/* Specialized bits of code needed to support construction and
destruction of file-scope objects in C++ code.
- Copyright (C) 1991, 94-97, 1998 Free Software Foundation, Inc.
+ Copyright (C) 1991, 1994, 1995, 1996, 1997, 1998,
+ 1999, 2000, 2001 Free Software Foundation, Inc.
Contributed by Ron Guilmette (rfg@monkeys.com).
This file is part of GNU CC.
the Free Software Foundation; either version 2, or (at your option)
any later version.
+In addition to the permissions in the GNU General Public License, the
+Free Software Foundation gives you unlimited permission to link the
+compiled version of this file into combinations with other programs,
+and to distribute those combinations without any restriction coming
+from the use of this file. (The General Public License restrictions
+do apply in other respects; for example, they cover modification of
+the file, and distribution when not linked into a combine
+executable.)
+
GNU CC 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
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
-/* As a special exception, if you link this library with files
- compiled with GCC to produce an executable, this does not cause
- the resulting executable to be covered by the GNU General Public License.
- This exception does not however invalidate any other reasons why
- the executable file might be covered by the GNU General Public License. */
-
/* This file is a bit like libgcc1.c/libgcc2.c in that it is compiled
multiple times and yields multiple .o files.
compiled for the target, and hence definitions concerning only the host
do not apply. */
+#include "auto-host.h"
#include "tm.h"
-#include "defaults.h"
-#include <stddef.h>
+#include "tsystem.h"
+
#include "frame.h"
+#ifndef CRT_CALL_STATIC_FUNCTION
+# define CRT_CALL_STATIC_FUNCTION(func) func ()
+#endif
+
+/* We do not want to add the weak attribute to the declarations of these
+ routines in frame.h because that will cause the definition of these
+ symbols to be weak as well.
+
+ This exposes a core issue, how to handle creating weak references vs
+ how to create weak definitions. Either we have to have the definition
+ of TARGET_WEAK_ATTRIBUTE be conditional in the shared header files or
+ have a second declaration if we want a function's references to be weak,
+ but not its definition.
+
+ Making TARGET_WEAK_ATTRIBUTE conditional seems like a good solution until
+ one thinks about scaling to larger problems -- ie, the condition under
+ which TARGET_WEAK_ATTRIBUTE is active will eventually get far too
+ complicated.
+
+ So, we take an approach similar to #pragma weak -- we have a second
+ declaration for functions that we want to have weak references.
+
+ Neither way is particularly good. */
+
+/* References to __register_frame_info and __deregister_frame_info should
+ be weak in this file if at all possible. */
+extern void __register_frame_info (void *, struct object *)
+ TARGET_ATTRIBUTE_WEAK;
+
+extern void *__deregister_frame_info (void *)
+ TARGET_ATTRIBUTE_WEAK;
+
+#ifndef OBJECT_FORMAT_MACHO
+
/* Provide default definitions for the pseudo-ops used to switch to the
.ctors and .dtors sections.
an additional check that you are doing everything right. But if you do
use the `-z text' option when building a shared library, you will get
errors unless the .ctors and .dtors sections are marked as writable
- via the SHF_WRITE attribute.) */
+ via the SHF_WRITE attribute.)
+
+ These defaults do not include leading spacing, as they will only be
+ used in asm:s here. */
#ifndef CTORS_SECTION_ASM_OP
#define CTORS_SECTION_ASM_OP ".section\t.ctors,\"aw\""
#ifndef DTORS_SECTION_ASM_OP
#define DTORS_SECTION_ASM_OP ".section\t.dtors,\"aw\""
#endif
-#if !defined (EH_FRAME_SECTION_ASM_OP) && defined (DWARF2_UNWIND_INFO) && defined(ASM_OUTPUT_SECTION_NAME)
-#define EH_FRAME_SECTION_ASM_OP ".section\t.eh_frame,\"aw\""
-#endif
#ifdef OBJECT_FORMAT_ELF
#include "gbl-ctors.h"
-#ifndef ON_EXIT
-#define ON_EXIT(a, b)
-#endif
#define STATIC
#endif /* OBJECT_FORMAT_ELF */
#ifdef OBJECT_FORMAT_ELF
+/* Declare the __dso_handle variable. It should have a unique value
+ in every shared-object; in a main program its value is zero. The
+ object should in any case be protected. This means the instance
+ in one DSO or the main program is not used in another object. The
+ dynamic linker takes care of this. */
+
+/* XXX Ideally the following should be implemented using
+ __attribute__ ((__visibility__ ("hidden")))
+ but the __attribute__ support is not yet there. */
+#ifdef HAVE_GAS_HIDDEN
+asm (".hidden\t__dso_handle");
+#endif
+
+#ifdef CRTSTUFFS_O
+void *__dso_handle = &__dso_handle;
+#else
+void *__dso_handle = 0;
+#endif
+
+/* The __cxa_finalize function may not be available so we use only a
+ weak declaration. */
+extern void __cxa_finalize (void *) TARGET_ATTRIBUTE_WEAK;
+
/* Run all the global destructors on exit from the program. */
/* Some systems place the number of pointers in the first word of the
