examples/ExceptionDemo/ExceptionDemo.cpp

   1 //===-- ExceptionDemo.cpp - An example using llvm Exceptions --------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // Demo program which implements an example LLVM exception implementation, and
  11 // shows several test cases including the handling of foreign exceptions.
  12 // It is run with type info types arguments to throw. A test will
  13 // be run for each given type info type. While type info types with the value
  14 // of -1 will trigger a foreign C++ exception to be thrown; type info types
  15 // <= 6 and >= 1 will cause the associated generated exceptions to be thrown
  16 // and caught by generated test functions; and type info types > 6
  17 // will result in exceptions which pass through to the test harness. All other
  18 // type info types are not supported and could cause a crash. In all cases,
  19 // the "finally" blocks of every generated test functions will executed
  20 // regardless of whether or not that test function ignores or catches the
  21 // thrown exception.
  22 //
  23 // examples:
  24 //
  25 // ExceptionDemo
  26 //
  27 //     causes a usage to be printed to stderr
  28 //
  29 // ExceptionDemo 2 3 7 -1
  30 //
  31 //     results in the following cases:
  32 //         - Value 2 causes an exception with a type info type of 2 to be
  33 //           thrown and caught by an inner generated test function.
  34 //         - Value 3 causes an exception with a type info type of 3 to be
  35 //           thrown and caught by an outer generated test function.
  36 //         - Value 7 causes an exception with a type info type of 7 to be
  37 //           thrown and NOT be caught by any generated function.
  38 //         - Value -1 causes a foreign C++ exception to be thrown and not be
  39 //           caught by any generated function
  40 //
  41 //     Cases -1 and 7 are caught by a C++ test harness where the validity of
  42 //         of a C++ catch(...) clause catching a generated exception with a
  43 //         type info type of 7 is explained by: example in rules 1.6.4 in
  44 //         http://sourcery.mentor.com/public/cxx-abi/abi-eh.html (v1.22)
  45 //
  46 // This code uses code from the llvm compiler-rt project and the llvm
  47 // Kaleidoscope project.
  48 //
  49 //===----------------------------------------------------------------------===//
  50
  51 #include "llvm/LLVMContext.h"
  52 #include "llvm/DerivedTypes.h"
  53 #include "llvm/ExecutionEngine/ExecutionEngine.h"
  54 #include "llvm/ExecutionEngine/JIT.h"
  55 #include "llvm/Module.h"
  56 #include "llvm/PassManager.h"
  57 #include "llvm/Intrinsics.h"
  58 #include "llvm/Analysis/Verifier.h"
  59 #include "llvm/Target/TargetData.h"
  60 #include "llvm/Target/TargetOptions.h"
  61 #include "llvm/Transforms/Scalar.h"
  62 #include "llvm/Support/IRBuilder.h"
  63 #include "llvm/Support/Dwarf.h"
  64 #include "llvm/Support/TargetSelect.h"
  65
  66 #ifdef OLD_EXC_SYSTEM
  67 // See use of UpgradeExceptionHandling(...) below
  68 #include "llvm/AutoUpgrade.h"
  69 #endif
  70
  71 // FIXME: Although all systems tested with (Linux, OS X), do not need this
  72 //        header file included. A user on ubuntu reported, undefined symbols
  73 //        for stderr, and fprintf, and the addition of this include fixed the
  74 //        issue for them. Given that LLVM's best practices include the goal
  75 //        of reducing the number of redundant header files included, the
  76 //        correct solution would be to find out why these symbols are not
  77 //        defined for the system in question, and fix the issue by finding out
  78 //        which LLVM header file, if any, would include these symbols.
  79 #include <cstdio>
  80
  81 #include <sstream>
  82 #include <stdexcept>
  83
  84
  85 #ifndef USE_GLOBAL_STR_CONSTS
  86 #define USE_GLOBAL_STR_CONSTS true
  87 #endif
  88
  89 // System C++ ABI unwind types from:
  90 //     http://sourcery.mentor.com/public/cxx-abi/abi-eh.html (v1.22)
  91
  92 extern "C" {
  93
  94   typedef enum {
  95     _URC_NO_REASON = 0,
  96     _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
  97     _URC_FATAL_PHASE2_ERROR = 2,
  98     _URC_FATAL_PHASE1_ERROR = 3,
  99     _URC_NORMAL_STOP = 4,
 100     _URC_END_OF_STACK = 5,
 101     _URC_HANDLER_FOUND = 6,
 102     _URC_INSTALL_CONTEXT = 7,
 103     _URC_CONTINUE_UNWIND = 8
 104   } _Unwind_Reason_Code;
 105
 106   typedef enum {
 107     _UA_SEARCH_PHASE = 1,
 108     _UA_CLEANUP_PHASE = 2,
 109     _UA_HANDLER_FRAME = 4,
 110     _UA_FORCE_UNWIND = 8,
 111     _UA_END_OF_STACK = 16
 112   } _Unwind_Action;
 113
 114   struct _Unwind_Exception;
 115
 116   typedef void (*_Unwind_Exception_Cleanup_Fn) (_Unwind_Reason_Code,
 117                                                 struct _Unwind_Exception *);
 118
 119   struct _Unwind_Exception {
 120     uint64_t exception_class;
 121     _Unwind_Exception_Cleanup_Fn exception_cleanup;
 122
 123     uintptr_t private_1;
 124     uintptr_t private_2;
 125
 126     // @@@ The IA-64 ABI says that this structure must be double-word aligned.
 127     //  Taking that literally does not make much sense generically.  Instead
 128     //  we provide the maximum alignment required by any type for the machine.
 129   } __attribute__((__aligned__));
 130
 131   struct _Unwind_Context;
 132   typedef struct _Unwind_Context *_Unwind_Context_t;
 133
 134   extern const uint8_t *_Unwind_GetLanguageSpecificData (_Unwind_Context_t c);
 135   extern uintptr_t _Unwind_GetGR (_Unwind_Context_t c, int i);
 136   extern void _Unwind_SetGR (_Unwind_Context_t c, int i, uintptr_t n);
 137   extern void _Unwind_SetIP (_Unwind_Context_t, uintptr_t new_value);
 138   extern uintptr_t _Unwind_GetIP (_Unwind_Context_t context);
 139   extern uintptr_t _Unwind_GetRegionStart (_Unwind_Context_t context);
 140
 141 } // extern "C"
 142
 143 //
 144 // Example types
 145 //
 146
 147 /// This is our simplistic type info
 148 struct OurExceptionType_t {
 149   /// type info type
 150   int type;
 151 };
 152
 153
 154 /// This is our Exception class which relies on a negative offset to calculate
 155 /// pointers to its instances from pointers to its unwindException member.
 156 ///
 157 /// Note: The above unwind.h defines struct _Unwind_Exception to be aligned
 158 ///       on a double word boundary. This is necessary to match the standard:
 159 ///       http://refspecs.freestandards.org/abi-eh-1.21.html
 160 struct OurBaseException_t {
 161   struct OurExceptionType_t type;
 162
 163   // Note: This is properly aligned in unwind.h
 164   struct _Unwind_Exception unwindException;
 165 };
 166
 167
 168 // Note: Not needed since we are C++
 169 typedef struct OurBaseException_t OurException;
 170 typedef struct _Unwind_Exception OurUnwindException;
 171
 172 //
 173 // Various globals used to support typeinfo and generatted exceptions in
 174 // general
 175 //
 176
 177 static std::map<std::string, llvm::Value*> namedValues;
 178
 179 int64_t ourBaseFromUnwindOffset;
 180
 181 const unsigned char ourBaseExcpClassChars[] =
 182 {'o', 'b', 'j', '\0', 'b', 'a', 's', '\0'};
 183
 184
 185 static uint64_t ourBaseExceptionClass = 0;
 186
 187 static std::vector<std::string> ourTypeInfoNames;
 188 static std::map<int, std::string> ourTypeInfoNamesIndex;
 189
 190 static llvm::StructType *ourTypeInfoType;
 191 #ifndef OLD_EXC_SYSTEM
 192 static llvm::StructType *ourCaughtResultType;
 193 #endif
 194 static llvm::StructType *ourExceptionType;
 195 static llvm::StructType *ourUnwindExceptionType;
 196
 197 static llvm::ConstantInt *ourExceptionNotThrownState;
 198 static llvm::ConstantInt *ourExceptionThrownState;
 199 static llvm::ConstantInt *ourExceptionCaughtState;
 200
 201 typedef std::vector<std::string> ArgNames;
 202 typedef std::vector<llvm::Type*> ArgTypes;
 203
 204 //
 205 // Code Generation Utilities
 206 //
 207
 208 /// Utility used to create a function, both declarations and definitions
 209 /// @param module for module instance
 210 /// @param retType function return type
 211 /// @param theArgTypes function's ordered argument types
 212 /// @param theArgNames function's ordered arguments needed if use of this
 213 ///        function corresponds to a function definition. Use empty
 214 ///        aggregate for function declarations.
 215 /// @param functName function name
 216 /// @param linkage function linkage
 217 /// @param declarationOnly for function declarations
 218 /// @param isVarArg function uses vararg arguments
 219 /// @returns function instance
 220 llvm::Function *createFunction(llvm::Module &module,
 221                                llvm::Type *retType,
 222                                const ArgTypes &theArgTypes,
 223                                const ArgNames &theArgNames,
 224                                const std::string &functName,
 225                                llvm::GlobalValue::LinkageTypes linkage,
 226                                bool declarationOnly,
 227                                bool isVarArg) {
 228   llvm::FunctionType *functType =
 229     llvm::FunctionType::get(retType, theArgTypes, isVarArg);
 230   llvm::Function *ret =
 231     llvm::Function::Create(functType, linkage, functName, &module);
 232   if (!ret || declarationOnly)
 233     return(ret);
 234
 235   namedValues.clear();
 236   unsigned i = 0;
 237   for (llvm::Function::arg_iterator argIndex = ret->arg_begin();
 238        i != theArgNames.size();
 239        ++argIndex, ++i) {
 240
 241     argIndex->setName(theArgNames[i]);
 242     namedValues[theArgNames[i]] = argIndex;
 243   }
 244
 245   return(ret);
 246 }
 247
 248
 249 /// Create an alloca instruction in the entry block of
 250 /// the parent function.  This is used for mutable variables etc.
