examples/ExceptionDemo/ExceptionDemo.cpp

   1 //===-- ExceptionDemo.cpp - An example using llvm Exceptions --------------===//
   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 // Demo program which implements an example LLVM exception implementation, and
  11 // shows several test cases including the handling of foreign exceptions.
  12 // It is run with type info types arguments to throw. A test will
  13 // be run for each given type info type. While type info types with the value
  14 // of -1 will trigger a foreign C++ exception to be thrown; type info types
  15 // <= 6 and >= 1 will cause the associated generated exceptions to be thrown
  16 // and caught by generated test functions; and type info types > 6
  17 // will result in exceptions which pass through to the test harness. All other
  18 // type info types are not supported and could cause a crash. In all cases,
  19 // the "finally" blocks of every generated test functions will executed
  20 // regardless of whether or not that test function ignores or catches the
  21 // thrown exception.
  22 //
  23 // examples:
  24 //
  25 // ExceptionDemo
  26 //
  27 //     causes a usage to be printed to stderr
  28 //
  29 // ExceptionDemo 2 3 7 -1
  30 //
  31 //     results in the following cases:
  32 //         - Value 2 causes an exception with a type info type of 2 to be
  33 //           thrown and caught by an inner generated test function.
  34 //         - Value 3 causes an exception with a type info type of 3 to be
  35 //           thrown and caught by an outer generated test function.
  36 //         - Value 7 causes an exception with a type info type of 7 to be
  37 //           thrown and NOT be caught by any generated function.
  38 //         - Value -1 causes a foreign C++ exception to be thrown and not be
  39 //           caught by any generated function
  40 //
  41 //     Cases -1 and 7 are caught by a C++ test harness where the validity of
  42 //         of a C++ catch(...) clause catching a generated exception with a
  43 //         type info type of 7 is questionable.
  44 //
  45 // This code uses code from the llvm compiler-rt project and the llvm
  46 // Kaleidoscope project.
  47 //
  48 //===----------------------------------------------------------------------===//
  49
  50 #include "llvm/LLVMContext.h"
  51 #include "llvm/DerivedTypes.h"
  52 #include "llvm/ExecutionEngine/ExecutionEngine.h"
  53 #include "llvm/ExecutionEngine/JIT.h"
  54 #include "llvm/Module.h"
  55 #include "llvm/PassManager.h"
  56 #include "llvm/Intrinsics.h"
  57 #include "llvm/Analysis/Verifier.h"
  58 #include "llvm/Target/TargetData.h"
  59 #include "llvm/Target/TargetOptions.h"
  60 #include "llvm/Transforms/Scalar.h"
  61 #include "llvm/Support/IRBuilder.h"
  62 #include "llvm/Support/Dwarf.h"
  63 #include "llvm/Support/TargetSelect.h"
  64
  65 #ifdef OLD_EXC_SYSTEM
  66 // See use of UpgradeExceptionHandling(...) below
  67 #include "llvm/AutoUpgrade.h"
  68 #endif
  69
  70 // FIXME: Although all systems tested with (Linux, OS X), do not need this
  71 //        header file included. A user on ubuntu reported, undefined symbols
  72 //        for stderr, and fprintf, and the addition of this include fixed the
  73 //        issue for them. Given that LLVM's best practices include the goal
  74 //        of reducing the number of redundant header files included, the
  75 //        correct solution would be to find out why these symbols are not
  76 //        defined for the system in question, and fix the issue by finding out
  77 //        which LLVM header file, if any, would include these symbols.
  78 #include <cstdio>
  79
  80 #include <sstream>
  81 #include <stdexcept>
  82
  83
  84 #ifndef USE_GLOBAL_STR_CONSTS
  85 #define USE_GLOBAL_STR_CONSTS true
  86 #endif
  87
  88 // System C++ ABI unwind types from:
  89 //     http://refspecs.freestandards.org/abi-eh-1.21.html
  90
  91 extern "C" {
  92
  93   typedef enum {
  94     _URC_NO_REASON = 0,
  95     _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
  96     _URC_FATAL_PHASE2_ERROR = 2,
  97     _URC_FATAL_PHASE1_ERROR = 3,
  98     _URC_NORMAL_STOP = 4,
  99     _URC_END_OF_STACK = 5,
 100     _URC_HANDLER_FOUND = 6,
 101     _URC_INSTALL_CONTEXT = 7,
 102     _URC_CONTINUE_UNWIND = 8
 103   } _Unwind_Reason_Code;
 104
 105   typedef enum {
 106     _UA_SEARCH_PHASE = 1,
 107     _UA_CLEANUP_PHASE = 2,
 108     _UA_HANDLER_FRAME = 4,
 109     _UA_FORCE_UNWIND = 8,
 110     _UA_END_OF_STACK = 16
 111   } _Unwind_Action;
 112
 113   struct _Unwind_Exception;
 114
 115   typedef void (*_Unwind_Exception_Cleanup_Fn) (_Unwind_Reason_Code,
 116                                                 struct _Unwind_Exception *);
 117
 118   struct _Unwind_Exception {
 119     uint64_t exception_class;
 120     _Unwind_Exception_Cleanup_Fn exception_cleanup;
 121
 122     uintptr_t private_1;
 123     uintptr_t private_2;
 124
 125     // @@@ The IA-64 ABI says that this structure must be double-word aligned.
 126     //  Taking that literally does not make much sense generically.  Instead
 127     //  we provide the maximum alignment required by any type for the machine.
 128   } __attribute__((__aligned__));
 129
 130   struct _Unwind_Context;
 131   typedef struct _Unwind_Context *_Unwind_Context_t;
 132
 133   extern const uint8_t *_Unwind_GetLanguageSpecificData (_Unwind_Context_t c);
 134   extern uintptr_t _Unwind_GetGR (_Unwind_Context_t c, int i);
 135   extern void _Unwind_SetGR (_Unwind_Context_t c, int i, uintptr_t n);
 136   extern void _Unwind_SetIP (_Unwind_Context_t, uintptr_t new_value);
 137   extern uintptr_t _Unwind_GetIP (_Unwind_Context_t context);
 138   extern uintptr_t _Unwind_GetRegionStart (_Unwind_Context_t context);
 139
 140 } // extern "C"
 141
 142 //
 143 // Example types
 144 //
 145
 146 /// This is our simplistic type info
 147 struct OurExceptionType_t {
 148   /// type info type
 149   int type;
 150 };
 151
 152
 153 /// This is our Exception class which relies on a negative offset to calculate
 154 /// pointers to its instances from pointers to its unwindException member.
 155 ///
 156 /// Note: The above unwind.h defines struct _Unwind_Exception to be aligned
 157 ///       on a double word boundary. This is necessary to match the standard:
 158 ///       http://refspecs.freestandards.org/abi-eh-1.21.html
 159 struct OurBaseException_t {
 160   struct OurExceptionType_t type;
 161
 162   // Note: This is properly aligned in unwind.h
 163   struct _Unwind_Exception unwindException;
 164 };
 165
 166
 167 // Note: Not needed since we are C++
 168 typedef struct OurBaseException_t OurException;
 169 typedef struct _Unwind_Exception OurUnwindException;
 170
 171 //
 172 // Various globals used to support typeinfo and generatted exceptions in
 173 // general
 174 //
 175
 176 static std::map<std::string, llvm::Value*> namedValues;
 177
 178 int64_t ourBaseFromUnwindOffset;
 179
 180 const unsigned char ourBaseExcpClassChars[] =
 181 {'o', 'b', 'j', '\0', 'b', 'a', 's', '\0'};
 182
 183
 184 static uint64_t ourBaseExceptionClass = 0;
 185
 186 static std::vector<std::string> ourTypeInfoNames;
 187 static std::map<int, std::string> ourTypeInfoNamesIndex;
 188
 189 static llvm::StructType *ourTypeInfoType;
 190 #ifndef OLD_EXC_SYSTEM
 191 static llvm::StructType *ourCaughtResultType;
 192 #endif
 193 static llvm::StructType *ourExceptionType;
 194 static llvm::StructType *ourUnwindExceptionType;
 195
 196 static llvm::ConstantInt *ourExceptionNotThrownState;
 197 static llvm::ConstantInt *ourExceptionThrownState;
 198 static llvm::ConstantInt *ourExceptionCaughtState;
 199
 200 typedef std::vector<std::string> ArgNames;
 201 typedef std::vector<llvm::Type*> ArgTypes;
 202
 203 //
 204 // Code Generation Utilities
 205 //
 206
 207 /// Utility used to create a function, both declarations and definitions
 208 /// @param module for module instance
 209 /// @param retType function return type
 210 /// @param theArgTypes function's ordered argument types
 211 /// @param theArgNames function's ordered arguments needed if use of this
 212 ///        function corresponds to a function definition. Use empty
 213 ///        aggregate for function declarations.
 214 /// @param functName function name
 215 /// @param linkage function linkage
 216 /// @param declarationOnly for function declarations
 217 /// @param isVarArg function uses vararg arguments
 218 /// @returns function instance
 219 llvm::Function *createFunction(llvm::Module &module,
 220                                llvm::Type *retType,
 221                                const ArgTypes &theArgTypes,
 222                                const ArgNames &theArgNames,
 223                                const std::string &functName,
 224                                llvm::GlobalValue::LinkageTypes linkage,
 225                                bool declarationOnly,
 226                                bool isVarArg) {
 227   llvm::FunctionType *functType =
 228     llvm::FunctionType::get(retType, theArgTypes, isVarArg);
 229   llvm::Function *ret =
 230     llvm::Function::Create(functType, linkage, functName, &module);
 231   if (!ret || declarationOnly)
 232     return(ret);
 233
 234   namedValues.clear();
 235   unsigned i = 0;
 236   for (llvm::Function::arg_iterator argIndex = ret->arg_begin();
 237        i != theArgNames.size();
 238        ++argIndex, ++i) {
 239
 240     argIndex->setName(theArgNames[i]);
 241     namedValues[theArgNames[i]] = argIndex;
 242   }
 243
 244   return(ret);
 245 }
 246
 247
 248 /// Create an alloca instruction in the entry block of
 249 /// the parent function.  This is used for mutable variables etc.
