 | streamer.emitInt16(w); |
| 82 | w = inst.Offset >> 16; |
| 83 | } else { |
| 84 | streamer.emitInt8(b2); |
| 85 | w = inst.Offset >> 3; |
| 86 | } |
| 87 | streamer.emitInt16(w); |
| 88 | break; |
| 89 | case Win64EH::UOP_AllocSmall: |
| 90 | b2 |= (((inst.Offset - 8) >> 3) & 0x0F) << 4; |
| 91 | EmitAbsDifference(streamer, inst.Label, begin); |
| 92 | streamer.emitInt8(b2); |
| 93 | break; |
| 94 | case Win64EH::UOP_SetFPReg: |
| 95 | EmitAbsDifference(streamer, inst.Label, begin); |
| 96 | streamer.emitInt8(b2); |
| 97 | break; |
| 98 | case Win64EH::UOP_SaveNonVol: |
| 99 | case Win64EH::UOP_SaveXMM128: |
| 100 | b2 |= (inst.Register & 0x0F) << 4; |
| 101 | EmitAbsDifference(streamer, inst.Label, begin); |
| 102 | streamer.emitInt8(b2); |
| 103 | w = inst.Offset >> 3; |
| 104 | if (inst.Operation == Win64EH::UOP_SaveXMM128) |
| 105 | w >>= 1; |
| 106 | streamer.emitInt16(w); |
| 107 | break; |
| 108 | case Win64EH::UOP_SaveNonVolBig: |
| 109 | case Win64EH::UOP_SaveXMM128Big: |
| 110 | b2 |= (inst.Register & 0x0F) << 4; |
| 111 | EmitAbsDifference(streamer, inst.Label, begin); |
| 112 | streamer.emitInt8(b2); |
| 113 | if (inst.Operation == Win64EH::UOP_SaveXMM128Big) |
| 114 | w = inst.Offset & 0xFFF0; |
| 115 | else |
| 116 | w = inst.Offset & 0xFFF8; |
| 117 | streamer.emitInt16(w); |
| 118 | w = inst.Offset >> 16; |
| 119 | streamer.emitInt16(w); |
| 120 | break; |
| 121 | case Win64EH::UOP_PushMachFrame: |
| 122 | if (inst.Offset == 1) |
| 123 | b2 |= 0x10; |
| 124 | EmitAbsDifference(streamer, inst.Label, begin); |
| 125 | streamer.emitInt8(b2); |
| 126 | break; |
| 127 | } |
| 128 | } |
| 129 | |
| 130 | static void EmitSymbolRefWithOfs(MCStreamer &streamer, |
| 131 | const MCSymbol *Base, |
| 132 | int64_t Offset) { |
| 133 | MCContext &Context = streamer.getContext(); |
| 134 | const MCConstantExpr *OffExpr = MCConstantExpr::create(Offset, Context); |
| 135 | const MCSymbolRefExpr *BaseRefRel = MCSymbolRefExpr::create(Base, |
| 136 | MCSymbolRefExpr::VK_COFF_IMGREL32, |
| 137 | Context); |
| 138 | streamer.emitValue(MCBinaryExpr::createAdd(BaseRefRel, OffExpr, Context), 4); |
| 139 | } |
| 140 | |
| 141 | static void EmitSymbolRefWithOfs(MCStreamer &streamer, |
| 142 | const MCSymbol *Base, |
| 143 | const MCSymbol *Other) { |
| 144 | MCContext &Context = streamer.getContext(); |
| 145 | const MCSymbolRefExpr *BaseRef = MCSymbolRefExpr::create(Base, Context); |
| 146 | const MCSymbolRefExpr *OtherRef = MCSymbolRefExpr::create(Other, Context); |
| 147 | const MCExpr *Ofs = MCBinaryExpr::createSub(OtherRef, BaseRef, Context); |
| 148 | const MCSymbolRefExpr *BaseRefRel = MCSymbolRefExpr::create(Base, |
| 149 | MCSymbolRefExpr::VK_COFF_IMGREL32, |
| 150 | Context); |
| 151 | streamer.emitValue(MCBinaryExpr::createAdd(BaseRefRel, Ofs, Context), 4); |
| 152 | } |
| 153 | |
| 154 | static void EmitRuntimeFunction(MCStreamer &streamer, |
| 155 | const WinEH::FrameInfo *info) { |
| 156 | MCContext &context = streamer.getContext(); |
| 157 | |
| 158 | streamer.emitValueToAlignment(Align(4)); |
| 159 | EmitSymbolRefWithOfs(streamer, info->Begin, info->Begin); |
| 160 | EmitSymbolRefWithOfs(streamer, info->Begin, info->End); |
| 161 | streamer.emitValue(MCSymbolRefExpr::create(info->Symbol, |
| 162 | MCSymbolRefExpr::VK_COFF_IMGREL32, |
| 163 | context), 4); |
| 164 | } |
| 165 | |
| 166 | static void EmitUnwindInfo(MCStreamer &streamer, WinEH::FrameInfo *info) { |
| 167 | // If this UNWIND_INFO already has a symbol, it's already been emitted. |
| 168 | if (info->Symbol) |
| 169 | return; |
| 170 | |
| 171 | MCContext &context = streamer.getContext(); |
| 172 | MCSymbol *Label = context.createTempSymbol(); |
| 173 | |
| 174 | streamer.emitValueToAlignment(Align(4)); |
| 175 | streamer.emitLabel(Label); |
| 176 | info->Symbol = Label; |
| 177 | |
| 178 | // Upper 3 bits are the version number (currently 1). |
| 179 | uint8_t flags = 0x01; |
| 180 | if (info->ChainedParent) |
| 181 | flags |= Win64EH::UNW_ChainInfo << 3; |
| 182 | else { |
| 183 | if (info->HandlesUnwind) |
| 184 | flags |= Win64EH::UNW_TerminateHandler << 3; |
| 185 | if (info->HandlesExceptions) |
| 186 | flags |= Win64EH::UNW_ExceptionHandler << 3; |
| 187 | } |
| 188 | streamer.emitInt8(flags); |
| 189 | |
| 190 | if (info->PrologEnd) |
| 191 | EmitAbsDifference(streamer, info->PrologEnd, info->Begin); |
| 192 | else |
| 193 | streamer.emitInt8(0); |
| 194 | |
| 195 | uint8_t numCodes = CountOfUnwindCodes(info->Instructions); |
| 196 | streamer.emitInt8(numCodes); |
| 197 | |
| 198 | uint8_t frame = 0; |
| 199 | if (info->LastFrameInst >= 0) { |
| 200 | WinEH::Instruction &frameInst = info->Instructions[info->LastFrameInst]; |
| 201 | assert(frameInst.Operation == Win64EH::UOP_SetFPReg)(static_cast <bool> (frameInst.Operation == Win64EH::UOP_SetFPReg ) ? void (0) : __assert_fail ("frameInst.Operation == Win64EH::UOP_SetFPReg" , "llvm/lib/MC/MCWin64EH.cpp", 201, __extension__ __PRETTY_FUNCTION__ )); |
| 202 | frame = (frameInst.Register & 0x0F) | (frameInst.Offset & 0xF0); |
| 203 | } |
| 204 | streamer.emitInt8(frame); |
| 205 | |
| 206 | // Emit unwind instructions (in reverse order). |
| 207 | uint8_t numInst = info->Instructions.size(); |
| 208 | for (uint8_t c = 0; c < numInst; ++c) { |
| 209 | WinEH::Instruction inst = info->Instructions.back(); |
| 210 | info->Instructions.pop_back(); |
| 211 | EmitUnwindCode(streamer, info->Begin, inst); |
| 212 | } |
| 213 | |
| 214 | // For alignment purposes, the instruction array will always have an even |
| 215 | // number of entries, with the final entry potentially unused (in which case |
| 216 | // the array will be one longer than indicated by the count of unwind codes |
| 217 | // field). |
| 218 | if (numCodes & 1) { |
| 219 | streamer.emitInt16(0); |
| 220 | } |
| 221 | |
| 222 | if (flags & (Win64EH::UNW_ChainInfo << 3)) |
| 223 | EmitRuntimeFunction(streamer, info->ChainedParent); |
| 224 | else if (flags & |
| 225 | ((Win64EH::UNW_TerminateHandler|Win64EH::UNW_ExceptionHandler) << 3)) |
| 226 | streamer.emitValue(MCSymbolRefExpr::create(info->ExceptionHandler, |
| 227 | MCSymbolRefExpr::VK_COFF_IMGREL32, |
| 228 | context), 4); |
| 229 | else if (numCodes == 0) { |
| 230 | // The minimum size of an UNWIND_INFO struct is 8 bytes. If we're not |
| 231 | // a chained unwind info, if there is no handler, and if there are fewer |
| 232 | // than 2 slots used in the unwind code array, we have to pad to 8 bytes. |
| 233 | streamer.emitInt32(0); |
| 234 | } |
| 235 | } |
| 236 | |
| 237 | void llvm::Win64EH::UnwindEmitter::Emit(MCStreamer &Streamer) const { |
| 238 | // Emit the unwind info structs first. |
| 239 | for (const auto &CFI : Streamer.getWinFrameInfos()) { |
| 240 | MCSection *XData = Streamer.getAssociatedXDataSection(CFI->TextSection); |
| 241 | Streamer.switchSection(XData); |
| 242 | ::EmitUnwindInfo(Streamer, CFI.get()); |
| 243 | } |
| 244 | |
| 245 | // Now emit RUNTIME_FUNCTION entries. |
| 246 | for (const auto &CFI : Streamer.getWinFrameInfos()) { |
| 247 | MCSection *PData = Streamer.getAssociatedPDataSection(CFI->TextSection); |
| 248 | Streamer.switchSection(PData); |
| 249 | EmitRuntimeFunction(Streamer, CFI.get()); |
| 250 | } |
| 251 | } |
| 252 | |
| 253 | void llvm::Win64EH::UnwindEmitter::EmitUnwindInfo(MCStreamer &Streamer, |
| 254 | WinEH::FrameInfo *info, |
| 255 | bool HandlerData) const { |
| 256 | // Switch sections (the static function above is meant to be called from |
| 257 | // here and from Emit(). |
| 258 | MCSection *XData = Streamer.getAssociatedXDataSection(info->TextSection); |
| 259 | Streamer.switchSection(XData); |
| 260 | |
| 261 | ::EmitUnwindInfo(Streamer, info); |
| 262 | } |
| 263 | |
| 264 | static const MCExpr *GetSubDivExpr(MCStreamer &Streamer, const MCSymbol *LHS, |
| 265 | const MCSymbol *RHS, int Div) { |
| 266 | MCContext &Context = Streamer.getContext(); |
| 267 | const MCExpr *Expr = |
| 268 | MCBinaryExpr::createSub(MCSymbolRefExpr::create(LHS, Context), |
| 269 | MCSymbolRefExpr::create(RHS, Context), Context); |
| 270 | if (Div != 1) |
| 271 | Expr = MCBinaryExpr::createDiv(Expr, MCConstantExpr::create(Div, Context), |
| 272 | Context); |
| 273 | return Expr; |
| 274 | } |
| 275 | |
| 276 | static std::optional<int64_t> GetOptionalAbsDifference(MCStreamer &Streamer, |
| 277 | const MCSymbol *LHS, |
| 278 | const MCSymbol *RHS) { |
| 279 | MCContext &Context = Streamer.getContext(); |
| 280 | const MCExpr *Diff = |
| 281 | MCBinaryExpr::createSub(MCSymbolRefExpr::create(LHS, Context), |
| 282 | MCSymbolRefExpr::create(RHS, Context), Context); |
| 283 | MCObjectStreamer *OS = (MCObjectStreamer *)(&Streamer); |
| 284 | // It should normally be possible to calculate the length of a function |
| 285 | // at this point, but it might not be possible in the presence of certain |
| 286 | // unusual constructs, like an inline asm with an alignment directive. |
| 287 | int64_t value; |
| 288 | if (!Diff->evaluateAsAbsolute(value, OS->getAssembler())) |
| 289 | return std::nullopt; |
| 290 | return value; |
| 291 | } |
| 292 | |
| 293 | static int64_t GetAbsDifference(MCStreamer &Streamer, const MCSymbol *LHS, |
| 294 | const MCSymbol *RHS) { |
| 295 | std::optional<int64_t> MaybeDiff = |
| 296 | GetOptionalAbsDifference(Streamer, LHS, RHS); |
| 297 | if (!MaybeDiff) |
| 298 | report_fatal_error("Failed to evaluate function length in SEH unwind info"); |
| 299 | return *MaybeDiff; |
| 300 | } |
| 301 | |
| 302 | static void checkARM64Instructions(MCStreamer &Streamer, |
| 303 | ArrayRef<WinEH::Instruction> Insns, |
| 304 | const MCSymbol *Begin, const MCSymbol *End, |
| 305 | StringRef Name, StringRef Type) { |
| 306 | if (!End) |
| 307 | return; |
| 308 | std::optional<int64_t> MaybeDistance = |
| 309 | GetOptionalAbsDifference(Streamer, End, Begin); |
| 310 | if (!MaybeDistance) |
| 311 | return; |
| 312 | uint32_t Distance = (uint32_t)*MaybeDistance; |
| 313 | |
| 314 | for (const auto &I : Insns) { |
| 315 | switch (static_cast<Win64EH::UnwindOpcodes>(I.Operation)) { |
| 316 | default: |
| 317 | break; |
| 318 | case Win64EH::UOP_TrapFrame: |
| 319 | case Win64EH::UOP_PushMachFrame: |
| 320 | case Win64EH::UOP_Context: |
| 321 | case Win64EH::UOP_ClearUnwoundToCall: |
| 322 | // Can't reason about these opcodes and how they map to actual |
| 323 | // instructions. |
| 324 | return; |
| 325 | } |
| 326 | } |
| 327 | // Exclude the end opcode which doesn't map to an instruction. |
| 328 | uint32_t InstructionBytes = 4 * (Insns.size() - 1); |
| 329 | if (Distance != InstructionBytes) { |
| 330 | Streamer.getContext().reportError( |
| 331 | SMLoc(), "Incorrect size for " + Name + " " + Type + ": " + |
| 332 | Twine(Distance) + |
| 333 | " bytes of instructions in range, but .seh directives " |
| 334 | "corresponding to " + |
| 335 | Twine(InstructionBytes) + " bytes\n"); |
| 336 | } |
| 337 | } |
| 338 | |
| 339 | static uint32_t ARM64CountOfUnwindCodes(ArrayRef<WinEH::Instruction> Insns) { |
| 340 | uint32_t Count = 0; |
| 341 | for (const auto &I : Insns) { |
| 342 | switch (static_cast<Win64EH::UnwindOpcodes>(I.Operation)) { |
| 343 | default: |
| 344 | llvm_unreachable("Unsupported ARM64 unwind code")::llvm::llvm_unreachable_internal("Unsupported ARM64 unwind code" , "llvm/lib/MC/MCWin64EH.cpp", 344); |
| 345 | case Win64EH::UOP_AllocSmall: |
| 346 | Count += 1; |
| 347 | break; |
| 348 | case Win64EH::UOP_AllocMedium: |
| 349 | Count += 2; |
| 350 | break; |
| 351 | case Win64EH::UOP_AllocLarge: |
| 352 | Count += 4; |
| 353 | break; |
| 354 | case Win64EH::UOP_SaveR19R20X: |
| 355 | Count += 1; |
| 356 | break; |
| 357 | case Win64EH::UOP_SaveFPLRX: |
| 358 | Count += 1; |
| 359 | break; |
| 360 | case Win64EH::UOP_SaveFPLR: |
| 361 | Count += 1; |
| 362 | break; |
| 363 | case Win64EH::UOP_SaveReg: |
| 364 | Count += 2; |
| 365 | break; |
| 366 | case Win64EH::UOP_SaveRegP: |
| 367 | Count += 2; |
| 368 | break; |
| 369 | case Win64EH::UOP_SaveRegPX: |
| 370 | Count += 2; |
| 371 | break; |
| 372 | case Win64EH::UOP_SaveRegX: |
| 373 | Count += 2; |
| 374 | break; |
| 375 | case Win64EH::UOP_SaveLRPair: |
| 376 | Count += 2; |
| 377 | break; |
| 378 | case Win64EH::UOP_SaveFReg: |
| 379 | Count += 2; |
| 380 | break; |
| 381 | case Win64EH::UOP_SaveFRegP: |
| 382 | Count += 2; |
| 383 | break; |
| 384 | case Win64EH::UOP_SaveFRegX: |
| 385 | Count += 2; |
| 386 | break; |
| 387 | case Win64EH::UOP_SaveFRegPX: |
| 388 | Count += 2; |
| 389 | break; |
| 390 | case Win64EH::UOP_SetFP: |
| 391 | Count += 1; |
| 392 | break; |
| 393 | case Win64EH::UOP_AddFP: |
| 394 | Count += 2; |
| 395 | break; |
| 396 | case Win64EH::UOP_Nop: |
| 397 | Count += 1; |
| 398 | break; |
| 399 | case Win64EH::UOP_End: |
| 400 | Count += 1; |
| 401 | break; |
| 402 | case Win64EH::UOP_SaveNext: |
| 403 | Count += 1; |
| 404 | break; |
| 405 | case Win64EH::UOP_TrapFrame: |
| 406 | Count += 1; |
| 407 | break; |
| 408 | case Win64EH::UOP_PushMachFrame: |
| 409 | Count += 1; |
| 410 | break; |
| 411 | case Win64EH::UOP_Context: |
| 412 | Count += 1; |
| 413 | break; |
| 414 | case Win64EH::UOP_ClearUnwoundToCall: |
| 415 | Count += 1; |
| 416 | break; |
| 417 | case Win64EH::UOP_PACSignLR: |
| 418 | Count += 1; |
| 419 | break; |
| 420 | case Win64EH::UOP_SaveAnyRegI: |
| 421 | case Win64EH::UOP_SaveAnyRegIP: |
| 422 | case Win64EH::UOP_SaveAnyRegD: |
| 423 | case Win64EH::UOP_SaveAnyRegDP: |
| 424 | case Win64EH::UOP_SaveAnyRegQ: |
| 425 | case Win64EH::UOP_SaveAnyRegQP: |
| 426 | case Win64EH::UOP_SaveAnyRegIX: |
| 427 | case Win64EH::UOP_SaveAnyRegIPX: |
| 428 | case Win64EH::UOP_SaveAnyRegDX: |
| 429 | case Win64EH::UOP_SaveAnyRegDPX: |
| 430 | case Win64EH::UOP_SaveAnyRegQX: |
| 431 | case Win64EH::UOP_SaveAnyRegQPX: |
| 432 | Count += 3; |
| 433 | break; |
| 434 | } |
| 435 | } |
| 436 | return Count; |
| 437 | } |
| 438 | |
| 439 | // Unwind opcode encodings and restrictions are documented at |
| 440 | // https://docs.microsoft.com/en-us/cpp/build/arm64-exception-handling |
| 441 | static void ARM64EmitUnwindCode(MCStreamer &streamer, |
| 442 | const WinEH::Instruction &inst) { |
| 443 | uint8_t b, reg; |
| 444 | switch (static_cast<Win64EH::UnwindOpcodes>(inst.Operation)) { |
| 445 | default: |
| 446 | llvm_unreachable("Unsupported ARM64 unwind code")::llvm::llvm_unreachable_internal("Unsupported ARM64 unwind code" , "llvm/lib/MC/MCWin64EH.cpp", 446); |
| 447 | case Win64EH::UOP_AllocSmall: |
| 448 | b = (inst.Offset >> 4) & 0x1F; |
| 449 | streamer.emitInt8(b); |
| 450 | break; |
