mirror of
https://sourceware.org/git/glibc.git
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2.5-18.1
This commit is contained in:
Jakub Jelinek
@@ -1,6 +1,7 @@
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/* Support macros for making weak and strong aliases for symbols,
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and for using symbol sets and linker warnings with GNU ld.
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Copyright (C) 1995-1998,2000-2003,2004 Free Software Foundation, Inc.
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Copyright (C) 1995-1998,2000-2003,2004,2005,2006
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Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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@@ -31,8 +32,6 @@
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* ASM_GLOBAL_DIRECTIVE with `.globl' or `.global'.
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* ASM_TYPE_DIRECTIVE_PREFIX with `@' or `#' or whatever for .type,
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or leave it undefined if there is no .type directive.
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* HAVE_GNU_LD if using GNU ld, with support for weak symbols in a.out,
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and for symbol set and warning messages extensions in a.out and ELF.
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* HAVE_ELF if using ELF, which supports weak symbols using `.weak'.
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* HAVE_ASM_WEAK_DIRECTIVE if we have weak symbols using `.weak'.
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* HAVE_ASM_WEAKEXT_DIRECTIVE if we have weak symbols using `.weakext'.
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@@ -56,7 +55,7 @@
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#include <config.h>
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/* The symbols in all the user (non-_) macros are C symbols.
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HAVE_GNU_LD without HAVE_ELF implies a.out. */
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NO HAVE_ELF implies a.out. */
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#if defined HAVE_ASM_WEAK_DIRECTIVE || defined HAVE_ASM_WEAKEXT_DIRECTIVE
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# define HAVE_WEAK_SYMBOLS
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@@ -220,55 +219,48 @@
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/* When a reference to SYMBOL is encountered, the linker will emit a
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warning message MSG. */
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#ifdef HAVE_GNU_LD
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# ifdef HAVE_ELF
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#ifdef HAVE_ELF
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/* We want the .gnu.warning.SYMBOL section to be unallocated. */
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# ifdef HAVE_ASM_PREVIOUS_DIRECTIVE
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# define __make_section_unallocated(section_string) \
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# ifdef HAVE_ASM_PREVIOUS_DIRECTIVE
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# define __make_section_unallocated(section_string) \
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asm (".section " section_string "\n\t.previous");
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# elif defined HAVE_ASM_POPSECTION_DIRECTIVE
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# define __make_section_unallocated(section_string) \
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# elif defined HAVE_ASM_POPSECTION_DIRECTIVE
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# define __make_section_unallocated(section_string) \
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asm (".pushsection " section_string "\n\t.popsection");
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# else
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# define __make_section_unallocated(section_string)
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# endif
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# else
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# define __make_section_unallocated(section_string)
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# endif
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/* Tacking on "\n\t#" to the section name makes gcc put it's bogus
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section attributes on what looks like a comment to the assembler. */
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# ifdef HAVE_SECTION_QUOTES
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# define __sec_comment "\"\n\t#\""
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# else
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# define __sec_comment "\n\t#"
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# endif
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# define link_warning(symbol, msg) \
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# ifdef HAVE_SECTION_QUOTES
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# define __sec_comment "\"\n\t#\""
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# else
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# define __sec_comment "\n\t#"
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# endif
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# define link_warning(symbol, msg) \
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__make_section_unallocated (".gnu.warning." #symbol) \
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static const char __evoke_link_warning_##symbol[] \
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__attribute__ ((used, section (".gnu.warning." #symbol __sec_comment))) \
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= msg;
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# define libc_freeres_ptr(decl) \
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# define libc_freeres_ptr(decl) \
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__make_section_unallocated ("__libc_freeres_ptrs, \"aw\", %nobits") \
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decl __attribute__ ((section ("__libc_freeres_ptrs" __sec_comment)))
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# define __libc_freeres_fn_section \
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# define __libc_freeres_fn_section \
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__attribute__ ((section ("__libc_freeres_fn")))
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# else /* Not ELF: a.out */
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# ifdef HAVE_XCOFF
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#else /* Not ELF: a.out */
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# ifdef HAVE_XCOFF
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/* XCOFF does not support .stabs.
