/*
 * Copyright 2012-2022, Haiku, Inc.
 * Distributed under the terms of the MIT License.
 *
 * Authors:
 *              Ithamar R. Adema <ithamar@upgrade-android.com>
 */

#include <string.h>
#include <stdio.h>
#include <stdlib.h>

#include "runtime_loader_private.h"

#include <runtime_loader.h>

//#define TRACE_RLD
#ifdef TRACE_RLD
#       define TRACE(x...) dprintf(x)
#else
#       define TRACE(x...) ;
#endif


static int
relocate_rel(image_t *rootImage, image_t *image, Elf32_Rel *rel, int rel_len,
        SymbolLookupCache* cache)
{
# define P      ((addr_t *)(image->regions[0].delta + rel[i].r_offset))
# define A      (*(P))
# define B      (image->regions[0].delta)

        for (int i = 0; i * (int)sizeof(Elf32_Rel) < rel_len; i++) {
                unsigned type = ELF32_R_TYPE(rel[i].r_info);
                unsigned symbolIndex = ELF32_R_SYM(rel[i].r_info);
                addr_t final_val;
                addr_t S;

                image_t* symbolImage = NULL;
                if (symbolIndex != 0) {
                        Elf32_Sym* sym = SYMBOL(image, symbolIndex);
                        status_t status = resolve_symbol(rootImage, image, sym, cache, &S,
                                        &symbolImage);
                        if (status < B_OK) {
                                TRACE("resolve symbol \"%s\" returned: %ld\n",
                                        SYMNAME(image, sym), status);
                                return status;
                        }
                }

                switch (type) {
                        case R_ARM_NONE:
                                continue;
                        case R_ARM_RELATIVE:
                                final_val = B + A;
                                break;
                        case R_ARM_JMP_SLOT:
                        case R_ARM_GLOB_DAT:
                                final_val = S;
                                break;
                        case R_ARM_ABS32:
                                final_val = S + A;
                                break;
                        default:
                                TRACE("unhandled relocation type %d\n", ELF32_R_TYPE(rel[i].r_info));
                                return B_NOT_ALLOWED;
                }

                *P = final_val;
        }

# undef P
# undef A
# undef B

        return B_NO_ERROR;
}


status_t
arch_relocate_image(image_t *rootImage, image_t *image,
        SymbolLookupCache* cache)
{
        status_t status;

        // deal with the rels first
        if (image->rel) {
                status = relocate_rel(rootImage, image, image->rel, image->rel_len,
                        cache);
                if (status < B_OK)
                        return status;
        }

        if (image->pltrel) {
                status = relocate_rel(rootImage, image, image->pltrel,
                        image->pltrel_len, cache);
                if (status < B_OK)
                        return status;
        }

        if (image->rela) {
                TRACE("RELA relocations not supported\n");
                return EOPNOTSUPP;
        }

        return B_OK;
}