| 451 | case Win64EH::UOP_AllocMedium: { |
| 452 | uint16_t hw = (inst.Offset >> 4) & 0x7FF; |
| 453 | b = 0xC0; |
| 454 | b |= (hw >> 8); |
| 455 | streamer.emitInt8(b); |
| 456 | b = hw & 0xFF; |
| 457 | streamer.emitInt8(b); |
| 458 | break; |
| 459 | } |
| 460 | case Win64EH::UOP_AllocLarge: { |
| 461 | uint32_t w; |
| 462 | b = 0xE0; |
| 463 | streamer.emitInt8(b); |
| 464 | w = inst.Offset >> 4; |
| 465 | b = (w & 0x00FF0000) >> 16; |
| 466 | streamer.emitInt8(b); |
| 467 | b = (w & 0x0000FF00) >> 8; |
| 468 | streamer.emitInt8(b); |
| 469 | b = w & 0x000000FF; |
| 470 | streamer.emitInt8(b); |
| 471 | break; |
| 472 | } |
| 473 | case Win64EH::UOP_SetFP: |
| 474 | b = 0xE1; |
| 475 | streamer.emitInt8(b); |
| 476 | break; |
| 477 | case Win64EH::UOP_AddFP: |
| 478 | b = 0xE2; |
| 479 | streamer.emitInt8(b); |
| 480 | b = (inst.Offset >> 3); |
| 481 | streamer.emitInt8(b); |
| 482 | break; |
| 483 | case Win64EH::UOP_Nop: |
| 484 | b = 0xE3; |
| 485 | streamer.emitInt8(b); |
| 486 | break; |
| 487 | case Win64EH::UOP_SaveR19R20X: |
| 488 | b = 0x20; |
| 489 | b |= (inst.Offset >> 3) & 0x1F; |
| 490 | streamer.emitInt8(b); |
| 491 | break; |
| 492 | case Win64EH::UOP_SaveFPLRX: |
| 493 | b = 0x80; |
| 494 | b |= ((inst.Offset - 1) >> 3) & 0x3F; |
| 495 | streamer.emitInt8(b); |
| 496 | break; |
| 497 | case Win64EH::UOP_SaveFPLR: |
| 498 | b = 0x40; |
| 499 | b |= (inst.Offset >> 3) & 0x3F; |
| 500 | streamer.emitInt8(b); |
| 501 | break; |
| 502 | case Win64EH::UOP_SaveReg: |
| 503 | assert(inst.Register >= 19 && "Saved reg must be >= 19")(static_cast <bool> (inst.Register >= 19 && "Saved reg must be >= 19" ) ? void (0) : __assert_fail ("inst.Register >= 19 && \"Saved reg must be >= 19\"" , "llvm/lib/MC/MCWin64EH.cpp", 503, __extension__ __PRETTY_FUNCTION__ )); |
| 504 | reg = inst.Register - 19; |
| 505 | b = 0xD0 | ((reg & 0xC) >> 2); |
| 506 | streamer.emitInt8(b); |
| 507 | b = ((reg & 0x3) << 6) | (inst.Offset >> 3); |
| 508 | streamer.emitInt8(b); |
| 509 | break; |
| 510 | case Win64EH::UOP_SaveRegX: |
| 511 | assert(inst.Register >= 19 && "Saved reg must be >= 19")(static_cast <bool> (inst.Register >= 19 && "Saved reg must be >= 19" ) ? void (0) : __assert_fail ("inst.Register >= 19 && \"Saved reg must be >= 19\"" , "llvm/lib/MC/MCWin64EH.cpp", 511, __extension__ __PRETTY_FUNCTION__ )); |
| 512 | reg = inst.Register - 19; |
| 513 | b = 0xD4 | ((reg & 0x8) >> 3); |
| 514 | streamer.emitInt8(b); |
| 515 | b = ((reg & 0x7) << 5) | ((inst.Offset >> 3) - 1); |
| 516 | streamer.emitInt8(b); |
| 517 | break; |
| 518 | case Win64EH::UOP_SaveRegP: |
| 519 | assert(inst.Register >= 19 && "Saved registers must be >= 19")(static_cast <bool> (inst.Register >= 19 && "Saved registers must be >= 19" ) ? void (0) : __assert_fail ("inst.Register >= 19 && \"Saved registers must be >= 19\"" , "llvm/lib/MC/MCWin64EH.cpp", 519, __extension__ __PRETTY_FUNCTION__ )); |
| 520 | reg = inst.Register - 19; |
| 521 | b = 0xC8 | ((reg & 0xC) >> 2); |
| 522 | streamer.emitInt8(b); |
| 523 | b = ((reg & 0x3) << 6) | (inst.Offset >> 3); |
| 524 | streamer.emitInt8(b); |
| 525 | break; |
| 526 | case Win64EH::UOP_SaveRegPX: |
| 527 | assert(inst.Register >= 19 && "Saved registers must be >= 19")(static_cast <bool> (inst.Register >= 19 && "Saved registers must be >= 19" ) ? void (0) : __assert_fail ("inst.Register >= 19 && \"Saved registers must be >= 19\"" , "llvm/lib/MC/MCWin64EH.cpp", 527, __extension__ __PRETTY_FUNCTION__ )); |
| 528 | reg = inst.Register - 19; |
| 529 | b = 0xCC | ((reg & 0xC) >> 2); |
| 530 | streamer.emitInt8(b); |
| 531 | b = ((reg & 0x3) << 6) | ((inst.Offset >> 3) - 1); |
| 532 | streamer.emitInt8(b); |
| 533 | break; |
| 534 | case Win64EH::UOP_SaveLRPair: |
| 535 | assert(inst.Register >= 19 && "Saved reg must be >= 19")(static_cast <bool> (inst.Register >= 19 && "Saved reg must be >= 19" ) ? void (0) : __assert_fail ("inst.Register >= 19 && \"Saved reg must be >= 19\"" , "llvm/lib/MC/MCWin64EH.cpp", 535, __extension__ __PRETTY_FUNCTION__ )); |
| 536 | reg = inst.Register - 19; |
| 537 | assert((reg % 2) == 0 && "Saved reg must be 19+2*X")(static_cast <bool> ((reg % 2) == 0 && "Saved reg must be 19+2*X" ) ? void (0) : __assert_fail ("(reg % 2) == 0 && \"Saved reg must be 19+2*X\"" , "llvm/lib/MC/MCWin64EH.cpp", 537, __extension__ __PRETTY_FUNCTION__ )); |
| 538 | reg /= 2; |
| 539 | b = 0xD6 | ((reg & 0x7) >> 2); |
| 540 | streamer.emitInt8(b); |
| 541 | b = ((reg & 0x3) << 6) | (inst.Offset >> 3); |
| 542 | streamer.emitInt8(b); |
| 543 | break; |
| 544 | case Win64EH::UOP_SaveFReg: |
| 545 | assert(inst.Register >= 8 && "Saved dreg must be >= 8")(static_cast <bool> (inst.Register >= 8 && "Saved dreg must be >= 8" ) ? void (0) : __assert_fail ("inst.Register >= 8 && \"Saved dreg must be >= 8\"" , "llvm/lib/MC/MCWin64EH.cpp", 545, __extension__ __PRETTY_FUNCTION__ )); |
| 546 | reg = inst.Register - 8; |
| 547 | b = 0xDC | ((reg & 0x4) >> 2); |
| 548 | streamer.emitInt8(b); |
| 549 | b = ((reg & 0x3) << 6) | (inst.Offset >> 3); |
| 550 | streamer.emitInt8(b); |
| 551 | break; |
| 552 | case Win64EH::UOP_SaveFRegX: |
| 553 | assert(inst.Register >= 8 && "Saved dreg must be >= 8")(static_cast <bool> (inst.Register >= 8 && "Saved dreg must be >= 8" ) ? void (0) : __assert_fail ("inst.Register >= 8 && \"Saved dreg must be >= 8\"" , "llvm/lib/MC/MCWin64EH.cpp", 553, __extension__ __PRETTY_FUNCTION__ )); |
| 554 | reg = inst.Register - 8; |
| 555 | b = 0xDE; |
| 556 | streamer.emitInt8(b); |
| 557 | b = ((reg & 0x7) << 5) | ((inst.Offset >> 3) - 1); |
| 558 | streamer.emitInt8(b); |
| 559 | break; |
| 560 | case Win64EH::UOP_SaveFRegP: |
| 561 | assert(inst.Register >= 8 && "Saved dregs must be >= 8")(static_cast <bool> (inst.Register >= 8 && "Saved dregs must be >= 8" ) ? void (0) : __assert_fail ("inst.Register >= 8 && \"Saved dregs must be >= 8\"" , "llvm/lib/MC/MCWin64EH.cpp", 561, __extension__ __PRETTY_FUNCTION__ )); |
| 562 | reg = inst.Register - 8; |
| 563 | b = 0xD8 | ((reg & 0x4) >> 2); |
| 564 | streamer.emitInt8(b); |
| 565 | b = ((reg & 0x3) << 6) | (inst.Offset >> 3); |
| 566 | streamer.emitInt8(b); |
| 567 | break; |
| 568 | case Win64EH::UOP_SaveFRegPX: |
| 569 | assert(inst.Register >= 8 && "Saved dregs must be >= 8")(static_cast <bool> (inst.Register >= 8 && "Saved dregs must be >= 8" ) ? void (0) : __assert_fail ("inst.Register >= 8 && \"Saved dregs must be >= 8\"" , "llvm/lib/MC/MCWin64EH.cpp", 569, __extension__ __PRETTY_FUNCTION__ )); |
| 570 | reg = inst.Register - 8; |
| 571 | b = 0xDA | ((reg & 0x4) >> 2); |
| 572 | streamer.emitInt8(b); |
| 573 | b = ((reg & 0x3) << 6) | ((inst.Offset >> 3) - 1); |
| 574 | streamer.emitInt8(b); |
| 575 | break; |
| 576 | case Win64EH::UOP_End: |
| 577 | b = 0xE4; |
| 578 | streamer.emitInt8(b); |
| 579 | break; |
| 580 | case Win64EH::UOP_SaveNext: |
| 581 | b = 0xE6; |
| 582 | streamer.emitInt8(b); |
| 583 | break; |
| 584 | case Win64EH::UOP_TrapFrame: |
| 585 | b = 0xE8; |
| 586 | streamer.emitInt8(b); |
| 587 | break; |
| 588 | case Win64EH::UOP_PushMachFrame: |
| 589 | b = 0xE9; |
| 590 | streamer.emitInt8(b); |
| 591 | break; |
| 592 | case Win64EH::UOP_Context: |
| 593 | b = 0xEA; |
| 594 | streamer.emitInt8(b); |
| 595 | break; |
| 596 | case Win64EH::UOP_ClearUnwoundToCall: |
| 597 | b = 0xEC; |
| 598 | streamer.emitInt8(b); |
| 599 | break; |
| 600 | case Win64EH::UOP_PACSignLR: |
| 601 | b = 0xFC; |
| 602 | streamer.emitInt8(b); |
| 603 | break; |
| 604 | case Win64EH::UOP_SaveAnyRegI: |
| 605 | case Win64EH::UOP_SaveAnyRegIP: |
| 606 | case Win64EH::UOP_SaveAnyRegD: |
| 607 | case Win64EH::UOP_SaveAnyRegDP: |
| 608 | case Win64EH::UOP_SaveAnyRegQ: |
| 609 | case Win64EH::UOP_SaveAnyRegQP: |
| 610 | case Win64EH::UOP_SaveAnyRegIX: |
| 611 | case Win64EH::UOP_SaveAnyRegIPX: |
| 612 | case Win64EH::UOP_SaveAnyRegDX: |
| 613 | case Win64EH::UOP_SaveAnyRegDPX: |
| 614 | case Win64EH::UOP_SaveAnyRegQX: |
| 615 | case Win64EH::UOP_SaveAnyRegQPX: { |
| 616 | // This assumes the opcodes are listed in the enum in a particular order. |
| 617 | int Op = inst.Operation - Win64EH::UOP_SaveAnyRegI; |
| 618 | int Writeback = Op / 6; |
| 619 | int Paired = Op % 2; |
| 620 | int Mode = (Op / 2) % 3; |
| 621 | int Offset = inst.Offset >> 3; |
| 622 | if (Writeback || Paired || Mode == 2) |
| 623 | Offset >>= 1; |
| 624 | if (Writeback) |
| 625 | --Offset; |
| 626 | b = 0xE7; |
| 627 | streamer.emitInt8(b); |
| 628 | assert(inst.Register < 32)(static_cast <bool> (inst.Register < 32) ? void (0) : __assert_fail ("inst.Register < 32", "llvm/lib/MC/MCWin64EH.cpp" , 628, __extension__ __PRETTY_FUNCTION__)); |
| 629 | b = inst.Register | (Writeback << 5) | (Paired << 6); |
| 630 | streamer.emitInt8(b); |
| 631 | b = Offset | (Mode << 6); |
| 632 | streamer.emitInt8(b); |
| 633 | break; |
| 634 | } |
| 635 | } |
| 636 | } |
| 637 | |
| 638 | // Returns the epilog symbol of an epilog with the exact same unwind code |
| 639 | // sequence, if it exists. Otherwise, returns nullptr. |
| 640 | // EpilogInstrs - Unwind codes for the current epilog. |
| 641 | // Epilogs - Epilogs that potentialy match the current epilog. |
| 642 | static MCSymbol* |
| 643 | FindMatchingEpilog(const std::vector<WinEH::Instruction>& EpilogInstrs, |
| 644 | const std::vector<MCSymbol *>& Epilogs, |
| 645 | const WinEH::FrameInfo *info) { |
| 646 | for (auto *EpilogStart : Epilogs) { |
| 647 | auto InstrsIter = info->EpilogMap.find(EpilogStart); |
| 648 | assert(InstrsIter != info->EpilogMap.end() &&(static_cast <bool> (InstrsIter != info->EpilogMap.end () && "Epilog not found in EpilogMap") ? void (0) : __assert_fail ("InstrsIter != info->EpilogMap.end() && \"Epilog not found in EpilogMap\"" , "llvm/lib/MC/MCWin64EH.cpp", 649, __extension__ __PRETTY_FUNCTION__ )) |
| 649 | "Epilog not found in EpilogMap")(static_cast <bool> (InstrsIter != info->EpilogMap.end () && "Epilog not found in EpilogMap") ? void (0) : __assert_fail ("InstrsIter != info->EpilogMap.end() && \"Epilog not found in EpilogMap\"" , "llvm/lib/MC/MCWin64EH.cpp", 649, __extension__ __PRETTY_FUNCTION__ )); |
| 650 | const auto &Instrs = InstrsIter->second.Instructions; |
| 651 | |
| 652 | if (Instrs.size() != EpilogInstrs.size()) |
| 653 | continue; |
| 654 | |
| 655 | bool Match = true; |
| 656 | for (unsigned i = 0; i < Instrs.size(); ++i) |
| 657 | if (Instrs[i] != EpilogInstrs[i]) { |
| 658 | Match = false; |
| 659 | break; |
| 660 | } |
| 661 | |
| 662 | if (Match) |
| 663 | return EpilogStart; |
| 664 | } |
| 665 | return nullptr; |
| 666 | } |
| 667 | |
| 668 | static void simplifyARM64Opcodes(std::vector<WinEH::Instruction> &Instructions, |
| 669 | bool Reverse) { |
| 670 | unsigned PrevOffset = -1; |
| 671 | unsigned PrevRegister = -1; |
| 672 | |
| 673 | auto VisitInstruction = [&](WinEH::Instruction &Inst) { |
| 674 | // Convert 2-byte opcodes into equivalent 1-byte ones. |
| 675 | if (Inst.Operation == Win64EH::UOP_SaveRegP && Inst.Register == 29) { |
| 676 | Inst.Operation = Win64EH::UOP_SaveFPLR; |
| 677 | Inst.Register = -1; |
| 678 | } else if (Inst.Operation == Win64EH::UOP_SaveRegPX && |
| 679 | Inst.Register == 29) { |
| 680 | Inst.Operation = Win64EH::UOP_SaveFPLRX; |
| 681 | Inst.Register = -1; |
| 682 | } else if (Inst.Operation == Win64EH::UOP_SaveRegPX && |
| 683 | Inst.Register == 19 && Inst.Offset <= 248) { |
| 684 | Inst.Operation = Win64EH::UOP_SaveR19R20X; |
| 685 | Inst.Register = -1; |
| 686 | } else if (Inst.Operation == Win64EH::UOP_AddFP && Inst.Offset == 0) { |
| 687 | Inst.Operation = Win64EH::UOP_SetFP; |
| 688 | } else if (Inst.Operation == Win64EH::UOP_SaveRegP && |
| 689 | Inst.Register == PrevRegister + 2 && |
| 690 | Inst.Offset == PrevOffset + 16) { |
| 691 | Inst.Operation = Win64EH::UOP_SaveNext; |
| 692 | Inst.Register = -1; |
| 693 | Inst.Offset = 0; |
| 694 | // Intentionally not creating UOP_SaveNext for float register pairs, |
| 695 | // as current versions of Windows (up to at least 20.04) is buggy |
| 696 | // regarding SaveNext for float pairs. |
| 697 | } |
| 698 | // Update info about the previous instruction, for detecting if |
| 699 | // the next one can be made a UOP_SaveNext |
| 700 | if (Inst.Operation == Win64EH::UOP_SaveR19R20X) { |
| 701 | PrevOffset = 0; |
| 702 | PrevRegister = 19; |
| 703 | } else if (Inst.Operation == Win64EH::UOP_SaveRegPX) { |
| 704 | PrevOffset = 0; |
| 705 | PrevRegister = Inst.Register; |
| 706 | } else if (Inst.Operation == Win64EH::UOP_SaveRegP) { |
| 707 | PrevOffset = Inst.Offset; |
| 708 | PrevRegister = Inst.Register; |
| 709 | } else if (Inst.Operation == Win64EH::UOP_SaveNext) { |
| 710 | PrevRegister += 2; |
| 711 | PrevOffset += 16; |
| 712 | } else { |
| 713 | PrevRegister = -1; |
| 714 | PrevOffset = -1; |
| 715 | } |
| 716 | }; |
| 717 | |
| 718 | // Iterate over instructions in a forward order (for prologues), |
| 719 | // backwards for epilogues (i.e. always reverse compared to how the |
| 720 | // opcodes are stored). |
| 721 | if (Reverse) { |
| 722 | for (auto It = Instructions.rbegin(); It != Instructions.rend(); It++) |
| 723 | VisitInstruction(*It); |
| 724 | } else { |
| 725 | for (WinEH::Instruction &Inst : Instructions) |
| 726 | VisitInstruction(Inst); |
| 727 | } |
| 728 | } |
| 729 | |
| 730 | // Check if an epilog exists as a subset of the end of a prolog (backwards). |
| 731 | static int |
| 732 | getARM64OffsetInProlog(const std::vector<WinEH::Instruction> &Prolog, |
| 733 | const std::vector<WinEH::Instruction> &Epilog) { |
| 734 | // Can't find an epilog as a subset if it is longer than the prolog. |
| 735 | if (Epilog.size() > Prolog.size()) |
| 736 | return -1; |
| 737 | |
| 738 | // Check that the epilog actually is a perfect match for the end (backwrds) |
| 739 | // of the prolog. |
| 740 | for (int I = Epilog.size() - 1; I >= 0; I--) { |
| 741 | if (Prolog[I] != Epilog[Epilog.size() - 1 - I]) |
| 742 | return -1; |
| 743 | } |
| 744 | |
| 745 | if (Epilog.size() == Prolog.size()) |
| 746 | return 0; |
| 747 | |
| 748 | // If the epilog was a subset of the prolog, find its offset. |
| 749 | return ARM64CountOfUnwindCodes(ArrayRef<WinEH::Instruction>( |
| 750 | &Prolog[Epilog.size()], Prolog.size() - Epilog.size())); |
| 751 | } |
| 752 | |
| 753 | static int checkARM64PackedEpilog(MCStreamer &streamer, WinEH::FrameInfo *info, |
| 754 | WinEH::FrameInfo::Segment *Seg, |
| 755 | int PrologCodeBytes) { |
| 756 | // Can only pack if there's one single epilog |
| 757 | if (Seg->Epilogs.size() != 1) |
| 758 | return -1; |
| 759 | |
| 760 | MCSymbol *Sym = Seg->Epilogs.begin()->first; |
