diff options
Diffstat (limited to 'include/libc-symbols.h')
| -rw-r--r-- | include/libc-symbols.h | 233 |
1 files changed, 145 insertions, 88 deletions
diff --git a/include/libc-symbols.h b/include/libc-symbols.h index da46f5e804..dcc46cc80f 100644 --- a/include/libc-symbols.h +++ b/include/libc-symbols.h @@ -1,7 +1,6 @@ /* Support macros for making weak and strong aliases for symbols, and for using symbol sets and linker warnings with GNU ld. - Copyright (C) 1995-1998,2000-2003,2004,2005,2006 - Free Software Foundation, Inc. + Copyright (C) 1995-1998,2000-2003,2004 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 @@ -32,6 +31,8 @@ * ASM_GLOBAL_DIRECTIVE with `.globl' or `.global'. * ASM_TYPE_DIRECTIVE_PREFIX with `@' or `#' or whatever for .type, or leave it undefined if there is no .type directive. + * 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'. @@ -55,7 +56,7 @@ #include <config.h> /* The symbols in all the user (non-_) macros are C symbols. - NO HAVE_ELF implies a.out. */ + HAVE_GNU_LD without HAVE_ELF implies a.out. */ #if defined HAVE_ASM_WEAK_DIRECTIVE || defined HAVE_ASM_WEAKEXT_DIRECTIVE # define HAVE_WEAK_SYMBOLS @@ -219,48 +220,55 @@ /* When a reference to SYMBOL is encountered, the linker will emit a warning message MSG. */ -#ifdef HAVE_ELF +#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) \ +# 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) \ +# 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 +# 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 __sec_comment "\"\n\t#\"" -# else -# define __sec_comment "\n\t#" -# endif -# define link_warning(symbol, msg) \ +# ifdef HAVE_SECTION_QUOTES +# define __sec_comment "\"\n\t#\"" +# else +# define __sec_comment "\n\t#" +# endif +# define link_warning(symbol, msg) \ __make_section_unallocated (".gnu.warning." #symbol) \ static const char __evoke_link_warning_##symbol[] \ __attribute__ ((used, section (".gnu.warning." #symbol __sec_comment))) \ = msg; -# define libc_freeres_ptr(decl) \ +# define libc_freeres_ptr(decl) \ __make_section_unallocated ("__libc_freeres_ptrs, \"aw\", %nobits") \ decl __attribute__ ((section ("__libc_freeres_ptrs" __sec_comment))) -# define __libc_freeres_fn_section \ +# define __libc_freeres_fn_section \ __attribute__ ((section ("__libc_freeres_fn"))) -#else /* Not ELF: a.out */ -# ifdef HAVE_XCOFF +# 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) \ +# 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 /* XCOFF */ +# define libc_freeres_ptr(decl) decl +# define __libc_freeres_fn_section +# endif +#else +/* We will never be heard; they will all die horribly. */ +# define link_warning(symbol, msg) # define libc_freeres_ptr(decl) decl # define __libc_freeres_fn_section #endif @@ -271,7 +279,6 @@ /* A canned warning for sysdeps/stub functions. */ #define stub_warning(name) \ - __make_section_unallocated (".gnu.glibc-stub." #name) \ link_warning (name, \ "warning: " #name " is not implemented and will always fail") @@ -317,79 +324,92 @@ for linking") */ +#ifdef HAVE_GNU_LD + /* Symbol set support macros. */ -#ifdef HAVE_ELF +# 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) +# 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) +# 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) +# 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 +# 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) \ +# define _elf_set_element(set, symbol) \ static const void *__elf_set_##set##_element_##symbol##__ \ __attribute__ ((used, section (#set))) = &(symbol) -# else -# define _elf_set_element(set, symbol) \ +# else +# define _elf_set_element(set, symbol) \ static const void *const __elf_set_##set##_element_##symbol##__ \ __attribute__ ((used, section (#set))) = &(symbol) -# endif +# 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) +# define symbol_set_define(set) symbol_set_declare(set) /* Declare SET for use in this module, if defined in another module. In a shared library, this is always local to that shared object. For static linking, the set might be wholly absent and so we use weak references. */ -# define symbol_set_declare(set) \ +# define symbol_set_declare(set) \ extern char const __start_##set[] __symbol_set_attribute; \ extern char const __stop_##set[] __symbol_set_attribute; -# ifdef SHARED -# define __symbol_set_attribute attribute_hidden -# else -# define __symbol_set_attribute __attribute__ ((weak)) -# endif +# ifdef SHARED +# define __symbol_set_attribute attribute_hidden +# else +# define __symbol_set_attribute __attribute__ ((weak)) +# endif /* Return a pointer (void *const *) to the first element of SET. */ -# define symbol_set_first_element(set) ((void *const *) (&__start_##set)) +# define symbol_set_first_element(set) ((void *const *) (&__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) >= (void *const *) &__stop_##set) +# define symbol_set_end_p(set, ptr) ((ptr) >= (void *const *) &__stop_##set) -#else /* Not ELF: a.out. */ +# else /* Not ELF: a.out. */ -# ifdef HAVE_XCOFF +# 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) \ +# 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) \ +# 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 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 /* ELF. */ +#endif /* Have GNU ld. */ #if DO_VERSIONING # define symbol_version(real, name, version) \ @@ -503,7 +523,7 @@ for linking") } libc_hidden_weak (foo) - Similarly for global data. If references