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 explained by: example in rules 1.6.4 in
  44 //         http://mentorembedded.github.com/cxx-abi/abi-eh.html (v1.22)
  45 //
  46 // This code uses code from the llvm compiler-rt project and the llvm
  47 // Kaleidoscope project.
  48 //
  49 //===----------------------------------------------------------------------===//
  50
  51 #include "llvm/ADT/STLExtras.h"
  52 #include "llvm/IR/Verifier.h"
  53 #include "llvm/ExecutionEngine/MCJIT.h"
  54 #include "llvm/ExecutionEngine/SectionMemoryManager.h"
  55 #include "llvm/IR/DataLayout.h"
  56 #include "llvm/IR/DerivedTypes.h"
  57 #include "llvm/IR/IRBuilder.h"
  58 #include "llvm/IR/Intrinsics.h"
  59 #include "llvm/IR/LLVMContext.h"
  60 #include "llvm/IR/LegacyPassManager.h"
  61 #include "llvm/IR/Module.h"
  62 #include "llvm/Support/Dwarf.h"
  63 #include "llvm/Support/TargetSelect.h"
  64 #include "llvm/Target/TargetOptions.h"
  65 #include "llvm/Transforms/Scalar.h"
  66
  67 // FIXME: Although all systems tested with (Linux, OS X), do not need this
  68 //        header file included. A user on ubuntu reported, undefined symbols
  69 //        for stderr, and fprintf, and the addition of this include fixed the
  70 //        issue for them. Given that LLVM's best practices include the goal
  71 //        of reducing the number of redundant header files included, the
  72 //        correct solution would be to find out why these symbols are not
  73 //        defined for the system in question, and fix the issue by finding out
  74 //        which LLVM header file, if any, would include these symbols.
  75 #include <cstdio>
  76
  77 #include <sstream>
  78 #include <stdexcept>
  79
  80
  81 #ifndef USE_GLOBAL_STR_CONSTS
  82 #define USE_GLOBAL_STR_CONSTS true
  83 #endif
  84
  85 // System C++ ABI unwind types from:
  86 //     http://mentorembedded.github.com/cxx-abi/abi-eh.html (v1.22)
  87
  88 extern "C" {
  89
  90   typedef enum {
  91     _URC_NO_REASON = 0,
  92     _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
  93     _URC_FATAL_PHASE2_ERROR = 2,
  94     _URC_FATAL_PHASE1_ERROR = 3,
  95     _URC_NORMAL_STOP = 4,
  96     _URC_END_OF_STACK = 5,
  97     _URC_HANDLER_FOUND = 6,
  98     _URC_INSTALL_CONTEXT = 7,
  99     _URC_CONTINUE_UNWIND = 8
 100   } _Unwind_Reason_Code;
 101
 102   typedef enum {
 103     _UA_SEARCH_PHASE = 1,
 104     _UA_CLEANUP_PHASE = 2,
 105     _UA_HANDLER_FRAME = 4,
 106     _UA_FORCE_UNWIND = 8,
 107     _UA_END_OF_STACK = 16
 108   } _Unwind_Action;
 109
 110   struct _Unwind_Exception;
 111
 112   typedef void (*_Unwind_Exception_Cleanup_Fn) (_Unwind_Reason_Code,
 113                                                 struct _Unwind_Exception *);
 114
 115   struct _Unwind_Exception {
 116     uint64_t exception_class;
 117     _Unwind_Exception_Cleanup_Fn exception_cleanup;
 118
 119     uintptr_t private_1;
 120     uintptr_t private_2;
 121
 122     // @@@ The IA-64 ABI says that this structure must be double-word aligned.
 123     //  Taking that literally does not make much sense generically.  Instead
 124     //  we provide the maximum alignment required by any type for the machine.
 125   } __attribute__((__aligned__));
 126
 127   struct _Unwind_Context;
 128   typedef struct _Unwind_Context *_Unwind_Context_t;
 129
 130   extern const uint8_t *_Unwind_GetLanguageSpecificData (_Unwind_Context_t c);
 131   extern uintptr_t _Unwind_GetGR (_Unwind_Context_t c, int i);
 132   extern void _Unwind_SetGR (_Unwind_Context_t c, int i, uintptr_t n);
 133   extern void _Unwind_SetIP (_Unwind_Context_t, uintptr_t new_value);
 134   extern uintptr_t _Unwind_GetIP (_Unwind_Context_t context);
 135   extern uintptr_t _Unwind_GetRegionStart (_Unwind_Context_t context);
 136
 137 } // extern "C"
 138
 139 //
 140 // Example types
 141 //
 142
 143 /// This is our simplistic type info
 144 struct OurExceptionType_t {
 145   /// type info type
 146   int type;
 147 };
 148
 149
 150 /// This is our Exception class which relies on a negative offset to calculate
 151 /// pointers to its instances from pointers to its unwindException member.
 152 ///
 153 /// Note: The above unwind.h defines struct _Unwind_Exception to be aligned
 154 ///       on a double word boundary. This is necessary to match the standard:
 155 ///       http://mentorembedded.github.com/cxx-abi/abi-eh.html
 156 struct OurBaseException_t {
 157   struct OurExceptionType_t type;
 158
 159   // Note: This is properly aligned in unwind.h
 160   struct _Unwind_Exception unwindException;
 161 };
 162
 163
 164 // Note: Not needed since we are C++
 165 typedef struct OurBaseException_t OurException;
 166 typedef struct _Unwind_Exception OurUnwindException;
 167
 168 //
 169 // Various globals used to support typeinfo and generatted exceptions in
 170 // general
 171 //
 172
 173 static std::map<std::string, llvm::Value*> namedValues;
 174
 175 int64_t ourBaseFromUnwindOffset;
 176
 177 const unsigned char ourBaseExcpClassChars[] =
 178 {'o', 'b', 'j', '\0', 'b', 'a', 's', '\0'};
 179
 180
 181 static uint64_t ourBaseExceptionClass = 0;
 182
 183 static std::vector<std::string> ourTypeInfoNames;
 184 static std::map<int, std::string> ourTypeInfoNamesIndex;
 185
 186 static llvm::StructType *ourTypeInfoType;
 187 static llvm::StructType *ourCaughtResultType;
 188 static llvm::StructType *ourExceptionType;
 189 static llvm::StructType *ourUnwindExceptionType;
 190
 191 static llvm::ConstantInt *ourExceptionNotThrownState;
 192 static llvm::ConstantInt *ourExceptionThrownState;
 193 static llvm::ConstantInt *ourExceptionCaughtState;
 194
 195 typedef std::vector<std::string> ArgNames;
 196 typedef std::vector<llvm::Type*> ArgTypes;
 197
 198 //
 199 // Code Generation Utilities
 200 //
 201
 202 /// Utility used to create a function, both declarations and definitions
 203 /// @param module for module instance
 204 /// @param retType function return type
 205 /// @param theArgTypes function's ordered argument types
 206 /// @param theArgNames function's ordered arguments needed if use of this
 207 ///        function corresponds to a function definition. Use empty
 208 ///        aggregate for function declarations.
 209 /// @param functName function name
 210 /// @param linkage function linkage
 211 /// @param declarationOnly for function declarations
 212 /// @param isVarArg function uses vararg arguments
 213 /// @returns function instance
 214 llvm::Function *createFunction(llvm::Module &module,
 215                                llvm::Type *retType,
 216                                const ArgTypes &theArgTypes,
 217                                const ArgNames &theArgNames,
 218                                const std::string &functName,
 219                                llvm::GlobalValue::LinkageTypes linkage,
 220                                bool declarationOnly,
 221                                bool isVarArg) {
 222   llvm::FunctionType *functType =
 223     llvm::FunctionType::get(retType, theArgTypes, isVarArg);
 224   llvm::Function *ret =
 225     llvm::Function::Create(functType, linkage, functName, &module);
 226   if (!ret || declarationOnly)
 227     return(ret);
 228
 229   namedValues.clear();
 230   unsigned i = 0;
 231   for (llvm::Function::arg_iterator argIndex = ret->arg_begin();
 232        i != theArgNames.size();
 233        ++argIndex, ++i) {
 234
 235     argIndex->setName(theArgNames[i]);
 236     namedValues[theArgNames[i]] = argIndex;
 237   }
 238
 239   return(ret);
 240 }
 241
 242
 243 /// Create an alloca instruction in the entry block of
 244 /// the parent function.  This is used for mutable variables etc.
 245 /// @param function parent instance
 246 /// @param varName stack variable name
 247 /// @param type stack variable type
 248 /// @param initWith optional constant initialization value
 249 /// @returns AllocaInst instance
 250 static llvm::AllocaInst *createEntryBlockAlloca(llvm::Function &function,
 251                                                 const std::string &varName,
 252                                                 llvm::Type *type,
 253                                                 llvm::Constant *initWith = 0) {
 254   llvm::BasicBlock &block = function.getEntryBlock();
 255   llvm::IRBuilder<> tmp(&block, block.begin());
 256   llvm::AllocaInst *ret = tmp.CreateAlloca(type, 0, varName.c_str());
 257
 258   if (initWith)
 259     tmp.CreateStore(initWith, ret);
 260
 261   return(ret);
 262 }
 263
 264
 265 //
 266 // Code Generation Utilities End
 267 //
 268
 269 //
 270 // Runtime C Library functions
 271 //
 272
 273 // Note: using an extern "C" block so that static functions can be used
 274 extern "C" {
 275
 276 // Note: Better ways to decide on bit width
 277 //
 278 /// Prints a 32 bit number, according to the format, to stderr.
