| //===-- ExceptionDemo.cpp - An example using llvm Exceptions --------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Demo program which implements an example LLVM exception implementation, and |
| // shows several test cases including the handling of foreign exceptions. |
| // It is run with type info types arguments to throw. A test will |
| // be run for each given type info type. While type info types with the value |
| // of -1 will trigger a foreign C++ exception to be thrown; type info types |
| // <= 6 and >= 1 will cause the associated generated exceptions to be thrown |
| // and caught by generated test functions; and type info types > 6 |
| // will result in exceptions which pass through to the test harness. All other |
| // type info types are not supported and could cause a crash. In all cases, |
| // the "finally" blocks of every generated test functions will executed |
| // regardless of whether or not that test function ignores or catches the |
| // thrown exception. |
| // |
| // examples: |
| // |
| // ExceptionDemo |
| // |
| // causes a usage to be printed to stderr |
| // |
| // ExceptionDemo 2 3 7 -1 |
| // |
| // results in the following cases: |
| // - Value 2 causes an exception with a type info type of 2 to be |
| // thrown and caught by an inner generated test function. |
| // - Value 3 causes an exception with a type info type of 3 to be |
| // thrown and caught by an outer generated test function. |
| // - Value 7 causes an exception with a type info type of 7 to be |
| // thrown and NOT be caught by any generated function. |
| // - Value -1 causes a foreign C++ exception to be thrown and not be |
| // caught by any generated function |
| // |
| // Cases -1 and 7 are caught by a C++ test harness where the validity of |
| // of a C++ catch(...) clause catching a generated exception with a |
| // type info type of 7 is explained by: example in rules 1.6.4 in |
| // http://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html (v1.22) |
| // |
| // This code uses code from the llvm compiler-rt project and the llvm |
| // Kaleidoscope project. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/ADT/STLExtras.h" |
| #include "llvm/BinaryFormat/Dwarf.h" |
| #include "llvm/ExecutionEngine/Orc/Core.h" |
| #include "llvm/ExecutionEngine/Orc/JITTargetMachineBuilder.h" |
| #include "llvm/ExecutionEngine/Orc/LLJIT.h" |
| #include "llvm/IR/DataLayout.h" |
| #include "llvm/IR/DerivedTypes.h" |
| #include "llvm/IR/IRBuilder.h" |
| #include "llvm/IR/Intrinsics.h" |
| #include "llvm/IR/LLVMContext.h" |
| #include "llvm/IR/LegacyPassManager.h" |
| #include "llvm/IR/Module.h" |
| #include "llvm/IR/Verifier.h" |
| #include "llvm/Support/TargetSelect.h" |
| #include "llvm/Target/TargetOptions.h" |
| #include "llvm/Transforms/Scalar.h" |
| |
| // FIXME: Although all systems tested with (Linux, OS X), do not need this |
| // header file included. A user on ubuntu reported, undefined symbols |
| // for stderr, and fprintf, and the addition of this include fixed the |
| // issue for them. Given that LLVM's best practices include the goal |
| // of reducing the number of redundant header files included, the |
| // correct solution would be to find out why these symbols are not |
| // defined for the system in question, and fix the issue by finding out |
| // which LLVM header file, if any, would include these symbols. |
| #include <cstdio> |
| |
| #include <sstream> |
| #include <stdexcept> |
| |
| #include <inttypes.h> |
| |
| #include <unwind.h> |
| |
| #ifndef USE_GLOBAL_STR_CONSTS |
| #define USE_GLOBAL_STR_CONSTS true |
| #endif |
| |
| llvm::ExitOnError ExitOnErr; |
| |
| // |
| // Example types |
| // |
| |
| /// This is our simplistic type info |
| struct OurExceptionType_t { |
| /// type info type |
| int type; |
| }; |
| |
| |
| /// This is our Exception class which relies on a negative offset to calculate |
| /// pointers to its instances from pointers to its unwindException member. |
| /// |
| /// Note: The above unwind.h defines struct _Unwind_Exception to be aligned |
| /// on a double word boundary. This is necessary to match the standard: |
| /// http://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html |
| struct OurBaseException_t { |
| struct OurExceptionType_t type; |
| |
| // Note: This is properly aligned in unwind.h |
| struct _Unwind_Exception unwindException; |
| }; |
| |
| |
| // Note: Not needed since we are C++ |
| typedef struct OurBaseException_t OurException; |
| typedef struct _Unwind_Exception OurUnwindException; |
| |
| // |
| // Various globals used to support typeinfo and generatted exceptions in |
| // general |
| // |
| |
| static std::map<std::string, llvm::Value*> namedValues; |
| |
| int64_t ourBaseFromUnwindOffset; |
| |
| const unsigned char ourBaseExcpClassChars[] = |
| {'o', 'b', 'j', '\0', 'b', 'a', 's', '\0'}; |
| |
| |
| static uint64_t ourBaseExceptionClass = 0; |
| |
| static std::vector<std::string> ourTypeInfoNames; |
| static std::map<int, std::string> ourTypeInfoNamesIndex; |
| |
| static llvm::StructType *ourTypeInfoType; |
| static llvm::StructType *ourCaughtResultType; |
| static llvm::StructType *ourExceptionType; |
| static llvm::StructType *ourUnwindExceptionType; |
| |
| static llvm::ConstantInt *ourExceptionNotThrownState; |
| static llvm::ConstantInt *ourExceptionThrownState; |
| static llvm::ConstantInt *ourExceptionCaughtState; |
| |
| typedef std::vector<std::string> ArgNames; |
| typedef std::vector<llvm::Type*> ArgTypes; |
| typedef llvm::ArrayRef<llvm::Type *> TypeArray; |
| |
| // |
| // Code Generation Utilities |
| // |
| |
| /// Utility used to create a function, both declarations and definitions |
| /// @param module for module instance |
| /// @param retType function return type |
| /// @param theArgTypes function's ordered argument types |
| /// @param theArgNames function's ordered arguments needed if use of this |
| /// function corresponds to a function definition. Use empty |
| /// aggregate for function declarations. |
| /// @param functName function name |
| /// @param linkage function linkage |
| /// @param declarationOnly for function declarations |
| /// @param isVarArg function uses vararg arguments |
| /// @returns function instance |
| llvm::Function *createFunction(llvm::Module &module, |
| llvm::Type *retType, |
| const ArgTypes &theArgTypes, |
| const ArgNames &theArgNames, |
| const std::string &functName, |
| llvm::GlobalValue::LinkageTypes linkage, |
| bool declarationOnly, |
| bool isVarArg) { |
| llvm::FunctionType *functType = |
| llvm::FunctionType::get(retType, theArgTypes, isVarArg); |
| llvm::Function *ret = |
| llvm::Function::Create(functType, linkage, functName, &module); |
| if (!ret || declarationOnly) |
| return(ret); |
| |
| namedValues.clear(); |
| unsigned i = 0; |
| for (llvm::Function::arg_iterator argIndex = ret->arg_begin(); |
| i != theArgNames.size(); |
| ++argIndex, ++i) { |
| |
| argIndex->setName(theArgNames[i]); |
| namedValues[theArgNames[i]] = argIndex; |
| } |
| |
| return(ret); |
| } |
| |
| |
| /// Create an alloca instruction in the entry block of |
| /// the parent function. This is used for mutable variables etc. |
| /// @param function parent instance |
| /// @param varName stack variable name |
| /// @param type stack variable type |
| /// @param initWith optional constant initialization value |
| /// @returns AllocaInst instance |
| static llvm::AllocaInst *createEntryBlockAlloca(llvm::Function &function, |
| const std::string &varName, |
| llvm::Type *type, |
| llvm::Constant *initWith = 0) { |
| llvm::BasicBlock &block = function.getEntryBlock(); |
| llvm::IRBuilder<> tmp(&block, block.begin()); |
| llvm::AllocaInst *ret = tmp.CreateAlloca(type, 0, varName); |
| |
| if (initWith) |
| tmp.CreateStore(initWith, ret); |
| |
| return(ret); |
| } |
| |
| |
| // |
