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1bac305b AC |
1 | /* GDB-specific functions for operating on agent expressions. |
2 | ||
4c38e0a4 | 3 | Copyright (C) 1998, 1999, 2000, 2001, 2003, 2007, 2008, 2009, 2010 |
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" |
c906108c | 43 | |
6426a772 JM |
44 | /* To make sense of this file, you should read doc/agentexpr.texi. |
45 | Then look at the types and enums in ax-gdb.h. For the code itself, | |
46 | look at gen_expr, towards the bottom; that's the main function that | |
47 | looks at the GDB expressions and calls everything else to generate | |
48 | code. | |
c906108c SS |
49 | |
50 | I'm beginning to wonder whether it wouldn't be nicer to internally | |
51 | generate trees, with types, and then spit out the bytecode in | |
52 | linear form afterwards; we could generate fewer `swap', `ext', and | |
53 | `zero_ext' bytecodes that way; it would make good constant folding | |
54 | easier, too. But at the moment, I think we should be willing to | |
55 | pay for the simplicity of this code with less-than-optimal bytecode | |
56 | strings. | |
57 | ||
c5aa993b JM |
58 | Remember, "GBD" stands for "Great Britain, Dammit!" So be careful. */ |
59 | \f | |
c906108c SS |
60 | |
61 | ||
c906108c SS |
62 | /* Prototypes for local functions. */ |
63 | ||
64 | /* There's a standard order to the arguments of these functions: | |
65 | union exp_element ** --- pointer into expression | |
66 | struct agent_expr * --- agent expression buffer to generate code into | |
67 | struct axs_value * --- describes value left on top of stack */ | |
c5aa993b | 68 | |
a14ed312 KB |
69 | static struct value *const_var_ref (struct symbol *var); |
70 | static struct value *const_expr (union exp_element **pc); | |
71 | static struct value *maybe_const_expr (union exp_element **pc); | |
72 | ||
400c6af0 | 73 | static void gen_traced_pop (struct gdbarch *, struct agent_expr *, struct axs_value *); |
a14ed312 KB |
74 | |
75 | static void gen_sign_extend (struct agent_expr *, struct type *); | |
76 | static void gen_extend (struct agent_expr *, struct type *); | |
77 | static void gen_fetch (struct agent_expr *, struct type *); | |
78 | static void gen_left_shift (struct agent_expr *, int); | |
79 | ||
80 | ||
f7c79c41 UW |
81 | static void gen_frame_args_address (struct gdbarch *, struct agent_expr *); |
82 | static void gen_frame_locals_address (struct gdbarch *, struct agent_expr *); | |
a14ed312 KB |
83 | static void gen_offset (struct agent_expr *ax, int offset); |
84 | static void gen_sym_offset (struct agent_expr *, struct symbol *); | |
f7c79c41 | 85 | static void gen_var_ref (struct gdbarch *, struct agent_expr *ax, |
a14ed312 KB |
86 | struct axs_value *value, struct symbol *var); |
87 | ||
88 | ||
89 | static void gen_int_literal (struct agent_expr *ax, | |
90 | struct axs_value *value, | |
91 | LONGEST k, struct type *type); | |
92 | ||
93 | ||
94 | static void require_rvalue (struct agent_expr *ax, struct axs_value *value); | |
f7c79c41 UW |
95 | static void gen_usual_unary (struct expression *exp, struct agent_expr *ax, |
96 | struct axs_value *value); | |
a14ed312 KB |
97 | static int type_wider_than (struct type *type1, struct type *type2); |
98 | static struct type *max_type (struct type *type1, struct type *type2); | |
99 | static void gen_conversion (struct agent_expr *ax, | |
100 | struct type *from, struct type *to); | |
