examples/ExceptionDemo/ExceptionDemo.cpp

   1 //===-- ExceptionDemo.cpp - An example using llvm Exceptions --------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // Demo program which implements an example LLVM exception implementation, and
  11 // shows several test cases including the handling of foreign exceptions.
  12 // It is run with type info types arguments to throw. A test will
  13 // be run for each given type info type. While type info types with the value
  14 // of -1 will trigger a foreign C++ exception to be thrown; type info types
  15 // <= 6 and >= 1 will cause the associated generated exceptions to be thrown
  16 // and caught by generated test functions; and type info types > 6
  17 // will result in exceptions which pass through to the test harness. All other
  18 // type info types are not supported and could cause a crash. In all cases,
  19 // the "finally" blocks of every generated test functions will executed
  20 // regardless of whether or not that test function ignores or catches the
  21 // thrown exception.
  22 //
  23 // examples:
  24 //
  25 // ExceptionDemo
  26 //
  27 //     causes a usage to be printed to stderr
  28 //
  29 // ExceptionDemo 2 3 7 -1
  30 //
  31 //     results in the following cases:
  32 //         - Value 2 causes an exception with a type info type of 2 to be
  33 //           thrown and caught by an inner generated test function.
  34 //         - Value 3 causes an exception with a type info type of 3 to be
  35 //           thrown and caught by an outer generated test function.
  36 //         - Value 7 causes an exception with a type info type of 7 to be
  37 //           thrown and NOT be caught by any generated function.
  38 //         - Value -1 causes a foreign C++ exception to be thrown and not be
  39 //           caught by any generated function
  40 //
  41 //     Cases -1 and 7 are caught by a C++ test harness where the validity of
  42 //         of a C++ catch(...) clause catching a generated exception with a
  43 //         type info type of 7 is explained by: example in rules 1.6.4 in
  44 //         http://mentorembedded.github.com/cxx-abi/abi-eh.html (v1.22)
  45 //
  46 // This code uses code from the llvm compiler-rt project and the llvm
  47 // Kaleidoscope project.
  48 //
  49 //===----------------------------------------------------------------------===//
  50
  51 #include "llvm/IR/Verifier.h"
  52 #include "llvm/ExecutionEngine/MCJIT.h"
  53 #include "llvm/ExecutionEngine/SectionMemoryManager.h"
  54 #include "llvm/IR/DataLayout.h"
  55 #include "llvm/IR/DerivedTypes.h"
  56 #include "llvm/IR/IRBuilder.h"
  57 #include "llvm/IR/Intrinsics.h"
  58 #include "llvm/IR/LLVMContext.h"
  59 #include "llvm/IR/LegacyPassManager.h"
  60 #include "llvm/IR/Module.h"
  61 #include "llvm/Support/Dwarf.h"
  62 #include "llvm/Support/TargetSelect.h"
  63 #include "llvm/Target/TargetOptions.h"
  64 #include "llvm/Transforms/Scalar.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://mentorembedded.github.com/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://mentorembedded.github.com/cxx-abi/abi-eh.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 See @link http://mentorembedded.github.com/cxx-abi/abi-eh.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 unsigned getEncodingSize(uint8_t Encoding) {
 422   if (Encoding == llvm::dwarf::DW_EH_PE_omit)
 423     return 0;
 424
 425   switch (Encoding & 0x0F) {
 426   case llvm::dwarf::DW_EH_PE_absptr:
 427     return sizeof(uintptr_t);
 428   case llvm::dwarf::DW_EH_PE_udata2:
 429     return sizeof(uint16_t);
 430   case llvm::dwarf::DW_EH_PE_udata4:
 431     return sizeof(uint32_t);
 432   case llvm::dwarf::DW_EH_PE_udata8:
 433     return sizeof(uint64_t);
 434   case llvm::dwarf::DW_EH_PE_sdata2:
 435     return sizeof(int16_t);
 436   case llvm::dwarf::DW_EH_PE_sdata4:
 437     return sizeof(int32_t);
 438   case llvm::dwarf::DW_EH_PE_sdata8:
 439     return sizeof(int64_t);
 440   default:
 441     // not supported
 442     abort();
 443   }
 444 }
 445
 446 /// Read a pointer encoded value and advance pointer
 447 /// See Variable Length Data in:
 448 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 449 /// @param data reference variable holding memory pointer to decode from
 450 /// @param encoding dwarf encoding type
 451 /// @returns decoded value
 452 static uintptr_t readEncodedPointer(const uint8_t **data, uint8_t encoding) {
 453   uintptr_t result = 0;
 454   const uint8_t *p = *data;
 455
 456   if (encoding == llvm::dwarf::DW_EH_PE_omit)
 457     return(result);
 458
 459   // first get value
 460   switch (encoding & 0x0F) {
 461     case llvm::dwarf::DW_EH_PE_absptr:
 462       result = *((uintptr_t*)p);
 463       p += sizeof(uintptr_t);
 464       break;
 465     case llvm::dwarf::DW_EH_PE_uleb128:
 466       result = readULEB128(&p);
 467       break;
 468       // Note: This case has not been tested
 469     case llvm::dwarf::DW_EH_PE_sleb128:
 470       result = readSLEB128(&p);
 471       break;
 472     case llvm::dwarf::DW_EH_PE_udata2:
 473       result = *((uint16_t*)p);
 474       p += sizeof(uint16_t);
 475       break;
 476     case llvm::dwarf::DW_EH_PE_udata4:
 477       result = *((uint32_t*)p);
 478       p += sizeof(uint32_t);
 479       break;
 480     case llvm::dwarf::DW_EH_PE_udata8:
 481       result = *((uint64_t*)p);
 482       p += sizeof(uint64_t);
 483       break;
 484     case llvm::dwarf::DW_EH_PE_sdata2:
 485       result = *((int16_t*)p);
 486       p += sizeof(int16_t);
 487       break;
 488     case llvm::dwarf::DW_EH_PE_sdata4:
 489       result = *((int32_t*)p);
 490       p += sizeof(int32_t);
 491       break;
 492     case llvm::dwarf::DW_EH_PE_sdata8:
 493       result = *((int64_t*)p);
 494       p += sizeof(int64_t);
 495       break;
 496     default:
 497       // not supported
 498       abort();
 499       break;
 500   }
 501
 502   // then add relative offset
 503   switch (encoding & 0x70) {
 504     case llvm::dwarf::DW_EH_PE_absptr:
 505       // do nothing
 506       break;
 507     case llvm::dwarf::DW_EH_PE_pcrel:
 508       result += (uintptr_t)(*data);
 509       break;
 510     case llvm::dwarf::DW_EH_PE_textrel:
 511     case llvm::dwarf::DW_EH_PE_datarel:
 512     case llvm::dwarf::DW_EH_PE_funcrel:
 513     case llvm::dwarf::DW_EH_PE_aligned:
 514     default:
 515       // not supported
 516       abort();
 517       break;
 518   }
 519
 520   // then apply indirection
 521   if (encoding & llvm::dwarf::DW_EH_PE_indirect) {
 522     result = *((uintptr_t*)result);
 523   }
 524
 525   *data = p;
 526
 527   return result;
 528 }
 529
 530
 531 /// Deals with Dwarf actions matching our type infos
 532 /// (OurExceptionType_t instances). Returns whether or not a dwarf emitted
 533 /// action matches the supplied exception type. If such a match succeeds,
 534 /// the resultAction argument will be set with > 0 index value. Only
 535 /// corresponding llvm.eh.selector type info arguments, cleanup arguments
 536 /// are supported. Filters are not supported.
 537 /// See Variable Length Data in:
 538 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 539 /// Also see @link http://mentorembedded.github.com/cxx-abi/abi-eh.html @unlink
 540 /// @param resultAction reference variable which will be set with result
 541 /// @param classInfo our array of type info pointers (to globals)
 542 /// @param actionEntry index into above type info array or 0 (clean up).
 543 ///        We do not support filters.
 544 /// @param exceptionClass exception class (_Unwind_Exception::exception_class)
 545 ///        of thrown exception.
 546 /// @param exceptionObject thrown _Unwind_Exception instance.
