591 lines
15 KiB
C
591 lines
15 KiB
C
/* Get info from stack frames;
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convert between frames, blocks, functions and pc values.
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Copyright (C) 1986, 1987, 1988, 1989 Free Software Foundation, Inc.
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This file is part of GDB.
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GDB 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 1, or (at your option)
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any later version.
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GDB 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 GDB; see the file COPYING. If not, write to
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the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
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#include "defs.h"
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#include "param.h"
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#include "symtab.h"
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#include "frame.h"
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#include <obstack.h>
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/* Start and end of object file containing the entry point.
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STARTUP_FILE_END is the first address of the next file.
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This file is assumed to be a startup file
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and frames with pc's inside it
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are treated as nonexistent.
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Setting these variables is necessary so that backtraces do not fly off
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the bottom of the stack. */
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CORE_ADDR startup_file_start;
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CORE_ADDR startup_file_end;
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/* Is ADDR outside the startup file? */
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int
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outside_startup_file (addr)
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CORE_ADDR addr;
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{
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return !(addr >= startup_file_start && addr < startup_file_end);
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}
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/* Address of innermost stack frame (contents of FP register) */
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static FRAME current_frame;
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struct block *block_for_pc ();
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CORE_ADDR get_pc_function_start ();
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/*
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* Cache for frame addresses already read by gdb. Valid only while
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* inferior is stopped. Control variables for the frame cache should
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* be local to this module.
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*/
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struct obstack frame_cache_obstack;
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/* Return the innermost (currently executing) stack frame. */
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FRAME
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get_current_frame ()
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{
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/* We assume its address is kept in a general register;
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param.h says which register. */
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return current_frame;
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}
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void
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set_current_frame (frame)
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FRAME frame;
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{
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current_frame = frame;
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}
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FRAME
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create_new_frame (addr, pc)
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FRAME_ADDR addr;
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CORE_ADDR pc;
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{
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struct frame_info *fci; /* Same type as FRAME */
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fci = (struct frame_info *)
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obstack_alloc (&frame_cache_obstack,
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sizeof (struct frame_info));
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/* Arbitrary frame */
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fci->next = (struct frame_info *) 0;
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fci->prev = (struct frame_info *) 0;
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fci->frame = addr;
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fci->next_frame = 0; /* Since arbitrary */
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fci->pc = pc;
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#ifdef INIT_EXTRA_FRAME_INFO
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INIT_EXTRA_FRAME_INFO (fci);
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#endif
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return fci;
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}
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/* Return the frame that called FRAME.
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If FRAME is the original frame (it has no caller), return 0. */
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FRAME
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get_prev_frame (frame)
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FRAME frame;
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{
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/* We're allowed to know that FRAME and "struct frame_info *" are
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the same */
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return get_prev_frame_info (frame);
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}
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/* Return the frame that FRAME calls (0 if FRAME is the innermost
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frame). */
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FRAME
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get_next_frame (frame)
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FRAME frame;
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{
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/* We're allowed to know that FRAME and "struct frame_info *" are
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the same */
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return frame->next;
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}
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/*
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* Flush the entire frame cache.