| 761 | const std::vector<WinEH::Instruction> &Epilog = |
| 762 | info->EpilogMap[Sym].Instructions; |
| 763 | |
| 764 | // Check that the epilog actually is at the very end of the function, |
| 765 | // otherwise it can't be packed. |
| 766 | uint32_t DistanceFromEnd = |
| 767 | (uint32_t)(Seg->Offset + Seg->Length - Seg->Epilogs.begin()->second); |
| 768 | if (DistanceFromEnd / 4 != Epilog.size()) |
| 769 | return -1; |
| 770 | |
| 771 | int RetVal = -1; |
| 772 | // Even if we don't end up sharing opcodes with the prolog, we can still |
| 773 | // write the offset as a packed offset, if the single epilog is located at |
| 774 | // the end of the function and the offset (pointing after the prolog) fits |
| 775 | // as a packed offset. |
| 776 | if (PrologCodeBytes <= 31 && |
| 777 | PrologCodeBytes + ARM64CountOfUnwindCodes(Epilog) <= 124) |
| 778 | RetVal = PrologCodeBytes; |
| 779 | |
| 780 | int Offset = getARM64OffsetInProlog(info->Instructions, Epilog); |
| 781 | if (Offset < 0) |
| 782 | return RetVal; |
| 783 | |
| 784 | // Check that the offset and prolog size fits in the first word; it's |
| 785 | // unclear whether the epilog count in the extension word can be taken |
| 786 | // as packed epilog offset. |
| 787 | if (Offset > 31 || PrologCodeBytes > 124) |
| 788 | return RetVal; |
| 789 | |
| 790 | // As we choose to express the epilog as part of the prolog, remove the |
| 791 | // epilog from the map, so we don't try to emit its opcodes. |
| 792 | info->EpilogMap.erase(Sym); |
| 793 | return Offset; |
| 794 | } |
| 795 | |
| 796 | static bool tryARM64PackedUnwind(WinEH::FrameInfo *info, uint32_t FuncLength, |
| 797 | int PackedEpilogOffset) { |
| 798 | if (PackedEpilogOffset == 0) { |
| 799 | // Fully symmetric prolog and epilog, should be ok for packed format. |
| 800 | // For CR=3, the corresponding synthesized epilog actually lacks the |
| 801 | // SetFP opcode, but unwinding should work just fine despite that |
| 802 | // (if at the SetFP opcode, the unwinder considers it as part of the |
| 803 | // function body and just unwinds the full prolog instead). |
| 804 | } else if (PackedEpilogOffset == 1) { |
| 805 | // One single case of differences between prolog and epilog is allowed: |
| 806 | // The epilog can lack a single SetFP that is the last opcode in the |
| 807 | // prolog, for the CR=3 case. |
| 808 | if (info->Instructions.back().Operation != Win64EH::UOP_SetFP) |
| 809 | return false; |
| 810 | } else { |
| 811 | // Too much difference between prolog and epilog. |
| 812 | return false; |
| 813 | } |
| 814 | unsigned RegI = 0, RegF = 0; |
| 815 | int Predecrement = 0; |
| 816 | enum { |
| 817 | Start, |
| 818 | Start2, |
| 819 | Start3, |
| 820 | IntRegs, |
| 821 | FloatRegs, |
| 822 | InputArgs, |
| 823 | StackAdjust, |
| 824 | FrameRecord, |
| 825 | End |
| 826 | } Location = Start; |
| 827 | bool StandaloneLR = false, FPLRPair = false; |
| 828 | bool PAC = false; |
| 829 | int StackOffset = 0; |
| 830 | int Nops = 0; |
| 831 | // Iterate over the prolog and check that all opcodes exactly match |
| 832 | // the canonical order and form. A more lax check could verify that |
| 833 | // all saved registers are in the expected locations, but not enforce |
| 834 | // the order - that would work fine when unwinding from within |
| 835 | // functions, but not be exactly right if unwinding happens within |
| 836 | // prologs/epilogs. |
| 837 | for (const WinEH::Instruction &Inst : info->Instructions) { |
| 838 | switch (Inst.Operation) { |
| 839 | case Win64EH::UOP_End: |
| 840 | if (Location != Start) |
| 841 | return false; |
| 842 | Location = Start2; |
| 843 | break; |
| 844 | case Win64EH::UOP_PACSignLR: |
| 845 | if (Location != Start2) |
| 846 | return false; |
| 847 | PAC = true; |
| 848 | Location = Start3; |
| 849 | break; |
| 850 | case Win64EH::UOP_SaveR19R20X: |
| 851 | if (Location != Start2 && Location != Start3) |
| 852 | return false; |
| 853 | Predecrement = Inst.Offset; |
| 854 | RegI = 2; |
| 855 | Location = IntRegs; |
| 856 | break; |
| 857 | case Win64EH::UOP_SaveRegX: |
| 858 | if (Location != Start2 && Location != Start3) |
| 859 | return false; |
| 860 | Predecrement = Inst.Offset; |
| 861 | if (Inst.Register == 19) |
| 862 | RegI += 1; |
| 863 | else if (Inst.Register == 30) |
| 864 | StandaloneLR = true; |
| 865 | else |
| 866 | return false; |
| 867 | // Odd register; can't be any further int registers. |
| 868 | Location = FloatRegs; |
| 869 | break; |
| 870 | case Win64EH::UOP_SaveRegPX: |
| 871 | // Can't have this in a canonical prologue. Either this has been |
| 872 | // canonicalized into SaveR19R20X or SaveFPLRX, or it's an unsupported |
| 873 | // register pair. |
| 874 | // It can't be canonicalized into SaveR19R20X if the offset is |
| 875 | // larger than 248 bytes, but even with the maximum case with |
| 876 | // RegI=10/RegF=8/CR=1/H=1, we end up with SavSZ = 216, which should |
| 877 | // fit into SaveR19R20X. |
| 878 | // The unwinding opcodes can't describe the otherwise seemingly valid |
| 879 | // case for RegI=1 CR=1, that would start with a |
| 880 | // "stp x19, lr, [sp, #-...]!" as that fits neither SaveRegPX nor |
| 881 | // SaveLRPair. |
| 882 | return false; |
| 883 | case Win64EH::UOP_SaveRegP: |
| 884 | if (Location != IntRegs || Inst.Offset != 8 * RegI || |
| 885 | Inst.Register != 19 + RegI) |
| 886 | return false; |
| 887 | RegI += 2; |
| 888 | break; |
| 889 | case Win64EH::UOP_SaveReg: |
| 890 | if (Location != IntRegs || Inst.Offset != 8 * RegI) |
| 891 | return false; |
| 892 | if (Inst.Register == 19 + RegI) |
| 893 | RegI += 1; |
| 894 | else if (Inst.Register == 30) |
| 895 | StandaloneLR = true; |
| 896 | else |
| 897 | return false; |
| 898 | // Odd register; can't be any further int registers. |
| 899 | Location = FloatRegs; |
| 900 | break; |
| 901 | case Win64EH::UOP_SaveLRPair: |
| 902 | if (Location != IntRegs || Inst.Offset != 8 * RegI || |
| 903 | Inst.Register != 19 + RegI) |
| 904 | return false; |
| 905 | RegI += 1; |
| 906 | StandaloneLR = true; |
| 907 | Location = FloatRegs; |
| 908 | break; |
| 909 | case Win64EH::UOP_SaveFRegX: |
| 910 | // Packed unwind can't handle prologs that only save one single |
| 911 | // float register. |
| 912 | return false; |
| 913 | case Win64EH::UOP_SaveFReg: |
| 914 | if (Location != FloatRegs || RegF == 0 || Inst.Register != 8 + RegF || |
| 915 | Inst.Offset != 8 * (RegI + (StandaloneLR ? 1 : 0) + RegF)) |
| 916 | return false; |
| 917 | RegF += 1; |
| 918 | Location = InputArgs; |
| 919 | break; |
| 920 | case Win64EH::UOP_SaveFRegPX: |
| 921 | if ((Location != Start2 && Location != Start3) || Inst.Register != 8) |
| 922 | return false; |
| 923 | Predecrement = Inst.Offset; |
| 924 | RegF = 2; |
| 925 | Location = FloatRegs; |
| 926 | break; |
| 927 | case Win64EH::UOP_SaveFRegP: |
| 928 | if ((Location != IntRegs && Location != FloatRegs) || |
| 929 | Inst.Register != 8 + RegF || |
| 930 | Inst.Offset != 8 * (RegI + (StandaloneLR ? 1 : 0) + RegF)) |
| 931 | return false; |
| 932 | RegF += 2; |
| 933 | Location = FloatRegs; |
| 934 | break; |
| 935 | case Win64EH::UOP_SaveNext: |
| 936 | if (Location == IntRegs) |
| 937 | RegI += 2; |
| 938 | else if (Location == FloatRegs) |
| 939 | RegF += 2; |
| 940 | else |
| 941 | return false; |
| 942 | break; |
| 943 | case Win64EH::UOP_Nop: |
| 944 | if (Location != IntRegs && Location != FloatRegs && Location != InputArgs) |
| 945 | return false; |
| 946 | Location = InputArgs; |
| 947 | Nops++; |
| 948 | break; |
| 949 | case Win64EH::UOP_AllocSmall: |
| 950 | case Win64EH::UOP_AllocMedium: |
| 951 | if (Location != Start2 && Location != Start3 && Location != IntRegs && |
| 952 | Location != FloatRegs && Location != InputArgs && |
| 953 | Location != StackAdjust) |
| 954 | return false; |
| 955 | // Can have either a single decrement, or a pair of decrements with |
| 956 | // 4080 and another decrement. |
| 957 | if (StackOffset == 0) |
| 958 | StackOffset = Inst.Offset; |
| 959 | else if (StackOffset != 4080) |
| 960 | return false; |
| 961 | else |
| 962 | StackOffset += Inst.Offset; |
| 963 | Location = StackAdjust; |
| 964 | break; |
| 965 | case Win64EH::UOP_SaveFPLRX: |
| 966 | // Not allowing FPLRX after StackAdjust; if a StackAdjust is used, it |
| 967 | // should be followed by a FPLR instead. |
| 968 | if (Location != Start2 && Location != Start3 && Location != IntRegs && |
| 969 | Location != FloatRegs && Location != InputArgs) |
| 970 | return false; |
| 971 | StackOffset = Inst.Offset; |
| 972 | Location = FrameRecord; |
| 973 | FPLRPair = true; |
| 974 | break; |
| 975 | case Win64EH::UOP_SaveFPLR: |
| 976 | // This can only follow after a StackAdjust |
| 977 | if (Location != StackAdjust || Inst.Offset != 0) |
| 978 | return false; |
| 979 | Location = FrameRecord; |
| 980 | FPLRPair = true; |
| 981 | break; |
| 982 | case Win64EH::UOP_SetFP: |
| 983 | if (Location != FrameRecord) |
| 984 | return false; |
| 985 | Location = End; |
| 986 | break; |
| 987 | case Win64EH::UOP_SaveAnyRegI: |
| 988 | case Win64EH::UOP_SaveAnyRegIP: |
| 989 | case Win64EH::UOP_SaveAnyRegD: |
| 990 | case Win64EH::UOP_SaveAnyRegDP: |
| 991 | case Win64EH::UOP_SaveAnyRegQ: |
| 992 | case Win64EH::UOP_SaveAnyRegQP: |
| 993 | case Win64EH::UOP_SaveAnyRegIX: |
| 994 | case Win64EH::UOP_SaveAnyRegIPX: |
| 995 | case Win64EH::UOP_SaveAnyRegDX: |
| 996 | case Win64EH::UOP_SaveAnyRegDPX: |
| 997 | case Win64EH::UOP_SaveAnyRegQX: |
| 998 | case Win64EH::UOP_SaveAnyRegQPX: |
| 999 | // These are never canonical; they don't show up with the usual Arm64 |
| 1000 | // calling convention. |
| 1001 | return false; |
| 1002 | case Win64EH::UOP_AllocLarge: |
| 1003 | // Allocations this large can't be represented in packed unwind (and |
| 1004 | // usually don't fit the canonical form anyway because we need to use |
| 1005 | // __chkstk to allocate the stack space). |
| 1006 | return false; |
| 1007 | case Win64EH::UOP_AddFP: |
| 1008 | // "add x29, sp, #N" doesn't show up in the canonical pattern (except for |
| 1009 | // N=0, which is UOP_SetFP). |
| 1010 | return false; |
| 1011 | case Win64EH::UOP_TrapFrame: |
| 1012 | case Win64EH::UOP_Context: |
| 1013 | case Win64EH::UOP_ClearUnwoundToCall: |
| 1014 | case Win64EH::UOP_PushMachFrame: |
| 1015 | // These are special opcodes that aren't normally generated. |
| 1016 | return false; |
| 1017 | default: |
| 1018 | report_fatal_error("Unknown Arm64 unwind opcode"); |
| 1019 | } |
| 1020 | } |
| 1021 | if (RegI > 10 || RegF > 8) |
| 1022 | return false; |
| 1023 | if (StandaloneLR && FPLRPair) |
| 1024 | return false; |
| 1025 | if (FPLRPair && Location != End) |
| 1026 | return false; |
| 1027 | if (Nops != 0 && Nops != 4) |
| 1028 | return false; |
| 1029 | if (PAC && !FPLRPair) |
| 1030 | return false; |
| 1031 | int H = Nops == 4; |
| 1032 | // There's an inconsistency regarding packed unwind info with homed |
| 1033 | // parameters; according to the documentation, the epilog shouldn't have |
| 1034 | // the same corresponding nops (and thus, to set the H bit, we should |
| 1035 | // require an epilog which isn't exactly symmetrical - we shouldn't accept |
| 1036 | // an exact mirrored epilog for those cases), but in practice, |
| 1037 | // RtlVirtualUnwind behaves as if it does expect the epilogue to contain |
| 1038 | // the same nops. See https://github.com/llvm/llvm-project/issues/54879. |
| 1039 | // To play it safe, don't produce packed unwind info with homed parameters. |
| 1040 | if (H) |
| 1041 | return false; |
| 1042 | int IntSZ = 8 * RegI; |
| 1043 | if (StandaloneLR) |
| 1044 | IntSZ += 8; |
| 1045 | int FpSZ = 8 * RegF; // RegF not yet decremented |
| 1046 | int SavSZ = (IntSZ + FpSZ + 8 * 8 * H + 0xF) & ~0xF; |
| 1047 | if (Predecrement != SavSZ) |
| 1048 | return false; |
| 1049 | if (FPLRPair && StackOffset < 16) |
| 1050 | return false; |
| 1051 | if (StackOffset % 16) |
| 1052 | return false; |
| 1053 | uint32_t FrameSize = (StackOffset + SavSZ) / 16; |
| 1054 | if (FrameSize > 0x1FF) |
| 1055 | return false; |
| 1056 | assert(RegF != 1 && "One single float reg not allowed")(static_cast <bool> (RegF != 1 && "One single float reg not allowed" ) ? void (0) : __assert_fail ("RegF != 1 && \"One single float reg not allowed\"" , "llvm/lib/MC/MCWin64EH.cpp", 1056, __extension__ __PRETTY_FUNCTION__ )); |
| 1057 | if (RegF > 0) |
| 1058 | RegF--; // Convert from actual number of registers, to value stored |
| 1059 | assert(FuncLength <= 0x7FF && "FuncLength should have been checked earlier")(static_cast <bool> (FuncLength <= 0x7FF && "FuncLength should have been checked earlier" ) ? void (0) : __assert_fail ("FuncLength <= 0x7FF && \"FuncLength should have been checked earlier\"" , "llvm/lib/MC/MCWin64EH.cpp", 1059, __extension__ __PRETTY_FUNCTION__ )); |
| 1060 | int Flag = 0x01; // Function segments not supported yet |
| 1061 | int CR = PAC ? 2 : FPLRPair ? 3 : StandaloneLR ? 1 : 0; |
| 1062 | info->PackedInfo |= Flag << 0; |
| 1063 | info->PackedInfo |= (FuncLength & 0x7FF) << 2; |
| 1064 | info->PackedInfo |= (RegF & 0x7) << 13; |
| 1065 | info->PackedInfo |= (RegI & 0xF) << 16; |
| 1066 | info->PackedInfo |= (H & 0x1) << 20; |
| 1067 | info->PackedInfo |= (CR & 0x3) << 21; |
| 1068 | info->PackedInfo |= (FrameSize & 0x1FF) << 23; |
| 1069 | return true; |
| 1070 | } |
| 1071 | |
| 1072 | static void ARM64ProcessEpilogs(WinEH::FrameInfo *info, |
| 1073 | WinEH::FrameInfo::Segment *Seg, |
| 1074 | uint32_t &TotalCodeBytes, |
| 1075 | MapVector<MCSymbol *, uint32_t> &EpilogInfo) { |
| 1076 | |
| 1077 | std::vector<MCSymbol *> EpilogStarts; |
| 1078 | for (auto &I : Seg->Epilogs) |
| 1079 | EpilogStarts.push_back(I.first); |
| 1080 | |
| 1081 | // Epilogs processed so far. |
| 1082 | std::vector<MCSymbol *> AddedEpilogs; |
| 1083 | for (auto *S : EpilogStarts) { |
| 1084 | MCSymbol *EpilogStart = S; |
| 1085 | auto &EpilogInstrs = info->EpilogMap[S].Instructions; |
| 1086 | uint32_t CodeBytes = ARM64CountOfUnwindCodes(EpilogInstrs); |
| 1087 | |
| 1088 | MCSymbol* MatchingEpilog = |
| 1089 | FindMatchingEpilog(EpilogInstrs, AddedEpilogs, info); |
| 1090 | int PrologOffset; |
| 1091 | if (MatchingEpilog) { |
| 1092 | assert(EpilogInfo.contains(MatchingEpilog) &&(static_cast <bool> (EpilogInfo.contains(MatchingEpilog ) && "Duplicate epilog not found") ? void (0) : __assert_fail ("EpilogInfo.contains(MatchingEpilog) && \"Duplicate epilog not found\"" , "llvm/lib/MC/MCWin64EH.cpp", 1093, __extension__ __PRETTY_FUNCTION__ )) |
