* This code is derived from software copyrighted by the Free Software
* Modified 1991 by Donn Seeley at UUNET Technologies, Inc.
* Modified 1990 by Van Jacobson at Lawrence Berkeley Laboratory.
static char sccsid
[] = "@(#)blockframe.c 6.4 (Berkeley) 5/11/91";
/* Get info from stack frames;
convert between frames, blocks, functions and pc values.
Copyright (C) 1986, 1987, 1988, 1989 Free Software Foundation, Inc.
This file is part of GDB.
GDB is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 1, or (at your option)
GDB is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GDB; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
#if defined(NEWVM) && defined(KERNELDEBUG)
#include <sys/param.h> /* XXX for FRAME_CHAIN_VALID */
/* Start and end of object file containing the entry point.
STARTUP_FILE_END is the first address of the next file.
This file is assumed to be a startup file
and frames with pc's inside it
are treated as nonexistent.
Setting these variables is necessary so that backtraces do not fly off
the bottom of the stack. */
CORE_ADDR startup_file_start
;
CORE_ADDR startup_file_end
;
/* Is ADDR outside the startup file? */
outside_startup_file (addr
)
return !(addr
>= startup_file_start
&& addr
< startup_file_end
);
/* Address of innermost stack frame (contents of FP register) */
static FRAME current_frame
;
struct block
*block_for_pc ();
CORE_ADDR
get_pc_function_start ();
* Cache for frame addresses already read by gdb. Valid only while
* inferior is stopped. Control variables for the frame cache should
* be local to this module.
struct obstack frame_cache_obstack
;
/* Return the innermost (currently executing) stack frame. */
/* We assume its address is kept in a general register;
param.h says which register. */
set_current_frame (frame
)
create_new_frame (addr
, pc
)
struct frame_info
*fci
; /* Same type as FRAME */
fci
= (struct frame_info
*)
obstack_alloc (&frame_cache_obstack
,
sizeof (struct frame_info
));
fci
->next
= (struct frame_info
*) 0;
fci
->prev
= (struct frame_info
*) 0;
fci
->next_frame
= 0; /* Since arbitrary */
#ifdef INIT_EXTRA_FRAME_INFO
INIT_EXTRA_FRAME_INFO (fci
);
/* Return the frame that called FRAME.
If FRAME is the original frame (it has no caller), return 0. */
/* We're allowed to know that FRAME and "struct frame_info *" are
return get_prev_frame_info (frame
);
/* Return the frame that FRAME calls (0 if FRAME is the innermost
/* We're allowed to know that FRAME and "struct frame_info *" are
* Flush the entire frame cache.
/* Since we can't really be sure what the first object allocated was */
obstack_free (&frame_cache_obstack
, 0);
obstack_init (&frame_cache_obstack
);
current_frame
= (struct frame_info
*) 0; /* Invalidate cache */
/* Return a structure containing various interesting information
about a specified stack frame. */
/* How do I justify including this function? Well, the FRAME
identifier format has gone through several changes recently, and
it's not completely inconceivable that it could happen again. If
it does, have this routine around will help */
/* If a machine allows frameless functions, it should define a macro
FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) in param.h. FI is the struct
frame_info for the frame, and FRAMELESS should be set to nonzero
if it represents a frameless function invocation. */
/* Many machines which allow frameless functions can detect them using
this macro. Such machines should define FRAMELESS_FUNCTION_INVOCATION
to just call this macro. */
#define FRAMELESS_LOOK_FOR_PROLOGUE(FI, FRAMELESS) \
CORE_ADDR func_start, after_prologue; \
func_start = (get_pc_function_start ((FI)->pc) + \
FUNCTION_START_OFFSET); \
after_prologue = func_start; \
SKIP_PROLOGUE (after_prologue); \
(FRAMELESS) = (after_prologue == func_start); \
/* If we can't find the start of the function, we don't really */ \
/* know whether the function is frameless, but we should be */ \
/* able to get a reasonable (i.e. best we can do under the */ \
/* circumstances) backtrace by saying that it isn't. */ \
/* Return a structure containing various interesting information
about the frame that called NEXT_FRAME. Returns NULL
if there is no such frame. */
get_prev_frame_info (next_frame
)
/* If the requested entry is in the cache, return it.
