X-Git-Url: https://gcc.gnu.org/git/?a=blobdiff_plain;f=gcc%2Fcrtstuff.c;h=53c76b39ba11dc6207a5e78f350256d1d103d9f3;hb=29d2c7a5fd673f8daa4a63c6d32c76a2ce42911b;hp=8dae8cf845f6e9818d8461dc78e276b699dd1707;hpb=329d2160a4f77a1409ae55f0067d699542498fa3;p=gcc.git

diff --git a/gcc/crtstuff.c b/gcc/crtstuff.c
index 8dae8cf845f6..53c76b39ba11 100644
--- a/gcc/crtstuff.c
+++ b/gcc/crtstuff.c
@@ -1,9 +1,8 @@
 /* Specialized bits of code needed to support construction and
    destruction of file-scope objects in C++ code.
-
-   Written by Ron Guilmette (rfg@ncd.com) with help from Richard Stallman.
-
-Copyright (C) 1991 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.
 
@@ -12,6 +11,15 @@ it under the terms of the GNU General Public License as published by
 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
@@ -19,15 +27,10 @@ GNU General Public License for more details.
 
 You should have received a copy of the GNU General Public License
 along with GNU CC; see the file COPYING.  If not, write to
-the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+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
+/* This file is a bit like libgcc2.c in that it is compiled
    multiple times and yields multiple .o files.
 
    This file is useful on target machines where the object file format
@@ -41,8 +44,10 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
    this file *will* make use of the .init section.  If that symbol is
    not defined however, then the .init section will not be used.
 
-   Currently, only ELF is actually supported.
-   The other formats probably need just alternative macro definitions.
+   Currently, only ELF and COFF are supported.  It is likely however that
+   ROSE could also be supported, if someone was willing to do the work to
+   make whatever (small?) adaptations are needed.  (Some work may be
+   needed on the ROSE assembler and linker also.)
 
    This file must be compiled with gcc.  */
 
@@ -50,52 +55,302 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
    compiled for the target, and hence definitions concerning only the host
    do not apply.  */
 
-#include "tm.h"
+/* We include auto-host.h here to get HAVE_GAS_HIDDEN.  This is
+   supposedly valid even though this is a "target" file.  */
+#include "auto-host.h"
+#include "tconfig.h"
+#include "tsystem.h"
+#include "unwind-dw2-fde.h"
 
-#ifndef CTORS_SECTION_ASM_OP
-#define CTORS_SECTION_ASM_OP	".section\t.ctors,\"a\",@progbits"
-#endif
-#ifndef DTORS_SECTION_ASM_OP
-#define DTORS_SECTION_ASM_OP	".section\t.dtors,\"a\",@progbits"
+#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 unwind-dw2-fde.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 __register_frame_info_bases (void *, struct object *,
+					 void *, void *)
+				  TARGET_ATTRIBUTE_WEAK;
+extern void *__deregister_frame_info (void *)
+				     TARGET_ATTRIBUTE_WEAK;
+extern void *__deregister_frame_info_bases (void *)
+				     TARGET_ATTRIBUTE_WEAK;
+
+/* Likewise for _Jv_RegisterClasses.  */
+extern void _Jv_RegisterClasses (void *) TARGET_ATTRIBUTE_WEAK;
+
+#ifndef OBJECT_FORMAT_MACHO
+
+#ifdef OBJECT_FORMAT_ELF
+
+/*  Declare a pointer to void function type.  */
+typedef void (*func_ptr) (void);
+#define STATIC static
+
+#else  /* OBJECT_FORMAT_ELF */
+
 #include "gbl-ctors.h"
 
-#ifndef ON_EXIT
-#define ON_EXIT(a, b)
-#endif
+#define STATIC
+
+#endif /* OBJECT_FORMAT_ELF */
 