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The native aix linker will remove the .stab and .stabstr sections
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The gnu linker will have a fatal error if there is a relocation for
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symbol in the .stab section. Silently disable this macro. */
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# define link_warning(symbol, msg)
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# else
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# define link_warning(symbol, msg) \
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# define link_warning(symbol, msg)
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# else
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# define link_warning(symbol, msg) \
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asm (".stabs \"" msg "\",30,0,0,0\n\t" \
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".stabs \"" __SYMBOL_PREFIX #symbol "\",1,0,0,0\n");
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# endif /* XCOFF */
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# define libc_freeres_ptr(decl) decl
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# define __libc_freeres_fn_section
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# endif
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#else
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/* We will never be heard; they will all die horribly. */
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# define link_warning(symbol, msg)
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# endif /* XCOFF */
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# define libc_freeres_ptr(decl) decl
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# define __libc_freeres_fn_section
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#endif
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@@ -279,6 +271,7 @@
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/* A canned warning for sysdeps/stub functions. */
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#define stub_warning(name) \
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__make_section_unallocated (".gnu.glibc-stub." #name) \
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link_warning (name, \
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"warning: " #name " is not implemented and will always fail")
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@@ -324,92 +317,79 @@ for linking")
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*/
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#ifdef HAVE_GNU_LD
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/* Symbol set support macros. */
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# ifdef HAVE_ELF
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#ifdef HAVE_ELF
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/* Make SYMBOL, which is in the text segment, an element of SET. */
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# define text_set_element(set, symbol) _elf_set_element(set, symbol)
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# define text_set_element(set, symbol) _elf_set_element(set, symbol)
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/* Make SYMBOL, which is in the data segment, an element of SET. */
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# define data_set_element(set, symbol) _elf_set_element(set, symbol)
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# define data_set_element(set, symbol) _elf_set_element(set, symbol)
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/* Make SYMBOL, which is in the bss segment, an element of SET. */
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# define bss_set_element(set, symbol) _elf_set_element(set, symbol)
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# define bss_set_element(set, symbol) _elf_set_element(set, symbol)
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/* These are all done the same way in ELF.
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There is a new section created for each set. */
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# ifdef SHARED
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# ifdef SHARED
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/* When building a shared library, make the set section writable,
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because it will need to be relocated at run time anyway. */
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# define _elf_set_element(set, symbol) \
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# define _elf_set_element(set, symbol) \
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static const void *__elf_set_##set##_element_##symbol##__ \
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__attribute__ ((used, section (#set))) = &(symbol)
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# else
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# define _elf_set_element(set, symbol) \
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# else
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# define _elf_set_element(set, symbol) \
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static const void *const __elf_set_##set##_element_##symbol##__ \
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__attribute__ ((used, section (#set))) = &(symbol)
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# endif
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# endif
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/* Define SET as a symbol set. This may be required (it is in a.out) to
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be able to use the set's contents. */
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# define symbol_set_define(set) symbol_set_declare(set)
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# define symbol_set_define(set) symbol_set_declare(set)
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/* Declare SET for use in this module, if defined in another module.
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In a shared library, this is always local to that shared object.
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For static linking, the set might be wholly absent and so we use
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weak references. */
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# define symbol_set_declare(set) \
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# define symbol_set_declare(set) \
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extern char const __start_##set[] __symbol_set_attribute; \
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extern char const __stop_##set[] __symbol_set_attribute;
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# ifdef SHARED
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# define __symbol_set_attribute attribute_hidden
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# else
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# define __symbol_set_attribute __attribute__ ((weak))
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# endif
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# ifdef SHARED
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# define __symbol_set_attribute attribute_hidden
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# else
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# define __symbol_set_attribute __attribute__ ((weak))
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# endif
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/* Return a pointer (void *const *) to the first element of SET. */
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# define symbol_set_first_element(set) ((void *const *) (&__start_##set))
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# define symbol_set_first_element(set) ((void *const *) (&__start_##set))
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/* Return true iff PTR (a void *const *) has been incremented
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past the last element in SET. */
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# define symbol_set_end_p(set, ptr) ((ptr) >= (void *const *) &__stop_##set)
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# define symbol_set_end_p(set, ptr) ((ptr) >= (void *const *) &__stop_##set)
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# else /* Not ELF: a.out. */
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#else /* Not ELF: a.out. */
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# ifdef HAVE_XCOFF
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# ifdef HAVE_XCOFF
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/* XCOFF does not support .stabs.
