John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 1 | //===-- CGCleanup.h - Classes for cleanups IR generation --------*- C++ -*-===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // These classes support the generation of LLVM IR for cleanups. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
| 14 | #ifndef CLANG_CODEGEN_CGCLEANUP_H |
| 15 | #define CLANG_CODEGEN_CGCLEANUP_H |
| 16 | |
| 17 | /// EHScopeStack is defined in CodeGenFunction.h, but its |
| 18 | /// implementation is in this file and in CGCleanup.cpp. |
| 19 | #include "CodeGenFunction.h" |
| 20 | |
| 21 | namespace llvm { |
| 22 | class Value; |
| 23 | class BasicBlock; |
| 24 | } |
| 25 | |
| 26 | namespace clang { |
| 27 | namespace CodeGen { |
| 28 | |
| 29 | /// A protected scope for zero-cost EH handling. |
| 30 | class EHScope { |
| 31 | llvm::BasicBlock *CachedLandingPad; |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 32 | llvm::BasicBlock *CachedEHDispatchBlock; |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 33 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 34 | EHScopeStack::stable_iterator EnclosingEHScope; |
| 35 | |
| 36 | class CommonBitFields { |
| 37 | friend class EHScope; |
| 38 | unsigned Kind : 2; |
| 39 | }; |
| 40 | enum { NumCommonBits = 2 }; |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 41 | |
| 42 | protected: |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 43 | class CatchBitFields { |
| 44 | friend class EHCatchScope; |
| 45 | unsigned : NumCommonBits; |
| 46 | |
| 47 | unsigned NumHandlers : 32 - NumCommonBits; |
| 48 | }; |
| 49 | |
| 50 | class CleanupBitFields { |
| 51 | friend class EHCleanupScope; |
| 52 | unsigned : NumCommonBits; |
| 53 | |
| 54 | /// Whether this cleanup needs to be run along normal edges. |
| 55 | unsigned IsNormalCleanup : 1; |
| 56 | |
| 57 | /// Whether this cleanup needs to be run along exception edges. |
| 58 | unsigned IsEHCleanup : 1; |
| 59 | |
| 60 | /// Whether this cleanup is currently active. |
| 61 | unsigned IsActive : 1; |
| 62 | |
| 63 | /// Whether the normal cleanup should test the activation flag. |
| 64 | unsigned TestFlagInNormalCleanup : 1; |
| 65 | |
| 66 | /// Whether the EH cleanup should test the activation flag. |
| 67 | unsigned TestFlagInEHCleanup : 1; |
| 68 | |
| 69 | /// The amount of extra storage needed by the Cleanup. |
| 70 | /// Always a multiple of the scope-stack alignment. |
| 71 | unsigned CleanupSize : 12; |
| 72 | |
| 73 | /// The number of fixups required by enclosing scopes (not including |
| 74 | /// this one). If this is the top cleanup scope, all the fixups |
| 75 | /// from this index onwards belong to this scope. |
| 76 | unsigned FixupDepth : 32 - 17 - NumCommonBits; // currently 13 |
| 77 | }; |
| 78 | |
| 79 | class FilterBitFields { |
| 80 | friend class EHFilterScope; |
| 81 | unsigned : NumCommonBits; |
| 82 | |
| 83 | unsigned NumFilters : 32 - NumCommonBits; |
| 84 | }; |
| 85 | |
| 86 | union { |
| 87 | CommonBitFields CommonBits; |
| 88 | CatchBitFields CatchBits; |
| 89 | CleanupBitFields CleanupBits; |
| 90 | FilterBitFields FilterBits; |
| 91 | }; |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 92 | |
| 93 | public: |
| 94 | enum Kind { Cleanup, Catch, Terminate, Filter }; |
| 95 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 96 | EHScope(Kind kind, EHScopeStack::stable_iterator enclosingEHScope) |
| 97 | : CachedLandingPad(0), CachedEHDispatchBlock(0), |
| 98 | EnclosingEHScope(enclosingEHScope) { |
| 99 | CommonBits.Kind = kind; |
| 100 | } |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 101 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 102 | Kind getKind() const { return static_cast<Kind>(CommonBits.Kind); } |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 103 | |
| 104 | llvm::BasicBlock *getCachedLandingPad() const { |
| 105 | return CachedLandingPad; |
