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1bac305b AC |
1 | /* GDB-specific functions for operating on agent expressions. |
2 | ||
7b6bb8da | 3 | Copyright (C) 1998, 1999, 2000, 2001, 2003, 2007, 2008, 2009, 2010, 2011 |
6aba47ca | 4 | Free Software Foundation, Inc. |
c906108c | 5 | |
c5aa993b | 6 | This file is part of GDB. |
c906108c | 7 | |
c5aa993b JM |
8 | This program is free software; you can redistribute it and/or modify |
9 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 10 | the Free Software Foundation; either version 3 of the License, or |
c5aa993b | 11 | (at your option) any later version. |
c906108c | 12 | |
c5aa993b JM |
13 | This program is distributed in the hope that it will be useful, |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
c906108c | 17 | |
c5aa993b | 18 | You should have received a copy of the GNU General Public License |
a9762ec7 | 19 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
c906108c | 20 | |
c906108c SS |
21 | #include "defs.h" |
22 | #include "symtab.h" | |
23 | #include "symfile.h" | |
24 | #include "gdbtypes.h" | |
b97aedf3 | 25 | #include "language.h" |
c906108c SS |
26 | #include "value.h" |
27 | #include "expression.h" | |
28 | #include "command.h" | |
29 | #include "gdbcmd.h" | |
30 | #include "frame.h" | |
31 | #include "target.h" | |
32 | #include "ax.h" | |
33 | #include "ax-gdb.h" | |
309367d4 | 34 | #include "gdb_string.h" |
fe898f56 | 35 | #include "block.h" |
7b83296f | 36 | #include "regcache.h" |
029a67e4 | 37 | #include "user-regs.h" |
f7c79c41 | 38 | #include "language.h" |
6c228b9c | 39 | #include "dictionary.h" |
00bf0b85 | 40 | #include "breakpoint.h" |
f61e138d | 41 | #include "tracepoint.h" |
b6e7192f | 42 | #include "cp-support.h" |
6710bf39 | 43 | #include "arch-utils.h" |
c906108c | 44 | |
3065dfb6 SS |
45 | #include "valprint.h" |
46 | #include "c-lang.h" | |
47 | ||
6426a772 JM |
48 | /* To make sense of this file, you should read doc/agentexpr.texi. |
49 | Then look at the types and enums in ax-gdb.h. For the code itself, | |
50 | look at gen_expr, towards the bottom; that's the main function that | |
51 | looks at the GDB expressions and calls everything else to generate | |
52 | code. | |
c906108c SS |
53 | |
54 | I'm beginning to wonder whether it wouldn't be nicer to internally | |
55 | generate trees, with types, and then spit out the bytecode in | |
56 | linear form afterwards; we could generate fewer `swap', `ext', and | |
57 | `zero_ext' bytecodes that way; it would make good constant folding | |
58 | easier, too. But at the moment, I think we should be willing to | |
59 | pay for the simplicity of this code with less-than-optimal bytecode | |
60 | strings. | |
61 | ||
c5aa993b JM |
62 | Remember, "GBD" stands for "Great Britain, Dammit!" So be careful. */ |
63 | \f | |
c906108c SS |
64 | |
65 | ||
0e2de366 | 66 | /* Prototypes for local functions. */ |
c906108c SS |
67 | |
68 | /* There's a standard order to the arguments of these functions: | |
69 | union exp_element ** --- pointer into expression | |
70 | struct agent_expr * --- agent expression buffer to generate code into | |
71 | struct axs_value * --- describes value left on top of stack */ | |
c5aa993b | 72 | |
a14ed312 KB |
73 | static struct value *const_var_ref (struct symbol *var); |
74 | static struct value *const_expr (union exp_element **pc); | |
75 | static struct value *maybe_const_expr (union exp_element **pc); | |
76 | ||
3e43a32a MS |
77 | static void gen_traced_pop (struct gdbarch *, struct agent_expr *, |
78 | struct axs_value *); | |
a14ed312 KB |
79 | |
80 | static void gen_sign_extend (struct agent_expr *, struct type *); | |
81 | static void gen_extend (struct agent_expr *, struct type *); | |
82 | static void gen_fetch (struct agent_expr *, struct type *); | |
83 | static void gen_left_shift (struct agent_expr *, int); | |
84 | ||
85 | ||
f7c79c41 UW |
86 | static void gen_frame_args_address (struct gdbarch *, struct agent_expr *); |
87 | static void gen_frame_locals_address (struct gdbarch *, struct agent_expr *); | |
a14ed312 KB |
88 | static void gen_offset (struct agent_expr *ax, int offset); |
89 | static void gen_sym_offset (struct agent_expr *, struct symbol *); | |
f7c79c41 | 90 | static void gen_var_ref (struct gdbarch *, struct agent_expr *ax, |
a14ed312 KB |
91 | struct axs_value *value, struct symbol *var); |
92 | ||
93 | ||
94 | static void gen_int_literal (struct agent_expr *ax, | |
95 | struct axs_value *value, | |
96 | LONGEST k, struct type *type); | |
97 | ||
98 | ||
99 | static void require_rvalue (struct agent_expr *ax, struct axs_value *value); | |
f7c79c41 UW |
100 | static void gen_usual_unary (struct expression *exp, struct agent_expr *ax, |
101 | struct axs_value *value); | |
a14ed312 KB |
102 | static int type_wider_than (struct type *type1, struct type *type2); |
103 | static struct type *max_type (struct type *type1, struct type *type2); | |
104 | static void gen_conversion (struct agent_expr *ax, | |
105 | struct type *from, struct type *to); | |
106 | static int is_nontrivial_conversion (struct type *from, struct type *to); | |
f7c79c41 UW |
107 | static void gen_usual_arithmetic (struct expression *exp, |
108 | struct agent_expr *ax, | |
a14ed312 KB |
109 | struct axs_value *value1, |
110 | struct axs_value *value2); | |
f7c79c41 UW |
111 | static void gen_integral_promotions (struct expression *exp, |
112 | struct agent_expr *ax, | |
a14ed312 KB |
113 | struct axs_value *value); |
114 | static void gen_cast (struct agent_expr *ax, | |
115 | struct axs_value *value, struct type *type); | |
116 | static void gen_scale (struct agent_expr *ax, | |
117 | enum agent_op op, struct type *type); | |
f7c79c41 UW |
118 | static void gen_ptradd (struct agent_expr *ax, struct axs_value *value, |
119 | struct axs_value *value1, struct axs_value *value2); | |
120 | static void gen_ptrsub (struct agent_expr *ax, struct axs_value *value, | |
121 | struct axs_value *value1, struct axs_value *value2); | |
122 | static void gen_ptrdiff (struct agent_expr *ax, struct axs_value *value, | |
123 | struct axs_value *value1, struct axs_value *value2, | |
124 | struct type *result_type); | |
a14ed312 KB |
125 | static void gen_binop (struct agent_expr *ax, |
126 | struct axs_value *value, | |
127 | struct axs_value *value1, | |
128 | struct axs_value *value2, | |
129 | enum agent_op op, | |
130 | enum agent_op op_unsigned, int may_carry, char *name); | |
f7c79c41 UW |
131 | static void gen_logical_not (struct agent_expr *ax, struct axs_value *value, |
132 | struct type *result_type); | |
a14ed312 KB |
133 | static void gen_complement (struct agent_expr *ax, struct axs_value *value); |
134 | static void gen_deref (struct agent_expr *, struct axs_value *); | |
135 | static void gen_address_of (struct agent_expr *, struct axs_value *); | |
505e835d | 136 | static void gen_bitfield_ref (struct expression *exp, struct agent_expr *ax, |
a14ed312 KB |
137 | struct axs_value *value, |
138 | struct type *type, int start, int end); | |
b6e7192f SS |
139 | static void gen_primitive_field (struct expression *exp, |
140 | struct agent_expr *ax, | |
141 | struct axs_value *value, | |
142 | int offset, int fieldno, struct type *type); | |
143 | static int gen_struct_ref_recursive (struct expression *exp, | |
144 | struct agent_expr *ax, | |
145 | struct axs_value *value, | |
146 | char *field, int offset, | |
147 | struct type *type); | |
505e835d | 148 | static void gen_struct_ref (struct expression *exp, struct agent_expr *ax, |
a14ed312 KB |
149 | struct axs_value *value, |
150 | char *field, | |
151 | char *operator_name, char *operand_name); | |
400c6af0 | 152 | static void gen_static_field (struct gdbarch *gdbarch, |
b6e7192f SS |
153 | struct agent_expr *ax, struct axs_value *value, |
154 | struct type *type, int fieldno); | |
f7c79c41 | 155 | static void gen_repeat (struct expression *exp, union exp_element **pc, |
a14ed312 | 156 | struct agent_expr *ax, struct axs_value *value); |
f7c79c41 UW |
157 | static void gen_sizeof (struct expression *exp, union exp_element **pc, |
158 | struct agent_expr *ax, struct axs_value *value, | |
159 | struct type *size_type); | |
160 | static void gen_expr (struct expression *exp, union exp_element **pc, | |
a14ed312 | 161 | struct agent_expr *ax, struct axs_value *value); |
f61e138d SS |
162 | static void gen_expr_binop_rest (struct expression *exp, |
163 | enum exp_opcode op, union exp_element **pc, | |
164 | struct agent_expr *ax, | |
165 | struct axs_value *value, | |
166 | struct axs_value *value1, | |
167 | struct axs_value *value2); | |
c5aa993b | 168 | |
a14ed312 | 169 | static void agent_command (char *exp, int from_tty); |
c906108c | 170 | \f |
c5aa993b | 171 | |
c906108c SS |
172 | /* Detecting constant expressions. */ |
173 | ||
174 | /* If the variable reference at *PC is a constant, return its value. | |
175 | Otherwise, return zero. | |
176 | ||
177 | Hey, Wally! How can a variable reference be a constant? | |
178 | ||
179 | Well, Beav, this function really handles the OP_VAR_VALUE operator, | |
180 | not specifically variable references. GDB uses OP_VAR_VALUE to | |
181 | refer to any kind of symbolic reference: function names, enum | |
182 | elements, and goto labels are all handled through the OP_VAR_VALUE | |
183 | operator, even though they're constants. It makes sense given the | |
184 | situation. | |
185 | ||
186 | Gee, Wally, don'cha wonder sometimes if data representations that | |
187 | subvert commonly accepted definitions of terms in favor of heavily | |
188 | context-specific interpretations are really just a tool of the | |
189 | programming hegemony to preserve their power and exclude the | |
190 | proletariat? */ | |
191 | ||
192 | static struct value * | |
fba45db2 | 193 | const_var_ref (struct symbol *var) |
c906108c SS |
194 | { |
195 | struct type *type = SYMBOL_TYPE (var); | |
196 | ||
197 | switch (SYMBOL_CLASS (var)) | |
198 | { | |
199 | case LOC_CONST: | |
200 | return value_from_longest (type, (LONGEST) SYMBOL_VALUE (var)); | |
201 | ||
202 | case LOC_LABEL: | |
4478b372 | 203 | return value_from_pointer (type, (CORE_ADDR) SYMBOL_VALUE_ADDRESS (var)); |
c906108c SS |
204 | |
205 | default: | |
206 | return 0; | |
207 | } | |
208 | } | |
209 | ||
210 | ||
211 | /* If the expression starting at *PC has a constant value, return it. | |
212 | Otherwise, return zero. If we return a value, then *PC will be | |
213 | advanced to the end of it. If we return zero, *PC could be | |
214 | anywhere. */ | |
215 | static struct value * | |
fba45db2 | 216 | const_expr (union exp_element **pc) |
c906108c SS |
217 | { |
218 | enum exp_opcode op = (*pc)->opcode; | |
219 | struct value *v1; | |
220 | ||
221 | switch (op) | |
222 | { | |
223 | case OP_LONG: | |
224 | { | |
225 | struct type *type = (*pc)[1].type; | |
226 | LONGEST k = (*pc)[2].longconst; | |
5b4ee69b | 227 | |
c906108c SS |
228 | (*pc) += 4; |
229 | return value_from_longest (type, k); | |
230 | } | |
231 | ||
232 | case OP_VAR_VALUE: | |
233 | { | |
234 | struct value *v = const_var_ref ((*pc)[2].symbol); | |
5b4ee69b | 235 | |
c906108c SS |
236 | (*pc) += 4; |
237 | return v; | |
238 | } | |
239 | ||
c5aa993b | 240 | /* We could add more operators in here. */ |
c906108c SS |
241 | |
242 | case UNOP_NEG: | |
243 | (*pc)++; | |
244 | v1 = const_expr (pc); | |
245 | if (v1) | |
246 | return value_neg (v1); | |
247 | else | |
248 | return 0; | |
249 | ||
250 | default: | |
251 | return 0; | |
252 | } | |
253 | } | |
254 | ||
255 | ||
256 | /* Like const_expr, but guarantee also that *PC is undisturbed if the | |
257 | expression is not constant. */ | |
258 | static struct value * | |
fba45db2 | 259 | maybe_const_expr (union exp_element **pc) |
c906108c SS |
260 | { |
261 | union exp_element *tentative_pc = *pc; | |
262 | struct value *v = const_expr (&tentative_pc); | |
263 | ||
264 | /* If we got a value, then update the real PC. */ | |
265 | if (v) | |
266 | *pc = tentative_pc; | |
c5aa993b | 267 | |
c906108c SS |
268 | return v; |
269 | } | |
c906108c | 270 | \f |
c5aa993b | 271 | |
c906108c SS |
272 | /* Generating bytecode from GDB expressions: general assumptions */ |
273 | ||
274 | /* Here are a few general assumptions made throughout the code; if you | |
275 | want to make a change that contradicts one of these, then you'd | |
276 | better scan things pretty thoroughly. | |
277 | ||
278 | - We assume that all values occupy one stack element. For example, | |
c5aa993b JM |
279 | sometimes we'll swap to get at the left argument to a binary |
280 | operator. If we decide that void values should occupy no stack | |
281 | elements, or that synthetic arrays (whose size is determined at | |
282 | run time, created by the `@' operator) should occupy two stack | |
283 | elements (address and length), then this will cause trouble. | |
c906108c SS |
284 | |
285 | - We assume the stack elements are infinitely wide, and that we | |
c5aa993b JM |
286 | don't have to worry what happens if the user requests an |
287 | operation that is wider than the actual interpreter's stack. | |
288 | That is, it's up to the interpreter to handle directly all the | |
289 | integer widths the user has access to. (Woe betide the language | |
290 | with bignums!) | |
c906108c SS |
291 | |
292 | - We don't support side effects. Thus, we don't have to worry about | |
c5aa993b | 293 | GCC's generalized lvalues, function calls, etc. |
c906108c SS |
294 | |
295 | - We don't support floating point. Many places where we switch on | |
c5aa993b JM |
296 | some type don't bother to include cases for floating point; there |
297 | may be even more subtle ways this assumption exists. For | |
298 | example, the arguments to % must be integers. | |
