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://sourcery.mentor.com/public/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/LLVMContext.h"
  52 #include "llvm/DerivedTypes.h"
  53 #include "llvm/ExecutionEngine/ExecutionEngine.h"
  54 #include "llvm/ExecutionEngine/JIT.h"
  55 #include "llvm/IRBuilder.h"
  56 #include "llvm/Module.h"
  57 #include "llvm/PassManager.h"
  58 #include "llvm/Intrinsics.h"
  59 #include "llvm/Analysis/Verifier.h"
  60 #include "llvm/Target/TargetData.h"
  61 #include "llvm/Target/TargetOptions.h"
  62 #include "llvm/Transforms/Scalar.h"
  63 #include "llvm/Support/Dwarf.h"
  64 #include "llvm/Support/TargetSelect.h"
  65
  66 // FIXME: Although all systems tested with (Linux, OS X), do not need this
  67 //        header file included. A user on ubuntu reported, undefined symbols
  68 //        for stderr, and fprintf, and the addition of this include fixed the
  69 //        issue for them. Given that LLVM's best practices include the goal
  70 //        of reducing the number of redundant header files included, the
  71 //        correct solution would be to find out why these symbols are not
  72 //        defined for the system in question, and fix the issue by finding out
  73 //        which LLVM header file, if any, would include these symbols.
  74 #include <cstdio>
  75
  76 #include <sstream>
  77 #include <stdexcept>
  78
  79
  80 #ifndef USE_GLOBAL_STR_CONSTS
  81 #define USE_GLOBAL_STR_CONSTS true
  82 #endif
  83
  84 // System C++ ABI unwind types from:
  85 //     http://sourcery.mentor.com/public/cxx-abi/abi-eh.html (v1.22)
  86
  87 extern "C" {
  88
  89   typedef enum {
  90     _URC_NO_REASON = 0,
  91     _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
  92     _URC_FATAL_PHASE2_ERROR = 2,
  93     _URC_FATAL_PHASE1_ERROR = 3,
  94     _URC_NORMAL_STOP = 4,
  95     _URC_END_OF_STACK = 5,
  96     _URC_HANDLER_FOUND = 6,
  97     _URC_INSTALL_CONTEXT = 7,
  98     _URC_CONTINUE_UNWIND = 8
  99   } _Unwind_Reason_Code;
 100
 101   typedef enum {
 102     _UA_SEARCH_PHASE = 1,
 103     _UA_CLEANUP_PHASE = 2,
 104     _UA_HANDLER_FRAME = 4,
 105     _UA_FORCE_UNWIND = 8,
 106     _UA_END_OF_STACK = 16
 107   } _Unwind_Action;
 108
 109   struct _Unwind_Exception;
 110
 111   typedef void (*_Unwind_Exception_Cleanup_Fn) (_Unwind_Reason_Code,
 112                                                 struct _Unwind_Exception *);
 113
 114   struct _Unwind_Exception {
 115     uint64_t exception_class;
 116     _Unwind_Exception_Cleanup_Fn exception_cleanup;
 117
 118     uintptr_t private_1;
 119     uintptr_t private_2;
 120
 121     // @@@ The IA-64 ABI says that this structure must be double-word aligned.
 122     //  Taking that literally does not make much sense generically.  Instead
 123     //  we provide the maximum alignment required by any type for the machine.
 124   } __attribute__((__aligned__));
 125
 126   struct _Unwind_Context;
 127   typedef struct _Unwind_Context *_Unwind_Context_t;
 128
 129   extern const uint8_t *_Unwind_GetLanguageSpecificData (_Unwind_Context_t c);
 130   extern uintptr_t _Unwind_GetGR (_Unwind_Context_t c, int i);
 131   extern void _Unwind_SetGR (_Unwind_Context_t c, int i, uintptr_t n);
 132   extern void _Unwind_SetIP (_Unwind_Context_t, uintptr_t new_value);
 133   extern uintptr_t _Unwind_GetIP (_Unwind_Context_t context);
 134   extern uintptr_t _Unwind_GetRegionStart (_Unwind_Context_t context);
 135
 136 } // extern "C"
 137
 138 //
 139 // Example types
 140 //
 141
 142 /// This is our simplistic type info
 143 struct OurExceptionType_t {
 144   /// type info type
 145   int type;
 146 };
 147
 148
 149 /// This is our Exception class which relies on a negative offset to calculate
 150 /// pointers to its instances from pointers to its unwindException member.
 151 ///
 152 /// Note: The above unwind.h defines struct _Unwind_Exception to be aligned
 153 ///       on a double word boundary. This is necessary to match the standard:
 154 ///       http://refspecs.freestandards.org/abi-eh-1.21.html
 155 struct OurBaseException_t {
 156   struct OurExceptionType_t type;
 157
 158   // Note: This is properly aligned in unwind.h
 159   struct _Unwind_Exception unwindException;
 160 };
 161
 162
 163 // Note: Not needed since we are C++
 164 typedef struct OurBaseException_t OurException;
 165 typedef struct _Unwind_Exception OurUnwindException;
 166
 167 //
 168 // Various globals used to support typeinfo and generatted exceptions in
 169 // general
 170 //
 171
 172 static std::map<std::string, llvm::Value*> namedValues;
 173
 174 int64_t ourBaseFromUnwindOffset;
 175
 176 const unsigned char ourBaseExcpClassChars[] =
 177 {'o', 'b', 'j', '\0', 'b', 'a', 's', '\0'};
 178
 179
 180 static uint64_t ourBaseExceptionClass = 0;
 181
 182 static std::vector<std::string> ourTypeInfoNames;
 183 static std::map<int, std::string> ourTypeInfoNamesIndex;
 184
 185 static llvm::StructType *ourTypeInfoType;
 186 static llvm::StructType *ourCaughtResultType;
 187 static llvm::StructType *ourExceptionType;
 188 static llvm::StructType *ourUnwindExceptionType;
 189
 190 static llvm::ConstantInt *ourExceptionNotThrownState;
 191 static llvm::ConstantInt *ourExceptionThrownState;
 192 static llvm::ConstantInt *ourExceptionCaughtState;
 193
 194 typedef std::vector<std::string> ArgNames;
 195 typedef std::vector<llvm::Type*> ArgTypes;
 196
 197 //
 198 // Code Generation Utilities
 199 //
 200
 201 /// Utility used to create a function, both declarations and definitions
 202 /// @param module for module instance
 203 /// @param retType function return type
 204 /// @param theArgTypes function's ordered argument types
 205 /// @param theArgNames function's ordered arguments needed if use of this
 206 ///        function corresponds to a function definition. Use empty
 207 ///        aggregate for function declarations.
 208 /// @param functName function name
 209 /// @param linkage function linkage
 210 /// @param declarationOnly for function declarations
 211 /// @param isVarArg function uses vararg arguments
 212 /// @returns function instance
 213 llvm::Function *createFunction(llvm::Module &module,
 214                                llvm::Type *retType,
 215                                const ArgTypes &theArgTypes,
 216                                const ArgNames &theArgNames,
 217                                const std::string &functName,
 218                                llvm::GlobalValue::LinkageTypes linkage,
 219                                bool declarationOnly,
 220                                bool isVarArg) {
 221   llvm::FunctionType *functType =
 222     llvm::FunctionType::get(retType, theArgTypes, isVarArg);
 223   llvm::Function *ret =
 224     llvm::Function::Create(functType, linkage, functName, &module);
 225   if (!ret || declarationOnly)
 226     return(ret);
 227
 228   namedValues.clear();
 229   unsigned i = 0;
 230   for (llvm::Function::arg_iterator argIndex = ret->arg_begin();
 231        i != theArgNames.size();
 232        ++argIndex, ++i) {
 233
 234     argIndex->setName(theArgNames[i]);
 235     namedValues[theArgNames[i]] = argIndex;
 236   }
 237
 238   return(ret);
 239 }
 240
 241
 242 /// Create an alloca instruction in the entry block of
 243 /// the parent function.  This is used for mutable variables etc.
 244 /// @param function parent instance
 245 /// @param varName stack variable name
 246 /// @param type stack variable type
 247 /// @param initWith optional constant initialization value
 248 /// @returns AllocaInst instance
 249 static llvm::AllocaInst *createEntryBlockAlloca(llvm::Function &function,
 250                                                 const std::string &varName,
 251                                                 llvm::Type *type,
 252                                                 llvm::Constant *initWith = 0) {
 253   llvm::BasicBlock &block = function.getEntryBlock();
 254   llvm::IRBuilder<> tmp(&block, block.begin());
 255   llvm::AllocaInst *ret = tmp.CreateAlloca(type, 0, varName.c_str());
 256
 257   if (initWith)
 258     tmp.CreateStore(initWith, ret);
 259
 260   return(ret);
 261 }
 262
 263
 264 //
 265 // Code Generation Utilities End
 266 //
 267
 268 //
 269 // Runtime C Library functions
 270 //
 271
 272 // Note: using an extern "C" block so that static functions can be used
 273 extern "C" {
 274
 275 // Note: Better ways to decide on bit width
 276 //
 277 /// Prints a 32 bit number, according to the format, to stderr.
