/*
  Copyright (C) 2000-2006 Silicon Graphics, Inc.  All Rights Reserved.
  Portions Copyright 2007-2010 Sun Microsystems, Inc. All rights reserved.
  Portions Copyright 2009-2011 SN Systems Ltd. All rights reserved.
  Portions Copyright 2008-2016 David Anderson. All rights reserved.

  This program is free software; you can redistribute it and/or modify it
  under the terms of version 2 of the GNU General Public License as
  published by the Free Software Foundation.

  This program is distributed in the hope that it would be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

  Further, this software is distributed without any warranty that it is
  free of the rightful claim of any third person regarding infringement
  or the like.  Any license provided herein, whether implied or
  otherwise, applies only to this software file.  Patent licenses, if
  any, provided herein do not apply to combinations of this program with
  other software, or any other product whatsoever.

  You should have received a copy of the GNU General Public License along
  with this program; if not, write the Free Software Foundation, Inc., 51
  Franklin Street - Fifth Floor, Boston MA 02110-1301, USA.
*/

/*  The address of the Free Software Foundation is
    Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
    Boston, MA 02110-1301, USA.
    SGI has moved from the Crittenden Lane address.
*/

#include "globals.h"
#include "naming.h"
#include "dwconf.h"
#include "esb.h"

#include "print_sections.h"


/* The following relevent for one specific Linker. */
#define SNLINKER_MAX_ATTRIB_COUNT  16
/* a warning limit which is arbitrary but leaves a bit more flexibility. */
#define GENERAL_MAX_ATTRIB_COUNT   32

/* Print data in .debug_abbrev
   This is inherently unsafe as it assumes there
   are no byte sequences in .debug_abbrev other than
   legal abbrev sequences.  But the Dwarf spec
   does not promise that. The spec only promises
   that any bytes at an offset referred to from
   .debug_info are legal sequences.
*/
extern void
print_abbrevs(Dwarf_Debug dbg)
{
    Dwarf_Abbrev ab;
    Dwarf_Unsigned offset = 0;
    Dwarf_Unsigned length = 0;
    Dwarf_Unsigned abbrev_entry_count = 0;
    /* Maximum defined tag is 0xffff, DW_TAG_hi_user. */
    Dwarf_Half tag = 0;
    Dwarf_Half attr = 0;
    Dwarf_Signed form = 0;
    Dwarf_Off off = 0;
    Dwarf_Unsigned i = 0;
    Dwarf_Unsigned abbrev_num = 1;
    Dwarf_Signed child_flag = 0;
    int abres = 0;
    int tres = 0;
    int acres = 0;
    Dwarf_Unsigned abbrev_code = 0;
    Dwarf_Error paerr = 0;

    current_section_id = DEBUG_ABBREV;

    if (glflags.gf_do_print_dwarf) {
        printf("\n.debug_abbrev\n");
    }
    while ((abres = dwarf_get_abbrev(dbg, offset, &ab,
        &length, &abbrev_entry_count, &paerr)) == DW_DLV_OK) {
        const char *tagname = "";

        /*  Here offset is the global offset in .debug_abbrev.
            The abbrev_num is a relatively worthless counter
            of all abbreviations.  */
        tres = dwarf_get_abbrev_tag(ab, &tag, &paerr);
        if (tres != DW_DLV_OK) {
            dwarf_dealloc(dbg, ab, DW_DLA_ABBREV);
            print_error(dbg, "dwarf_get_abbrev_tag", tres, paerr);
        }
        tres = dwarf_get_abbrev_code(ab, &abbrev_code, &paerr);
        if (tres != DW_DLV_OK) {
            dwarf_dealloc(dbg, ab, DW_DLA_ABBREV);
            print_error(dbg, "dwarf_get_abbrev_code", tres, paerr);
        }
        tagname = get_TAG_name(tag,dwarf_names_print_on_error);
        if (!tag) {
            tagname = "Abbrev 0: null abbrev entry";
        }
        if (dense) {
            printf("<%" DW_PR_DUu "><0x%" DW_PR_XZEROS  DW_PR_DUx
                "><code: %" DW_PR_DUu ">",
                abbrev_num, offset,abbrev_code);
            if (verbose) {
                printf("<length: 0x%" DW_PR_XZEROS  DW_PR_DUx ">",
                    length);
            }
            printf(" %s", tagname);
        }
        else {
            printf("<%5" DW_PR_DUu "><0x%" DW_PR_XZEROS DW_PR_DUx
                "><code: %3" DW_PR_DUu ">",
                abbrev_num, offset, abbrev_code);
            if (verbose) {
                printf("<length: 0x%" DW_PR_XZEROS  DW_PR_DUx ">",
                    length);
            }
            printf(" %-27s", tagname);
        }
        /* Process specific TAGs specially. */
        tag_specific_checks_setup(tag,0);
        ++abbrev_num;
        acres = dwarf_get_abbrev_children_flag(ab, &child_flag, &paerr);
        if (acres == DW_DLV_ERROR) {
            dwarf_dealloc(dbg, ab, DW_DLA_ABBREV);
            print_error(dbg, "dwarf_get_abbrev_children_flag", acres,
                paerr);
        }
        if (acres == DW_DLV_NO_ENTRY) {
            child_flag = 0;
        }
        /*  If tag is zero, it is a null byte, not a real abbreviation,
            so there is no 'children' flag to print.  */
        if (tag) {
            const char * child_name = 0;