c906108c SS |
299 | |
300 | - We assume all subexpressions have a static, unchanging type. If | |
c5aa993b JM |
301 | we tried to support convenience variables, this would be a |
302 | problem. | |
c906108c SS |
303 | |
304 | - All values on the stack should always be fully zero- or | |
c5aa993b JM |
305 | sign-extended. |
306 | ||
307 | (I wasn't sure whether to choose this or its opposite --- that | |
308 | only addresses are assumed extended --- but it turns out that | |
309 | neither convention completely eliminates spurious extend | |
310 | operations (if everything is always extended, then you have to | |
311 | extend after add, because it could overflow; if nothing is | |
312 | extended, then you end up producing extends whenever you change | |
313 | sizes), and this is simpler.) */ | |
c906108c | 314 | \f |
c5aa993b | 315 | |
c906108c SS |
316 | /* Generating bytecode from GDB expressions: the `trace' kludge */ |
317 | ||
318 | /* The compiler in this file is a general-purpose mechanism for | |
319 | translating GDB expressions into bytecode. One ought to be able to | |
320 | find a million and one uses for it. | |
321 | ||
322 | However, at the moment it is HOPELESSLY BRAIN-DAMAGED for the sake | |
323 | of expediency. Let he who is without sin cast the first stone. | |
324 | ||
325 | For the data tracing facility, we need to insert `trace' bytecodes | |
326 | before each data fetch; this records all the memory that the | |
327 | expression touches in the course of evaluation, so that memory will | |
328 | be available when the user later tries to evaluate the expression | |
329 | in GDB. | |
330 | ||
331 | This should be done (I think) in a post-processing pass, that walks | |
332 | an arbitrary agent expression and inserts `trace' operations at the | |
333 | appropriate points. But it's much faster to just hack them | |
334 | directly into the code. And since we're in a crunch, that's what | |
335 | I've done. | |
336 | ||
337 | Setting the flag trace_kludge to non-zero enables the code that | |
338 | emits the trace bytecodes at the appropriate points. */ | |
08922a10 | 339 | int trace_kludge; |
c906108c | 340 | |
3065dfb6 SS |
341 | /* Inspired by trace_kludge, this indicates that pointers to chars |
342 | should get an added tracenz bytecode to record nonzero bytes, up to | |
343 | a length that is the value of trace_string_kludge. */ | |
344 | int trace_string_kludge; | |
345 | ||
400c6af0 SS |
346 | /* Scan for all static fields in the given class, including any base |
347 | classes, and generate tracing bytecodes for each. */ | |
348 | ||
349 | static void | |
350 | gen_trace_static_fields (struct gdbarch *gdbarch, | |
351 | struct agent_expr *ax, | |
352 | struct type *type) | |
353 | { | |
354 | int i, nbases = TYPE_N_BASECLASSES (type); | |
355 | struct axs_value value; | |
356 | ||
357 | CHECK_TYPEDEF (type); | |
358 | ||
359 | for (i = TYPE_NFIELDS (type) - 1; i >= nbases; i--) | |
360 | { | |
361 | if (field_is_static (&TYPE_FIELD (type, i))) | |
362 | { | |
363 | gen_static_field (gdbarch, ax, &value, type, i); | |
364 | if (value.optimized_out) | |
365 | continue; | |
366 | switch (value.kind) | |
367 | { | |
368 | case axs_lvalue_memory: | |
369 | { | |
370 | int length = TYPE_LENGTH (check_typedef (value.type)); | |
371 | ||
372 | ax_const_l (ax, length); | |
373 | ax_simple (ax, aop_trace); | |
374 | } | |
375 | break; | |
376 | ||
377 | case axs_lvalue_register: | |
35c9c7ba SS |
378 | /* We don't actually need the register's value to be pushed, |
379 | just note that we need it to be collected. */ | |
380 | ax_reg_mask (ax, value.u.reg); | |
400c6af0 SS |
381 | |
382 | default: | |
383 | break; | |
384 | } | |
385 | } | |
386 | } | |
387 | ||
388 | /* Now scan through base classes recursively. */ | |
389 | for (i = 0; i < nbases; i++) | |
390 | { | |
391 | struct type *basetype = check_typedef (TYPE_BASECLASS (type, i)); | |
392 | ||
393 | gen_trace_static_fields (gdbarch, ax, basetype); | |
394 | } | |
395 | } | |
396 | ||
c906108c SS |
397 | /* Trace the lvalue on the stack, if it needs it. In either case, pop |
398 | the value. Useful on the left side of a comma, and at the end of | |
399 | an expression being used for tracing. */ | |
400 | static void | |
400c6af0 SS |
401 | gen_traced_pop (struct gdbarch *gdbarch, |
402 | struct agent_expr *ax, struct axs_value *value) | |
c906108c | 403 | { |
3065dfb6 SS |
404 | int string_trace = 0; |
405 | if (trace_string_kludge | |
406 | && TYPE_CODE (value->type) == TYPE_CODE_PTR | |
407 | && c_textual_element_type (check_typedef (TYPE_TARGET_TYPE (value->type)), | |
408 | 's')) | |
409 | string_trace = 1; | |
410 | ||
c906108c SS |
411 | if (trace_kludge) |
412 | switch (value->kind) | |
413 | { | |
414 | case axs_rvalue: | |
3065dfb6 SS |
415 | if (string_trace) |
416 | { | |
417 | ax_const_l (ax, trace_string_kludge); | |
418 | ax_simple (ax, aop_tracenz); | |
419 | } | |
420 | else | |
421 | /* We don't trace rvalues, just the lvalues necessary to | |
422 | produce them. So just dispose of this value. */ | |
423 | ax_simple (ax, aop_pop); | |
c906108c SS |
424 | break; |
425 | ||
426 | case axs_lvalue_memory: | |
427 | { | |
648027cc | 428 | int length = TYPE_LENGTH (check_typedef (value->type)); |
c906108c | 429 | |
3065dfb6 SS |
430 | if (string_trace) |
431 | ax_simple (ax, aop_dup); | |
432 | ||
c906108c SS |
433 | /* There's no point in trying to use a trace_quick bytecode |
434 | here, since "trace_quick SIZE pop" is three bytes, whereas | |
435 | "const8 SIZE trace" is also three bytes, does the same | |
436 | thing, and the simplest code which generates that will also | |
437 | work correctly for objects with large sizes. */ | |
438 | ax_const_l (ax, length); | |
439 | ax_simple (ax, aop_trace); | |
3065dfb6 SS |
440 | |
441 | if (string_trace) | |
442 | { | |
443 | ax_simple (ax, aop_ref32); | |
444 | ax_const_l (ax, trace_string_kludge); | |
445 | ax_simple (ax, aop_tracenz); | |
446 | } | |
c906108c | 447 | } |
c5aa993b | 448 | break; |
c906108c SS |
449 | |
450 | case axs_lvalue_register: | |
35c9c7ba SS |
451 | /* We don't actually need the register's value to be on the |
452 | stack, and the target will get heartburn if the register is | |
453 | larger than will fit in a stack, so just mark it for | |
454 | collection and be done with it. */ | |
455 | ax_reg_mask (ax, value->u.reg); | |
3065dfb6 SS |
456 | |
457 | /* But if the register points to a string, assume the value | |
458 | will fit on the stack and push it anyway. */ | |
459 | if (string_trace) | |
460 | { | |
461 | ax_reg (ax, value->u.reg); | |
462 | ax_const_l (ax, trace_string_kludge); | |
463 | ax_simple (ax, aop_tracenz); | |
464 | } | |
c906108c SS |
465 | break; |
466 | } | |
467 | else | |
468 | /* If we're not tracing, just pop the value. */ | |
469 | ax_simple (ax, aop_pop); | |
400c6af0 SS |
470 | |
471 | /* To trace C++ classes with static fields stored elsewhere. */ | |
472 | if (trace_kludge | |
473 | && (TYPE_CODE (value->type) == TYPE_CODE_STRUCT | |
474 | || TYPE_CODE (value->type) == TYPE_CODE_UNION)) | |
475 | gen_trace_static_fields (gdbarch, ax, value->type); | |
c906108c | 476 | } |
c5aa993b | 477 | \f |
c906108c SS |
478 | |
479 | ||
c906108c SS |
480 | /* Generating bytecode from GDB expressions: helper functions */ |
481 | ||
482 | /* Assume that the lower bits of the top of the stack is a value of | |
483 | type TYPE, and the upper bits are zero. Sign-extend if necessary. */ | |
484 | static void | |
fba45db2 | 485 | gen_sign_extend (struct agent_expr *ax, struct type *type) |
c906108c SS |
486 | { |
487 | /* Do we need to sign-extend this? */ | |
c5aa993b | 488 | if (!TYPE_UNSIGNED (type)) |
0004e5a2 | 489 | ax_ext (ax, TYPE_LENGTH (type) * TARGET_CHAR_BIT); |
c906108c SS |
490 | } |
491 | ||
492 | ||
493 | /* Assume the lower bits of the top of the stack hold a value of type | |
494 | TYPE, and the upper bits are garbage. Sign-extend or truncate as | |
495 | needed. */ | |
496 | static void | |
fba45db2 | 497 | gen_extend (struct agent_expr *ax, struct type *type) |
c906108c | 498 | { |
0004e5a2 | 499 | int bits = TYPE_LENGTH (type) * TARGET_CHAR_BIT; |
5b4ee69b | 500 | |
c906108c SS |
501 | /* I just had to. */ |
502 | ((TYPE_UNSIGNED (type) ? ax_zero_ext : ax_ext) (ax, bits)); | |
503 | } | |
504 | ||
505 | ||
506 | /* Assume that the top of the stack contains a value of type "pointer | |
507 | to TYPE"; generate code to fetch its value. Note that TYPE is the | |
508 | target type, not the pointer type. */ | |
509 | static void | |
fba45db2 | 510 | gen_fetch (struct agent_expr *ax, struct type *type) |
c906108c SS |
511 | { |
512 | if (trace_kludge) | |
513 | { | |
514 | /* Record the area of memory we're about to fetch. */ | |
515 | ax_trace_quick (ax, TYPE_LENGTH (type)); | |
516 | } | |
517 | ||
0004e5a2 | 518 | switch (TYPE_CODE (type)) |
c906108c SS |
519 | { |
520 | case TYPE_CODE_PTR: | |
b97aedf3 | 521 | case TYPE_CODE_REF: |
c906108c SS |
522 | case TYPE_CODE_ENUM: |
523 | case TYPE_CODE_INT: | |
524 | case TYPE_CODE_CHAR: | |
3b11a015 | 525 | case TYPE_CODE_BOOL: |
c906108c SS |
526 | /* It's a scalar value, so we know how to dereference it. How |
527 | many bytes long is it? */ | |
0004e5a2 | 528 | switch (TYPE_LENGTH (type)) |
c906108c | 529 | { |
c5aa993b JM |
530 | case 8 / TARGET_CHAR_BIT: |
531 | ax_simple (ax, aop_ref8); | |
532 | break; | |
533 | case 16 / TARGET_CHAR_BIT: | |
534 | ax_simple (ax, aop_ref16); | |
535 | break; | |
536 | case 32 / TARGET_CHAR_BIT: | |
537 | ax_simple (ax, aop_ref32); | |
538 | break; | |
539 | case 64 / TARGET_CHAR_BIT: | |
540 | ax_simple (ax, aop_ref64); | |
541 | break; | |
c906108c SS |
542 | |
543 | /* Either our caller shouldn't have asked us to dereference | |
544 | that pointer (other code's fault), or we're not | |
545 | implementing something we should be (this code's fault). | |
546 | In any case, it's a bug the user shouldn't see. */ | |
547 | default: | |
8e65ff28 | 548 | internal_error (__FILE__, __LINE__, |
3d263c1d | 549 | _("gen_fetch: strange size")); |
c906108c SS |
550 | } |
551 | ||
552 | gen_sign_extend (ax, type); | |
553 | break; | |
554 | ||
555 | default: | |
556 | /* Either our caller shouldn't have asked us to dereference that | |
c5aa993b JM |
557 | pointer (other code's fault), or we're not implementing |
558 | something we should be (this code's fault). In any case, | |
559 | it's a bug the user shouldn't see. */ | |
8e65ff28 | 560 | internal_error (__FILE__, __LINE__, |
3d263c1d | 561 | _("gen_fetch: bad type code")); |
c906108c SS |
562 | } |
563 | } | |
564 | ||
565 | ||
566 | /* Generate code to left shift the top of the stack by DISTANCE bits, or | |
567 | right shift it by -DISTANCE bits if DISTANCE < 0. This generates | |
568 | unsigned (logical) right shifts. */ | |
569 | static void | |
fba45db2 | 570 | gen_left_shift (struct agent_expr *ax, int distance) |
c906108c SS |
571 | { |
572 | if (distance > 0) | |
573 | { | |
574 | ax_const_l (ax, distance); | |
575 | ax_simple (ax, aop_lsh); | |
576 | } | |
577 | else if (distance < 0) | |
578 | { | |
579 | ax_const_l (ax, -distance); | |
580 | ax_simple (ax, aop_rsh_unsigned); | |
581 | } | |
582 | } | |
c5aa993b | 583 | \f |
c906108c SS |
584 | |
585 | ||
c906108c SS |
586 | /* Generating bytecode from GDB expressions: symbol references */ |
587 | ||
588 | /* Generate code to push the base address of the argument portion of | |
589 | the top stack frame. */ | |
590 | static void | |
f7c79c41 | 591 | gen_frame_args_address (struct gdbarch *gdbarch, struct agent_expr *ax) |
c906108c | 592 | { |
39d4ef09 AC |
593 | int frame_reg; |
594 | LONGEST frame_offset; | |
c906108c | 595 | |
f7c79c41 | 596 | gdbarch_virtual_frame_pointer (gdbarch, |
c7bb205c | 597 | ax->scope, &frame_reg, &frame_offset); |
c5aa993b | 598 | ax_reg (ax, frame_reg); |
c906108c SS |
599 | gen_offset (ax, frame_offset); |
600 | } | |
601 | ||
602 | ||
603 | /* Generate code to push the base address of the locals portion of the | |
604 | top stack frame. */ | |
605 | static void | |
f7c79c41 | 606 | gen_frame_locals_address (struct gdbarch *gdbarch, struct agent_expr *ax) |
c906108c | 607 | { |
39d4ef09 AC |
608 | int frame_reg; |
609 | LONGEST frame_offset; | |
c906108c | 610 | |
f7c79c41 | 611 | gdbarch_virtual_frame_pointer (gdbarch, |
c7bb205c | 612 | ax->scope, &frame_reg, &frame_offset); |
c5aa993b | 613 | ax_reg (ax, frame_reg); |
c906108c SS |
614 | gen_offset (ax, frame_offset); |
615 | } | |
616 | ||
617 | ||
618 | /* Generate code to add OFFSET to the top of the stack. Try to | |
619 | generate short and readable code. We use this for getting to | |
620 | variables on the stack, and structure members. If we were | |
621 | programming in ML, it would be clearer why these are the same | |
622 | thing. */ | |
623 | static void | |
fba45db2 | 624 | gen_offset (struct agent_expr *ax, int offset) |
c906108c SS |
625 | { |
626 | /* It would suffice to simply push the offset and add it, but this | |
627 | makes it easier to read positive and negative offsets in the | |
628 | bytecode. */ | |
629 | if (offset > 0) | |
630 | { | |
631 | ax_const_l (ax, offset); | |
632 | ax_simple (ax, aop_add); | |
633 | } | |
634 | else if (offset < 0) | |
635 | { | |
636 | ax_const_l (ax, -offset); | |
637 | ax_simple (ax, aop_sub); | |
638 | } | |
639 | } | |
640 | ||
641 | ||
642 | /* In many cases, a symbol's value is the offset from some other | |
643 | address (stack frame, base register, etc.) Generate code to add | |
644 | VAR's value to the top of the stack. */ | |
645 | static void | |
fba45db2 | 646 | gen_sym_offset (struct agent_expr *ax, struct symbol *var) |
c906108c SS |
647 | { |
648 | gen_offset (ax, SYMBOL_VALUE (var)); | |