 278 /// @param intToPrint integer to print
 279 /// @param format printf like format to use when printing
 280 void print32Int(int intToPrint, const char *format) {
 281   if (format) {
 282     // Note: No NULL check
 283     fprintf(stderr, format, intToPrint);
 284   }
 285   else {
 286     // Note: No NULL check
 287     fprintf(stderr, "::print32Int(...):NULL arg.\n");
 288   }
 289 }
 290
 291
 292 // Note: Better ways to decide on bit width
 293 //
 294 /// Prints a 64 bit number, according to the format, to stderr.
 295 /// @param intToPrint integer to print
 296 /// @param format printf like format to use when printing
 297 void print64Int(long int intToPrint, const char *format) {
 298   if (format) {
 299     // Note: No NULL check
 300     fprintf(stderr, format, intToPrint);
 301   }
 302   else {
 303     // Note: No NULL check
 304     fprintf(stderr, "::print64Int(...):NULL arg.\n");
 305   }
 306 }
 307
 308
 309 /// Prints a C string to stderr
 310 /// @param toPrint string to print
 311 void printStr(char *toPrint) {
 312   if (toPrint) {
 313     fprintf(stderr, "%s", toPrint);
 314   }
 315   else {
 316     fprintf(stderr, "::printStr(...):NULL arg.\n");
 317   }
 318 }
 319
 320
 321 /// Deletes the true previosly allocated exception whose address
 322 /// is calculated from the supplied OurBaseException_t::unwindException
 323 /// member address. Handles (ignores), NULL pointers.
 324 /// @param expToDelete exception to delete
 325 void deleteOurException(OurUnwindException *expToDelete) {
 326 #ifdef DEBUG
 327   fprintf(stderr,
 328           "deleteOurException(...).\n");
 329 #endif
 330
 331   if (expToDelete &&
 332       (expToDelete->exception_class == ourBaseExceptionClass)) {
 333
 334     free(((char*) expToDelete) + ourBaseFromUnwindOffset);
 335   }
 336 }
 337
 338
 339 /// This function is the struct _Unwind_Exception API mandated delete function
 340 /// used by foreign exception handlers when deleting our exception
 341 /// (OurException), instances.
 342 /// @param reason @link http://refspecs.freestandards.org/abi-eh-1.21.html
 343 /// @unlink
 344 /// @param expToDelete exception instance to delete
 345 void deleteFromUnwindOurException(_Unwind_Reason_Code reason,
 346                                   OurUnwindException *expToDelete) {
 347 #ifdef DEBUG
 348   fprintf(stderr,
 349           "deleteFromUnwindOurException(...).\n");
 350 #endif
 351
 352   deleteOurException(expToDelete);
 353 }
 354
 355
 356 /// Creates (allocates on the heap), an exception (OurException instance),
 357 /// of the supplied type info type.
 358 /// @param type type info type
 359 OurUnwindException *createOurException(int type) {
 360   size_t size = sizeof(OurException);
 361   OurException *ret = (OurException*) memset(malloc(size), 0, size);
 362   (ret->type).type = type;
 363   (ret->unwindException).exception_class = ourBaseExceptionClass;
 364   (ret->unwindException).exception_cleanup = deleteFromUnwindOurException;
 365
 366   return(&(ret->unwindException));
 367 }
 368
 369
 370 /// Read a uleb128 encoded value and advance pointer
 371 /// See Variable Length Data in:
 372 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 373 /// @param data reference variable holding memory pointer to decode from
 374 /// @returns decoded value
 375 static uintptr_t readULEB128(const uint8_t **data) {
 376   uintptr_t result = 0;
 377   uintptr_t shift = 0;
 378   unsigned char byte;
 379   const uint8_t *p = *data;
 380
 381   do {
 382     byte = *p++;
 383     result |= (byte & 0x7f) << shift;
 384     shift += 7;
 385   }
 386   while (byte & 0x80);
 387
 388   *data = p;
 389
 390   return result;
 391 }
 392
 393
 394 /// Read a sleb128 encoded value and advance pointer
 395 /// See Variable Length Data in:
 396 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 397 /// @param data reference variable holding memory pointer to decode from
 398 /// @returns decoded value
 399 static uintptr_t readSLEB128(const uint8_t **data) {
 400   uintptr_t result = 0;
 401   uintptr_t shift = 0;
 402   unsigned char byte;
 403   const uint8_t *p = *data;
 404
 405   do {
 406     byte = *p++;
 407     result |= (byte & 0x7f) << shift;
 408     shift += 7;
 409   }
 410   while (byte & 0x80);
 411
 412   *data = p;
 413
 414   if ((byte & 0x40) && (shift < (sizeof(result) << 3))) {
 415     result |= (~0 << shift);
 416   }
 417
 418   return result;
 419 }
 420
 421
 422 /// Read a pointer encoded value and advance pointer
 423 /// See Variable Length Data in:
 424 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 425 /// @param data reference variable holding memory pointer to decode from
 426 /// @param encoding dwarf encoding type
 427 /// @returns decoded value
 428 static uintptr_t readEncodedPointer(const uint8_t **data, uint8_t encoding) {
 429   uintptr_t result = 0;
 430   const uint8_t *p = *data;
 431
 432   if (encoding == llvm::dwarf::DW_EH_PE_omit)
 433     return(result);
 434
 435   // first get value
 436   switch (encoding & 0x0F) {
 437     case llvm::dwarf::DW_EH_PE_absptr:
 438       result = *((uintptr_t*)p);
 439       p += sizeof(uintptr_t);
 440       break;
 441     case llvm::dwarf::DW_EH_PE_uleb128:
 442       result = readULEB128(&p);
 443       break;
 444       // Note: This case has not been tested
 445     case llvm::dwarf::DW_EH_PE_sleb128:
 446       result = readSLEB128(&p);
 447       break;
 448     case llvm::dwarf::DW_EH_PE_udata2:
 449       result = *((uint16_t*)p);
 450       p += sizeof(uint16_t);
 451       break;
 452     case llvm::dwarf::DW_EH_PE_udata4:
 453       result = *((uint32_t*)p);
 454       p += sizeof(uint32_t);
 455       break;
 456     case llvm::dwarf::DW_EH_PE_udata8:
 457       result = *((uint64_t*)p);
 458       p += sizeof(uint64_t);
 459       break;
 460     case llvm::dwarf::DW_EH_PE_sdata2:
 461       result = *((int16_t*)p);
 462       p += sizeof(int16_t);
 463       break;
 464     case llvm::dwarf::DW_EH_PE_sdata4:
 465       result = *((int32_t*)p);
 466       p += sizeof(int32_t);
 467       break;
 468     case llvm::dwarf::DW_EH_PE_sdata8:
 469       result = *((int64_t*)p);
 470       p += sizeof(int64_t);
 471       break;
 472     default:
 473       // not supported
 474       abort();
 475       break;
 476   }
 477
 478   // then add relative offset
 479   switch (encoding & 0x70) {
 480     case llvm::dwarf::DW_EH_PE_absptr:
 481       // do nothing
 482       break;
 483     case llvm::dwarf::DW_EH_PE_pcrel:
 484       result += (uintptr_t)(*data);
 485       break;
 486     case llvm::dwarf::DW_EH_PE_textrel:
 487     case llvm::dwarf::DW_EH_PE_datarel:
 488     case llvm::dwarf::DW_EH_PE_funcrel:
 489     case llvm::dwarf::DW_EH_PE_aligned:
 490     default:
 491       // not supported
 492       abort();
 493       break;
 494   }
 495
 496   // then apply indirection
 497   if (encoding & llvm::dwarf::DW_EH_PE_indirect) {
 498     result = *((uintptr_t*)result);
 499   }
 500
 501   *data = p;
 502
 503   return result;
 504 }
 505
 506
 507 /// Deals with Dwarf actions matching our type infos
 508 /// (OurExceptionType_t instances). Returns whether or not a dwarf emitted
 509 /// action matches the supplied exception type. If such a match succeeds,
 510 /// the resultAction argument will be set with > 0 index value. Only
 511 /// corresponding llvm.eh.selector type info arguments, cleanup arguments
 512 /// are supported. Filters are not supported.
 513 /// See Variable Length Data in:
 514 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 515 /// Also see @link http://refspecs.freestandards.org/abi-eh-1.21.html @unlink
 516 /// @param resultAction reference variable which will be set with result
 517 /// @param classInfo our array of type info pointers (to globals)
 518 /// @param actionEntry index into above type info array or 0 (clean up).
 519 ///        We do not support filters.
 520 /// @param exceptionClass exception class (_Unwind_Exception::exception_class)
 521 ///        of thrown exception.
 522 /// @param exceptionObject thrown _Unwind_Exception instance.
 523 /// @returns whether or not a type info was found. False is returned if only
 524 ///          a cleanup was found
 525 static bool handleActionValue(int64_t *resultAction,
 526                               struct OurExceptionType_t **classInfo,
 527                               uintptr_t actionEntry,
 528                               uint64_t exceptionClass,
 529                               struct _Unwind_Exception *exceptionObject) {
 530   bool ret = false;
 531
 532   if (!resultAction ||
 533       !exceptionObject ||
 534       (exceptionClass != ourBaseExceptionClass))
 535     return(ret);
 536
 537   struct OurBaseException_t *excp = (struct OurBaseException_t*)
 538   (((char*) exceptionObject) + ourBaseFromUnwindOffset);
 539   struct OurExceptionType_t *excpType = &(excp->type);
 540   int type = excpType->type;
 541
 542 #ifdef DEBUG
 543   fprintf(stderr,
 544           "handleActionValue(...): exceptionObject = <%p>, "
 545           "excp = <%p>.\n",
 546           exceptionObject,
 547           excp);
 548 #endif
 549
 550   const uint8_t *actionPos = (uint8_t*) actionEntry,
 551   *tempActionPos;
 552   int64_t typeOffset = 0,
 553   actionOffset;
 554
 555   for (int i = 0; true; ++i) {
 556     // Each emitted dwarf action corresponds to a 2 tuple of
 557     // type info address offset, and action offset to the next
 558     // emitted action.
