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Diffstat (limited to 'lib/ExecutionEngine/JIT/Intercept.cpp')
| -rw-r--r-- | lib/ExecutionEngine/JIT/Intercept.cpp | 162 |
1 files changed, 0 insertions, 162 deletions
diff --git a/lib/ExecutionEngine/JIT/Intercept.cpp b/lib/ExecutionEngine/JIT/Intercept.cpp deleted file mode 100644 index 2251a8e6b0..0000000000 --- a/lib/ExecutionEngine/JIT/Intercept.cpp +++ /dev/null @@ -1,162 +0,0 @@ -//===-- 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 "JIT.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 *JIT::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; -} |