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d2427a71 | 1 | /* Target-dependent mdebug code for the ALPHA architecture. |
6aba47ca | 2 | Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, |
4c38e0a4 | 3 | 2003, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. |
d2427a71 RH |
4 | |
5 | This file is part of GDB. | |
6 | ||
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 | |
a9762ec7 | 9 | the Free Software Foundation; either version 3 of the License, or |
d2427a71 RH |
10 | (at your option) any later version. |
11 | ||
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. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
d2427a71 RH |
19 | |
20 | #include "defs.h" | |
21 | #include "frame.h" | |
22 | #include "frame-unwind.h" | |
23 | #include "frame-base.h" | |
d2427a71 | 24 | #include "symtab.h" |
d2427a71 | 25 | #include "gdbcore.h" |
d2427a71 RH |
26 | #include "block.h" |
27 | #include "gdb_assert.h" | |
62f6180c | 28 | #include "gdb_string.h" |
0cd9ab92 | 29 | #include "trad-frame.h" |
d2427a71 | 30 | |
d2427a71 | 31 | #include "alpha-tdep.h" |
5f6a2351 | 32 | #include "mdebugread.h" |
d2427a71 RH |
33 | |
34 | /* FIXME: Some of this code should perhaps be merged with mips. */ | |
35 | ||
36 | /* *INDENT-OFF* */ | |
37 | /* Layout of a stack frame on the alpha: | |
38 | ||
39 | | | | |
40 | pdr members: | 7th ... nth arg, | | |
41 | | `pushed' by caller. | | |
42 | | | | |
43 | ----------------|-------------------------------|<-- old_sp == vfp | |
44 | ^ ^ ^ ^ | | | |
45 | | | | | | | | |
46 | | |localoff | Copies of 1st .. 6th | | |
47 | | | | | | argument if necessary. | | |
48 | | | | v | | | |
42efa47a | 49 | | | | --- |-------------------------------|<-- LOCALS_ADDRESS |
d2427a71 RH |
50 | | | | | | |
51 | | | | | Locals and temporaries. | | |
52 | | | | | | | |
53 | | | | |-------------------------------| | |
54 | | | | | | | |
55 | |-fregoffset | Saved float registers. | | |
56 | | | | | F9 | | |
57 | | | | | . | | |
58 | | | | | . | | |
59 | | | | | F2 | | |
60 | | | v | | | |
61 | | | -------|-------------------------------| | |
62 | | | | | | |
63 | | | | Saved registers. | | |
64 | | | | S6 | | |
65 | |-regoffset | . | | |
66 | | | | . | | |
67 | | | | S0 | | |
68 | | | | pdr.pcreg | | |
69 | | v | | | |
70 | | ----------|-------------------------------| | |
71 | | | | | |
72 | frameoffset | Argument build area, gets | | |
73 | | | 7th ... nth arg for any | | |
74 | | | called procedure. | | |
75 | v | | | |
76 | -------------|-------------------------------|<-- sp | |
77 | | | | |
78 | */ | |
79 | /* *INDENT-ON* */ | |
80 | ||
81 | #define PROC_LOW_ADDR(proc) ((proc)->pdr.adr) | |
82 | #define PROC_FRAME_OFFSET(proc) ((proc)->pdr.frameoffset) | |
83 | #define PROC_FRAME_REG(proc) ((proc)->pdr.framereg) | |
84 | #define PROC_REG_MASK(proc) ((proc)->pdr.regmask) | |
85 | #define PROC_FREG_MASK(proc) ((proc)->pdr.fregmask) | |
86 | #define PROC_REG_OFFSET(proc) ((proc)->pdr.regoffset) | |
87 | #define PROC_FREG_OFFSET(proc) ((proc)->pdr.fregoffset) | |
88 | #define PROC_PC_REG(proc) ((proc)->pdr.pcreg) | |
89 | #define PROC_LOCALOFF(proc) ((proc)->pdr.localoff) | |
90 | \f | |
91 | /* Locate the mdebug PDR for the given PC. Return null if one can't | |
