1 /* Target-dependent code for the ALPHA architecture, for GDB, the GNU Debugger.
3 Copyright (C) 1993-2018 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 3 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, see <http://www.gnu.org/licenses/>. */
22 #include "frame-unwind.h"
23 #include "frame-base.h"
24 #include "dwarf2-frame.h"
35 #include "reggroups.h"
36 #include "arch-utils.h"
40 #include "trad-frame.h"
44 #include "alpha-tdep.h"
47 /* Instruction decoding. The notations for registers, immediates and
48 opcodes are the same as the one used in Compaq's Alpha architecture
51 #define INSN_OPCODE(insn) ((insn & 0xfc000000) >> 26)
53 /* Memory instruction format */
54 #define MEM_RA(insn) ((insn & 0x03e00000) >> 21)
55 #define MEM_RB(insn) ((insn & 0x001f0000) >> 16)
56 #define MEM_DISP(insn) \
57 (((insn & 0x8000) == 0) ? (insn & 0xffff) : -((-insn) & 0xffff))
59 static const int lda_opcode
= 0x08;
60 static const int stq_opcode
= 0x2d;
62 /* Branch instruction format */
63 #define BR_RA(insn) MEM_RA(insn)
65 static const int br_opcode
= 0x30;
66 static const int bne_opcode
= 0x3d;
68 /* Operate instruction format */
69 #define OPR_FUNCTION(insn) ((insn & 0xfe0) >> 5)
70 #define OPR_HAS_IMMEDIATE(insn) ((insn & 0x1000) == 0x1000)
71 #define OPR_RA(insn) MEM_RA(insn)
72 #define OPR_RC(insn) ((insn & 0x1f))
73 #define OPR_LIT(insn) ((insn & 0x1fe000) >> 13)
75 static const int subq_opcode
= 0x10;
76 static const int subq_function
= 0x29;
79 /* Return the name of the REGNO register.
81 An empty name corresponds to a register number that used to
82 be used for a virtual register. That virtual register has
83 been removed, but the index is still reserved to maintain
84 compatibility with existing remote alpha targets. */
87 alpha_register_name (struct gdbarch
*gdbarch
, int regno
)
89 static const char * const register_names
[] =
91 "v0", "t0", "t1", "t2", "t3", "t4", "t5", "t6",
92 "t7", "s0", "s1", "s2", "s3", "s4", "s5", "fp",
93 "a0", "a1", "a2", "a3", "a4", "a5", "t8", "t9",
94 "t10", "t11", "ra", "t12", "at", "gp", "sp", "zero",
95 "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",
96 "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15",
97 "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23",
98 "f24", "f25", "f26", "f27", "f28", "f29", "f30", "fpcr",
104 if (regno
>= ARRAY_SIZE(register_names
))
106 return register_names
[regno
];
110 alpha_cannot_fetch_register (struct gdbarch
*gdbarch
, int regno
)
112 return (strlen (alpha_register_name (gdbarch
, regno
)) == 0);
116 alpha_cannot_store_register (struct gdbarch
*gdbarch
, int regno
)
118 return (regno
== ALPHA_ZERO_REGNUM
119 || strlen (alpha_register_name (gdbarch
, regno
)) == 0);
123 alpha_register_type (struct gdbarch
*gdbarch
, int regno
)
125 if (regno
== ALPHA_SP_REGNUM
|| regno
== ALPHA_GP_REGNUM
)
126 return builtin_type (gdbarch
)->builtin_data_ptr
;
127 if (regno
== ALPHA_PC_REGNUM
)
128 return builtin_type (gdbarch
)->builtin_func_ptr
;
130 /* Don't need to worry about little vs big endian until
131 some jerk tries to port to alpha-unicosmk. */
132 if (regno
>= ALPHA_FP0_REGNUM
&& regno
< ALPHA_FP0_REGNUM
+ 31)
133 return builtin_type (gdbarch
)->builtin_double
;
135 return builtin_type (gdbarch
)->builtin_int64
;
138 /* Is REGNUM a member of REGGROUP? */
141 alpha_register_reggroup_p (struct gdbarch
*gdbarch
, int regnum
,
142 struct reggroup
*group
)
144 /* Filter out any registers eliminated, but whose regnum is
145 reserved for backward compatibility, e.g. the vfp. */
146 if (gdbarch_register_name (gdbarch
, regnum
) == NULL
147 || *gdbarch_register_name (gdbarch
, regnum
) == '\0')
150 if (group
== all_reggroup
)
153 /* Zero should not be saved or restored. Technically it is a general
154 register (just as $f31 would be a float if we represented it), but
155 there's no point displaying it during "info regs", so leave it out
156 of all groups except for "all". */
157 if (regnum
== ALPHA_ZERO_REGNUM
)
160 /* All other registers are saved and restored. */
161 if (group
== save_reggroup
|| group
== restore_reggroup
)
164 /* All other groups are non-overlapping. */
166 /* Since this is really a PALcode memory slot... */
167 if (regnum
== ALPHA_UNIQUE_REGNUM
)
168 return group
== system_reggroup
;
170 /* Force the FPCR to be considered part of the floating point state. */
171 if (regnum
== ALPHA_FPCR_REGNUM
)
172 return group
== float_reggroup
;
174 if (regnum
>= ALPHA_FP0_REGNUM
&& regnum
< ALPHA_FP0_REGNUM
+ 31)
175 return group
== float_reggroup
;
177 return group
== general_reggroup
;
180 /* The following represents exactly the conversion performed by
181 the LDS instruction. This applies to both single-precision
182 floating point and 32-bit integers. */
185 alpha_lds (struct gdbarch
*gdbarch
, void *out
, const void *in
)
187 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
189 = extract_unsigned_integer ((const gdb_byte
*) in
, 4, byte_order
);
190 ULONGEST frac
= (mem
>> 0) & 0x7fffff;
191 ULONGEST sign
= (mem
>> 31) & 1;
192 ULONGEST exp_msb
= (mem
>> 30) & 1;
193 ULONGEST exp_low
= (mem
>> 23) & 0x7f;
196 exp
= (exp_msb
<< 10) | exp_low
;
208 reg
= (sign
<< 63) | (exp
<< 52) | (frac
<< 29);
209 store_unsigned_integer ((gdb_byte
*) out
, 8, byte_order
, reg
);
212 /* Similarly, this represents exactly the conversion performed by
213 the STS instruction. */
216 alpha_sts (struct gdbarch
*gdbarch
, void *out
, const void *in
)
218 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
221 reg
= extract_unsigned_integer ((const gdb_byte
*) in
, 8, byte_order
);
222 mem
= ((reg
>> 32) & 0xc0000000) | ((reg
>> 29) & 0x3fffffff);
223 store_unsigned_integer ((gdb_byte
*) out
, 4, byte_order
, mem
);
226 /* The alpha needs a conversion between register and memory format if the
227 register is a floating point register and memory format is float, as the
228 register format must be double or memory format is an integer with 4
229 bytes, as the representation of integers in floating point
230 registers is different. */
233 alpha_convert_register_p (struct gdbarch
*gdbarch
, int regno
,
236 return (regno
>= ALPHA_FP0_REGNUM
&& regno
< ALPHA_FP0_REGNUM
+ 31
237 && TYPE_LENGTH (type
) == 4);
241 alpha_register_to_value (struct frame_info
*frame
, int regnum
,
242 struct type
*valtype
, gdb_byte
*out
,
243 int *optimizedp
, int *unavailablep
)
245 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
246 struct value
*value
= get_frame_register_value (frame
, regnum
);
248 gdb_assert (value
!= NULL
);
249 *optimizedp
= value_optimized_out (value
);
250 *unavailablep
= !value_entirely_available (value
);
252 if (*optimizedp
|| *unavailablep
)
254 release_value (value
);
259 /* Convert to VALTYPE. */
261 gdb_assert (TYPE_LENGTH (valtype
) == 4);
262 alpha_sts (gdbarch
, out
, value_contents_all (value
));
264 release_value (value
);
270 alpha_value_to_register (struct frame_info
*frame
, int regnum
,
271 struct type
*valtype
, const gdb_byte
*in
)
273 gdb_byte out
[ALPHA_REGISTER_SIZE
];
275 gdb_assert (TYPE_LENGTH (valtype
) == 4);
276 gdb_assert (register_size (get_frame_arch (frame
), regnum
)
277 <= ALPHA_REGISTER_SIZE
);
278 alpha_lds (get_frame_arch (frame
), out
, in
);
280 put_frame_register (frame
, regnum
, out
);
284 /* The alpha passes the first six arguments in the registers, the rest on
285 the stack. The register arguments are stored in ARG_REG_BUFFER, and
286 then moved into the register file; this simplifies the passing of a
287 large struct which extends from the registers to the stack, plus avoids
288 three ptrace invocations per word.