 250 /// @param function parent instance
 251 /// @param varName stack variable name
 252 /// @param type stack variable type
 253 /// @param initWith optional constant initialization value
 254 /// @returns AllocaInst instance
 255 static llvm::AllocaInst *createEntryBlockAlloca(llvm::Function &function,
 256                                                 const std::string &varName,
 257                                                 llvm::Type *type,
 258                                                 llvm::Constant *initWith = 0) {
 259   llvm::BasicBlock &block = function.getEntryBlock();
 260   llvm::IRBuilder<> tmp(&block, block.begin());
 261   llvm::AllocaInst *ret = tmp.CreateAlloca(type, 0, varName.c_str());
 262
 263   if (initWith)
 264     tmp.CreateStore(initWith, ret);
 265
 266   return(ret);
 267 }
 268
 269
 270 //
 271 // Code Generation Utilities End
 272 //
 273
 274 //
 275 // Runtime C Library functions
 276 //
 277
 278 // Note: using an extern "C" block so that static functions can be used
 279 extern "C" {
 280
 281 // Note: Better ways to decide on bit width
 282 //
 283 /// Prints a 32 bit number, according to the format, to stderr.
 284 /// @param intToPrint integer to print
 285 /// @param format printf like format to use when printing
 286 void print32Int(int intToPrint, const char *format) {
 287   if (format) {
 288     // Note: No NULL check
 289     fprintf(stderr, format, intToPrint);
 290   }
 291   else {
 292     // Note: No NULL check
 293     fprintf(stderr, "::print32Int(...):NULL arg.\n");
 294   }
 295 }
 296
 297
 298 // Note: Better ways to decide on bit width
 299 //
 300 /// Prints a 64 bit number, according to the format, to stderr.
 301 /// @param intToPrint integer to print
 302 /// @param format printf like format to use when printing
 303 void print64Int(long int intToPrint, const char *format) {
 304   if (format) {
 305     // Note: No NULL check
 306     fprintf(stderr, format, intToPrint);
 307   }
 308   else {
 309     // Note: No NULL check
 310     fprintf(stderr, "::print64Int(...):NULL arg.\n");
 311   }
 312 }
 313
 314
 315 /// Prints a C string to stderr
 316 /// @param toPrint string to print
 317 void printStr(char *toPrint) {
 318   if (toPrint) {
 319     fprintf(stderr, "%s", toPrint);
 320   }
 321   else {
 322     fprintf(stderr, "::printStr(...):NULL arg.\n");
 323   }
 324 }
 325
 326
 327 /// Deletes the true previosly allocated exception whose address
 328 /// is calculated from the supplied OurBaseException_t::unwindException
 329 /// member address. Handles (ignores), NULL pointers.
 330 /// @param expToDelete exception to delete
 331 void deleteOurException(OurUnwindException *expToDelete) {
 332 #ifdef DEBUG
 333   fprintf(stderr,
 334           "deleteOurException(...).\n");
 335 #endif
 336
 337   if (expToDelete &&
 338       (expToDelete->exception_class == ourBaseExceptionClass)) {
 339
 340     free(((char*) expToDelete) + ourBaseFromUnwindOffset);
 341   }
 342 }
 343
 344
 345 /// This function is the struct _Unwind_Exception API mandated delete function
 346 /// used by foreign exception handlers when deleting our exception
 347 /// (OurException), instances.
 348 /// @param reason @link http://refspecs.freestandards.org/abi-eh-1.21.html
 349 /// @unlink
 350 /// @param expToDelete exception instance to delete
 351 void deleteFromUnwindOurException(_Unwind_Reason_Code reason,
 352                                   OurUnwindException *expToDelete) {
 353 #ifdef DEBUG
 354   fprintf(stderr,
 355           "deleteFromUnwindOurException(...).\n");
 356 #endif
 357
 358   deleteOurException(expToDelete);
 359 }
 360
 361
 362 /// Creates (allocates on the heap), an exception (OurException instance),
 363 /// of the supplied type info type.
 364 /// @param type type info type
 365 OurUnwindException *createOurException(int type) {
 366   size_t size = sizeof(OurException);
 367   OurException *ret = (OurException*) memset(malloc(size), 0, size);
 368   (ret->type).type = type;
 369   (ret->unwindException).exception_class = ourBaseExceptionClass;
 370   (ret->unwindException).exception_cleanup = deleteFromUnwindOurException;
 371
 372   return(&(ret->unwindException));
 373 }
 374
 375
 376 /// Read a uleb128 encoded value and advance pointer
 377 /// See Variable Length Data in:
 378 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 379 /// @param data reference variable holding memory pointer to decode from
 380 /// @returns decoded value
 381 static uintptr_t readULEB128(const uint8_t **data) {
 382   uintptr_t result = 0;
 383   uintptr_t shift = 0;
 384   unsigned char byte;
 385   const uint8_t *p = *data;
 386
 387   do {
 388     byte = *p++;
 389     result |= (byte & 0x7f) << shift;
 390     shift += 7;
 391   }
 392   while (byte & 0x80);
 393
 394   *data = p;
 395
 396   return result;
 397 }
 398
 399
 400 /// Read a sleb128 encoded value and advance pointer
 401 /// See Variable Length Data in:
 402 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 403 /// @param data reference variable holding memory pointer to decode from
 404 /// @returns decoded value
 405 static uintptr_t readSLEB128(const uint8_t **data) {
 406   uintptr_t result = 0;
 407   uintptr_t shift = 0;
 408   unsigned char byte;
 409   const uint8_t *p = *data;
 410
 411   do {
 412     byte = *p++;
 413     result |= (byte & 0x7f) << shift;
 414     shift += 7;
 415   }
 416   while (byte & 0x80);
 417
 418   *data = p;
 419
 420   if ((byte & 0x40) && (shift < (sizeof(result) << 3))) {
 421     result |= (~0 << shift);
 422   }
 423
 424   return result;
 425 }
 426
 427
 428 /// Read a pointer encoded value and advance pointer
 429 /// See Variable Length Data in:
 430 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 431 /// @param data reference variable holding memory pointer to decode from
 432 /// @param encoding dwarf encoding type
 433 /// @returns decoded value
 434 static uintptr_t readEncodedPointer(const uint8_t **data, uint8_t encoding) {
 435   uintptr_t result = 0;
 436   const uint8_t *p = *data;
 437
 438   if (encoding == llvm::dwarf::DW_EH_PE_omit)
 439     return(result);
 440
 441   // first get value
 442   switch (encoding & 0x0F) {
 443     case llvm::dwarf::DW_EH_PE_absptr:
 444       result = *((uintptr_t*)p);
 445       p += sizeof(uintptr_t);
 446       break;
 447     case llvm::dwarf::DW_EH_PE_uleb128:
 448       result = readULEB128(&p);
 449       break;
 450       // Note: This case has not been tested
 451     case llvm::dwarf::DW_EH_PE_sleb128:
 452       result = readSLEB128(&p);
 453       break;
 454     case llvm::dwarf::DW_EH_PE_udata2:
 455       result = *((uint16_t*)p);
 456       p += sizeof(uint16_t);
 457       break;
 458     case llvm::dwarf::DW_EH_PE_udata4:
 459       result = *((uint32_t*)p);
 460       p += sizeof(uint32_t);
 461       break;
 462     case llvm::dwarf::DW_EH_PE_udata8:
 463       result = *((uint64_t*)p);
 464       p += sizeof(uint64_t);
 465       break;
 466     case llvm::dwarf::DW_EH_PE_sdata2:
 467       result = *((int16_t*)p);
 468       p += sizeof(int16_t);
 469       break;
 470     case llvm::dwarf::DW_EH_PE_sdata4:
 471       result = *((int32_t*)p);
 472       p += sizeof(int32_t);
 473       break;
 474     case llvm::dwarf::DW_EH_PE_sdata8:
 475       result = *((int64_t*)p);
 476       p += sizeof(int64_t);
 477       break;
 478     default:
 479       // not supported
 480       abort();
 481       break;
 482   }
 483
 484   // then add relative offset
 485   switch (encoding & 0x70) {
 486     case llvm::dwarf::DW_EH_PE_absptr:
 487       // do nothing
 488       break;
 489     case llvm::dwarf::DW_EH_PE_pcrel:
 490       result += (uintptr_t)(*data);
 491       break;
 492     case llvm::dwarf::DW_EH_PE_textrel:
 493     case llvm::dwarf::DW_EH_PE_datarel:
 494     case llvm::dwarf::DW_EH_PE_funcrel:
 495     case llvm::dwarf::DW_EH_PE_aligned:
 496     default:
 497       // not supported
 498       abort();
 499       break;
 500   }
 501
 502   // then apply indirection
 503   if (encoding & llvm::dwarf::DW_EH_PE_indirect) {
 504     result = *((uintptr_t*)result);
 505   }
 506
 507   *data = p;
 508
 509   return result;
 510 }
 511
 512
 513 /// Deals with Dwarf actions matching our type infos
 514 /// (OurExceptionType_t instances). Returns whether or not a dwarf emitted
 515 /// action matches the supplied exception type. If such a match succeeds,
 516 /// the resultAction argument will be set with > 0 index value. Only
 517 /// corresponding llvm.eh.selector type info arguments, cleanup arguments
 518 /// are supported. Filters are not supported.
 519 /// See Variable Length Data in:
 520 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 521 /// Also see @link http://refspecs.freestandards.org/abi-eh-1.21.html @unlink
 522 /// @param resultAction reference variable which will be set with result
 523 /// @param classInfo our array of type info pointers (to globals)
 524 /// @param actionEntry index into above type info array or 0 (clean up).
 525 ///        We do not support filters.
 526 /// @param exceptionClass exception class (_Unwind_Exception::exception_class)
 527 ///        of thrown exception.