649 | } | |
650 | ||
651 | ||
652 | /* Generate code for a variable reference to AX. The variable is the | |
653 | symbol VAR. Set VALUE to describe the result. */ | |
654 | ||
655 | static void | |
f7c79c41 UW |
656 | gen_var_ref (struct gdbarch *gdbarch, struct agent_expr *ax, |
657 | struct axs_value *value, struct symbol *var) | |
c906108c | 658 | { |
0e2de366 | 659 | /* Dereference any typedefs. */ |
c906108c | 660 | value->type = check_typedef (SYMBOL_TYPE (var)); |
400c6af0 | 661 | value->optimized_out = 0; |
c906108c SS |
662 | |
663 | /* I'm imitating the code in read_var_value. */ | |
664 | switch (SYMBOL_CLASS (var)) | |
665 | { | |
666 | case LOC_CONST: /* A constant, like an enum value. */ | |
667 | ax_const_l (ax, (LONGEST) SYMBOL_VALUE (var)); | |
668 | value->kind = axs_rvalue; | |
669 | break; | |
670 | ||
671 | case LOC_LABEL: /* A goto label, being used as a value. */ | |
672 | ax_const_l (ax, (LONGEST) SYMBOL_VALUE_ADDRESS (var)); | |
673 | value->kind = axs_rvalue; | |
674 | break; | |
675 | ||
676 | case LOC_CONST_BYTES: | |
8e65ff28 | 677 | internal_error (__FILE__, __LINE__, |
3e43a32a MS |
678 | _("gen_var_ref: LOC_CONST_BYTES " |
679 | "symbols are not supported")); | |
c906108c SS |
680 | |
681 | /* Variable at a fixed location in memory. Easy. */ | |
682 | case LOC_STATIC: | |
683 | /* Push the address of the variable. */ | |
684 | ax_const_l (ax, SYMBOL_VALUE_ADDRESS (var)); | |
685 | value->kind = axs_lvalue_memory; | |
686 | break; | |
687 | ||
688 | case LOC_ARG: /* var lives in argument area of frame */ | |
f7c79c41 | 689 | gen_frame_args_address (gdbarch, ax); |
c906108c SS |
690 | gen_sym_offset (ax, var); |
691 | value->kind = axs_lvalue_memory; | |
692 | break; | |
693 | ||
694 | case LOC_REF_ARG: /* As above, but the frame slot really | |
695 | holds the address of the variable. */ | |
f7c79c41 | 696 | gen_frame_args_address (gdbarch, ax); |
c906108c SS |
697 | gen_sym_offset (ax, var); |
698 | /* Don't assume any particular pointer size. */ | |
f7c79c41 | 699 | gen_fetch (ax, builtin_type (gdbarch)->builtin_data_ptr); |
c906108c SS |
700 | value->kind = axs_lvalue_memory; |
701 | break; | |
702 | ||
703 | case LOC_LOCAL: /* var lives in locals area of frame */ | |
f7c79c41 | 704 | gen_frame_locals_address (gdbarch, ax); |
c906108c SS |
705 | gen_sym_offset (ax, var); |
706 | value->kind = axs_lvalue_memory; | |
707 | break; | |
708 | ||
c906108c | 709 | case LOC_TYPEDEF: |
3d263c1d | 710 | error (_("Cannot compute value of typedef `%s'."), |
de5ad195 | 711 | SYMBOL_PRINT_NAME (var)); |
c906108c SS |
712 | break; |
713 | ||
714 | case LOC_BLOCK: | |
715 | ax_const_l (ax, BLOCK_START (SYMBOL_BLOCK_VALUE (var))); | |
716 | value->kind = axs_rvalue; | |
717 | break; | |
718 | ||
719 | case LOC_REGISTER: | |
c906108c SS |
720 | /* Don't generate any code at all; in the process of treating |
721 | this as an lvalue or rvalue, the caller will generate the | |
722 | right code. */ | |
723 | value->kind = axs_lvalue_register; | |
768a979c | 724 | value->u.reg = SYMBOL_REGISTER_OPS (var)->register_number (var, gdbarch); |
c906108c SS |
725 | break; |
726 | ||
727 | /* A lot like LOC_REF_ARG, but the pointer lives directly in a | |
2a2d4dc3 AS |
728 | register, not on the stack. Simpler than LOC_REGISTER |
729 | because it's just like any other case where the thing | |
730 | has a real address. */ | |
c906108c | 731 | case LOC_REGPARM_ADDR: |
768a979c | 732 | ax_reg (ax, SYMBOL_REGISTER_OPS (var)->register_number (var, gdbarch)); |
c906108c SS |
733 | value->kind = axs_lvalue_memory; |
734 | break; | |
735 | ||
736 | case LOC_UNRESOLVED: | |
737 | { | |
c5aa993b | 738 | struct minimal_symbol *msym |
3567439c | 739 | = lookup_minimal_symbol (SYMBOL_LINKAGE_NAME (var), NULL, NULL); |
5b4ee69b | 740 | |
c5aa993b | 741 | if (!msym) |
3d263c1d | 742 | error (_("Couldn't resolve symbol `%s'."), SYMBOL_PRINT_NAME (var)); |
c5aa993b | 743 | |
c906108c SS |
744 | /* Push the address of the variable. */ |
745 | ax_const_l (ax, SYMBOL_VALUE_ADDRESS (msym)); | |
746 | value->kind = axs_lvalue_memory; | |
747 | } | |
c5aa993b | 748 | break; |
c906108c | 749 | |
a55cc764 | 750 | case LOC_COMPUTED: |
a67af2b9 | 751 | /* FIXME: cagney/2004-01-26: It should be possible to |
768a979c | 752 | unconditionally call the SYMBOL_COMPUTED_OPS method when available. |
d3efc286 | 753 | Unfortunately DWARF 2 stores the frame-base (instead of the |
a67af2b9 AC |
754 | function) location in a function's symbol. Oops! For the |
755 | moment enable this when/where applicable. */ | |
505e835d | 756 | SYMBOL_COMPUTED_OPS (var)->tracepoint_var_ref (var, gdbarch, ax, value); |
a55cc764 DJ |
757 | break; |
758 | ||
c906108c | 759 | case LOC_OPTIMIZED_OUT: |
400c6af0 SS |
760 | /* Flag this, but don't say anything; leave it up to callers to |
761 | warn the user. */ | |
762 | value->optimized_out = 1; | |
c906108c SS |
763 | break; |
764 | ||
765 | default: | |
3d263c1d | 766 | error (_("Cannot find value of botched symbol `%s'."), |
de5ad195 | 767 | SYMBOL_PRINT_NAME (var)); |
c906108c SS |
768 | break; |
769 | } | |
770 | } | |
c5aa993b | 771 | \f |
c906108c SS |
772 | |
773 | ||
c906108c SS |
774 | /* Generating bytecode from GDB expressions: literals */ |
775 | ||
776 | static void | |
fba45db2 KB |
777 | gen_int_literal (struct agent_expr *ax, struct axs_value *value, LONGEST k, |
778 | struct type *type) | |
c906108c SS |
779 | { |
780 | ax_const_l (ax, k); | |
781 | value->kind = axs_rvalue; | |
648027cc | 782 | value->type = check_typedef (type); |
c906108c | 783 | } |
c5aa993b | 784 | \f |
c906108c SS |
785 | |
786 | ||
c906108c SS |
787 | /* Generating bytecode from GDB expressions: unary conversions, casts */ |
788 | ||
789 | /* Take what's on the top of the stack (as described by VALUE), and | |
790 | try to make an rvalue out of it. Signal an error if we can't do | |
791 | that. */ | |
792 | static void | |
fba45db2 | 793 | require_rvalue (struct agent_expr *ax, struct axs_value *value) |
c906108c | 794 | { |
3a96536b SS |
795 | /* Only deal with scalars, structs and such may be too large |
796 | to fit in a stack entry. */ | |
797 | value->type = check_typedef (value->type); | |
798 | if (TYPE_CODE (value->type) == TYPE_CODE_ARRAY | |
799 | || TYPE_CODE (value->type) == TYPE_CODE_STRUCT | |
800 | || TYPE_CODE (value->type) == TYPE_CODE_UNION | |
801 | || TYPE_CODE (value->type) == TYPE_CODE_FUNC) | |
1c40aa62 | 802 | error (_("Value not scalar: cannot be an rvalue.")); |
3a96536b | 803 | |
c906108c SS |
804 | switch (value->kind) |
805 | { | |
806 | case axs_rvalue: | |
807 | /* It's already an rvalue. */ | |
808 | break; | |
809 | ||
810 | case axs_lvalue_memory: | |
811 | /* The top of stack is the address of the object. Dereference. */ | |
812 | gen_fetch (ax, value->type); | |
813 | break; | |
814 | ||
815 | case axs_lvalue_register: | |
816 | /* There's nothing on the stack, but value->u.reg is the | |
817 | register number containing the value. | |
818 | ||
c5aa993b JM |
819 | When we add floating-point support, this is going to have to |
820 | change. What about SPARC register pairs, for example? */ | |
c906108c SS |
821 | ax_reg (ax, value->u.reg); |
822 | gen_extend (ax, value->type); | |
823 | break; | |
824 | } | |
825 | ||
826 | value->kind = axs_rvalue; | |
827 | } | |
828 | ||
829 | ||
830 | /* Assume the top of the stack is described by VALUE, and perform the | |
831 | usual unary conversions. This is motivated by ANSI 6.2.2, but of | |
832 | course GDB expressions are not ANSI; they're the mishmash union of | |
833 | a bunch of languages. Rah. | |
834 | ||
835 | NOTE! This function promises to produce an rvalue only when the | |
836 | incoming value is of an appropriate type. In other words, the | |
837 | consumer of the value this function produces may assume the value | |
838 | is an rvalue only after checking its type. | |
839 | ||
840 | The immediate issue is that if the user tries to use a structure or | |
841 | union as an operand of, say, the `+' operator, we don't want to try | |
842 | to convert that structure to an rvalue; require_rvalue will bomb on | |
843 | structs and unions. Rather, we want to simply pass the struct | |
844 | lvalue through unchanged, and let `+' raise an error. */ | |
845 | ||
846 | static void | |
f7c79c41 UW |
847 | gen_usual_unary (struct expression *exp, struct agent_expr *ax, |
848 | struct axs_value *value) | |
c906108c SS |
849 | { |
850 | /* We don't have to generate any code for the usual integral | |
851 | conversions, since values are always represented as full-width on | |
852 | the stack. Should we tweak the type? */ | |
853 | ||
854 | /* Some types require special handling. */ | |
0004e5a2 | 855 | switch (TYPE_CODE (value->type)) |
c906108c SS |
856 | { |
857 | /* Functions get converted to a pointer to the function. */ | |
858 | case TYPE_CODE_FUNC: | |
859 | value->type = lookup_pointer_type (value->type); | |
860 | value->kind = axs_rvalue; /* Should always be true, but just in case. */ | |
861 | break; | |
862 | ||
863 | /* Arrays get converted to a pointer to their first element, and | |
c5aa993b | 864 | are no longer an lvalue. */ |
c906108c SS |
865 | case TYPE_CODE_ARRAY: |
866 | { | |
867 | struct type *elements = TYPE_TARGET_TYPE (value->type); | |
5b4ee69b | 868 | |
c906108c SS |
869 | value->type = lookup_pointer_type (elements); |
870 | value->kind = axs_rvalue; | |
871 | /* We don't need to generate any code; the address of the array | |
872 | is also the address of its first element. */ | |
873 | } | |
c5aa993b | 874 | break; |
c906108c | 875 | |
c5aa993b JM |
876 | /* Don't try to convert structures and unions to rvalues. Let the |
877 | consumer signal an error. */ | |
c906108c SS |
878 | case TYPE_CODE_STRUCT: |
879 | case TYPE_CODE_UNION: | |
880 | return; | |
881 | ||
3b11a015 | 882 | /* If the value is an enum or a bool, call it an integer. */ |
c906108c | 883 | case TYPE_CODE_ENUM: |
3b11a015 | 884 | case TYPE_CODE_BOOL: |
f7c79c41 | 885 | value->type = builtin_type (exp->gdbarch)->builtin_int; |
c906108c SS |
886 | break; |
887 | } | |
888 | ||
889 | /* If the value is an lvalue, dereference it. */ | |
890 | require_rvalue (ax, value); | |
891 | } | |
892 | ||
893 | ||
894 | /* Return non-zero iff the type TYPE1 is considered "wider" than the | |
895 | type TYPE2, according to the rules described in gen_usual_arithmetic. */ | |
896 | static int | |
fba45db2 | 897 | type_wider_than (struct type *type1, struct type *type2) |
c906108c SS |
898 | { |
899 | return (TYPE_LENGTH (type1) > TYPE_LENGTH (type2) | |
900 | || (TYPE_LENGTH (type1) == TYPE_LENGTH (type2) | |
901 | && TYPE_UNSIGNED (type1) | |
c5aa993b | 902 | && !TYPE_UNSIGNED (type2))); |
c906108c SS |
903 | } |
904 | ||
905 | ||
906 | /* Return the "wider" of the two types TYPE1 and TYPE2. */ | |
907 | static struct type * | |
fba45db2 | 908 | max_type (struct type *type1, struct type *type2) |
c906108c SS |
909 | { |
910 | return type_wider_than (type1, type2) ? type1 : type2; | |
911 | } | |
912 | ||
913 | ||
914 | /* Generate code to convert a scalar value of type FROM to type TO. */ | |
915 | static void | |
fba45db2 | 916 | gen_conversion (struct agent_expr *ax, struct type *from, struct type *to) |
c906108c SS |
917 | { |
918 | /* Perhaps there is a more graceful way to state these rules. */ | |
919 | ||
920 | /* If we're converting to a narrower type, then we need to clear out | |
921 | the upper bits. */ | |
922 | if (TYPE_LENGTH (to) < TYPE_LENGTH (from)) | |
923 | gen_extend (ax, from); | |
924 | ||
925 | /* If the two values have equal width, but different signednesses, | |
926 | then we need to extend. */ | |
927 | else if (TYPE_LENGTH (to) == TYPE_LENGTH (from)) | |
928 | { | |
929 | if (TYPE_UNSIGNED (from) != TYPE_UNSIGNED (to)) | |
930 | gen_extend (ax, to); | |
931 | } | |
932 | ||
933 | /* If we're converting to a wider type, and becoming unsigned, then | |
934 | we need to zero out any possible sign bits. */ | |
935 | else if (TYPE_LENGTH (to) > TYPE_LENGTH (from)) | |
936 | { | |
937 | if (TYPE_UNSIGNED (to)) | |
938 | gen_extend (ax, to); | |
939 | } | |
940 | } | |
941 | ||
942 | ||
943 | /* Return non-zero iff the type FROM will require any bytecodes to be | |
944 | emitted to be converted to the type TO. */ | |
945 | static int | |
fba45db2 | 946 | is_nontrivial_conversion (struct type *from, struct type *to) |
c906108c | 947 | { |
35c9c7ba | 948 | struct agent_expr *ax = new_agent_expr (NULL, 0); |
c906108c SS |
949 | int nontrivial; |
950 | ||
951 | /* Actually generate the code, and see if anything came out. At the | |
952 | moment, it would be trivial to replicate the code in | |
953 | gen_conversion here, but in the future, when we're supporting | |
954 | floating point and the like, it may not be. Doing things this | |
955 | way allows this function to be independent of the logic in | |
956 | gen_conversion. */ | |
957 | gen_conversion (ax, from, to); | |
958 | nontrivial = ax->len > 0; | |
959 | free_agent_expr (ax); | |
960 | return nontrivial; | |
961 | } | |
962 | ||
963 | ||
964 | /* Generate code to perform the "usual arithmetic conversions" (ANSI C | |
965 | 6.2.1.5) for the two operands of an arithmetic operator. This | |
966 | effectively finds a "least upper bound" type for the two arguments, | |
967 | and promotes each argument to that type. *VALUE1 and *VALUE2 | |
968 | describe the values as they are passed in, and as they are left. */ | |
969 | static void | |
f7c79c41 UW |
970 | gen_usual_arithmetic (struct expression *exp, struct agent_expr *ax, |
971 | struct axs_value *value1, struct axs_value *value2) | |
c906108c SS |
972 | { |
973 | /* Do the usual binary conversions. */ | |