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*/
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void
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flush_cached_frames ()
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{
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/* Since we can't really be sure what the first object allocated was */
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obstack_free (&frame_cache_obstack, 0);
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obstack_init (&frame_cache_obstack);
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current_frame = (struct frame_info *) 0; /* Invalidate cache */
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}
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/* Return a structure containing various interesting information
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about a specified stack frame. */
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/* How do I justify including this function? Well, the FRAME
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identifier format has gone through several changes recently, and
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it's not completely inconceivable that it could happen again. If
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it does, have this routine around will help */
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struct frame_info *
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get_frame_info (frame)
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FRAME frame;
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{
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return frame;
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}
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/* If a machine allows frameless functions, it should define a macro
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FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) in param.h. FI is the struct
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frame_info for the frame, and FRAMELESS should be set to nonzero
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if it represents a frameless function invocation. */
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/* Many machines which allow frameless functions can detect them using
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this macro. Such machines should define FRAMELESS_FUNCTION_INVOCATION
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to just call this macro. */
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#define FRAMELESS_LOOK_FOR_PROLOGUE(FI, FRAMELESS) \
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{ \
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CORE_ADDR func_start, after_prologue; \
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func_start = (get_pc_function_start ((FI)->pc) + \
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FUNCTION_START_OFFSET); \
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if (func_start) \
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{ \
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after_prologue = func_start; \
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SKIP_PROLOGUE (after_prologue); \
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(FRAMELESS) = (after_prologue == func_start); \
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} \
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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 */ \
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/* able 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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(FRAMELESS) = 0; \
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}
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/* Return a structure containing various interesting information
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about the frame that called NEXT_FRAME. */
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struct frame_info *
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get_prev_frame_info (next_frame)
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FRAME next_frame;
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{
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FRAME_ADDR address;
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struct frame_info *prev;
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int fromleaf = 0;
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/* If the requested entry is in the cache, return it.
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Otherwise, figure out what the address should be for the entry
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we're about to add to the cache. */
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if (!next_frame)
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{
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if (!current_frame)
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{
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if (!have_inferior_p () && !have_core_file_p ())
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fatal ("get_prev_frame_info: Called before cache primed. \"Shouldn't happen.\"");
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else
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error ("No inferior or core file.");
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}
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return current_frame;
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}
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/* If we have the prev one, return it */
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if (next_frame->prev)
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return next_frame->prev;
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/* On some machines it is possible to call a function without
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setting up a stack frame for it. On these machines, we
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define this macro to take two args; a frameinfo pointer
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identifying a frame and a variable to set or clear if it is
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or isn't leafless. */
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#ifdef FRAMELESS_FUNCTION_INVOCATION
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/* Still don't want to worry about this except on the innermost
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frame. This macro will set FROMLEAF if NEXT_FRAME is a
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frameless function invocation. */
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if (!(next_frame->next))
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{
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FRAMELESS_FUNCTION_INVOCATION (next_frame, fromleaf);
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if (fromleaf)
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address = next_frame->frame;
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}
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#endif
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if (!fromleaf)
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{
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/* Two macros defined in param.h specify the machine-dependent
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actions to be performed here.
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First, get the frame's chain-pointer.
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If that is zero, the frame is the outermost frame or a leaf
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called by the outermost frame. This means that if start
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calls main without a frame, we'll return 0 (which is fine
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anyway).
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Nope; there's a problem. This also returns when the current
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routine is a leaf of main. This is unacceptable. We move
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this to after the ffi test; I'd rather have backtraces from
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start go curfluy than have an abort called from main not show
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main. */
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address = FRAME_CHAIN (next_frame);
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if (!FRAME_CHAIN_VALID (address, next_frame))
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return 0;
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/* If this frame is a leaf, this will be superceeded by the
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code below. */
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address = FRAME_CHAIN_COMBINE (address, next_frame);
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}
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prev = (struct frame_info *)
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obstack_alloc (&frame_cache_obstack,
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sizeof (struct frame_info));
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if (next_frame)
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next_frame->prev = prev;
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prev->next = next_frame;
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prev->prev = (struct frame_info *) 0;
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prev->frame = address;
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prev->next_frame = prev->next ? prev->next->frame : 0;
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#ifdef INIT_EXTRA_FRAME_INFO
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INIT_EXTRA_FRAME_INFO(prev);
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#endif
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/* This entry is in the frame queue now, which is good since
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FRAME_SAVED_PC may use that queue to figure out it's value
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(see m-sparc.h). We want the pc saved in the inferior frame. */
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prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (next_frame) :