 251 /// @param function parent instance
 252 /// @param varName stack variable name
 253 /// @param type stack variable type
 254 /// @param initWith optional constant initialization value
 255 /// @returns AllocaInst instance
 256 static llvm::AllocaInst *createEntryBlockAlloca(llvm::Function &function,
 257                                                 const std::string &varName,
 258                                                 llvm::Type *type,
 259                                                 llvm::Constant *initWith = 0) {
 260   llvm::BasicBlock &block = function.getEntryBlock();
 261   llvm::IRBuilder<> tmp(&block, block.begin());
 262   llvm::AllocaInst *ret = tmp.CreateAlloca(type, 0, varName.c_str());
 263
 264   if (initWith)
 265     tmp.CreateStore(initWith, ret);
 266
 267   return(ret);
 268 }
 269
 270
 271 //
 272 // Code Generation Utilities End
 273 //
 274
 275 //
 276 // Runtime C Library functions
 277 //
 278
 279 // Note: using an extern "C" block so that static functions can be used
 280 extern "C" {
 281
 282 // Note: Better ways to decide on bit width
 283 //
 284 /// Prints a 32 bit number, according to the format, to stderr.
 285 /// @param intToPrint integer to print
 286 /// @param format printf like format to use when printing
 287 void print32Int(int intToPrint, const char *format) {
 288   if (format) {
 289     // Note: No NULL check
 290     fprintf(stderr, format, intToPrint);
 291   }
 292   else {
 293     // Note: No NULL check
 294     fprintf(stderr, "::print32Int(...):NULL arg.\n");
 295   }
 296 }
 297
 298
 299 // Note: Better ways to decide on bit width
 300 //
 301 /// Prints a 64 bit number, according to the format, to stderr.
 302 /// @param intToPrint integer to print
 303 /// @param format printf like format to use when printing
 304 void print64Int(long int intToPrint, const char *format) {
 305   if (format) {
 306     // Note: No NULL check
 307     fprintf(stderr, format, intToPrint);
 308   }
 309   else {
 310     // Note: No NULL check
 311     fprintf(stderr, "::print64Int(...):NULL arg.\n");
 312   }
 313 }
 314
 315
 316 /// Prints a C string to stderr
 317 /// @param toPrint string to print
 318 void printStr(char *toPrint) {
 319   if (toPrint) {
 320     fprintf(stderr, "%s", toPrint);
 321   }
 322   else {
 323     fprintf(stderr, "::printStr(...):NULL arg.\n");
 324   }
 325 }
 326
 327
 328 /// Deletes the true previosly allocated exception whose address
 329 /// is calculated from the supplied OurBaseException_t::unwindException
 330 /// member address. Handles (ignores), NULL pointers.
 331 /// @param expToDelete exception to delete
 332 void deleteOurException(OurUnwindException *expToDelete) {
 333 #ifdef DEBUG
 334   fprintf(stderr,
 335           "deleteOurException(...).\n");
 336 #endif
 337
 338   if (expToDelete &&
 339       (expToDelete->exception_class == ourBaseExceptionClass)) {
 340
 341     free(((char*) expToDelete) + ourBaseFromUnwindOffset);
 342   }
 343 }
 344
 345
 346 /// This function is the struct _Unwind_Exception API mandated delete function
 347 /// used by foreign exception handlers when deleting our exception
 348 /// (OurException), instances.
 349 /// @param reason @link http://refspecs.freestandards.org/abi-eh-1.21.html
 350 /// @unlink
 351 /// @param expToDelete exception instance to delete
 352 void deleteFromUnwindOurException(_Unwind_Reason_Code reason,
 353                                   OurUnwindException *expToDelete) {
 354 #ifdef DEBUG
 355   fprintf(stderr,
 356           "deleteFromUnwindOurException(...).\n");
 357 #endif
 358
 359   deleteOurException(expToDelete);
 360 }
 361
 362
 363 /// Creates (allocates on the heap), an exception (OurException instance),
 364 /// of the supplied type info type.
 365 /// @param type type info type
 366 OurUnwindException *createOurException(int type) {
 367   size_t size = sizeof(OurException);
 368   OurException *ret = (OurException*) memset(malloc(size), 0, size);
 369   (ret->type).type = type;
 370   (ret->unwindException).exception_class = ourBaseExceptionClass;
 371   (ret->unwindException).exception_cleanup = deleteFromUnwindOurException;
 372
 373   return(&(ret->unwindException));
 374 }
 375
 376
 377 /// Read a uleb128 encoded value and advance pointer
 378 /// See Variable Length Data in:
 379 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 380 /// @param data reference variable holding memory pointer to decode from
 381 /// @returns decoded value
 382 static uintptr_t readULEB128(const uint8_t **data) {
 383   uintptr_t result = 0;
 384   uintptr_t shift = 0;
 385   unsigned char byte;
 386   const uint8_t *p = *data;
 387
 388   do {
 389     byte = *p++;
 390     result |= (byte & 0x7f) << shift;
 391     shift += 7;
 392   }
 393   while (byte & 0x80);
 394
 395   *data = p;
 396
 397   return result;
 398 }
 399
 400
 401 /// Read a sleb128 encoded value and advance pointer
 402 /// See Variable Length Data in:
 403 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 404 /// @param data reference variable holding memory pointer to decode from
 405 /// @returns decoded value
 406 static uintptr_t readSLEB128(const uint8_t **data) {
 407   uintptr_t result = 0;
 408   uintptr_t shift = 0;
 409   unsigned char byte;
 410   const uint8_t *p = *data;
 411
 412   do {
 413     byte = *p++;
 414     result |= (byte & 0x7f) << shift;
 415     shift += 7;
 416   }
 417   while (byte & 0x80);
 418
 419   *data = p;
 420
 421   if ((byte & 0x40) && (shift < (sizeof(result) << 3))) {
 422     result |= (~0 << shift);
 423   }
 424
 425   return result;
 426 }
 427
 428
 429 /// Read a pointer encoded value and advance pointer
 430 /// See Variable Length Data in:
 431 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 432 /// @param data reference variable holding memory pointer to decode from
 433 /// @param encoding dwarf encoding type
 434 /// @returns decoded value
 435 static uintptr_t readEncodedPointer(const uint8_t **data, uint8_t encoding) {
 436   uintptr_t result = 0;
 437   const uint8_t *p = *data;
 438
 439   if (encoding == llvm::dwarf::DW_EH_PE_omit)
 440     return(result);
 441
 442   // first get value
 443   switch (encoding & 0x0F) {
 444     case llvm::dwarf::DW_EH_PE_absptr:
 445       result = *((uintptr_t*)p);
 446       p += sizeof(uintptr_t);
 447       break;
 448     case llvm::dwarf::DW_EH_PE_uleb128:
 449       result = readULEB128(&p);
 450       break;
 451       // Note: This case has not been tested
 452     case llvm::dwarf::DW_EH_PE_sleb128:
 453       result = readSLEB128(&p);
 454       break;
 455     case llvm::dwarf::DW_EH_PE_udata2:
 456       result = *((uint16_t*)p);
 457       p += sizeof(uint16_t);
 458       break;
 459     case llvm::dwarf::DW_EH_PE_udata4:
 460       result = *((uint32_t*)p);
 461       p += sizeof(uint32_t);
 462       break;
 463     case llvm::dwarf::DW_EH_PE_udata8:
 464       result = *((uint64_t*)p);
 465       p += sizeof(uint64_t);
 466       break;
 467     case llvm::dwarf::DW_EH_PE_sdata2:
 468       result = *((int16_t*)p);
 469       p += sizeof(int16_t);
 470       break;
 471     case llvm::dwarf::DW_EH_PE_sdata4:
 472       result = *((int32_t*)p);
 473       p += sizeof(int32_t);
 474       break;
 475     case llvm::dwarf::DW_EH_PE_sdata8:
 476       result = *((int64_t*)p);
 477       p += sizeof(int64_t);
 478       break;
 479     default:
 480       // not supported
 481       abort();
 482       break;
 483   }
 484
 485   // then add relative offset
 486   switch (encoding & 0x70) {
 487     case llvm::dwarf::DW_EH_PE_absptr:
 488       // do nothing
 489       break;
 490     case llvm::dwarf::DW_EH_PE_pcrel:
 491       result += (uintptr_t)(*data);
 492       break;
 493     case llvm::dwarf::DW_EH_PE_textrel:
 494     case llvm::dwarf::DW_EH_PE_datarel:
 495     case llvm::dwarf::DW_EH_PE_funcrel:
 496     case llvm::dwarf::DW_EH_PE_aligned:
 497     default:
 498       // not supported
 499       abort();
 500       break;
 501   }
 502
 503   // then apply indirection
 504   if (encoding & llvm::dwarf::DW_EH_PE_indirect) {
 505     result = *((uintptr_t*)result);
 506   }
 507
 508   *data = p;
 509
 510   return result;
 511 }
 512
 513
 514 /// Deals with Dwarf actions matching our type infos
 515 /// (OurExceptionType_t instances). Returns whether or not a dwarf emitted
 516 /// action matches the supplied exception type. If such a match succeeds,
 517 /// the resultAction argument will be set with > 0 index value. Only
 518 /// corresponding llvm.eh.selector type info arguments, cleanup arguments
 519 /// are supported. Filters are not supported.
 520 /// See Variable Length Data in:
 521 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 522 /// Also see @link http://refspecs.freestandards.org/abi-eh-1.21.html @unlink
 523 /// @param resultAction reference variable which will be set with result
 524 /// @param classInfo our array of type info pointers (to globals)
 525 /// @param actionEntry index into above type info array or 0 (clean up).
