sortix--sortix/libc/init.cpp

/*******************************************************************************

    Copyright(C) Jonas 'Sortie' Termansen 2011, 2012.

    This file is part of the Sortix C Library.

    The Sortix C Library is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 of the License, or (at your
    option) any later version.

    The Sortix 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 Lesser General Public
    License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.

    init.cpp
    Initializes the process by setting up the heap, signal handling, static
    memory and other useful things.

*******************************************************************************/

#include <malloc.h>
#include <string.h>

extern "C" { char* program_invocation_name; }
extern "C" { char* program_invocation_short_name; }

extern "C" void init_error_functions();
extern "C" void init_stdio();
extern "C" void init_signal();

static char* find_last_elem(char* str)
{
	size_t len = strlen(str);
	for ( size_t i = len; i; i-- )
		if ( str[i-1] == '/' )
			return str + i;
	return str;
}

extern "C" void initialize_standard_library(int argc, char* argv[])
{
	// We got ourselves a little bootstrap problem. We'd like these variables to
	// be available during early startup - however, we can't create a copy yet
	// because the heap isn't initialized yet. Instead, we'll simply point at
	// the original value - we're safe since argv[0] is not supposed to be
	// modified until main is run. Once we heap is up, we'll strdup.
	const char* argv0 = argc ? argv[0] : "";
	program_invocation_name = (char*) argv0;
	program_invocation_short_name = find_last_elem((char*) argv0);

	// Initialize stuff such as errno.
	init_error_functions();

	// It's probably best to initialize the Unix signals early on.
	init_signal();

	// Initialize the dynamic heap.
	_init_heap();

	// Initialize stdio.
	init_stdio();

	// We can now create a copy of the program name variables safely.
	program_invocation_name = strdup(program_invocation_name);
	program_invocation_short_name = find_last_elem(program_invocation_name);
}