974 | if (TYPE_CODE (value1->type) == TYPE_CODE_INT | |
975 | && TYPE_CODE (value2->type) == TYPE_CODE_INT) | |
976 | { | |
977 | /* The ANSI integral promotions seem to work this way: Order the | |
c5aa993b JM |
978 | integer types by size, and then by signedness: an n-bit |
979 | unsigned type is considered "wider" than an n-bit signed | |
980 | type. Promote to the "wider" of the two types, and always | |
981 | promote at least to int. */ | |
f7c79c41 | 982 | struct type *target = max_type (builtin_type (exp->gdbarch)->builtin_int, |
c906108c SS |
983 | max_type (value1->type, value2->type)); |
984 | ||
985 | /* Deal with value2, on the top of the stack. */ | |
986 | gen_conversion (ax, value2->type, target); | |
987 | ||
988 | /* Deal with value1, not on the top of the stack. Don't | |
989 | generate the `swap' instructions if we're not actually going | |
990 | to do anything. */ | |
991 | if (is_nontrivial_conversion (value1->type, target)) | |
992 | { | |
993 | ax_simple (ax, aop_swap); | |
994 | gen_conversion (ax, value1->type, target); | |
995 | ax_simple (ax, aop_swap); | |
996 | } | |
997 | ||
648027cc | 998 | value1->type = value2->type = check_typedef (target); |
c906108c SS |
999 | } |
1000 | } | |
1001 | ||
1002 | ||
1003 | /* Generate code to perform the integral promotions (ANSI 6.2.1.1) on | |
1004 | the value on the top of the stack, as described by VALUE. Assume | |
1005 | the value has integral type. */ | |
1006 | static void | |
f7c79c41 UW |
1007 | gen_integral_promotions (struct expression *exp, struct agent_expr *ax, |
1008 | struct axs_value *value) | |
c906108c | 1009 | { |
f7c79c41 UW |
1010 | const struct builtin_type *builtin = builtin_type (exp->gdbarch); |
1011 | ||
1012 | if (!type_wider_than (value->type, builtin->builtin_int)) | |
c906108c | 1013 | { |
f7c79c41 UW |
1014 | gen_conversion (ax, value->type, builtin->builtin_int); |
1015 | value->type = builtin->builtin_int; | |
c906108c | 1016 | } |
f7c79c41 | 1017 | else if (!type_wider_than (value->type, builtin->builtin_unsigned_int)) |
c906108c | 1018 | { |
f7c79c41 UW |
1019 | gen_conversion (ax, value->type, builtin->builtin_unsigned_int); |
1020 | value->type = builtin->builtin_unsigned_int; | |
c906108c SS |
1021 | } |
1022 | } | |
1023 | ||
1024 | ||
1025 | /* Generate code for a cast to TYPE. */ | |
1026 | static void | |
fba45db2 | 1027 | gen_cast (struct agent_expr *ax, struct axs_value *value, struct type *type) |
c906108c SS |
1028 | { |
1029 | /* GCC does allow casts to yield lvalues, so this should be fixed | |
1030 | before merging these changes into the trunk. */ | |
1031 | require_rvalue (ax, value); | |
0e2de366 | 1032 | /* Dereference typedefs. */ |
c906108c SS |
1033 | type = check_typedef (type); |
1034 | ||
0004e5a2 | 1035 | switch (TYPE_CODE (type)) |
c906108c SS |
1036 | { |
1037 | case TYPE_CODE_PTR: | |
b97aedf3 | 1038 | case TYPE_CODE_REF: |
c906108c SS |
1039 | /* It's implementation-defined, and I'll bet this is what GCC |
1040 | does. */ | |
1041 | break; | |
1042 | ||
1043 | case TYPE_CODE_ARRAY: | |
1044 | case TYPE_CODE_STRUCT: | |
1045 | case TYPE_CODE_UNION: | |
1046 | case TYPE_CODE_FUNC: | |
3d263c1d | 1047 | error (_("Invalid type cast: intended type must be scalar.")); |
c906108c SS |
1048 | |
1049 | case TYPE_CODE_ENUM: | |
3b11a015 | 1050 | case TYPE_CODE_BOOL: |
c906108c SS |
1051 | /* We don't have to worry about the size of the value, because |
1052 | all our integral values are fully sign-extended, and when | |
1053 | casting pointers we can do anything we like. Is there any | |
74b35824 JB |
1054 | way for us to know what GCC actually does with a cast like |
1055 | this? */ | |
c906108c | 1056 | break; |
c5aa993b | 1057 | |
c906108c SS |
1058 | case TYPE_CODE_INT: |
1059 | gen_conversion (ax, value->type, type); | |
1060 | break; | |
1061 | ||
1062 | case TYPE_CODE_VOID: | |
1063 | /* We could pop the value, and rely on everyone else to check | |
c5aa993b JM |
1064 | the type and notice that this value doesn't occupy a stack |
1065 | slot. But for now, leave the value on the stack, and | |
1066 | preserve the "value == stack element" assumption. */ | |
c906108c SS |
1067 | break; |
1068 | ||
1069 | default: | |
3d263c1d | 1070 | error (_("Casts to requested type are not yet implemented.")); |
c906108c SS |
1071 | } |
1072 | ||
1073 | value->type = type; | |
1074 | } | |
c5aa993b | 1075 | \f |
c906108c SS |
1076 | |
1077 | ||
c906108c SS |
1078 | /* Generating bytecode from GDB expressions: arithmetic */ |
1079 | ||
1080 | /* Scale the integer on the top of the stack by the size of the target | |
1081 | of the pointer type TYPE. */ | |
1082 | static void | |
fba45db2 | 1083 | gen_scale (struct agent_expr *ax, enum agent_op op, struct type *type) |
c906108c SS |
1084 | { |
1085 | struct type *element = TYPE_TARGET_TYPE (type); | |
1086 | ||
0004e5a2 | 1087 | if (TYPE_LENGTH (element) != 1) |
c906108c | 1088 | { |
0004e5a2 | 1089 | ax_const_l (ax, TYPE_LENGTH (element)); |
c906108c SS |
1090 | ax_simple (ax, op); |
1091 | } | |
1092 | } | |
1093 | ||
1094 | ||
f7c79c41 | 1095 | /* Generate code for pointer arithmetic PTR + INT. */ |
c906108c | 1096 | static void |
f7c79c41 UW |
1097 | gen_ptradd (struct agent_expr *ax, struct axs_value *value, |
1098 | struct axs_value *value1, struct axs_value *value2) | |
c906108c | 1099 | { |
b97aedf3 | 1100 | gdb_assert (pointer_type (value1->type)); |
f7c79c41 | 1101 | gdb_assert (TYPE_CODE (value2->type) == TYPE_CODE_INT); |
c906108c | 1102 | |
f7c79c41 UW |
1103 | gen_scale (ax, aop_mul, value1->type); |
1104 | ax_simple (ax, aop_add); | |
1105 | gen_extend (ax, value1->type); /* Catch overflow. */ | |
1106 | value->type = value1->type; | |
1107 | value->kind = axs_rvalue; | |
1108 | } | |
c906108c | 1109 | |
c906108c | 1110 | |
f7c79c41 UW |
1111 | /* Generate code for pointer arithmetic PTR - INT. */ |
1112 | static void | |
1113 | gen_ptrsub (struct agent_expr *ax, struct axs_value *value, | |
1114 | struct axs_value *value1, struct axs_value *value2) | |
1115 | { | |
b97aedf3 | 1116 | gdb_assert (pointer_type (value1->type)); |
f7c79c41 | 1117 | gdb_assert (TYPE_CODE (value2->type) == TYPE_CODE_INT); |
c906108c | 1118 | |
f7c79c41 UW |
1119 | gen_scale (ax, aop_mul, value1->type); |
1120 | ax_simple (ax, aop_sub); | |
1121 | gen_extend (ax, value1->type); /* Catch overflow. */ | |
1122 | value->type = value1->type; | |
c906108c SS |
1123 | value->kind = axs_rvalue; |
1124 | } | |
1125 | ||
1126 | ||
f7c79c41 | 1127 | /* Generate code for pointer arithmetic PTR - PTR. */ |
c906108c | 1128 | static void |
f7c79c41 UW |
1129 | gen_ptrdiff (struct agent_expr *ax, struct axs_value *value, |
1130 | struct axs_value *value1, struct axs_value *value2, | |
1131 | struct type *result_type) | |
c906108c | 1132 | { |
b97aedf3 SS |
1133 | gdb_assert (pointer_type (value1->type)); |
1134 | gdb_assert (pointer_type (value2->type)); | |
c906108c | 1135 | |
f7c79c41 UW |
1136 | if (TYPE_LENGTH (TYPE_TARGET_TYPE (value1->type)) |
1137 | != TYPE_LENGTH (TYPE_TARGET_TYPE (value2->type))) | |
ac74f770 MS |
1138 | error (_("\ |
1139 | First argument of `-' is a pointer, but second argument is neither\n\ | |
1140 | an integer nor a pointer of the same type.")); | |
c906108c | 1141 | |
f7c79c41 UW |
1142 | ax_simple (ax, aop_sub); |
1143 | gen_scale (ax, aop_div_unsigned, value1->type); | |
1144 | value->type = result_type; | |
c906108c SS |
1145 | value->kind = axs_rvalue; |
1146 | } | |
1147 | ||
3b11a015 SS |
1148 | static void |
1149 | gen_equal (struct agent_expr *ax, struct axs_value *value, | |
1150 | struct axs_value *value1, struct axs_value *value2, | |
1151 | struct type *result_type) | |
1152 | { | |
1153 | if (pointer_type (value1->type) || pointer_type (value2->type)) | |
1154 | ax_simple (ax, aop_equal); | |
1155 | else | |
1156 | gen_binop (ax, value, value1, value2, | |
1157 | aop_equal, aop_equal, 0, "equal"); | |
1158 | value->type = result_type; | |
1159 | value->kind = axs_rvalue; | |
1160 | } | |
1161 | ||
1162 | static void | |
1163 | gen_less (struct agent_expr *ax, struct axs_value *value, | |
1164 | struct axs_value *value1, struct axs_value *value2, | |
1165 | struct type *result_type) | |
1166 | { | |
1167 | if (pointer_type (value1->type) || pointer_type (value2->type)) | |
1168 | ax_simple (ax, aop_less_unsigned); | |
1169 | else | |
1170 | gen_binop (ax, value, value1, value2, | |
1171 | aop_less_signed, aop_less_unsigned, 0, "less than"); | |
1172 | value->type = result_type; | |
1173 | value->kind = axs_rvalue; | |
1174 | } | |
f7c79c41 | 1175 | |
c906108c SS |
1176 | /* Generate code for a binary operator that doesn't do pointer magic. |
1177 | We set VALUE to describe the result value; we assume VALUE1 and | |
1178 | VALUE2 describe the two operands, and that they've undergone the | |
1179 | usual binary conversions. MAY_CARRY should be non-zero iff the | |
1180 | result needs to be extended. NAME is the English name of the | |
1181 | operator, used in error messages */ | |
1182 | static void | |
fba45db2 | 1183 | gen_binop (struct agent_expr *ax, struct axs_value *value, |
3e43a32a MS |
1184 | struct axs_value *value1, struct axs_value *value2, |
1185 | enum agent_op op, enum agent_op op_unsigned, | |
1186 | int may_carry, char *name) | |
c906108c SS |
1187 | { |
1188 | /* We only handle INT op INT. */ | |
0004e5a2 DJ |
1189 | if ((TYPE_CODE (value1->type) != TYPE_CODE_INT) |
1190 | || (TYPE_CODE (value2->type) != TYPE_CODE_INT)) | |
3d263c1d | 1191 | error (_("Invalid combination of types in %s."), name); |
c5aa993b | 1192 | |
c906108c SS |
1193 | ax_simple (ax, |
1194 | TYPE_UNSIGNED (value1->type) ? op_unsigned : op); | |
1195 | if (may_carry) | |
c5aa993b | 1196 | gen_extend (ax, value1->type); /* catch overflow */ |
c906108c SS |
1197 | value->type = value1->type; |
1198 | value->kind = axs_rvalue; | |
1199 | } | |
1200 | ||
1201 | ||
1202 | static void | |
f7c79c41 UW |
1203 | gen_logical_not (struct agent_expr *ax, struct axs_value *value, |
1204 | struct type *result_type) | |
c906108c SS |
1205 | { |
1206 | if (TYPE_CODE (value->type) != TYPE_CODE_INT | |
1207 | && TYPE_CODE (value->type) != TYPE_CODE_PTR) | |
3d263c1d | 1208 | error (_("Invalid type of operand to `!'.")); |
c906108c | 1209 | |
c906108c | 1210 | ax_simple (ax, aop_log_not); |
f7c79c41 | 1211 | value->type = result_type; |
c906108c SS |
1212 | } |
1213 | ||
1214 | ||
1215 | static void | |
fba45db2 | 1216 | gen_complement (struct agent_expr *ax, struct axs_value *value) |
c906108c SS |
1217 | { |
1218 | if (TYPE_CODE (value->type) != TYPE_CODE_INT) | |
3d263c1d | 1219 | error (_("Invalid type of operand to `~'.")); |
c906108c | 1220 | |
c906108c SS |
1221 | ax_simple (ax, aop_bit_not); |
1222 | gen_extend (ax, value->type); | |
1223 | } | |
c5aa993b | 1224 | \f |
c906108c SS |
1225 | |
1226 | ||
c906108c SS |
1227 | /* Generating bytecode from GDB expressions: * & . -> @ sizeof */ |
1228 | ||
1229 | /* Dereference the value on the top of the stack. */ | |
1230 | static void | |
fba45db2 | 1231 | gen_deref (struct agent_expr *ax, struct axs_value *value) |
c906108c SS |
1232 | { |
1233 | /* The caller should check the type, because several operators use | |
1234 | this, and we don't know what error message to generate. */ | |
b97aedf3 | 1235 | if (!pointer_type (value->type)) |
8e65ff28 | 1236 | internal_error (__FILE__, __LINE__, |
3d263c1d | 1237 | _("gen_deref: expected a pointer")); |
c906108c SS |
1238 | |
1239 | /* We've got an rvalue now, which is a pointer. We want to yield an | |
1240 | lvalue, whose address is exactly that pointer. So we don't | |
1241 | actually emit any code; we just change the type from "Pointer to | |
1242 | T" to "T", and mark the value as an lvalue in memory. Leave it | |
1243 | to the consumer to actually dereference it. */ | |
1244 | value->type = check_typedef (TYPE_TARGET_TYPE (value->type)); | |
b1028c8e PA |
1245 | if (TYPE_CODE (value->type) == TYPE_CODE_VOID) |
1246 | error (_("Attempt to dereference a generic pointer.")); | |
0004e5a2 | 1247 | value->kind = ((TYPE_CODE (value->type) == TYPE_CODE_FUNC) |
c906108c SS |
1248 | ? axs_rvalue : axs_lvalue_memory); |
1249 | } | |
1250 | ||
1251 | ||
1252 | /* Produce the address of the lvalue on the top of the stack. */ | |
1253 | static void | |
fba45db2 | 1254 | gen_address_of (struct agent_expr *ax, struct axs_value *value) |
c906108c SS |
1255 | { |
1256 | /* Special case for taking the address of a function. The ANSI | |
1257 | standard describes this as a special case, too, so this | |
1258 | arrangement is not without motivation. */ | |
0004e5a2 | 1259 | if (TYPE_CODE (value->type) == TYPE_CODE_FUNC) |
c906108c SS |
1260 | /* The value's already an rvalue on the stack, so we just need to |
1261 | change the type. */ | |
1262 | value->type = lookup_pointer_type (value->type); | |
1263 | else | |
1264 | switch (value->kind) | |
1265 | { | |
1266 | case axs_rvalue: | |
3d263c1d | 1267 | error (_("Operand of `&' is an rvalue, which has no address.")); |
c906108c SS |
1268 | |
1269 | case axs_lvalue_register: | |
3d263c1d | 1270 | error (_("Operand of `&' is in a register, and has no address.")); |
c906108c SS |
1271 | |
1272 | case axs_lvalue_memory: | |
1273 | value->kind = axs_rvalue; | |
1274 | value->type = lookup_pointer_type (value->type); | |
1275 | break; | |
1276 | } | |
1277 | } | |
1278 | ||
c906108c SS |
1279 | /* Generate code to push the value of a bitfield of a structure whose |
1280 | address is on the top of the stack. START and END give the | |
1281 | starting and one-past-ending *bit* numbers of the field within the | |
1282 | structure. */ | |
1283 | static void | |
505e835d UW |
1284 | gen_bitfield_ref (struct expression *exp, struct agent_expr *ax, |
