1 /* Target-dependent code for the ALPHA architecture, for GDB, the GNU Debugger.
2 Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
3 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
32 #include "gdb_string.h"
36 #include "arch-utils.h"
41 #include "alpha-tdep.h"
43 static gdbarch_init_ftype alpha_gdbarch_init
;
45 static gdbarch_register_name_ftype alpha_register_name
;
46 static gdbarch_register_raw_size_ftype alpha_register_raw_size
;
47 static gdbarch_register_virtual_size_ftype alpha_register_virtual_size
;
48 static gdbarch_register_virtual_type_ftype alpha_register_virtual_type
;
49 static gdbarch_register_byte_ftype alpha_register_byte
;
50 static gdbarch_cannot_fetch_register_ftype alpha_cannot_fetch_register
;
51 static gdbarch_cannot_store_register_ftype alpha_cannot_store_register
;
52 static gdbarch_register_convertible_ftype alpha_register_convertible
;
53 static gdbarch_register_convert_to_virtual_ftype
54 alpha_register_convert_to_virtual
;
55 static gdbarch_register_convert_to_raw_ftype alpha_register_convert_to_raw
;
56 static gdbarch_store_struct_return_ftype alpha_store_struct_return
;
57 static gdbarch_deprecated_extract_return_value_ftype alpha_extract_return_value
;
58 static gdbarch_deprecated_extract_struct_value_address_ftype
59 alpha_extract_struct_value_address
;
60 static gdbarch_use_struct_convention_ftype alpha_use_struct_convention
;
62 static gdbarch_breakpoint_from_pc_ftype alpha_breakpoint_from_pc
;
64 static gdbarch_frame_args_address_ftype alpha_frame_args_address
;
65 static gdbarch_frame_locals_address_ftype alpha_frame_locals_address
;
67 static gdbarch_skip_prologue_ftype alpha_skip_prologue
;
68 static gdbarch_saved_pc_after_call_ftype alpha_saved_pc_after_call
;
69 static gdbarch_frame_chain_ftype alpha_frame_chain
;
70 static gdbarch_frame_saved_pc_ftype alpha_frame_saved_pc
;
71 static gdbarch_frame_init_saved_regs_ftype alpha_frame_init_saved_regs
;
73 static gdbarch_push_arguments_ftype alpha_push_arguments
;
74 static gdbarch_push_dummy_frame_ftype alpha_push_dummy_frame
;
75 static gdbarch_pop_frame_ftype alpha_pop_frame
;
76 static gdbarch_fix_call_dummy_ftype alpha_fix_call_dummy
;
77 static gdbarch_init_extra_frame_info_ftype alpha_init_extra_frame_info
;
79 static gdbarch_get_longjmp_target_ftype alpha_get_longjmp_target
;
81 struct frame_extra_info
83 alpha_extra_func_info_t proc_desc
;
88 /* FIXME: Some of this code should perhaps be merged with mips-tdep.c. */
90 /* Prototypes for local functions. */
92 static void alpha_find_saved_regs (struct frame_info
*);
94 static alpha_extra_func_info_t
push_sigtramp_desc (CORE_ADDR low_addr
);
96 static CORE_ADDR
read_next_frame_reg (struct frame_info
*, int);
98 static CORE_ADDR
heuristic_proc_start (CORE_ADDR
);
100 static alpha_extra_func_info_t
heuristic_proc_desc (CORE_ADDR
,
102 struct frame_info
*);
104 static alpha_extra_func_info_t
find_proc_desc (CORE_ADDR
,
105 struct frame_info
*);
108 static int alpha_in_lenient_prologue (CORE_ADDR
, CORE_ADDR
);
111 static void reinit_frame_cache_sfunc (char *, int, struct cmd_list_element
*);
113 static CORE_ADDR
after_prologue (CORE_ADDR pc
,
114 alpha_extra_func_info_t proc_desc
);
116 static int alpha_in_prologue (CORE_ADDR pc
,
117 alpha_extra_func_info_t proc_desc
);
119 static int alpha_about_to_return (CORE_ADDR pc
);
121 void _initialize_alpha_tdep (void);
123 /* Heuristic_proc_start may hunt through the text section for a long
124 time across a 2400 baud serial line. Allows the user to limit this
126 static unsigned int heuristic_fence_post
= 0;
128 /* Layout of a stack frame on the alpha:
131 pdr members: | 7th ... nth arg, |
132 | `pushed' by caller. |
134 ----------------|-------------------------------|<-- old_sp == vfp
137 | |localoff | Copies of 1st .. 6th |
138 | | | | | argument if necessary. |
140 | | | --- |-------------------------------|<-- FRAME_LOCALS_ADDRESS
142 | | | | Locals and temporaries. |
144 | | | |-------------------------------|
146 |-fregoffset | Saved float registers. |
152 | | -------|-------------------------------|
154 | | | Saved registers. |
161 | ----------|-------------------------------|
163 frameoffset | Argument build area, gets |
164 | | 7th ... nth arg for any |
165 | | called procedure. |
167 -------------|-------------------------------|<-- sp
172 #define PROC_LOW_ADDR(proc) ((proc)->pdr.adr) /* least address */
173 /* These next two fields are kind of being hijacked. I wonder if
174 iline is too small for the values it needs to hold, if GDB is
175 running on a 32-bit host. */
176 #define PROC_HIGH_ADDR(proc) ((proc)->pdr.iline) /* upper address bound */
177 #define PROC_DUMMY_FRAME(proc) ((proc)->pdr.cbLineOffset) /*CALL_DUMMY frame */
178 #define PROC_FRAME_OFFSET(proc) ((proc)->pdr.frameoffset)
179 #define PROC_FRAME_REG(proc) ((proc)->pdr.framereg)
180 #define PROC_REG_MASK(proc) ((proc)->pdr.regmask)
181 #define PROC_FREG_MASK(proc) ((proc)->pdr.fregmask)
182 #define PROC_REG_OFFSET(proc) ((proc)->pdr.regoffset)
183 #define PROC_FREG_OFFSET(proc) ((proc)->pdr.fregoffset)
184 #define PROC_PC_REG(proc) ((proc)->pdr.pcreg)
185 #define PROC_LOCALOFF(proc) ((proc)->pdr.localoff)
186 #define PROC_SYMBOL(proc) (*(struct symbol**)&(proc)->pdr.isym)
187 #define _PROC_MAGIC_ 0x0F0F0F0F
188 #define PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym == _PROC_MAGIC_)
189 #define SET_PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym = _PROC_MAGIC_)
191 struct linked_proc_info
193 struct alpha_extra_func_info info
;
194 struct linked_proc_info
*next
;
196 *linked_proc_desc_table
= NULL
;
199 alpha_frame_past_sigtramp_frame (struct frame_info
*frame
, CORE_ADDR pc
)
201 struct gdbarch_tdep
*tdep
= gdbarch_tdep (current_gdbarch
);
203 if (tdep
->skip_sigtramp_frame
!= NULL
)
204 return (tdep
->skip_sigtramp_frame (frame
, pc
));
210 alpha_dynamic_sigtramp_offset (CORE_ADDR pc
)
212 struct gdbarch_tdep
*tdep
= gdbarch_tdep (current_gdbarch
);
214 /* Must be provided by OS/ABI variant code if supported. */
215 if (tdep
->dynamic_sigtramp_offset
!= NULL
)
216 return (tdep
->dynamic_sigtramp_offset (pc
));
221 #define ALPHA_PROC_SIGTRAMP_MAGIC 0x0e0f0f0f
223 /* Return TRUE if the procedure descriptor PROC is a procedure
224 descriptor that refers to a dynamically generated signal
225 trampoline routine. */
227 alpha_proc_desc_is_dyn_sigtramp (struct alpha_extra_func_info
*proc
)
229 struct gdbarch_tdep
*tdep
= gdbarch_tdep (current_gdbarch
);
231 if (tdep
->dynamic_sigtramp_offset
!= NULL
)
232 return (proc
->pdr
.isym
== ALPHA_PROC_SIGTRAMP_MAGIC
);
238 alpha_set_proc_desc_is_dyn_sigtramp (struct alpha_extra_func_info
*proc
)
240 struct gdbarch_tdep
*tdep
= gdbarch_tdep (current_gdbarch
);
242 if (tdep
->dynamic_sigtramp_offset
!= NULL
)
243 proc
->pdr
.isym
= ALPHA_PROC_SIGTRAMP_MAGIC
;
246 /* Dynamically create a signal-handler caller procedure descriptor for
247 the signal-handler return code starting at address LOW_ADDR. The
248 descriptor is added to the linked_proc_desc_table. */
250 static alpha_extra_func_info_t
251 push_sigtramp_desc (CORE_ADDR low_addr
)
253 struct linked_proc_info
*link
;
254 alpha_extra_func_info_t proc_desc
;
256 link
= (struct linked_proc_info
*)
257 xmalloc (sizeof (struct linked_proc_info
));
258 link
->next
= linked_proc_desc_table
;
259 linked_proc_desc_table
= link
;
261 proc_desc
= &link
->info
;
263 proc_desc