 526 ///        We do not support filters.
 527 /// @param exceptionClass exception class (_Unwind_Exception::exception_class)
 528 ///        of thrown exception.
 529 /// @param exceptionObject thrown _Unwind_Exception instance.
 530 /// @returns whether or not a type info was found. False is returned if only
 531 ///          a cleanup was found
 532 static bool handleActionValue(int64_t *resultAction,
 533                               struct OurExceptionType_t **classInfo,
 534                               uintptr_t actionEntry,
 535                               uint64_t exceptionClass,
 536                               struct _Unwind_Exception *exceptionObject) {
 537   bool ret = false;
 538
 539   if (!resultAction ||
 540       !exceptionObject ||
 541       (exceptionClass != ourBaseExceptionClass))
 542     return(ret);
 543
 544   struct OurBaseException_t *excp = (struct OurBaseException_t*)
 545   (((char*) exceptionObject) + ourBaseFromUnwindOffset);
 546   struct OurExceptionType_t *excpType = &(excp->type);
 547   int type = excpType->type;
 548
 549 #ifdef DEBUG
 550   fprintf(stderr,
 551           "handleActionValue(...): exceptionObject = <%p>, "
 552           "excp = <%p>.\n",
 553           exceptionObject,
 554           excp);
 555 #endif
 556
 557   const uint8_t *actionPos = (uint8_t*) actionEntry,
 558   *tempActionPos;
 559   int64_t typeOffset = 0,
 560   actionOffset;
 561
 562   for (int i = 0; true; ++i) {
 563     // Each emitted dwarf action corresponds to a 2 tuple of
 564     // type info address offset, and action offset to the next
 565     // emitted action.
 566     typeOffset = readSLEB128(&actionPos);
 567     tempActionPos = actionPos;
 568     actionOffset = readSLEB128(&tempActionPos);
 569
 570 #ifdef DEBUG
 571     fprintf(stderr,
 572             "handleActionValue(...):typeOffset: <%lld>, "
 573             "actionOffset: <%lld>.\n",
 574             typeOffset,
 575             actionOffset);
 576 #endif
 577     assert((typeOffset >= 0) &&
 578            "handleActionValue(...):filters are not supported.");
 579
 580     // Note: A typeOffset == 0 implies that a cleanup llvm.eh.selector
 581     //       argument has been matched.
 582     if ((typeOffset > 0) &&
 583         (type == (classInfo[-typeOffset])->type)) {
 584 #ifdef DEBUG
 585       fprintf(stderr,
 586               "handleActionValue(...):actionValue <%d> found.\n",
 587               i);
 588 #endif
 589       *resultAction = i + 1;
 590       ret = true;
 591       break;
 592     }
 593
 594 #ifdef DEBUG
 595     fprintf(stderr,
 596             "handleActionValue(...):actionValue not found.\n");
 597 #endif
 598     if (!actionOffset)
 599       break;
 600
 601     actionPos += actionOffset;
 602   }
 603
 604   return(ret);
 605 }
 606
 607
 608 /// Deals with the Language specific data portion of the emitted dwarf code.
 609 /// See @link http://refspecs.freestandards.org/abi-eh-1.21.html @unlink
 610 /// @param version unsupported (ignored), unwind version
 611 /// @param lsda language specific data area
 612 /// @param _Unwind_Action actions minimally supported unwind stage
 613 ///        (forced specifically not supported)
 614 /// @param exceptionClass exception class (_Unwind_Exception::exception_class)
 615 ///        of thrown exception.
 616 /// @param exceptionObject thrown _Unwind_Exception instance.
 617 /// @param context unwind system context
 618 /// @returns minimally supported unwinding control indicator
 619 static _Unwind_Reason_Code handleLsda(int version,
 620                                       const uint8_t *lsda,
 621                                       _Unwind_Action actions,
 622                                       uint64_t exceptionClass,
 623                                     struct _Unwind_Exception *exceptionObject,
 624                                       _Unwind_Context_t context) {
 625   _Unwind_Reason_Code ret = _URC_CONTINUE_UNWIND;
 626
 627   if (!lsda)
 628     return(ret);
 629
 630 #ifdef DEBUG
 631   fprintf(stderr,
 632           "handleLsda(...):lsda is non-zero.\n");
 633 #endif
 634
 635   // Get the current instruction pointer and offset it before next
 636   // instruction in the current frame which threw the exception.
 637   uintptr_t pc = _Unwind_GetIP(context)-1;
 638
 639   // Get beginning current frame's code (as defined by the
 640   // emitted dwarf code)
 641   uintptr_t funcStart = _Unwind_GetRegionStart(context);
 642   uintptr_t pcOffset = pc - funcStart;
 643   struct OurExceptionType_t **classInfo = NULL;
 644
 645   // Note: See JITDwarfEmitter::EmitExceptionTable(...) for corresponding
 646   //       dwarf emission
 647
 648   // Parse LSDA header.
 649   uint8_t lpStartEncoding = *lsda++;
 650
 651   if (lpStartEncoding != llvm::dwarf::DW_EH_PE_omit) {
 652     readEncodedPointer(&lsda, lpStartEncoding);
 653   }
 654
 655   uint8_t ttypeEncoding = *lsda++;
 656   uintptr_t classInfoOffset;
 657
 658   if (ttypeEncoding != llvm::dwarf::DW_EH_PE_omit) {
 659     // Calculate type info locations in emitted dwarf code which
 660     // were flagged by type info arguments to llvm.eh.selector
 661     // intrinsic
 662     classInfoOffset = readULEB128(&lsda);
 663     classInfo = (struct OurExceptionType_t**) (lsda + classInfoOffset);
 664   }
 665
 666   // Walk call-site table looking for range that
 667   // includes current PC.
 668
 669   uint8_t         callSiteEncoding = *lsda++;
 670   uint32_t        callSiteTableLength = readULEB128(&lsda);
 671   const uint8_t   *callSiteTableStart = lsda;
 672   const uint8_t   *callSiteTableEnd = callSiteTableStart +
 673   callSiteTableLength;
 674   const uint8_t   *actionTableStart = callSiteTableEnd;
 675   const uint8_t   *callSitePtr = callSiteTableStart;
 676
 677   bool foreignException = false;
 678
 679   while (callSitePtr < callSiteTableEnd) {
 680     uintptr_t start = readEncodedPointer(&callSitePtr,
 681                                          callSiteEncoding);
 682     uintptr_t length = readEncodedPointer(&callSitePtr,
 683                                           callSiteEncoding);
 684     uintptr_t landingPad = readEncodedPointer(&callSitePtr,
 685                                               callSiteEncoding);
 686
 687     // Note: Action value
 688     uintptr_t actionEntry = readULEB128(&callSitePtr);
 689
 690     if (exceptionClass != ourBaseExceptionClass) {
 691       // We have been notified of a foreign exception being thrown,
 692       // and we therefore need to execute cleanup landing pads
 693       actionEntry = 0;
 694       foreignException = true;
 695     }
 696
 697     if (landingPad == 0) {
 698 #ifdef DEBUG
 699       fprintf(stderr,
 700               "handleLsda(...): No landing pad found.\n");
 701 #endif
 702
 703       continue; // no landing pad for this entry
 704     }
 705
 706     if (actionEntry) {
 707       actionEntry += ((uintptr_t) actionTableStart) - 1;
 708     }
 709     else {
 710 #ifdef DEBUG
 711       fprintf(stderr,
 712               "handleLsda(...):No action table found.\n");
 713 #endif
 714     }
 715
 716     bool exceptionMatched = false;
 717
 718     if ((start <= pcOffset) && (pcOffset < (start + length))) {
 719 #ifdef DEBUG
 720       fprintf(stderr,
 721               "handleLsda(...): Landing pad found.\n");
 722 #endif
 723       int64_t actionValue = 0;
 724
 725       if (actionEntry) {
 726         exceptionMatched = handleActionValue(&actionValue,
 727                                              classInfo,
 728                                              actionEntry,
 729                                              exceptionClass,
 730                                              exceptionObject);
 731       }
 732
 733       if (!(actions & _UA_SEARCH_PHASE)) {
 734 #ifdef DEBUG
 735         fprintf(stderr,
 736                 "handleLsda(...): installed landing pad "
 737                 "context.\n");
 738 #endif
 739
 740         // Found landing pad for the PC.
 741         // Set Instruction Pointer to so we re-enter function
 742         // at landing pad. The landing pad is created by the
 743         // compiler to take two parameters in registers.
 744         _Unwind_SetGR(context,
 745                       __builtin_eh_return_data_regno(0),
 746                       (uintptr_t)exceptionObject);
 747
 748         // Note: this virtual register directly corresponds
 749         //       to the return of the llvm.eh.selector intrinsic
 750         if (!actionEntry || !exceptionMatched) {
 751           // We indicate cleanup only
 752           _Unwind_SetGR(context,
 753                         __builtin_eh_return_data_regno(1),
 754                         0);
 755         }
 756         else {
 757           // Matched type info index of llvm.eh.selector intrinsic
 758           // passed here.
 759           _Unwind_SetGR(context,
 760                         __builtin_eh_return_data_regno(1),
 761                         actionValue);
 762         }
 763
 764         // To execute landing pad set here
 765         _Unwind_SetIP(context, funcStart + landingPad);
 766         ret = _URC_INSTALL_CONTEXT;
 767       }
 768       else if (exceptionMatched) {
 769 #ifdef DEBUG
 770         fprintf(stderr,
 771                 "handleLsda(...): setting handler found.\n");
 772 #endif
 773         ret = _URC_HANDLER_FOUND;
 774       }
 775       else {
 776         // Note: Only non-clean up handlers are marked as
 777         //       found. Otherwise the clean up handlers will be
 778         //       re-found and executed during the clean up
 779         //       phase.
 780 #ifdef DEBUG
 781         fprintf(stderr,
 782                 "handleLsda(...): cleanup handler found.\n");
 783 #endif
 784       }
 785
 786       break;
 787     }
 788   }
 789
 790   return(ret);
 791 }
 792
 793
 794 /// This is the personality function which is embedded (dwarf emitted), in the
 795 /// dwarf unwind info block. Again see: JITDwarfEmitter.cpp.