 547 /// @returns whether or not a type info was found. False is returned if only
 548 ///          a cleanup was found
 549 static bool handleActionValue(int64_t *resultAction,
 550                               uint8_t TTypeEncoding,
 551                               const uint8_t *ClassInfo,
 552                               uintptr_t actionEntry,
 553                               uint64_t exceptionClass,
 554                               struct _Unwind_Exception *exceptionObject) {
 555   bool ret = false;
 556
 557   if (!resultAction ||
 558       !exceptionObject ||
 559       (exceptionClass != ourBaseExceptionClass))
 560     return(ret);
 561
 562   struct OurBaseException_t *excp = (struct OurBaseException_t*)
 563   (((char*) exceptionObject) + ourBaseFromUnwindOffset);
 564   struct OurExceptionType_t *excpType = &(excp->type);
 565   int type = excpType->type;
 566
 567 #ifdef DEBUG
 568   fprintf(stderr,
 569           "handleActionValue(...): exceptionObject = <%p>, "
 570           "excp = <%p>.\n",
 571           exceptionObject,
 572           excp);
 573 #endif
 574
 575   const uint8_t *actionPos = (uint8_t*) actionEntry,
 576   *tempActionPos;
 577   int64_t typeOffset = 0,
 578   actionOffset;
 579
 580   for (int i = 0; true; ++i) {
 581     // Each emitted dwarf action corresponds to a 2 tuple of
 582     // type info address offset, and action offset to the next
 583     // emitted action.
 584     typeOffset = readSLEB128(&actionPos);
 585     tempActionPos = actionPos;
 586     actionOffset = readSLEB128(&tempActionPos);
 587
 588 #ifdef DEBUG
 589     fprintf(stderr,
 590             "handleActionValue(...):typeOffset: <%lld>, "
 591             "actionOffset: <%lld>.\n",
 592             typeOffset,
 593             actionOffset);
 594 #endif
 595     assert((typeOffset >= 0) &&
 596            "handleActionValue(...):filters are not supported.");
 597
 598     // Note: A typeOffset == 0 implies that a cleanup llvm.eh.selector
 599     //       argument has been matched.
 600     if (typeOffset > 0) {
 601 #ifdef DEBUG
 602       fprintf(stderr,
 603               "handleActionValue(...):actionValue <%d> found.\n",
 604               i);
 605 #endif
 606       unsigned EncSize = getEncodingSize(TTypeEncoding);
 607       const uint8_t *EntryP = ClassInfo - typeOffset * EncSize;
 608       uintptr_t P = readEncodedPointer(&EntryP, TTypeEncoding);
 609       struct OurExceptionType_t *ThisClassInfo =
 610         reinterpret_cast<struct OurExceptionType_t *>(P);
 611       if (ThisClassInfo->type == type) {
 612         *resultAction = i + 1;
 613         ret = true;
 614         break;
 615       }
 616     }
 617
 618 #ifdef DEBUG
 619     fprintf(stderr,
 620             "handleActionValue(...):actionValue not found.\n");
 621 #endif
 622     if (!actionOffset)
 623       break;
 624
 625     actionPos += actionOffset;
 626   }
 627
 628   return(ret);
 629 }
 630
 631
 632 /// Deals with the Language specific data portion of the emitted dwarf code.
 633 /// See @link http://mentorembedded.github.com/cxx-abi/abi-eh.html @unlink
 634 /// @param version unsupported (ignored), unwind version
 635 /// @param lsda language specific data area
 636 /// @param _Unwind_Action actions minimally supported unwind stage
 637 ///        (forced specifically not supported)
 638 /// @param exceptionClass exception class (_Unwind_Exception::exception_class)
 639 ///        of thrown exception.
 640 /// @param exceptionObject thrown _Unwind_Exception instance.
 641 /// @param context unwind system context
 642 /// @returns minimally supported unwinding control indicator
 643 static _Unwind_Reason_Code handleLsda(int version,
 644                                       const uint8_t *lsda,
 645                                       _Unwind_Action actions,
 646                                       uint64_t exceptionClass,
 647                                     struct _Unwind_Exception *exceptionObject,
 648                                       _Unwind_Context_t context) {
 649   _Unwind_Reason_Code ret = _URC_CONTINUE_UNWIND;
 650
 651   if (!lsda)
 652     return(ret);
 653
 654 #ifdef DEBUG
 655   fprintf(stderr,
 656           "handleLsda(...):lsda is non-zero.\n");
 657 #endif
 658
 659   // Get the current instruction pointer and offset it before next
 660   // instruction in the current frame which threw the exception.
 661   uintptr_t pc = _Unwind_GetIP(context)-1;
 662
 663   // Get beginning current frame's code (as defined by the
 664   // emitted dwarf code)
 665   uintptr_t funcStart = _Unwind_GetRegionStart(context);
 666   uintptr_t pcOffset = pc - funcStart;
 667   const uint8_t *ClassInfo = NULL;
 668
 669   // Note: See JITDwarfEmitter::EmitExceptionTable(...) for corresponding
 670   //       dwarf emission
 671
 672   // Parse LSDA header.
 673   uint8_t lpStartEncoding = *lsda++;
 674
 675   if (lpStartEncoding != llvm::dwarf::DW_EH_PE_omit) {
 676     readEncodedPointer(&lsda, lpStartEncoding);
 677   }
 678
 679   uint8_t ttypeEncoding = *lsda++;
 680   uintptr_t classInfoOffset;
 681
 682   if (ttypeEncoding != llvm::dwarf::DW_EH_PE_omit) {
 683     // Calculate type info locations in emitted dwarf code which
 684     // were flagged by type info arguments to llvm.eh.selector
 685     // intrinsic
 686     classInfoOffset = readULEB128(&lsda);
 687     ClassInfo = lsda + classInfoOffset;
 688   }
 689
 690   // Walk call-site table looking for range that
 691   // includes current PC.
 692
 693   uint8_t         callSiteEncoding = *lsda++;
 694   uint32_t        callSiteTableLength = readULEB128(&lsda);
 695   const uint8_t   *callSiteTableStart = lsda;
 696   const uint8_t   *callSiteTableEnd = callSiteTableStart +
 697   callSiteTableLength;
 698   const uint8_t   *actionTableStart = callSiteTableEnd;
 699   const uint8_t   *callSitePtr = callSiteTableStart;
 700
 701   while (callSitePtr < callSiteTableEnd) {
 702     uintptr_t start = readEncodedPointer(&callSitePtr,
 703                                          callSiteEncoding);
 704     uintptr_t length = readEncodedPointer(&callSitePtr,
 705                                           callSiteEncoding);
 706     uintptr_t landingPad = readEncodedPointer(&callSitePtr,
 707                                               callSiteEncoding);
 708
 709     // Note: Action value
 710     uintptr_t actionEntry = readULEB128(&callSitePtr);
 711
 712     if (exceptionClass != ourBaseExceptionClass) {
 713       // We have been notified of a foreign exception being thrown,
 714       // and we therefore need to execute cleanup landing pads
 715       actionEntry = 0;
 716     }
 717
 718     if (landingPad == 0) {
 719 #ifdef DEBUG
 720       fprintf(stderr,
 721               "handleLsda(...): No landing pad found.\n");
 722 #endif
 723
 724       continue; // no landing pad for this entry
 725     }
 726
 727     if (actionEntry) {
 728       actionEntry += ((uintptr_t) actionTableStart) - 1;
 729     }
 730     else {
 731 #ifdef DEBUG
 732       fprintf(stderr,
 733               "handleLsda(...):No action table found.\n");
 734 #endif
 735     }
 736
 737     bool exceptionMatched = false;
 738
 739     if ((start <= pcOffset) && (pcOffset < (start + length))) {
 740 #ifdef DEBUG
 741       fprintf(stderr,
 742               "handleLsda(...): Landing pad found.\n");
 743 #endif
 744       int64_t actionValue = 0;
 745
 746       if (actionEntry) {
 747         exceptionMatched = handleActionValue(&actionValue,
 748                                              ttypeEncoding,
 749                                              ClassInfo,
 750                                              actionEntry,
 751                                              exceptionClass,
 752                                              exceptionObject);
 753       }
 754
 755       if (!(actions & _UA_SEARCH_PHASE)) {
 756 #ifdef DEBUG
 757         fprintf(stderr,
 758                 "handleLsda(...): installed landing pad "
 759                 "context.\n");
 760 #endif
 761
 762         // Found landing pad for the PC.
