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d2427a71 | 1 | /* Target-dependent mdebug code for the ALPHA architecture. |
6aba47ca DJ |
2 | Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, |
3 | 2003, 2007 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" | |
28 | ||
d2427a71 | 29 | #include "alpha-tdep.h" |
5f6a2351 | 30 | #include "mdebugread.h" |
d2427a71 RH |
31 | |
32 | /* FIXME: Some of this code should perhaps be merged with mips. */ | |
33 | ||
34 | /* *INDENT-OFF* */ | |
35 | /* Layout of a stack frame on the alpha: | |
36 | ||
37 | | | | |
38 | pdr members: | 7th ... nth arg, | | |
39 | | `pushed' by caller. | | |
40 | | | | |
41 | ----------------|-------------------------------|<-- old_sp == vfp | |
42 | ^ ^ ^ ^ | | | |
43 | | | | | | | | |
44 | | |localoff | Copies of 1st .. 6th | | |
45 | | | | | | argument if necessary. | | |
46 | | | | v | | | |
42efa47a | 47 | | | | --- |-------------------------------|<-- LOCALS_ADDRESS |
d2427a71 RH |
48 | | | | | | |
49 | | | | | Locals and temporaries. | | |
50 | | | | | | | |
51 | | | | |-------------------------------| | |
52 | | | | | | | |
53 | |-fregoffset | Saved float registers. | | |
54 | | | | | F9 | | |
55 | | | | | . | | |
56 | | | | | . | | |
57 | | | | | F2 | | |
58 | | | v | | | |
59 | | | -------|-------------------------------| | |
60 | | | | | | |
61 | | | | Saved registers. | | |
62 | | | | S6 | | |
63 | |-regoffset | . | | |
64 | | | | . | | |
65 | | | | S0 | | |
66 | | | | pdr.pcreg | | |
67 | | v | | | |
68 | | ----------|-------------------------------| | |
69 | | | | | |
70 | frameoffset | Argument build area, gets | | |
71 | | | 7th ... nth arg for any | | |
72 | | | called procedure. | | |
73 | v | | | |
74 | -------------|-------------------------------|<-- sp | |
75 | | | | |
76 | */ | |
77 | /* *INDENT-ON* */ | |
78 | ||
79 | #define PROC_LOW_ADDR(proc) ((proc)->pdr.adr) | |
80 | #define PROC_FRAME_OFFSET(proc) ((proc)->pdr.frameoffset) | |
81 | #define PROC_FRAME_REG(proc) ((proc)->pdr.framereg) | |
82 | #define PROC_REG_MASK(proc) ((proc)->pdr.regmask) | |
83 | #define PROC_FREG_MASK(proc) ((proc)->pdr.fregmask) | |
84 | #define PROC_REG_OFFSET(proc) ((proc)->pdr.regoffset) | |
85 | #define PROC_FREG_OFFSET(proc) ((proc)->pdr.fregoffset) | |
86 | #define PROC_PC_REG(proc) ((proc)->pdr.pcreg) | |
87 | #define PROC_LOCALOFF(proc) ((proc)->pdr.localoff) | |
88 | \f | |
89 | /* Locate the mdebug PDR for the given PC. Return null if one can't | |
90 | be found; you'll have to fall back to other methods in that case. */ | |
91 | ||
5f6a2351 | 92 | static struct mdebug_extra_func_info * |
d2427a71 RH |
93 | find_proc_desc (CORE_ADDR pc) |
94 | { | |
95 | struct block *b = block_for_pc (pc); | |
5f6a2351 | 96 | struct mdebug_extra_func_info *proc_desc = NULL; |
d2427a71 RH |
97 | struct symbol *sym = NULL; |
98 | ||
99 | if (b) | |
100 | { | |
101 | CORE_ADDR startaddr; | |
102 | find_pc_partial_function (pc, NULL, &startaddr, NULL); | |
103 | ||
104 | if (startaddr > BLOCK_START (b)) | |
105 | /* This is the "pathological" case referred to in a comment in | |
106 | print_frame_info. It might be better to move this check into | |
107 | symbol reading. */ | |
108 | sym = NULL; | |
109 | else | |
f92761ec | 110 | sym = lookup_symbol (MDEBUG_EFI_SYMBOL_NAME, b, LABEL_DOMAIN, 0, NULL); |
d2427a71 RH |
111 | } |
112 | ||
113 | if (sym) | |
114 | { | |