| // Code Generation Utilities End |
| // |
| |
| // |
| // Runtime C Library functions |
| // |
| |
| namespace { |
| template <typename Type_> |
| uintptr_t ReadType(const uint8_t *&p) { |
| Type_ value; |
| memcpy(&value, p, sizeof(Type_)); |
| p += sizeof(Type_); |
| return static_cast<uintptr_t>(value); |
| } |
| } |
| |
| // Note: using an extern "C" block so that static functions can be used |
| extern "C" { |
| |
| // Note: Better ways to decide on bit width |
| // |
| /// Prints a 32 bit number, according to the format, to stderr. |
| /// @param intToPrint integer to print |
| /// @param format printf like format to use when printing |
| void print32Int(int intToPrint, const char *format) { |
| if (format) { |
| // Note: No NULL check |
| fprintf(stderr, format, intToPrint); |
| } |
| else { |
| // Note: No NULL check |
| fprintf(stderr, "::print32Int(...):NULL arg.\n"); |
| } |
| } |
| |
| |
| // Note: Better ways to decide on bit width |
| // |
| /// Prints a 64 bit number, according to the format, to stderr. |
| /// @param intToPrint integer to print |
| /// @param format printf like format to use when printing |
| void print64Int(long int intToPrint, const char *format) { |
| if (format) { |
| // Note: No NULL check |
| fprintf(stderr, format, intToPrint); |
| } |
| else { |
| // Note: No NULL check |
| fprintf(stderr, "::print64Int(...):NULL arg.\n"); |
| } |
| } |
| |
| |
| /// Prints a C string to stderr |
| /// @param toPrint string to print |
| void printStr(char *toPrint) { |
| if (toPrint) { |
| fprintf(stderr, "%s", toPrint); |
| } |
| else { |
| fprintf(stderr, "::printStr(...):NULL arg.\n"); |
| } |
| } |
| |
| |
| /// Deletes the true previously allocated exception whose address |
| /// is calculated from the supplied OurBaseException_t::unwindException |
| /// member address. Handles (ignores), NULL pointers. |
| /// @param expToDelete exception to delete |
| void deleteOurException(OurUnwindException *expToDelete) { |
| #ifdef DEBUG |
| fprintf(stderr, |
| "deleteOurException(...).\n"); |
| #endif |
| |
| if (expToDelete && |
| (expToDelete->exception_class == ourBaseExceptionClass)) { |
| |
| free(((char*) expToDelete) + ourBaseFromUnwindOffset); |
| } |
| } |
| |
| |
| /// This function is the struct _Unwind_Exception API mandated delete function |
| /// used by foreign exception handlers when deleting our exception |
| /// (OurException), instances. |
| /// @param reason See @link http://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html |
| /// @unlink |
| /// @param expToDelete exception instance to delete |
| void deleteFromUnwindOurException(_Unwind_Reason_Code reason, |
| OurUnwindException *expToDelete) { |
| #ifdef DEBUG |
| fprintf(stderr, |
| "deleteFromUnwindOurException(...).\n"); |
| #endif |
| |
| deleteOurException(expToDelete); |
| } |
| |
| |
| /// Creates (allocates on the heap), an exception (OurException instance), |
| /// of the supplied type info type. |
| /// @param type type info type |
| OurUnwindException *createOurException(int type) { |
| size_t size = sizeof(OurException); |
| OurException *ret = (OurException*) memset(malloc(size), 0, size); |
| (ret->type).type = type; |
| (ret->unwindException).exception_class = ourBaseExceptionClass; |
| (ret->unwindException).exception_cleanup = deleteFromUnwindOurException; |
| |
| return(&(ret->unwindException)); |
| } |
| |
| |
| /// Read a uleb128 encoded value and advance pointer |
| /// See Variable Length Data in: |
| /// @link http://dwarfstd.org/Dwarf3.pdf @unlink |
| /// @param data reference variable holding memory pointer to decode from |
| /// @returns decoded value |
| static uintptr_t readULEB128(const uint8_t **data) { |
| uintptr_t result = 0; |
| uintptr_t shift = 0; |
| unsigned char byte; |
| const uint8_t *p = *data; |
| |
| do { |
| byte = *p++; |
| result |= (byte & 0x7f) << shift; |
| shift += 7; |
| } |
| while (byte & 0x80); |
| |
| *data = p; |
| |
| return result; |
| } |
| |
| |
| /// Read a sleb128 encoded value and advance pointer |
| /// See Variable Length Data in: |
| /// @link http://dwarfstd.org/Dwarf3.pdf @unlink |
| /// @param data reference variable holding memory pointer to decode from |
| /// @returns decoded value |
| static uintptr_t readSLEB128(const uint8_t **data) { |
| uintptr_t result = 0; |
| uintptr_t shift = 0; |
| unsigned char byte; |
| const uint8_t *p = *data; |
| |
| do { |
| byte = *p++; |
| result |= (byte & 0x7f) << shift; |
| shift += 7; |
| } |
| while (byte & 0x80); |
| |
| *data = p; |
| |
| if ((byte & 0x40) && (shift < (sizeof(result) << 3))) { |
| result |= (~0 << shift); |
| } |
| |
| return result; |
| } |
| |
| unsigned getEncodingSize(uint8_t Encoding) { |
| if (Encoding == llvm::dwarf::DW_EH_PE_omit) |
| return 0; |
| |
| switch (Encoding & 0x0F) { |
| case llvm::dwarf::DW_EH_PE_absptr: |
| return sizeof(uintptr_t); |
| case llvm::dwarf::DW_EH_PE_udata2: |
| return sizeof(uint16_t); |
| case llvm::dwarf::DW_EH_PE_udata4: |
| return sizeof(uint32_t); |
| case llvm::dwarf::DW_EH_PE_udata8: |
| return sizeof(uint64_t); |
| case llvm::dwarf::DW_EH_PE_sdata2: |
| return sizeof(int16_t); |
| case llvm::dwarf::DW_EH_PE_sdata4: |
| return sizeof(int32_t); |
| case llvm::dwarf::DW_EH_PE_sdata8: |
| return sizeof(int64_t); |
| default: |
| // not supported |
| abort(); |
| } |
| } |
| |
| /// Read a pointer encoded value and advance pointer |
| /// See Variable Length Data in: |
| /// @link http://dwarfstd.org/Dwarf3.pdf @unlink |
| /// @param data reference variable holding memory pointer to decode from |
| /// @param encoding dwarf encoding type |
| /// @returns decoded value |
| static uintptr_t readEncodedPointer(const uint8_t **data, uint8_t encoding) { |
| uintptr_t result = 0; |
| const uint8_t *p = *data; |
| |
| if (encoding == llvm::dwarf::DW_EH_PE_omit) |
| return(result); |
| |
| // first get value |
| switch (encoding & 0x0F) { |
| case llvm::dwarf::DW_EH_PE_absptr: |
| result = ReadType<uintptr_t>(p); |
| break; |
| case llvm::dwarf::DW_EH_PE_uleb128: |
| result = readULEB128(&p); |
| break; |
| // Note: This case has not been tested |
| case llvm::dwarf::DW_EH_PE_sleb128: |
| result = readSLEB128(&p); |
| break; |
| case llvm::dwarf::DW_EH_PE_udata2: |
| result = ReadType<uint16_t>(p); |
| break; |
| case llvm::dwarf::DW_EH_PE_udata4: |
| result = ReadType<uint32_t>(p); |
| break; |
| case llvm::dwarf::DW_EH_PE_udata8: |
| result = ReadType<uint64_t>(p); |
| break; |
| case llvm::dwarf::DW_EH_PE_sdata2: |
| result = ReadType<int16_t>(p); |
| break; |
| case llvm::dwarf::DW_EH_PE_sdata4: |
| result = ReadType<int32_t>(p); |
| break; |
| case llvm::dwarf::DW_EH_PE_sdata8: |
| result = ReadType<int64_t>(p); |
| break; |
| default: |
| // not supported |
| abort(); |
| break; |
| } |
| |
| // then add relative offset |
| switch (encoding & 0x70) { |
| case llvm::dwarf::DW_EH_PE_absptr: |
| // do nothing |
| break; |
| case llvm::dwarf::DW_EH_PE_pcrel: |
| result += (uintptr_t)(*data); |
| break; |
| case llvm::dwarf::DW_EH_PE_textrel: |
| case llvm::dwarf::DW_EH_PE_datarel: |
| case llvm::dwarf::DW_EH_PE_funcrel: |
| case llvm::dwarf::DW_EH_PE_aligned: |
| default: |
| // not supported |
| abort(); |
| break; |
| } |
| |
| // then apply indirection |
| if (encoding & llvm::dwarf::DW_EH_PE_indirect) { |
| result = *((uintptr_t*)result); |
| } |
| |
| *data = p; |
| |
| return result; |
| } |
| |
| |
| /// Deals with Dwarf actions matching our type infos |
| /// (OurExceptionType_t instances). Returns whether or not a dwarf emitted |
| /// action matches the supplied exception type. If such a match succeeds, |
| /// the resultAction argument will be set with > 0 index value. Only |
| /// corresponding llvm.eh.selector type info arguments, cleanup arguments |
| /// are supported. Filters are not supported. |
| /// See Variable Length Data in: |