 763         // Set Instruction Pointer to so we re-enter function
 764         // at landing pad. The landing pad is created by the
 765         // compiler to take two parameters in registers.
 766         _Unwind_SetGR(context,
 767                       __builtin_eh_return_data_regno(0),
 768                       (uintptr_t)exceptionObject);
 769
 770         // Note: this virtual register directly corresponds
 771         //       to the return of the llvm.eh.selector intrinsic
 772         if (!actionEntry || !exceptionMatched) {
 773           // We indicate cleanup only
 774           _Unwind_SetGR(context,
 775                         __builtin_eh_return_data_regno(1),
 776                         0);
 777         }
 778         else {
 779           // Matched type info index of llvm.eh.selector intrinsic
 780           // passed here.
 781           _Unwind_SetGR(context,
 782                         __builtin_eh_return_data_regno(1),
 783                         actionValue);
 784         }
 785
 786         // To execute landing pad set here
 787         _Unwind_SetIP(context, funcStart + landingPad);
 788         ret = _URC_INSTALL_CONTEXT;
 789       }
 790       else if (exceptionMatched) {
 791 #ifdef DEBUG
 792         fprintf(stderr,
 793                 "handleLsda(...): setting handler found.\n");
 794 #endif
 795         ret = _URC_HANDLER_FOUND;
 796       }
 797       else {
 798         // Note: Only non-clean up handlers are marked as
 799         //       found. Otherwise the clean up handlers will be
 800         //       re-found and executed during the clean up
 801         //       phase.
 802 #ifdef DEBUG
 803         fprintf(stderr,
 804                 "handleLsda(...): cleanup handler found.\n");
 805 #endif
 806       }
 807
 808       break;
 809     }
 810   }
 811
 812   return(ret);
 813 }
 814
 815
 816 /// This is the personality function which is embedded (dwarf emitted), in the
 817 /// dwarf unwind info block. Again see: JITDwarfEmitter.cpp.
 818 /// See @link http://mentorembedded.github.com/cxx-abi/abi-eh.html @unlink
 819 /// @param version unsupported (ignored), unwind version
 820 /// @param _Unwind_Action actions minimally supported unwind stage
 821 ///        (forced specifically not supported)
 822 /// @param exceptionClass exception class (_Unwind_Exception::exception_class)
 823 ///        of thrown exception.
 824 /// @param exceptionObject thrown _Unwind_Exception instance.
 825 /// @param context unwind system context
 826 /// @returns minimally supported unwinding control indicator
 827 _Unwind_Reason_Code ourPersonality(int version,
 828                                    _Unwind_Action actions,
 829                                    uint64_t exceptionClass,
 830                                    struct _Unwind_Exception *exceptionObject,
 831                                    _Unwind_Context_t context) {
 832 #ifdef DEBUG
 833   fprintf(stderr,
 834           "We are in ourPersonality(...):actions is <%d>.\n",
 835           actions);
 836
 837   if (actions & _UA_SEARCH_PHASE) {
 838     fprintf(stderr, "ourPersonality(...):In search phase.\n");
 839   }
 840   else {
 841     fprintf(stderr, "ourPersonality(...):In non-search phase.\n");
 842   }
 843 #endif
 844
 845   const uint8_t *lsda = _Unwind_GetLanguageSpecificData(context);
 846
 847 #ifdef DEBUG
 848   fprintf(stderr,
 849           "ourPersonality(...):lsda = <%p>.\n",
 850           lsda);
 851 #endif
 852
 853   // The real work of the personality function is captured here
 854   return(handleLsda(version,
 855                     lsda,
 856                     actions,
 857                     exceptionClass,
 858                     exceptionObject,
 859                     context));
 860 }
 861
 862
 863 /// Generates our _Unwind_Exception class from a given character array.
 864 /// thereby handling arbitrary lengths (not in standard), and handling
 865 /// embedded \0s.
 866 /// See @link http://mentorembedded.github.com/cxx-abi/abi-eh.html @unlink
 867 /// @param classChars char array to encode. NULL values not checkedf
 868 /// @param classCharsSize number of chars in classChars. Value is not checked.
 869 /// @returns class value
 870 uint64_t genClass(const unsigned char classChars[], size_t classCharsSize)
 871 {
 872   uint64_t ret = classChars[0];
 873
 874   for (unsigned i = 1; i < classCharsSize; ++i) {
 875     ret <<= 8;
 876     ret += classChars[i];
 877   }
 878
 879   return(ret);
 880 }
 881
 882 } // extern "C"
 883
 884 //
 885 // Runtime C Library functions End
 886 //
 887
 888 //
 889 // Code generation functions
 890 //
 891
 892 /// Generates code to print given constant string
 893 /// @param context llvm context
 894 /// @param module code for module instance
 895 /// @param builder builder instance
 896 /// @param toPrint string to print
 897 /// @param useGlobal A value of true (default) indicates a GlobalValue is
 898 ///        generated, and is used to hold the constant string. A value of
 899 ///        false indicates that the constant string will be stored on the
 900 ///        stack.
 901 void generateStringPrint(llvm::LLVMContext &context,
 902                          llvm::Module &module,
 903                          llvm::IRBuilder<> &builder,
 904                          std::string toPrint,
 905                          bool useGlobal = true) {
 906   llvm::Function *printFunct = module.getFunction("printStr");
 907
 908   llvm::Value *stringVar;
 909   llvm::Constant *stringConstant =
 910   llvm::ConstantDataArray::getString(context, toPrint);
 911
 912   if (useGlobal) {
 913     // Note: Does not work without allocation
 914     stringVar =
 915     new llvm::GlobalVariable(module,
 916                              stringConstant->getType(),
 917                              true,
 918                              llvm::GlobalValue::PrivateLinkage,
 919                              stringConstant,
 920                              "");
 921   }
 922   else {
 923     stringVar = builder.CreateAlloca(stringConstant->getType());
 924     builder.CreateStore(stringConstant, stringVar);
 925   }
 926
 927   llvm::Value *cast = builder.CreatePointerCast(stringVar,
 928                                                 builder.getInt8PtrTy());
 929   builder.CreateCall(printFunct, cast);
 930 }
 931
 932
 933 /// Generates code to print given runtime integer according to constant
 934 /// string format, and a given print function.
 935 /// @param context llvm context
 936 /// @param module code for module instance
 937 /// @param builder builder instance
 938 /// @param printFunct function used to "print" integer
 939 /// @param toPrint string to print
 940 /// @param format printf like formating string for print
 941 /// @param useGlobal A value of true (default) indicates a GlobalValue is
 942 ///        generated, and is used to hold the constant string. A value of
 943 ///        false indicates that the constant string will be stored on the
 944 ///        stack.
 945 void generateIntegerPrint(llvm::LLVMContext &context,
 946                           llvm::Module &module,
 947                           llvm::IRBuilder<> &builder,
 948                           llvm::Function &printFunct,
 949                           llvm::Value &toPrint,
 950                           std::string format,
 951                           bool useGlobal = true) {
 952   llvm::Constant *stringConstant =
 953     llvm::ConstantDataArray::getString(context, format);
 954   llvm::Value *stringVar;
 955
 956   if (useGlobal) {
 957     // Note: Does not seem to work without allocation
 958     stringVar =
 959     new llvm::GlobalVariable(module,
 960                              stringConstant->getType(),
 961                              true,
 962                              llvm::GlobalValue::PrivateLinkage,
 963                              stringConstant,
 964                              "");
 965   }
 966   else {
 967     stringVar = builder.CreateAlloca(stringConstant->getType());
 968     builder.CreateStore(stringConstant, stringVar);
 969   }
 970
 971   llvm::Value *cast = builder.CreateBitCast(stringVar,
 972                                             builder.getInt8PtrTy());
 973   builder.CreateCall2(&printFunct, &toPrint, cast);
 974 }
 975
 976
 977 /// Generates code to handle finally block type semantics: always runs
 978 /// regardless of whether a thrown exception is passing through or the
 979 /// parent function is simply exiting. In addition to printing some state
 980 /// to stderr, this code will resume the exception handling--runs the
 981 /// unwind resume block, if the exception has not been previously caught
 982 /// by a catch clause, and will otherwise execute the end block (terminator
 983 /// block). In addition this function creates the corresponding function's
 984 /// stack storage for the exception pointer and catch flag status.
