554 lines
17 KiB
C
554 lines
17 KiB
C
/* Get info from stack frames; convert between frames, blocks,
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functions and pc values.
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Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
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1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
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Free Software Foundation, Inc.
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This file is part of GDB.
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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
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU 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,
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Boston, MA 02111-1307, USA. */
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#include "defs.h"
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#include "symtab.h"
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#include "bfd.h"
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#include "objfiles.h"
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#include "frame.h"
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#include "gdbcore.h"
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#include "value.h" /* for read_register */
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#include "target.h" /* for target_has_stack */
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#include "inferior.h" /* for read_pc */
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#include "annotate.h"
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#include "regcache.h"
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#include "gdb_assert.h"
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#include "dummy-frame.h"
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#include "command.h"
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#include "gdbcmd.h"
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#include "block.h"
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/* Prototypes for exported functions. */
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void _initialize_blockframe (void);
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/* Test whether PC is in the range of addresses that corresponds to
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the "main" function. */
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int
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inside_main_func (CORE_ADDR pc)
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{
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struct minimal_symbol *msymbol;
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if (symfile_objfile == 0)
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return 0;
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msymbol = lookup_minimal_symbol (main_name (), NULL, symfile_objfile);
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/* If the address range hasn't been set up at symbol reading time,
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set it up now. */
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if (msymbol != NULL
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&& symfile_objfile->ei.main_func_lowpc == INVALID_ENTRY_LOWPC
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&& symfile_objfile->ei.main_func_highpc == INVALID_ENTRY_HIGHPC)
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{
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/* brobecker/2003-10-10: We used to rely on lookup_symbol() to
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search the symbol associated to the "main" function.
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Unfortunately, lookup_symbol() uses the current-language
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la_lookup_symbol_nonlocal function to do the global symbol
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search. Depending on the language, this can introduce
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certain side-effects, because certain languages, for instance
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Ada, may find more than one match. Therefore we prefer to
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search the "main" function symbol using its address rather
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than its name. */
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struct symbol *mainsym =
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find_pc_function (SYMBOL_VALUE_ADDRESS (msymbol));
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if (mainsym && SYMBOL_CLASS (mainsym) == LOC_BLOCK)
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{
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symfile_objfile->ei.main_func_lowpc =
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BLOCK_START (SYMBOL_BLOCK_VALUE (mainsym));
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symfile_objfile->ei.main_func_highpc =
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BLOCK_END (SYMBOL_BLOCK_VALUE (mainsym));
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}
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}
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/* Not in the normal symbol tables, see if "main" is in the partial
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symbol table. If it's not, then give up. */
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if (msymbol != NULL && MSYMBOL_TYPE (msymbol) == mst_text)
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{
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CORE_ADDR maddr = SYMBOL_VALUE_ADDRESS (msymbol);
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asection *msect = SYMBOL_BFD_SECTION (msymbol);
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struct obj_section *osect = find_pc_sect_section (maddr, msect);
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if (osect != NULL)
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{
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int i;
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/* Step over other symbols at this same address, and symbols
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in other sections, to find the next symbol in this
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section with a different address. */
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for (i = 1; SYMBOL_LINKAGE_NAME (msymbol + i) != NULL; i++)
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{
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if (SYMBOL_VALUE_ADDRESS (msymbol + i) != maddr
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&& SYMBOL_BFD_SECTION (msymbol + i) == msect)
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break;
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}
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symfile_objfile->ei.main_func_lowpc = maddr;
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/* Use the lesser of the next minimal symbol in the same
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section, or the end of the section, as the end of the
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function. */
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if (SYMBOL_LINKAGE_NAME (msymbol + i) != NULL
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&& SYMBOL_VALUE_ADDRESS (msymbol + i) < osect->endaddr)
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symfile_objfile->ei.main_func_highpc =
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SYMBOL_VALUE_ADDRESS (msymbol + i);
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else
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/* We got the start address from the last msymbol in the
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objfile. So the end address is the end of the
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section. */
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symfile_objfile->ei.main_func_highpc = osect->endaddr;
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}
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}
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return (symfile_objfile->ei.main_func_lowpc <= pc
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&& symfile_objfile->ei.main_func_highpc > pc);
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}
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/* Test whether THIS_FRAME is inside the process entry point function. */
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int
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inside_entry_func (struct frame_info *this_frame)
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{
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return (get_frame_func (this_frame) == entry_point_address ());
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}
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/* Similar to inside_entry_func, but accomodating legacy frame code. */
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static int
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legacy_inside_entry_func (CORE_ADDR pc)
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{
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if (symfile_objfile == 0)
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return 0;
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if (CALL_DUMMY_LOCATION == AT_ENTRY_POINT)
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{
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/* Do not stop backtracing if the program counter is in the call
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dummy at the entry point. */
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/* FIXME: This won't always work with zeros for the last two
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arguments. */
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if (DEPRECATED_PC_IN_CALL_DUMMY (pc, 0, 0))
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return 0;
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}
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return (symfile_objfile->ei.entry_func_lowpc <= pc
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&& symfile_objfile->ei.entry_func_highpc > pc);
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}
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/* Return nonzero if the function for this frame lacks a prologue.
