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Diffstat (limited to 'newlib/libc/sys/linux/linuxthreads/libc-symbols.h')
| -rw-r--r-- | newlib/libc/sys/linux/linuxthreads/libc-symbols.h | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/newlib/libc/sys/linux/linuxthreads/libc-symbols.h b/newlib/libc/sys/linux/linuxthreads/libc-symbols.h new file mode 100644 index 000000000..97b672643 --- /dev/null +++ b/newlib/libc/sys/linux/linuxthreads/libc-symbols.h @@ -0,0 +1,352 @@ +/* Support macros for making weak and strong aliases for symbols, + and for using symbol sets and linker warnings with GNU ld. + Copyright (C) 1995,1996,1997,1998,2000,2001 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#ifndef _LIBC_SYMBOLS_H +#define _LIBC_SYMBOLS_H 1 + +/* This file's macros are included implicitly in the compilation of every + file in the C library by -imacros. + + We include config.h which is generated by configure. + It should define for us the following symbols: + + * HAVE_ASM_SET_DIRECTIVE if we have `.set B, A' instead of `A = B'. + * ASM_GLOBAL_DIRECTIVE with `.globl' or `.global'. + * HAVE_GNU_LD if using GNU ld, with support for weak symbols in a.out, + and for symbol set and warning messages extensions in a.out and ELF. + * HAVE_ELF if using ELF, which supports weak symbols using `.weak'. + * HAVE_ASM_WEAK_DIRECTIVE if we have weak symbols using `.weak'. + * HAVE_ASM_WEAKEXT_DIRECTIVE if we have weak symbols using `.weakext'. + + */ + +/* This is defined for the compilation of all C library code. features.h + tests this to avoid inclusion of stubs.h while compiling the library, + before stubs.h has been generated. Some library code that is shared + with other packages also tests this symbol to see if it is being + compiled as part of the C library. We must define this before including + config.h, because it makes some definitions conditional on whether libc + itself is being compiled, or just some generator program. */ +#define _LIBC 1 + +/* Enable declarations of GNU extensions, since we are compiling them. */ +#define _GNU_SOURCE 1 +/* And we also need the data for the reentrant functions. */ +#define _REENTRANT 1 + +#include <config.h> + +/* The symbols in all the user (non-_) macros are C symbols. + HAVE_GNU_LD without HAVE_ELF implies a.out. */ + +#if defined HAVE_ASM_WEAK_DIRECTIVE || defined HAVE_ASM_WEAKEXT_DIRECTIVE +# define HAVE_WEAK_SYMBOLS +#endif + +#ifndef __SYMBOL_PREFIX +# ifdef NO_UNDERSCORES +# define __SYMBOL_PREFIX +# else +# define __SYMBOL_PREFIX "_" +# endif +#endif + +#ifndef C_SYMBOL_NAME +# ifdef NO_UNDERSCORES +# define C_SYMBOL_NAME(name) name +# else +# define C_SYMBOL_NAME(name) _##name +# endif +#endif + +#ifndef ASM_LINE_SEP +# define ASM_LINE_SEP ; +#endif + +#ifndef C_SYMBOL_DOT_NAME +# define C_SYMBOL_DOT_NAME(name) .##name +#endif + +#ifndef __ASSEMBLER__ +/* GCC understands weak symbols and aliases; use its interface where + possible, instead of embedded assembly language. */ + +/* Define ALIASNAME as a strong alias for NAME. */ +# define strong_alias(name, aliasname) _strong_alias(name, aliasname) +# define _strong_alias(name, aliasname) \ + extern __typeof (name) aliasname __attribute__ ((alias (#name))); + +/* This comes between the return type and function name in + a function definition to make that definition weak. */ +# define weak_function __attribute__ ((weak)) +# define weak_const_function __attribute__ ((weak, __const__)) + +# ifdef HAVE_WEAK_SYMBOLS + +/* Define ALIASNAME as a weak alias for NAME. + If weak aliases are not available, this defines a strong alias. */ +# define weak_alias(name, aliasname) _weak_alias (name, aliasname) +# define _weak_alias(name, aliasname) \ + extern __typeof (name) aliasname __attribute__ ((weak, alias (#name))); + +/* Declare SYMBOL as weak undefined symbol (resolved to 0 if not defined). */ +# define weak_extern(symbol) _weak_extern (symbol) +# ifdef HAVE_ASM_WEAKEXT_DIRECTIVE +# define _weak_extern(symbol) asm (".weakext " __SYMBOL_PREFIX #symbol); +# else +# define _weak_extern(symbol) asm (".weak " __SYMBOL_PREFIX #symbol); +# endif + +# else + +# define weak_alias(name, aliasname) strong_alias(name, aliasname) +# define weak_extern(symbol) /* Nothing. */ + +# endif + +#else /* __ASSEMBLER__ */ + +# ifdef HAVE_ASM_SET_DIRECTIVE +# define strong_alias(original, alias) \ + ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ + .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) +# else +# ifdef HAVE_ASM_GLOBAL_DOT_NAME +# define strong_alias(original, alias) \ + ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ + C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP \ + ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ + C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) +# else +# define strong_alias(original, alias) \ + ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ + C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) +# endif +# endif + +# ifdef HAVE_WEAK_SYMBOLS +# ifdef HAVE_ASM_WEAKEXT_DIRECTIVE +# define weak_alias(original, alias) \ + .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) +# define weak_extern(symbol) \ + .weakext C_SYMBOL_NAME (symbol) + +# else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ + +# ifdef HAVE_ASM_GLOBAL_DOT_NAME +# define weak_alias(original, alias) \ + .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP \ + C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP \ + ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ + C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) +# else +# define weak_alias(original, alias) \ + .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP \ + C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) +# endif + +# define weak_extern(symbol) \ + .weak C_SYMBOL_NAME (symbol) + +# endif /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ + +# else /* ! HAVE_WEAK_SYMBOLS */ + +# define weak_alias(original, alias) strong_alias(original, alias) +# define weak_extern(symbol) /* Nothing */ +# endif /* ! HAVE_WEAK_SYMBOLS */ + +#endif /* __ASSEMBLER__ */ + +/* On some platforms we can make internal function calls (i.e., calls of + functions not exported) a bit faster by using a different calling + convention. */ +#ifndef internal_function +# define internal_function /* empty */ +#endif + +/* Prepare for the case that `__builtin_expect' is not available. */ +#ifndef HAVE_BUILTIN_EXPECT +# define __builtin_expect(expr, val) (expr) +#endif + +/* Determine the return address. */ +#define RETURN_ADDRESS(nr) \ + __builtin_extract_return_addr (__builtin_return_address (nr)) + +/* When a reference to SYMBOL is encountered, the linker will emit a + warning message MSG. */ +#ifdef HAVE_GNU_LD +# ifdef HAVE_ELF + +/* We want the .gnu.warning.SYMBOL section to be unallocated. */ +# ifdef HAVE_ASM_PREVIOUS_DIRECTIVE +# define __make_section_unallocated(section_string) \ + asm (".section " section_string "\n\t.previous"); +# elif defined HAVE_ASM_POPSECTION_DIRECTIVE +# define __make_section_unallocated(section_string) \ + asm (".pushsection " section_string "\n\t.popsection"); +# else +# define __make_section_unallocated(section_string) +# endif + +/* Tacking on "\n\t#" to the section name makes gcc put it's bogus + section attributes on what looks like a comment to the assembler. */ +# ifdef HAVE_SECTION_QUOTES +# define link_warning(symbol, msg) \ + __make_section_unallocated (".gnu.warning." #symbol) \ + static const char __evoke_link_warning_##symbol[] \ + __attribute__ ((section (".gnu.warning." #symbol "\"\n\t#\""))) = msg; +# else +# define link_warning(symbol, msg) \ + __make_section_unallocated (".gnu.warning." #symbol) \ + static const char __evoke_link_warning_##symbol[] \ + __attribute__ ((section (".gnu.warning." #symbol "\n\t#"))) = msg; +# endif +# else /* Not ELF: a.out */ +# ifdef HAVE_XCOFF +/* XCOFF does not support .stabs. + The native aix linker will remove the .stab and .stabstr sections + The gnu linker will have a fatal error if there is a relocation for + symbol in the .stab section. Silently disable this macro. */ +# define link_warning(symbol, msg) +# else +# define link_warning(symbol, msg) \ + asm (".stabs \"" msg "\",30,0,0,0\n\t" \ + ".stabs \"" __SYMBOL_PREFIX #symbol "\",1,0,0,0\n"); +# endif /* XCOFF */ +# endif +#else +/* We will never be heard; they will all die horribly. */ +# define link_warning(symbol, msg) +#endif + +/* A canned warning for sysdeps/stub