diff options
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/generic/initfini.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/sysdeps/generic/initfini.c b/sysdeps/generic/initfini.c new file mode 100644 index 0000000000..c68a5cff00 --- /dev/null +++ b/sysdeps/generic/initfini.c @@ -0,0 +1,138 @@ +/* Special .init and .fini section support. + Copyright (C) 1995, 1996, 1997 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 modify it under the terms of the GNU Library General Public + License as published by the Free Software Foundation; either + version 2 of the License, or (at your option) any later version. + + In addition to the permissions in the GNU Library General Public + License, the Free Software Foundation gives you unlimited + permission to link the compiled version of this file with other + programs, and to distribute those programs without any restriction + coming from the use of this file. (The Library General Public + License restrictions do apply in other respects; for example, they + cover modification of the file, and distribution when not linked + into another program.) + + The GNU C Library 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 + GNU Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +/* This file is compiled into assembly code which is then munged by a sed + script into two files: crti.s and crtn.s. + + * crti.s puts a function prologue at the beginning of the + .init and .fini sections and defines global symbols for + those addresses, so they can be called as functions. + + * crtn.s puts the corresponding function epilogues + in the .init and .fini sections. */ + +#include <stdlib.h> + +/* We use embedded asm for .section unconditionally, as this makes it + easier to insert the necessary directives into crtn.S. */ +#define SECTION(x) asm (".section " x ); + +/* Embed an #include to pull in the alignment and .end directives. */ +asm ("\n#include \"defs.h\""); + +/* The initial common code ends here. */ +asm ("\n/*@HEADER_ENDS*/"); + +/* To determine whether we need .end and .align: */ +asm ("\n/*@TESTS_BEGIN*/"); +void +dummy (void (*foo) (void)) +{ + if (foo) + (*foo) (); +} +asm ("\n/*@TESTS_END*/"); + +/* The beginning of _init: */ +asm ("\n/*@_init_PROLOG_BEGINS*/"); + +SECTION (".init") +void +_init (void) +{ + /* We cannot use the normal constructor mechanism in gcrt1.o because it + appears before crtbegin.o in the link, so the header elt of .ctors + would come after the elt for __gmon_start__. One approach is for + gcrt1.o to reference a symbol which would be defined by some library + module which has a constructor; but then user code's constructors + would come first, and not be profiled. */ + extern void __gmon_start__ (void) __attribute__ ((weak)); /*weak_extern (__gmon_start__);*/ + +#ifndef WEAK_GMON_START + __gmon_start__ (); +#else + if (__gmon_start__) + __gmon_start__ (); +#endif + + asm ("ALIGN"); + asm("END_INIT"); + /* Now the epilog. */ + asm ("\n/*@_init_PROLOG_ENDS*/"); + asm ("\n/*@_init_EPILOG_BEGINS*/"); + SECTION(".init"); +} +asm ("END_INIT"); +#ifndef WEAK_GMON_START +SECTION(".text"); + +/* This version of __gmon_start__ is used if no other is found. By providing + a default function we avoid the need to test whether the pointer is NULL, + which can be painful on some machines. */ + +void __attribute__ ((weak)) +__gmon_start__ (void) +{ + /* do nothing */ +} +#endif + +/* End of the _init epilog, beginning of the _fini prolog. */ +asm ("\n/*@_init_EPILOG_ENDS*/"); +asm ("\n/*@_fini_PROLOG_BEGINS*/"); + +SECTION (".fini") +void +_fini (void) +{ + + /* End of the _fini prolog. */ + asm ("ALIGN"); + asm ("END_FINI"); + asm ("\n/*@_fini_PROLOG_ENDS*/"); + + { + /* Let GCC know that _fini is not a leaf function by having a dummy + function call here. We arrange for this call to be omitted from + either crt file. */ + extern void i_am_not_a_leaf (void); + i_am_not_a_leaf (); + } + + /* Beginning of the _fini epilog. */ + asm ("\n/*@_fini_EPILOG_BEGINS*/"); + SECTION (".fini"); +} +asm ("END_FINI"); + +/* End of the _fini epilog. Any further generated assembly (e.g. .ident) + is shared between both crt files. */ +asm ("\n/*@_fini_EPILOG_ENDS*/"); +asm ("\n/*@TRAILER_BEGINS*/"); + +/* End of file. */ |