->numargs
= 0;
264 PROC_LOW_ADDR (proc_desc
) = low_addr
;
265 PROC_HIGH_ADDR (proc_desc
) = low_addr
+ 3 * 4;
266 PROC_DUMMY_FRAME (proc_desc
) = 0;
267 PROC_FRAME_OFFSET (proc_desc
) = 0x298; /* sizeof(struct sigcontext_struct) */
268 PROC_FRAME_REG (proc_desc
) = SP_REGNUM
;
269 PROC_REG_MASK (proc_desc
) = 0xffff;
270 PROC_FREG_MASK (proc_desc
) = 0xffff;
271 PROC_PC_REG (proc_desc
) = 26;
272 PROC_LOCALOFF (proc_desc
) = 0;
273 alpha_set_proc_desc_is_dyn_sigtramp (proc_desc
);
279 alpha_register_name (int regno
)
281 static char *register_names
[] =
283 "v0", "t0", "t1", "t2", "t3", "t4", "t5", "t6",
284 "t7", "s0", "s1", "s2", "s3", "s4", "s5", "fp",
285 "a0", "a1", "a2", "a3", "a4", "a5", "t8", "t9",
286 "t10", "t11", "ra", "t12", "at", "gp", "sp", "zero",
287 "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",
288 "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15",
289 "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23",
290 "f24", "f25", "f26", "f27", "f28", "f29", "f30", "fpcr",
296 if (regno
>= (sizeof(register_names
) / sizeof(*register_names
)))
298 return (register_names
[regno
]);
302 alpha_cannot_fetch_register (int regno
)
304 return (regno
== FP_REGNUM
|| regno
== ALPHA_ZERO_REGNUM
);
308 alpha_cannot_store_register (int regno
)
310 return (regno
== FP_REGNUM
|| regno
== ALPHA_ZERO_REGNUM
);
314 alpha_register_convertible (int regno
)
316 return (regno
>= FP0_REGNUM
&& regno
<= FP0_REGNUM
+ 31);
320 alpha_register_virtual_type (int regno
)
322 return ((regno
>= FP0_REGNUM
&& regno
< (FP0_REGNUM
+31))
323 ? builtin_type_double
: builtin_type_long
);
327 alpha_register_byte (int regno
)
333 alpha_register_raw_size (int regno
)
339 alpha_register_virtual_size (int regno
)
346 alpha_sigcontext_addr (struct frame_info
*fi
)
348 struct gdbarch_tdep
*tdep
= gdbarch_tdep (current_gdbarch
);
350 if (tdep
->sigcontext_addr
)
351 return (tdep
->sigcontext_addr (fi
));
356 /* Guaranteed to set frame->saved_regs to some values (it never leaves it
360 alpha_find_saved_regs (struct frame_info
*frame
)
363 CORE_ADDR reg_position
;
365 alpha_extra_func_info_t proc_desc
;
368 frame_saved_regs_zalloc (frame
);
370 /* If it is the frame for __sigtramp, the saved registers are located
371 in a sigcontext structure somewhere on the stack. __sigtramp
372 passes a pointer to the sigcontext structure on the stack.
373 If the stack layout for __sigtramp changes, or if sigcontext offsets
374 change, we might have to update this code. */
375 #ifndef SIGFRAME_PC_OFF
376 #define SIGFRAME_PC_OFF (2 * 8)
377 #define SIGFRAME_REGSAVE_OFF (4 * 8)
378 #define SIGFRAME_FPREGSAVE_OFF (SIGFRAME_REGSAVE_OFF + 32 * 8 + 8)
380 if ((get_frame_type (frame
) == SIGTRAMP_FRAME
))
382 CORE_ADDR sigcontext_addr
;
384 sigcontext_addr
= alpha_sigcontext_addr (frame
);
385 if (sigcontext_addr
== 0)
387 /* Don't know where the sigcontext is; just bail. */
390 for (ireg
= 0; ireg
< 32; ireg
++)
392 reg_position
= sigcontext_addr
+ SIGFRAME_REGSAVE_OFF
+ ireg
* 8;
393 get_frame_saved_regs (frame
)[ireg
] = reg_position
;
395 for (ireg
= 0; ireg
< 32; ireg
++)
397 reg_position
= sigcontext_addr
+ SIGFRAME_FPREGSAVE_OFF
+ ireg
* 8;
398 get_frame_saved_regs (frame
)[FP0_REGNUM
+ ireg
] = reg_position
;
400 get_frame_saved_regs (frame
)[PC_REGNUM
] = sigcontext_addr
+ SIGFRAME_PC_OFF
;
404 proc_desc
= frame
->extra_info
->proc_desc
;
405 if (proc_desc
== NULL
)
406 /* I'm not sure how/whether this can happen. Normally when we can't
407 find a proc_desc, we "synthesize" one using heuristic_proc_desc
408 and set the saved_regs right away. */
411 /* Fill in the offsets for the registers which gen_mask says
414 reg_position
= get_frame_base (frame
) + PROC_REG_OFFSET (proc_desc
);
415 mask
= PROC_REG_MASK (proc_desc
);
417 returnreg
= PROC_PC_REG (proc_desc
);
419 /* Note that RA is always saved first, regardless of its actual
421 if (mask
& (1 << returnreg
))
423 get_frame_saved_regs (frame
)[returnreg
] = reg_position
;
425 mask
&= ~(1 << returnreg
); /* Clear bit for RA so we
426 don't save again later. */
429 for (ireg
= 0; ireg
<= 31; ++ireg
)
430 if (mask
& (1 << ireg
))
432 get_frame_saved_regs (frame
)[ireg
] = reg_position
;
436 /* Fill in the offsets for the registers which float_mask says
439 reg_position
= get_frame_base (frame
) + PROC_FREG_OFFSET (proc_desc
);
440 mask
= PROC_FREG_MASK (proc_desc
);
442 for (ireg
= 0; ireg
<= 31; ++ireg
)
443 if (mask
& (1 << ireg
))
445 get_frame_saved_regs (frame
)[FP0_REGNUM
+ ireg
] = reg_position
;
449 get_frame_saved_regs (frame
)[PC_REGNUM
] = get_frame_saved_regs (frame
)[returnreg
];
453 alpha_frame_init_saved_regs (struct frame_info
*fi
)
455 if (get_frame_saved_regs (fi
) == NULL
)
456 alpha_find_saved_regs (fi
);
457 get_frame_saved_regs (fi
)[SP_REGNUM
] = get_frame_base (fi
);
461 alpha_init_frame_pc_first (int fromleaf
, struct frame_info
*prev
)
463 return (fromleaf
? SAVED_PC_AFTER_CALL (get_next_frame (prev
))
464 : get_next_frame (prev
) ? FRAME_SAVED_PC (get_next_frame (prev
))
469 read_next_frame_reg (struct frame_info
*fi
, int regno
)
471 for (; fi
; fi
= get_next_frame (fi
))
473 /* We have to get the saved sp from the sigcontext
474 if it is a signal handler frame. */
475 if (regno
== SP_REGNUM
&& !(get_frame_type (fi
) == SIGTRAMP_FRAME
))
476 return get_frame_base (fi
);
479 if (get_frame_saved_regs (fi
) == NULL
)
480 alpha_find_saved_regs (fi
);
481 if (get_frame_saved_regs (fi
)[regno
])
482 return read_memory_integer (get_frame_saved_regs (fi
)[regno
], 8);
485 return read_register (regno
);
489 alpha_frame_saved_pc (struct frame_info
*frame
)
491 alpha_extra_func_info_t proc_desc
= frame
->extra_info
->proc_desc
;
492 /* We have to get the saved pc from the sigcontext
493 if it is a signal handler frame. */
494 int pcreg
= (get_frame_type (frame
) == SIGTRAMP_FRAME
) ? PC_REGNUM
495 : frame
->extra_info
->pc_reg
;
497 if (proc_desc
&& PROC_DESC_IS_DUMMY (proc_desc
))
498 return read_memory_integer (get_frame_base (frame
) - 8, 8);
500 return read_next_frame_reg (frame
, pcreg
);
504 alpha_saved_pc_after_call (struct frame_info
*frame
)
506 CORE_ADDR pc
= get_frame_pc (frame
);
508 alpha_extra_func_info_t proc_desc
;
511 /* Skip over shared library trampoline if necessary. */
512 tmp
= SKIP_TRAMPOLINE_CODE (pc
);
516 proc_desc
= find_proc_desc (pc
, get_next_frame (frame
));
517 pcreg
= proc_desc
? PROC_PC_REG (proc_desc
) : ALPHA_RA_REGNUM
;
519 if ((get_frame_type (frame
) == SIGTRAMP_FRAME
))
520 return alpha_frame_saved_pc (frame
);
522 return read_register (pcreg
);
526 static struct alpha_extra_func_info temp_proc_desc
;
527 static CORE_ADDR temp_saved_regs
[ALPHA_NUM_REGS
];
529 /* Nonzero if instruction at PC is a return instruction. "ret
530 $zero,($ra),1" on alpha. */
533 alpha_about_to_return (CORE_ADDR pc
)
535 return read_memory_integer (pc
, 4) == 0x6bfa8001;
540 /* This fencepost looks highly suspicious to me. Removing it also
541 seems suspicious as it could affect remote debugging across serial
545 heuristic_proc_start (CORE_ADDR pc
)
547 struct gdbarch_tdep
*tdep
= gdbarch_tdep (current_gdbarch
);
548 CORE_ADDR start_pc
= pc
;
549 CORE_ADDR fence
= start_pc
- heuristic_fence_post
;
554 if (heuristic_fence_post
== UINT_MAX
555 || fence
< tdep
->vm_min_address
)
556 fence
= tdep
->vm_min_address
;
558 /* search back for previous return */
559 for (start_pc
-= 4;; start_pc
