examples/ExceptionDemo/ExceptionDemo.cpp

   1 //===-- examples/ExceptionDemo/ExceptionDemo.cpp -
   2 //                      An example use of the llvm Exception mechanism --===//
   3 //
   4 //                     The LLVM Compiler Infrastructure
   5 //
   6 // This file is distributed under the University of Illinois Open Source
   7 // License. See LICENSE.TXT for details.
   8 //
   9 //===--------------------------------------------------------------------===//
  10 //
  11 // Demo program which implements an example LLVM exception implementation, and
  12 // shows several test cases including the handling of foreign exceptions.
  13 // It is run with type info types arguments to throw. A test will
  14 // be run for each given type info type. While type info types with the value
  15 // of -1 will trigger a foreign C++ exception to be thrown; type info types
  16 // <= 6 and >= 1 will cause the associated generated exceptions to be thrown
  17 // and caught by generated test functions; and type info types > 6
  18 // will result in exceptions which pass through to the test harness. All other
  19 // type info types are not supported and could cause a crash. In all cases,
  20 // the "finally" blocks of every generated test functions will executed
  21 // regardless of whether or not that test function ignores or catches the
  22 // thrown exception.
  23 //
  24 // examples:
  25 //
  26 // ExceptionDemo
  27 //
  28 //     causes a usage to be printed to stderr
  29 //
  30 // ExceptionDemo 2 3 7 -1
  31 //
  32 //     results in the following cases:
  33 //         - Value 2 causes an exception with a type info type of 2 to be
  34 //           thrown and caught by an inner generated test function.
  35 //         - Value 3 causes an exception with a type info type of 3 to be
  36 //           thrown and caught by an outer generated test function.
  37 //         - Value 7 causes an exception with a type info type of 7 to be
  38 //           thrown and NOT be caught by any generated function.
  39 //         - Value -1 causes a foreign C++ exception to be thrown and not be
  40 //           caught by any generated function
  41 //
  42 //     Cases -1 and 7 are caught by a C++ test harness where the validity of
  43 //         of a C++ catch(...) clause catching a generated exception with a
  44 //         type info type of 7 is questionable.
  45 //
  46 // This code uses code from the llvm compiler-rt project and the llvm
  47 // Kaleidoscope project.
  48 //
  49 //===--------------------------------------------------------------------===//
  50
  51
  52 #include "llvm/LLVMContext.h"
  53 #include "llvm/DerivedTypes.h"
  54 #include "llvm/ExecutionEngine/ExecutionEngine.h"
  55 #include "llvm/ExecutionEngine/JIT.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/TargetSelect.h"
  62 #include "llvm/Target/TargetOptions.h"
  63 #include "llvm/Transforms/Scalar.h"
  64 #include "llvm/Support/IRBuilder.h"
  65 #include "llvm/Support/Dwarf.h"
  66
  67 #include <cstdio>
  68 #include <string>
  69 #include <sstream>
  70 #include <map>
  71 #include <vector>
  72 #include <stdexcept>
  73
  74
  75 #ifndef USE_GLOBAL_STR_CONSTS
  76 #define USE_GLOBAL_STR_CONSTS true
  77 #endif
  78
  79 // System C++ ABI unwind types from:
  80 //     http://refspecs.freestandards.org/abi-eh-1.21.html
  81
  82 extern "C" {
  83
  84 typedef enum {
  85     _URC_NO_REASON = 0,
  86     _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
  87     _URC_FATAL_PHASE2_ERROR = 2,
  88     _URC_FATAL_PHASE1_ERROR = 3,
  89     _URC_NORMAL_STOP = 4,
  90     _URC_END_OF_STACK = 5,
  91     _URC_HANDLER_FOUND = 6,
  92     _URC_INSTALL_CONTEXT = 7,
  93     _URC_CONTINUE_UNWIND = 8
  94 } _Unwind_Reason_Code;
  95
  96 typedef enum {
  97     _UA_SEARCH_PHASE = 1,
  98     _UA_CLEANUP_PHASE = 2,
  99     _UA_HANDLER_FRAME = 4,
 100     _UA_FORCE_UNWIND = 8,
 101     _UA_END_OF_STACK = 16
 102 } _Unwind_Action;
 103
 104 struct _Unwind_Exception;
 105
 106 typedef void (*_Unwind_Exception_Cleanup_Fn) (_Unwind_Reason_Code,
 107                                               struct _Unwind_Exception *);
 108
 109 struct _Unwind_Exception {
 110     uint64_t exception_class;
 111     _Unwind_Exception_Cleanup_Fn exception_cleanup;
 112
 113     uintptr_t private_1;
 114     uintptr_t private_2;
 115
 116     // @@@ The IA-64 ABI says that this structure must be double-word aligned.
 117     //  Taking that literally does not make much sense generically.  Instead
 118     //  we provide the maximum alignment required by any type for the machine.
 119 } __attribute__((__aligned__));
 120
 121 struct _Unwind_Context;
 122 typedef struct _Unwind_Context* _Unwind_Context_t;
 123
 124 extern const uint8_t* _Unwind_GetLanguageSpecificData (_Unwind_Context_t c);
 125 extern uintptr_t _Unwind_GetGR (_Unwind_Context_t c, int i);
 126 extern void _Unwind_SetGR (_Unwind_Context_t c, int i, uintptr_t n);
 127 extern void _Unwind_SetIP (_Unwind_Context_t, uintptr_t new_value);
 128 extern uintptr_t _Unwind_GetIP (_Unwind_Context_t context);
 129 extern uintptr_t _Unwind_GetRegionStart (_Unwind_Context_t context);
 130
 131 } // extern "C"
 132
 133 //
 134 // Example types
 135 //
 136
 137 /// This is our simplistic type info
 138 struct OurExceptionType_t {
 139     /// type info type
 140     int type;
 141 };
 142
 143
 144 /// This is our Exception class which relies on a negative offset to calculate
 145 /// pointers to its instances from pointers to its unwindException member.
 146 ///
 147 /// Note: The above unwind.h defines struct _Unwind_Exception to be aligned
 148 ///       on a double word boundary. This is necessary to match the standard:
 149 ///       http://refspecs.freestandards.org/abi-eh-1.21.html
 150 struct OurBaseException_t {
 151     struct OurExceptionType_t type;
 152
 153     // Note: This is properly aligned in unwind.h
 154     struct _Unwind_Exception unwindException;
 155 };
 156
 157
 158 // Note: Not needed since we are C++
 159 typedef struct OurBaseException_t OurException;
 160 typedef struct _Unwind_Exception OurUnwindException;
 161
 162 //
 163 // Various globals used to support typeinfo and generatted exceptions in
 164 // general
 165 //
 166
 167 static std::map<std::string, llvm::Value*> namedValues;
 168
 169 int64_t ourBaseFromUnwindOffset;
 170
 171 const unsigned char ourBaseExcpClassChars[] =
 172                                 {'o', 'b', 'j', '\0', 'b', 'a', 's', '\0'};
 173
 174
 175 static uint64_t ourBaseExceptionClass = 0;
 176
 177 static std::vector<std::string> ourTypeInfoNames;
 178 static std::map<int, std::string> ourTypeInfoNamesIndex;
 179
 180 static llvm::StructType* ourTypeInfoType;
 181 static llvm::StructType* ourExceptionType;
 182 static llvm::StructType* ourUnwindExceptionType;
 183
 184 static llvm::ConstantInt* ourExceptionNotThrownState;
 185 static llvm::ConstantInt* ourExceptionThrownState;
 186 static llvm::ConstantInt* ourExceptionCaughtState;
 187
 188 typedef std::vector<std::string> ArgNames;
 189 typedef std::vector<const llvm::Type*> ArgTypes;
 190
 191 //
 192 // Code Generation Utilities
 193 //
 194
 195 /// Utility used to create a function, both declarations and definitions
 196 /// @param module for module instance
 197 /// @param retType function return type
 198 /// @param theArgTypes function's ordered argument types
 199 /// @param theArgNames function's ordered arguments needed if use of this
 200 ///        function corresponds to a function definition. Use empty
 201 ///        aggregate for function declarations.
 202 /// @param functName function name
 203 /// @param linkage function linkage
 204 /// @param declarationOnly for function declarations
 205 /// @param isVarArg function uses vararg arguments
 206 /// @returns function instance
 207 llvm::Function *createFunction(llvm::Module& module,
 208                                const llvm::Type* retType,
 209                                const ArgTypes& theArgTypes,
 210                                const ArgNames& theArgNames,
 211                                const std::string& functName,
 212                                llvm::GlobalValue::LinkageTypes linkage,
 213                                bool declarationOnly,
 214                                bool isVarArg) {
 215     llvm::FunctionType* functType = llvm::FunctionType::get(retType,
 216                                                             theArgTypes,
 217                                                             isVarArg);
 218     llvm::Function* ret = llvm::Function::Create(functType,
 219                                                  linkage,
 220                                                  functName,
 221                                                  &module);
 222     if (!ret || declarationOnly)
 223         return(ret);
 224
 225     namedValues.clear();
 226     unsigned i = 0;
 227     for (llvm::Function::arg_iterator argIndex = ret->arg_begin();
 228          i != theArgNames.size();
 229          ++argIndex, ++i) {
 230
 231         argIndex->setName(theArgNames[i]);
 232         namedValues[theArgNames[i]] = argIndex;
 233     }
 234
 235     return(ret);
 236 }
 237
 238
 239 /// Create an alloca instruction in the entry block of
 240 /// the parent function.  This is used for mutable variables etc.