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next_frame ? FRAME_SAVED_PC (next_frame) : read_pc ());
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return prev;
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}
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CORE_ADDR
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get_frame_pc (frame)
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FRAME frame;
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{
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struct frame_info *fi;
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fi = get_frame_info (frame);
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return fi->pc;
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}
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/* Find the addresses in which registers are saved in FRAME. */
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void
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get_frame_saved_regs (frame_info_addr, saved_regs_addr)
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struct frame_info *frame_info_addr;
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struct frame_saved_regs *saved_regs_addr;
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{
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FRAME_FIND_SAVED_REGS (frame_info_addr, *saved_regs_addr);
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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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struct block *
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get_frame_block (frame)
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FRAME frame;
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{
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struct frame_info *fi;
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fi = get_frame_info (frame);
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return block_for_pc (fi->pc);
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}
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struct block *
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get_current_block ()
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{
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return block_for_pc (read_pc ());
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}
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CORE_ADDR
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get_pc_function_start (pc)
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CORE_ADDR pc;
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{
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register struct block *bl = block_for_pc (pc);
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register struct symbol *symbol;
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if (bl == 0 || (symbol = block_function (bl)) == 0)
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{
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register int misc_index = find_pc_misc_function (pc);
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if (misc_index >= 0)
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return misc_function_vector[misc_index].address;
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return 0;
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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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/* Return the symbol for the function executing in frame FRAME. */
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struct symbol *
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get_frame_function (frame)
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FRAME frame;
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{
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register struct block *bl = get_frame_block (frame);
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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 innermost lexical block containing the specified pc value,
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or 0 if there is none. */
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extern struct symtab *psymtab_to_symtab ();
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struct block *
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block_for_pc (pc)
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register CORE_ADDR pc;
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{
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register struct block *b;
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register int bot, top, half;
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register struct symtab *s;
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register struct partial_symtab *ps;
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struct blockvector *bl;
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/* First search all symtabs for one whose file contains our pc */
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for (s = symtab_list; s; s = s->next)
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{
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bl = BLOCKVECTOR (s);
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b = BLOCKVECTOR_BLOCK (bl, 0);
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if (BLOCK_START (b) <= pc
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&& BLOCK_END (b) > pc)
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break;
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}
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if (s == 0)
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for (ps = partial_symtab_list; ps; ps = ps->next)
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{
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if (ps->textlow <= pc
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&& ps->texthigh > pc)
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{
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if (ps->readin)
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fatal ("Internal error: pc found in readin psymtab and not in any symtab.");
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s = psymtab_to_symtab (ps);
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bl = BLOCKVECTOR (s);
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b = BLOCKVECTOR_BLOCK (bl, 0);
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break;
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}
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}
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if (s == 0)
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return 0;
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/* Then search that symtab for the smallest block that wins. */
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/* Use binary search to find the last block that starts before PC. */
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bot = 0;
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top = BLOCKVECTOR_NBLOCKS (bl);
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while (top - bot > 1)
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{
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half = (top - bot + 1) >> 1;
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b = BLOCKVECTOR_BLOCK (bl, bot + half);
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if (BLOCK_START (b) <= pc)
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bot += half;
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else
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top = bot + half;
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}
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/* Now search backward for a block that ends after PC. */
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while (bot >= 0)
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{
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b = BLOCKVECTOR_BLOCK (bl, bot);
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if (BLOCK_END (b) > pc)
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return b;
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bot--;
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}
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return 0;
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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. */
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struct symbol *
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find_pc_function (pc)
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CORE_ADDR pc;
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{
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register struct block *b = block_for_pc (pc);
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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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/* Finds the "function" (text symbol) that is smaller than PC
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but greatest of all of the potential text symbols. Sets
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*NAME and/or *ADDRESS conditionally if that pointer is non-zero.
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Returns 0 if it couldn't find anything, 1 if it did. */
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int
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find_pc_partial_function (pc, name, address)
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CORE_ADDR pc;
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char **name;
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CORE_ADDR *address;
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{
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struct partial_symtab *pst = find_pc_psymtab (pc);
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struct symbol *f;
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int miscfunc;
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struct partial_symbol *psb;
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if (pst)
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{
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if (pst->readin)
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{
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/* The information we want has already been read in.