 528 /// @param exceptionObject thrown _Unwind_Exception instance.
 529 /// @returns whether or not a type info was found. False is returned if only
 530 ///          a cleanup was found
 531 static bool handleActionValue(int64_t *resultAction,
 532                               struct OurExceptionType_t **classInfo,
 533                               uintptr_t actionEntry,
 534                               uint64_t exceptionClass,
 535                               struct _Unwind_Exception *exceptionObject) {
 536   bool ret = false;
 537
 538   if (!resultAction ||
 539       !exceptionObject ||
 540       (exceptionClass != ourBaseExceptionClass))
 541     return(ret);
 542
 543   struct OurBaseException_t *excp = (struct OurBaseException_t*)
 544   (((char*) exceptionObject) + ourBaseFromUnwindOffset);
 545   struct OurExceptionType_t *excpType = &(excp->type);
 546   int type = excpType->type;
 547
 548 #ifdef DEBUG
 549   fprintf(stderr,
 550           "handleActionValue(...): exceptionObject = <%p>, "
 551           "excp = <%p>.\n",
 552           exceptionObject,
 553           excp);
 554 #endif
 555
 556   const uint8_t *actionPos = (uint8_t*) actionEntry,
 557   *tempActionPos;
 558   int64_t typeOffset = 0,
 559   actionOffset;
 560
 561   for (int i = 0; true; ++i) {
 562     // Each emitted dwarf action corresponds to a 2 tuple of
 563     // type info address offset, and action offset to the next
 564     // emitted action.
 565     typeOffset = readSLEB128(&actionPos);
 566     tempActionPos = actionPos;
 567     actionOffset = readSLEB128(&tempActionPos);
 568
 569 #ifdef DEBUG
 570     fprintf(stderr,
 571             "handleActionValue(...):typeOffset: <%lld>, "
 572             "actionOffset: <%lld>.\n",
 573             typeOffset,
 574             actionOffset);
 575 #endif
 576     assert((typeOffset >= 0) &&
 577            "handleActionValue(...):filters are not supported.");
 578
 579     // Note: A typeOffset == 0 implies that a cleanup llvm.eh.selector
 580     //       argument has been matched.
 581     if ((typeOffset > 0) &&
 582         (type == (classInfo[-typeOffset])->type)) {
 583 #ifdef DEBUG
 584       fprintf(stderr,
 585               "handleActionValue(...):actionValue <%d> found.\n",
 586               i);
 587 #endif
 588       *resultAction = i + 1;
 589       ret = true;
 590       break;
 591     }
 592
 593 #ifdef DEBUG
 594     fprintf(stderr,
 595             "handleActionValue(...):actionValue not found.\n");
 596 #endif
 597     if (!actionOffset)
 598       break;
 599
 600     actionPos += actionOffset;
 601   }
 602
 603   return(ret);
 604 }
 605
 606
 607 /// Deals with the Language specific data portion of the emitted dwarf code.
 608 /// See @link http://refspecs.freestandards.org/abi-eh-1.21.html @unlink
 609 /// @param version unsupported (ignored), unwind version
 610 /// @param lsda language specific data area
 611 /// @param _Unwind_Action actions minimally supported unwind stage
 612 ///        (forced specifically not supported)
 613 /// @param exceptionClass exception class (_Unwind_Exception::exception_class)
 614 ///        of thrown exception.
 615 /// @param exceptionObject thrown _Unwind_Exception instance.
 616 /// @param context unwind system context
 617 /// @returns minimally supported unwinding control indicator
 618 static _Unwind_Reason_Code handleLsda(int version,
 619                                       const uint8_t *lsda,
 620                                       _Unwind_Action actions,
 621                                       uint64_t exceptionClass,
 622                                     struct _Unwind_Exception *exceptionObject,
 623                                       _Unwind_Context_t context) {
 624   _Unwind_Reason_Code ret = _URC_CONTINUE_UNWIND;
 625
 626   if (!lsda)
 627     return(ret);
 628
 629 #ifdef DEBUG
 630   fprintf(stderr,
 631           "handleLsda(...):lsda is non-zero.\n");
 632 #endif
 633
 634   // Get the current instruction pointer and offset it before next
 635   // instruction in the current frame which threw the exception.
 636   uintptr_t pc = _Unwind_GetIP(context)-1;
 637
 638   // Get beginning current frame's code (as defined by the
 639   // emitted dwarf code)
 640   uintptr_t funcStart = _Unwind_GetRegionStart(context);
 641   uintptr_t pcOffset = pc - funcStart;
 642   struct OurExceptionType_t **classInfo = NULL;
 643
 644   // Note: See JITDwarfEmitter::EmitExceptionTable(...) for corresponding
 645   //       dwarf emission
 646
 647   // Parse LSDA header.
 648   uint8_t lpStartEncoding = *lsda++;
 649
 650   if (lpStartEncoding != llvm::dwarf::DW_EH_PE_omit) {
 651     readEncodedPointer(&lsda, lpStartEncoding);
 652   }
 653
 654   uint8_t ttypeEncoding = *lsda++;
 655   uintptr_t classInfoOffset;
 656
 657   if (ttypeEncoding != llvm::dwarf::DW_EH_PE_omit) {
 658     // Calculate type info locations in emitted dwarf code which
 659     // were flagged by type info arguments to llvm.eh.selector
 660     // intrinsic
 661     classInfoOffset = readULEB128(&lsda);
 662     classInfo = (struct OurExceptionType_t**) (lsda + classInfoOffset);
 663   }
 664
 665   // Walk call-site table looking for range that
 666   // includes current PC.
 667
 668   uint8_t         callSiteEncoding = *lsda++;
 669   uint32_t        callSiteTableLength = readULEB128(&lsda);
 670   const uint8_t   *callSiteTableStart = lsda;
 671   const uint8_t   *callSiteTableEnd = callSiteTableStart +
 672   callSiteTableLength;
 673   const uint8_t   *actionTableStart = callSiteTableEnd;
 674   const uint8_t   *callSitePtr = callSiteTableStart;
 675
 676   bool foreignException = false;
 677
 678   while (callSitePtr < callSiteTableEnd) {
 679     uintptr_t start = readEncodedPointer(&callSitePtr,
 680                                          callSiteEncoding);
 681     uintptr_t length = readEncodedPointer(&callSitePtr,
 682                                           callSiteEncoding);
 683     uintptr_t landingPad = readEncodedPointer(&callSitePtr,
 684                                               callSiteEncoding);
 685
 686     // Note: Action value
 687     uintptr_t actionEntry = readULEB128(&callSitePtr);
 688
 689     if (exceptionClass != ourBaseExceptionClass) {
 690       // We have been notified of a foreign exception being thrown,
 691       // and we therefore need to execute cleanup landing pads
 692       actionEntry = 0;
 693       foreignException = true;
 694     }
 695
 696     if (landingPad == 0) {
 697 #ifdef DEBUG
 698       fprintf(stderr,
 699               "handleLsda(...): No landing pad found.\n");
 700 #endif
 701
 702       continue; // no landing pad for this entry
 703     }
 704
 705     if (actionEntry) {
 706       actionEntry += ((uintptr_t) actionTableStart) - 1;
 707     }
 708     else {
 709 #ifdef DEBUG
 710       fprintf(stderr,
 711               "handleLsda(...):No action table found.\n");
 712 #endif
 713     }
 714
 715     bool exceptionMatched = false;
 716
 717     if ((start <= pcOffset) && (pcOffset < (start + length))) {
 718 #ifdef DEBUG
 719       fprintf(stderr,
 720               "handleLsda(...): Landing pad found.\n");
 721 #endif
 722       int64_t actionValue = 0;
 723
 724       if (actionEntry) {
 725         exceptionMatched = handleActionValue(&actionValue,
 726                                              classInfo,
 727                                              actionEntry,
 728                                              exceptionClass,
 729                                              exceptionObject);
 730       }
 731
 732       if (!(actions & _UA_SEARCH_PHASE)) {
 733 #ifdef DEBUG
 734         fprintf(stderr,
 735                 "handleLsda(...): installed landing pad "
 736                 "context.\n");
 737 #endif
 738
 739         // Found landing pad for the PC.
 740         // Set Instruction Pointer to so we re-enter function
 741         // at landing pad. The landing pad is created by the
 742         // compiler to take two parameters in registers.
 743         _Unwind_SetGR(context,
 744                       __builtin_eh_return_data_regno(0),
 745                       (uintptr_t)exceptionObject);
 746
 747         // Note: this virtual register directly corresponds
 748         //       to the return of the llvm.eh.selector intrinsic
 749         if (!actionEntry || !exceptionMatched) {
 750           // We indicate cleanup only
 751           _Unwind_SetGR(context,
 752                         __builtin_eh_return_data_regno(1),
 753                         0);
 754         }
 755         else {
 756           // Matched type info index of llvm.eh.selector intrinsic
 757           // passed here.
 758           _Unwind_SetGR(context,
 759                         __builtin_eh_return_data_regno(1),
 760                         actionValue);
 761         }
 762
 763         // To execute landing pad set here
 764         _Unwind_SetIP(context, funcStart + landingPad);
 765         ret = _URC_INSTALL_CONTEXT;
 766       }
 767       else if (exceptionMatched) {
 768 #ifdef DEBUG
 769         fprintf(stderr,
 770                 "handleLsda(...): setting handler found.\n");
 771 #endif
 772         ret = _URC_HANDLER_FOUND;
 773       }
 774       else {
 775         // Note: Only non-clean up handlers are marked as
 776         //       found. Otherwise the clean up handlers will be
 777         //       re-found and executed during the clean up
 778         //       phase.
 779 #ifdef DEBUG
 780         fprintf(stderr,
 781                 "handleLsda(...): cleanup handler found.\n");
 782 #endif
 783       }
 784
 785       break;
 786     }
 787   }
 788
 789   return(ret);
 790 }
 791
 792
 793 /// This is the personality function which is embedded (dwarf emitted), in the
 794 /// dwarf unwind info block. Again see: JITDwarfEmitter.cpp.