| 106 | } |
| 107 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 108 | void setCachedLandingPad(llvm::BasicBlock *block) { |
| 109 | CachedLandingPad = block; |
| 110 | } |
| 111 | |
| 112 | llvm::BasicBlock *getCachedEHDispatchBlock() const { |
| 113 | return CachedEHDispatchBlock; |
| 114 | } |
| 115 | |
| 116 | void setCachedEHDispatchBlock(llvm::BasicBlock *block) { |
| 117 | CachedEHDispatchBlock = block; |
| 118 | } |
| 119 | |
| 120 | bool hasEHBranches() const { |
| 121 | if (llvm::BasicBlock *block = getCachedEHDispatchBlock()) |
| 122 | return !block->use_empty(); |
| 123 | return false; |
| 124 | } |
| 125 | |
| 126 | EHScopeStack::stable_iterator getEnclosingEHScope() const { |
| 127 | return EnclosingEHScope; |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 128 | } |
| 129 | }; |
| 130 | |
| 131 | /// A scope which attempts to handle some, possibly all, types of |
| 132 | /// exceptions. |
| 133 | /// |
James Dennett | 2ee5ba3 | 2012-06-15 22:10:14 +0000 | [diff] [blame] | 134 | /// Objective C \@finally blocks are represented using a cleanup scope |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 135 | /// after the catch scope. |
| 136 | class EHCatchScope : public EHScope { |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 137 | // In effect, we have a flexible array member |
| 138 | // Handler Handlers[0]; |
| 139 | // But that's only standard in C99, not C++, so we have to do |
| 140 | // annoying pointer arithmetic instead. |
| 141 | |
| 142 | public: |
| 143 | struct Handler { |
| 144 | /// A type info value, or null (C++ null, not an LLVM null pointer) |
| 145 | /// for a catch-all. |
| 146 | llvm::Value *Type; |
| 147 | |
| 148 | /// The catch handler for this type. |
| 149 | llvm::BasicBlock *Block; |
| 150 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 151 | bool isCatchAll() const { return Type == 0; } |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 152 | }; |
| 153 | |
| 154 | private: |
| 155 | friend class EHScopeStack; |
| 156 | |
| 157 | Handler *getHandlers() { |
| 158 | return reinterpret_cast<Handler*>(this+1); |
| 159 | } |
| 160 | |
| 161 | const Handler *getHandlers() const { |
| 162 | return reinterpret_cast<const Handler*>(this+1); |
| 163 | } |
| 164 | |
| 165 | public: |
| 166 | static size_t getSizeForNumHandlers(unsigned N) { |
| 167 | return sizeof(EHCatchScope) + N * sizeof(Handler); |
| 168 | } |
| 169 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 170 | EHCatchScope(unsigned numHandlers, |
| 171 | EHScopeStack::stable_iterator enclosingEHScope) |
| 172 | : EHScope(Catch, enclosingEHScope) { |
| 173 | CatchBits.NumHandlers = numHandlers; |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 174 | } |
| 175 | |
| 176 | unsigned getNumHandlers() const { |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 177 | return CatchBits.NumHandlers; |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 178 | } |
| 179 | |
| 180 | void setCatchAllHandler(unsigned I, llvm::BasicBlock *Block) { |
| 181 | setHandler(I, /*catchall*/ 0, Block); |
| 182 | } |
| 183 | |
| 184 | void setHandler(unsigned I, llvm::Value *Type, llvm::BasicBlock *Block) { |
| 185 | assert(I < getNumHandlers()); |
| 186 | getHandlers()[I].Type = Type; |
| 187 | getHandlers()[I].Block = Block; |
| 188 | } |
| 189 | |
| 190 | const Handler &getHandler(unsigned I) const { |
| 191 | assert(I < getNumHandlers()); |
| 192 | return getHandlers()[I]; |
| 193 | } |
| 194 | |
| 195 | typedef const Handler *iterator; |
| 196 | iterator begin() const { return getHandlers(); } |
| 197 | iterator end() const { return getHandlers() + getNumHandlers(); } |
| 198 | |
| 199 | static bool classof(const EHScope *Scope) { |
| 200 | return Scope->getKind() == Catch; |
| 201 | } |
| 202 | }; |
| 203 | |
| 204 | /// A cleanup scope which generates the cleanup blocks lazily. |
