diff options
Diffstat (limited to 'lib/ExecutionEngine/MCJIT')
| -rw-r--r-- | lib/ExecutionEngine/MCJIT/CMakeLists.txt | 1 | ||||
| -rw-r--r-- | lib/ExecutionEngine/MCJIT/Intercept.cpp | 162 | ||||
| -rw-r--r-- | lib/ExecutionEngine/MCJIT/MCJIT.cpp | 20 | ||||
| -rw-r--r-- | lib/ExecutionEngine/MCJIT/MCJIT.h | 1 | ||||
| -rw-r--r-- | lib/ExecutionEngine/MCJIT/MCJITMemoryManager.h | 39 |
5 files changed, 197 insertions, 26 deletions
diff --git a/lib/ExecutionEngine/MCJIT/CMakeLists.txt b/lib/ExecutionEngine/MCJIT/CMakeLists.txt index fef71768b4..2c0f8d6519 100644 --- a/lib/ExecutionEngine/MCJIT/CMakeLists.txt +++ b/lib/ExecutionEngine/MCJIT/CMakeLists.txt @@ -1,4 +1,5 @@ add_llvm_library(LLVMMCJIT MCJIT.cpp MCJITMemoryManager.cpp + Intercept.cpp ) diff --git a/lib/ExecutionEngine/MCJIT/Intercept.cpp b/lib/ExecutionEngine/MCJIT/Intercept.cpp new file mode 100644 index 0000000000..f83f4282e0 --- /dev/null +++ b/lib/ExecutionEngine/MCJIT/Intercept.cpp @@ -0,0 +1,162 @@ +//===-- Intercept.cpp - System function interception routines -------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// If a function call occurs to an external function, the JIT is designed to use +// the dynamic loader interface to find a function to call. This is useful for +// calling system calls and library functions that are not available in LLVM. +// Some system calls, however, need to be handled specially. For this reason, +// we intercept some of them here and use our own stubs to handle them. +// +//===----------------------------------------------------------------------===// + +#include "MCJIT.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/DynamicLibrary.h" +#include "llvm/Config/config.h" +using namespace llvm; + +// AtExitHandlers - List of functions to call when the program exits, +// registered with the atexit() library function. +static std::vector<void (*)()> AtExitHandlers; + +/// runAtExitHandlers - Run any functions registered by the program's +/// calls to atexit(3), which we intercept and store in +/// AtExitHandlers. +/// +static void runAtExitHandlers() { + while (!AtExitHandlers.empty()) { + void (*Fn)() = AtExitHandlers.back(); + AtExitHandlers.pop_back(); + Fn(); + } +} + +//===----------------------------------------------------------------------===// +// Function stubs that are invoked instead of certain library calls +//===----------------------------------------------------------------------===// + +// Force the following functions to be linked in to anything that uses the +// JIT. This is a hack designed to work around the all-too-clever Glibc +// strategy of making these functions work differently when inlined vs. when +// not inlined, and hiding their real definitions in a separate archive file +// that the dynamic linker can't see. For more info, search for +// 'libc_nonshared.a' on Google, or read http://llvm.org/PR274. +#if defined(__linux__) +#if defined(HAVE_SYS_STAT_H) +#include <sys/stat.h> +#endif +#include <fcntl.h> +#include <unistd.h> +/* stat functions are redirecting to __xstat with a version number. On x86-64 + * linking with libc_nonshared.a and -Wl,--export-dynamic doesn't make 'stat' + * available as an exported symbol, so we have to add it explicitly. + */ +namespace { +class StatSymbols { +public: + StatSymbols() { + sys::DynamicLibrary::AddSymbol("stat", (void*)(intptr_t)stat); + sys::DynamicLibrary::AddSymbol("fstat", (void*)(intptr_t)fstat); + sys::DynamicLibrary::AddSymbol("lstat", (void*)(intptr_t)lstat); + sys::DynamicLibrary::AddSymbol("stat64", (void*)(intptr_t)stat64); + sys::DynamicLibrary::AddSymbol("\x1stat64", (void*)(intptr_t)stat64); + sys::DynamicLibrary::AddSymbol("\x1open64", (void*)(intptr_t)open64); + sys::DynamicLibrary::AddSymbol("\x1lseek64", (void*)(intptr_t)lseek64); + sys::DynamicLibrary::AddSymbol("fstat64", (void*)(intptr_t)fstat64); + sys::DynamicLibrary::AddSymbol("lstat64", (void*)(intptr_t)lstat64); + sys::DynamicLibrary::AddSymbol("atexit", (void*)(intptr_t)atexit); + sys::DynamicLibrary::AddSymbol("mknod", (void*)(intptr_t)mknod); + } +}; +} +static