| /// @link http://dwarfstd.org/Dwarf3.pdf @unlink |
| /// Also see @link http://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html @unlink |
| /// @param resultAction reference variable which will be set with result |
| /// @param classInfo our array of type info pointers (to globals) |
| /// @param actionEntry index into above type info array or 0 (clean up). |
| /// We do not support filters. |
| /// @param exceptionClass exception class (_Unwind_Exception::exception_class) |
| /// of thrown exception. |
| /// @param exceptionObject thrown _Unwind_Exception instance. |
| /// @returns whether or not a type info was found. False is returned if only |
| /// a cleanup was found |
| static bool handleActionValue(int64_t *resultAction, |
| uint8_t TTypeEncoding, |
| const uint8_t *ClassInfo, |
| uintptr_t actionEntry, |
| uint64_t exceptionClass, |
| struct _Unwind_Exception *exceptionObject) { |
| bool ret = false; |
| |
| if (!resultAction || |
| !exceptionObject || |
| (exceptionClass != ourBaseExceptionClass)) |
| return(ret); |
| |
| struct OurBaseException_t *excp = (struct OurBaseException_t*) |
| (((char*) exceptionObject) + ourBaseFromUnwindOffset); |
| struct OurExceptionType_t *excpType = &(excp->type); |
| int type = excpType->type; |
| |
| #ifdef DEBUG |
| fprintf(stderr, |
| "handleActionValue(...): exceptionObject = <%p>, " |
| "excp = <%p>.\n", |
| (void*)exceptionObject, |
| (void*)excp); |
| #endif |
| |
| const uint8_t *actionPos = (uint8_t*) actionEntry, |
| *tempActionPos; |
| int64_t typeOffset = 0, |
| actionOffset; |
| |
| for (int i = 0; true; ++i) { |
| // Each emitted dwarf action corresponds to a 2 tuple of |
| // type info address offset, and action offset to the next |
| // emitted action. |
| typeOffset = readSLEB128(&actionPos); |
| tempActionPos = actionPos; |
| actionOffset = readSLEB128(&tempActionPos); |
| |
| #ifdef DEBUG |
| fprintf(stderr, |
| "handleActionValue(...):typeOffset: <%" PRIi64 ">, " |
| "actionOffset: <%" PRIi64 ">.\n", |
| typeOffset, |
| actionOffset); |
| #endif |
| assert((typeOffset >= 0) && |
| "handleActionValue(...):filters are not supported."); |
| |
| // Note: A typeOffset == 0 implies that a cleanup llvm.eh.selector |
| // argument has been matched. |
| if (typeOffset > 0) { |
| #ifdef DEBUG |
| fprintf(stderr, |
| "handleActionValue(...):actionValue <%d> found.\n", |
| i); |
| #endif |
| unsigned EncSize = getEncodingSize(TTypeEncoding); |
| const uint8_t *EntryP = ClassInfo - typeOffset * EncSize; |
| uintptr_t P = readEncodedPointer(&EntryP, TTypeEncoding); |
| struct OurExceptionType_t *ThisClassInfo = |
| reinterpret_cast<struct OurExceptionType_t *>(P); |
| if (ThisClassInfo->type == type) { |
| *resultAction = i + 1; |
| ret = true; |
| break; |
| } |
| } |
| |
| #ifdef DEBUG |
| fprintf(stderr, |
| "handleActionValue(...):actionValue not found.\n"); |
| #endif |
| if (!actionOffset) |
| break; |
| |
| actionPos += actionOffset; |
| } |
| |
| return(ret); |
| } |
| |
| |
| /// Deals with the Language specific data portion of the emitted dwarf code. |
| /// See @link http://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html @unlink |
| /// @param version unsupported (ignored), unwind version |
| /// @param lsda language specific data area |
| /// @param _Unwind_Action actions minimally supported unwind stage |
| /// (forced specifically not supported) |
| /// @param exceptionClass exception class (_Unwind_Exception::exception_class) |
| /// of thrown exception. |
| /// @param exceptionObject thrown _Unwind_Exception instance. |
| /// @param context unwind system context |
| /// @returns minimally supported unwinding control indicator |
| static _Unwind_Reason_Code handleLsda(int version, const uint8_t *lsda, |
| _Unwind_Action actions, |
| _Unwind_Exception_Class exceptionClass, |
| struct _Unwind_Exception *exceptionObject, |
| struct _Unwind_Context *context) { |
| _Unwind_Reason_Code ret = _URC_CONTINUE_UNWIND; |
| |
| if (!lsda) |
| return(ret); |
| |
| #ifdef DEBUG |
| fprintf(stderr, |
| "handleLsda(...):lsda is non-zero.\n"); |
| #endif |
| |
| // Get the current instruction pointer and offset it before next |
| // instruction in the current frame which threw the exception. |
| uintptr_t pc = _Unwind_GetIP(context)-1; |
| |
| // Get beginning current frame's code (as defined by the |
| // emitted dwarf code) |
| uintptr_t funcStart = _Unwind_GetRegionStart(context); |
| uintptr_t pcOffset = pc - funcStart; |
| const uint8_t *ClassInfo = NULL; |
| |
| // Note: See JITDwarfEmitter::EmitExceptionTable(...) for corresponding |
| // dwarf emission |
| |
| // Parse LSDA header. |
| uint8_t lpStartEncoding = *lsda++; |
| |
| if (lpStartEncoding != llvm::dwarf::DW_EH_PE_omit) { |
| readEncodedPointer(&lsda, lpStartEncoding); |
| } |
| |
| uint8_t ttypeEncoding = *lsda++; |
| uintptr_t classInfoOffset; |
| |
| if (ttypeEncoding != llvm::dwarf::DW_EH_PE_omit) { |
| // Calculate type info locations in emitted dwarf code which |
| // were flagged by type info arguments to llvm.eh.selector |
| // intrinsic |
| classInfoOffset = readULEB128(&lsda); |
| ClassInfo = lsda + classInfoOffset; |
| } |
| |
| // Walk call-site table looking for range that |
| // includes current PC. |
| |
| uint8_t callSiteEncoding = *lsda++; |
| uint32_t callSiteTableLength = readULEB128(&lsda); |
| const uint8_t *callSiteTableStart = lsda; |
| const uint8_t *callSiteTableEnd = callSiteTableStart + |
| callSiteTableLength; |
| const uint8_t *actionTableStart = callSiteTableEnd; |
| const uint8_t *callSitePtr = callSiteTableStart; |
| |
| while (callSitePtr < callSiteTableEnd) { |
| uintptr_t start = readEncodedPointer(&callSitePtr, |
| callSiteEncoding); |
| uintptr_t length = readEncodedPointer(&callSitePtr, |
| callSiteEncoding); |
| uintptr_t landingPad = readEncodedPointer(&callSitePtr, |
| callSiteEncoding); |
| |
| // Note: Action value |
| uintptr_t actionEntry = readULEB128(&callSitePtr); |
| |
| if (exceptionClass != ourBaseExceptionClass) { |
| // We have been notified of a foreign exception being thrown, |
| // and we therefore need to execute cleanup landing pads |
| actionEntry = 0; |
| } |
| |
| if (landingPad == 0) { |
| #ifdef DEBUG |
| fprintf(stderr, |
| "handleLsda(...): No landing pad found.\n"); |
| #endif |
| |
| continue; // no landing pad for this entry |
| } |
| |
| if (actionEntry) { |
| actionEntry += ((uintptr_t) actionTableStart) - 1; |
| } |
| else { |
| #ifdef DEBUG |
| fprintf(stderr, |
| "handleLsda(...):No action table found.\n"); |
| #endif |
| } |
| |
| bool exceptionMatched = false; |
| |
| if ((start <= pcOffset) && (pcOffset < (start + length))) { |
| #ifdef DEBUG |
| fprintf(stderr, |
| "handleLsda(...): Landing pad found.\n"); |
| #endif |
| int64_t actionValue = 0; |
| |
| if (actionEntry) { |
| exceptionMatched = handleActionValue(&actionValue, |
| ttypeEncoding, |
| ClassInfo, |
| actionEntry, |
| exceptionClass, |
| exceptionObject); |
| } |
| |
| if (!(actions & _UA_SEARCH_PHASE)) { |
| #ifdef DEBUG |
| fprintf(stderr, |
| "handleLsda(...): installed landing pad " |
| "context.\n"); |
| #endif |
| |
| // Found landing pad for the PC. |
| // Set Instruction Pointer to so we re-enter function |
| // at landing pad. The landing pad is created by the |
| // compiler to take two parameters in registers. |
| _Unwind_SetGR(context, |
| __builtin_eh_return_data_regno(0), |
| (uintptr_t)exceptionObject); |
| |
| // Note: this virtual register directly corresponds |
| // to the return of the llvm.eh.selector intrinsic |
| if (!actionEntry || !exceptionMatched) { |
| // We indicate cleanup only |
| _Unwind_SetGR(context, |
| __builtin_eh_return_data_regno(1), |
| 0); |
| } |
| else { |
| // Matched type info index of llvm.eh.selector intrinsic |
| // passed here. |
| _Unwind_SetGR(context, |
| __builtin_eh_return_data_regno(1), |
| actionValue); |