 559     typeOffset = readSLEB128(&actionPos);
 560     tempActionPos = actionPos;
 561     actionOffset = readSLEB128(&tempActionPos);
 562
 563 #ifdef DEBUG
 564     fprintf(stderr,
 565             "handleActionValue(...):typeOffset: <%lld>, "
 566             "actionOffset: <%lld>.\n",
 567             typeOffset,
 568             actionOffset);
 569 #endif
 570     assert((typeOffset >= 0) &&
 571            "handleActionValue(...):filters are not supported.");
 572
 573     // Note: A typeOffset == 0 implies that a cleanup llvm.eh.selector
 574     //       argument has been matched.
 575     if ((typeOffset > 0) &&
 576         (type == (classInfo[-typeOffset])->type)) {
 577 #ifdef DEBUG
 578       fprintf(stderr,
 579               "handleActionValue(...):actionValue <%d> found.\n",
 580               i);
 581 #endif
 582       *resultAction = i + 1;
 583       ret = true;
 584       break;
 585     }
 586
 587 #ifdef DEBUG
 588     fprintf(stderr,
 589             "handleActionValue(...):actionValue not found.\n");
 590 #endif
 591     if (!actionOffset)
 592       break;
 593
 594     actionPos += actionOffset;
 595   }
 596
 597   return(ret);
 598 }
 599
 600
 601 /// Deals with the Language specific data portion of the emitted dwarf code.
 602 /// See @link http://refspecs.freestandards.org/abi-eh-1.21.html @unlink
 603 /// @param version unsupported (ignored), unwind version
 604 /// @param lsda language specific data area
 605 /// @param _Unwind_Action actions minimally supported unwind stage
 606 ///        (forced specifically not supported)
 607 /// @param exceptionClass exception class (_Unwind_Exception::exception_class)
 608 ///        of thrown exception.
 609 /// @param exceptionObject thrown _Unwind_Exception instance.
 610 /// @param context unwind system context
 611 /// @returns minimally supported unwinding control indicator
 612 static _Unwind_Reason_Code handleLsda(int version,
 613                                       const uint8_t *lsda,
 614                                       _Unwind_Action actions,
 615                                       uint64_t exceptionClass,
 616                                     struct _Unwind_Exception *exceptionObject,
 617                                       _Unwind_Context_t context) {
 618   _Unwind_Reason_Code ret = _URC_CONTINUE_UNWIND;
 619
 620   if (!lsda)
 621     return(ret);
 622
 623 #ifdef DEBUG
 624   fprintf(stderr,
 625           "handleLsda(...):lsda is non-zero.\n");
 626 #endif
 627
 628   // Get the current instruction pointer and offset it before next
 629   // instruction in the current frame which threw the exception.
 630   uintptr_t pc = _Unwind_GetIP(context)-1;
 631
 632   // Get beginning current frame's code (as defined by the
 633   // emitted dwarf code)
 634   uintptr_t funcStart = _Unwind_GetRegionStart(context);
 635   uintptr_t pcOffset = pc - funcStart;
 636   struct OurExceptionType_t **classInfo = NULL;
 637
 638   // Note: See JITDwarfEmitter::EmitExceptionTable(...) for corresponding
 639   //       dwarf emission
 640
 641   // Parse LSDA header.
 642   uint8_t lpStartEncoding = *lsda++;
 643
 644   if (lpStartEncoding != llvm::dwarf::DW_EH_PE_omit) {
 645     readEncodedPointer(&lsda, lpStartEncoding);
 646   }
 647
 648   uint8_t ttypeEncoding = *lsda++;
 649   uintptr_t classInfoOffset;
 650
 651   if (ttypeEncoding != llvm::dwarf::DW_EH_PE_omit) {
 652     // Calculate type info locations in emitted dwarf code which
 653     // were flagged by type info arguments to llvm.eh.selector
 654     // intrinsic
 655     classInfoOffset = readULEB128(&lsda);
 656     classInfo = (struct OurExceptionType_t**) (lsda + classInfoOffset);
 657   }
 658
 659   // Walk call-site table looking for range that
 660   // includes current PC.
 661
 662   uint8_t         callSiteEncoding = *lsda++;
 663   uint32_t        callSiteTableLength = readULEB128(&lsda);
 664   const uint8_t   *callSiteTableStart = lsda;
 665   const uint8_t   *callSiteTableEnd = callSiteTableStart +
 666   callSiteTableLength;
 667   const uint8_t   *actionTableStart = callSiteTableEnd;
 668   const uint8_t   *callSitePtr = callSiteTableStart;
 669
 670   bool foreignException = false;
 671
 672   while (callSitePtr < callSiteTableEnd) {
 673     uintptr_t start = readEncodedPointer(&callSitePtr,
 674                                          callSiteEncoding);
 675     uintptr_t length = readEncodedPointer(&callSitePtr,
 676                                           callSiteEncoding);
 677     uintptr_t landingPad = readEncodedPointer(&callSitePtr,
 678                                               callSiteEncoding);
 679
 680     // Note: Action value
 681     uintptr_t actionEntry = readULEB128(&callSitePtr);
 682
 683     if (exceptionClass != ourBaseExceptionClass) {
 684       // We have been notified of a foreign exception being thrown,
 685       // and we therefore need to execute cleanup landing pads
 686       actionEntry = 0;
 687       foreignException = true;
 688     }
 689
 690     if (landingPad == 0) {
 691 #ifdef DEBUG
 692       fprintf(stderr,
 693               "handleLsda(...): No landing pad found.\n");
 694 #endif
 695
 696       continue; // no landing pad for this entry
 697     }
 698
 699     if (actionEntry) {
 700       actionEntry += ((uintptr_t) actionTableStart) - 1;
 701     }
 702     else {
 703 #ifdef DEBUG
 704       fprintf(stderr,
 705               "handleLsda(...):No action table found.\n");
 706 #endif
 707     }
 708
 709     bool exceptionMatched = false;
 710
 711     if ((start <= pcOffset) && (pcOffset < (start + length))) {
 712 #ifdef DEBUG
 713       fprintf(stderr,
 714               "handleLsda(...): Landing pad found.\n");
 715 #endif
 716       int64_t actionValue = 0;
 717
 718       if (actionEntry) {
 719         exceptionMatched = handleActionValue(&actionValue,
 720                                              classInfo,
 721                                              actionEntry,
 722                                              exceptionClass,
 723                                              exceptionObject);
 724       }
 725
 726       if (!(actions & _UA_SEARCH_PHASE)) {
 727 #ifdef DEBUG
 728         fprintf(stderr,
 729                 "handleLsda(...): installed landing pad "
 730                 "context.\n");
 731 #endif
 732
 733         // Found landing pad for the PC.
 734         // Set Instruction Pointer to so we re-enter function
 735         // at landing pad. The landing pad is created by the
 736         // compiler to take two parameters in registers.
 737         _Unwind_SetGR(context,
 738                       __builtin_eh_return_data_regno(0),
 739                       (uintptr_t)exceptionObject);
 740
 741         // Note: this virtual register directly corresponds
 742         //       to the return of the llvm.eh.selector intrinsic
 743         if (!actionEntry || !exceptionMatched) {
 744           // We indicate cleanup only
 745           _Unwind_SetGR(context,
 746                         __builtin_eh_return_data_regno(1),
 747                         0);
 748         }
 749         else {
 750           // Matched type info index of llvm.eh.selector intrinsic
 751           // passed here.
 752           _Unwind_SetGR(context,
 753                         __builtin_eh_return_data_regno(1),
 754                         actionValue);
 755         }
 756
 757         // To execute landing pad set here
 758         _Unwind_SetIP(context, funcStart + landingPad);
 759         ret = _URC_INSTALL_CONTEXT;
 760       }
 761       else if (exceptionMatched) {
 762 #ifdef DEBUG
 763         fprintf(stderr,
 764                 "handleLsda(...): setting handler found.\n");
 765 #endif
 766         ret = _URC_HANDLER_FOUND;
 767       }
 768       else {
 769         // Note: Only non-clean up handlers are marked as
 770         //       found. Otherwise the clean up handlers will be
 771         //       re-found and executed during the clean up
 772         //       phase.
 773 #ifdef DEBUG
 774         fprintf(stderr,
 775                 "handleLsda(...): cleanup handler found.\n");
 776 #endif
 777       }
 778
 779       break;
 780     }
 781   }
 782
 783   return(ret);
 784 }
 785
 786
 787 /// This is the personality function which is embedded (dwarf emitted), in the
 788 /// dwarf unwind info block. Again see: JITDwarfEmitter.cpp.
