diff options
Diffstat (limited to 'gcc/crtstuff.c')
| -rw-r--r-- | gcc/crtstuff.c | 91 |
1 files changed, 83 insertions, 8 deletions
diff --git a/gcc/crtstuff.c b/gcc/crtstuff.c index e6238de5e9b..ce2c9561e64 100644 --- a/gcc/crtstuff.c +++ b/gcc/crtstuff.c @@ -56,6 +56,8 @@ Boston, MA 02111-1307, USA. */ #include <stddef.h> #include "frame.h" +#ifndef OBJECT_FORMAT_MACHO + /* Provide default definitions for the pseudo-ops used to switch to the .ctors and .dtors sections. @@ -150,7 +152,7 @@ __do_global_dtors_aux () /* Stick a call to __do_global_dtors_aux into the .fini section. */ -static void +static void __attribute__ ((__unused__)) fini_dummy () { asm (FINI_SECTION_ASM_OP); @@ -173,7 +175,7 @@ frame_dummy () __register_frame_info (__EH_FRAME_BEGIN__, &object); } -static void +static void __attribute__ ((__unused__)) init_dummy () { asm (INIT_SECTION_ASM_OP); @@ -274,7 +276,7 @@ __frame_dummy () #endif /* defined(INIT_SECTION_ASM_OP) */ /* Force cc1 to switch to .data section. */ -static func_ptr force_to_data[0] = { }; +static func_ptr force_to_data[0] __attribute__ ((__unused__)) = { }; /* NOTE: In order to be able to support SVR4 shared libraries, we arrange to have one set of symbols { __CTOR_LIST__, __DTOR_LIST__, __CTOR_END__, @@ -294,7 +296,8 @@ static func_ptr force_to_data[0] = { }; CTOR_LIST_BEGIN; #else asm (CTORS_SECTION_ASM_OP); /* cc1 doesn't know that we are switching! */ -STATIC func_ptr __CTOR_LIST__[1] = { (func_ptr) (-1) }; +STATIC func_ptr __CTOR_LIST__[1] __attribute__ ((__unused__)) + = { (func_ptr) (-1) }; #endif #ifdef DTOR_LIST_BEGIN @@ -334,7 +337,7 @@ __do_global_ctors_aux () /* Stick a call to __do_global_ctors_aux into the .init section. */ -static void +static void __attribute__ ((__unused__)) init_dummy () { asm (INIT_SECTION_ASM_OP); @@ -406,6 +409,9 @@ asm (TEXT_SECTION_ASM_OP); not an SVR4-style .init section. __do_global_ctors can be non-static in this case because we protect it with -hidden_symbol. */ static func_ptr __CTOR_END__[]; +#ifdef EH_FRAME_SECTION_ASM_OP +extern void __frame_dummy (void); +#endif void __do_global_ctors () { @@ -421,7 +427,7 @@ __do_global_ctors () #endif /* defined(INIT_SECTION_ASM_OP) */ /* Force cc1 to switch to .data section. */ -static func_ptr force_to_data[0] = { }; +static func_ptr force_to_data[0] __attribute__ ((__unused__)) = { }; /* Put a word containing zero at the end of each of our two lists of function addresses. Note that the words defined here go into the .ctors and .dtors @@ -440,7 +446,8 @@ STATIC func_ptr __CTOR_END__[1] = { (func_ptr) 0 }; DTOR_LIST_END; #else asm (DTORS_SECTION_ASM_OP); /* cc1 doesn't know that we are switching! */ -STATIC func_ptr __DTOR_END__[1] = { (func_ptr) 0 }; +STATIC func_ptr __DTOR_END__[1] __attribute__ ((__unused__)) + = { (func_ptr) 0 }; #endif #ifdef EH_FRAME_SECTION_ASM_OP @@ -449,7 +456,75 @@ STATIC func_ptr __DTOR_END__[1] = { (func_ptr) 0 }; typedef unsigned int ui32 __attribute__ ((mode (SI))); asm (EH_FRAME_SECTION_ASM_OP); -STATIC ui32 __FRAME_END__[] = { 0 }; +STATIC ui32 __FRAME_END__[] __attribute__ ((__unused__)) = { 0 }; #endif /* EH_FRAME_SECTION */ #endif /* defined(CRT_END) */ + +#else /* OBJECT_FORMAT_MACHO */ + +/* For Mach-O format executables, we assume that the system's runtime is + smart enough to handle constructors and destructors, but doesn't have + an init section (if it can't even handle constructors/destructors + you should be using INVOKE__main, not crtstuff). All we need to do + is install/deinstall the frame information for exceptions. We do this + by putting a constructor in crtbegin.o and a destructor in crtend.o. + + crtend.o also puts in the terminating zero in the frame information + segment. */ + +/* The crtstuff for other object formats use the symbol __EH_FRAME_BEGIN__ + to figure out the start of the exception frame, but here we use + getsectbynamefromheader to find this value. Either method would work, + but this method avoids creating any global symbols, which seems + cleaner. */ + +#include <mach-o/ldsyms.h> +extern const struct section * + getsectbynamefromheader (const struct mach_header *, + const char *, const char *); + +#ifdef CRT_BEGIN + +static void __reg_frame_ctor () __attribute__ ((constructor)); + +static void +__reg_frame_ctor () +{ + static struct object object; + const struct section *eh_frame; + + eh_frame = getsectbynamefromheader (&_mh_execute_header, + "__TEXT", "__eh_frame"); + __register_frame_info ((void *) eh_frame->addr, &object); +} + +#endif /* CRT_BEGIN */ + +#ifdef CRT_END + +static void __dereg_frame_dtor () __attribute__ ((destructor)); + +static +void __dereg_frame_dtor () +{ + const struct section *eh_frame; + + eh_frame = getsectbynamefromheader (&_mh_execute_header, + "__TEXT", "__eh_frame"); + __deregister_frame_info ((void *) eh_frame->addr); +} + +/* Terminate the frame section with a final zero. */ + +/* Force cc1 to switch to .data section. */ +static void * force_to_data[0] __attribute__ ((__unused__)) = { }; + +typedef unsigned int ui32 __attribute__ ((mode (SI))); +asm (EH_FRAME_SECTION_ASM_OP); +static ui32 __FRAME_END__[] __attribute__ ((__unused__)) = { 0 }; + +#endif /* CRT_END */ + +#endif /* OBJECT_FORMAT_MACHO */ + |