-= 4)
560 if (start_pc
< fence
)
562 /* It's not clear to me why we reach this point when
563 stop_soon_quietly, but with this test, at least we
564 don't print out warnings for every child forked (eg, on
565 decstation). 22apr93 rich@cygnus.com. */
566 if (!stop_soon_quietly
)
568 static int blurb_printed
= 0;
570 if (fence
== tdep
->vm_min_address
)
571 warning ("Hit beginning of text section without finding");
573 warning ("Hit heuristic-fence-post without finding");
575 warning ("enclosing function for address 0x%s", paddr_nz (pc
));
579 This warning occurs if you are debugging a function without any symbols\n\
580 (for example, in a stripped executable). In that case, you may wish to\n\
581 increase the size of the search with the `set heuristic-fence-post' command.\n\
583 Otherwise, you told GDB there was a function where there isn't one, or\n\
584 (more likely) you have encountered a bug in GDB.\n");
591 else if (alpha_about_to_return (start_pc
))
594 start_pc
+= 4; /* skip return */
598 static alpha_extra_func_info_t
599 heuristic_proc_desc (CORE_ADDR start_pc
, CORE_ADDR limit_pc
,
600 struct frame_info
*next_frame
)
602 CORE_ADDR sp
= read_next_frame_reg (next_frame
, SP_REGNUM
);
606 int has_frame_reg
= 0;
607 unsigned long reg_mask
= 0;
613 memset (&temp_proc_desc
, '\0', sizeof (temp_proc_desc
));
614 memset (&temp_saved_regs
, '\0', SIZEOF_FRAME_SAVED_REGS
);
615 PROC_LOW_ADDR (&temp_proc_desc
) = start_pc
;
617 if (start_pc
+ 200 < limit_pc
)
618 limit_pc
= start_pc
+ 200;
620 for (cur_pc
= start_pc
; cur_pc
< limit_pc
; cur_pc
+= 4)
626 status
= read_memory_nobpt (cur_pc
, buf
, 4);
628 memory_error (status
, cur_pc
);
629 word
= extract_unsigned_integer (buf
, 4);
631 if ((word
& 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */
635 /* Consider only the first stack allocation instruction
636 to contain the static size of the frame. */
638 frame_size
+= (-word
) & 0xffff;
641 /* Exit loop if a positive stack adjustment is found, which
642 usually means that the stack cleanup code in the function
643 epilogue is reached. */
646 else if ((word
& 0xfc1f0000) == 0xb41e0000 /* stq reg,n($sp) */
647 && (word
& 0xffff0000) != 0xb7fe0000) /* reg != $zero */
649 int reg
= (word
& 0x03e00000) >> 21;
650 reg_mask
|= 1 << reg
;
652 /* Do not compute the address where the register was saved yet,
653 because we don't know yet if the offset will need to be
654 relative to $sp or $fp (we can not compute the address relative
655 to $sp if $sp is updated during the execution of the current
656 subroutine, for instance when doing some alloca). So just store
657 the offset for the moment, and compute the address later
658 when we know whether this frame has a frame pointer or not.
660 temp_saved_regs
[reg
] = (short) word
;
662 /* Starting with OSF/1-3.2C, the system libraries are shipped
663 without local symbols, but they still contain procedure
664 descriptors without a symbol reference. GDB is currently
665 unable to find these procedure descriptors and uses
666 heuristic_proc_desc instead.
667 As some low level compiler support routines (__div*, __add*)
668 use a non-standard return address register, we have to
669 add some heuristics to determine the return address register,
670 or stepping over these routines will fail.
671 Usually the return address register is the first register
672 saved on the stack, but assembler optimization might
673 rearrange the register saves.
674 So we recognize only a few registers (t7, t9, ra) within
675 the procedure prologue as valid return address registers.
676 If we encounter a return instruction, we extract the
677 the return address register from it.
679 FIXME: Rewriting GDB to access the procedure descriptors,
680 e.g. via the minimal symbol table, might obviate this hack. */
682 && cur_pc
< (start_pc
+ 80)
683 && (reg
== ALPHA_T7_REGNUM
|| reg
== ALPHA_T9_REGNUM
684 || reg
== ALPHA_RA_REGNUM
))
687 else if ((word
& 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */
688 pcreg
= (word
>> 16) & 0x1f;
689 else if (word
== 0x47de040f || word
== 0x47fe040f) /* bis sp,sp fp */
691 /* ??? I am not sure what instruction is 0x47fe040f, and I
692 am suspecting that there was a typo and should have been
693 0x47fe040f. I'm keeping it in the test above until further
696 vfp
= read_next_frame_reg (next_frame
, ALPHA_GCC_FP_REGNUM
);
701 /* If we haven't found a valid return address register yet,
702 keep searching in the procedure prologue. */
703 while (cur_pc
< (limit_pc
+ 80) && cur_pc
< (start_pc
+ 80))
708 if (read_memory_nobpt (cur_pc
, buf
, 4))
711 word
= extract_unsigned_integer (buf
, 4);
713 if ((word
& 0xfc1f0000) == 0xb41e0000 /* stq reg,n($sp) */
714 && (word
& 0xffff0000) != 0xb7fe0000) /* reg != $zero */
716 int reg
= (word
& 0x03e00000) >> 21;
717 if (reg
== ALPHA_T7_REGNUM
|| reg
== ALPHA_T9_REGNUM
718 || reg
== ALPHA_RA_REGNUM
)
724 else if ((word
& 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */
726 pcreg
= (word
>> 16) & 0x1f;
733 PROC_FRAME_REG (&temp_proc_desc
) = ALPHA_GCC_FP_REGNUM
;
735 PROC_FRAME_REG (&temp_proc_desc
) = SP_REGNUM
;
737 /* At this point, we know which of the Stack Pointer or the Frame Pointer
738 to use as the reference address to compute the saved registers address.
739 But in both cases, the processing above has set vfp to this reference
740 address, so just need to increment the offset of each saved register
742 for (regno
= 0; regno
< NUM_REGS
; regno
++)
744 if (reg_mask
& 1 << regno
)
745 temp_saved_regs
[regno
] += vfp
;
748 PROC_FRAME_OFFSET (&temp_proc_desc
) = frame_size
;
749 PROC_REG_MASK (&temp_proc_desc
) = reg_mask
;
750 PROC_PC_REG (&temp_proc_desc
) = (pcreg
== -1) ? ALPHA_RA_REGNUM
: pcreg
;
751 PROC_LOCALOFF (&temp_proc_desc
) = 0; /* XXX - bogus */
752 return &temp_proc_desc
;
755 /* This returns the PC of the first inst after the prologue. If we can't
756 find the prologue, then return 0. */
759 after_prologue (CORE_ADDR pc
, alpha_extra_func_info_t proc_desc
)
761 struct symtab_and_line sal
;
762 CORE_ADDR func_addr
, func_end
;
765 proc_desc
= find_proc_desc (pc
, NULL
);
769 if (alpha_proc_desc_is_dyn_sigtramp (proc_desc
))
770 return PROC_LOW_ADDR (proc_desc
); /* "prologue" is in kernel */
772 /* If function is frameless, then we need to do it the hard way. I
773 strongly suspect that frameless always means prologueless... */
774 if (PROC_FRAME_REG (proc_desc
) == SP_REGNUM
775 && PROC_FRAME_OFFSET (proc_desc
) == 0)
779 if (!find_pc_partial_function (pc
, NULL
, &func_addr
, &func_end
))
780 return 0; /* Unknown */
782 sal
= find_pc_line (func_addr
, 0);
784 if (sal
.end
< func_end
)
787 /* The line after the prologue is after the end of the function. In this
788 case, tell the caller to find the prologue the hard way. */
793 /* Return non-zero if we *might* be in a function prologue. Return zero if we
794 are definitively *not* in a function prologue. */
797 alpha_in_prologue (CORE_ADDR pc
, alpha_extra_func_info_t proc_desc
)
799 CORE_ADDR after_prologue_pc
;
801 after_prologue_pc
= after_prologue (pc
, proc_desc
);
803 if (after_prologue_pc
== 0
804 || pc
< after_prologue_pc
)
810 static alpha_extra_func_info_t
811 find_proc_desc (CORE_ADDR pc
, struct frame_info
*next_frame
)
813 alpha_extra_func_info_t proc_desc
;
818 /* Try to get the proc_desc from the linked call dummy proc_descs
819 if the pc is in the call dummy.