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Many machines can define DEPRECATED_FRAMELESS_FUNCTION_INVOCATION
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to just call this function. */
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int
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legacy_frameless_look_for_prologue (struct frame_info *frame)
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{
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CORE_ADDR func_start;
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func_start = get_frame_func (frame);
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if (func_start)
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{
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func_start += FUNCTION_START_OFFSET;
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/* NOTE: cagney/2004-02-09: Eliminated per-architecture
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PROLOGUE_FRAMELESS_P call as architectures with custom
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implementations had all been deleted. Eventually even this
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function can go - GDB no longer tries to differentiate
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between framed, frameless and stackless functions. They are
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all now considered equally evil :-^. */
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/* If skipping the prologue ends up skips nothing, there must be
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no prologue and hence no code creating a frame. There for
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the function is "frameless" :-/. */
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return func_start == SKIP_PROLOGUE (func_start);
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}
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else if (get_frame_pc (frame) == 0)
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/* A frame with a zero PC is usually created by dereferencing a
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NULL function pointer, normally causing an immediate core dump
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of the inferior. Mark function as frameless, as the inferior
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has no chance of setting up a stack frame. */
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return 1;
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else
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/* If we can't find the start of the function, we don't really
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know whether the function is frameless, but we should be able
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to get a reasonable (i.e. best we can do under the
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circumstances) backtrace by saying that it isn't. */
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return 0;
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}
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/* Return the innermost lexical block in execution
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in a specified stack frame. The frame address is assumed valid.
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If ADDR_IN_BLOCK is non-zero, set *ADDR_IN_BLOCK to the exact code
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address we used to choose the block. We use this to find a source
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line, to decide which macro definitions are in scope.
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The value returned in *ADDR_IN_BLOCK isn't necessarily the frame's
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PC, and may not really be a valid PC at all. For example, in the
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caller of a function declared to never return, the code at the
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return address will never be reached, so the call instruction may
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be the very last instruction in the block. So the address we use
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to choose the block is actually one byte before the return address
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--- hopefully pointing us at the call instruction, or its delay
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slot instruction. */
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struct block *
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get_frame_block (struct frame_info *frame, CORE_ADDR *addr_in_block)
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{
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const CORE_ADDR pc = get_frame_address_in_block (frame);
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if (addr_in_block)
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*addr_in_block = pc;
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return block_for_pc (pc);
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}
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CORE_ADDR
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get_pc_function_start (CORE_ADDR pc)
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{
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struct block *bl;
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struct minimal_symbol *msymbol;
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bl = block_for_pc (pc);
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if (bl)
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{
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struct symbol *symbol = block_function (bl);
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if (symbol)
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{
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bl = SYMBOL_BLOCK_VALUE (symbol);
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return BLOCK_START (bl);
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}
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}
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msymbol = lookup_minimal_symbol_by_pc (pc);
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if (msymbol)
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{
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CORE_ADDR fstart = SYMBOL_VALUE_ADDRESS (msymbol);
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if (find_pc_section (fstart))
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return fstart;
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}
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return 0;
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}
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/* Return the symbol for the function executing in frame FRAME. */
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struct symbol *
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get_frame_function (struct frame_info *frame)
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{
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struct block *bl = get_frame_block (frame, 0);
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if (bl == 0)
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return 0;
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return block_function (bl);
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}
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/* Return the function containing pc value PC in section SECTION.
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Returns 0 if function is not known. */
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struct symbol *
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find_pc_sect_function (CORE_ADDR pc, struct bfd_section *section)
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{
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struct block *b = block_for_pc_sect (pc, section);
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if (b == 0)
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return 0;
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return block_function (b);
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}
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/* Return the function containing pc value PC.