290 We don't bother tracking which register values should go in integer
291 regs or fp regs; we load the same values into both.
293 If the called function is returning a structure, the address of the
294 structure to be returned is passed as a hidden first argument. */
297 alpha_push_dummy_call (struct gdbarch
*gdbarch
, struct value
*function
,
298 struct regcache
*regcache
, CORE_ADDR bp_addr
,
299 int nargs
, struct value
**args
, CORE_ADDR sp
,
300 int struct_return
, CORE_ADDR struct_addr
)
302 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
304 int accumulate_size
= struct_return
? 8 : 0;
307 const gdb_byte
*contents
;
311 struct alpha_arg
*alpha_args
= XALLOCAVEC (struct alpha_arg
, nargs
);
312 struct alpha_arg
*m_arg
;
313 gdb_byte arg_reg_buffer
[ALPHA_REGISTER_SIZE
* ALPHA_NUM_ARG_REGS
];
314 int required_arg_regs
;
315 CORE_ADDR func_addr
= find_function_addr (function
, NULL
);
317 /* The ABI places the address of the called function in T12. */
318 regcache_cooked_write_signed (regcache
, ALPHA_T12_REGNUM
, func_addr
);
320 /* Set the return address register to point to the entry point
321 of the program, where a breakpoint lies in wait. */
322 regcache_cooked_write_signed (regcache
, ALPHA_RA_REGNUM
, bp_addr
);
324 /* Lay out the arguments in memory. */
325 for (i
= 0, m_arg
= alpha_args
; i
< nargs
; i
++, m_arg
++)
327 struct value
*arg
= args
[i
];
328 struct type
*arg_type
= check_typedef (value_type (arg
));
330 /* Cast argument to long if necessary as the compiler does it too. */
331 switch (TYPE_CODE (arg_type
))
336 case TYPE_CODE_RANGE
:
338 if (TYPE_LENGTH (arg_type
) == 4)
340 /* 32-bit values must be sign-extended to 64 bits
341 even if the base data type is unsigned. */
342 arg_type
= builtin_type (gdbarch
)->builtin_int32
;
343 arg
= value_cast (arg_type
, arg
);
345 if (TYPE_LENGTH (arg_type
) < ALPHA_REGISTER_SIZE
)
347 arg_type
= builtin_type (gdbarch
)->builtin_int64
;
348 arg
= value_cast (arg_type
, arg
);
353 /* "float" arguments loaded in registers must be passed in
354 register format, aka "double". */
355 if (accumulate_size
< sizeof (arg_reg_buffer
)
356 && TYPE_LENGTH (arg_type
) == 4)
358 arg_type
= builtin_type (gdbarch
)->builtin_double
;
359 arg
= value_cast (arg_type
, arg
);
361 /* Tru64 5.1 has a 128-bit long double, and passes this by
362 invisible reference. No one else uses this data type. */
363 else if (TYPE_LENGTH (arg_type
) == 16)
365 /* Allocate aligned storage. */
366 sp
= (sp
& -16) - 16;
368 /* Write the real data into the stack. */
369 write_memory (sp
, value_contents (arg
), 16);
371 /* Construct the indirection. */
372 arg_type
= lookup_pointer_type (arg_type
);
373 arg
= value_from_pointer (arg_type
, sp
);
377 case TYPE_CODE_COMPLEX
:
378 /* ??? The ABI says that complex values are passed as two
379 separate scalar values. This distinction only matters
380 for complex float. However, GCC does not implement this. */
382 /* Tru64 5.1 has a 128-bit long double, and passes this by
383 invisible reference. */
384 if (TYPE_LENGTH (arg_type
) == 32)
386 /* Allocate aligned storage. */
387 sp
= (sp
& -16) - 16;
389 /* Write the real data into the stack. */
390 write_memory (sp
, value_contents (arg
), 32);
392 /* Construct the indirection. */
393 arg_type
= lookup_pointer_type (arg_type
);
394 arg
= value_from_pointer (arg_type
, sp
);
401 m_arg
->len
= TYPE_LENGTH (arg_type
);
402 m_arg
->offset
= accumulate_size
;
403 accumulate_size
= (accumulate_size
+ m_arg
->len
+ 7) & ~7;
404 m_arg
->contents
= value_contents (arg
);
407 /* Determine required argument register loads, loading an argument register
408 is expensive as it uses three ptrace calls. */
409 required_arg_regs
= accumulate_size
/ 8;
410 if (required_arg_regs
> ALPHA_NUM_ARG_REGS
)
411 required_arg_regs
= ALPHA_NUM_ARG_REGS
;
413 /* Make room for the arguments on the stack. */
414 if (accumulate_size
< sizeof(arg_reg_buffer
))
417 accumulate_size
-= sizeof(arg_reg_buffer
);
418 sp
-= accumulate_size
;
420 /* Keep sp aligned to a multiple of 16 as the ABI requires. */
423 /* `Push' arguments on the stack. */
424 for (i
= nargs
; m_arg
--, --i
>= 0;)
426 const gdb_byte
*contents
= m_arg
->contents
;
427 int offset
= m_arg
->offset
;
428 int len
= m_arg
->len
;
430 /* Copy the bytes destined for registers into arg_reg_buffer. */
431 if (offset
< sizeof(arg_reg_buffer
))
433 if (offset
+ len
<= sizeof(arg_reg_buffer
))
435 memcpy (arg_reg_buffer
+ offset
, contents
, len
);
440 int tlen
= sizeof(arg_reg_buffer
) - offset
;
441 memcpy (arg_reg_buffer
+ offset
, contents
, tlen
);
448 /* Everything else goes to the stack. */
449 write_memory (sp
+ offset
- sizeof(arg_reg_buffer
), contents
, len
);
452 store_unsigned_integer (arg_reg_buffer
, ALPHA_REGISTER_SIZE
,
453 byte_order
, struct_addr
);
455 /* Load the argument registers. */
456 for (i
= 0; i
< required_arg_regs
; i
++)
458 regcache_cooked_write (regcache
, ALPHA_A0_REGNUM
+ i
,
459 arg_reg_buffer
+ i
*ALPHA_REGISTER_SIZE
);
460 regcache_cooked_write (regcache
, ALPHA_FPA0_REGNUM
+ i
,
461 arg_reg_buffer
+ i
*ALPHA_REGISTER_SIZE
);
464 /* Finally, update the stack pointer. */
465 regcache_cooked_write_signed (regcache
, ALPHA_SP_REGNUM
, sp
);
470 /* Extract from REGCACHE the value about to be returned from a function
471 and copy it into VALBUF. */
474 alpha_extract_return_value (struct type
*valtype
, struct regcache
*regcache
,
477 struct gdbarch
*gdbarch
= regcache
->arch ();
478 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
479 gdb_byte raw_buffer
[ALPHA_REGISTER_SIZE
];
482 switch (TYPE_CODE (valtype
))
485 switch (TYPE_LENGTH (valtype
))
488 regcache_cooked_read (regcache
, ALPHA_FP0_REGNUM
, raw_buffer
);
489 alpha_sts (gdbarch
, valbuf
, raw_buffer
);
493 regcache_cooked_read (regcache
, ALPHA_FP0_REGNUM