820 This is hairy. In the case of nested dummy calls we have to find the
821 right proc_desc, but we might not yet know the frame for the dummy
822 as it will be contained in the proc_desc we are searching for.
823 So we have to find the proc_desc whose frame is closest to the current
826 if (DEPRECATED_PC_IN_CALL_DUMMY (pc
, 0, 0))
828 struct linked_proc_info
*link
;
829 CORE_ADDR sp
= read_next_frame_reg (next_frame
, SP_REGNUM
);
830 alpha_extra_func_info_t found_proc_desc
= NULL
;
831 long min_distance
= LONG_MAX
;
833 for (link
= linked_proc_desc_table
; link
; link
= link
->next
)
835 long distance
= (CORE_ADDR
) PROC_DUMMY_FRAME (&link
->info
) - sp
;
836 if (distance
> 0 && distance
< min_distance
)
838 min_distance
= distance
;
839 found_proc_desc
= &link
->info
;
842 if (found_proc_desc
!= NULL
)
843 return found_proc_desc
;
846 b
= block_for_pc (pc
);
848 find_pc_partial_function (pc
, NULL
, &startaddr
, NULL
);
853 if (startaddr
> BLOCK_START (b
))
854 /* This is the "pathological" case referred to in a comment in
855 print_frame_info. It might be better to move this check into
859 sym
= lookup_symbol (MIPS_EFI_SYMBOL_NAME
, b
, LABEL_NAMESPACE
,
863 /* If we never found a PDR for this function in symbol reading, then
864 examine prologues to find the information. */
865 if (sym
&& ((mips_extra_func_info_t
) SYMBOL_VALUE (sym
))->pdr
.framereg
== -1)
870 /* IF this is the topmost frame AND
871 * (this proc does not have debugging information OR
872 * the PC is in the procedure prologue)
873 * THEN create a "heuristic" proc_desc (by analyzing
874 * the actual code) to replace the "official" proc_desc.
876 proc_desc
= (alpha_extra_func_info_t
) SYMBOL_VALUE (sym
);
877 if (next_frame
== NULL
)
879 if (PROC_DESC_IS_DUMMY (proc_desc
) || alpha_in_prologue (pc
, proc_desc
))
881 alpha_extra_func_info_t found_heuristic
=
882 heuristic_proc_desc (PROC_LOW_ADDR (proc_desc
),
886 PROC_LOCALOFF (found_heuristic
) =
887 PROC_LOCALOFF (proc_desc
);
888 PROC_PC_REG (found_heuristic
) = PROC_PC_REG (proc_desc
);
889 proc_desc
= found_heuristic
;
898 /* Is linked_proc_desc_table really necessary? It only seems to be used
899 by procedure call dummys. However, the procedures being called ought
900 to have their own proc_descs, and even if they don't,
901 heuristic_proc_desc knows how to create them! */
903 register struct linked_proc_info
*link
;
904 for (link
= linked_proc_desc_table
; link
; link
= link
->next
)
905 if (PROC_LOW_ADDR (&link
->info
) <= pc
906 && PROC_HIGH_ADDR (&link
->info
) > pc
)
909 /* If PC is inside a dynamically generated sigtramp handler,
910 create and push a procedure descriptor for that code: */
911 offset
= alpha_dynamic_sigtramp_offset (pc
);
913 return push_sigtramp_desc (pc
- offset
);
915 /* If heuristic_fence_post is non-zero, determine the procedure
916 start address by examining the instructions.
917 This allows us to find the start address of static functions which
918 have no symbolic information, as startaddr would have been set to
919 the preceding global function start address by the
920 find_pc_partial_function call above. */
921 if (startaddr
== 0 || heuristic_fence_post
!= 0)
922 startaddr
= heuristic_proc_start (pc
);
925 heuristic_proc_desc (startaddr
, pc
, next_frame
);
930 alpha_extra_func_info_t cached_proc_desc
;
933 alpha_frame_chain (struct frame_info
*frame
)
935 alpha_extra_func_info_t proc_desc
;
936 CORE_ADDR saved_pc
= FRAME_SAVED_PC (frame
);
938 if (saved_pc
== 0 || inside_entry_file (saved_pc
))
941 proc_desc
= find_proc_desc (saved_pc
, frame
);
945 cached_proc_desc
= proc_desc
;
947 /* Fetch the frame pointer for a dummy frame from the procedure
949 if (PROC_DESC_IS_DUMMY (proc_desc
))
950 return (CORE_ADDR
) PROC_DUMMY_FRAME (proc_desc
);
952 /* If no frame pointer and frame size is zero, we must be at end
953 of stack (or otherwise hosed). If we don't check frame size,
954 we loop forever if we see a zero size frame. */
955 if (PROC_FRAME_REG (proc_desc
) == SP_REGNUM
956 && PROC_FRAME_OFFSET (proc_desc
) == 0
957 /* The previous frame from a sigtramp frame might be frameless
958 and have frame size zero. */
959 && !(get_frame_type (frame
) == SIGTRAMP_FRAME
))
960 return alpha_frame_past_sigtramp_frame (frame
, saved_pc
);
962 return read_next_frame_reg (frame
, PROC_FRAME_REG (proc_desc
))
963 + PROC_FRAME_OFFSET (proc_desc
);
967 alpha_print_extra_frame_info (struct frame_info
*fi
)
971 && fi
->extra_info
->proc_desc
972 && fi
->extra_info
->proc_desc
->pdr
.framereg
< NUM_REGS
)
973 printf_filtered (" frame pointer is at %s+%s\n",
974 REGISTER_NAME (fi
->extra_info
->proc_desc
->pdr
.framereg
),
975 paddr_d (fi
->extra_info
->proc_desc
->pdr
.frameoffset
));
979 alpha_init_extra_frame_info (int fromleaf
, struct frame_info
*frame
)
981 /* Use proc_desc calculated in frame_chain */
982 alpha_extra_func_info_t proc_desc
=
983 get_next_frame (frame
)
985 : find_proc_desc (get_frame_pc (frame
), get_next_frame (frame
));
987 frame_extra_info_zalloc (frame
, sizeof (struct frame_extra_info
));
989 /* NOTE: cagney/2003-01-03: No need to set saved_regs to NULL,
990 always NULL by default. */
991 /* frame->saved_regs = NULL; */
992 frame
->extra_info
->localoff
= 0;
993 frame
->extra_info
->pc_reg
= ALPHA_RA_REGNUM
;
994 frame
->extra_info
->proc_desc
= proc_desc
== &temp_proc_desc
? 0 : proc_desc
;
997 /* Get the locals offset and the saved pc register from the
998 procedure descriptor, they are valid even if we are in the
999 middle of the prologue. */
1000 frame
->extra_info
->localoff
= PROC_LOCALOFF (proc_desc
);
1001 frame
->extra_info
->pc_reg
= PROC_PC_REG (proc_desc
);
1003 /* Fixup frame-pointer - only needed for top frame */
1005 /* Fetch the frame pointer for a dummy frame from the procedure
1007 if (PROC_DESC_IS_DUMMY (proc_desc
))
1008 deprecated_update_frame_base_hack (frame
, (CORE_ADDR
) PROC_DUMMY_FRAME (proc_desc
));
1010 /* This may not be quite right, if proc has a real frame register.
1011 Get the value of the frame relative sp, procedure might have been
1012 interrupted by a signal at it's very start. */
1013 else if (get_frame_pc (frame
) == PROC_LOW_ADDR (proc_desc
)
1014 && !alpha_proc_desc_is_dyn_sigtramp (proc_desc
))
1015 deprecated_update_frame_base_hack (frame
, read_next_frame_reg (get_next_frame (frame
), SP_REGNUM
));
1017 deprecated_update_frame_base_hack (frame
, read_next_frame_reg (get_next_frame (frame
), PROC_FRAME_REG (proc_desc
))
1018 + PROC_FRAME_OFFSET (proc_desc
));
1020 if (proc_desc
== &temp_proc_desc
)
1024 /* Do not set the saved registers for a sigtramp frame,
1025 alpha_find_saved_registers will do that for us. We can't
1026 use (get_frame_type (frame) == SIGTRAMP_FRAME), it is not
1028 /* FIXME: cagney/2002-11-18: This problem will go away once
1029 frame.c:get_prev_frame() is modified to set the frame's
1030 type before calling functions like this. */
1031 find_pc_partial_function (get_frame_pc (frame
), &name
,
1032 (CORE_ADDR
*) NULL
, (CORE_ADDR
*) NULL
);
1033 if (!PC_IN_SIGTRAMP (get_frame_pc (frame
), name
))
1035 frame_saved_regs_zalloc (frame
);
1036 memcpy (get_frame_saved_regs (frame
), temp_saved_regs
,
1037 SIZEOF_FRAME_SAVED_REGS
);
1038 get_frame_saved_regs (frame
)[PC_REGNUM
]
1039 = get_frame_saved_regs (frame
)[ALPHA_RA_REGNUM
];
1046 alpha_frame_locals_address (struct frame_info
*fi
)
1048 return (get_frame_base (fi
) - fi
->extra_info
->localoff
);
1052 alpha_frame_args_address (struct frame_info
*fi
)
1054 return (get_frame_base (fi
) - (ALPHA_NUM_ARG_REGS
* 8));
1057 /* ALPHA stack frames are almost impenetrable. When execution stops,
1058 we basically have to look at symbol information for the function
1059 that we stopped in, which tells us *which* register (if any) is
1060 the base of the frame pointer, and what offset from that register
1061 the frame itself is at.
