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c906108c | 1 | /* Target-dependent code for the ALPHA architecture, for GDB, the GNU Debugger. |
1e698235 | 2 | Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003 |
b6ba6518 | 3 | Free Software Foundation, Inc. |
c906108c | 4 | |
c5aa993b | 5 | This file is part of GDB. |
c906108c | 6 | |
c5aa993b JM |
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. | |
c906108c | 11 | |
c5aa993b JM |
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. | |
c906108c | 16 | |
c5aa993b JM |
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. */ | |
c906108c SS |
21 | |
22 | #include "defs.h" | |
615967cb | 23 | #include "doublest.h" |
c906108c | 24 | #include "frame.h" |
d2427a71 RH |
25 | #include "frame-unwind.h" |
26 | #include "frame-base.h" | |
c906108c SS |
27 | #include "inferior.h" |
28 | #include "symtab.h" | |
29 | #include "value.h" | |
30 | #include "gdbcmd.h" | |
31 | #include "gdbcore.h" | |
32 | #include "dis-asm.h" | |
33 | #include "symfile.h" | |
34 | #include "objfiles.h" | |
35 | #include "gdb_string.h" | |
c5f0f3d0 | 36 | #include "linespec.h" |
4e052eda | 37 | #include "regcache.h" |
615967cb | 38 | #include "reggroups.h" |
dc129d82 | 39 | #include "arch-utils.h" |
4be87837 | 40 | #include "osabi.h" |
fe898f56 | 41 | #include "block.h" |
dc129d82 JT |
42 | |
43 | #include "elf-bfd.h" | |
44 | ||
45 | #include "alpha-tdep.h" | |
46 | ||
c906108c | 47 | \f |
fa88f677 | 48 | static const char * |
636a6dfc JT |
49 | alpha_register_name (int regno) |
50 | { | |
5ab84872 | 51 | static const char * const register_names[] = |
636a6dfc JT |
52 | { |
53 | "v0", "t0", "t1", "t2", "t3", "t4", "t5", "t6", | |
54 | "t7", "s0", "s1", "s2", "s3", "s4", "s5", "fp", | |
55 | "a0", "a1", "a2", "a3", "a4", "a5", "t8", "t9", | |
56 | "t10", "t11", "ra", "t12", "at", "gp", "sp", "zero", | |
57 | "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", | |
58 | "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", | |
59 | "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23", | |
60 | "f24", "f25", "f26", "f27", "f28", "f29", "f30", "fpcr", | |
44d88583 | 61 | "pc", "", "unique" |
636a6dfc JT |
62 | }; |
63 | ||
64 | if (regno < 0) | |
5ab84872 | 65 | return NULL; |
636a6dfc | 66 | if (regno >= (sizeof(register_names) / sizeof(*register_names))) |
5ab84872 RH |
67 | return NULL; |
68 | return register_names[regno]; | |
636a6dfc | 69 | } |
d734c450 | 70 | |
dc129d82 | 71 | static int |
d734c450 JT |
72 | alpha_cannot_fetch_register (int regno) |
73 | { | |
44d88583 | 74 | return regno == ALPHA_ZERO_REGNUM; |
d734c450 JT |
75 | } |
76 | ||
dc129d82 | 77 | static int |
d734c450 JT |
78 | alpha_cannot_store_register (int regno) |
79 | { | |
44d88583 | 80 | return regno == ALPHA_ZERO_REGNUM; |
d734c450 JT |
81 | } |
82 | ||
dc129d82 | 83 | static int |
d734c450 JT |
84 | alpha_register_convertible (int regno) |
85 | { | |
86 | return (regno >= FP0_REGNUM && regno <= FP0_REGNUM + 31); | |
87 | } | |
0d056799 | 88 | |
dc129d82 | 89 | static struct type * |
0d056799 JT |
90 | alpha_register_virtual_type (int regno) |
91 | { | |
72667056 RH |
92 | if (regno == ALPHA_SP_REGNUM || regno == ALPHA_GP_REGNUM) |
93 | return builtin_type_void_data_ptr; | |
94 | if (regno == ALPHA_PC_REGNUM) | |
95 | return builtin_type_void_func_ptr; | |
96 | ||
97 | /* Don't need to worry about little vs big endian until | |
98 | some jerk tries to port to alpha-unicosmk. */ | |
99 | if (regno >= FP0_REGNUM && regno < FP0_REGNUM + 31) | |
100 | return builtin_type_ieee_double_little; | |
101 | ||
102 | return builtin_type_int64; | |
0d056799 | 103 | } |
f8453e34 | 104 | |
615967cb RH |
105 | /* Is REGNUM a member of REGGROUP? */ |
106 | ||
107 | static int | |
108 | alpha_register_reggroup_p (struct gdbarch *gdbarch, int regnum, | |
109 | struct reggroup *group) | |
110 | { | |
111 | /* Filter out any registers eliminated, but whose regnum is | |
112 | reserved for backward compatibility, e.g. the vfp. */ | |
113 | if (REGISTER_NAME (regnum) == NULL || *REGISTER_NAME (regnum) == '\0') | |
114 | return 0; | |
115 | ||
116 | /* Since we implement no pseudo registers, save/restore is equal to all. */ | |
117 | if (group == all_reggroup | |
118 | || group == save_reggroup | |
119 | || group == restore_reggroup) | |
120 | return 1; | |
121 | ||
122 | /* All other groups are non-overlapping. */ | |
123 | ||
124 | /* Since this is really a PALcode memory slot... */ | |
125 | if (regnum == ALPHA_UNIQUE_REGNUM) | |
126 | return group == system_reggroup; | |
127 | ||
128 | /* Force the FPCR to be considered part of the floating point state. */ | |
129 | if (regnum == ALPHA_FPCR_REGNUM) | |
130 | return group == float_reggroup; | |
131 | ||
132 | if (regnum >= ALPHA_FP0_REGNUM && regnum < ALPHA_FP0_REGNUM + 31) | |
133 | return group == float_reggroup; | |
134 | else | |
135 | return group == general_reggroup; | |
136 | } | |
137 | ||
dc129d82 | 138 | static int |
f8453e34 JT |
139 | alpha_register_byte (int regno) |
140 | { | |
141 | return (regno * 8); | |
142 | } | |
143 | ||
dc129d82 | 144 | static int |
f8453e34 JT |
145 | alpha_register_raw_size (int regno) |
146 | { | |
147 | return 8; | |
148 | } | |
149 | ||
dc129d82 | 150 | static int |
f8453e34 JT |
151 | alpha_register_virtual_size (int regno) |
152 | { | |
153 | return 8; | |
154 | } | |
636a6dfc | 155 | |
d2427a71 RH |
156 | /* The alpha needs a conversion between register and memory format if the |
157 | register is a floating point register and memory format is float, as the | |
158 | register format must be double or memory format is an integer with 4 | |
159 | bytes or less, as the representation of integers in floating point | |
160 | registers is different. */ | |
161 | ||
162 | static void | |
163 | alpha_register_convert_to_virtual (int regnum, struct type *valtype, | |
164 | char *raw_buffer, char *virtual_buffer) | |
5868c862 | 165 | { |
d2427a71 RH |
166 | if (TYPE_LENGTH (valtype) >= REGISTER_RAW_SIZE (regnum)) |
167 | { | |
168 | memcpy (virtual_buffer, raw_buffer, REGISTER_VIRTUAL_SIZE (regnum)); | |
169 | return; | |
170 | } | |
171 | ||
172 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) | |
173 | { | |
174 | double d = deprecated_extract_floating (raw_buffer, REGISTER_RAW_SIZE (regnum)); | |
175 | deprecated_store_floating (virtual_buffer, TYPE_LENGTH (valtype), d); | |
176 | } | |
177 | else if (TYPE_CODE (valtype) == TYPE_CODE_INT && TYPE_LENGTH (valtype) <= 4) | |
178 | { | |
179 | ULONGEST l; | |
180 | l = extract_unsigned_integer (raw_buffer, REGISTER_RAW_SIZE (regnum)); | |
181 | l = ((l >> 32) & 0xc0000000) | ((l >> 29) & 0x3fffffff); | |
182 | store_unsigned_integer (virtual_buffer, TYPE_LENGTH (valtype), l); | |
183 | } | |
184 | else | |
185 | error ("Cannot retrieve value from floating point register"); | |
186 | } | |
5868c862 | 187 | |
d2427a71 RH |
188 | static void |
189 | alpha_register_convert_to_raw (struct type *valtype, int regnum, | |
190 | char *virtual_buffer, char *raw_buffer) | |
191 | { | |
192 | if (TYPE_LENGTH (valtype) >= REGISTER_RAW_SIZE (regnum)) | |
193 | { | |
194 | memcpy (raw_buffer, virtual_buffer, REGISTER_RAW_SIZE (regnum)); | |
195 | return; | |
196 | } | |
5868c862 | 197 | |