| 1093 | "Duplicate epilog not found")(static_cast <bool> (EpilogInfo.contains(MatchingEpilog ) && "Duplicate epilog not found") ? void (0) : __assert_fail ("EpilogInfo.contains(MatchingEpilog) && \"Duplicate epilog not found\"" , "llvm/lib/MC/MCWin64EH.cpp", 1093, __extension__ __PRETTY_FUNCTION__ )); |
| 1094 | EpilogInfo[EpilogStart] = EpilogInfo.lookup(MatchingEpilog); |
| 1095 | // Clear the unwind codes in the EpilogMap, so that they don't get output |
| 1096 | // in ARM64EmitUnwindInfoForSegment(). |
| 1097 | EpilogInstrs.clear(); |
| 1098 | } else if ((PrologOffset = getARM64OffsetInProlog(info->Instructions, |
| 1099 | EpilogInstrs)) >= 0) { |
| 1100 | EpilogInfo[EpilogStart] = PrologOffset; |
| 1101 | // If the segment doesn't have a prolog, an end_c will be emitted before |
| 1102 | // prolog opcodes. So epilog start index in opcodes array is moved by 1. |
| 1103 | if (!Seg->HasProlog) |
| 1104 | EpilogInfo[EpilogStart] += 1; |
| 1105 | // Clear the unwind codes in the EpilogMap, so that they don't get output |
| 1106 | // in ARM64EmitUnwindInfoForSegment(). |
| 1107 | EpilogInstrs.clear(); |
| 1108 | } else { |
| 1109 | EpilogInfo[EpilogStart] = TotalCodeBytes; |
| 1110 | TotalCodeBytes += CodeBytes; |
| 1111 | AddedEpilogs.push_back(EpilogStart); |
| 1112 | } |
| 1113 | } |
| 1114 | } |
| 1115 | |
| 1116 | static void ARM64FindSegmentsInFunction(MCStreamer &streamer, |
| 1117 | WinEH::FrameInfo *info, |
| 1118 | int64_t RawFuncLength) { |
| 1119 | if (info->PrologEnd) |
| 1120 | checkARM64Instructions(streamer, info->Instructions, info->Begin, |
| 1121 | info->PrologEnd, info->Function->getName(), |
| 1122 | "prologue"); |
| 1123 | struct EpilogStartEnd { |
| 1124 | MCSymbol *Start; |
| 1125 | int64_t Offset; |
| 1126 | int64_t End; |
| 1127 | }; |
| 1128 | // Record Start and End of each epilog. |
| 1129 | SmallVector<struct EpilogStartEnd, 4> Epilogs; |
| 1130 | for (auto &I : info->EpilogMap) { |
| 1131 | MCSymbol *Start = I.first; |
| 1132 | auto &Instrs = I.second.Instructions; |
| 1133 | int64_t Offset = GetAbsDifference(streamer, Start, info->Begin); |
| 1134 | checkARM64Instructions(streamer, Instrs, Start, I.second.End, |
| 1135 | info->Function->getName(), "epilogue"); |
| 1136 | assert((Epilogs.size() == 0 || Offset >= Epilogs.back().End) &&(static_cast <bool> ((Epilogs.size() == 0 || Offset >= Epilogs.back().End) && "Epilogs should be monotonically ordered" ) ? void (0) : __assert_fail ("(Epilogs.size() == 0 || Offset >= Epilogs.back().End) && \"Epilogs should be monotonically ordered\"" , "llvm/lib/MC/MCWin64EH.cpp", 1137, __extension__ __PRETTY_FUNCTION__ )) |
| 1137 | "Epilogs should be monotonically ordered")(static_cast <bool> ((Epilogs.size() == 0 || Offset >= Epilogs.back().End) && "Epilogs should be monotonically ordered" ) ? void (0) : __assert_fail ("(Epilogs.size() == 0 || Offset >= Epilogs.back().End) && \"Epilogs should be monotonically ordered\"" , "llvm/lib/MC/MCWin64EH.cpp", 1137, __extension__ __PRETTY_FUNCTION__ )); |
| 1138 | // Exclue the end opcode from Instrs.size() when calculating the end of the |
| 1139 | // epilog. |
| 1140 | Epilogs.push_back({Start, Offset, Offset + (int64_t)(Instrs.size() - 1) * 4}); |
| 1141 | } |
| 1142 | |
| 1143 | unsigned E = 0; |
| 1144 | int64_t SegLimit = 0xFFFFC; |
| 1145 | int64_t SegOffset = 0; |
| 1146 | |
| 1147 | if (RawFuncLength > SegLimit) { |
| 1148 | |
| 1149 | int64_t RemainingLength = RawFuncLength; |
| 1150 | |
| 1151 | while (RemainingLength > SegLimit) { |
| 1152 | // Try divide the function into segments, requirements: |
| 1153 | // 1. Segment length <= 0xFFFFC; |
| 1154 | // 2. Each Prologue or Epilogue must be fully within a segment. |
| 1155 | int64_t SegLength = SegLimit; |
| 1156 | int64_t SegEnd = SegOffset + SegLength; |
| 1157 | // Keep record on symbols and offsets of epilogs in this segment. |
| 1158 | MapVector<MCSymbol *, int64_t> EpilogsInSegment; |
| 1159 | |
| 1160 | while (E < Epilogs.size() && Epilogs[E].End < SegEnd) { |
| 1161 | // Epilogs within current segment. |
| 1162 | EpilogsInSegment[Epilogs[E].Start] = Epilogs[E].Offset; |
| 1163 | ++E; |
| 1164 | } |
| 1165 | |
| 1166 | // At this point, we have: |
| 1167 | // 1. Put all epilogs in segments already. No action needed here; or |
| 1168 | // 2. Found an epilog that will cross segments boundry. We need to |
| 1169 | // move back current segment's end boundry, so the epilog is entirely |
| 1170 | // in the next segment; or |
| 1171 | // 3. Left at least one epilog that is entirely after this segment. |
| 1172 | // It'll be handled by the next iteration, or the last segment. |
| 1173 | if (E < Epilogs.size() && Epilogs[E].Offset <= SegEnd) |
| 1174 | // Move back current Segment's end boundry. |
| 1175 | SegLength = Epilogs[E].Offset - SegOffset; |
| 1176 | |
| 1177 | auto Seg = WinEH::FrameInfo::Segment( |
| 1178 | SegOffset, SegLength, /* HasProlog */!SegOffset); |
| 1179 | Seg.Epilogs = std::move(EpilogsInSegment); |
| 1180 | info->Segments.push_back(Seg); |
| 1181 | |
| 1182 | SegOffset += SegLength; |
| 1183 | RemainingLength -= SegLength; |
| 1184 | } |
| 1185 | } |
| 1186 | |
| 1187 | // Add the last segment when RawFuncLength > 0xFFFFC, |
| 1188 | // or the only segment otherwise. |
| 1189 | auto LastSeg = |
| 1190 | WinEH::FrameInfo::Segment(SegOffset, RawFuncLength - SegOffset, |
| 1191 | /* HasProlog */!SegOffset); |
| 1192 | for (; E < Epilogs.size(); ++E) |
| 1193 | LastSeg.Epilogs[Epilogs[E].Start] = Epilogs[E].Offset; |
| 1194 | info->Segments.push_back(LastSeg); |
| 1195 | } |
| 1196 | |
| 1197 | static void ARM64EmitUnwindInfoForSegment(MCStreamer &streamer, |
| 1198 | WinEH::FrameInfo *info, |
| 1199 | WinEH::FrameInfo::Segment &Seg, |
| 1200 | bool TryPacked = true) { |
| 1201 | MCContext &context = streamer.getContext(); |
| 1202 | MCSymbol *Label = context.createTempSymbol(); |
| 1203 | |
| 1204 | streamer.emitValueToAlignment(Align(4)); |
| 1205 | streamer.emitLabel(Label); |
| 1206 | Seg.Symbol = Label; |
| 1207 | // Use the 1st segemnt's label as function's. |
| 1208 | if (Seg.Offset == 0) |
| 1209 | info->Symbol = Label; |
| 1210 | |
| 1211 | bool HasProlog = Seg.HasProlog; |
| 1212 | bool HasEpilogs = (Seg.Epilogs.size() != 0); |
| 1213 | |
| 1214 | uint32_t SegLength = (uint32_t)Seg.Length / 4; |
| 1215 | uint32_t PrologCodeBytes = info->PrologCodeBytes; |
| 1216 | |
| 1217 | int PackedEpilogOffset = HasEpilogs ? |
| 1218 | checkARM64PackedEpilog(streamer, info, &Seg, PrologCodeBytes) : -1; |
| 1219 | |
| 1220 | // TODO: |
| 1221 | // 1. Enable packed unwind info (.pdata only) for multi-segment functions. |
| 1222 | // 2. Emit packed unwind info (.pdata only) for segments that have neithor |
| 1223 | // prolog nor epilog. |
| 1224 | if (info->Segments.size() == 1 && PackedEpilogOffset >= 0 && |
| 1225 | uint32_t(PackedEpilogOffset) < PrologCodeBytes && |
| 1226 | !info->HandlesExceptions && SegLength <= 0x7ff && TryPacked) { |
| 1227 | // Matching prolog/epilog and no exception handlers; check if the |
| 1228 | // prolog matches the patterns that can be described by the packed |
| 1229 | // format. |
| 1230 | |
| 1231 | // info->Symbol was already set even if we didn't actually write any |
| 1232 | // unwind info there. Keep using that as indicator that this unwind |
| 1233 | // info has been generated already. |
| 1234 | if (tryARM64PackedUnwind(info, SegLength, PackedEpilogOffset)) |
| 1235 | return; |
| 1236 | } |
| 1237 | |
| 1238 | // If the prolog is not in this segment, we need to emit an end_c, which takes |
| 1239 | // 1 byte, before prolog unwind ops. |
| 1240 | if (!HasProlog) { |
| 1241 | PrologCodeBytes += 1; |
| 1242 | if (PackedEpilogOffset >= 0) |
| 1243 | PackedEpilogOffset += 1; |
| 1244 | // If a segment has neither prolog nor epilog, "With full .xdata record, |
| 1245 | // Epilog Count = 1. Epilog Start Index points to end_c." |
| 1246 | // https://docs.microsoft.com/en-us/cpp/build/arm64-exception-handling#function-fragments |
| 1247 | // TODO: We can remove this if testing shows zero epilog scope is ok with |
| 1248 | // MS unwinder. |
| 1249 | if (!HasEpilogs) |
| 1250 | // Pack the fake epilog into phantom prolog. |
| 1251 | PackedEpilogOffset = 0; |
| 1252 | } |
| 1253 | |
| 1254 | uint32_t TotalCodeBytes = PrologCodeBytes; |
| 1255 | |
| 1256 | // Process epilogs. |
| 1257 | MapVector<MCSymbol *, uint32_t> EpilogInfo; |
| 1258 | ARM64ProcessEpilogs(info, &Seg, TotalCodeBytes, EpilogInfo); |
| 1259 | |
| 1260 | // Code Words, Epilog count, E, X, Vers, Function Length |
| 1261 | uint32_t row1 = 0x0; |
| 1262 | uint32_t CodeWords = TotalCodeBytes / 4; |
| 1263 | uint32_t CodeWordsMod = TotalCodeBytes % 4; |
| 1264 | if (CodeWordsMod) |
| 1265 | CodeWords++; |
| 1266 | uint32_t EpilogCount = |
| 1267 | PackedEpilogOffset >= 0 ? PackedEpilogOffset : Seg.Epilogs.size(); |
| 1268 | bool ExtensionWord = EpilogCount > 31 || TotalCodeBytes > 124; |
| 1269 | if (!ExtensionWord) { |
| 1270 | row1 |= (EpilogCount & 0x1F) << 22; |
| 1271 | row1 |= (CodeWords & 0x1F) << 27; |
| 1272 | } |
| 1273 | if (info->HandlesExceptions) // X |
| 1274 | row1 |= 1 << 20; |
| 1275 | if (PackedEpilogOffset >= 0) // E |
| 1276 | row1 |= 1 << 21; |
| 1277 | row1 |= SegLength & 0x3FFFF; |
| 1278 | streamer.emitInt32(row1); |
| 1279 | |
| 1280 | // Extended Code Words, Extended Epilog Count |
| 1281 | if (ExtensionWord) { |
| 1282 | // FIXME: We should be able to split unwind info into multiple sections. |
| 1283 | if (CodeWords > 0xFF || EpilogCount > 0xFFFF) |
| 1284 | report_fatal_error( |
| 1285 | "SEH unwind data splitting is only implemented for large functions, " |
| 1286 | "cases of too many code words or too many epilogs will be done " |
| 1287 | "later"); |
| 1288 | uint32_t row2 = 0x0; |
| 1289 | row2 |= (CodeWords & 0xFF) << 16; |
| 1290 | row2 |= (EpilogCount & 0xFFFF); |
| 1291 | streamer.emitInt32(row2); |
| 1292 | } |
| 1293 | |
| 1294 | if (PackedEpilogOffset < 0) { |
| 1295 | // Epilog Start Index, Epilog Start Offset |
| 1296 | for (auto &I : EpilogInfo) { |
| 1297 | MCSymbol *EpilogStart = I.first; |
| 1298 | uint32_t EpilogIndex = I.second; |
| 1299 | // Epilog offset within the Segment. |
| 1300 | uint32_t EpilogOffset = (uint32_t)(Seg.Epilogs[EpilogStart] - Seg.Offset); |
| 1301 | if (EpilogOffset) |
| 1302 | EpilogOffset /= 4; |
| 1303 | uint32_t row3 = EpilogOffset; |
| 1304 | row3 |= (EpilogIndex & 0x3FF) << 22; |
| 1305 | streamer.emitInt32(row3); |
| 1306 | } |
| 1307 | } |
| 1308 | |
| 1309 | // Note that even for segments that have no prolog, we still need to emit |
| 1310 | // prolog unwinding opcodes so that the unwinder knows how to unwind from |
| 1311 | // such a segment. |
| 1312 | // The end_c opcode at the start indicates to the unwinder that the actual |
| 1313 | // prolog is outside of the current segment, and the unwinder shouldn't try |
| 1314 | // to check for unwinding from a partial prolog. |
| 1315 | if (!HasProlog) |
| 1316 | // Emit an end_c. |
| 1317 | streamer.emitInt8((uint8_t)0xE5); |
| 1318 | |
| 1319 | // Emit prolog unwind instructions (in reverse order). |
| 1320 | for (auto Inst : llvm::reverse(info->Instructions)) |
| 1321 | ARM64EmitUnwindCode(streamer, Inst); |
| 1322 | |
| 1323 | // Emit epilog unwind instructions |
| 1324 | for (auto &I : Seg.Epilogs) { |
| 1325 | auto &EpilogInstrs = info->EpilogMap[I.first].Instructions; |
| 1326 | for (const WinEH::Instruction &inst : EpilogInstrs) |
| 1327 | ARM64EmitUnwindCode(streamer, inst); |
| 1328 | } |
| 1329 | |
| 1330 | int32_t BytesMod = CodeWords * 4 - TotalCodeBytes; |
| 1331 | assert(BytesMod >= 0)(static_cast <bool> (BytesMod >= 0) ? void (0) : __assert_fail ("BytesMod >= 0", "llvm/lib/MC/MCWin64EH.cpp", 1331, __extension__ __PRETTY_FUNCTION__)); |
| 1332 | for (int i = 0; i < BytesMod; i++) |
| 1333 | streamer.emitInt8(0xE3); |
| 1334 | |
| 1335 | if (info->HandlesExceptions) |
| 1336 | streamer.emitValue( |
| 1337 | MCSymbolRefExpr::create(info->ExceptionHandler, |
| 1338 | MCSymbolRefExpr::VK_COFF_IMGREL32, context), |
| 1339 | 4); |
| 1340 | } |
| 1341 | |
| 1342 | // Populate the .xdata section. The format of .xdata on ARM64 is documented at |
| 1343 | // https://docs.microsoft.com/en-us/cpp/build/arm64-exception-handling |
| 1344 | static void ARM64EmitUnwindInfo(MCStreamer &streamer, WinEH::FrameInfo *info, |
| 1345 | bool TryPacked = true) { |
| 1346 | // If this UNWIND_INFO already has a symbol, it's already been emitted. |
| 1347 | if (info->Symbol) |
| 1348 | return; |
| 1349 | // If there's no unwind info here (not even a terminating UOP_End), the |
| 1350 | // unwind info is considered bogus and skipped. If this was done in |
| 1351 | // response to an explicit .seh_handlerdata, the associated trailing |
| 1352 | // handler data is left orphaned in the xdata section. |
| 1353 | if (info->empty()) { |
| 1354 | info->EmitAttempted = true; |
| 1355 | return; |
| 1356 | } |
| 1357 | if (info->EmitAttempted) { |
| 1358 | // If we tried to emit unwind info before (due to an explicit |
| 1359 | // .seh_handlerdata directive), but skipped it (because there was no |
| 1360 | // valid information to emit at the time), and it later got valid unwind |
| 1361 | // opcodes, we can't emit it here, because the trailing handler data |
| 1362 | // was already emitted elsewhere in the xdata section. |
| 1363 | streamer.getContext().reportError( |
| 1364 | SMLoc(), "Earlier .seh_handlerdata for " + info->Function->getName() + |
| 1365 | " skipped due to no unwind info at the time " |
| 1366 | "(.seh_handlerdata too early?), but the function later " |
| 1367 | "did get unwind info that can't be emitted"); |
| 1368 | return; |
| 1369 | } |
| 1370 | |
| 1371 | simplifyARM64Opcodes(info->Instructions, false); |
| 1372 | for (auto &I : info->EpilogMap) |
| 1373 | simplifyARM64Opcodes(I.second.Instructions, true); |
| 1374 | |
| 1375 | int64_t RawFuncLength; |
| 1376 | if (!info->FuncletOrFuncEnd) { |
| 1377 | report_fatal_error("FuncletOrFuncEnd not set"); |
| 1378 | } else { |
| 1379 | // FIXME: GetAbsDifference tries to compute the length of the function |
| 1380 | // immediately, before the whole file is emitted, but in general |
| 1381 | // that's impossible: the size in bytes of certain assembler directives |
| 1382 | // like .align and .fill is not known until the whole file is parsed and |
| 1383 | // relaxations are applied. Currently, GetAbsDifference fails with a fatal |
| 1384 | // error in that case. (We mostly don't hit this because inline assembly |