 796 /// See @link http://refspecs.freestandards.org/abi-eh-1.21.html @unlink
 797 /// @param version unsupported (ignored), unwind version
 798 /// @param _Unwind_Action actions minimally supported unwind stage
 799 ///        (forced specifically not supported)
 800 /// @param exceptionClass exception class (_Unwind_Exception::exception_class)
 801 ///        of thrown exception.
 802 /// @param exceptionObject thrown _Unwind_Exception instance.
 803 /// @param context unwind system context
 804 /// @returns minimally supported unwinding control indicator
 805 _Unwind_Reason_Code ourPersonality(int version,
 806                                    _Unwind_Action actions,
 807                                    uint64_t exceptionClass,
 808                                    struct _Unwind_Exception *exceptionObject,
 809                                    _Unwind_Context_t context) {
 810 #ifdef DEBUG
 811   fprintf(stderr,
 812           "We are in ourPersonality(...):actions is <%d>.\n",
 813           actions);
 814
 815   if (actions & _UA_SEARCH_PHASE) {
 816     fprintf(stderr, "ourPersonality(...):In search phase.\n");
 817   }
 818   else {
 819     fprintf(stderr, "ourPersonality(...):In non-search phase.\n");
 820   }
 821 #endif
 822
 823   const uint8_t *lsda = _Unwind_GetLanguageSpecificData(context);
 824
 825 #ifdef DEBUG
 826   fprintf(stderr,
 827           "ourPersonality(...):lsda = <%p>.\n",
 828           lsda);
 829 #endif
 830
 831   // The real work of the personality function is captured here
 832   return(handleLsda(version,
 833                     lsda,
 834                     actions,
 835                     exceptionClass,
 836                     exceptionObject,
 837                     context));
 838 }
 839
 840
 841 /// Generates our _Unwind_Exception class from a given character array.
 842 /// thereby handling arbitrary lengths (not in standard), and handling
 843 /// embedded \0s.
 844 /// See @link http://refspecs.freestandards.org/abi-eh-1.21.html @unlink
 845 /// @param classChars char array to encode. NULL values not checkedf
 846 /// @param classCharsSize number of chars in classChars. Value is not checked.
 847 /// @returns class value
 848 uint64_t genClass(const unsigned char classChars[], size_t classCharsSize)
 849 {
 850   uint64_t ret = classChars[0];
 851
 852   for (unsigned i = 1; i < classCharsSize; ++i) {
 853     ret <<= 8;
 854     ret += classChars[i];
 855   }
 856
 857   return(ret);
 858 }
 859
 860 } // extern "C"
 861
 862 //
 863 // Runtime C Library functions End
 864 //
 865
 866 //
 867 // Code generation functions
 868 //
 869
 870 /// Generates code to print given constant string
 871 /// @param context llvm context
 872 /// @param module code for module instance
 873 /// @param builder builder instance
 874 /// @param toPrint string to print
 875 /// @param useGlobal A value of true (default) indicates a GlobalValue is
 876 ///        generated, and is used to hold the constant string. A value of
 877 ///        false indicates that the constant string will be stored on the
 878 ///        stack.
 879 void generateStringPrint(llvm::LLVMContext &context,
 880                          llvm::Module &module,
 881                          llvm::IRBuilder<> &builder,
 882                          std::string toPrint,
 883                          bool useGlobal = true) {
 884   llvm::Function *printFunct = module.getFunction("printStr");
 885
 886   llvm::Value *stringVar;
 887   llvm::Constant *stringConstant =
 888   llvm::ConstantArray::get(context, toPrint);
 889
 890   if (useGlobal) {
 891     // Note: Does not work without allocation
 892     stringVar =
 893     new llvm::GlobalVariable(module,
 894                              stringConstant->getType(),
 895                              true,
 896                              llvm::GlobalValue::LinkerPrivateLinkage,
 897                              stringConstant,
 898                              "");
 899   }
 900   else {
 901     stringVar = builder.CreateAlloca(stringConstant->getType());
 902     builder.CreateStore(stringConstant, stringVar);
 903   }
 904
 905   llvm::Value *cast = builder.CreatePointerCast(stringVar,
 906                                                 builder.getInt8PtrTy());
 907   builder.CreateCall(printFunct, cast);
 908 }
 909
 910
 911 /// Generates code to print given runtime integer according to constant
 912 /// string format, and a given print function.
 913 /// @param context llvm context
 914 /// @param module code for module instance
 915 /// @param builder builder instance
 916 /// @param printFunct function used to "print" integer
 917 /// @param toPrint string to print
 918 /// @param format printf like formating string for print
 919 /// @param useGlobal A value of true (default) indicates a GlobalValue is
 920 ///        generated, and is used to hold the constant string. A value of
 921 ///        false indicates that the constant string will be stored on the
 922 ///        stack.
 923 void generateIntegerPrint(llvm::LLVMContext &context,
 924                           llvm::Module &module,
 925                           llvm::IRBuilder<> &builder,
 926                           llvm::Function &printFunct,
 927                           llvm::Value &toPrint,
 928                           std::string format,
 929                           bool useGlobal = true) {
 930   llvm::Constant *stringConstant = llvm::ConstantArray::get(context, format);
 931   llvm::Value *stringVar;
 932
 933   if (useGlobal) {
 934     // Note: Does not seem to work without allocation
 935     stringVar =
 936     new llvm::GlobalVariable(module,
 937                              stringConstant->getType(),
 938                              true,
 939                              llvm::GlobalValue::LinkerPrivateLinkage,
 940                              stringConstant,
 941                              "");
 942   }
 943   else {
 944     stringVar = builder.CreateAlloca(stringConstant->getType());
 945     builder.CreateStore(stringConstant, stringVar);
 946   }
 947
 948   llvm::Value *cast = builder.CreateBitCast(stringVar,
 949                                             builder.getInt8PtrTy());
 950   builder.CreateCall2(&printFunct, &toPrint, cast);
 951 }
 952
 953
 954 /// Generates code to handle finally block type semantics: always runs
 955 /// regardless of whether a thrown exception is passing through or the
 956 /// parent function is simply exiting. In addition to printing some state
 957 /// to stderr, this code will resume the exception handling--runs the
 958 /// unwind resume block, if the exception has not been previously caught
 959 /// by a catch clause, and will otherwise execute the end block (terminator
 960 /// block). In addition this function creates the corresponding function's
 961 /// stack storage for the exception pointer and catch flag status.
 962 /// @param context llvm context
 963 /// @param module code for module instance
 964 /// @param builder builder instance
 965 /// @param toAddTo parent function to add block to
 966 /// @param blockName block name of new "finally" block.
 967 /// @param functionId output id used for printing
 968 /// @param terminatorBlock terminator "end" block
 969 /// @param unwindResumeBlock unwind resume block
 970 /// @param exceptionCaughtFlag reference exception caught/thrown status storage
 971 /// @param exceptionStorage reference to exception pointer storage
 972 #ifndef OLD_EXC_SYSTEM
 973 /// @param caughtResultStorage reference to landingpad result storage
 974 #endif
 975 /// @returns newly created block
 976 static llvm::BasicBlock *createFinallyBlock(llvm::LLVMContext &context,
 977                                             llvm::Module &module,
 978                                             llvm::IRBuilder<> &builder,
 979                                             llvm::Function &toAddTo,
 980                                             std::string &blockName,
 981                                             std::string &functionId,
 982                                             llvm::BasicBlock &terminatorBlock,
 983                                             llvm::BasicBlock &unwindResumeBlock,
 984                                             llvm::Value **exceptionCaughtFlag,
 985                                             llvm::Value **exceptionStorage
 986 #ifndef OLD_EXC_SYSTEM
 987                                             ,llvm::Value **caughtResultStorage
 988 #endif
 989                                             ) {
 990   assert(exceptionCaughtFlag &&
 991          "ExceptionDemo::createFinallyBlock(...):exceptionCaughtFlag "
 992          "is NULL");
 993   assert(exceptionStorage &&
 994          "ExceptionDemo::createFinallyBlock(...):exceptionStorage "
 995          "is NULL");
 996
 997 #ifndef OLD_EXC_SYSTEM
 998   assert(caughtResultStorage &&
 999          "ExceptionDemo::createFinallyBlock(...):caughtResultStorage "
1000          "is NULL");
1001 #endif
1002
1003   *exceptionCaughtFlag = createEntryBlockAlloca(toAddTo,
1004                                          "exceptionCaught",
1005                                          ourExceptionNotThrownState->getType(),
1006                                          ourExceptionNotThrownState);
1007
1008   llvm::PointerType *exceptionStorageType = builder.getInt8PtrTy();
1009   *exceptionStorage = createEntryBlockAlloca(toAddTo,
1010                                              "exceptionStorage",
1011                                              exceptionStorageType,
1012                                              llvm::ConstantPointerNull::get(
1013                                                exceptionStorageType));
1014 #ifndef OLD_EXC_SYSTEM
1015   *caughtResultStorage = createEntryBlockAlloca(toAddTo,
1016                                               "caughtResultStorage",
1017                                               ourCaughtResultType,
1018                                               llvm::ConstantAggregateZero::get(
1019                                                 ourCaughtResultType));
1020 #endif
1021
1022   llvm::BasicBlock *ret = llvm::BasicBlock::Create(context,
1023                                                    blockName,
1024                                                    &toAddTo);
1025
1026   builder.SetInsertPoint(ret);
1027
1028   std::ostringstream bufferToPrint;
1029   bufferToPrint << "Gen: Executing finally block "
1030     << blockName << " in " << functionId << "\n";
1031   generateStringPrint(context,
1032                       module,
1033                       builder,
1034                       bufferToPrint.str(),
1035                       USE_GLOBAL_STR_CONSTS);
1036
1037   llvm::SwitchInst *theSwitch = builder.CreateSwitch(builder.CreateLoad(
1038                                                        *exceptionCaughtFlag),
1039                                                      &terminatorBlock,
1040                                                      2);
1041   theSwitch->addCase(ourExceptionCaughtState, &terminatorBlock);
1042   theSwitch->addCase(ourExceptionThrownState, &unwindResumeBlock);
1043
1044   return(ret);
1045 }
1046
1047
1048 /// Generates catch block semantics which print a string to indicate type of
1049 /// catch executed, sets an exception caught flag, and executes passed in
1050 /// end block (terminator block).
