/*

  Copyright (C) 2000, 2004, 2006 Silicon Graphics, Inc.  All Rights Reserved.

  Portions Copyright (C) 2011 David Anderson. All Rights Reserved.

  This program is free software; you can redistribute it and/or modify it

  under the terms of version 2.1 of the GNU Lesser 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 Lesser 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 dwarf 2.0 standard dictates that only the following

    fields can be read when an unexpected augmentation string

    (in the cie) is encountered: CIE length, CIE_id, version and

    augmentation; FDE: length, CIE pointer, initial location and

    address range. Unfortunately, with the above restrictions, it

    is impossible to read the instruction table from a CIE or a FDE

    when a new augmentation string is encountered.

    To fix this problem, the following layout is used, if the

    augmentation string starts with the string "z".

        CIE                        FDE

        length                     length

        CIE_id                     CIE_pointer

        version                    initial_location

        augmentation               address_range

        -                          length_of_augmented_fields (*NEW*)

        code_alignment_factor      Any new fields as necessary

        data_alignment_factor      instruction_table

        return_address

        length_of_augmented fields

        Any new fields as necessary

        initial_instructions

    The type of all the old data items are the same as what is

    described in dwarf 2.0 standard. The length_of_augmented_fields

    is an LEB128 data item that denotes the size (in bytes) of

    the augmented fields (not including the size of

    "length_of_augmented_fields" itself).

    Handling of cie augmentation strings is necessarly a heuristic.

    See dwarf_frame.c for the currently known augmentation strings.

    ---START SGI-ONLY COMMENT:

    SGI-IRIX versions of cie or fde  were intended to use "z1", "z2" as the

    augmenter strings if required for new augmentation.

    However, that never happened (as of March 2005).

    The fde's augmented by the string "z" have a new field

    (signed constant, 4 byte field)

    called offset_into_exception_tables, following the

    length_of_augmented field.   This field contains an offset

    into the "_MIPS_eh_region", which describes

    the IRIX CC exception handling tables.

    ---END SGI-ONLY COMMENT

    GNU .eh_frame has an augmentation string of z[RLP]* (gcc 3.4)

    The similarity to IRIX 'z' (and proposed but never

    implemented IRIX z1, z2 etc) was confusing things.

    If the section is .eh_frame then 'z' means GNU exception

    information 'Augmentation Data' not IRIX 'z'.

    See The Linux Standard Base Core Specification version 3.0

*/

#define DW_DEBUG_FRAME_VERSION     1 /* DWARF2 */

#define DW_DEBUG_FRAME_VERSION3    3 /* DWARF3 */

#define DW_DEBUG_FRAME_VERSION4    4 /* DWARF4 */

/*  The following is SGI/IRIX specific, and probably no longer

    in use anywhere. */

#define DW_DEBUG_FRAME_AUGMENTER_STRING     	"mti v1"

/* The value of the offset field for Cie's. */

#define DW_CIE_OFFSET		~(0x0)

/* The augmentation string may be NULL.	*/

#define DW_EMPTY_STRING		""

#define DW_FRAME_INSTR_OPCODE_SHIFT		6

#define DW_FRAME_INSTR_OFFSET_MASK		0x3f

/*

    This struct denotes the rule for a register in a row of

    the frame table.  In other words, it is one element of

    the table.

*/

struct Dwarf_Reg_Rule_s {

    /*  Is a flag indicating whether the rule includes the offset

        field, ie whether the ru_offset field is valid or not.

        Applies only if DW_EXPR_OFFSET or DW_EXPR_VAL_OFFSET.

        It is important, since reg+offset (offset of 0) is different from

        just 'register' since the former means 'read memory at address

        given by the sum of register contents plus offset to get the

        value'. whereas the latter means 'the value is in the register'.

        The 'register' numbers are either real registers (ie, table

        columns defined as real registers) or defined entries that are

        not really hardware registers, such as DW_FRAME_SAME_VAL or

        DW_FRAME_CFA_COL.  */

    Dwarf_Sbyte ru_is_off;

    /*  DW_EXPR_OFFSET (0, DWARF2)

        DW_EXPR_VAL_OFFSET 1 (dwarf2/3)

        DW_EXPR_EXPRESSION 2  (dwarf2/3)

        DW_EXPR_VAL_EXPRESSION 3 (dwarf2/3)

        See dwarf_frame.h. */

    Dwarf_Sbyte ru_value_type;

    /* Register involved in this rule. */

    Dwarf_Half ru_register;

    /*  Offset to add to register, if indicated by ru_is_offset

        and if DW_EXPR_OFFSET or DW_EXPR_VAL_OFFSET.