92 | be found; you'll have to fall back to other methods in that case. */ | |
93 | ||
5f6a2351 | 94 | static struct mdebug_extra_func_info * |
d2427a71 RH |
95 | find_proc_desc (CORE_ADDR pc) |
96 | { | |
97 | struct block *b = block_for_pc (pc); | |
5f6a2351 | 98 | struct mdebug_extra_func_info *proc_desc = NULL; |
d2427a71 | 99 | struct symbol *sym = NULL; |
62f6180c | 100 | char *sh_name = NULL; |
d2427a71 RH |
101 | |
102 | if (b) | |
103 | { | |
104 | CORE_ADDR startaddr; | |
62f6180c | 105 | find_pc_partial_function (pc, &sh_name, &startaddr, NULL); |
d2427a71 RH |
106 | |
107 | if (startaddr > BLOCK_START (b)) | |
108 | /* This is the "pathological" case referred to in a comment in | |
109 | print_frame_info. It might be better to move this check into | |
110 | symbol reading. */ | |
111 | sym = NULL; | |
112 | else | |
2570f2b7 | 113 | sym = lookup_symbol (MDEBUG_EFI_SYMBOL_NAME, b, LABEL_DOMAIN, 0); |
d2427a71 RH |
114 | } |
115 | ||
116 | if (sym) | |
117 | { | |
5f6a2351 | 118 | proc_desc = (struct mdebug_extra_func_info *) SYMBOL_VALUE (sym); |
d2427a71 | 119 | |
62f6180c UW |
120 | /* Correct incorrect setjmp procedure descriptor from the library |
121 | to make backtrace through setjmp work. */ | |
122 | if (proc_desc->pdr.pcreg == 0 | |
123 | && strcmp (sh_name, "setjmp") == 0) | |
124 | { | |
125 | proc_desc->pdr.pcreg = ALPHA_RA_REGNUM; | |
126 | proc_desc->pdr.regmask = 0x80000000; | |
127 | proc_desc->pdr.regoffset = -4; | |
128 | } | |
129 | ||
d2427a71 RH |
130 | /* If we never found a PDR for this function in symbol reading, |
131 | then examine prologues to find the information. */ | |
132 | if (proc_desc->pdr.framereg == -1) | |
133 | proc_desc = NULL; | |
134 | } | |
135 | ||
136 | return proc_desc; | |
137 | } | |
138 | ||
3a48e6ff JG |
139 | /* Return a non-zero result if the function is frameless; zero otherwise. */ |
140 | ||
141 | static int | |
142 | alpha_mdebug_frameless (struct mdebug_extra_func_info *proc_desc) | |
143 | { | |
144 | return (PROC_FRAME_REG (proc_desc) == ALPHA_SP_REGNUM | |
145 | && PROC_FRAME_OFFSET (proc_desc) == 0); | |
146 | } | |
147 | ||
d2427a71 RH |
148 | /* This returns the PC of the first inst after the prologue. If we can't |
149 | find the prologue, then return 0. */ | |
150 | ||
151 | static CORE_ADDR | |
5f6a2351 | 152 | alpha_mdebug_after_prologue (CORE_ADDR pc, struct mdebug_extra_func_info *proc_desc) |
d2427a71 RH |
153 | { |
154 | if (proc_desc) | |
155 | { | |
156 | /* If function is frameless, then we need to do it the hard way. I | |
157 | strongly suspect that frameless always means prologueless... */ | |
3a48e6ff | 158 | if (alpha_mdebug_frameless (proc_desc)) |
d2427a71 RH |
159 | return 0; |
160 | } | |
161 | ||
162 | return alpha_after_prologue (pc); | |
163 | } | |
164 | ||
165 | /* Return non-zero if we *might* be in a function prologue. Return zero | |
166 | if we are definitively *not* in a function prologue. */ | |
167 | ||
168 | static int | |
5f6a2351 | 169 | alpha_mdebug_in_prologue (CORE_ADDR pc, struct mdebug_extra_func_info *proc_desc) |
d2427a71 RH |
170 | { |
171 | CORE_ADDR after_prologue_pc = alpha_mdebug_after_prologue (pc, proc_desc); | |
172 | return (after_prologue_pc == 0 || pc < after_prologue_pc); | |
173 | } | |
