Reading .debug_macro data (DWARF5)

Example reading DWARF5 macro data.

This builds an list or some other data structure (not defined) to give an import somewhere to list the import offset and then later to enquire if the list has unexamined offsets. The code compiles but is not yet tested.

This example does not actually do the import at the correct time as this is just checking import offsets, not creating a proper full list (in the proper order) of the macros with the imports inserted. Here we find the macro context for a DIE, report those macro entries, noting any macro_import in a list loop extracting unchecked macro offsets from the list note any import in a list Of course some functions are not implemented here...

*/
int   has_unchecked_import_in_list(void)
{
    /* Do something */
    return DW_DLV_OK;
}
Dwarf_Unsigned get_next_import_from_list(void)
{
    /* Do something */
    return 22;
}
void  mark_this_offset_as_examined(
    Dwarf_Unsigned macro_unit_offset)
{
    /* do something */
    /*  avoid compiler warnings. */
    (void)macro_unit_offset;
}
void  add_offset_to_list(Dwarf_Unsigned offset)
{
    /* do something */
    /*  avoid compiler warnings. */
    (void)offset;;
}
int  examplep5(Dwarf_Die cu_die,Dwarf_Error *error)
{
    int lres = 0;
    Dwarf_Unsigned      k = 0;
    Dwarf_Unsigned      version = 0;
    Dwarf_Macro_Context macro_context = 0;
    Dwarf_Unsigned      macro_unit_offset = 0;
    Dwarf_Unsigned      number_of_ops = 0;
    Dwarf_Unsigned      ops_total_byte_len = 0;
    Dwarf_Bool          is_primary = TRUE;
 
    /*  Just call once each way to test both.
        Really the second is just for imported units.*/
    for ( ; ; ) {
        if (is_primary) {
            lres = dwarf_get_macro_context(cu_die,
                &version,&macro_context,
                &macro_unit_offset,
                &number_of_ops,
                &ops_total_byte_len,
                error);
            is_primary = FALSE;
        } else {
            if (has_unchecked_import_in_list()) {
                macro_unit_offset = get_next_import_from_list();
            } else {
                /* We are done */
                break;
            }
            lres = dwarf_get_macro_context_by_offset(cu_die,
                macro_unit_offset,
                &version,
                &macro_context,
                &number_of_ops,
                &ops_total_byte_len,
                error);
            mark_this_offset_as_examined(macro_unit_offset);
        }
 
        if (lres == DW_DLV_ERROR) {
            /* Something is wrong. */
            return lres;
        }
        if (lres == DW_DLV_NO_ENTRY) {
            /* We are done. */
            break;
        }
        /* lres ==  DW_DLV_OK) */
        for (k = 0; k < number_of_ops; ++k) {
            Dwarf_Unsigned  section_offset = 0;
            Dwarf_Half      macro_operator = 0;
            Dwarf_Half      forms_count = 0;
            const Dwarf_Small *formcode_array = 0;
            Dwarf_Unsigned  line_number = 0;
            Dwarf_Unsigned  index = 0;
            Dwarf_Unsigned  offset =0;
            const char    * macro_string =0;
            int lres2 = 0;
 
            lres2 = dwarf_get_macro_op(macro_context,
                k, &section_offset,&macro_operator,
                &forms_count, &formcode_array,error);
            if (lres2 != DW_DLV_OK) {
                /* Some error. Deal with it */
                dwarf_dealloc_macro_context(macro_context);
                return lres2;
            }
            switch(macro_operator) {
            case 0:
                /* Nothing to do. */
                break;
            case DW_MACRO_end_file:
                /* Do something */
                break;
            case DW_MACRO_define:
            case DW_MACRO_undef:
            case DW_MACRO_define_strp:
            case DW_MACRO_undef_strp:
            case DW_MACRO_define_strx:
            case DW_MACRO_undef_strx:
            case DW_MACRO_define_sup:
            case DW_MACRO_undef_sup: {
                lres2 = dwarf_get_macro_defundef(macro_context,
                    k,
                    &line_number,
                    &index,
                    &offset,
                    &forms_count,
                    &macro_string,
                    error);
                if (lres2 != DW_DLV_OK) {
                    /* Some error. Deal with it */
                    dwarf_dealloc_macro_context(macro_context);
                    return lres2;
                }
                /* do something */
                }
                break;
            case DW_MACRO_start_file: {
                lres2 = dwarf_get_macro_startend_file(macro_context,
                    k,&line_number,
                    &index,
                    &macro_string,error);
                if (lres2 != DW_DLV_OK) {
                    /* Some error. Deal with it */
                    dwarf_dealloc_macro_context(macro_context);
                    return lres2;
                }
                /* do something */
                }
                break;
            case DW_MACRO_import: {
                lres2 = dwarf_get_macro_import(macro_context,
                    k,&offset,error);
                if (lres2 != DW_DLV_OK) {
                    /* Some error. Deal with it */
                    dwarf_dealloc_macro_context(macro_context);
                    return lres2;
                }
                add_offset_to_list(offset);
                }
                break;
            case DW_MACRO_import_sup: {
                lres2 = dwarf_get_macro_import(macro_context,
                    k,&offset,error);
                if (lres2 != DW_DLV_OK) {
                    /* Some error. Deal with it */
                    dwarf_dealloc_macro_context(macro_context);
                    return lres2;
                }
                /* do something */
                }
                break;
            default:
                /*  This is an error or an omission
                    in the code here.  We do not
                    know what to do.
                    Do something appropriate, print something?. */
                break;
            }
        }
        dwarf_dealloc_macro_context(macro_context);
        macro_context = 0;
    }
    return DW_DLV_OK;
}
/*