 985 /// @param context llvm context
 986 /// @param module code for module instance
 987 /// @param builder builder instance
 988 /// @param toAddTo parent function to add block to
 989 /// @param blockName block name of new "finally" block.
 990 /// @param functionId output id used for printing
 991 /// @param terminatorBlock terminator "end" block
 992 /// @param unwindResumeBlock unwind resume block
 993 /// @param exceptionCaughtFlag reference exception caught/thrown status storage
 994 /// @param exceptionStorage reference to exception pointer storage
 995 /// @param caughtResultStorage reference to landingpad result storage
 996 /// @returns newly created block
 997 static llvm::BasicBlock *createFinallyBlock(llvm::LLVMContext &context,
 998                                             llvm::Module &module,
 999                                             llvm::IRBuilder<> &builder,
1000                                             llvm::Function &toAddTo,
1001                                             std::string &blockName,
1002                                             std::string &functionId,
1003                                             llvm::BasicBlock &terminatorBlock,
1004                                             llvm::BasicBlock &unwindResumeBlock,
1005                                             llvm::Value **exceptionCaughtFlag,
1006                                             llvm::Value **exceptionStorage,
1007                                             llvm::Value **caughtResultStorage) {
1008   assert(exceptionCaughtFlag &&
1009          "ExceptionDemo::createFinallyBlock(...):exceptionCaughtFlag "
1010          "is NULL");
1011   assert(exceptionStorage &&
1012          "ExceptionDemo::createFinallyBlock(...):exceptionStorage "
1013          "is NULL");
1014   assert(caughtResultStorage &&
1015          "ExceptionDemo::createFinallyBlock(...):caughtResultStorage "
1016          "is NULL");
1017
1018   *exceptionCaughtFlag = createEntryBlockAlloca(toAddTo,
1019                                          "exceptionCaught",
1020                                          ourExceptionNotThrownState->getType(),
1021                                          ourExceptionNotThrownState);
1022
1023   llvm::PointerType *exceptionStorageType = builder.getInt8PtrTy();
1024   *exceptionStorage = createEntryBlockAlloca(toAddTo,
1025                                              "exceptionStorage",
1026                                              exceptionStorageType,
1027                                              llvm::ConstantPointerNull::get(
1028                                                exceptionStorageType));
1029   *caughtResultStorage = createEntryBlockAlloca(toAddTo,
1030                                               "caughtResultStorage",
1031                                               ourCaughtResultType,
1032                                               llvm::ConstantAggregateZero::get(
1033                                                 ourCaughtResultType));
1034
1035   llvm::BasicBlock *ret = llvm::BasicBlock::Create(context,
1036                                                    blockName,
1037                                                    &toAddTo);
1038
1039   builder.SetInsertPoint(ret);
1040
1041   std::ostringstream bufferToPrint;
1042   bufferToPrint << "Gen: Executing finally block "
1043     << blockName << " in " << functionId << "\n";
1044   generateStringPrint(context,
1045                       module,
1046                       builder,
1047                       bufferToPrint.str(),
1048                       USE_GLOBAL_STR_CONSTS);
1049
1050   llvm::SwitchInst *theSwitch = builder.CreateSwitch(builder.CreateLoad(
1051                                                        *exceptionCaughtFlag),
1052                                                      &terminatorBlock,
1053                                                      2);
1054   theSwitch->addCase(ourExceptionCaughtState, &terminatorBlock);
1055   theSwitch->addCase(ourExceptionThrownState, &unwindResumeBlock);
1056
1057   return(ret);
1058 }
1059
1060
1061 /// Generates catch block semantics which print a string to indicate type of
1062 /// catch executed, sets an exception caught flag, and executes passed in
1063 /// end block (terminator block).
1064 /// @param context llvm context
1065 /// @param module code for module instance
1066 /// @param builder builder instance
1067 /// @param toAddTo parent function to add block to
1068 /// @param blockName block name of new "catch" block.
1069 /// @param functionId output id used for printing
1070 /// @param terminatorBlock terminator "end" block
1071 /// @param exceptionCaughtFlag exception caught/thrown status
1072 /// @returns newly created block
1073 static llvm::BasicBlock *createCatchBlock(llvm::LLVMContext &context,
1074                                           llvm::Module &module,
1075                                           llvm::IRBuilder<> &builder,
1076                                           llvm::Function &toAddTo,
1077                                           std::string &blockName,
1078                                           std::string &functionId,
1079                                           llvm::BasicBlock &terminatorBlock,
1080                                           llvm::Value &exceptionCaughtFlag) {
1081
1082   llvm::BasicBlock *ret = llvm::BasicBlock::Create(context,
1083                                                    blockName,
1084                                                    &toAddTo);
1085
1086   builder.SetInsertPoint(ret);
1087
1088   std::ostringstream bufferToPrint;
1089   bufferToPrint << "Gen: Executing catch block "
1090   << blockName
1091   << " in "
1092   << functionId
1093   << std::endl;
1094   generateStringPrint(context,
1095                       module,
1096                       builder,
1097                       bufferToPrint.str(),
1098                       USE_GLOBAL_STR_CONSTS);
1099   builder.CreateStore(ourExceptionCaughtState, &exceptionCaughtFlag);
1100   builder.CreateBr(&terminatorBlock);
1101
1102   return(ret);
1103 }
1104
1105
1106 /// Generates a function which invokes a function (toInvoke) and, whose
1107 /// unwind block will "catch" the type info types correspondingly held in the
1108 /// exceptionTypesToCatch argument. If the toInvoke function throws an
1109 /// exception which does not match any type info types contained in
1110 /// exceptionTypesToCatch, the generated code will call _Unwind_Resume
1111 /// with the raised exception. On the other hand the generated code will
1112 /// normally exit if the toInvoke function does not throw an exception.
1113 /// The generated "finally" block is always run regardless of the cause of
1114 /// the generated function exit.
1115 /// The generated function is returned after being verified.
1116 /// @param module code for module instance
1117 /// @param builder builder instance
1118 /// @param fpm a function pass manager holding optional IR to IR
1119 ///        transformations
1120 /// @param toInvoke inner function to invoke
1121 /// @param ourId id used to printing purposes
1122 /// @param numExceptionsToCatch length of exceptionTypesToCatch array
1123 /// @param exceptionTypesToCatch array of type info types to "catch"
1124 /// @returns generated function
1125 static llvm::Function *createCatchWrappedInvokeFunction(
1126     llvm::Module &module, llvm::IRBuilder<> &builder,
1127     llvm::legacy::FunctionPassManager &fpm, llvm::Function &toInvoke,
1128     std::string ourId, unsigned numExceptionsToCatch,
1129     unsigned exceptionTypesToCatch[]) {
1130
1131   llvm::LLVMContext &context = module.getContext();
1132   llvm::Function *toPrint32Int = module.getFunction("print32Int");
1133
1134   ArgTypes argTypes;
1135   argTypes.push_back(builder.getInt32Ty());
1136
1137   ArgNames argNames;
1138   argNames.push_back("exceptTypeToThrow");
1139
1140   llvm::Function *ret = createFunction(module,
1141                                        builder.getVoidTy(),
1142                                        argTypes,
1143                                        argNames,
1144                                        ourId,
1145                                        llvm::Function::ExternalLinkage,
1146                                        false,
1147                                        false);
1148
1149   // Block which calls invoke
1150   llvm::BasicBlock *entryBlock = llvm::BasicBlock::Create(context,
1151                                                           "entry",
1152                                                           ret);
1153   // Normal block for invoke
1154   llvm::BasicBlock *normalBlock = llvm::BasicBlock::Create(context,
1155                                                            "normal",
1156                                                            ret);
1157   // Unwind block for invoke
1158   llvm::BasicBlock *exceptionBlock = llvm::BasicBlock::Create(context,
1159                                                               "exception",
1160                                                               ret);
1161
1162   // Block which routes exception to correct catch handler block
1163   llvm::BasicBlock *exceptionRouteBlock = llvm::BasicBlock::Create(context,
1164                                                              "exceptionRoute",
1165                                                              ret);
1166
1167   // Foreign exception handler
1168   llvm::BasicBlock *externalExceptionBlock = llvm::BasicBlock::Create(context,
1169                                                           "externalException",
1170                                                           ret);
1171
1172   // Block which calls _Unwind_Resume
1173   llvm::BasicBlock *unwindResumeBlock = llvm::BasicBlock::Create(context,
1174                                                                "unwindResume",
1175                                                                ret);
1176
1177   // Clean up block which delete exception if needed
1178   llvm::BasicBlock *endBlock = llvm::BasicBlock::Create(context, "end", ret);
1179
1180   std::string nextName;
1181   std::vector<llvm::BasicBlock*> catchBlocks(numExceptionsToCatch);
1182   llvm::Value *exceptionCaughtFlag = NULL;
1183   llvm::Value *exceptionStorage = NULL;
1184   llvm::Value *caughtResultStorage = NULL;
1185
1186   // Finally block which will branch to unwindResumeBlock if
1187   // exception is not caught. Initializes/allocates stack locations.