1051 /// @param context llvm context
1052 /// @param module code for module instance
1053 /// @param builder builder instance
1054 /// @param toAddTo parent function to add block to
1055 /// @param blockName block name of new "catch" block.
1056 /// @param functionId output id used for printing
1057 /// @param terminatorBlock terminator "end" block
1058 /// @param exceptionCaughtFlag exception caught/thrown status
1059 /// @returns newly created block
1060 static llvm::BasicBlock *createCatchBlock(llvm::LLVMContext &context,
1061                                           llvm::Module &module,
1062                                           llvm::IRBuilder<> &builder,
1063                                           llvm::Function &toAddTo,
1064                                           std::string &blockName,
1065                                           std::string &functionId,
1066                                           llvm::BasicBlock &terminatorBlock,
1067                                           llvm::Value &exceptionCaughtFlag) {
1068
1069   llvm::BasicBlock *ret = llvm::BasicBlock::Create(context,
1070                                                    blockName,
1071                                                    &toAddTo);
1072
1073   builder.SetInsertPoint(ret);
1074
1075   std::ostringstream bufferToPrint;
1076   bufferToPrint << "Gen: Executing catch block "
1077   << blockName
1078   << " in "
1079   << functionId
1080   << std::endl;
1081   generateStringPrint(context,
1082                       module,
1083                       builder,
1084                       bufferToPrint.str(),
1085                       USE_GLOBAL_STR_CONSTS);
1086   builder.CreateStore(ourExceptionCaughtState, &exceptionCaughtFlag);
1087   builder.CreateBr(&terminatorBlock);
1088
1089   return(ret);
1090 }
1091
1092
1093 /// Generates a function which invokes a function (toInvoke) and, whose
1094 /// unwind block will "catch" the type info types correspondingly held in the
1095 /// exceptionTypesToCatch argument. If the toInvoke function throws an
1096 /// exception which does not match any type info types contained in
1097 /// exceptionTypesToCatch, the generated code will call _Unwind_Resume
1098 /// with the raised exception. On the other hand the generated code will
1099 /// normally exit if the toInvoke function does not throw an exception.
1100 /// The generated "finally" block is always run regardless of the cause of
1101 /// the generated function exit.
1102 /// The generated function is returned after being verified.
1103 /// @param module code for module instance
1104 /// @param builder builder instance
1105 /// @param fpm a function pass manager holding optional IR to IR
1106 ///        transformations
1107 /// @param toInvoke inner function to invoke
1108 /// @param ourId id used to printing purposes
1109 /// @param numExceptionsToCatch length of exceptionTypesToCatch array
1110 /// @param exceptionTypesToCatch array of type info types to "catch"
1111 /// @returns generated function
1112 static
1113 llvm::Function *createCatchWrappedInvokeFunction(llvm::Module &module,
1114                                              llvm::IRBuilder<> &builder,
1115                                              llvm::FunctionPassManager &fpm,
1116                                              llvm::Function &toInvoke,
1117                                              std::string ourId,
1118                                              unsigned numExceptionsToCatch,
1119                                              unsigned exceptionTypesToCatch[]) {
1120
1121   llvm::LLVMContext &context = module.getContext();
1122   llvm::Function *toPrint32Int = module.getFunction("print32Int");
1123
1124   ArgTypes argTypes;
1125   argTypes.push_back(builder.getInt32Ty());
1126
1127   ArgNames argNames;
1128   argNames.push_back("exceptTypeToThrow");
1129
1130   llvm::Function *ret = createFunction(module,
1131                                        builder.getVoidTy(),
1132                                        argTypes,
1133                                        argNames,
1134                                        ourId,
1135                                        llvm::Function::ExternalLinkage,
1136                                        false,
1137                                        false);
1138
1139   // Block which calls invoke
1140   llvm::BasicBlock *entryBlock = llvm::BasicBlock::Create(context,
1141                                                           "entry",
1142                                                           ret);
1143   // Normal block for invoke
1144   llvm::BasicBlock *normalBlock = llvm::BasicBlock::Create(context,
1145                                                            "normal",
1146                                                            ret);
1147   // Unwind block for invoke
1148   llvm::BasicBlock *exceptionBlock = llvm::BasicBlock::Create(context,
1149                                                               "exception",
1150                                                               ret);
1151
1152   // Block which routes exception to correct catch handler block
1153   llvm::BasicBlock *exceptionRouteBlock = llvm::BasicBlock::Create(context,
1154                                                              "exceptionRoute",
1155                                                              ret);
1156
1157   // Foreign exception handler
1158   llvm::BasicBlock *externalExceptionBlock = llvm::BasicBlock::Create(context,
1159                                                           "externalException",
1160                                                           ret);
1161
1162   // Block which calls _Unwind_Resume
1163   llvm::BasicBlock *unwindResumeBlock = llvm::BasicBlock::Create(context,
1164                                                                "unwindResume",
1165                                                                ret);
1166
1167   // Clean up block which delete exception if needed
1168   llvm::BasicBlock *endBlock = llvm::BasicBlock::Create(context, "end", ret);
1169
1170   std::string nextName;
1171   std::vector<llvm::BasicBlock*> catchBlocks(numExceptionsToCatch);
1172   llvm::Value *exceptionCaughtFlag = NULL;
1173   llvm::Value *exceptionStorage = NULL;
1174 #ifndef OLD_EXC_SYSTEM
1175   llvm::Value *caughtResultStorage = NULL;
1176 #endif
1177
1178   // Finally block which will branch to unwindResumeBlock if
1179   // exception is not caught. Initializes/allocates stack locations.
1180   llvm::BasicBlock *finallyBlock = createFinallyBlock(context,
1181                                                       module,
1182                                                       builder,
1183                                                       *ret,
1184                                                       nextName = "finally",
1185                                                       ourId,
1186                                                       *endBlock,
1187                                                       *unwindResumeBlock,
1188                                                       &exceptionCaughtFlag,
1189                                                       &exceptionStorage
1190 #ifndef OLD_EXC_SYSTEM
1191                                                       ,&caughtResultStorage
1192 #endif
1193                                                       );
1194
1195   for (unsigned i = 0; i < numExceptionsToCatch; ++i) {
1196     nextName = ourTypeInfoNames[exceptionTypesToCatch[i]];
1197
1198     // One catch block per type info to be caught
1199     catchBlocks[i] = createCatchBlock(context,
1200                                       module,
1201                                       builder,
1202                                       *ret,
1203                                       nextName,
1204                                       ourId,
1205                                       *finallyBlock,
1206                                       *exceptionCaughtFlag);
1207   }
1208
1209   // Entry Block
1210
1211   builder.SetInsertPoint(entryBlock);
1212
1213   std::vector<llvm::Value*> args;
1214   args.push_back(namedValues["exceptTypeToThrow"]);
1215   builder.CreateInvoke(&toInvoke,
1216                        normalBlock,
1217                        exceptionBlock,
1218                        args);
1219
1220   // End Block
1221
1222   builder.SetInsertPoint(endBlock);
1223
1224   generateStringPrint(context,
1225                       module,
1226                       builder,
1227                       "Gen: In end block: exiting in " + ourId + ".\n",
1228                       USE_GLOBAL_STR_CONSTS);
1229   llvm::Function *deleteOurException = module.getFunction("deleteOurException");
1230
1231   // Note: function handles NULL exceptions
1232   builder.CreateCall(deleteOurException,
1233                      builder.CreateLoad(exceptionStorage));
1234   builder.CreateRetVoid();
1235
1236   // Normal Block
1237
1238   builder.SetInsertPoint(normalBlock);
1239
1240   generateStringPrint(context,
1241                       module,
1242                       builder,
1243                       "Gen: No exception in " + ourId + "!\n",
1244                       USE_GLOBAL_STR_CONSTS);
1245
1246   // Finally block is always called
1247   builder.CreateBr(finallyBlock);
1248
1249   // Unwind Resume Block
1250
1251   builder.SetInsertPoint(unwindResumeBlock);
1252
1253
1254 #ifndef OLD_EXC_SYSTEM
1255   builder.CreateResume(builder.CreateLoad(caughtResultStorage));
1256 #else
1257   llvm::Function *resumeOurException = module.getFunction("_Unwind_Resume");
1258   builder.CreateCall(resumeOurException,
1259                      builder.CreateLoad(exceptionStorage));
1260   builder.CreateUnreachable();
1261 #endif
1262
1263   // Exception Block
1264
1265   builder.SetInsertPoint(exceptionBlock);
1266
1267   llvm::Function *personality = module.getFunction("ourPersonality");
1268
1269 #ifndef OLD_EXC_SYSTEM
1270   llvm::LandingPadInst *caughtResult =
1271     builder.CreateLandingPad(ourCaughtResultType,
1272                              personality,
1273                              numExceptionsToCatch,
1274                              "landingPad");
1275
1276   caughtResult->setCleanup(true);
1277
1278   for (unsigned i = 0; i < numExceptionsToCatch; ++i) {
1279     // Set up type infos to be caught
1280     caughtResult->addClause(module.getGlobalVariable(
1281                              ourTypeInfoNames[exceptionTypesToCatch[i]]));
1282   }
1283
1284   llvm::Value *unwindException = builder.CreateExtractValue(caughtResult, 0);
1285   llvm::Value *retTypeInfoIndex = builder.CreateExtractValue(caughtResult, 1);
1286
1287   // FIXME: Redundant storage which, beyond utilizing value of
1288   //        caughtResultStore for unwindException storage, may be alleviated
1289   //        alltogether with a block rearrangement
1290   builder.CreateStore(caughtResult, caughtResultStorage);
1291   builder.CreateStore(unwindException, exceptionStorage);
1292   builder.CreateStore(ourExceptionThrownState, exceptionCaughtFlag);
1293 #else
1294   llvm::Function *ehException = module.getFunction("llvm.eh.exception");
1295
1296   // Retrieve thrown exception
1297   llvm::Value *unwindException = builder.CreateCall(ehException);
1298
1299   // Store exception and flag
1300   builder.CreateStore(unwindException, exceptionStorage);
1301   builder.CreateStore(ourExceptionThrownState, exceptionCaughtFlag);
1302   llvm::Value *functPtr = builder.CreatePointerCast(personality,
1303                                                     builder.getInt8PtrTy());
1304
1305   args.clear();
1306   args.push_back(unwindException);
1307   args.push_back(functPtr);
1308
1309   // Note: Skipping index 0
1310   for (unsigned i = 0; i < numExceptionsToCatch; ++i) {
1311     // Set up type infos to be caught
1312     args.push_back(module.getGlobalVariable(
1313                                   ourTypeInfoNames[exceptionTypesToCatch[i]]));
1314   }
1315
1316   args.push_back(llvm::ConstantInt::get(builder.getInt32Ty(), 0));
1317
1318   llvm::Function *ehSelector = module.getFunction("llvm.eh.selector");
1319
1320   // Set up this exeption block as the landing pad which will handle
1321   // given type infos. See case Intrinsic::eh_selector in
1322   // SelectionDAGBuilder::visitIntrinsicCall(...) and AddCatchInfo(...)