5f6a2351 | 115 | proc_desc = (struct mdebug_extra_func_info *) SYMBOL_VALUE (sym); |
d2427a71 RH |
116 | |
117 | /* If we never found a PDR for this function in symbol reading, | |
118 | then examine prologues to find the information. */ | |
119 | if (proc_desc->pdr.framereg == -1) | |
120 | proc_desc = NULL; | |
121 | } | |
122 | ||
123 | return proc_desc; | |
124 | } | |
125 | ||
126 | /* This returns the PC of the first inst after the prologue. If we can't | |
127 | find the prologue, then return 0. */ | |
128 | ||
129 | static CORE_ADDR | |
5f6a2351 | 130 | alpha_mdebug_after_prologue (CORE_ADDR pc, struct mdebug_extra_func_info *proc_desc) |
d2427a71 RH |
131 | { |
132 | if (proc_desc) | |
133 | { | |
134 | /* If function is frameless, then we need to do it the hard way. I | |
135 | strongly suspect that frameless always means prologueless... */ | |
087779b1 | 136 | if (PROC_FRAME_REG (proc_desc) == ALPHA_SP_REGNUM |
d2427a71 RH |
137 | && PROC_FRAME_OFFSET (proc_desc) == 0) |
138 | return 0; | |
139 | } | |
140 | ||
141 | return alpha_after_prologue (pc); | |
142 | } | |
143 | ||
144 | /* Return non-zero if we *might* be in a function prologue. Return zero | |
145 | if we are definitively *not* in a function prologue. */ | |
146 | ||
147 | static int | |
5f6a2351 | 148 | alpha_mdebug_in_prologue (CORE_ADDR pc, struct mdebug_extra_func_info *proc_desc) |
d2427a71 RH |
149 | { |
150 | CORE_ADDR after_prologue_pc = alpha_mdebug_after_prologue (pc, proc_desc); | |
151 | return (after_prologue_pc == 0 || pc < after_prologue_pc); | |
152 | } | |
153 | ||
154 | \f | |
155 | /* Frame unwinder that reads mdebug PDRs. */ | |
156 | ||
157 | struct alpha_mdebug_unwind_cache | |
158 | { | |
5f6a2351 | 159 | struct mdebug_extra_func_info *proc_desc; |
d2427a71 RH |
160 | CORE_ADDR vfp; |
161 | CORE_ADDR *saved_regs; | |
d2427a71 RH |
162 | }; |
163 | ||
164 | /* Extract all of the information about the frame from PROC_DESC | |
165 | and store the resulting register save locations in the structure. */ | |
166 | ||
167 | static struct alpha_mdebug_unwind_cache * | |
168 | alpha_mdebug_frame_unwind_cache (struct frame_info *next_frame, | |
169 | void **this_prologue_cache) | |
170 | { | |
171 | struct alpha_mdebug_unwind_cache *info; | |
5f6a2351 | 172 | struct mdebug_extra_func_info *proc_desc; |
d2427a71 RH |
173 | ULONGEST vfp; |
174 | CORE_ADDR pc, reg_position; | |
175 | unsigned long mask; | |
176 | int ireg, returnreg; | |
177 | ||
178 | if (*this_prologue_cache) | |
179 | return *this_prologue_cache; | |
180 | ||
181 | info = FRAME_OBSTACK_ZALLOC (struct alpha_mdebug_unwind_cache); | |
182 | *this_prologue_cache = info; | |
183 | pc = frame_pc_unwind (next_frame); | |
184 | ||
185 | /* ??? We don't seem to be able to cache the lookup of the PDR | |
186 | from alpha_mdebug_frame_p. It'd be nice if we could change | |
187 | the arguments to that function. Oh well. */ | |
188 | proc_desc = find_proc_desc (pc); | |
189 | info->proc_desc = proc_desc; | |
190 | gdb_assert (proc_desc != NULL); | |
191 | ||
d2427a71 RH |
192 | info->saved_regs = frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS); |
193 | ||
194 | /* The VFP of the frame is at FRAME_REG+FRAME_OFFSET. */ | |
195 | frame_unwind_unsigned_register (next_frame, PROC_FRAME_REG (proc_desc), &vfp); | |
196 | vfp += PROC_FRAME_OFFSET (info->proc_desc); | |
197 | info->vfp = vfp; | |
198 | ||
199 | /* Fill in the offsets for the registers which gen_mask says were saved. */ | |