1188   llvm::BasicBlock *finallyBlock = createFinallyBlock(context,
1189                                                       module,
1190                                                       builder,
1191                                                       *ret,
1192                                                       nextName = "finally",
1193                                                       ourId,
1194                                                       *endBlock,
1195                                                       *unwindResumeBlock,
1196                                                       &exceptionCaughtFlag,
1197                                                       &exceptionStorage,
1198                                                       &caughtResultStorage
1199                                                       );
1200
1201   for (unsigned i = 0; i < numExceptionsToCatch; ++i) {
1202     nextName = ourTypeInfoNames[exceptionTypesToCatch[i]];
1203
1204     // One catch block per type info to be caught
1205     catchBlocks[i] = createCatchBlock(context,
1206                                       module,
1207                                       builder,
1208                                       *ret,
1209                                       nextName,
1210                                       ourId,
1211                                       *finallyBlock,
1212                                       *exceptionCaughtFlag);
1213   }
1214
1215   // Entry Block
1216
1217   builder.SetInsertPoint(entryBlock);
1218
1219   std::vector<llvm::Value*> args;
1220   args.push_back(namedValues["exceptTypeToThrow"]);
1221   builder.CreateInvoke(&toInvoke,
1222                        normalBlock,
1223                        exceptionBlock,
1224                        args);
1225
1226   // End Block
1227
1228   builder.SetInsertPoint(endBlock);
1229
1230   generateStringPrint(context,
1231                       module,
1232                       builder,
1233                       "Gen: In end block: exiting in " + ourId + ".\n",
1234                       USE_GLOBAL_STR_CONSTS);
1235   llvm::Function *deleteOurException = module.getFunction("deleteOurException");
1236
1237   // Note: function handles NULL exceptions
1238   builder.CreateCall(deleteOurException,
1239                      builder.CreateLoad(exceptionStorage));
1240   builder.CreateRetVoid();
1241
1242   // Normal Block
1243
1244   builder.SetInsertPoint(normalBlock);
1245
1246   generateStringPrint(context,
1247                       module,
1248                       builder,
1249                       "Gen: No exception in " + ourId + "!\n",
1250                       USE_GLOBAL_STR_CONSTS);
1251
1252   // Finally block is always called
1253   builder.CreateBr(finallyBlock);
1254
1255   // Unwind Resume Block
1256
1257   builder.SetInsertPoint(unwindResumeBlock);
1258
1259   builder.CreateResume(builder.CreateLoad(caughtResultStorage));
1260
1261   // Exception Block
1262
1263   builder.SetInsertPoint(exceptionBlock);
1264
1265   llvm::Function *personality = module.getFunction("ourPersonality");
1266
1267   llvm::LandingPadInst *caughtResult =
1268     builder.CreateLandingPad(ourCaughtResultType,
1269                              personality,
1270                              numExceptionsToCatch,
1271                              "landingPad");
1272
1273   caughtResult->setCleanup(true);
1274
1275   for (unsigned i = 0; i < numExceptionsToCatch; ++i) {
1276     // Set up type infos to be caught
1277     caughtResult->addClause(module.getGlobalVariable(
1278                              ourTypeInfoNames[exceptionTypesToCatch[i]]));
1279   }
1280
1281   llvm::Value *unwindException = builder.CreateExtractValue(caughtResult, 0);
1282   llvm::Value *retTypeInfoIndex = builder.CreateExtractValue(caughtResult, 1);
1283
1284   // FIXME: Redundant storage which, beyond utilizing value of
1285   //        caughtResultStore for unwindException storage, may be alleviated
1286   //        altogether with a block rearrangement
1287   builder.CreateStore(caughtResult, caughtResultStorage);
1288   builder.CreateStore(unwindException, exceptionStorage);
1289   builder.CreateStore(ourExceptionThrownState, exceptionCaughtFlag);
1290
1291   // Retrieve exception_class member from thrown exception
1292   // (_Unwind_Exception instance). This member tells us whether or not
1293   // the exception is foreign.
1294   llvm::Value *unwindExceptionClass =
1295     builder.CreateLoad(builder.CreateStructGEP(
1296              builder.CreatePointerCast(unwindException,
1297                                        ourUnwindExceptionType->getPointerTo()),
1298                                                0));
1299
1300   // Branch to the externalExceptionBlock if the exception is foreign or
1301   // to a catch router if not. Either way the finally block will be run.
1302   builder.CreateCondBr(builder.CreateICmpEQ(unwindExceptionClass,
1303                             llvm::ConstantInt::get(builder.getInt64Ty(),
1304                                                    ourBaseExceptionClass)),
1305                        exceptionRouteBlock,
1306                        externalExceptionBlock);
1307
1308   // External Exception Block
1309
1310   builder.SetInsertPoint(externalExceptionBlock);
1311
1312   generateStringPrint(context,
1313                       module,
1314                       builder,
1315                       "Gen: Foreign exception received.\n",
1316                       USE_GLOBAL_STR_CONSTS);
1317
1318   // Branch to the finally block
1319   builder.CreateBr(finallyBlock);
1320
1321   // Exception Route Block
1322
1323   builder.SetInsertPoint(exceptionRouteBlock);
1324
1325   // Casts exception pointer (_Unwind_Exception instance) to parent
1326   // (OurException instance).
1327   //
1328   // Note: ourBaseFromUnwindOffset is usually negative
1329   llvm::Value *typeInfoThrown = builder.CreatePointerCast(
1330                                   builder.CreateConstGEP1_64(unwindException,
1331                                                        ourBaseFromUnwindOffset),
1332                                   ourExceptionType->getPointerTo());
1333
1334   // Retrieve thrown exception type info type
1335   //
1336   // Note: Index is not relative to pointer but instead to structure
1337   //       unlike a true getelementptr (GEP) instruction
1338   typeInfoThrown = builder.CreateStructGEP(typeInfoThrown, 0);
1339
1340   llvm::Value *typeInfoThrownType =
1341   builder.CreateStructGEP(typeInfoThrown, 0);
1342
1343   generateIntegerPrint(context,
1344                        module,
1345                        builder,
1346                        *toPrint32Int,
1347                        *(builder.CreateLoad(typeInfoThrownType)),
1348                        "Gen: Exception type <%d> received (stack unwound) "
1349                        " in " +
1350                        ourId +
1351                        ".\n",
1352                        USE_GLOBAL_STR_CONSTS);
1353
1354   // Route to matched type info catch block or run cleanup finally block
1355   llvm::SwitchInst *switchToCatchBlock = builder.CreateSwitch(retTypeInfoIndex,
1356                                                           finallyBlock,
1357                                                           numExceptionsToCatch);
1358
1359   unsigned nextTypeToCatch;
1360
1361   for (unsigned i = 1; i <= numExceptionsToCatch; ++i) {
1362     nextTypeToCatch = i - 1;
1363     switchToCatchBlock->addCase(llvm::ConstantInt::get(
1364                                    llvm::Type::getInt32Ty(context), i),
1365                                 catchBlocks[nextTypeToCatch]);
1366   }
1367
1368   llvm::verifyFunction(*ret);
1369   fpm.run(*ret);
1370
1371   return(ret);
1372 }
1373
1374
1375 /// Generates function which throws either an exception matched to a runtime
1376 /// determined type info type (argument to generated function), or if this
1377 /// runtime value matches nativeThrowType, throws a foreign exception by
1378 /// calling nativeThrowFunct.