1063 This presents a problem when trying to examine a stack in memory
1064 (that isn't executing at the moment), using the "frame" command. We
1065 don't have a PC, nor do we have any registers except SP.
1067 This routine takes two arguments, SP and PC, and tries to make the
1068 cached frames look as if these two arguments defined a frame on the
1069 cache. This allows the rest of info frame to extract the important
1070 arguments without difficulty. */
1073 alpha_setup_arbitrary_frame (int argc
, CORE_ADDR
*argv
)
1076 error ("ALPHA frame specifications require two arguments: sp and pc");
1078 return create_new_frame (argv
[0], argv
[1]);
1081 /* The alpha passes the first six arguments in the registers, the rest on
1082 the stack. The register arguments are eventually transferred to the
1083 argument transfer area immediately below the stack by the called function
1084 anyway. So we `push' at least six arguments on the stack, `reload' the
1085 argument registers and then adjust the stack pointer to point past the
1086 sixth argument. This algorithm simplifies the passing of a large struct
1087 which extends from the registers to the stack.
1088 If the called function is returning a structure, the address of the
1089 structure to be returned is passed as a hidden first argument. */
1092 alpha_push_arguments (int nargs
, struct value
**args
, CORE_ADDR sp
,
1093 int struct_return
, CORE_ADDR struct_addr
)
1096 int accumulate_size
= struct_return
? 8 : 0;
1097 int arg_regs_size
= ALPHA_NUM_ARG_REGS
* 8;
1104 struct alpha_arg
*alpha_args
=
1105 (struct alpha_arg
*) alloca (nargs
* sizeof (struct alpha_arg
));
1106 register struct alpha_arg
*m_arg
;
1107 char raw_buffer
[sizeof (CORE_ADDR
)];
1108 int required_arg_regs
;
1110 for (i
= 0, m_arg
= alpha_args
; i
< nargs
; i
++, m_arg
++)
1112 struct value
*arg
= args
[i
];
1113 struct type
*arg_type
= check_typedef (VALUE_TYPE (arg
));
1114 /* Cast argument to long if necessary as the compiler does it too. */
1115 switch (TYPE_CODE (arg_type
))
1118 case TYPE_CODE_BOOL
:
1119 case TYPE_CODE_CHAR
:
1120 case TYPE_CODE_RANGE
:
1121 case TYPE_CODE_ENUM
:
1122 if (TYPE_LENGTH (arg_type
) < TYPE_LENGTH (builtin_type_long
))
1124 arg_type
= builtin_type_long
;
1125 arg
= value_cast (arg_type
, arg
);
1131 m_arg
->len
= TYPE_LENGTH (arg_type
);
1132 m_arg
->offset
= accumulate_size
;
1133 accumulate_size
= (accumulate_size
+ m_arg
->len
+ 7) & ~7;
1134 m_arg
->contents
= VALUE_CONTENTS (arg
);
1137 /* Determine required argument register loads, loading an argument register
1138 is expensive as it uses three ptrace calls. */
1139 required_arg_regs
= accumulate_size
/ 8;
1140 if (required_arg_regs
> ALPHA_NUM_ARG_REGS
)
1141 required_arg_regs
= ALPHA_NUM_ARG_REGS
;
1143 /* Make room for the arguments on the stack. */
1144 if (accumulate_size
< arg_regs_size
)
1145 accumulate_size
= arg_regs_size
;
1146 sp
-= accumulate_size
;
1148 /* Keep sp aligned to a multiple of 16 as the compiler does it too. */
1151 /* `Push' arguments on the stack. */
1152 for (i
= nargs
; m_arg
--, --i
>= 0;)
1153 write_memory (sp
+ m_arg
->offset
, m_arg
->contents
, m_arg
->len
);
1156 store_address (raw_buffer
, sizeof (CORE_ADDR
), struct_addr
);
1157 write_memory (sp
, raw_buffer
, sizeof (CORE_ADDR
));
1160 /* Load the argument registers. */
1161 for (i
= 0; i
< required_arg_regs
; i
++)
1165 val
= read_memory_integer (sp
+ i
* 8, 8);
1166 write_register (ALPHA_A0_REGNUM
+ i
, val
);
1167 write_register (ALPHA_FPA0_REGNUM
+ i
, val
);
1170 return sp
+ arg_regs_size
;
1174 alpha_push_dummy_frame (void)
1177 struct linked_proc_info
*link
;
1178 alpha_extra_func_info_t proc_desc
;
1179 CORE_ADDR sp
= read_register (SP_REGNUM
);
1180 CORE_ADDR save_address
;
1181 char raw_buffer
[ALPHA_MAX_REGISTER_RAW_SIZE
];
1184 link
= (struct linked_proc_info
*) xmalloc (sizeof (struct linked_proc_info
));
1185 link
->next
= linked_proc_desc_table
;
1186 linked_proc_desc_table
= link
;
1188 proc_desc
= &link
->info
;
1191 * The registers we must save are all those not preserved across
1193 * In addition, we must save the PC and RA.
1195 * Dummy frame layout:
1205 * Parameter build area
1209 /* MASK(i,j) == (1<<i) + (1<<(i+1)) + ... + (1<<j)). Assume i<=j<31. */
1210 #define MASK(i,j) ((((LONGEST)1 << ((j)+1)) - 1) ^ (((LONGEST)1 << (i)) - 1))
1211 #define GEN_REG_SAVE_MASK (MASK(0,8) | MASK(16,29))
1212 #define GEN_REG_SAVE_COUNT 24
1213 #define FLOAT_REG_SAVE_MASK (MASK(0,1) | MASK(10,30))
1214 #define FLOAT_REG_SAVE_COUNT 23
1215 /* The special register is the PC as we have no bit for it in the save masks.
1216 alpha_frame_saved_pc knows where the pc is saved in a dummy frame. */
1217 #define SPECIAL_REG_SAVE_COUNT 1
1219 PROC_REG_MASK (proc_desc
) = GEN_REG_SAVE_MASK
;
1220 PROC_FREG_MASK (proc_desc
) = FLOAT_REG_SAVE_MASK
;
1221 /* PROC_REG_OFFSET is the offset from the dummy frame to the saved RA,
1222 but keep SP aligned to a multiple of 16. */
1223 PROC_REG_OFFSET (proc_desc
) =
1224 -((8 * (SPECIAL_REG_SAVE_COUNT
1225 + GEN_REG_SAVE_COUNT
1226 + FLOAT_REG_SAVE_COUNT
)
1228 PROC_FREG_OFFSET (proc_desc
) =
1229 PROC_REG_OFFSET (proc_desc
) + 8 * GEN_REG_SAVE_COUNT
;
1231 /* Save general registers.
1232 The return address register is the first saved register, all other
1233 registers follow in ascending order.
1234 The PC is saved immediately below the SP. */
1235 save_address
= sp
+ PROC_REG_OFFSET (proc_desc
);
1236 store_address (raw_buffer
, 8, read_register (ALPHA_RA_REGNUM
));
1237 write_memory (save_address
, raw_buffer
, 8);
1239 mask
= PROC_REG_MASK (proc_desc
) & 0xffffffffL
;
1240 for (ireg
= 0; mask
; ireg
++, mask
>>= 1)
1243 if (ireg
== ALPHA_RA_REGNUM
)
1245 store_address (raw_buffer
, 8, read_register (ireg
));
1246 write_memory (save_address
, raw_buffer
, 8);
1250 store_address (raw_buffer
, 8, read_register (PC_REGNUM
));
1251 write_memory (sp
- 8, raw_buffer
, 8);
1253 /* Save floating point registers. */
1254 save_address
= sp
+ PROC_FREG_OFFSET (proc_desc
);
1255 mask
= PROC_FREG_MASK (proc_desc
) & 0xffffffffL
;
1256 for (ireg
= 0; mask
; ireg
++, mask
>>= 1)
1259 store_address (raw_buffer
, 8, read_register (ireg
+ FP0_REGNUM
));
1260 write_memory (save_address
, raw_buffer
, 8);
1264 /* Set and save the frame address for the dummy.