174 | ||
175 | \f | |
176 | /* Frame unwinder that reads mdebug PDRs. */ | |
177 | ||
178 | struct alpha_mdebug_unwind_cache | |
179 | { | |
5f6a2351 | 180 | struct mdebug_extra_func_info *proc_desc; |
d2427a71 | 181 | CORE_ADDR vfp; |
0cd9ab92 | 182 | struct trad_frame_saved_reg *saved_regs; |
d2427a71 RH |
183 | }; |
184 | ||
185 | /* Extract all of the information about the frame from PROC_DESC | |
186 | and store the resulting register save locations in the structure. */ | |
187 | ||
188 | static struct alpha_mdebug_unwind_cache * | |
6834c9bb | 189 | alpha_mdebug_frame_unwind_cache (struct frame_info *this_frame, |
d2427a71 RH |
190 | void **this_prologue_cache) |
191 | { | |
192 | struct alpha_mdebug_unwind_cache *info; | |
5f6a2351 | 193 | struct mdebug_extra_func_info *proc_desc; |
d2427a71 RH |
194 | ULONGEST vfp; |
195 | CORE_ADDR pc, reg_position; | |
196 | unsigned long mask; | |
197 | int ireg, returnreg; | |
198 | ||
199 | if (*this_prologue_cache) | |
200 | return *this_prologue_cache; | |
201 | ||
202 | info = FRAME_OBSTACK_ZALLOC (struct alpha_mdebug_unwind_cache); | |
203 | *this_prologue_cache = info; | |
88828b32 | 204 | pc = get_frame_address_in_block (this_frame); |
d2427a71 RH |
205 | |
206 | /* ??? We don't seem to be able to cache the lookup of the PDR | |
207 | from alpha_mdebug_frame_p. It'd be nice if we could change | |
208 | the arguments to that function. Oh well. */ | |
209 | proc_desc = find_proc_desc (pc); | |
210 | info->proc_desc = proc_desc; | |
211 | gdb_assert (proc_desc != NULL); | |
212 | ||
0cd9ab92 | 213 | info->saved_regs = trad_frame_alloc_saved_regs (this_frame); |
d2427a71 RH |
214 | |
215 | /* The VFP of the frame is at FRAME_REG+FRAME_OFFSET. */ | |
6834c9bb | 216 | vfp = get_frame_register_unsigned (this_frame, PROC_FRAME_REG (proc_desc)); |
d2427a71 RH |
217 | vfp += PROC_FRAME_OFFSET (info->proc_desc); |
218 | info->vfp = vfp; | |
219 | ||
220 | /* Fill in the offsets for the registers which gen_mask says were saved. */ | |
221 | ||
222 | reg_position = vfp + PROC_REG_OFFSET (proc_desc); | |
223 | mask = PROC_REG_MASK (proc_desc); | |
224 | returnreg = PROC_PC_REG (proc_desc); | |
225 | ||
226 | /* Note that RA is always saved first, regardless of its actual | |
227 | register number. */ | |
228 | if (mask & (1 << returnreg)) | |
229 | { | |
230 | /* Clear bit for RA so we don't save it again later. */ | |
231 | mask &= ~(1 << returnreg); | |
232 | ||
0cd9ab92 | 233 | info->saved_regs[returnreg].addr = reg_position; |
d2427a71 RH |
234 | reg_position += 8; |
235 | } | |
236 | ||
237 | for (ireg = 0; ireg <= 31; ++ireg) | |
238 | if (mask & (1 << ireg)) | |
239 | { | |
0cd9ab92 | 240 | info->saved_regs[ireg].addr = reg_position; |
d2427a71 RH |
241 | reg_position += 8; |
242 | } | |
243 | ||
244 | reg_position = vfp + PROC_FREG_OFFSET (proc_desc); | |
245 | mask = PROC_FREG_MASK (proc_desc); | |
246 | ||
247 | for (ireg = 0; ireg <= 31; ++ireg) | |
248 | if (mask & (1 << ireg)) | |
249 | { | |
0cd9ab92 | 250 | info->saved_regs[ALPHA_FP0_REGNUM + ireg].addr = reg_position; |
d2427a71 RH |
251 | reg_position += 8; |
252 | } | |
253 | ||
0cd9ab92 UW |
254 | /* The stack pointer of the previous frame is computed by popping |
255 | the current stack frame. */ | |
