llvm-6502/lib/ExecutionEngine/RTDyldMemoryManager.cpp
Benjamin Kramer f102f31e15 Preserve const correctness.
GCC complains about casting away const.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183216 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-04 09:09:15 +00:00

119 lines
4.0 KiB
C++

//===-- RTDyldMemoryManager.cpp - Memory manager for MC-JIT -----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Implementation of the runtime dynamic memory manager base class.
//
//===----------------------------------------------------------------------===//
#include "llvm/Config/config.h"
#include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
#include "llvm/Support/DynamicLibrary.h"
#include "llvm/Support/ErrorHandling.h"
#include <cstdlib>
#ifdef __linux__
// These includes used by RTDyldMemoryManager::getPointerToNamedFunction()
// for Glibc trickery. See comments in this function for more information.
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#include <fcntl.h>
#include <unistd.h>
#endif
namespace llvm {
RTDyldMemoryManager::~RTDyldMemoryManager() {}
// Determine whether we can register EH tables.
#if (defined(__GNUC__) && !defined(__ARM_EABI__) && \
!defined(__USING_SJLJ_EXCEPTIONS__))
#define HAVE_EHTABLE_SUPPORT 1
#else
#define HAVE_EHTABLE_SUPPORT 0
#endif
#if HAVE_EHTABLE_SUPPORT
extern "C" void __register_frame(void*);
static const char *processFDE(const char *Entry) {
const char *P = Entry;
uint32_t Length = *((const uint32_t *)P);
P += 4;
uint32_t Offset = *((const uint32_t *)P);
if (Offset != 0)
__register_frame(const_cast<char *>(Entry));
return P + Length;
}
#endif
void RTDyldMemoryManager::registerEHFrames(StringRef SectionData) {
#if HAVE_EHTABLE_SUPPORT
const char *P = SectionData.data();
const char *End = SectionData.data() + SectionData.size();
do {
P = processFDE(P);
} while(P != End);
#endif
}
static int jit_noop() {
return 0;
}
void *RTDyldMemoryManager::getPointerToNamedFunction(const std::string &Name,
bool AbortOnFailure) {
#if defined(__linux__)
//===--------------------------------------------------------------------===//
// 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 (Name == "stat") return (void*)(intptr_t)&stat;
if (Name == "fstat") return (void*)(intptr_t)&fstat;
if (Name == "lstat") return (void*)(intptr_t)&lstat;
if (Name == "stat64") return (void*)(intptr_t)&stat64;
if (Name == "fstat64") return (void*)(intptr_t)&fstat64;
if (Name == "lstat64") return (void*)(intptr_t)&lstat64;
if (Name == "atexit") return (void*)(intptr_t)&atexit;
if (Name == "mknod") return (void*)(intptr_t)&mknod;
#endif // __linux__
// 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();
void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr);
if (Ptr) return Ptr;
// If it wasn't found and if it starts with an underscore ('_') character,
// try again without the underscore.
if (NameStr[0] == '_') {
Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr+1);
if (Ptr) return Ptr;
}
if (AbortOnFailure)
report_fatal_error("Program used external function '" + Name +
"' which could not be resolved!");
return 0;
}
} // namespace llvm