 279 /// @param intToPrint integer to print
 280 /// @param format printf like format to use when printing
 281 void print32Int(int intToPrint, const char *format) {
 282   if (format) {
 283     // Note: No NULL check
 284     fprintf(stderr, format, intToPrint);
 285   }
 286   else {
 287     // Note: No NULL check
 288     fprintf(stderr, "::print32Int(...):NULL arg.\n");
 289   }
 290 }
 291
 292
 293 // Note: Better ways to decide on bit width
 294 //
 295 /// Prints a 64 bit number, according to the format, to stderr.
 296 /// @param intToPrint integer to print
 297 /// @param format printf like format to use when printing
 298 void print64Int(long int intToPrint, const char *format) {
 299   if (format) {
 300     // Note: No NULL check
 301     fprintf(stderr, format, intToPrint);
 302   }
 303   else {
 304     // Note: No NULL check
 305     fprintf(stderr, "::print64Int(...):NULL arg.\n");
 306   }
 307 }
 308
 309
 310 /// Prints a C string to stderr
 311 /// @param toPrint string to print
 312 void printStr(char *toPrint) {
 313   if (toPrint) {
 314     fprintf(stderr, "%s", toPrint);
 315   }
 316   else {
 317     fprintf(stderr, "::printStr(...):NULL arg.\n");
 318   }
 319 }
 320
 321
 322 /// Deletes the true previosly allocated exception whose address
 323 /// is calculated from the supplied OurBaseException_t::unwindException
 324 /// member address. Handles (ignores), NULL pointers.
 325 /// @param expToDelete exception to delete
 326 void deleteOurException(OurUnwindException *expToDelete) {
 327 #ifdef DEBUG
 328   fprintf(stderr,
 329           "deleteOurException(...).\n");
 330 #endif
 331
 332   if (expToDelete &&
 333       (expToDelete->exception_class == ourBaseExceptionClass)) {
 334
 335     free(((char*) expToDelete) + ourBaseFromUnwindOffset);
 336   }
 337 }
 338
 339
 340 /// This function is the struct _Unwind_Exception API mandated delete function
 341 /// used by foreign exception handlers when deleting our exception
 342 /// (OurException), instances.
 343 /// @param reason See @link http://mentorembedded.github.com/cxx-abi/abi-eh.html
 344 /// @unlink
 345 /// @param expToDelete exception instance to delete
 346 void deleteFromUnwindOurException(_Unwind_Reason_Code reason,
 347                                   OurUnwindException *expToDelete) {
 348 #ifdef DEBUG
 349   fprintf(stderr,
 350           "deleteFromUnwindOurException(...).\n");
 351 #endif
 352
 353   deleteOurException(expToDelete);
 354 }
 355
 356
 357 /// Creates (allocates on the heap), an exception (OurException instance),
 358 /// of the supplied type info type.
 359 /// @param type type info type
 360 OurUnwindException *createOurException(int type) {
 361   size_t size = sizeof(OurException);
 362   OurException *ret = (OurException*) memset(malloc(size), 0, size);
 363   (ret->type).type = type;
 364   (ret->unwindException).exception_class = ourBaseExceptionClass;
 365   (ret->unwindException).exception_cleanup = deleteFromUnwindOurException;
 366
 367   return(&(ret->unwindException));
 368 }
 369
 370
 371 /// Read a uleb128 encoded value and advance pointer
 372 /// See Variable Length Data in:
 373 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 374 /// @param data reference variable holding memory pointer to decode from
 375 /// @returns decoded value
 376 static uintptr_t readULEB128(const uint8_t **data) {
 377   uintptr_t result = 0;
 378   uintptr_t shift = 0;
 379   unsigned char byte;
 380   const uint8_t *p = *data;
 381
 382   do {
 383     byte = *p++;
 384     result |= (byte & 0x7f) << shift;
 385     shift += 7;
 386   }
 387   while (byte & 0x80);
 388
 389   *data = p;
 390
 391   return result;
 392 }
 393
 394
 395 /// Read a sleb128 encoded value and advance pointer
 396 /// See Variable Length Data in:
 397 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 398 /// @param data reference variable holding memory pointer to decode from
 399 /// @returns decoded value
 400 static uintptr_t readSLEB128(const uint8_t **data) {
 401   uintptr_t result = 0;
 402   uintptr_t shift = 0;
 403   unsigned char byte;
 404   const uint8_t *p = *data;
 405
 406   do {
 407     byte = *p++;
 408     result |= (byte & 0x7f) << shift;
 409     shift += 7;
 410   }
 411   while (byte & 0x80);
 412
 413   *data = p;
 414
 415   if ((byte & 0x40) && (shift < (sizeof(result) << 3))) {
 416     result |= (~0 << shift);
 417   }
 418
 419   return result;
 420 }
 421
 422 unsigned getEncodingSize(uint8_t Encoding) {
 423   if (Encoding == llvm::dwarf::DW_EH_PE_omit)
 424     return 0;
 425
 426   switch (Encoding & 0x0F) {
 427   case llvm::dwarf::DW_EH_PE_absptr:
 428     return sizeof(uintptr_t);
 429   case llvm::dwarf::DW_EH_PE_udata2:
 430     return sizeof(uint16_t);
 431   case llvm::dwarf::DW_EH_PE_udata4:
 432     return sizeof(uint32_t);
 433   case llvm::dwarf::DW_EH_PE_udata8:
 434     return sizeof(uint64_t);
 435   case llvm::dwarf::DW_EH_PE_sdata2:
 436     return sizeof(int16_t);
 437   case llvm::dwarf::DW_EH_PE_sdata4:
 438     return sizeof(int32_t);
 439   case llvm::dwarf::DW_EH_PE_sdata8:
 440     return sizeof(int64_t);
 441   default:
 442     // not supported
 443     abort();
 444   }
 445 }
 446
 447 /// Read a pointer encoded value and advance pointer
 448 /// See Variable Length Data in:
 449 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 450 /// @param data reference variable holding memory pointer to decode from
 451 /// @param encoding dwarf encoding type
 452 /// @returns decoded value
 453 static uintptr_t readEncodedPointer(const uint8_t **data, uint8_t encoding) {
 454   uintptr_t result = 0;
 455   const uint8_t *p = *data;
 456
 457   if (encoding == llvm::dwarf::DW_EH_PE_omit)
 458     return(result);
 459
 460   // first get value
 461   switch (encoding & 0x0F) {
 462     case llvm::dwarf::DW_EH_PE_absptr:
 463       result = *((uintptr_t*)p);
 464       p += sizeof(uintptr_t);
 465       break;
 466     case llvm::dwarf::DW_EH_PE_uleb128:
 467       result = readULEB128(&p);
 468       break;
 469       // Note: This case has not been tested
 470     case llvm::dwarf::DW_EH_PE_sleb128:
 471       result = readSLEB128(&p);
 472       break;
 473     case llvm::dwarf::DW_EH_PE_udata2:
 474       result = *((uint16_t*)p);
 475       p += sizeof(uint16_t);
 476       break;
 477     case llvm::dwarf::DW_EH_PE_udata4:
 478       result = *((uint32_t*)p);
 479       p += sizeof(uint32_t);
 480       break;
 481     case llvm::dwarf::DW_EH_PE_udata8:
 482       result = *((uint64_t*)p);
 483       p += sizeof(uint64_t);
 484       break;
 485     case llvm::dwarf::DW_EH_PE_sdata2:
 486       result = *((int16_t*)p);
 487       p += sizeof(int16_t);
 488       break;
 489     case llvm::dwarf::DW_EH_PE_sdata4:
 490       result = *((int32_t*)p);
 491       p += sizeof(int32_t);
 492       break;
 493     case llvm::dwarf::DW_EH_PE_sdata8:
 494       result = *((int64_t*)p);
 495       p += sizeof(int64_t);
 496       break;
 497     default:
 498       // not supported
 499       abort();
 500       break;
 501   }
 502
 503   // then add relative offset
 504   switch (encoding & 0x70) {
 505     case llvm::dwarf::DW_EH_PE_absptr:
 506       // do nothing
 507       break;
 508     case llvm::dwarf::DW_EH_PE_pcrel:
 509       result += (uintptr_t)(*data);
 510       break;
 511     case llvm::dwarf::DW_EH_PE_textrel:
 512     case llvm::dwarf::DW_EH_PE_datarel:
 513     case llvm::dwarf::DW_EH_PE_funcrel:
 514     case llvm::dwarf::DW_EH_PE_aligned:
 515     default:
 516       // not supported
 517       abort();
 518       break;
 519   }
 520
 521   // then apply indirection
 522   if (encoding & llvm::dwarf::DW_EH_PE_indirect) {
 523     result = *((uintptr_t*)result);
 524   }
 525
 526   *data = p;
 527
 528   return result;
 529 }
 530
 531
 532 /// Deals with Dwarf actions matching our type infos
 533 /// (OurExceptionType_t instances). Returns whether or not a dwarf emitted
 534 /// action matches the supplied exception type. If such a match succeeds,
 535 /// the resultAction argument will be set with > 0 index value. Only
 536 /// corresponding llvm.eh.selector type info arguments, cleanup arguments
 537 /// are supported. Filters are not supported.
 538 /// See Variable Length Data in:
 539 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 540 /// Also see @link http://mentorembedded.github.com/cxx-abi/abi-eh.html @unlink
 541 /// @param resultAction reference variable which will be set with result
 542 /// @param classInfo our array of type info pointers (to globals)
 543 /// @param actionEntry index into above type info array or 0 (clean up).
 544 ///        We do not support filters.
