| /* Definitions for a frame unwinder, for GDB, the GNU debugger. |
| |
| Copyright (C) 2003-2004, 2007-2012 Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| 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 3 of the License, or |
| (at your option) any later version. |
| |
| 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 this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| #if !defined (FRAME_UNWIND_H) |
| #define FRAME_UNWIND_H 1 |
| |
| struct frame_data; |
| struct frame_info; |
| struct frame_id; |
| struct frame_unwind; |
| struct gdbarch; |
| struct regcache; |
| struct value; |
| |
| #include "frame.h" /* For enum frame_type. */ |
| |
| /* The following unwind functions assume a chain of frames forming the |
| sequence: (outer) prev <-> this <-> next (inner). All the |
| functions are called with this frame's `struct frame_info' and |
| prologue cache. |
| |
| THIS frame's register values can be obtained by unwinding NEXT |
| frame's registers (a recursive operation). |
| |
| THIS frame's prologue cache can be used to cache information such |
| as where this frame's prologue stores the previous frame's |
| registers. */ |
| |
| /* Given THIS frame, take a whiff of its registers (namely |
| the PC and attributes) and if SELF is the applicable unwinder, |
| return non-zero. Possibly also initialize THIS_PROLOGUE_CACHE; but |
| only if returning 1. Initializing THIS_PROLOGUE_CACHE in other |
| cases (0 return, or exception) is invalid. */ |
| |
| typedef int (frame_sniffer_ftype) (const struct frame_unwind *self, |
| struct frame_info *this_frame, |
| void **this_prologue_cache); |
| |
| typedef enum unwind_stop_reason (frame_unwind_stop_reason_ftype) |
| (struct frame_info *this_frame, void **this_prologue_cache); |
| |
| /* A default frame sniffer which always accepts the frame. Used by |
| fallback prologue unwinders. */ |
| |
| int default_frame_sniffer (const struct frame_unwind *self, |
| struct frame_info *this_frame, |
| void **this_prologue_cache); |
| |
| /* A default stop_reason callback which always claims the frame is |
| unwindable. */ |
| |
| enum unwind_stop_reason |
| default_frame_unwind_stop_reason (struct frame_info *this_frame, |
| void **this_cache); |
| |
| /* Assuming the frame chain: (outer) prev <-> this <-> next (inner); |
| use THIS frame, and through it the NEXT frame's register unwind |
| method, to determine the frame ID of THIS frame. |
| |
| A frame ID provides an invariant that can be used to re-identify an |
| instance of a frame. It is a combination of the frame's `base' and |
| the frame's function's code address. |
| |
| Traditionally, THIS frame's ID was determined by examining THIS |
| frame's function's prologue, and identifying the register/offset |
| used as THIS frame's base. |
| |
| Example: An examination of THIS frame's prologue reveals that, on |
| entry, it saves the PC(+12), SP(+8), and R1(+4) registers |
| (decrementing the SP by 12). Consequently, the frame ID's base can |
| be determined by adding 12 to the THIS frame's stack-pointer, and |
| the value of THIS frame's SP can be obtained by unwinding the NEXT |
| frame's SP. |
| |
| THIS_PROLOGUE_CACHE can be used to share any prolog analysis data |
| with the other unwind methods. Memory for that cache should be |
| allocated using FRAME_OBSTACK_ZALLOC(). */ |
| |
| typedef void (frame_this_id_ftype) (struct frame_info *this_frame, |
| void **this_prologue_cache, |
| struct frame_id *this_id); |
| |
| /* Assuming the frame chain: (outer) prev <-> this <-> next (inner); |
| use THIS frame, and implicitly the NEXT frame's register unwind |
| method, to unwind THIS frame's registers (returning the value of |
| the specified register REGNUM in the previous frame). |
| |
| Traditionally, THIS frame's registers were unwound by examining |
| THIS frame's function's prologue and identifying which registers |
| that prolog code saved on the stack. |
| |
| Example: An examination of THIS frame's prologue reveals that, on |
| entry, it saves the PC(+12), SP(+8), and R1(+4) registers |
| (decrementing the SP by 12). Consequently, the value of the PC |
| register in the previous frame is found in memory at SP+12, and |
| THIS frame's SP can be obtained by unwinding the NEXT frame's SP. |
| |
| This function takes THIS_FRAME as an argument. It can find the |