d2427a71 RH |
198 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) |
199 | { | |
200 | double d = deprecated_extract_floating (virtual_buffer, TYPE_LENGTH (valtype)); | |
201 | deprecated_store_floating (raw_buffer, REGISTER_RAW_SIZE (regnum), d); | |
202 | } | |
203 | else if (TYPE_CODE (valtype) == TYPE_CODE_INT && TYPE_LENGTH (valtype) <= 4) | |
204 | { | |
205 | ULONGEST l; | |
206 | if (TYPE_UNSIGNED (valtype)) | |
207 | l = extract_unsigned_integer (virtual_buffer, TYPE_LENGTH (valtype)); | |
208 | else | |
209 | l = extract_signed_integer (virtual_buffer, TYPE_LENGTH (valtype)); | |
210 | l = ((l & 0xc0000000) << 32) | ((l & 0x3fffffff) << 29); | |
211 | store_unsigned_integer (raw_buffer, REGISTER_RAW_SIZE (regnum), l); | |
212 | } | |
213 | else | |
214 | error ("Cannot store value in floating point register"); | |
5868c862 JT |
215 | } |
216 | ||
d2427a71 RH |
217 | \f |
218 | /* The alpha passes the first six arguments in the registers, the rest on | |
c88e30c0 RH |
219 | the stack. The register arguments are stored in ARG_REG_BUFFER, and |
220 | then moved into the register file; this simplifies the passing of a | |
221 | large struct which extends from the registers to the stack, plus avoids | |
222 | three ptrace invocations per word. | |
223 | ||
224 | We don't bother tracking which register values should go in integer | |
225 | regs or fp regs; we load the same values into both. | |
226 | ||
d2427a71 RH |
227 | If the called function is returning a structure, the address of the |
228 | structure to be returned is passed as a hidden first argument. */ | |
c906108c | 229 | |
d2427a71 | 230 | static CORE_ADDR |
c88e30c0 RH |
231 | alpha_push_dummy_call (struct gdbarch *gdbarch, CORE_ADDR func_addr, |
232 | struct regcache *regcache, CORE_ADDR bp_addr, | |
233 | int nargs, struct value **args, CORE_ADDR sp, | |
234 | int struct_return, CORE_ADDR struct_addr) | |
c906108c | 235 | { |
d2427a71 RH |
236 | int i; |
237 | int accumulate_size = struct_return ? 8 : 0; | |
d2427a71 | 238 | struct alpha_arg |
c906108c | 239 | { |
d2427a71 RH |
240 | char *contents; |
241 | int len; | |
242 | int offset; | |
243 | }; | |
c88e30c0 RH |
244 | struct alpha_arg *alpha_args |
245 | = (struct alpha_arg *) alloca (nargs * sizeof (struct alpha_arg)); | |
d2427a71 | 246 | register struct alpha_arg *m_arg; |
c88e30c0 | 247 | char arg_reg_buffer[ALPHA_REGISTER_SIZE * ALPHA_NUM_ARG_REGS]; |
d2427a71 | 248 | int required_arg_regs; |
c906108c | 249 | |
c88e30c0 RH |
250 | /* The ABI places the address of the called function in T12. */ |
251 | regcache_cooked_write_signed (regcache, ALPHA_T12_REGNUM, func_addr); | |
252 | ||
253 | /* Set the return address register to point to the entry point | |
254 | of the program, where a breakpoint lies in wait. */ | |
255 | regcache_cooked_write_signed (regcache, ALPHA_RA_REGNUM, bp_addr); | |
256 | ||
257 | /* Lay out the arguments in memory. */ | |
d2427a71 RH |
258 | for (i = 0, m_arg = alpha_args; i < nargs; i++, m_arg++) |
259 | { | |
260 | struct value *arg = args[i]; | |
261 | struct type *arg_type = check_typedef (VALUE_TYPE (arg)); | |
c88e30c0 | 262 | |
d2427a71 RH |
263 | /* Cast argument to long if necessary as the compiler does it too. */ |
264 | switch (TYPE_CODE (arg_type)) | |
c906108c | 265 | { |
d2427a71 RH |
266 | case TYPE_CODE_INT: |
267 | case TYPE_CODE_BOOL: | |
268 | case TYPE_CODE_CHAR: | |
269 | case TYPE_CODE_RANGE: | |
270 | case TYPE_CODE_ENUM: | |
271 | if (TYPE_LENGTH (arg_type) < TYPE_LENGTH (builtin_type_long)) | |
272 | { | |
273 | arg_type = builtin_type_long; | |
274 | arg = value_cast (arg_type, arg); | |
275 | } | |
276 | break; | |
c88e30c0 RH |
277 | case TYPE_CODE_FLT: |
278 | /* "float" arguments loaded in registers must be passed in | |
279 | register format, aka "double". */ | |
280 | if (accumulate_size < sizeof (arg_reg_buffer) | |
281 | && TYPE_LENGTH (arg_type) == 4) | |
282 | { | |
283 | arg_type = builtin_type_double; | |
284 | arg = value_cast (arg_type, arg); | |
285 | } | |
286 | /* Tru64 5.1 has a 128-bit long double, and passes this by | |
287 | invisible reference. No one else uses this data type. */ | |
288 | else if (TYPE_LENGTH (arg_type) == 16) | |
289 | { | |
290 | /* Allocate aligned storage. */ | |
291 | sp = (sp & -16) - 16; | |
292 | ||
293 | /* Write the real data into the stack. */ | |
294 | write_memory (sp, VALUE_CONTENTS (arg), 16); | |
295 | ||
296 | /* Construct the indirection. */ | |
297 | arg_type = lookup_pointer_type (arg_type); | |
298 | arg = value_from_pointer (arg_type, sp); | |
299 | } | |
300 | break; | |
d2427a71 RH |
301 | default: |
302 | break; | |
c906108c | 303 | } |
d2427a71 RH |
304 | m_arg->len = TYPE_LENGTH (arg_type); |
305 | m_arg->offset = accumulate_size; | |
306 | accumulate_size = (accumulate_size + m_arg->len + 7) & ~7; | |
307 | m_arg->contents = VALUE_CONTENTS (arg); | |
c906108c SS |
308 | } |
309 | ||
d2427a71 RH |
310 | /* Determine required argument register loads, loading an argument register |
311 | is expensive as it uses three ptrace calls. */ | |
312 | required_arg_regs = accumulate_size / 8; | |
313 | if (required_arg_regs > ALPHA_NUM_ARG_REGS) | |
314 | required_arg_regs = ALPHA_NUM_ARG_REGS; | |
c906108c | 315 | |
d2427a71 | 316 | /* Make room for the arguments on the stack. */ |
c88e30c0 RH |
317 | if (accumulate_size < sizeof(arg_reg_buffer)) |
318 | accumulate_size = 0; | |
319 | else | |
320 | accumulate_size -= sizeof(arg_reg_buffer); | |
d2427a71 | 321 | sp -= accumulate_size; |
c906108c | 322 | |
c88e30c0 | 323 | /* Keep sp aligned to a multiple of 16 as the ABI requires. */ |
d2427a71 | 324 | sp &= ~15; |
c906108c | 325 | |
d2427a71 RH |
326 | /* `Push' arguments on the stack. */ |
327 | for (i = nargs; m_arg--, --i >= 0;) | |
c906108c | 328 | { |
c88e30c0 RH |
329 | char *contents = m_arg->contents; |
330 | int offset = m_arg->offset; | |
331 | int len = m_arg->len; | |
332 | ||
333 | /* Copy the bytes destined for registers into arg_reg_buffer. */ | |
334 | if (offset < sizeof(arg_reg_buffer)) | |
335 | { | |
336 | if (offset + len <= sizeof(arg_reg_buffer)) | |
337 | { | |
338 | memcpy (arg_reg_buffer + offset, contents, len); | |
339 | continue; | |
340 | } | |
341 | else | |
342 | { | |
343 | int tlen = sizeof(arg_reg_buffer) - offset; | |
344 | memcpy (arg_reg_buffer + offset, contents, tlen); | |
345 | offset += tlen; | |
346 | contents += tlen; | |
347 | len -= tlen; | |
348 | } | |
349 | } | |
350 | ||
351 | /* Everything else goes to the stack. */ | |
352 | write_memory (sp + offset - sizeof(arg_reg_buffer), contents, len); | |
c906108c | 353 | } |
c88e30c0 RH |
354 | if (struct_return) |
355 | store_unsigned_integer (arg_reg_buffer, ALPHA_REGISTER_SIZE, struct_addr); | |
c906108c | 356 | |
d2427a71 RH |
357 | /* Load the argument registers. */ |
358 | for (i = 0; i < required_arg_regs; i++) | |
359 | { | |
09cc52fd RH |
360 | regcache_cooked_write (regcache, ALPHA_A0_REGNUM + i, |
361 | arg_reg_buffer + i*ALPHA_REGISTER_SIZE); | |
362 | regcache_cooked_write (regcache, ALPHA_FPA0_REGNUM + i, | |
363 | arg_reg_buffer + i*ALPHA_REGISTER_SIZE); | |
d2427a71 | 364 | } |
c906108c | 365 | |
09cc52fd RH |
366 | /* Finally, update the stack pointer. */ |