1323   // implemented in FunctionLoweringInfo.cpp to see how the implementation
1324   // handles this call. This landing pad (this exception block), will be
1325   // called either because it nees to cleanup (call finally) or a type
1326   // info was found which matched the thrown exception.
1327   llvm::Value *retTypeInfoIndex = builder.CreateCall(ehSelector, args);
1328 #endif
1329
1330   // Retrieve exception_class member from thrown exception
1331   // (_Unwind_Exception instance). This member tells us whether or not
1332   // the exception is foreign.
1333   llvm::Value *unwindExceptionClass =
1334     builder.CreateLoad(builder.CreateStructGEP(
1335              builder.CreatePointerCast(unwindException,
1336                                        ourUnwindExceptionType->getPointerTo()),
1337                                                0));
1338
1339   // Branch to the externalExceptionBlock if the exception is foreign or
1340   // to a catch router if not. Either way the finally block will be run.
1341   builder.CreateCondBr(builder.CreateICmpEQ(unwindExceptionClass,
1342                             llvm::ConstantInt::get(builder.getInt64Ty(),
1343                                                    ourBaseExceptionClass)),
1344                        exceptionRouteBlock,
1345                        externalExceptionBlock);
1346
1347   // External Exception Block
1348
1349   builder.SetInsertPoint(externalExceptionBlock);
1350
1351   generateStringPrint(context,
1352                       module,
1353                       builder,
1354                       "Gen: Foreign exception received.\n",
1355                       USE_GLOBAL_STR_CONSTS);
1356
1357   // Branch to the finally block
1358   builder.CreateBr(finallyBlock);
1359
1360   // Exception Route Block
1361
1362   builder.SetInsertPoint(exceptionRouteBlock);
1363
1364   // Casts exception pointer (_Unwind_Exception instance) to parent
1365   // (OurException instance).
1366   //
1367   // Note: ourBaseFromUnwindOffset is usually negative
1368   llvm::Value *typeInfoThrown = builder.CreatePointerCast(
1369                                   builder.CreateConstGEP1_64(unwindException,
1370                                                        ourBaseFromUnwindOffset),
1371                                   ourExceptionType->getPointerTo());
1372
1373   // Retrieve thrown exception type info type
1374   //
1375   // Note: Index is not relative to pointer but instead to structure
1376   //       unlike a true getelementptr (GEP) instruction
1377   typeInfoThrown = builder.CreateStructGEP(typeInfoThrown, 0);
1378
1379   llvm::Value *typeInfoThrownType =
1380   builder.CreateStructGEP(typeInfoThrown, 0);
1381
1382   generateIntegerPrint(context,
1383                        module,
1384                        builder,
1385                        *toPrint32Int,
1386                        *(builder.CreateLoad(typeInfoThrownType)),
1387                        "Gen: Exception type <%d> received (stack unwound) "
1388                        " in " +
1389                        ourId +
1390                        ".\n",
1391                        USE_GLOBAL_STR_CONSTS);
1392
1393   // Route to matched type info catch block or run cleanup finally block
1394   llvm::SwitchInst *switchToCatchBlock = builder.CreateSwitch(retTypeInfoIndex,
1395                                                           finallyBlock,
1396                                                           numExceptionsToCatch);
1397
1398   unsigned nextTypeToCatch;
1399
1400   for (unsigned i = 1; i <= numExceptionsToCatch; ++i) {
1401     nextTypeToCatch = i - 1;
1402     switchToCatchBlock->addCase(llvm::ConstantInt::get(
1403                                    llvm::Type::getInt32Ty(context), i),
1404                                 catchBlocks[nextTypeToCatch]);
1405   }
1406
1407 #ifdef OLD_EXC_SYSTEM
1408   // Must be run before verifier
1409   UpgradeExceptionHandling(&module);
1410 #endif
1411
1412
1413   llvm::verifyFunction(*ret);
1414   fpm.run(*ret);
1415
1416   return(ret);
1417 }
1418
1419
1420 /// Generates function which throws either an exception matched to a runtime
1421 /// determined type info type (argument to generated function), or if this
1422 /// runtime value matches nativeThrowType, throws a foreign exception by
1423 /// calling nativeThrowFunct.
1424 /// @param module code for module instance
1425 /// @param builder builder instance
1426 /// @param fpm a function pass manager holding optional IR to IR
1427 ///        transformations
1428 /// @param ourId id used to printing purposes
1429 /// @param nativeThrowType a runtime argument of this value results in
1430 ///        nativeThrowFunct being called to generate/throw exception.
1431 /// @param nativeThrowFunct function which will throw a foreign exception
1432 ///        if the above nativeThrowType matches generated function's arg.
1433 /// @returns generated function
1434 static
1435 llvm::Function *createThrowExceptionFunction(llvm::Module &module,
1436                                              llvm::IRBuilder<> &builder,
1437                                              llvm::FunctionPassManager &fpm,
1438                                              std::string ourId,
1439                                              int32_t nativeThrowType,
1440                                              llvm::Function &nativeThrowFunct) {
1441   llvm::LLVMContext &context = module.getContext();
1442   namedValues.clear();
1443   ArgTypes unwindArgTypes;
1444   unwindArgTypes.push_back(builder.getInt32Ty());
1445   ArgNames unwindArgNames;
1446   unwindArgNames.push_back("exceptTypeToThrow");
1447
1448   llvm::Function *ret = createFunction(module,
1449                                        builder.getVoidTy(),
1450                                        unwindArgTypes,
1451                                        unwindArgNames,
1452                                        ourId,
1453                                        llvm::Function::ExternalLinkage,
1454                                        false,
1455                                        false);
1456
1457   // Throws either one of our exception or a native C++ exception depending
1458   // on a runtime argument value containing a type info type.
1459   llvm::BasicBlock *entryBlock = llvm::BasicBlock::Create(context,
1460                                                           "entry",
1461                                                           ret);
1462   // Throws a foreign exception
1463   llvm::BasicBlock *nativeThrowBlock = llvm::BasicBlock::Create(context,
1464                                                                 "nativeThrow",
1465                                                                 ret);
1466   // Throws one of our Exceptions
1467   llvm::BasicBlock *generatedThrowBlock = llvm::BasicBlock::Create(context,
1468                                                              "generatedThrow",
1469                                                              ret);
1470   // Retrieved runtime type info type to throw
1471   llvm::Value *exceptionType = namedValues["exceptTypeToThrow"];
1472
1473   // nativeThrowBlock block
1474
1475   builder.SetInsertPoint(nativeThrowBlock);
1476
1477   // Throws foreign exception
1478   builder.CreateCall(&nativeThrowFunct, exceptionType);
1479   builder.CreateUnreachable();
1480
1481   // entry block
1482
1483   builder.SetInsertPoint(entryBlock);
1484
1485   llvm::Function *toPrint32Int = module.getFunction("print32Int");
1486   generateIntegerPrint(context,
1487                        module,
1488                        builder,
1489                        *toPrint32Int,
1490                        *exceptionType,
1491                        "\nGen: About to throw exception type <%d> in " +
1492                        ourId +
1493                        ".\n",
1494                        USE_GLOBAL_STR_CONSTS);
1495
1496   // Switches on runtime type info type value to determine whether or not
1497   // a foreign exception is thrown. Defaults to throwing one of our
1498   // generated exceptions.
1499   llvm::SwitchInst *theSwitch = builder.CreateSwitch(exceptionType,
1500                                                      generatedThrowBlock,
1501                                                      1);
1502
1503   theSwitch->addCase(llvm::ConstantInt::get(llvm::Type::getInt32Ty(context),
1504                                             nativeThrowType),
1505                      nativeThrowBlock);
1506
1507   // generatedThrow block
1508
1509   builder.SetInsertPoint(generatedThrowBlock);
1510
1511   llvm::Function *createOurException = module.getFunction("createOurException");
1512   llvm::Function *raiseOurException = module.getFunction(
1513                                         "_Unwind_RaiseException");
1514
1515   // Creates exception to throw with runtime type info type.