StatSymbols initStatSymbols; +#endif // __linux__ + +// jit_exit - Used to intercept the "exit" library call. +static void jit_exit(int Status) { + runAtExitHandlers(); // Run atexit handlers... + exit(Status); +} + +// jit_atexit - Used to intercept the "atexit" library call. +static int jit_atexit(void (*Fn)()) { + AtExitHandlers.push_back(Fn); // Take note of atexit handler... + return 0; // Always successful +} + +static int jit_noop() { + return 0; +} + +//===----------------------------------------------------------------------===// +// +/// getPointerToNamedFunction - This method returns the address of the specified +/// function by using the dynamic loader interface. As such it is only useful +/// for resolving library symbols, not code generated symbols. +/// +void *MCJIT::getPointerToNamedFunction(const std::string &Name, + bool AbortOnFailure) { + if (!isSymbolSearchingDisabled()) { + // Check to see if this is one of the functions we want to intercept. Note, + // we cast to intptr_t here to silence a -pedantic warning that complains + // about casting a function pointer to a normal pointer. + if (Name == "exit") return (void*)(intptr_t)&jit_exit; + if (Name == "atexit") return (void*)(intptr_t)&jit_atexit; + + // We should not invoke parent's ctors/dtors from generated main()! + // On Mingw and Cygwin, the symbol __main is resolved to + // callee's(eg. tools/lli) one, to invoke wrong duplicated ctors + // (and register wrong callee's dtors with atexit(3)). + // We expect ExecutionEngine::runStaticConstructorsDestructors() + // is called before ExecutionEngine::runFunctionAsMain() is called. + if (Name == "__main") return (void*)(intptr_t)&jit_noop; + + const char *NameStr = Name.c_str(); + // If this is an asm specifier, skip the sentinal. + if (NameStr[0] == 1) ++NameStr; + + // If it's an external function, look it up in the process image... + void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr); + if (Ptr) return Ptr; + + // If it wasn't found and if it starts with an underscore ('_') character, + // and has an asm specifier, try again without the underscore. + if (Name[0] == 1 && NameStr[0] == '_') { + Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr+1); + if (Ptr) return Ptr; + } + + // Darwin/PPC adds $LDBLStub suffixes to various symbols like printf. These + // are references to hidden visibility symbols that dlsym cannot resolve. + // If we have one of these, strip off $LDBLStub and try again. +#if defined(__APPLE__) && defined(__ppc__) + if (Name.size() > 9 && Name[Name.size()-9] == '$' && + memcmp(&Name[Name.size()-8], "LDBLStub", 8) == 0) { + // First try turning $LDBLStub into $LDBL128. If that fails, strip it off. + // This mirrors logic in libSystemStubs.a. + std::string Prefix = std::string(Name.begin(), Name.end()-9); + if (void *Ptr = getPointerToNamedFunction(Prefix+"$LDBL128", false)) + return Ptr; + if (void *Ptr = getPointerToNamedFunction(Prefix, false)) + return Ptr; + } +#endif + } + + /// If a LazyFunctionCreator is installed, use it to get/create the function. + if (LazyFunctionCreator) + if (void *RP = LazyFunctionCreator(Name)) + return RP; + + if (AbortOnFailure) { + report_fatal_error("Program used external function '"+Name+ + "' which could not be resolved!"); + } + return 0; +} diff --git a/lib/ExecutionEngine/MCJIT/MCJIT.cpp b/lib/ExecutionEngine/MCJIT/MCJIT.cpp index