 #ifdef CRT_BEGIN
 
+/* 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__,
+   __DTOR_END__ } per root executable and also one set of these symbols
+   per shared library.  So in any given whole process image, we may have
+   multiple definitions of each of these symbols.  In order to prevent
+   these definitions from conflicting with one another, and in order to
+   ensure that the proper lists are used for the initialization/finalization
+   of each individual shared library (respectively), we give these symbols
+   only internal (i.e. `static') linkage, and we also make it a point to
+   refer to only the __CTOR_END__ symbol in crtend.o and the __DTOR_LIST__
+   symbol in crtbegin.o, where they are defined.  */
+
+/* The -1 is a flag to __do_global_[cd]tors indicating that this table
+   does not start with a count of elements.  */
+#ifdef CTOR_LIST_BEGIN
+CTOR_LIST_BEGIN;
+#elif defined(CTORS_SECTION_ASM_OP)
+/* Hack: force cc1 to switch to .data section early, so that assembling
+   __CTOR_LIST__ does not undo our behind-the-back change to .ctors.  */
+static func_ptr force_to_data[1] __attribute__ ((__unused__)) = { };
+asm (CTORS_SECTION_ASM_OP);
+STATIC func_ptr __CTOR_LIST__[1]
+  __attribute__ ((__unused__, aligned(sizeof(func_ptr))))
+  = { (func_ptr) (-1) };
+#else
+STATIC func_ptr __CTOR_LIST__[1]
+  __attribute__ ((__unused__, section(".ctors"), aligned(sizeof(func_ptr))))
+  = { (func_ptr) (-1) };
+#endif /* __CTOR_LIST__ alternatives */
+
+#ifdef DTOR_LIST_BEGIN
+DTOR_LIST_BEGIN;
+#elif defined(DTORS_SECTION_ASM_OP)
+asm (DTORS_SECTION_ASM_OP);
+STATIC func_ptr __DTOR_LIST__[1]
+  __attribute__ ((aligned(sizeof(func_ptr))))
+  = { (func_ptr) (-1) };
+#else
+STATIC func_ptr __DTOR_LIST__[1]
+  __attribute__((section(".dtors"), aligned(sizeof(func_ptr))))
+  = { (func_ptr) (-1) };
+#endif /* __DTOR_LIST__ alternatives */
+
+#ifdef EH_FRAME_SECTION_NAME
+/* Stick a label at the beginning of the frame unwind info so we can register
+   and deregister it with the exception handling library code.  */
+STATIC char __EH_FRAME_BEGIN__[]
+     __attribute__((section(EH_FRAME_SECTION_NAME), aligned(4)))
+     = { };
+#endif /* EH_FRAME_SECTION_NAME */
+
+#ifdef JCR_SECTION_NAME
+/* Stick a label at the beginning of the java class registration info
+   so we can register them properly.  */
+STATIC void *__JCR_LIST__[]
+  __attribute__ ((unused, section(JCR_SECTION_NAME), aligned(sizeof(void*))))
+  = { };
+#endif /* JCR_SECTION_NAME */
+
 #ifdef INIT_SECTION_ASM_OP
 