1285 | struct axs_value *value, struct type *type, | |
1286 | int start, int end) | |
c906108c SS |
1287 | { |
1288 | /* Note that ops[i] fetches 8 << i bits. */ | |
1289 | static enum agent_op ops[] | |
5b4ee69b | 1290 | = {aop_ref8, aop_ref16, aop_ref32, aop_ref64}; |
c906108c SS |
1291 | static int num_ops = (sizeof (ops) / sizeof (ops[0])); |
1292 | ||
1293 | /* We don't want to touch any byte that the bitfield doesn't | |
1294 | actually occupy; we shouldn't make any accesses we're not | |
1295 | explicitly permitted to. We rely here on the fact that the | |
1296 | bytecode `ref' operators work on unaligned addresses. | |
1297 | ||
1298 | It takes some fancy footwork to get the stack to work the way | |
1299 | we'd like. Say we're retrieving a bitfield that requires three | |
1300 | fetches. Initially, the stack just contains the address: | |
c5aa993b | 1301 | addr |
c906108c | 1302 | For the first fetch, we duplicate the address |
c5aa993b | 1303 | addr addr |
c906108c SS |
1304 | then add the byte offset, do the fetch, and shift and mask as |
1305 | needed, yielding a fragment of the value, properly aligned for | |
1306 | the final bitwise or: | |
c5aa993b | 1307 | addr frag1 |
c906108c | 1308 | then we swap, and repeat the process: |
c5aa993b JM |
1309 | frag1 addr --- address on top |
1310 | frag1 addr addr --- duplicate it | |
1311 | frag1 addr frag2 --- get second fragment | |
1312 | frag1 frag2 addr --- swap again | |
1313 | frag1 frag2 frag3 --- get third fragment | |
c906108c SS |
1314 | Notice that, since the third fragment is the last one, we don't |
1315 | bother duplicating the address this time. Now we have all the | |
1316 | fragments on the stack, and we can simply `or' them together, | |
1317 | yielding the final value of the bitfield. */ | |
1318 | ||
1319 | /* The first and one-after-last bits in the field, but rounded down | |
1320 | and up to byte boundaries. */ | |
1321 | int bound_start = (start / TARGET_CHAR_BIT) * TARGET_CHAR_BIT; | |
c5aa993b JM |
1322 | int bound_end = (((end + TARGET_CHAR_BIT - 1) |
1323 | / TARGET_CHAR_BIT) | |
1324 | * TARGET_CHAR_BIT); | |
c906108c SS |
1325 | |
1326 | /* current bit offset within the structure */ | |
1327 | int offset; | |
1328 | ||
1329 | /* The index in ops of the opcode we're considering. */ | |
1330 | int op; | |
1331 | ||
1332 | /* The number of fragments we generated in the process. Probably | |
1333 | equal to the number of `one' bits in bytesize, but who cares? */ | |
1334 | int fragment_count; | |
1335 | ||
0e2de366 | 1336 | /* Dereference any typedefs. */ |
c906108c SS |
1337 | type = check_typedef (type); |
1338 | ||
1339 | /* Can we fetch the number of bits requested at all? */ | |
1340 | if ((end - start) > ((1 << num_ops) * 8)) | |
8e65ff28 | 1341 | internal_error (__FILE__, __LINE__, |
3d263c1d | 1342 | _("gen_bitfield_ref: bitfield too wide")); |
c906108c SS |
1343 | |
1344 | /* Note that we know here that we only need to try each opcode once. | |
1345 | That may not be true on machines with weird byte sizes. */ | |
1346 | offset = bound_start; | |
1347 | fragment_count = 0; | |
1348 | for (op = num_ops - 1; op >= 0; op--) | |
1349 | { | |
1350 | /* number of bits that ops[op] would fetch */ | |
1351 | int op_size = 8 << op; | |
1352 | ||
1353 | /* The stack at this point, from bottom to top, contains zero or | |
c5aa993b JM |
1354 | more fragments, then the address. */ |
1355 | ||
c906108c SS |
1356 | /* Does this fetch fit within the bitfield? */ |
1357 | if (offset + op_size <= bound_end) | |
1358 | { | |
1359 | /* Is this the last fragment? */ | |
1360 | int last_frag = (offset + op_size == bound_end); | |
1361 | ||
c5aa993b JM |
1362 | if (!last_frag) |
1363 | ax_simple (ax, aop_dup); /* keep a copy of the address */ | |
1364 | ||
c906108c SS |
1365 | /* Add the offset. */ |
1366 | gen_offset (ax, offset / TARGET_CHAR_BIT); | |
1367 | ||
1368 | if (trace_kludge) | |
1369 | { | |
1370 | /* Record the area of memory we're about to fetch. */ | |
1371 | ax_trace_quick (ax, op_size / TARGET_CHAR_BIT); | |
1372 | } | |
1373 | ||
1374 | /* Perform the fetch. */ | |
1375 | ax_simple (ax, ops[op]); | |
c5aa993b JM |
1376 | |
1377 | /* Shift the bits we have to their proper position. | |
c906108c SS |
1378 | gen_left_shift will generate right shifts when the operand |
1379 | is negative. | |
1380 | ||
c5aa993b JM |
1381 | A big-endian field diagram to ponder: |
1382 | byte 0 byte 1 byte 2 byte 3 byte 4 byte 5 byte 6 byte 7 | |
1383 | +------++------++------++------++------++------++------++------+ | |
1384 | xxxxAAAAAAAAAAAAAAAAAAAAAAAAAAAABBBBBBBBBBBBBBBBCCCCCxxxxxxxxxxx | |
1385 | ^ ^ ^ ^ | |
1386 | bit number 16 32 48 53 | |
c906108c SS |
1387 | These are bit numbers as supplied by GDB. Note that the |
1388 | bit numbers run from right to left once you've fetched the | |
1389 | value! | |
1390 | ||
c5aa993b JM |
1391 | A little-endian field diagram to ponder: |
1392 | byte 7 byte 6 byte 5 byte 4 byte 3 byte 2 byte 1 byte 0 | |
1393 | +------++------++------++------++------++------++------++------+ | |
1394 | xxxxxxxxxxxAAAAABBBBBBBBBBBBBBBBCCCCCCCCCCCCCCCCCCCCCCCCCCCCxxxx | |
1395 | ^ ^ ^ ^ ^ | |
1396 | bit number 48 32 16 4 0 | |
1397 | ||
1398 | In both cases, the most significant end is on the left | |
1399 | (i.e. normal numeric writing order), which means that you | |
1400 | don't go crazy thinking about `left' and `right' shifts. | |
1401 | ||
1402 | We don't have to worry about masking yet: | |
1403 | - If they contain garbage off the least significant end, then we | |
1404 | must be looking at the low end of the field, and the right | |
1405 | shift will wipe them out. | |
1406 | - If they contain garbage off the most significant end, then we | |
1407 | must be looking at the most significant end of the word, and | |
1408 | the sign/zero extension will wipe them out. | |
1409 | - If we're in the interior of the word, then there is no garbage | |
1410 | on either end, because the ref operators zero-extend. */ | |
505e835d | 1411 | if (gdbarch_byte_order (exp->gdbarch) == BFD_ENDIAN_BIG) |
c906108c | 1412 | gen_left_shift (ax, end - (offset + op_size)); |
c5aa993b | 1413 | else |
c906108c SS |
1414 | gen_left_shift (ax, offset - start); |
1415 | ||
c5aa993b | 1416 | if (!last_frag) |
c906108c SS |
1417 | /* Bring the copy of the address up to the top. */ |
1418 | ax_simple (ax, aop_swap); | |
1419 | ||
1420 | offset += op_size; | |
1421 | fragment_count++; | |
1422 | } | |
1423 | } | |
1424 | ||
1425 | /* Generate enough bitwise `or' operations to combine all the | |
1426 | fragments we left on the stack. */ | |
1427 | while (fragment_count-- > 1) | |
1428 | ax_simple (ax, aop_bit_or); | |
1429 | ||
1430 | /* Sign- or zero-extend the value as appropriate. */ | |
1431 | ((TYPE_UNSIGNED (type) ? ax_zero_ext : ax_ext) (ax, end - start)); | |
1432 | ||
1433 | /* This is *not* an lvalue. Ugh. */ | |
1434 | value->kind = axs_rvalue; | |
1435 | value->type = type; | |
1436 | } | |
1437 | ||
b6e7192f SS |
1438 | /* Generate bytecodes for field number FIELDNO of type TYPE. OFFSET |
1439 | is an accumulated offset (in bytes), will be nonzero for objects | |
1440 | embedded in other objects, like C++ base classes. Behavior should | |
1441 | generally follow value_primitive_field. */ | |
1442 | ||
1443 | static void | |
1444 | gen_primitive_field (struct expression *exp, | |
1445 | struct agent_expr *ax, struct axs_value *value, | |
1446 | int offset, int fieldno, struct type *type) | |
1447 | { | |
1448 | /* Is this a bitfield? */ | |
1449 | if (TYPE_FIELD_PACKED (type, fieldno)) | |
1450 | gen_bitfield_ref (exp, ax, value, TYPE_FIELD_TYPE (type, fieldno), | |
1451 | (offset * TARGET_CHAR_BIT | |
1452 | + TYPE_FIELD_BITPOS (type, fieldno)), | |
1453 | (offset * TARGET_CHAR_BIT | |
1454 | + TYPE_FIELD_BITPOS (type, fieldno) | |
1455 | + TYPE_FIELD_BITSIZE (type, fieldno))); | |
1456 | else | |
1457 | { | |
1458 | gen_offset (ax, offset | |
1459 | + TYPE_FIELD_BITPOS (type, fieldno) / TARGET_CHAR_BIT); | |
1460 | value->kind = axs_lvalue_memory; | |
1461 | value->type = TYPE_FIELD_TYPE (type, fieldno); | |
1462 | } | |
1463 | } | |
1464 | ||
1465 | /* Search for the given field in either the given type or one of its | |
1466 | base classes. Return 1 if found, 0 if not. */ | |
1467 | ||
1468 | static int | |
1469 | gen_struct_ref_recursive (struct expression *exp, struct agent_expr *ax, | |
1470 | struct axs_value *value, | |
1471 | char *field, int offset, struct type *type) | |
1472 | { | |
1473 | int i, rslt; | |
1474 | int nbases = TYPE_N_BASECLASSES (type); | |
1475 | ||
1476 | CHECK_TYPEDEF (type); | |
1477 | ||
1478 | for (i = TYPE_NFIELDS (type) - 1; i >= nbases; i--) | |
1479 | { | |
1480 | char *this_name = TYPE_FIELD_NAME (type, i); | |
1481 | ||
1482 | if (this_name) | |
1483 | { | |
1484 | if (strcmp (field, this_name) == 0) | |
1485 | { | |
1486 | /* Note that bytecodes for the struct's base (aka | |
1487 | "this") will have been generated already, which will | |
1488 | be unnecessary but not harmful if the static field is | |
1489 | being handled as a global. */ | |
1490 | if (field_is_static (&TYPE_FIELD (type, i))) | |
1491 | { | |
400c6af0 SS |
1492 | gen_static_field (exp->gdbarch, ax, value, type, i); |
1493 | if (value->optimized_out) | |
3e43a32a MS |
1494 | error (_("static field `%s' has been " |
1495 | "optimized out, cannot use"), | |
400c6af0 | 1496 | field); |
b6e7192f SS |
1497 | return 1; |
1498 | } | |
1499 | ||
1500 | gen_primitive_field (exp, ax, value, offset, i, type); | |
1501 | return 1; | |
1502 | } | |
1503 | #if 0 /* is this right? */ | |
1504 | if (this_name[0] == '\0') | |
1505 | internal_error (__FILE__, __LINE__, | |
1506 | _("find_field: anonymous unions not supported")); | |
1507 | #endif | |
1508 | } | |
1509 | } | |
1510 | ||
1511 | /* Now scan through base classes recursively. */ | |
1512 | for (i = 0; i < nbases; i++) | |
1513 | { | |
1514 | struct type *basetype = check_typedef (TYPE_BASECLASS (type, i)); | |
1515 | ||
1516 | rslt = gen_struct_ref_recursive (exp, ax, value, field, | |
3e43a32a MS |
1517 | offset + TYPE_BASECLASS_BITPOS (type, i) |
1518 | / TARGET_CHAR_BIT, | |
b6e7192f SS |
1519 | basetype); |
1520 | if (rslt) | |
1521 | return 1; | |
1522 | } | |
1523 | ||
1524 | /* Not found anywhere, flag so caller can complain. */ | |
1525 | return 0; | |
1526 | } | |
c906108c SS |
1527 | |
1528 | /* Generate code to reference the member named FIELD of a structure or | |
1529 | union. The top of the stack, as described by VALUE, should have | |
1530 | type (pointer to a)* struct/union. OPERATOR_NAME is the name of | |
1531 | the operator being compiled, and OPERAND_NAME is the kind of thing | |
1532 | it operates on; we use them in error messages. */ | |
1533 | static void | |
505e835d UW |
1534 | gen_struct_ref (struct expression *exp, struct agent_expr *ax, |
1535 | struct axs_value *value, char *field, | |
fba45db2 | 1536 | char *operator_name, char *operand_name) |
c906108c SS |
1537 | { |
1538 | struct type *type; | |
b6e7192f | 1539 | int found; |
c906108c SS |
1540 | |
1541 | /* Follow pointers until we reach a non-pointer. These aren't the C | |
1542 | semantics, but they're what the normal GDB evaluator does, so we | |
1543 | should at least be consistent. */ | |
b97aedf3 | 1544 | while (pointer_type (value->type)) |
c906108c | 1545 | { |
f7c79c41 | 1546 | require_rvalue (ax, value); |
c906108c SS |
1547 | gen_deref (ax, value); |
1548 | } | |
e8860ec2 | 1549 | type = check_typedef (value->type); |
c906108c SS |
1550 | |
1551 | /* This must yield a structure or a union. */ | |
1552 | if (TYPE_CODE (type) != TYPE_CODE_STRUCT | |
1553 | && TYPE_CODE (type) != TYPE_CODE_UNION) | |
3d263c1d | 1554 | error (_("The left operand of `%s' is not a %s."), |
c906108c SS |
1555 | operator_name, operand_name); |
1556 | ||
1557 | /* And it must be in memory; we don't deal with structure rvalues, | |
1558 | or structures living in registers. */ | |
1559 | if (value->kind != axs_lvalue_memory) | |
3d263c1d | 1560 | error (_("Structure does not live in memory.")); |
c906108c | 1561 | |
b6e7192f SS |
1562 | /* Search through fields and base classes recursively. */ |
1563 | found = gen_struct_ref_recursive (exp, ax, value, field, 0, type); | |
1564 | ||
1565 | if (!found) | |
1566 | error (_("Couldn't find member named `%s' in struct/union/class `%s'"), | |
1567 | field, TYPE_TAG_NAME (type)); | |
1568 | } | |
c5aa993b | 1569 | |
b6e7192f SS |
1570 | static int |
1571 | gen_namespace_elt (struct expression *exp, | |
1572 | struct agent_expr *ax, struct axs_value *value, | |
1573 | const struct type *curtype, char *name); | |
1574 | static int | |
1575 | gen_maybe_namespace_elt (struct expression *exp, | |
1576 | struct agent_expr *ax, struct axs_value *value, | |
1577 | const struct type *curtype, char *name); | |
1578 | ||
1579 | static void | |
400c6af0 | 1580 | gen_static_field (struct gdbarch *gdbarch, |
b6e7192f SS |
1581 | struct agent_expr *ax, struct axs_value *value, |
1582 | struct type *type, int fieldno) | |
1583 | { | |
1584 | if (TYPE_FIELD_LOC_KIND (type, fieldno) == FIELD_LOC_KIND_PHYSADDR) | |
c906108c | 1585 | { |
b6e7192f | 1586 | ax_const_l (ax, TYPE_FIELD_STATIC_PHYSADDR (type, fieldno)); |
c906108c | 1587 | value->kind = axs_lvalue_memory; |
b6e7192f | 1588 | value->type = TYPE_FIELD_TYPE (type, fieldno); |
400c6af0 | 1589 | value->optimized_out = 0; |
b6e7192f SS |
1590 | } |
1591 | else | |
1592 | { | |
ff355380 | 1593 | const char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno); |
b6e7192f | 1594 | struct symbol *sym = lookup_symbol (phys_name, 0, VAR_DOMAIN, 0); |
b6e7192f | 1595 | |
400c6af0 SS |
1596 | if (sym) |
1597 | { | |
