* blockframe.c, frame.h (sigtramp_saved_pc): New routine to fetch

	the saved pc from sigcontext on the stack for BSD signal handling.
	* config/i386/tm-i386bsd.h (SIGTRAMP_START, SIGTRAMP_END, FRAME_CHAIN,
	FRAMELESS_FUNCTION_INVOCATION, FRAME_SAVED_PC, SIGCONTEXT_PC_OFFSET):
	Define to make backtracing through sigtramp work.
	* config/vax/tm-vax.h (SIGTRAMP_START, SIGTRAMP_END, TARGET_UPAGES,
	FRAME_SAVED_PC, SIGCONTEXT_PC_OFFSET):  Ditto.

1 files changed, 203 insertions, 75 deletions

diff --git a/gdb/frame.h b/gdb/frame.h
index 5c98c9c..c0da682 100644
--- a/gdb/frame.h
+++ b/gdb/frame.h
@@ -1,81 +1,113 @@
 /* Definitions for dealing with stack frames, for GDB, the GNU debugger.
-   Copyright (C) 1986, 1989 Free Software Foundation, Inc.
+   Copyright 1986, 1989, 1991, 1992 Free Software Foundation, Inc.
 
 This file is part of GDB.
 
-GDB is free software; you can redistribute it and/or modify
+This program 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)
-any later version.
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
 
-GDB is distributed in the hope that it will be useful,
+This program 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.  */
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 
 #if !defined (FRAME_H)
 #define FRAME_H 1
-#include "param.h"
-
-/*
- * FRAME is the type of the identifier of a specific stack frame.  It
- * is a pointer to the frame cache item corresponding to this frame.
- * Please note that frame id's are *not* constant over calls to the
- * inferior.  Use frame addresses, which are.
- *
- * FRAME_ADDR is the type of the address of a specific frame.  I
- * cannot imagine a case in which this would not be CORE_ADDR, so
- * maybe it's silly to give it it's own type.  Life's rough.
- *
- * FRAME_FP is a macro which converts from a frame identifier into a
- * frame_address.
- *
- * FRAME_INFO_ID is a macro which "converts" from a frame info pointer
- * to a frame id.  This is here in case I or someone else decides to
- * change the FRAME type again.
- *
- * This file and blockframe.c are the only places which are allowed to
- * use the equivalence between FRAME and struct frame_info *.  EXCEPTION:
- * value.h uses CORE_ADDR instead of FRAME_ADDR because the compiler
- * will accept that in the absense of this file.
- */
+
+/* A FRAME identifies a specific stack frame.  It is not constant over
+   calls to the inferior (frame addresses are, see below).
+
+   This is implemented as a "struct frame_info *".  This file and
+   blockframe.c are the only places which are allowed to use the
+   equivalence between FRAME and struct frame_info *.  Exception:
+   Prototypes in other files use "struct frame_info *" because this
+   file might not be included.
+
+   The distinction between a FRAME and a "struct frame_info *" is made
+   with the idea of maybe someday changing a FRAME to be something else,
+   but seems to me that a "struct frame_info *" is fully general (since
+   any necessarily fields can be added; changing the meaning of existing
+   fields is not helped by the FRAME distinction), and this distinction
+   merely creates unnecessary hair.  -kingdon, 18 May 93.  */
 typedef struct frame_info *FRAME;
+
+/* Convert from a "struct frame_info *" into a FRAME.  */
+#define FRAME_INFO_ID(f)	(f)
+
+/* Convert from a FRAME into a "struct frame_info *".  */
+extern struct frame_info *
+get_frame_info PARAMS ((FRAME));
+
+/* Type of the address of a frame.  It is widely assumed (at least in
+   prototypes in headers which might not include this header) that
+   this is the same as CORE_ADDR, and no one can think of a case in
+   which it wouldn't be, so it might be best to remove this typedef.  */
 typedef CORE_ADDR	FRAME_ADDR;
+
+/* Convert from a FRAME into a frame address.  Except in the
+   machine-dependent *FRAME* macros, a frame address has no defined
+   meaning other than as a magic cookie which identifies a frame over
+   calls to the inferior.  The only known exception is inferior.h
+   (PC_IN_CALL_DUMMY) [ON_STACK]; see comments there.  You cannot
+   assume that a frame address contains enough information to
+   reconstruct the frame; if you want more than just to identify the
+   frame (e.g. be able to fetch variables relative to that frame),
+   then save the whole struct frame_info (and the next struct
+   frame_info, since the latter is used for fetching variables on some
+   machines).  */
+
 #define FRAME_FP(fr)	((fr)->frame)
-#define FRAME_INFO_ID(f)	(f)
 