Otherwise, figure out what the address should be for the entry
we're about to add to the cache. */
if (!have_inferior_p () && !have_core_file_p ())
fatal ("get_prev_frame_info: Called before cache primed. \"Shouldn't happen.\"");
error ("No inferior or core file.");
/* If we have the prev one, return it */
/* On some machines it is possible to call a function without
setting up a stack frame for it. On these machines, we
define this macro to take two args; a frameinfo pointer
identifying a frame and a variable to set or clear if it is
#ifdef FRAMELESS_FUNCTION_INVOCATION
/* Still don't want to worry about this except on the innermost
frame. This macro will set FROMLEAF if NEXT_FRAME is a
frameless function invocation. */
FRAMELESS_FUNCTION_INVOCATION (next_frame
, fromleaf
);
address
= next_frame
->frame
;
/* Two macros defined in param.h specify the machine-dependent
actions to be performed here.
First, get the frame's chain-pointer.
If that is zero, the frame is the outermost frame or a leaf
called by the outermost frame. This means that if start
calls main without a frame, we'll return 0 (which is fine
Nope; there's a problem. This also returns when the current
routine is a leaf of main. This is unacceptable. We move
this to after the ffi test; I'd rather have backtraces from
start go curfluy than have an abort called from main not show
address
= FRAME_CHAIN (next_frame
);
if (!FRAME_CHAIN_VALID (address
, next_frame
))
/* If this frame is a leaf, this will be superceeded by the
address
= FRAME_CHAIN_COMBINE (address
, next_frame
);
prev
= (struct frame_info
*)
obstack_alloc (&frame_cache_obstack
,
sizeof (struct frame_info
));
prev
->prev
= (struct frame_info
*) 0;
prev
->next_frame
= prev
->next
? prev
->next
->frame
: 0;
#ifdef INIT_EXTRA_FRAME_INFO
INIT_EXTRA_FRAME_INFO(prev
);
/* This entry is in the frame queue now, which is good since
FRAME_SAVED_PC may use that queue to figure out it's value
(see m-sparc.h). We want the pc saved in the inferior frame. */
prev
->pc
= (fromleaf
? SAVED_PC_AFTER_CALL (next_frame
) :
next_frame
? FRAME_SAVED_PC (next_frame
) : read_pc ());
fi
= get_frame_info (frame
);
/* Find the addresses in which registers are saved in FRAME. */
get_frame_saved_regs (frame_info_addr
, saved_regs_addr
)
struct frame_info
*frame_info_addr
;
struct frame_saved_regs
*saved_regs_addr
;
FRAME_FIND_SAVED_REGS (frame_info_addr
, *saved_regs_addr
);
/* Return the innermost lexical block in execution
in a specified stack frame. The frame address is assumed valid. */
fi
= get_frame_info (frame
);
/* We are not in the innermost frame. We need to subtract one to
get the correct block, in case the call instruction was the
last instruction of the block. If there are any machines on
which the saved pc does not point to after the call insn, we
probably want to make fi->pc point after the call insn anyway. */
return block_for_pc (pc
);
return block_for_pc (read_pc ());
get_pc_function_start (pc
)
register struct block
*bl
= block_for_pc (pc
);
register struct symbol
*symbol
;
if (bl
== 0 || (symbol
= block_function (bl
)) == 0)
register int misc_index
= find_pc_misc_function (pc
);
return misc_function_vector
[misc_index
].address
;
bl
= SYMBOL_BLOCK_VALUE (symbol
);
/* Return the symbol for the function executing in frame FRAME. */
get_frame_function (frame
)
register struct block
*bl
= get_frame_block (frame
);
return block_function (bl
);
/* Return the innermost lexical block containing the specified pc value,
or 0 if there is none. */
extern struct symtab
*psymtab_to_symtab ();
register struct block
*b
;
register int bot
, top
, half
;
register struct symtab
*s
;
register struct partial_symtab
*ps
;
/* First search all symtabs for one whose file contains our pc */
for (s
= symtab_list
; s
; s
= s
->next
)
b
= BLOCKVECTOR_BLOCK (bl
, 0);
if (BLOCK_START (b
) <= pc
for (ps
= partial_symtab_list
; ps
; ps
= ps
->next
)
fatal ("Internal error: pc found in readin psymtab and not in any symtab.");
s
= psymtab_to_symtab (ps
);
b
= BLOCKVECTOR_BLOCK (bl
, 0);
/* Then search that symtab for the smallest block that wins. */
/* Use binary search to find the last block that starts before PC. */
top
= BLOCKVECTOR_NBLOCKS (bl
);
half
= (top
- bot
+ 1) >> 1;
b
= BLOCKVECTOR_BLOCK (bl
, bot
+ half
);
if (BLOCK_START (b
) <= pc
)
/* Now search backward for a block that ends after PC. */
b
= BLOCKVECTOR_BLOCK (bl
, bot
);
/* Return the function containing pc value PC.