 545 /// @param exceptionClass exception class (_Unwind_Exception::exception_class)
 546 ///        of thrown exception.
 547 /// @param exceptionObject thrown _Unwind_Exception instance.
 548 /// @returns whether or not a type info was found. False is returned if only
 549 ///          a cleanup was found
 550 static bool handleActionValue(int64_t *resultAction,
 551                               uint8_t TTypeEncoding,
 552                               const uint8_t *ClassInfo,
 553                               uintptr_t actionEntry,
 554                               uint64_t exceptionClass,
 555                               struct _Unwind_Exception *exceptionObject) {
 556   bool ret = false;
 557
 558   if (!resultAction ||
 559       !exceptionObject ||
 560       (exceptionClass != ourBaseExceptionClass))
 561     return(ret);
 562
 563   struct OurBaseException_t *excp = (struct OurBaseException_t*)
 564   (((char*) exceptionObject) + ourBaseFromUnwindOffset);
 565   struct OurExceptionType_t *excpType = &(excp->type);
 566   int type = excpType->type;
 567
 568 #ifdef DEBUG
 569   fprintf(stderr,
 570           "handleActionValue(...): exceptionObject = <%p>, "
 571           "excp = <%p>.\n",
 572           exceptionObject,
 573           excp);
 574 #endif
 575
 576   const uint8_t *actionPos = (uint8_t*) actionEntry,
 577   *tempActionPos;
 578   int64_t typeOffset = 0,
 579   actionOffset;
 580
 581   for (int i = 0; true; ++i) {
 582     // Each emitted dwarf action corresponds to a 2 tuple of
 583     // type info address offset, and action offset to the next
 584     // emitted action.
 585     typeOffset = readSLEB128(&actionPos);
 586     tempActionPos = actionPos;
 587     actionOffset = readSLEB128(&tempActionPos);
 588
 589 #ifdef DEBUG
 590     fprintf(stderr,
 591             "handleActionValue(...):typeOffset: <%lld>, "
 592             "actionOffset: <%lld>.\n",
 593             typeOffset,
 594             actionOffset);
 595 #endif
 596     assert((typeOffset >= 0) &&
 597            "handleActionValue(...):filters are not supported.");
 598
 599     // Note: A typeOffset == 0 implies that a cleanup llvm.eh.selector
 600     //       argument has been matched.
 601     if (typeOffset > 0) {
 602 #ifdef DEBUG
 603       fprintf(stderr,
 604               "handleActionValue(...):actionValue <%d> found.\n",
 605               i);
 606 #endif
 607       unsigned EncSize = getEncodingSize(TTypeEncoding);
 608       const uint8_t *EntryP = ClassInfo - typeOffset * EncSize;
 609       uintptr_t P = readEncodedPointer(&EntryP, TTypeEncoding);
 610       struct OurExceptionType_t *ThisClassInfo =
 611         reinterpret_cast<struct OurExceptionType_t *>(P);
 612       if (ThisClassInfo->type == type) {
 613         *resultAction = i + 1;
 614         ret = true;
 615         break;
 616       }
 617     }
 618
 619 #ifdef DEBUG
 620     fprintf(stderr,
 621             "handleActionValue(...):actionValue not found.\n");
 622 #endif
 623     if (!actionOffset)
 624       break;
 625
 626     actionPos += actionOffset;
 627   }
 628
 629   return(ret);
 630 }
 631
 632
 633 /// Deals with the Language specific data portion of the emitted dwarf code.
 634 /// See @link http://mentorembedded.github.com/cxx-abi/abi-eh.html @unlink
 635 /// @param version unsupported (ignored), unwind version
 636 /// @param lsda language specific data area
 637 /// @param _Unwind_Action actions minimally supported unwind stage
 638 ///        (forced specifically not supported)
 639 /// @param exceptionClass exception class (_Unwind_Exception::exception_class)
 640 ///        of thrown exception.
 641 /// @param exceptionObject thrown _Unwind_Exception instance.
 642 /// @param context unwind system context
 643 /// @returns minimally supported unwinding control indicator
 644 static _Unwind_Reason_Code handleLsda(int version,
 645                                       const uint8_t *lsda,
 646                                       _Unwind_Action actions,
 647                                       uint64_t exceptionClass,
 648                                     struct _Unwind_Exception *exceptionObject,
 649                                       _Unwind_Context_t context) {
 650   _Unwind_Reason_Code ret = _URC_CONTINUE_UNWIND;
 651
 652   if (!lsda)
 653     return(ret);
 654
 655 #ifdef DEBUG
 656   fprintf(stderr,
 657           "handleLsda(...):lsda is non-zero.\n");
 658 #endif
 659
 660   // Get the current instruction pointer and offset it before next
 661   // instruction in the current frame which threw the exception.
 662   uintptr_t pc = _Unwind_GetIP(context)-1;
 663
 664   // Get beginning current frame's code (as defined by the
 665   // emitted dwarf code)
 666   uintptr_t funcStart = _Unwind_GetRegionStart(context);
 667   uintptr_t pcOffset = pc - funcStart;
 668   const uint8_t *ClassInfo = NULL;
 669
 670   // Note: See JITDwarfEmitter::EmitExceptionTable(...) for corresponding
 671   //       dwarf emission
 672
 673   // Parse LSDA header.
 674   uint8_t lpStartEncoding = *lsda++;
 675
 676   if (lpStartEncoding != llvm::dwarf::DW_EH_PE_omit) {
 677     readEncodedPointer(&lsda, lpStartEncoding);
 678   }
 679
 680   uint8_t ttypeEncoding = *lsda++;
 681   uintptr_t classInfoOffset;
 682
 683   if (ttypeEncoding != llvm::dwarf::DW_EH_PE_omit) {
 684     // Calculate type info locations in emitted dwarf code which
 685     // were flagged by type info arguments to llvm.eh.selector
 686     // intrinsic
 687     classInfoOffset = readULEB128(&lsda);
 688     ClassInfo = lsda + classInfoOffset;
 689   }
 690
 691   // Walk call-site table looking for range that
 692   // includes current PC.
 693
 694   uint8_t         callSiteEncoding = *lsda++;
 695   uint32_t        callSiteTableLength = readULEB128(&lsda);
 696   const uint8_t   *callSiteTableStart = lsda;
 697   const uint8_t   *callSiteTableEnd = callSiteTableStart +
 698   callSiteTableLength;
 699   const uint8_t   *actionTableStart = callSiteTableEnd;
 700   const uint8_t   *callSitePtr = callSiteTableStart;
 701
 702   while (callSitePtr < callSiteTableEnd) {
 703     uintptr_t start = readEncodedPointer(&callSitePtr,
 704                                          callSiteEncoding);
 705     uintptr_t length = readEncodedPointer(&callSitePtr,
 706                                           callSiteEncoding);
 707     uintptr_t landingPad = readEncodedPointer(&callSitePtr,
 708                                               callSiteEncoding);
 709
 710     // Note: Action value
 711     uintptr_t actionEntry = readULEB128(&callSitePtr);
 712
 713     if (exceptionClass != ourBaseExceptionClass) {
 714       // We have been notified of a foreign exception being thrown,
 715       // and we therefore need to execute cleanup landing pads
 716       actionEntry = 0;
 717     }
 718
 719     if (landingPad == 0) {
 720 #ifdef DEBUG
 721       fprintf(stderr,
 722               "handleLsda(...): No landing pad found.\n");
 723 #endif
 724
 725       continue; // no landing pad for this entry
 726     }
 727
 728     if (actionEntry) {
 729       actionEntry += ((uintptr_t) actionTableStart) - 1;
 730     }
 731     else {
 732 #ifdef DEBUG
 733       fprintf(stderr,
 734               "handleLsda(...):No action table found.\n");
 735 #endif
 736     }
 737
 738     bool exceptionMatched = false;
 739
 740     if ((start <= pcOffset) && (pcOffset < (start + length))) {
 741 #ifdef DEBUG
 742       fprintf(stderr,
 743               "handleLsda(...): Landing pad found.\n");
 744 #endif
 745       int64_t actionValue = 0;
 746
 747       if (actionEntry) {
 748         exceptionMatched = handleActionValue(&actionValue,
 749                                              ttypeEncoding,
 750                                              ClassInfo,
 751                                              actionEntry,
 752                                              exceptionClass,
 753                                              exceptionObject);
 754       }
 755
 756       if (!(actions & _UA_SEARCH_PHASE)) {
 757 #ifdef DEBUG
 758         fprintf(stderr,
 759                 "handleLsda(...): installed landing pad "
 760                 "context.\n");
 761 #endif
 762
 763         // Found landing pad for the PC.
 764         // Set Instruction Pointer to so we re-enter function
 765         // at landing pad. The landing pad is created by the
 766         // compiler to take two parameters in registers.
 767         _Unwind_SetGR(context,
 768                       __builtin_eh_return_data_regno(0),
 769                       (uintptr_t)exceptionObject);
 770
 771         // Note: this virtual register directly corresponds
 772         //       to the return of the llvm.eh.selector intrinsic
 773         if (!actionEntry || !exceptionMatched) {
 774           // We indicate cleanup only
 775           _Unwind_SetGR(context,
 776                         __builtin_eh_return_data_regno(1),
 777                         0);
 778         }
 779         else {
 780           // Matched type info index of llvm.eh.selector intrinsic
 781           // passed here.