1265 This is tricky. The only registers that are suitable for a frame save
1266 are those that are preserved across procedure calls (s0-s6). But if
1267 a read system call is interrupted and then a dummy call is made
1268 (see testsuite/gdb.t17/interrupt.exp) the dummy call hangs till the read
1269 is satisfied. Then it returns with the s0-s6 registers set to the values
1270 on entry to the read system call and our dummy frame pointer would be
1271 destroyed. So we save the dummy frame in the proc_desc and handle the
1272 retrieval of the frame pointer of a dummy specifically. The frame register
1273 is set to the virtual frame (pseudo) register, it's value will always
1274 be read as zero and will help us to catch any errors in the dummy frame
1276 PROC_DUMMY_FRAME (proc_desc
) = sp
;
1277 PROC_FRAME_REG (proc_desc
) = FP_REGNUM
;
1278 PROC_FRAME_OFFSET (proc_desc
) = 0;
1279 sp
+= PROC_REG_OFFSET (proc_desc
);
1280 write_register (SP_REGNUM
, sp
);
1282 PROC_LOW_ADDR (proc_desc
) = CALL_DUMMY_ADDRESS ();
1283 PROC_HIGH_ADDR (proc_desc
) = PROC_LOW_ADDR (proc_desc
) + 4;
1285 SET_PROC_DESC_IS_DUMMY (proc_desc
);
1286 PROC_PC_REG (proc_desc
) = ALPHA_RA_REGNUM
;
1290 alpha_pop_frame (void)
1292 register int regnum
;
1293 struct frame_info
*frame
= get_current_frame ();
1294 CORE_ADDR new_sp
= get_frame_base (frame
);
1296 alpha_extra_func_info_t proc_desc
= frame
->extra_info
->proc_desc
;
1298 /* we need proc_desc to know how to restore the registers;
1299 if it is NULL, construct (a temporary) one */
1300 if (proc_desc
== NULL
)
1301 proc_desc
= find_proc_desc (get_frame_pc (frame
), get_next_frame (frame
));
1303 /* Question: should we copy this proc_desc and save it in
1304 frame->proc_desc? If we do, who will free it?
1305 For now, we don't save a copy... */
1307 write_register (PC_REGNUM
, FRAME_SAVED_PC (frame
));
1308 if (get_frame_saved_regs (frame
) == NULL
)
1309 alpha_find_saved_regs (frame
);
1312 for (regnum
= 32; --regnum
>= 0;)
1313 if (PROC_REG_MASK (proc_desc
) & (1 << regnum
))
1314 write_register (regnum
,
1315 read_memory_integer (get_frame_saved_regs (frame
)[regnum
],
1317 for (regnum
= 32; --regnum
>= 0;)
1318 if (PROC_FREG_MASK (proc_desc
) & (1 << regnum
))
1319 write_register (regnum
+ FP0_REGNUM
,
1320 read_memory_integer (get_frame_saved_regs (frame
)[regnum
+ FP0_REGNUM
], 8));
1322 write_register (SP_REGNUM
, new_sp
);
1323 flush_cached_frames ();
1325 if (proc_desc
&& (PROC_DESC_IS_DUMMY (proc_desc
)
1326 || alpha_proc_desc_is_dyn_sigtramp (proc_desc
)))
1328 struct linked_proc_info
*pi_ptr
, *prev_ptr
;
1330 for (pi_ptr
= linked_proc_desc_table
, prev_ptr
= NULL
;
1332 prev_ptr
= pi_ptr
, pi_ptr
= pi_ptr
->next
)
1334 if (&pi_ptr
->info
== proc_desc
)
1339 error ("Can't locate dummy extra frame info\n");
1341 if (prev_ptr
!= NULL
)
1342 prev_ptr
->next
= pi_ptr
->next
;
1344 linked_proc_desc_table
= pi_ptr
->next
;
1350 /* To skip prologues, I use this predicate. Returns either PC itself
1351 if the code at PC does not look like a function prologue; otherwise
1352 returns an address that (if we're lucky) follows the prologue. If
1353 LENIENT, then we must skip everything which is involved in setting
1354 up the frame (it's OK to skip more, just so long as we don't skip
1355 anything which might clobber the registers which are being saved.
1356 Currently we must not skip more on the alpha, but we might need the
1357 lenient stuff some day. */
1360 alpha_skip_prologue_internal (CORE_ADDR pc
, int lenient
)
1364 CORE_ADDR post_prologue_pc
;
1367 /* Silently return the unaltered pc upon memory errors.
1368 This could happen on OSF/1 if decode_line_1 tries to skip the
1369 prologue for quickstarted shared library functions when the
1370 shared library is not yet mapped in.
1371 Reading target memory is slow over serial lines, so we perform
1372 this check only if the target has shared libraries (which all
1373 Alpha targets do). */
1374 if (target_read_memory (pc
, buf
, 4))
1377 /* See if we can determine the end of the prologue via the symbol table.
1378 If so, then return either PC, or the PC after the prologue, whichever
1381 post_prologue_pc
= after_prologue (pc
, NULL
);
1383 if (post_prologue_pc
!= 0)
1384 return max (pc
, post_prologue_pc
);
1386 /* Can't determine prologue from the symbol table, need to examine
1389 /* Skip the typical prologue instructions. These are the stack adjustment
1390 instruction and the instructions that save registers on the stack
1391 or in the gcc frame. */
1392 for (offset
= 0; offset
< 100; offset
+= 4)
1396 status
= read_memory_nobpt (pc
+ offset
, buf
, 4);
1398 memory_error (status
, pc
+ offset
);
1399 inst
= extract_unsigned_integer (buf
, 4);
1401 /* The alpha has no delay slots. But let's keep the lenient stuff,
1402 we might need it for something else in the future. */
1406 if ((inst
& 0xffff0000) == 0x27bb0000) /* ldah $gp,n($t12) */
1408 if ((inst
& 0xffff0000) == 0x23bd0000) /* lda $gp,n($gp) */
1410 if ((inst
& 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */
1412 if ((inst
& 0xffe01fff) == 0x43c0153e) /* subq $sp,n,$sp */
1415 if ((inst
& 0xfc1f0000) == 0xb41e0000
1416 && (inst
& 0xffff0000) != 0xb7fe0000)
1417 continue; /* stq reg,n($sp) */
1419 if ((inst
& 0xfc1f0000) == 0x9c1e0000
1420 && (inst
& 0xffff0000) != 0x9ffe0000)
1421 continue; /* stt reg,n($sp) */
1423 if (inst
== 0x47de040f) /* bis sp,sp,fp */
1432 alpha_skip_prologue (CORE_ADDR addr
)
1434 return (alpha_skip_prologue_internal (addr
, 0));
1438 /* Is address PC in the prologue (loosely defined) for function at
1442 alpha_in_lenient_prologue (CORE_ADDR startaddr
, CORE_ADDR pc
)
1444 CORE_ADDR end_prologue
= alpha_skip_prologue_internal (startaddr
, 1);
1445 return pc
>= startaddr
&& pc
< end_prologue
;
1449 /* The alpha needs a conversion between register and memory format if
1450 the register is a floating point register and
1451 memory format is float, as the register format must be double
1453 memory format is an integer with 4 bytes or less, as the representation
1454 of integers in floating point registers is different. */
1456 alpha_register_convert_to_virtual (int regnum
, struct type
*valtype
,
1457 char *raw_buffer
, char *virtual_buffer
)
1459 if (TYPE_LENGTH (valtype
) >= REGISTER_RAW_SIZE (regnum
))
1461 memcpy (virtual_buffer
, raw_buffer
, REGISTER_VIRTUAL_SIZE (regnum
));
1465 if (TYPE_CODE (valtype
) == TYPE_CODE_FLT
)
1467 double d
= extract_floating (raw_buffer
, REGISTER_RAW_SIZE (regnum
));
1468 store_floating (virtual_buffer
, TYPE_LENGTH (valtype
), d
);
1470 else if (TYPE_CODE (valtype
) == TYPE_CODE_INT
&& TYPE_LENGTH (valtype
) <= 4)
1473 l
= extract_unsigned_integer (raw_buffer
, REGISTER_RAW_SIZE (regnum
));
1474 l
= ((l
>> 32) & 0xc0000000) | ((l
>> 29) & 0x3fffffff);
1475 store_unsigned_integer (virtual_buffer
, TYPE_LENGTH (valtype
), l
);
1478 error ("Cannot retrieve value from floating point register");
1482 alpha_register_convert_to_raw (struct type
*valtype
, int regnum
,
1483 char *virtual_buffer
, char *raw_buffer
)
1485 if (TYPE_LENGTH (valtype
) >= REGISTER_RAW_SIZE (regnum
))
1487 memcpy (raw_buffer
, virtual_buffer
, REGISTER_RAW_SIZE (regnum
));
1491 if (TYPE_CODE (valtype
) == TYPE_CODE_FLT
)
1493 double d
= extract_floating (virtual_buffer
, TYPE_LENGTH (valtype
));
1494 store_floating (raw_buffer
, REGISTER_RAW_SIZE (regnum
), d
);
1496 else if (TYPE_CODE (valtype
) == TYPE_CODE_INT
&& TYPE_LENGTH (valtype
) <= 4)
1499 if (TYPE_UNSIGNED (valtype
))
1500 l
= extract_unsigned_integer (virtual_buffer
, TYPE_LENGTH (valtype
));
1502 l
= extract_signed_integer (virtual_buffer
, TYPE_LENGTH (valtype
));
1503 l
= ((l
& 0xc0000000) << 32) | ((l
& 0x3fffffff) << 29);
1504 store_unsigned_integer (raw_buffer
, REGISTER_RAW_SIZE (regnum
), l
);
1507 error ("Cannot store value in floating point register");
1510 static const unsigned char *
1511 alpha_breakpoint_from_pc (CORE_ADDR
*pcptr
, int *lenptr
)
1513 static const unsigned char alpha_breakpoint
[] =
1514 { 0x80, 0, 0, 0 }; /* call_pal bpt */
1516 *lenptr
= sizeof(alpha_breakpoint
);
1517 return (alpha_breakpoint
);
1520 /* Given a return value in `regbuf' with a type `valtype',
1521 extract and copy its value into `valbuf'. */
1524 alpha_extract_return_value (struct type
*valtype
,
1525 char regbuf
[ALPHA_REGISTER_BYTES
], char *valbuf
)
1527 if (TYPE_CODE (valtype
) == TYPE_CODE_FLT
)
1528 alpha_register_convert_to_virtual (FP0_REGNUM
, valtype
,
1529 regbuf
+ REGISTER_BYTE (FP0_REGNUM
),
1532 memcpy (valbuf
, regbuf
+ REGISTER_BYTE (ALPHA_V0_REGNUM
),
1533 TYPE_LENGTH (valtype
));
1536 /* Given a return value in `regbuf' with a type `valtype',
1537 write its value into the appropriate register. */
1540 alpha_store_return_value (struct type
*valtype
, char *valbuf
)
1542 char raw_buffer
[ALPHA_MAX_REGISTER_RAW_SIZE
];
1543 int regnum
= ALPHA_V0_REGNUM
;
1544 int length
= TYPE_LENGTH (valtype
);
1546 if (TYPE_CODE (valtype
) == TYPE_CODE_FLT
)
1548 regnum
= FP0_REGNUM
;
1549 length
= REGISTER_RAW_SIZE (regnum
);
1550 alpha_register_convert_to_raw (valtype
, regnum
, valbuf
, raw_buffer
);
1553 memcpy (raw_buffer
, valbuf
, length
);
1555 deprecated_write_register_bytes (REGISTER_BYTE (regnum
), raw_buffer
, length
);
1558 /* Just like reinit_frame_cache, but with the right arguments to be
1559 callable as an sfunc. */
1562 reinit_frame_cache_sfunc (char *args
, int from_tty
, struct cmd_list_element
*c
)
1564 reinit_frame_cache ();
1567 /* This is the definition of CALL_DUMMY_ADDRESS. It's a heuristic that is used
1568 to find a convenient place in the text segment to stick a breakpoint to
1569 detect the completion of a target function call (ala call_function_by_hand).