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Returns 0 if function is not known. Backward compatibility, no section */
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struct symbol *
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find_pc_function (CORE_ADDR pc)
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{
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return find_pc_sect_function (pc, find_pc_mapped_section (pc));
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}
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/* These variables are used to cache the most recent result
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* of find_pc_partial_function. */
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static CORE_ADDR cache_pc_function_low = 0;
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static CORE_ADDR cache_pc_function_high = 0;
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static char *cache_pc_function_name = 0;
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static struct bfd_section *cache_pc_function_section = NULL;
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/* Clear cache, e.g. when symbol table is discarded. */
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void
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clear_pc_function_cache (void)
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{
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cache_pc_function_low = 0;
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cache_pc_function_high = 0;
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cache_pc_function_name = (char *) 0;
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cache_pc_function_section = NULL;
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}
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/* Finds the "function" (text symbol) that is smaller than PC but
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greatest of all of the potential text symbols in SECTION. Sets
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*NAME and/or *ADDRESS conditionally if that pointer is non-null.
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If ENDADDR is non-null, then set *ENDADDR to be the end of the
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function (exclusive), but passing ENDADDR as non-null means that
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the function might cause symbols to be read. This function either
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succeeds or fails (not halfway succeeds). If it succeeds, it sets
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*NAME, *ADDRESS, and *ENDADDR to real information and returns 1.
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If it fails, it sets *NAME, *ADDRESS, and *ENDADDR to zero and
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returns 0. */
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/* Backward compatibility, no section argument. */
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int
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find_pc_partial_function (CORE_ADDR pc, char **name, CORE_ADDR *address,
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CORE_ADDR *endaddr)
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{
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struct bfd_section *section;
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struct partial_symtab *pst;
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struct symbol *f;
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struct minimal_symbol *msymbol;
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struct partial_symbol *psb;
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struct obj_section *osect;
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int i;
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CORE_ADDR mapped_pc;
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/* To ensure that the symbol returned belongs to the correct setion
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(and that the last [random] symbol from the previous section
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isn't returned) try to find the section containing PC. First try
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the overlay code (which by default returns NULL); and second try
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the normal section code (which almost always succeeds). */
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section = find_pc_overlay (pc);
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if (section == NULL)
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{
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struct obj_section *obj_section = find_pc_section (pc);
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if (obj_section == NULL)
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section = NULL;
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else
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section = obj_section->the_bfd_section;
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}
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mapped_pc = overlay_mapped_address (pc, section);
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if (mapped_pc >= cache_pc_function_low
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&& mapped_pc < cache_pc_function_high
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&& section == cache_pc_function_section)
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goto return_cached_value;
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msymbol = lookup_minimal_symbol_by_pc_section (mapped_pc, section);
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pst = find_pc_sect_psymtab (mapped_pc, section);
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if (pst)
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{
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/* Need to read the symbols to get a good value for the end address. */
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if (endaddr != NULL && !pst->readin)
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{
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/* Need to get the terminal in case symbol-reading produces
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output. */
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target_terminal_ours_for_output ();
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PSYMTAB_TO_SYMTAB (pst);
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}
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if (pst->readin)
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{
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/* Checking whether the msymbol has a larger value is for the
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"pathological" case mentioned in print_frame_info. */
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f = find_pc_sect_function (mapped_pc, section);
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if (f != NULL
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&& (msymbol == NULL
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|| (BLOCK_START (SYMBOL_BLOCK_VALUE (f))
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>= SYMBOL_VALUE_ADDRESS (msymbol))))
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{
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cache_pc_function_low = BLOCK_START (SYMBOL_BLOCK_VALUE (f));
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cache_pc_function_high = BLOCK_END (SYMBOL_BLOCK_VALUE (f));
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cache_pc_function_name = DEPRECATED_SYMBOL_NAME (f);
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cache_pc_function_section = section;
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goto return_cached_value;
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}
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}
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else
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{
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/* Now that static symbols go in the minimal symbol table, perhaps
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we could just ignore the partial symbols. But at least for now
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we use the partial or minimal symbol, whichever is larger. */
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psb = find_pc_sect_psymbol (pst, mapped_pc, section);
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if (psb
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&& (msymbol == NULL ||
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(SYMBOL_VALUE_ADDRESS (psb)
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>= SYMBOL_VALUE_ADDRESS (msymbol))))
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{
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/* This case isn't being cached currently. */
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if (address)
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*address = SYMBOL_VALUE_ADDRESS (psb);
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if (name)
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*name = DEPRECATED_SYMBOL_NAME (psb);
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/* endaddr non-NULL can't happen here. */
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return 1;
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}
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}
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}
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/* Not in the normal symbol tables, see if the pc is in a known section.
