Chris Lattner | 6701a86 | 2003-05-14 13:26:47 +0000 | [diff] [blame] | 1 | //===-- Intercept.cpp - System function interception routines -------------===// |
Misha Brukman | f976c85 | 2005-04-21 22:55:34 +0000 | [diff] [blame] | 2 | // |
John Criswell | b576c94 | 2003-10-20 19:43:21 +0000 | [diff] [blame] | 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
Chris Lattner | 4ee451d | 2007-12-29 20:36:04 +0000 | [diff] [blame] | 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
Misha Brukman | f976c85 | 2005-04-21 22:55:34 +0000 | [diff] [blame] | 7 | // |
John Criswell | b576c94 | 2003-10-20 19:43:21 +0000 | [diff] [blame] | 8 | //===----------------------------------------------------------------------===// |
Chris Lattner | 6701a86 | 2003-05-14 13:26:47 +0000 | [diff] [blame] | 9 | // |
| 10 | // If a function call occurs to an external function, the JIT is designed to use |
Brian Gaeke | 322cdb2 | 2003-10-10 17:02:42 +0000 | [diff] [blame] | 11 | // the dynamic loader interface to find a function to call. This is useful for |
Chris Lattner | 6701a86 | 2003-05-14 13:26:47 +0000 | [diff] [blame] | 12 | // calling system calls and library functions that are not available in LLVM. |
| 13 | // Some system calls, however, need to be handled specially. For this reason, |
| 14 | // we intercept some of them here and use our own stubs to handle them. |
| 15 | // |
| 16 | //===----------------------------------------------------------------------===// |
| 17 | |
Chris Lattner | 4d326fa | 2003-12-20 01:46:27 +0000 | [diff] [blame] | 18 | #include "JIT.h" |
Reid Spencer | df5a37e | 2004-11-29 14:11:29 +0000 | [diff] [blame] | 19 | #include "llvm/System/DynamicLibrary.h" |
Reid Spencer | 099557b | 2004-12-20 06:34:02 +0000 | [diff] [blame] | 20 | #include "llvm/Config/config.h" |
Chris Lattner | c19aade | 2003-12-08 08:06:28 +0000 | [diff] [blame] | 21 | using namespace llvm; |
Brian Gaeke | d0fde30 | 2003-11-11 22:41:34 +0000 | [diff] [blame] | 22 | |
Brian Gaeke | 70975ee | 2003-09-05 18:42:01 +0000 | [diff] [blame] | 23 | // AtExitHandlers - List of functions to call when the program exits, |
| 24 | // registered with the atexit() library function. |
| 25 | static std::vector<void (*)()> AtExitHandlers; |
Chris Lattner | 22080f9 | 2003-05-14 13:53:40 +0000 | [diff] [blame] | 26 | |
Brian Gaeke | 70975ee | 2003-09-05 18:42:01 +0000 | [diff] [blame] | 27 | /// runAtExitHandlers - Run any functions registered by the program's |
| 28 | /// calls to atexit(3), which we intercept and store in |
| 29 | /// AtExitHandlers. |
| 30 | /// |
Chris Lattner | ff0f1bb | 2003-12-26 06:13:47 +0000 | [diff] [blame] | 31 | static void runAtExitHandlers() { |
Brian Gaeke | 70975ee | 2003-09-05 18:42:01 +0000 | [diff] [blame] | 32 | while (!AtExitHandlers.empty()) { |
| 33 | void (*Fn)() = AtExitHandlers.back(); |
| 34 | AtExitHandlers.pop_back(); |
Chris Lattner | 22080f9 | 2003-05-14 13:53:40 +0000 | [diff] [blame] | 35 | Fn(); |
| 36 | } |
| 37 | } |
| 38 | |
Chris Lattner | 6701a86 | 2003-05-14 13:26:47 +0000 | [diff] [blame] | 39 | //===----------------------------------------------------------------------===// |
Brian Gaeke | 70975ee | 2003-09-05 18:42:01 +0000 | [diff] [blame] | 40 | // Function stubs that are invoked instead of certain library calls |
Chris Lattner | 6701a86 | 2003-05-14 13:26:47 +0000 | [diff] [blame] | 41 | //===----------------------------------------------------------------------===// |
| 42 | |
Brian Gaeke | 00f0a29 | 2004-03-09 05:22:10 +0000 | [diff] [blame] | 43 | // Force the following functions to be linked in to anything that uses the |