| 1385 | // specifying those directives is rare, and we don't normally try to |
| 1386 | // align loops on AArch64.) |
| 1387 | // |
| 1388 | // There are two potential approaches to delaying the computation. One, |
| 1389 | // we could emit something like ".word (endfunc-beginfunc)/4+0x10800000", |
| 1390 | // as long as we have some conservative estimate we could use to prove |
| 1391 | // that we don't need to split the unwind data. Emitting the constant |
| 1392 | // is straightforward, but there's no existing code for estimating the |
| 1393 | // size of the function. |
| 1394 | // |
| 1395 | // The other approach would be to use a dedicated, relaxable fragment, |
| 1396 | // which could grow to accommodate splitting the unwind data if |
| 1397 | // necessary. This is more straightforward, since it automatically works |
| 1398 | // without any new infrastructure, and it's consistent with how we handle |
| 1399 | // relaxation in other contexts. But it would require some refactoring |
| 1400 | // to move parts of the pdata/xdata emission into the implementation of |
| 1401 | // a fragment. We could probably continue to encode the unwind codes |
| 1402 | // here, but we'd have to emit the pdata, the xdata header, and the |
| 1403 | // epilogue scopes later, since they depend on whether the we need to |
| 1404 | // split the unwind data. |
| 1405 | RawFuncLength = GetAbsDifference(streamer, info->FuncletOrFuncEnd, |
| 1406 | info->Begin); |
| 1407 | } |
| 1408 | |
| 1409 | ARM64FindSegmentsInFunction(streamer, info, RawFuncLength); |
| 1410 | |
| 1411 | info->PrologCodeBytes = ARM64CountOfUnwindCodes(info->Instructions); |
| 1412 | for (auto &S : info->Segments) |
| 1413 | ARM64EmitUnwindInfoForSegment(streamer, info, S, TryPacked); |
| 1414 | |
| 1415 | // Clear prolog instructions after unwind info is emitted for all segments. |
| 1416 | info->Instructions.clear(); |
| 1417 | } |
| 1418 | |
| 1419 | static uint32_t ARMCountOfUnwindCodes(ArrayRef<WinEH::Instruction> Insns) { |
| 1420 | uint32_t Count = 0; |
| 1421 | for (const auto &I : Insns) { |
| 1422 | switch (static_cast<Win64EH::UnwindOpcodes>(I.Operation)) { |
| 1423 | default: |
| 1424 | llvm_unreachable("Unsupported ARM unwind code")::llvm::llvm_unreachable_internal("Unsupported ARM unwind code" , "llvm/lib/MC/MCWin64EH.cpp", 1424); |
| 1425 | case Win64EH::UOP_AllocSmall: |
| 1426 | Count += 1; |
| 1427 | break; |
| 1428 | case Win64EH::UOP_AllocLarge: |
| 1429 | Count += 3; |
| 1430 | break; |
| 1431 | case Win64EH::UOP_AllocHuge: |
| 1432 | Count += 4; |
| 1433 | break; |
| 1434 | case Win64EH::UOP_WideAllocMedium: |
| 1435 | Count += 2; |
| 1436 | break; |
| 1437 | case Win64EH::UOP_WideAllocLarge: |
| 1438 | Count += 3; |
| 1439 | break; |
| 1440 | case Win64EH::UOP_WideAllocHuge: |
| 1441 | Count += 4; |
| 1442 | break; |
| 1443 | case Win64EH::UOP_WideSaveRegMask: |
| 1444 | Count += 2; |
| 1445 | break; |
| 1446 | case Win64EH::UOP_SaveSP: |
| 1447 | Count += 1; |
| 1448 | break; |
| 1449 | case Win64EH::UOP_SaveRegsR4R7LR: |
| 1450 | Count += 1; |
| 1451 | break; |
| 1452 | case Win64EH::UOP_WideSaveRegsR4R11LR: |
| 1453 | Count += 1; |
| 1454 | break; |
| 1455 | case Win64EH::UOP_SaveFRegD8D15: |
| 1456 | Count += 1; |
| 1457 | break; |
| 1458 | case Win64EH::UOP_SaveRegMask: |
| 1459 | Count += 2; |
| 1460 | break; |
| 1461 | case Win64EH::UOP_SaveLR: |
| 1462 | Count += 2; |
| 1463 | break; |
| 1464 | case Win64EH::UOP_SaveFRegD0D15: |
| 1465 | Count += 2; |
| 1466 | break; |
| 1467 | case Win64EH::UOP_SaveFRegD16D31: |
| 1468 | Count += 2; |
| 1469 | break; |
| 1470 | case Win64EH::UOP_Nop: |
| 1471 | case Win64EH::UOP_WideNop: |
| 1472 | case Win64EH::UOP_End: |
| 1473 | case Win64EH::UOP_EndNop: |
| 1474 | case Win64EH::UOP_WideEndNop: |
| 1475 | Count += 1; |
| 1476 | break; |
| 1477 | case Win64EH::UOP_Custom: { |
| 1478 | int J; |
| 1479 | for (J = 3; J > 0; J--) |
| 1480 | if (I.Offset & (0xffu << (8 * J))) |
| 1481 | break; |
| 1482 | Count += J + 1; |
| 1483 | break; |
| 1484 | } |
| 1485 | } |
| 1486 | } |
| 1487 | return Count; |
| 1488 | } |
| 1489 | |
| 1490 | static uint32_t ARMCountOfInstructionBytes(ArrayRef<WinEH::Instruction> Insns, |
| 1491 | bool *HasCustom = nullptr) { |
| 1492 | uint32_t Count = 0; |
| 1493 | for (const auto &I : Insns) { |
| 1494 | switch (static_cast<Win64EH::UnwindOpcodes>(I.Operation)) { |
| 1495 | default: |
| 1496 | llvm_unreachable("Unsupported ARM unwind code")::llvm::llvm_unreachable_internal("Unsupported ARM unwind code" , "llvm/lib/MC/MCWin64EH.cpp", 1496); |
| 1497 | case Win64EH::UOP_AllocSmall: |
| 1498 | case Win64EH::UOP_AllocLarge: |
| 1499 | case Win64EH::UOP_AllocHuge: |
| 1500 | Count += 2; |
| 1501 | break; |
| 1502 | case Win64EH::UOP_WideAllocMedium: |
| 1503 | case Win64EH::UOP_WideAllocLarge: |
| 1504 | case Win64EH::UOP_WideAllocHuge: |
| 1505 | Count += 4; |
| 1506 | break; |
| 1507 | case Win64EH::UOP_WideSaveRegMask: |
| 1508 | case Win64EH::UOP_WideSaveRegsR4R11LR: |
| 1509 | Count += 4; |
| 1510 | break; |
| 1511 | case Win64EH::UOP_SaveSP: |
| 1512 | Count += 2; |
| 1513 | break; |
| 1514 | case Win64EH::UOP_SaveRegMask: |
| 1515 | case Win64EH::UOP_SaveRegsR4R7LR: |
| 1516 | Count += 2; |
| 1517 | break; |
| 1518 | case Win64EH::UOP_SaveFRegD8D15: |
| 1519 | case Win64EH::UOP_SaveFRegD0D15: |
| 1520 | case Win64EH::UOP_SaveFRegD16D31: |
| 1521 | Count += 4; |
| 1522 | break; |
| 1523 | case Win64EH::UOP_SaveLR: |
| 1524 | Count += 4; |
| 1525 | break; |
| 1526 | case Win64EH::UOP_Nop: |
| 1527 | case Win64EH::UOP_EndNop: |
| 1528 | Count += 2; |
| 1529 | break; |
| 1530 | case Win64EH::UOP_WideNop: |
| 1531 | case Win64EH::UOP_WideEndNop: |
| 1532 | Count += 4; |
| 1533 | break; |
| 1534 | case Win64EH::UOP_End: |
| 1535 | // This doesn't map to any instruction |
| 1536 | break; |
| 1537 | case Win64EH::UOP_Custom: |
| 1538 | // We can't reason about what instructions this maps to; return a |
| 1539 | // phony number to make sure we don't accidentally do epilog packing. |
| 1540 | Count += 1000; |
| 1541 | if (HasCustom) |
| 1542 | *HasCustom = true; |
| 1543 | break; |
| 1544 | } |
| 1545 | } |
| 1546 | return Count; |
| 1547 | } |
| 1548 | |
| 1549 | static void checkARMInstructions(MCStreamer &Streamer, |
| 1550 | ArrayRef<WinEH::Instruction> Insns, |
| 1551 | const MCSymbol *Begin, const MCSymbol *End, |
| 1552 | StringRef Name, StringRef Type) { |
| 1553 | if (!End) |
| 1554 | return; |
| 1555 | std::optional<int64_t> MaybeDistance = |
| 1556 | GetOptionalAbsDifference(Streamer, End, Begin); |
| 1557 | if (!MaybeDistance) |
| 1558 | return; |
| 1559 | uint32_t Distance = (uint32_t)*MaybeDistance; |
| 1560 | bool HasCustom = false; |
| 1561 | uint32_t InstructionBytes = ARMCountOfInstructionBytes(Insns, &HasCustom); |
| 1562 | if (HasCustom) |
| 1563 | return; |
| 1564 | if (Distance != InstructionBytes) { |
| 1565 | Streamer.getContext().reportError( |
| 1566 | SMLoc(), "Incorrect size for " + Name + " " + Type + ": " + |
| 1567 | Twine(Distance) + |
| 1568 | " bytes of instructions in range, but .seh directives " |
| 1569 | "corresponding to " + |
| 1570 | Twine(InstructionBytes) + " bytes\n"); |
| 1571 | } |
| 1572 | } |
| 1573 | |
| 1574 | static bool isARMTerminator(const WinEH::Instruction &inst) { |
| 1575 | switch (static_cast<Win64EH::UnwindOpcodes>(inst.Operation)) { |
| 1576 | case Win64EH::UOP_End: |
| 1577 | case Win64EH::UOP_EndNop: |
| 1578 | case Win64EH::UOP_WideEndNop: |
| 1579 | return true; |
| 1580 | default: |
| 1581 | return false; |
| 1582 | } |
| 1583 | } |
| 1584 | |
| 1585 | // Unwind opcode encodings and restrictions are documented at |
| 1586 | // https://docs.microsoft.com/en-us/cpp/build/arm-exception-handling |
| 1587 | static void ARMEmitUnwindCode(MCStreamer &streamer, |
| 1588 | const WinEH::Instruction &inst) { |
| 1589 | uint32_t w, lr; |
| 1590 | int i; |
| 1591 | switch (static_cast<Win64EH::UnwindOpcodes>(inst.Operation)) { |
| 1592 | default: |
| 1593 | llvm_unreachable("Unsupported ARM unwind code")::llvm::llvm_unreachable_internal("Unsupported ARM unwind code" , "llvm/lib/MC/MCWin64EH.cpp", 1593); |
| 1594 | case Win64EH::UOP_AllocSmall: |
| 1595 | assert((inst.Offset & 3) == 0)(static_cast <bool> ((inst.Offset & 3) == 0) ? void (0) : __assert_fail ("(inst.Offset & 3) == 0", "llvm/lib/MC/MCWin64EH.cpp" , 1595, __extension__ __PRETTY_FUNCTION__)); |
| 1596 | assert(inst.Offset / 4 <= 0x7f)(static_cast <bool> (inst.Offset / 4 <= 0x7f) ? void (0) : __assert_fail ("inst.Offset / 4 <= 0x7f", "llvm/lib/MC/MCWin64EH.cpp" , 1596, __extension__ __PRETTY_FUNCTION__)); |
| 1597 | streamer.emitInt8(inst.Offset / 4); |
| 1598 | break; |
| 1599 | case Win64EH::UOP_WideSaveRegMask: |
| 1600 | assert((inst.Register & ~0x5fff) == 0)(static_cast <bool> ((inst.Register & ~0x5fff) == 0 ) ? void (0) : __assert_fail ("(inst.Register & ~0x5fff) == 0" , "llvm/lib/MC/MCWin64EH.cpp", 1600, __extension__ __PRETTY_FUNCTION__ )); |
| 1601 | lr = (inst.Register >> 14) & 1; |
| 1602 | w = 0x8000 | (inst.Register & 0x1fff) | (lr << 13); |
| 1603 | streamer.emitInt8((w >> 8) & 0xff); |
| 1604 | streamer.emitInt8((w >> 0) & 0xff); |
| 1605 | break; |
| 1606 | case Win64EH::UOP_SaveSP: |
| 1607 | assert(inst.Register <= 0x0f)(static_cast <bool> (inst.Register <= 0x0f) ? void ( 0) : __assert_fail ("inst.Register <= 0x0f", "llvm/lib/MC/MCWin64EH.cpp" , 1607, __extension__ __PRETTY_FUNCTION__)); |
| 1608 | streamer.emitInt8(0xc0 | inst.Register); |
| 1609 | break; |
| 1610 | case Win64EH::UOP_SaveRegsR4R7LR: |
| 1611 | assert(inst.Register >= 4 && inst.Register <= 7)(static_cast <bool> (inst.Register >= 4 && inst .Register <= 7) ? void (0) : __assert_fail ("inst.Register >= 4 && inst.Register <= 7" , "llvm/lib/MC/MCWin64EH.cpp", 1611, __extension__ __PRETTY_FUNCTION__ )); |
| 1612 | assert(inst.Offset <= 1)(static_cast <bool> (inst.Offset <= 1) ? void (0) : __assert_fail ("inst.Offset <= 1", "llvm/lib/MC/MCWin64EH.cpp", 1612, __extension__ __PRETTY_FUNCTION__)); |
| 1613 | streamer.emitInt8(0xd0 | (inst.Register - 4) | (inst.Offset << 2)); |
| 1614 | break; |
| 1615 | case Win64EH::UOP_WideSaveRegsR4R11LR: |
| 1616 | assert(inst.Register >= 8 && inst.Register <= 11)(static_cast <bool> (inst.Register >= 8 && inst .Register <= 11) ? void (0) : __assert_fail ("inst.Register >= 8 && inst.Register <= 11" , "llvm/lib/MC/MCWin64EH.cpp", 1616, __extension__ __PRETTY_FUNCTION__ )); |
| 1617 | assert(inst.Offset <= 1)(static_cast <bool> (inst.Offset <= 1) ? void (0) : __assert_fail ("inst.Offset <= 1", "llvm/lib/MC/MCWin64EH.cpp", 1617, __extension__ __PRETTY_FUNCTION__)); |
| 1618 | streamer.emitInt8(0xd8 | (inst.Register - 8) | (inst.Offset << 2)); |
| 1619 | break; |
| 1620 | case Win64EH::UOP_SaveFRegD8D15: |
| 1621 | assert(inst.Register >= 8 && inst.Register <= 15)(static_cast <bool> (inst.Register >= 8 && inst .Register <= 15) ? void (0) : __assert_fail ("inst.Register >= 8 && inst.Register <= 15" , "llvm/lib/MC/MCWin64EH.cpp", 1621, __extension__ __PRETTY_FUNCTION__ )); |
| 1622 | streamer.emitInt8(0xe0 | (inst.Register - 8)); |
| 1623 | break; |
| 1624 | case Win64EH::UOP_WideAllocMedium: |
| 1625 | assert((inst.Offset & 3) == 0)(static_cast <bool> ((inst.Offset & 3) == 0) ? void (0) : __assert_fail ("(inst.Offset & 3) == 0", "llvm/lib/MC/MCWin64EH.cpp" , 1625, __extension__ __PRETTY_FUNCTION__)); |
| 1626 | assert(inst.Offset / 4 <= 0x3ff)(static_cast <bool> (inst.Offset / 4 <= 0x3ff) ? void (0) : __assert_fail ("inst.Offset / 4 <= 0x3ff", "llvm/lib/MC/MCWin64EH.cpp" , 1626, __extension__ __PRETTY_FUNCTION__)); |
| 1627 | w = 0xe800 | (inst.Offset / 4); |
| 1628 | streamer.emitInt8((w >> 8) & 0xff); |
| 1629 | streamer.emitInt8((w >> 0) & 0xff); |
| 1630 | break; |
| 1631 | case Win64EH::UOP_SaveRegMask: |
| 1632 | assert((inst.Register & ~0x40ff) == 0)(static_cast <bool> ((inst.Register & ~0x40ff) == 0 ) ? void (0) : __assert_fail ("(inst.Register & ~0x40ff) == 0" , "llvm/lib/MC/MCWin64EH.cpp", 1632, __extension__ __PRETTY_FUNCTION__ )); |
| 1633 | lr = (inst.Register >> 14) & 1; |
| 1634 | w = 0xec00 | (inst.Register & 0x0ff) | (lr << 8); |
| 1635 | streamer.emitInt8((w >> 8) & 0xff); |
| 1636 | streamer.emitInt8((w >> 0) & 0xff); |
| 1637 | break; |
| 1638 | case Win64EH::UOP_SaveLR: |
| 1639 | assert((inst.Offset & 3) == 0)(static_cast <bool> ((inst.Offset & 3) == 0) ? void (0) : __assert_fail ("(inst.Offset & 3) == 0", "llvm/lib/MC/MCWin64EH.cpp" , 1639, __extension__ __PRETTY_FUNCTION__)); |
| 1640 | assert(inst.Offset / 4 <= 0x0f)(static_cast <bool> (inst.Offset / 4 <= 0x0f) ? void (0) : __assert_fail ("inst.Offset / 4 <= 0x0f", "llvm/lib/MC/MCWin64EH.cpp" , 1640, __extension__ __PRETTY_FUNCTION__)); |
| 1641 | streamer.emitInt8(0xef); |
| 1642 | streamer.emitInt8(inst.Offset / 4); |
| 1643 | break; |
| 1644 | case Win64EH::UOP_SaveFRegD0D15: |
| 1645 | assert(inst.Register <= 15)(static_cast <bool> (inst.Register <= 15) ? void (0) : __assert_fail ("inst.Register <= 15", "llvm/lib/MC/MCWin64EH.cpp" , 1645, __extension__ __PRETTY_FUNCTION__)); |
| 1646 | assert(inst.Offset <= 15)(static_cast <bool> (inst.Offset <= 15) ? void (0) : __assert_fail ("inst.Offset <= 15", "llvm/lib/MC/MCWin64EH.cpp" , 1646, __extension__ __PRETTY_FUNCTION__)); |
| 1647 | assert(inst.Register <= inst.Offset)(static_cast <bool> (inst.Register <= inst.Offset) ? void (0) : __assert_fail ("inst.Register <= inst.Offset", "llvm/lib/MC/MCWin64EH.cpp", 1647, __extension__ __PRETTY_FUNCTION__ )); |
| 1648 | streamer.emitInt8(0xf5); |
| 1649 | streamer.emitInt8((inst.Register << 4) | inst.Offset); |
| 1650 | break; |
| 1651 | case Win64EH::UOP_SaveFRegD16D31: |
| 1652 | assert(inst.Register >= 16 && inst.Register <= 31)(static_cast <bool> (inst.Register >= 16 && inst .Register <= 31) ? void (0) : __assert_fail ("inst.Register >= 16 && inst.Register <= 31" , "llvm/lib/MC/MCWin64EH.cpp", 1652, __extension__ __PRETTY_FUNCTION__ )); |
| 1653 | assert(inst.Offset >= 16 && inst.Offset <= 31)(static_cast <bool> (inst.Offset >= 16 && inst .Offset <= 31) ? void (0) : __assert_fail ("inst.Offset >= 16 && inst.Offset <= 31" , "llvm/lib/MC/MCWin64EH.cpp", 1653, __extension__ __PRETTY_FUNCTION__ )); |
| 1654 | assert(inst.Register <= inst.Offset)(static_cast <bool> (inst.Register <= inst.Offset) ? void (0) : __assert_fail ("inst.Register <= inst.Offset", "llvm/lib/MC/MCWin64EH.cpp", 1654, __extension__ __PRETTY_FUNCTION__ )); |
| 1655 | streamer.emitInt8(0xf6); |
| 1656 | streamer.emitInt8(((inst.Register - 16) << 4) | (inst.Offset - 16)); |
| 1657 | break; |
| 1658 | case Win64EH::UOP_AllocLarge: |