| } |
| |
| // To execute landing pad set here |
| _Unwind_SetIP(context, funcStart + landingPad); |
| ret = _URC_INSTALL_CONTEXT; |
| } |
| else if (exceptionMatched) { |
| #ifdef DEBUG |
| fprintf(stderr, |
| "handleLsda(...): setting handler found.\n"); |
| #endif |
| ret = _URC_HANDLER_FOUND; |
| } |
| else { |
| // Note: Only non-clean up handlers are marked as |
| // found. Otherwise the clean up handlers will be |
| // re-found and executed during the clean up |
| // phase. |
| #ifdef DEBUG |
| fprintf(stderr, |
| "handleLsda(...): cleanup handler found.\n"); |
| #endif |
| } |
| |
| break; |
| } |
| } |
| |
| return(ret); |
| } |
| |
| |
| /// This is the personality function which is embedded (dwarf emitted), in the |
| /// dwarf unwind info block. Again see: JITDwarfEmitter.cpp. |
| /// See @link http://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html @unlink |
| /// @param version unsupported (ignored), unwind version |
| /// @param _Unwind_Action actions minimally supported unwind stage |
| /// (forced specifically not supported) |
| /// @param exceptionClass exception class (_Unwind_Exception::exception_class) |
| /// of thrown exception. |
| /// @param exceptionObject thrown _Unwind_Exception instance. |
| /// @param context unwind system context |
| /// @returns minimally supported unwinding control indicator |
| _Unwind_Reason_Code ourPersonality(int version, _Unwind_Action actions, |
| _Unwind_Exception_Class exceptionClass, |
| struct _Unwind_Exception *exceptionObject, |
| struct _Unwind_Context *context) { |
| #ifdef DEBUG |
| fprintf(stderr, |
| "We are in ourPersonality(...):actions is <%d>.\n", |
| actions); |
| |
| if (actions & _UA_SEARCH_PHASE) { |
| fprintf(stderr, "ourPersonality(...):In search phase.\n"); |
| } |
| else { |
| fprintf(stderr, "ourPersonality(...):In non-search phase.\n"); |
| } |
| #endif |
| |
| const uint8_t *lsda = (const uint8_t *)_Unwind_GetLanguageSpecificData(context); |
| |
| #ifdef DEBUG |
| fprintf(stderr, |
| "ourPersonality(...):lsda = <%p>.\n", |
| (void*)lsda); |
| #endif |
| |
| // The real work of the personality function is captured here |
| return(handleLsda(version, |
| lsda, |
| actions, |
| exceptionClass, |
| exceptionObject, |
| context)); |
| } |
| |
| |
| /// Generates our _Unwind_Exception class from a given character array. |
| /// thereby handling arbitrary lengths (not in standard), and handling |
| /// embedded \0s. |
| /// See @link http://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html @unlink |
| /// @param classChars char array to encode. NULL values not checkedf |
| /// @param classCharsSize number of chars in classChars. Value is not checked. |
| /// @returns class value |
| uint64_t genClass(const unsigned char classChars[], size_t classCharsSize) |
| { |
| uint64_t ret = classChars[0]; |
| |
| for (unsigned i = 1; i < classCharsSize; ++i) { |
| ret <<= 8; |
| ret += classChars[i]; |
| } |
| |
| return(ret); |
| } |
| |
| } // extern "C" |
| |
| // |
| // Runtime C Library functions End |
| // |
| |
| // |
| // Code generation functions |
| // |
| |
| /// Generates code to print given constant string |
| /// @param context llvm context |
| /// @param module code for module instance |
| /// @param builder builder instance |
| /// @param toPrint string to print |
| /// @param useGlobal A value of true (default) indicates a GlobalValue is |
| /// generated, and is used to hold the constant string. A value of |
| /// false indicates that the constant string will be stored on the |
| /// stack. |
| void generateStringPrint(llvm::LLVMContext &context, |
| llvm::Module &module, |
| llvm::IRBuilder<> &builder, |
| std::string toPrint, |
| bool useGlobal = true) { |
| llvm::Function *printFunct = module.getFunction("printStr"); |
| |
| llvm::Value *stringVar; |
| llvm::Constant *stringConstant = |
| llvm::ConstantDataArray::getString(context, toPrint); |
| |
| if (useGlobal) { |
| // Note: Does not work without allocation |
| stringVar = |
| new llvm::GlobalVariable(module, |
| stringConstant->getType(), |
| true, |
| llvm::GlobalValue::PrivateLinkage, |
| stringConstant, |
| ""); |
| } |
| else { |
| stringVar = builder.CreateAlloca(stringConstant->getType()); |
| builder.CreateStore(stringConstant, stringVar); |
| } |
| |
| llvm::Value *cast = builder.CreatePointerCast(stringVar, |
| builder.getPtrTy()); |
| builder.CreateCall(printFunct, cast); |
| } |
| |
| /// Generates code to print given runtime integer according to constant |
| /// string format, and a given print function. |
| /// @param context llvm context |
| /// @param module code for module instance |
| /// @param builder builder instance |
| /// @param printFunct function used to "print" integer |
| /// @param toPrint string to print |
| /// @param format printf like formatting string for print |
| /// @param useGlobal A value of true (default) indicates a GlobalValue is |
| /// generated, and is used to hold the constant string. A value of |
| /// false indicates that the constant string will be stored on the |
| /// stack. |
| void generateIntegerPrint(llvm::LLVMContext &context, llvm::Module &module, |
| llvm::IRBuilder<> &builder, |
| llvm::Function &printFunct, llvm::Value *toPrint, |
| std::string format, bool useGlobal = true) { |
| llvm::Constant *stringConstant = |
| llvm::ConstantDataArray::getString(context, format); |
| llvm::Value *stringVar; |
| |
| if (useGlobal) { |
| // Note: Does not seem to work without allocation |
| stringVar = |
| new llvm::GlobalVariable(module, |
| stringConstant->getType(), |
| true, |
| llvm::GlobalValue::PrivateLinkage, |
| stringConstant, |
| ""); |
| } |
| else { |
| stringVar = builder.CreateAlloca(stringConstant->getType()); |
| builder.CreateStore(stringConstant, stringVar); |
| } |
| |
| llvm::Value *cast = builder.CreateBitCast(stringVar, |
| builder.getPtrTy()); |
| builder.CreateCall(&printFunct, {toPrint, cast}); |
| } |
| |
| /// Generates code to handle finally block type semantics: always runs |
| /// regardless of whether a thrown exception is passing through or the |
| /// parent function is simply exiting. In addition to printing some state |
| /// to stderr, this code will resume the exception handling--runs the |
| /// unwind resume block, if the exception has not been previously caught |
| /// by a catch clause, and will otherwise execute the end block (terminator |
| /// block). In addition this function creates the corresponding function's |
| /// stack storage for the exception pointer and catch flag status. |
| /// @param context llvm context |
| /// @param module code for module instance |
| /// @param builder builder instance |
| /// @param toAddTo parent function to add block to |
| /// @param blockName block name of new "finally" block. |
| /// @param functionId output id used for printing |
| /// @param terminatorBlock terminator "end" block |
| /// @param unwindResumeBlock unwind resume block |
| /// @param exceptionCaughtFlag reference exception caught/thrown status storage |
| /// @param exceptionStorage reference to exception pointer storage |
| /// @param caughtResultStorage reference to landingpad result storage |
| /// @returns newly created block |
| static llvm::BasicBlock *createFinallyBlock(llvm::LLVMContext &context, |
| llvm::Module &module, |
| llvm::IRBuilder<> &builder, |
| llvm::Function &toAddTo, |
| std::string &blockName, |
| std::string &functionId, |
| llvm::BasicBlock &terminatorBlock, |
| llvm::BasicBlock &unwindResumeBlock, |
| llvm::Value **exceptionCaughtFlag, |
| llvm::Value **exceptionStorage, |
| llvm::Value **caughtResultStorage) { |
| assert(exceptionCaughtFlag && |
| "ExceptionDemo::createFinallyBlock(...):exceptionCaughtFlag " |
| "is NULL"); |
| assert(exceptionStorage && |
| "ExceptionDemo::createFinallyBlock(...):exceptionStorage " |
| "is NULL"); |