            child_name = get_children_name(child_flag,
                dwarf_names_print_on_error);
            printf(" %s", child_name);
        }
        if(!dense) {
            printf("\n");
        }
        /*  Abbrev just contains the format of a die, which debug_info
            then points to with the real data. So here we just print the
            given format. */
        for (i = 0; i < abbrev_entry_count; i++) {
            int aeres = 0;

            aeres = dwarf_get_abbrev_entry(ab, i, &attr, &form, &off,
                &paerr);
            if (aeres == DW_DLV_ERROR) {
                dwarf_dealloc(dbg, ab, DW_DLA_ABBREV);
                print_error(dbg, "dwarf_get_abbrev_entry", aeres, paerr);
            }
            if (aeres == DW_DLV_NO_ENTRY) {
                attr = -1LL;
                form = -1LL;
            }
            if (dense) {
                printf(" <%ld>%s<%s>", (unsigned long) off,
                    get_AT_name(attr,dwarf_names_print_on_error),
                    get_FORM_name((Dwarf_Half) form,
                        dwarf_names_print_on_error));
            } else {
                printf("       <0x%08lx>              %-28s%s\n",
                    (unsigned long) off,
                    get_AT_name(attr,
                        dwarf_names_print_on_error),
                    get_FORM_name((Dwarf_Half) form,
                        dwarf_names_print_on_error));
            }
        }
        dwarf_dealloc(dbg, ab, DW_DLA_ABBREV);
        offset += length;
        if (dense) {
            printf("\n");
        }
    }
    if (abres == DW_DLV_ERROR) {
        print_error(dbg, "dwarf_get_abbrev", abres, paerr);
    }
}

/*  Abbreviations array info for checking  abbrev tags.
    The [zero] entry is not used.
    We never shrink the array, but it never grows beyond
    the largest abbreviation count of all the CUs.
    It is set up when we start a new CU and
    used to validate abbreviations on each DIE in the CU.
    See print_die.c
*/

static Dwarf_Unsigned *abbrev_array = NULL;
/*  Size of the array, the same as the abbrev tag
    count of the CU with the most of them.
    Be careful as abbrev_array[abbrev_array_size]
    is outside the high bound. */
static Dwarf_Unsigned abbrev_array_size = 0;
#define ABBREV_ARRAY_INITIAL_SIZE 64

void
destruct_abbrev_array(void)
{
    free(abbrev_array);
    abbrev_array = 0;
    abbrev_array_size = 0;
}

/*  Normally abbreviation numbers are allocated in sequence from 1
    and increase by 1
    but in case of a compiler bug or a damaged object file one can
    see strange things. This looks for surprises and reports them.
    Returns the abbrev_code unless the value looks very wrong,
    and then it returns zero as we do not want a gigantic
    abbrev code to cause trouble.
*/
static Dwarf_Unsigned
check_abbrev_num_sequence(Dwarf_Unsigned abbrev_code,
    Dwarf_Unsigned last_abbrev_code,
    UNUSEDARG Dwarf_Unsigned l_abbrev_array_size,
    UNUSEDARG Dwarf_Unsigned abbrev_entry_count,
    UNUSEDARG Dwarf_Unsigned total_abbrevs_counted)
{
    char buf[128];