 789 /// See @link http://refspecs.freestandards.org/abi-eh-1.21.html @unlink
 790 /// @param version unsupported (ignored), unwind version
 791 /// @param _Unwind_Action actions minimally supported unwind stage
 792 ///        (forced specifically not supported)
 793 /// @param exceptionClass exception class (_Unwind_Exception::exception_class)
 794 ///        of thrown exception.
 795 /// @param exceptionObject thrown _Unwind_Exception instance.
 796 /// @param context unwind system context
 797 /// @returns minimally supported unwinding control indicator
 798 _Unwind_Reason_Code ourPersonality(int version,
 799                                    _Unwind_Action actions,
 800                                    uint64_t exceptionClass,
 801                                    struct _Unwind_Exception *exceptionObject,
 802                                    _Unwind_Context_t context) {
 803 #ifdef DEBUG
 804   fprintf(stderr,
 805           "We are in ourPersonality(...):actions is <%d>.\n",
 806           actions);
 807
 808   if (actions & _UA_SEARCH_PHASE) {
 809     fprintf(stderr, "ourPersonality(...):In search phase.\n");
 810   }
 811   else {
 812     fprintf(stderr, "ourPersonality(...):In non-search phase.\n");
 813   }
 814 #endif
 815
 816   const uint8_t *lsda = _Unwind_GetLanguageSpecificData(context);
 817
 818 #ifdef DEBUG
 819   fprintf(stderr,
 820           "ourPersonality(...):lsda = <%p>.\n",
 821           lsda);
 822 #endif
 823
 824   // The real work of the personality function is captured here
 825   return(handleLsda(version,
 826                     lsda,
 827                     actions,
 828                     exceptionClass,
 829                     exceptionObject,
 830                     context));
 831 }
 832
 833
 834 /// Generates our _Unwind_Exception class from a given character array.
 835 /// thereby handling arbitrary lengths (not in standard), and handling
 836 /// embedded \0s.
 837 /// See @link http://refspecs.freestandards.org/abi-eh-1.21.html @unlink
 838 /// @param classChars char array to encode. NULL values not checkedf
 839 /// @param classCharsSize number of chars in classChars. Value is not checked.
 840 /// @returns class value
 841 uint64_t genClass(const unsigned char classChars[], size_t classCharsSize)
 842 {
 843   uint64_t ret = classChars[0];
 844
 845   for (unsigned i = 1; i < classCharsSize; ++i) {
 846     ret <<= 8;
 847     ret += classChars[i];
 848   }
 849
 850   return(ret);
 851 }
 852
 853 } // extern "C"
 854
 855 //
 856 // Runtime C Library functions End
 857 //
 858
 859 //
 860 // Code generation functions
 861 //
 862
 863 /// Generates code to print given constant string
 864 /// @param context llvm context
 865 /// @param module code for module instance
 866 /// @param builder builder instance
 867 /// @param toPrint string to print
 868 /// @param useGlobal A value of true (default) indicates a GlobalValue is
 869 ///        generated, and is used to hold the constant string. A value of
 870 ///        false indicates that the constant string will be stored on the
 871 ///        stack.
 872 void generateStringPrint(llvm::LLVMContext &context,
 873                          llvm::Module &module,
 874                          llvm::IRBuilder<> &builder,
 875                          std::string toPrint,
 876                          bool useGlobal = true) {
 877   llvm::Function *printFunct = module.getFunction("printStr");
 878
 879   llvm::Value *stringVar;
 880   llvm::Constant *stringConstant =
 881   llvm::ConstantDataArray::getString(context, toPrint);
 882
 883   if (useGlobal) {
 884     // Note: Does not work without allocation
 885     stringVar =
 886     new llvm::GlobalVariable(module,
 887                              stringConstant->getType(),
 888                              true,
 889                              llvm::GlobalValue::LinkerPrivateLinkage,
 890                              stringConstant,
 891                              "");
 892   }
 893   else {
 894     stringVar = builder.CreateAlloca(stringConstant->getType());
 895     builder.CreateStore(stringConstant, stringVar);
 896   }
 897
 898   llvm::Value *cast = builder.CreatePointerCast(stringVar,
 899                                                 builder.getInt8PtrTy());
 900   builder.CreateCall(printFunct, cast);
 901 }
 902
 903
 904 /// Generates code to print given runtime integer according to constant
 905 /// string format, and a given print function.
 906 /// @param context llvm context
 907 /// @param module code for module instance
 908 /// @param builder builder instance
 909 /// @param printFunct function used to "print" integer
 910 /// @param toPrint string to print
 911 /// @param format printf like formating string for print
 912 /// @param useGlobal A value of true (default) indicates a GlobalValue is
 913 ///        generated, and is used to hold the constant string. A value of
 914 ///        false indicates that the constant string will be stored on the
 915 ///        stack.
 916 void generateIntegerPrint(llvm::LLVMContext &context,
 917                           llvm::Module &module,
 918                           llvm::IRBuilder<> &builder,
 919                           llvm::Function &printFunct,
 920                           llvm::Value &toPrint,
 921                           std::string format,
 922                           bool useGlobal = true) {
 923   llvm::Constant *stringConstant =
 924     llvm::ConstantDataArray::getString(context, format);
 925   llvm::Value *stringVar;
 926
 927   if (useGlobal) {
 928     // Note: Does not seem to work without allocation
 929     stringVar =
 930     new llvm::GlobalVariable(module,
 931                              stringConstant->getType(),
 932                              true,
 933                              llvm::GlobalValue::LinkerPrivateLinkage,
 934                              stringConstant,
 935                              "");
 936   }
 937   else {
 938     stringVar = builder.CreateAlloca(stringConstant->getType());
 939     builder.CreateStore(stringConstant, stringVar);
 940   }
 941
 942   llvm::Value *cast = builder.CreateBitCast(stringVar,
 943                                             builder.getInt8PtrTy());
 944   builder.CreateCall2(&printFunct, &toPrint, cast);
 945 }
 946
 947
 948 /// Generates code to handle finally block type semantics: always runs
 949 /// regardless of whether a thrown exception is passing through or the
 950 /// parent function is simply exiting. In addition to printing some state
 951 /// to stderr, this code will resume the exception handling--runs the
 952 /// unwind resume block, if the exception has not been previously caught
 953 /// by a catch clause, and will otherwise execute the end block (terminator
 954 /// block). In addition this function creates the corresponding function's
 955 /// stack storage for the exception pointer and catch flag status.
 956 /// @param context llvm context
 957 /// @param module code for module instance
 958 /// @param builder builder instance
 959 /// @param toAddTo parent function to add block to
 960 /// @param blockName block name of new "finally" block.
 961 /// @param functionId output id used for printing
 962 /// @param terminatorBlock terminator "end" block
 963 /// @param unwindResumeBlock unwind resume block
 964 /// @param exceptionCaughtFlag reference exception caught/thrown status storage
 965 /// @param exceptionStorage reference to exception pointer storage
 966 /// @param caughtResultStorage reference to landingpad result storage
 967 /// @returns newly created block
 968 static llvm::BasicBlock *createFinallyBlock(llvm::LLVMContext &context,
 969                                             llvm::Module &module,
 970                                             llvm::IRBuilder<> &builder,
 971                                             llvm::Function &toAddTo,
 972                                             std::string &blockName,
 973                                             std::string &functionId,
 974                                             llvm::BasicBlock &terminatorBlock,
 975                                             llvm::BasicBlock &unwindResumeBlock,
 976                                             llvm::Value **exceptionCaughtFlag,
 977                                             llvm::Value **exceptionStorage,
 978                                             llvm::Value **caughtResultStorage) {
 979   assert(exceptionCaughtFlag &&
 980          "ExceptionDemo::createFinallyBlock(...):exceptionCaughtFlag "
 981          "is NULL");
 982   assert(exceptionStorage &&
 983          "ExceptionDemo::createFinallyBlock(...):exceptionStorage "
 984          "is NULL");
 985   assert(caughtResultStorage &&
 986          "ExceptionDemo::createFinallyBlock(...):caughtResultStorage "
 987          "is NULL");
 988
 989   *exceptionCaughtFlag = createEntryBlockAlloca(toAddTo,
 990                                          "exceptionCaught",
 991                                          ourExceptionNotThrownState->getType(),
 992                                          ourExceptionNotThrownState);
 993
 994   llvm::PointerType *exceptionStorageType = builder.getInt8PtrTy();
 995   *exceptionStorage = createEntryBlockAlloca(toAddTo,
 996                                              "exceptionStorage",
 997                                              exceptionStorageType,
 998                                              llvm::ConstantPointerNull::get(
 999                                                exceptionStorageType));
1000   *caughtResultStorage = createEntryBlockAlloca(toAddTo,
1001                                               "caughtResultStorage",
1002                                               ourCaughtResultType,
1003                                               llvm::ConstantAggregateZero::get(
1004                                                 ourCaughtResultType));
1005
1006   llvm::BasicBlock *ret = llvm::BasicBlock::Create(context,
1007                                                    blockName,
1008                                                    &toAddTo);
1009
1010   builder.SetInsertPoint(ret);
1011
1012   std::ostringstream bufferToPrint;
1013   bufferToPrint << "Gen: Executing finally block "
1014     << blockName << " in " << functionId << "\n";
1015   generateStringPrint(context,
1016                       module,
1017                       builder,
1018                       bufferToPrint.str(),
1019                       USE_GLOBAL_STR_CONSTS);
1020
1021   llvm::SwitchInst *theSwitch = builder.CreateSwitch(builder.CreateLoad(
1022                                                        *exceptionCaughtFlag),
1023                                                      &terminatorBlock,
1024                                                      2);
1025   theSwitch->addCase(ourExceptionCaughtState, &terminatorBlock);
1026   theSwitch->addCase(ourExceptionThrownState, &unwindResumeBlock);
1027
1028   return(ret);
1029 }
1030
1031
1032 /// Generates catch block semantics which print a string to indicate type of
1033 /// catch executed, sets an exception caught flag, and executes passed in
1034 /// end block (terminator block).