1598 | gen_var_ref (gdbarch, ax, value, sym); | |
1599 | ||
1600 | /* Don't error if the value was optimized out, we may be | |
1601 | scanning all static fields and just want to pass over this | |
1602 | and continue with the rest. */ | |
1603 | } | |
1604 | else | |
1605 | { | |
1606 | /* Silently assume this was optimized out; class printing | |
1607 | will let the user know why the data is missing. */ | |
1608 | value->optimized_out = 1; | |
1609 | } | |
b6e7192f SS |
1610 | } |
1611 | } | |
1612 | ||
1613 | static int | |
1614 | gen_struct_elt_for_reference (struct expression *exp, | |
1615 | struct agent_expr *ax, struct axs_value *value, | |
1616 | struct type *type, char *fieldname) | |
1617 | { | |
1618 | struct type *t = type; | |
1619 | int i; | |
b6e7192f SS |
1620 | |
1621 | if (TYPE_CODE (t) != TYPE_CODE_STRUCT | |
1622 | && TYPE_CODE (t) != TYPE_CODE_UNION) | |
1623 | internal_error (__FILE__, __LINE__, | |
1624 | _("non-aggregate type to gen_struct_elt_for_reference")); | |
1625 | ||
1626 | for (i = TYPE_NFIELDS (t) - 1; i >= TYPE_N_BASECLASSES (t); i--) | |
1627 | { | |
1628 | char *t_field_name = TYPE_FIELD_NAME (t, i); | |
1629 | ||
1630 | if (t_field_name && strcmp (t_field_name, fieldname) == 0) | |
1631 | { | |
1632 | if (field_is_static (&TYPE_FIELD (t, i))) | |
1633 | { | |
400c6af0 SS |
1634 | gen_static_field (exp->gdbarch, ax, value, t, i); |
1635 | if (value->optimized_out) | |
3e43a32a MS |
1636 | error (_("static field `%s' has been " |
1637 | "optimized out, cannot use"), | |
400c6af0 | 1638 | fieldname); |
b6e7192f SS |
1639 | return 1; |
1640 | } | |
1641 | if (TYPE_FIELD_PACKED (t, i)) | |
1642 | error (_("pointers to bitfield members not allowed")); | |
1643 | ||
1644 | /* FIXME we need a way to do "want_address" equivalent */ | |
1645 | ||
1646 | error (_("Cannot reference non-static field \"%s\""), fieldname); | |
1647 | } | |
c906108c | 1648 | } |
b6e7192f SS |
1649 | |
1650 | /* FIXME add other scoped-reference cases here */ | |
1651 | ||
1652 | /* Do a last-ditch lookup. */ | |
1653 | return gen_maybe_namespace_elt (exp, ax, value, type, fieldname); | |
c906108c SS |
1654 | } |
1655 | ||
b6e7192f SS |
1656 | /* C++: Return the member NAME of the namespace given by the type |
1657 | CURTYPE. */ | |
1658 | ||
1659 | static int | |
1660 | gen_namespace_elt (struct expression *exp, | |
1661 | struct agent_expr *ax, struct axs_value *value, | |
1662 | const struct type *curtype, char *name) | |
1663 | { | |
1664 | int found = gen_maybe_namespace_elt (exp, ax, value, curtype, name); | |
1665 | ||
1666 | if (!found) | |
1667 | error (_("No symbol \"%s\" in namespace \"%s\"."), | |
1668 | name, TYPE_TAG_NAME (curtype)); | |
1669 | ||
1670 | return found; | |
1671 | } | |
1672 | ||
1673 | /* A helper function used by value_namespace_elt and | |
1674 | value_struct_elt_for_reference. It looks up NAME inside the | |
1675 | context CURTYPE; this works if CURTYPE is a namespace or if CURTYPE | |
1676 | is a class and NAME refers to a type in CURTYPE itself (as opposed | |
1677 | to, say, some base class of CURTYPE). */ | |
1678 | ||
1679 | static int | |
1680 | gen_maybe_namespace_elt (struct expression *exp, | |
1681 | struct agent_expr *ax, struct axs_value *value, | |
1682 | const struct type *curtype, char *name) | |
1683 | { | |
1684 | const char *namespace_name = TYPE_TAG_NAME (curtype); | |
1685 | struct symbol *sym; | |
1686 | ||
1687 | sym = cp_lookup_symbol_namespace (namespace_name, name, | |
1688 | block_for_pc (ax->scope), | |
ac0cd78b | 1689 | VAR_DOMAIN); |
b6e7192f SS |
1690 | |
1691 | if (sym == NULL) | |
1692 | return 0; | |
1693 | ||
1694 | gen_var_ref (exp->gdbarch, ax, value, sym); | |
1695 | ||
400c6af0 SS |
1696 | if (value->optimized_out) |
1697 | error (_("`%s' has been optimized out, cannot use"), | |
1698 | SYMBOL_PRINT_NAME (sym)); | |
1699 | ||
b6e7192f SS |
1700 | return 1; |
1701 | } | |
1702 | ||
1703 | ||
1704 | static int | |
1705 | gen_aggregate_elt_ref (struct expression *exp, | |
1706 | struct agent_expr *ax, struct axs_value *value, | |
1707 | struct type *type, char *field, | |
1708 | char *operator_name, char *operand_name) | |
1709 | { | |
1710 | switch (TYPE_CODE (type)) | |
1711 | { | |
1712 | case TYPE_CODE_STRUCT: | |
1713 | case TYPE_CODE_UNION: | |
1714 | return gen_struct_elt_for_reference (exp, ax, value, type, field); | |
1715 | break; | |
1716 | case TYPE_CODE_NAMESPACE: | |
1717 | return gen_namespace_elt (exp, ax, value, type, field); | |
1718 | break; | |
1719 | default: | |
1720 | internal_error (__FILE__, __LINE__, | |
1721 | _("non-aggregate type in gen_aggregate_elt_ref")); | |
1722 | } | |
1723 | ||
1724 | return 0; | |
1725 | } | |
c906108c | 1726 | |
0e2de366 | 1727 | /* Generate code for GDB's magical `repeat' operator. |
c906108c SS |
1728 | LVALUE @ INT creates an array INT elements long, and whose elements |
1729 | have the same type as LVALUE, located in memory so that LVALUE is | |
1730 | its first element. For example, argv[0]@argc gives you the array | |
1731 | of command-line arguments. | |
1732 | ||
1733 | Unfortunately, because we have to know the types before we actually | |
1734 | have a value for the expression, we can't implement this perfectly | |
1735 | without changing the type system, having values that occupy two | |
1736 | stack slots, doing weird things with sizeof, etc. So we require | |
1737 | the right operand to be a constant expression. */ | |
1738 | static void | |
f7c79c41 UW |
1739 | gen_repeat (struct expression *exp, union exp_element **pc, |
1740 | struct agent_expr *ax, struct axs_value *value) | |
c906108c SS |
1741 | { |
1742 | struct axs_value value1; | |
5b4ee69b | 1743 | |
c906108c SS |
1744 | /* We don't want to turn this into an rvalue, so no conversions |
1745 | here. */ | |
f7c79c41 | 1746 | gen_expr (exp, pc, ax, &value1); |
c906108c | 1747 | if (value1.kind != axs_lvalue_memory) |
3d263c1d | 1748 | error (_("Left operand of `@' must be an object in memory.")); |
c906108c SS |
1749 | |
1750 | /* Evaluate the length; it had better be a constant. */ | |
1751 | { | |
1752 | struct value *v = const_expr (pc); | |
1753 | int length; | |
1754 | ||
c5aa993b | 1755 | if (!v) |
3e43a32a MS |
1756 | error (_("Right operand of `@' must be a " |
1757 | "constant, in agent expressions.")); | |
04624583 | 1758 | if (TYPE_CODE (value_type (v)) != TYPE_CODE_INT) |
3d263c1d | 1759 | error (_("Right operand of `@' must be an integer.")); |
c906108c SS |
1760 | length = value_as_long (v); |
1761 | if (length <= 0) | |
3d263c1d | 1762 | error (_("Right operand of `@' must be positive.")); |
c906108c SS |
1763 | |
1764 | /* The top of the stack is already the address of the object, so | |
1765 | all we need to do is frob the type of the lvalue. */ | |
1766 | { | |
1767 | /* FIXME-type-allocation: need a way to free this type when we are | |
c5aa993b | 1768 | done with it. */ |
e3506a9f UW |
1769 | struct type *array |
1770 | = lookup_array_range_type (value1.type, 0, length - 1); | |
c906108c SS |
1771 | |
1772 | value->kind = axs_lvalue_memory; | |
1773 | value->type = array; | |
1774 | } | |
1775 | } | |
1776 | } | |
1777 | ||
1778 | ||
1779 | /* Emit code for the `sizeof' operator. | |
1780 | *PC should point at the start of the operand expression; we advance it | |
1781 | to the first instruction after the operand. */ | |
1782 | static void | |
f7c79c41 UW |
1783 | gen_sizeof (struct expression *exp, union exp_element **pc, |
1784 | struct agent_expr *ax, struct axs_value *value, | |
1785 | struct type *size_type) | |
c906108c SS |
1786 | { |
1787 | /* We don't care about the value of the operand expression; we only | |
1788 | care about its type. However, in the current arrangement, the | |
1789 | only way to find an expression's type is to generate code for it. | |
1790 | So we generate code for the operand, and then throw it away, | |
1791 | replacing it with code that simply pushes its size. */ | |
1792 | int start = ax->len; | |
5b4ee69b | 1793 | |
f7c79c41 | 1794 | gen_expr (exp, pc, ax, value); |
c906108c SS |
1795 | |
1796 | /* Throw away the code we just generated. */ | |
1797 | ax->len = start; | |
c5aa993b | 1798 | |
c906108c SS |
1799 | ax_const_l (ax, TYPE_LENGTH (value->type)); |
1800 | value->kind = axs_rvalue; | |
f7c79c41 | 1801 | value->type = size_type; |
c906108c | 1802 | } |
c906108c | 1803 | \f |
c5aa993b | 1804 | |
c906108c SS |
1805 | /* Generating bytecode from GDB expressions: general recursive thingy */ |
1806 | ||
3d263c1d | 1807 | /* XXX: i18n */ |
c906108c SS |
1808 | /* A gen_expr function written by a Gen-X'er guy. |
1809 | Append code for the subexpression of EXPR starting at *POS_P to AX. */ | |
1810 | static void | |
f7c79c41 UW |
1811 | gen_expr (struct expression *exp, union exp_element **pc, |
1812 | struct agent_expr *ax, struct axs_value *value) | |
c906108c SS |
1813 | { |
1814 | /* Used to hold the descriptions of operand expressions. */ | |
09d559e4 | 1815 | struct axs_value value1, value2, value3; |
f61e138d | 1816 | enum exp_opcode op = (*pc)[0].opcode, op2; |
09d559e4 | 1817 | int if1, go1, if2, go2, end; |
3b11a015 | 1818 | struct type *int_type = builtin_type (exp->gdbarch)->builtin_int; |
c906108c SS |
1819 | |
1820 | /* If we're looking at a constant expression, just push its value. */ | |
1821 | { | |
1822 | struct value *v = maybe_const_expr (pc); | |
c5aa993b | 1823 | |
c906108c SS |
1824 | if (v) |
1825 | { | |
1826 | ax_const_l (ax, value_as_long (v)); | |
1827 | value->kind = axs_rvalue; | |
df407dfe | 1828 | value->type = check_typedef (value_type (v)); |
c906108c SS |
1829 | return; |
1830 | } | |
1831 | } | |
1832 | ||
1833 | /* Otherwise, go ahead and generate code for it. */ | |
1834 | switch (op) | |
1835 | { | |
1836 | /* Binary arithmetic operators. */ | |
1837 | case BINOP_ADD: | |
1838 | case BINOP_SUB: | |
1839 | case BINOP_MUL: | |
1840 | case BINOP_DIV: | |
1841 | case BINOP_REM: | |
948103cf SS |
1842 | case BINOP_LSH: |
1843 | case BINOP_RSH: | |
c906108c SS |
1844 | case BINOP_SUBSCRIPT: |
1845 | case BINOP_BITWISE_AND: | |
1846 | case BINOP_BITWISE_IOR: | |
1847 | case BINOP_BITWISE_XOR: | |
782b2b07 SS |
1848 | case BINOP_EQUAL: |
1849 | case BINOP_NOTEQUAL: | |
1850 | case BINOP_LESS: | |
1851 | case BINOP_GTR: | |
1852 | case BINOP_LEQ: | |
1853 | case BINOP_GEQ: | |
c906108c | 1854 | (*pc)++; |
f7c79c41 UW |
1855 | gen_expr (exp, pc, ax, &value1); |
1856 | gen_usual_unary (exp, ax, &value1); | |
f61e138d SS |
1857 | gen_expr_binop_rest (exp, op, pc, ax, value, &value1, &value2); |
1858 | break; | |
1859 | ||
09d559e4 SS |
1860 | case BINOP_LOGICAL_AND: |
1861 | (*pc)++; | |
1862 | /* Generate the obvious sequence of tests and jumps. */ | |
1863 | gen_expr (exp, pc, ax, &value1); | |
1864 | gen_usual_unary (exp, ax, &value1); | |
1865 | if1 = ax_goto (ax, aop_if_goto); | |
1866 | go1 = ax_goto (ax, aop_goto); | |
1867 | ax_label (ax, if1, ax->len); | |
1868 | gen_expr (exp, pc, ax, &value2); | |
1869 | gen_usual_unary (exp, ax, &value2); | |
1870 | if2 = ax_goto (ax, aop_if_goto); | |
1871 | go2 = ax_goto (ax, aop_goto); | |
1872 | ax_label (ax, if2, ax->len); | |
1873 | ax_const_l (ax, 1); | |
1874 | end = ax_goto (ax, aop_goto); | |
1875 | ax_label (ax, go1, ax->len); | |
1876 | ax_label (ax, go2, ax->len); | |
1877 | ax_const_l (ax, 0); | |
1878 | ax_label (ax, end, ax->len); | |
1879 | value->kind = axs_rvalue; | |
3b11a015 | 1880 | value->type = int_type; |
09d559e4 SS |
1881 | break; |
1882 | ||
1883 | case BINOP_LOGICAL_OR: | |
1884 | (*pc)++; | |
1885 | /* Generate the obvious sequence of tests and jumps. */ | |
1886 | gen_expr (exp, pc, ax, &value1); | |
1887 | gen_usual_unary (exp, ax, &value1); | |
1888 | if1 = ax_goto (ax, aop_if_goto); | |
1889 | gen_expr (exp, pc, ax, &value2); | |
1890 | gen_usual_unary (exp, ax, &value2); | |
1891 | if2 = ax_goto (ax, aop_if_goto); | |
1892 | ax_const_l (ax, 0); | |
1893 | end = ax_goto (ax, aop_goto); | |
1894 | ax_label (ax, if1, ax->len); | |
1895 | ax_label (ax, if2, ax->len); | |
1896 | ax_const_l (ax, 1); | |
1897 | ax_label (ax, end, ax->len); | |
1898 | value->kind = axs_rvalue; | |
3b11a015 | 1899 | value->type = int_type; |
09d559e4 SS |
1900 | break; |
1901 | ||
1902 | case TERNOP_COND: | |
1903 | (*pc)++; | |
1904 | gen_expr (exp, pc, ax, &value1); | |
1905 | gen_usual_unary (exp, ax, &value1); | |
1906 | /* For (A ? B : C), it's easiest to generate subexpression | |
1907 | bytecodes in order, but if_goto jumps on true, so we invert | |
1908 | the sense of A. Then we can do B by dropping through, and | |
1909 | jump to do C. */ | |
3b11a015 | 1910 | gen_logical_not (ax, &value1, int_type); |
09d559e4 SS |
1911 | if1 = ax_goto (ax, aop_if_goto); |
1912 | gen_expr (exp, pc, ax, &value2); | |
1913 | gen_usual_unary (exp, ax, &value2); | |
1914 | end = ax_goto (ax, aop_goto); | |
1915 | ax_label (ax, if1, ax->len); | |
1916 | gen_expr (exp, pc, ax, &value3); | |
1917 | gen_usual_unary (exp, ax, &value3); | |
1918 | ax_label (ax, end, ax->len); | |
1919 | /* This is arbitary - what if B and C are incompatible types? */ | |
1920 | value->type = value2.type; | |
1921 | value->kind = value2.kind; | |
1922 | break; | |
1923 | ||
f61e138d SS |
1924 | case BINOP_ASSIGN: |
1925 | (*pc)++; | |
1926 | if ((*pc)[0].opcode == OP_INTERNALVAR) | |
c906108c | 1927 | { |
f61e138d SS |
1928 | char *name = internalvar_name ((*pc)[1].internalvar); |
1929 | struct trace_state_variable *tsv; | |
5b4ee69b | 1930 | |
f61e138d SS |
1931 | (*pc) += 3; |
1932 | gen_expr (exp, pc, ax, value); | |
1933 | tsv = find_trace_state_variable (name); | |
1934 | if (tsv) | |
f7c79c41 | 1935 | { |
f61e138d SS |
1936 | ax_tsv (ax, aop_setv, tsv->number); |
1937 | if (trace_kludge) | |
