/* Special .init and .fini section support. Copyright (C) 1995, 1996 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. 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, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* This file is compiled into assembly code which is then surrounded by the lines `cat > crtcommon.tmp <<\EOF_common' and `EOF_common' and thus becomes a shell script which creates three files of assembly code. * The first file is crti.s-new; this 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. * The second file is crtn.s-new; this puts the corresponding function epilogues in the .init and .fini sections. * The third file is crtcommon.tmp, which is whatever miscellaneous cruft the compiler generated at the end; it should be appended to both crti.s-new and crtn.s-new. */ #include #ifdef HAVE_ELF /* These declarations make the functions go in the right sections when we define them below. GCC syntax does not allow the attribute specifications to be in the function definitions themselves. */ void _init (void) __attribute__ ((section (".init"))); void _fini (void) __attribute__ ((section (".fini"))); #define SECTION(x) /* Put nothing extra before the defn. */ #else /* Some non-ELF systems support .init and .fini sections, but the __attribute__ syntax only works for ELF. */ #define SECTION(x) asm (".section " x); #endif /* End the here document containing the initial common code. Then move the output file crtcommon.tmp to crti.s-new and crtn.s-new. */ asm ("\nEOF_common\n\ rm -f crti.s-new crtn.s-new\n\ mv crtcommon.tmp crti.s-new\n\ cp crti.s-new crtn.s-new"); /* Extract a `.end' if one is produced by the compiler. */ asm ("fgrep .end >/dev/null 2>&1 <<\\EOF.end && need_end=yes"); void useless_function (void) { return; } asm ("\nEOF.end\n"); /* Append the .init prologue to crti.s-new. */ asm ("cat >> crti.s-new <<\\EOF.crti.init"); 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); weak_extern (__gmon_start__) if (__gmon_start__) __gmon_start__ (); /* End the here document containing the .init prologue code. Then fetch the .section directive just written and append that to crtn.s-new, followed by the function epilogue. */ asm ("\n\ EOF.crti.init\n\ test -n \"$need_end\" && echo .end _init >> crti.s-new\n\ fgrep .init crti.s-new >>crtn.s-new\n\ fgrep -v .end >> crtn.s-new <<\\EOF.crtn.init"); } /* End the here document containing the .init epilogue code. Then append the .fini prologue to crti.s-new. */ asm ("\nEOF.crtn.init\ \n\ cat >> crti.s-new <<\\EOF.crti.fini"); SECTION (".fini") void _fini (void) { /* End the here document containing the .fini prologue code. Then fetch the .section directive just written and append that to crtn.s-new, followed by the function epilogue. */ asm ("\nEOF.crti.fini\n\ test -n \"$need_end\" && echo .end _fini >> crti.s-new\n\ cat > /dev/null <<\\EOF.fini.skip"); { /* 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 (); } asm ("\nEOF.fini.skip\ \n\ fgrep .fini crti.s-new >>crtn.s-new\n\ fgrep -v .end >> crtn.s-new <<\\EOF.crtn.fini"); } /* End the here document containing the .fini epilogue code. Finally, put the remainder of the generated assembly into crtcommon.tmp. */ asm ("\nEOF.crtn.fini\ \n\ cat > crtcommon.tmp <<\\EOF_common");