1035 /// @param context llvm context
1036 /// @param module code for module instance
1037 /// @param builder builder instance
1038 /// @param toAddTo parent function to add block to
1039 /// @param blockName block name of new "catch" block.
1040 /// @param functionId output id used for printing
1041 /// @param terminatorBlock terminator "end" block
1042 /// @param exceptionCaughtFlag exception caught/thrown status
1043 /// @returns newly created block
1044 static llvm::BasicBlock *createCatchBlock(llvm::LLVMContext &context,
1045                                           llvm::Module &module,
1046                                           llvm::IRBuilder<> &builder,
1047                                           llvm::Function &toAddTo,
1048                                           std::string &blockName,
1049                                           std::string &functionId,
1050                                           llvm::BasicBlock &terminatorBlock,
1051                                           llvm::Value &exceptionCaughtFlag) {
1052
1053   llvm::BasicBlock *ret = llvm::BasicBlock::Create(context,
1054                                                    blockName,
1055                                                    &toAddTo);
1056
1057   builder.SetInsertPoint(ret);
1058
1059   std::ostringstream bufferToPrint;
1060   bufferToPrint << "Gen: Executing catch block "
1061   << blockName
1062   << " in "
1063   << functionId
1064   << std::endl;
1065   generateStringPrint(context,
1066                       module,
1067                       builder,
1068                       bufferToPrint.str(),
1069                       USE_GLOBAL_STR_CONSTS);
1070   builder.CreateStore(ourExceptionCaughtState, &exceptionCaughtFlag);
1071   builder.CreateBr(&terminatorBlock);
1072
1073   return(ret);
1074 }
1075
1076
1077 /// Generates a function which invokes a function (toInvoke) and, whose
1078 /// unwind block will "catch" the type info types correspondingly held in the
1079 /// exceptionTypesToCatch argument. If the toInvoke function throws an
1080 /// exception which does not match any type info types contained in
1081 /// exceptionTypesToCatch, the generated code will call _Unwind_Resume
1082 /// with the raised exception. On the other hand the generated code will
1083 /// normally exit if the toInvoke function does not throw an exception.
1084 /// The generated "finally" block is always run regardless of the cause of
1085 /// the generated function exit.
1086 /// The generated function is returned after being verified.
1087 /// @param module code for module instance
1088 /// @param builder builder instance
1089 /// @param fpm a function pass manager holding optional IR to IR
1090 ///        transformations
1091 /// @param toInvoke inner function to invoke
1092 /// @param ourId id used to printing purposes
1093 /// @param numExceptionsToCatch length of exceptionTypesToCatch array
1094 /// @param exceptionTypesToCatch array of type info types to "catch"
1095 /// @returns generated function
1096 static
1097 llvm::Function *createCatchWrappedInvokeFunction(llvm::Module &module,
1098                                              llvm::IRBuilder<> &builder,
1099                                              llvm::FunctionPassManager &fpm,
1100                                              llvm::Function &toInvoke,
1101                                              std::string ourId,
1102                                              unsigned numExceptionsToCatch,
1103                                              unsigned exceptionTypesToCatch[]) {
1104
1105   llvm::LLVMContext &context = module.getContext();
1106   llvm::Function *toPrint32Int = module.getFunction("print32Int");
1107
1108   ArgTypes argTypes;
1109   argTypes.push_back(builder.getInt32Ty());
1110
1111   ArgNames argNames;
1112   argNames.push_back("exceptTypeToThrow");
1113
1114   llvm::Function *ret = createFunction(module,
1115                                        builder.getVoidTy(),
1116                                        argTypes,
1117                                        argNames,
1118                                        ourId,
1119                                        llvm::Function::ExternalLinkage,
1120                                        false,
1121                                        false);
1122
1123   // Block which calls invoke
1124   llvm::BasicBlock *entryBlock = llvm::BasicBlock::Create(context,
1125                                                           "entry",
1126                                                           ret);
1127   // Normal block for invoke
1128   llvm::BasicBlock *normalBlock = llvm::BasicBlock::Create(context,
1129                                                            "normal",
1130                                                            ret);
1131   // Unwind block for invoke
1132   llvm::BasicBlock *exceptionBlock = llvm::BasicBlock::Create(context,
1133                                                               "exception",
1134                                                               ret);
1135
1136   // Block which routes exception to correct catch handler block
1137   llvm::BasicBlock *exceptionRouteBlock = llvm::BasicBlock::Create(context,
1138                                                              "exceptionRoute",
1139                                                              ret);
1140
1141   // Foreign exception handler
1142   llvm::BasicBlock *externalExceptionBlock = llvm::BasicBlock::Create(context,
1143                                                           "externalException",
1144                                                           ret);
1145
1146   // Block which calls _Unwind_Resume
1147   llvm::BasicBlock *unwindResumeBlock = llvm::BasicBlock::Create(context,
1148                                                                "unwindResume",
1149                                                                ret);
1150
1151   // Clean up block which delete exception if needed
1152   llvm::BasicBlock *endBlock = llvm::BasicBlock::Create(context, "end", ret);
1153
1154   std::string nextName;
1155   std::vector<llvm::BasicBlock*> catchBlocks(numExceptionsToCatch);
1156   llvm::Value *exceptionCaughtFlag = NULL;
1157   llvm::Value *exceptionStorage = NULL;
1158   llvm::Value *caughtResultStorage = NULL;
1159
1160   // Finally block which will branch to unwindResumeBlock if
1161   // exception is not caught. Initializes/allocates stack locations.
1162   llvm::BasicBlock *finallyBlock = createFinallyBlock(context,
1163                                                       module,
1164                                                       builder,
1165                                                       *ret,
1166                                                       nextName = "finally",
1167                                                       ourId,
1168                                                       *endBlock,
1169                                                       *unwindResumeBlock,
1170                                                       &exceptionCaughtFlag,
1171                                                       &exceptionStorage,
1172                                                       &caughtResultStorage
1173                                                       );
1174
1175   for (unsigned i = 0; i < numExceptionsToCatch; ++i) {
1176     nextName = ourTypeInfoNames[exceptionTypesToCatch[i]];
1177
1178     // One catch block per type info to be caught
1179     catchBlocks[i] = createCatchBlock(context,
1180                                       module,
1181                                       builder,
1182                                       *ret,
1183                                       nextName,
1184                                       ourId,
1185                                       *finallyBlock,
1186                                       *exceptionCaughtFlag);
1187   }
1188
1189   // Entry Block
1190
1191   builder.SetInsertPoint(entryBlock);
1192
1193   std::vector<llvm::Value*> args;
1194   args.push_back(namedValues["exceptTypeToThrow"]);
1195   builder.CreateInvoke(&toInvoke,
1196                        normalBlock,
1197                        exceptionBlock,
1198                        args);
1199
1200   // End Block
1201
1202   builder.SetInsertPoint(endBlock);
1203
1204   generateStringPrint(context,
1205                       module,
1206                       builder,
1207                       "Gen: In end block: exiting in " + ourId + ".\n",
1208                       USE_GLOBAL_STR_CONSTS);
1209   llvm::Function *deleteOurException = module.getFunction("deleteOurException");
1210
1211   // Note: function handles NULL exceptions
1212   builder.CreateCall(deleteOurException,
1213                      builder.CreateLoad(exceptionStorage));
1214   builder.CreateRetVoid();
1215
1216   // Normal Block
1217
1218   builder.SetInsertPoint(normalBlock);
1219
1220   generateStringPrint(context,
1221                       module,
1222                       builder,
1223                       "Gen: No exception in " + ourId + "!\n",
1224                       USE_GLOBAL_STR_CONSTS);
1225
1226   // Finally block is always called
1227   builder.CreateBr(finallyBlock);
1228
1229   // Unwind Resume Block
1230
1231   builder.SetInsertPoint(unwindResumeBlock);
1232
1233   builder.CreateResume(builder.CreateLoad(caughtResultStorage));
1234
1235   // Exception Block
1236
1237   builder.SetInsertPoint(exceptionBlock);
1238
1239   llvm::Function *personality = module.getFunction("ourPersonality");
1240
1241   llvm::LandingPadInst *caughtResult =
1242     builder.CreateLandingPad(ourCaughtResultType,
1243                              personality,
1244                              numExceptionsToCatch,
1245                              "landingPad");
1246
1247   caughtResult->setCleanup(true);
1248
1249   for (unsigned i = 0; i < numExceptionsToCatch; ++i) {
1250     // Set up type infos to be caught
1251     caughtResult->addClause(module.getGlobalVariable(
1252                              ourTypeInfoNames[exceptionTypesToCatch[i]]));
1253   }
1254
1255   llvm::Value *unwindException = builder.CreateExtractValue(caughtResult, 0);
1256   llvm::Value *retTypeInfoIndex = builder.CreateExtractValue(caughtResult, 1);
1257
1258   // FIXME: Redundant storage which, beyond utilizing value of
1259   //        caughtResultStore for unwindException storage, may be alleviated
1260   //        altogether with a block rearrangement
1261   builder.CreateStore(caughtResult, caughtResultStorage);
1262   builder.CreateStore(unwindException, exceptionStorage);
1263   builder.CreateStore(ourExceptionThrownState, exceptionCaughtFlag);
1264
1265   // Retrieve exception_class member from thrown exception
1266   // (_Unwind_Exception instance). This member tells us whether or not
1267   // the exception is foreign.