 782           _Unwind_SetGR(context,
 783                         __builtin_eh_return_data_regno(1),
 784                         actionValue);
 785         }
 786
 787         // To execute landing pad set here
 788         _Unwind_SetIP(context, funcStart + landingPad);
 789         ret = _URC_INSTALL_CONTEXT;
 790       }
 791       else if (exceptionMatched) {
 792 #ifdef DEBUG
 793         fprintf(stderr,
 794                 "handleLsda(...): setting handler found.\n");
 795 #endif
 796         ret = _URC_HANDLER_FOUND;
 797       }
 798       else {
 799         // Note: Only non-clean up handlers are marked as
 800         //       found. Otherwise the clean up handlers will be
 801         //       re-found and executed during the clean up
 802         //       phase.
 803 #ifdef DEBUG
 804         fprintf(stderr,
 805                 "handleLsda(...): cleanup handler found.\n");
 806 #endif
 807       }
 808
 809       break;
 810     }
 811   }
 812
 813   return(ret);
 814 }
 815
 816
 817 /// This is the personality function which is embedded (dwarf emitted), in the
 818 /// dwarf unwind info block. Again see: JITDwarfEmitter.cpp.
 819 /// See @link http://mentorembedded.github.com/cxx-abi/abi-eh.html @unlink
 820 /// @param version unsupported (ignored), unwind version
 821 /// @param _Unwind_Action actions minimally supported unwind stage
 822 ///        (forced specifically not supported)
 823 /// @param exceptionClass exception class (_Unwind_Exception::exception_class)
 824 ///        of thrown exception.
 825 /// @param exceptionObject thrown _Unwind_Exception instance.
 826 /// @param context unwind system context
 827 /// @returns minimally supported unwinding control indicator
 828 _Unwind_Reason_Code ourPersonality(int version,
 829                                    _Unwind_Action actions,
 830                                    uint64_t exceptionClass,
 831                                    struct _Unwind_Exception *exceptionObject,
 832                                    _Unwind_Context_t context) {
 833 #ifdef DEBUG
 834   fprintf(stderr,
 835           "We are in ourPersonality(...):actions is <%d>.\n",
 836           actions);
 837
 838   if (actions & _UA_SEARCH_PHASE) {
 839     fprintf(stderr, "ourPersonality(...):In search phase.\n");
 840   }
 841   else {
 842     fprintf(stderr, "ourPersonality(...):In non-search phase.\n");
 843   }
 844 #endif
 845
 846   const uint8_t *lsda = _Unwind_GetLanguageSpecificData(context);
 847
 848 #ifdef DEBUG
 849   fprintf(stderr,
 850           "ourPersonality(...):lsda = <%p>.\n",
 851           lsda);
 852 #endif
 853
 854   // The real work of the personality function is captured here
 855   return(handleLsda(version,
 856                     lsda,
 857                     actions,
 858                     exceptionClass,
 859                     exceptionObject,
 860                     context));
 861 }
 862
 863
 864 /// Generates our _Unwind_Exception class from a given character array.
 865 /// thereby handling arbitrary lengths (not in standard), and handling
 866 /// embedded \0s.
 867 /// See @link http://mentorembedded.github.com/cxx-abi/abi-eh.html @unlink
 868 /// @param classChars char array to encode. NULL values not checkedf
 869 /// @param classCharsSize number of chars in classChars. Value is not checked.
 870 /// @returns class value
 871 uint64_t genClass(const unsigned char classChars[], size_t classCharsSize)
 872 {
 873   uint64_t ret = classChars[0];
 874
 875   for (unsigned i = 1; i < classCharsSize; ++i) {
 876     ret <<= 8;
 877     ret += classChars[i];
 878   }
 879
 880   return(ret);
 881 }
 882
 883 } // extern "C"
 884
 885 //
 886 // Runtime C Library functions End
 887 //
 888
 889 //
 890 // Code generation functions
 891 //
 892
 893 /// Generates code to print given constant string
 894 /// @param context llvm context
 895 /// @param module code for module instance
 896 /// @param builder builder instance
 897 /// @param toPrint string to print
 898 /// @param useGlobal A value of true (default) indicates a GlobalValue is
 899 ///        generated, and is used to hold the constant string. A value of
 900 ///        false indicates that the constant string will be stored on the
 901 ///        stack.
 902 void generateStringPrint(llvm::LLVMContext &context,
 903                          llvm::Module &module,
 904                          llvm::IRBuilder<> &builder,
 905                          std::string toPrint,
 906                          bool useGlobal = true) {
 907   llvm::Function *printFunct = module.getFunction("printStr");
 908
 909   llvm::Value *stringVar;
 910   llvm::Constant *stringConstant =
 911   llvm::ConstantDataArray::getString(context, toPrint);
 912
 913   if (useGlobal) {
 914     // Note: Does not work without allocation
 915     stringVar =
 916     new llvm::GlobalVariable(module,
 917                              stringConstant->getType(),
 918                              true,
 919                              llvm::GlobalValue::PrivateLinkage,
 920                              stringConstant,
 921                              "");
 922   }
 923   else {
 924     stringVar = builder.CreateAlloca(stringConstant->getType());
 925     builder.CreateStore(stringConstant, stringVar);
 926   }
 927
 928   llvm::Value *cast = builder.CreatePointerCast(stringVar,
 929                                                 builder.getInt8PtrTy());
 930   builder.CreateCall(printFunct, cast);
 931 }
 932
 933
 934 /// Generates code to print given runtime integer according to constant
 935 /// string format, and a given print function.
 936 /// @param context llvm context
 937 /// @param module code for module instance
 938 /// @param builder builder instance
 939 /// @param printFunct function used to "print" integer
 940 /// @param toPrint string to print
 941 /// @param format printf like formating string for print
 942 /// @param useGlobal A value of true (default) indicates a GlobalValue is
 943 ///        generated, and is used to hold the constant string. A value of
 944 ///        false indicates that the constant string will be stored on the
 945 ///        stack.
 946 void generateIntegerPrint(llvm::LLVMContext &context,
 947                           llvm::Module &module,
 948                           llvm::IRBuilder<> &builder,
 949                           llvm::Function &printFunct,
 950                           llvm::Value &toPrint,
 951                           std::string format,
 952                           bool useGlobal = true) {
 953   llvm::Constant *stringConstant =
 954     llvm::ConstantDataArray::getString(context, format);
 955   llvm::Value *stringVar;
 956
 957   if (useGlobal) {
 958     // Note: Does not seem to work without allocation
 959     stringVar =
 960     new llvm::GlobalVariable(module,
 961                              stringConstant->getType(),
 962                              true,
 963                              llvm::GlobalValue::PrivateLinkage,
 964                              stringConstant,
 965                              "");
 966   }
 967   else {
 968     stringVar = builder.CreateAlloca(stringConstant->getType());
 969     builder.CreateStore(stringConstant, stringVar);
 970   }
 971
 972   llvm::Value *cast = builder.CreateBitCast(stringVar,
 973                                             builder.getInt8PtrTy());
 974   builder.CreateCall2(&printFunct, &toPrint, cast);
 975 }
 976
 977
 978 /// Generates code to handle finally block type semantics: always runs
 979 /// regardless of whether a thrown exception is passing through or the
 980 /// parent function is simply exiting. In addition to printing some state
 981 /// to stderr, this code will resume the exception handling--runs the
 982 /// unwind resume block, if the exception has not been previously caught
 983 /// by a catch clause, and will otherwise execute the end block (terminator
 984 /// block). In addition this function creates the corresponding function's
 985 /// stack storage for the exception pointer and catch flag status.
 986 /// @param context llvm context
 987 /// @param module code for module instance
 988 /// @param builder builder instance
 989 /// @param toAddTo parent function to add block to
 990 /// @param blockName block name of new "finally" block.
 991 /// @param functionId output id used for printing
 992 /// @param terminatorBlock terminator "end" block
 993 /// @param unwindResumeBlock unwind resume block
 994 /// @param exceptionCaughtFlag reference exception caught/thrown status storage
 995 /// @param exceptionStorage reference to exception pointer storage
 996 /// @param caughtResultStorage reference to landingpad result storage
 997 /// @returns newly created block
 998 static llvm::BasicBlock *createFinallyBlock(llvm::LLVMContext &context,
 999                                             llvm::Module &module,
1000                                             llvm::IRBuilder<> &builder,
1001                                             llvm::Function &toAddTo,
1002                                             std::string &blockName,
1003                                             std::string &functionId,
1004                                             llvm::BasicBlock &terminatorBlock,
1005                                             llvm::BasicBlock &unwindResumeBlock,
1006                                             llvm::Value **exceptionCaughtFlag,
1007                                             llvm::Value **exceptionStorage,
1008                                             llvm::Value **caughtResultStorage) {
1009   assert(exceptionCaughtFlag &&
1010          "ExceptionDemo::createFinallyBlock(...):exceptionCaughtFlag "
1011          "is NULL");
1012   assert(exceptionStorage &&
1013          "ExceptionDemo::createFinallyBlock(...):exceptionStorage "
1014          "is NULL");
1015   assert(caughtResultStorage &&
1016          "ExceptionDemo::createFinallyBlock(...):caughtResultStorage "
1017          "is NULL");
1018
1019   *exceptionCaughtFlag = createEntryBlockAlloca(toAddTo,
1020                                          "exceptionCaught",
1021                                          ourExceptionNotThrownState->getType(),
1022                                          ourExceptionNotThrownState);
1023
1024   llvm::PointerType *exceptionStorageType = builder.getInt8PtrTy();
1025   *exceptionStorage = createEntryBlockAlloca(toAddTo,
1026                                              "exceptionStorage",
1027                                              exceptionStorageType,
1028                                              llvm::ConstantPointerNull::get(
1029                                                exceptionStorageType));
1030   *caughtResultStorage = createEntryBlockAlloca(toAddTo,
1031                                               "caughtResultStorage",
1032                                               ourCaughtResultType,
1033                                               llvm::ConstantAggregateZero::get(
1034                                                 ourCaughtResultType));
1035
1036   llvm::BasicBlock *ret = llvm::BasicBlock::Create(context,
1037                                                    blockName,
1038                                                    &toAddTo);
1039
1040   builder.SetInsertPoint(ret);
1041
1042   std::ostringstream bufferToPrint;
1043   bufferToPrint << "Gen: Executing finally block "
1044     << blockName << " in " << functionId << "\n";
1045   generateStringPrint(context,
1046                       module,
1047                       builder,
1048                       bufferToPrint.str(),
1049                       USE_GLOBAL_STR_CONSTS);
1050
1051   llvm::SwitchInst *theSwitch = builder.CreateSwitch(builder.CreateLoad(
1052                                                        *exceptionCaughtFlag),
1053                                                      &terminatorBlock,
1054                                                      2);
1055   theSwitch->addCase(ourExceptionCaughtState, &terminatorBlock);
1056   theSwitch->addCase(ourExceptionThrownState, &unwindResumeBlock);
1057
1058   return(ret);
1059 }
1060
1061
1062 /// Generates catch block semantics which print a string to indicate type of
1063 /// catch executed, sets an exception caught flag, and executes passed in
1064 /// end block (terminator block).