static char __EH_FRAME_BEGIN__[];
static func_ptr __DTOR_LIST__[];
static void
-__do_global_dtors_aux ()
+__do_global_dtors_aux (void)
{
static func_ptr *p = __DTOR_LIST__ + 1;
static int completed = 0;
if (completed)
return;
+#ifdef CRTSTUFFS_O
+ if (__cxa_finalize)
+ __cxa_finalize (__dso_handle);
+#endif
+
while (*p)
{
p++;
}
#ifdef EH_FRAME_SECTION_ASM_OP
- __deregister_frame_info (__EH_FRAME_BEGIN__);
+ if (__deregister_frame_info)
+ __deregister_frame_info (__EH_FRAME_BEGIN__);
#endif
completed = 1;
}
/* Stick a call to __do_global_dtors_aux into the .fini section. */
-static void
-fini_dummy ()
+static void __attribute__ ((__unused__))
+fini_dummy (void)
{
asm (FINI_SECTION_ASM_OP);
- __do_global_dtors_aux ();
+ CRT_CALL_STATIC_FUNCTION (__do_global_dtors_aux);
#ifdef FORCE_FINI_SECTION_ALIGN
FORCE_FINI_SECTION_ALIGN;
#endif
call in another function. */
static void
-frame_dummy ()
+frame_dummy (void)
{
static struct object object;
- __register_frame_info (__EH_FRAME_BEGIN__, &object);
+ if (__register_frame_info)
+ __register_frame_info (__EH_FRAME_BEGIN__, &object);
}
-static void
-init_dummy ()
+static void __attribute__ ((__unused__))
+init_dummy (void)
{
asm (INIT_SECTION_ASM_OP);
- frame_dummy ();
+ CRT_CALL_STATIC_FUNCTION (frame_dummy);
#ifdef FORCE_INIT_SECTION_ALIGN
FORCE_INIT_SECTION_ALIGN;
#endif
INVOKE__main is defined. This has the additional effect of forcing cc1
to switch to the .text section. */
-static void __do_global_ctors_aux ();
-void __do_global_ctors ()
+static void __do_global_ctors_aux (void);
+void
+__do_global_ctors (void)
{
#ifdef INVOKE__main /* If __main won't actually call __do_global_ctors
then it doesn't matter what's inside the function.
file-scope static-storage C++ objects within shared libraries. */
static void
-__do_global_ctors_aux () /* prologue goes in .init section */
+__do_global_ctors_aux (void) /* prologue goes in .init section */
{
#ifdef FORCE_INIT_SECTION_ALIGN
FORCE_INIT_SECTION_ALIGN; /* Explicit align before switch to .text */
#endif
asm (TEXT_SECTION_ASM_OP); /* don't put epilogue and body in .init */
DO_GLOBAL_CTORS_BODY;
- ON_EXIT (__do_global_dtors, 0);
+ atexit (__do_global_dtors);
}
#endif /* OBJECT_FORMAT_ELF */
static char __EH_FRAME_BEGIN__[];
static func_ptr __DTOR_LIST__[];
void
-__do_global_dtors ()
+__do_global_dtors (void)
{
func_ptr *p;
for (p = __DTOR_LIST__ + 1; *p; p++)
(*p) ();
#ifdef EH_FRAME_SECTION_ASM_OP
- __deregister_frame_info (__EH_FRAME_BEGIN__);
+ if (__deregister_frame_info)
+ __deregister_frame_info (__EH_FRAME_BEGIN__);
#endif
}
after libgcc.a, and hence can't call libgcc.a functions directly. That
can lead to unresolved function references. */
void
-__frame_dummy ()
+__frame_dummy (void)
{
static struct object object;
- __register_frame_info (__EH_FRAME_BEGIN__, &object);
+ if (__register_frame_info)
+ __register_frame_info (__EH_FRAME_BEGIN__, &object);
}
#endif
#endif
#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[1] __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__,
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
static func_ptr __CTOR_END__[];
static void
-__do_global_ctors_aux ()
+__do_global_ctors_aux (void)
{
func_ptr *p;
for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
/* Stick a call to __do_global_ctors_aux into the .init section. */
-static void
-init_dummy ()
+static void __attribute__ ((__unused__))
+init_dummy (void)
{
asm (INIT_SECTION_ASM_OP);
- __do_global_ctors_aux ();
+ CRT_CALL_STATIC_FUNCTION (__do_global_ctors_aux);
#ifdef FORCE_INIT_SECTION_ALIGN
FORCE_INIT_SECTION_ALIGN;
#endif
extern char **__environ;
___brk_addr = __environ;
- atexit ();
+ atexit (0);
}
#endif
}
before we start to execute any of the user's code. */
static void
-__do_global_ctors_aux () /* prologue goes in .text section */
+__do_global_ctors_aux (void) /* prologue goes in .text section */
{
asm (INIT_SECTION_ASM_OP);
DO_GLOBAL_CTORS_BODY;
- ON_EXIT (__do_global_dtors, 0);
+ atexit (__do_global_dtors);
+} /* epilogue and body go in .init section */
+
#ifdef FORCE_INIT_SECTION_ALIGN
- FORCE_INIT_SECTION_ALIGN;
+FORCE_INIT_SECTION_ALIGN;
#endif
-} /* epilogue and body go in .init section */
+
+asm (TEXT_SECTION_ASM_OP);
#endif /* OBJECT_FORMAT_ELF */
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 ()
+__do_global_ctors (void)
{
func_ptr *p;
#ifdef EH_FRAME_SECTION_ASM_OP
#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[1] __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
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
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 (void) __attribute__ ((constructor));
+
+static void
+__reg_frame_ctor (void)
+{
+ 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 (void) __attribute__ ((destructor));
+
+static void
+__dereg_frame_dtor (void)
+{
+ 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[1] __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 */
+
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