101 | static int is_nontrivial_conversion (struct type *from, struct type *to); | |
f7c79c41 UW |
102 | static void gen_usual_arithmetic (struct expression *exp, |
103 | struct agent_expr *ax, | |
a14ed312 KB |
104 | struct axs_value *value1, |
105 | struct axs_value *value2); | |
f7c79c41 UW |
106 | static void gen_integral_promotions (struct expression *exp, |
107 | struct agent_expr *ax, | |
a14ed312 KB |
108 | struct axs_value *value); |
109 | static void gen_cast (struct agent_expr *ax, | |
110 | struct axs_value *value, struct type *type); | |
111 | static void gen_scale (struct agent_expr *ax, | |
112 | enum agent_op op, struct type *type); | |
f7c79c41 UW |
113 | static void gen_ptradd (struct agent_expr *ax, struct axs_value *value, |
114 | struct axs_value *value1, struct axs_value *value2); | |
115 | static void gen_ptrsub (struct agent_expr *ax, struct axs_value *value, | |
116 | struct axs_value *value1, struct axs_value *value2); | |
117 | static void gen_ptrdiff (struct agent_expr *ax, struct axs_value *value, | |
118 | struct axs_value *value1, struct axs_value *value2, | |
119 | struct type *result_type); | |
a14ed312 KB |
120 | static void gen_binop (struct agent_expr *ax, |
121 | struct axs_value *value, | |
122 | struct axs_value *value1, | |
123 | struct axs_value *value2, | |
124 | enum agent_op op, | |
125 | enum agent_op op_unsigned, int may_carry, char *name); | |
f7c79c41 UW |
126 | static void gen_logical_not (struct agent_expr *ax, struct axs_value *value, |
127 | struct type *result_type); | |
a14ed312 KB |
128 | static void gen_complement (struct agent_expr *ax, struct axs_value *value); |
129 | static void gen_deref (struct agent_expr *, struct axs_value *); | |
130 | static void gen_address_of (struct agent_expr *, struct axs_value *); | |
505e835d | 131 | static void gen_bitfield_ref (struct expression *exp, struct agent_expr *ax, |
a14ed312 KB |
132 | struct axs_value *value, |
133 | struct type *type, int start, int end); | |
b6e7192f SS |
134 | static void gen_primitive_field (struct expression *exp, |
135 | struct agent_expr *ax, | |
136 | struct axs_value *value, | |
137 | int offset, int fieldno, struct type *type); | |
138 | static int gen_struct_ref_recursive (struct expression *exp, | |
139 | struct agent_expr *ax, | |
140 | struct axs_value *value, | |
141 | char *field, int offset, | |
142 | struct type *type); | |
505e835d | 143 | static void gen_struct_ref (struct expression *exp, struct agent_expr *ax, |
a14ed312 KB |
144 | struct axs_value *value, |
145 | char *field, | |
146 | char *operator_name, char *operand_name); | |
400c6af0 | 147 | static void gen_static_field (struct gdbarch *gdbarch, |
b6e7192f SS |
148 | struct agent_expr *ax, struct axs_value *value, |
149 | struct type *type, int fieldno); | |
f7c79c41 | 150 | static void gen_repeat (struct expression *exp, union exp_element **pc, |
a14ed312 | 151 | struct agent_expr *ax, struct axs_value *value); |
f7c79c41 UW |
152 | static void gen_sizeof (struct expression *exp, union exp_element **pc, |
153 | struct agent_expr *ax, struct axs_value *value, | |
154 | struct type *size_type); | |
155 | static void gen_expr (struct expression *exp, union exp_element **pc, | |
a14ed312 | 156 | struct agent_expr *ax, struct axs_value *value); |
f61e138d SS |
157 | static void gen_expr_binop_rest (struct expression *exp, |
158 | enum exp_opcode op, union exp_element **pc, | |