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If it's not, then give up. This ensures that anything beyond the end
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of the text seg doesn't appear to be part of the last function in the
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text segment. */
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osect = find_pc_sect_section (mapped_pc, section);
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if (!osect)
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msymbol = NULL;
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/* Must be in the minimal symbol table. */
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if (msymbol == NULL)
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{
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/* No available symbol. */
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if (name != NULL)
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*name = 0;
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if (address != NULL)
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*address = 0;
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if (endaddr != NULL)
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*endaddr = 0;
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return 0;
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}
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cache_pc_function_low = SYMBOL_VALUE_ADDRESS (msymbol);
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cache_pc_function_name = DEPRECATED_SYMBOL_NAME (msymbol);
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cache_pc_function_section = section;
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/* Use the lesser of the next minimal symbol in the same section, or
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the end of the section, as the end of the function. */
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/* Step over other symbols at this same address, and symbols in
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other sections, to find the next symbol in this section with
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a different address. */
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for (i = 1; DEPRECATED_SYMBOL_NAME (msymbol + i) != NULL; i++)
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{
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if (SYMBOL_VALUE_ADDRESS (msymbol + i) != SYMBOL_VALUE_ADDRESS (msymbol)
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&& SYMBOL_BFD_SECTION (msymbol + i) == SYMBOL_BFD_SECTION (msymbol))
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break;
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}
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if (DEPRECATED_SYMBOL_NAME (msymbol + i) != NULL
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&& SYMBOL_VALUE_ADDRESS (msymbol + i) < osect->endaddr)
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cache_pc_function_high = SYMBOL_VALUE_ADDRESS (msymbol + i);
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else
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/* We got the start address from the last msymbol in the objfile.
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So the end address is the end of the section. */
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cache_pc_function_high = osect->endaddr;
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return_cached_value:
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if (address)
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{
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if (pc_in_unmapped_range (pc, section))
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*address = overlay_unmapped_address (cache_pc_function_low, section);
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else
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*address = cache_pc_function_low;
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}
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if (name)
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*name = cache_pc_function_name;
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if (endaddr)
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{
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if (pc_in_unmapped_range (pc, section))
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{
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/* Because the high address is actually beyond the end of
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the function (and therefore possibly beyond the end of
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the overlay), we must actually convert (high - 1) and
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then add one to that. */
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*endaddr = 1 + overlay_unmapped_address (cache_pc_function_high - 1,
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section);
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}
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else
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*endaddr = cache_pc_function_high;
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}
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return 1;
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}
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/* Return the innermost stack frame executing inside of BLOCK,
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or NULL if there is no such frame. If BLOCK is NULL, just return NULL. */
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struct frame_info *
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block_innermost_frame (struct block *block)
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{
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struct frame_info *frame;
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CORE_ADDR start;
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CORE_ADDR end;
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CORE_ADDR calling_pc;
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if (block == NULL)
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return NULL;
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start = BLOCK_START (block);
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end = BLOCK_END (block);
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frame = NULL;
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while (1)
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{
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frame = get_prev_frame (frame);
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if (frame == NULL)
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return NULL;
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calling_pc = get_frame_address_in_block (frame);
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if (calling_pc >= start && calling_pc < end)
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return frame;
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}
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}
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/* Are we in a call dummy? The code below which allows DECR_PC_AFTER_BREAK
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||
below is for infrun.c, which may give the macro a pc without that
|
||
subtracted out. */
|
||
|
||
/* Returns true for a user frame or a call_function_by_hand dummy
|
||
frame, and false for the CRT0 start-up frame. Purpose is to
|
||
terminate backtrace. */
|
||
|
||
int
|
||
legacy_frame_chain_valid (CORE_ADDR fp, struct frame_info *fi)
|
||
{
|
||
/* Don't prune CALL_DUMMY frames. */
|
||
if (DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (fi), 0, 0))
|
||
return 1;
|
||
|
||
/* If the new frame pointer is zero, then it isn't valid. */
|
||
if (fp == 0)
|
||
return 0;
|
||
|
||
/* If the new frame would be inside (younger than) the previous frame,
|
||
then it isn't valid. */
|
||
if (INNER_THAN (fp, get_frame_base (fi)))
|
||
return 0;
|
||
|
||
/* If the architecture has a custom DEPRECATED_FRAME_CHAIN_VALID,
|
||
call it now. */
|
||
if (DEPRECATED_FRAME_CHAIN_VALID_P ())
|
||
return DEPRECATED_FRAME_CHAIN_VALID (fp, fi);
|
||
|
||
/* If we're already inside the entry function for the main objfile, then it
|
||
isn't valid. */
|
||
if (legacy_inside_entry_func (get_frame_pc (fi)))
|
||
return 0;
|
||
|
||
return 1;
|
||
}
|