| 44 | // JIT. This is a hack designed to work around the all-too-clever Glibc |
| 45 | // strategy of making these functions work differently when inlined vs. when |
| 46 | // not inlined, and hiding their real definitions in a separate archive file |
| 47 | // that the dynamic linker can't see. For more info, search for |
Reid Spencer | 9dce2b3 | 2006-03-14 05:54:52 +0000 | [diff] [blame] | 48 | // 'libc_nonshared.a' on Google, or read http://llvm.org/PR274. |
Brian Gaeke | d0f3c5e | 2004-03-10 17:38:28 +0000 | [diff] [blame] | 49 | #if defined(__linux__) |
Reid Spencer | 099557b | 2004-12-20 06:34:02 +0000 | [diff] [blame] | 50 | #if defined(HAVE_SYS_STAT_H) |
Reid Spencer | 6b4bd6b | 2004-12-17 19:09:16 +0000 | [diff] [blame] | 51 | #include <sys/stat.h> |
Misha Brukman | f976c85 | 2005-04-21 22:55:34 +0000 | [diff] [blame] | 52 | #endif |
Brian Gaeke | 00f0a29 | 2004-03-09 05:22:10 +0000 | [diff] [blame] | 53 | void *FunctionPointers[] = { |
Chris Lattner | 35a1446 | 2006-07-27 00:04:14 +0000 | [diff] [blame] | 54 | (void *)(intptr_t) stat, |
| 55 | (void *)(intptr_t) fstat, |
| 56 | (void *)(intptr_t) lstat, |
| 57 | (void *)(intptr_t) stat64, |
| 58 | (void *)(intptr_t) fstat64, |
| 59 | (void *)(intptr_t) lstat64, |
| 60 | (void *)(intptr_t) atexit, |
| 61 | (void *)(intptr_t) mknod |
Brian Gaeke | 00f0a29 | 2004-03-09 05:22:10 +0000 | [diff] [blame] | 62 | }; |
Brian Gaeke | d0f3c5e | 2004-03-10 17:38:28 +0000 | [diff] [blame] | 63 | #endif // __linux__ |
Brian Gaeke | 00f0a29 | 2004-03-09 05:22:10 +0000 | [diff] [blame] | 64 | |
Brian Gaeke | 70975ee | 2003-09-05 18:42:01 +0000 | [diff] [blame] | 65 | // jit_exit - Used to intercept the "exit" library call. |
Chris Lattner | 6701a86 | 2003-05-14 13:26:47 +0000 | [diff] [blame] | 66 | static void jit_exit(int Status) { |
Chris Lattner | ff0f1bb | 2003-12-26 06:13:47 +0000 | [diff] [blame] | 67 | runAtExitHandlers(); // Run atexit handlers... |
Chris Lattner | 22080f9 | 2003-05-14 13:53:40 +0000 | [diff] [blame] | 68 | exit(Status); |
Chris Lattner | 6701a86 | 2003-05-14 13:26:47 +0000 | [diff] [blame] | 69 | } |
| 70 | |
Brian Gaeke | 70975ee | 2003-09-05 18:42:01 +0000 | [diff] [blame] | 71 | // jit_atexit - Used to intercept the "atexit" library call. |
Chris Lattner | 6701a86 | 2003-05-14 13:26:47 +0000 | [diff] [blame] | 72 | static int jit_atexit(void (*Fn)(void)) { |
Brian Gaeke | 70975ee | 2003-09-05 18:42:01 +0000 | [diff] [blame] | 73 | AtExitHandlers.push_back(Fn); // Take note of atexit handler... |
Chris Lattner | 22080f9 | 2003-05-14 13:53:40 +0000 | [diff] [blame] | 74 | return 0; // Always successful |
Chris Lattner | 6701a86 | 2003-05-14 13:26:47 +0000 | [diff] [blame] | 75 | } |
| 76 | |
| 77 | //===----------------------------------------------------------------------===// |
Misha Brukman | f976c85 | 2005-04-21 22:55:34 +0000 | [diff] [blame] | 78 | // |
Chris Lattner | 6701a86 | 2003-05-14 13:26:47 +0000 | [diff] [blame] | 79 | /// getPointerToNamedFunction - This method returns the address of the specified |
Misha Brukman | f976c85 | 2005-04-21 22:55:34 +0000 | [diff] [blame] | 80 | /// function by using the dynamic loader interface. As such it is only useful |
Brian Gaeke | 322cdb2 | 2003-10-10 17:02:42 +0000 | [diff] [blame] | 81 | /// for resolving library symbols, not code generated symbols. |
Chris Lattner | 6701a86 | 2003-05-14 13:26:47 +0000 | [diff] [blame] | 82 | /// |
Chris Lattner | 4d326fa | 2003-12-20 01:46:27 +0000 | [diff] [blame] | 83 | void *JIT::getPointerToNamedFunction(const std::string &Name) { |