 241 /// @param function parent instance
 242 /// @param varName stack variable name
 243 /// @param type stack variable type
 244 /// @param initWith optional constant initialization value
 245 /// @returns AllocaInst instance
 246 static llvm::AllocaInst *createEntryBlockAlloca(llvm::Function& function,
 247                                             const std::string &varName,
 248                                             const llvm::Type* type,
 249                                             llvm::Constant* initWith = NULL) {
 250     llvm::BasicBlock& block = function.getEntryBlock();
 251     llvm::IRBuilder<> tmp(&block, block.begin());
 252     llvm::AllocaInst* ret = tmp.CreateAlloca(type, 0, varName.c_str());
 253
 254     if (initWith)
 255         tmp.CreateStore(initWith, ret);
 256
 257     return(ret);
 258 }
 259
 260
 261 //
 262 // Code Generation Utilities End
 263 //
 264
 265 //
 266 // Runtime C Library functions
 267 //
 268
 269 // Note: using an extern "C" block so that static functions can be used
 270 extern "C" {
 271
 272 // Note: Better ways to decide on bit width
 273 //
 274 /// Prints a 32 bit number, according to the format, to stderr.
 275 /// @param intToPrint integer to print
 276 /// @param format printf like format to use when printing
 277 void print32Int(int intToPrint, const char* format) {
 278     if (format) {
 279         // Note: No NULL check
 280         fprintf(stderr, format, intToPrint);
 281     }
 282     else {
 283         // Note: No NULL check
 284         fprintf(stderr, "::print32Int(...):NULL arg.\n");
 285     }
 286 }
 287
 288
 289 // Note: Better ways to decide on bit width
 290 //
 291 /// Prints a 64 bit number, according to the format, to stderr.
 292 /// @param intToPrint integer to print
 293 /// @param format printf like format to use when printing
 294 void print64Int(long int intToPrint, const char* format) {
 295     if (format) {
 296         // Note: No NULL check
 297         fprintf(stderr, format, intToPrint);
 298     }
 299     else {
 300         // Note: No NULL check
 301         fprintf(stderr, "::print64Int(...):NULL arg.\n");
 302     }
 303 }
 304
 305
 306 /// Prints a C string to stderr
 307 /// @param toPrint string to print
 308 void printStr(char* toPrint) {
 309     if (toPrint) {
 310         fprintf(stderr, "%s", toPrint);
 311     }
 312     else {
 313         fprintf(stderr, "::printStr(...):NULL arg.\n");
 314     }
 315 }
 316
 317
 318 /// Deletes the true previosly allocated exception whose address
 319 /// is calculated from the supplied OurBaseException_t::unwindException
 320 /// member address. Handles (ignores), NULL pointers.
 321 /// @param expToDelete exception to delete
 322 void deleteOurException(OurUnwindException* expToDelete) {
 323 #ifdef DEBUG
 324     fprintf(stderr,
 325             "deleteOurException(...).\n");
 326 #endif
 327
 328     if (expToDelete &&
 329         (expToDelete->exception_class == ourBaseExceptionClass)) {
 330
 331         free(((char*) expToDelete) + ourBaseFromUnwindOffset);
 332     }
 333 }
 334
 335
 336 /// This function is the struct _Unwind_Exception API mandated delete function
 337 /// used by foreign exception handlers when deleting our exception
 338 /// (OurException), instances.
 339 /// @param reason @link http://refspecs.freestandards.org/abi-eh-1.21.html
 340 /// @unlink
 341 /// @param expToDelete exception instance to delete
 342 void deleteFromUnwindOurException(_Unwind_Reason_Code reason,
 343                                   OurUnwindException* expToDelete) {
 344 #ifdef DEBUG
 345     fprintf(stderr,
 346             "deleteFromUnwindOurException(...).\n");
 347 #endif
 348
 349     deleteOurException(expToDelete);
 350 }
 351
 352
 353 /// Creates (allocates on the heap), an exception (OurException instance),
 354 /// of the supplied type info type.
 355 /// @param type type info type
 356 OurUnwindException* createOurException(int type) {
 357     size_t size = sizeof(OurException);
 358     OurException* ret = (OurException*) memset(malloc(size), 0, size);
 359     (ret->type).type = type;
 360     (ret->unwindException).exception_class = ourBaseExceptionClass;
 361     (ret->unwindException).exception_cleanup = deleteFromUnwindOurException;
 362
 363     return(&(ret->unwindException));
 364 }
 365
 366
 367 /// Read a uleb128 encoded value and advance pointer
 368 /// See Variable Length Data in:
 369 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 370 /// @param data reference variable holding memory pointer to decode from
 371 /// @returns decoded value
 372 static uintptr_t readULEB128(const uint8_t** data) {
 373     uintptr_t result = 0;
 374     uintptr_t shift = 0;
 375     unsigned char byte;
 376     const uint8_t* p = *data;
 377
 378     do {
 379         byte = *p++;
 380         result |= (byte & 0x7f) << shift;
 381         shift += 7;
 382     }
 383     while (byte & 0x80);
 384
 385     *data = p;
 386
 387     return result;
 388 }
 389
 390
 391 /// Read a sleb128 encoded value and advance pointer
 392 /// See Variable Length Data in:
 393 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 394 /// @param data reference variable holding memory pointer to decode from
 395 /// @returns decoded value
 396 static uintptr_t readSLEB128(const uint8_t** data) {
 397     uintptr_t result = 0;
 398     uintptr_t shift = 0;
 399     unsigned char byte;
 400     const uint8_t* p = *data;
 401
 402     do {
 403         byte = *p++;
 404         result |= (byte & 0x7f) << shift;
 405         shift += 7;
 406     }
 407     while (byte & 0x80);
 408
 409     *data = p;
 410
 411     if ((byte & 0x40) && (shift < (sizeof(result) << 3))) {
 412         result |= (~0 << shift);
 413     }
 414
 415     return result;
 416 }
 417
 418
 419 /// Read a pointer encoded value and advance pointer
 420 /// See Variable Length Data in:
 421 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 422 /// @param data reference variable holding memory pointer to decode from
 423 /// @param encoding dwarf encoding type
 424 /// @returns decoded value
 425 static uintptr_t readEncodedPointer(const uint8_t** data, uint8_t encoding) {
 426     uintptr_t result = 0;
 427     const uint8_t* p = *data;
 428
 429     if (encoding == llvm::dwarf::DW_EH_PE_omit)
 430         return(result);
 431
 432     // first get value
 433     switch (encoding & 0x0F) {
 434         case llvm::dwarf::DW_EH_PE_absptr:
 435             result = *((uintptr_t*)p);
 436             p += sizeof(uintptr_t);
 437             break;
 438         case llvm::dwarf::DW_EH_PE_uleb128:
 439             result = readULEB128(&p);
 440             break;
 441         // Note: This case has not been tested
 442         case llvm::dwarf::DW_EH_PE_sleb128:
 443             result = readSLEB128(&p);
 444             break;
 445         case llvm::dwarf::DW_EH_PE_udata2:
 446             result = *((uint16_t*)p);
 447             p += sizeof(uint16_t);
 448             break;
 449         case llvm::dwarf::DW_EH_PE_udata4:
 450             result = *((uint32_t*)p);
 451             p += sizeof(uint32_t);
 452             break;
 453         case llvm::dwarf::DW_EH_PE_udata8:
 454             result = *((uint64_t*)p);
 455             p += sizeof(uint64_t);
 456             break;
 457         case llvm::dwarf::DW_EH_PE_sdata2:
 458             result = *((int16_t*)p);
 459             p += sizeof(int16_t);
 460             break;
 461         case llvm::dwarf::DW_EH_PE_sdata4:
 462             result = *((int32_t*)p);
 463             p += sizeof(int32_t);
 464             break;
 465         case llvm::dwarf::DW_EH_PE_sdata8:
 466             result = *((int64_t*)p);
 467             p += sizeof(int64_t);
 468             break;
 469         default:
 470             // not supported
 471             abort();
 472             break;
 473     }
 474
 475     // then add relative offset
 476     switch (encoding & 0x70) {
 477         case llvm::dwarf::DW_EH_PE_absptr:
 478             // do nothing
 479             break;
 480         case llvm::dwarf::DW_EH_PE_pcrel:
 481             result += (uintptr_t)(*data);
 482             break;
 483         case llvm::dwarf::DW_EH_PE_textrel:
 484         case llvm::dwarf::DW_EH_PE_datarel:
 485         case llvm::dwarf::DW_EH_PE_funcrel:
 486         case llvm::dwarf::DW_EH_PE_aligned:
 487         default:
 488             // not supported
 489             abort();
 490             break;
 491     }
 492
 493     // then apply indirection
 494     if (encoding & llvm::dwarf::DW_EH_PE_indirect) {
 495         result = *((uintptr_t*)result);
 496     }
 497
 498     *data = p;
 499
 500     return result;
 501 }
 502
 503
 504 /// Deals with Dwarf actions matching our type infos
 505 /// (OurExceptionType_t instances). Returns whether or not a dwarf emitted
 506 /// action matches the supplied exception type. If such a match succeeds,
 507 /// the resultAction argument will be set with > 0 index value. Only
 508 /// corresponding llvm.eh.selector type info arguments, cleanup arguments
 509 /// are supported. Filters are not supported.