    DWARF_CHECK_COUNT(abbreviations_result,1);
    if (abbrev_code > last_abbrev_code) {
        if ((abbrev_code-last_abbrev_code) > 100 ) {
            snprintf(buf, sizeof(buf),
                "Abbrev code %" DW_PR_DUu
                " skips up by %" DW_PR_DUu
                " from last abbrev code of %" DW_PR_DUu ,
                abbrev_code,
                (abbrev_code-last_abbrev_code),
                last_abbrev_code);
            DWARF_CHECK_ERROR2(abbreviations_result,buf,
                "Questionable abbreviation code! Not checking reuse.");
            return 0;
        } else if ((abbrev_code-last_abbrev_code) > 1 ) {
            snprintf(buf, sizeof(buf),
                "Abbrev code %" DW_PR_DUu
                " skips up by %" DW_PR_DUu
                " from last abbrev code of %" DW_PR_DUu ,
                abbrev_code,
                (abbrev_code-last_abbrev_code),
                last_abbrev_code);
            DWARF_CHECK_ERROR2(abbreviations_result,buf,
                "Questionable abbreviation code.");
        }
    } else if (abbrev_code < last_abbrev_code) {
        snprintf(buf, sizeof(buf),
            "Abbrev code %" DW_PR_DUu
            " skips down by %" DW_PR_DUu
            " from last abbrev code of %" DW_PR_DUu ,
            abbrev_code,
            (last_abbrev_code - abbrev_code),
            last_abbrev_code);
        DWARF_CHECK_ERROR2(abbreviations_result,buf,
            "Questionable abbreviation code.");
    } else {
        snprintf(buf, sizeof(buf),
            "Abbrev code %" DW_PR_DUu
            " unchanged from last abbrev code!.",
            abbrev_code);
        DWARF_CHECK_ERROR2(abbreviations_result,buf,
            "Questionable abbreviation code.");
    }
    return abbrev_code;
}

static void
check_reused_code(Dwarf_Unsigned abbrev_code,
    Dwarf_Unsigned abbrev_entry_count)
{
    char buf[128];

    if (abbrev_code >= abbrev_array_size) {
        snprintf(buf, sizeof(buf),
            "Abbrev code %" DW_PR_DUu
            " entry_count unchecked: %" DW_PR_DUu  " ",
            abbrev_code,abbrev_entry_count);
        DWARF_CHECK_ERROR2(abbreviations_result,buf,
            "Questionable abbreviation code.");
        return;
    }
    if (abbrev_array[abbrev_code]) {
        DWARF_CHECK_COUNT(abbreviations_result,1);
        /* This abbrev code slot was used before. */
        if (abbrev_array[abbrev_code] == abbrev_entry_count) {
            snprintf(buf, sizeof(buf),
                "Abbrev code %" DW_PR_DUu
                " reused for same entry_count: %" DW_PR_DUu  " ",
                abbrev_code,abbrev_entry_count);
            DWARF_CHECK_ERROR2(abbreviations_result,buf,
                "Questionable abbreviation code.");
        } else {
            snprintf(buf, sizeof(buf),
                "Abbrev code %" DW_PR_DUu
                " reused for different entry_count. "
                " %" DW_PR_DUu " now %" DW_PR_DUu
                " ",
                abbrev_code,
                abbrev_array[abbrev_code],
                abbrev_entry_count);
            DWARF_CHECK_ERROR2(abbreviations_result,buf,
                "Invalid abbreviation code.");
        }
    }
}


/* Calculate the number of abbreviations for the
   current CU and set up basic abbreviations array info,
   storing the number of attributes per abbreviation
*/
void
get_abbrev_array_info(Dwarf_Debug dbg, Dwarf_Unsigned offset_in)
{
    Dwarf_Unsigned offset = offset_in;
    if (glflags.gf_check_abbreviations) {
        Dwarf_Abbrev ab = 0;
        Dwarf_Unsigned length = 0;
        Dwarf_Unsigned abbrev_entry_count = 0;
        Dwarf_Unsigned abbrev_code;
        int abres = DW_DLV_OK;
        Dwarf_Error aberr = 0;
        Dwarf_Unsigned last_abbrev_code = 0;

        Dwarf_Bool bMore = TRUE;
        Dwarf_Unsigned CU_abbrev_count = 0;

        if (abbrev_array == NULL) {
            /* Allocate initial abbreviation array info */
            abbrev_array_size = ABBREV_ARRAY_INITIAL_SIZE;
            abbrev_array = (Dwarf_Unsigned *)
                calloc(abbrev_array_size,sizeof(Dwarf_Unsigned));
        } else {
            /* Clear out values from previous CU */
            memset((void *)abbrev_array,0,
                (abbrev_array_size) * sizeof(Dwarf_Unsigned));
        }

