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/* DWARF 1 find nearest line (_bfd_dwarf1_find_nearest_line).
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Copyright 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
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Written by Gavin Romig-Koch of Cygnus Solutions (gavin@cygnus.com).
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This file is part of BFD.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or (at
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your option) any later version.
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This program is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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#include "libiberty.h"
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#include "elf/dwarf.h"
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/* dwarf1_debug is the starting point for all dwarf1 info. */
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/* The bfd we are working with. */
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/* List of already parsed compilation units. */
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struct dwarf1_unit* lastUnit;
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/* The buffer for the .debug section.
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Zero indicates that the .debug section failed to load. */
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/* Pointer to the end of the .debug_info section memory buffer. */
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char* debug_section_end;
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/* The buffer for the .line section. */
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/* End of that buffer. */
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char* line_section_end;
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/* The current or next unread die within the .debug section. */
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/* One dwarf1_unit for each parsed compilation unit die. */
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/* Linked starting from stash->lastUnit. */
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struct dwarf1_unit* prev;
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/* Name of the compilation unit. */
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/* The highest and lowest address used in the compilation unit. */
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unsigned long high_pc;
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/* Does this unit have a statement list? */
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/* If any, the offset of the line number table in the .line section. */
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unsigned long stmt_list_offset;
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/* If non-zero, a pointer to the first child of this unit. */
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/* How many line entries? */
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unsigned long line_count;
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/* The decoded line number table (line_count entries). */
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struct linenumber* linenumber_table;
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/* The list of functions in this unit. */
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struct dwarf1_func* func_list;
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/* One dwarf1_func for each parsed function die. */
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/* Linked starting from aUnit->func_list. */
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struct dwarf1_func* prev;
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/* Name of function. */
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/* The highest and lowest address used in the compilation unit. */
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unsigned long high_pc;
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/* Used to return info about a parsed die. */
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unsigned long length;
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unsigned long sibling;
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unsigned long low_pc;
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unsigned long high_pc;
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unsigned long stmt_list_offset;
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/* Parsed line number information. */
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/* First address in the line. */
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/* The line number. */
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unsigned long linenumber;
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/* Find the form of an attr, from the attr field. */
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#define FORM_FROM_ATTR(attr) ((attr) & 0xF) /* Implicitly specified */
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static struct dwarf1_unit *alloc_dwarf1_unit PARAMS ((struct dwarf1_debug *));
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static struct dwarf1_func *alloc_dwarf1_func
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PARAMS ((struct dwarf1_debug *, struct dwarf1_unit *));
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static boolean parse_die PARAMS ((bfd *, struct die_info *, char *, char *));
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static boolean parse_line_table
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PARAMS ((struct dwarf1_debug *, struct dwarf1_unit *));
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static boolean parse_functions_in_unit
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PARAMS ((struct dwarf1_debug *, struct dwarf1_unit *));
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static boolean dwarf1_unit_find_nearest_line
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PARAMS ((struct dwarf1_debug *, struct dwarf1_unit *, unsigned long,
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const char **, const char **, unsigned int *));
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/* Return a newly allocated dwarf1_unit. It should be cleared and
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then attached into the 'stash' at 'stash->lastUnit'. */
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static struct dwarf1_unit*
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alloc_dwarf1_unit (stash)
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struct dwarf1_debug* stash;
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bfd_size_type amt = sizeof (struct dwarf1_unit);
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struct dwarf1_unit* x = (struct dwarf1_unit*) bfd_zalloc (stash->abfd, amt);
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x->prev = stash->lastUnit;
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/* Return a newly allocated dwarf1_func. It must be cleared and
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attached into 'aUnit' at 'aUnit->func_list'. */
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static struct dwarf1_func*
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alloc_dwarf1_func (stash, aUnit)
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struct dwarf1_debug* stash;
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struct dwarf1_unit* aUnit;
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bfd_size_type amt = sizeof (struct dwarf1_func);
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struct dwarf1_func* x = (struct dwarf1_func*) bfd_zalloc (stash->abfd, amt);
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x->prev = aUnit->func_list;
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aUnit->func_list = x;
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/* parse_die - parse a Dwarf1 die.
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Parse the die starting at 'aDiePtr' into 'aDieInfo'.
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'abfd' must be the bfd from which the section that 'aDiePtr'
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points to was pulled from.