159 | struct agent_expr *ax, | |
160 | struct axs_value *value, | |
161 | struct axs_value *value1, | |
162 | struct axs_value *value2); | |
c5aa993b | 163 | |
a14ed312 | 164 | static void agent_command (char *exp, int from_tty); |
c906108c | 165 | \f |
c5aa993b | 166 | |
c906108c SS |
167 | /* Detecting constant expressions. */ |
168 | ||
169 | /* If the variable reference at *PC is a constant, return its value. | |
170 | Otherwise, return zero. | |
171 | ||
172 | Hey, Wally! How can a variable reference be a constant? | |
173 | ||
174 | Well, Beav, this function really handles the OP_VAR_VALUE operator, | |
175 | not specifically variable references. GDB uses OP_VAR_VALUE to | |
176 | refer to any kind of symbolic reference: function names, enum | |
177 | elements, and goto labels are all handled through the OP_VAR_VALUE | |
178 | operator, even though they're constants. It makes sense given the | |
179 | situation. | |
180 | ||
181 | Gee, Wally, don'cha wonder sometimes if data representations that | |
182 | subvert commonly accepted definitions of terms in favor of heavily | |
183 | context-specific interpretations are really just a tool of the | |
184 | programming hegemony to preserve their power and exclude the | |
185 | proletariat? */ | |
186 | ||
187 | static struct value * | |
fba45db2 | 188 | const_var_ref (struct symbol *var) |
c906108c SS |
189 | { |
190 | struct type *type = SYMBOL_TYPE (var); | |
191 | ||
192 | switch (SYMBOL_CLASS (var)) | |
193 | { | |
194 | case LOC_CONST: | |
195 | return value_from_longest (type, (LONGEST) SYMBOL_VALUE (var)); | |
196 | ||
197 | case LOC_LABEL: | |
4478b372 | 198 | return value_from_pointer (type, (CORE_ADDR) SYMBOL_VALUE_ADDRESS (var)); |
c906108c SS |
199 | |
200 | default: | |
201 | return 0; | |
202 | } | |
203 | } | |
204 | ||
205 | ||
206 | /* If the expression starting at *PC has a constant value, return it. | |
207 | Otherwise, return zero. If we return a value, then *PC will be | |
208 | advanced to the end of it. If we return zero, *PC could be | |
209 | anywhere. */ | |
210 | static struct value * | |
fba45db2 | 211 | const_expr (union exp_element **pc) |
c906108c SS |
212 | { |
213 | enum exp_opcode op = (*pc)->opcode; | |
214 | struct value *v1; | |
215 | ||
216 | switch (op) | |
217 | { | |
218 | case OP_LONG: | |
219 | { | |
220 | struct type *type = (*pc)[1].type; | |
221 | LONGEST k = (*pc)[2].longconst; | |
222 | (*pc) += 4; | |
223 | return value_from_longest (type, k); | |
224 | } | |
225 | ||
226 | case OP_VAR_VALUE: | |
227 | { | |
228 | struct value *v = const_var_ref ((*pc)[2].symbol); | |
229 | (*pc) += 4; | |
230 | return v; | |
231 | } | |
232 | ||
c5aa993b | 233 | /* We could add more operators in here. */ |
c906108c SS |
234 | |
235 | case UNOP_NEG: | |
236 | (*pc)++; | |
237 | v1 = const_expr (pc); | |
238 | if (v1) | |
239 | return value_neg (v1); | |
240 | else | |
241 | return 0; | |
242 | ||
243 | default: | |
244 | return 0; | |
245 | } | |
246 | } | |
247 | ||
248 | ||
249 | /* Like const_expr, but guarantee also that *PC is undisturbed if the | |
250 | expression is not constant. */ | |
251 | static struct value * | |
fba45db2 | 252 | maybe_const_expr (union exp_element **pc) |
c906108c SS |
253 | { |
254 | union exp_element *tentative_pc = *pc; | |
255 | struct value *v = const_expr (&tentative_pc); | |
256 | ||
257 | /* If we got a value, then update the real PC. */ | |
258 | if (v) | |