        If DW_EXPR_EXPRESSION or DW_EXPR_VAL_EXPRESSION

        this is DW_FORM_block block-length, not offset. */

    Dwarf_Unsigned ru_offset_or_block_len;

    /*  For DW_EXPR_EXPRESSION DW_EXPR_VAL_EXPRESSION these is set,

        else 0. */

    Dwarf_Small *ru_block;

};

typedef struct Dwarf_Frame_s *Dwarf_Frame;

/*

    This structure represents a row of the frame table.

    Fr_loc is the pc value for this row, and Fr_reg

    contains the rule for each column.

    Entry DW_FRAME_CFA_COL of fr_reg was the tradional MIPS

    way of setting CFA.  cfa_rule is the new one.

*/

struct Dwarf_Frame_s {

    /* Pc value corresponding to this row of the frame table. */

    Dwarf_Addr fr_loc;

    /* Rules for all the registers in this row. */

    struct Dwarf_Reg_Rule_s fr_cfa_rule;

    /*  fr_reg_count is the the number of

        entries of the fr_reg array. */

    unsigned long            fr_reg_count;

    struct Dwarf_Reg_Rule_s *fr_reg;

    Dwarf_Frame fr_next;

};

typedef struct Dwarf_Frame_Op_List_s *Dwarf_Frame_Op_List;

/* This is used to chain together Dwarf_Frame_Op structures. */

struct Dwarf_Frame_Op_List_s {

    Dwarf_Frame_Op *fl_frame_instr;

    Dwarf_Frame_Op_List fl_next;

};

/* See dwarf_frame.c for the heuristics used to set the

   Dwarf_Cie ci_augmentation_type.

   This succinctly helps interpret the size and meaning of .debug_frame

   and (for gcc) .eh_frame.

   In the case of gcc .eh_frame (gcc 3.3, 3.4)

   z may be followed by one or more of

   L R P.

*/

enum Dwarf_augmentation_type {

    aug_empty_string, /* Default empty augmentation string.  */

    aug_irix_exception_table,  /* IRIX  plain  "z",

        for exception handling, IRIX CC compiler.

        Proposed z1 z2 ... never implemented.  */

    aug_gcc_eh_z,       /* gcc z augmentation,  (including

        L R P variations). gcc 3.3 3.4 exception

        handling in eh_frame.  */

    aug_irix_mti_v1,  /* IRIX "mti v1" augmentation string. Probably

        never in any released SGI-IRIX compiler. */

    aug_eh,           /* For gcc .eh_frame, "eh" is the string.,

        gcc 1,2, egcs. Older values.  */

    aug_armcc,  /* "armcc+" meaning the  cfa calculation

        is corrected to be standard (output by

        Arm C RVCT 3.0 SP1 and later). See

        http://sourceware.org/ml/gdb-patches/2006-12/msg00249.html

        for details. */

    aug_unknown,      /* Unknown augmentation, we cannot do much. */

    /*  HC, From http://sourceforge.net/p/elftoolchain/tickets/397/ */

    aug_metaware,

    aug_past_last

};

/*

    This structure contains all the pertinent info for a Cie. Most

    of the fields are taken straight from the definition of a Cie.

    Ci_cie_start points to the address (in .debug_frame) where this

    Cie begins.  Ci_cie_instr_start points to the first byte of the

    frame instructions for this Cie.  Ci_dbg points to the associated

    Dwarf_Debug structure.  Ci_initial_table is a pointer to the table

    row generated by the instructions for this Cie.

*/

struct Dwarf_Cie_s {

    Dwarf_Unsigned ci_length;

    char *ci_augmentation;

    Dwarf_Small ci_code_alignment_factor;

    Dwarf_Sbyte ci_data_alignment_factor;

    Dwarf_Small ci_return_address_register;

    Dwarf_Small *ci_cie_start;

    Dwarf_Small *ci_cie_instr_start;

    Dwarf_Small *ci_cie_end;

    Dwarf_Debug ci_dbg;

    Dwarf_Frame ci_initial_table;

    Dwarf_Cie ci_next;

    Dwarf_Small ci_length_size;

    Dwarf_Small ci_extension_size;

    Dwarf_Half ci_cie_version_number;

    enum Dwarf_augmentation_type ci_augmentation_type;

    /*  The following 2 for GNU .eh_frame exception handling

        Augmentation Data. Set if ci_augmentation_type

        is aug_gcc_eh_z. Zero if unused. */

    Dwarf_Unsigned ci_gnu_eh_augmentation_len;

    Dwarf_Ptr      ci_gnu_eh_augmentation_bytes;

    /*  These are extracted from the gnu eh_frame

        augmentation if the

        augmentation begins with 'z'. See Linux LSB documents.