1573 alpha_call_dummy_address (void)
1576 struct minimal_symbol
*sym
;
1578 entry
= entry_point_address ();
1583 sym
= lookup_minimal_symbol ("_Prelude", NULL
, symfile_objfile
);
1585 if (!sym
|| MSYMBOL_TYPE (sym
) != mst_text
)
1588 return SYMBOL_VALUE_ADDRESS (sym
) + 4;
1592 alpha_fix_call_dummy (char *dummy
, CORE_ADDR pc
, CORE_ADDR fun
, int nargs
,
1593 struct value
**args
, struct type
*type
, int gcc_p
)
1595 CORE_ADDR bp_address
= CALL_DUMMY_ADDRESS ();
1597 if (bp_address
== 0)
1598 error ("no place to put call");
1599 write_register (ALPHA_RA_REGNUM
, bp_address
);
1600 write_register (ALPHA_T12_REGNUM
, fun
);
1603 /* On the Alpha, the call dummy code is nevery copied to user space
1604 (see alpha_fix_call_dummy() above). The contents of this do not
1606 LONGEST alpha_call_dummy_words
[] = { 0 };
1609 alpha_use_struct_convention (int gcc_p
, struct type
*type
)
1611 /* Structures are returned by ref in extra arg0. */
1616 alpha_store_struct_return (CORE_ADDR addr
, CORE_ADDR sp
)
1618 /* Store the address of the place in which to copy the structure the
1619 subroutine will return. Handled by alpha_push_arguments. */
1623 alpha_extract_struct_value_address (char *regbuf
)
1625 return (extract_address (regbuf
+ REGISTER_BYTE (ALPHA_V0_REGNUM
),
1626 REGISTER_RAW_SIZE (ALPHA_V0_REGNUM
)));
1629 /* Figure out where the longjmp will land.
1630 We expect the first arg to be a pointer to the jmp_buf structure from
1631 which we extract the PC (JB_PC) that we will land at. The PC is copied
1632 into the "pc". This routine returns true on success. */
1635 alpha_get_longjmp_target (CORE_ADDR
*pc
)
1637 struct gdbarch_tdep
*tdep
= gdbarch_tdep (current_gdbarch
);
1639 char raw_buffer
[ALPHA_MAX_REGISTER_RAW_SIZE
];
1641 jb_addr
= read_register (ALPHA_A0_REGNUM
);
1643 if (target_read_memory (jb_addr
+ (tdep
->jb_pc
* tdep
->jb_elt_size
),
1644 raw_buffer
, tdep
->jb_elt_size
))
1647 *pc
= extract_address (raw_buffer
, tdep
->jb_elt_size
);
1651 /* alpha_software_single_step() is called just before we want to resume
1652 the inferior, if we want to single-step it but there is no hardware
1653 or kernel single-step support (NetBSD on Alpha, for example). We find
1654 the target of the coming instruction and breakpoint it.
1656 single_step is also called just after the inferior stops. If we had
1657 set up a simulated single-step, we undo our damage. */
1660 alpha_next_pc (CORE_ADDR pc
)
1667 insn
= read_memory_unsigned_integer (pc
, sizeof (insn
));
1669 /* Opcode is top 6 bits. */
1670 op
= (insn
>> 26) & 0x3f;
1674 /* Jump format: target PC is:
1676 return (read_register ((insn
>> 16) & 0x1f) & ~3);
1679 if ((op
& 0x30) == 0x30)
1681 /* Branch format: target PC is:
1682 (new PC) + (4 * sext(displacement)) */
1683 if (op
== 0x30 || /* BR */
1684 op
== 0x34) /* BSR */
1687 offset
= (insn
& 0x001fffff);
1688 if (offset
& 0x00100000)
1689 offset
|= 0xffe00000;
1691 return (pc
+ 4 + offset
);
1694 /* Need to determine if branch is taken; read RA. */
1695 rav
= (LONGEST
) read_register ((insn
>> 21) & 0x1f);
1698 case 0x38: /* BLBC */
1702 case 0x3c: /* BLBS */
1706 case 0x39: /* BEQ */
1710 case 0x3d: /* BNE */
1714 case 0x3a: /* BLT */
1718 case 0x3b: /* BLE */
1722 case 0x3f: /* BGT */
1726 case 0x3e: /* BGE */
1733 /* Not a branch or branch not taken; target PC is:
1739 alpha_software_single_step (enum target_signal sig
, int insert_breakpoints_p
)
1741 static CORE_ADDR next_pc
;
1742 typedef char binsn_quantum
[BREAKPOINT_MAX
];
1743 static binsn_quantum break_mem
;
1746 if (insert_breakpoints_p
)
1749 next_pc
= alpha_next_pc (pc
);
1751 target_insert_breakpoint (next_pc
, break_mem
);
1755 target_remove_breakpoint (next_pc
, break_mem
);
1762 /* Initialize the current architecture based on INFO. If possible, re-use an
1763 architecture from ARCHES, which is a list of architectures already created
1764 during this debugging session.