-/*
- * Caching structure for stack frames.  This is also the structure
- * used for extended info about stack frames.  May add more to this
- * structure as it becomes necessary.
- *
- * Note that the first entry in the cache will always refer to the
- * innermost executing frame.  This value should be set (is it?
- * Check) in something like normal_stop.
- */
+/* We keep a cache of stack frames, each of which is a "struct
+   frame_info".  The innermost one gets allocated (in
+   wait_for_inferior) each time the inferior stops; current_frame
+   points to it.  Additional frames get allocated (in
+   get_prev_frame_info) as needed, and are chained through the next
+   and prev fields.  Any time that the frame cache becomes invalid
+   (most notably when we execute something, but also if we change how
+   we interpret the frames (e.g. "set heuristic-fence-post" in
+   mips-tdep.c, or anything which reads new symbols)), we should call
+   reinit_frame_cache.  */
+
 struct frame_info
   {
-    /* Nominal address of the frame described.  */
+    /* Nominal address of the frame described.  See comments at FRAME_FP
+       about what this means outside the *FRAME* macros; in the *FRAME*
+       macros, it can mean whatever makes most sense for this machine.  */
     FRAME_ADDR frame;
+
     /* Address at which execution is occurring in this frame.
        For the innermost frame, it's the current pc.
        For other frames, it is a pc saved in the next frame.  */
     CORE_ADDR pc;
-    /* The frame called by the frame we are describing, or 0.
-       This may be set even if there isn't a frame called by the one
-       we are describing (.->next == 0); in that case it is simply the
-       bottom of this frame */
-    FRAME_ADDR next_frame;
+
+    /* Nonzero if this is a frame associated with calling a signal handler.
+
+       Set by machine-dependent code.  On some machines, if
+       the machine-dependent code fails to check for this, the backtrace
+       will look relatively normal.  For example, on the i386
+         #3  0x158728 in sighold ()
+       On other machines (e.g. rs6000), the machine-dependent code better
+       set this to prevent us from trying to print it like a normal frame.  */
+    int signal_handler_caller;
+
     /* Anything extra for this structure that may have been defined
        in the machine depedent files. */
 #ifdef EXTRA_FRAME_INFO
     EXTRA_FRAME_INFO
 #endif
-    /* Pointers to the next and previous frame_info's in this stack.  */
+
+    /* We should probably also store a "struct frame_saved_regs" here.
+       This is already done by some machines (e.g. config/m88k/tm-m88k.h)
+       but there is no reason it couldn't be general.  */
+
+    /* Pointers to the next and previous frame_info's in the frame cache.  */
     FRAME next, prev;
   };
 
@@ -83,46 +115,142 @@ struct frame_info
 
 struct frame_saved_regs
   {
-    /* For each register, address of where it was saved on entry to the frame,
-       or zero if it was not saved on entry to this frame.  */
+
+    /* For each register, address of where it was saved on entry to
+       the frame, or zero if it was not saved on entry to this frame.
+       This includes special registers such as pc and fp saved in
+       special ways in the stack frame.  The SP_REGNUM is even more
+       special, the address here is the sp for the next frame, not the
+       address where the sp was saved.  */
+
     CORE_ADDR regs[NUM_REGS];
   };
 
