Initial revision

From-SVN: r407

gcc/crtstuff.c

+/* 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.
+
+This file is part of GNU CC.
+
+GNU CC is free software; you can redistribute it and/or modify
+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.
+
+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
+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.  */
+
+/* This file is a bit like libgcc1.c/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
+   supports multiple "user-defined" sections (e.g. COFF, ELF, ROSE).  On
+   such systems, this file allows us to avoid running collect (or any
+   other such slow and painful kludge).  Additionally, if the target
+   system supports a .init section, this file allows us to support the
+   linking of C++ code with a non-C++ main program.
+
+   Note that if INIT_SECTION_ASM_OP is defined in the tm.h file, then
+   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.
+
+   This file must be compiled with gcc.  */
+
+/* It is incorrect to include config.h here, because this file is being
+   compiled for the target, and hence definitions concerning only the host
+   do not apply.  */
+
+#include "tm.h"
+
+#ifndef CTORS_SECTION_ASM_OP
+#define CTORS_SECTION_ASM_OP	"\t.section\t.ctors,\"a\",@progbits"
+#endif
+#ifndef DTORS_SECTION_ASM_OP
+#define DTORS_SECTION_ASM_OP	"\t.section\t.dtors,\"a\",@progbits"
+#endif
+
+#include "gbl-ctors.h"
+
+#ifndef ON_EXIT
+#define ON_EXIT(a, b)
+#endif
+
+#ifdef CRT_BEGIN
+
+#ifdef INIT_SECTION_ASM_OP
+
+/* Force cc1 to switch to .text section.  */
+static void force_to_text () { }
+
+asm (INIT_SECTION_ASM_OP);	/* cc1 doesn't know that we are switching! */
+
+/* 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.   */
+
+static void
+__do_global_ctors ()		/* prologue goes in .init section */
+{
+  asm (TEXT_SECTION_ASM_OP);	/* don't put epilogue and body in .init */
+  DO_GLOBAL_CTORS_BODY;
+  ON_EXIT (__do_global_dtors, 0);
+}
+
+#endif /* defined(INIT_SECTION_ASM_OP) */
+
+/* Force cc1 to switch to .data section.  */
+static func_ptr force_to_data[0] = { };
+
+/* The -1 is a flag to __do_global_[cd]tors
+   indicating that this table does not start with a count of elements.  */
+asm (CTORS_SECTION_ASM_OP);	/* cc1 doesn't know that we are switching! */
+func_ptr __CTOR_LIST__[1] = { (func_ptr) (-1) };
+
+asm (DTORS_SECTION_ASM_OP);	/* cc1 doesn't know that we are switching! */
+func_ptr __DTOR_LIST__[1] = { (func_ptr) (-1) };
+
+#endif /* defined(CRT_BEGIN) */
+
+#ifdef CRT_END
+
+#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.
+
+   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.)
+*/
+
+static void
+__do_global_ctors ()		/* prologue goes in .text section */
+{
+  asm (INIT_SECTION_ASM_OP);
+  DO_GLOBAL_CTORS_BODY;
+  ON_EXIT (__do_global_dtors, 0);
+}				/* epilogue and body go in .init section */
+
+#endif /* defined(INIT_SECTION_ASM_OP) */
+
+/* Force cc1 to switch to .data section.  */
+static func_ptr force_to_data[0] = { };
+
+asm (CTORS_SECTION_ASM_OP);	/* cc1 doesn't know that we are switching! */
+func_ptr __CTOR_END__[1] = { (func_ptr) 0 };
+
+asm (DTORS_SECTION_ASM_OP);	/* cc1 doesn't know that we are switching! */
+func_ptr __DTOR_END__[1] = { (func_ptr) 0 };
+
+#endif /* defined(CRT_END) */