 795 /// See @link http://refspecs.freestandards.org/abi-eh-1.21.html @unlink
 796 /// @param version unsupported (ignored), unwind version
 797 /// @param _Unwind_Action actions minimally supported unwind stage
 798 ///        (forced specifically not supported)
 799 /// @param exceptionClass exception class (_Unwind_Exception::exception_class)
 800 ///        of thrown exception.
 801 /// @param exceptionObject thrown _Unwind_Exception instance.
 802 /// @param context unwind system context
 803 /// @returns minimally supported unwinding control indicator
 804 _Unwind_Reason_Code ourPersonality(int version,
 805                                    _Unwind_Action actions,
 806                                    uint64_t exceptionClass,
 807                                    struct _Unwind_Exception *exceptionObject,
 808                                    _Unwind_Context_t context) {
 809 #ifdef DEBUG
 810   fprintf(stderr,
 811           "We are in ourPersonality(...):actions is <%d>.\n",
 812           actions);
 813
 814   if (actions & _UA_SEARCH_PHASE) {
 815     fprintf(stderr, "ourPersonality(...):In search phase.\n");
 816   }
 817   else {
 818     fprintf(stderr, "ourPersonality(...):In non-search phase.\n");
 819   }
 820 #endif
 821
 822   const uint8_t *lsda = _Unwind_GetLanguageSpecificData(context);
 823
 824 #ifdef DEBUG
 825   fprintf(stderr,
 826           "ourPersonality(...):lsda = <%p>.\n",
 827           lsda);
 828 #endif
 829
 830   // The real work of the personality function is captured here
 831   return(handleLsda(version,
 832                     lsda,
 833                     actions,
 834                     exceptionClass,
 835                     exceptionObject,
 836                     context));
 837 }
 838
 839
 840 /// Generates our _Unwind_Exception class from a given character array.
 841 /// thereby handling arbitrary lengths (not in standard), and handling
 842 /// embedded \0s.
 843 /// See @link http://refspecs.freestandards.org/abi-eh-1.21.html @unlink
 844 /// @param classChars char array to encode. NULL values not checkedf
 845 /// @param classCharsSize number of chars in classChars. Value is not checked.
 846 /// @returns class value
 847 uint64_t genClass(const unsigned char classChars[], size_t classCharsSize)
 848 {
 849   uint64_t ret = classChars[0];
 850
 851   for (unsigned i = 1; i < classCharsSize; ++i) {
 852     ret <<= 8;
 853     ret += classChars[i];
 854   }
 855
 856   return(ret);
 857 }
 858
 859 } // extern "C"
 860
 861 //
 862 // Runtime C Library functions End
 863 //
 864
 865 //
 866 // Code generation functions
 867 //
 868
 869 /// Generates code to print given constant string
 870 /// @param context llvm context
 871 /// @param module code for module instance
 872 /// @param builder builder instance
 873 /// @param toPrint string to print
 874 /// @param useGlobal A value of true (default) indicates a GlobalValue is
 875 ///        generated, and is used to hold the constant string. A value of
 876 ///        false indicates that the constant string will be stored on the
 877 ///        stack.
 878 void generateStringPrint(llvm::LLVMContext &context,
 879                          llvm::Module &module,
 880                          llvm::IRBuilder<> &builder,
 881                          std::string toPrint,
 882                          bool useGlobal = true) {
 883   llvm::Function *printFunct = module.getFunction("printStr");
 884
 885   llvm::Value *stringVar;
 886   llvm::Constant *stringConstant =
 887   llvm::ConstantArray::get(context, toPrint);
 888
 889   if (useGlobal) {
 890     // Note: Does not work without allocation
 891     stringVar =
 892     new llvm::GlobalVariable(module,
 893                              stringConstant->getType(),
 894                              true,
 895                              llvm::GlobalValue::LinkerPrivateLinkage,
 896                              stringConstant,
 897                              "");
 898   }
 899   else {
 900     stringVar = builder.CreateAlloca(stringConstant->getType());
 901     builder.CreateStore(stringConstant, stringVar);
 902   }
 903
 904   llvm::Value *cast = builder.CreatePointerCast(stringVar,
 905                                                 builder.getInt8PtrTy());
 906   builder.CreateCall(printFunct, cast);
 907 }
 908
 909
 910 /// Generates code to print given runtime integer according to constant
 911 /// string format, and a given print function.
 912 /// @param context llvm context
 913 /// @param module code for module instance
 914 /// @param builder builder instance
 915 /// @param printFunct function used to "print" integer
 916 /// @param toPrint string to print
 917 /// @param format printf like formating string for print
 918 /// @param useGlobal A value of true (default) indicates a GlobalValue is
 919 ///        generated, and is used to hold the constant string. A value of
 920 ///        false indicates that the constant string will be stored on the
 921 ///        stack.
 922 void generateIntegerPrint(llvm::LLVMContext &context,
 923                           llvm::Module &module,
 924                           llvm::IRBuilder<> &builder,
 925                           llvm::Function &printFunct,
 926                           llvm::Value &toPrint,
 927                           std::string format,
 928                           bool useGlobal = true) {
 929   llvm::Constant *stringConstant = llvm::ConstantArray::get(context, format);
 930   llvm::Value *stringVar;
 931
 932   if (useGlobal) {
 933     // Note: Does not seem to work without allocation
 934     stringVar =
 935     new llvm::GlobalVariable(module,
 936                              stringConstant->getType(),
 937                              true,
 938                              llvm::GlobalValue::LinkerPrivateLinkage,
 939                              stringConstant,
 940                              "");
 941   }
 942   else {
 943     stringVar = builder.CreateAlloca(stringConstant->getType());
 944     builder.CreateStore(stringConstant, stringVar);
 945   }
 946
 947   llvm::Value *cast = builder.CreateBitCast(stringVar,
 948                                             builder.getInt8PtrTy());
 949   builder.CreateCall2(&printFunct, &toPrint, cast);
 950 }
 951
 952
 953 /// Generates code to handle finally block type semantics: always runs
 954 /// regardless of whether a thrown exception is passing through or the
 955 /// parent function is simply exiting. In addition to printing some state
 956 /// to stderr, this code will resume the exception handling--runs the
 957 /// unwind resume block, if the exception has not been previously caught
 958 /// by a catch clause, and will otherwise execute the end block (terminator
 959 /// block). In addition this function creates the corresponding function's
 960 /// stack storage for the exception pointer and catch flag status.
 961 /// @param context llvm context
 962 /// @param module code for module instance
 963 /// @param builder builder instance
 964 /// @param toAddTo parent function to add block to
 965 /// @param blockName block name of new "finally" block.
 966 /// @param functionId output id used for printing
 967 /// @param terminatorBlock terminator "end" block
 968 /// @param unwindResumeBlock unwind resume block
 969 /// @param exceptionCaughtFlag reference exception caught/thrown status storage
 970 /// @param exceptionStorage reference to exception pointer storage
 971 #ifndef OLD_EXC_SYSTEM
 972 /// @param caughtResultStorage reference to landingpad result storage
 973 #endif
 974 /// @returns newly created block
 975 static llvm::BasicBlock *createFinallyBlock(llvm::LLVMContext &context,
 976                                             llvm::Module &module,
 977                                             llvm::IRBuilder<> &builder,
 978                                             llvm::Function &toAddTo,
 979                                             std::string &blockName,
 980                                             std::string &functionId,
 981                                             llvm::BasicBlock &terminatorBlock,
 982                                             llvm::BasicBlock &unwindResumeBlock,
 983                                             llvm::Value **exceptionCaughtFlag,
 984                                             llvm::Value **exceptionStorage
 985 #ifndef OLD_EXC_SYSTEM
 986                                             ,llvm::Value **caughtResultStorage
 987 #endif
 988                                             ) {
 989   assert(exceptionCaughtFlag &&
 990          "ExceptionDemo::createFinallyBlock(...):exceptionCaughtFlag "
 991          "is NULL");
 992   assert(exceptionStorage &&
 993          "ExceptionDemo::createFinallyBlock(...):exceptionStorage "
 994          "is NULL");
 995
 996 #ifndef OLD_EXC_SYSTEM
 997   assert(caughtResultStorage &&
 998          "ExceptionDemo::createFinallyBlock(...):caughtResultStorage "
 999          "is NULL");
1000 #endif
1001
1002   *exceptionCaughtFlag = createEntryBlockAlloca(toAddTo,
1003                                          "exceptionCaught",
1004                                          ourExceptionNotThrownState->getType(),
1005                                          ourExceptionNotThrownState);
1006
1007   llvm::PointerType *exceptionStorageType = builder.getInt8PtrTy();
1008   *exceptionStorage = createEntryBlockAlloca(toAddTo,
1009                                              "exceptionStorage",
1010                                              exceptionStorageType,
1011                                              llvm::ConstantPointerNull::get(
1012                                                exceptionStorageType));
1013 #ifndef OLD_EXC_SYSTEM
1014   *caughtResultStorage = createEntryBlockAlloca(toAddTo,
1015                                               "caughtResultStorage",
1016                                               ourCaughtResultType,
1017                                               llvm::ConstantAggregateZero::get(
1018                                                 ourCaughtResultType));
1019 #endif
1020
1021   llvm::BasicBlock *ret = llvm::BasicBlock::Create(context,
1022                                                    blockName,
1023                                                    &toAddTo);
1024
1025   builder.SetInsertPoint(ret);
1026
1027   std::ostringstream bufferToPrint;
1028   bufferToPrint << "Gen: Executing finally block "
1029     << blockName << " in " << functionId << "\n";
1030   generateStringPrint(context,
1031                       module,
1032                       builder,
1033                       bufferToPrint.str(),
1034                       USE_GLOBAL_STR_CONSTS);
1035
1036   llvm::SwitchInst *theSwitch = builder.CreateSwitch(builder.CreateLoad(
1037                                                        *exceptionCaughtFlag),
1038                                                      &terminatorBlock,
1039                                                      2);
1040   theSwitch->addCase(ourExceptionCaughtState, &terminatorBlock);
1041   theSwitch->addCase(ourExceptionThrownState, &unwindResumeBlock);
1042
1043   return(ret);
1044 }
1045
1046
1047 /// Generates catch block semantics which print a string to indicate type of
1048 /// catch executed, sets an exception caught flag, and executes passed in
1049 /// end block (terminator block).