| assert(caughtResultStorage && |
| "ExceptionDemo::createFinallyBlock(...):caughtResultStorage " |
| "is NULL"); |
| |
| *exceptionCaughtFlag = createEntryBlockAlloca(toAddTo, |
| "exceptionCaught", |
| ourExceptionNotThrownState->getType(), |
| ourExceptionNotThrownState); |
| |
| llvm::PointerType *exceptionStorageType = builder.getPtrTy(); |
| *exceptionStorage = createEntryBlockAlloca(toAddTo, |
| "exceptionStorage", |
| exceptionStorageType, |
| llvm::ConstantPointerNull::get( |
| exceptionStorageType)); |
| *caughtResultStorage = createEntryBlockAlloca(toAddTo, |
| "caughtResultStorage", |
| ourCaughtResultType, |
| llvm::ConstantAggregateZero::get( |
| ourCaughtResultType)); |
| |
| llvm::BasicBlock *ret = llvm::BasicBlock::Create(context, |
| blockName, |
| &toAddTo); |
| |
| builder.SetInsertPoint(ret); |
| |
| std::ostringstream bufferToPrint; |
| bufferToPrint << "Gen: Executing finally block " |
| << blockName << " in " << functionId << "\n"; |
| generateStringPrint(context, |
| module, |
| builder, |
| bufferToPrint.str(), |
| USE_GLOBAL_STR_CONSTS); |
| |
| llvm::SwitchInst *theSwitch = builder.CreateSwitch( |
| builder.CreateLoad(ourExceptionNotThrownState->getType(), |
| *exceptionCaughtFlag), |
| &terminatorBlock, 2); |
| theSwitch->addCase(ourExceptionCaughtState, &terminatorBlock); |
| theSwitch->addCase(ourExceptionThrownState, &unwindResumeBlock); |
| |
| return(ret); |
| } |
| |
| |
| /// Generates catch block semantics which print a string to indicate type of |
| /// catch executed, sets an exception caught flag, and executes passed in |
| /// end block (terminator block). |
| /// @param context llvm context |
| /// @param module code for module instance |
| /// @param builder builder instance |
| /// @param toAddTo parent function to add block to |
| /// @param blockName block name of new "catch" block. |
| /// @param functionId output id used for printing |
| /// @param terminatorBlock terminator "end" block |
| /// @param exceptionCaughtFlag exception caught/thrown status |
| /// @returns newly created block |
| static llvm::BasicBlock *createCatchBlock(llvm::LLVMContext &context, |
| llvm::Module &module, |
| llvm::IRBuilder<> &builder, |
| llvm::Function &toAddTo, |
| std::string &blockName, |
| std::string &functionId, |
| llvm::BasicBlock &terminatorBlock, |
| llvm::Value &exceptionCaughtFlag) { |
| |
| llvm::BasicBlock *ret = llvm::BasicBlock::Create(context, |
| blockName, |
| &toAddTo); |
| |
| builder.SetInsertPoint(ret); |
| |
| std::ostringstream bufferToPrint; |
| bufferToPrint << "Gen: Executing catch block " |
| << blockName |
| << " in " |
| << functionId |
| << std::endl; |
| generateStringPrint(context, |
| module, |
| builder, |
| bufferToPrint.str(), |
| USE_GLOBAL_STR_CONSTS); |
| builder.CreateStore(ourExceptionCaughtState, &exceptionCaughtFlag); |
| builder.CreateBr(&terminatorBlock); |
| |
| return(ret); |
| } |
| |
| |
| /// Generates a function which invokes a function (toInvoke) and, whose |
| /// unwind block will "catch" the type info types correspondingly held in the |
| /// exceptionTypesToCatch argument. If the toInvoke function throws an |
| /// exception which does not match any type info types contained in |
| /// exceptionTypesToCatch, the generated code will call _Unwind_Resume |
| /// with the raised exception. On the other hand the generated code will |
| /// normally exit if the toInvoke function does not throw an exception. |
| /// The generated "finally" block is always run regardless of the cause of |
| /// the generated function exit. |
| /// The generated function is returned after being verified. |
| /// @param module code for module instance |
| /// @param builder builder instance |
| /// @param fpm a function pass manager holding optional IR to IR |
| /// transformations |
| /// @param toInvoke inner function to invoke |
| /// @param ourId id used to printing purposes |
| /// @param numExceptionsToCatch length of exceptionTypesToCatch array |
| /// @param exceptionTypesToCatch array of type info types to "catch" |
| /// @returns generated function |
| static llvm::Function *createCatchWrappedInvokeFunction( |
| llvm::Module &module, llvm::IRBuilder<> &builder, |
| llvm::legacy::FunctionPassManager &fpm, llvm::Function &toInvoke, |
| std::string ourId, unsigned numExceptionsToCatch, |
| unsigned exceptionTypesToCatch[]) { |
| |
| llvm::LLVMContext &context = module.getContext(); |
| llvm::Function *toPrint32Int = module.getFunction("print32Int"); |
| |
| ArgTypes argTypes; |
| argTypes.push_back(builder.getInt32Ty()); |
| |
| ArgNames argNames; |
| argNames.push_back("exceptTypeToThrow"); |
| |
| llvm::Function *ret = createFunction(module, |
| builder.getVoidTy(), |
| argTypes, |
| argNames, |
| ourId, |
| llvm::Function::ExternalLinkage, |
| false, |
| false); |
| |
| // Block which calls invoke |
| llvm::BasicBlock *entryBlock = llvm::BasicBlock::Create(context, |
| "entry", |
| ret); |
| // Normal block for invoke |
| llvm::BasicBlock *normalBlock = llvm::BasicBlock::Create(context, |
| "normal", |
| ret); |
| // Unwind block for invoke |
| llvm::BasicBlock *exceptionBlock = llvm::BasicBlock::Create(context, |
| "exception", |
| ret); |
| |
| // Block which routes exception to correct catch handler block |
| llvm::BasicBlock *exceptionRouteBlock = llvm::BasicBlock::Create(context, |
| "exceptionRoute", |
| ret); |
| |
| // Foreign exception handler |
| llvm::BasicBlock *externalExceptionBlock = llvm::BasicBlock::Create(context, |
| "externalException", |
| ret); |
| |
| // Block which calls _Unwind_Resume |
| llvm::BasicBlock *unwindResumeBlock = llvm::BasicBlock::Create(context, |
| "unwindResume", |
| ret); |
| |
| // Clean up block which delete exception if needed |
| llvm::BasicBlock *endBlock = llvm::BasicBlock::Create(context, "end", ret); |
| |
| std::string nextName; |
| std::vector<llvm::BasicBlock*> catchBlocks(numExceptionsToCatch); |
| llvm::Value *exceptionCaughtFlag = NULL; |
| llvm::Value *exceptionStorage = NULL; |
| llvm::Value *caughtResultStorage = NULL; |
| |
| // Finally block which will branch to unwindResumeBlock if |
| // exception is not caught. Initializes/allocates stack locations. |
| llvm::BasicBlock *finallyBlock = createFinallyBlock(context, |
| module, |
| builder, |
| *ret, |
| nextName = "finally", |
| ourId, |
| *endBlock, |
| *unwindResumeBlock, |
| &exceptionCaughtFlag, |
| &exceptionStorage, |
| &caughtResultStorage |
| ); |
| |
| for (unsigned i = 0; i < numExceptionsToCatch; ++i) { |
| nextName = ourTypeInfoNames[exceptionTypesToCatch[i]]; |
| |
| // One catch block per type info to be caught |
| catchBlocks[i] = createCatchBlock(context, |
| module, |
| builder, |
| *ret, |
| nextName, |
| ourId, |
| *finallyBlock, |
| *exceptionCaughtFlag); |
| } |
| |
| // Entry Block |
| |
| builder.SetInsertPoint(entryBlock); |
| |
| std::vector<llvm::Value*> args; |
| args.push_back(namedValues["exceptTypeToThrow"]); |
| builder.CreateInvoke(&toInvoke, |
| normalBlock, |
| exceptionBlock, |
| args); |
| |
| // End Block |
| |
| builder.SetInsertPoint(endBlock); |
| |
| generateStringPrint(context, |
| module, |
| builder, |
| "Gen: In end block: exiting in " + ourId + ".\n", |
| USE_GLOBAL_STR_CONSTS); |
| llvm::Function *deleteOurException = module.getFunction("deleteOurException"); |
| |
| // Note: function handles NULL exceptions |
| builder.CreateCall(deleteOurException, |
| builder.CreateLoad(builder.getPtrTy(), exceptionStorage)); |
| builder.CreateRetVoid(); |
| |
| // Normal Block |
| |
| builder.SetInsertPoint(normalBlock); |
| |
| generateStringPrint(context, |
| module, |
| builder, |
| "Gen: No exception in " + ourId + "!\n", |
| USE_GLOBAL_STR_CONSTS); |
| |
| // Finally block is always called |
| builder.CreateBr(finallyBlock); |
| |
| // Unwind Resume Block |
| |
| builder.SetInsertPoint(unwindResumeBlock); |