+/* Define a default FRAME_CHAIN_VALID, in the form that is suitable for most
+   targets.  If FRAME_CHAIN_VALID returns zero it means that the given frame
+   is the outermost one and has no caller.
+
+   If a particular target needs a different definition, then it can override
+   the definition here by providing one in the tm file. */
+
+#if !defined (FRAME_CHAIN_VALID)
+
+#if defined (FRAME_CHAIN_VALID_ALTERNATE)
+
+/* Use the alternate method of avoiding running up off the end of the frame
+   chain or following frames back into the startup code.  See the comments
+   in objfiles.h. */
+   
+#define FRAME_CHAIN_VALID(chain, thisframe)	\
+  ((chain) != 0					\
+   && !inside_main_func ((thisframe) -> pc)	\
+   && !inside_entry_func ((thisframe) -> pc))
+
+#else
+
+#define FRAME_CHAIN_VALID(chain, thisframe)	\
+  ((chain) != 0					\
+   && !inside_entry_file (FRAME_SAVED_PC (thisframe)))
+
+#endif	/* FRAME_CHAIN_VALID_ALTERNATE */
+
+#endif	/* FRAME_CHAIN_VALID */
+
+/* If we encounter a request to use base register addressing of variables
+   on a machine for which gdb has not been configured to support such
+   access, report the failure to support this access mode. */
+
+#if !defined (FRAME_GET_BASEREG_VALUE)
+
+#define FRAME_GET_BASEREG_VALUE(frame, regno) \
+  (error ("Missing valid method for finding contents of base register."),0)
+
+#endif
+
 /* The stack frame that the user has specified for commands to act on.
    Note that one cannot assume this is the address of valid data.  */
 
 extern FRAME selected_frame;
 
-extern struct frame_info *get_frame_info ();
-extern struct frame_info *get_prev_frame_info ();
+/* Level of the selected frame:
+   0 for innermost, 1 for its caller, ...
+   or -1 for frame specified by address with no defined level.  */
+
+extern int selected_frame_level;
+
+extern struct frame_info *
+get_prev_frame_info PARAMS ((FRAME));
+
+extern FRAME
+create_new_frame PARAMS ((FRAME_ADDR, CORE_ADDR));
+
+extern void
+flush_cached_frames PARAMS ((void));
+
+extern void
+reinit_frame_cache PARAMS ((void));
+
+extern void
+get_frame_saved_regs PARAMS ((struct frame_info *, struct frame_saved_regs *));
+
+extern void
+set_current_frame PARAMS ((FRAME));
+
+extern FRAME
+get_prev_frame PARAMS ((FRAME));
+
+extern FRAME
+get_current_frame PARAMS ((void));
+
+extern FRAME
+get_next_frame PARAMS ((FRAME));
+
+extern struct block *
+get_frame_block PARAMS ((FRAME));
+
+extern struct block *
+get_current_block PARAMS ((void));
+
+extern struct block *
+get_selected_block PARAMS ((void));
+
+extern struct symbol *
+get_frame_function PARAMS ((FRAME));
+
+extern CORE_ADDR
+get_frame_pc PARAMS ((FRAME));
+
+extern CORE_ADDR
+get_pc_function_start PARAMS ((CORE_ADDR));
+
+extern struct block *
+block_for_pc PARAMS ((CORE_ADDR));
+
+extern int
+frameless_look_for_prologue PARAMS ((FRAME));
+
+extern void
+print_frame_args PARAMS ((struct symbol *, struct frame_info *, int, FILE *));
 
-extern FRAME create_new_frame ();
-extern void  flush_cached_frames ();
+extern FRAME
+find_relative_frame PARAMS ((FRAME, int*));
 
-extern void get_frame_saved_regs ();
+extern void
+print_stack_frame PARAMS ((FRAME, int, int));
 
-extern void  set_current_frame ();
-extern FRAME get_prev_frame ();
-extern FRAME get_current_frame ();
-extern FRAME get_next_frame ();
+extern void
+select_frame PARAMS ((FRAME, int));
 
-extern struct block *get_frame_block ();
-extern struct block *get_current_block ();
-extern struct block *get_selected_block ();
-extern struct symbol *get_frame_function ();
-extern CORE_ADDR get_frame_pc ();
-extern CORE_ADDR get_pc_function_start ();
-struct block *block_for_pc ();
+extern void
+record_selected_frame PARAMS ((FRAME_ADDR *, int *));
 
-int frameless_look_for_prologue ();
+extern void
+print_frame_info PARAMS ((struct frame_info *, int, int, int));
 
-void print_frame_args ();
+extern CORE_ADDR
+find_saved_register PARAMS ((FRAME, int));
 
-/* In stack.c */
-extern FRAME find_relative_frame ();
-extern void print_selected_frame ();
-extern void print_sel_frame ();
-extern void select_frame ();
-extern void record_selected_frame ();
+extern CORE_ADDR
+sigtramp_saved_pc PARAMS ((FRAME));
 
-#endif /* frame.h not already included.  */
+#endif /* !defined (FRAME_H)  */