        Otherwize these are zero. */

    unsigned char    ci_gnu_personality_handler_encoding;

    unsigned char    ci_gnu_lsda_encoding;

    unsigned char    ci_gnu_fde_begin_encoding;

    /*  If 'P' augmentation present, is handler addr. Else

        is zero. */

    Dwarf_Addr     ci_gnu_personality_handler_addr;

    /*  In creating list of cie's (which will become an array)

        record the position so fde can get it on fde creation. */

    Dwarf_Unsigned ci_index;

    Dwarf_Small *  ci_section_ptr;

    Dwarf_Unsigned ci_section_length;

    Dwarf_Small *  ci_section_end;

    /*  DWARF4 adds address size and segment size to the CIE: the .debug_info

        section may not always be present to allow libdwarf to

        find address_size from the compilation-unit. */

    Dwarf_Half   ci_address_size;

    Dwarf_Half   ci_segment_size;

};

/*

    This structure contains all the pertinent info for a Fde.

    Most of the fields are taken straight from the definition.

    fd_cie_index is the index of the Cie associated with this

    Fde in the list of Cie's for this debug_frame.  Fd_cie

    points to the corresponsing Dwarf_Cie structure.  Fd_fde_start

    points to the start address of the Fde.  Fd_fde_instr_start

    points to the start of the instructions for this Fde.  Fd_dbg

    points to the associated Dwarf_Debug structure.

*/

struct Dwarf_Fde_s {

    Dwarf_Unsigned fd_length;

    Dwarf_Addr fd_cie_offset;

    Dwarf_Unsigned fd_cie_index;

    Dwarf_Cie fd_cie;

    Dwarf_Addr fd_initial_location;

    Dwarf_Small *fd_initial_loc_pos;

    Dwarf_Addr fd_address_range;

    Dwarf_Small *fd_fde_start;

    Dwarf_Small *fd_fde_instr_start;

    Dwarf_Small *fd_fde_end;

    Dwarf_Debug fd_dbg;

    /*  fd_offset_into_exception_tables is SGI/IRIX exception table

        offset. Unused and zero if not IRIX .debug_frame. */

    Dwarf_Signed fd_offset_into_exception_tables;

    Dwarf_Fde fd_next;

    Dwarf_Small fd_length_size;

    Dwarf_Small fd_extension_size;

    /*  So we know from an fde which 'count' of fde-s in

        Dwarf_Debug applies:  eh or standard. */

    Dwarf_Small fd_is_eh;

    /*  The following 2 for GNU .eh_frame exception handling

        Augmentation Data. Set if CIE ci_augmentation_type

        is aug_gcc_eh_z. Zero if unused. */

    Dwarf_Unsigned fd_gnu_eh_augmentation_len;

    Dwarf_Bool fd_gnu_eh_aug_present;

    Dwarf_Ptr fd_gnu_eh_augmentation_bytes;

    Dwarf_Addr fd_gnu_eh_lsda; /* If 'L' augmentation letter

        present:  is address of the

        Language Specific Data Area (LSDA). If not 'L" is zero. */

    /* The following 3 are about the Elf section the FDEs come from. */

    Dwarf_Small * fd_section_ptr;

    Dwarf_Unsigned fd_section_length;

    Dwarf_Unsigned fd_section_index;

    Dwarf_Small * fd_section_end;

    /*  If fd_eh_table_value_set is true, then fd_eh_table_value is

        meaningful.  Never meaningful for .debug_frame, is

        part of .eh_frame. */

    Dwarf_Unsigned fd_eh_table_value;

    Dwarf_Bool fd_eh_table_value_set;

    /* The following are memoization to save recalculation. */

    struct Dwarf_Frame_s fd_fde_table;

    Dwarf_Addr    fd_fde_pc_requested;

    Dwarf_Bool    fd_have_fde_tab;