1050 /// @param context llvm context
1051 /// @param module code for module instance
1052 /// @param builder builder instance
1053 /// @param toAddTo parent function to add block to
1054 /// @param blockName block name of new "catch" block.
1055 /// @param functionId output id used for printing
1056 /// @param terminatorBlock terminator "end" block
1057 /// @param exceptionCaughtFlag exception caught/thrown status
1058 /// @returns newly created block
1059 static llvm::BasicBlock *createCatchBlock(llvm::LLVMContext &context,
1060                                           llvm::Module &module,
1061                                           llvm::IRBuilder<> &builder,
1062                                           llvm::Function &toAddTo,
1063                                           std::string &blockName,
1064                                           std::string &functionId,
1065                                           llvm::BasicBlock &terminatorBlock,
1066                                           llvm::Value &exceptionCaughtFlag) {
1067
1068   llvm::BasicBlock *ret = llvm::BasicBlock::Create(context,
1069                                                    blockName,
1070                                                    &toAddTo);
1071
1072   builder.SetInsertPoint(ret);
1073
1074   std::ostringstream bufferToPrint;
1075   bufferToPrint << "Gen: Executing catch block "
1076   << blockName
1077   << " in "
1078   << functionId
1079   << std::endl;
1080   generateStringPrint(context,
1081                       module,
1082                       builder,
1083                       bufferToPrint.str(),
1084                       USE_GLOBAL_STR_CONSTS);
1085   builder.CreateStore(ourExceptionCaughtState, &exceptionCaughtFlag);
1086   builder.CreateBr(&terminatorBlock);
1087
1088   return(ret);
1089 }
1090
1091
1092 /// Generates a function which invokes a function (toInvoke) and, whose
1093 /// unwind block will "catch" the type info types correspondingly held in the
1094 /// exceptionTypesToCatch argument. If the toInvoke function throws an
1095 /// exception which does not match any type info types contained in
1096 /// exceptionTypesToCatch, the generated code will call _Unwind_Resume
1097 /// with the raised exception. On the other hand the generated code will
1098 /// normally exit if the toInvoke function does not throw an exception.
1099 /// The generated "finally" block is always run regardless of the cause of
1100 /// the generated function exit.
1101 /// The generated function is returned after being verified.
1102 /// @param module code for module instance
1103 /// @param builder builder instance
1104 /// @param fpm a function pass manager holding optional IR to IR
1105 ///        transformations
1106 /// @param toInvoke inner function to invoke
1107 /// @param ourId id used to printing purposes
1108 /// @param numExceptionsToCatch length of exceptionTypesToCatch array
1109 /// @param exceptionTypesToCatch array of type info types to "catch"
1110 /// @returns generated function
1111 static
1112 llvm::Function *createCatchWrappedInvokeFunction(llvm::Module &module,
1113                                              llvm::IRBuilder<> &builder,
1114                                              llvm::FunctionPassManager &fpm,
1115                                              llvm::Function &toInvoke,
1116                                              std::string ourId,
1117                                              unsigned numExceptionsToCatch,
1118                                              unsigned exceptionTypesToCatch[]) {
1119
1120   llvm::LLVMContext &context = module.getContext();
1121   llvm::Function *toPrint32Int = module.getFunction("print32Int");
1122
1123   ArgTypes argTypes;
1124   argTypes.push_back(builder.getInt32Ty());
1125
1126   ArgNames argNames;
1127   argNames.push_back("exceptTypeToThrow");
1128
1129   llvm::Function *ret = createFunction(module,
1130                                        builder.getVoidTy(),
1131                                        argTypes,
1132                                        argNames,
1133                                        ourId,
1134                                        llvm::Function::ExternalLinkage,
1135                                        false,
1136                                        false);
1137
1138   // Block which calls invoke
1139   llvm::BasicBlock *entryBlock = llvm::BasicBlock::Create(context,
1140                                                           "entry",
1141                                                           ret);
1142   // Normal block for invoke
1143   llvm::BasicBlock *normalBlock = llvm::BasicBlock::Create(context,
1144                                                            "normal",
1145                                                            ret);
1146   // Unwind block for invoke
1147   llvm::BasicBlock *exceptionBlock = llvm::BasicBlock::Create(context,
1148                                                               "exception",
1149                                                               ret);
1150
1151   // Block which routes exception to correct catch handler block
1152   llvm::BasicBlock *exceptionRouteBlock = llvm::BasicBlock::Create(context,
1153                                                              "exceptionRoute",
1154                                                              ret);
1155
1156   // Foreign exception handler
1157   llvm::BasicBlock *externalExceptionBlock = llvm::BasicBlock::Create(context,
1158                                                           "externalException",
1159                                                           ret);
1160
1161   // Block which calls _Unwind_Resume
1162   llvm::BasicBlock *unwindResumeBlock = llvm::BasicBlock::Create(context,
1163                                                                "unwindResume",
1164                                                                ret);
1165
1166   // Clean up block which delete exception if needed
1167   llvm::BasicBlock *endBlock = llvm::BasicBlock::Create(context, "end", ret);
1168
1169   std::string nextName;
1170   std::vector<llvm::BasicBlock*> catchBlocks(numExceptionsToCatch);
1171   llvm::Value *exceptionCaughtFlag = NULL;
1172   llvm::Value *exceptionStorage = NULL;
1173 #ifndef OLD_EXC_SYSTEM
1174   llvm::Value *caughtResultStorage = NULL;
1175 #endif
1176
1177   // Finally block which will branch to unwindResumeBlock if
1178   // exception is not caught. Initializes/allocates stack locations.
1179   llvm::BasicBlock *finallyBlock = createFinallyBlock(context,
1180                                                       module,
1181                                                       builder,
1182                                                       *ret,
1183                                                       nextName = "finally",
1184                                                       ourId,
1185                                                       *endBlock,
1186                                                       *unwindResumeBlock,
1187                                                       &exceptionCaughtFlag,
1188                                                       &exceptionStorage
1189 #ifndef OLD_EXC_SYSTEM
1190                                                       ,&caughtResultStorage
1191 #endif
1192                                                       );
1193
1194   for (unsigned i = 0; i < numExceptionsToCatch; ++i) {
1195     nextName = ourTypeInfoNames[exceptionTypesToCatch[i]];
1196
1197     // One catch block per type info to be caught
1198     catchBlocks[i] = createCatchBlock(context,
1199                                       module,
1200                                       builder,
1201                                       *ret,
1202                                       nextName,
1203                                       ourId,
1204                                       *finallyBlock,
1205                                       *exceptionCaughtFlag);
1206   }
1207
1208   // Entry Block
1209
1210   builder.SetInsertPoint(entryBlock);
1211
1212   std::vector<llvm::Value*> args;
1213   args.push_back(namedValues["exceptTypeToThrow"]);
1214   builder.CreateInvoke(&toInvoke,
1215                        normalBlock,
1216                        exceptionBlock,
1217                        args);
1218
1219   // End Block
1220
1221   builder.SetInsertPoint(endBlock);
1222
1223   generateStringPrint(context,
1224                       module,
1225                       builder,
1226                       "Gen: In end block: exiting in " + ourId + ".\n",
1227                       USE_GLOBAL_STR_CONSTS);
1228   llvm::Function *deleteOurException = module.getFunction("deleteOurException");
1229
1230   // Note: function handles NULL exceptions
1231   builder.CreateCall(deleteOurException,
1232                      builder.CreateLoad(exceptionStorage));
1233   builder.CreateRetVoid();
1234
1235   // Normal Block
1236
1237   builder.SetInsertPoint(normalBlock);
1238
1239   generateStringPrint(context,
1240                       module,
1241                       builder,
1242                       "Gen: No exception in " + ourId + "!\n",
1243                       USE_GLOBAL_STR_CONSTS);
1244
1245   // Finally block is always called
1246   builder.CreateBr(finallyBlock);
1247
1248   // Unwind Resume Block
1249
1250   builder.SetInsertPoint(unwindResumeBlock);
1251
1252
1253 #ifndef OLD_EXC_SYSTEM
1254   builder.CreateResume(builder.CreateLoad(caughtResultStorage));
1255 #else
1256   llvm::Function *resumeOurException = module.getFunction("_Unwind_Resume");
1257   builder.CreateCall(resumeOurException,
1258                      builder.CreateLoad(exceptionStorage));
1259   builder.CreateUnreachable();
1260 #endif
1261
1262   // Exception Block
1263
1264   builder.SetInsertPoint(exceptionBlock);
1265
1266   llvm::Function *personality = module.getFunction("ourPersonality");
1267
1268 #ifndef OLD_EXC_SYSTEM
1269   llvm::LandingPadInst *caughtResult =
1270     builder.CreateLandingPad(ourCaughtResultType,
1271                              personality,
1272                              numExceptionsToCatch,
1273                              "landingPad");
1274
1275   caughtResult->setCleanup(true);
1276
1277   for (unsigned i = 0; i < numExceptionsToCatch; ++i) {
1278     // Set up type infos to be caught
1279     caughtResult->addClause(module.getGlobalVariable(
1280                              ourTypeInfoNames[exceptionTypesToCatch[i]]));
1281   }
1282
1283   llvm::Value *unwindException = builder.CreateExtractValue(caughtResult, 0);
1284   llvm::Value *retTypeInfoIndex = builder.CreateExtractValue(caughtResult, 1);
1285
1286   // FIXME: Redundant storage which, beyond utilizing value of
1287   //        caughtResultStore for unwindException storage, may be alleviated
1288   //        alltogether with a block rearrangement
1289   builder.CreateStore(caughtResult, caughtResultStorage);
1290   builder.CreateStore(unwindException, exceptionStorage);
1291   builder.CreateStore(ourExceptionThrownState, exceptionCaughtFlag);
1292 #else
1293   llvm::Function *ehException = module.getFunction("llvm.eh.exception");
1294
1295   // Retrieve thrown exception
1296   llvm::Value *unwindException = builder.CreateCall(ehException);
1297
1298   // Store exception and flag
1299   builder.CreateStore(unwindException, exceptionStorage);
1300   builder.CreateStore(ourExceptionThrownState, exceptionCaughtFlag);
1301   llvm::Value *functPtr = builder.CreatePointerCast(personality,
1302                                                     builder.getInt8PtrTy());
1303
1304   args.clear();
1305   args.push_back(unwindException);
1306   args.push_back(functPtr);
1307
1308   // Note: Skipping index 0
1309   for (unsigned i = 0; i < numExceptionsToCatch; ++i) {
1310     // Set up type infos to be caught
1311     args.push_back(module.getGlobalVariable(
1312                                   ourTypeInfoNames[exceptionTypesToCatch[i]]));
1313   }
1314
1315   args.push_back(llvm::ConstantInt::get(builder.getInt32Ty(), 0));
1316
1317   llvm::Function *ehSelector = module.getFunction("llvm.eh.selector");
1318
1319   // Set up this exeption block as the landing pad which will handle
1320   // given type infos. See case Intrinsic::eh_selector in
1321   // SelectionDAGBuilder::visitIntrinsicCall(...) and AddCatchInfo(...)