 510 /// See Variable Length Data in:
 511 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 512 /// Also see @link http://refspecs.freestandards.org/abi-eh-1.21.html @unlink
 513 /// @param resultAction reference variable which will be set with result
 514 /// @param classInfo our array of type info pointers (to globals)
 515 /// @param actionEntry index into above type info array or 0 (clean up).
 516 ///        We do not support filters.
 517 /// @param exceptionClass exception class (_Unwind_Exception::exception_class)
 518 ///        of thrown exception.
 519 /// @param exceptionObject thrown _Unwind_Exception instance.
 520 /// @returns whether or not a type info was found. False is returned if only
 521 ///          a cleanup was found
 522 static bool handleActionValue(int64_t *resultAction,
 523                               struct OurExceptionType_t **classInfo,
 524                               uintptr_t actionEntry,
 525                               uint64_t exceptionClass,
 526                               struct _Unwind_Exception *exceptionObject) {
 527     bool ret = false;
 528
 529     if (!resultAction ||
 530         !exceptionObject ||
 531         (exceptionClass != ourBaseExceptionClass))
 532         return(ret);
 533
 534     struct OurBaseException_t* excp = (struct OurBaseException_t*)
 535                         (((char*) exceptionObject) + ourBaseFromUnwindOffset);
 536     struct OurExceptionType_t *excpType = &(excp->type);
 537     int type = excpType->type;
 538
 539 #ifdef DEBUG
 540     fprintf(stderr,
 541             "handleActionValue(...): exceptionObject = <%p>, "
 542                 "excp = <%p>.\n",
 543             exceptionObject,
 544             excp);
 545 #endif
 546
 547     const uint8_t *actionPos = (uint8_t*) actionEntry,
 548                   *tempActionPos;
 549     int64_t typeOffset = 0,
 550             actionOffset;
 551
 552     for (int i = 0; true; ++i) {
 553         // Each emitted dwarf action corresponds to a 2 tuple of
 554         // type info address offset, and action offset to the next
 555         // emitted action.
 556         typeOffset = readSLEB128(&actionPos);
 557         tempActionPos = actionPos;
 558         actionOffset = readSLEB128(&tempActionPos);
 559
 560 #ifdef DEBUG
 561         fprintf(stderr,
 562                 "handleActionValue(...):typeOffset: <%lld>, "
 563                     "actionOffset: <%lld>.\n",
 564                 typeOffset,
 565                 actionOffset);
 566 #endif
 567         assert((typeOffset >= 0) &&
 568                "handleActionValue(...):filters are not supported.");
 569
 570         // Note: A typeOffset == 0 implies that a cleanup llvm.eh.selector
 571         //       argument has been matched.
 572         if ((typeOffset > 0) &&
 573             (type == (classInfo[-typeOffset])->type)) {
 574 #ifdef DEBUG
 575             fprintf(stderr,
 576                     "handleActionValue(...):actionValue <%d> found.\n",
 577                     i);
 578 #endif
 579             *resultAction = i + 1;
 580             ret = true;
 581             break;
 582         }
 583
 584 #ifdef DEBUG
 585         fprintf(stderr,
 586                 "handleActionValue(...):actionValue not found.\n");
 587 #endif
 588         if (!actionOffset)
 589             break;
 590
 591         actionPos += actionOffset;
 592     }
 593
 594     return(ret);
 595 }
 596
 597
 598 /// Deals with the Language specific data portion of the emitted dwarf code.
 599 /// See @link http://refspecs.freestandards.org/abi-eh-1.21.html @unlink
 600 /// @param version unsupported (ignored), unwind version
 601 /// @param lsda language specific data area
 602 /// @param _Unwind_Action actions minimally supported unwind stage
 603 ///        (forced specifically not supported)
 604 /// @param exceptionClass exception class (_Unwind_Exception::exception_class)
 605 ///        of thrown exception.
 606 /// @param exceptionObject thrown _Unwind_Exception instance.
 607 /// @param context unwind system context
 608 /// @returns minimally supported unwinding control indicator
 609 static _Unwind_Reason_Code handleLsda(int version,
 610                                   const uint8_t* lsda,
 611                                   _Unwind_Action actions,
 612                                   uint64_t exceptionClass,
 613                                   struct _Unwind_Exception* exceptionObject,
 614                                   _Unwind_Context_t context) {
 615     _Unwind_Reason_Code ret = _URC_CONTINUE_UNWIND;
 616
 617     if (!lsda)
 618         return(ret);
 619
 620 #ifdef DEBUG
 621     fprintf(stderr,
 622             "handleLsda(...):lsda is non-zero.\n");
 623 #endif
 624
 625     // Get the current instruction pointer and offset it before next
 626     // instruction in the current frame which threw the exception.
 627     uintptr_t pc = _Unwind_GetIP(context)-1;
 628
 629     // Get beginning current frame's code (as defined by the
 630     // emitted dwarf code)
 631     uintptr_t funcStart = _Unwind_GetRegionStart(context);
 632     uintptr_t pcOffset = pc - funcStart;
 633     struct OurExceptionType_t** classInfo = NULL;
 634
 635     // Note: See JITDwarfEmitter::EmitExceptionTable(...) for corresponding
 636     //       dwarf emission
 637
 638     // Parse LSDA header.
 639     uint8_t lpStartEncoding = *lsda++;
 640
 641     if (lpStartEncoding != llvm::dwarf::DW_EH_PE_omit) {
 642         readEncodedPointer(&lsda, lpStartEncoding);
 643     }
 644
 645     uint8_t ttypeEncoding = *lsda++;
 646     uintptr_t classInfoOffset;
 647
 648     if (ttypeEncoding != llvm::dwarf::DW_EH_PE_omit) {
 649         // Calculate type info locations in emitted dwarf code which
 650         // were flagged by type info arguments to llvm.eh.selector
 651         // intrinsic
 652         classInfoOffset = readULEB128(&lsda);
 653         classInfo = (struct OurExceptionType_t**) (lsda + classInfoOffset);
 654     }
 655
 656     // Walk call-site table looking for range that
 657     // includes current PC.
 658
 659     uint8_t         callSiteEncoding = *lsda++;
 660     uint32_t        callSiteTableLength = readULEB128(&lsda);
 661     const uint8_t*  callSiteTableStart = lsda;
 662     const uint8_t*  callSiteTableEnd = callSiteTableStart +
 663                                                     callSiteTableLength;
 664     const uint8_t*  actionTableStart = callSiteTableEnd;
 665     const uint8_t*  callSitePtr = callSiteTableStart;
 666
 667     bool foreignException = false;
 668
 669     while (callSitePtr < callSiteTableEnd) {
 670         uintptr_t start = readEncodedPointer(&callSitePtr,
 671                                              callSiteEncoding);
 672         uintptr_t length = readEncodedPointer(&callSitePtr,
 673                                               callSiteEncoding);
 674         uintptr_t landingPad = readEncodedPointer(&callSitePtr,
 675                                                   callSiteEncoding);
 676
 677         // Note: Action value
 678         uintptr_t actionEntry = readULEB128(&callSitePtr);
 679
 680         if (exceptionClass != ourBaseExceptionClass) {
 681             // We have been notified of a foreign exception being thrown,
 682             // and we therefore need to execute cleanup landing pads
 683             actionEntry = 0;
 684             foreignException = true;
 685         }
 686
 687         if (landingPad == 0) {
 688 #ifdef DEBUG
 689             fprintf(stderr,
 690                     "handleLsda(...): No landing pad found.\n");
 691 #endif
 692
 693             continue; // no landing pad for this entry
 694         }
 695
 696         if (actionEntry) {
 697             actionEntry += ((uintptr_t) actionTableStart) - 1;
 698         }
 699         else {
 700 #ifdef DEBUG
 701             fprintf(stderr,
 702                     "handleLsda(...):No action table found.\n");
 703 #endif
 704         }
 705
 706         bool exceptionMatched = false;
 707
 708         if ((start <= pcOffset) && (pcOffset < (start + length))) {
 709 #ifdef DEBUG
 710             fprintf(stderr,
 711                     "handleLsda(...): Landing pad found.\n");
 712 #endif
 713             int64_t actionValue = 0;
 714
 715             if (actionEntry) {
 716                 exceptionMatched = handleActionValue
 717                                    (
 718                                        &actionValue,
 719                                        classInfo,
 720                                        actionEntry,
 721                                        exceptionClass,
 722                                        exceptionObject
 723                                    );
 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 = (uint8_t*)
 817                             _Unwind_GetLanguageSpecificData(context);
 818
 819 #ifdef DEBUG
 820     fprintf(stderr,
 821             "ourPersonality(...):lsda = <%p>.\n",
 822             lsda);
 823 #endif
 824
 825     // The real work of the personality function is captured here
 826     return(handleLsda(version,
 827                       lsda,
 828                       actions,
 829                       exceptionClass,
 830                       exceptionObject,
 831                       context));
 832 }
 833
 834
 835 /// Generates our _Unwind_Exception class from a given character array.