1268   llvm::Value *unwindExceptionClass =
1269     builder.CreateLoad(builder.CreateStructGEP(
1270              builder.CreatePointerCast(unwindException,
1271                                        ourUnwindExceptionType->getPointerTo()),
1272                                                0));
1273
1274   // Branch to the externalExceptionBlock if the exception is foreign or
1275   // to a catch router if not. Either way the finally block will be run.
1276   builder.CreateCondBr(builder.CreateICmpEQ(unwindExceptionClass,
1277                             llvm::ConstantInt::get(builder.getInt64Ty(),
1278                                                    ourBaseExceptionClass)),
1279                        exceptionRouteBlock,
1280                        externalExceptionBlock);
1281
1282   // External Exception Block
1283
1284   builder.SetInsertPoint(externalExceptionBlock);
1285
1286   generateStringPrint(context,
1287                       module,
1288                       builder,
1289                       "Gen: Foreign exception received.\n",
1290                       USE_GLOBAL_STR_CONSTS);
1291
1292   // Branch to the finally block
1293   builder.CreateBr(finallyBlock);
1294
1295   // Exception Route Block
1296
1297   builder.SetInsertPoint(exceptionRouteBlock);
1298
1299   // Casts exception pointer (_Unwind_Exception instance) to parent
1300   // (OurException instance).
1301   //
1302   // Note: ourBaseFromUnwindOffset is usually negative
1303   llvm::Value *typeInfoThrown = builder.CreatePointerCast(
1304                                   builder.CreateConstGEP1_64(unwindException,
1305                                                        ourBaseFromUnwindOffset),
1306                                   ourExceptionType->getPointerTo());
1307
1308   // Retrieve thrown exception type info type
1309   //
1310   // Note: Index is not relative to pointer but instead to structure
1311   //       unlike a true getelementptr (GEP) instruction
1312   typeInfoThrown = builder.CreateStructGEP(typeInfoThrown, 0);
1313
1314   llvm::Value *typeInfoThrownType =
1315   builder.CreateStructGEP(typeInfoThrown, 0);
1316
1317   generateIntegerPrint(context,
1318                        module,
1319                        builder,
1320                        *toPrint32Int,
1321                        *(builder.CreateLoad(typeInfoThrownType)),
1322                        "Gen: Exception type <%d> received (stack unwound) "
1323                        " in " +
1324                        ourId +
1325                        ".\n",
1326                        USE_GLOBAL_STR_CONSTS);
1327
1328   // Route to matched type info catch block or run cleanup finally block
1329   llvm::SwitchInst *switchToCatchBlock = builder.CreateSwitch(retTypeInfoIndex,
1330                                                           finallyBlock,
1331                                                           numExceptionsToCatch);
1332
1333   unsigned nextTypeToCatch;
1334
1335   for (unsigned i = 1; i <= numExceptionsToCatch; ++i) {
1336     nextTypeToCatch = i - 1;
1337     switchToCatchBlock->addCase(llvm::ConstantInt::get(
1338                                    llvm::Type::getInt32Ty(context), i),
1339                                 catchBlocks[nextTypeToCatch]);
1340   }
1341
1342   llvm::verifyFunction(*ret);
1343   fpm.run(*ret);
1344
1345   return(ret);
1346 }
1347
1348
1349 /// Generates function which throws either an exception matched to a runtime
1350 /// determined type info type (argument to generated function), or if this
1351 /// runtime value matches nativeThrowType, throws a foreign exception by
1352 /// calling nativeThrowFunct.
1353 /// @param module code for module instance
1354 /// @param builder builder instance
1355 /// @param fpm a function pass manager holding optional IR to IR
1356 ///        transformations
1357 /// @param ourId id used to printing purposes
1358 /// @param nativeThrowType a runtime argument of this value results in
1359 ///        nativeThrowFunct being called to generate/throw exception.
1360 /// @param nativeThrowFunct function which will throw a foreign exception
1361 ///        if the above nativeThrowType matches generated function's arg.
1362 /// @returns generated function
1363 static
1364 llvm::Function *createThrowExceptionFunction(llvm::Module &module,
1365                                              llvm::IRBuilder<> &builder,
1366                                              llvm::FunctionPassManager &fpm,
1367                                              std::string ourId,
1368                                              int32_t nativeThrowType,
1369                                              llvm::Function &nativeThrowFunct) {
1370   llvm::LLVMContext &context = module.getContext();
1371   namedValues.clear();
1372   ArgTypes unwindArgTypes;
1373   unwindArgTypes.push_back(builder.getInt32Ty());
1374   ArgNames unwindArgNames;
1375   unwindArgNames.push_back("exceptTypeToThrow");
1376
1377   llvm::Function *ret = createFunction(module,
1378                                        builder.getVoidTy(),
1379                                        unwindArgTypes,
1380                                        unwindArgNames,
1381                                        ourId,
1382                                        llvm::Function::ExternalLinkage,
1383                                        false,
1384                                        false);
1385
1386   // Throws either one of our exception or a native C++ exception depending
1387   // on a runtime argument value containing a type info type.
1388   llvm::BasicBlock *entryBlock = llvm::BasicBlock::Create(context,
1389                                                           "entry",
1390                                                           ret);
1391   // Throws a foreign exception
1392   llvm::BasicBlock *nativeThrowBlock = llvm::BasicBlock::Create(context,
1393                                                                 "nativeThrow",
1394                                                                 ret);
1395   // Throws one of our Exceptions
1396   llvm::BasicBlock *generatedThrowBlock = llvm::BasicBlock::Create(context,
1397                                                              "generatedThrow",
1398                                                              ret);
1399   // Retrieved runtime type info type to throw
1400   llvm::Value *exceptionType = namedValues["exceptTypeToThrow"];
1401
1402   // nativeThrowBlock block
1403
1404   builder.SetInsertPoint(nativeThrowBlock);
1405
1406   // Throws foreign exception
1407   builder.CreateCall(&nativeThrowFunct, exceptionType);
1408   builder.CreateUnreachable();
1409
1410   // entry block
1411
1412   builder.SetInsertPoint(entryBlock);
1413
1414   llvm::Function *toPrint32Int = module.getFunction("print32Int");
1415   generateIntegerPrint(context,
1416                        module,
1417                        builder,
1418                        *toPrint32Int,
1419                        *exceptionType,
1420                        "\nGen: About to throw exception type <%d> in " +
1421                        ourId +
1422                        ".\n",
1423                        USE_GLOBAL_STR_CONSTS);
1424
1425   // Switches on runtime type info type value to determine whether or not
1426   // a foreign exception is thrown. Defaults to throwing one of our
1427   // generated exceptions.
1428   llvm::SwitchInst *theSwitch = builder.CreateSwitch(exceptionType,
1429                                                      generatedThrowBlock,
1430                                                      1);
1431
1432   theSwitch->addCase(llvm::ConstantInt::get(llvm::Type::getInt32Ty(context),
1433                                             nativeThrowType),
1434                      nativeThrowBlock);
1435
1436   // generatedThrow block
1437
1438   builder.SetInsertPoint(generatedThrowBlock);
1439
1440   llvm::Function *createOurException = module.getFunction("createOurException");
1441   llvm::Function *raiseOurException = module.getFunction(
1442                                         "_Unwind_RaiseException");
1443
1444   // Creates exception to throw with runtime type info type.
1445   llvm::Value *exception = builder.CreateCall(createOurException,
1446                                               namedValues["exceptTypeToThrow"]);
1447
1448   // Throw generated Exception
1449   builder.CreateCall(raiseOurException, exception);
1450   builder.CreateUnreachable();
1451
1452   llvm::verifyFunction(*ret);
1453   fpm.run(*ret);
1454
1455   return(ret);
1456 }
1457
1458 static void createStandardUtilityFunctions(unsigned numTypeInfos,
1459                                            llvm::Module &module,
1460                                            llvm::IRBuilder<> &builder);
1461
1462 /// Creates test code by generating and organizing these functions into the
1463 /// test case. The test case consists of an outer function setup to invoke
1464 /// an inner function within an environment having multiple catch and single
1465 /// finally blocks. This inner function is also setup to invoke a throw
1466 /// function within an evironment similar in nature to the outer function's
1467 /// catch and finally blocks. Each of these two functions catch mutually
1468 /// exclusive subsets (even or odd) of the type info types configured
1469 /// for this this. All generated functions have a runtime argument which
1470 /// holds a type info type to throw that each function takes and passes it
1471 /// to the inner one if such a inner function exists. This type info type is
1472 /// looked at by the generated throw function to see whether or not it should
1473 /// throw a generated exception with the same type info type, or instead call
1474 /// a supplied a function which in turn will throw a foreign exception.