| |
| builder.CreateResume( |
| builder.CreateLoad(ourCaughtResultType, caughtResultStorage)); |
| |
| // Exception Block |
| |
| builder.SetInsertPoint(exceptionBlock); |
| |
| llvm::Function *personality = module.getFunction("ourPersonality"); |
| ret->setPersonalityFn(personality); |
| |
| llvm::LandingPadInst *caughtResult = |
| builder.CreateLandingPad(ourCaughtResultType, |
| numExceptionsToCatch, |
| "landingPad"); |
| |
| caughtResult->setCleanup(true); |
| |
| for (unsigned i = 0; i < numExceptionsToCatch; ++i) { |
| // Set up type infos to be caught |
| caughtResult->addClause(module.getGlobalVariable( |
| ourTypeInfoNames[exceptionTypesToCatch[i]])); |
| } |
| |
| llvm::Value *unwindException = builder.CreateExtractValue(caughtResult, 0); |
| llvm::Value *retTypeInfoIndex = builder.CreateExtractValue(caughtResult, 1); |
| |
| // FIXME: Redundant storage which, beyond utilizing value of |
| // caughtResultStore for unwindException storage, may be alleviated |
| // altogether with a block rearrangement |
| builder.CreateStore(caughtResult, caughtResultStorage); |
| builder.CreateStore(unwindException, exceptionStorage); |
| builder.CreateStore(ourExceptionThrownState, exceptionCaughtFlag); |
| |
| // Retrieve exception_class member from thrown exception |
| // (_Unwind_Exception instance). This member tells us whether or not |
| // the exception is foreign. |
| llvm::Value *unwindExceptionClass = builder.CreateLoad( |
| builder.getInt64Ty(), |
| builder.CreateStructGEP(ourUnwindExceptionType, unwindException, 0)); |
| |
| // Branch to the externalExceptionBlock if the exception is foreign or |
| // to a catch router if not. Either way the finally block will be run. |
| builder.CreateCondBr(builder.CreateICmpEQ(unwindExceptionClass, |
| llvm::ConstantInt::get(builder.getInt64Ty(), |
| ourBaseExceptionClass)), |
| exceptionRouteBlock, |
| externalExceptionBlock); |
| |
| // External Exception Block |
| |
| builder.SetInsertPoint(externalExceptionBlock); |
| |
| generateStringPrint(context, |
| module, |
| builder, |
| "Gen: Foreign exception received.\n", |
| USE_GLOBAL_STR_CONSTS); |
| |
| // Branch to the finally block |
| builder.CreateBr(finallyBlock); |
| |
| // Exception Route Block |
| |
| builder.SetInsertPoint(exceptionRouteBlock); |
| |
| // Casts exception pointer (_Unwind_Exception instance) to parent |
| // (OurException instance). |
| // |
| // Note: ourBaseFromUnwindOffset is usually negative |
| llvm::Value *typeInfoThrown = builder.CreateConstGEP1_64( |
| builder.getInt8Ty(), unwindException, ourBaseFromUnwindOffset); |
| |
| // Retrieve thrown exception type info type |
| // |
| // Note: Index is not relative to pointer but instead to structure |
| // unlike a true getelementptr (GEP) instruction |
| typeInfoThrown = builder.CreateStructGEP(ourExceptionType, typeInfoThrown, 0); |
| |
| llvm::Value *typeInfoThrownType = |
| builder.CreateStructGEP(ourTypeInfoType, typeInfoThrown, 0); |
| |
| llvm::Value *ti32 = |
| builder.CreateLoad(builder.getInt32Ty(), typeInfoThrownType); |
| generateIntegerPrint(context, module, builder, *toPrint32Int, ti32, |
| "Gen: Exception type <%d> received (stack unwound) " |
| " in " + |
| ourId + ".\n", |
| USE_GLOBAL_STR_CONSTS); |
| |
| // Route to matched type info catch block or run cleanup finally block |
| llvm::SwitchInst *switchToCatchBlock = builder.CreateSwitch(retTypeInfoIndex, |
| finallyBlock, |
| numExceptionsToCatch); |
| |
| unsigned nextTypeToCatch; |
| |
| for (unsigned i = 1; i <= numExceptionsToCatch; ++i) { |
| nextTypeToCatch = i - 1; |
| switchToCatchBlock->addCase(llvm::ConstantInt::get(builder.getInt32Ty(), i), |
| catchBlocks[nextTypeToCatch]); |
| } |
| |
| llvm::verifyFunction(*ret); |
| fpm.run(*ret); |
| |
| return(ret); |
| } |
| |
| |
| /// Generates function which throws either an exception matched to a runtime |
| /// determined type info type (argument to generated function), or if this |
| /// runtime value matches nativeThrowType, throws a foreign exception by |
| /// calling nativeThrowFunct. |
| /// @param module code for module instance |
| /// @param builder builder instance |
| /// @param fpm a function pass manager holding optional IR to IR |
| /// transformations |
| /// @param ourId id used to printing purposes |
| /// @param nativeThrowType a runtime argument of this value results in |
| /// nativeThrowFunct being called to generate/throw exception. |
| /// @param nativeThrowFunct function which will throw a foreign exception |
| /// if the above nativeThrowType matches generated function's arg. |
| /// @returns generated function |
| static llvm::Function * |
| createThrowExceptionFunction(llvm::Module &module, llvm::IRBuilder<> &builder, |
| llvm::legacy::FunctionPassManager &fpm, |
| std::string ourId, int32_t nativeThrowType, |
| llvm::Function &nativeThrowFunct) { |
| llvm::LLVMContext &context = module.getContext(); |
| namedValues.clear(); |
| ArgTypes unwindArgTypes; |
| unwindArgTypes.push_back(builder.getInt32Ty()); |
| ArgNames unwindArgNames; |
| unwindArgNames.push_back("exceptTypeToThrow"); |
| |
| llvm::Function *ret = createFunction(module, |
| builder.getVoidTy(), |
| unwindArgTypes, |
| unwindArgNames, |
| ourId, |
| llvm::Function::ExternalLinkage, |
| false, |
| false); |
| |
| // Throws either one of our exception or a native C++ exception depending |
| // on a runtime argument value containing a type info type. |
| llvm::BasicBlock *entryBlock = llvm::BasicBlock::Create(context, |
| "entry", |
| ret); |
| // Throws a foreign exception |
| llvm::BasicBlock *nativeThrowBlock = llvm::BasicBlock::Create(context, |
| "nativeThrow", |
| ret); |
| // Throws one of our Exceptions |
| llvm::BasicBlock *generatedThrowBlock = llvm::BasicBlock::Create(context, |
| "generatedThrow", |
| ret); |
| // Retrieved runtime type info type to throw |
| llvm::Value *exceptionType = namedValues["exceptTypeToThrow"]; |
| |
| // nativeThrowBlock block |
| |
| builder.SetInsertPoint(nativeThrowBlock); |
| |
| // Throws foreign exception |
| builder.CreateCall(&nativeThrowFunct, exceptionType); |
| builder.CreateUnreachable(); |
| |
| // entry block |
| |
| builder.SetInsertPoint(entryBlock); |
| |
| llvm::Function *toPrint32Int = module.getFunction("print32Int"); |
| generateIntegerPrint(context, module, builder, *toPrint32Int, |
| builder.CreateZExt(exceptionType, builder.getInt32Ty()), |
| "\nGen: About to throw exception type <%d> in " + ourId + |
| ".\n", |
| USE_GLOBAL_STR_CONSTS); |
| |
| // Switches on runtime type info type value to determine whether or not |
| // a foreign exception is thrown. Defaults to throwing one of our |
| // generated exceptions. |
| llvm::SwitchInst *theSwitch = builder.CreateSwitch(exceptionType, |
| generatedThrowBlock, |
| 1); |
| |
| theSwitch->addCase(llvm::ConstantInt::get(llvm::Type::getInt32Ty(context), |
| nativeThrowType), |
| nativeThrowBlock); |
| |
| // generatedThrow block |
| |
| builder.SetInsertPoint(generatedThrowBlock); |
| |
| llvm::Function *createOurException = module.getFunction("createOurException"); |
| llvm::Function *raiseOurException = module.getFunction( |
| "_Unwind_RaiseException"); |
| |
| // Creates exception to throw with runtime type info type. |
| llvm::Value *exception = builder.CreateCall(createOurException, |
| namedValues["exceptTypeToThrow"]); |
| |
| // Throw generated Exception |
| builder.CreateCall(raiseOurException, exception); |
| builder.CreateUnreachable(); |
| |
| llvm::verifyFunction(*ret); |
| fpm.run(*ret); |
| |
| return(ret); |
| } |
| |
| static void createStandardUtilityFunctions(unsigned numTypeInfos, |
| llvm::Module &module, |
| llvm::IRBuilder<> &builder); |
| |
| /// Creates test code by generating and organizing these functions into the |
| /// test case. The test case consists of an outer function setup to invoke |