| 205 | class EHCleanupScope : public EHScope { |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 206 | /// The nearest normal cleanup scope enclosing this one. |
| 207 | EHScopeStack::stable_iterator EnclosingNormal; |
| 208 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 209 | /// The nearest EH scope enclosing this one. |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 210 | EHScopeStack::stable_iterator EnclosingEH; |
| 211 | |
| 212 | /// The dual entry/exit block along the normal edge. This is lazily |
| 213 | /// created if needed before the cleanup is popped. |
| 214 | llvm::BasicBlock *NormalBlock; |
| 215 | |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 216 | /// An optional i1 variable indicating whether this cleanup has been |
| 217 | /// activated yet. |
| 218 | llvm::AllocaInst *ActiveFlag; |
| 219 | |
| 220 | /// Extra information required for cleanups that have resolved |
| 221 | /// branches through them. This has to be allocated on the side |
| 222 | /// because everything on the cleanup stack has be trivially |
| 223 | /// movable. |
| 224 | struct ExtInfo { |
| 225 | /// The destinations of normal branch-afters and branch-throughs. |
| 226 | llvm::SmallPtrSet<llvm::BasicBlock*, 4> Branches; |
| 227 | |
| 228 | /// Normal branch-afters. |
Chris Lattner | 686775d | 2011-07-20 06:58:45 +0000 | [diff] [blame] | 229 | SmallVector<std::pair<llvm::BasicBlock*,llvm::ConstantInt*>, 4> |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 230 | BranchAfters; |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 231 | }; |
| 232 | mutable struct ExtInfo *ExtInfo; |
| 233 | |
| 234 | struct ExtInfo &getExtInfo() { |
| 235 | if (!ExtInfo) ExtInfo = new struct ExtInfo(); |
| 236 | return *ExtInfo; |
| 237 | } |
| 238 | |
| 239 | const struct ExtInfo &getExtInfo() const { |
| 240 | if (!ExtInfo) ExtInfo = new struct ExtInfo(); |
| 241 | return *ExtInfo; |
| 242 | } |
| 243 | |
| 244 | public: |
| 245 | /// Gets the size required for a lazy cleanup scope with the given |
| 246 | /// cleanup-data requirements. |
| 247 | static size_t getSizeForCleanupSize(size_t Size) { |
| 248 | return sizeof(EHCleanupScope) + Size; |
| 249 | } |
| 250 | |
| 251 | size_t getAllocatedSize() const { |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 252 | return sizeof(EHCleanupScope) + CleanupBits.CleanupSize; |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 253 | } |
| 254 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 255 | EHCleanupScope(bool isNormal, bool isEH, bool isActive, |
| 256 | unsigned cleanupSize, unsigned fixupDepth, |
| 257 | EHScopeStack::stable_iterator enclosingNormal, |
| 258 | EHScopeStack::stable_iterator enclosingEH) |
| 259 | : EHScope(EHScope::Cleanup, enclosingEH), EnclosingNormal(enclosingNormal), |
| 260 | NormalBlock(0), ActiveFlag(0), ExtInfo(0) { |
| 261 | CleanupBits.IsNormalCleanup = isNormal; |
| 262 | CleanupBits.IsEHCleanup = isEH; |
| 263 | CleanupBits.IsActive = isActive; |
| 264 | CleanupBits.TestFlagInNormalCleanup = false; |
| 265 | CleanupBits.TestFlagInEHCleanup = false; |
| 266 | CleanupBits.CleanupSize = cleanupSize; |
| 267 | CleanupBits.FixupDepth = fixupDepth; |
| 268 | |
| 269 | assert(CleanupBits.CleanupSize == cleanupSize && "cleanup size overflow"); |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 270 | } |
| 271 | |
| 272 | ~EHCleanupScope() { |
| 273 | delete ExtInfo; |
| 274 | } |
| 275 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 276 | bool isNormalCleanup() const { return CleanupBits.IsNormalCleanup; } |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 277 | llvm::BasicBlock *getNormalBlock() const { return NormalBlock; } |
| 278 | void setNormalBlock(llvm::BasicBlock *BB) { NormalBlock = BB; } |
| 279 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 280 | bool isEHCleanup() const { return CleanupBits.IsEHCleanup; } |