 836 /// thereby handling arbitrary lengths (not in standard), and handling
 837 /// embedded \0s.
 838 /// See @link http://refspecs.freestandards.org/abi-eh-1.21.html @unlink
 839 /// @param classChars char array to encode. NULL values not checkedf
 840 /// @param classCharsSize number of chars in classChars. Value is not checked.
 841 /// @returns class value
 842 uint64_t genClass(const unsigned char classChars[], size_t classCharsSize)
 843 {
 844     uint64_t ret = classChars[0];
 845
 846     for (unsigned i = 1; i < classCharsSize; ++i) {
 847         ret <<= 8;
 848         ret += classChars[i];
 849     }
 850
 851     return(ret);
 852 }
 853
 854 } // extern "C"
 855
 856 //
 857 // Runtime C Library functions End
 858 //
 859
 860 //
 861 // Code generation functions
 862 //
 863
 864 /// Generates code to print given constant string
 865 /// @param context llvm context
 866 /// @param module code for module instance
 867 /// @param builder builder instance
 868 /// @param toPrint string to print
 869 /// @param useGlobal A value of true (default) indicates a GlobalValue is
 870 ///        generated, and is used to hold the constant string. A value of
 871 ///        false indicates that the constant string will be stored on the
 872 ///        stack.
 873 void generateStringPrint(llvm::LLVMContext& context,
 874                          llvm::Module& module,
 875                          llvm::IRBuilder<>& builder,
 876                          std::string toPrint,
 877                          bool useGlobal = true) {
 878     llvm::Function *printFunct = module.getFunction("printStr");
 879
 880     llvm::Value *stringVar;
 881     llvm::Constant* stringConstant =
 882         llvm::ConstantArray::get(context, toPrint);
 883
 884     if (useGlobal) {
 885         // Note: Does not work without allocation
 886         stringVar =
 887             new llvm::GlobalVariable(module,
 888                                      stringConstant->getType(),
 889                                      true,
 890                                      llvm::GlobalValue::LinkerPrivateLinkage,
 891                                      stringConstant,
 892                                      "");
 893     }
 894     else {
 895         stringVar = builder.CreateAlloca(stringConstant->getType());
 896         builder.CreateStore(stringConstant, stringVar);
 897     }
 898
 899     llvm::Value* cast =
 900         builder.CreatePointerCast(stringVar,
 901                                   builder.getInt8Ty()->getPointerTo());
 902     builder.CreateCall(printFunct, cast);
 903 }
 904
 905
 906 /// Generates code to print given runtime integer according to constant
 907 /// string format, and a given print function.
 908 /// @param context llvm context
 909 /// @param module code for module instance
 910 /// @param builder builder instance
 911 /// @param printFunct function used to "print" integer
 912 /// @param toPrint string to print
 913 /// @param format printf like formating string for print
 914 /// @param useGlobal A value of true (default) indicates a GlobalValue is
 915 ///        generated, and is used to hold the constant string. A value of
 916 ///        false indicates that the constant string will be stored on the
 917 ///        stack.
 918 void generateIntegerPrint(llvm::LLVMContext& context,
 919                           llvm::Module& module,
 920                           llvm::IRBuilder<>& builder,
 921                           llvm::Function& printFunct,
 922                           llvm::Value& toPrint,
 923                           std::string format,
 924                           bool useGlobal = true) {
 925     llvm::Constant *stringConstant = llvm::ConstantArray::get(context, format);
 926     llvm::Value *stringVar;
 927
 928     if (useGlobal) {
 929         // Note: Does not seem to work without allocation
 930         stringVar =
 931             new llvm::GlobalVariable(module,
 932                                      stringConstant->getType(),
 933                                     true,
 934                                      llvm::GlobalValue::LinkerPrivateLinkage,
 935                                      stringConstant,
 936                                      "");
 937     }
 938     else {
 939         stringVar = builder.CreateAlloca(stringConstant->getType());
 940         builder.CreateStore(stringConstant, stringVar);
 941     }
 942
 943     llvm::Value* cast =
 944         builder.CreateBitCast(stringVar,
 945                               builder.getInt8Ty()->getPointerTo());
 946     builder.CreateCall2(&printFunct, &toPrint, cast);
 947 }
 948
 949
 950 /// Generates code to handle finally block type semantics: always runs
 951 /// regardless of whether a thrown exception is passing through or the
 952 /// parent function is simply exiting. In addition to printing some state
 953 /// to stderr, this code will resume the exception handling--runs the
 954 /// unwind resume block, if the exception has not been previously caught
 955 /// by a catch clause, and will otherwise execute the end block (terminator
 956 /// block). In addition this function creates the corresponding function's
 957 /// stack storage for the exception pointer and catch flag status.
 958 /// @param context llvm context
 959 /// @param module code for module instance
 960 /// @param builder builder instance
 961 /// @param toAddTo parent function to add block to
 962 /// @param blockName block name of new "finally" block.
 963 /// @param functionId output id used for printing
 964 /// @param terminatorBlock terminator "end" block
 965 /// @param unwindResumeBlock unwind resume block
 966 /// @param exceptionCaughtFlag reference exception caught/thrown status storage
 967 /// @param exceptionStorage reference to exception pointer storage
 968 /// @returns newly created block
 969 static llvm::BasicBlock* createFinallyBlock(llvm::LLVMContext& context,
 970                              llvm::Module& module,
 971                              llvm::IRBuilder<>& builder,
 972                              llvm::Function& toAddTo,
 973                              std::string& blockName,
 974                              std::string& functionId,
 975                              llvm::BasicBlock& terminatorBlock,
 976                              llvm::BasicBlock& unwindResumeBlock,
 977                              llvm::Value** exceptionCaughtFlag,
 978                              llvm::Value** exceptionStorage) {
 979     assert(exceptionCaughtFlag &&
 980            "ExceptionDemo::createFinallyBlock(...):exceptionCaughtFlag "
 981                "is NULL");
 982     assert(exceptionStorage &&
 983            "ExceptionDemo::createFinallyBlock(...):exceptionStorage "
 984                "is NULL");
 985
 986     *exceptionCaughtFlag =
 987         createEntryBlockAlloca(toAddTo,
 988                                "exceptionCaught",
 989                                ourExceptionNotThrownState->getType(),
 990                                ourExceptionNotThrownState);
 991
 992     const llvm::PointerType* exceptionStorageType =
 993                                 builder.getInt8Ty()->getPointerTo();
 994     *exceptionStorage =
 995         createEntryBlockAlloca(toAddTo,
 996                                "exceptionStorage",
 997                                exceptionStorageType,
 998                                llvm::ConstantPointerNull::get(
 999                                    exceptionStorageType));
1000
1001     llvm::BasicBlock *ret = llvm::BasicBlock::Create(context,
1002                                                      blockName,
1003                                                      &toAddTo);
1004
1005     builder.SetInsertPoint(ret);
1006
1007     std::ostringstream bufferToPrint;
1008     bufferToPrint << "Gen: Executing finally block "
1009                   << blockName
1010                   << " in "
1011                   << functionId
1012                   << std::endl;
1013     generateStringPrint(context,
1014                         module,
1015                         builder,
1016                         bufferToPrint.str(),
1017                         USE_GLOBAL_STR_CONSTS);
1018
1019     llvm::SwitchInst* theSwitch =
1020         builder.CreateSwitch(builder.CreateLoad(*exceptionCaughtFlag),
1021                              &terminatorBlock,
1022                              2);
1023     theSwitch->addCase(ourExceptionCaughtState, &terminatorBlock);
1024     theSwitch->addCase(ourExceptionThrownState, &unwindResumeBlock);
1025
1026     return(ret);
1027 }
1028
1029
1030 /// Generates catch block semantics which print a string to indicate type of
1031 /// catch executed, sets an exception caught flag, and executes passed in
1032 /// end block (terminator block).
1033 /// @param context llvm context
1034 /// @param module code for module instance
1035 /// @param builder builder instance
1036 /// @param toAddTo parent function to add block to
1037 /// @param blockName block name of new "catch" block.
