llvm-6502/lib/ExecutionEngine/RTDyldMemoryManager.cpp
Filip Pizlo a4ea4a7203 Put RTDyldMemoryManager into its own file, and make it linked into
libExecutionEngine. Move method implementations that aren't specific to 
allocation out of SectionMemoryManager and into RTDyldMemoryManager.

This is in preparation for exposing RTDyldMemoryManager through the C 
API.

This is a fixed version of r182407 and r182411. That first revision 
broke builds because I forgot to move the conditional includes of 
various POSIX headers from SectionMemoryManager into 
RTDyldMemoryManager. Those includes are necessary because of how 
getPointerToNamedFunction works around the glibc libc_nonshared.a thing. 
The latter revision still broke things because I forgot to include 
llvm/Config/config.h.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182418 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-21 20:24:07 +00:00

117 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"
#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 = *((uint32_t*)P);
P += 4;
uint32_t Offset = *((uint32_t*)P);
if (Offset != 0)
__register_frame((void*)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