X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=gcc%2Fcrtstuff.c;h=2a5864dca71c6b0047cc3672b39a118aba5d6fee;hb=a0a6c970550ba1c28cab6660fb1daa96cd1a39c3;hp=a0ecbbeb040aad308c5c78ef735b109cf33bc22e;hpb=635d52b752235f43c3e2c0da634b9bfdbfa67a5d;p=pf3gnuchains%2Fgcc-fork.git

diff --git a/gcc/crtstuff.c b/gcc/crtstuff.c
index a0ecbbeb040..2a5864dca71 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 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
@@ -19,13 +27,8 @@ 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.  */
-
-/* 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.  */
+the Free Software Foundation, 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
 
 /* This file is a bit like libgcc1.c/libgcc2.c in that it is compiled
    multiple times and yields multiple .o files.
@@ -52,33 +55,215 @@ 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 "auto-host.h"
 #include "tm.h"
+#include "tsystem.h"
+
+#include "defaults.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.
+ 
+   Note that we want to give these sections the SHF_WRITE attribute
+   because these sections will actually contain data (i.e. tables of
+   addresses of functions in the current root executable or shared library
+   file) and, in the case of a shared library, the relocatable addresses
+   will have to be properly resolved/relocated (and then written into) by
+   the dynamic linker when it actually attaches the given shared library
+   to the executing process.  (Note that on SVR4, you may wish to use the
+   `-z text' option to the ELF linker, when building a shared library, as
+   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.)
+
+   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,\"a\",@progbits"
+#define CTORS_SECTION_ASM_OP	".section\t.ctors,\"aw\""
 #endif
 #ifndef DTORS_SECTION_ASM_OP
-#define DTORS_SECTION_ASM_OP	".section\t.dtors,\"a\",@progbits"
+#define DTORS_SECTION_ASM_OP	".section\t.dtors,\"aw\""
 #endif
 
+#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
 
 #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 char __EH_FRAME_BEGIN__[];
+static func_ptr __DTOR_LIST__[];
+static void
+__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++;
+      (*(p-1)) ();
+    }
+
+#ifdef EH_FRAME_SECTION_ASM_OP
+  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 __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);
+}
+
+#ifdef EH_FRAME_SECTION_ASM_OP
+/* 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)
+{
+  static struct object object;
+  if (__register_frame_info)
+    __register_frame_info (__EH_FRAME_BEGIN__, &object);
+}
+
+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_ASM_OP */
+
+#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.
@@ -92,12 +277,12 @@ void __do_global_ctors ()
 
 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
@@ -108,20 +293,70 @@ 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 /* OBJECT_FORMAT_ELF */
+
+#else /* defined(INIT_SECTION_ASM_OP) */
+
+#ifdef HAS_INIT_SECTION
+/* 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.  */
+
+static char __EH_FRAME_BEGIN__[];
+static func_ptr __DTOR_LIST__[];
+void
+__do_global_dtors (void)
+{
+  func_ptr *p;
+  for (p = __DTOR_LIST__ + 1; *p; p++)
+    (*p) ();
+
+#ifdef EH_FRAME_SECTION_ASM_OP
+  if (__deregister_frame_info)
+    __deregister_frame_info (__EH_FRAME_BEGIN__);
+#endif
+}
+
+#ifdef EH_FRAME_SECTION_ASM_OP
+/* Define a function here to call __register_frame.  crtend.o is linked in
+   after libgcc.a, and hence can't call libgcc.a functions directly.  That
+   can lead to unresolved function references.  */
+void
+__frame_dummy (void)
+{
+  static struct object 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__,
+   __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.  */
@@ -129,15 +364,27 @@ static func_ptr force_to_data[0] = { };
 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) };
+STATIC func_ptr __CTOR_LIST__[1] __attribute__ ((__unused__))
+  = { (func_ptr) (-1) };
 #endif
 
 #ifdef DTOR_LIST_BEGIN
 DTOR_LIST_BEGIN;
 #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 __DTOR_LIST__[1] = { (func_ptr) (-1) };
+#endif
+
+#ifdef EH_FRAME_SECTION_ASM_OP
+/* Stick a label at the beginning of the frame unwind info so we can register
+   and deregister it with the exception handling library code.  */
+
+asm (EH_FRAME_SECTION_ASM_OP);
+#ifdef INIT_SECTION_ASM_OP
+STATIC
 #endif
+char __EH_FRAME_BEGIN__[] = { };
+#endif /* EH_FRAME_SECTION_ASM_OP */
 
 #endif /* defined(CRT_BEGIN) */
 
@@ -145,43 +392,207 @@ func_ptr __DTOR_LIST__[1] = { (func_ptr) (-1) };
 
 #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 func_ptr __CTOR_END__[];
+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);
+
+/* This is a kludge. The i386 GNU/Linux dynamic linker needs ___brk_addr,
+   __environ and atexit (). We have to make sure they are in the .dynsym
+   section. We accomplish it by making a dummy call here. This
+   code is never reached.  */
+ 
+#if defined(__linux__) && defined(__PIC__) && defined(__i386__)
+  {
+    extern void *___brk_addr;
+    extern char **__environ;
+
+    ___brk_addr = __environ;
+    atexit (0);
+  }
+#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.
 
-   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.)
-*/
+   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.
+
+   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 */
 
+#ifdef FORCE_INIT_SECTION_ALIGN
+FORCE_INIT_SECTION_ALIGN;
+#endif
+
+asm (TEXT_SECTION_ASM_OP);
+
+#endif /* OBJECT_FORMAT_ELF */
+
+#else /* defined(INIT_SECTION_ASM_OP) */
+
+#ifdef HAS_INIT_SECTION
+/* 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.  */
+static func_ptr __CTOR_END__[];
+#ifdef EH_FRAME_SECTION_ASM_OP
+extern void __frame_dummy (void);
+#endif
+void
+__do_global_ctors (void)
+{
+  func_ptr *p;
+#ifdef EH_FRAME_SECTION_ASM_OP
+  __frame_dummy ();
+#endif
+  for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
+    (*p) ();
+}
+#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__)) = { };
+
+/* 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;
 #else
 asm (CTORS_SECTION_ASM_OP);	/* cc1 doesn't know that we are switching! */
-func_ptr __CTOR_END__[1] = { (func_ptr) 0 };
+STATIC func_ptr __CTOR_END__[1] = { (func_ptr) 0 };
 #endif
 
 #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 };
+STATIC func_ptr __DTOR_END__[1] __attribute__ ((__unused__))
+  = { (func_ptr) 0 };
 #endif
 
+#ifdef EH_FRAME_SECTION_ASM_OP
+/* Terminate the frame unwind info section with a 4byte 0 as a sentinel;
+   this would be the 'length' field in a real FDE.  */
+
+typedef unsigned int ui32 __attribute__ ((mode (SI)));
+asm (EH_FRAME_SECTION_ASM_OP);
+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 */
+