256 | if (!trad_frame_addr_p (info->saved_regs, ALPHA_SP_REGNUM)) | |
257 | trad_frame_set_value (info->saved_regs, ALPHA_SP_REGNUM, vfp); | |
258 | ||
d2427a71 RH |
259 | return info; |
260 | } | |
261 | ||
262 | /* Given a GDB frame, determine the address of the calling function's | |
263 | frame. This will be used to create a new GDB frame struct. */ | |
264 | ||
265 | static void | |
6834c9bb | 266 | alpha_mdebug_frame_this_id (struct frame_info *this_frame, |
d2427a71 RH |
267 | void **this_prologue_cache, |
268 | struct frame_id *this_id) | |
269 | { | |
270 | struct alpha_mdebug_unwind_cache *info | |
6834c9bb | 271 | = alpha_mdebug_frame_unwind_cache (this_frame, this_prologue_cache); |
d2427a71 | 272 | |
6834c9bb | 273 | *this_id = frame_id_build (info->vfp, get_frame_func (this_frame)); |
d2427a71 RH |
274 | } |
275 | ||
276 | /* Retrieve the value of REGNUM in FRAME. Don't give up! */ | |
277 | ||
6834c9bb JB |
278 | static struct value * |
279 | alpha_mdebug_frame_prev_register (struct frame_info *this_frame, | |
280 | void **this_prologue_cache, int regnum) | |
d2427a71 RH |
281 | { |
282 | struct alpha_mdebug_unwind_cache *info | |
6834c9bb | 283 | = alpha_mdebug_frame_unwind_cache (this_frame, this_prologue_cache); |
d2427a71 | 284 | |
d2427a71 RH |
285 | /* The PC of the previous frame is stored in the link register of |
286 | the current frame. Frob regnum so that we pull the value from | |
287 | the correct place. */ | |
087779b1 | 288 | if (regnum == ALPHA_PC_REGNUM) |
d2427a71 RH |
289 | regnum = PROC_PC_REG (info->proc_desc); |
290 | ||
0cd9ab92 | 291 | return trad_frame_get_prev_register (this_frame, info->saved_regs, regnum); |
d2427a71 RH |
292 | } |
293 | ||
3a48e6ff JG |
294 | /* Return a non-zero result if the size of the stack frame exceeds the |
295 | maximum debuggable frame size (512 Kbytes); zero otherwise. */ | |
296 | ||
297 | static int | |
298 | alpha_mdebug_max_frame_size_exceeded (struct mdebug_extra_func_info *proc_desc) | |
299 | { | |
300 | /* If frame offset is null, we can be in two cases: either the | |
301 | function is frameless (the stack frame is null) or its | |
302 | frame exceeds the maximum debuggable frame size (512 Kbytes). */ | |
303 | ||
304 | return (PROC_FRAME_OFFSET (proc_desc) == 0 | |
305 | && !alpha_mdebug_frameless (proc_desc)); | |
306 | } | |
307 | ||
6834c9bb JB |
308 | static int |
309 | alpha_mdebug_frame_sniffer (const struct frame_unwind *self, | |
310 | struct frame_info *this_frame, | |
311 | void **this_cache) | |
d2427a71 | 312 | { |
6834c9bb | 313 | CORE_ADDR pc = get_frame_address_in_block (this_frame); |
5f6a2351 | 314 | struct mdebug_extra_func_info *proc_desc; |
d2427a71 RH |
315 | |
316 | /* If this PC does not map to a PDR, then clearly this isn't an | |
317 | mdebug frame. */ | |
318 | proc_desc = find_proc_desc (pc); | |
319 | if (proc_desc == NULL) | |
6834c9bb | 320 | return 0; |
d2427a71 | 321 | |
fbe586ae RH |
322 | /* If we're in the prologue, the PDR for this frame is not yet valid. |
323 | Say no here and we'll fall back on the heuristic unwinder. */ | |
324 | if (alpha_mdebug_in_prologue (pc, proc_desc)) | |
6834c9bb | 325 | return 0; |
fbe586ae | 326 | |
3a48e6ff JG |
327 | /* If the maximum debuggable frame size has been exceeded, the |