1379 /// @param module code for module instance
1380 /// @param builder builder instance
1381 /// @param fpm a function pass manager holding optional IR to IR
1382 ///        transformations
1383 /// @param ourId id used to printing purposes
1384 /// @param nativeThrowType a runtime argument of this value results in
1385 ///        nativeThrowFunct being called to generate/throw exception.
1386 /// @param nativeThrowFunct function which will throw a foreign exception
1387 ///        if the above nativeThrowType matches generated function's arg.
1388 /// @returns generated function
1389 static llvm::Function *
1390 createThrowExceptionFunction(llvm::Module &module, llvm::IRBuilder<> &builder,
1391                              llvm::legacy::FunctionPassManager &fpm,
1392                              std::string ourId, int32_t nativeThrowType,
1393                              llvm::Function &nativeThrowFunct) {
1394   llvm::LLVMContext &context = module.getContext();
1395   namedValues.clear();
1396   ArgTypes unwindArgTypes;
1397   unwindArgTypes.push_back(builder.getInt32Ty());
1398   ArgNames unwindArgNames;
1399   unwindArgNames.push_back("exceptTypeToThrow");
1400
1401   llvm::Function *ret = createFunction(module,
1402                                        builder.getVoidTy(),
1403                                        unwindArgTypes,
1404                                        unwindArgNames,
1405                                        ourId,
1406                                        llvm::Function::ExternalLinkage,
1407                                        false,
1408                                        false);
1409
1410   // Throws either one of our exception or a native C++ exception depending
1411   // on a runtime argument value containing a type info type.
1412   llvm::BasicBlock *entryBlock = llvm::BasicBlock::Create(context,
1413                                                           "entry",
1414                                                           ret);
1415   // Throws a foreign exception
1416   llvm::BasicBlock *nativeThrowBlock = llvm::BasicBlock::Create(context,
1417                                                                 "nativeThrow",
1418                                                                 ret);
1419   // Throws one of our Exceptions
1420   llvm::BasicBlock *generatedThrowBlock = llvm::BasicBlock::Create(context,
1421                                                              "generatedThrow",
1422                                                              ret);
1423   // Retrieved runtime type info type to throw
1424   llvm::Value *exceptionType = namedValues["exceptTypeToThrow"];
1425
1426   // nativeThrowBlock block
1427
1428   builder.SetInsertPoint(nativeThrowBlock);
1429
1430   // Throws foreign exception
1431   builder.CreateCall(&nativeThrowFunct, exceptionType);
1432   builder.CreateUnreachable();
1433
1434   // entry block
1435
1436   builder.SetInsertPoint(entryBlock);
1437
1438   llvm::Function *toPrint32Int = module.getFunction("print32Int");
1439   generateIntegerPrint(context,
1440                        module,
1441                        builder,
1442                        *toPrint32Int,
1443                        *exceptionType,
1444                        "\nGen: About to throw exception type <%d> in " +
1445                        ourId +
1446                        ".\n",
1447                        USE_GLOBAL_STR_CONSTS);
1448
1449   // Switches on runtime type info type value to determine whether or not
1450   // a foreign exception is thrown. Defaults to throwing one of our
1451   // generated exceptions.
1452   llvm::SwitchInst *theSwitch = builder.CreateSwitch(exceptionType,
1453                                                      generatedThrowBlock,
1454                                                      1);
1455
1456   theSwitch->addCase(llvm::ConstantInt::get(llvm::Type::getInt32Ty(context),
1457                                             nativeThrowType),
1458                      nativeThrowBlock);
1459
1460   // generatedThrow block
1461
1462   builder.SetInsertPoint(generatedThrowBlock);
1463
1464   llvm::Function *createOurException = module.getFunction("createOurException");
1465   llvm::Function *raiseOurException = module.getFunction(
1466                                         "_Unwind_RaiseException");
1467
1468   // Creates exception to throw with runtime type info type.
1469   llvm::Value *exception = builder.CreateCall(createOurException,
1470                                               namedValues["exceptTypeToThrow"]);
1471
1472   // Throw generated Exception
1473   builder.CreateCall(raiseOurException, exception);
1474   builder.CreateUnreachable();
1475
1476   llvm::verifyFunction(*ret);
1477   fpm.run(*ret);
1478
1479   return(ret);
1480 }
1481
1482 static void createStandardUtilityFunctions(unsigned numTypeInfos,
1483                                            llvm::Module &module,
1484                                            llvm::IRBuilder<> &builder);
1485
1486 /// Creates test code by generating and organizing these functions into the
1487 /// test case. The test case consists of an outer function setup to invoke
1488 /// an inner function within an environment having multiple catch and single
1489 /// finally blocks. This inner function is also setup to invoke a throw
1490 /// function within an evironment similar in nature to the outer function's
1491 /// catch and finally blocks. Each of these two functions catch mutually
1492 /// exclusive subsets (even or odd) of the type info types configured
1493 /// for this this. All generated functions have a runtime argument which
1494 /// holds a type info type to throw that each function takes and passes it
1495 /// to the inner one if such a inner function exists. This type info type is
1496 /// looked at by the generated throw function to see whether or not it should
1497 /// throw a generated exception with the same type info type, or instead call
1498 /// a supplied a function which in turn will throw a foreign exception.
1499 /// @param module code for module instance
1500 /// @param builder builder instance
1501 /// @param fpm a function pass manager holding optional IR to IR
1502 ///        transformations
1503 /// @param nativeThrowFunctName name of external function which will throw
1504 ///        a foreign exception
1505 /// @returns outermost generated test function.
1506 llvm::Function *
1507 createUnwindExceptionTest(llvm::Module &module, llvm::IRBuilder<> &builder,
1508                           llvm::legacy::FunctionPassManager &fpm,
1509                           std::string nativeThrowFunctName) {
1510   // Number of type infos to generate
1511   unsigned numTypeInfos = 6;
1512
1513   // Initialze intrisics and external functions to use along with exception
1514   // and type info globals.
1515   createStandardUtilityFunctions(numTypeInfos,
1516                                  module,
1517                                  builder);
1518   llvm::Function *nativeThrowFunct = module.getFunction(nativeThrowFunctName);
1519
1520   // Create exception throw function using the value ~0 to cause
1521   // foreign exceptions to be thrown.
1522   llvm::Function *throwFunct = 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 = createCatchWrappedInvokeFunction(module,
1535                                                     builder,
1536                                                     fpm,
1537                                                     *throwFunct,
1538                                                     "innerCatchFunct",
1539                                                     numExceptionTypesToCatch,
1540                                                     innerExceptionTypesToCatch);
1541
1542   // Outer function will catch odd type infos
1543   unsigned outerExceptionTypesToCatch[] = {3, 1, 5};
1544   numExceptionTypesToCatch = sizeof(outerExceptionTypesToCatch) /
1545   sizeof(unsigned);
1546
1547   // Generate outer function
1548   llvm::Function *outerCatchFunct = createCatchWrappedInvokeFunction(module,
1549                                                     builder,
1550                                                     fpm,
1551                                                     *innerCatchFunct,
1552                                                     "outerCatchFunct",
1553                                                     numExceptionTypesToCatch,
1554                                                     outerExceptionTypesToCatch);
1555
1556   // Return outer function to run
1557   return(outerCatchFunct);
1558 }
1559
1560 namespace {
1561 /// Represents our foreign exceptions
1562 class OurCppRunException : public std::runtime_error {
1563 public:
1564   OurCppRunException(const std::string reason) :
1565   std::runtime_error(reason) {}
1566
1567   OurCppRunException (const OurCppRunException &toCopy) :
1568   std::runtime_error(toCopy) {}
1569
1570   OurCppRunException &operator = (const OurCppRunException &toCopy) {
1571     return(reinterpret_cast<OurCppRunException&>(
1572                                  std::runtime_error::operator=(toCopy)));
1573   }
1574
1575   virtual ~OurCppRunException (void) throw () {}
1576 };
1577 } // end anonymous namespace
1578
1579 /// Throws foreign C++ exception.