, valbuf
);
497 regcache_cooked_read_unsigned (regcache
, ALPHA_V0_REGNUM
, &l
);
498 read_memory (l
, valbuf
, 16);
502 internal_error (__FILE__
, __LINE__
,
503 _("unknown floating point width"));
507 case TYPE_CODE_COMPLEX
:
508 switch (TYPE_LENGTH (valtype
))
511 /* ??? This isn't correct wrt the ABI, but it's what GCC does. */
512 regcache_cooked_read (regcache
, ALPHA_FP0_REGNUM
, valbuf
);
516 regcache_cooked_read (regcache
, ALPHA_FP0_REGNUM
, valbuf
);
517 regcache_cooked_read (regcache
, ALPHA_FP0_REGNUM
+ 1, valbuf
+ 8);
521 regcache_cooked_read_unsigned (regcache
, ALPHA_V0_REGNUM
, &l
);
522 read_memory (l
, valbuf
, 32);
526 internal_error (__FILE__
, __LINE__
,
527 _("unknown floating point width"));
532 /* Assume everything else degenerates to an integer. */
533 regcache_cooked_read_unsigned (regcache
, ALPHA_V0_REGNUM
, &l
);
534 store_unsigned_integer (valbuf
, TYPE_LENGTH (valtype
), byte_order
, l
);
539 /* Insert the given value into REGCACHE as if it was being
540 returned by a function. */
543 alpha_store_return_value (struct type
*valtype
, struct regcache
*regcache
,
544 const gdb_byte
*valbuf
)
546 struct gdbarch
*gdbarch
= regcache
->arch ();
547 gdb_byte raw_buffer
[ALPHA_REGISTER_SIZE
];
550 switch (TYPE_CODE (valtype
))
553 switch (TYPE_LENGTH (valtype
))
556 alpha_lds (gdbarch
, raw_buffer
, valbuf
);
557 regcache_cooked_write (regcache
, ALPHA_FP0_REGNUM
, raw_buffer
);
561 regcache_cooked_write (regcache
, ALPHA_FP0_REGNUM
, valbuf
);
565 /* FIXME: 128-bit long doubles are returned like structures:
566 by writing into indirect storage provided by the caller
567 as the first argument. */
568 error (_("Cannot set a 128-bit long double return value."));
571 internal_error (__FILE__
, __LINE__
,
572 _("unknown floating point width"));
576 case TYPE_CODE_COMPLEX
:
577 switch (TYPE_LENGTH (valtype
))
580 /* ??? This isn't correct wrt the ABI, but it's what GCC does. */
581 regcache_cooked_write (regcache
, ALPHA_FP0_REGNUM
, valbuf
);
585 regcache_cooked_write (regcache
, ALPHA_FP0_REGNUM
, valbuf
);
586 regcache_cooked_write (regcache
, ALPHA_FP0_REGNUM
+ 1, valbuf
+ 8);
590 /* FIXME: 128-bit long doubles are returned like structures:
591 by writing into indirect storage provided by the caller
592 as the first argument. */
593 error (_("Cannot set a 128-bit long double return value."));
596 internal_error (__FILE__
, __LINE__
,
597 _("unknown floating point width"));
602 /* Assume everything else degenerates to an integer. */
603 /* 32-bit values must be sign-extended to 64 bits
604 even if the base data type is unsigned. */
605 if (TYPE_LENGTH (valtype
) == 4)
606 valtype
= builtin_type (gdbarch
)->builtin_int32
;
607 l
= unpack_long (valtype
, valbuf
);
608 regcache_cooked_write_unsigned (regcache
, ALPHA_V0_REGNUM
, l
);
613 static enum return_value_convention
614 alpha_return_value (struct gdbarch
*gdbarch
, struct value
*function
,
615 struct type
*type
, struct regcache
*regcache
,
616 gdb_byte
*readbuf
, const gdb_byte
*writebuf
)
618 enum type_code code
= TYPE_CODE (type
);
620 if ((code
== TYPE_CODE_STRUCT
621 || code
== TYPE_CODE_UNION
622 || code
== TYPE_CODE_ARRAY
)
623 && gdbarch_tdep (gdbarch
)->return_in_memory (type
))
628 regcache_raw_read_unsigned (regcache
, ALPHA_V0_REGNUM
, &addr
);
629 read_memory (addr
, readbuf
, TYPE_LENGTH (type
));
632 return RETURN_VALUE_ABI_RETURNS_ADDRESS
;
636 alpha_extract_return_value (type
, regcache
, readbuf
);
638 alpha_store_return_value (type
, regcache
, writebuf
);
640 return RETURN_VALUE_REGISTER_CONVENTION
;
644 alpha_return_in_memory_always (struct type
*type
)
650 constexpr gdb_byte alpha_break_insn
[] = { 0x80, 0, 0, 0 }; /* call_pal bpt */
652 typedef BP_MANIPULATION (alpha_break_insn
) alpha_breakpoint
;
655 /* This returns the PC of the first insn after the prologue.
656 If we can't find the prologue, then return 0. */
659 alpha_after_prologue (CORE_ADDR pc
)
661 struct symtab_and_line sal
;
662 CORE_ADDR func_addr
, func_end
;
664 if (!find_pc_partial_function (pc
, NULL
, &func_addr
, &func_end
))
667 sal
= find_pc_line (func_addr
, 0);
668 if (sal
.end
< func_end
)
671 /* The line after the prologue is after the end of the function. In this
672 case, tell the caller to find the prologue the hard way. */
676 /* Read an instruction from memory at PC, looking through breakpoints. */
679 alpha_read_insn (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
681 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
682 gdb_byte buf
[ALPHA_INSN_SIZE
];
685 res
= target_read_memory (pc
, buf
, sizeof (buf
));
687 memory_error (TARGET_XFER_E_IO
, pc
);
688 return extract_unsigned_integer (buf
, sizeof (buf
), byte_order
);
691 /* To skip prologues, I use this predicate. Returns either PC itself
692 if the code at PC does not look like a function prologue; otherwise
693 returns an address that (if we're lucky) follows the prologue. If
694 LENIENT, then we must skip everything which is involved in setting
695 up the frame (it's OK to skip more, just so long as we don't skip
696 anything which might clobber the registers which are being saved. */
699 alpha_skip_prologue (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
703 CORE_ADDR post_prologue_pc
;
704 gdb_byte buf
[ALPHA_INSN_SIZE
];
706 /* Silently return the unaltered pc upon memory errors.
707 This could happen on OSF/1 if decode_line_1 tries to skip the
708 prologue for quickstarted shared library functions when the
709 shared library is not yet mapped in.
710 Reading target memory is slow over serial lines, so we perform
711 this check only if the target has shared libraries (which all
712 Alpha targets do). */
713 if (target_read_memory (pc
, buf
, sizeof (buf
)))
716 /* See if we can determine the end of the prologue via the symbol table.