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Return false if the die is invalidly formatted; true otherwise. */
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parse_die (abfd, aDieInfo, aDiePtr, aDiePtrEnd)
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struct die_info* aDieInfo;
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char* this_die = aDiePtr;
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char* xptr = this_die;
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memset (aDieInfo,0,sizeof (*aDieInfo));
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/* First comes the length. */
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aDieInfo->length = bfd_get_32 (abfd, (bfd_byte *) xptr);
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if (aDieInfo->length == 0
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|| (this_die + aDieInfo->length) >= aDiePtrEnd)
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if (aDieInfo->length < 6)
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/* Just padding bytes. */
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aDieInfo->tag = TAG_padding;
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aDieInfo->tag = bfd_get_16 (abfd, (bfd_byte *) xptr);
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/* Then the attributes. */
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while (xptr < (this_die + aDieInfo->length))
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/* Parse the attribute based on its form. This section
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must handle all dwarf1 forms, but need only handle the
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actual attributes that we care about. */
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attr = bfd_get_16 (abfd, (bfd_byte *) xptr);
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switch (FORM_FROM_ATTR (attr))
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if (attr == AT_sibling)
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aDieInfo->sibling = bfd_get_32 (abfd, (bfd_byte *) xptr);
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else if (attr == AT_stmt_list)
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aDieInfo->stmt_list_offset = bfd_get_32 (abfd, (bfd_byte *) xptr);
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aDieInfo->has_stmt_list = 1;
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if (attr == AT_low_pc)
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aDieInfo->low_pc = bfd_get_32 (abfd, (bfd_byte *) xptr);
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else if (attr == AT_high_pc)
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aDieInfo->high_pc = bfd_get_32 (abfd, (bfd_byte *) xptr);
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xptr += 2 + bfd_get_16 (abfd, (bfd_byte *) xptr);
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xptr += 4 + bfd_get_32 (abfd, (bfd_byte *) xptr);
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aDieInfo->name = xptr;
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xptr += strlen (xptr) + 1;
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/* Parse a dwarf1 line number table for 'aUnit->stmt_list_offset'
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into 'aUnit->linenumber_table'. Return false if an error
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occurs; true otherwise. */
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parse_line_table (stash, aUnit)
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struct dwarf1_debug* stash;
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struct dwarf1_unit* aUnit;
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/* Load the ".line" section from the bfd if we haven't already. */
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if (stash->line_section == 0)
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msec = bfd_get_section_by_name (stash->abfd, ".line");
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size = bfd_get_section_size_before_reloc (msec);
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stash->line_section = (char *) bfd_alloc (stash->abfd, size);
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if (! stash->line_section)
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if (! bfd_get_section_contents (stash->abfd, msec, stash->line_section,
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stash->line_section = 0;
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stash->line_section_end = stash->line_section + size;
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xptr = stash->line_section + aUnit->stmt_list_offset;
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if (xptr < stash->line_section_end)
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unsigned long eachLine;
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/* First comes the length. */
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tblend = bfd_get_32 (stash->abfd, (bfd_byte *) xptr) + xptr;
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/* Then the base address for each address in the table. */
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base = bfd_get_32 (stash->abfd, (bfd_byte *) xptr);
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/* How many line entrys?
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10 = 4 (line number) + 2 (pos in line) + 4 (address in line) */
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aUnit->line_count = (tblend - xptr) / 10;
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/* Allocate an array for the entries. */
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amt = sizeof (struct linenumber) * aUnit->line_count;
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aUnit->linenumber_table = ((struct linenumber *)
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bfd_alloc (stash->abfd, amt));
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for (eachLine = 0; eachLine < aUnit->line_count; eachLine++)
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aUnit->linenumber_table[eachLine].linenumber
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= bfd_get_32 (stash->abfd, (bfd_byte *) xptr);
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/* Skip the position within the line. */
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/* And finally the address. */
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aUnit->linenumber_table[eachLine].addr
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= base + bfd_get_32 (stash->abfd, (bfd_byte *) xptr);
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/* Parse each function die in a compilation unit 'aUnit'.
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The first child die of 'aUnit' should be in 'aUnit->first_child',
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the result is placed in 'aUnit->func_list'.
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Return false if error; true otherwise. */
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parse_functions_in_unit (stash, aUnit)
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struct dwarf1_debug* stash;
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struct dwarf1_unit* aUnit;
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if (aUnit->first_child)
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for (eachDie = aUnit->first_child;
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eachDie < stash->debug_section_end;
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struct die_info eachDieInfo;
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if (! parse_die (stash->abfd, &eachDieInfo, eachDie,
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stash->debug_section_end))
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if (eachDieInfo.tag == TAG_global_subroutine
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|| eachDieInfo.tag == TAG_subroutine
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|| eachDieInfo.tag == TAG_inlined_subroutine
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|| eachDieInfo.tag == TAG_entry_point)
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struct dwarf1_func* aFunc = alloc_dwarf1_func (stash,aUnit);
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aFunc->name = eachDieInfo.name;
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aFunc->low_pc = eachDieInfo.low_pc;
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aFunc->high_pc = eachDieInfo.high_pc;
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/* Move to next sibling, if none, end loop */
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if (eachDieInfo.sibling)
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eachDie = stash->debug_section + eachDieInfo.sibling;
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/* Find the nearest line to 'addr' in 'aUnit'.