};

int

_dwarf_frame_address_offsets(Dwarf_Debug dbg, Dwarf_Addr ** addrlist,

    Dwarf_Off ** offsetlist,

    Dwarf_Signed * returncount,

    Dwarf_Error * err);

int

_dwarf_get_fde_list_internal(Dwarf_Debug dbg,

    Dwarf_Cie ** cie_data,

    Dwarf_Signed * cie_element_count,

    Dwarf_Fde ** fde_data,

    Dwarf_Signed * fde_element_count,

    Dwarf_Small * section_ptr,

    Dwarf_Unsigned section_index,

    Dwarf_Unsigned section_length,

    Dwarf_Unsigned cie_id_value,

    int use_gnu_cie_calc,  /* If non-zero,

    this is gcc eh_frame. */

    Dwarf_Error * error);

enum Dwarf_augmentation_type

_dwarf_get_augmentation_type(Dwarf_Debug dbg,

    Dwarf_Small *augmentation_string,

    int is_gcc_eh_frame);

int _dwarf_get_return_address_reg(Dwarf_Small *frame_ptr,

    int version,

    Dwarf_Debug dbg,

    Dwarf_Byte_Ptr section_end,

    unsigned long *size,

    Dwarf_Unsigned *return_address_register,

    Dwarf_Error *error);

/*  Temporary recording of crucial cie/fde prefix data.

    Vastly simplifies some argument lists.  */

struct cie_fde_prefix_s {

    /*  cf_start_addr is a pointer to the first byte

        of this fde/cie (meaning the length field itself) */

    Dwarf_Small *  cf_start_addr;

    /*  cf_addr_after_prefix is a pointer

        to the first byte of this fde/cie

        we are reading now, immediately following

        the length field read by READ_AREA_LENGTH. */

    Dwarf_Small *  cf_addr_after_prefix;

    /*  cf_length is the length field value from the cie/fde

        header.   */

    Dwarf_Unsigned cf_length;

    int            cf_local_length_size;

    int            cf_local_extension_size;

    Dwarf_Unsigned cf_cie_id;

    Dwarf_Small *  cf_cie_id_addr; /* used for eh_frame calculations. */

    /*  Simplifies passing around these values to create fde having

        these here. */

    /*  cf_section_ptr is a pointer to the first byte

        of the object section the prefix is read from.  */

    Dwarf_Small *  cf_section_ptr;

    Dwarf_Unsigned cf_section_index;

    Dwarf_Unsigned cf_section_length;

};

int

_dwarf_exec_frame_instr(Dwarf_Bool make_instr,

    Dwarf_Frame_Op ** ret_frame_instr,

    Dwarf_Bool search_pc,

    Dwarf_Addr search_pc_val,

    Dwarf_Addr initial_loc,

    Dwarf_Small * start_instr_ptr,

    Dwarf_Small * final_instr_ptr,

    Dwarf_Frame table,

    Dwarf_Cie cie,

    Dwarf_Debug dbg,

    Dwarf_Half reg_num_of_cfa,

    Dwarf_Sword * returned_count,

    Dwarf_Bool  * has_more_rows,

    Dwarf_Addr  * subsequent_pc,

    Dwarf_Error * error);

int dwarf_read_cie_fde_prefix(Dwarf_Debug dbg,

    Dwarf_Small *frame_ptr_in,

    Dwarf_Small *section_ptr_in,

    Dwarf_Unsigned section_index_in,

    Dwarf_Unsigned section_length_in,

    struct cie_fde_prefix_s *prefix_out,

    Dwarf_Error *error);

int dwarf_create_fde_from_after_start(Dwarf_Debug dbg,

    struct cie_fde_prefix_s *  prefix,

    Dwarf_Small *section_pointer,

    Dwarf_Small *frame_ptr,

    Dwarf_Small *section_ptr_end,

    int use_gnu_cie_calc,

    Dwarf_Cie  cie_ptr_in,

    Dwarf_Fde *fde_ptr_out,

    Dwarf_Error *error);

int dwarf_create_cie_from_after_start(Dwarf_Debug dbg,

    struct cie_fde_prefix_s *prefix,

    Dwarf_Small* section_pointer,

    Dwarf_Small* frame_ptr,

    Dwarf_Small *section_ptr_end,

    Dwarf_Unsigned cie_count,

    int use_gnu_cie_calc,

    Dwarf_Cie *cie_ptr_out,

        Dwarf_Error *error);

int _dwarf_frame_constructor(Dwarf_Debug dbg,void * );

void _dwarf_frame_destructor (void *);

void _dwarf_fde_destructor (void *);