367 | regcache_cooked_write_signed (regcache, ALPHA_SP_REGNUM, sp); | |
368 | ||
c88e30c0 | 369 | return sp; |
c906108c SS |
370 | } |
371 | ||
d2427a71 RH |
372 | /* Given a return value in `regbuf' with a type `valtype', |
373 | extract and copy its value into `valbuf'. */ | |
374 | ||
dc129d82 | 375 | static void |
d2427a71 RH |
376 | alpha_extract_return_value (struct type *valtype, |
377 | char regbuf[ALPHA_REGISTER_BYTES], char *valbuf) | |
140f9984 | 378 | { |
d2427a71 RH |
379 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) |
380 | alpha_register_convert_to_virtual (FP0_REGNUM, valtype, | |
381 | regbuf + REGISTER_BYTE (FP0_REGNUM), | |
382 | valbuf); | |
383 | else | |
384 | memcpy (valbuf, regbuf + REGISTER_BYTE (ALPHA_V0_REGNUM), | |
385 | TYPE_LENGTH (valtype)); | |
140f9984 JT |
386 | } |
387 | ||
d2427a71 RH |
388 | /* Given a return value in `regbuf' with a type `valtype', |
389 | write its value into the appropriate register. */ | |
0d056799 | 390 | |
d2427a71 RH |
391 | static void |
392 | alpha_store_return_value (struct type *valtype, char *valbuf) | |
c906108c | 393 | { |
5ab84872 | 394 | char raw_buffer[ALPHA_REGISTER_SIZE]; |
d2427a71 RH |
395 | int regnum = ALPHA_V0_REGNUM; |
396 | int length = TYPE_LENGTH (valtype); | |
397 | ||
398 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) | |
c906108c | 399 | { |
d2427a71 | 400 | regnum = FP0_REGNUM; |
5ab84872 | 401 | length = ALPHA_REGISTER_SIZE; |
d2427a71 | 402 | alpha_register_convert_to_raw (valtype, regnum, valbuf, raw_buffer); |
c906108c | 403 | } |
d2427a71 RH |
404 | else |
405 | memcpy (raw_buffer, valbuf, length); | |
406 | ||
407 | deprecated_write_register_bytes (REGISTER_BYTE (regnum), raw_buffer, length); | |
c906108c SS |
408 | } |
409 | ||
d2427a71 RH |
410 | static int |
411 | alpha_use_struct_convention (int gcc_p, struct type *type) | |
c906108c | 412 | { |
d2427a71 RH |
413 | /* Structures are returned by ref in extra arg0. */ |
414 | return 1; | |
415 | } | |
c906108c | 416 | |
d2427a71 RH |
417 | static void |
418 | alpha_store_struct_return (CORE_ADDR addr, CORE_ADDR sp) | |
419 | { | |
420 | /* Store the address of the place in which to copy the structure the | |
421 | subroutine will return. Handled by alpha_push_arguments. */ | |
c906108c SS |
422 | } |
423 | ||
dc129d82 | 424 | static CORE_ADDR |
d2427a71 | 425 | alpha_extract_struct_value_address (char *regbuf) |
c906108c | 426 | { |
7c0b4a20 AC |
427 | return (extract_unsigned_integer (regbuf + REGISTER_BYTE (ALPHA_V0_REGNUM), |
428 | REGISTER_RAW_SIZE (ALPHA_V0_REGNUM))); | |
c906108c SS |
429 | } |
430 | ||
d2427a71 RH |
431 | \f |
432 | static const unsigned char * | |
433 | alpha_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenptr) | |
c906108c | 434 | { |
d2427a71 RH |
435 | static const unsigned char alpha_breakpoint[] = |
436 | { 0x80, 0, 0, 0 }; /* call_pal bpt */ | |
c906108c | 437 | |
d2427a71 RH |
438 | *lenptr = sizeof(alpha_breakpoint); |
439 | return (alpha_breakpoint); | |
440 | } | |
c906108c | 441 | |
d2427a71 RH |
442 | \f |
443 | /* This returns the PC of the first insn after the prologue. | |
444 | If we can't find the prologue, then return 0. */ | |
c906108c | 445 | |
d2427a71 RH |
446 | CORE_ADDR |
447 | alpha_after_prologue (CORE_ADDR pc) | |
c906108c | 448 | { |
d2427a71 RH |
449 | struct symtab_and_line sal; |
450 | CORE_ADDR func_addr, func_end; | |
c906108c | 451 | |
d2427a71 | 452 | if (!find_pc_partial_function (pc, NULL, &func_addr, &func_end)) |
c5aa993b | 453 | return 0; |
c906108c | 454 | |
d2427a71 RH |
455 | sal = find_pc_line (func_addr, 0); |
456 | if (sal.end < func_end) | |
457 | return sal.end; | |
c5aa993b | 458 | |
d2427a71 RH |
459 | /* The line after the prologue is after the end of the function. In this |
460 | case, tell the caller to find the prologue the hard way. */ | |
461 | return 0; | |
c906108c SS |
462 | } |
463 | ||
d2427a71 RH |
464 | /* Read an instruction from memory at PC, looking through breakpoints. */ |
465 | ||
466 | unsigned int | |
467 | alpha_read_insn (CORE_ADDR pc) | |
c906108c | 468 | { |
d2427a71 RH |
469 | char buf[4]; |
470 | int status; | |
c5aa993b | 471 | |
d2427a71 RH |
472 | status = read_memory_nobpt (pc, buf, 4); |
473 | if (status) | |
474 | memory_error (status, pc); | |
475 | return extract_unsigned_integer (buf, 4); | |
476 | } | |
c5aa993b | 477 | |
d2427a71 RH |
478 | /* To skip prologues, I use this predicate. Returns either PC itself |
479 | if the code at PC does not look like a function prologue; otherwise | |
480 | returns an address that (if we're lucky) follows the prologue. If | |
481 | LENIENT, then we must skip everything which is involved in setting | |
482 | up the frame (it's OK to skip more, just so long as we don't skip | |
483 | anything which might clobber the registers which are being saved. */ | |
c906108c | 484 | |
d2427a71 RH |
485 | static CORE_ADDR |
486 | alpha_skip_prologue (CORE_ADDR pc) | |
487 | { | |
488 | unsigned long inst; | |
489 | int offset; | |
490 | CORE_ADDR post_prologue_pc; | |
491 | char buf[4]; | |
c906108c | 492 | |
d2427a71 RH |
493 | /* Silently return the unaltered pc upon memory errors. |
494 | This could happen on OSF/1 if decode_line_1 tries to skip the | |
495 | prologue for quickstarted shared library functions when the | |
496 | shared library is not yet mapped in. | |
497 | Reading target memory is slow over serial lines, so we perform | |
498 | this check only if the target has shared libraries (which all | |
499 | Alpha targets do). */ | |
500 | if (target_read_memory (pc, buf, 4)) | |
501 | return pc; | |
c906108c | 502 | |
d2427a71 RH |
503 | /* See if we can determine the end of the prologue via the symbol table. |
504 | If so, then return either PC, or the PC after the prologue, whichever | |
505 | is greater. */ | |
c906108c | 506 | |
d2427a71 RH |
507 | post_prologue_pc = alpha_after_prologue (pc); |
508 | if (post_prologue_pc != 0) | |
509 | return max (pc, post_prologue_pc); | |
c906108c | 510 | |
d2427a71 RH |
511 | /* Can't determine prologue from the symbol table, need to examine |
512 | instructions. */ | |
dc1b0db2 | 513 | |
d2427a71 RH |
514 | /* Skip the typical prologue instructions. These are the stack adjustment |
515 | instruction and the instructions that save registers on the stack | |
516 | or in the gcc frame. */ | |
517 | for (offset = 0; offset < 100; offset += 4) | |
518 | { | |
519 | inst = alpha_read_insn (pc + offset); | |
c906108c | 520 | |
d2427a71 RH |
521 | if ((inst & 0xffff0000) == 0x27bb0000) /* ldah $gp,n($t12) */ |
522 | continue; | |
523 | if ((inst & 0xffff0000) == 0x23bd0000) /* lda $gp,n($gp) */ | |
524 | continue; | |
525 | if ((inst & 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */ | |
526 | continue; | |
527 | if ((inst & 0xffe01fff) == 0x43c0153e) /* subq $sp,n,$sp */ | |
528 | continue; | |
c906108c | 529 | |
d2427a71 RH |
530 | if (((inst & 0xfc1f0000) == 0xb41e0000 /* stq reg,n($sp) */ |
531 | || (inst & 0xfc1f0000) == 0x9c1e0000) /* stt reg,n($sp) */ | |
532 | && (inst & 0x03e00000) != 0x03e00000) /* reg != $zero */ | |
533 | continue; | |
c906108c | 534 | |
d2427a71 RH |
535 | if (inst == 0x47de040f) /* bis sp,sp,fp */ |
536 | continue; | |