328 | proc desc is bogus. Fall back on the heuristic unwinder. */ | |
329 | if (alpha_mdebug_max_frame_size_exceeded (proc_desc)) | |
330 | return 0; | |
331 | ||
6834c9bb | 332 | return 1; |
d2427a71 RH |
333 | } |
334 | ||
6834c9bb JB |
335 | static const struct frame_unwind alpha_mdebug_frame_unwind = { |
336 | NORMAL_FRAME, | |
337 | alpha_mdebug_frame_this_id, | |
338 | alpha_mdebug_frame_prev_register, | |
339 | NULL, | |
340 | alpha_mdebug_frame_sniffer | |
341 | }; | |
342 | ||
d2427a71 | 343 | static CORE_ADDR |
6834c9bb | 344 | alpha_mdebug_frame_base_address (struct frame_info *this_frame, |
d2427a71 RH |
345 | void **this_prologue_cache) |
346 | { | |
347 | struct alpha_mdebug_unwind_cache *info | |
6834c9bb | 348 | = alpha_mdebug_frame_unwind_cache (this_frame, this_prologue_cache); |
d2427a71 | 349 | |
fbe586ae | 350 | return info->vfp; |
d2427a71 RH |
351 | } |
352 | ||
353 | static CORE_ADDR | |
6834c9bb | 354 | alpha_mdebug_frame_locals_address (struct frame_info *this_frame, |
d2427a71 RH |
355 | void **this_prologue_cache) |
356 | { | |
357 | struct alpha_mdebug_unwind_cache *info | |
6834c9bb | 358 | = alpha_mdebug_frame_unwind_cache (this_frame, this_prologue_cache); |
d2427a71 | 359 | |
fbe586ae | 360 | return info->vfp - PROC_LOCALOFF (info->proc_desc); |
d2427a71 RH |
361 | } |
362 | ||
363 | static CORE_ADDR | |
6834c9bb | 364 | alpha_mdebug_frame_args_address (struct frame_info *this_frame, |
d2427a71 RH |
365 | void **this_prologue_cache) |
366 | { | |
367 | struct alpha_mdebug_unwind_cache *info | |
6834c9bb | 368 | = alpha_mdebug_frame_unwind_cache (this_frame, this_prologue_cache); |
d2427a71 | 369 | |
fbe586ae | 370 | return info->vfp - ALPHA_NUM_ARG_REGS * 8; |
d2427a71 RH |
371 | } |
372 | ||
373 | static const struct frame_base alpha_mdebug_frame_base = { | |
374 | &alpha_mdebug_frame_unwind, | |
375 | alpha_mdebug_frame_base_address, | |
376 | alpha_mdebug_frame_locals_address, | |
377 | alpha_mdebug_frame_args_address | |
378 | }; | |
379 | ||
380 | static const struct frame_base * | |
6834c9bb | 381 | alpha_mdebug_frame_base_sniffer (struct frame_info *this_frame) |
d2427a71 | 382 | { |
6834c9bb | 383 | CORE_ADDR pc = get_frame_address_in_block (this_frame); |
5f6a2351 | 384 | struct mdebug_extra_func_info *proc_desc; |
d2427a71 RH |
385 | |
386 | /* If this PC does not map to a PDR, then clearly this isn't an | |
387 | mdebug frame. */ | |
388 | proc_desc = find_proc_desc (pc); | |
389 | if (proc_desc == NULL) | |
390 | return NULL; | |
391 | ||
3a48e6ff JG |
392 | /* If the maximum debuggable frame size has been exceeded, the |
393 | proc desc is bogus. Fall back on the heuristic unwinder. */ | |
394 | if (alpha_mdebug_max_frame_size_exceeded (proc_desc)) | |
395 | return 0; | |
396 | ||
d2427a71 RH |
397 | return &alpha_mdebug_frame_base; |
398 | } | |
399 | ||
400 | \f | |
401 | void | |
402 | alpha_mdebug_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
403 | { | |
404 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
405 | ||
6834c9bb | 406 | frame_unwind_append_unwinder (gdbarch, &alpha_mdebug_frame_unwind); |
336d1bba | 407 | frame_base_append_sniffer (gdbarch, alpha_mdebug_frame_base_sniffer); |
d2427a71 | 408 | } |