1475 /// @param module code for module instance
1476 /// @param builder builder instance
1477 /// @param fpm a function pass manager holding optional IR to IR
1478 ///        transformations
1479 /// @param nativeThrowFunctName name of external function which will throw
1480 ///        a foreign exception
1481 /// @returns outermost generated test function.
1482 llvm::Function *createUnwindExceptionTest(llvm::Module &module,
1483                                           llvm::IRBuilder<> &builder,
1484                                           llvm::FunctionPassManager &fpm,
1485                                           std::string nativeThrowFunctName) {
1486   // Number of type infos to generate
1487   unsigned numTypeInfos = 6;
1488
1489   // Initialze intrisics and external functions to use along with exception
1490   // and type info globals.
1491   createStandardUtilityFunctions(numTypeInfos,
1492                                  module,
1493                                  builder);
1494   llvm::Function *nativeThrowFunct = module.getFunction(nativeThrowFunctName);
1495
1496   // Create exception throw function using the value ~0 to cause
1497   // foreign exceptions to be thrown.
1498   llvm::Function *throwFunct = createThrowExceptionFunction(module,
1499                                                             builder,
1500                                                             fpm,
1501                                                             "throwFunct",
1502                                                             ~0,
1503                                                             *nativeThrowFunct);
1504   // Inner function will catch even type infos
1505   unsigned innerExceptionTypesToCatch[] = {6, 2, 4};
1506   size_t numExceptionTypesToCatch = sizeof(innerExceptionTypesToCatch) /
1507                                     sizeof(unsigned);
1508
1509   // Generate inner function.
1510   llvm::Function *innerCatchFunct = createCatchWrappedInvokeFunction(module,
1511                                                     builder,
1512                                                     fpm,
1513                                                     *throwFunct,
1514                                                     "innerCatchFunct",
1515                                                     numExceptionTypesToCatch,
1516                                                     innerExceptionTypesToCatch);
1517
1518   // Outer function will catch odd type infos
1519   unsigned outerExceptionTypesToCatch[] = {3, 1, 5};
1520   numExceptionTypesToCatch = sizeof(outerExceptionTypesToCatch) /
1521   sizeof(unsigned);
1522
1523   // Generate outer function
1524   llvm::Function *outerCatchFunct = createCatchWrappedInvokeFunction(module,
1525                                                     builder,
1526                                                     fpm,
1527                                                     *innerCatchFunct,
1528                                                     "outerCatchFunct",
1529                                                     numExceptionTypesToCatch,
1530                                                     outerExceptionTypesToCatch);
1531
1532   // Return outer function to run
1533   return(outerCatchFunct);
1534 }
1535
1536
1537 /// Represents our foreign exceptions
1538 class OurCppRunException : public std::runtime_error {
1539 public:
1540   OurCppRunException(const std::string reason) :
1541   std::runtime_error(reason) {}
1542
1543   OurCppRunException (const OurCppRunException &toCopy) :
1544   std::runtime_error(toCopy) {}
1545
1546   OurCppRunException &operator = (const OurCppRunException &toCopy) {
1547     return(reinterpret_cast<OurCppRunException&>(
1548                                  std::runtime_error::operator=(toCopy)));
1549   }
1550
1551   ~OurCppRunException (void) throw () {}
1552 };
1553
1554
1555 /// Throws foreign C++ exception.
1556 /// @param ignoreIt unused parameter that allows function to match implied
1557 ///        generated function contract.
1558 extern "C"
1559 void throwCppException (int32_t ignoreIt) {
1560   throw(OurCppRunException("thrown by throwCppException(...)"));
1561 }
1562
1563 typedef void (*OurExceptionThrowFunctType) (int32_t typeToThrow);
1564
1565 /// This is a test harness which runs test by executing generated
1566 /// function with a type info type to throw. Harness wraps the execution
1567 /// of generated function in a C++ try catch clause.
1568 /// @param engine execution engine to use for executing generated function.
1569 ///        This demo program expects this to be a JIT instance for demo
1570 ///        purposes.
1571 /// @param function generated test function to run
1572 /// @param typeToThrow type info type of generated exception to throw, or
1573 ///        indicator to cause foreign exception to be thrown.
1574 static
1575 void runExceptionThrow(llvm::ExecutionEngine *engine,
1576                        llvm::Function *function,
1577                        int32_t typeToThrow) {
1578
1579   // Find test's function pointer
1580   OurExceptionThrowFunctType functPtr =
1581     reinterpret_cast<OurExceptionThrowFunctType>(
1582        reinterpret_cast<intptr_t>(engine->getPointerToFunction(function)));
1583
1584   try {
1585     // Run test
1586     (*functPtr)(typeToThrow);
1587   }
1588   catch (OurCppRunException exc) {
1589     // Catch foreign C++ exception
1590     fprintf(stderr,
1591             "\nrunExceptionThrow(...):In C++ catch OurCppRunException "
1592             "with reason: %s.\n",
1593             exc.what());
1594   }
1595   catch (...) {
1596     // Catch all exceptions including our generated ones. This latter
1597     // functionality works according to the example in rules 1.6.4 of
1598     // http://sourcery.mentor.com/public/cxx-abi/abi-eh.html (v1.22),
1599     // given that these will be exceptions foreign to C++
1600     // (the _Unwind_Exception::exception_class should be different from
1601     // the one used by C++).
1602     fprintf(stderr,
1603             "\nrunExceptionThrow(...):In C++ catch all.\n");
1604   }
1605 }
1606
1607 //
1608 // End test functions
1609 //
1610
1611 typedef llvm::ArrayRef<llvm::Type*> TypeArray;
1612
1613 /// This initialization routine creates type info globals and
1614 /// adds external function declarations to module.
1615 /// @param numTypeInfos number of linear type info associated type info types
1616 ///        to create as GlobalVariable instances, starting with the value 1.
1617 /// @param module code for module instance
1618 /// @param builder builder instance
1619 static void createStandardUtilityFunctions(unsigned numTypeInfos,
1620                                            llvm::Module &module,
1621                                            llvm::IRBuilder<> &builder) {
1622
1623   llvm::LLVMContext &context = module.getContext();
1624
1625   // Exception initializations
1626
1627   // Setup exception catch state
1628   ourExceptionNotThrownState =
1629     llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 0),
1630   ourExceptionThrownState =
1631     llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 1),
1632   ourExceptionCaughtState =
1633     llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 2),
1634
1635
1636
1637   // Create our type info type
1638   ourTypeInfoType = llvm::StructType::get(context,
1639                                           TypeArray(builder.getInt32Ty()));
1640
1641   llvm::Type *caughtResultFieldTypes[] = {
1642     builder.getInt8PtrTy(),
1643     builder.getInt32Ty()
1644   };
1645
1646   // Create our landingpad result type
1647   ourCaughtResultType = llvm::StructType::get(context,
1648                                             TypeArray(caughtResultFieldTypes));
1649
1650   // Create OurException type
1651   ourExceptionType = llvm::StructType::get(context,
1652                                            TypeArray(ourTypeInfoType));
1653
1654   // Create portion of _Unwind_Exception type
1655   //
1656   // Note: Declaring only a portion of the _Unwind_Exception struct.
1657   //       Does this cause problems?
1658   ourUnwindExceptionType =
1659     llvm::StructType::get(context,
1660                     TypeArray(builder.getInt64Ty()));
1661
1662   struct OurBaseException_t dummyException;
1663
1664   // Calculate offset of OurException::unwindException member.
1665   ourBaseFromUnwindOffset = ((uintptr_t) &dummyException) -
1666                             ((uintptr_t) &(dummyException.unwindException));
1667
1668 #ifdef DEBUG
1669   fprintf(stderr,
1670           "createStandardUtilityFunctions(...):ourBaseFromUnwindOffset "
1671           "= %lld, sizeof(struct OurBaseException_t) - "
1672           "sizeof(struct _Unwind_Exception) = %lu.\n",
1673           ourBaseFromUnwindOffset,
1674           sizeof(struct OurBaseException_t) -
1675           sizeof(struct _Unwind_Exception));
1676 #endif
1677
1678   size_t numChars = sizeof(ourBaseExcpClassChars) / sizeof(char);
1679
1680   // Create our _Unwind_Exception::exception_class value
1681   ourBaseExceptionClass = genClass(ourBaseExcpClassChars, numChars);
1682
1683   // Type infos
1684
1685   std::string baseStr = "typeInfo", typeInfoName;
1686   std::ostringstream typeInfoNameBuilder;
1687   std::vector<llvm::Constant*> structVals;
1688
1689   llvm::Constant *nextStruct;
1690   llvm::GlobalVariable *nextGlobal = NULL;
1691
1692   // Generate each type info
1693   //
1694   // Note: First type info is not used.