| 1659 | assert((inst.Offset & 3) == 0)(static_cast <bool> ((inst.Offset & 3) == 0) ? void (0) : __assert_fail ("(inst.Offset & 3) == 0", "llvm/lib/MC/MCWin64EH.cpp" , 1659, __extension__ __PRETTY_FUNCTION__)); |
| 1660 | assert(inst.Offset / 4 <= 0xffff)(static_cast <bool> (inst.Offset / 4 <= 0xffff) ? void (0) : __assert_fail ("inst.Offset / 4 <= 0xffff", "llvm/lib/MC/MCWin64EH.cpp" , 1660, __extension__ __PRETTY_FUNCTION__)); |
| 1661 | w = inst.Offset / 4; |
| 1662 | streamer.emitInt8(0xf7); |
| 1663 | streamer.emitInt8((w >> 8) & 0xff); |
| 1664 | streamer.emitInt8((w >> 0) & 0xff); |
| 1665 | break; |
| 1666 | case Win64EH::UOP_AllocHuge: |
| 1667 | assert((inst.Offset & 3) == 0)(static_cast <bool> ((inst.Offset & 3) == 0) ? void (0) : __assert_fail ("(inst.Offset & 3) == 0", "llvm/lib/MC/MCWin64EH.cpp" , 1667, __extension__ __PRETTY_FUNCTION__)); |
| 1668 | assert(inst.Offset / 4 <= 0xffffff)(static_cast <bool> (inst.Offset / 4 <= 0xffffff) ? void (0) : __assert_fail ("inst.Offset / 4 <= 0xffffff", "llvm/lib/MC/MCWin64EH.cpp" , 1668, __extension__ __PRETTY_FUNCTION__)); |
| 1669 | w = inst.Offset / 4; |
| 1670 | streamer.emitInt8(0xf8); |
| 1671 | streamer.emitInt8((w >> 16) & 0xff); |
| 1672 | streamer.emitInt8((w >> 8) & 0xff); |
| 1673 | streamer.emitInt8((w >> 0) & 0xff); |
| 1674 | break; |
| 1675 | case Win64EH::UOP_WideAllocLarge: |
| 1676 | assert((inst.Offset & 3) == 0)(static_cast <bool> ((inst.Offset & 3) == 0) ? void (0) : __assert_fail ("(inst.Offset & 3) == 0", "llvm/lib/MC/MCWin64EH.cpp" , 1676, __extension__ __PRETTY_FUNCTION__)); |
| 1677 | assert(inst.Offset / 4 <= 0xffff)(static_cast <bool> (inst.Offset / 4 <= 0xffff) ? void (0) : __assert_fail ("inst.Offset / 4 <= 0xffff", "llvm/lib/MC/MCWin64EH.cpp" , 1677, __extension__ __PRETTY_FUNCTION__)); |
| 1678 | w = inst.Offset / 4; |
| 1679 | streamer.emitInt8(0xf9); |
| 1680 | streamer.emitInt8((w >> 8) & 0xff); |
| 1681 | streamer.emitInt8((w >> 0) & 0xff); |
| 1682 | break; |
| 1683 | case Win64EH::UOP_WideAllocHuge: |
| 1684 | assert((inst.Offset & 3) == 0)(static_cast <bool> ((inst.Offset & 3) == 0) ? void (0) : __assert_fail ("(inst.Offset & 3) == 0", "llvm/lib/MC/MCWin64EH.cpp" , 1684, __extension__ __PRETTY_FUNCTION__)); |
| 1685 | assert(inst.Offset / 4 <= 0xffffff)(static_cast <bool> (inst.Offset / 4 <= 0xffffff) ? void (0) : __assert_fail ("inst.Offset / 4 <= 0xffffff", "llvm/lib/MC/MCWin64EH.cpp" , 1685, __extension__ __PRETTY_FUNCTION__)); |
| 1686 | w = inst.Offset / 4; |
| 1687 | streamer.emitInt8(0xfa); |
| 1688 | streamer.emitInt8((w >> 16) & 0xff); |
| 1689 | streamer.emitInt8((w >> 8) & 0xff); |
| 1690 | streamer.emitInt8((w >> 0) & 0xff); |
| 1691 | break; |
| 1692 | case Win64EH::UOP_Nop: |
| 1693 | streamer.emitInt8(0xfb); |
| 1694 | break; |
| 1695 | case Win64EH::UOP_WideNop: |
| 1696 | streamer.emitInt8(0xfc); |
| 1697 | break; |
| 1698 | case Win64EH::UOP_EndNop: |
| 1699 | streamer.emitInt8(0xfd); |
| 1700 | break; |
| 1701 | case Win64EH::UOP_WideEndNop: |
| 1702 | streamer.emitInt8(0xfe); |
| 1703 | break; |
| 1704 | case Win64EH::UOP_End: |
| 1705 | streamer.emitInt8(0xff); |
| 1706 | break; |
| 1707 | case Win64EH::UOP_Custom: |
| 1708 | for (i = 3; i > 0; i--) |
| 1709 | if (inst.Offset & (0xffu << (8 * i))) |
| 1710 | break; |
| 1711 | for (; i >= 0; i--) |
| 1712 | streamer.emitInt8((inst.Offset >> (8 * i)) & 0xff); |
| 1713 | break; |
| 1714 | } |
| 1715 | } |
| 1716 | |
| 1717 | // Check if an epilog exists as a subset of the end of a prolog (backwards). |
| 1718 | // An epilog may end with one out of three different end opcodes; if this |
| 1719 | // is the first epilog that shares opcodes with the prolog, we can tolerate |
| 1720 | // that this opcode differs (and the caller will update the prolog to use |
| 1721 | // the same end opcode as the epilog). If another epilog already shares |
| 1722 | // opcodes with the prolog, the ending opcode must be a strict match. |
| 1723 | static int getARMOffsetInProlog(const std::vector<WinEH::Instruction> &Prolog, |
| 1724 | const std::vector<WinEH::Instruction> &Epilog, |
| 1725 | bool CanTweakProlog) { |
| 1726 | // Can't find an epilog as a subset if it is longer than the prolog. |
| 1727 | if (Epilog.size() > Prolog.size()) |
| 1728 | return -1; |
| 1729 | |
| 1730 | // Check that the epilog actually is a perfect match for the end (backwrds) |
| 1731 | // of the prolog. |
| 1732 | // If we can adjust the prolog afterwards, don't check that the end opcodes |
| 1733 | // match. |
| 1734 | int EndIdx = CanTweakProlog ? 1 : 0; |
| 1735 | for (int I = Epilog.size() - 1; I >= EndIdx; I--) { |
| 1736 | // TODO: Could also allow minor mismatches, e.g. "add sp, #16" vs |
| 1737 | // "push {r0-r3}". |
| 1738 | if (Prolog[I] != Epilog[Epilog.size() - 1 - I]) |
| 1739 | return -1; |
| 1740 | } |
| 1741 | |
| 1742 | if (CanTweakProlog) { |
| 1743 | // Check that both prolog and epilog end with an expected end opcode. |
| 1744 | if (Prolog.front().Operation != Win64EH::UOP_End) |
| 1745 | return -1; |
| 1746 | if (Epilog.back().Operation != Win64EH::UOP_End && |
| 1747 | Epilog.back().Operation != Win64EH::UOP_EndNop && |
| 1748 | Epilog.back().Operation != Win64EH::UOP_WideEndNop) |
| 1749 | return -1; |
| 1750 | } |
| 1751 | |
| 1752 | // If the epilog was a subset of the prolog, find its offset. |
| 1753 | if (Epilog.size() == Prolog.size()) |
| 1754 | return 0; |
| 1755 | return ARMCountOfUnwindCodes(ArrayRef<WinEH::Instruction>( |
| 1756 | &Prolog[Epilog.size()], Prolog.size() - Epilog.size())); |
| 1757 | } |
| 1758 | |
| 1759 | static int checkARMPackedEpilog(MCStreamer &streamer, WinEH::FrameInfo *info, |
| 1760 | int PrologCodeBytes) { |
| 1761 | // Can only pack if there's one single epilog |
| 1762 | if (info->EpilogMap.size() != 1) |
| 1763 | return -1; |
| 1764 | |
| 1765 | const WinEH::FrameInfo::Epilog &EpilogInfo = info->EpilogMap.begin()->second; |
| 1766 | // Can only pack if the epilog is unconditional |
| 1767 | if (EpilogInfo.Condition != 0xe) // ARMCC::AL |
| 1768 | return -1; |
| 1769 | |
| 1770 | const std::vector<WinEH::Instruction> &Epilog = EpilogInfo.Instructions; |
| 1771 | // Make sure we have at least the trailing end opcode |
| 1772 | if (info->Instructions.empty() || Epilog.empty()) |
| 1773 | return -1; |
| 1774 | |
| 1775 | // Check that the epilog actually is at the very end of the function, |
| 1776 | // otherwise it can't be packed. |
| 1777 | std::optional<int64_t> MaybeDistance = GetOptionalAbsDifference( |
| 1778 | streamer, info->FuncletOrFuncEnd, info->EpilogMap.begin()->first); |
| 1779 | if (!MaybeDistance) |
| 1780 | return -1; |
| 1781 | uint32_t DistanceFromEnd = (uint32_t)*MaybeDistance; |
| 1782 | uint32_t InstructionBytes = ARMCountOfInstructionBytes(Epilog); |
| 1783 | if (DistanceFromEnd != InstructionBytes) |
| 1784 | return -1; |
| 1785 | |
| 1786 | int RetVal = -1; |
| 1787 | // Even if we don't end up sharing opcodes with the prolog, we can still |
| 1788 | // write the offset as a packed offset, if the single epilog is located at |
| 1789 | // the end of the function and the offset (pointing after the prolog) fits |
| 1790 | // as a packed offset. |
| 1791 | if (PrologCodeBytes <= 31 && |
| 1792 | PrologCodeBytes + ARMCountOfUnwindCodes(Epilog) <= 63) |
| 1793 | RetVal = PrologCodeBytes; |
| 1794 | |
| 1795 | int Offset = |
| 1796 | getARMOffsetInProlog(info->Instructions, Epilog, /*CanTweakProlog=*/true); |
| 1797 | if (Offset < 0) |
| 1798 | return RetVal; |
| 1799 | |
| 1800 | // Check that the offset and prolog size fits in the first word; it's |
| 1801 | // unclear whether the epilog count in the extension word can be taken |
| 1802 | // as packed epilog offset. |
| 1803 | if (Offset > 31 || PrologCodeBytes > 63) |
| 1804 | return RetVal; |
| 1805 | |
| 1806 | // Replace the regular end opcode of the prolog with the one from the |
| 1807 | // epilog. |
| 1808 | info->Instructions.front() = Epilog.back(); |
| 1809 | |
| 1810 | // As we choose to express the epilog as part of the prolog, remove the |
| 1811 | // epilog from the map, so we don't try to emit its opcodes. |
| 1812 | info->EpilogMap.clear(); |
| 1813 | return Offset; |
| 1814 | } |
| 1815 | |
| 1816 | static bool parseRegMask(unsigned Mask, bool &HasLR, bool &HasR11, |
| 1817 | unsigned &Folded, int &IntRegs) { |
| 1818 | if (Mask & (1 << 14)) { |
| 1819 | HasLR = true; |
| 1820 | Mask &= ~(1 << 14); |
| 1821 | } |
| 1822 | if (Mask & (1 << 11)) { |
| 1823 | HasR11 = true; |
| 1824 | Mask &= ~(1 << 11); |
| 1825 | } |
| 1826 | Folded = 0; |
| 1827 | IntRegs = -1; |
| 1828 | if (!Mask) |
| 1829 | return true; |
| 1830 | int First = 0; |
| 1831 | // Shift right until we have the bits at the bottom |
| 1832 | while ((Mask & 1) == 0) { |
| 1833 | First++; |
| 1834 | Mask >>= 1; |
| 1835 | } |
| 1836 | if ((Mask & (Mask + 1)) != 0) |
| 1837 | return false; // Not a consecutive series of bits? Can't be packed. |
| 1838 | // Count the bits |
| 1839 | int N = 0; |
| 1840 | while (Mask & (1 << N)) |
| 1841 | N++; |
| 1842 | if (First < 4) { |
| 1843 | if (First + N < 4) |
| 1844 | return false; |
| 1845 | Folded = 4 - First; |
| 1846 | N -= Folded; |
| 1847 | First = 4; |
| 1848 | } |
| 1849 | if (First > 4) |
| 1850 | return false; // Can't be packed |
| 1851 | if (N >= 1) |
| 1852 | IntRegs = N - 1; |
| 1853 | return true; |
| 1854 | } |
| 1855 | |
| 1856 | static bool tryARMPackedUnwind(MCStreamer &streamer, WinEH::FrameInfo *info, |
| 1857 | uint32_t FuncLength) { |
| 1858 | int Step = 0; |
| 1859 | bool Homing = false; |
| 1860 | bool HasR11 = false; |
| 1861 | bool HasChain = false; |
| 1862 | bool HasLR = false; |
| 1863 | int IntRegs = -1; // r4 - r(4+N) |
| 1864 | int FloatRegs = -1; // d8 - d(8+N) |
| 1865 | unsigned PF = 0; // Number of extra pushed registers |
| 1866 | unsigned StackAdjust = 0; |
| 1867 | // Iterate over the prolog and check that all opcodes exactly match |
| 1868 | // the canonical order and form. |
| 1869 | for (const WinEH::Instruction &Inst : info->Instructions) { |
| 1870 | switch (Inst.Operation) { |
| 1871 | default: |
| 1872 | llvm_unreachable("Unsupported ARM unwind code")::llvm::llvm_unreachable_internal("Unsupported ARM unwind code" , "llvm/lib/MC/MCWin64EH.cpp", 1872); |
| 1873 | case Win64EH::UOP_Custom: |
| 1874 | case Win64EH::UOP_AllocLarge: |
| 1875 | case Win64EH::UOP_AllocHuge: |
| 1876 | case Win64EH::UOP_WideAllocLarge: |
| 1877 | case Win64EH::UOP_WideAllocHuge: |
| 1878 | case Win64EH::UOP_SaveFRegD0D15: |
| 1879 | case Win64EH::UOP_SaveFRegD16D31: |
| 1880 | // Can't be packed |
| 1881 | return false; |
| 1882 | case Win64EH::UOP_SaveSP: |
| 1883 | // Can't be packed; we can't rely on restoring sp from r11 when |
| 1884 | // unwinding a packed prologue. |
| 1885 | return false; |
| 1886 | case Win64EH::UOP_SaveLR: |
| 1887 | // Can't be present in a packed prologue |
| 1888 | return false; |
| 1889 | |
| 1890 | case Win64EH::UOP_End: |
| 1891 | case Win64EH::UOP_EndNop: |
| 1892 | case Win64EH::UOP_WideEndNop: |
| 1893 | if (Step != 0) |
| 1894 | return false; |
| 1895 | Step = 1; |
| 1896 | break; |
| 1897 | |
| 1898 | case Win64EH::UOP_SaveRegsR4R7LR: |
| 1899 | case Win64EH::UOP_WideSaveRegsR4R11LR: |
| 1900 | // push {r4-r11,lr} |
| 1901 | if (Step != 1 && Step != 2) |
| 1902 | return false; |
| 1903 | assert(Inst.Register >= 4 && Inst.Register <= 11)(static_cast <bool> (Inst.Register >= 4 && Inst .Register <= 11) ? void (0) : __assert_fail ("Inst.Register >= 4 && Inst.Register <= 11" , "llvm/lib/MC/MCWin64EH.cpp", 1903, __extension__ __PRETTY_FUNCTION__ )); // r4-rX |
| 1904 | assert(Inst.Offset <= 1)(static_cast <bool> (Inst.Offset <= 1) ? void (0) : __assert_fail ("Inst.Offset <= 1", "llvm/lib/MC/MCWin64EH.cpp", 1904, __extension__ __PRETTY_FUNCTION__)); // Lr |
| 1905 | IntRegs = Inst.Register - 4; |
| 1906 | if (Inst.Register == 11) { |
| 1907 | HasR11 = true; |
| 1908 | IntRegs--; |
| 1909 | } |
| 1910 | if (Inst.Offset) |
| 1911 | HasLR = true; |
| 1912 | Step = 3; |
| 1913 | break; |
| 1914 | |
| 1915 | case Win64EH::UOP_SaveRegMask: |
| 1916 | if (Step == 1 && Inst.Register == 0x0f) { |
| 1917 | // push {r0-r3} |
| 1918 | Homing = true; |
| 1919 | Step = 2; |
| 1920 | break; |
| 1921 | } |
| 1922 | [[fallthrough]]; |
| 1923 | case Win64EH::UOP_WideSaveRegMask: |
| 1924 | if (Step != 1 && Step != 2) |
| 1925 | return false; |
| 1926 | // push {r4-r9,r11,lr} |
| 1927 | // push {r11,lr} |
| 1928 | // push {r1-r5} |
| 1929 | if (!parseRegMask(Inst.Register, HasLR, HasR11, PF, IntRegs)) |
| 1930 | return false; |
| 1931 | Step = 3; |
| 1932 | break; |
| 1933 | |
| 1934 | case Win64EH::UOP_Nop: |
| 1935 | // mov r11, sp |
| 1936 | if (Step != 3 || !HasR11 || IntRegs >= 0 || PF > 0) |
| 1937 | return false; |
| 1938 | HasChain = true; |
| 1939 | Step = 4; |
| 1940 | break; |
| 1941 | case Win64EH::UOP_WideNop: |
| 1942 | // add.w r11, sp, #xx |
| 1943 | if (Step != 3 || !HasR11 || (IntRegs < 0 && PF == 0)) |
| 1944 | return false; |
| 1945 | HasChain = true; |
| 1946 | Step = 4; |
| 1947 | break; |
| 1948 | |
| 1949 | case Win64EH::UOP_SaveFRegD8D15: |
| 1950 | if (Step != 1 && Step != 2 && Step != 3 && Step != 4) |
| 1951 | return false; |
| 1952 | assert(Inst.Register >= 8 && Inst.Register <= 15)(static_cast <bool> (Inst.Register >= 8 && Inst .Register <= 15) ? void (0) : __assert_fail ("Inst.Register >= 8 && Inst.Register <= 15" , "llvm/lib/MC/MCWin64EH.cpp", 1952, __extension__ __PRETTY_FUNCTION__ )); |
| 1953 | if (Inst.Register == 15) |
| 1954 | return false; // Can't pack this case, R==7 means no IntRegs |
| 1955 | if (IntRegs >= 0) |
| 1956 | return false; |
| 1957 | FloatRegs = Inst.Register - 8; |
| 1958 | Step = 5; |
| 1959 | break; |
| 1960 | |
| 1961 | case Win64EH::UOP_AllocSmall: |
| 1962 | case Win64EH::UOP_WideAllocMedium: |
| 1963 | if (Step != 1 && Step != 2 && Step != 3 && Step != 4 && Step != 5) |
| 1964 | return false; |
| 1965 | if (PF > 0) // Can't have both folded and explicit stack allocation |
| 1966 | return false; |
| 1967 | if (Inst.Offset / 4 >= 0x3f4) |
| 1968 | return false; |
| 1969 | StackAdjust = Inst.Offset / 4; |
| 1970 | Step = 6; |
| 1971 | break; |
| 1972 | } |
| 1973 | } |
| 1974 | if (HasR11 && !HasChain) { |
| 1975 | if (IntRegs + 4 == 10) { |
| 1976 | // r11 stored, but not chaining; can be packed if already saving r4-r10 |
| 1977 | // and we can fit r11 into this range. |
| 1978 | IntRegs++; |
| 1979 | HasR11 = false; |
Value stored to 'HasR11' is never read | |
| 1980 | } else |
| 1981 | return false; |