| 281 | llvm::BasicBlock *getEHBlock() const { return getCachedEHDispatchBlock(); } |
| 282 | void setEHBlock(llvm::BasicBlock *BB) { setCachedEHDispatchBlock(BB); } |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 283 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 284 | bool isActive() const { return CleanupBits.IsActive; } |
| 285 | void setActive(bool A) { CleanupBits.IsActive = A; } |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 286 | |
| 287 | llvm::AllocaInst *getActiveFlag() const { return ActiveFlag; } |
| 288 | void setActiveFlag(llvm::AllocaInst *Var) { ActiveFlag = Var; } |
| 289 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 290 | void setTestFlagInNormalCleanup() { |
| 291 | CleanupBits.TestFlagInNormalCleanup = true; |
| 292 | } |
| 293 | bool shouldTestFlagInNormalCleanup() const { |
| 294 | return CleanupBits.TestFlagInNormalCleanup; |
| 295 | } |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 296 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 297 | void setTestFlagInEHCleanup() { |
| 298 | CleanupBits.TestFlagInEHCleanup = true; |
| 299 | } |
| 300 | bool shouldTestFlagInEHCleanup() const { |
| 301 | return CleanupBits.TestFlagInEHCleanup; |
| 302 | } |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 303 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 304 | unsigned getFixupDepth() const { return CleanupBits.FixupDepth; } |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 305 | EHScopeStack::stable_iterator getEnclosingNormalCleanup() const { |
| 306 | return EnclosingNormal; |
| 307 | } |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 308 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 309 | size_t getCleanupSize() const { return CleanupBits.CleanupSize; } |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 310 | void *getCleanupBuffer() { return this + 1; } |
| 311 | |
| 312 | EHScopeStack::Cleanup *getCleanup() { |
| 313 | return reinterpret_cast<EHScopeStack::Cleanup*>(getCleanupBuffer()); |
| 314 | } |
| 315 | |
| 316 | /// True if this cleanup scope has any branch-afters or branch-throughs. |
| 317 | bool hasBranches() const { return ExtInfo && !ExtInfo->Branches.empty(); } |
| 318 | |
| 319 | /// Add a branch-after to this cleanup scope. A branch-after is a |
| 320 | /// branch from a point protected by this (normal) cleanup to a |
| 321 | /// point in the normal cleanup scope immediately containing it. |
| 322 | /// For example, |
| 323 | /// for (;;) { A a; break; } |
| 324 | /// contains a branch-after. |
| 325 | /// |
| 326 | /// Branch-afters each have their own destination out of the |
| 327 | /// cleanup, guaranteed distinct from anything else threaded through |
| 328 | /// it. Therefore branch-afters usually force a switch after the |
| 329 | /// cleanup. |
| 330 | void addBranchAfter(llvm::ConstantInt *Index, |
| 331 | llvm::BasicBlock *Block) { |
| 332 | struct ExtInfo &ExtInfo = getExtInfo(); |
| 333 | if (ExtInfo.Branches.insert(Block)) |
| 334 | ExtInfo.BranchAfters.push_back(std::make_pair(Block, Index)); |
| 335 | } |
| 336 | |
| 337 | /// Return the number of unique branch-afters on this scope. |
| 338 | unsigned getNumBranchAfters() const { |
| 339 | return ExtInfo ? ExtInfo->BranchAfters.size() : 0; |
| 340 | } |
| 341 | |
| 342 | llvm::BasicBlock *getBranchAfterBlock(unsigned I) const { |
| 343 | assert(I < getNumBranchAfters()); |
| 344 | return ExtInfo->BranchAfters[I].first; |
| 345 | } |
| 346 | |
| 347 | llvm::ConstantInt *getBranchAfterIndex(unsigned I) const { |
| 348 | assert(I < getNumBranchAfters()); |
| 349 | return ExtInfo->BranchAfters[I].second; |
| 350 | } |
| 351 | |
| 352 | /// Add a branch-through to this cleanup scope. A branch-through is |
| 353 | /// a branch from a scope protected by this (normal) cleanup to an |