+#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
+   table.  On SVR4 however, that word is -1.  In all cases, the table is
+   null-terminated.  On SVR4, we start from the beginning of the list and
+   invoke each per-compilation-unit destructor routine in order
+   until we find that null.
+
+   Note that this function MUST be static.  There will be one of these
+   functions in each root executable and one in each shared library, but
+   although they all have the same code, each one is unique in that it
+   refers to one particular associated `__DTOR_LIST__' which belongs to the
+   same particular root executable or shared library file.
+
+   On some systems, this routine is run more than once from the .fini,
+   when exit is called recursively, so we arrange to remember where in
+   the list we left off processing, and we resume at that point,
+   should we be re-invoked.  */
+
+static void
+__do_global_dtors_aux (void)
+{
+  static func_ptr *p = __DTOR_LIST__ + 1;
+  static int completed;
+  func_ptr f;
+
+  if (__builtin_expect (completed, 0))
+    return;
+
+#ifdef CRTSTUFFS_O
+  if (__cxa_finalize)
+    __cxa_finalize (__dso_handle);
+#endif
+
+  while ((f = *p))
+    {
+      p++;
+      f ();
+    }
+
+#ifdef EH_FRAME_SECTION_NAME
+#if defined(CRT_GET_RFIB_TEXT) || defined(CRT_GET_RFIB_DATA)
+  /* If we used the new __register_frame_info_bases interface,
+     make sure that we deregister from the same place.  */
+  if (__deregister_frame_info_bases)
+    __deregister_frame_info_bases (__EH_FRAME_BEGIN__);
+#else
+  if (__deregister_frame_info)
+    __deregister_frame_info (__EH_FRAME_BEGIN__);
+#endif
+#endif
+
+  completed = 1;
+}
+
+
+/* Stick a call to __do_global_dtors_aux into the .fini section.  */
+
+static void __attribute__ ((__unused__))
+fini_dummy (void)
+{
+  asm (FINI_SECTION_ASM_OP);
+  CRT_CALL_STATIC_FUNCTION (__do_global_dtors_aux);
+#ifdef FORCE_FINI_SECTION_ALIGN
+  FORCE_FINI_SECTION_ALIGN;
+#endif
+  asm (TEXT_SECTION_ASM_OP);
+}
+
+#if defined(EH_FRAME_SECTION_NAME) || defined(JCR_SECTION_NAME)
+/* Stick a call to __register_frame_info into the .init section.  For some
+   reason calls with no arguments work more reliably in .init, so stick the
+   call in another function.  */
+
+static void
+frame_dummy (void)
+{
+#ifdef EH_FRAME_SECTION_NAME
+  static struct object object;
+#if defined(CRT_GET_RFIB_TEXT) || defined(CRT_GET_RFIB_DATA)
+  void *tbase, *dbase;
+#ifdef CRT_GET_RFIB_TEXT
+  CRT_GET_RFIB_TEXT (tbase);
+#else
+  tbase = 0;
+#endif
+#ifdef CRT_GET_RFIB_DATA
+  CRT_GET_RFIB_DATA (dbase);
+#else
+  dbase = 0;
+#endif
+  if (__register_frame_info_bases)
+    __register_frame_info_bases (__EH_FRAME_BEGIN__, &object, tbase, dbase);
+#else
+  if (__register_frame_info)
+    __register_frame_info (__EH_FRAME_BEGIN__, &object);
+#endif
+#endif /* EH_FRAME_SECTION_NAME */
+#ifdef JCR_SECTION_NAME
+  if (__JCR_LIST__[0] && _Jv_RegisterClasses)
+    _Jv_RegisterClasses (__JCR_LIST__);
+#endif /* JCR_SECTION_NAME */
+}
+
+static void __attribute__ ((__unused__))
+init_dummy (void)
+{
+  asm (INIT_SECTION_ASM_OP);
+  CRT_CALL_STATIC_FUNCTION (frame_dummy);
+#ifdef FORCE_INIT_SECTION_ALIGN
+  FORCE_INIT_SECTION_ALIGN;
+#endif
+  asm (TEXT_SECTION_ASM_OP);
+}
+#endif /* EH_FRAME_SECTION_NAME || JCR_SECTION_NAME */
+
+#else  /* OBJECT_FORMAT_ELF */
+
 /* The function __do_global_ctors_aux is compiled twice (once in crtbegin.o
    and once in crtend.o).  It must be declared static to avoid a link
    error.  Here, we define __do_global_ctors as an externally callable
    function.  It is externally callable so that __main can invoke it when
    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.
-			The inside of __do_global_ctors_aux is called
-			automatically in that case.
-			And the Alliant fx2800 linker crashes
-			on this reference.  So prevent the crash.  */
+#ifdef INVOKE__main
+  /* If __main won't actually call __do_global_ctors then it doesn't matter
+     what's inside the function.  The inside of __do_global_ctors_aux is
+     called automatically in that case.  And the Alliant fx2800 linker
+     crashes on this reference.  So prevent the crash.  */
   __do_global_ctors_aux ();
 #endif
 }
 
 asm (INIT_SECTION_ASM_OP);	/* cc1 doesn't know that we are switching! */
 
-/* On some svr4 systems, the .init section preamble code provided in
-   crti.o may do some evil things which we have to undo before we reach
-   the function prologue code for __do_global_ctors (directly below).
-   For such systems, define the macro INIT_SECTION_PREAMBLE to
-   expand into the code needed to undo the actions of the crti.o file.  */
-   
+/* On some svr4 systems, the initial .init section preamble code provided in
+   crti.o may do something, such as bump the stack, which we have to 
+   undo before we reach the function prologue code for __do_global_ctors 
+   (directly below).  For such systems, define the macro INIT_SECTION_PREAMBLE
+   to expand into the code needed to undo the actions of the crti.o file.  */
+
 #ifdef INIT_SECTION_PREAMBLE
   INIT_SECTION_PREAMBLE;
 #endif
@@ -106,77 +361,267 @@ asm (INIT_SECTION_ASM_OP);	/* cc1 doesn't know that we are switching! */
    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 /* defined(INIT_SECTION_ASM_OP) */
+#endif /* OBJECT_FORMAT_ELF */
 
-/* Force cc1 to switch to .data section.  */
-static func_ptr force_to_data[0] = { };
+#elif defined(HAS_INIT_SECTION) /* ! INIT_SECTION_ASM_OP */
 