1038 /// @param functionId output id used for printing
1039 /// @param terminatorBlock terminator "end" block
1040 /// @param exceptionCaughtFlag exception caught/thrown status
1041 /// @returns newly created block
1042 static llvm::BasicBlock* createCatchBlock(llvm::LLVMContext& context,
1043                                           llvm::Module& module,
1044                                           llvm::IRBuilder<>& builder,
1045                                           llvm::Function& toAddTo,
1046                                           std::string& blockName,
1047                                           std::string& functionId,
1048                                           llvm::BasicBlock& terminatorBlock,
1049                                           llvm::Value& exceptionCaughtFlag) {
1050
1051     llvm::BasicBlock *ret = llvm::BasicBlock::Create(context,
1052                                                      blockName,
1053                                                      &toAddTo);
1054
1055     builder.SetInsertPoint(ret);
1056
1057     std::ostringstream bufferToPrint;
1058     bufferToPrint << "Gen: Executing catch block "
1059                   << blockName
1060                   << " in "
1061                   << functionId
1062                   << std::endl;
1063     generateStringPrint(context,
1064                         module,
1065                         builder,
1066                         bufferToPrint.str(),
1067                         USE_GLOBAL_STR_CONSTS);
1068     builder.CreateStore(ourExceptionCaughtState, &exceptionCaughtFlag);
1069     builder.CreateBr(&terminatorBlock);
1070
1071     return(ret);
1072 }
1073
1074
1075 /// Generates a function which invokes a function (toInvoke) and, whose
1076 /// unwind block will "catch" the type info types correspondingly held in the
1077 /// exceptionTypesToCatch argument. If the toInvoke function throws an
1078 /// exception which does not match any type info types contained in
1079 /// exceptionTypesToCatch, the generated code will call _Unwind_Resume
1080 /// with the raised exception. On the other hand the generated code will
1081 /// normally exit if the toInvoke function does not throw an exception.
1082 /// The generated "finally" block is always run regardless of the cause of
1083 /// the generated function exit.
1084 /// The generated function is returned after being verified.
1085 /// @param module code for module instance
1086 /// @param builder builder instance
1087 /// @param fpm a function pass manager holding optional IR to IR
1088 ///        transformations
1089 /// @param toInvoke inner function to invoke
1090 /// @param ourId id used to printing purposes
1091 /// @param numExceptionsToCatch length of exceptionTypesToCatch array
1092 /// @param exceptionTypesToCatch array of type info types to "catch"
1093 /// @returns generated function
1094 static
1095 llvm::Function* createCatchWrappedInvokeFunction(llvm::Module& module,
1096                     llvm::IRBuilder<>& builder,
1097                     llvm::FunctionPassManager& fpm,
1098                     llvm::Function& toInvoke,
1099                     std::string ourId,
1100                     unsigned numExceptionsToCatch,
1101                     unsigned exceptionTypesToCatch[]) {
1102
1103     llvm::LLVMContext& context = module.getContext();
1104     llvm::Function *toPrint32Int = module.getFunction("print32Int");
1105
1106     ArgTypes argTypes;
1107     argTypes.push_back(builder.getInt32Ty());
1108
1109     ArgNames argNames;
1110     argNames.push_back("exceptTypeToThrow");
1111
1112     llvm::Function* ret = createFunction(module,
1113                                          builder.getVoidTy(),
1114                                          argTypes,
1115                                          argNames,
1116                                          ourId,
1117                                          llvm::Function::ExternalLinkage,
1118                                          false,
1119                                          false);
1120
1121     // Block which calls invoke
1122     llvm::BasicBlock *entryBlock = llvm::BasicBlock::Create(context,
1123                                                             "entry",
1124                                                             ret);
1125     // Normal block for invoke
1126     llvm::BasicBlock *normalBlock = llvm::BasicBlock::Create(context,
1127                                                              "normal",
1128                                                              ret);
1129     // Unwind block for invoke
1130     llvm::BasicBlock *exceptionBlock =
1131         llvm::BasicBlock::Create(context, "exception", ret);
1132
1133     // Block which routes exception to correct catch handler block
1134     llvm::BasicBlock *exceptionRouteBlock =
1135         llvm::BasicBlock::Create(context, "exceptionRoute", ret);
1136
1137     // Foreign exception handler
1138     llvm::BasicBlock *externalExceptionBlock =
1139         llvm::BasicBlock::Create(context, "externalException", ret);
1140
1141     // Block which calls _Unwind_Resume
1142     llvm::BasicBlock *unwindResumeBlock =
1143         llvm::BasicBlock::Create(context, "unwindResume", ret);
1144
1145     // Clean up block which delete exception if needed
1146     llvm::BasicBlock *endBlock =
1147         llvm::BasicBlock::Create(context, "end", ret);
1148
1149     std::string nextName;
1150     std::vector<llvm::BasicBlock*> catchBlocks(numExceptionsToCatch);
1151     llvm::Value* exceptionCaughtFlag = NULL;
1152     llvm::Value* exceptionStorage = NULL;
1153
1154     // Finally block which will branch to unwindResumeBlock if
1155     // exception is not caught. Initializes/allocates stack locations.
1156     llvm::BasicBlock* finallyBlock = createFinallyBlock(context,
1157                                                         module,
1158                                                         builder,
1159                                                         *ret,
1160                                                         nextName = "finally",
1161                                                         ourId,
1162                                                         *endBlock,
1163                                                         *unwindResumeBlock,
1164                                                         &exceptionCaughtFlag,
1165                                                         &exceptionStorage);
1166
1167     for (unsigned i = 0; i < numExceptionsToCatch; ++i) {
1168         nextName = ourTypeInfoNames[exceptionTypesToCatch[i]];
1169
1170         // One catch block per type info to be caught
1171         catchBlocks[i] = createCatchBlock(context,
1172                                           module,
1173                                           builder,
1174                                           *ret,
1175                                           nextName,
1176                                           ourId,
1177                                           *finallyBlock,
1178                                           *exceptionCaughtFlag);
1179     }
1180
1181     // Entry Block
1182
1183     builder.SetInsertPoint(entryBlock);
1184
1185     std::vector<llvm::Value*> args;
1186     args.push_back(namedValues["exceptTypeToThrow"]);
1187     builder.CreateInvoke(&toInvoke,
1188                          normalBlock,
1189                          exceptionBlock,
1190                          args.begin(),
1191                          args.end());
1192
1193     // End Block
1194
1195     builder.SetInsertPoint(endBlock);
1196
1197     generateStringPrint(context,
1198                         module,
1199                         builder,
1200                         "Gen: In end block: exiting in " + ourId + ".\n",
1201                         USE_GLOBAL_STR_CONSTS);
1202     llvm::Function *deleteOurException =
1203                                     module.getFunction("deleteOurException");
1204
1205     // Note: function handles NULL exceptions
1206     builder.CreateCall(deleteOurException,
1207                        builder.CreateLoad(exceptionStorage));
1208     builder.CreateRetVoid();
1209
1210     // Normal Block
1211
1212     builder.SetInsertPoint(normalBlock);
1213
1214     generateStringPrint(context,
1215                         module,
1216                         builder,
1217                         "Gen: No exception in " + ourId + "!\n",
1218                         USE_GLOBAL_STR_CONSTS);
1219
1220     // Finally block is always called
1221     builder.CreateBr(finallyBlock);
1222
1223     // Unwind Resume Block
1224
1225     builder.SetInsertPoint(unwindResumeBlock);
1226
1227     llvm::Function *resumeOurException =
1228                 module.getFunction("_Unwind_Resume");
1229     builder.CreateCall(resumeOurException,
1230                        builder.CreateLoad(exceptionStorage));
1231     builder.CreateUnreachable();
1232
1233     // Exception Block
1234
1235     builder.SetInsertPoint(exceptionBlock);
1236
1237     llvm::Function *ehException = module.getFunction("llvm.eh.exception");
1238
1239     // Retrieve thrown exception
1240     llvm::Value* unwindException = builder.CreateCall(ehException);
1241
1242     // Store exception and flag
1243     builder.CreateStore(unwindException, exceptionStorage);
1244     builder.CreateStore(ourExceptionThrownState, exceptionCaughtFlag);
1245     llvm::Function *personality = module.getFunction("ourPersonality");
1246     llvm::Value* functPtr =
1247         builder.CreatePointerCast(personality,
1248                               builder.getInt8Ty()->getPointerTo());
1249
1250     args.clear();
1251     args.push_back(unwindException);
1252     args.push_back(functPtr);
1253
1254     // Note: Skipping index 0
1255     for (unsigned i = 0; i < numExceptionsToCatch; ++i) {
1256         // Set up type infos to be caught
1257         args.push_back(
1258             module.getGlobalVariable(
1259                 ourTypeInfoNames[exceptionTypesToCatch[i]]));
1260     }
1261
1262     args.push_back(llvm::ConstantInt::get(builder.getInt32Ty(), 0));
1263
1264     llvm::Function *ehSelector = module.getFunction("llvm.eh.selector");
1265
1266     // Set up this exeption block as the landing pad which will handle
1267     // given type infos. See case Intrinsic::eh_selector in
1268     // SelectionDAGBuilder::visitIntrinsicCall(...) and AddCatchInfo(...)