537 | if (inst == 0x47fe040f) /* bis zero,sp,fp */ | |
538 | continue; | |
c906108c | 539 | |
d2427a71 | 540 | break; |
c906108c | 541 | } |
d2427a71 RH |
542 | return pc + offset; |
543 | } | |
c906108c | 544 | |
d2427a71 RH |
545 | \f |
546 | /* Figure out where the longjmp will land. | |
547 | We expect the first arg to be a pointer to the jmp_buf structure from | |
548 | which we extract the PC (JB_PC) that we will land at. The PC is copied | |
549 | into the "pc". This routine returns true on success. */ | |
c906108c SS |
550 | |
551 | static int | |
d2427a71 | 552 | alpha_get_longjmp_target (CORE_ADDR *pc) |
c906108c | 553 | { |
d2427a71 RH |
554 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); |
555 | CORE_ADDR jb_addr; | |
5ab84872 | 556 | char raw_buffer[ALPHA_REGISTER_SIZE]; |
c906108c | 557 | |
d2427a71 | 558 | jb_addr = read_register (ALPHA_A0_REGNUM); |
c906108c | 559 | |
d2427a71 RH |
560 | if (target_read_memory (jb_addr + (tdep->jb_pc * tdep->jb_elt_size), |
561 | raw_buffer, tdep->jb_elt_size)) | |
c906108c | 562 | return 0; |
d2427a71 | 563 | |
7c0b4a20 | 564 | *pc = extract_unsigned_integer (raw_buffer, tdep->jb_elt_size); |
d2427a71 | 565 | return 1; |
c906108c SS |
566 | } |
567 | ||
d2427a71 RH |
568 | \f |
569 | /* Frame unwinder for signal trampolines. We use alpha tdep bits that | |
570 | describe the location and shape of the sigcontext structure. After | |
571 | that, all registers are in memory, so it's easy. */ | |
572 | /* ??? Shouldn't we be able to do this generically, rather than with | |
573 | OSABI data specific to Alpha? */ | |
574 | ||
575 | struct alpha_sigtramp_unwind_cache | |
c906108c | 576 | { |
d2427a71 RH |
577 | CORE_ADDR sigcontext_addr; |
578 | }; | |
c906108c | 579 | |
d2427a71 RH |
580 | static struct alpha_sigtramp_unwind_cache * |
581 | alpha_sigtramp_frame_unwind_cache (struct frame_info *next_frame, | |
582 | void **this_prologue_cache) | |
583 | { | |
584 | struct alpha_sigtramp_unwind_cache *info; | |
585 | struct gdbarch_tdep *tdep; | |
c906108c | 586 | |
d2427a71 RH |
587 | if (*this_prologue_cache) |
588 | return *this_prologue_cache; | |
c906108c | 589 | |
d2427a71 RH |
590 | info = FRAME_OBSTACK_ZALLOC (struct alpha_sigtramp_unwind_cache); |
591 | *this_prologue_cache = info; | |
c906108c | 592 | |
d2427a71 RH |
593 | tdep = gdbarch_tdep (current_gdbarch); |
594 | info->sigcontext_addr = tdep->sigcontext_addr (next_frame); | |
c906108c | 595 | |
d2427a71 | 596 | return info; |
c906108c SS |
597 | } |
598 | ||
d2427a71 RH |
599 | /* Return the address of REGNO in a sigtramp frame. Since this is all |
600 | arithmetic, it doesn't seem worthwhile to cache it. */ | |
c5aa993b | 601 | |
d2427a71 RH |
602 | #ifndef SIGFRAME_PC_OFF |
603 | #define SIGFRAME_PC_OFF (2 * 8) | |
604 | #define SIGFRAME_REGSAVE_OFF (4 * 8) | |
605 | #define SIGFRAME_FPREGSAVE_OFF (SIGFRAME_REGSAVE_OFF + 32 * 8 + 8) | |
606 | #endif | |
c5aa993b | 607 | |
d2427a71 RH |
608 | static CORE_ADDR |
609 | alpha_sigtramp_register_address (CORE_ADDR sigcontext_addr, unsigned int regno) | |
610 | { | |
611 | if (regno < 32) | |
612 | return sigcontext_addr + SIGFRAME_REGSAVE_OFF + regno * 8; | |
613 | if (regno >= FP0_REGNUM && regno < FP0_REGNUM + 32) | |
614 | return sigcontext_addr + SIGFRAME_FPREGSAVE_OFF + regno * 8; | |
615 | if (regno == PC_REGNUM) | |
616 | return sigcontext_addr + SIGFRAME_PC_OFF; | |
c5aa993b | 617 | |
d2427a71 | 618 | return 0; |
c906108c SS |
619 | } |
620 | ||
d2427a71 RH |
621 | /* Given a GDB frame, determine the address of the calling function's |
622 | frame. This will be used to create a new GDB frame struct. */ | |
140f9984 | 623 | |
dc129d82 | 624 | static void |
d2427a71 RH |
625 | alpha_sigtramp_frame_this_id (struct frame_info *next_frame, |
626 | void **this_prologue_cache, | |
627 | struct frame_id *this_id) | |
c906108c | 628 | { |
d2427a71 RH |
629 | struct alpha_sigtramp_unwind_cache *info |
630 | = alpha_sigtramp_frame_unwind_cache (next_frame, this_prologue_cache); | |
631 | struct gdbarch_tdep *tdep; | |
632 | CORE_ADDR stack_addr, code_addr; | |
633 | ||
634 | /* If the OSABI couldn't locate the sigcontext, give up. */ | |
635 | if (info->sigcontext_addr == 0) | |
636 | return; | |
637 | ||
638 | /* If we have dynamic signal trampolines, find their start. | |
639 | If we do not, then we must assume there is a symbol record | |
640 | that can provide the start address. */ | |
641 | tdep = gdbarch_tdep (current_gdbarch); | |
642 | if (tdep->dynamic_sigtramp_offset) | |
c906108c | 643 | { |
d2427a71 RH |
644 | int offset; |
645 | code_addr = frame_pc_unwind (next_frame); | |
646 | offset = tdep->dynamic_sigtramp_offset (code_addr); | |
647 | if (offset >= 0) | |
648 | code_addr -= offset; | |
c906108c | 649 | else |
d2427a71 | 650 | code_addr = 0; |
c906108c | 651 | } |
d2427a71 RH |
652 | else |
653 | code_addr = frame_func_unwind (next_frame); | |
c906108c | 654 | |
d2427a71 RH |
655 | /* The stack address is trivially read from the sigcontext. */ |
656 | stack_addr = alpha_sigtramp_register_address (info->sigcontext_addr, | |
657 | ALPHA_SP_REGNUM); | |
658 | stack_addr = read_memory_unsigned_integer (stack_addr, ALPHA_REGISTER_SIZE); | |
c906108c | 659 | |
d2427a71 | 660 | *this_id = frame_id_build (stack_addr, code_addr); |
c906108c SS |
661 | } |
662 | ||
d2427a71 | 663 | /* Retrieve the value of REGNUM in FRAME. Don't give up! */ |
c906108c | 664 | |
d2427a71 RH |
665 | static void |
666 | alpha_sigtramp_frame_prev_register (struct frame_info *next_frame, | |
667 | void **this_prologue_cache, | |
668 | int regnum, int *optimizedp, | |
669 | enum lval_type *lvalp, CORE_ADDR *addrp, | |
670 | int *realnump, void *bufferp) | |
c906108c | 671 | { |
d2427a71 RH |
672 | struct alpha_sigtramp_unwind_cache *info |
673 | = alpha_sigtramp_frame_unwind_cache (next_frame, this_prologue_cache); | |
674 | CORE_ADDR addr; | |
c906108c | 675 | |
d2427a71 | 676 | if (info->sigcontext_addr != 0) |
c906108c | 677 | { |
d2427a71 RH |
678 | /* All integer and fp registers are stored in memory. */ |
679 | addr = alpha_sigtramp_register_address (info->sigcontext_addr, regnum); | |
680 | if (addr != 0) | |
c906108c | 681 | { |
d2427a71 RH |
682 | *optimizedp = 0; |
683 | *lvalp = lval_memory; | |
684 | *addrp = addr; | |
685 | *realnump = -1; | |
686 | if (bufferp != NULL) | |
687 | read_memory (addr, bufferp, ALPHA_REGISTER_SIZE); | |
688 | return; | |
c906108c | 689 | } |
c906108c SS |
690 | } |
691 | ||
d2427a71 RH |
692 | /* This extra register may actually be in the sigcontext, but our |
693 | current description of it in alpha_sigtramp_frame_unwind_cache | |
694 | doesn't include it. Too bad. Fall back on whatever's in the | |
695 | outer frame. */ | |
696 | frame_register (next_frame, regnum, optimizedp, lvalp, addrp, | |
697 | realnump, bufferp); | |
698 | } | |
c906108c | 699 | |
d2427a71 RH |
700 | static const struct frame_unwind alpha_sigtramp_frame_unwind = { |
701 | SIGTRAMP_FRAME, | |
702 | alpha_sigtramp_frame_this_id, | |
703 | alpha_sigtramp_frame_prev_register | |
704 | }; | |
c906108c | 705 | |
d2427a71 RH |
706 | static const struct frame_unwind * |
707 | alpha_sigtramp_frame_p (CORE_ADDR pc) | |
708 | { | |
709 | char *name; | |
c906108c | 710 | |