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Return whether we found the line (or a function) without error. */
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dwarf1_unit_find_nearest_line (stash, aUnit, addr,
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filename_ptr, functionname_ptr,
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struct dwarf1_debug* stash;
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struct dwarf1_unit* aUnit;
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const char **filename_ptr;
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const char **functionname_ptr;
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unsigned int *linenumber_ptr;
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if (aUnit->low_pc <= addr && addr < aUnit->high_pc)
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if (aUnit->has_stmt_list)
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struct dwarf1_func* eachFunc;
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if (! aUnit->linenumber_table)
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if (! parse_line_table (stash, aUnit))
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if (! aUnit->func_list)
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if (! parse_functions_in_unit (stash, aUnit))
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for (i = 0; i < aUnit->line_count; i++)
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if (aUnit->linenumber_table[i].addr <= addr
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&& addr < aUnit->linenumber_table[i+1].addr)
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*filename_ptr = aUnit->name;
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*linenumber_ptr = aUnit->linenumber_table[i].linenumber;
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for (eachFunc = aUnit->func_list;
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eachFunc = eachFunc->prev)
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if (eachFunc->low_pc <= addr
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&& addr < eachFunc->high_pc)
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*functionname_ptr = eachFunc->name;
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return line_p || func_p;
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/* The DWARF 1 version of find_nearest line.
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Return true if the line is found without error. */
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_bfd_dwarf1_find_nearest_line (abfd, section, symbols, offset,
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filename_ptr, functionname_ptr, linenumber_ptr)
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asymbol **symbols ATTRIBUTE_UNUSED;
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const char **filename_ptr;
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const char **functionname_ptr;
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unsigned int *linenumber_ptr;
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struct dwarf1_debug *stash = elf_tdata (abfd)->dwarf1_find_line_info;
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struct dwarf1_unit* eachUnit;
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/* What address are we looking for? */
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unsigned long addr = (unsigned long)(offset + section->vma);
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*filename_ptr = NULL;
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*functionname_ptr = NULL;
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bfd_size_type size = sizeof (struct dwarf1_debug);
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stash = elf_tdata (abfd)->dwarf1_find_line_info
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= (struct dwarf1_debug *) bfd_zalloc (abfd, size);
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msec = bfd_get_section_by_name (abfd, ".debug");
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/* No dwarf1 info. Note that at this point the stash
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has been allocated, but contains zeros, this lets
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future calls to this function fail quicker. */
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size = bfd_get_section_size_before_reloc (msec);
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stash->debug_section = (char *) bfd_alloc (abfd, size);
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if (! stash->debug_section)
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if (! bfd_get_section_contents (abfd, msec, stash->debug_section,
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stash->debug_section = 0;
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stash->debug_section_end = stash->debug_section + size;
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stash->currentDie = stash->debug_section;
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/* A null debug_section indicates that there was no dwarf1 info
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or that an error occured while setting up the stash. */
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if (! stash->debug_section)
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/* Look at the previously parsed units to see if any contain
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for (eachUnit = stash->lastUnit; eachUnit; eachUnit = eachUnit->prev)
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if (eachUnit->low_pc <= addr && addr < eachUnit->high_pc)
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return dwarf1_unit_find_nearest_line (stash, eachUnit, addr,
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while (stash->currentDie < stash->debug_section_end)
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struct die_info aDieInfo;
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if (! parse_die (stash->abfd, &aDieInfo, stash->currentDie,
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stash->debug_section_end))
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if (aDieInfo.tag == TAG_compile_unit)
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struct dwarf1_unit* aUnit
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= alloc_dwarf1_unit (stash);
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aUnit->name = aDieInfo.name;
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aUnit->low_pc = aDieInfo.low_pc;
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aUnit->high_pc = aDieInfo.high_pc;
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aUnit->has_stmt_list = aDieInfo.has_stmt_list;
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aUnit->stmt_list_offset = aDieInfo.stmt_list_offset;
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/* A die has a child if it's followed by a die that is
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&& stash->currentDie + aDieInfo.length
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< stash->debug_section_end
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&& stash->currentDie + aDieInfo.length
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!= stash->debug_section + aDieInfo.sibling)
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aUnit->first_child = stash->currentDie + aDieInfo.length;
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aUnit->first_child = 0;
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if (aUnit->low_pc <= addr && addr < aUnit->high_pc)
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return dwarf1_unit_find_nearest_line (stash, aUnit, addr,
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if (aDieInfo.sibling != 0)
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stash->currentDie = stash->debug_section + aDieInfo.sibling;
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stash->currentDie += aDieInfo.length;