717 If so, then return either PC, or the PC after the prologue, whichever
720 post_prologue_pc
= alpha_after_prologue (pc
);
721 if (post_prologue_pc
!= 0)
722 return std::max (pc
, post_prologue_pc
);
724 /* Can't determine prologue from the symbol table, need to examine
727 /* Skip the typical prologue instructions. These are the stack adjustment
728 instruction and the instructions that save registers on the stack
729 or in the gcc frame. */
730 for (offset
= 0; offset
< 100; offset
+= ALPHA_INSN_SIZE
)
732 inst
= alpha_read_insn (gdbarch
, pc
+ offset
);
734 if ((inst
& 0xffff0000) == 0x27bb0000) /* ldah $gp,n($t12) */
736 if ((inst
& 0xffff0000) == 0x23bd0000) /* lda $gp,n($gp) */
738 if ((inst
& 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */
740 if ((inst
& 0xffe01fff) == 0x43c0153e) /* subq $sp,n,$sp */
743 if (((inst
& 0xfc1f0000) == 0xb41e0000 /* stq reg,n($sp) */
744 || (inst
& 0xfc1f0000) == 0x9c1e0000) /* stt reg,n($sp) */
745 && (inst
& 0x03e00000) != 0x03e00000) /* reg != $zero */
748 if (inst
== 0x47de040f) /* bis sp,sp,fp */
750 if (inst
== 0x47fe040f) /* bis zero,sp,fp */
759 static const int ldl_l_opcode
= 0x2a;
760 static const int ldq_l_opcode
= 0x2b;
761 static const int stl_c_opcode
= 0x2e;
762 static const int stq_c_opcode
= 0x2f;
764 /* Checks for an atomic sequence of instructions beginning with a LDL_L/LDQ_L
765 instruction and ending with a STL_C/STQ_C instruction. If such a sequence
766 is found, attempt to step through it. A breakpoint is placed at the end of
769 static std::vector
<CORE_ADDR
>
770 alpha_deal_with_atomic_sequence (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
772 CORE_ADDR breaks
[2] = {-1, -1};
774 CORE_ADDR closing_insn
; /* Instruction that closes the atomic sequence. */
775 unsigned int insn
= alpha_read_insn (gdbarch
, loc
);
778 int last_breakpoint
= 0; /* Defaults to 0 (no breakpoints placed). */
779 const int atomic_sequence_length
= 16; /* Instruction sequence length. */
780 int bc_insn_count
= 0; /* Conditional branch instruction count. */
782 /* Assume all atomic sequences start with a LDL_L/LDQ_L instruction. */
783 if (INSN_OPCODE (insn
) != ldl_l_opcode
784 && INSN_OPCODE (insn
) != ldq_l_opcode
)
787 /* Assume that no atomic sequence is longer than "atomic_sequence_length"
789 for (insn_count
= 0; insn_count
< atomic_sequence_length
; ++insn_count
)
791 loc
+= ALPHA_INSN_SIZE
;
792 insn
= alpha_read_insn (gdbarch
, loc
);
794 /* Assume that there is at most one branch in the atomic
795 sequence. If a branch is found, put a breakpoint in
796 its destination address. */
797 if (INSN_OPCODE (insn
) >= br_opcode
)
799 int immediate
= (insn
& 0x001fffff) << 2;
801 immediate
= (immediate
^ 0x400000) - 0x400000;
803 if (bc_insn_count
>= 1)
804 return {}; /* More than one branch found, fallback
805 to the standard single-step code. */
807 breaks
[1] = loc
+ ALPHA_INSN_SIZE
+ immediate
;
813 if (INSN_OPCODE (insn
) == stl_c_opcode
814 || INSN_OPCODE (insn
) == stq_c_opcode
)
818 /* Assume that the atomic sequence ends with a STL_C/STQ_C instruction. */
819 if (INSN_OPCODE (insn
) != stl_c_opcode
820 && INSN_OPCODE (insn
) != stq_c_opcode
)
824 loc
+= ALPHA_INSN_SIZE
;
826 /* Insert a breakpoint right after the end of the atomic sequence. */
829 /* Check for duplicated breakpoints. Check also for a breakpoint
830 placed (branch instruction's destination) anywhere in sequence. */
832 && (breaks
[1] == breaks
[0]
833 || (breaks
[1] >= pc
&& breaks
[1] <= closing_insn
)))
836 std::vector
<CORE_ADDR
> next_pcs
;
838 for (index
= 0; index
<= last_breakpoint
; index
++)
839 next_pcs
.push_back (breaks
[index
]);
845 /* Figure out where the longjmp will land.
846 We expect the first arg to be a pointer to the jmp_buf structure from
847 which we extract the PC (JB_PC) that we will land at. The PC is copied
848 into the "pc". This routine returns true on success. */
851 alpha_get_longjmp_target (struct frame_info
*frame
, CORE_ADDR
*pc
)
853 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
854 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
855 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
857 gdb_byte raw_buffer
[ALPHA_REGISTER_SIZE
];
859 jb_addr
= get_frame_register_unsigned (frame
, ALPHA_A0_REGNUM
);
861 if (target_read_memory (jb_addr
+ (tdep
->jb_pc
* tdep
->jb_elt_size
),
862 raw_buffer
, tdep
->jb_elt_size
))
865 *pc
= extract_unsigned_integer (raw_buffer
, tdep
->jb_elt_size
, byte_order
);
870 /* Frame unwinder for signal trampolines. We use alpha tdep bits that
871 describe the location and shape of the sigcontext structure. After
872 that, all registers are in memory, so it's easy. */
873 /* ??? Shouldn't we be able to do this generically, rather than with
874 OSABI data specific to Alpha? */
876 struct alpha_sigtramp_unwind_cache
878 CORE_ADDR sigcontext_addr
;
881 static struct alpha_sigtramp_unwind_cache
*
882 alpha_sigtramp_frame_unwind_cache (struct frame_info
*this_frame
,
883 void **this_prologue_cache
)
885 struct alpha_sigtramp_unwind_cache
*info
;
886 struct gdbarch_tdep
*tdep
;
888 if (*this_prologue_cache
)
889 return (struct alpha_sigtramp_unwind_cache
*) *this_prologue_cache
;
891 info
= FRAME_OBSTACK_ZALLOC (struct alpha_sigtramp_unwind_cache
);
892 *this_prologue_cache
= info
;
894 tdep
= gdbarch_tdep (get_frame_arch (this_frame
));
895 info
->sigcontext_addr
= tdep
->sigcontext_addr (this_frame
);
900 /* Return the address of REGNUM in a sigtramp frame. Since this is
901 all arithmetic, it doesn't seem worthwhile to cache it. */
904 alpha_sigtramp_register_address (struct gdbarch
*gdbarch
,
905 CORE_ADDR sigcontext_addr
, int regnum
)
907 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
909 if (regnum
>= 0 && regnum
< 32)
910 return sigcontext_addr
+ tdep
->sc_regs_offset
+ regnum
* 8;
911 else if (regnum
>= ALPHA_FP0_REGNUM
&& regnum
< ALPHA_FP0_REGNUM
+ 32)
912 return sigcontext_addr
+ tdep
->sc_fpregs_offset
+ regnum
* 8;
913 else if (regnum
== ALPHA_PC_REGNUM
)
914 return sigcontext_addr
+ tdep
->sc_pc_offset
;
919 /* Given a GDB frame, determine the address of the calling function's
920 frame. This will be used to create a new GDB frame struct. */
923 alpha_sigtramp_frame_this_id (struct frame_info
*this_frame
,
924 void **this_prologue_cache
,
925 struct frame_id
*this_id
)
927 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
928 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
929 struct alpha_sigtramp_unwind_cache
*info
930 = alpha_sigtramp_frame_unwind_cache (this_frame
, this_prologue_cache
);
931 CORE_ADDR stack_addr
, code_addr
;
933 /* If the OSABI couldn't locate the sigcontext, give up. */
934 if (info
->sigcontext_addr
== 0)
937 /* If we have dynamic signal trampolines, find their start.