1269     // implemented in FunctionLoweringInfo.cpp to see how the implementation
1270     // handles this call. This landing pad (this exception block), will be
1271     // called either because it nees to cleanup (call finally) or a type
1272     // info was found which matched the thrown exception.
1273     llvm::Value* retTypeInfoIndex = builder.CreateCall(ehSelector,
1274                                                        args.begin(),
1275                                                        args.end());
1276
1277     // Retrieve exception_class member from thrown exception
1278     // (_Unwind_Exception instance). This member tells us whether or not
1279     // the exception is foreign.
1280     llvm::Value* unwindExceptionClass =
1281         builder.CreateLoad(
1282             builder.CreateStructGEP(
1283                 builder.CreatePointerCast(
1284                     unwindException,
1285                     ourUnwindExceptionType->getPointerTo()),
1286                 0));
1287
1288     // Branch to the externalExceptionBlock if the exception is foreign or
1289     // to a catch router if not. Either way the finally block will be run.
1290     builder.CreateCondBr(
1291         builder.CreateICmpEQ(unwindExceptionClass,
1292                              llvm::ConstantInt::get(builder.getInt64Ty(),
1293                                                     ourBaseExceptionClass)),
1294         exceptionRouteBlock,
1295         externalExceptionBlock);
1296
1297     // External Exception Block
1298
1299     builder.SetInsertPoint(externalExceptionBlock);
1300
1301     generateStringPrint(context,
1302                         module,
1303                         builder,
1304                         "Gen: Foreign exception received.\n",
1305                         USE_GLOBAL_STR_CONSTS);
1306
1307     // Branch to the finally block
1308     builder.CreateBr(finallyBlock);
1309
1310     // Exception Route Block
1311
1312     builder.SetInsertPoint(exceptionRouteBlock);
1313
1314     // Casts exception pointer (_Unwind_Exception instance) to parent
1315     // (OurException instance).
1316     //
1317     // Note: ourBaseFromUnwindOffset is usually negative
1318     llvm::Value* typeInfoThrown =
1319         builder.CreatePointerCast(
1320             builder.CreateConstGEP1_64(unwindException,
1321                                        ourBaseFromUnwindOffset),
1322             ourExceptionType->getPointerTo());
1323
1324     // Retrieve thrown exception type info type
1325     //
1326     // Note: Index is not relative to pointer but instead to structure
1327     //       unlike a true getelementptr (GEP) instruction
1328     typeInfoThrown = builder.CreateStructGEP(typeInfoThrown, 0);
1329
1330     llvm::Value* typeInfoThrownType =
1331                      builder.CreateStructGEP(typeInfoThrown, 0);
1332
1333     generateIntegerPrint(context,
1334                          module,
1335                          builder,
1336                          *toPrint32Int,
1337                          *(builder.CreateLoad(typeInfoThrownType)),
1338                          "Gen: Exception type <%d> received (stack unwound) "
1339                                  " in " +
1340                              ourId +
1341                              ".\n",
1342                          USE_GLOBAL_STR_CONSTS);
1343
1344     // Route to matched type info catch block or run cleanup finally block
1345     llvm::SwitchInst* switchToCatchBlock =
1346         builder.CreateSwitch(retTypeInfoIndex,
1347                              finallyBlock,
1348                              numExceptionsToCatch);
1349
1350     unsigned nextTypeToCatch;
1351
1352     for (unsigned i = 1; i <= numExceptionsToCatch; ++i) {
1353         nextTypeToCatch = i - 1;
1354         switchToCatchBlock->addCase(llvm::ConstantInt::get(
1355                                         llvm::Type::getInt32Ty(context),
1356                                         i),
1357                                     catchBlocks[nextTypeToCatch]);
1358     }
1359
1360     llvm::verifyFunction(*ret);
1361     fpm.run(*ret);
1362
1363     return(ret);
1364 }
1365
1366
1367 /// Generates function which throws either an exception matched to a runtime
1368 /// determined type info type (argument to generated function), or if this
1369 /// runtime value matches nativeThrowType, throws a foreign exception by
1370 /// calling nativeThrowFunct.
1371 /// @param module code for module instance
1372 /// @param builder builder instance
1373 /// @param fpm a function pass manager holding optional IR to IR
1374 ///        transformations
1375 /// @param ourId id used to printing purposes
1376 /// @param nativeThrowType a runtime argument of this value results in
1377 ///        nativeThrowFunct being called to generate/throw exception.
1378 /// @param nativeThrowFunct function which will throw a foreign exception
1379 ///        if the above nativeThrowType matches generated function's arg.
1380 /// @returns generated function
1381 static
1382 llvm::Function* createThrowExceptionFunction(llvm::Module& module,
1383                                          llvm::IRBuilder<>& builder,
1384                                          llvm::FunctionPassManager& fpm,
1385                                          std::string ourId,
1386                                          int32_t nativeThrowType,
1387                                          llvm::Function& nativeThrowFunct) {
1388     llvm::LLVMContext& context = module.getContext();
1389     namedValues.clear();
1390     ArgTypes unwindArgTypes;
1391     unwindArgTypes.push_back(builder.getInt32Ty());
1392     ArgNames unwindArgNames;
1393     unwindArgNames.push_back("exceptTypeToThrow");
1394
1395     llvm::Function *ret = createFunction(module,
1396                                          builder.getVoidTy(),
1397                                          unwindArgTypes,
1398                                          unwindArgNames,
1399                                          ourId,
1400                                          llvm::Function::ExternalLinkage,
1401                                          false,
1402                                          false);
1403
1404     // Throws either one of our exception or a native C++ exception depending
1405     // on a runtime argument value containing a type info type.
1406     llvm::BasicBlock *entryBlock = llvm::BasicBlock::Create(context,
1407                                                             "entry",
1408                                                             ret);
1409     // Throws a foreign exception
1410     llvm::BasicBlock *nativeThrowBlock =
1411                                 llvm::BasicBlock::Create(context,
1412                                                          "nativeThrow",
1413                                                          ret);
1414     // Throws one of our Exceptions
1415     llvm::BasicBlock *generatedThrowBlock =
1416                                 llvm::BasicBlock::Create(context,
1417                                                          "generatedThrow",
1418                                                          ret);
1419     // Retrieved runtime type info type to throw
1420     llvm::Value* exceptionType = namedValues["exceptTypeToThrow"];
1421
1422     // nativeThrowBlock block
1423
1424     builder.SetInsertPoint(nativeThrowBlock);
1425
1426     // Throws foreign exception
1427     builder.CreateCall(&nativeThrowFunct, exceptionType);
1428     builder.CreateUnreachable();
1429
1430     // entry block
1431
1432     builder.SetInsertPoint(entryBlock);
1433
1434     llvm::Function *toPrint32Int = module.getFunction("print32Int");
1435     generateIntegerPrint(context,
1436                          module,
1437                          builder,
1438                          *toPrint32Int,
1439                          *exceptionType,
1440                          "\nGen: About to throw exception type <%d> in " +
1441                              ourId +
1442                              ".\n",
1443                          USE_GLOBAL_STR_CONSTS);
1444
1445     // Switches on runtime type info type value to determine whether or not
1446     // a foreign exception is thrown. Defaults to throwing one of our
1447     // generated exceptions.
1448     llvm::SwitchInst* theSwitch = builder.CreateSwitch(exceptionType,
1449                                                        generatedThrowBlock,
1450                                                        1);
1451
1452     theSwitch->addCase(llvm::ConstantInt::get(llvm::Type::getInt32Ty(context),
1453                                               nativeThrowType),
1454                        nativeThrowBlock);
1455
1456     // generatedThrow block
1457
1458     builder.SetInsertPoint(generatedThrowBlock);
1459
1460     llvm::Function *createOurException =
1461                 module.getFunction("createOurException");
1462     llvm::Function *raiseOurException =
1463                 module.getFunction("_Unwind_RaiseException");
1464
1465     // Creates exception to throw with runtime type info type.
1466     llvm::Value* exception =
1467         builder.CreateCall(createOurException,
1468                            namedValues["exceptTypeToThrow"]);
1469
1470     // Throw generated Exception
1471     builder.CreateCall(raiseOurException, exception);
1472     builder.CreateUnreachable();
1473
1474     llvm::verifyFunction(*ret);
1475     fpm.run(*ret);
1476
1477     return(ret);
1478 }
1479
1480 static void createStandardUtilityFunctions(unsigned numTypeInfos,
1481                                            llvm::Module& module,
1482                                            llvm::IRBuilder<>& builder);
1483
1484 /// Creates test code by generating and organizing these functions into the
1485 /// test case. The test case consists of an outer function setup to invoke
1486 /// an inner function within an environment having multiple catch and single
1487 /// finally blocks. This inner function is also setup to invoke a throw
1488 /// function within an evironment similar in nature to the outer function's
1489 /// catch and finally blocks. Each of these two functions catch mutually
1490 /// exclusive subsets (even or odd) of the type info types configured
1491 /// for this this. All generated functions have a runtime argument which
1492 /// holds a type info type to throw that each function takes and passes it
1493 /// to the inner one if such a inner function exists. This type info type is
1494 /// looked at by the generated throw function to see whether or not it should
1495 /// throw a generated exception with the same type info type, or instead call
1496 /// a supplied a function which in turn will throw a foreign exception.