259 | *pc = tentative_pc; | |
c5aa993b | 260 | |
c906108c SS |
261 | return v; |
262 | } | |
c906108c | 263 | \f |
c5aa993b | 264 | |
c906108c SS |
265 | /* Generating bytecode from GDB expressions: general assumptions */ |
266 | ||
267 | /* Here are a few general assumptions made throughout the code; if you | |
268 | want to make a change that contradicts one of these, then you'd | |
269 | better scan things pretty thoroughly. | |
270 | ||
271 | - We assume that all values occupy one stack element. For example, | |
c5aa993b JM |
272 | sometimes we'll swap to get at the left argument to a binary |
273 | operator. If we decide that void values should occupy no stack | |
274 | elements, or that synthetic arrays (whose size is determined at | |
275 | run time, created by the `@' operator) should occupy two stack | |
276 | elements (address and length), then this will cause trouble. | |
c906108c SS |
277 | |
278 | - We assume the stack elements are infinitely wide, and that we | |
c5aa993b JM |
279 | don't have to worry what happens if the user requests an |
280 | operation that is wider than the actual interpreter's stack. | |
281 | That is, it's up to the interpreter to handle directly all the | |
282 | integer widths the user has access to. (Woe betide the language | |
283 | with bignums!) | |
c906108c SS |
284 | |
285 | - We don't support side effects. Thus, we don't have to worry about | |
c5aa993b | 286 | GCC's generalized lvalues, function calls, etc. |
c906108c SS |
287 | |
288 | - We don't support floating point. Many places where we switch on | |
c5aa993b JM |
289 | some type don't bother to include cases for floating point; there |
290 | may be even more subtle ways this assumption exists. For | |
291 | example, the arguments to % must be integers. | |
c906108c SS |
292 | |
293 | - We assume all subexpressions have a static, unchanging type. If | |
c5aa993b JM |
294 | we tried to support convenience variables, this would be a |
295 | problem. | |
c906108c SS |
296 | |
297 | - All values on the stack should always be fully zero- or | |
c5aa993b JM |
298 | sign-extended. |
299 | ||
300 | (I wasn't sure whether to choose this or its opposite --- that | |
301 | only addresses are assumed extended --- but it turns out that | |
302 | neither convention completely eliminates spurious extend | |
303 | operations (if everything is always extended, then you have to | |
304 | extend after add, because it could overflow; if nothing is | |
305 | extended, then you end up producing extends whenever you change | |
306 | sizes), and this is simpler.) */ | |
c906108c | 307 | \f |
c5aa993b | 308 | |
c906108c SS |
309 | /* Generating bytecode from GDB expressions: the `trace' kludge */ |
310 | ||
311 | /* The compiler in this file is a general-purpose mechanism for | |
312 | translating GDB expressions into bytecode. One ought to be able to | |
313 | find a million and one uses for it. | |
314 | ||
315 | However, at the moment it is HOPELESSLY BRAIN-DAMAGED for the sake | |
316 | of expediency. Let he who is without sin cast the first stone. | |
317 | ||
318 | For the data tracing facility, we need to insert `trace' bytecodes | |
319 | before each data fetch; this records all the memory that the | |
320 | expression touches in the course of evaluation, so that memory will | |
321 | be available when the user later tries to evaluate the expression | |
322 | in GDB. | |
323 | ||