| /// an inner function within an environment having multiple catch and single |
| /// finally blocks. This inner function is also setup to invoke a throw |
| /// function within an evironment similar in nature to the outer function's |
| /// catch and finally blocks. Each of these two functions catch mutually |
| /// exclusive subsets (even or odd) of the type info types configured |
| /// for this this. All generated functions have a runtime argument which |
| /// holds a type info type to throw that each function takes and passes it |
| /// to the inner one if such a inner function exists. This type info type is |
| /// looked at by the generated throw function to see whether or not it should |
| /// throw a generated exception with the same type info type, or instead call |
| /// a supplied a function which in turn will throw a foreign exception. |
| /// @param module code for module instance |
| /// @param builder builder instance |
| /// @param fpm a function pass manager holding optional IR to IR |
| /// transformations |
| /// @param nativeThrowFunctName name of external function which will throw |
| /// a foreign exception |
| /// @returns outermost generated test function. |
| llvm::Function * |
| createUnwindExceptionTest(llvm::Module &module, llvm::IRBuilder<> &builder, |
| llvm::legacy::FunctionPassManager &fpm, |
| std::string nativeThrowFunctName) { |
| // Number of type infos to generate |
| unsigned numTypeInfos = 6; |
| |
| // Initialze intrisics and external functions to use along with exception |
| // and type info globals. |
| createStandardUtilityFunctions(numTypeInfos, |
| module, |
| builder); |
| llvm::Function *nativeThrowFunct = module.getFunction(nativeThrowFunctName); |
| |
| // Create exception throw function using the value ~0 to cause |
| // foreign exceptions to be thrown. |
| llvm::Function *throwFunct = createThrowExceptionFunction(module, |
| builder, |
| fpm, |
| "throwFunct", |
| ~0, |
| *nativeThrowFunct); |
| // Inner function will catch even type infos |
| unsigned innerExceptionTypesToCatch[] = {6, 2, 4}; |
| size_t numExceptionTypesToCatch = sizeof(innerExceptionTypesToCatch) / |
| sizeof(unsigned); |
| |
| // Generate inner function. |
| llvm::Function *innerCatchFunct = createCatchWrappedInvokeFunction(module, |
| builder, |
| fpm, |
| *throwFunct, |
| "innerCatchFunct", |
| numExceptionTypesToCatch, |
| innerExceptionTypesToCatch); |
| |
| // Outer function will catch odd type infos |
| unsigned outerExceptionTypesToCatch[] = {3, 1, 5}; |
| numExceptionTypesToCatch = sizeof(outerExceptionTypesToCatch) / |
| sizeof(unsigned); |
| |
| // Generate outer function |
| llvm::Function *outerCatchFunct = createCatchWrappedInvokeFunction(module, |
| builder, |
| fpm, |
| *innerCatchFunct, |
| "outerCatchFunct", |
| numExceptionTypesToCatch, |
| outerExceptionTypesToCatch); |
| |
| // Return outer function to run |
| return(outerCatchFunct); |
| } |
| |
| namespace { |
| /// Represents our foreign exceptions |
| class OurCppRunException : public std::runtime_error { |
| public: |
| OurCppRunException(const std::string reason) : |
| std::runtime_error(reason) {} |
| |
| OurCppRunException (const OurCppRunException &toCopy) : |
| std::runtime_error(toCopy) {} |
| |
| OurCppRunException &operator = (const OurCppRunException &toCopy) { |
| return(reinterpret_cast<OurCppRunException&>( |
| std::runtime_error::operator=(toCopy))); |
| } |
| |
| ~OurCppRunException(void) throw() override {} |
| }; |
| } // end anonymous namespace |
| |
| /// Throws foreign C++ exception. |
| /// @param ignoreIt unused parameter that allows function to match implied |
| /// generated function contract. |
| extern "C" |
| void throwCppException (int32_t ignoreIt) { |
| throw(OurCppRunException("thrown by throwCppException(...)")); |
| } |
| |
| typedef void (*OurExceptionThrowFunctType) (int32_t typeToThrow); |
| |
| /// This is a test harness which runs test by executing generated |
| /// function with a type info type to throw. Harness wraps the execution |
| /// of generated function in a C++ try catch clause. |
| /// @param engine execution engine to use for executing generated function. |
| /// This demo program expects this to be a JIT instance for demo |
| /// purposes. |
| /// @param function generated test function to run |
| /// @param typeToThrow type info type of generated exception to throw, or |
| /// indicator to cause foreign exception to be thrown. |
| static void runExceptionThrow(llvm::orc::LLJIT *JIT, std::string function, |
| int32_t typeToThrow) { |
| |
| // Find test's function pointer |
| OurExceptionThrowFunctType functPtr = |
| ExitOnErr(JIT->lookup(function)).toPtr<OurExceptionThrowFunctType>(); |
| |
| try { |
| // Run test |
| (*functPtr)(typeToThrow); |
| } |
| catch (OurCppRunException exc) { |
| // Catch foreign C++ exception |
| fprintf(stderr, |
| "\nrunExceptionThrow(...):In C++ catch OurCppRunException " |
| "with reason: %s.\n", |
| exc.what()); |
| } |
| catch (...) { |
| // Catch all exceptions including our generated ones. This latter |
| // functionality works according to the example in rules 1.6.4 of |
| // http://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html (v1.22), |
| // given that these will be exceptions foreign to C++ |
| // (the _Unwind_Exception::exception_class should be different from |
| // the one used by C++). |
| fprintf(stderr, |
| "\nrunExceptionThrow(...):In C++ catch all.\n"); |
| } |
| } |
| |
| // |
| // End test functions |
| // |
| |
| /// This initialization routine creates type info globals and |
| /// adds external function declarations to module. |
| /// @param numTypeInfos number of linear type info associated type info types |
| /// to create as GlobalVariable instances, starting with the value 1. |
| /// @param module code for module instance |
| /// @param builder builder instance |
| static void createStandardUtilityFunctions(unsigned numTypeInfos, |
| llvm::Module &module, |
| llvm::IRBuilder<> &builder) { |
| |
| llvm::LLVMContext &context = module.getContext(); |
| |
| // Exception initializations |
| |
| // Setup exception catch state |
| ourExceptionNotThrownState = |
| llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 0), |
| ourExceptionThrownState = |
| llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 1), |
| ourExceptionCaughtState = |
| llvm::ConstantInt::get(llvm::Type::getInt8Ty(context), 2), |
| |
| |
| |
| // Create our type info type |
| ourTypeInfoType = llvm::StructType::get(context, |
| TypeArray(builder.getInt32Ty())); |
| |
| llvm::Type *caughtResultFieldTypes[] = { |
| builder.getPtrTy(), |
| builder.getInt32Ty() |
| }; |
| |
| // Create our landingpad result type |
| ourCaughtResultType = llvm::StructType::get(context, |
| TypeArray(caughtResultFieldTypes)); |
| |
| // Create OurException type |
| ourExceptionType = llvm::StructType::get(context, |
| TypeArray(ourTypeInfoType)); |
| |
| // Create portion of _Unwind_Exception type |
| // |
| // Note: Declaring only a portion of the _Unwind_Exception struct. |
| // Does this cause problems? |
| ourUnwindExceptionType = |
| llvm::StructType::get(context, |
| TypeArray(builder.getInt64Ty())); |
| |
| struct OurBaseException_t dummyException; |
| |
| // Calculate offset of OurException::unwindException member. |
| ourBaseFromUnwindOffset = ((uintptr_t) &dummyException) - |
| ((uintptr_t) &(dummyException.unwindException)); |
| |
| #ifdef DEBUG |
| fprintf(stderr, |
| "createStandardUtilityFunctions(...):ourBaseFromUnwindOffset " |
| "= %" PRIi64 ", sizeof(struct OurBaseException_t) - " |
| "sizeof(struct _Unwind_Exception) = %lu.\n", |
| ourBaseFromUnwindOffset, |
| sizeof(struct OurBaseException_t) - |
| sizeof(struct _Unwind_Exception)); |
| #endif |
| |
| size_t numChars = sizeof(ourBaseExcpClassChars) / sizeof(char); |
| |