938 If we do not, then we must assume there is a symbol record
939 that can provide the start address. */
940 if (tdep
->dynamic_sigtramp_offset
)
943 code_addr
= get_frame_pc (this_frame
);
944 offset
= tdep
->dynamic_sigtramp_offset (gdbarch
, code_addr
);
951 code_addr
= get_frame_func (this_frame
);
953 /* The stack address is trivially read from the sigcontext. */
954 stack_addr
= alpha_sigtramp_register_address (gdbarch
, info
->sigcontext_addr
,
956 stack_addr
= get_frame_memory_unsigned (this_frame
, stack_addr
,
957 ALPHA_REGISTER_SIZE
);
959 *this_id
= frame_id_build (stack_addr
, code_addr
);
962 /* Retrieve the value of REGNUM in FRAME. Don't give up! */
964 static struct value
*
965 alpha_sigtramp_frame_prev_register (struct frame_info
*this_frame
,
966 void **this_prologue_cache
, int regnum
)
968 struct alpha_sigtramp_unwind_cache
*info
969 = alpha_sigtramp_frame_unwind_cache (this_frame
, this_prologue_cache
);
972 if (info
->sigcontext_addr
!= 0)
974 /* All integer and fp registers are stored in memory. */
975 addr
= alpha_sigtramp_register_address (get_frame_arch (this_frame
),
976 info
->sigcontext_addr
, regnum
);
978 return frame_unwind_got_memory (this_frame
, regnum
, addr
);
981 /* This extra register may actually be in the sigcontext, but our
982 current description of it in alpha_sigtramp_frame_unwind_cache
983 doesn't include it. Too bad. Fall back on whatever's in the
985 return frame_unwind_got_register (this_frame
, regnum
, regnum
);
989 alpha_sigtramp_frame_sniffer (const struct frame_unwind
*self
,
990 struct frame_info
*this_frame
,
991 void **this_prologue_cache
)
993 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
994 CORE_ADDR pc
= get_frame_pc (this_frame
);
997 /* NOTE: cagney/2004-04-30: Do not copy/clone this code. Instead
998 look at tramp-frame.h and other simplier per-architecture
999 sigtramp unwinders. */
1001 /* We shouldn't even bother to try if the OSABI didn't register a
1002 sigcontext_addr handler or pc_in_sigtramp hander. */
1003 if (gdbarch_tdep (gdbarch
)->sigcontext_addr
== NULL
)
1005 if (gdbarch_tdep (gdbarch
)->pc_in_sigtramp
== NULL
)
1008 /* Otherwise we should be in a signal frame. */
1009 find_pc_partial_function (pc
, &name
, NULL
, NULL
);
1010 if (gdbarch_tdep (gdbarch
)->pc_in_sigtramp (gdbarch
, pc
, name
))
1016 static const struct frame_unwind alpha_sigtramp_frame_unwind
= {
1018 default_frame_unwind_stop_reason
,
1019 alpha_sigtramp_frame_this_id
,
1020 alpha_sigtramp_frame_prev_register
,
1022 alpha_sigtramp_frame_sniffer
1027 /* Heuristic_proc_start may hunt through the text section for a long
1028 time across a 2400 baud serial line. Allows the user to limit this
1030 static int heuristic_fence_post
= 0;
1032 /* Attempt to locate the start of the function containing PC. We assume that
1033 the previous function ends with an about_to_return insn. Not foolproof by
1034 any means, since gcc is happy to put the epilogue in the middle of a
1035 function. But we're guessing anyway... */
1038 alpha_heuristic_proc_start (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
1040 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
1041 CORE_ADDR last_non_nop
= pc
;
1042 CORE_ADDR fence
= pc
- heuristic_fence_post
;
1043 CORE_ADDR orig_pc
= pc
;
1045 struct inferior
*inf
;
1050 /* First see if we can find the start of the function from minimal
1051 symbol information. This can succeed with a binary that doesn't
1052 have debug info, but hasn't been stripped. */
1053 func
= get_pc_function_start (pc
);
1057 if (heuristic_fence_post
== -1
1058 || fence
< tdep
->vm_min_address
)
1059 fence
= tdep
->vm_min_address
;
1061 /* Search back for previous return; also stop at a 0, which might be
1062 seen for instance before the start of a code section. Don't include
1063 nops, since this usually indicates padding between functions. */
1064 for (pc
-= ALPHA_INSN_SIZE
; pc
>= fence
; pc
-= ALPHA_INSN_SIZE
)
1066 unsigned int insn
= alpha_read_insn (gdbarch
, pc
);
1069 case 0: /* invalid insn */
1070 case 0x6bfa8001: /* ret $31,($26),1 */
1071 return last_non_nop
;
1073 case 0x2ffe0000: /* unop: ldq_u $31,0($30) */
1074 case 0x47ff041f: /* nop: bis $31,$31,$31 */
1083 inf
= current_inferior ();
1085 /* It's not clear to me why we reach this point when stopping quietly,
1086 but with this test, at least we don't print out warnings for every
1087 child forked (eg, on decstation). 22apr93 rich@cygnus.com. */
1088 if (inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
1090 static int blurb_printed
= 0;
1092 if (fence
== tdep
->vm_min_address
)
1093 warning (_("Hit beginning of text section without finding \
1094 enclosing function for address %s"), paddress (gdbarch
, orig_pc
));
1096 warning (_("Hit heuristic-fence-post without finding \
1097 enclosing function for address %s"), paddress (gdbarch
, orig_pc
));
1101 printf_filtered (_("\
1102 This warning occurs if you are debugging a function without any symbols\n\
1103 (for example, in a stripped executable). In that case, you may wish to\n\
1104 increase the size of the search with the `set heuristic-fence-post' command.\n\
1106 Otherwise, you told GDB there was a function where there isn't one, or\n\
1107 (more likely) you have encountered a bug in GDB.\n"));
1115 /* Fallback alpha frame unwinder. Uses instruction scanning and knows
1116 something about the traditional layout of alpha stack frames. */
1118 struct alpha_heuristic_unwind_cache
1122 struct trad_frame_saved_reg
*saved_regs
;
1126 /* If a probing loop sequence starts at PC, simulate it and compute
1127 FRAME_SIZE and PC after its execution. Otherwise, return with PC and
1128 FRAME_SIZE unchanged. */
1131 alpha_heuristic_analyze_probing_loop (struct gdbarch
*gdbarch
, CORE_ADDR
*pc
,
1134 CORE_ADDR cur_pc
= *pc
;
1135 int cur_frame_size
= *frame_size
;
1136 int nb_of_iterations
, reg_index
, reg_probe
;
1139 /* The following pattern is recognized as a probing loop:
1141 lda REG_INDEX,NB_OF_ITERATIONS
1142 lda REG_PROBE,<immediate>(sp)
1145 stq zero,<immediate>(REG_PROBE)
1146 subq REG_INDEX,0x1,REG_INDEX
1147 lda REG_PROBE,<immediate>(REG_PROBE)
1148 bne REG_INDEX, LOOP_START
1150 lda sp,<immediate>(REG_PROBE)
1152 If anything different is found, the function returns without
1153 changing PC and FRAME_SIZE. Otherwise, PC will point immediately
1154 after this sequence, and FRAME_SIZE will be updated. */
1156 /* lda REG_INDEX,NB_OF_ITERATIONS */
1158 insn
= alpha_read_insn (gdbarch
, cur_pc
);
1159 if (INSN_OPCODE (insn
) != lda_opcode
)
1161 reg_index
= MEM_RA (insn
);
1162 nb_of_iterations
= MEM_DISP (insn
);
1164 /* lda REG_PROBE,<immediate>(sp) */
1166 cur_pc
+= ALPHA_INSN_SIZE
;
1167 insn
= alpha_read_insn (gdbarch
, cur_pc
);
1168 if (INSN_OPCODE (insn
) != lda_opcode
1169 || MEM_RB (insn
) != ALPHA_SP_REGNUM
)
1171 reg_probe
= MEM_RA (insn
);
1172 cur_frame_size
-= MEM_DISP (insn
);
1174 /* stq zero,<immediate>(REG_PROBE) */
1176 cur_pc
+= ALPHA_INSN_SIZE
;
1177 insn
= alpha_read_insn (gdbarch
, cur_pc
);
1178 if (INSN_OPCODE (insn
) != stq_opcode
1179 || MEM_RA (insn
) != 0x1f
1180 || MEM_RB (insn
) != reg_probe
)
1183 /* subq REG_INDEX,0x1,REG_INDEX */
1185 cur_pc
+= ALPHA_INSN_SIZE
;
1186 insn
= alpha_read_insn (gdbarch
, cur_pc
);
1187 if (INSN_OPCODE (insn
) != subq_opcode
1188 || !OPR_HAS_IMMEDIATE (insn
)
1189 || OPR_FUNCTION (insn
) != subq_function
1190 || OPR_LIT(insn
) != 1
1191 || OPR_RA (insn
) != reg_index
1192 || OPR_RC (insn
) != reg_index
)
1195 /* lda REG_PROBE,<immediate>(REG_PROBE) */
1197 cur_pc
+= ALPHA_INSN_SIZE
;
1198 insn
= alpha_read_insn (gdbarch
, cur_pc
);
1199 if (INSN_OPCODE (insn
) != lda_opcode
1200 || MEM_RA (insn
) != reg_probe
1201 || MEM_RB (insn
) != reg_probe
)
1203 cur_frame_size
-= MEM_DISP (insn
) * nb_of_iterations
;
1205 /* bne REG_INDEX, LOOP_START */
1207 cur_pc
+= ALPHA_INSN_SIZE
;
1208 insn
= alpha_read_insn (gdbarch
, cur_pc
);
1209 if (INSN_OPCODE (insn
) != bne_opcode
1210 || MEM_RA (insn
) != reg_index
)
1213 /* lda sp,<immediate>(REG_PROBE) */
1215 cur_pc
+= ALPHA_INSN_SIZE
;
1216 insn
= alpha_read_insn (gdbarch
, cur_pc
);
1217 if (INSN_OPCODE (insn
) != lda_opcode
1218 || MEM_RA (insn
) != ALPHA_SP_REGNUM
1219 || MEM_RB (insn
) != reg_probe
)
1221 cur_frame_size
-= MEM_DISP (insn
);
1224 *frame_size
= cur_frame_size
;
1227 static struct alpha_heuristic_unwind_cache
*
1228 alpha_heuristic_frame_unwind_cache (struct frame_info
*this_frame
,
1229 void **this_prologue_cache
,
1232 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
1233 struct alpha_heuristic_unwind_cache
*info
;
1235 CORE_ADDR limit_pc
, cur_pc
;
1236 int frame_reg
, frame_size
, return_reg
, reg
;
1238 if (*this_prologue_cache
)
1239 return (struct alpha_heuristic_unwind_cache
*) *this_prologue_cache
;
1241 info
= FRAME_OBSTACK_ZALLOC (struct alpha_heuristic_unwind_cache
);
1242 *this_prologue_cache
= info
;
1243 info
->saved_regs
= trad_frame_alloc_saved_regs (this_frame
);
1245 limit_pc
= get_frame_pc (this_frame
);
1247 start_pc
= alpha_heuristic_proc_start (gdbarch
, limit_pc
);
1248 info
->start_pc
= start_pc
;
1250 frame_reg
= ALPHA_SP_REGNUM
;
1254 /* If we've identified a likely place to start, do code scanning. */
1257 /* Limit the forward search to 50 instructions. */
1258 if (start_pc
+ 200 < limit_pc
)
1259 limit_pc
= start_pc
+ 200;
1261 for (cur_pc
= start_pc
; cur_pc
< limit_pc
; cur_pc
+= ALPHA_INSN_SIZE
)
1263 unsigned int word
= alpha_read_insn (gdbarch
, cur_pc
);
1265 if ((word
& 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */
1269 /* Consider only the first stack allocation instruction
1270 to contain the static size of the frame. */
1271 if (frame_size
== 0)
1272 frame_size
= (-word
) & 0xffff;
1276 /* Exit loop if a positive stack adjustment is found, which
1277 usually means that the stack cleanup code in the function
1278 epilogue is reached. */
1282 else if ((word
& 0xfc1f0000) == 0xb41e0000) /* stq reg,n($sp) */
1284 reg
= (word
& 0x03e00000) >> 21;
1286 /* Ignore this instruction if we have already encountered
1287 an instruction saving the same register earlier in the
1288 function code. The current instruction does not tell
1289 us where the original value upon function entry is saved.