functions. */ +#define stub_warning(name) \ + link_warning (name, \ + "warning: " #name " is not implemented and will always fail") + +/* + +*/ + +#ifdef HAVE_GNU_LD + +/* Symbol set support macros. */ + +# ifdef HAVE_ELF + +/* Make SYMBOL, which is in the text segment, an element of SET. */ +# define text_set_element(set, symbol) _elf_set_element(set, symbol) +/* Make SYMBOL, which is in the data segment, an element of SET. */ +# define data_set_element(set, symbol) _elf_set_element(set, symbol) +/* Make SYMBOL, which is in the bss segment, an element of SET. */ +# define bss_set_element(set, symbol) _elf_set_element(set, symbol) + +/* These are all done the same way in ELF. + There is a new section created for each set. */ +# ifdef SHARED +/* When building a shared library, make the set section writable, + because it will need to be relocated at run time anyway. */ +# define _elf_set_element(set, symbol) \ + static const void *__elf_set_##set##_element_##symbol##__ \ + __attribute__ ((unused, section (#set))) = &(symbol) +# else +# define _elf_set_element(set, symbol) \ + static const void *const __elf_set_##set##_element_##symbol##__ \ + __attribute__ ((unused, section (#set))) = &(symbol) +# endif + +/* Define SET as a symbol set. This may be required (it is in a.out) to + be able to use the set's contents. */ +# define symbol_set_define(set) symbol_set_declare(set) + +/* Declare SET for use in this module, if defined in another module. */ +# define symbol_set_declare(set) \ + extern void *const __start_##set __attribute__ ((__weak__)); \ + extern void *const __stop_##set __attribute__ ((__weak__)); \ + weak_extern (__start_##set) weak_extern (__stop_##set) + +/* Return a pointer (void *const *) to the first element of SET. */ +# define symbol_set_first_element(set) (&__start_##set) + +/* Return true iff PTR (a void *const *) has been incremented + past the last element in SET. */ +# define symbol_set_end_p(set, ptr) ((ptr) >= &__stop_##set) + +# else /* Not ELF: a.out. */ + +# ifdef HAVE_XCOFF +/* XCOFF does not support .stabs. + The native aix linker will remove the .stab and .stabstr sections + The gnu linker will have a fatal error if there is a relocation for + symbol in the .stab section. Silently disable these macros. */ +# define text_set_element(set, symbol) +# define data_set_element(set, symbol) +# define bss_set_element(set, symbol) +# else +# define text_set_element(set, symbol) \ + asm (".stabs \"" __SYMBOL_PREFIX #set "\",23,0,0," __SYMBOL_PREFIX #symbol) +# define data_set_element(set, symbol) \ + asm (".stabs \"" __SYMBOL_PREFIX #set "\",25,0,0," __SYMBOL_PREFIX #symbol) +# define bss_set_element(set, symbol) ?error Must use initialized data. +# endif /* XCOFF */ +# define symbol_set_define(set) void *const (set)[1]; +# define symbol_set_declare(set) extern void *const (set)[1]; + +# define symbol_set_first_element(set) &(set)[1] +# define symbol_set_end_p(set, ptr) (*(ptr) == 0) + +# endif /* ELF. */ +#else +/* We cannot do anything in generial. */ +# define text_set_element(set, symbol) asm ("") +# define data_set_element(set, symbol) asm ("") +# define bss_set_element(set, symbol) asm ("") +# define symbol_set_define(set) void *const (set)[1]; +# define symbol_set_declare(set) extern void *const (set)[1]; + +# define symbol_set_first_element(set) &(set)[1] +# define symbol_set_end_p(set, ptr) (*(ptr) == 0) +#endif /* Have GNU ld. */ + +#if DO_VERSIONING +# define symbol_version(real, name, version) \ + _symbol_version(real, name, version) +# define default_symbol_version(real, name, version) \ + _default_symbol_version(real, name, version) +# ifdef __ASSEMBLER__ +# define _symbol_version(real, name, version) \ + .symver real, name##@##version +# define _default_symbol_version(real, name, version) \ + .symver real, name##@##@##version +# else +# define _symbol_version(real, name, version) \ + __asm__ (".symver " #real "," #name "@" #version) +# define _default_symbol_version(real, name, version) \ + __asm__ (".symver " #real "," #name "@@" #version) +# endif +#else +# define symbol_version(real, name, version) +# define default_symbol_version(real, name, version) \ + strong_alias(real, name) +#endif + +#endif /* libc-symbols.h */ |