1938 | ax_tsv (ax, aop_tracev, tsv->number); | |
f7c79c41 | 1939 | } |
f7c79c41 | 1940 | else |
3e43a32a MS |
1941 | error (_("$%s is not a trace state variable, " |
1942 | "may not assign to it"), name); | |
f61e138d SS |
1943 | } |
1944 | else | |
1945 | error (_("May only assign to trace state variables")); | |
1946 | break; | |
782b2b07 | 1947 | |
f61e138d SS |
1948 | case BINOP_ASSIGN_MODIFY: |
1949 | (*pc)++; | |
1950 | op2 = (*pc)[0].opcode; | |
1951 | (*pc)++; | |
1952 | (*pc)++; | |
1953 | if ((*pc)[0].opcode == OP_INTERNALVAR) | |
1954 | { | |
1955 | char *name = internalvar_name ((*pc)[1].internalvar); | |
1956 | struct trace_state_variable *tsv; | |
5b4ee69b | 1957 | |
f61e138d SS |
1958 | (*pc) += 3; |
1959 | tsv = find_trace_state_variable (name); | |
1960 | if (tsv) | |
1961 | { | |
1962 | /* The tsv will be the left half of the binary operation. */ | |
1963 | ax_tsv (ax, aop_getv, tsv->number); | |
1964 | if (trace_kludge) | |
1965 | ax_tsv (ax, aop_tracev, tsv->number); | |
1966 | /* Trace state variables are always 64-bit integers. */ | |
1967 | value1.kind = axs_rvalue; | |
1968 | value1.type = builtin_type (exp->gdbarch)->builtin_long_long; | |
1969 | /* Now do right half of expression. */ | |
1970 | gen_expr_binop_rest (exp, op2, pc, ax, value, &value1, &value2); | |
1971 | /* We have a result of the binary op, set the tsv. */ | |
1972 | ax_tsv (ax, aop_setv, tsv->number); | |
1973 | if (trace_kludge) | |
1974 | ax_tsv (ax, aop_tracev, tsv->number); | |
1975 | } | |
1976 | else | |
3e43a32a MS |
1977 | error (_("$%s is not a trace state variable, " |
1978 | "may not assign to it"), name); | |
c906108c | 1979 | } |
f61e138d SS |
1980 | else |
1981 | error (_("May only assign to trace state variables")); | |
c906108c SS |
1982 | break; |
1983 | ||
1984 | /* Note that we need to be a little subtle about generating code | |
c5aa993b JM |
1985 | for comma. In C, we can do some optimizations here because |
1986 | we know the left operand is only being evaluated for effect. | |
1987 | However, if the tracing kludge is in effect, then we always | |
1988 | need to evaluate the left hand side fully, so that all the | |
1989 | variables it mentions get traced. */ | |
c906108c SS |
1990 | case BINOP_COMMA: |
1991 | (*pc)++; | |
f7c79c41 | 1992 | gen_expr (exp, pc, ax, &value1); |
c906108c | 1993 | /* Don't just dispose of the left operand. We might be tracing, |
c5aa993b JM |
1994 | in which case we want to emit code to trace it if it's an |
1995 | lvalue. */ | |
400c6af0 | 1996 | gen_traced_pop (exp->gdbarch, ax, &value1); |
f7c79c41 | 1997 | gen_expr (exp, pc, ax, value); |
c906108c SS |
1998 | /* It's the consumer's responsibility to trace the right operand. */ |
1999 | break; | |
c5aa993b | 2000 | |
c906108c SS |
2001 | case OP_LONG: /* some integer constant */ |
2002 | { | |
2003 | struct type *type = (*pc)[1].type; | |
2004 | LONGEST k = (*pc)[2].longconst; | |
5b4ee69b | 2005 | |
c906108c SS |
2006 | (*pc) += 4; |
2007 | gen_int_literal (ax, value, k, type); | |
2008 | } | |
c5aa993b | 2009 | break; |
c906108c SS |
2010 | |
2011 | case OP_VAR_VALUE: | |
f7c79c41 | 2012 | gen_var_ref (exp->gdbarch, ax, value, (*pc)[2].symbol); |
400c6af0 SS |
2013 | |
2014 | if (value->optimized_out) | |
2015 | error (_("`%s' has been optimized out, cannot use"), | |
2016 | SYMBOL_PRINT_NAME ((*pc)[2].symbol)); | |
2017 | ||
c906108c SS |
2018 | (*pc) += 4; |
2019 | break; | |
2020 | ||
2021 | case OP_REGISTER: | |
2022 | { | |
67f3407f DJ |
2023 | const char *name = &(*pc)[2].string; |
2024 | int reg; | |
5b4ee69b | 2025 | |
67f3407f | 2026 | (*pc) += 4 + BYTES_TO_EXP_ELEM ((*pc)[1].longconst + 1); |
f7c79c41 | 2027 | reg = user_reg_map_name_to_regnum (exp->gdbarch, name, strlen (name)); |
67f3407f DJ |
2028 | if (reg == -1) |
2029 | internal_error (__FILE__, __LINE__, | |
2030 | _("Register $%s not available"), name); | |
6ab12e0f PA |
2031 | /* No support for tracing user registers yet. */ |
2032 | if (reg >= gdbarch_num_regs (exp->gdbarch) | |
2033 | + gdbarch_num_pseudo_regs (exp->gdbarch)) | |
abc1f4cd HZ |
2034 | error (_("'%s' is a user-register; " |
2035 | "GDB cannot yet trace user-register contents."), | |
6ab12e0f | 2036 | name); |
c906108c SS |
2037 | value->kind = axs_lvalue_register; |
2038 | value->u.reg = reg; | |
f7c79c41 | 2039 | value->type = register_type (exp->gdbarch, reg); |
c906108c | 2040 | } |
c5aa993b | 2041 | break; |
c906108c SS |
2042 | |
2043 | case OP_INTERNALVAR: | |
f61e138d SS |
2044 | { |
2045 | const char *name = internalvar_name ((*pc)[1].internalvar); | |
2046 | struct trace_state_variable *tsv; | |
5b4ee69b | 2047 | |
f61e138d SS |
2048 | (*pc) += 3; |
2049 | tsv = find_trace_state_variable (name); | |
2050 | if (tsv) | |
2051 | { | |
2052 | ax_tsv (ax, aop_getv, tsv->number); | |
2053 | if (trace_kludge) | |
2054 | ax_tsv (ax, aop_tracev, tsv->number); | |
2055 | /* Trace state variables are always 64-bit integers. */ | |
2056 | value->kind = axs_rvalue; | |
2057 | value->type = builtin_type (exp->gdbarch)->builtin_long_long; | |
2058 | } | |
2059 | else | |
3e43a32a MS |
2060 | error (_("$%s is not a trace state variable; GDB agent " |
2061 | "expressions cannot use convenience variables."), name); | |
f61e138d SS |
2062 | } |
2063 | break; | |
c906108c | 2064 | |
c5aa993b | 2065 | /* Weirdo operator: see comments for gen_repeat for details. */ |
c906108c SS |
2066 | case BINOP_REPEAT: |
2067 | /* Note that gen_repeat handles its own argument evaluation. */ | |
2068 | (*pc)++; | |
f7c79c41 | 2069 | gen_repeat (exp, pc, ax, value); |
c906108c SS |
2070 | break; |
2071 | ||
2072 | case UNOP_CAST: | |
2073 | { | |
2074 | struct type *type = (*pc)[1].type; | |
5b4ee69b | 2075 | |
c906108c | 2076 | (*pc) += 3; |
f7c79c41 | 2077 | gen_expr (exp, pc, ax, value); |
c906108c SS |
2078 | gen_cast (ax, value, type); |
2079 | } | |
c5aa993b | 2080 | break; |
c906108c SS |
2081 | |
2082 | case UNOP_MEMVAL: | |
2083 | { | |
2084 | struct type *type = check_typedef ((*pc)[1].type); | |
5b4ee69b | 2085 | |
c906108c | 2086 | (*pc) += 3; |
f7c79c41 | 2087 | gen_expr (exp, pc, ax, value); |
a0c78a73 PA |
2088 | |
2089 | /* If we have an axs_rvalue or an axs_lvalue_memory, then we | |
2090 | already have the right value on the stack. For | |
2091 | axs_lvalue_register, we must convert. */ | |
2092 | if (value->kind == axs_lvalue_register) | |
2093 | require_rvalue (ax, value); | |
2094 | ||
c906108c SS |
2095 | value->type = type; |
2096 | value->kind = axs_lvalue_memory; | |
2097 | } | |
c5aa993b | 2098 | break; |
c906108c | 2099 | |
36e9969c NS |
2100 | case UNOP_PLUS: |
2101 | (*pc)++; | |
0e2de366 | 2102 | /* + FOO is equivalent to 0 + FOO, which can be optimized. */ |
f7c79c41 UW |
2103 | gen_expr (exp, pc, ax, value); |
2104 | gen_usual_unary (exp, ax, value); | |
36e9969c NS |
2105 | break; |
2106 | ||
c906108c SS |
2107 | case UNOP_NEG: |
2108 | (*pc)++; | |
2109 | /* -FOO is equivalent to 0 - FOO. */ | |
22601c15 UW |
2110 | gen_int_literal (ax, &value1, 0, |
2111 | builtin_type (exp->gdbarch)->builtin_int); | |
f7c79c41 UW |
2112 | gen_usual_unary (exp, ax, &value1); /* shouldn't do much */ |
2113 | gen_expr (exp, pc, ax, &value2); | |
2114 | gen_usual_unary (exp, ax, &value2); | |
2115 | gen_usual_arithmetic (exp, ax, &value1, &value2); | |
2116 | gen_binop (ax, value, &value1, &value2, aop_sub, aop_sub, 1, "negation"); | |
c906108c SS |
2117 | break; |
2118 | ||
2119 | case UNOP_LOGICAL_NOT: | |
2120 | (*pc)++; | |
f7c79c41 UW |
2121 | gen_expr (exp, pc, ax, value); |
2122 | gen_usual_unary (exp, ax, value); | |
3b11a015 | 2123 | gen_logical_not (ax, value, int_type); |
c906108c SS |
2124 | break; |
2125 | ||
2126 | case UNOP_COMPLEMENT: | |
2127 | (*pc)++; | |
f7c79c41 UW |
2128 | gen_expr (exp, pc, ax, value); |
2129 | gen_usual_unary (exp, ax, value); | |
2130 | gen_integral_promotions (exp, ax, value); | |
c906108c SS |
2131 | gen_complement (ax, value); |
2132 | break; | |
2133 | ||
2134 | case UNOP_IND: | |
2135 | (*pc)++; | |
f7c79c41 UW |
2136 | gen_expr (exp, pc, ax, value); |
2137 | gen_usual_unary (exp, ax, value); | |
b97aedf3 | 2138 | if (!pointer_type (value->type)) |
3d263c1d | 2139 | error (_("Argument of unary `*' is not a pointer.")); |
c906108c SS |
2140 | gen_deref (ax, value); |
2141 | break; | |
2142 | ||
2143 | case UNOP_ADDR: | |
2144 | (*pc)++; | |
f7c79c41 | 2145 | gen_expr (exp, pc, ax, value); |
c906108c SS |
2146 | gen_address_of (ax, value); |
2147 | break; | |
2148 | ||
2149 | case UNOP_SIZEOF: | |
2150 | (*pc)++; | |
2151 | /* Notice that gen_sizeof handles its own operand, unlike most | |
c5aa993b JM |
2152 | of the other unary operator functions. This is because we |
2153 | have to throw away the code we generate. */ | |
f7c79c41 UW |
2154 | gen_sizeof (exp, pc, ax, value, |
2155 | builtin_type (exp->gdbarch)->builtin_int); | |
c906108c SS |
2156 | break; |
2157 | ||
2158 | case STRUCTOP_STRUCT: | |
2159 | case STRUCTOP_PTR: | |
2160 | { | |
2161 | int length = (*pc)[1].longconst; | |
2162 | char *name = &(*pc)[2].string; | |
2163 | ||
2164 | (*pc) += 4 + BYTES_TO_EXP_ELEM (length + 1); | |
f7c79c41 | 2165 | gen_expr (exp, pc, ax, value); |
c906108c | 2166 | if (op == STRUCTOP_STRUCT) |
505e835d | 2167 | gen_struct_ref (exp, ax, value, name, ".", "structure or union"); |
c906108c | 2168 | else if (op == STRUCTOP_PTR) |
505e835d | 2169 | gen_struct_ref (exp, ax, value, name, "->", |
c906108c SS |
2170 | "pointer to a structure or union"); |
2171 | else | |
2172 | /* If this `if' chain doesn't handle it, then the case list | |
c5aa993b | 2173 | shouldn't mention it, and we shouldn't be here. */ |
8e65ff28 | 2174 | internal_error (__FILE__, __LINE__, |
3d263c1d | 2175 | _("gen_expr: unhandled struct case")); |
c906108c | 2176 | } |
c5aa993b | 2177 | break; |
c906108c | 2178 | |
6c228b9c SS |
2179 | case OP_THIS: |
2180 | { | |
6a0fc12f | 2181 | char *this_name; |
66a17cb6 | 2182 | struct symbol *sym, *func; |
6c228b9c | 2183 | struct block *b; |
66a17cb6 | 2184 | const struct language_defn *lang; |
6c228b9c | 2185 | |
66a17cb6 TT |
2186 | b = block_for_pc (ax->scope); |
2187 | func = block_linkage_function (b); | |
2188 | lang = language_def (SYMBOL_LANGUAGE (func)); | |
6c228b9c | 2189 | |
66a17cb6 | 2190 | sym = lookup_language_this (lang, b); |
6c228b9c | 2191 | if (!sym) |
66a17cb6 | 2192 | error (_("no `%s' found"), lang->la_name_of_this); |
6c228b9c SS |
2193 | |
2194 | gen_var_ref (exp->gdbarch, ax, value, sym); | |
400c6af0 SS |
2195 | |
2196 | if (value->optimized_out) | |
2197 | error (_("`%s' has been optimized out, cannot use"), | |
2198 | SYMBOL_PRINT_NAME (sym)); | |
2199 | ||
6c228b9c SS |
2200 | (*pc) += 2; |
2201 | } | |
2202 | break; | |
2203 | ||
b6e7192f SS |
2204 | case OP_SCOPE: |
2205 | { | |
2206 | struct type *type = (*pc)[1].type; | |
2207 | int length = longest_to_int ((*pc)[2].longconst); | |
2208 | char *name = &(*pc)[3].string; | |
2209 | int found; | |
2210 | ||
2211 | found = gen_aggregate_elt_ref (exp, ax, value, type, name, | |
2212 | "?", "??"); | |
2213 | if (!found) | |
2214 | error (_("There is no field named %s"), name); | |
2215 | (*pc) += 5 + BYTES_TO_EXP_ELEM (length + 1); | |
2216 | } | |
2217 | break; | |
2218 | ||
c906108c | 2219 | case OP_TYPE: |
3d263c1d | 2220 | error (_("Attempt to use a type name as an expression.")); |
c906108c SS |
2221 | |
2222 | default: | |
b6e7192f SS |
2223 | error (_("Unsupported operator %s (%d) in expression."), |
2224 | op_string (op), op); | |
c906108c SS |
2225 | } |
2226 | } | |
f61e138d SS |
2227 | |
2228 | /* This handles the middle-to-right-side of code generation for binary | |
2229 | expressions, which is shared between regular binary operations and | |
2230 | assign-modify (+= and friends) expressions. */ | |
2231 | ||
2232 | static void | |
2233 | gen_expr_binop_rest (struct expression *exp, | |
2234 | enum exp_opcode op, union exp_element **pc, | |
2235 | struct agent_expr *ax, struct axs_value *value, | |
2236 | struct axs_value *value1, struct axs_value *value2) | |
2237 | { | |
3b11a015 SS |
2238 | struct type *int_type = builtin_type (exp->gdbarch)->builtin_int; |
2239 | ||
f61e138d SS |
2240 | gen_expr (exp, pc, ax, value2); |
2241 | gen_usual_unary (exp, ax, value2); | |
2242 | gen_usual_arithmetic (exp, ax, value1, value2); | |
2243 | switch (op) | |
2244 | { | |
2245 | case BINOP_ADD: | |
2246 | if (TYPE_CODE (value1->type) == TYPE_CODE_INT | |
b97aedf3 | 2247 | && pointer_type (value2->type)) |
f61e138d SS |
2248 | { |
2249 | /* Swap the values and proceed normally. */ | |
2250 | ax_simple (ax, aop_swap); | |
2251 | gen_ptradd (ax, value, value2, value1); | |
2252 | } | |
b97aedf3 | 2253 | else if (pointer_type (value1->type) |
f61e138d SS |
2254 | && TYPE_CODE (value2->type) == TYPE_CODE_INT) |
2255 | gen_ptradd (ax, value, value1, value2); | |
2256 | else | |
2257 | gen_binop (ax, value, value1, value2, | |
2258 | aop_add, aop_add, 1, "addition"); | |
2259 | break; | |
2260 | case BINOP_SUB: | |
b97aedf3 | 2261 | if (pointer_type (value1->type) |
f61e138d SS |
2262 | && TYPE_CODE (value2->type) == TYPE_CODE_INT) |
2263 | gen_ptrsub (ax,value, value1, value2); | |
b97aedf3 SS |
2264 | else if (pointer_type (value1->type) |
2265 | && pointer_type (value2->type)) | |
f61e138d SS |
2266 | /* FIXME --- result type should be ptrdiff_t */ |
2267 | gen_ptrdiff (ax, value, value1, value2, | |
2268 | builtin_type (exp->gdbarch)->builtin_long); | |
2269 | else | |
2270 | gen_binop (ax, value, value1, value2, | |
2271 | aop_sub, aop_sub, 1, "subtraction"); | |
2272 | break; | |
2273 | case BINOP_MUL: | |
2274 | gen_binop (ax, value, value1, value2, | |
2275 | aop_mul, aop_mul, 1, "multiplication"); | |
2276 | break; | |
2277 | case BINOP_DIV: | |