1290 All it says is that the function we are scanning reused
1291 that register for some computation of its own, and is now
1292 saving its result. */
1293 if (trad_frame_addr_p(info
->saved_regs
, reg
))
1299 /* Do not compute the address where the register was saved yet,
1300 because we don't know yet if the offset will need to be
1301 relative to $sp or $fp (we can not compute the address
1302 relative to $sp if $sp is updated during the execution of
1303 the current subroutine, for instance when doing some alloca).
1304 So just store the offset for the moment, and compute the
1305 address later when we know whether this frame has a frame
1307 /* Hack: temporarily add one, so that the offset is non-zero
1308 and we can tell which registers have save offsets below. */
1309 info
->saved_regs
[reg
].addr
= (word
& 0xffff) + 1;
1311 /* Starting with OSF/1-3.2C, the system libraries are shipped
1312 without local symbols, but they still contain procedure
1313 descriptors without a symbol reference. GDB is currently
1314 unable to find these procedure descriptors and uses
1315 heuristic_proc_desc instead.
1316 As some low level compiler support routines (__div*, __add*)
1317 use a non-standard return address register, we have to
1318 add some heuristics to determine the return address register,
1319 or stepping over these routines will fail.
1320 Usually the return address register is the first register
1321 saved on the stack, but assembler optimization might
1322 rearrange the register saves.
1323 So we recognize only a few registers (t7, t9, ra) within
1324 the procedure prologue as valid return address registers.
1325 If we encounter a return instruction, we extract the
1326 return address register from it.
1328 FIXME: Rewriting GDB to access the procedure descriptors,
1329 e.g. via the minimal symbol table, might obviate this
1331 if (return_reg
== -1
1332 && cur_pc
< (start_pc
+ 80)
1333 && (reg
== ALPHA_T7_REGNUM
1334 || reg
== ALPHA_T9_REGNUM
1335 || reg
== ALPHA_RA_REGNUM
))
1338 else if ((word
& 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */
1339 return_reg
= (word
>> 16) & 0x1f;
1340 else if (word
== 0x47de040f) /* bis sp,sp,fp */
1341 frame_reg
= ALPHA_GCC_FP_REGNUM
;
1342 else if (word
== 0x47fe040f) /* bis zero,sp,fp */
1343 frame_reg
= ALPHA_GCC_FP_REGNUM
;
1345 alpha_heuristic_analyze_probing_loop (gdbarch
, &cur_pc
, &frame_size
);
1348 /* If we haven't found a valid return address register yet, keep
1349 searching in the procedure prologue. */
1350 if (return_reg
== -1)
1352 while (cur_pc
< (limit_pc
+ 80) && cur_pc
< (start_pc
+ 80))
1354 unsigned int word
= alpha_read_insn (gdbarch
, cur_pc
);
1356 if ((word
& 0xfc1f0000) == 0xb41e0000) /* stq reg,n($sp) */
1358 reg
= (word
& 0x03e00000) >> 21;
1359 if (reg
== ALPHA_T7_REGNUM
1360 || reg
== ALPHA_T9_REGNUM
1361 || reg
== ALPHA_RA_REGNUM
)
1367 else if ((word
& 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */
1369 return_reg
= (word
>> 16) & 0x1f;
1373 cur_pc
+= ALPHA_INSN_SIZE
;
1378 /* Failing that, do default to the customary RA. */
1379 if (return_reg
== -1)
1380 return_reg
= ALPHA_RA_REGNUM
;
1381 info
->return_reg
= return_reg
;
1383 val
= get_frame_register_unsigned (this_frame
, frame_reg
);
1384 info
->vfp
= val
+ frame_size
;
1386 /* Convert offsets to absolute addresses. See above about adding
1387 one to the offsets to make all detected offsets non-zero. */
1388 for (reg
= 0; reg
< ALPHA_NUM_REGS
; ++reg
)
1389 if (trad_frame_addr_p(info
->saved_regs
, reg
))
1390 info
->saved_regs
[reg
].addr
+= val
- 1;
1392 /* The stack pointer of the previous frame is computed by popping
1393 the current stack frame. */
1394 if (!trad_frame_addr_p (info
->saved_regs
, ALPHA_SP_REGNUM
))
1395 trad_frame_set_value (info
->saved_regs
, ALPHA_SP_REGNUM
, info
->vfp
);
1400 /* Given a GDB frame, determine the address of the calling function's
1401 frame. This will be used to create a new GDB frame struct. */
1404 alpha_heuristic_frame_this_id (struct frame_info
*this_frame
,
1405 void **this_prologue_cache
,
1406 struct frame_id
*this_id
)
1408 struct alpha_heuristic_unwind_cache
*info
1409 = alpha_heuristic_frame_unwind_cache (this_frame
, this_prologue_cache
, 0);
1411 *this_id
= frame_id_build (info
->vfp
, info
->start_pc
);
1414 /* Retrieve the value of REGNUM in FRAME. Don't give up! */
1416 static struct value
*
1417 alpha_heuristic_frame_prev_register (struct frame_info
*this_frame
,
1418 void **this_prologue_cache
, int regnum
)
1420 struct alpha_heuristic_unwind_cache
*info
1421 = alpha_heuristic_frame_unwind_cache (this_frame
, this_prologue_cache
, 0);
1423 /* The PC of the previous frame is stored in the link register of
1424 the current frame. Frob regnum so that we pull the value from
1425 the correct place. */
1426 if (regnum
== ALPHA_PC_REGNUM
)
1427 regnum
= info
->return_reg
;
1429 return trad_frame_get_prev_register (this_frame
, info
->saved_regs
, regnum
);
1432 static const struct frame_unwind alpha_heuristic_frame_unwind
= {
1434 default_frame_unwind_stop_reason
,
1435 alpha_heuristic_frame_this_id
,
1436 alpha_heuristic_frame_prev_register
,
1438 default_frame_sniffer
1442 alpha_heuristic_frame_base_address (struct frame_info
*this_frame
,
1443 void **this_prologue_cache
)
1445 struct alpha_heuristic_unwind_cache
*info
1446 = alpha_heuristic_frame_unwind_cache (this_frame
, this_prologue_cache
, 0);
1451 static const struct frame_base alpha_heuristic_frame_base
= {
1452 &alpha_heuristic_frame_unwind
,
1453 alpha_heuristic_frame_base_address
,
1454 alpha_heuristic_frame_base_address
,
1455 alpha_heuristic_frame_base_address
1458 /* Just like reinit_frame_cache, but with the right arguments to be
1459 callable as an sfunc. Used by the "set heuristic-fence-post" command. */
1462 reinit_frame_cache_sfunc (const char *args
,
1463 int from_tty
, struct cmd_list_element
*c
)
1465 reinit_frame_cache ();
1469 /* Assuming NEXT_FRAME->prev is a dummy, return the frame ID of that
1470 dummy frame. The frame ID's base needs to match the TOS value
1471 saved by save_dummy_frame_tos(), and the PC match the dummy frame's