200 | ||
201 | reg_position = vfp + PROC_REG_OFFSET (proc_desc); | |
202 | mask = PROC_REG_MASK (proc_desc); | |
203 | returnreg = PROC_PC_REG (proc_desc); | |
204 | ||
205 | /* Note that RA is always saved first, regardless of its actual | |
206 | register number. */ | |
207 | if (mask & (1 << returnreg)) | |
208 | { | |
209 | /* Clear bit for RA so we don't save it again later. */ | |
210 | mask &= ~(1 << returnreg); | |
211 | ||
212 | info->saved_regs[returnreg] = reg_position; | |
213 | reg_position += 8; | |
214 | } | |
215 | ||
216 | for (ireg = 0; ireg <= 31; ++ireg) | |
217 | if (mask & (1 << ireg)) | |
218 | { | |
219 | info->saved_regs[ireg] = reg_position; | |
220 | reg_position += 8; | |
221 | } | |
222 | ||
223 | reg_position = vfp + PROC_FREG_OFFSET (proc_desc); | |
224 | mask = PROC_FREG_MASK (proc_desc); | |
225 | ||
226 | for (ireg = 0; ireg <= 31; ++ireg) | |
227 | if (mask & (1 << ireg)) | |
228 | { | |
087779b1 | 229 | info->saved_regs[ALPHA_FP0_REGNUM + ireg] = reg_position; |
d2427a71 RH |
230 | reg_position += 8; |
231 | } | |
232 | ||
233 | return info; | |
234 | } | |
235 | ||
236 | /* Given a GDB frame, determine the address of the calling function's | |
237 | frame. This will be used to create a new GDB frame struct. */ | |
238 | ||
239 | static void | |
240 | alpha_mdebug_frame_this_id (struct frame_info *next_frame, | |
241 | void **this_prologue_cache, | |
242 | struct frame_id *this_id) | |
243 | { | |
244 | struct alpha_mdebug_unwind_cache *info | |
245 | = alpha_mdebug_frame_unwind_cache (next_frame, this_prologue_cache); | |
246 | ||
93d42b30 DJ |
247 | *this_id = frame_id_build (info->vfp, |
248 | frame_func_unwind (next_frame, NORMAL_FRAME)); | |
d2427a71 RH |
249 | } |
250 | ||
251 | /* Retrieve the value of REGNUM in FRAME. Don't give up! */ | |
252 | ||
253 | static void | |
254 | alpha_mdebug_frame_prev_register (struct frame_info *next_frame, | |
255 | void **this_prologue_cache, | |
256 | int regnum, int *optimizedp, | |
257 | enum lval_type *lvalp, CORE_ADDR *addrp, | |
5b819568 | 258 | int *realnump, gdb_byte *bufferp) |
d2427a71 RH |
259 | { |
260 | struct alpha_mdebug_unwind_cache *info | |
261 | = alpha_mdebug_frame_unwind_cache (next_frame, this_prologue_cache); | |
262 | ||
d2427a71 RH |
263 | /* The PC of the previous frame is stored in the link register of |
264 | the current frame. Frob regnum so that we pull the value from | |
265 | the correct place. */ | |
087779b1 | 266 | if (regnum == ALPHA_PC_REGNUM) |
d2427a71 RH |
267 | regnum = PROC_PC_REG (info->proc_desc); |
268 | ||
269 | /* For all registers known to be saved in the current frame, | |
270 | do the obvious and pull the value out. */ | |
271 | if (info->saved_regs[regnum]) | |
272 | { | |
273 | *optimizedp = 0; | |
274 | *lvalp = lval_memory; | |
275 | *addrp = info->saved_regs[regnum]; | |
276 | *realnump = -1; | |
277 | if (bufferp != NULL) | |
b21fd293 | 278 | get_frame_memory (next_frame, *addrp, bufferp, ALPHA_REGISTER_SIZE); |
d2427a71 RH |
279 | return; |
280 | } | |
281 | ||
282 | /* The stack pointer of the previous frame is computed by popping | |
283 | the current stack frame. */ | |
087779b1 | 284 | if (regnum == ALPHA_SP_REGNUM) |
d2427a71 RH |
285 | { |
286 | *optimizedp = 0; | |
287 | *lvalp = not_lval; | |
288 | *addrp = 0; | |
289 | *realnump = -1; | |
290 | if (bufferp != NULL) | |
291 | store_unsigned_integer (bufferp, ALPHA_REGISTER_SIZE, info->vfp); | |