2278 | gen_binop (ax, value, value1, value2, | |
2279 | aop_div_signed, aop_div_unsigned, 1, "division"); | |
2280 | break; | |
2281 | case BINOP_REM: | |
2282 | gen_binop (ax, value, value1, value2, | |
2283 | aop_rem_signed, aop_rem_unsigned, 1, "remainder"); | |
2284 | break; | |
948103cf SS |
2285 | case BINOP_LSH: |
2286 | gen_binop (ax, value, value1, value2, | |
2287 | aop_lsh, aop_lsh, 1, "left shift"); | |
2288 | break; | |
2289 | case BINOP_RSH: | |
2290 | gen_binop (ax, value, value1, value2, | |
2291 | aop_rsh_signed, aop_rsh_unsigned, 1, "right shift"); | |
2292 | break; | |
f61e138d | 2293 | case BINOP_SUBSCRIPT: |
be636754 PA |
2294 | { |
2295 | struct type *type; | |
2296 | ||
2297 | if (binop_types_user_defined_p (op, value1->type, value2->type)) | |
2298 | { | |
3e43a32a MS |
2299 | error (_("cannot subscript requested type: " |
2300 | "cannot call user defined functions")); | |
be636754 PA |
2301 | } |
2302 | else | |
2303 | { | |
2304 | /* If the user attempts to subscript something that is not | |
2305 | an array or pointer type (like a plain int variable for | |
2306 | example), then report this as an error. */ | |
2307 | type = check_typedef (value1->type); | |
2308 | if (TYPE_CODE (type) != TYPE_CODE_ARRAY | |
2309 | && TYPE_CODE (type) != TYPE_CODE_PTR) | |
2310 | { | |
2311 | if (TYPE_NAME (type)) | |
2312 | error (_("cannot subscript something of type `%s'"), | |
2313 | TYPE_NAME (type)); | |
2314 | else | |
2315 | error (_("cannot subscript requested type")); | |
2316 | } | |
2317 | } | |
2318 | ||
5d5b640e | 2319 | if (!is_integral_type (value2->type)) |
3e43a32a MS |
2320 | error (_("Argument to arithmetic operation " |
2321 | "not a number or boolean.")); | |
5d5b640e | 2322 | |
be636754 PA |
2323 | gen_ptradd (ax, value, value1, value2); |
2324 | gen_deref (ax, value); | |
2325 | break; | |
2326 | } | |
f61e138d SS |
2327 | case BINOP_BITWISE_AND: |
2328 | gen_binop (ax, value, value1, value2, | |
2329 | aop_bit_and, aop_bit_and, 0, "bitwise and"); | |
2330 | break; | |
2331 | ||
2332 | case BINOP_BITWISE_IOR: | |
2333 | gen_binop (ax, value, value1, value2, | |
2334 | aop_bit_or, aop_bit_or, 0, "bitwise or"); | |
2335 | break; | |
2336 | ||
2337 | case BINOP_BITWISE_XOR: | |
2338 | gen_binop (ax, value, value1, value2, | |
2339 | aop_bit_xor, aop_bit_xor, 0, "bitwise exclusive-or"); | |
2340 | break; | |
2341 | ||
2342 | case BINOP_EQUAL: | |
3b11a015 | 2343 | gen_equal (ax, value, value1, value2, int_type); |
f61e138d SS |
2344 | break; |
2345 | ||
2346 | case BINOP_NOTEQUAL: | |
3b11a015 SS |
2347 | gen_equal (ax, value, value1, value2, int_type); |
2348 | gen_logical_not (ax, value, int_type); | |
f61e138d SS |
2349 | break; |
2350 | ||
2351 | case BINOP_LESS: | |
3b11a015 | 2352 | gen_less (ax, value, value1, value2, int_type); |
f61e138d SS |
2353 | break; |
2354 | ||
2355 | case BINOP_GTR: | |
2356 | ax_simple (ax, aop_swap); | |
3b11a015 | 2357 | gen_less (ax, value, value1, value2, int_type); |
f61e138d SS |
2358 | break; |
2359 | ||
2360 | case BINOP_LEQ: | |
2361 | ax_simple (ax, aop_swap); | |
3b11a015 SS |
2362 | gen_less (ax, value, value1, value2, int_type); |
2363 | gen_logical_not (ax, value, int_type); | |
f61e138d SS |
2364 | break; |
2365 | ||
2366 | case BINOP_GEQ: | |
3b11a015 SS |
2367 | gen_less (ax, value, value1, value2, int_type); |
2368 | gen_logical_not (ax, value, int_type); | |
f61e138d SS |
2369 | break; |
2370 | ||
2371 | default: | |
2372 | /* We should only list operators in the outer case statement | |
2373 | that we actually handle in the inner case statement. */ | |
2374 | internal_error (__FILE__, __LINE__, | |
2375 | _("gen_expr: op case sets don't match")); | |
2376 | } | |
2377 | } | |
c906108c | 2378 | \f |
c5aa993b | 2379 | |
0936ad1d SS |
2380 | /* Given a single variable and a scope, generate bytecodes to trace |
2381 | its value. This is for use in situations where we have only a | |
2382 | variable's name, and no parsed expression; for instance, when the | |
2383 | name comes from a list of local variables of a function. */ | |
2384 | ||
2385 | struct agent_expr * | |
400c6af0 SS |
2386 | gen_trace_for_var (CORE_ADDR scope, struct gdbarch *gdbarch, |
2387 | struct symbol *var) | |
0936ad1d SS |
2388 | { |
2389 | struct cleanup *old_chain = 0; | |
35c9c7ba | 2390 | struct agent_expr *ax = new_agent_expr (gdbarch, scope); |
0936ad1d SS |
2391 | struct axs_value value; |
2392 | ||
2393 | old_chain = make_cleanup_free_agent_expr (ax); | |
2394 | ||
2395 | trace_kludge = 1; | |
400c6af0 SS |
2396 | gen_var_ref (gdbarch, ax, &value, var); |
2397 | ||
2398 | /* If there is no actual variable to trace, flag it by returning | |
2399 | an empty agent expression. */ | |
2400 | if (value.optimized_out) | |
2401 | { | |
2402 | do_cleanups (old_chain); | |
2403 | return NULL; | |
2404 | } | |
0936ad1d SS |
2405 | |
2406 | /* Make sure we record the final object, and get rid of it. */ | |
400c6af0 | 2407 | gen_traced_pop (gdbarch, ax, &value); |
0936ad1d SS |
2408 | |
2409 | /* Oh, and terminate. */ | |
2410 | ax_simple (ax, aop_end); | |
2411 | ||
2412 | /* We have successfully built the agent expr, so cancel the cleanup | |
2413 | request. If we add more cleanups that we always want done, this | |
2414 | will have to get more complicated. */ | |
2415 | discard_cleanups (old_chain); | |
2416 | return ax; | |
2417 | } | |
c5aa993b | 2418 | |
c906108c SS |
2419 | /* Generating bytecode from GDB expressions: driver */ |
2420 | ||
c906108c SS |
2421 | /* Given a GDB expression EXPR, return bytecode to trace its value. |
2422 | The result will use the `trace' and `trace_quick' bytecodes to | |
2423 | record the value of all memory touched by the expression. The | |
2424 | caller can then use the ax_reqs function to discover which | |
2425 | registers it relies upon. */ | |
2426 | struct agent_expr * | |
fba45db2 | 2427 | gen_trace_for_expr (CORE_ADDR scope, struct expression *expr) |
c906108c SS |
2428 | { |
2429 | struct cleanup *old_chain = 0; | |
35c9c7ba | 2430 | struct agent_expr *ax = new_agent_expr (expr->gdbarch, scope); |
c906108c SS |
2431 | union exp_element *pc; |
2432 | struct axs_value value; | |
2433 | ||
f23d52e0 | 2434 | old_chain = make_cleanup_free_agent_expr (ax); |
c906108c SS |
2435 | |
2436 | pc = expr->elts; | |
2437 | trace_kludge = 1; | |
35c9c7ba | 2438 | value.optimized_out = 0; |
f7c79c41 | 2439 | gen_expr (expr, &pc, ax, &value); |
c906108c SS |
2440 | |
2441 | /* Make sure we record the final object, and get rid of it. */ | |
400c6af0 | 2442 | gen_traced_pop (expr->gdbarch, ax, &value); |
c906108c SS |
2443 | |
2444 | /* Oh, and terminate. */ | |
2445 | ax_simple (ax, aop_end); | |
2446 | ||
2447 | /* We have successfully built the agent expr, so cancel the cleanup | |
2448 | request. If we add more cleanups that we always want done, this | |
2449 | will have to get more complicated. */ | |
2450 | discard_cleanups (old_chain); | |
2451 | return ax; | |
2452 | } | |
c906108c | 2453 | |
782b2b07 SS |
2454 | /* Given a GDB expression EXPR, return a bytecode sequence that will |
2455 | evaluate and return a result. The bytecodes will do a direct | |
2456 | evaluation, using the current data on the target, rather than | |
2457 | recording blocks of memory and registers for later use, as | |
2458 | gen_trace_for_expr does. The generated bytecode sequence leaves | |
2459 | the result of expression evaluation on the top of the stack. */ | |
2460 | ||
2461 | struct agent_expr * | |
2462 | gen_eval_for_expr (CORE_ADDR scope, struct expression *expr) | |
2463 | { | |
2464 | struct cleanup *old_chain = 0; | |
35c9c7ba | 2465 | struct agent_expr *ax = new_agent_expr (expr->gdbarch, scope); |
782b2b07 SS |
2466 | union exp_element *pc; |
2467 | struct axs_value value; | |
2468 | ||
2469 | old_chain = make_cleanup_free_agent_expr (ax); | |
2470 | ||
2471 | pc = expr->elts; | |
2472 | trace_kludge = 0; | |
35c9c7ba | 2473 | value.optimized_out = 0; |
782b2b07 SS |
2474 | gen_expr (expr, &pc, ax, &value); |
2475 | ||
35c9c7ba SS |
2476 | require_rvalue (ax, &value); |
2477 | ||
782b2b07 SS |
2478 | /* Oh, and terminate. */ |
2479 | ax_simple (ax, aop_end); | |
2480 | ||
2481 | /* We have successfully built the agent expr, so cancel the cleanup | |
2482 | request. If we add more cleanups that we always want done, this | |
2483 | will have to get more complicated. */ | |
2484 | discard_cleanups (old_chain); | |
2485 | return ax; | |
2486 | } | |
2487 | ||
6710bf39 SS |
2488 | struct agent_expr * |
2489 | gen_trace_for_return_address (CORE_ADDR scope, struct gdbarch *gdbarch) | |
2490 | { | |
2491 | struct cleanup *old_chain = 0; | |
2492 | struct agent_expr *ax = new_agent_expr (gdbarch, scope); | |
2493 | struct axs_value value; | |
2494 | ||
2495 | old_chain = make_cleanup_free_agent_expr (ax); | |
2496 | ||
2497 | trace_kludge = 1; | |
2498 | ||
2499 | gdbarch_gen_return_address (gdbarch, ax, &value, scope); | |
2500 | ||
2501 | /* Make sure we record the final object, and get rid of it. */ | |
2502 | gen_traced_pop (gdbarch, ax, &value); | |
2503 | ||
2504 | /* Oh, and terminate. */ | |
2505 | ax_simple (ax, aop_end); | |
2506 | ||
2507 | /* We have successfully built the agent expr, so cancel the cleanup | |
2508 | request. If we add more cleanups that we always want done, this | |
2509 | will have to get more complicated. */ | |
2510 | discard_cleanups (old_chain); | |
2511 | return ax; | |
2512 | } | |
2513 | ||
c906108c | 2514 | static void |
fba45db2 | 2515 | agent_command (char *exp, int from_tty) |
c906108c SS |
2516 | { |
2517 | struct cleanup *old_chain = 0; | |
2518 | struct expression *expr; | |
2519 | struct agent_expr *agent; | |
6426a772 | 2520 | struct frame_info *fi = get_current_frame (); /* need current scope */ |
c906108c SS |
2521 | |
2522 | /* We don't deal with overlay debugging at the moment. We need to | |
2523 | think more carefully about this. If you copy this code into | |
2524 | another command, change the error message; the user shouldn't | |
2525 | have to know anything about agent expressions. */ | |
2526 | if (overlay_debugging) | |
3d263c1d | 2527 | error (_("GDB can't do agent expression translation with overlays.")); |
c906108c SS |
2528 | |
2529 | if (exp == 0) | |
3d263c1d | 2530 | error_no_arg (_("expression to translate")); |
c5aa993b | 2531 | |
3065dfb6 SS |
2532 | trace_string_kludge = 0; |
2533 | if (*exp == '/') | |
2534 | exp = decode_agent_options (exp); | |
2535 | ||
6710bf39 SS |
2536 | /* Recognize the return address collection directive specially. Note |
2537 | that it is not really an expression of any sort. */ | |
2538 | if (strcmp (exp, "$_ret") == 0) | |
2539 | { | |
2540 | agent = gen_trace_for_return_address (get_frame_pc (fi), | |
2541 | get_current_arch ()); | |
2542 | old_chain = make_cleanup_free_agent_expr (agent); | |
2543 | } | |
2544 | else | |
2545 | { | |
2546 | expr = parse_expression (exp); | |
2547 | old_chain = make_cleanup (free_current_contents, &expr); | |
2548 | agent = gen_trace_for_expr (get_frame_pc (fi), expr); | |
2549 | make_cleanup_free_agent_expr (agent); | |
2550 | } | |
2551 | ||
35c9c7ba | 2552 | ax_reqs (agent); |
c906108c | 2553 | ax_print (gdb_stdout, agent); |
085dd6e6 JM |
2554 | |
2555 | /* It would be nice to call ax_reqs here to gather some general info | |
2556 | about the expression, and then print out the result. */ | |
c906108c SS |
2557 | |
2558 | do_cleanups (old_chain); | |
2559 | dont_repeat (); | |
2560 | } | |
782b2b07 SS |
2561 | |
2562 | /* Parse the given expression, compile it into an agent expression | |
2563 | that does direct evaluation, and display the resulting | |
2564 | expression. */ | |
2565 | ||
2566 | static void | |
2567 | agent_eval_command (char *exp, int from_tty) | |
2568 | { | |
2569 | struct cleanup *old_chain = 0; | |
2570 | struct expression *expr; | |
2571 | struct agent_expr *agent; | |
2572 | struct frame_info *fi = get_current_frame (); /* need current scope */ | |
2573 | ||
2574 | /* We don't deal with overlay debugging at the moment. We need to | |
2575 | think more carefully about this. If you copy this code into | |
2576 | another command, change the error message; the user shouldn't | |
2577 | have to know anything about agent expressions. */ | |
2578 | if (overlay_debugging) | |
2579 | error (_("GDB can't do agent expression translation with overlays.")); | |
2580 | ||
2581 | if (exp == 0) | |
2582 | error_no_arg (_("expression to translate")); | |
2583 | ||
2584 | expr = parse_expression (exp); | |
2585 | old_chain = make_cleanup (free_current_contents, &expr); | |
2586 | agent = gen_eval_for_expr (get_frame_pc (fi), expr); | |
2587 | make_cleanup_free_agent_expr (agent); | |
35c9c7ba | 2588 | ax_reqs (agent); |
782b2b07 SS |
2589 | ax_print (gdb_stdout, agent); |
2590 | ||
2591 | /* It would be nice to call ax_reqs here to gather some general info | |
2592 | about the expression, and then print out the result. */ | |
2593 | ||
2594 | do_cleanups (old_chain); | |
2595 | dont_repeat (); | |
2596 | } | |
c906108c | 2597 | \f |
c5aa993b | 2598 | |
c906108c SS |
2599 | /* Initialization code. */ |
2600 | ||
a14ed312 | 2601 | void _initialize_ax_gdb (void); |
c906108c | 2602 | void |
fba45db2 | 2603 | _initialize_ax_gdb (void) |
c906108c | 2604 | { |
c906108c | 2605 | add_cmd ("agent", class_maintenance, agent_command, |
3e43a32a MS |
2606 | _("Translate an expression into " |
2607 | "remote agent bytecode for tracing."), | |
782b2b07 SS |
2608 | &maintenancelist); |
2609 | ||
2610 | add_cmd ("agent-eval", class_maintenance, agent_eval_command, | |
3e43a32a MS |
2611 | _("Translate an expression into remote " |
2612 | "agent bytecode for evaluation."), | |
c906108c SS |
2613 | &maintenancelist); |
2614 | } |