to foo within libc.so should + Simularly for global data. If references to foo within libc.so should always go to foo defined in libc.so, then in include/foo.h you add: libc_hidden_proto (foo) @@ -518,7 +538,7 @@ for linking") int foo = INITIAL_FOO_VALUE; libc_hidden_data_weak (foo) - If foo is normally just an alias (strong or weak) to some other function, + If foo is normally just an alias (strong or weak) of some other function, you should use the normal strong_alias first, then add libc_hidden_def or libc_hidden_weak: @@ -562,23 +582,78 @@ for linking") # define hidden_proto(name, attrs...) \ __hidden_proto (name, __GI_##name, ##attrs) # define __hidden_proto(name, internal, attrs...) \ + extern __typeof (name) internal; \ extern __typeof (name) name __asm__ (__hidden_asmname (#internal)) \ __hidden_proto_hiddenattr (attrs); # define __hidden_asmname(name) \ __hidden_asmname1 (__USER_LABEL_PREFIX__, name) # define __hidden_asmname1(prefix, name) __hidden_asmname2(prefix, name) # define __hidden_asmname2(prefix, name) #prefix name -# define __hidden_ver1(local, internal, name) \ - extern __typeof (name) __EI_##name __asm__(__hidden_asmname (#internal)); \ - extern __typeof (name) __EI_##name \ - __attribute__((alias (__hidden_asmname (#local)))) -# define hidden_ver(local, name) __hidden_ver1(local, __GI_##name, name); -# define hidden_data_ver(local, name) hidden_ver(local, name) -# define hidden_def(name) __hidden_ver1(__GI_##name, name, name); -# define hidden_data_def(name) hidden_def(name) -# define hidden_weak(name) \ - __hidden_ver1(__GI_##name, name, name) __attribute__((weak)); -# define hidden_data_weak(name) hidden_weak(name) +# ifdef HAVE_ASM_SET_DIRECTIVE +# define __hidden_def1(original, alias) \ + ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ + .set C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) +# ifdef HAVE_ASM_GLOBAL_DOT_NAME +# define __hidden_dot_def1(original, alias) ASM_LINE_SEP \ + ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ + .set C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original) +# else +# define __hidden_dot_def1(original, alias) +# endif +# else +# define __hidden_def1(original, alias) \ + ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ + C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) +# ifdef HAVE_ASM_GLOBAL_DOT_NAME +# define __hidden_dot_def1(original, alias) 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 __hidden_dot_def1(original, alias) +# endif +# endif +# define __hidden_def2(...) #__VA_ARGS__ +# define __hidden_def3(...) __hidden_def2 (__VA_ARGS__) +# define hidden_def(name) \ + __asm__ (__hidden_def3 (__hidden_def1 (__GI_##name, name) \ + __hidden_dot_def1 (__GI_##name, name))); +# define hidden_data_def(name) \ + __asm__ (__hidden_def3 (__hidden_def1 (__GI_##name, name))); +# define hidden_ver(local, name) \ + __asm__ (__hidden_def3 (__hidden_def1 (local, __GI_##name) \ + __hidden_dot_def1 (local, __GI_##name))); +# define hidden_data_ver(local, name) \ + __asm__ (__hidden_def3 (__hidden_def1 (local, __GI_##name))); +# ifdef HAVE_WEAK_SYMBOLS +# ifdef HAVE_ASM_WEAKEXT_DIRECTIVE +# define __hidden_weak1(original, alias) \ + .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) +# ifdef HAVE_ASM_GLOBAL_DOT_NAME +# define __hidden_dot_weak1(original, alias) ASM_LINE_SEP \ + .weakext C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original) +# else +# define __hidden_dot_weak1(original, alias) +# endif +# else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ +# define __hidden_weak1(original, alias) \ + .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP \ + C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) +# ifdef HAVE_ASM_GLOBAL_DOT_NAME +# define __hidden_dot_weak1(original, alias) ASM_LINE_SEP \ + .weak C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ + C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) +# else +# define __hidden_dot_weak1(original, alias) +# endif +# endif +# define hidden_weak(name) \ + __asm__ (__hidden_def3 (__hidden_weak1 (__GI_##name, name) \ + __hidden_dot_weak1 (__GI_##name, name))); +# define hidden_data_weak(name) \ + __asm__ (__hidden_def3 (__hidden_weak1 (__GI_##name, name))); +# else +# define hidden_weak(name) hidden_def (name) +# endif # else /* For assembly, we need to do the opposite of what we do in C: in assembly gcc __REDIRECT stuff is not in place, so functions @@ -687,24 +762,6 @@ for linking") # define libresolv_hidden_data_ver(local, name) #endif -#if defined NOT_IN_libc && defined IS_IN_librt -# define librt_hidden_proto(name, attrs...) hidden_proto (name, ##attrs) -# define librt_hidden_def(name) hidden_def (name) -# define librt_hidden_weak(name) hidden_weak (name) -# define librt_hidden_ver(local, name) hidden_ver (local, name) -# define librt_hidden_data_def(name) hidden_data_def (name) -# define librt_hidden_data_weak(name) hidden_data_weak (name) -# define librt_hidden_data_ver(local, name) hidden_data_ver (local, name) -#else -# define librt_hidden_proto(name, attrs...) -# define librt_hidden_def(name) -# define librt_hidden_weak(name) -# define librt_hidden_ver(local, name) -# define librt_hidden_data_def(name) -# define librt_hidden_data_weak(name) -# define librt_hidden_data_ver(local, name) -#endif - #if defined NOT_IN_libc && defined IS_IN_libdl # define libdl_hidden_proto(name, attrs...) hidden_proto (name, ##attrs) # define libdl_hidden_def(name) hidden_def (name) |