1580 /// @param ignoreIt unused parameter that allows function to match implied
1581 ///        generated function contract.
1582 extern "C"
1583 void throwCppException (int32_t ignoreIt) {
1584   throw(OurCppRunException("thrown by throwCppException(...)"));
1585 }
1586
1587 typedef void (*OurExceptionThrowFunctType) (int32_t typeToThrow);
1588
1589 /// This is a test harness which runs test by executing generated
1590 /// function with a type info type to throw. Harness wraps the execution
1591 /// of generated function in a C++ try catch clause.
1592 /// @param engine execution engine to use for executing generated function.
1593 ///        This demo program expects this to be a JIT instance for demo
1594 ///        purposes.
1595 /// @param function generated test function to run
1596 /// @param typeToThrow type info type of generated exception to throw, or
1597 ///        indicator to cause foreign exception to be thrown.
1598 static
1599 void runExceptionThrow(llvm::ExecutionEngine *engine,
1600                        llvm::Function *function,
1601                        int32_t typeToThrow) {
1602
1603   // Find test's function pointer
1604   OurExceptionThrowFunctType functPtr =
1605     reinterpret_cast<OurExceptionThrowFunctType>(
1606        reinterpret_cast<intptr_t>(engine->getPointerToFunction(function)));
1607
1608   try {
1609     // Run test
1610     (*functPtr)(typeToThrow);
1611   }
1612   catch (OurCppRunException exc) {
1613     // Catch foreign C++ exception
1614     fprintf(stderr,
1615             "\nrunExceptionThrow(...):In C++ catch OurCppRunException "
1616             "with reason: %s.\n",
1617             exc.what());
1618   }
1619   catch (...) {
1620     // Catch all exceptions including our generated ones. This latter
1621     // functionality works according to the example in rules 1.6.4 of
1622     // http://mentorembedded.github.com/cxx-abi/abi-eh.html (v1.22),
1623     // given that these will be exceptions foreign to C++
1624     // (the _Unwind_Exception::exception_class should be different from
1625     // the one used by C++).
1626     fprintf(stderr,
1627             "\nrunExceptionThrow(...):In C++ catch all.\n");
1628   }
1629 }
1630
1631 //
1632 // End test functions
1633 //
1634
1635 typedef llvm::ArrayRef<llvm::Type*> TypeArray;
1636
1637 /// This initialization routine creates type info globals and
1638 /// adds external function declarations to module.
1639 /// @param numTypeInfos number of linear type info associated type info types
1640 ///        to create as GlobalVariable instances, starting with the value 1.
1641 /// @param module code for module instance
1642 /// @param builder builder instance
1643 static void createStandardUtilityFunctions(unsigned numTypeInfos,
1644                                            llvm::Module &module,
1645                                            llvm::IRBuilder<> &builder) {
1646
1647   llvm::LLVMContext &context = module.getContext();
1648
1649   // Exception initializations
1650
1651   // Setup exception catch state
1652   ourExceptionNotThrownState =
1653     llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 0),
1654   ourExceptionThrownState =
1655     llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 1),
1656   ourExceptionCaughtState =
1657     llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 2),
1658
1659
1660
1661   // Create our type info type
1662   ourTypeInfoType = llvm::StructType::get(context,
1663                                           TypeArray(builder.getInt32Ty()));
1664
1665   llvm::Type *caughtResultFieldTypes[] = {
1666     builder.getInt8PtrTy(),
1667     builder.getInt32Ty()
1668   };
1669
1670   // Create our landingpad result type
1671   ourCaughtResultType = llvm::StructType::get(context,
1672                                             TypeArray(caughtResultFieldTypes));
1673
1674   // Create OurException type
1675   ourExceptionType = llvm::StructType::get(context,
1676                                            TypeArray(ourTypeInfoType));
1677
1678   // Create portion of _Unwind_Exception type
1679   //
1680   // Note: Declaring only a portion of the _Unwind_Exception struct.
1681   //       Does this cause problems?
1682   ourUnwindExceptionType =
1683     llvm::StructType::get(context,
1684                     TypeArray(builder.getInt64Ty()));
1685
1686   struct OurBaseException_t dummyException;
1687
1688   // Calculate offset of OurException::unwindException member.
1689   ourBaseFromUnwindOffset = ((uintptr_t) &dummyException) -
1690                             ((uintptr_t) &(dummyException.unwindException));
1691
1692 #ifdef DEBUG
1693   fprintf(stderr,
1694           "createStandardUtilityFunctions(...):ourBaseFromUnwindOffset "
1695           "= %lld, sizeof(struct OurBaseException_t) - "
1696           "sizeof(struct _Unwind_Exception) = %lu.\n",
1697           ourBaseFromUnwindOffset,
1698           sizeof(struct OurBaseException_t) -
1699           sizeof(struct _Unwind_Exception));
1700 #endif
1701
1702   size_t numChars = sizeof(ourBaseExcpClassChars) / sizeof(char);
1703
1704   // Create our _Unwind_Exception::exception_class value
1705   ourBaseExceptionClass = genClass(ourBaseExcpClassChars, numChars);
1706
1707   // Type infos
1708
1709   std::string baseStr = "typeInfo", typeInfoName;
1710   std::ostringstream typeInfoNameBuilder;
1711   std::vector<llvm::Constant*> structVals;
1712
1713   llvm::Constant *nextStruct;
1714
1715   // Generate each type info
1716   //
1717   // Note: First type info is not used.