1065 /// @param context llvm context
1066 /// @param module code for module instance
1067 /// @param builder builder instance
1068 /// @param toAddTo parent function to add block to
1069 /// @param blockName block name of new "catch" block.
1070 /// @param functionId output id used for printing
1071 /// @param terminatorBlock terminator "end" block
1072 /// @param exceptionCaughtFlag exception caught/thrown status
1073 /// @returns newly created block
1074 static llvm::BasicBlock *createCatchBlock(llvm::LLVMContext &context,
1075                                           llvm::Module &module,
1076                                           llvm::IRBuilder<> &builder,
1077                                           llvm::Function &toAddTo,
1078                                           std::string &blockName,
1079                                           std::string &functionId,
1080                                           llvm::BasicBlock &terminatorBlock,
1081                                           llvm::Value &exceptionCaughtFlag) {
1082
1083   llvm::BasicBlock *ret = llvm::BasicBlock::Create(context,
1084                                                    blockName,
1085                                                    &toAddTo);
1086
1087   builder.SetInsertPoint(ret);
1088
1089   std::ostringstream bufferToPrint;
1090   bufferToPrint << "Gen: Executing catch block "
1091   << blockName
1092   << " in "
1093   << functionId
1094   << std::endl;
1095   generateStringPrint(context,
1096                       module,
1097                       builder,
1098                       bufferToPrint.str(),
1099                       USE_GLOBAL_STR_CONSTS);
1100   builder.CreateStore(ourExceptionCaughtState, &exceptionCaughtFlag);
1101   builder.CreateBr(&terminatorBlock);
1102
1103   return(ret);
1104 }
1105
1106
1107 /// Generates a function which invokes a function (toInvoke) and, whose
1108 /// unwind block will "catch" the type info types correspondingly held in the
1109 /// exceptionTypesToCatch argument. If the toInvoke function throws an
1110 /// exception which does not match any type info types contained in
1111 /// exceptionTypesToCatch, the generated code will call _Unwind_Resume
1112 /// with the raised exception. On the other hand the generated code will
1113 /// normally exit if the toInvoke function does not throw an exception.
1114 /// The generated "finally" block is always run regardless of the cause of
1115 /// the generated function exit.
1116 /// The generated function is returned after being verified.
1117 /// @param module code for module instance
1118 /// @param builder builder instance
1119 /// @param fpm a function pass manager holding optional IR to IR
1120 ///        transformations
1121 /// @param toInvoke inner function to invoke
1122 /// @param ourId id used to printing purposes
1123 /// @param numExceptionsToCatch length of exceptionTypesToCatch array
1124 /// @param exceptionTypesToCatch array of type info types to "catch"
1125 /// @returns generated function
1126 static llvm::Function *createCatchWrappedInvokeFunction(
1127     llvm::Module &module, llvm::IRBuilder<> &builder,
1128     llvm::legacy::FunctionPassManager &fpm, llvm::Function &toInvoke,
1129     std::string ourId, unsigned numExceptionsToCatch,
1130     unsigned exceptionTypesToCatch[]) {
1131
1132   llvm::LLVMContext &context = module.getContext();
1133   llvm::Function *toPrint32Int = module.getFunction("print32Int");
1134
1135   ArgTypes argTypes;
1136   argTypes.push_back(builder.getInt32Ty());
1137
1138   ArgNames argNames;
1139   argNames.push_back("exceptTypeToThrow");
1140
1141   llvm::Function *ret = createFunction(module,
1142                                        builder.getVoidTy(),
1143                                        argTypes,
1144                                        argNames,
1145                                        ourId,
1146                                        llvm::Function::ExternalLinkage,
1147                                        false,
1148                                        false);
1149
1150   // Block which calls invoke
1151   llvm::BasicBlock *entryBlock = llvm::BasicBlock::Create(context,
1152                                                           "entry",
1153                                                           ret);
1154   // Normal block for invoke
1155   llvm::BasicBlock *normalBlock = llvm::BasicBlock::Create(context,
1156                                                            "normal",
1157                                                            ret);
1158   // Unwind block for invoke
1159   llvm::BasicBlock *exceptionBlock = llvm::BasicBlock::Create(context,
1160                                                               "exception",
1161                                                               ret);
1162
1163   // Block which routes exception to correct catch handler block
1164   llvm::BasicBlock *exceptionRouteBlock = llvm::BasicBlock::Create(context,
1165                                                              "exceptionRoute",
1166                                                              ret);
1167
1168   // Foreign exception handler
1169   llvm::BasicBlock *externalExceptionBlock = llvm::BasicBlock::Create(context,
1170                                                           "externalException",
1171                                                           ret);
1172
1173   // Block which calls _Unwind_Resume
1174   llvm::BasicBlock *unwindResumeBlock = llvm::BasicBlock::Create(context,
1175                                                                "unwindResume",
1176                                                                ret);
1177
1178   // Clean up block which delete exception if needed
1179   llvm::BasicBlock *endBlock = llvm::BasicBlock::Create(context, "end", ret);
1180
1181   std::string nextName;
1182   std::vector<llvm::BasicBlock*> catchBlocks(numExceptionsToCatch);
1183   llvm::Value *exceptionCaughtFlag = NULL;
1184   llvm::Value *exceptionStorage = NULL;
1185   llvm::Value *caughtResultStorage = NULL;
1186
1187   // Finally block which will branch to unwindResumeBlock if
1188   // exception is not caught. Initializes/allocates stack locations.
1189   llvm::BasicBlock *finallyBlock = createFinallyBlock(context,
1190                                                       module,
1191                                                       builder,
1192                                                       *ret,
1193                                                       nextName = "finally",
1194                                                       ourId,
1195                                                       *endBlock,
1196                                                       *unwindResumeBlock,
1197                                                       &exceptionCaughtFlag,
1198                                                       &exceptionStorage,
1199                                                       &caughtResultStorage
1200                                                       );
1201
1202   for (unsigned i = 0; i < numExceptionsToCatch; ++i) {
1203     nextName = ourTypeInfoNames[exceptionTypesToCatch[i]];
1204
1205     // One catch block per type info to be caught
1206     catchBlocks[i] = createCatchBlock(context,
1207                                       module,
1208                                       builder,
1209                                       *ret,
1210                                       nextName,
1211                                       ourId,
1212                                       *finallyBlock,
1213                                       *exceptionCaughtFlag);
1214   }
1215
1216   // Entry Block
1217
1218   builder.SetInsertPoint(entryBlock);
1219
1220   std::vector<llvm::Value*> args;
1221   args.push_back(namedValues["exceptTypeToThrow"]);
1222   builder.CreateInvoke(&toInvoke,
1223                        normalBlock,
1224                        exceptionBlock,
1225                        args);
1226
1227   // End Block
1228
1229   builder.SetInsertPoint(endBlock);
1230
1231   generateStringPrint(context,
1232                       module,
1233                       builder,
1234                       "Gen: In end block: exiting in " + ourId + ".\n",
1235                       USE_GLOBAL_STR_CONSTS);
1236   llvm::Function *deleteOurException = module.getFunction("deleteOurException");
1237
1238   // Note: function handles NULL exceptions
1239   builder.CreateCall(deleteOurException,
1240                      builder.CreateLoad(exceptionStorage));
1241   builder.CreateRetVoid();
1242
1243   // Normal Block
1244
1245   builder.SetInsertPoint(normalBlock);
1246
1247   generateStringPrint(context,
1248                       module,
1249                       builder,
1250                       "Gen: No exception in " + ourId + "!\n",
1251                       USE_GLOBAL_STR_CONSTS);
1252
1253   // Finally block is always called
1254   builder.CreateBr(finallyBlock);
1255
1256   // Unwind Resume Block
1257
1258   builder.SetInsertPoint(unwindResumeBlock);
1259
1260   builder.CreateResume(builder.CreateLoad(caughtResultStorage));
1261
1262   // Exception Block
1263
1264   builder.SetInsertPoint(exceptionBlock);
1265
1266   llvm::Function *personality = module.getFunction("ourPersonality");
1267
1268   llvm::LandingPadInst *caughtResult =
1269     builder.CreateLandingPad(ourCaughtResultType,
1270                              personality,
1271                              numExceptionsToCatch,
1272                              "landingPad");
1273
1274   caughtResult->setCleanup(true);
1275
1276   for (unsigned i = 0; i < numExceptionsToCatch; ++i) {
1277     // Set up type infos to be caught
1278     caughtResult->addClause(module.getGlobalVariable(
1279                              ourTypeInfoNames[exceptionTypesToCatch[i]]));
1280   }
1281
1282   llvm::Value *unwindException = builder.CreateExtractValue(caughtResult, 0);
1283   llvm::Value *retTypeInfoIndex = builder.CreateExtractValue(caughtResult, 1);
1284
1285   // FIXME: Redundant storage which, beyond utilizing value of
1286   //        caughtResultStore for unwindException storage, may be alleviated
1287   //        altogether with a block rearrangement
1288   builder.CreateStore(caughtResult, caughtResultStorage);
1289   builder.CreateStore(unwindException, exceptionStorage);
1290   builder.CreateStore(ourExceptionThrownState, exceptionCaughtFlag);
1291
1292   // Retrieve exception_class member from thrown exception
1293   // (_Unwind_Exception instance). This member tells us whether or not
1294   // the exception is foreign.
