Elf Crash

/*
 * crtbegin.c
 *
 * :ts=4
 *
 * Handles global constructors and destructors for the OS4 GCC build.
 *
 *
 * Portable ISO 'C' (1994) runtime library for the Amiga computer
 * Copyright (c) 2002-2015 by Olaf Barthel <obarthel (at) gmx.net>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Neither the name of Olaf Barthel nor the names of contributors
 *     may be used to endorse or promote products derived from this
 *     software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef EXEC_TYPES_H
#include <exec/types.h>
#endif /* EXEC_TYPES_H */
#include <proto/exec.h>
#include <proto/dos.h>
#include <proto/elf.h>


#ifndef _STDLIB_HEADERS_H
#include "stdlib_headers.h"
#endif /* _STDLIB_HEADERS_H */

#ifndef _MACROS_H
#include "macros.h"
#endif /* _MACROS_H */


/*
 * Dummy constructor and destructor array. The linker script will put these at the
 * very beginning of section ".ctors" and ".dtors". crtend.o contains a similar entry
 * with a NULL pointer entry and is put at the end of the sections. This way, the init
 * code can find the global constructor/destructor pointers.
 *
 * WARNING:
 * This hack does not work correctly with GCC 5 and higher. The optimizer
 * will see a one element array and act appropriately. The current workaround
 * is to use -fno-aggressive-loop-optimizations when compiling this file.
 */

/****************************************************************************/
void _init(void (*__CTOR_LIST__[])(void));
void _fini(void (*__DTOR_LIST__[])(void));

extern int _main(void);
extern int _start(char *args, int arglen, struct ExecBase *sysbase);
static BOOL open_libraries(struct ExecBase *sysbase);
static void close_libraries(void);

#ifndef _STDLIB_HEADERS_H
#include "stdlib_headers.h"
#endif /* _STDLIB_HEADERS_H */

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

#include <libraries/elf.h>
#include <proto/elf.h>

struct Library  *ElfBase;
struct ElfIFace *IElf;

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

void shared_obj_init(void);
void shared_obj_exit(void);

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

static void SHLibsInit(BOOL init) {
    Elf32_Handle hSelf = (Elf32_Handle)NULL;
    BPTR segment_list = GetProcSegList(NULL, GPSLF_RUN | GPSLF_SEG);
    if (segment_list != ZERO)
    {
        int ret = GetSegListInfoTags(segment_list, GSLI_ElfHandle, &hSelf, TAG_DONE);
        if (ret == 1)
        {
            if (hSelf != NULL)
            {
                Printf("Below the crash\n");
                /* Trigger the constructors, etc. in the shared objects linked to this binary. */
                InitSHLibs(hSelf, init);
                Printf("No crash on static linking\n");
            }
        }
    }
}

void shared_obj_exit(void)
{
    /* If we got what we wanted, trigger the destructors, etc. in the shared objects linked to this binary. */
    SHLibsInit(FALSE);
}

void shared_obj_init()
{
    SHLibsInit(TRUE);
}

void _init(void (*__CTOR_LIST__[])(void))
{
    int num_ctors, i;
    int j;

    for (i = 1, num_ctors = 0; __CTOR_LIST__[i] != NULL; i++)
        num_ctors++;

    for (j = 0; j < num_ctors; j++)
    {
        __CTOR_LIST__[num_ctors - j]();
    }
}

void _fini(void (*__DTOR_LIST__[])(void))
{
    int num_dtors, i;
    static int j;
    extern void shared_obj_exit(void);

    for (i = 1, num_dtors = 0; __DTOR_LIST__[i] != NULL; i++)
        num_dtors++;

    while (j++ < num_dtors)
        __DTOR_LIST__[j]();

    /* The shared objects need to be cleaned up after all local
       destructors have been invoked. */
    shared_obj_exit();
}

int
_start(char *args, int arglen, struct ExecBase *sysbase)
{
    int result = -1;
    extern void shared_obj_init(void);

    /* Try to open the libraries we need to proceed. */
    if (CANNOT open_libraries(sysbase))
    {
        const char *error_message;

        /* If available, use the error message provided by the client. */
        error_message = __minimum_os_lib_error;

        if (error_message == NULL)
            error_message = "This program requires AmigaOS 4.1 or higher.";

        __show_error(error_message);
        goto out;
    }

    /* The shared objects need to be set up before any local
       constructors are invoked. */
    shared_obj_init();

    result = _main();

out:
    close_libraries();
    return result;
}

static BOOL
open_libraries(struct ExecBase *sysbase)
{
    BOOL success = FALSE;

    /* Get exec interface */
    IExec = (struct ExecIFace *)((struct ExecBase *)sysbase)->MainInterface;

    /* Open the minimum required libraries. */
    DOSBase = (struct Library *)OpenLibrary("dos.library", 54);
    if (DOSBase == NULL)
        goto out;

    __UtilityBase = OpenLibrary("utility.library", 54);
    if (__UtilityBase == NULL)
        goto out;

    /* Obtain the interfaces for these libraries. */
    IDOS = (struct DOSIFace *)GetInterface(DOSBase, "main", 1, 0);
    if (IDOS == NULL)
        goto out;

    __IUtility = (struct UtilityIFace *)GetInterface(__UtilityBase, "main", 1, 0);
    if (__IUtility == NULL)
        goto out;

    /* We need elf.library V52.2 or higher. */
    ElfBase = OpenLibrary("elf.library", 0);
    if (ElfBase == NULL || (ElfBase->lib_Version < 52) || (ElfBase->lib_Version == 52 && ElfBase->lib_Revision < 2))
        goto out;

    IElf = (struct ElfIFace *)GetInterface(ElfBase, "main", 1, NULL);
    if (IElf == NULL)
        goto out;

    success = TRUE;

out:

    return (success);
}

static void close_libraries(void) {

    if (IDOS != NULL)
    {
        DropInterface((struct Interface *)IDOS);
        IDOS = NULL;
    }

    if (DOSBase != NULL)
    {
        CloseLibrary(DOSBase);
        DOSBase = NULL;
    }

    if (IElf != NULL)
    {
        DropInterface((struct Interface *)IElf);
        IElf = NULL;
    }

    if (ElfBase != NULL)
    {
        CloseLibrary(ElfBase);
        ElfBase = NULL;
    }
}