1 //===-- RTDyldMemoryManager.cpp - Memory manager for MC-JIT -----*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Implementation of the runtime dynamic memory manager base class.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
15 #include "llvm/Support/DynamicLibrary.h"
16 #include "llvm/Support/ErrorHandling.h"
19 // These includes used by SectionMemoryManager::getPointerToNamedFunction()
20 // for Glibc trickery. See comments in this function for more information.
21 #ifdef HAVE_SYS_STAT_H
30 RTDyldMemoryManager::~RTDyldMemoryManager() {}
32 // Determine whether we can register EH tables.
33 #if (defined(__GNUC__) && !defined(__ARM_EABI__) && \
34 !defined(__USING_SJLJ_EXCEPTIONS__))
35 #define HAVE_EHTABLE_SUPPORT 1
37 #define HAVE_EHTABLE_SUPPORT 0
40 #if HAVE_EHTABLE_SUPPORT
41 extern "C" void __register_frame(void*);
43 static const char *processFDE(const char *Entry) {
44 const char *P = Entry;
45 uint32_t Length = *((uint32_t*)P);
47 uint32_t Offset = *((uint32_t*)P);
49 __register_frame((void*)Entry);
54 void RTDyldMemoryManager::registerEHFrames(StringRef SectionData) {
55 #if HAVE_EHTABLE_SUPPORT
56 const char *P = SectionData.data();
57 const char *End = SectionData.data() + SectionData.size();
64 static int jit_noop() {
68 void *RTDyldMemoryManager::getPointerToNamedFunction(const std::string &Name,
69 bool AbortOnFailure) {
70 #if defined(__linux__)
71 //===--------------------------------------------------------------------===//
72 // Function stubs that are invoked instead of certain library calls
74 // Force the following functions to be linked in to anything that uses the
75 // JIT. This is a hack designed to work around the all-too-clever Glibc
76 // strategy of making these functions work differently when inlined vs. when
77 // not inlined, and hiding their real definitions in a separate archive file
78 // that the dynamic linker can't see. For more info, search for
79 // 'libc_nonshared.a' on Google, or read http://llvm.org/PR274.
80 if (Name == "stat") return (void*)(intptr_t)&stat;
81 if (Name == "fstat") return (void*)(intptr_t)&fstat;
82 if (Name == "lstat") return (void*)(intptr_t)&lstat;
83 if (Name == "stat64") return (void*)(intptr_t)&stat64;
84 if (Name == "fstat64") return (void*)(intptr_t)&fstat64;
85 if (Name == "lstat64") return (void*)(intptr_t)&lstat64;
86 if (Name == "atexit") return (void*)(intptr_t)&atexit;
87 if (Name == "mknod") return (void*)(intptr_t)&mknod;
90 // We should not invoke parent's ctors/dtors from generated main()!
91 // On Mingw and Cygwin, the symbol __main is resolved to
92 // callee's(eg. tools/lli) one, to invoke wrong duplicated ctors
93 // (and register wrong callee's dtors with atexit(3)).
94 // We expect ExecutionEngine::runStaticConstructorsDestructors()
95 // is called before ExecutionEngine::runFunctionAsMain() is called.
96 if (Name == "__main") return (void*)(intptr_t)&jit_noop;
98 const char *NameStr = Name.c_str();
99 void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr);
102 // If it wasn't found and if it starts with an underscore ('_') character,
103 // try again without the underscore.
104 if (NameStr[0] == '_') {
105 Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr+1);
110 report_fatal_error("Program used external function '" + Name +
111 "' which could not be resolved!");