1295   llvm::Value *unwindExceptionClass =
1296     builder.CreateLoad(builder.CreateStructGEP(
1297              builder.CreatePointerCast(unwindException,
1298                                        ourUnwindExceptionType->getPointerTo()),
1299                                                0));
1300
1301   // Branch to the externalExceptionBlock if the exception is foreign or
1302   // to a catch router if not. Either way the finally block will be run.
1303   builder.CreateCondBr(builder.CreateICmpEQ(unwindExceptionClass,
1304                             llvm::ConstantInt::get(builder.getInt64Ty(),
1305                                                    ourBaseExceptionClass)),
1306                        exceptionRouteBlock,
1307                        externalExceptionBlock);
1308
1309   // External Exception Block
1310
1311   builder.SetInsertPoint(externalExceptionBlock);
1312
1313   generateStringPrint(context,
1314                       module,
1315                       builder,
1316                       "Gen: Foreign exception received.\n",
1317                       USE_GLOBAL_STR_CONSTS);
1318
1319   // Branch to the finally block
1320   builder.CreateBr(finallyBlock);
1321
1322   // Exception Route Block
1323
1324   builder.SetInsertPoint(exceptionRouteBlock);
1325
1326   // Casts exception pointer (_Unwind_Exception instance) to parent
1327   // (OurException instance).
1328   //
1329   // Note: ourBaseFromUnwindOffset is usually negative
1330   llvm::Value *typeInfoThrown = builder.CreatePointerCast(
1331                                   builder.CreateConstGEP1_64(unwindException,
1332                                                        ourBaseFromUnwindOffset),
1333                                   ourExceptionType->getPointerTo());
1334
1335   // Retrieve thrown exception type info type
1336   //
1337   // Note: Index is not relative to pointer but instead to structure
1338   //       unlike a true getelementptr (GEP) instruction
1339   typeInfoThrown = builder.CreateStructGEP(typeInfoThrown, 0);
1340
1341   llvm::Value *typeInfoThrownType =
1342   builder.CreateStructGEP(typeInfoThrown, 0);
1343
1344   generateIntegerPrint(context,
1345                        module,
1346                        builder,
1347                        *toPrint32Int,
1348                        *(builder.CreateLoad(typeInfoThrownType)),
1349                        "Gen: Exception type <%d> received (stack unwound) "
1350                        " in " +
1351                        ourId +
1352                        ".\n",
1353                        USE_GLOBAL_STR_CONSTS);
1354
1355   // Route to matched type info catch block or run cleanup finally block
1356   llvm::SwitchInst *switchToCatchBlock = builder.CreateSwitch(retTypeInfoIndex,
1357                                                           finallyBlock,
1358                                                           numExceptionsToCatch);
1359
1360   unsigned nextTypeToCatch;
1361
1362   for (unsigned i = 1; i <= numExceptionsToCatch; ++i) {
1363     nextTypeToCatch = i - 1;
1364     switchToCatchBlock->addCase(llvm::ConstantInt::get(
1365                                    llvm::Type::getInt32Ty(context), i),
1366                                 catchBlocks[nextTypeToCatch]);
1367   }
1368
1369   llvm::verifyFunction(*ret);
1370   fpm.run(*ret);
1371
1372   return(ret);
1373 }
1374
1375
1376 /// Generates function which throws either an exception matched to a runtime
1377 /// determined type info type (argument to generated function), or if this
1378 /// runtime value matches nativeThrowType, throws a foreign exception by
1379 /// calling nativeThrowFunct.
1380 /// @param module code for module instance
1381 /// @param builder builder instance
1382 /// @param fpm a function pass manager holding optional IR to IR
1383 ///        transformations
1384 /// @param ourId id used to printing purposes
1385 /// @param nativeThrowType a runtime argument of this value results in
1386 ///        nativeThrowFunct being called to generate/throw exception.
1387 /// @param nativeThrowFunct function which will throw a foreign exception
1388 ///        if the above nativeThrowType matches generated function's arg.
1389 /// @returns generated function
1390 static llvm::Function *
1391 createThrowExceptionFunction(llvm::Module &module, llvm::IRBuilder<> &builder,
1392                              llvm::legacy::FunctionPassManager &fpm,
1393                              std::string ourId, int32_t nativeThrowType,
1394                              llvm::Function &nativeThrowFunct) {
1395   llvm::LLVMContext &context = module.getContext();
1396   namedValues.clear();
1397   ArgTypes unwindArgTypes;
1398   unwindArgTypes.push_back(builder.getInt32Ty());
1399   ArgNames unwindArgNames;
1400   unwindArgNames.push_back("exceptTypeToThrow");
1401
1402   llvm::Function *ret = createFunction(module,
1403                                        builder.getVoidTy(),
1404                                        unwindArgTypes,
1405                                        unwindArgNames,
1406                                        ourId,
1407                                        llvm::Function::ExternalLinkage,
1408                                        false,
1409                                        false);
1410
1411   // Throws either one of our exception or a native C++ exception depending
1412   // on a runtime argument value containing a type info type.
1413   llvm::BasicBlock *entryBlock = llvm::BasicBlock::Create(context,
1414                                                           "entry",
1415                                                           ret);
1416   // Throws a foreign exception
1417   llvm::BasicBlock *nativeThrowBlock = llvm::BasicBlock::Create(context,
1418                                                                 "nativeThrow",
1419                                                                 ret);
1420   // Throws one of our Exceptions
1421   llvm::BasicBlock *generatedThrowBlock = llvm::BasicBlock::Create(context,
1422                                                              "generatedThrow",
1423                                                              ret);
1424   // Retrieved runtime type info type to throw
1425   llvm::Value *exceptionType = namedValues["exceptTypeToThrow"];
1426
1427   // nativeThrowBlock block
1428
1429   builder.SetInsertPoint(nativeThrowBlock);
1430
1431   // Throws foreign exception
1432   builder.CreateCall(&nativeThrowFunct, exceptionType);
1433   builder.CreateUnreachable();
1434
1435   // entry block
1436
1437   builder.SetInsertPoint(entryBlock);
1438
1439   llvm::Function *toPrint32Int = module.getFunction("print32Int");
1440   generateIntegerPrint(context,
1441                        module,
1442                        builder,
1443                        *toPrint32Int,
1444                        *exceptionType,
1445                        "\nGen: About to throw exception type <%d> in " +
1446                        ourId +
1447                        ".\n",
1448                        USE_GLOBAL_STR_CONSTS);
1449
1450   // Switches on runtime type info type value to determine whether or not
1451   // a foreign exception is thrown. Defaults to throwing one of our
1452   // generated exceptions.
1453   llvm::SwitchInst *theSwitch = builder.CreateSwitch(exceptionType,
1454                                                      generatedThrowBlock,
1455                                                      1);
1456
1457   theSwitch->addCase(llvm::ConstantInt::get(llvm::Type::getInt32Ty(context),
1458                                             nativeThrowType),
1459                      nativeThrowBlock);
1460
1461   // generatedThrow block
1462
1463   builder.SetInsertPoint(generatedThrowBlock);
1464
1465   llvm::Function *createOurException = module.getFunction("createOurException");
1466   llvm::Function *raiseOurException = module.getFunction(
1467                                         "_Unwind_RaiseException");
1468
1469   // Creates exception to throw with runtime type info type.
1470   llvm::Value *exception = builder.CreateCall(createOurException,
1471                                               namedValues["exceptTypeToThrow"]);
1472
1473   // Throw generated Exception
1474   builder.CreateCall(raiseOurException, exception);
1475   builder.CreateUnreachable();
1476
1477   llvm::verifyFunction(*ret);
1478   fpm.run(*ret);
1479
1480   return(ret);
1481 }
1482
1483 static void createStandardUtilityFunctions(unsigned numTypeInfos,
1484                                            llvm::Module &module,
1485                                            llvm::IRBuilder<> &builder);
1486
1487 /// Creates test code by generating and organizing these functions into the
1488 /// test case. The test case consists of an outer function setup to invoke
1489 /// an inner function within an environment having multiple catch and single
1490 /// finally blocks. This inner function is also setup to invoke a throw
1491 /// function within an evironment similar in nature to the outer function's
1492 /// catch and finally blocks. Each of these two functions catch mutually
1493 /// exclusive subsets (even or odd) of the type info types configured
1494 /// for this this. All generated functions have a runtime argument which
1495 /// holds a type info type to throw that each function takes and passes it
1496 /// to the inner one if such a inner function exists. This type info type is
1497 /// looked at by the generated throw function to see whether or not it should
1498 /// throw a generated exception with the same type info type, or instead call
1499 /// a supplied a function which in turn will throw a foreign exception.