1474 static struct frame_id
1475 alpha_dummy_id (struct gdbarch
*gdbarch
, struct frame_info
*this_frame
)
1478 base
= get_frame_register_unsigned (this_frame
, ALPHA_SP_REGNUM
);
1479 return frame_id_build (base
, get_frame_pc (this_frame
));
1483 alpha_unwind_pc (struct gdbarch
*gdbarch
, struct frame_info
*next_frame
)
1486 pc
= frame_unwind_register_unsigned (next_frame
, ALPHA_PC_REGNUM
);
1491 /* Helper routines for alpha*-nat.c files to move register sets to and
1492 from core files. The UNIQUE pointer is allowed to be NULL, as most
1493 targets don't supply this value in their core files. */
1496 alpha_supply_int_regs (struct regcache
*regcache
, int regno
,
1497 const void *r0_r30
, const void *pc
, const void *unique
)
1499 const gdb_byte
*regs
= (const gdb_byte
*) r0_r30
;
1502 for (i
= 0; i
< 31; ++i
)
1503 if (regno
== i
|| regno
== -1)
1504 regcache_raw_supply (regcache
, i
, regs
+ i
* 8);
1506 if (regno
== ALPHA_ZERO_REGNUM
|| regno
== -1)
1508 const gdb_byte zero
[8] = { 0 };
1510 regcache_raw_supply (regcache
, ALPHA_ZERO_REGNUM
, zero
);
1513 if (regno
== ALPHA_PC_REGNUM
|| regno
== -1)
1514 regcache_raw_supply (regcache
, ALPHA_PC_REGNUM
, pc
);
1516 if (regno
== ALPHA_UNIQUE_REGNUM
|| regno
== -1)
1517 regcache_raw_supply (regcache
, ALPHA_UNIQUE_REGNUM
, unique
);
1521 alpha_fill_int_regs (const struct regcache
*regcache
,
1522 int regno
, void *r0_r30
, void *pc
, void *unique
)
1524 gdb_byte
*regs
= (gdb_byte
*) r0_r30
;
1527 for (i
= 0; i
< 31; ++i
)
1528 if (regno
== i
|| regno
== -1)
1529 regcache_raw_collect (regcache
, i
, regs
+ i
* 8);
1531 if (regno
== ALPHA_PC_REGNUM
|| regno
== -1)
1532 regcache_raw_collect (regcache
, ALPHA_PC_REGNUM
, pc
);
1534 if (unique
&& (regno
== ALPHA_UNIQUE_REGNUM
|| regno
== -1))
1535 regcache_raw_collect (regcache
, ALPHA_UNIQUE_REGNUM
, unique
);
1539 alpha_supply_fp_regs (struct regcache
*regcache
, int regno
,
1540 const void *f0_f30
, const void *fpcr
)
1542 const gdb_byte
*regs
= (const gdb_byte
*) f0_f30
;
1545 for (i
= ALPHA_FP0_REGNUM
; i
< ALPHA_FP0_REGNUM
+ 31; ++i
)
1546 if (regno
== i
|| regno
== -1)
1547 regcache_raw_supply (regcache
, i
,
1548 regs
+ (i
- ALPHA_FP0_REGNUM
) * 8);
1550 if (regno
== ALPHA_FPCR_REGNUM
|| regno
== -1)
1551 regcache_raw_supply (regcache
, ALPHA_FPCR_REGNUM
, fpcr
);
1555 alpha_fill_fp_regs (const struct regcache
*regcache
,
1556 int regno
, void *f0_f30
, void *fpcr
)
1558 gdb_byte
*regs
= (gdb_byte
*) f0_f30
;
1561 for (i
= ALPHA_FP0_REGNUM
; i
< ALPHA_FP0_REGNUM
+ 31; ++i
)
1562 if (regno
== i
|| regno
== -1)
1563 regcache_raw_collect (regcache
, i
,
1564 regs
+ (i
- ALPHA_FP0_REGNUM
) * 8);
1566 if (regno
== ALPHA_FPCR_REGNUM
|| regno
== -1)
1567 regcache_raw_collect (regcache
, ALPHA_FPCR_REGNUM
, fpcr
);
1572 /* Return nonzero if the G_floating register value in REG is equal to
1573 zero for FP control instructions. */
1576 fp_register_zero_p (LONGEST reg
)
1578 /* Check that all bits except the sign bit are zero. */
1579 const LONGEST zero_mask
= ((LONGEST
) 1 << 63) ^ -1;
1581 return ((reg
& zero_mask
) == 0);
1584 /* Return the value of the sign bit for the G_floating register
1585 value held in REG. */
1588 fp_register_sign_bit (LONGEST reg
)
1590 const LONGEST sign_mask
= (LONGEST
) 1 << 63;
1592 return ((reg
& sign_mask
) != 0);
1595 /* alpha_software_single_step() is called just before we want to resume
1596 the inferior, if we want to single-step it but there is no hardware
1597 or kernel single-step support (NetBSD on Alpha, for example). We find
1598 the target of the coming instruction and breakpoint it. */
1601 alpha_next_pc (struct regcache
*regcache
, CORE_ADDR pc
)
1603 struct gdbarch
*gdbarch
= regcache
->arch ();
1610 insn
= alpha_read_insn (gdbarch
, pc
);
1612 /* Opcode is top 6 bits. */
1613 op
= (insn
>> 26) & 0x3f;
1617 /* Jump format: target PC is:
1619 return (regcache_raw_get_unsigned (regcache
, (insn
>> 16) & 0x1f) & ~3);
1622 if ((op
& 0x30) == 0x30)
1624 /* Branch format: target PC is:
1625 (new PC) + (4 * sext(displacement)) */
1626 if (op
== 0x30 /* BR */
1627 || op
== 0x34) /* BSR */
1630 offset
= (insn
& 0x001fffff);
1631 if (offset
& 0x00100000)
1632 offset
|= 0xffe00000;
1633 offset
*= ALPHA_INSN_SIZE
;
1634 return (pc
+ ALPHA_INSN_SIZE
+ offset
);
1637 /* Need to determine if branch is taken; read RA. */
1638 regno
= (insn
>> 21) & 0x1f;
1641 case 0x31: /* FBEQ */
1642 case 0x36: /* FBGE */
1643 case 0x37: /* FBGT */
1644 case 0x33: /* FBLE */
1645 case 0x32: /* FBLT */
1646 case 0x35: /* FBNE */
1647 regno
+= gdbarch_fp0_regnum (gdbarch
);
1650 rav
= regcache_raw_get_signed (regcache
, regno
);
1654 case 0x38: /* BLBC */
1658 case 0x3c: /* BLBS */
1662 case 0x39: /* BEQ */
1666 case 0x3d: /* BNE */
1670 case 0x3a: /* BLT */
1674 case 0x3b: /* BLE */
1678 case 0x3f: /* BGT */
1682 case 0x3e: /* BGE */
1687 /* Floating point branches. */
1689 case 0x31: /* FBEQ */
1690 if (fp_register_zero_p (rav
))
1693 case 0x36: /* FBGE */
1694 if (fp_register_sign_bit (rav
) == 0 || fp_register_zero_p (rav
))
1697 case 0x37: /* FBGT */
1698 if (fp_register_sign_bit (rav
) == 0 && ! fp_register_zero_p (rav
))
1701 case 0x33: /* FBLE */
1702 if (fp_register_sign_bit (rav
) == 1 || fp_register_zero_p (rav
))
1705 case 0x32: /* FBLT */
1706 if (fp_register_sign_bit (rav
) == 1 && ! fp_register_zero_p (rav
))
1709 case 0x35: /* FBNE */
1710 if (! fp_register_zero_p (rav
))
1716 /* Not a branch or branch not taken; target PC is:
1718 return (pc
+ ALPHA_INSN_SIZE
);
1721 std::vector
<CORE_ADDR
>
1722 alpha_software_single_step (struct regcache
*regcache
)
1724 struct gdbarch
*gdbarch
= regcache
->arch ();
1726 CORE_ADDR pc
= regcache_read_pc (regcache
);
1728 std::vector
<CORE_ADDR
> next_pcs
1729 = alpha_deal_with_atomic_sequence (gdbarch
, pc
);
1730 if (!next_pcs
.empty ())
1733 CORE_ADDR next_pc
= alpha_next_pc (regcache
, pc
);
1738 /* Initialize the current architecture based on INFO. If possible, re-use an
1739 architecture from ARCHES, which is a list of architectures already created
1740 during this debugging session.