1516   llvm::Value *exception = builder.CreateCall(createOurException,
1517                                               namedValues["exceptTypeToThrow"]);
1518
1519   // Throw generated Exception
1520   builder.CreateCall(raiseOurException, exception);
1521   builder.CreateUnreachable();
1522
1523   llvm::verifyFunction(*ret);
1524   fpm.run(*ret);
1525
1526   return(ret);
1527 }
1528
1529 static void createStandardUtilityFunctions(unsigned numTypeInfos,
1530                                            llvm::Module &module,
1531                                            llvm::IRBuilder<> &builder);
1532
1533 /// Creates test code by generating and organizing these functions into the
1534 /// test case. The test case consists of an outer function setup to invoke
1535 /// an inner function within an environment having multiple catch and single
1536 /// finally blocks. This inner function is also setup to invoke a throw
1537 /// function within an evironment similar in nature to the outer function's
1538 /// catch and finally blocks. Each of these two functions catch mutually
1539 /// exclusive subsets (even or odd) of the type info types configured
1540 /// for this this. All generated functions have a runtime argument which
1541 /// holds a type info type to throw that each function takes and passes it
1542 /// to the inner one if such a inner function exists. This type info type is
1543 /// looked at by the generated throw function to see whether or not it should
1544 /// throw a generated exception with the same type info type, or instead call
1545 /// a supplied a function which in turn will throw a foreign exception.
1546 /// @param module code for module instance
1547 /// @param builder builder instance
1548 /// @param fpm a function pass manager holding optional IR to IR
1549 ///        transformations
1550 /// @param nativeThrowFunctName name of external function which will throw
1551 ///        a foreign exception
1552 /// @returns outermost generated test function.
1553 llvm::Function *createUnwindExceptionTest(llvm::Module &module,
1554                                           llvm::IRBuilder<> &builder,
1555                                           llvm::FunctionPassManager &fpm,
1556                                           std::string nativeThrowFunctName) {
1557   // Number of type infos to generate
1558   unsigned numTypeInfos = 6;
1559
1560   // Initialze intrisics and external functions to use along with exception
1561   // and type info globals.
1562   createStandardUtilityFunctions(numTypeInfos,
1563                                  module,
1564                                  builder);
1565   llvm::Function *nativeThrowFunct = module.getFunction(nativeThrowFunctName);
1566
1567   // Create exception throw function using the value ~0 to cause
1568   // foreign exceptions to be thrown.
1569   llvm::Function *throwFunct = createThrowExceptionFunction(module,
1570                                                             builder,
1571                                                             fpm,
1572                                                             "throwFunct",
1573                                                             ~0,
1574                                                             *nativeThrowFunct);
1575   // Inner function will catch even type infos
1576   unsigned innerExceptionTypesToCatch[] = {6, 2, 4};
1577   size_t numExceptionTypesToCatch = sizeof(innerExceptionTypesToCatch) /
1578                                     sizeof(unsigned);
1579
1580   // Generate inner function.
1581   llvm::Function *innerCatchFunct = createCatchWrappedInvokeFunction(module,
1582                                                     builder,
1583                                                     fpm,
1584                                                     *throwFunct,
1585                                                     "innerCatchFunct",
1586                                                     numExceptionTypesToCatch,
1587                                                     innerExceptionTypesToCatch);
1588
1589   // Outer function will catch odd type infos
1590   unsigned outerExceptionTypesToCatch[] = {3, 1, 5};
1591   numExceptionTypesToCatch = sizeof(outerExceptionTypesToCatch) /
1592   sizeof(unsigned);
1593
1594   // Generate outer function
1595   llvm::Function *outerCatchFunct = createCatchWrappedInvokeFunction(module,
1596                                                     builder,
1597                                                     fpm,
1598                                                     *innerCatchFunct,
1599                                                     "outerCatchFunct",
1600                                                     numExceptionTypesToCatch,
1601                                                     outerExceptionTypesToCatch);
1602
1603   // Return outer function to run
1604   return(outerCatchFunct);
1605 }
1606
1607
1608 /// Represents our foreign exceptions
1609 class OurCppRunException : public std::runtime_error {
1610 public:
1611   OurCppRunException(const std::string reason) :
1612   std::runtime_error(reason) {}
1613
1614   OurCppRunException (const OurCppRunException &toCopy) :
1615   std::runtime_error(toCopy) {}
1616
1617   OurCppRunException &operator = (const OurCppRunException &toCopy) {
1618     return(reinterpret_cast<OurCppRunException&>(
1619                                  std::runtime_error::operator=(toCopy)));
1620   }
1621
1622   ~OurCppRunException (void) throw () {}
1623 };
1624
1625
1626 /// Throws foreign C++ exception.
1627 /// @param ignoreIt unused parameter that allows function to match implied
1628 ///        generated function contract.
1629 extern "C"
1630 void throwCppException (int32_t ignoreIt) {
1631   throw(OurCppRunException("thrown by throwCppException(...)"));
1632 }
1633
1634 typedef void (*OurExceptionThrowFunctType) (int32_t typeToThrow);
1635
1636 /// This is a test harness which runs test by executing generated
1637 /// function with a type info type to throw. Harness wraps the execution
1638 /// of generated function in a C++ try catch clause.
1639 /// @param engine execution engine to use for executing generated function.
1640 ///        This demo program expects this to be a JIT instance for demo
1641 ///        purposes.
1642 /// @param function generated test function to run
1643 /// @param typeToThrow type info type of generated exception to throw, or
1644 ///        indicator to cause foreign exception to be thrown.
1645 static
1646 void runExceptionThrow(llvm::ExecutionEngine *engine,
1647                        llvm::Function *function,
1648                        int32_t typeToThrow) {
1649
1650   // Find test's function pointer
1651   OurExceptionThrowFunctType functPtr =
1652     reinterpret_cast<OurExceptionThrowFunctType>(
1653        reinterpret_cast<intptr_t>(engine->getPointerToFunction(function)));
1654
1655   try {
1656     // Run test
1657     (*functPtr)(typeToThrow);
1658   }
1659   catch (OurCppRunException exc) {
1660     // Catch foreign C++ exception
1661     fprintf(stderr,
1662             "\nrunExceptionThrow(...):In C++ catch OurCppRunException "
1663             "with reason: %s.\n",
1664             exc.what());
1665   }
1666   catch (...) {
1667     // Catch all exceptions including our generated ones. This latter
1668     // functionality works according to the example in rules 1.6.4 of
1669     // http://sourcery.mentor.com/public/cxx-abi/abi-eh.html (v1.22),
1670     // given that these will be exceptions foreign to C++
1671     // (the _Unwind_Exception::exception_class should be different from
1672     // the one used by C++).
1673     fprintf(stderr,
1674             "\nrunExceptionThrow(...):In C++ catch all.\n");
1675   }
1676 }
1677
1678 //
1679 // End test functions
1680 //
1681
1682 typedef llvm::ArrayRef<llvm::Type*> TypeArray;
1683
1684 /// This initialization routine creates type info globals and
1685 /// adds external function declarations to module.
1686 /// @param numTypeInfos number of linear type info associated type info types
1687 ///        to create as GlobalVariable instances, starting with the value 1.
1688 /// @param module code for module instance
1689 /// @param builder builder instance
1690 static void createStandardUtilityFunctions(unsigned numTypeInfos,
1691                                            llvm::Module &module,
1692                                            llvm::IRBuilder<> &builder) {
1693
1694   llvm::LLVMContext &context = module.getContext();
1695
1696   // Exception initializations
1697
1698   // Setup exception catch state
1699   ourExceptionNotThrownState =
1700     llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 0),
1701   ourExceptionThrownState =
1702     llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 1),
1703   ourExceptionCaughtState =
1704     llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 2),
1705
1706
1707
1708   // Create our type info type
1709   ourTypeInfoType = llvm::StructType::get(context,
1710                                           TypeArray(builder.getInt32Ty()));
1711
1712 #ifndef OLD_EXC_SYSTEM
1713
1714   llvm::Type *caughtResultFieldTypes[] = {
1715     builder.getInt8PtrTy(),
1716     builder.getInt32Ty()
1717   };
1718
1719   // Create our landingpad result type
1720   ourCaughtResultType = llvm::StructType::get(context,
1721                                             TypeArray(caughtResultFieldTypes));
1722
1723 #endif
1724
1725   // Create OurException type
1726   ourExceptionType = llvm::StructType::get(context,
1727                                            TypeArray(ourTypeInfoType));
1728
1729   // Create portion of _Unwind_Exception type
1730   //
1731   // Note: Declaring only a portion of the _Unwind_Exception struct.
1732   //       Does this cause problems?
1733   ourUnwindExceptionType =
1734     llvm::StructType::get(context,
1735                     TypeArray(builder.getInt64Ty()));
1736
1737   struct OurBaseException_t dummyException;
1738
1739   // Calculate offset of OurException::unwindException member.
1740   ourBaseFromUnwindOffset = ((uintptr_t) &dummyException) -
1741                             ((uintptr_t) &(dummyException.unwindException));
1742
1743 #ifdef DEBUG
1744   fprintf(stderr,
1745           "createStandardUtilityFunctions(...):ourBaseFromUnwindOffset "
1746           "= %lld, sizeof(struct OurBaseException_t) - "
1747           "sizeof(struct _Unwind_Exception) = %lu.\n",
1748           ourBaseFromUnwindOffset,
1749           sizeof(struct OurBaseException_t) -
1750           sizeof(struct _Unwind_Exception));
1751 #endif
1752
1753   size_t numChars = sizeof(ourBaseExcpClassChars) / sizeof(char);
1754
1755   // Create our _Unwind_Exception::exception_class value
1756   ourBaseExceptionClass = genClass(ourBaseExcpClassChars, numChars);
1757
1758   // Type infos
1759
1760   std::string baseStr = "typeInfo", typeInfoName;
1761   std::ostringstream typeInfoNameBuilder;
1762   std::vector<llvm::Constant*> structVals;
1763
1764   llvm::Constant *nextStruct;
1765   llvm::GlobalVariable *nextGlobal = NULL;
1766
1767   // Generate each type info
1768   //
1769   // Note: First type info is not used.