324 | This should be done (I think) in a post-processing pass, that walks | |
325 | an arbitrary agent expression and inserts `trace' operations at the | |
326 | appropriate points. But it's much faster to just hack them | |
327 | directly into the code. And since we're in a crunch, that's what | |
328 | I've done. | |
329 | ||
330 | Setting the flag trace_kludge to non-zero enables the code that | |
331 | emits the trace bytecodes at the appropriate points. */ | |
08922a10 | 332 | int trace_kludge; |
c906108c | 333 | |
400c6af0 SS |
334 | /* Scan for all static fields in the given class, including any base |
335 | classes, and generate tracing bytecodes for each. */ | |
336 | ||
337 | static void | |
338 | gen_trace_static_fields (struct gdbarch *gdbarch, | |
339 | struct agent_expr *ax, | |
340 | struct type *type) | |
341 | { | |
342 | int i, nbases = TYPE_N_BASECLASSES (type); | |
343 | struct axs_value value; | |
344 | ||
345 | CHECK_TYPEDEF (type); | |
346 | ||
347 | for (i = TYPE_NFIELDS (type) - 1; i >= nbases; i--) | |
348 | { | |
349 | if (field_is_static (&TYPE_FIELD (type, i))) | |
350 | { | |
351 | gen_static_field (gdbarch, ax, &value, type, i); | |
352 | if (value.optimized_out) | |
353 | continue; | |
354 | switch (value.kind) | |
355 | { | |
356 | case axs_lvalue_memory: | |
357 | { | |
358 | int length = TYPE_LENGTH (check_typedef (value.type)); | |
359 | ||
360 | ax_const_l (ax, length); | |
361 | ax_simple (ax, aop_trace); | |
362 | } | |
363 | break; | |
364 | ||
365 | case axs_lvalue_register: | |
35c9c7ba SS |
366 | /* We don't actually need the register's value to be pushed, |
367 | just note that we need it to be collected. */ | |
368 | ax_reg_mask (ax, value.u.reg); | |
400c6af0 SS |
369 | |
370 | default: | |
371 | break; | |
372 | } | |
373 | } | |
374 | } | |
375 | ||
376 | /* Now scan through base classes recursively. */ | |
377 | for (i = 0; i < nbases; i++) | |
378 | { | |
379 | struct type *basetype = check_typedef (TYPE_BASECLASS (type, i)); | |
380 | ||
381 | gen_trace_static_fields (gdbarch, ax, basetype); | |
382 | } | |
383 | } | |
384 | ||
c906108c SS |
385 | /* Trace the lvalue on the stack, if it needs it. In either case, pop |
386 | the value. Useful on the left side of a comma, and at the end of | |
387 | an expression being used for tracing. */ | |
388 | static void | |
400c6af0 SS |
389 | gen_traced_pop (struct gdbarch *gdbarch, |
390 | struct agent_expr *ax, struct axs_value *value) | |
c906108c SS |
391 | { |
392 | if (trace_kludge) | |
393 | switch (value->kind) | |
394 | { | |
395 | case axs_rvalue: | |
396 | /* We don't trace rvalues, just the lvalues necessary to | |
c5aa993b | 397 | produce them. So just dispose of this value. */ |
c906108c SS |
398 | ax_simple (ax, aop_pop); |
399 | break; | |
400 | ||
401 | case axs_lvalue_memory: | |
402 | { | |
648027cc | 403 | int length = TYPE_LENGTH (check_typedef (value->type)); |
c906108c SS |
404 | |
405 | /* There's no point in trying to use a trace_quick bytecode | |
406 | here, since "trace_quick SIZE pop" is three bytes, whereas | |
407 | "const8 SIZE trace" is also three bytes, does the same | |
408 | thing, and the simplest code which generates that will also | |
409 | work correctly for objects with large sizes. */ | |
410 | ax_const_l (ax, length); | |
411 | ax_simple (ax, aop_trace); | |
412 | } | |
c5aa993b | 413 | break; |
c906108c SS |
414 | |
415 | case axs_lvalue_register: | |