d2427a71 RH |
711 | /* We shouldn't even bother to try if the OSABI didn't register |
712 | a sigcontext_addr handler. */ | |
713 | if (!gdbarch_tdep (current_gdbarch)->sigcontext_addr) | |
714 | return NULL; | |
c906108c | 715 | |
d2427a71 RH |
716 | /* Otherwise we should be in a signal frame. */ |
717 | find_pc_partial_function (pc, &name, NULL, NULL); | |
718 | if (PC_IN_SIGTRAMP (pc, name)) | |
719 | return &alpha_sigtramp_frame_unwind; | |
c906108c | 720 | |
d2427a71 | 721 | return NULL; |
c906108c | 722 | } |
d2427a71 RH |
723 | \f |
724 | /* Fallback alpha frame unwinder. Uses instruction scanning and knows | |
725 | something about the traditional layout of alpha stack frames. */ | |
c906108c | 726 | |
d2427a71 | 727 | struct alpha_heuristic_unwind_cache |
c906108c | 728 | { |
d2427a71 RH |
729 | CORE_ADDR *saved_regs; |
730 | CORE_ADDR vfp; | |
731 | CORE_ADDR start_pc; | |
732 | int return_reg; | |
733 | }; | |
c906108c | 734 | |
d2427a71 RH |
735 | /* Heuristic_proc_start may hunt through the text section for a long |
736 | time across a 2400 baud serial line. Allows the user to limit this | |
737 | search. */ | |
738 | static unsigned int heuristic_fence_post = 0; | |
c906108c | 739 | |
d2427a71 RH |
740 | /* Attempt to locate the start of the function containing PC. We assume that |
741 | the previous function ends with an about_to_return insn. Not foolproof by | |
742 | any means, since gcc is happy to put the epilogue in the middle of a | |
743 | function. But we're guessing anyway... */ | |
c906108c | 744 | |
d2427a71 RH |
745 | static CORE_ADDR |
746 | alpha_heuristic_proc_start (CORE_ADDR pc) | |
747 | { | |
748 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); | |
749 | CORE_ADDR last_non_nop = pc; | |
750 | CORE_ADDR fence = pc - heuristic_fence_post; | |
751 | CORE_ADDR orig_pc = pc; | |
fbe586ae | 752 | CORE_ADDR func; |
9e0b60a8 | 753 | |
d2427a71 RH |
754 | if (pc == 0) |
755 | return 0; | |
9e0b60a8 | 756 | |
fbe586ae RH |
757 | /* First see if we can find the start of the function from minimal |
758 | symbol information. This can succeed with a binary that doesn't | |
759 | have debug info, but hasn't been stripped. */ | |
760 | func = get_pc_function_start (pc); | |
761 | if (func) | |
762 | return func; | |
763 | ||
d2427a71 RH |
764 | if (heuristic_fence_post == UINT_MAX |
765 | || fence < tdep->vm_min_address) | |
766 | fence = tdep->vm_min_address; | |
c906108c | 767 | |
d2427a71 RH |
768 | /* Search back for previous return; also stop at a 0, which might be |
769 | seen for instance before the start of a code section. Don't include | |
770 | nops, since this usually indicates padding between functions. */ | |
771 | for (pc -= 4; pc >= fence; pc -= 4) | |
c906108c | 772 | { |
d2427a71 RH |
773 | unsigned int insn = alpha_read_insn (pc); |
774 | switch (insn) | |
c906108c | 775 | { |
d2427a71 RH |
776 | case 0: /* invalid insn */ |
777 | case 0x6bfa8001: /* ret $31,($26),1 */ | |
778 | return last_non_nop; | |
779 | ||
780 | case 0x2ffe0000: /* unop: ldq_u $31,0($30) */ | |
781 | case 0x47ff041f: /* nop: bis $31,$31,$31 */ | |
782 | break; | |
783 | ||
784 | default: | |
785 | last_non_nop = pc; | |
786 | break; | |
c906108c | 787 | } |
d2427a71 | 788 | } |
c906108c | 789 | |
d2427a71 RH |
790 | /* It's not clear to me why we reach this point when stopping quietly, |
791 | but with this test, at least we don't print out warnings for every | |
792 | child forked (eg, on decstation). 22apr93 rich@cygnus.com. */ | |
793 | if (stop_soon == NO_STOP_QUIETLY) | |
794 | { | |
795 | static int blurb_printed = 0; | |
c906108c | 796 | |
d2427a71 RH |
797 | if (fence == tdep->vm_min_address) |
798 | warning ("Hit beginning of text section without finding"); | |
c906108c | 799 | else |
d2427a71 RH |
800 | warning ("Hit heuristic-fence-post without finding"); |
801 | warning ("enclosing function for address 0x%s", paddr_nz (orig_pc)); | |
c906108c | 802 | |
d2427a71 RH |
803 | if (!blurb_printed) |
804 | { | |
805 | printf_filtered ("\ | |
806 | This warning occurs if you are debugging a function without any symbols\n\ | |
807 | (for example, in a stripped executable). In that case, you may wish to\n\ | |
808 | increase the size of the search with the `set heuristic-fence-post' command.\n\ | |
809 | \n\ | |
810 | Otherwise, you told GDB there was a function where there isn't one, or\n\ | |
811 | (more likely) you have encountered a bug in GDB.\n"); | |
812 | blurb_printed = 1; | |
813 | } | |
814 | } | |
c906108c | 815 | |
d2427a71 RH |
816 | return 0; |
817 | } | |
c906108c | 818 | |
fbe586ae | 819 | static struct alpha_heuristic_unwind_cache * |
d2427a71 RH |
820 | alpha_heuristic_frame_unwind_cache (struct frame_info *next_frame, |
821 | void **this_prologue_cache, | |
822 | CORE_ADDR start_pc) | |
823 | { | |
824 | struct alpha_heuristic_unwind_cache *info; | |
825 | ULONGEST val; | |
826 | CORE_ADDR limit_pc, cur_pc; | |
827 | int frame_reg, frame_size, return_reg, reg; | |
c906108c | 828 | |
d2427a71 RH |
829 | if (*this_prologue_cache) |
830 | return *this_prologue_cache; | |
c906108c | 831 | |
d2427a71 RH |
832 | info = FRAME_OBSTACK_ZALLOC (struct alpha_heuristic_unwind_cache); |
833 | *this_prologue_cache = info; | |
834 | info->saved_regs = frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS); | |
c906108c | 835 | |
d2427a71 RH |
836 | limit_pc = frame_pc_unwind (next_frame); |
837 | if (start_pc == 0) | |
838 | start_pc = alpha_heuristic_proc_start (limit_pc); | |
839 | info->start_pc = start_pc; | |
c906108c | 840 | |
d2427a71 RH |
841 | frame_reg = ALPHA_SP_REGNUM; |
842 | frame_size = 0; | |
843 | return_reg = -1; | |
c906108c | 844 | |
d2427a71 RH |
845 | /* If we've identified a likely place to start, do code scanning. */ |
846 | if (start_pc != 0) | |
c5aa993b | 847 | { |
d2427a71 RH |
848 | /* Limit the forward search to 50 instructions. */ |
849 | if (start_pc + 200 < limit_pc) | |
850 | limit_pc = start_pc + 200; | |
c5aa993b | 851 | |
d2427a71 RH |
852 | for (cur_pc = start_pc; cur_pc < limit_pc; cur_pc += 4) |
853 | { | |
854 | unsigned int word = alpha_read_insn (cur_pc); | |
c5aa993b | 855 | |
d2427a71 RH |
856 | if ((word & 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */ |
857 | { | |
858 | if (word & 0x8000) | |
859 | { | |
860 | /* Consider only the first stack allocation instruction | |
861 | to contain the static size of the frame. */ | |
862 | if (frame_size == 0) | |
863 | frame_size = (-word) & 0xffff; | |
864 | } | |
865 | else | |
866 | { | |
867 | /* Exit loop if a positive stack adjustment is found, which | |
868 | usually means that the stack cleanup code in the function | |
869 | epilogue is reached. */ | |
870 | break; | |
871 | } | |
872 | } | |
873 | else if ((word & 0xfc1f0000) == 0xb41e0000) /* stq reg,n($sp) */ | |
874 | { | |
875 | reg = (word & 0x03e00000) >> 21; | |
876 | ||
877 | if (reg == 31) | |
878 | continue; | |
879 | ||
880 | /* Do not compute the address where the register was saved yet, | |
881 | because we don't know yet if the offset will need to be | |
882 | relative to $sp or $fp (we can not compute the address | |
883 | relative to $sp if $sp is updated during the execution of | |