-/* The -1 is a flag to __do_global_[cd]tors
-   indicating that this table does not start with a count of elements.  */
-#ifdef CTOR_LIST_BEGIN
-CTOR_LIST_BEGIN;
-#else
-asm (CTORS_SECTION_ASM_OP);	/* cc1 doesn't know that we are switching! */
-func_ptr __CTOR_LIST__[1] = { (func_ptr) (-1) };
+/* This case is used by the Irix 6 port, which supports named sections but
+   not an SVR4-style .fini section.  __do_global_dtors can be non-static
+   in this case because we protect it with -hidden_symbol.  */
+
+void
+__do_global_dtors (void)
+{
+  func_ptr *p, f;
+  for (p = __DTOR_LIST__ + 1; (f = *p); p++)
+    f ();
+
+#ifdef EH_FRAME_SECTION_NAME
+  if (__deregister_frame_info)
+    __deregister_frame_info (__EH_FRAME_BEGIN__);
 #endif
+}
 
-#ifdef DTOR_LIST_BEGIN
-DTOR_LIST_BEGIN;
+#if defined(EH_FRAME_SECTION_NAME) || defined(JCR_SECTION_NAME)
+/* A helper function for __do_global_ctors, which is in crtend.o.  Here
+   in crtbegin.o, we can reference a couple of symbols not visible there.
+   Plus, since we're before libgcc.a, we have no problems referencing
+   functions from there.  */
+void
+__do_global_ctors_1(void)
+{
+#ifdef EH_FRAME_SECTION_NAME
+  static struct object object;
+  if (__register_frame_info)
+    __register_frame_info (__EH_FRAME_BEGIN__, &object);
+#endif
+#ifdef JCR_SECTION_NAME
+  if (__JCR_LIST__[0] && _Jv_RegisterClasses)
+    _Jv_RegisterClasses (__JCR_LIST__);
+#endif
+}
+#endif /* EH_FRAME_SECTION_NAME || JCR_SECTION_NAME */
+
+#else /* ! INIT_SECTION_ASM_OP && ! HAS_INIT_SECTION */
+#error "What are you doing with crtstuff.c, then?"
+#endif
+
+#elif defined(CRT_END) /* ! CRT_BEGIN */
+
+/* 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
+   sections of the crtend.o file, and since that file is always linked in
+   last, these words naturally end up at the very ends of the two lists
+   contained in these two sections.  */
+
+#ifdef CTOR_LIST_END
+CTOR_LIST_END;
+#elif defined(CTORS_SECTION_ASM_OP)
+/* Hack: force cc1 to switch to .data section early, so that assembling
+   __CTOR_LIST__ does not undo our behind-the-back change to .ctors.  */
+static func_ptr force_to_data[1] __attribute__ ((__unused__)) = { };
+asm (CTORS_SECTION_ASM_OP);
+STATIC func_ptr __CTOR_END__[1]
+  __attribute__((aligned(sizeof(func_ptr))))
+  = { (func_ptr) 0 };
 #else
-asm (DTORS_SECTION_ASM_OP);	/* cc1 doesn't know that we are switching! */
-func_ptr __DTOR_LIST__[1] = { (func_ptr) (-1) };
+STATIC func_ptr __CTOR_END__[1]
+  __attribute__((section(".ctors"), aligned(sizeof(func_ptr))))
+  = { (func_ptr) 0 };
 #endif
 
-#endif /* defined(CRT_BEGIN) */
+#ifdef DTOR_LIST_END
+DTOR_LIST_END;
+#elif defined(DTORS_SECTION_ASM_OP)
+asm (DTORS_SECTION_ASM_OP);
+STATIC func_ptr __DTOR_END__[1]
+  __attribute__ ((unused, aligned(sizeof(func_ptr))))
+  = { (func_ptr) 0 };
+#else
+STATIC func_ptr __DTOR_END__[1]
+  __attribute__((unused, section(".dtors"), aligned(sizeof(func_ptr))))
+  = { (func_ptr) 0 };
+#endif
 
-#ifdef CRT_END
+#ifdef EH_FRAME_SECTION_NAME
+/* Terminate the frame unwind info section with a 4byte 0 as a sentinel;
+   this would be the 'length' field in a real FDE.  */
+STATIC int __FRAME_END__[]
+     __attribute__ ((unused, mode(SI), section(EH_FRAME_SECTION_NAME),
+		     aligned(4)))
+     = { 0 };
+#endif /* EH_FRAME_SECTION */
+
+#ifdef JCR_SECTION_NAME
+/* Null terminate the .jcr section array.  */
+STATIC void *__JCR_END__[1] 
+   __attribute__ ((unused, section(JCR_SECTION_NAME),
+		   aligned(sizeof(void *))))
+   = { 0 };
+#endif /* JCR_SECTION_NAME */
 