1497 /// @param module code for module instance
1498 /// @param builder builder instance
1499 /// @param fpm a function pass manager holding optional IR to IR
1500 ///        transformations
1501 /// @param nativeThrowFunctName name of external function which will throw
1502 ///        a foreign exception
1503 /// @returns outermost generated test function.
1504 llvm::Function* createUnwindExceptionTest(llvm::Module& module,
1505                                           llvm::IRBuilder<>& builder,
1506                                           llvm::FunctionPassManager& fpm,
1507                                           std::string nativeThrowFunctName) {
1508     // Number of type infos to generate
1509     unsigned numTypeInfos = 6;
1510
1511     // Initialze intrisics and external functions to use along with exception
1512     // and type info globals.
1513     createStandardUtilityFunctions(numTypeInfos,
1514                                    module,
1515                                    builder);
1516     llvm::Function *nativeThrowFunct =
1517         module.getFunction(nativeThrowFunctName);
1518
1519     // Create exception throw function using the value ~0 to cause
1520     // foreign exceptions to be thrown.
1521     llvm::Function* throwFunct =
1522                             createThrowExceptionFunction(module,
1523                                                          builder,
1524                                                          fpm,
1525                                                          "throwFunct",
1526                                                          ~0,
1527                                                          *nativeThrowFunct);
1528     // Inner function will catch even type infos
1529     unsigned innerExceptionTypesToCatch[] = {6, 2, 4};
1530     size_t numExceptionTypesToCatch = sizeof(innerExceptionTypesToCatch) /
1531                                           sizeof(unsigned);
1532
1533     // Generate inner function.
1534     llvm::Function* innerCatchFunct =
1535         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 =
1550         createCatchWrappedInvokeFunction(module,
1551                                          builder,
1552                                          fpm,
1553                                          *innerCatchFunct,
1554                                          "outerCatchFunct",
1555                                          numExceptionTypesToCatch,
1556                                          outerExceptionTypesToCatch);
1557
1558     // Return outer function to run
1559     return(outerCatchFunct);
1560 }
1561
1562
1563 /// Represents our foreign exceptions
1564 class OurCppRunException : public std::runtime_error {
1565 public:
1566     OurCppRunException(const std::string reason) :
1567         std::runtime_error(reason) {}
1568
1569     OurCppRunException (const OurCppRunException& toCopy) :
1570         std::runtime_error(toCopy) {}
1571
1572     OurCppRunException& operator = (const OurCppRunException& toCopy) {
1573         return(reinterpret_cast<OurCppRunException&>(
1574                    std::runtime_error::operator = (toCopy)
1575                ));
1576     }
1577
1578     ~OurCppRunException (void) throw () {};
1579 };
1580
1581
1582 /// Throws foreign C++ exception.
1583 /// @param ignoreIt unused parameter that allows function to match implied
1584 ///        generated function contract.
1585 extern "C"
1586 void throwCppException (int32_t ignoreIt) {
1587     throw(OurCppRunException("thrown by throwCppException(...)"));
1588 }
1589
1590 typedef void (*OurExceptionThrowFunctType) (int32_t typeToThrow);
1591
1592 /// This is a test harness which runs test by executing generated
1593 /// function with a type info type to throw. Harness wraps the excecution
1594 /// of generated function in a C++ try catch clause.
1595 /// @param engine execution engine to use for executing generated function.
1596 ///        This demo program expects this to be a JIT instance for demo
1597 ///        purposes.
1598 /// @param function generated test function to run
1599 /// @param typeToThrow type info type of generated exception to throw, or
1600 ///        indicator to cause foreign exception to be thrown.
1601 static
1602 void runExceptionThrow(llvm::ExecutionEngine* engine,
1603                        llvm::Function* function,
1604                        int32_t typeToThrow) {
1605
1606     // Find test's function pointer
1607     OurExceptionThrowFunctType functPtr =
1608           reinterpret_cast<OurExceptionThrowFunctType>(
1609               reinterpret_cast<intptr_t>(
1610                   engine->getPointerToFunction(function)
1611               )
1612           );
1613
1614     try {
1615         // Run test
1616         (*functPtr)(typeToThrow);
1617     }
1618     catch (OurCppRunException exc) {
1619         // Catch foreign C++ exception
1620         fprintf(stderr,
1621                 "\nrunExceptionThrow(...):In C++ catch OurCppRunException "
1622                     "with reason: %s.\n",
1623                 exc.what());
1624     }
1625     catch (...) {
1626         // Catch all exceptions including our generated ones. I'm not sure
1627         // why this latter functionality should work, as it seems that
1628         // our exceptions should be foreign to C++ (the _Unwind_Exception::
1629         // exception_class should be different from the one used by C++), and
1630         // therefore C++ should ignore the generated exceptions.
1631
1632         fprintf(stderr,
1633                 "\nrunExceptionThrow(...):In C++ catch all.\n");
1634     }
1635 }
1636
1637 //
1638 // End test functions
1639 //
1640
1641 /// This initialization routine creates type info globals and
1642 /// adds external function declarations to module.
1643 /// @param numTypeInfos number of linear type info associated type info types
1644 ///        to create as GlobalVariable instances, starting with the value 1.
1645 /// @param module code for module instance
1646 /// @param builder builder instance
1647 static void createStandardUtilityFunctions(unsigned numTypeInfos,
1648                                            llvm::Module& module,
1649                                            llvm::IRBuilder<>& builder) {
1650
1651     llvm::LLVMContext& context = module.getContext();
1652
1653     // Exception initializations
1654
1655     // Setup exception catch state
1656     ourExceptionNotThrownState =
1657                     llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 0),
1658     ourExceptionThrownState =
1659                     llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 1),
1660     ourExceptionCaughtState =
1661                     llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 2),
1662
1663
1664     // Create our type info type
1665     ourTypeInfoType = llvm::StructType::get(context,
1666                                             builder.getInt32Ty(),
1667                                             NULL);
1668
1669     // Create OurException type
1670     ourExceptionType = llvm::StructType::get(context,
1671                                              ourTypeInfoType,
1672                                              NULL);
1673
1674     // Create portion of _Unwind_Exception type
1675     //
1676     // Note: Declaring only a portion of the _Unwind_Exception struct.
1677     //       Does this cause problems?
1678     ourUnwindExceptionType = llvm::StructType::get(context,
1679                                                    builder.getInt64Ty(),
1680                                                    NULL);
1681     struct OurBaseException_t dummyException;
1682
1683     // Calculate offset of OurException::unwindException member.
1684     ourBaseFromUnwindOffset = ((uintptr_t) &dummyException) -
1685                            ((uintptr_t) &(dummyException.unwindException));
1686
1687 #ifdef DEBUG
1688     fprintf(stderr,
1689             "createStandardUtilityFunctions(...):ourBaseFromUnwindOffset "
1690                 "= %lld, sizeof(struct OurBaseException_t) - "
1691                 "sizeof(struct _Unwind_Exception) = %lu.\n",
1692             ourBaseFromUnwindOffset,
1693             sizeof(struct OurBaseException_t) -
1694                 sizeof(struct _Unwind_Exception));
1695 #endif
1696
1697     size_t numChars = sizeof(ourBaseExcpClassChars) / sizeof(char);
1698
1699     // Create our _Unwind_Exception::exception_class value
1700     ourBaseExceptionClass = genClass(ourBaseExcpClassChars, numChars);
1701
1702     // Type infos
1703
1704     std::string baseStr = "typeInfo", typeInfoName;
1705     std::ostringstream typeInfoNameBuilder;
1706     std::vector<llvm::Constant*> structVals;
1707
1708     llvm::Constant *nextStruct;
1709     llvm::GlobalVariable* nextGlobal = NULL;
1710
1711     // Generate each type info
1712     //
1713     // Note: First type info is not used.