1718   for (unsigned i = 0; i <= numTypeInfos; ++i) {
1719     structVals.clear();
1720     structVals.push_back(llvm::ConstantInt::get(builder.getInt32Ty(), i));
1721     nextStruct = llvm::ConstantStruct::get(ourTypeInfoType, structVals);
1722
1723     typeInfoNameBuilder.str("");
1724     typeInfoNameBuilder << baseStr << i;
1725     typeInfoName = typeInfoNameBuilder.str();
1726
1727     // Note: Does not seem to work without allocation
1728     new llvm::GlobalVariable(module,
1729                              ourTypeInfoType,
1730                              true,
1731                              llvm::GlobalValue::ExternalLinkage,
1732                              nextStruct,
1733                              typeInfoName);
1734
1735     ourTypeInfoNames.push_back(typeInfoName);
1736     ourTypeInfoNamesIndex[i] = typeInfoName;
1737   }
1738
1739   ArgNames argNames;
1740   ArgTypes argTypes;
1741   llvm::Function *funct = NULL;
1742
1743   // print32Int
1744
1745   llvm::Type *retType = builder.getVoidTy();
1746
1747   argTypes.clear();
1748   argTypes.push_back(builder.getInt32Ty());
1749   argTypes.push_back(builder.getInt8PtrTy());
1750
1751   argNames.clear();
1752
1753   createFunction(module,
1754                  retType,
1755                  argTypes,
1756                  argNames,
1757                  "print32Int",
1758                  llvm::Function::ExternalLinkage,
1759                  true,
1760                  false);
1761
1762   // print64Int
1763
1764   retType = builder.getVoidTy();
1765
1766   argTypes.clear();
1767   argTypes.push_back(builder.getInt64Ty());
1768   argTypes.push_back(builder.getInt8PtrTy());
1769
1770   argNames.clear();
1771
1772   createFunction(module,
1773                  retType,
1774                  argTypes,
1775                  argNames,
1776                  "print64Int",
1777                  llvm::Function::ExternalLinkage,
1778                  true,
1779                  false);
1780
1781   // printStr
1782
1783   retType = builder.getVoidTy();
1784
1785   argTypes.clear();
1786   argTypes.push_back(builder.getInt8PtrTy());
1787
1788   argNames.clear();
1789
1790   createFunction(module,
1791                  retType,
1792                  argTypes,
1793                  argNames,
1794                  "printStr",
1795                  llvm::Function::ExternalLinkage,
1796                  true,
1797                  false);
1798
1799   // throwCppException
1800
1801   retType = builder.getVoidTy();
1802
1803   argTypes.clear();
1804   argTypes.push_back(builder.getInt32Ty());
1805
1806   argNames.clear();
1807
1808   createFunction(module,
1809                  retType,
1810                  argTypes,
1811                  argNames,
1812                  "throwCppException",
1813                  llvm::Function::ExternalLinkage,
1814                  true,
1815                  false);
1816
1817   // deleteOurException
1818
1819   retType = builder.getVoidTy();
1820
1821   argTypes.clear();
1822   argTypes.push_back(builder.getInt8PtrTy());
1823
1824   argNames.clear();
1825
1826   createFunction(module,
1827                  retType,
1828                  argTypes,
1829                  argNames,
1830                  "deleteOurException",
1831                  llvm::Function::ExternalLinkage,
1832                  true,
1833                  false);
1834
1835   // createOurException
1836
1837   retType = builder.getInt8PtrTy();
1838
1839   argTypes.clear();
1840   argTypes.push_back(builder.getInt32Ty());
1841
1842   argNames.clear();
1843
1844   createFunction(module,
1845                  retType,
1846                  argTypes,
1847                  argNames,
1848                  "createOurException",
1849                  llvm::Function::ExternalLinkage,
1850                  true,
1851                  false);
1852
1853   // _Unwind_RaiseException
1854
1855   retType = builder.getInt32Ty();
1856
1857   argTypes.clear();
1858   argTypes.push_back(builder.getInt8PtrTy());
1859
1860   argNames.clear();
1861
1862   funct = createFunction(module,
1863                          retType,
1864                          argTypes,
1865                          argNames,
1866                          "_Unwind_RaiseException",
1867                          llvm::Function::ExternalLinkage,
1868                          true,
1869                          false);
1870
1871   funct->setDoesNotReturn();
1872
1873   // _Unwind_Resume
1874
1875   retType = builder.getInt32Ty();
1876
1877   argTypes.clear();
1878   argTypes.push_back(builder.getInt8PtrTy());
1879
1880   argNames.clear();
1881
1882   funct = createFunction(module,
1883                          retType,
1884                          argTypes,
1885                          argNames,
1886                          "_Unwind_Resume",
1887                          llvm::Function::ExternalLinkage,
1888                          true,
1889                          false);
1890
1891   funct->setDoesNotReturn();
1892
1893   // ourPersonality
1894
1895   retType = builder.getInt32Ty();
1896
1897   argTypes.clear();
1898   argTypes.push_back(builder.getInt32Ty());
1899   argTypes.push_back(builder.getInt32Ty());
1900   argTypes.push_back(builder.getInt64Ty());
1901   argTypes.push_back(builder.getInt8PtrTy());
1902   argTypes.push_back(builder.getInt8PtrTy());
1903
1904   argNames.clear();
1905
1906   createFunction(module,
1907                  retType,
1908                  argTypes,
1909                  argNames,
1910                  "ourPersonality",
1911                  llvm::Function::ExternalLinkage,
1912                  true,
1913                  false);
1914
1915   // llvm.eh.typeid.for intrinsic
1916
1917   getDeclaration(&module, llvm::Intrinsic::eh_typeid_for);
1918 }
1919
1920
1921 //===----------------------------------------------------------------------===//
1922 // Main test driver code.
1923 //===----------------------------------------------------------------------===//
1924
1925 /// Demo main routine which takes the type info types to throw. A test will
1926 /// be run for each given type info type. While type info types with the value
1927 /// of -1 will trigger a foreign C++ exception to be thrown; type info types
1928 /// <= 6 and >= 1 will be caught by test functions; and type info types > 6
1929 /// will result in exceptions which pass through to the test harness. All other
1930 /// type info types are not supported and could cause a crash.
1931 int main(int argc, char *argv[]) {
1932   if (argc == 1) {
1933     fprintf(stderr,
1934             "\nUsage: ExceptionDemo <exception type to throw> "
1935             "[<type 2>...<type n>].\n"
1936             "   Each type must have the value of 1 - 6 for "
1937             "generated exceptions to be caught;\n"
1938             "   the value -1 for foreign C++ exceptions to be "
1939             "generated and thrown;\n"
1940             "   or the values > 6 for exceptions to be ignored.\n"
1941             "\nTry: ExceptionDemo 2 3 7 -1\n"
1942             "   for a full test.\n\n");
1943     return(0);
1944   }
1945
1946   // If not set, exception handling will not be turned on
1947   llvm::TargetOptions Opts;
1948
1949   llvm::InitializeNativeTarget();
1950   llvm::InitializeNativeTargetAsmPrinter();
1951   llvm::LLVMContext &context = llvm::getGlobalContext();
1952   llvm::IRBuilder<> theBuilder(context);
1953
1954   // Make the module, which holds all the code.
1955   std::unique_ptr<llvm::Module> Owner =
1956       llvm::make_unique<llvm::Module>("my cool jit", context);
1957   llvm::Module *module = Owner.get();
1958
1959   std::unique_ptr<llvm::RTDyldMemoryManager> MemMgr(new llvm::SectionMemoryManager());
1960
1961   // Build engine with JIT
1962   llvm::EngineBuilder factory(std::move(Owner));
1963   factory.setEngineKind(llvm::EngineKind::JIT);
1964   factory.setTargetOptions(Opts);
1965   factory.setMCJITMemoryManager(std::move(MemMgr));
1966   llvm::ExecutionEngine *executionEngine = factory.create();
1967
1968   {
1969     llvm::legacy::FunctionPassManager fpm(module);
1970
1971     // Set up the optimizer pipeline.
1972     // Start with registering info about how the
1973     // target lays out data structures.
1974     module->setDataLayout(executionEngine->getDataLayout());
1975     fpm.add(new llvm::DataLayoutPass());
1976
1977     // Optimizations turned on
1978 #ifdef ADD_OPT_PASSES
1979
1980     // Basic AliasAnslysis support for GVN.
1981     fpm.add(llvm::createBasicAliasAnalysisPass());
1982
1983     // Promote allocas to registers.
1984     fpm.add(llvm::createPromoteMemoryToRegisterPass());
1985
1986     // Do simple "peephole" optimizations and bit-twiddling optzns.
1987     fpm.add(llvm::createInstructionCombiningPass());
1988
1989     // Reassociate expressions.
1990     fpm.add(llvm::createReassociatePass());
1991
1992     // Eliminate Common SubExpressions.
1993     fpm.add(llvm::createGVNPass());
1994
1995     // Simplify the control flow graph (deleting unreachable
1996     // blocks, etc).
1997     fpm.add(llvm::createCFGSimplificationPass());
1998 #endif  // ADD_OPT_PASSES
1999
2000     fpm.doInitialization();
2001
2002     // Generate test code using function throwCppException(...) as
2003     // the function which throws foreign exceptions.
2004     llvm::Function *toRun =
2005     createUnwindExceptionTest(*module,
2006                               theBuilder,
2007                               fpm,
2008                               "throwCppException");
2009
2010     executionEngine->finalizeObject();
2011
2012     fprintf(stderr, "\nBegin module dump:\n\n");
2013
2014     module->dump();
2015
2016     fprintf(stderr, "\nEnd module dump:\n");
2017
2018     fprintf(stderr, "\n\nBegin Test:\n");
2019
2020     for (int i = 1; i < argc; ++i) {
2021       // Run test for each argument whose value is the exception
2022       // type to throw.
2023       runExceptionThrow(executionEngine,
2024                         toRun,
2025                         (unsigned) strtoul(argv[i], NULL, 10));
2026     }
2027
2028     fprintf(stderr, "\nEnd Test:\n\n");
2029   }
2030
2031   delete executionEngine;
2032
2033   return 0;
2034 }