1742 Called e.g. at program startup, when reading a core file, and when reading
1745 static struct gdbarch
*
1746 alpha_gdbarch_init (struct gdbarch_info info
, struct gdbarch_list
*arches
)
1748 struct gdbarch_tdep
*tdep
;
1749 struct gdbarch
*gdbarch
;
1751 /* Find a candidate among extant architectures. */
1752 arches
= gdbarch_list_lookup_by_info (arches
, &info
);
1754 return arches
->gdbarch
;
1756 tdep
= XCNEW (struct gdbarch_tdep
);
1757 gdbarch
= gdbarch_alloc (&info
, tdep
);
1759 /* Lowest text address. This is used by heuristic_proc_start()
1760 to decide when to stop looking. */
1761 tdep
->vm_min_address
= (CORE_ADDR
) 0x120000000LL
;
1763 tdep
->dynamic_sigtramp_offset
= NULL
;
1764 tdep
->sigcontext_addr
= NULL
;
1765 tdep
->sc_pc_offset
= 2 * 8;
1766 tdep
->sc_regs_offset
= 4 * 8;
1767 tdep
->sc_fpregs_offset
= tdep
->sc_regs_offset
+ 32 * 8 + 8;
1769 tdep
->jb_pc
= -1; /* longjmp support not enabled by default. */
1771 tdep
->return_in_memory
= alpha_return_in_memory_always
;
1774 set_gdbarch_short_bit (gdbarch
, 16);
1775 set_gdbarch_int_bit (gdbarch
, 32);
1776 set_gdbarch_long_bit (gdbarch
, 64);
1777 set_gdbarch_long_long_bit (gdbarch
, 64);
1778 set_gdbarch_wchar_bit (gdbarch
, 64);
1779 set_gdbarch_wchar_signed (gdbarch
, 0);
1780 set_gdbarch_float_bit (gdbarch
, 32);
1781 set_gdbarch_double_bit (gdbarch
, 64);
1782 set_gdbarch_long_double_bit (gdbarch
, 64);
1783 set_gdbarch_ptr_bit (gdbarch
, 64);
1786 set_gdbarch_num_regs (gdbarch
, ALPHA_NUM_REGS
);
1787 set_gdbarch_sp_regnum (gdbarch
, ALPHA_SP_REGNUM
);
1788 set_gdbarch_pc_regnum (gdbarch
, ALPHA_PC_REGNUM
);
1789 set_gdbarch_fp0_regnum (gdbarch
, ALPHA_FP0_REGNUM
);
1791 set_gdbarch_register_name (gdbarch
, alpha_register_name
);
1792 set_gdbarch_register_type (gdbarch
, alpha_register_type
);
1794 set_gdbarch_cannot_fetch_register (gdbarch
, alpha_cannot_fetch_register
);
1795 set_gdbarch_cannot_store_register (gdbarch
, alpha_cannot_store_register
);
1797 set_gdbarch_convert_register_p (gdbarch
, alpha_convert_register_p
);
1798 set_gdbarch_register_to_value (gdbarch
, alpha_register_to_value
);
1799 set_gdbarch_value_to_register (gdbarch
, alpha_value_to_register
);
1801 set_gdbarch_register_reggroup_p (gdbarch
, alpha_register_reggroup_p
);
1803 /* Prologue heuristics. */
1804 set_gdbarch_skip_prologue (gdbarch
, alpha_skip_prologue
);
1808 set_gdbarch_return_value (gdbarch
, alpha_return_value
);
1810 /* Settings for calling functions in the inferior. */
1811 set_gdbarch_push_dummy_call (gdbarch
, alpha_push_dummy_call
);
1813 /* Methods for saving / extracting a dummy frame's ID. */
1814 set_gdbarch_dummy_id (gdbarch
, alpha_dummy_id
);
1816 /* Return the unwound PC value. */
1817 set_gdbarch_unwind_pc (gdbarch
, alpha_unwind_pc
);
1819 set_gdbarch_inner_than (gdbarch
, core_addr_lessthan
);
1820 set_gdbarch_skip_trampoline_code (gdbarch
, find_solib_trampoline_target
);
1822 set_gdbarch_breakpoint_kind_from_pc (gdbarch
,
1823 alpha_breakpoint::kind_from_pc
);
1824 set_gdbarch_sw_breakpoint_from_kind (gdbarch
,
1825 alpha_breakpoint::bp_from_kind
);
1826 set_gdbarch_decr_pc_after_break (gdbarch
, ALPHA_INSN_SIZE
);
1827 set_gdbarch_cannot_step_breakpoint (gdbarch
, 1);
1829 /* Handles single stepping of atomic sequences. */
1830 set_gdbarch_software_single_step (gdbarch
, alpha_software_single_step
);
1832 /* Hook in ABI-specific overrides, if they have been registered. */
1833 gdbarch_init_osabi (info
, gdbarch
);
1835 /* Now that we have tuned the configuration, set a few final things
1836 based on what the OS ABI has told us. */
1838 if (tdep
->jb_pc
>= 0)
1839 set_gdbarch_get_longjmp_target (gdbarch
, alpha_get_longjmp_target
);
1841 frame_unwind_append_unwinder (gdbarch
, &alpha_sigtramp_frame_unwind
);
1842 frame_unwind_append_unwinder (gdbarch
, &alpha_heuristic_frame_unwind
);
1844 frame_base_set_default (gdbarch
, &alpha_heuristic_frame_base
);
1850 alpha_dwarf2_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
1852 dwarf2_append_unwinders (gdbarch
);
1853 frame_base_append_sniffer (gdbarch
, dwarf2_frame_base_sniffer
);
1857 _initialize_alpha_tdep (void)
1860 gdbarch_register (bfd_arch_alpha
, alpha_gdbarch_init
, NULL
);
1862 /* Let the user set the fence post for heuristic_proc_start. */
1864 /* We really would like to have both "0" and "unlimited" work, but
1865 command.c doesn't deal with that. So make it a var_zinteger
1866 because the user can always use "999999" or some such for unlimited. */
1867 /* We need to throw away the frame cache when we set this, since it
1868 might change our ability to get backtraces. */
1869 add_setshow_zinteger_cmd ("heuristic-fence-post", class_support
,
1870 &heuristic_fence_post
, _("\
1871 Set the distance searched for the start of a function."), _("\
1872 Show the distance searched for the start of a function."), _("\
1873 If you are debugging a stripped executable, GDB needs to search through the\n\
1874 program for the start of a function. This command sets the distance of the\n\
1875 search. The only need to set it is when debugging a stripped executable."),
1876 reinit_frame_cache_sfunc
,
1877 NULL
, /* FIXME: i18n: The distance searched for
1878 the start of a function is \"%d\". */
1879 &setlist
, &showlist
);