1714     for (unsigned i = 0; i <= numTypeInfos; ++i) {
1715         structVals.clear();
1716         structVals.push_back(llvm::ConstantInt::get(builder.getInt32Ty(), i));
1717         nextStruct = llvm::ConstantStruct::get(ourTypeInfoType, structVals);
1718
1719         typeInfoNameBuilder.str("");
1720         typeInfoNameBuilder << baseStr << i;
1721         typeInfoName = typeInfoNameBuilder.str();
1722
1723         // Note: Does not seem to work without allocation
1724         nextGlobal =
1725             new llvm::GlobalVariable(module,
1726                                      ourTypeInfoType,
1727                                      true,
1728                                      llvm::GlobalValue::ExternalLinkage,
1729                                      nextStruct,
1730                                      typeInfoName);
1731
1732         ourTypeInfoNames.push_back(typeInfoName);
1733         ourTypeInfoNamesIndex[i] = typeInfoName;
1734     }
1735
1736     ArgNames argNames;
1737     ArgTypes argTypes;
1738     llvm::Function* funct = NULL;
1739
1740     // print32Int
1741
1742     const llvm::Type* retType = builder.getVoidTy();
1743
1744     argTypes.clear();
1745     argTypes.push_back(builder.getInt32Ty());
1746     argTypes.push_back(builder.getInt8Ty()->getPointerTo());
1747
1748     argNames.clear();
1749
1750     createFunction(module,
1751                    retType,
1752                    argTypes,
1753                    argNames,
1754                    "print32Int",
1755                    llvm::Function::ExternalLinkage,
1756                    true,
1757                    false);
1758
1759     // print64Int
1760
1761     retType = builder.getVoidTy();
1762
1763     argTypes.clear();
1764     argTypes.push_back(builder.getInt64Ty());
1765     argTypes.push_back(builder.getInt8Ty()->getPointerTo());
1766
1767     argNames.clear();
1768
1769     createFunction(module,
1770                    retType,
1771                    argTypes,
1772                    argNames,
1773                    "print64Int",
1774                    llvm::Function::ExternalLinkage,
1775                    true,
1776                    false);
1777
1778     // printStr
1779
1780     retType = builder.getVoidTy();
1781
1782     argTypes.clear();
1783     argTypes.push_back(builder.getInt8Ty()->getPointerTo());
1784
1785     argNames.clear();
1786
1787     createFunction(module,
1788                    retType,
1789                    argTypes,
1790                    argNames,
1791                    "printStr",
1792                    llvm::Function::ExternalLinkage,
1793                    true,
1794                    false);
1795
1796     // throwCppException
1797
1798     retType = builder.getVoidTy();
1799
1800     argTypes.clear();
1801     argTypes.push_back(builder.getInt32Ty());
1802
1803     argNames.clear();
1804
1805     createFunction(module,
1806                    retType,
1807                    argTypes,
1808                    argNames,
1809                    "throwCppException",
1810                    llvm::Function::ExternalLinkage,
1811                    true,
1812                    false);
1813
1814     // deleteOurException
1815
1816     retType = builder.getVoidTy();
1817
1818     argTypes.clear();
1819     argTypes.push_back(builder.getInt8Ty()->getPointerTo());
1820
1821     argNames.clear();
1822
1823     createFunction(module,
1824                    retType,
1825                    argTypes,
1826                    argNames,
1827                    "deleteOurException",
1828                    llvm::Function::ExternalLinkage,
1829                    true,
1830                    false);
1831
1832     // createOurException
1833
1834     retType = builder.getInt8Ty()->getPointerTo();
1835
1836     argTypes.clear();
1837     argTypes.push_back(builder.getInt32Ty());
1838
1839     argNames.clear();
1840
1841     createFunction(module,
1842                    retType,
1843                    argTypes,
1844                    argNames,
1845                    "createOurException",
1846                    llvm::Function::ExternalLinkage,
1847                    true,
1848                    false);
1849
1850     // _Unwind_RaiseException
1851
1852     retType = builder.getInt32Ty();
1853
1854     argTypes.clear();
1855     argTypes.push_back(builder.getInt8Ty()->getPointerTo());
1856
1857     argNames.clear();
1858
1859     funct = createFunction(module,
1860                            retType,
1861                            argTypes,
1862                            argNames,
1863                            "_Unwind_RaiseException",
1864                            llvm::Function::ExternalLinkage,
1865                            true,
1866                            false);
1867
1868     funct->addFnAttr(llvm::Attribute::NoReturn);
1869
1870     // _Unwind_Resume
1871
1872     retType = builder.getInt32Ty();
1873
1874     argTypes.clear();
1875     argTypes.push_back(builder.getInt8Ty()->getPointerTo());
1876
1877     argNames.clear();
1878
1879     funct = createFunction(module,
1880                            retType,
1881                            argTypes,
1882                            argNames,
1883                            "_Unwind_Resume",
1884                            llvm::Function::ExternalLinkage,
1885                            true,
1886                            false);
1887
1888     funct->addFnAttr(llvm::Attribute::NoReturn);
1889
1890     // ourPersonality
1891
1892     retType = builder.getInt32Ty();
1893
1894     argTypes.clear();
1895     argTypes.push_back(builder.getInt32Ty());
1896     argTypes.push_back(builder.getInt32Ty());
1897     argTypes.push_back(builder.getInt64Ty());
1898     argTypes.push_back(builder.getInt8Ty()->getPointerTo());
1899     argTypes.push_back(builder.getInt8Ty()->getPointerTo());
1900
1901     argNames.clear();
1902
1903     createFunction(module,
1904                    retType,
1905                    argTypes,
1906                    argNames,
1907                    "ourPersonality",
1908                    llvm::Function::ExternalLinkage,
1909                    true,
1910                    false);
1911
1912     // llvm.eh.selector intrinsic
1913
1914     getDeclaration(&module, llvm::Intrinsic::eh_selector);
1915
1916     // llvm.eh.exception intrinsic
1917
1918     getDeclaration(&module, llvm::Intrinsic::eh_exception);
1919
1920     // llvm.eh.typeid.for intrinsic
1921
1922     getDeclaration(&module, llvm::Intrinsic::eh_typeid_for);
1923 }
1924
1925
1926 //===---------------------------------------------------------------------===//
1927 // Main test driver code.
1928 //===---------------------------------------------------------------------===//
1929
1930 /// Demo main routine which takes the type info types to throw. A test will
1931 /// be run for each given type info type. While type info types with the value
1932 /// of -1 will trigger a foreign C++ exception to be thrown; type info types
1933 /// <= 6 and >= 1 will be caught by test functions; and type info types > 6
1934 /// will result in exceptions which pass through to the test harness. All other
1935 /// type info types are not supported and could cause a crash.
1936 int main(int argc, char* argv[]) {
1937     if (argc == 1) {
1938         fprintf(stderr,
1939                 "\nUsage: ExceptionDemo <exception type to throw> "
1940                     "[<type 2>...<type n>].\n"
1941                     "   Each type must have the value of 1 - 6 for "
1942                     "generated exceptions to be caught;\n"
1943                     "   the value -1 for foreign C++ exceptions to be "
1944                     "generated and thrown;\n"
1945                     "   or the values > 6 for exceptions to be ignored.\n"
1946                     "\nTry: ExceptionDemo 2 3 7 -1\n"
1947                     "   for a full test.\n\n");
1948         return(0);
1949     }
1950
1951     // If not set, exception handling will not be turned on
1952     llvm::DwarfExceptionHandling = true;
1953
1954     llvm::InitializeNativeTarget();
1955     llvm::LLVMContext& context = llvm::getGlobalContext();
1956     llvm::IRBuilder<> theBuilder(context);
1957
1958     // Make the module, which holds all the code.
1959     llvm::Module* module = new llvm::Module("my cool jit", context);
1960
1961     // Build engine with JIT
1962     llvm::EngineBuilder factory(module);
1963     factory.setEngineKind(llvm::EngineKind::JIT);
1964     factory.setAllocateGVsWithCode(false);
1965     llvm::ExecutionEngine* executionEngine = factory.create();
1966
1967     {
1968         llvm::FunctionPassManager fpm(module);
1969
1970         // Set up the optimizer pipeline.
1971         // Start with registering info about how the
1972         // target lays out data structures.
1973         fpm.add(new llvm::TargetData(*executionEngine->getTargetData()));
1974
1975         // Optimizations turned on
1976 #ifdef ADD_OPT_PASSES
1977
1978         // Promote allocas to registers.
1979         fpm.add(llvm::createPromoteMemoryToRegisterPass());
1980
1981         // Do simple "peephole" optimizations and bit-twiddling optzns.
1982         fpm.add(llvm::createInstructionCombiningPass());
1983
1984         // Reassociate expressions.
1985         fpm.add(llvm::createReassociatePass());
1986
1987         // Eliminate Common SubExpressions.
1988         fpm.add(llvm::createGVNPass());
1989
1990         // Simplify the control flow graph (deleting unreachable
1991         // blocks, etc).
1992         fpm.add(llvm::createCFGSimplificationPass());
1993 #endif  // ADD_OPT_PASSES
1994
1995         fpm.doInitialization();
1996
1997         // Generate test code using function throwCppException(...) as
1998         // the function which throws foreign exceptions.
1999         llvm::Function* toRun =
2000                           createUnwindExceptionTest(*module,
2001                                                     theBuilder,
2002                                                     fpm,
2003                                                     "throwCppException");
2004
2005         fprintf(stderr, "\nBegin module dump:\n\n");
2006
2007         module->dump();
2008
2009         fprintf(stderr, "\nEnd module dump:\n");
2010
2011         fprintf(stderr, "\n\nBegin Test:\n");
2012
2013         for (int i = 1; i < argc; ++i) {
2014             // Run test for each argument whose value is the exception
2015             // type to throw.
2016             runExceptionThrow(executionEngine,
2017                               toRun,
2018                               (unsigned) strtoul(argv[i], NULL, 10));
2019         }
2020
2021         fprintf(stderr, "\nEnd Test:\n\n");
2022     }
2023
2024     delete executionEngine;
2025
2026     return 0;
2027 }
2028