1322   // implemented in FunctionLoweringInfo.cpp to see how the implementation
1323   // handles this call. This landing pad (this exception block), will be
1324   // called either because it nees to cleanup (call finally) or a type
1325   // info was found which matched the thrown exception.
1326   llvm::Value *retTypeInfoIndex = builder.CreateCall(ehSelector, args);
1327 #endif
1328
1329   // Retrieve exception_class member from thrown exception
1330   // (_Unwind_Exception instance). This member tells us whether or not
1331   // the exception is foreign.
1332   llvm::Value *unwindExceptionClass =
1333     builder.CreateLoad(builder.CreateStructGEP(
1334              builder.CreatePointerCast(unwindException,
1335                                        ourUnwindExceptionType->getPointerTo()),
1336                                                0));
1337
1338   // Branch to the externalExceptionBlock if the exception is foreign or
1339   // to a catch router if not. Either way the finally block will be run.
1340   builder.CreateCondBr(builder.CreateICmpEQ(unwindExceptionClass,
1341                             llvm::ConstantInt::get(builder.getInt64Ty(),
1342                                                    ourBaseExceptionClass)),
1343                        exceptionRouteBlock,
1344                        externalExceptionBlock);
1345
1346   // External Exception Block
1347
1348   builder.SetInsertPoint(externalExceptionBlock);
1349
1350   generateStringPrint(context,
1351                       module,
1352                       builder,
1353                       "Gen: Foreign exception received.\n",
1354                       USE_GLOBAL_STR_CONSTS);
1355
1356   // Branch to the finally block
1357   builder.CreateBr(finallyBlock);
1358
1359   // Exception Route Block
1360
1361   builder.SetInsertPoint(exceptionRouteBlock);
1362
1363   // Casts exception pointer (_Unwind_Exception instance) to parent
1364   // (OurException instance).
1365   //
1366   // Note: ourBaseFromUnwindOffset is usually negative
1367   llvm::Value *typeInfoThrown = builder.CreatePointerCast(
1368                                   builder.CreateConstGEP1_64(unwindException,
1369                                                        ourBaseFromUnwindOffset),
1370                                   ourExceptionType->getPointerTo());
1371
1372   // Retrieve thrown exception type info type
1373   //
1374   // Note: Index is not relative to pointer but instead to structure
1375   //       unlike a true getelementptr (GEP) instruction
1376   typeInfoThrown = builder.CreateStructGEP(typeInfoThrown, 0);
1377
1378   llvm::Value *typeInfoThrownType =
1379   builder.CreateStructGEP(typeInfoThrown, 0);
1380
1381   generateIntegerPrint(context,
1382                        module,
1383                        builder,
1384                        *toPrint32Int,
1385                        *(builder.CreateLoad(typeInfoThrownType)),
1386                        "Gen: Exception type <%d> received (stack unwound) "
1387                        " in " +
1388                        ourId +
1389                        ".\n",
1390                        USE_GLOBAL_STR_CONSTS);
1391
1392   // Route to matched type info catch block or run cleanup finally block
1393   llvm::SwitchInst *switchToCatchBlock = builder.CreateSwitch(retTypeInfoIndex,
1394                                                           finallyBlock,
1395                                                           numExceptionsToCatch);
1396
1397   unsigned nextTypeToCatch;
1398
1399   for (unsigned i = 1; i <= numExceptionsToCatch; ++i) {
1400     nextTypeToCatch = i - 1;
1401     switchToCatchBlock->addCase(llvm::ConstantInt::get(
1402                                    llvm::Type::getInt32Ty(context), i),
1403                                 catchBlocks[nextTypeToCatch]);
1404   }
1405
1406 #ifdef OLD_EXC_SYSTEM
1407   // Must be run before verifier
1408   UpgradeExceptionHandling(&module);
1409 #endif
1410
1411
1412   llvm::verifyFunction(*ret);
1413   fpm.run(*ret);
1414
1415   return(ret);
1416 }
1417
1418
1419 /// Generates function which throws either an exception matched to a runtime
1420 /// determined type info type (argument to generated function), or if this
1421 /// runtime value matches nativeThrowType, throws a foreign exception by
1422 /// calling nativeThrowFunct.
1423 /// @param module code for module instance
1424 /// @param builder builder instance
1425 /// @param fpm a function pass manager holding optional IR to IR
1426 ///        transformations
1427 /// @param ourId id used to printing purposes
1428 /// @param nativeThrowType a runtime argument of this value results in
1429 ///        nativeThrowFunct being called to generate/throw exception.
1430 /// @param nativeThrowFunct function which will throw a foreign exception
1431 ///        if the above nativeThrowType matches generated function's arg.
1432 /// @returns generated function
1433 static
1434 llvm::Function *createThrowExceptionFunction(llvm::Module &module,
1435                                              llvm::IRBuilder<> &builder,
1436                                              llvm::FunctionPassManager &fpm,
1437                                              std::string ourId,
1438                                              int32_t nativeThrowType,
1439                                              llvm::Function &nativeThrowFunct) {
1440   llvm::LLVMContext &context = module.getContext();
1441   namedValues.clear();
1442   ArgTypes unwindArgTypes;
1443   unwindArgTypes.push_back(builder.getInt32Ty());
1444   ArgNames unwindArgNames;
1445   unwindArgNames.push_back("exceptTypeToThrow");
1446
1447   llvm::Function *ret = createFunction(module,
1448                                        builder.getVoidTy(),
1449                                        unwindArgTypes,
1450                                        unwindArgNames,
1451                                        ourId,
1452                                        llvm::Function::ExternalLinkage,
1453                                        false,
1454                                        false);
1455
1456   // Throws either one of our exception or a native C++ exception depending
1457   // on a runtime argument value containing a type info type.
1458   llvm::BasicBlock *entryBlock = llvm::BasicBlock::Create(context,
1459                                                           "entry",
1460                                                           ret);
1461   // Throws a foreign exception
1462   llvm::BasicBlock *nativeThrowBlock = llvm::BasicBlock::Create(context,
1463                                                                 "nativeThrow",
1464                                                                 ret);
1465   // Throws one of our Exceptions
1466   llvm::BasicBlock *generatedThrowBlock = llvm::BasicBlock::Create(context,
1467                                                              "generatedThrow",
1468                                                              ret);
1469   // Retrieved runtime type info type to throw
1470   llvm::Value *exceptionType = namedValues["exceptTypeToThrow"];
1471
1472   // nativeThrowBlock block
1473
1474   builder.SetInsertPoint(nativeThrowBlock);
1475
1476   // Throws foreign exception
1477   builder.CreateCall(&nativeThrowFunct, exceptionType);
1478   builder.CreateUnreachable();
1479
1480   // entry block
1481
1482   builder.SetInsertPoint(entryBlock);
1483
1484   llvm::Function *toPrint32Int = module.getFunction("print32Int");
1485   generateIntegerPrint(context,
1486                        module,
1487                        builder,
1488                        *toPrint32Int,
1489                        *exceptionType,
1490                        "\nGen: About to throw exception type <%d> in " +
1491                        ourId +
1492                        ".\n",
1493                        USE_GLOBAL_STR_CONSTS);
1494
1495   // Switches on runtime type info type value to determine whether or not
1496   // a foreign exception is thrown. Defaults to throwing one of our
1497   // generated exceptions.
1498   llvm::SwitchInst *theSwitch = builder.CreateSwitch(exceptionType,
1499                                                      generatedThrowBlock,
1500                                                      1);
1501
1502   theSwitch->addCase(llvm::ConstantInt::get(llvm::Type::getInt32Ty(context),
1503                                             nativeThrowType),
1504                      nativeThrowBlock);
1505
1506   // generatedThrow block
1507
1508   builder.SetInsertPoint(generatedThrowBlock);
1509
1510   llvm::Function *createOurException = module.getFunction("createOurException");
1511   llvm::Function *raiseOurException = module.getFunction(
1512                                         "_Unwind_RaiseException");
1513
1514   // Creates exception to throw with runtime type info type.