35c9c7ba SS |
416 | /* We don't actually need the register's value to be on the |
417 | stack, and the target will get heartburn if the register is | |
418 | larger than will fit in a stack, so just mark it for | |
419 | collection and be done with it. */ | |
420 | ax_reg_mask (ax, value->u.reg); | |
c906108c SS |
421 | break; |
422 | } | |
423 | else | |
424 | /* If we're not tracing, just pop the value. */ | |
425 | ax_simple (ax, aop_pop); | |
400c6af0 SS |
426 | |
427 | /* To trace C++ classes with static fields stored elsewhere. */ | |
428 | if (trace_kludge | |
429 | && (TYPE_CODE (value->type) == TYPE_CODE_STRUCT | |
430 | || TYPE_CODE (value->type) == TYPE_CODE_UNION)) | |
431 | gen_trace_static_fields (gdbarch, ax, value->type); | |
c906108c | 432 | } |
c5aa993b | 433 | \f |
c906108c SS |
434 | |
435 | ||
c906108c SS |
436 | /* Generating bytecode from GDB expressions: helper functions */ |
437 | ||
438 | /* Assume that the lower bits of the top of the stack is a value of | |
439 | type TYPE, and the upper bits are zero. Sign-extend if necessary. */ | |
440 | static void | |
fba45db2 | 441 | gen_sign_extend (struct agent_expr *ax, struct type *type) |
c906108c SS |
442 | { |
443 | /* Do we need to sign-extend this? */ | |
c5aa993b | 444 | if (!TYPE_UNSIGNED (type)) |
0004e5a2 | 445 | ax_ext (ax, TYPE_LENGTH (type) * TARGET_CHAR_BIT); |
c906108c SS |
446 | } |
447 | ||
448 | ||
449 | /* Assume the lower bits of the top of the stack hold a value of type | |
450 | TYPE, and the upper bits are garbage. Sign-extend or truncate as | |
451 | needed. */ | |
452 | static void | |
fba45db2 | 453 | gen_extend (struct agent_expr *ax, struct type *type) |
c906108c | 454 | { |
0004e5a2 | 455 | int bits = TYPE_LENGTH (type) * TARGET_CHAR_BIT; |
c906108c SS |
456 | /* I just had to. */ |
457 | ((TYPE_UNSIGNED (type) ? ax_zero_ext : ax_ext) (ax, bits)); | |
458 | } | |
459 | ||
460 | ||
461 | /* Assume that the top of the stack contains a value of type "pointer | |
462 | to TYPE"; generate code to fetch its value. Note that TYPE is the | |
463 | target type, not the pointer type. */ | |
464 | static void | |
fba45db2 | 465 | gen_fetch (struct agent_expr *ax, struct type *type) |
c906108c SS |
466 | { |
467 | if (trace_kludge) | |
468 | { | |
469 | /* Record the area of memory we're about to fetch. */ | |
470 | ax_trace_quick (ax, TYPE_LENGTH (type)); | |
471 | } | |
472 | ||
0004e5a2 | 473 | switch (TYPE_CODE (type)) |
c906108c SS |
474 | { |
475 | case TYPE_CODE_PTR: | |
b97aedf3 | 476 | case TYPE_CODE_REF: |
c906108c SS |
477 | case TYPE_CODE_ENUM: |
478 | case TYPE_CODE_INT: | |
479 | case TYPE_CODE_CHAR: | |
3b11a015 | 480 | case TYPE_CODE_BOOL: |
c906108c SS |
481 | /* It's a scalar value, so we know how to dereference it. How |
482 | many bytes long is it? */ | |
0004e5a2 | 483 | switch (TYPE_LENGTH (type)) |
c906108c | 484 | { |
c5aa993b JM |
485 | case 8 / TARGET_CHAR_BIT: |
486 | ax_simple (ax, aop_ref8); | |
487 | break; | |
488 | case 16 / TARGET_CHAR_BIT: | |
489 | ax_simple (ax, aop_ref16); | |
490 | break; | |
491 | case 32 / TARGET_CHAR_BIT: | |
492 | ax_simple (ax, aop_ref32); | |
493 | break; | |
494 | case 64 / TARGET_CHAR_BIT: | |
495 | ax_simple (ax, aop_ref64); | |
496 | break; | |
c906108c SS |
497 | |
498 | /* Either our caller shouldn't have asked us to dereference | |
499 | that pointer (other code's fault), or we're not | |
500 | implementing something we should be (this code's fault). | |