884 | the current subroutine, for instance when doing some alloca). | |
885 | So just store the offset for the moment, and compute the | |
886 | address later when we know whether this frame has a frame | |
887 | pointer or not. */ | |
888 | /* Hack: temporarily add one, so that the offset is non-zero | |
889 | and we can tell which registers have save offsets below. */ | |
890 | info->saved_regs[reg] = (word & 0xffff) + 1; | |
891 | ||
892 | /* Starting with OSF/1-3.2C, the system libraries are shipped | |
893 | without local symbols, but they still contain procedure | |
894 | descriptors without a symbol reference. GDB is currently | |
895 | unable to find these procedure descriptors and uses | |
896 | heuristic_proc_desc instead. | |
897 | As some low level compiler support routines (__div*, __add*) | |
898 | use a non-standard return address register, we have to | |
899 | add some heuristics to determine the return address register, | |
900 | or stepping over these routines will fail. | |
901 | Usually the return address register is the first register | |
902 | saved on the stack, but assembler optimization might | |
903 | rearrange the register saves. | |
904 | So we recognize only a few registers (t7, t9, ra) within | |
905 | the procedure prologue as valid return address registers. | |
906 | If we encounter a return instruction, we extract the | |
907 | the return address register from it. | |
908 | ||
909 | FIXME: Rewriting GDB to access the procedure descriptors, | |
910 | e.g. via the minimal symbol table, might obviate this hack. */ | |
911 | if (return_reg == -1 | |
912 | && cur_pc < (start_pc + 80) | |
913 | && (reg == ALPHA_T7_REGNUM | |
914 | || reg == ALPHA_T9_REGNUM | |
915 | || reg == ALPHA_RA_REGNUM)) | |
916 | return_reg = reg; | |
917 | } | |
918 | else if ((word & 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */ | |
919 | return_reg = (word >> 16) & 0x1f; | |
920 | else if (word == 0x47de040f) /* bis sp,sp,fp */ | |
921 | frame_reg = ALPHA_GCC_FP_REGNUM; | |
922 | else if (word == 0x47fe040f) /* bis zero,sp,fp */ | |
923 | frame_reg = ALPHA_GCC_FP_REGNUM; | |
924 | } | |
c5aa993b | 925 | |
d2427a71 RH |
926 | /* If we haven't found a valid return address register yet, keep |
927 | searching in the procedure prologue. */ | |
928 | if (return_reg == -1) | |
929 | { | |
930 | while (cur_pc < (limit_pc + 80) && cur_pc < (start_pc + 80)) | |
931 | { | |
932 | unsigned int word = alpha_read_insn (cur_pc); | |
c5aa993b | 933 | |
d2427a71 RH |
934 | if ((word & 0xfc1f0000) == 0xb41e0000) /* stq reg,n($sp) */ |
935 | { | |
936 | reg = (word & 0x03e00000) >> 21; | |
937 | if (reg == ALPHA_T7_REGNUM | |
938 | || reg == ALPHA_T9_REGNUM | |
939 | || reg == ALPHA_RA_REGNUM) | |
940 | { | |
941 | return_reg = reg; | |
942 | break; | |
943 | } | |
944 | } | |
945 | else if ((word & 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */ | |
946 | { | |
947 | return_reg = (word >> 16) & 0x1f; | |
948 | break; | |
949 | } | |
85b32d22 RH |
950 | |
951 | cur_pc += 4; | |
d2427a71 RH |
952 | } |
953 | } | |
c906108c | 954 | } |
c906108c | 955 | |
d2427a71 RH |
956 | /* Failing that, do default to the customary RA. */ |
957 | if (return_reg == -1) | |
958 | return_reg = ALPHA_RA_REGNUM; | |
959 | info->return_reg = return_reg; | |
f8453e34 | 960 | |
d2427a71 RH |
961 | frame_unwind_unsigned_register (next_frame, frame_reg, &val); |
962 | info->vfp = val + frame_size; | |
c906108c | 963 | |
d2427a71 RH |
964 | /* Convert offsets to absolute addresses. See above about adding |
965 | one to the offsets to make all detected offsets non-zero. */ | |
966 | for (reg = 0; reg < ALPHA_NUM_REGS; ++reg) | |
967 | if (info->saved_regs[reg]) | |
968 | info->saved_regs[reg] += val - 1; | |
969 | ||
970 | return info; | |
c906108c | 971 | } |
c906108c | 972 | |
d2427a71 RH |
973 | /* Given a GDB frame, determine the address of the calling function's |
974 | frame. This will be used to create a new GDB frame struct. */ | |
975 | ||
fbe586ae | 976 | static void |
d2427a71 RH |
977 | alpha_heuristic_frame_this_id (struct frame_info *next_frame, |
978 | void **this_prologue_cache, | |
979 | struct frame_id *this_id) | |
c906108c | 980 | { |
d2427a71 RH |
981 | struct alpha_heuristic_unwind_cache *info |
982 | = alpha_heuristic_frame_unwind_cache (next_frame, this_prologue_cache, 0); | |
c906108c | 983 | |
fbe586ae RH |
984 | /* This is meant to halt the backtrace at "_start". Make sure we |
985 | don't halt it at a generic dummy frame. */ | |
986 | if (inside_entry_file (info->start_pc)) | |
987 | return; | |
988 | ||
d2427a71 | 989 | *this_id = frame_id_build (info->vfp, info->start_pc); |
c906108c SS |
990 | } |
991 | ||
d2427a71 RH |
992 | /* Retrieve the value of REGNUM in FRAME. Don't give up! */ |
993 | ||
fbe586ae | 994 | static void |
d2427a71 RH |
995 | alpha_heuristic_frame_prev_register (struct frame_info *next_frame, |
996 | void **this_prologue_cache, | |
997 | int regnum, int *optimizedp, | |
998 | enum lval_type *lvalp, CORE_ADDR *addrp, | |
999 | int *realnump, void *bufferp) | |
c906108c | 1000 | { |
d2427a71 RH |
1001 | struct alpha_heuristic_unwind_cache *info |
1002 | = alpha_heuristic_frame_unwind_cache (next_frame, this_prologue_cache, 0); | |
1003 | ||
1004 | /* The PC of the previous frame is stored in the link register of | |
1005 | the current frame. Frob regnum so that we pull the value from | |
1006 | the correct place. */ | |
1007 | if (regnum == ALPHA_PC_REGNUM) | |
1008 | regnum = info->return_reg; | |
1009 | ||
1010 | /* For all registers known to be saved in the current frame, | |
1011 | do the obvious and pull the value out. */ | |
1012 | if (info->saved_regs[regnum]) | |
c906108c | 1013 | { |
d2427a71 RH |
1014 | *optimizedp = 0; |
1015 | *lvalp = lval_memory; | |
1016 | *addrp = info->saved_regs[regnum]; | |
1017 | *realnump = -1; | |
1018 | if (bufferp != NULL) | |
1019 | read_memory (*addrp, bufferp, ALPHA_REGISTER_SIZE); | |
c906108c SS |
1020 | return; |
1021 | } | |
1022 | ||
d2427a71 RH |
1023 | /* The stack pointer of the previous frame is computed by popping |
1024 | the current stack frame. */ | |
1025 | if (regnum == ALPHA_SP_REGNUM) | |
c906108c | 1026 | { |
d2427a71 RH |
1027 | *optimizedp = 0; |
1028 | *lvalp = not_lval; | |
1029 | *addrp = 0; | |
1030 | *realnump = -1; | |
1031 | if (bufferp != NULL) | |
1032 | store_unsigned_integer (bufferp, ALPHA_REGISTER_SIZE, info->vfp); | |
1033 | return; | |
c906108c | 1034 | } |
95b80706 | 1035 | |
d2427a71 RH |
1036 | /* Otherwise assume the next frame has the same register value. */ |
1037 | frame_register (next_frame, regnum, optimizedp, lvalp, addrp, | |
1038 | realnump, bufferp); | |
95b80706 JT |
1039 | } |
1040 | ||
d2427a71 RH |
1041 | static const struct frame_unwind alpha_heuristic_frame_unwind = { |
1042 | NORMAL_FRAME, | |
1043 | alpha_heuristic_frame_this_id, | |
1044 | alpha_heuristic_frame_prev_register | |
1045 | }; | |
c906108c | 1046 | |
d2427a71 RH |
1047 | static const struct frame_unwind * |
1048 | alpha_heuristic_frame_p (CORE_ADDR pc) | |
c906108c | 1049 | { |
d2427a71 | 1050 | return &alpha_heuristic_frame_unwind; |
c906108c SS |
1051 | } |
1052 | ||
fbe586ae | 1053 | static CORE_ADDR |
d2427a71 RH |
