genode/tool/link.h
Christian Prochaska 2706e4cd75 tool_chain: cleanup
Fixes #1517
2015-05-26 09:39:49 +02:00

159 lines
4.9 KiB
C

/*
* \brief Stub for compiling GCC support libraries without libc
* \author Norman Feske
* \date 2011-08-31
*
* The target components of GCC tool chains (i.e. libsupc++, libgcc_eh, and
* libstdc++) depend on the presence of libc includes. For this reason, a C
* library for the target platform is normally regarded as a prerequisite for
* building a complete tool chain. However, for low-level operating-system
* code, this prerequisite is not satisfied.
*
* There are two traditional solutions to this problem. The first is to leave
* out those target components from the tool chain and live without full C++
* support (using '-fno-rtti' and '-fno-exceptions'). Because Genode relies on
* such C++ features however, this is no option. The other traditional solution
* is to use a tool chain compiled for a different target platform such as
* Linux. However, this approach calls for subtle problems because the target
* components are compiled against glibc and make certain presumptions about
* the underlying OS environment. E.g., the 'libstdc++' library of a Linux tool
* chain contains references to glibc's 'stderr' symbol, which does not exist
* on Genode's libc derived from FreeBSD. More critical assumptions are related
* to the mechanism used for thread-local storage.
*
* This header file overcomes these problems by providing all function
* prototypes and type declarations that are mandatory for compiling GCC's
* target components. Using this libc stub, all GCC target components can be
* built without the need for additional libc support. Of course, for actually
* using these target components, the target OS has to provide the
* implementation of a small subset of functions declared herein. On Genode,
* this subset is provided by the 'cxx' library.
*
* The code of the target components expects usual C header file names such as
* 'stdio.h'. It does not include 'libgcc_libc_stub.h'. By creating symlinks
* for all those file names pointing to this file, we ensure that this file is
* always included on the first occurrence of the inclusion of any libc header
* file. The set of symlinks pointing to this libc stub are created
* automatically by the 'tool_chain' script.
*/
/*
* Copyright (C) 2011-2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _LINK_H_
#define _LINK_H_
#include <stddef.h>
/*****************
** sys/types.h **
*****************/
#ifdef _LP64
typedef signed char __int8_t;
typedef signed short __int16_t;
typedef signed int __int32_t;
typedef signed long __int64_t;
typedef unsigned char __uint8_t;
typedef unsigned short __uint16_t;
typedef unsigned int __uint32_t;
typedef unsigned long __uint64_t;
#else /* _LP64 */
typedef signed char __int8_t;
typedef signed short __int16_t;
typedef signed long __int32_t;
typedef unsigned char __uint8_t;
typedef unsigned short __uint16_t;
typedef unsigned long __uint32_t;
#ifndef __STRICT_ANSI__
typedef signed long long __int64_t;
typedef unsigned long long __uint64_t;
#endif /* __STRICT_ANSI__ */
#endif /* _LP64 */
/***********
** elf.h **
***********/
/*
* The following defines and types are solely needed to compile libgcc's
* 'unwind-dw2-fde-glibc.c' in libc mode. This is needed because Genode's
* dynamic linker relies on the the "new" exception mechanism, which is not
* compiled-in when compiling libgcc with the 'inhibit_libc' flag.
*
* The following types are loosely based on glibc's 'link.h' and 'elf.h'.
*/
typedef __uint32_t Elf64_Word;
typedef __uint64_t Elf64_Addr;
typedef __uint64_t Elf64_Xword;
typedef __uint64_t Elf64_Off;
typedef __uint16_t Elf64_Half;
typedef struct
{
Elf64_Word p_type;
Elf64_Word p_flags;
Elf64_Off p_offset;
Elf64_Addr p_vaddr;
Elf64_Addr p_paddr;
Elf64_Xword p_filesz;
Elf64_Xword p_memsz;
Elf64_Xword p_align;
} Elf64_Phdr;
typedef __uint32_t Elf32_Word;
typedef __uint32_t Elf32_Addr;
typedef __uint64_t Elf32_Xword;
typedef __uint32_t Elf32_Off;
typedef __uint16_t Elf32_Half;
typedef struct
{
Elf32_Word p_type;
Elf32_Off p_offset;
Elf32_Addr p_vaddr;
Elf32_Addr p_paddr;
Elf32_Word p_filesz;
Elf32_Word p_memsz;
Elf32_Word p_flags;
Elf32_Word p_align;
} Elf32_Phdr;
#define PT_LOAD 1
#define PT_DYNAMIC 2
#define PT_LOOS 0x60000000
/************
** link.h **
************/
/* definitions according to glibc */
#ifdef _LP64
#define ElfW(type) Elf64_##type
#else
#define ElfW(type) Elf32_##type
#endif /* _LP64 */
struct dl_phdr_info
{
ElfW(Addr) dlpi_addr;
const char *dlpi_name;
const ElfW(Phdr) *dlpi_phdr;
ElfW(Half) dlpi_phnum;
unsigned long long int dlpi_adds;
unsigned long long int dlpi_subs;
size_t dlpi_tls_modid;
void *dlpi_tls_data;
};
extern int dl_iterate_phdr(int (*__callback) (struct dl_phdr_info *,
size_t, void *), void *__data);
#endif /* _LINK_H_ */