501 | In any case, it's a bug the user shouldn't see. */ | |
502 | default: | |
8e65ff28 | 503 | internal_error (__FILE__, __LINE__, |
3d263c1d | 504 | _("gen_fetch: strange size")); |
c906108c SS |
505 | } |
506 | ||
507 | gen_sign_extend (ax, type); | |
508 | break; | |
509 | ||
510 | default: | |
511 | /* Either our caller shouldn't have asked us to dereference that | |
c5aa993b JM |
512 | pointer (other code's fault), or we're not implementing |
513 | something we should be (this code's fault). In any case, | |
514 | it's a bug the user shouldn't see. */ | |
8e65ff28 | 515 | internal_error (__FILE__, __LINE__, |
3d263c1d | 516 | _("gen_fetch: bad type code")); |
c906108c SS |
517 | } |
518 | } | |
519 | ||
520 | ||
521 | /* Generate code to left shift the top of the stack by DISTANCE bits, or | |
522 | right shift it by -DISTANCE bits if DISTANCE < 0. This generates | |
523 | unsigned (logical) right shifts. */ | |
524 | static void | |
fba45db2 | 525 | gen_left_shift (struct agent_expr *ax, int distance) |
c906108c SS |
526 | { |
527 | if (distance > 0) | |
528 | { | |
529 | ax_const_l (ax, distance); | |
530 | ax_simple (ax, aop_lsh); | |
531 | } | |
532 | else if (distance < 0) | |
533 | { | |
534 | ax_const_l (ax, -distance); | |
535 | ax_simple (ax, aop_rsh_unsigned); | |
536 | } | |
537 | } | |
c5aa993b | 538 | \f |
c906108c SS |
539 | |
540 | ||
c906108c SS |
541 | /* Generating bytecode from GDB expressions: symbol references */ |
542 | ||
543 | /* Generate code to push the base address of the argument portion of | |
544 | the top stack frame. */ | |
545 | static void | |
f7c79c41 | 546 | gen_frame_args_address (struct gdbarch *gdbarch, struct agent_expr *ax) |
c906108c | 547 | { |
39d4ef09 AC |
548 | int frame_reg; |
549 | LONGEST frame_offset; | |
c906108c | 550 | |
f7c79c41 | 551 | gdbarch_virtual_frame_pointer (gdbarch, |
c7bb205c | 552 | ax->scope, &frame_reg, &frame_offset); |
c5aa993b | 553 | ax_reg (ax, frame_reg); |
c906108c SS |
554 | gen_offset (ax, frame_offset); |
555 | } | |
556 | ||
557 | ||
558 | /* Generate code to push the base address of the locals portion of the | |
559 | top stack frame. */ | |
560 | static void | |
f7c79c41 | 561 | gen_frame_locals_address (struct gdbarch *gdbarch, struct agent_expr *ax) |
c906108c | 562 | { |
39d4ef09 AC |
563 | int frame_reg; |
564 | LONGEST frame_offset; | |
c906108c | 565 | |
f7c79c41 | 566 | gdbarch_virtual_frame_pointer (gdbarch, |
c7bb205c | 567 | ax->scope, &frame_reg, &frame_offset); |
c5aa993b | 568 | ax_reg (ax, frame_reg); |
c906108c SS |
569 | gen_offset (ax, frame_offset); |
570 | } | |
571 | ||
572 | ||
573 | /* Generate code to add OFFSET to the top of the stack. Try to | |
574 | generate short and readable code. We use this for getting to | |
575 | variables on the stack, and structure members. If we were | |
576 | programming in ML, it would be clearer why these are the same | |
577 | thing. */ | |
578 | static void | |
fba45db2 | 579 | gen_offset (struct agent_expr *ax, int offset) |
c906108c SS |
580 | { |
581 | /* It would suffice to simply push the offset and add it, but this | |
582 | makes it easier to read positive and negative offsets in the | |
583 | bytecode. */ | |
584 | if (offset > 0) | |
585 | { | |
586 | ax_const_l (ax, offset); | |
587 | ax_simple (ax, aop_add); | |
588 | } | |
589 | else if (offset < 0) | |
590 | { | |
591 | ax_const_l (ax, -offset); | |