1054 | alpha_heuristic_frame_base_address (struct frame_info *next_frame, |
1055 | void **this_prologue_cache) | |
c906108c | 1056 | { |
d2427a71 RH |
1057 | struct alpha_heuristic_unwind_cache *info |
1058 | = alpha_heuristic_frame_unwind_cache (next_frame, this_prologue_cache, 0); | |
c906108c | 1059 | |
d2427a71 | 1060 | return info->vfp; |
c906108c SS |
1061 | } |
1062 | ||
d2427a71 RH |
1063 | static const struct frame_base alpha_heuristic_frame_base = { |
1064 | &alpha_heuristic_frame_unwind, | |
1065 | alpha_heuristic_frame_base_address, | |
1066 | alpha_heuristic_frame_base_address, | |
1067 | alpha_heuristic_frame_base_address | |
1068 | }; | |
1069 | ||
c906108c | 1070 | /* Just like reinit_frame_cache, but with the right arguments to be |
d2427a71 | 1071 | callable as an sfunc. Used by the "set heuristic-fence-post" command. */ |
c906108c SS |
1072 | |
1073 | static void | |
fba45db2 | 1074 | reinit_frame_cache_sfunc (char *args, int from_tty, struct cmd_list_element *c) |
c906108c SS |
1075 | { |
1076 | reinit_frame_cache (); | |
1077 | } | |
1078 | ||
d2427a71 RH |
1079 | \f |
1080 | /* ALPHA stack frames are almost impenetrable. When execution stops, | |
1081 | we basically have to look at symbol information for the function | |
1082 | that we stopped in, which tells us *which* register (if any) is | |
1083 | the base of the frame pointer, and what offset from that register | |
1084 | the frame itself is at. | |
c906108c | 1085 | |
d2427a71 RH |
1086 | This presents a problem when trying to examine a stack in memory |
1087 | (that isn't executing at the moment), using the "frame" command. We | |
1088 | don't have a PC, nor do we have any registers except SP. | |
c906108c | 1089 | |
d2427a71 RH |
1090 | This routine takes two arguments, SP and PC, and tries to make the |
1091 | cached frames look as if these two arguments defined a frame on the | |
1092 | cache. This allows the rest of info frame to extract the important | |
1093 | arguments without difficulty. */ | |
ec32e4be | 1094 | |
d2427a71 RH |
1095 | struct frame_info * |
1096 | alpha_setup_arbitrary_frame (int argc, CORE_ADDR *argv) | |
0d056799 | 1097 | { |
d2427a71 RH |
1098 | if (argc != 2) |
1099 | error ("ALPHA frame specifications require two arguments: sp and pc"); | |
0d056799 | 1100 | |
d2427a71 | 1101 | return create_new_frame (argv[0], argv[1]); |
0d056799 JT |
1102 | } |
1103 | ||
d2427a71 RH |
1104 | /* Assuming NEXT_FRAME->prev is a dummy, return the frame ID of that |
1105 | dummy frame. The frame ID's base needs to match the TOS value | |
1106 | saved by save_dummy_frame_tos(), and the PC match the dummy frame's | |
1107 | breakpoint. */ | |
d734c450 | 1108 | |
d2427a71 RH |
1109 | static struct frame_id |
1110 | alpha_unwind_dummy_id (struct gdbarch *gdbarch, struct frame_info *next_frame) | |
0d056799 | 1111 | { |
d2427a71 RH |
1112 | ULONGEST base; |
1113 | frame_unwind_unsigned_register (next_frame, ALPHA_SP_REGNUM, &base); | |
1114 | return frame_id_build (base, frame_pc_unwind (next_frame)); | |
0d056799 JT |
1115 | } |
1116 | ||
dc129d82 | 1117 | static CORE_ADDR |
d2427a71 | 1118 | alpha_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame) |
accc6d1f | 1119 | { |
d2427a71 RH |
1120 | ULONGEST pc; |
1121 | frame_unwind_unsigned_register (next_frame, ALPHA_PC_REGNUM, &pc); | |
1122 | return pc; | |
accc6d1f JT |
1123 | } |
1124 | ||
d2427a71 | 1125 | \f |
ec32e4be JT |
1126 | /* alpha_software_single_step() is called just before we want to resume |
1127 | the inferior, if we want to single-step it but there is no hardware | |
1128 | or kernel single-step support (NetBSD on Alpha, for example). We find | |
1129 | the target of the coming instruction and breakpoint it. | |
1130 | ||
1131 | single_step is also called just after the inferior stops. If we had | |
1132 | set up a simulated single-step, we undo our damage. */ | |
1133 | ||
1134 | static CORE_ADDR | |
1135 | alpha_next_pc (CORE_ADDR pc) | |
1136 | { | |
1137 | unsigned int insn; | |
1138 | unsigned int op; | |
1139 | int offset; | |
1140 | LONGEST rav; | |
1141 | ||
1142 | insn = read_memory_unsigned_integer (pc, sizeof (insn)); | |
1143 | ||
1144 | /* Opcode is top 6 bits. */ | |
1145 | op = (insn >> 26) & 0x3f; | |
1146 | ||
1147 | if (op == 0x1a) | |
1148 | { | |
1149 | /* Jump format: target PC is: | |
1150 | RB & ~3 */ | |
1151 | return (read_register ((insn >> 16) & 0x1f) & ~3); | |
1152 | } | |
1153 | ||
1154 | if ((op & 0x30) == 0x30) | |
1155 | { | |
1156 | /* Branch format: target PC is: | |
1157 | (new PC) + (4 * sext(displacement)) */ | |
1158 | if (op == 0x30 || /* BR */ | |
1159 | op == 0x34) /* BSR */ | |
1160 | { | |
1161 | branch_taken: | |
1162 | offset = (insn & 0x001fffff); | |
1163 | if (offset & 0x00100000) | |
1164 | offset |= 0xffe00000; | |
1165 | offset *= 4; | |
1166 | return (pc + 4 + offset); | |
1167 | } | |
1168 | ||
1169 | /* Need to determine if branch is taken; read RA. */ | |
1170 | rav = (LONGEST) read_register ((insn >> 21) & 0x1f); | |
1171 | switch (op) | |
1172 | { | |
1173 | case 0x38: /* BLBC */ | |
1174 | if ((rav & 1) == 0) | |
1175 | goto branch_taken; | |
1176 | break; | |
1177 | case 0x3c: /* BLBS */ | |
1178 | if (rav & 1) | |
1179 | goto branch_taken; | |
1180 | break; | |
1181 | case 0x39: /* BEQ */ | |
1182 | if (rav == 0) | |
1183 | goto branch_taken; | |
1184 | break; | |
1185 | case 0x3d: /* BNE */ | |
1186 | if (rav != 0) | |
1187 | goto branch_taken; | |
1188 | break; | |
1189 | case 0x3a: /* BLT */ | |
1190 | if (rav < 0) | |
1191 | goto branch_taken; | |
1192 | break; | |
1193 | case 0x3b: /* BLE */ | |
1194 | if (rav <= 0) | |
1195 | goto branch_taken; | |
1196 | break; | |
1197 | case 0x3f: /* BGT */ | |
1198 | if (rav > 0) | |
1199 | goto branch_taken; | |
1200 | break; | |
1201 | case 0x3e: /* BGE */ | |
1202 | if (rav >= 0) | |
1203 | goto branch_taken; | |
1204 | break; | |
d2427a71 RH |
1205 | |
1206 | /* ??? Missing floating-point branches. */ | |
ec32e4be JT |
1207 | } |
1208 | } | |
1209 | ||
1210 | /* Not a branch or branch not taken; target PC is: | |
1211 | pc + 4 */ | |
1212 | return (pc + 4); | |
1213 | } | |
1214 | ||
1215 | void | |
1216 | alpha_software_single_step (enum target_signal sig, int insert_breakpoints_p) | |
1217 | { | |
1218 | static CORE_ADDR next_pc; | |
1219 | typedef char binsn_quantum[BREAKPOINT_MAX]; | |
1220 | static binsn_quantum break_mem; | |
1221 | CORE_ADDR pc; | |
1222 | ||
1223 | if (insert_breakpoints_p) | |
1224 | { | |
1225 | pc = read_pc (); | |
1226 | next_pc = alpha_next_pc (pc); | |
1227 | ||
1228 | target_insert_breakpoint (next_pc, break_mem); | |
1229 | } | |
1230 | else | |
1231 | { | |
1232 | target_remove_breakpoint (next_pc, break_mem); | |
1233 | write_pc (next_pc); | |
1234 | } | |
c906108c SS |
1235 | } |
1236 | ||
dc129d82 | 1237 | \f |
dc129d82 JT |
1238 | /* Initialize the current architecture based on INFO. If possible, re-use an |
1239 | architecture from ARCHES, which is a list of architectures already created | |
1240 | during this debugging session. | |
1241 | ||
1242 | Called e.g. at program startup, when reading a core file, and when reading | |
1243 | a binary file. */ | |
1244 | ||
1245 | static struct gdbarch * | |
1246 | alpha_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) | |