| 354 | /// enclosing scope other than the immediately-enclosing normal |
| 355 | /// cleanup scope. |
| 356 | /// |
| 357 | /// In the following example, the branch through B's scope is a |
| 358 | /// branch-through, while the branch through A's scope is a |
| 359 | /// branch-after: |
| 360 | /// for (;;) { A a; B b; break; } |
| 361 | /// |
| 362 | /// All branch-throughs have a common destination out of the |
| 363 | /// cleanup, one possibly shared with the fall-through. Therefore |
| 364 | /// branch-throughs usually don't force a switch after the cleanup. |
| 365 | /// |
| 366 | /// \return true if the branch-through was new to this scope |
| 367 | bool addBranchThrough(llvm::BasicBlock *Block) { |
| 368 | return getExtInfo().Branches.insert(Block); |
| 369 | } |
| 370 | |
| 371 | /// Determines if this cleanup scope has any branch throughs. |
| 372 | bool hasBranchThroughs() const { |
| 373 | if (!ExtInfo) return false; |
| 374 | return (ExtInfo->BranchAfters.size() != ExtInfo->Branches.size()); |
| 375 | } |
| 376 | |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 377 | static bool classof(const EHScope *Scope) { |
| 378 | return (Scope->getKind() == Cleanup); |
| 379 | } |
| 380 | }; |
| 381 | |
| 382 | /// An exceptions scope which filters exceptions thrown through it. |
| 383 | /// Only exceptions matching the filter types will be permitted to be |
| 384 | /// thrown. |
| 385 | /// |
| 386 | /// This is used to implement C++ exception specifications. |
| 387 | class EHFilterScope : public EHScope { |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 388 | // Essentially ends in a flexible array member: |
| 389 | // llvm::Value *FilterTypes[0]; |
| 390 | |
| 391 | llvm::Value **getFilters() { |
| 392 | return reinterpret_cast<llvm::Value**>(this+1); |
| 393 | } |
| 394 | |
| 395 | llvm::Value * const *getFilters() const { |
| 396 | return reinterpret_cast<llvm::Value* const *>(this+1); |
| 397 | } |
| 398 | |
| 399 | public: |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 400 | EHFilterScope(unsigned numFilters) |
| 401 | : EHScope(Filter, EHScopeStack::stable_end()) { |
| 402 | FilterBits.NumFilters = numFilters; |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 403 | } |
| 404 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 405 | static size_t getSizeForNumFilters(unsigned numFilters) { |
| 406 | return sizeof(EHFilterScope) + numFilters * sizeof(llvm::Value*); |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 407 | } |
| 408 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 409 | unsigned getNumFilters() const { return FilterBits.NumFilters; } |
| 410 | |
| 411 | void setFilter(unsigned i, llvm::Value *filterValue) { |
| 412 | assert(i < getNumFilters()); |
| 413 | getFilters()[i] = filterValue; |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 414 | } |
| 415 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 416 | llvm::Value *getFilter(unsigned i) const { |
| 417 | assert(i < getNumFilters()); |
| 418 | return getFilters()[i]; |
| 419 | } |
| 420 | |
| 421 | static bool classof(const EHScope *scope) { |
| 422 | return scope->getKind() == Filter; |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 423 | } |
| 424 | }; |
| 425 | |
| 426 | /// An exceptions scope which calls std::terminate if any exception |
| 427 | /// reaches it. |
| 428 | class EHTerminateScope : public EHScope { |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 429 | public: |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 430 | EHTerminateScope(EHScopeStack::stable_iterator enclosingEHScope) |
| 431 | : EHScope(Terminate, enclosingEHScope) {} |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 432 | static size_t getSize() { return sizeof(EHTerminateScope); } |
| 433 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 434 | static bool classof(const EHScope *scope) { |