292 | return; | |
293 | } | |
294 | ||
295 | /* Otherwise assume the next frame has the same register value. */ | |
5efde112 DJ |
296 | *optimizedp = 0; |
297 | *lvalp = lval_register; | |
298 | *addrp = 0; | |
299 | *realnump = regnum; | |
300 | if (bufferp) | |
301 | frame_unwind_register (next_frame, *realnump, bufferp); | |
d2427a71 RH |
302 | } |
303 | ||
304 | static const struct frame_unwind alpha_mdebug_frame_unwind = { | |
305 | NORMAL_FRAME, | |
306 | alpha_mdebug_frame_this_id, | |
307 | alpha_mdebug_frame_prev_register | |
308 | }; | |
309 | ||
310 | const struct frame_unwind * | |
336d1bba | 311 | alpha_mdebug_frame_sniffer (struct frame_info *next_frame) |
d2427a71 | 312 | { |
93d42b30 | 313 | CORE_ADDR pc = frame_unwind_address_in_block (next_frame, NORMAL_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) | |
320 | return NULL; | |
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)) | |
325 | return NULL; | |
326 | ||
d2427a71 RH |
327 | return &alpha_mdebug_frame_unwind; |
328 | } | |
329 | ||
330 | static CORE_ADDR | |
331 | alpha_mdebug_frame_base_address (struct frame_info *next_frame, | |
332 | void **this_prologue_cache) | |
333 | { | |
334 | struct alpha_mdebug_unwind_cache *info | |
335 | = alpha_mdebug_frame_unwind_cache (next_frame, this_prologue_cache); | |
336 | ||
fbe586ae | 337 | return info->vfp; |
d2427a71 RH |
338 | } |
339 | ||
340 | static CORE_ADDR | |
341 | alpha_mdebug_frame_locals_address (struct frame_info *next_frame, | |
342 | void **this_prologue_cache) | |
343 | { | |
344 | struct alpha_mdebug_unwind_cache *info | |
345 | = alpha_mdebug_frame_unwind_cache (next_frame, this_prologue_cache); | |
d2427a71 | 346 | |
fbe586ae | 347 | return info->vfp - PROC_LOCALOFF (info->proc_desc); |
d2427a71 RH |
348 | } |
349 | ||
350 | static CORE_ADDR | |
351 | alpha_mdebug_frame_args_address (struct frame_info *next_frame, | |
352 | void **this_prologue_cache) | |
353 | { | |
354 | struct alpha_mdebug_unwind_cache *info | |
355 | = alpha_mdebug_frame_unwind_cache (next_frame, this_prologue_cache); | |
d2427a71 | 356 | |
fbe586ae | 357 | return info->vfp - ALPHA_NUM_ARG_REGS * 8; |
d2427a71 RH |
358 | } |
359 | ||
360 | static const struct frame_base alpha_mdebug_frame_base = { | |
361 | &alpha_mdebug_frame_unwind, | |
362 | alpha_mdebug_frame_base_address, | |
363 | alpha_mdebug_frame_locals_address, | |
364 | alpha_mdebug_frame_args_address | |
365 | }; | |
366 | ||
367 | static const struct frame_base * | |
336d1bba | 368 | alpha_mdebug_frame_base_sniffer (struct frame_info *next_frame) |
d2427a71 | 369 | { |
93d42b30 | 370 | CORE_ADDR pc = frame_unwind_address_in_block (next_frame, NORMAL_FRAME); |
5f6a2351 | 371 | struct mdebug_extra_func_info *proc_desc; |
d2427a71 RH |
372 | |
373 | /* If this PC does not map to a PDR, then clearly this isn't an | |
374 | mdebug frame. */ | |
375 | proc_desc = find_proc_desc (pc); | |
376 | if (proc_desc == NULL) | |
377 | return NULL; | |
378 | ||
379 | return &alpha_mdebug_frame_base; | |
380 | } | |
381 | ||
382 | \f | |
383 | void | |
384 | alpha_mdebug_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
385 | { | |
386 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
387 | ||
336d1bba AC |
388 | frame_unwind_append_sniffer (gdbarch, alpha_mdebug_frame_sniffer); |
389 | frame_base_append_sniffer (gdbarch, alpha_mdebug_frame_base_sniffer); | |
d2427a71 | 390 | } |