1500 /// @param module code for module instance
1501 /// @param builder builder instance
1502 /// @param fpm a function pass manager holding optional IR to IR
1503 ///        transformations
1504 /// @param nativeThrowFunctName name of external function which will throw
1505 ///        a foreign exception
1506 /// @returns outermost generated test function.
1507 llvm::Function *
1508 createUnwindExceptionTest(llvm::Module &module, llvm::IRBuilder<> &builder,
1509                           llvm::legacy::FunctionPassManager &fpm,
1510                           std::string nativeThrowFunctName) {
1511   // Number of type infos to generate
1512   unsigned numTypeInfos = 6;
1513
1514   // Initialze intrisics and external functions to use along with exception
1515   // and type info globals.
1516   createStandardUtilityFunctions(numTypeInfos,
1517                                  module,
1518                                  builder);
1519   llvm::Function *nativeThrowFunct = module.getFunction(nativeThrowFunctName);
1520
1521   // Create exception throw function using the value ~0 to cause
1522   // foreign exceptions to be thrown.
1523   llvm::Function *throwFunct = createThrowExceptionFunction(module,
1524                                                             builder,
1525                                                             fpm,
1526                                                             "throwFunct",
1527                                                             ~0,
1528                                                             *nativeThrowFunct);
1529   // Inner function will catch even type infos
1530   unsigned innerExceptionTypesToCatch[] = {6, 2, 4};
1531   size_t numExceptionTypesToCatch = sizeof(innerExceptionTypesToCatch) /
1532                                     sizeof(unsigned);
1533
1534   // Generate inner function.
1535   llvm::Function *innerCatchFunct = createCatchWrappedInvokeFunction(module,
1536                                                     builder,
1537                                                     fpm,
1538                                                     *throwFunct,
1539                                                     "innerCatchFunct",
1540                                                     numExceptionTypesToCatch,
1541                                                     innerExceptionTypesToCatch);
1542
1543   // Outer function will catch odd type infos
1544   unsigned outerExceptionTypesToCatch[] = {3, 1, 5};
1545   numExceptionTypesToCatch = sizeof(outerExceptionTypesToCatch) /
1546   sizeof(unsigned);
1547
1548   // Generate outer function
1549   llvm::Function *outerCatchFunct = createCatchWrappedInvokeFunction(module,
1550                                                     builder,
1551                                                     fpm,
1552                                                     *innerCatchFunct,
1553                                                     "outerCatchFunct",
1554                                                     numExceptionTypesToCatch,
1555                                                     outerExceptionTypesToCatch);
1556
1557   // Return outer function to run
1558   return(outerCatchFunct);
1559 }
1560
1561 namespace {
1562 /// Represents our foreign exceptions
1563 class OurCppRunException : public std::runtime_error {
1564 public:
1565   OurCppRunException(const std::string reason) :
1566   std::runtime_error(reason) {}
1567
1568   OurCppRunException (const OurCppRunException &toCopy) :
1569   std::runtime_error(toCopy) {}
1570
1571   OurCppRunException &operator = (const OurCppRunException &toCopy) {
1572     return(reinterpret_cast<OurCppRunException&>(
1573                                  std::runtime_error::operator=(toCopy)));
1574   }
1575
1576   virtual ~OurCppRunException (void) throw () {}
1577 };
1578 } // end anonymous namespace
1579
1580 /// Throws foreign C++ exception.
1581 /// @param ignoreIt unused parameter that allows function to match implied
1582 ///        generated function contract.
1583 extern "C"
1584 void throwCppException (int32_t ignoreIt) {
1585   throw(OurCppRunException("thrown by throwCppException(...)"));
1586 }
1587
1588 typedef void (*OurExceptionThrowFunctType) (int32_t typeToThrow);
1589
1590 /// This is a test harness which runs test by executing generated
1591 /// function with a type info type to throw. Harness wraps the execution
1592 /// of generated function in a C++ try catch clause.
1593 /// @param engine execution engine to use for executing generated function.
1594 ///        This demo program expects this to be a JIT instance for demo
1595 ///        purposes.
1596 /// @param function generated test function to run
1597 /// @param typeToThrow type info type of generated exception to throw, or
1598 ///        indicator to cause foreign exception to be thrown.
1599 static
1600 void runExceptionThrow(llvm::ExecutionEngine *engine,
1601                        llvm::Function *function,
1602                        int32_t typeToThrow) {
1603
1604   // Find test's function pointer
1605   OurExceptionThrowFunctType functPtr =
1606     reinterpret_cast<OurExceptionThrowFunctType>(
1607        reinterpret_cast<intptr_t>(engine->getPointerToFunction(function)));
1608
1609   try {
1610     // Run test
1611     (*functPtr)(typeToThrow);
1612   }
1613   catch (OurCppRunException exc) {
1614     // Catch foreign C++ exception
1615     fprintf(stderr,
1616             "\nrunExceptionThrow(...):In C++ catch OurCppRunException "
1617             "with reason: %s.\n",
1618             exc.what());
1619   }
1620   catch (...) {
1621     // Catch all exceptions including our generated ones. This latter
1622     // functionality works according to the example in rules 1.6.4 of
1623     // http://mentorembedded.github.com/cxx-abi/abi-eh.html (v1.22),
1624     // given that these will be exceptions foreign to C++
1625     // (the _Unwind_Exception::exception_class should be different from
1626     // the one used by C++).
1627     fprintf(stderr,
1628             "\nrunExceptionThrow(...):In C++ catch all.\n");
1629   }
1630 }
1631
1632 //
1633 // End test functions
1634 //
1635
1636 typedef llvm::ArrayRef<llvm::Type*> TypeArray;
1637
1638 /// This initialization routine creates type info globals and
1639 /// adds external function declarations to module.
1640 /// @param numTypeInfos number of linear type info associated type info types
1641 ///        to create as GlobalVariable instances, starting with the value 1.
1642 /// @param module code for module instance
1643 /// @param builder builder instance
1644 static void createStandardUtilityFunctions(unsigned numTypeInfos,
1645                                            llvm::Module &module,
1646                                            llvm::IRBuilder<> &builder) {
1647
1648   llvm::LLVMContext &context = module.getContext();
1649
1650   // Exception initializations
1651
1652   // Setup exception catch state
1653   ourExceptionNotThrownState =
1654     llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 0),
1655   ourExceptionThrownState =
1656     llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 1),
1657   ourExceptionCaughtState =
1658     llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 2),
1659
1660
1661
1662   // Create our type info type
1663   ourTypeInfoType = llvm::StructType::get(context,
1664                                           TypeArray(builder.getInt32Ty()));
1665
1666   llvm::Type *caughtResultFieldTypes[] = {
1667     builder.getInt8PtrTy(),
1668     builder.getInt32Ty()
1669   };
1670
1671   // Create our landingpad result type
1672   ourCaughtResultType = llvm::StructType::get(context,
1673                                             TypeArray(caughtResultFieldTypes));
1674
1675   // Create OurException type
1676   ourExceptionType = llvm::StructType::get(context,
1677                                            TypeArray(ourTypeInfoType));
1678
1679   // Create portion of _Unwind_Exception type
1680   //
1681   // Note: Declaring only a portion of the _Unwind_Exception struct.
1682   //       Does this cause problems?
1683   ourUnwindExceptionType =
1684     llvm::StructType::get(context,
1685                     TypeArray(builder.getInt64Ty()));
1686
1687   struct OurBaseException_t dummyException;
1688
1689   // Calculate offset of OurException::unwindException member.
1690   ourBaseFromUnwindOffset = ((uintptr_t) &dummyException) -
1691                             ((uintptr_t) &(dummyException.unwindException));
1692
1693 #ifdef DEBUG
1694   fprintf(stderr,
1695           "createStandardUtilityFunctions(...):ourBaseFromUnwindOffset "
1696           "= %lld, sizeof(struct OurBaseException_t) - "
1697           "sizeof(struct _Unwind_Exception) = %lu.\n",
1698           ourBaseFromUnwindOffset,
1699           sizeof(struct OurBaseException_t) -
1700           sizeof(struct _Unwind_Exception));
1701 #endif
1702
1703   size_t numChars = sizeof(ourBaseExcpClassChars) / sizeof(char);
1704
1705   // Create our _Unwind_Exception::exception_class value
1706   ourBaseExceptionClass = genClass(ourBaseExcpClassChars, numChars);
1707
1708   // Type infos
1709
1710   std::string baseStr = "typeInfo", typeInfoName;
1711   std::ostringstream typeInfoNameBuilder;
1712   std::vector<llvm::Constant*> structVals;
1713
1714   llvm::Constant *nextStruct;
1715
1716   // Generate each type info
1717   //
1718   // Note: First type info is not used.