1766 Called e.g. at program startup, when reading a core file, and when reading
1769 static struct gdbarch
*
1770 alpha_gdbarch_init (struct gdbarch_info info
, struct gdbarch_list
*arches
)
1772 struct gdbarch_tdep
*tdep
;
1773 struct gdbarch
*gdbarch
;
1775 /* Try to determine the ABI of the object we are loading. */
1776 if (info
.abfd
!= NULL
&& info
.osabi
== GDB_OSABI_UNKNOWN
)
1778 /* If it's an ECOFF file, assume it's OSF/1. */
1779 if (bfd_get_flavour (info
.abfd
) == bfd_target_ecoff_flavour
)
1780 info
.osabi
= GDB_OSABI_OSF1
;
1783 /* Find a candidate among extant architectures. */
1784 arches
= gdbarch_list_lookup_by_info (arches
, &info
);
1786 return arches
->gdbarch
;
1788 tdep
= xmalloc (sizeof (struct gdbarch_tdep
));
1789 gdbarch
= gdbarch_alloc (&info
, tdep
);
1791 /* Lowest text address. This is used by heuristic_proc_start() to
1792 decide when to stop looking. */
1793 tdep
->vm_min_address
= (CORE_ADDR
) 0x120000000;
1795 tdep
->dynamic_sigtramp_offset
= NULL
;
1796 tdep
->skip_sigtramp_frame
= NULL
;
1797 tdep
->sigcontext_addr
= NULL
;
1799 tdep
->jb_pc
= -1; /* longjmp support not enabled by default */
1802 set_gdbarch_short_bit (gdbarch
, 16);
1803 set_gdbarch_int_bit (gdbarch
, 32);
1804 set_gdbarch_long_bit (gdbarch
, 64);
1805 set_gdbarch_long_long_bit (gdbarch
, 64);
1806 set_gdbarch_float_bit (gdbarch
, 32);
1807 set_gdbarch_double_bit (gdbarch
, 64);
1808 set_gdbarch_long_double_bit (gdbarch
, 64);
1809 set_gdbarch_ptr_bit (gdbarch
, 64);
1812 set_gdbarch_num_regs (gdbarch
, ALPHA_NUM_REGS
);
1813 set_gdbarch_sp_regnum (gdbarch
, ALPHA_SP_REGNUM
);
1814 set_gdbarch_fp_regnum (gdbarch
, ALPHA_FP_REGNUM
);
1815 set_gdbarch_pc_regnum (gdbarch
, ALPHA_PC_REGNUM
);
1816 set_gdbarch_fp0_regnum (gdbarch
, ALPHA_FP0_REGNUM
);
1818 set_gdbarch_register_name (gdbarch
, alpha_register_name
);
1819 set_gdbarch_register_size (gdbarch
, ALPHA_REGISTER_SIZE
);
1820 set_gdbarch_register_bytes (gdbarch
, ALPHA_REGISTER_BYTES
);
1821 set_gdbarch_register_byte (gdbarch
, alpha_register_byte
);
1822 set_gdbarch_register_raw_size (gdbarch
, alpha_register_raw_size
);
1823 set_gdbarch_max_register_raw_size (gdbarch
, ALPHA_MAX_REGISTER_RAW_SIZE
);
1824 set_gdbarch_register_virtual_size (gdbarch
, alpha_register_virtual_size
);
1825 set_gdbarch_max_register_virtual_size (gdbarch
,
1826 ALPHA_MAX_REGISTER_VIRTUAL_SIZE
);
1827 set_gdbarch_register_virtual_type (gdbarch
, alpha_register_virtual_type
);
1829 set_gdbarch_cannot_fetch_register (gdbarch
, alpha_cannot_fetch_register
);
1830 set_gdbarch_cannot_store_register (gdbarch
, alpha_cannot_store_register
);
1832 set_gdbarch_register_convertible (gdbarch
, alpha_register_convertible
);
1833 set_gdbarch_register_convert_to_virtual (gdbarch
,
1834 alpha_register_convert_to_virtual
);
1835 set_gdbarch_register_convert_to_raw (gdbarch
, alpha_register_convert_to_raw
);
1837 set_gdbarch_skip_prologue (gdbarch
, alpha_skip_prologue
);
1839 set_gdbarch_frame_num_args (gdbarch
, frame_num_args_unknown
);
1840 set_gdbarch_frameless_function_invocation (gdbarch
,
1841 generic_frameless_function_invocation_not
);
1843 set_gdbarch_saved_pc_after_call (gdbarch
, alpha_saved_pc_after_call
);
1845 set_gdbarch_frame_chain (gdbarch
, alpha_frame_chain
);
1846 set_gdbarch_frame_saved_pc (gdbarch
, alpha_frame_saved_pc
);
1848 set_gdbarch_frame_init_saved_regs (gdbarch
, alpha_frame_init_saved_regs
);
1850 set_gdbarch_use_struct_convention (gdbarch
, alpha_use_struct_convention
);
1851 set_gdbarch_deprecated_extract_return_value (gdbarch
, alpha_extract_return_value
);
1853 set_gdbarch_store_struct_return (gdbarch
, alpha_store_struct_return
);
1854 set_gdbarch_deprecated_store_return_value (gdbarch
, alpha_store_return_value
);
1855 set_gdbarch_deprecated_extract_struct_value_address (gdbarch
,
1856 alpha_extract_struct_value_address
);
1858 /* Settings for calling functions in the inferior. */
1859 set_gdbarch_deprecated_use_generic_dummy_frames (gdbarch
, 0);
1860 set_gdbarch_call_dummy_length (gdbarch
, 0);
1861 set_gdbarch_push_arguments (gdbarch
, alpha_push_arguments
);
1862 set_gdbarch_pop_frame (gdbarch
, alpha_pop_frame
);
1864 /* On the Alpha, the call dummy code is never copied to user space,
1865 stopping the user call is achieved via a bp_call_dummy breakpoint.
1866 But we need a fake CALL_DUMMY definition to enable the proper
1867 call_function_by_hand and to avoid zero length array warnings. */
1868 set_gdbarch_call_dummy_p (gdbarch
, 1);
1869 set_gdbarch_call_dummy_words (gdbarch
, alpha_call_dummy_words
);
1870 set_gdbarch_sizeof_call_dummy_words (gdbarch
, 0);
1871 set_gdbarch_frame_args_address (gdbarch
, alpha_frame_args_address
);
1872 set_gdbarch_frame_locals_address (gdbarch
, alpha_frame_locals_address
);
1873 set_gdbarch_init_extra_frame_info (gdbarch
, alpha_init_extra_frame_info
);
1875 /* Alpha OSF/1 inhibits execution of code on the stack. But there is
1876 no need for a dummy on the Alpha. PUSH_ARGUMENTS takes care of all
1877 argument handling and bp_call_dummy takes care of stopping the dummy. */
1878 set_gdbarch_call_dummy_address (gdbarch
, alpha_call_dummy_address
);
1879 set_gdbarch_call_dummy_breakpoint_offset_p (gdbarch
, 1);
1880 set_gdbarch_call_dummy_breakpoint_offset (gdbarch
, 0);
1881 set_gdbarch_call_dummy_start_offset (gdbarch
, 0);
1882 set_gdbarch_deprecated_pc_in_call_dummy (gdbarch
, deprecated_pc_in_call_dummy_at_entry_point
);
1883 set_gdbarch_call_dummy_stack_adjust_p (gdbarch
, 0);
1884 set_gdbarch_push_dummy_frame (gdbarch
, alpha_push_dummy_frame
);
1885 set_gdbarch_fix_call_dummy (gdbarch
, alpha_fix_call_dummy
);
1886 set_gdbarch_deprecated_init_frame_pc (gdbarch
, init_frame_pc_noop
);
1887 set_gdbarch_deprecated_init_frame_pc_first (gdbarch
, alpha_init_frame_pc_first
);
1889 set_gdbarch_inner_than (gdbarch
, core_addr_lessthan
);
1890 set_gdbarch_skip_trampoline_code (gdbarch
, find_solib_trampoline_target
);
1892 set_gdbarch_breakpoint_from_pc (gdbarch
, alpha_breakpoint_from_pc
);
1893 set_gdbarch_decr_pc_after_break (gdbarch
, 4);
1895 set_gdbarch_function_start_offset (gdbarch
, 0);
1896 set_gdbarch_frame_args_skip (gdbarch
, 0);
1898 /* Hook in ABI-specific overrides, if they have been registered. */
1899 gdbarch_init_osabi (info
, gdbarch
);
1901 /* Now that we have tuned the configuration, set a few final things
1902 based on what the OS ABI has told us. */
1904 if (tdep
->jb_pc
>= 0)
1905 set_gdbarch_get_longjmp_target (gdbarch
, alpha_get_longjmp_target
);
1911 alpha_dump_tdep (struct gdbarch
*current_gdbarch
, struct ui_file
*file
)
1913 struct gdbarch_tdep
*tdep
= gdbarch_tdep (current_gdbarch
);
1918 fprintf_unfiltered (file
,
1919 "alpha_dump_tdep: vm_min_address = 0x%lx\n",
1920 (long) tdep
->vm_min_address
);
1922 fprintf_unfiltered (file
,
1923 "alpha_dump_tdep: jb_pc = %d\n",
1925 fprintf_unfiltered (file
,
1926 "alpha_dump_tdep: jb_elt_size = %ld\n",
1927 (long) tdep
->jb_elt_size
);
1931 _initialize_alpha_tdep (void)
1933 struct cmd_list_element
*c
;
1935 gdbarch_register (bfd_arch_alpha
, alpha_gdbarch_init
, alpha_dump_tdep
);
1937 tm_print_insn
= print_insn_alpha
;
1939 /* Let the user set the fence post for heuristic_proc_start. */
1941 /* We really would like to have both "0" and "unlimited" work, but
1942 command.c doesn't deal with that. So make it a var_zinteger
1943 because the user can always use "999999" or some such for unlimited. */
1944 c
= add_set_cmd ("heuristic-fence-post", class_support
, var_zinteger
,
1945 (char *) &heuristic_fence_post
,
1947 Set the distance searched for the start of a function.\n\
1948 If you are debugging a stripped executable, GDB needs to search through the\n\
1949 program for the start of a function. This command sets the distance of the\n\
1950 search. The only need to set it is when debugging a stripped executable.",
1952 /* We need to throw away the frame cache when we set this, since it
1953 might change our ability to get backtraces. */
1954 set_cmd_sfunc (c
, reinit_frame_cache_sfunc
);
1955 add_show_from_set (c
, &showlist
);