| 1982 | } |
| 1983 | if (HasChain && !HasLR) |
| 1984 | return false; |
| 1985 | |
| 1986 | // Packed uneind info can't express multiple epilogues. |
| 1987 | if (info->EpilogMap.size() > 1) |
| 1988 | return false; |
| 1989 | |
| 1990 | unsigned EF = 0; |
| 1991 | int Ret = 0; |
| 1992 | if (info->EpilogMap.size() == 0) { |
| 1993 | Ret = 3; // No epilogue |
| 1994 | } else { |
| 1995 | // As the prologue and epilogue aren't exact mirrors of each other, |
| 1996 | // we have to check the epilogue too and see if it matches what we've |
| 1997 | // concluded from the prologue. |
| 1998 | const WinEH::FrameInfo::Epilog &EpilogInfo = |
| 1999 | info->EpilogMap.begin()->second; |
| 2000 | if (EpilogInfo.Condition != 0xe) // ARMCC::AL |
| 2001 | return false; |
| 2002 | const std::vector<WinEH::Instruction> &Epilog = EpilogInfo.Instructions; |
| 2003 | std::optional<int64_t> MaybeDistance = GetOptionalAbsDifference( |
| 2004 | streamer, info->FuncletOrFuncEnd, info->EpilogMap.begin()->first); |
| 2005 | if (!MaybeDistance) |
| 2006 | return false; |
| 2007 | uint32_t DistanceFromEnd = (uint32_t)*MaybeDistance; |
| 2008 | uint32_t InstructionBytes = ARMCountOfInstructionBytes(Epilog); |
| 2009 | if (DistanceFromEnd != InstructionBytes) |
| 2010 | return false; |
| 2011 | |
| 2012 | bool GotStackAdjust = false; |
| 2013 | bool GotFloatRegs = false; |
| 2014 | bool GotIntRegs = false; |
| 2015 | bool GotHomingRestore = false; |
| 2016 | bool GotLRRestore = false; |
| 2017 | bool NeedsReturn = false; |
| 2018 | bool GotReturn = false; |
| 2019 | |
| 2020 | Step = 6; |
| 2021 | for (const WinEH::Instruction &Inst : Epilog) { |
| 2022 | switch (Inst.Operation) { |
| 2023 | default: |
| 2024 | llvm_unreachable("Unsupported ARM unwind code")::llvm::llvm_unreachable_internal("Unsupported ARM unwind code" , "llvm/lib/MC/MCWin64EH.cpp", 2024); |
| 2025 | case Win64EH::UOP_Custom: |
| 2026 | case Win64EH::UOP_AllocLarge: |
| 2027 | case Win64EH::UOP_AllocHuge: |
| 2028 | case Win64EH::UOP_WideAllocLarge: |
| 2029 | case Win64EH::UOP_WideAllocHuge: |
| 2030 | case Win64EH::UOP_SaveFRegD0D15: |
| 2031 | case Win64EH::UOP_SaveFRegD16D31: |
| 2032 | case Win64EH::UOP_SaveSP: |
| 2033 | case Win64EH::UOP_Nop: |
| 2034 | case Win64EH::UOP_WideNop: |
| 2035 | // Can't be packed in an epilogue |
| 2036 | return false; |
| 2037 | |
| 2038 | case Win64EH::UOP_AllocSmall: |
| 2039 | case Win64EH::UOP_WideAllocMedium: |
| 2040 | if (Inst.Offset / 4 >= 0x3f4) |
| 2041 | return false; |
| 2042 | if (Step == 6) { |
| 2043 | if (Homing && FloatRegs < 0 && IntRegs < 0 && StackAdjust == 0 && |
| 2044 | PF == 0 && Inst.Offset == 16) { |
| 2045 | GotHomingRestore = true; |
| 2046 | Step = 10; |
| 2047 | } else { |
| 2048 | if (StackAdjust > 0) { |
| 2049 | // Got stack adjust in prologue too; must match. |
| 2050 | if (StackAdjust != Inst.Offset / 4) |
| 2051 | return false; |
| 2052 | GotStackAdjust = true; |
| 2053 | } else if (PF == Inst.Offset / 4) { |
| 2054 | // Folded prologue, non-folded epilogue |
| 2055 | StackAdjust = Inst.Offset / 4; |
| 2056 | GotStackAdjust = true; |
| 2057 | } else { |
| 2058 | // StackAdjust == 0 in prologue, mismatch |
| 2059 | return false; |
| 2060 | } |
| 2061 | Step = 7; |
| 2062 | } |
| 2063 | } else if (Step == 7 || Step == 8 || Step == 9) { |
| 2064 | if (!Homing || Inst.Offset != 16) |
| 2065 | return false; |
| 2066 | GotHomingRestore = true; |
| 2067 | Step = 10; |
| 2068 | } else |
| 2069 | return false; |
| 2070 | break; |
| 2071 | |
| 2072 | case Win64EH::UOP_SaveFRegD8D15: |
| 2073 | if (Step != 6 && Step != 7) |
| 2074 | return false; |
| 2075 | assert(Inst.Register >= 8 && Inst.Register <= 15)(static_cast <bool> (Inst.Register >= 8 && Inst .Register <= 15) ? void (0) : __assert_fail ("Inst.Register >= 8 && Inst.Register <= 15" , "llvm/lib/MC/MCWin64EH.cpp", 2075, __extension__ __PRETTY_FUNCTION__ )); |
| 2076 | if (FloatRegs != (int)(Inst.Register - 8)) |
| 2077 | return false; |
| 2078 | GotFloatRegs = true; |
| 2079 | Step = 8; |
| 2080 | break; |
| 2081 | |
| 2082 | case Win64EH::UOP_SaveRegsR4R7LR: |
| 2083 | case Win64EH::UOP_WideSaveRegsR4R11LR: { |
| 2084 | // push {r4-r11,lr} |
| 2085 | if (Step != 6 && Step != 7 && Step != 8) |
| 2086 | return false; |
| 2087 | assert(Inst.Register >= 4 && Inst.Register <= 11)(static_cast <bool> (Inst.Register >= 4 && Inst .Register <= 11) ? void (0) : __assert_fail ("Inst.Register >= 4 && Inst.Register <= 11" , "llvm/lib/MC/MCWin64EH.cpp", 2087, __extension__ __PRETTY_FUNCTION__ )); // r4-rX |
| 2088 | assert(Inst.Offset <= 1)(static_cast <bool> (Inst.Offset <= 1) ? void (0) : __assert_fail ("Inst.Offset <= 1", "llvm/lib/MC/MCWin64EH.cpp", 2088, __extension__ __PRETTY_FUNCTION__)); // Lr |
| 2089 | if (Homing && HasLR) { |
| 2090 | // If homing and LR is backed up, we can either restore LR here |
| 2091 | // and return with Ret == 1 or 2, or return with SaveLR below |
| 2092 | if (Inst.Offset) { |
| 2093 | GotLRRestore = true; |
| 2094 | NeedsReturn = true; |
| 2095 | } else { |
| 2096 | // Expecting a separate SaveLR below |
| 2097 | } |
| 2098 | } else { |
| 2099 | if (HasLR != (Inst.Offset == 1)) |
| 2100 | return false; |
| 2101 | } |
| 2102 | GotLRRestore = Inst.Offset == 1; |
| 2103 | if (IntRegs < 0) // This opcode must include r4 |
| 2104 | return false; |
| 2105 | int Expected = IntRegs; |
| 2106 | if (HasChain) { |
| 2107 | // Can't express r11 here unless IntRegs describe r4-r10 |
| 2108 | if (IntRegs != 6) |
| 2109 | return false; |
| 2110 | Expected++; |
| 2111 | } |
| 2112 | if (Expected != (int)(Inst.Register - 4)) |
| 2113 | return false; |
| 2114 | GotIntRegs = true; |
| 2115 | Step = 9; |
| 2116 | break; |
| 2117 | } |
| 2118 | |
| 2119 | case Win64EH::UOP_SaveRegMask: |
| 2120 | case Win64EH::UOP_WideSaveRegMask: { |
| 2121 | if (Step != 6 && Step != 7 && Step != 8) |
| 2122 | return false; |
| 2123 | // push {r4-r9,r11,lr} |
| 2124 | // push {r11,lr} |
| 2125 | // push {r1-r5} |
| 2126 | bool CurHasLR = false, CurHasR11 = false; |
| 2127 | int Regs; |
| 2128 | if (!parseRegMask(Inst.Register, CurHasLR, CurHasR11, EF, Regs)) |
| 2129 | return false; |
| 2130 | if (EF > 0) { |
| 2131 | if (EF != PF && EF != StackAdjust) |
| 2132 | return false; |
| 2133 | } |
| 2134 | if (Homing && HasLR) { |
| 2135 | // If homing and LR is backed up, we can either restore LR here |
| 2136 | // and return with Ret == 1 or 2, or return with SaveLR below |
| 2137 | if (CurHasLR) { |
| 2138 | GotLRRestore = true; |
| 2139 | NeedsReturn = true; |
| 2140 | } else { |
| 2141 | // Expecting a separate SaveLR below |
| 2142 | } |
| 2143 | } else { |
| 2144 | if (CurHasLR != HasLR) |
| 2145 | return false; |
| 2146 | GotLRRestore = CurHasLR; |
| 2147 | } |
| 2148 | int Expected = IntRegs; |
| 2149 | if (HasChain) { |
| 2150 | // If we have chaining, the mask must have included r11. |
| 2151 | if (!CurHasR11) |
| 2152 | return false; |
| 2153 | } else if (Expected == 7) { |
| 2154 | // If we don't have chaining, the mask could still include r11, |
| 2155 | // expressed as part of IntRegs Instead. |
| 2156 | Expected--; |
| 2157 | if (!CurHasR11) |
| 2158 | return false; |
| 2159 | } else { |
| 2160 | // Neither HasChain nor r11 included in IntRegs, must not have r11 |
| 2161 | // here either. |
| 2162 | if (CurHasR11) |
| 2163 | return false; |
| 2164 | } |
| 2165 | if (Expected != Regs) |
| 2166 | return false; |
| 2167 | GotIntRegs = true; |
| 2168 | Step = 9; |
| 2169 | break; |
| 2170 | } |
| 2171 | |
| 2172 | case Win64EH::UOP_SaveLR: |
| 2173 | if (Step != 6 && Step != 7 && Step != 8 && Step != 9) |
| 2174 | return false; |
| 2175 | if (!Homing || Inst.Offset != 20 || GotLRRestore) |
| 2176 | return false; |
| 2177 | GotLRRestore = true; |
| 2178 | GotHomingRestore = true; |
| 2179 | Step = 10; |
| 2180 | break; |
| 2181 | |
| 2182 | case Win64EH::UOP_EndNop: |
| 2183 | case Win64EH::UOP_WideEndNop: |
| 2184 | GotReturn = true; |
| 2185 | Ret = (Inst.Operation == Win64EH::UOP_EndNop) ? 1 : 2; |
| 2186 | [[fallthrough]]; |
| 2187 | case Win64EH::UOP_End: |
| 2188 | if (Step != 6 && Step != 7 && Step != 8 && Step != 9 && Step != 10) |
| 2189 | return false; |
| 2190 | Step = 11; |
| 2191 | break; |
| 2192 | } |
| 2193 | } |
| 2194 | |
| 2195 | if (Step != 11) |
| 2196 | return false; |
| 2197 | if (StackAdjust > 0 && !GotStackAdjust && EF == 0) |
| 2198 | return false; |
| 2199 | if (FloatRegs >= 0 && !GotFloatRegs) |
| 2200 | return false; |
| 2201 | if (IntRegs >= 0 && !GotIntRegs) |
| 2202 | return false; |
| 2203 | if (Homing && !GotHomingRestore) |
| 2204 | return false; |
| 2205 | if (HasLR && !GotLRRestore) |
| 2206 | return false; |
| 2207 | if (NeedsReturn && !GotReturn) |
| 2208 | return false; |
| 2209 | } |
| 2210 | |
| 2211 | assert(PF == 0 || EF == 0 ||(static_cast <bool> (PF == 0 || EF == 0 || StackAdjust == 0) ? void (0) : __assert_fail ("PF == 0 || EF == 0 || StackAdjust == 0" , "llvm/lib/MC/MCWin64EH.cpp", 2212, __extension__ __PRETTY_FUNCTION__ )) |
| 2212 | StackAdjust == 0)(static_cast <bool> (PF == 0 || EF == 0 || StackAdjust == 0) ? void (0) : __assert_fail ("PF == 0 || EF == 0 || StackAdjust == 0" , "llvm/lib/MC/MCWin64EH.cpp", 2212, __extension__ __PRETTY_FUNCTION__ )); // Can't have adjust in all three |
| 2213 | if (PF > 0 || EF > 0) { |
| 2214 | StackAdjust = PF > 0 ? (PF - 1) : (EF - 1); |
| 2215 | assert(StackAdjust <= 3)(static_cast <bool> (StackAdjust <= 3) ? void (0) : __assert_fail ("StackAdjust <= 3", "llvm/lib/MC/MCWin64EH.cpp", 2215, __extension__ __PRETTY_FUNCTION__)); |
| 2216 | StackAdjust |= 0x3f0; |
| 2217 | if (PF > 0) |
| 2218 | StackAdjust |= 1 << 2; |
| 2219 | if (EF > 0) |
| 2220 | StackAdjust |= 1 << 3; |
| 2221 | } |
| 2222 | |
| 2223 | assert(FuncLength <= 0x7FF && "FuncLength should have been checked earlier")(static_cast <bool> (FuncLength <= 0x7FF && "FuncLength should have been checked earlier" ) ? void (0) : __assert_fail ("FuncLength <= 0x7FF && \"FuncLength should have been checked earlier\"" , "llvm/lib/MC/MCWin64EH.cpp", 2223, __extension__ __PRETTY_FUNCTION__ )); |
| 2224 | int Flag = info->Fragment ? 0x02 : 0x01; |
| 2225 | int H = Homing ? 1 : 0; |
| 2226 | int L = HasLR ? 1 : 0; |
| 2227 | int C = HasChain ? 1 : 0; |
| 2228 | assert(IntRegs < 0 || FloatRegs < 0)(static_cast <bool> (IntRegs < 0 || FloatRegs < 0 ) ? void (0) : __assert_fail ("IntRegs < 0 || FloatRegs < 0" , "llvm/lib/MC/MCWin64EH.cpp", 2228, __extension__ __PRETTY_FUNCTION__ )); |
| 2229 | unsigned Reg, R; |
| 2230 | if (IntRegs >= 0) { |
| 2231 | Reg = IntRegs; |
| 2232 | assert(Reg <= 7)(static_cast <bool> (Reg <= 7) ? void (0) : __assert_fail ("Reg <= 7", "llvm/lib/MC/MCWin64EH.cpp", 2232, __extension__ __PRETTY_FUNCTION__)); |
| 2233 | R = 0; |
| 2234 | } else if (FloatRegs >= 0) { |
| 2235 | Reg = FloatRegs; |
| 2236 | assert(Reg < 7)(static_cast <bool> (Reg < 7) ? void (0) : __assert_fail ("Reg < 7", "llvm/lib/MC/MCWin64EH.cpp", 2236, __extension__ __PRETTY_FUNCTION__)); |
| 2237 | R = 1; |
| 2238 | } else { |
| 2239 | // No int or float regs stored (except possibly R11,LR) |
| 2240 | Reg = 7; |
| 2241 | R = 1; |
| 2242 | } |
| 2243 | info->PackedInfo |= Flag << 0; |
| 2244 | info->PackedInfo |= (FuncLength & 0x7FF) << 2; |
| 2245 | info->PackedInfo |= (Ret & 0x3) << 13; |
| 2246 | info->PackedInfo |= H << 15; |
| 2247 | info->PackedInfo |= Reg << 16; |
| 2248 | info->PackedInfo |= R << 19; |
| 2249 | info->PackedInfo |= L << 20; |
| 2250 | info->PackedInfo |= C << 21; |
| 2251 | assert(StackAdjust <= 0x3ff)(static_cast <bool> (StackAdjust <= 0x3ff) ? void (0 ) : __assert_fail ("StackAdjust <= 0x3ff", "llvm/lib/MC/MCWin64EH.cpp" , 2251, __extension__ __PRETTY_FUNCTION__)); |
| 2252 | info->PackedInfo |= StackAdjust << 22; |
| 2253 | return true; |
| 2254 | } |
| 2255 | |
| 2256 | // Populate the .xdata section. The format of .xdata on ARM is documented at |
| 2257 | // https://docs.microsoft.com/en-us/cpp/build/arm-exception-handling |
| 2258 | static void ARMEmitUnwindInfo(MCStreamer &streamer, WinEH::FrameInfo *info, |
| 2259 | bool TryPacked = true) { |
| 2260 | // If this UNWIND_INFO already has a symbol, it's already been emitted. |
| 2261 | if (info->Symbol) |
| 2262 | return; |
| 2263 | // If there's no unwind info here (not even a terminating UOP_End), the |
| 2264 | // unwind info is considered bogus and skipped. If this was done in |
| 2265 | // response to an explicit .seh_handlerdata, the associated trailing |
| 2266 | // handler data is left orphaned in the xdata section. |
| 2267 | if (info->empty()) { |
| 2268 | info->EmitAttempted = true; |
| 2269 | return; |
| 2270 | } |
| 2271 | if (info->EmitAttempted) { |
| 2272 | // If we tried to emit unwind info before (due to an explicit |
| 2273 | // .seh_handlerdata directive), but skipped it (because there was no |
| 2274 | // valid information to emit at the time), and it later got valid unwind |
| 2275 | // opcodes, we can't emit it here, because the trailing handler data |
| 2276 | // was already emitted elsewhere in the xdata section. |
| 2277 | streamer.getContext().reportError( |
| 2278 | SMLoc(), "Earlier .seh_handlerdata for " + info->Function->getName() + |
| 2279 | " skipped due to no unwind info at the time " |
| 2280 | "(.seh_handlerdata too early?), but the function later " |
| 2281 | "did get unwind info that can't be emitted"); |
| 2282 | return; |
| 2283 | } |
| 2284 | |
| 2285 | MCContext &context = streamer.getContext(); |
| 2286 | MCSymbol *Label = context.createTempSymbol(); |
| 2287 | |
| 2288 | streamer.emitValueToAlignment(Align(4)); |
| 2289 | streamer.emitLabel(Label); |
| 2290 | info->Symbol = Label; |
| 2291 | |
| 2292 | if (!info->PrologEnd) |
| 2293 | streamer.getContext().reportError(SMLoc(), "Prologue in " + |
| 2294 | info->Function->getName() + |
| 2295 | " not correctly terminated"); |
| 2296 | |
| 2297 | if (info->PrologEnd && !info->Fragment) |
| 2298 | checkARMInstructions(streamer, info->Instructions, info->Begin, |
| 2299 | info->PrologEnd, info->Function->getName(), |
| 2300 | "prologue"); |
| 2301 | for (auto &I : info->EpilogMap) { |
| 2302 | MCSymbol *EpilogStart = I.first; |
| 2303 | auto &Epilog = I.second; |
| 2304 | checkARMInstructions(streamer, Epilog.Instructions, EpilogStart, Epilog.End, |
| 2305 | info->Function->getName(), "epilogue"); |
| 2306 | if (Epilog.Instructions.empty() || |
| 2307 | !isARMTerminator(Epilog.Instructions.back())) |
| 2308 | streamer.getContext().reportError( |
| 2309 | SMLoc(), "Epilogue in " + info->Function->getName() + |