1719   for (unsigned i = 0; i <= numTypeInfos; ++i) {
1720     structVals.clear();
1721     structVals.push_back(llvm::ConstantInt::get(builder.getInt32Ty(), i));
1722     nextStruct = llvm::ConstantStruct::get(ourTypeInfoType, structVals);
1723
1724     typeInfoNameBuilder.str("");
1725     typeInfoNameBuilder << baseStr << i;
1726     typeInfoName = typeInfoNameBuilder.str();
1727
1728     // Note: Does not seem to work without allocation
1729     new llvm::GlobalVariable(module,
1730                              ourTypeInfoType,
1731                              true,
1732                              llvm::GlobalValue::ExternalLinkage,
1733                              nextStruct,
1734                              typeInfoName);
1735
1736     ourTypeInfoNames.push_back(typeInfoName);
1737     ourTypeInfoNamesIndex[i] = typeInfoName;
1738   }
1739
1740   ArgNames argNames;
1741   ArgTypes argTypes;
1742   llvm::Function *funct = NULL;
1743
1744   // print32Int
1745
1746   llvm::Type *retType = builder.getVoidTy();
1747
1748   argTypes.clear();
1749   argTypes.push_back(builder.getInt32Ty());
1750   argTypes.push_back(builder.getInt8PtrTy());
1751
1752   argNames.clear();
1753
1754   createFunction(module,
1755                  retType,
1756                  argTypes,
1757                  argNames,
1758                  "print32Int",
1759                  llvm::Function::ExternalLinkage,
1760                  true,
1761                  false);
1762
1763   // print64Int
1764
1765   retType = builder.getVoidTy();
1766
1767   argTypes.clear();
1768   argTypes.push_back(builder.getInt64Ty());
1769   argTypes.push_back(builder.getInt8PtrTy());
1770
1771   argNames.clear();
1772
1773   createFunction(module,
1774                  retType,
1775                  argTypes,
1776                  argNames,
1777                  "print64Int",
1778                  llvm::Function::ExternalLinkage,
1779                  true,
1780                  false);
1781
1782   // printStr
1783
1784   retType = builder.getVoidTy();
1785
1786   argTypes.clear();
1787   argTypes.push_back(builder.getInt8PtrTy());
1788
1789   argNames.clear();
1790
1791   createFunction(module,
1792                  retType,
1793                  argTypes,
1794                  argNames,
1795                  "printStr",
1796                  llvm::Function::ExternalLinkage,
1797                  true,
1798                  false);
1799
1800   // throwCppException
1801
1802   retType = builder.getVoidTy();
1803
1804   argTypes.clear();
1805   argTypes.push_back(builder.getInt32Ty());
1806
1807   argNames.clear();
1808
1809   createFunction(module,
1810                  retType,
1811                  argTypes,
1812                  argNames,
1813                  "throwCppException",
1814                  llvm::Function::ExternalLinkage,
1815                  true,
1816                  false);
1817
1818   // deleteOurException
1819
1820   retType = builder.getVoidTy();
1821
1822   argTypes.clear();
1823   argTypes.push_back(builder.getInt8PtrTy());
1824
1825   argNames.clear();
1826
1827   createFunction(module,
1828                  retType,
1829                  argTypes,
1830                  argNames,
1831                  "deleteOurException",
1832                  llvm::Function::ExternalLinkage,
1833                  true,
1834                  false);
1835
1836   // createOurException
1837
1838   retType = builder.getInt8PtrTy();
1839
1840   argTypes.clear();
1841   argTypes.push_back(builder.getInt32Ty());
1842
1843   argNames.clear();
1844
1845   createFunction(module,
1846                  retType,
1847                  argTypes,
1848                  argNames,
1849                  "createOurException",
1850                  llvm::Function::ExternalLinkage,
1851                  true,
1852                  false);
1853
1854   // _Unwind_RaiseException
1855
1856   retType = builder.getInt32Ty();
1857
1858   argTypes.clear();
1859   argTypes.push_back(builder.getInt8PtrTy());
1860
1861   argNames.clear();
1862
1863   funct = createFunction(module,
1864                          retType,
1865                          argTypes,
1866                          argNames,
1867                          "_Unwind_RaiseException",
1868                          llvm::Function::ExternalLinkage,
1869                          true,
1870                          false);
1871
1872   funct->setDoesNotReturn();
1873
1874   // _Unwind_Resume
1875
1876   retType = builder.getInt32Ty();
1877
1878   argTypes.clear();
1879   argTypes.push_back(builder.getInt8PtrTy());
1880
1881   argNames.clear();
1882
1883   funct = createFunction(module,
1884                          retType,
1885                          argTypes,
1886                          argNames,
1887                          "_Unwind_Resume",
1888                          llvm::Function::ExternalLinkage,
1889                          true,
1890                          false);
1891
1892   funct->setDoesNotReturn();
1893
1894   // ourPersonality
1895
1896   retType = builder.getInt32Ty();
1897
1898   argTypes.clear();
1899   argTypes.push_back(builder.getInt32Ty());
1900   argTypes.push_back(builder.getInt32Ty());
1901   argTypes.push_back(builder.getInt64Ty());
1902   argTypes.push_back(builder.getInt8PtrTy());
1903   argTypes.push_back(builder.getInt8PtrTy());
1904
1905   argNames.clear();
1906
1907   createFunction(module,
1908                  retType,
1909                  argTypes,
1910                  argNames,
1911                  "ourPersonality",
1912                  llvm::Function::ExternalLinkage,
1913                  true,
1914                  false);
1915
1916   // llvm.eh.typeid.for intrinsic
1917
1918   getDeclaration(&module, llvm::Intrinsic::eh_typeid_for);
1919 }
1920
1921
1922 //===----------------------------------------------------------------------===//
1923 // Main test driver code.
1924 //===----------------------------------------------------------------------===//
1925
1926 /// Demo main routine which takes the type info types to throw. A test will
1927 /// be run for each given type info type. While type info types with the value
1928 /// of -1 will trigger a foreign C++ exception to be thrown; type info types
1929 /// <= 6 and >= 1 will be caught by test functions; and type info types > 6
1930 /// will result in exceptions which pass through to the test harness. All other
1931 /// type info types are not supported and could cause a crash.
1932 int main(int argc, char *argv[]) {
1933   if (argc == 1) {
1934     fprintf(stderr,
1935             "\nUsage: ExceptionDemo <exception type to throw> "
1936             "[<type 2>...<type n>].\n"
1937             "   Each type must have the value of 1 - 6 for "
1938             "generated exceptions to be caught;\n"
1939             "   the value -1 for foreign C++ exceptions to be "
1940             "generated and thrown;\n"
1941             "   or the values > 6 for exceptions to be ignored.\n"
1942             "\nTry: ExceptionDemo 2 3 7 -1\n"
1943             "   for a full test.\n\n");
1944     return(0);
1945   }
1946
1947   // If not set, exception handling will not be turned on
1948   llvm::TargetOptions Opts;
1949
1950   llvm::InitializeNativeTarget();
1951   llvm::InitializeNativeTargetAsmPrinter();
1952   llvm::LLVMContext &context = llvm::getGlobalContext();
1953   llvm::IRBuilder<> theBuilder(context);
1954
1955   // Make the module, which holds all the code.
1956   std::unique_ptr<llvm::Module> Owner =
1957       llvm::make_unique<llvm::Module>("my cool jit", context);
1958   llvm::Module *module = Owner.get();
1959
1960   std::unique_ptr<llvm::RTDyldMemoryManager> MemMgr(new llvm::SectionMemoryManager());
1961
1962   // Build engine with JIT
1963   llvm::EngineBuilder factory(std::move(Owner));
1964   factory.setEngineKind(llvm::EngineKind::JIT);
1965   factory.setTargetOptions(Opts);
1966   factory.setMCJITMemoryManager(std::move(MemMgr));
1967   llvm::ExecutionEngine *executionEngine = factory.create();
1968
1969   {
1970     llvm::legacy::FunctionPassManager fpm(module);
1971
1972     // Set up the optimizer pipeline.
1973     // Start with registering info about how the
1974     // target lays out data structures.
1975     module->setDataLayout(executionEngine->getDataLayout());
1976
1977     // Optimizations turned on
1978 #ifdef ADD_OPT_PASSES
1979
1980     // Basic AliasAnslysis support for GVN.
1981     fpm.add(llvm::createBasicAliasAnalysisPass());
1982
1983     // Promote allocas to registers.
1984     fpm.add(llvm::createPromoteMemoryToRegisterPass());
1985
1986     // Do simple "peephole" optimizations and bit-twiddling optzns.
1987     fpm.add(llvm::createInstructionCombiningPass());
1988
1989     // Reassociate expressions.
1990     fpm.add(llvm::createReassociatePass());
1991
1992     // Eliminate Common SubExpressions.
1993     fpm.add(llvm::createGVNPass());
1994
1995     // Simplify the control flow graph (deleting unreachable
1996     // blocks, etc).
1997     fpm.add(llvm::createCFGSimplificationPass());
1998 #endif  // ADD_OPT_PASSES
1999
2000     fpm.doInitialization();
2001
2002     // Generate test code using function throwCppException(...) as
2003     // the function which throws foreign exceptions.
2004     llvm::Function *toRun =
2005     createUnwindExceptionTest(*module,
2006                               theBuilder,
2007                               fpm,
2008                               "throwCppException");
2009
2010     executionEngine->finalizeObject();
2011
2012     fprintf(stderr, "\nBegin module dump:\n\n");
2013
2014     module->dump();
2015
2016     fprintf(stderr, "\nEnd module dump:\n");
2017
2018     fprintf(stderr, "\n\nBegin Test:\n");
2019
2020     for (int i = 1; i < argc; ++i) {
2021       // Run test for each argument whose value is the exception
2022       // type to throw.
2023       runExceptionThrow(executionEngine,
2024                         toRun,
2025                         (unsigned) strtoul(argv[i], NULL, 10));
2026     }
2027
2028     fprintf(stderr, "\nEnd Test:\n\n");
2029   }
2030
2031   delete executionEngine;
2032
2033   return 0;
2034 }