Chris Lattner | fea34a1 | 2006-06-01 17:12:14 +0000 | [diff] [blame] | 84 | // Check to see if this is one of the functions we want to intercept. Note, |
| 85 | // we cast to intptr_t here to silence a -pedantic warning that complains |
| 86 | // about casting a function pointer to a normal pointer. |
| 87 | if (Name == "exit") return (void*)(intptr_t)&jit_exit; |
| 88 | if (Name == "atexit") return (void*)(intptr_t)&jit_atexit; |
Chris Lattner | 6701a86 | 2003-05-14 13:26:47 +0000 | [diff] [blame] | 89 | |
Chris Lattner | 513748d | 2006-07-28 21:11:31 +0000 | [diff] [blame] | 90 | const char *NameStr = Name.c_str(); |
| 91 | // If this is an asm specifier, skip the sentinal. |
| 92 | if (NameStr[0] == 1) ++NameStr; |
| 93 | |
Chris Lattner | 6701a86 | 2003-05-14 13:26:47 +0000 | [diff] [blame] | 94 | // If it's an external function, look it up in the process image... |
Chris Lattner | 513748d | 2006-07-28 21:11:31 +0000 | [diff] [blame] | 95 | void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr); |
Chris Lattner | abf1cd3 | 2004-06-01 21:49:00 +0000 | [diff] [blame] | 96 | if (Ptr) return Ptr; |
Chris Lattner | 513748d | 2006-07-28 21:11:31 +0000 | [diff] [blame] | 97 | |
| 98 | // If it wasn't found and if it starts with an underscore ('_') character, and |
| 99 | // has an asm specifier, try again without the underscore. |
| 100 | if (Name[0] == 1 && NameStr[0] == '_') { |
| 101 | Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr+1); |
| 102 | if (Ptr) return Ptr; |
| 103 | } |
Chris Lattner | d958a5a | 2007-10-22 02:50:12 +0000 | [diff] [blame] | 104 | |
Chris Lattner | 1c8f374 | 2007-11-27 20:41:32 +0000 | [diff] [blame] | 105 | // darwin/ppc adds $LDBLStub suffixes to various symbols like printf. These |
| 106 | // are references to hidden visibility symbols that dlsym cannot resolve. If |
| 107 | // we have one of these, strip off $LDBLStub and try again. |
| 108 | #if defined(__APPLE__) && defined(__ppc__) |
| 109 | if (Name.size() > 9 && Name[Name.size()-9] == '$' && |
Chris Lattner | a8d7001 | 2007-11-27 20:45:25 +0000 | [diff] [blame] | 110 | memcmp(&Name[Name.size()-8], "LDBLStub", 8) == 0) { |
| 111 | // First try turning $LDBLStub into $LDBL128. If that fails, strip it off. |
| 112 | // This mirrors logic in libSystemStubs.a. |
| 113 | std::string Prefix = std::string(Name.begin(), Name.end()-9); |
| 114 | if (void *Ptr = getPointerToNamedFunction(Prefix+"$LDBL128")) |
| 115 | return Ptr; |
Chris Lattner | 5e037fc | 2007-11-28 18:30:18 +0000 | [diff] [blame] | 116 | if (void *Ptr = getPointerToNamedFunction(Prefix)) |
| 117 | return Ptr; |
Chris Lattner | a8d7001 | 2007-11-27 20:45:25 +0000 | [diff] [blame] | 118 | } |
Chris Lattner | 1c8f374 | 2007-11-27 20:41:32 +0000 | [diff] [blame] | 119 | #endif |
| 120 | |
Chris Lattner | d958a5a | 2007-10-22 02:50:12 +0000 | [diff] [blame] | 121 | /// If a LazyFunctionCreator is installed, use it to get/create the function. |
| 122 | if (LazyFunctionCreator) |
| 123 | if (void *RP = LazyFunctionCreator(Name)) |
| 124 | return RP; |
Chris Lattner | abf1cd3 | 2004-06-01 21:49:00 +0000 | [diff] [blame] | 125 | |
Bill Wendling | 832171c | 2006-12-07 20:04:42 +0000 | [diff] [blame] | 126 | cerr << "ERROR: Program used external function '" << Name |
| 127 | << "' which could not be resolved!\n"; |
Chris Lattner | abf1cd3 | 2004-06-01 21:49:00 +0000 | [diff] [blame] | 128 | abort(); |
| 129 | return 0; |
Chris Lattner | 6701a86 | 2003-05-14 13:26:47 +0000 | [diff] [blame] | 130 | } |