 #ifdef INIT_SECTION_ASM_OP
 
-/* A routine to invoke all of the global constructors upon entry to the
-   program.  We put this into the .init section (for systems that have
-   such a thing) so that we can properly perform the construction of
-   file-scope static-storage C++ objects within shared libraries.
+#ifdef OBJECT_FORMAT_ELF
+
+static void
+__do_global_ctors_aux (void)
+{
+  func_ptr *p;
+  for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
+    (*p) ();
+}
+
+/* Stick a call to __do_global_ctors_aux into the .init section.  */
+
+static void __attribute__ ((__unused__))
+init_dummy (void)
+{
+  asm (INIT_SECTION_ASM_OP);
+  CRT_CALL_STATIC_FUNCTION (__do_global_ctors_aux);
+#ifdef FORCE_INIT_SECTION_ALIGN
+  FORCE_INIT_SECTION_ALIGN;
+#endif
+  asm (TEXT_SECTION_ASM_OP);
+#ifdef CRT_END_INIT_DUMMY
+  CRT_END_INIT_DUMMY;
+#endif
+}
+
+#else  /* OBJECT_FORMAT_ELF */
+
+/* Stick the real initialization code, followed by a normal sort of
+   function epilogue at the very end of the .init section for this
+   entire root executable file or for this entire shared library file.
+
+   Note that we use some tricks here to get *just* the body and just
+   a function epilogue (but no function prologue) into the .init
+   section of the crtend.o file.  Specifically, we switch to the .text
+   section, start to define a function, and then we switch to the .init
+   section just before the body code.
 
-   This must be virtually identical to the one above so that we can
-   insure that the function prologue from the one above works correctly
-   with the epilogue from this one.  (They will both go into the .init
-   section as the first and last things (respectively) that the linker
-   will put in that section.)
-*/
+   Earlier on, we put the corresponding function prologue into the .init
+   section of the crtbegin.o file (which will be linked in first).
+
+   Note that we want to invoke all constructors for C++ file-scope static-
+   storage objects AFTER any other possible initialization actions which
+   may be performed by the code in the .init section contributions made by
+   other libraries, etc.  That's because those other initializations may
+   include setup operations for very primitive things (e.g. initializing
+   the state of the floating-point coprocessor, etc.) which should be done
+   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 */
 
-#endif /* defined(INIT_SECTION_ASM_OP) */
+#ifdef FORCE_INIT_SECTION_ALIGN
+FORCE_INIT_SECTION_ALIGN;
+#endif
 
-/* Force cc1 to switch to .data section.  */
-static func_ptr force_to_data[0] = { };
+asm (TEXT_SECTION_ASM_OP);
 
-#ifdef CTOR_LIST_END
-CTOR_LIST_END;
-#else
-asm (CTORS_SECTION_ASM_OP);	/* cc1 doesn't know that we are switching! */
-func_ptr __CTOR_END__[1] = { (func_ptr) 0 };
+#endif /* OBJECT_FORMAT_ELF */
+
+#elif defined(HAS_INIT_SECTION) /* ! INIT_SECTION_ASM_OP */
+
+/* This case is used by the Irix 6 port, which supports named sections but
+   not an SVR4-style .init section.  __do_global_ctors can be non-static
+   in this case because we protect it with -hidden_symbol.  */
+extern void __do_global_ctors_1(void);
+void
+__do_global_ctors (void)
+{
+  func_ptr *p;
+#if defined(EH_FRAME_SECTION_NAME) || defined(JCR_SECTION_NAME)
+  __do_global_ctors_1();
 #endif
+  for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
+    (*p) ();
+}
 
-#ifdef DTOR_LIST_END
-DTOR_LIST_END;
-#else
-asm (DTORS_SECTION_ASM_OP);	/* cc1 doesn't know that we are switching! */
-func_ptr __DTOR_END__[1] = { (func_ptr) 0 };
+#else /* ! INIT_SECTION_ASM_OP && ! HAS_INIT_SECTION */
+#error "What are you doing with crtstuff.c, then?"
+#endif
+
+#else /* ! CRT_BEGIN && ! CRT_END */
+#error "One of CRT_BEGIN or CRT_END must be defined."
+#endif
+
+#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);
+}
+
+#elif defined(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.  */
+STATIC int __FRAME_END__[]
+     __attribute__ ((unused, mode(SI), section(EH_FRAME_SECTION_NAME),
+		     aligned(4)))
+     = { 0 };
+
+#else /* ! CRT_BEGIN && ! CRT_END */
+#error "One of CRT_BEGIN or CRT_END must be defined."
 #endif
 
-#endif /* defined(CRT_END) */
+#endif /* OBJECT_FORMAT_MACHO */