1695   for (unsigned i = 0; i <= numTypeInfos; ++i) {
1696     structVals.clear();
1697     structVals.push_back(llvm::ConstantInt::get(builder.getInt32Ty(), i));
1698     nextStruct = llvm::ConstantStruct::get(ourTypeInfoType, structVals);
1699
1700     typeInfoNameBuilder.str("");
1701     typeInfoNameBuilder << baseStr << i;
1702     typeInfoName = typeInfoNameBuilder.str();
1703
1704     // Note: Does not seem to work without allocation
1705     nextGlobal =
1706     new llvm::GlobalVariable(module,
1707                              ourTypeInfoType,
1708                              true,
1709                              llvm::GlobalValue::ExternalLinkage,
1710                              nextStruct,
1711                              typeInfoName);
1712
1713     ourTypeInfoNames.push_back(typeInfoName);
1714     ourTypeInfoNamesIndex[i] = typeInfoName;
1715   }
1716
1717   ArgNames argNames;
1718   ArgTypes argTypes;
1719   llvm::Function *funct = NULL;
1720
1721   // print32Int
1722
1723   llvm::Type *retType = builder.getVoidTy();
1724
1725   argTypes.clear();
1726   argTypes.push_back(builder.getInt32Ty());
1727   argTypes.push_back(builder.getInt8PtrTy());
1728
1729   argNames.clear();
1730
1731   createFunction(module,
1732                  retType,
1733                  argTypes,
1734                  argNames,
1735                  "print32Int",
1736                  llvm::Function::ExternalLinkage,
1737                  true,
1738                  false);
1739
1740   // print64Int
1741
1742   retType = builder.getVoidTy();
1743
1744   argTypes.clear();
1745   argTypes.push_back(builder.getInt64Ty());
1746   argTypes.push_back(builder.getInt8PtrTy());
1747
1748   argNames.clear();
1749
1750   createFunction(module,
1751                  retType,
1752                  argTypes,
1753                  argNames,
1754                  "print64Int",
1755                  llvm::Function::ExternalLinkage,
1756                  true,
1757                  false);
1758
1759   // printStr
1760
1761   retType = builder.getVoidTy();
1762
1763   argTypes.clear();
1764   argTypes.push_back(builder.getInt8PtrTy());
1765
1766   argNames.clear();
1767
1768   createFunction(module,
1769                  retType,
1770                  argTypes,
1771                  argNames,
1772                  "printStr",
1773                  llvm::Function::ExternalLinkage,
1774                  true,
1775                  false);
1776
1777   // throwCppException
1778
1779   retType = builder.getVoidTy();
1780
1781   argTypes.clear();
1782   argTypes.push_back(builder.getInt32Ty());
1783
1784   argNames.clear();
1785
1786   createFunction(module,
1787                  retType,
1788                  argTypes,
1789                  argNames,
1790                  "throwCppException",
1791                  llvm::Function::ExternalLinkage,
1792                  true,
1793                  false);
1794
1795   // deleteOurException
1796
1797   retType = builder.getVoidTy();
1798
1799   argTypes.clear();
1800   argTypes.push_back(builder.getInt8PtrTy());
1801
1802   argNames.clear();
1803
1804   createFunction(module,
1805                  retType,
1806                  argTypes,
1807                  argNames,
1808                  "deleteOurException",
1809                  llvm::Function::ExternalLinkage,
1810                  true,
1811                  false);
1812
1813   // createOurException
1814
1815   retType = builder.getInt8PtrTy();
1816
1817   argTypes.clear();
1818   argTypes.push_back(builder.getInt32Ty());
1819
1820   argNames.clear();
1821
1822   createFunction(module,
1823                  retType,
1824                  argTypes,
1825                  argNames,
1826                  "createOurException",
1827                  llvm::Function::ExternalLinkage,
1828                  true,
1829                  false);
1830
1831   // _Unwind_RaiseException
1832
1833   retType = builder.getInt32Ty();
1834
1835   argTypes.clear();
1836   argTypes.push_back(builder.getInt8PtrTy());
1837
1838   argNames.clear();
1839
1840   funct = createFunction(module,
1841                          retType,
1842                          argTypes,
1843                          argNames,
1844                          "_Unwind_RaiseException",
1845                          llvm::Function::ExternalLinkage,
1846                          true,
1847                          false);
1848
1849   funct->addFnAttr(llvm::Attribute::NoReturn);
1850
1851   // _Unwind_Resume
1852
1853   retType = builder.getInt32Ty();
1854
1855   argTypes.clear();
1856   argTypes.push_back(builder.getInt8PtrTy());
1857
1858   argNames.clear();
1859
1860   funct = createFunction(module,
1861                          retType,
1862                          argTypes,
1863                          argNames,
1864                          "_Unwind_Resume",
1865                          llvm::Function::ExternalLinkage,
1866                          true,
1867                          false);
1868
1869   funct->addFnAttr(llvm::Attribute::NoReturn);
1870
1871   // ourPersonality
1872
1873   retType = builder.getInt32Ty();
1874
1875   argTypes.clear();
1876   argTypes.push_back(builder.getInt32Ty());
1877   argTypes.push_back(builder.getInt32Ty());
1878   argTypes.push_back(builder.getInt64Ty());
1879   argTypes.push_back(builder.getInt8PtrTy());
1880   argTypes.push_back(builder.getInt8PtrTy());
1881
1882   argNames.clear();
1883
1884   createFunction(module,
1885                  retType,
1886                  argTypes,
1887                  argNames,
1888                  "ourPersonality",
1889                  llvm::Function::ExternalLinkage,
1890                  true,
1891                  false);
1892
1893   // llvm.eh.typeid.for intrinsic
1894
1895   getDeclaration(&module, llvm::Intrinsic::eh_typeid_for);
1896 }
1897
1898
1899 //===----------------------------------------------------------------------===//
1900 // Main test driver code.
1901 //===----------------------------------------------------------------------===//
1902
1903 /// Demo main routine which takes the type info types to throw. A test will
1904 /// be run for each given type info type. While type info types with the value
1905 /// of -1 will trigger a foreign C++ exception to be thrown; type info types
1906 /// <= 6 and >= 1 will be caught by test functions; and type info types > 6
1907 /// will result in exceptions which pass through to the test harness. All other
1908 /// type info types are not supported and could cause a crash.
1909 int main(int argc, char *argv[]) {
1910   if (argc == 1) {
1911     fprintf(stderr,
1912             "\nUsage: ExceptionDemo <exception type to throw> "
1913             "[<type 2>...<type n>].\n"
1914             "   Each type must have the value of 1 - 6 for "
1915             "generated exceptions to be caught;\n"
1916             "   the value -1 for foreign C++ exceptions to be "
1917             "generated and thrown;\n"
1918             "   or the values > 6 for exceptions to be ignored.\n"
1919             "\nTry: ExceptionDemo 2 3 7 -1\n"
1920             "   for a full test.\n\n");
1921     return(0);
1922   }
1923
1924   // If not set, exception handling will not be turned on
1925   llvm::TargetOptions Opts;
1926   Opts.JITExceptionHandling = true;
1927
1928   llvm::InitializeNativeTarget();
1929   llvm::LLVMContext &context = llvm::getGlobalContext();
1930   llvm::IRBuilder<> theBuilder(context);
1931
1932   // Make the module, which holds all the code.
1933   llvm::Module *module = new llvm::Module("my cool jit", context);
1934
1935   // Build engine with JIT
1936   llvm::EngineBuilder factory(module);
1937   factory.setEngineKind(llvm::EngineKind::JIT);
1938   factory.setAllocateGVsWithCode(false);
1939   factory.setTargetOptions(Opts);
1940   llvm::ExecutionEngine *executionEngine = factory.create();
1941
1942   {
1943     llvm::FunctionPassManager fpm(module);
1944
1945     // Set up the optimizer pipeline.
1946     // Start with registering info about how the
1947     // target lays out data structures.
1948     fpm.add(new llvm::TargetData(*executionEngine->getTargetData()));
1949
1950     // Optimizations turned on
1951 #ifdef ADD_OPT_PASSES
1952
1953     // Basic AliasAnslysis support for GVN.
1954     fpm.add(llvm::createBasicAliasAnalysisPass());
1955
1956     // Promote allocas to registers.
1957     fpm.add(llvm::createPromoteMemoryToRegisterPass());
1958
1959     // Do simple "peephole" optimizations and bit-twiddling optzns.
1960     fpm.add(llvm::createInstructionCombiningPass());
1961
1962     // Reassociate expressions.
1963     fpm.add(llvm::createReassociatePass());
1964
1965     // Eliminate Common SubExpressions.
1966     fpm.add(llvm::createGVNPass());
1967
1968     // Simplify the control flow graph (deleting unreachable
1969     // blocks, etc).
1970     fpm.add(llvm::createCFGSimplificationPass());
1971 #endif  // ADD_OPT_PASSES
1972
1973     fpm.doInitialization();
1974
1975     // Generate test code using function throwCppException(...) as
1976     // the function which throws foreign exceptions.
1977     llvm::Function *toRun =
1978     createUnwindExceptionTest(*module,
1979                               theBuilder,
1980                               fpm,
1981                               "throwCppException");
1982
1983     fprintf(stderr, "\nBegin module dump:\n\n");
1984
1985     module->dump();
1986
1987     fprintf(stderr, "\nEnd module dump:\n");
1988
1989     fprintf(stderr, "\n\nBegin Test:\n");
1990
1991     for (int i = 1; i < argc; ++i) {
1992       // Run test for each argument whose value is the exception
1993       // type to throw.
1994       runExceptionThrow(executionEngine,
1995                         toRun,
1996                         (unsigned) strtoul(argv[i], NULL, 10));
1997     }
1998
1999     fprintf(stderr, "\nEnd Test:\n\n");
2000   }
2001
2002   delete executionEngine;
2003
2004   return 0;
2005 }
2006