| 2310 | " not correctly terminated"); |
| 2311 | } |
| 2312 | |
| 2313 | std::optional<int64_t> RawFuncLength; |
| 2314 | const MCExpr *FuncLengthExpr = nullptr; |
| 2315 | if (!info->FuncletOrFuncEnd) { |
| 2316 | report_fatal_error("FuncletOrFuncEnd not set"); |
| 2317 | } else { |
| 2318 | // As the size of many thumb2 instructions isn't known until later, |
| 2319 | // we can't always rely on being able to calculate the absolute |
| 2320 | // length of the function here. If we can't calculate it, defer it |
| 2321 | // to a relocation. |
| 2322 | // |
| 2323 | // In such a case, we won't know if the function is too long so that |
| 2324 | // the unwind info would need to be split (but this isn't implemented |
| 2325 | // anyway). |
| 2326 | RawFuncLength = |
| 2327 | GetOptionalAbsDifference(streamer, info->FuncletOrFuncEnd, info->Begin); |
| 2328 | if (!RawFuncLength) |
| 2329 | FuncLengthExpr = |
| 2330 | GetSubDivExpr(streamer, info->FuncletOrFuncEnd, info->Begin, 2); |
| 2331 | } |
| 2332 | uint32_t FuncLength = 0; |
| 2333 | if (RawFuncLength) |
| 2334 | FuncLength = (uint32_t)*RawFuncLength / 2; |
| 2335 | if (FuncLength > 0x3FFFF) |
| 2336 | report_fatal_error("SEH unwind data splitting not yet implemented"); |
| 2337 | uint32_t PrologCodeBytes = ARMCountOfUnwindCodes(info->Instructions); |
| 2338 | uint32_t TotalCodeBytes = PrologCodeBytes; |
| 2339 | |
| 2340 | if (!info->HandlesExceptions && RawFuncLength && FuncLength <= 0x7ff && |
| 2341 | TryPacked) { |
| 2342 | // No exception handlers; check if the prolog and epilog matches the |
| 2343 | // patterns that can be described by the packed format. If we don't |
| 2344 | // know the exact function length yet, we can't do this. |
| 2345 | |
| 2346 | // info->Symbol was already set even if we didn't actually write any |
| 2347 | // unwind info there. Keep using that as indicator that this unwind |
| 2348 | // info has been generated already. |
| 2349 | |
| 2350 | if (tryARMPackedUnwind(streamer, info, FuncLength)) |
| 2351 | return; |
| 2352 | } |
| 2353 | |
| 2354 | int PackedEpilogOffset = |
| 2355 | checkARMPackedEpilog(streamer, info, PrologCodeBytes); |
| 2356 | |
| 2357 | // Process epilogs. |
| 2358 | MapVector<MCSymbol *, uint32_t> EpilogInfo; |
| 2359 | // Epilogs processed so far. |
| 2360 | std::vector<MCSymbol *> AddedEpilogs; |
| 2361 | |
| 2362 | bool CanTweakProlog = true; |
| 2363 | for (auto &I : info->EpilogMap) { |
| 2364 | MCSymbol *EpilogStart = I.first; |
| 2365 | auto &EpilogInstrs = I.second.Instructions; |
| 2366 | uint32_t CodeBytes = ARMCountOfUnwindCodes(EpilogInstrs); |
| 2367 | |
| 2368 | MCSymbol *MatchingEpilog = |
| 2369 | FindMatchingEpilog(EpilogInstrs, AddedEpilogs, info); |
| 2370 | int PrologOffset; |
| 2371 | if (MatchingEpilog) { |
| 2372 | assert(EpilogInfo.contains(MatchingEpilog) &&(static_cast <bool> (EpilogInfo.contains(MatchingEpilog ) && "Duplicate epilog not found") ? void (0) : __assert_fail ("EpilogInfo.contains(MatchingEpilog) && \"Duplicate epilog not found\"" , "llvm/lib/MC/MCWin64EH.cpp", 2373, __extension__ __PRETTY_FUNCTION__ )) |
| 2373 | "Duplicate epilog not found")(static_cast <bool> (EpilogInfo.contains(MatchingEpilog ) && "Duplicate epilog not found") ? void (0) : __assert_fail ("EpilogInfo.contains(MatchingEpilog) && \"Duplicate epilog not found\"" , "llvm/lib/MC/MCWin64EH.cpp", 2373, __extension__ __PRETTY_FUNCTION__ )); |
| 2374 | EpilogInfo[EpilogStart] = EpilogInfo.lookup(MatchingEpilog); |
| 2375 | // Clear the unwind codes in the EpilogMap, so that they don't get output |
| 2376 | // in the logic below. |
| 2377 | EpilogInstrs.clear(); |
| 2378 | } else if ((PrologOffset = getARMOffsetInProlog( |
| 2379 | info->Instructions, EpilogInstrs, CanTweakProlog)) >= 0) { |
| 2380 | if (CanTweakProlog) { |
| 2381 | // Replace the regular end opcode of the prolog with the one from the |
| 2382 | // epilog. |
| 2383 | info->Instructions.front() = EpilogInstrs.back(); |
| 2384 | // Later epilogs need a strict match for the end opcode. |
| 2385 | CanTweakProlog = false; |
| 2386 | } |
| 2387 | EpilogInfo[EpilogStart] = PrologOffset; |
| 2388 | // Clear the unwind codes in the EpilogMap, so that they don't get output |
| 2389 | // in the logic below. |
| 2390 | EpilogInstrs.clear(); |
| 2391 | } else { |
| 2392 | EpilogInfo[EpilogStart] = TotalCodeBytes; |
| 2393 | TotalCodeBytes += CodeBytes; |
| 2394 | AddedEpilogs.push_back(EpilogStart); |
| 2395 | } |
| 2396 | } |
| 2397 | |
| 2398 | // Code Words, Epilog count, F, E, X, Vers, Function Length |
| 2399 | uint32_t row1 = 0x0; |
| 2400 | uint32_t CodeWords = TotalCodeBytes / 4; |
| 2401 | uint32_t CodeWordsMod = TotalCodeBytes % 4; |
| 2402 | if (CodeWordsMod) |
| 2403 | CodeWords++; |
| 2404 | uint32_t EpilogCount = |
| 2405 | PackedEpilogOffset >= 0 ? PackedEpilogOffset : info->EpilogMap.size(); |
| 2406 | bool ExtensionWord = EpilogCount > 31 || CodeWords > 15; |
| 2407 | if (!ExtensionWord) { |
| 2408 | row1 |= (EpilogCount & 0x1F) << 23; |
| 2409 | row1 |= (CodeWords & 0x0F) << 28; |
| 2410 | } |
| 2411 | if (info->HandlesExceptions) // X |
| 2412 | row1 |= 1 << 20; |
| 2413 | if (PackedEpilogOffset >= 0) // E |
| 2414 | row1 |= 1 << 21; |
| 2415 | if (info->Fragment) // F |
| 2416 | row1 |= 1 << 22; |
| 2417 | row1 |= FuncLength & 0x3FFFF; |
| 2418 | if (RawFuncLength) |
| 2419 | streamer.emitInt32(row1); |
| 2420 | else |
| 2421 | streamer.emitValue( |
| 2422 | MCBinaryExpr::createOr(FuncLengthExpr, |
| 2423 | MCConstantExpr::create(row1, context), context), |
| 2424 | 4); |
| 2425 | |
| 2426 | // Extended Code Words, Extended Epilog Count |
| 2427 | if (ExtensionWord) { |
| 2428 | // FIXME: We should be able to split unwind info into multiple sections. |
| 2429 | if (CodeWords > 0xFF || EpilogCount > 0xFFFF) |
| 2430 | report_fatal_error("SEH unwind data splitting not yet implemented"); |
| 2431 | uint32_t row2 = 0x0; |
| 2432 | row2 |= (CodeWords & 0xFF) << 16; |
| 2433 | row2 |= (EpilogCount & 0xFFFF); |
| 2434 | streamer.emitInt32(row2); |
| 2435 | } |
| 2436 | |
| 2437 | if (PackedEpilogOffset < 0) { |
| 2438 | // Epilog Start Index, Epilog Start Offset |
| 2439 | for (auto &I : EpilogInfo) { |
| 2440 | MCSymbol *EpilogStart = I.first; |
| 2441 | uint32_t EpilogIndex = I.second; |
| 2442 | |
| 2443 | std::optional<int64_t> MaybeEpilogOffset = |
| 2444 | GetOptionalAbsDifference(streamer, EpilogStart, info->Begin); |
| 2445 | const MCExpr *OffsetExpr = nullptr; |
| 2446 | uint32_t EpilogOffset = 0; |
| 2447 | if (MaybeEpilogOffset) |
| 2448 | EpilogOffset = *MaybeEpilogOffset / 2; |
| 2449 | else |
| 2450 | OffsetExpr = GetSubDivExpr(streamer, EpilogStart, info->Begin, 2); |
| 2451 | |
| 2452 | assert(info->EpilogMap.contains(EpilogStart))(static_cast <bool> (info->EpilogMap.contains(EpilogStart )) ? void (0) : __assert_fail ("info->EpilogMap.contains(EpilogStart)" , "llvm/lib/MC/MCWin64EH.cpp", 2452, __extension__ __PRETTY_FUNCTION__ )); |
| 2453 | unsigned Condition = info->EpilogMap[EpilogStart].Condition; |
| 2454 | assert(Condition <= 0xf)(static_cast <bool> (Condition <= 0xf) ? void (0) : __assert_fail ("Condition <= 0xf", "llvm/lib/MC/MCWin64EH.cpp", 2454, __extension__ __PRETTY_FUNCTION__)); |
| 2455 | |
| 2456 | uint32_t row3 = EpilogOffset; |
| 2457 | row3 |= Condition << 20; |
| 2458 | row3 |= (EpilogIndex & 0x3FF) << 24; |
| 2459 | if (MaybeEpilogOffset) |
| 2460 | streamer.emitInt32(row3); |
| 2461 | else |
| 2462 | streamer.emitValue( |
| 2463 | MCBinaryExpr::createOr( |
| 2464 | OffsetExpr, MCConstantExpr::create(row3, context), context), |
| 2465 | 4); |
| 2466 | } |
| 2467 | } |
| 2468 | |
| 2469 | // Emit prolog unwind instructions (in reverse order). |
| 2470 | uint8_t numInst = info->Instructions.size(); |
| 2471 | for (uint8_t c = 0; c < numInst; ++c) { |
| 2472 | WinEH::Instruction inst = info->Instructions.back(); |
| 2473 | info->Instructions.pop_back(); |
| 2474 | ARMEmitUnwindCode(streamer, inst); |
| 2475 | } |
| 2476 | |
| 2477 | // Emit epilog unwind instructions |
| 2478 | for (auto &I : info->EpilogMap) { |
| 2479 | auto &EpilogInstrs = I.second.Instructions; |
| 2480 | for (const WinEH::Instruction &inst : EpilogInstrs) |
| 2481 | ARMEmitUnwindCode(streamer, inst); |
| 2482 | } |
| 2483 | |
| 2484 | int32_t BytesMod = CodeWords * 4 - TotalCodeBytes; |
| 2485 | assert(BytesMod >= 0)(static_cast <bool> (BytesMod >= 0) ? void (0) : __assert_fail ("BytesMod >= 0", "llvm/lib/MC/MCWin64EH.cpp", 2485, __extension__ __PRETTY_FUNCTION__)); |
| 2486 | for (int i = 0; i < BytesMod; i++) |
| 2487 | streamer.emitInt8(0xFB); |
| 2488 | |
| 2489 | if (info->HandlesExceptions) |
| 2490 | streamer.emitValue( |
| 2491 | MCSymbolRefExpr::create(info->ExceptionHandler, |
| 2492 | MCSymbolRefExpr::VK_COFF_IMGREL32, context), |
| 2493 | 4); |
| 2494 | } |
| 2495 | |
| 2496 | static void ARM64EmitRuntimeFunction(MCStreamer &streamer, |
| 2497 | const WinEH::FrameInfo *info) { |
| 2498 | MCContext &context = streamer.getContext(); |
| 2499 | |
| 2500 | streamer.emitValueToAlignment(Align(4)); |
| 2501 | for (const auto &S : info->Segments) { |
| 2502 | EmitSymbolRefWithOfs(streamer, info->Begin, S.Offset); |
| 2503 | if (info->PackedInfo) |
| 2504 | streamer.emitInt32(info->PackedInfo); |
| 2505 | else |
| 2506 | streamer.emitValue( |
| 2507 | MCSymbolRefExpr::create(S.Symbol, MCSymbolRefExpr::VK_COFF_IMGREL32, |
| 2508 | context), |
| 2509 | 4); |
| 2510 | } |
| 2511 | } |
| 2512 | |
| 2513 | |
| 2514 | static void ARMEmitRuntimeFunction(MCStreamer &streamer, |
| 2515 | const WinEH::FrameInfo *info) { |
| 2516 | MCContext &context = streamer.getContext(); |
| 2517 | |
| 2518 | streamer.emitValueToAlignment(Align(4)); |
| 2519 | EmitSymbolRefWithOfs(streamer, info->Begin, info->Begin); |
| 2520 | if (info->PackedInfo) |
| 2521 | streamer.emitInt32(info->PackedInfo); |
| 2522 | else |
| 2523 | streamer.emitValue( |
| 2524 | MCSymbolRefExpr::create(info->Symbol, MCSymbolRefExpr::VK_COFF_IMGREL32, |
| 2525 | context), |
| 2526 | 4); |
| 2527 | } |
| 2528 | |
| 2529 | void llvm::Win64EH::ARM64UnwindEmitter::Emit(MCStreamer &Streamer) const { |
| 2530 | // Emit the unwind info structs first. |
| 2531 | for (const auto &CFI : Streamer.getWinFrameInfos()) { |
| 2532 | WinEH::FrameInfo *Info = CFI.get(); |
| 2533 | if (Info->empty()) |
| 2534 | continue; |
| 2535 | MCSection *XData = Streamer.getAssociatedXDataSection(CFI->TextSection); |
| 2536 | Streamer.switchSection(XData); |
| 2537 | ARM64EmitUnwindInfo(Streamer, Info); |
| 2538 | } |
| 2539 | |
| 2540 | // Now emit RUNTIME_FUNCTION entries. |
| 2541 | for (const auto &CFI : Streamer.getWinFrameInfos()) { |
| 2542 | WinEH::FrameInfo *Info = CFI.get(); |
| 2543 | // ARM64EmitUnwindInfo above clears the info struct, so we can't check |
| 2544 | // empty here. But if a Symbol is set, we should create the corresponding |
| 2545 | // pdata entry. |
| 2546 | if (!Info->Symbol) |
| 2547 | continue; |
| 2548 | MCSection *PData = Streamer.getAssociatedPDataSection(CFI->TextSection); |
| 2549 | Streamer.switchSection(PData); |
| 2550 | ARM64EmitRuntimeFunction(Streamer, Info); |
| 2551 | } |
| 2552 | } |
| 2553 | |
| 2554 | void llvm::Win64EH::ARM64UnwindEmitter::EmitUnwindInfo(MCStreamer &Streamer, |
| 2555 | WinEH::FrameInfo *info, |
| 2556 | bool HandlerData) const { |
| 2557 | // Called if there's an .seh_handlerdata directive before the end of the |
| 2558 | // function. This forces writing the xdata record already here - and |
| 2559 | // in this case, the function isn't actually ended already, but the xdata |
| 2560 | // record needs to know the function length. In these cases, if the funclet |
| 2561 | // end hasn't been marked yet, the xdata function length won't cover the |
| 2562 | // whole function, only up to this point. |
| 2563 | if (!info->FuncletOrFuncEnd) { |
| 2564 | Streamer.switchSection(info->TextSection); |
| 2565 | info->FuncletOrFuncEnd = Streamer.emitCFILabel(); |
| 2566 | } |
| 2567 | // Switch sections (the static function above is meant to be called from |
| 2568 | // here and from Emit(). |
| 2569 | MCSection *XData = Streamer.getAssociatedXDataSection(info->TextSection); |
| 2570 | Streamer.switchSection(XData); |
| 2571 | ARM64EmitUnwindInfo(Streamer, info, /* TryPacked = */ !HandlerData); |
| 2572 | } |
| 2573 | |
| 2574 | void llvm::Win64EH::ARMUnwindEmitter::Emit(MCStreamer &Streamer) const { |
| 2575 | // Emit the unwind info structs first. |
| 2576 | for (const auto &CFI : Streamer.getWinFrameInfos()) { |
| 2577 | WinEH::FrameInfo *Info = CFI.get(); |
| 2578 | if (Info->empty()) |
| 2579 | continue; |
| 2580 | MCSection *XData = Streamer.getAssociatedXDataSection(CFI->TextSection); |
| 2581 | Streamer.switchSection(XData); |
| 2582 | ARMEmitUnwindInfo(Streamer, Info); |
| 2583 | } |
| 2584 | |
| 2585 | // Now emit RUNTIME_FUNCTION entries. |
| 2586 | for (const auto &CFI : Streamer.getWinFrameInfos()) { |
| 2587 | WinEH::FrameInfo *Info = CFI.get(); |
| 2588 | // ARMEmitUnwindInfo above clears the info struct, so we can't check |
| 2589 | // empty here. But if a Symbol is set, we should create the corresponding |
| 2590 | // pdata entry. |
| 2591 | if (!Info->Symbol) |
| 2592 | continue; |
| 2593 | MCSection *PData = Streamer.getAssociatedPDataSection(CFI->TextSection); |
| 2594 | Streamer.switchSection(PData); |
| 2595 | ARMEmitRuntimeFunction(Streamer, Info); |
| 2596 | } |
| 2597 | } |
| 2598 | |
| 2599 | void llvm::Win64EH::ARMUnwindEmitter::EmitUnwindInfo(MCStreamer &Streamer, |
| 2600 | WinEH::FrameInfo *info, |
| 2601 | bool HandlerData) const { |
| 2602 | // Called if there's an .seh_handlerdata directive before the end of the |
| 2603 | // function. This forces writing the xdata record already here - and |
| 2604 | // in this case, the function isn't actually ended already, but the xdata |
| 2605 | // record needs to know the function length. In these cases, if the funclet |
| 2606 | // end hasn't been marked yet, the xdata function length won't cover the |
| 2607 | // whole function, only up to this point. |
| 2608 | if (!info->FuncletOrFuncEnd) { |
| 2609 | Streamer.switchSection(info->TextSection); |
| 2610 | info->FuncletOrFuncEnd = Streamer.emitCFILabel(); |
| 2611 | } |
| 2612 | // Switch sections (the static function above is meant to be called from |
| 2613 | // here and from Emit(). |
| 2614 | MCSection *XData = Streamer.getAssociatedXDataSection(info->TextSection); |
| 2615 | Streamer.switchSection(XData); |
| 2616 | ARMEmitUnwindInfo(Streamer, info, /* TryPacked = */ !HandlerData); |
| 2617 | } |