Returns 0 if function is not known. */
register struct block
*b
= block_for_pc (pc
);
return block_function (b
);
/* Finds the "function" (text symbol) that is smaller than PC
but greatest of all of the potential text symbols. Sets
*NAME and/or *ADDRESS conditionally if that pointer is non-zero.
Returns 0 if it couldn't find anything, 1 if it did. On a zero
return, *NAME and *ADDRESS are always set to zero. On a 1 return,
*NAME and *ADDRESS contain real information. */
find_pc_partial_function (pc
, name
, address
)
struct partial_symtab
*pst
= find_pc_psymtab (pc
);
struct partial_symbol
*psb
;
/* The information we want has already been read in.
We can go to the already readin symbols and we'll get
the best possible answer. */
f
= find_pc_function (pc
);
/* No availible symbol. */
*address
= BLOCK_START (SYMBOL_BLOCK_VALUE (f
));
/* Get the information from a combination of the pst
(static symbols), and the misc function vector (extern
miscfunc
= find_pc_misc_function (pc
);
psb
= find_pc_psymbol (pst
, pc
);
if (!psb
&& miscfunc
== -1)
< misc_function_vector
[miscfunc
].address
)))
*address
= misc_function_vector
[miscfunc
].address
;
*name
= misc_function_vector
[miscfunc
].name
;
*address
= SYMBOL_VALUE (psb
);
*name
= SYMBOL_NAME (psb
);
/* Must be in the misc function stuff. */
miscfunc
= find_pc_misc_function (pc
);
*address
= misc_function_vector
[miscfunc
].address
;
*name
= misc_function_vector
[miscfunc
].name
;
/* Find the misc function whose address is the largest
while being less than PC. Return its index in misc_function_vector.
Returns -1 if PC is not in suitable range. */
find_pc_misc_function (pc
)
register int hi
= misc_function_count
-1;
/* Note that the last thing in the vector is always _etext. */
/* Actually, "end", now that non-functions
go on the misc_function_vector. */
/* Above statement is not *always* true - fix for case where there are */
/* no misc functions at all (ie no symbol table has been read). */
if (hi
< 0) return -1; /* no misc functions recorded */
/* trivial reject range test */
if (pc
< misc_function_vector
[0].address
||
pc
> misc_function_vector
[hi
].address
)
/* Note that the following search will not return hi if
pc == misc_function_vector[hi].address. If "end" points to the
first unused location, this is correct and the above test
simply needs to be changed to
"pc >= misc_function_vector[hi].address". */
distance
= misc_function_vector
[new].address
- pc
;
return new; /* an exact match */
/* if here, we had no exact match, so return the lower choice */
/* Return the innermost stack frame executing inside of the specified block,
or zero if there is no such frame. */
block_innermost_frame (block
)
register CORE_ADDR start
= BLOCK_START (block
);
register CORE_ADDR end
= BLOCK_END (block
);
frame
= get_prev_frame (frame
);
fi
= get_frame_info (frame
);
if (fi
->pc
>= start
&& fi
->pc
< end
)
_initialize_blockframe ()
obstack_init (&frame_cache_obstack
);