cbb23d361d..5f93a8d3ca 100644 --- a/lib/ExecutionEngine/MCJIT/MCJIT.cpp +++ b/lib/ExecutionEngine/MCJIT/MCJIT.cpp @@ -215,23 +215,3 @@ GenericValue MCJIT::runFunction(Function *F, llvm_unreachable("Full-featured argument passing not supported yet!"); } - -void *MCJIT::getPointerToNamedFunction(const std::string &Name, - bool AbortOnFailure){ - if (!isSymbolSearchingDisabled()) { - void *ptr = MemMgr->getPointerToNamedFunction(Name, false); - if (ptr) - return ptr; - } - - /// If a LazyFunctionCreator is installed, use it to get/create the function. - if (LazyFunctionCreator) - if (void *RP = LazyFunctionCreator(Name)) - return RP; - - if (AbortOnFailure) { - report_fatal_error("Program used external function '"+Name+ - "' which could not be resolved!"); - } - return 0; -} diff --git a/lib/ExecutionEngine/MCJIT/MCJIT.h b/lib/ExecutionEngine/MCJIT/MCJIT.h index 2b3df9884e..7f4ae77343 100644 --- a/lib/ExecutionEngine/MCJIT/MCJIT.h +++ b/lib/ExecutionEngine/MCJIT/MCJIT.h @@ -67,7 +67,6 @@ public: /// virtual void *getPointerToNamedFunction(const std::string &Name, bool AbortOnFailure = true); - /// mapSectionAddress - map a section to its target address space value. /// Map the address of a JIT section as returned from the memory manager /// to the address in the target process as the running code will see it. diff --git a/lib/ExecutionEngine/MCJIT/MCJITMemoryManager.h b/lib/ExecutionEngine/MCJIT/MCJITMemoryManager.h index dac8b26291..ac8c15579e 100644 --- a/lib/ExecutionEngine/MCJIT/MCJITMemoryManager.h +++ b/lib/ExecutionEngine/MCJIT/MCJITMemoryManager.h @@ -33,17 +33,46 @@ public: uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment, unsigned SectionID) { - return JMM->allocateSpace(Size, Alignment); + return JMM->allocateDataSection(Size, Alignment, SectionID); } uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment, unsigned SectionID) { - return JMM->allocateSpace(Size, Alignment); + return JMM->allocateCodeSection(Size, Alignment, SectionID); } - virtual void *getPointerToNamedFunction(const std::string &Name, - bool AbortOnFailure = true) { - return JMM->getPointerToNamedFunction(Name, AbortOnFailure); + // Allocate ActualSize bytes, or more, for the named function. Return + // a pointer to the allocated memory and update Size to reflect how much + // memory was acutally allocated. + uint8_t *startFunctionBody(const char *Name, uintptr_t &Size) { + // FIXME: This should really reference the MCAsmInfo to get the global + // prefix. + if (Name[0] == '_') ++Name; + Function *F = M->getFunction(Name); + // Some ObjC names have a prefixed \01 in the IR. If we failed to find + // the symbol and it's of the ObjC conventions (starts with "-" or + // "+"), try prepending a \01 and see if we can find it that way. + if (!F && (Name[0] == '-' || Name[0] == '+')) + F = M->getFunction((Twine("\1") + Name).str()); + assert(F && "No matching function in JIT IR Module!"); + return JMM->startFunctionBody(F, Size); + } + + // Mark the end of the function, including how much of the allocated + // memory was actually used. + void endFunctionBody(const char *Name, uint8_t *FunctionStart, + uint8_t *FunctionEnd) { + // FIXME: This should really reference the MCAsmInfo to get the global + // prefix. + if (Name[0] == '_') ++Name; + Function *F = M->getFunction(Name); + // Some ObjC names have a prefixed \01 in the IR. If we failed to find + // the symbol and it's of the ObjC conventions (starts with "-" or + // "+"), try prepending a \01 and see if we can find it that way. + if (!F && (Name[0] == '-' || Name[0] == '+')) + F = M->getFunction((Twine("\1") + Name).str()); + assert(F && "No matching function in JIT IR Module!"); + JMM->endFunctionBody(F, FunctionStart, FunctionEnd); } }; |