| 435 | return scope->getKind() == Terminate; |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 436 | } |
| 437 | }; |
| 438 | |
| 439 | /// A non-stable pointer into the scope stack. |
| 440 | class EHScopeStack::iterator { |
| 441 | char *Ptr; |
| 442 | |
| 443 | friend class EHScopeStack; |
| 444 | explicit iterator(char *Ptr) : Ptr(Ptr) {} |
| 445 | |
| 446 | public: |
| 447 | iterator() : Ptr(0) {} |
| 448 | |
| 449 | EHScope *get() const { |
| 450 | return reinterpret_cast<EHScope*>(Ptr); |
| 451 | } |
| 452 | |
| 453 | EHScope *operator->() const { return get(); } |
| 454 | EHScope &operator*() const { return *get(); } |
| 455 | |
| 456 | iterator &operator++() { |
| 457 | switch (get()->getKind()) { |
| 458 | case EHScope::Catch: |
| 459 | Ptr += EHCatchScope::getSizeForNumHandlers( |
| 460 | static_cast<const EHCatchScope*>(get())->getNumHandlers()); |
| 461 | break; |
| 462 | |
| 463 | case EHScope::Filter: |
| 464 | Ptr += EHFilterScope::getSizeForNumFilters( |
| 465 | static_cast<const EHFilterScope*>(get())->getNumFilters()); |
| 466 | break; |
| 467 | |
| 468 | case EHScope::Cleanup: |
| 469 | Ptr += static_cast<const EHCleanupScope*>(get()) |
| 470 | ->getAllocatedSize(); |
| 471 | break; |
| 472 | |
| 473 | case EHScope::Terminate: |
| 474 | Ptr += EHTerminateScope::getSize(); |
| 475 | break; |
| 476 | } |
| 477 | |
| 478 | return *this; |
| 479 | } |
| 480 | |
| 481 | iterator next() { |
| 482 | iterator copy = *this; |
| 483 | ++copy; |
| 484 | return copy; |
| 485 | } |
| 486 | |
| 487 | iterator operator++(int) { |
| 488 | iterator copy = *this; |
| 489 | operator++(); |
| 490 | return copy; |
| 491 | } |
| 492 | |
| 493 | bool encloses(iterator other) const { return Ptr >= other.Ptr; } |
| 494 | bool strictlyEncloses(iterator other) const { return Ptr > other.Ptr; } |
| 495 | |
| 496 | bool operator==(iterator other) const { return Ptr == other.Ptr; } |
| 497 | bool operator!=(iterator other) const { return Ptr != other.Ptr; } |
| 498 | }; |
| 499 | |
| 500 | inline EHScopeStack::iterator EHScopeStack::begin() const { |
| 501 | return iterator(StartOfData); |
| 502 | } |
| 503 | |
| 504 | inline EHScopeStack::iterator EHScopeStack::end() const { |
| 505 | return iterator(EndOfBuffer); |
| 506 | } |
| 507 | |
| 508 | inline void EHScopeStack::popCatch() { |
| 509 | assert(!empty() && "popping exception stack when not empty"); |
| 510 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 511 | EHCatchScope &scope = cast<EHCatchScope>(*begin()); |
| 512 | InnermostEHScope = scope.getEnclosingEHScope(); |
| 513 | StartOfData += EHCatchScope::getSizeForNumHandlers(scope.getNumHandlers()); |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 514 | } |
| 515 | |
| 516 | inline void EHScopeStack::popTerminate() { |
| 517 | assert(!empty() && "popping exception stack when not empty"); |
| 518 | |
John McCall | 777d6e5 | 2011-08-11 02:22:43 +0000 | [diff] [blame] | 519 | EHTerminateScope &scope = cast<EHTerminateScope>(*begin()); |
| 520 | InnermostEHScope = scope.getEnclosingEHScope(); |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 521 | StartOfData += EHTerminateScope::getSize(); |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 522 | } |
| 523 | |
| 524 | inline EHScopeStack::iterator EHScopeStack::find(stable_iterator sp) const { |
| 525 | assert(sp.isValid() && "finding invalid savepoint"); |
| 526 | assert(sp.Size <= stable_begin().Size && "finding savepoint after pop"); |
| 527 | return iterator(EndOfBuffer - sp.Size); |
| 528 | } |
| 529 | |
| 530 | inline EHScopeStack::stable_iterator |
| 531 | EHScopeStack::stabilize(iterator ir) const { |
| 532 | assert(StartOfData <= ir.Ptr && ir.Ptr <= EndOfBuffer); |
| 533 | return stable_iterator(EndOfBuffer - ir.Ptr); |
| 534 | } |
| 535 | |
John McCall | 36f893c | 2011-01-28 11:13:47 +0000 | [diff] [blame] | 536 | } |
| 537 | } |
| 538 | |
| 539 | #endif |