1515   llvm::Value *exception = builder.CreateCall(createOurException,
1516                                               namedValues["exceptTypeToThrow"]);
1517
1518   // Throw generated Exception
1519   builder.CreateCall(raiseOurException, exception);
1520   builder.CreateUnreachable();
1521
1522   llvm::verifyFunction(*ret);
1523   fpm.run(*ret);
1524
1525   return(ret);
1526 }
1527
1528 static void createStandardUtilityFunctions(unsigned numTypeInfos,
1529                                            llvm::Module &module,
1530                                            llvm::IRBuilder<> &builder);
1531
1532 /// Creates test code by generating and organizing these functions into the
1533 /// test case. The test case consists of an outer function setup to invoke
1534 /// an inner function within an environment having multiple catch and single
1535 /// finally blocks. This inner function is also setup to invoke a throw
1536 /// function within an evironment similar in nature to the outer function's
1537 /// catch and finally blocks. Each of these two functions catch mutually
1538 /// exclusive subsets (even or odd) of the type info types configured
1539 /// for this this. All generated functions have a runtime argument which
1540 /// holds a type info type to throw that each function takes and passes it
1541 /// to the inner one if such a inner function exists. This type info type is
1542 /// looked at by the generated throw function to see whether or not it should
1543 /// throw a generated exception with the same type info type, or instead call
1544 /// a supplied a function which in turn will throw a foreign exception.
1545 /// @param module code for module instance
1546 /// @param builder builder instance
1547 /// @param fpm a function pass manager holding optional IR to IR
1548 ///        transformations
1549 /// @param nativeThrowFunctName name of external function which will throw
1550 ///        a foreign exception
1551 /// @returns outermost generated test function.
1552 llvm::Function *createUnwindExceptionTest(llvm::Module &module,
1553                                           llvm::IRBuilder<> &builder,
1554                                           llvm::FunctionPassManager &fpm,
1555                                           std::string nativeThrowFunctName) {
1556   // Number of type infos to generate
1557   unsigned numTypeInfos = 6;
1558
1559   // Initialze intrisics and external functions to use along with exception
1560   // and type info globals.
1561   createStandardUtilityFunctions(numTypeInfos,
1562                                  module,
1563                                  builder);
1564   llvm::Function *nativeThrowFunct = module.getFunction(nativeThrowFunctName);
1565
1566   // Create exception throw function using the value ~0 to cause
1567   // foreign exceptions to be thrown.
1568   llvm::Function *throwFunct = createThrowExceptionFunction(module,
1569                                                             builder,
1570                                                             fpm,
1571                                                             "throwFunct",
1572                                                             ~0,
1573                                                             *nativeThrowFunct);
1574   // Inner function will catch even type infos
1575   unsigned innerExceptionTypesToCatch[] = {6, 2, 4};
1576   size_t numExceptionTypesToCatch = sizeof(innerExceptionTypesToCatch) /
1577                                     sizeof(unsigned);
1578
1579   // Generate inner function.
1580   llvm::Function *innerCatchFunct = createCatchWrappedInvokeFunction(module,
1581                                                     builder,
1582                                                     fpm,
1583                                                     *throwFunct,
1584                                                     "innerCatchFunct",
1585                                                     numExceptionTypesToCatch,
1586                                                     innerExceptionTypesToCatch);
1587
1588   // Outer function will catch odd type infos
1589   unsigned outerExceptionTypesToCatch[] = {3, 1, 5};
1590   numExceptionTypesToCatch = sizeof(outerExceptionTypesToCatch) /
1591   sizeof(unsigned);
1592
1593   // Generate outer function
1594   llvm::Function *outerCatchFunct = createCatchWrappedInvokeFunction(module,
1595                                                     builder,
1596                                                     fpm,
1597                                                     *innerCatchFunct,
1598                                                     "outerCatchFunct",
1599                                                     numExceptionTypesToCatch,
1600                                                     outerExceptionTypesToCatch);
1601
1602   // Return outer function to run
1603   return(outerCatchFunct);
1604 }
1605
1606
1607 /// Represents our foreign exceptions
1608 class OurCppRunException : public std::runtime_error {
1609 public:
1610   OurCppRunException(const std::string reason) :
1611   std::runtime_error(reason) {}
1612
1613   OurCppRunException (const OurCppRunException &toCopy) :
1614   std::runtime_error(toCopy) {}
1615
1616   OurCppRunException &operator = (const OurCppRunException &toCopy) {
1617     return(reinterpret_cast<OurCppRunException&>(
1618                                  std::runtime_error::operator=(toCopy)));
1619   }
1620
1621   ~OurCppRunException (void) throw () {}
1622 };
1623
1624
1625 /// Throws foreign C++ exception.
1626 /// @param ignoreIt unused parameter that allows function to match implied
1627 ///        generated function contract.
1628 extern "C"
1629 void throwCppException (int32_t ignoreIt) {
1630   throw(OurCppRunException("thrown by throwCppException(...)"));
1631 }
1632
1633 typedef void (*OurExceptionThrowFunctType) (int32_t typeToThrow);
1634
1635 /// This is a test harness which runs test by executing generated
1636 /// function with a type info type to throw. Harness wraps the execution
1637 /// of generated function in a C++ try catch clause.
1638 /// @param engine execution engine to use for executing generated function.
1639 ///        This demo program expects this to be a JIT instance for demo
1640 ///        purposes.
1641 /// @param function generated test function to run
1642 /// @param typeToThrow type info type of generated exception to throw, or
1643 ///        indicator to cause foreign exception to be thrown.
1644 static
1645 void runExceptionThrow(llvm::ExecutionEngine *engine,
1646                        llvm::Function *function,
1647                        int32_t typeToThrow) {
1648
1649   // Find test's function pointer
1650   OurExceptionThrowFunctType functPtr =
1651     reinterpret_cast<OurExceptionThrowFunctType>(
1652        reinterpret_cast<intptr_t>(engine->getPointerToFunction(function)));
1653
1654   try {
1655     // Run test
1656     (*functPtr)(typeToThrow);
1657   }
1658   catch (OurCppRunException exc) {
1659     // Catch foreign C++ exception
1660     fprintf(stderr,
1661             "\nrunExceptionThrow(...):In C++ catch OurCppRunException "
1662             "with reason: %s.\n",
1663             exc.what());
1664   }
1665   catch (...) {
1666     // Catch all exceptions including our generated ones. I'm not sure
1667     // why this latter functionality should work, as it seems that
1668     // our exceptions should be foreign to C++ (the _Unwind_Exception::
1669     // exception_class should be different from the one used by C++), and
1670     // therefore C++ should ignore the generated exceptions.
1671
1672     fprintf(stderr,
1673             "\nrunExceptionThrow(...):In C++ catch all.\n");
1674   }
1675 }
1676
1677 //
1678 // End test functions
1679 //
1680
1681 typedef llvm::ArrayRef<llvm::Type*> TypeArray;
1682
1683 /// This initialization routine creates type info globals and
1684 /// adds external function declarations to module.
1685 /// @param numTypeInfos number of linear type info associated type info types
1686 ///        to create as GlobalVariable instances, starting with the value 1.
1687 /// @param module code for module instance
1688 /// @param builder builder instance
1689 static void createStandardUtilityFunctions(unsigned numTypeInfos,
1690                                            llvm::Module &module,
1691                                            llvm::IRBuilder<> &builder) {
1692
1693   llvm::LLVMContext &context = module.getContext();
1694
1695   // Exception initializations
1696
1697   // Setup exception catch state
1698   ourExceptionNotThrownState =
1699     llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 0),
1700   ourExceptionThrownState =
1701     llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 1),
1702   ourExceptionCaughtState =
1703     llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 2),
1704
1705
1706
1707   // Create our type info type
1708   ourTypeInfoType = llvm::StructType::get(context,
1709                                           TypeArray(builder.getInt32Ty()));
1710
1711 #ifndef OLD_EXC_SYSTEM
1712
1713   llvm::Type *caughtResultFieldTypes[] = {
1714     builder.getInt8PtrTy(),
1715     builder.getInt32Ty()
1716   };
1717
1718   // Create our landingpad result type
1719   ourCaughtResultType = llvm::StructType::get(context,
1720                                             TypeArray(caughtResultFieldTypes));
1721
1722 #endif
1723
1724   // Create OurException type
1725   ourExceptionType = llvm::StructType::get(context,
1726                                            TypeArray(ourTypeInfoType));
1727
1728   // Create portion of _Unwind_Exception type
1729   //
1730   // Note: Declaring only a portion of the _Unwind_Exception struct.
1731   //       Does this cause problems?
1732   ourUnwindExceptionType =
1733     llvm::StructType::get(context,
1734                     TypeArray(builder.getInt64Ty()));
1735
1736   struct OurBaseException_t dummyException;
1737
1738   // Calculate offset of OurException::unwindException member.
1739   ourBaseFromUnwindOffset = ((uintptr_t) &dummyException) -
1740                             ((uintptr_t) &(dummyException.unwindException));
1741
1742 #ifdef DEBUG
1743   fprintf(stderr,
1744           "createStandardUtilityFunctions(...):ourBaseFromUnwindOffset "
1745           "= %lld, sizeof(struct OurBaseException_t) - "
1746           "sizeof(struct _Unwind_Exception) = %lu.\n",
1747           ourBaseFromUnwindOffset,
1748           sizeof(struct OurBaseException_t) -
1749           sizeof(struct _Unwind_Exception));
1750 #endif
1751
1752   size_t numChars = sizeof(ourBaseExcpClassChars) / sizeof(char);
1753
1754   // Create our _Unwind_Exception::exception_class value
1755   ourBaseExceptionClass = genClass(ourBaseExcpClassChars, numChars);
1756
1757   // Type infos
1758
1759   std::string baseStr = "typeInfo", typeInfoName;
1760   std::ostringstream typeInfoNameBuilder;
1761   std::vector<llvm::Constant*> structVals;
1762
1763   llvm::Constant *nextStruct;
1764   llvm::GlobalVariable *nextGlobal = NULL;
1765
1766   // Generate each type info
1767   //
1768   // Note: First type info is not used.