1770   for (unsigned i = 0; i <= numTypeInfos; ++i) {
1771     structVals.clear();
1772     structVals.push_back(llvm::ConstantInt::get(builder.getInt32Ty(), i));
1773     nextStruct = llvm::ConstantStruct::get(ourTypeInfoType, structVals);
1774
1775     typeInfoNameBuilder.str("");
1776     typeInfoNameBuilder << baseStr << i;
1777     typeInfoName = typeInfoNameBuilder.str();
1778
1779     // Note: Does not seem to work without allocation
1780     nextGlobal =
1781     new llvm::GlobalVariable(module,
1782                              ourTypeInfoType,
1783                              true,
1784                              llvm::GlobalValue::ExternalLinkage,
1785                              nextStruct,
1786                              typeInfoName);
1787
1788     ourTypeInfoNames.push_back(typeInfoName);
1789     ourTypeInfoNamesIndex[i] = typeInfoName;
1790   }
1791
1792   ArgNames argNames;
1793   ArgTypes argTypes;
1794   llvm::Function *funct = NULL;
1795
1796   // print32Int
1797
1798   llvm::Type *retType = builder.getVoidTy();
1799
1800   argTypes.clear();
1801   argTypes.push_back(builder.getInt32Ty());
1802   argTypes.push_back(builder.getInt8PtrTy());
1803
1804   argNames.clear();
1805
1806   createFunction(module,
1807                  retType,
1808                  argTypes,
1809                  argNames,
1810                  "print32Int",
1811                  llvm::Function::ExternalLinkage,
1812                  true,
1813                  false);
1814
1815   // print64Int
1816
1817   retType = builder.getVoidTy();
1818
1819   argTypes.clear();
1820   argTypes.push_back(builder.getInt64Ty());
1821   argTypes.push_back(builder.getInt8PtrTy());
1822
1823   argNames.clear();
1824
1825   createFunction(module,
1826                  retType,
1827                  argTypes,
1828                  argNames,
1829                  "print64Int",
1830                  llvm::Function::ExternalLinkage,
1831                  true,
1832                  false);
1833
1834   // printStr
1835
1836   retType = builder.getVoidTy();
1837
1838   argTypes.clear();
1839   argTypes.push_back(builder.getInt8PtrTy());
1840
1841   argNames.clear();
1842
1843   createFunction(module,
1844                  retType,
1845                  argTypes,
1846                  argNames,
1847                  "printStr",
1848                  llvm::Function::ExternalLinkage,
1849                  true,
1850                  false);
1851
1852   // throwCppException
1853
1854   retType = builder.getVoidTy();
1855
1856   argTypes.clear();
1857   argTypes.push_back(builder.getInt32Ty());
1858
1859   argNames.clear();
1860
1861   createFunction(module,
1862                  retType,
1863                  argTypes,
1864                  argNames,
1865                  "throwCppException",
1866                  llvm::Function::ExternalLinkage,
1867                  true,
1868                  false);
1869
1870   // deleteOurException
1871
1872   retType = builder.getVoidTy();
1873
1874   argTypes.clear();
1875   argTypes.push_back(builder.getInt8PtrTy());
1876
1877   argNames.clear();
1878
1879   createFunction(module,
1880                  retType,
1881                  argTypes,
1882                  argNames,
1883                  "deleteOurException",
1884                  llvm::Function::ExternalLinkage,
1885                  true,
1886                  false);
1887
1888   // createOurException
1889
1890   retType = builder.getInt8PtrTy();
1891
1892   argTypes.clear();
1893   argTypes.push_back(builder.getInt32Ty());
1894
1895   argNames.clear();
1896
1897   createFunction(module,
1898                  retType,
1899                  argTypes,
1900                  argNames,
1901                  "createOurException",
1902                  llvm::Function::ExternalLinkage,
1903                  true,
1904                  false);
1905
1906   // _Unwind_RaiseException
1907
1908   retType = builder.getInt32Ty();
1909
1910   argTypes.clear();
1911   argTypes.push_back(builder.getInt8PtrTy());
1912
1913   argNames.clear();
1914
1915   funct = createFunction(module,
1916                          retType,
1917                          argTypes,
1918                          argNames,
1919                          "_Unwind_RaiseException",
1920                          llvm::Function::ExternalLinkage,
1921                          true,
1922                          false);
1923
1924   funct->addFnAttr(llvm::Attribute::NoReturn);
1925
1926   // _Unwind_Resume
1927
1928   retType = builder.getInt32Ty();
1929
1930   argTypes.clear();
1931   argTypes.push_back(builder.getInt8PtrTy());
1932
1933   argNames.clear();
1934
1935   funct = createFunction(module,
1936                          retType,
1937                          argTypes,
1938                          argNames,
1939                          "_Unwind_Resume",
1940                          llvm::Function::ExternalLinkage,
1941                          true,
1942                          false);
1943
1944   funct->addFnAttr(llvm::Attribute::NoReturn);
1945
1946   // ourPersonality
1947
1948   retType = builder.getInt32Ty();
1949
1950   argTypes.clear();
1951   argTypes.push_back(builder.getInt32Ty());
1952   argTypes.push_back(builder.getInt32Ty());
1953   argTypes.push_back(builder.getInt64Ty());
1954   argTypes.push_back(builder.getInt8PtrTy());
1955   argTypes.push_back(builder.getInt8PtrTy());
1956
1957   argNames.clear();
1958
1959   createFunction(module,
1960                  retType,
1961                  argTypes,
1962                  argNames,
1963                  "ourPersonality",
1964                  llvm::Function::ExternalLinkage,
1965                  true,
1966                  false);
1967
1968   // llvm.eh.selector intrinsic
1969
1970   getDeclaration(&module, llvm::Intrinsic::eh_selector);
1971
1972   // llvm.eh.exception intrinsic
1973
1974   getDeclaration(&module, llvm::Intrinsic::eh_exception);
1975
1976   // llvm.eh.typeid.for intrinsic
1977
1978   getDeclaration(&module, llvm::Intrinsic::eh_typeid_for);
1979 }
1980
1981
1982 //===----------------------------------------------------------------------===//
1983 // Main test driver code.
1984 //===----------------------------------------------------------------------===//
1985
1986 /// Demo main routine which takes the type info types to throw. A test will
1987 /// be run for each given type info type. While type info types with the value
1988 /// of -1 will trigger a foreign C++ exception to be thrown; type info types
1989 /// <= 6 and >= 1 will be caught by test functions; and type info types > 6
1990 /// will result in exceptions which pass through to the test harness. All other
1991 /// type info types are not supported and could cause a crash.
1992 int main(int argc, char *argv[]) {
1993   if (argc == 1) {
1994     fprintf(stderr,
1995             "\nUsage: ExceptionDemo <exception type to throw> "
1996             "[<type 2>...<type n>].\n"
1997             "   Each type must have the value of 1 - 6 for "
1998             "generated exceptions to be caught;\n"
1999             "   the value -1 for foreign C++ exceptions to be "
2000             "generated and thrown;\n"
2001             "   or the values > 6 for exceptions to be ignored.\n"
2002             "\nTry: ExceptionDemo 2 3 7 -1\n"
2003             "   for a full test.\n\n");
2004     return(0);
2005   }
2006
2007   // If not set, exception handling will not be turned on
2008   llvm::JITExceptionHandling = true;
2009
2010   llvm::InitializeNativeTarget();
2011   llvm::LLVMContext &context = llvm::getGlobalContext();
2012   llvm::IRBuilder<> theBuilder(context);
2013
2014   // Make the module, which holds all the code.
2015   llvm::Module *module = new llvm::Module("my cool jit", context);
2016
2017   // Build engine with JIT
2018   llvm::EngineBuilder factory(module);
2019   factory.setEngineKind(llvm::EngineKind::JIT);
2020   factory.setAllocateGVsWithCode(false);
2021   llvm::ExecutionEngine *executionEngine = factory.create();
2022
2023   {
2024     llvm::FunctionPassManager fpm(module);
2025
2026     // Set up the optimizer pipeline.
2027     // Start with registering info about how the
2028     // target lays out data structures.
2029     fpm.add(new llvm::TargetData(*executionEngine->getTargetData()));
2030
2031     // Optimizations turned on
2032 #ifdef ADD_OPT_PASSES
2033
2034     // Basic AliasAnslysis support for GVN.
2035     fpm.add(llvm::createBasicAliasAnalysisPass());
2036
2037     // Promote allocas to registers.
2038     fpm.add(llvm::createPromoteMemoryToRegisterPass());
2039
2040     // Do simple "peephole" optimizations and bit-twiddling optzns.
2041     fpm.add(llvm::createInstructionCombiningPass());
2042
2043     // Reassociate expressions.
2044     fpm.add(llvm::createReassociatePass());
2045
2046     // Eliminate Common SubExpressions.
2047     fpm.add(llvm::createGVNPass());
2048
2049     // Simplify the control flow graph (deleting unreachable
2050     // blocks, etc).
2051     fpm.add(llvm::createCFGSimplificationPass());
2052 #endif  // ADD_OPT_PASSES
2053
2054     fpm.doInitialization();
2055
2056     // Generate test code using function throwCppException(...) as
2057     // the function which throws foreign exceptions.
2058     llvm::Function *toRun =
2059     createUnwindExceptionTest(*module,
2060                               theBuilder,
2061                               fpm,
2062                               "throwCppException");
2063
2064     fprintf(stderr, "\nBegin module dump:\n\n");
2065
2066     module->dump();
2067
2068     fprintf(stderr, "\nEnd module dump:\n");
2069
2070     fprintf(stderr, "\n\nBegin Test:\n");
2071
2072     for (int i = 1; i < argc; ++i) {
2073       // Run test for each argument whose value is the exception
2074       // type to throw.
2075       runExceptionThrow(executionEngine,
2076                         toRun,
2077                         (unsigned) strtoul(argv[i], NULL, 10));
2078     }
2079
2080     fprintf(stderr, "\nEnd Test:\n\n");
2081   }
2082
2083   delete executionEngine;
2084
2085   return 0;
2086 }
2087