        while (bMore && (abres = dwarf_get_abbrev(dbg, offset, &ab,
            &length, &abbrev_entry_count,
            &aberr)) == DW_DLV_OK) {
            dwarf_get_abbrev_code(ab,&abbrev_code,&aberr);
            if (abbrev_code == 0) {
                /* End of abbreviation table for this CU */
                ++offset; /* Skip abbreviation code */
                bMore = FALSE;
            } else {
                /* Valid abbreviation code. We hope. */
                if (abbrev_code > 0) {
                    Dwarf_Unsigned abhigh = check_abbrev_num_sequence(
                        abbrev_code,
                        last_abbrev_code,
                        abbrev_array_size,abbrev_entry_count,
                        CU_abbrev_count);
                    if (abhigh >= abbrev_array_size) {
                        /*  It is a new high, but is not outrageous. */
                        while (abbrev_code >= abbrev_array_size) {
                            Dwarf_Unsigned old_size = abbrev_array_size;
                            size_t addl_size_bytes = old_size *
                                sizeof(Dwarf_Unsigned);

                            /*  Resize abbreviation array.
                                Only a bogus abbreviation number
                                will iterate
                                more than once. The abhigh check.
                                prevents a runaway. */
                            abbrev_array_size *= 2;
                            abbrev_array = (Dwarf_Unsigned *)
                                realloc(abbrev_array,
                                abbrev_array_size * sizeof(Dwarf_Unsigned));
                            /* Zero out the new bytes. */
                            memset(abbrev_array + old_size,0,
                                addl_size_bytes);
                        }
                        last_abbrev_code = abbrev_code;
                        check_reused_code(abbrev_code,
                            abbrev_entry_count);
                        abbrev_array[abbrev_code] = abbrev_entry_count;
                    } else {
                        /* Zero is the case of 'too high' abbev_code. */
                        if (abhigh > 0) {
                            /*  More or less normal abbrev_code. */
                            last_abbrev_code = abbrev_code;
                            check_reused_code(abbrev_code,
                                abbrev_entry_count);
                            abbrev_array[abbrev_code] =
                                abbrev_entry_count;
                        }
                    }
                    ++CU_abbrev_count;
                    offset += length;
                } else {
                    /* Invalid abbreviation code */
                    print_error(dbg, "get_abbrev_array_info",
                        abres, aberr);
                    last_abbrev_code = abbrev_code;
                }
            }
            dwarf_dealloc(dbg, ab, DW_DLA_ABBREV);
        }
    }
}

/*  Validate an abbreviation for the current CU.
    In case of bogus abbrev input the CU_abbrev_count
    might not be as large as abbrev_array_size says
    the array is.  This should catch that case. */
void
validate_abbrev_code(UNUSEDARG Dwarf_Debug dbg,
    Dwarf_Unsigned abbrev_code)
{
    char buf[128];

    DWARF_CHECK_COUNT(abbreviations_result,1);
    if (abbrev_code && abbrev_code >= abbrev_array_size) {
        snprintf(buf, sizeof(buf),
            "Abbrev code %" DW_PR_DUu
            " outside valid range of [0-%" DW_PR_DUu "]",
            abbrev_code,abbrev_array_size);
        DWARF_CHECK_ERROR2(abbreviations_result,buf,
            "Invalid abbreviation code.");
    } else {
        Dwarf_Unsigned abbrev_entry_count =
            abbrev_array[abbrev_code];
        if (abbrev_entry_count > SNLINKER_MAX_ATTRIB_COUNT) {
            if (abbrev_entry_count > GENERAL_MAX_ATTRIB_COUNT) {
                snprintf(buf, sizeof(buf),
                    "Abbrev code %" DW_PR_DUu
                    ", with %" DW_PR_DUu " attributes: "
                    "outside a sanity-check maximum of %d.",
                    abbrev_code,
                    abbrev_entry_count,
                    GENERAL_MAX_ATTRIB_COUNT);
                DWARF_CHECK_ERROR2(abbreviations_result,buf,
                    "Number of attributes exceeds sanity check");
            } else {
                /*  These apply only to one compiliation environment,
                    and are not generally applicable.  */
                snprintf(buf, sizeof(buf),
                    "Abbrev code %" DW_PR_DUu
                    ", with %" DW_PR_DUu " attributes: "
                    "outside an SN-LINKER expected-maximum of %d.",
                    abbrev_code,
                    abbrev_entry_count,
                    SNLINKER_MAX_ATTRIB_COUNT);
                DWARF_CHECK_ERROR2(abbreviations_result,buf,
                    "Number of attributes exceeds SN-LINKER-specific sanity check.");
            }
        }
    }
}