1247 | { | |
1248 | struct gdbarch_tdep *tdep; | |
1249 | struct gdbarch *gdbarch; | |
dc129d82 JT |
1250 | |
1251 | /* Try to determine the ABI of the object we are loading. */ | |
4be87837 | 1252 | if (info.abfd != NULL && info.osabi == GDB_OSABI_UNKNOWN) |
dc129d82 | 1253 | { |
4be87837 DJ |
1254 | /* If it's an ECOFF file, assume it's OSF/1. */ |
1255 | if (bfd_get_flavour (info.abfd) == bfd_target_ecoff_flavour) | |
aff87235 | 1256 | info.osabi = GDB_OSABI_OSF1; |
dc129d82 JT |
1257 | } |
1258 | ||
1259 | /* Find a candidate among extant architectures. */ | |
4be87837 DJ |
1260 | arches = gdbarch_list_lookup_by_info (arches, &info); |
1261 | if (arches != NULL) | |
1262 | return arches->gdbarch; | |
dc129d82 JT |
1263 | |
1264 | tdep = xmalloc (sizeof (struct gdbarch_tdep)); | |
1265 | gdbarch = gdbarch_alloc (&info, tdep); | |
1266 | ||
d2427a71 RH |
1267 | /* Lowest text address. This is used by heuristic_proc_start() |
1268 | to decide when to stop looking. */ | |
d9b023cc JT |
1269 | tdep->vm_min_address = (CORE_ADDR) 0x120000000; |
1270 | ||
36a6271d | 1271 | tdep->dynamic_sigtramp_offset = NULL; |
5868c862 | 1272 | tdep->sigcontext_addr = NULL; |
36a6271d | 1273 | |
accc6d1f JT |
1274 | tdep->jb_pc = -1; /* longjmp support not enabled by default */ |
1275 | ||
dc129d82 JT |
1276 | /* Type sizes */ |
1277 | set_gdbarch_short_bit (gdbarch, 16); | |
1278 | set_gdbarch_int_bit (gdbarch, 32); | |
1279 | set_gdbarch_long_bit (gdbarch, 64); | |
1280 | set_gdbarch_long_long_bit (gdbarch, 64); | |
1281 | set_gdbarch_float_bit (gdbarch, 32); | |
1282 | set_gdbarch_double_bit (gdbarch, 64); | |
1283 | set_gdbarch_long_double_bit (gdbarch, 64); | |
1284 | set_gdbarch_ptr_bit (gdbarch, 64); | |
1285 | ||
1286 | /* Register info */ | |
1287 | set_gdbarch_num_regs (gdbarch, ALPHA_NUM_REGS); | |
1288 | set_gdbarch_sp_regnum (gdbarch, ALPHA_SP_REGNUM); | |
dc129d82 JT |
1289 | set_gdbarch_pc_regnum (gdbarch, ALPHA_PC_REGNUM); |
1290 | set_gdbarch_fp0_regnum (gdbarch, ALPHA_FP0_REGNUM); | |
1291 | ||
1292 | set_gdbarch_register_name (gdbarch, alpha_register_name); | |
dc129d82 JT |
1293 | set_gdbarch_register_byte (gdbarch, alpha_register_byte); |
1294 | set_gdbarch_register_raw_size (gdbarch, alpha_register_raw_size); | |
dc129d82 | 1295 | set_gdbarch_register_virtual_size (gdbarch, alpha_register_virtual_size); |
dc129d82 JT |
1296 | set_gdbarch_register_virtual_type (gdbarch, alpha_register_virtual_type); |
1297 | ||
1298 | set_gdbarch_cannot_fetch_register (gdbarch, alpha_cannot_fetch_register); | |
1299 | set_gdbarch_cannot_store_register (gdbarch, alpha_cannot_store_register); | |
1300 | ||
1301 | set_gdbarch_register_convertible (gdbarch, alpha_register_convertible); | |
1302 | set_gdbarch_register_convert_to_virtual (gdbarch, | |
1303 | alpha_register_convert_to_virtual); | |
1304 | set_gdbarch_register_convert_to_raw (gdbarch, alpha_register_convert_to_raw); | |
1305 | ||
615967cb RH |
1306 | set_gdbarch_register_reggroup_p (gdbarch, alpha_register_reggroup_p); |
1307 | ||
d2427a71 | 1308 | /* Prologue heuristics. */ |
dc129d82 JT |
1309 | set_gdbarch_skip_prologue (gdbarch, alpha_skip_prologue); |
1310 | ||
5ef165c2 RH |
1311 | /* Disassembler. */ |
1312 | set_gdbarch_print_insn (gdbarch, print_insn_alpha); | |
1313 | ||
d2427a71 | 1314 | /* Call info. */ |
dc129d82 JT |
1315 | set_gdbarch_frame_num_args (gdbarch, frame_num_args_unknown); |
1316 | set_gdbarch_frameless_function_invocation (gdbarch, | |
1317 | generic_frameless_function_invocation_not); | |
1318 | ||
dc129d82 | 1319 | set_gdbarch_use_struct_convention (gdbarch, alpha_use_struct_convention); |
26e9b323 | 1320 | set_gdbarch_deprecated_extract_return_value (gdbarch, alpha_extract_return_value); |
4183d812 | 1321 | set_gdbarch_deprecated_store_struct_return (gdbarch, alpha_store_struct_return); |
ebba8386 | 1322 | set_gdbarch_deprecated_store_return_value (gdbarch, alpha_store_return_value); |
26e9b323 | 1323 | set_gdbarch_deprecated_extract_struct_value_address (gdbarch, |
dc129d82 JT |
1324 | alpha_extract_struct_value_address); |
1325 | ||
1326 | /* Settings for calling functions in the inferior. */ | |
c88e30c0 | 1327 | set_gdbarch_push_dummy_call (gdbarch, alpha_push_dummy_call); |
d2427a71 RH |
1328 | |
1329 | /* Methods for saving / extracting a dummy frame's ID. */ | |
1330 | set_gdbarch_unwind_dummy_id (gdbarch, alpha_unwind_dummy_id); | |
1331 | set_gdbarch_save_dummy_frame_tos (gdbarch, generic_save_dummy_frame_tos); | |
1332 | ||
1333 | /* Return the unwound PC value. */ | |
1334 | set_gdbarch_unwind_pc (gdbarch, alpha_unwind_pc); | |
dc129d82 JT |
1335 | |
1336 | set_gdbarch_inner_than (gdbarch, core_addr_lessthan); | |
36a6271d | 1337 | set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); |
dc129d82 | 1338 | |
95b80706 | 1339 | set_gdbarch_breakpoint_from_pc (gdbarch, alpha_breakpoint_from_pc); |
dc129d82 | 1340 | set_gdbarch_decr_pc_after_break (gdbarch, 4); |
95b80706 JT |
1341 | |
1342 | set_gdbarch_function_start_offset (gdbarch, 0); | |
dc129d82 JT |
1343 | set_gdbarch_frame_args_skip (gdbarch, 0); |
1344 | ||
44dffaac | 1345 | /* Hook in ABI-specific overrides, if they have been registered. */ |
4be87837 | 1346 | gdbarch_init_osabi (info, gdbarch); |
44dffaac | 1347 | |
accc6d1f JT |
1348 | /* Now that we have tuned the configuration, set a few final things |
1349 | based on what the OS ABI has told us. */ | |
1350 | ||
1351 | if (tdep->jb_pc >= 0) | |
1352 | set_gdbarch_get_longjmp_target (gdbarch, alpha_get_longjmp_target); | |
1353 | ||
d2427a71 RH |
1354 | frame_unwind_append_predicate (gdbarch, alpha_sigtramp_frame_p); |
1355 | frame_unwind_append_predicate (gdbarch, alpha_heuristic_frame_p); | |
dc129d82 | 1356 | |
d2427a71 | 1357 | frame_base_set_default (gdbarch, &alpha_heuristic_frame_base); |
accc6d1f | 1358 | |
d2427a71 | 1359 | return gdbarch; |
dc129d82 JT |
1360 | } |
1361 | ||
c906108c | 1362 | void |
fba45db2 | 1363 | _initialize_alpha_tdep (void) |
c906108c SS |
1364 | { |
1365 | struct cmd_list_element *c; | |
1366 | ||
d2427a71 | 1367 | gdbarch_register (bfd_arch_alpha, alpha_gdbarch_init, NULL); |
c906108c SS |
1368 | |
1369 | /* Let the user set the fence post for heuristic_proc_start. */ | |
1370 | ||
1371 | /* We really would like to have both "0" and "unlimited" work, but | |
1372 | command.c doesn't deal with that. So make it a var_zinteger | |
1373 | because the user can always use "999999" or some such for unlimited. */ | |
1374 | c = add_set_cmd ("heuristic-fence-post", class_support, var_zinteger, | |
1375 | (char *) &heuristic_fence_post, | |
1376 | "\ | |
1377 | Set the distance searched for the start of a function.\n\ | |
1378 | If you are debugging a stripped executable, GDB needs to search through the\n\ | |
1379 | program for the start of a function. This command sets the distance of the\n\ | |
1380 | search. The only need to set it is when debugging a stripped executable.", | |
1381 | &setlist); | |
1382 | /* We need to throw away the frame cache when we set this, since it | |
1383 | might change our ability to get backtraces. */ | |
9f60d481 | 1384 | set_cmd_sfunc (c, reinit_frame_cache_sfunc); |
c906108c SS |
1385 | add_show_from_set (c, &showlist); |
1386 | } |