| values of registers in THIS frame by calling get_frame_register |
| (THIS_FRAME), and reinvoke itself to find other registers in the |
| PREVIOUS frame by calling frame_unwind_register (THIS_FRAME). |
| |
| The result is a GDB value object describing the register value. It |
| may be a lazy reference to memory, a lazy reference to the value of |
| a register in THIS frame, or a non-lvalue. |
| |
| THIS_PROLOGUE_CACHE can be used to share any prolog analysis data |
| with the other unwind methods. Memory for that cache should be |
| allocated using FRAME_OBSTACK_ZALLOC(). */ |
| |
| typedef struct value * (frame_prev_register_ftype) |
| (struct frame_info *this_frame, void **this_prologue_cache, |
| int regnum); |
| |
| /* Deallocate extra memory associated with the frame cache if any. */ |
| |
| typedef void (frame_dealloc_cache_ftype) (struct frame_info *self, |
| void *this_cache); |
| |
| /* Assuming the frame chain: (outer) prev <-> this <-> next (inner); |
| use THIS frame, and implicitly the NEXT frame's register unwind |
| method, return PREV frame's architecture. */ |
| |
| typedef struct gdbarch *(frame_prev_arch_ftype) (struct frame_info *this_frame, |
| void **this_prologue_cache); |
| |
| struct frame_unwind |
| { |
| /* The frame's type. Should this instead be a collection of |
| predicates that test the frame for various attributes? */ |
| enum frame_type type; |
| /* Should an attribute indicating the frame's address-in-block go |
| here? */ |
| frame_unwind_stop_reason_ftype *stop_reason; |
| frame_this_id_ftype *this_id; |
| frame_prev_register_ftype *prev_register; |
| const struct frame_data *unwind_data; |
| frame_sniffer_ftype *sniffer; |
| frame_dealloc_cache_ftype *dealloc_cache; |
| frame_prev_arch_ftype *prev_arch; |
| }; |
| |
| /* Register a frame unwinder, _prepending_ it to the front of the |
| search list (so it is sniffed before previously registered |
| unwinders). By using a prepend, later calls can install unwinders |
| that override earlier calls. This allows, for instance, an OSABI |
| to install a more specific sigtramp unwinder that overrides the |
| traditional brute-force unwinder. */ |
| extern void frame_unwind_prepend_unwinder (struct gdbarch *, |
| const struct frame_unwind *); |
| |
| /* Add a frame sniffer to the list. The predicates are polled in the |
| order that they are appended. The initial list contains the dummy |
| frame sniffer. */ |
| |
| extern void frame_unwind_append_unwinder (struct gdbarch *gdbarch, |
| const struct frame_unwind *unwinder); |
| |
| /* Iterate through sniffers for THIS_FRAME frame until one returns with an |
| unwinder implementation. THIS_FRAME->UNWIND must be NULL, it will get set |
| by this function. Possibly initialize THIS_CACHE. */ |
| |
| extern void frame_unwind_find_by_frame (struct frame_info *this_frame, |
| void **this_cache); |
| |
| /* Helper functions for value-based register unwinding. These return |
| a (possibly lazy) value of the appropriate type. */ |
| |
| /* Return a value which indicates that FRAME did not save REGNUM. */ |
| |
| struct value *frame_unwind_got_optimized (struct frame_info *frame, |
| int regnum); |
| |
| /* Return a value which indicates that FRAME copied REGNUM into |
| register NEW_REGNUM. */ |
| |
| struct value *frame_unwind_got_register (struct frame_info *frame, int regnum, |
| int new_regnum); |
| |
| /* Return a value which indicates that FRAME saved REGNUM in memory at |
| ADDR. */ |
| |
| struct value *frame_unwind_got_memory (struct frame_info *frame, int regnum, |
| CORE_ADDR addr); |
| |
| /* Return a value which indicates that FRAME's saved version of |
| REGNUM has a known constant (computed) value of VAL. */ |
| |
| struct value *frame_unwind_got_constant (struct frame_info *frame, int regnum, |
| ULONGEST val); |
| |
| /* Return a value which indicates that FRAME's saved version of |
| REGNUM has a known constant (computed) value which is stored |
| inside BUF. */ |
| |
| struct value *frame_unwind_got_bytes (struct frame_info *frame, int regnum, |
| gdb_byte *buf); |
| |
| /* Return a value which indicates that FRAME's saved version of REGNUM |
| has a known constant (computed) value of ADDR. Convert the |
| CORE_ADDR to a target address if necessary. */ |
| |
| struct value *frame_unwind_got_address (struct frame_info *frame, int regnum, |
| CORE_ADDR addr); |
| |
| #endif |