| // Create our _Unwind_Exception::exception_class value |
| ourBaseExceptionClass = genClass(ourBaseExcpClassChars, numChars); |
| |
| // Type infos |
| |
| std::string baseStr = "typeInfo", typeInfoName; |
| std::ostringstream typeInfoNameBuilder; |
| std::vector<llvm::Constant*> structVals; |
| |
| llvm::Constant *nextStruct; |
| |
| // Generate each type info |
| // |
| // Note: First type info is not used. |
| for (unsigned i = 0; i <= numTypeInfos; ++i) { |
| structVals.clear(); |
| structVals.push_back(llvm::ConstantInt::get(builder.getInt32Ty(), i)); |
| nextStruct = llvm::ConstantStruct::get(ourTypeInfoType, structVals); |
| |
| typeInfoNameBuilder.str(""); |
| typeInfoNameBuilder << baseStr << i; |
| typeInfoName = typeInfoNameBuilder.str(); |
| |
| // Note: Does not seem to work without allocation |
| new llvm::GlobalVariable(module, |
| ourTypeInfoType, |
| true, |
| llvm::GlobalValue::ExternalLinkage, |
| nextStruct, |
| typeInfoName); |
| |
| ourTypeInfoNames.push_back(typeInfoName); |
| ourTypeInfoNamesIndex[i] = typeInfoName; |
| } |
| |
| ArgNames argNames; |
| ArgTypes argTypes; |
| llvm::Function *funct = NULL; |
| |
| // print32Int |
| |
| llvm::Type *retType = builder.getVoidTy(); |
| |
| argTypes.clear(); |
| argTypes.push_back(builder.getInt32Ty()); |
| argTypes.push_back(builder.getPtrTy()); |
| |
| argNames.clear(); |
| |
| createFunction(module, |
| retType, |
| argTypes, |
| argNames, |
| "print32Int", |
| llvm::Function::ExternalLinkage, |
| true, |
| false); |
| |
| // print64Int |
| |
| retType = builder.getVoidTy(); |
| |
| argTypes.clear(); |
| argTypes.push_back(builder.getInt64Ty()); |
| argTypes.push_back(builder.getPtrTy()); |
| |
| argNames.clear(); |
| |
| createFunction(module, |
| retType, |
| argTypes, |
| argNames, |
| "print64Int", |
| llvm::Function::ExternalLinkage, |
| true, |
| false); |
| |
| // printStr |
| |
| retType = builder.getVoidTy(); |
| |
| argTypes.clear(); |
| argTypes.push_back(builder.getPtrTy()); |
| |
| argNames.clear(); |
| |
| createFunction(module, |
| retType, |
| argTypes, |
| argNames, |
| "printStr", |
| llvm::Function::ExternalLinkage, |
| true, |
| false); |
| |
| // throwCppException |
| |
| retType = builder.getVoidTy(); |
| |
| argTypes.clear(); |
| argTypes.push_back(builder.getInt32Ty()); |
| |
| argNames.clear(); |
| |
| createFunction(module, |
| retType, |
| argTypes, |
| argNames, |
| "throwCppException", |
| llvm::Function::ExternalLinkage, |
| true, |
| false); |
| |
| // deleteOurException |
| |
| retType = builder.getVoidTy(); |
| |
| argTypes.clear(); |
| argTypes.push_back(builder.getPtrTy()); |
| |
| argNames.clear(); |
| |
| createFunction(module, |
| retType, |
| argTypes, |
| argNames, |
| "deleteOurException", |
| llvm::Function::ExternalLinkage, |
| true, |
| false); |
| |
| // createOurException |
| |
| retType = builder.getPtrTy(); |
| |
| argTypes.clear(); |
| argTypes.push_back(builder.getInt32Ty()); |
| |
| argNames.clear(); |
| |
| createFunction(module, |
| retType, |
| argTypes, |
| argNames, |
| "createOurException", |
| llvm::Function::ExternalLinkage, |
| true, |
| false); |
| |
| // _Unwind_RaiseException |
| |
| retType = builder.getInt32Ty(); |
| |
| argTypes.clear(); |
| argTypes.push_back(builder.getPtrTy()); |
| |
| argNames.clear(); |
| |
| funct = createFunction(module, |
| retType, |
| argTypes, |
| argNames, |
| "_Unwind_RaiseException", |
| llvm::Function::ExternalLinkage, |
| true, |
| false); |
| |
| funct->setDoesNotReturn(); |
| |
| // _Unwind_Resume |
| |
| retType = builder.getInt32Ty(); |
| |
| argTypes.clear(); |
| argTypes.push_back(builder.getPtrTy()); |
| |
| argNames.clear(); |
| |
| funct = createFunction(module, |
| retType, |
| argTypes, |
| argNames, |
| "_Unwind_Resume", |
| llvm::Function::ExternalLinkage, |
| true, |
| false); |
| |
| funct->setDoesNotReturn(); |
| |
| // ourPersonality |
| |
| retType = builder.getInt32Ty(); |
| |
| argTypes.clear(); |
| argTypes.push_back(builder.getInt32Ty()); |
| argTypes.push_back(builder.getInt32Ty()); |
| argTypes.push_back(builder.getInt64Ty()); |
| argTypes.push_back(builder.getPtrTy()); |
| argTypes.push_back(builder.getPtrTy()); |
| |
| argNames.clear(); |
| |
| createFunction(module, |
| retType, |
| argTypes, |
| argNames, |
| "ourPersonality", |
| llvm::Function::ExternalLinkage, |
| true, |
| false); |
| |
| // llvm.eh.typeid.for intrinsic |
| |
| getOrInsertDeclaration(&module, llvm::Intrinsic::eh_typeid_for, |
| builder.getPtrTy()); |
| } |
| |
| |
| //===----------------------------------------------------------------------===// |
| // Main test driver code. |
| //===----------------------------------------------------------------------===// |
| |
| /// Demo main routine which takes the type info types to throw. A test will |
| /// be run for each given type info type. While type info types with the value |
| /// of -1 will trigger a foreign C++ exception to be thrown; type info types |
| /// <= 6 and >= 1 will be caught by test functions; and type info types > 6 |
| /// will result in exceptions which pass through to the test harness. All other |
| /// type info types are not supported and could cause a crash. |
| int main(int argc, char *argv[]) { |
| if (argc == 1) { |
| fprintf(stderr, |
| "\nUsage: ExceptionDemo <exception type to throw> " |
| "[<type 2>...<type n>].\n" |
| " Each type must have the value of 1 - 6 for " |
| "generated exceptions to be caught;\n" |
| " the value -1 for foreign C++ exceptions to be " |
| "generated and thrown;\n" |
| " or the values > 6 for exceptions to be ignored.\n" |
| "\nTry: ExceptionDemo 2 3 7 -1\n" |
| " for a full test.\n\n"); |
| return(0); |
| } |
| |
| llvm::InitializeNativeTarget(); |
| llvm::InitializeNativeTargetAsmPrinter(); |
| auto Context = std::make_unique<llvm::LLVMContext>(); |
| llvm::IRBuilder<> theBuilder(*Context); |
| |
| // Make the module, which holds all the code. |
| std::unique_ptr<llvm::Module> Owner = |
| std::make_unique<llvm::Module>("my cool jit", *Context); |
| llvm::Module *module = Owner.get(); |
| |
| // Build LLJIT |
| std::unique_ptr<llvm::orc::LLJIT> JIT = |
| ExitOnErr(llvm::orc::LLJITBuilder().create()); |
| |
| // Set up the optimizer pipeline. |
| llvm::legacy::FunctionPassManager fpm(module); |
| |
| // Optimizations turned on |
| #ifdef ADD_OPT_PASSES |
| |
| // Basic AliasAnslysis support for GVN. |
| fpm.add(llvm::createBasicAliasAnalysisPass()); |
| |
| // Promote allocas to registers. |
| fpm.add(llvm::createPromoteMemoryToRegisterPass()); |
| |
| // Do simple "peephole" optimizations and bit-twiddling optzns. |
| fpm.add(llvm::createInstructionCombiningPass()); |
| |
| // Reassociate expressions. |
| fpm.add(llvm::createReassociatePass()); |
| |
| // Eliminate Common SubExpressions. |
| fpm.add(llvm::createGVNPass()); |
| |
| // Simplify the control flow graph (deleting unreachable |
| // blocks, etc). |
| fpm.add(llvm::createCFGSimplificationPass()); |
| #endif // ADD_OPT_PASSES |
| |
| fpm.doInitialization(); |
| |
| // Generate test code using function throwCppException(...) as |
| // the function which throws foreign exceptions. |
| createUnwindExceptionTest(*module, theBuilder, fpm, "throwCppException"); |
| |
| ExitOnErr(JIT->addIRModule( |
| llvm::orc::ThreadSafeModule(std::move(Owner), std::move(Context)))); |
| |
| #ifndef NDEBUG |
| fprintf(stderr, "\nBegin module dump:\n\n"); |
| |
| module->print(llvm::errs(), nullptr); |
| |
| fprintf(stderr, "\nEnd module dump:\n"); |
| #endif |
| |
| fprintf(stderr, "\n\nBegin Test:\n"); |
| std::string toRun = "outerCatchFunct"; |
| |
| for (int i = 1; i < argc; ++i) { |
| // Run test for each argument whose value is the exception |
| // type to throw. |
| runExceptionThrow(JIT.get(), toRun, (unsigned)strtoul(argv[i], NULL, 10)); |
| } |
| |
| fprintf(stderr, "\nEnd Test:\n\n"); |
| |
| return 0; |
| } |