1769   for (unsigned i = 0; i <= numTypeInfos; ++i) {
1770     structVals.clear();
1771     structVals.push_back(llvm::ConstantInt::get(builder.getInt32Ty(), i));
1772     nextStruct = llvm::ConstantStruct::get(ourTypeInfoType, structVals);
1773
1774     typeInfoNameBuilder.str("");
1775     typeInfoNameBuilder << baseStr << i;
1776     typeInfoName = typeInfoNameBuilder.str();
1777
1778     // Note: Does not seem to work without allocation
1779     nextGlobal =
1780     new llvm::GlobalVariable(module,
1781                              ourTypeInfoType,
1782                              true,
1783                              llvm::GlobalValue::ExternalLinkage,
1784                              nextStruct,
1785                              typeInfoName);
1786
1787     ourTypeInfoNames.push_back(typeInfoName);
1788     ourTypeInfoNamesIndex[i] = typeInfoName;
1789   }
1790
1791   ArgNames argNames;
1792   ArgTypes argTypes;
1793   llvm::Function *funct = NULL;
1794
1795   // print32Int
1796
1797   llvm::Type *retType = builder.getVoidTy();
1798
1799   argTypes.clear();
1800   argTypes.push_back(builder.getInt32Ty());
1801   argTypes.push_back(builder.getInt8PtrTy());
1802
1803   argNames.clear();
1804
1805   createFunction(module,
1806                  retType,
1807                  argTypes,
1808                  argNames,
1809                  "print32Int",
1810                  llvm::Function::ExternalLinkage,
1811                  true,
1812                  false);
1813
1814   // print64Int
1815
1816   retType = builder.getVoidTy();
1817
1818   argTypes.clear();
1819   argTypes.push_back(builder.getInt64Ty());
1820   argTypes.push_back(builder.getInt8PtrTy());
1821
1822   argNames.clear();
1823
1824   createFunction(module,
1825                  retType,
1826                  argTypes,
1827                  argNames,
1828                  "print64Int",
1829                  llvm::Function::ExternalLinkage,
1830                  true,
1831                  false);
1832
1833   // printStr
1834
1835   retType = builder.getVoidTy();
1836
1837   argTypes.clear();
1838   argTypes.push_back(builder.getInt8PtrTy());
1839
1840   argNames.clear();
1841
1842   createFunction(module,
1843                  retType,
1844                  argTypes,
1845                  argNames,
1846                  "printStr",
1847                  llvm::Function::ExternalLinkage,
1848                  true,
1849                  false);
1850
1851   // throwCppException
1852
1853   retType = builder.getVoidTy();
1854
1855   argTypes.clear();
1856   argTypes.push_back(builder.getInt32Ty());
1857
1858   argNames.clear();
1859
1860   createFunction(module,
1861                  retType,
1862                  argTypes,
1863                  argNames,
1864                  "throwCppException",
1865                  llvm::Function::ExternalLinkage,
1866                  true,
1867                  false);
1868
1869   // deleteOurException
1870
1871   retType = builder.getVoidTy();
1872
1873   argTypes.clear();
1874   argTypes.push_back(builder.getInt8PtrTy());
1875
1876   argNames.clear();
1877
1878   createFunction(module,
1879                  retType,
1880                  argTypes,
1881                  argNames,
1882                  "deleteOurException",
1883                  llvm::Function::ExternalLinkage,
1884                  true,
1885                  false);
1886
1887   // createOurException
1888
1889   retType = builder.getInt8PtrTy();
1890
1891   argTypes.clear();
1892   argTypes.push_back(builder.getInt32Ty());
1893
1894   argNames.clear();
1895
1896   createFunction(module,
1897                  retType,
1898                  argTypes,
1899                  argNames,
1900                  "createOurException",
1901                  llvm::Function::ExternalLinkage,
1902                  true,
1903                  false);
1904
1905   // _Unwind_RaiseException
1906
1907   retType = builder.getInt32Ty();
1908
1909   argTypes.clear();
1910   argTypes.push_back(builder.getInt8PtrTy());
1911
1912   argNames.clear();
1913
1914   funct = createFunction(module,
1915                          retType,
1916                          argTypes,
1917                          argNames,
1918                          "_Unwind_RaiseException",
1919                          llvm::Function::ExternalLinkage,
1920                          true,
1921                          false);
1922
1923   funct->addFnAttr(llvm::Attribute::NoReturn);
1924
1925   // _Unwind_Resume
1926
1927   retType = builder.getInt32Ty();
1928
1929   argTypes.clear();
1930   argTypes.push_back(builder.getInt8PtrTy());
1931
1932   argNames.clear();
1933
1934   funct = createFunction(module,
1935                          retType,
1936                          argTypes,
1937                          argNames,
1938                          "_Unwind_Resume",
1939                          llvm::Function::ExternalLinkage,
1940                          true,
1941                          false);
1942
1943   funct->addFnAttr(llvm::Attribute::NoReturn);
1944
1945   // ourPersonality
1946
1947   retType = builder.getInt32Ty();
1948
1949   argTypes.clear();
1950   argTypes.push_back(builder.getInt32Ty());
1951   argTypes.push_back(builder.getInt32Ty());
1952   argTypes.push_back(builder.getInt64Ty());
1953   argTypes.push_back(builder.getInt8PtrTy());
1954   argTypes.push_back(builder.getInt8PtrTy());
1955
1956   argNames.clear();
1957
1958   createFunction(module,
1959                  retType,
1960                  argTypes,
1961                  argNames,
1962                  "ourPersonality",
1963                  llvm::Function::ExternalLinkage,
1964                  true,
1965                  false);
1966
1967   // llvm.eh.selector intrinsic
1968
1969   getDeclaration(&module, llvm::Intrinsic::eh_selector);
1970
1971   // llvm.eh.exception intrinsic
1972
1973   getDeclaration(&module, llvm::Intrinsic::eh_exception);
1974
1975   // llvm.eh.typeid.for intrinsic
1976
1977   getDeclaration(&module, llvm::Intrinsic::eh_typeid_for);
1978 }
1979
1980
1981 //===----------------------------------------------------------------------===//
1982 // Main test driver code.
1983 //===----------------------------------------------------------------------===//
1984
1985 /// Demo main routine which takes the type info types to throw. A test will
1986 /// be run for each given type info type. While type info types with the value
1987 /// of -1 will trigger a foreign C++ exception to be thrown; type info types
1988 /// <= 6 and >= 1 will be caught by test functions; and type info types > 6
1989 /// will result in exceptions which pass through to the test harness. All other
1990 /// type info types are not supported and could cause a crash.
1991 int main(int argc, char *argv[]) {
1992   if (argc == 1) {
1993     fprintf(stderr,
1994             "\nUsage: ExceptionDemo <exception type to throw> "
1995             "[<type 2>...<type n>].\n"
1996             "   Each type must have the value of 1 - 6 for "
1997             "generated exceptions to be caught;\n"
1998             "   the value -1 for foreign C++ exceptions to be "
1999             "generated and thrown;\n"
2000             "   or the values > 6 for exceptions to be ignored.\n"
2001             "\nTry: ExceptionDemo 2 3 7 -1\n"
2002             "   for a full test.\n\n");
2003     return(0);
2004   }
2005
2006   // If not set, exception handling will not be turned on
2007   llvm::JITExceptionHandling = true;
2008
2009   llvm::InitializeNativeTarget();
2010   llvm::LLVMContext &context = llvm::getGlobalContext();
2011   llvm::IRBuilder<> theBuilder(context);
2012
2013   // Make the module, which holds all the code.
2014   llvm::Module *module = new llvm::Module("my cool jit", context);
2015
2016   // Build engine with JIT
2017   llvm::EngineBuilder factory(module);
2018   factory.setEngineKind(llvm::EngineKind::JIT);
2019   factory.setAllocateGVsWithCode(false);
2020   llvm::ExecutionEngine *executionEngine = factory.create();
2021
2022   {
2023     llvm::FunctionPassManager fpm(module);
2024
2025     // Set up the optimizer pipeline.
2026     // Start with registering info about how the
2027     // target lays out data structures.
2028     fpm.add(new llvm::TargetData(*executionEngine->getTargetData()));
2029
2030     // Optimizations turned on
2031 #ifdef ADD_OPT_PASSES
2032
2033     // Basic AliasAnslysis support for GVN.
2034     fpm.add(llvm::createBasicAliasAnalysisPass());
2035
2036     // Promote allocas to registers.
2037     fpm.add(llvm::createPromoteMemoryToRegisterPass());
2038
2039     // Do simple "peephole" optimizations and bit-twiddling optzns.
2040     fpm.add(llvm::createInstructionCombiningPass());
2041
2042     // Reassociate expressions.
2043     fpm.add(llvm::createReassociatePass());
2044
2045     // Eliminate Common SubExpressions.
2046     fpm.add(llvm::createGVNPass());
2047
2048     // Simplify the control flow graph (deleting unreachable
2049     // blocks, etc).
2050     fpm.add(llvm::createCFGSimplificationPass());
2051 #endif  // ADD_OPT_PASSES
2052
2053     fpm.doInitialization();
2054
2055     // Generate test code using function throwCppException(...) as
2056     // the function which throws foreign exceptions.
2057     llvm::Function *toRun =
2058     createUnwindExceptionTest(*module,
2059                               theBuilder,
2060                               fpm,
2061                               "throwCppException");
2062
2063     fprintf(stderr, "\nBegin module dump:\n\n");
2064
2065     module->dump();
2066
2067     fprintf(stderr, "\nEnd module dump:\n");
2068
2069     fprintf(stderr, "\n\nBegin Test:\n");
2070
2071     for (int i = 1; i < argc; ++i) {
2072       // Run test for each argument whose value is the exception
2073       // type to throw.
2074       runExceptionThrow(executionEngine,
2075                         toRun,
2076                         (unsigned) strtoul(argv[i], NULL, 10));
2077     }
2078
2079     fprintf(stderr, "\nEnd Test:\n\n");
2080   }
2081
2082   delete executionEngine;
2083
2084   return 0;
2085 }
2086