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The native aix linker will remove the .stab and .stabstr sections
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The gnu linker will have a fatal error if there is a relocation for
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symbol in the .stab section. Silently disable these macros. */
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# define text_set_element(set, symbol)
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# define data_set_element(set, symbol)
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# define bss_set_element(set, symbol)
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# else
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# define text_set_element(set, symbol) \
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# define text_set_element(set, symbol)
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# define data_set_element(set, symbol)
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# define bss_set_element(set, symbol)
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# else
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# define text_set_element(set, symbol) \
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asm (".stabs \"" __SYMBOL_PREFIX #set "\",23,0,0," __SYMBOL_PREFIX #symbol)
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# define data_set_element(set, symbol) \
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# define data_set_element(set, symbol) \
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asm (".stabs \"" __SYMBOL_PREFIX #set "\",25,0,0," __SYMBOL_PREFIX #symbol)
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# define bss_set_element(set, symbol) ?error Must use initialized data.
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# endif /* XCOFF */
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# define symbol_set_define(set) void *const (set)[1];
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# define symbol_set_declare(set) extern void *const (set)[1];
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# define symbol_set_first_element(set) &(set)[1]
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# define symbol_set_end_p(set, ptr) (*(ptr) == 0)
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# endif /* ELF. */
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#else
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/* We cannot do anything in generial. */
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# define text_set_element(set, symbol) asm ("")
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# define data_set_element(set, symbol) asm ("")
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# define bss_set_element(set, symbol) asm ("")
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# define symbol_set_define(set) void *const (set)[1];
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# define bss_set_element(set, symbol) ?error Must use initialized data.
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# endif /* XCOFF */
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# define symbol_set_define(set) void *const (set)[1];
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# define symbol_set_declare(set) extern void *const (set)[1];
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# define symbol_set_first_element(set) &(set)[1]
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# define symbol_set_end_p(set, ptr) (*(ptr) == 0)
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#endif /* Have GNU ld. */
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#endif /* ELF. */
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#if DO_VERSIONING
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# define symbol_version(real, name, version) \
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@@ -523,7 +503,7 @@ for linking")
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}
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libc_hidden_weak (foo)
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Simularly for global data. If references to foo within libc.so should
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Similarly for global data. If references to foo within libc.so should
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always go to foo defined in libc.so, then in include/foo.h you add:
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libc_hidden_proto (foo)
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@@ -538,7 +518,7 @@ for linking")
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int foo = INITIAL_FOO_VALUE;
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libc_hidden_data_weak (foo)
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If foo is normally just an alias (strong or weak) of some other function,
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If foo is normally just an alias (strong or weak) to some other function,
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you should use the normal strong_alias first, then add libc_hidden_def
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or libc_hidden_weak:
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@@ -582,78 +562,23 @@ for linking")
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# define hidden_proto(name, attrs...) \
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__hidden_proto (name, __GI_##name, ##attrs)
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# define __hidden_proto(name, internal, attrs...) \
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extern __typeof (name) internal; \
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extern __typeof (name) name __asm__ (__hidden_asmname (#internal)) \
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__hidden_proto_hiddenattr (attrs);
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# define __hidden_asmname(name) \
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__hidden_asmname1 (__USER_LABEL_PREFIX__, name)
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# define __hidden_asmname1(prefix, name) __hidden_asmname2(prefix, name)
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# define __hidden_asmname2(prefix, name) #prefix name
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# ifdef HAVE_ASM_SET_DIRECTIVE
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# define __hidden_def1(original, alias) \
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ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \
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.set C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original)
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# ifdef HAVE_ASM_GLOBAL_DOT_NAME
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# define __hidden_dot_def1(original, alias) ASM_LINE_SEP \
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ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \
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.set C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original)
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# else
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# define __hidden_dot_def1(original, alias)
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# endif
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# else
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# define __hidden_def1(original, alias) \
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ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \
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C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
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# ifdef HAVE_ASM_GLOBAL_DOT_NAME
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# define __hidden_dot_def1(original, alias) ASM_LINE_SEP \
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ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \
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C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original)
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# else
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# define __hidden_dot_def1(original, alias)
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# endif
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# endif
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# define __hidden_def2(...) #__VA_ARGS__
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# define __hidden_def3(...) __hidden_def2 (__VA_ARGS__)
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# define hidden_def(name) \
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__asm__ (__hidden_def3 (__hidden_def1 (__GI_##name, name) \
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__hidden_dot_def1 (__GI_##name, name)));
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# define hidden_data_def(name) \
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__asm__ (__hidden_def3 (__hidden_def1 (__GI_##name, name)));
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# define hidden_ver(local, name) \
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__asm__ (__hidden_def3 (__hidden_def1 (local, __GI_##name) \
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__hidden_dot_def1 (local, __GI_##name)));
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# define hidden_data_ver(local, name) \
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__asm__ (__hidden_def3 (__hidden_def1 (local, __GI_##name)));
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# ifdef HAVE_WEAK_SYMBOLS
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# ifdef HAVE_ASM_WEAKEXT_DIRECTIVE
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# define __hidden_weak1(original, alias) \
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.weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original)
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# ifdef HAVE_ASM_GLOBAL_DOT_NAME
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# define __hidden_dot_weak1(original, alias) ASM_LINE_SEP \
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.weakext C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original)
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# else
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# define __hidden_dot_weak1(original, alias)
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# endif
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# else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
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# define __hidden_weak1(original, alias) \
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.weak C_SYMBOL_NAME (alias) ASM_LINE_SEP \
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C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
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# ifdef HAVE_ASM_GLOBAL_DOT_NAME
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# define __hidden_dot_weak1(original, alias) ASM_LINE_SEP \
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.weak C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \
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C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original)
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# else
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# define __hidden_dot_weak1(original, alias)
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# endif
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# endif
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# define hidden_weak(name) \
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__asm__ (__hidden_def3 (__hidden_weak1 (__GI_##name, name) \
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__hidden_dot_weak1 (__GI_##name, name)));
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# define hidden_data_weak(name) \
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__asm__ (__hidden_def3 (__hidden_weak1 (__GI_##name, name)));
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# else
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# define hidden_weak(name) hidden_def (name)
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# endif
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# define __hidden_ver1(local, internal, name) \
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extern __typeof (name) __EI_##name __asm__(__hidden_asmname (#internal)); \
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extern __typeof (name) __EI_##name \
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__attribute__((alias (__hidden_asmname (#local))))
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# define hidden_ver(local, name) __hidden_ver1(local, __GI_##name, name);
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# define hidden_data_ver(local, name) hidden_ver(local, name)
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# define hidden_def(name) __hidden_ver1(__GI_##name, name, name);
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# define hidden_data_def(name) hidden_def(name)
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# define hidden_weak(name) \
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__hidden_ver1(__GI_##name, name, name) __attribute__((weak));
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# define hidden_data_weak(name) hidden_weak(name)
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# else
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/* For assembly, we need to do the opposite of what we do in C:
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in assembly gcc __REDIRECT stuff is not in place, so functions
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@@ -762,6 +687,24 @@ for linking")
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# define libresolv_hidden_data_ver(local, name)
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#endif
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#if defined NOT_IN_libc && defined IS_IN_librt
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# define librt_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
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# define librt_hidden_def(name) hidden_def (name)
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# define librt_hidden_weak(name) hidden_weak (name)
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# define librt_hidden_ver(local, name) hidden_ver (local, name)
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# define librt_hidden_data_def(name) hidden_data_def (name)
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# define librt_hidden_data_weak(name) hidden_data_weak (name)
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# define librt_hidden_data_ver(local, name) hidden_data_ver (local, name)
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#else
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# define librt_hidden_proto(name, attrs...)
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# define librt_hidden_def(name)
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# define librt_hidden_weak(name)
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# define librt_hidden_ver(local, name)
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# define librt_hidden_data_def(name)
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# define librt_hidden_data_weak(name)
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# define librt_hidden_data_ver(local, name)
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#endif
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#if defined NOT_IN_libc && defined IS_IN_libdl
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# define libdl_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
|
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# define libdl_hidden_def(name) hidden_def (name)
|
||||
|
||||
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