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We can go to the already readin symbols and we'll get
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the best possible answer. */
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f = find_pc_function (pc);
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if (!f)
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{
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/* No availible symbol. */
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if (name != 0)
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*name = 0;
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if (address != 0)
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*address = 0;
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return 0;
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}
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if (name)
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*name = SYMBOL_NAME (f);
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if (address)
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*address = SYMBOL_VALUE (f);
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}
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/* Get the information from a combination of the pst
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(static symbols), and the misc function vector (extern
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symbols). */
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miscfunc = find_pc_misc_function (pc);
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psb = find_pc_psymbol (pst, pc);
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if (!psb && miscfunc == -1)
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{
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if (address != 0)
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*address = 0;
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if (name != 0)
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*name = 0;
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return 0;
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}
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if (!psb
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|| (miscfunc != -1
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&& SYMBOL_VALUE(psb) < misc_function_vector[miscfunc].address))
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{
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if (address)
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*address = misc_function_vector[miscfunc].address;
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if (name)
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*name = misc_function_vector[miscfunc].name;
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}
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else
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{
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if (address)
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*address = SYMBOL_VALUE (psb);
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if (name)
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*name = SYMBOL_NAME (psb);
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}
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}
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else
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/* Must be in the misc function stuff. */
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{
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miscfunc = find_pc_misc_function (pc);
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if (miscfunc == -1)
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return 0;
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if (address)
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*address = misc_function_vector[miscfunc].address;
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if (name)
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*name = misc_function_vector[miscfunc].name;
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}
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return 1;
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}
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/* Find the misc function whose address is the largest
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while being less than PC. Return its index in misc_function_vector.
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Returns -1 if PC is not in suitable range. */
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int
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find_pc_misc_function (pc)
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register CORE_ADDR pc;
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{
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register int lo = 0;
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register int hi = misc_function_count-1;
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register int new;
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register int distance;
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/* Note that the last thing in the vector is always _etext. */
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/* Actually, "end", now that non-functions
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go on the misc_function_vector. */
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/* Above statement is not *always* true - fix for case where there are */
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/* no misc functions at all (ie no symbol table has been read). */
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if (hi < 0) return -1; /* no misc functions recorded */
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/* trivial reject range test */
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if (pc < misc_function_vector[0].address ||
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pc > misc_function_vector[hi].address)
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return -1;
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/* Note that the following search will not return hi if
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pc == misc_function_vector[hi].address. If "end" points to the
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first unused location, this is correct and the above test
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simply needs to be changed to
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"pc >= misc_function_vector[hi].address". */
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do {
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new = (lo + hi) >> 1;
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distance = misc_function_vector[new].address - pc;
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if (distance == 0)
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return new; /* an exact match */
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else if (distance > 0)
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hi = new;
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else
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lo = new;
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} while (hi-lo != 1);
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/* if here, we had no exact match, so return the lower choice */
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return lo;
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}
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/* Return the innermost stack frame executing inside of the specified block,
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or zero if there is no such frame. */
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||
|
||
FRAME
|
||
block_innermost_frame (block)
|
||
struct block *block;
|
||
{
|
||
struct frame_info *fi;
|
||
register FRAME frame;
|
||
register CORE_ADDR start = BLOCK_START (block);
|
||
register CORE_ADDR end = BLOCK_END (block);
|
||
|
||
frame = 0;
|
||
while (1)
|
||
{
|
||
frame = get_prev_frame (frame);
|
||
if (frame == 0)
|
||
return 0;
|
||
fi = get_frame_info (frame);
|
||
if (fi->pc >= start && fi->pc < end)
|
||
return frame;
|
||
}
|
||
}
|
||
|
||
void
|
||
_initialize_blockframe ()
|
||
{
|
||
obstack_init (&frame_cache_obstack);
|
||
}
|