592 | ax_simple (ax, aop_sub); | |
593 | } | |
594 | } | |
595 | ||
596 | ||
597 | /* In many cases, a symbol's value is the offset from some other | |
598 | address (stack frame, base register, etc.) Generate code to add | |
599 | VAR's value to the top of the stack. */ | |
600 | static void | |
fba45db2 | 601 | gen_sym_offset (struct agent_expr *ax, struct symbol *var) |
c906108c SS |
602 | { |
603 | gen_offset (ax, SYMBOL_VALUE (var)); | |
604 | } | |
605 | ||
606 | ||
607 | /* Generate code for a variable reference to AX. The variable is the | |
608 | symbol VAR. Set VALUE to describe the result. */ | |
609 | ||
610 | static void | |
f7c79c41 UW |
611 | gen_var_ref (struct gdbarch *gdbarch, struct agent_expr *ax, |
612 | struct axs_value *value, struct symbol *var) | |
c906108c SS |
613 | { |
614 | /* Dereference any typedefs. */ | |
615 | value->type = check_typedef (SYMBOL_TYPE (var)); | |
400c6af0 | 616 | value->optimized_out = 0; |
c906108c SS |
617 | |
618 | /* I'm imitating the code in read_var_value. */ | |
619 | switch (SYMBOL_CLASS (var)) | |
620 | { | |
621 | case LOC_CONST: /* A constant, like an enum value. */ | |
622 | ax_const_l (ax, (LONGEST) SYMBOL_VALUE (var)); | |
623 | value->kind = axs_rvalue; | |
624 | break; | |
625 | ||
626 | case LOC_LABEL: /* A goto label, being used as a value. */ | |
627 | ax_const_l (ax, (LONGEST) SYMBOL_VALUE_ADDRESS (var)); | |
628 | value->kind = axs_rvalue; | |
629 | break; | |
630 | ||
631 | case LOC_CONST_BYTES: | |
8e65ff28 | 632 | internal_error (__FILE__, __LINE__, |
3d263c1d | 633 | _("gen_var_ref: LOC_CONST_BYTES symbols are not supported")); |
c906108c SS |
634 | |
635 | /* Variable at a fixed location in memory. Easy. */ | |
636 | case LOC_STATIC: | |
637 | /* Push the address of the variable. */ | |
638 | ax_const_l (ax, SYMBOL_VALUE_ADDRESS (var)); | |
639 | value->kind = axs_lvalue_memory; | |
640 | break; | |
641 | ||
642 | case LOC_ARG: /* var lives in argument area of frame */ | |
f7c79c41 | 643 | gen_frame_args_address (gdbarch, ax); |
c906108c SS |
644 | gen_sym_offset (ax, var); |
645 | value->kind = axs_lvalue_memory; | |
646 | break; | |
647 | ||
648 | case LOC_REF_ARG: /* As above, but the frame slot really | |
649 | holds the address of the variable. */ | |
f7c79c41 | 650 | gen_frame_args_address (gdbarch, ax); |
c906108c SS |
651 | gen_sym_offset (ax, var); |
652 | /* Don't assume any particular pointer size. */ | |
f7c79c41 | 653 | gen_fetch (ax, builtin_type (gdbarch)->builtin_data_ptr); |
c906108c SS |
654 | value->kind = axs_lvalue_memory; |
655 | break; | |
656 | ||
657 | case LOC_LOCAL: /* var lives in locals area of frame */ | |
f7c79c41 | 658 | gen_frame_locals_address (gdbarch, ax); |
c906108c SS |
659 | gen_sym_offset (ax, var); |
660 | value->kind = axs_lvalue_memory; | |
661 | break; | |
662 | ||
c906108c | 663 | case LOC_TYPEDEF: |
3d263c1d | 664 | error (_("Cannot compute value of typedef `%s'."), |
de5ad195 | 665 | SYMBOL_PRINT_NAME (var)); |
c906108c SS |
666 | break; |
667 | ||
668 | case LOC_BLOCK: | |
669 | ax_const_l (ax, BLOCK_START (SYMBOL_BLOCK_VALUE (var))); | |
670 | value->kind = axs_rvalue; | |
671 | break; | |
672 | ||
673 | case LOC_REGISTER: | |
c906108c SS |
674 | /* Don't generate any code at all; in the process of treating |
675 | this as an lvalue or rvalue, the caller will generate the | |
676 | right code. */ | |
677 | value->kind = axs_lvalue_register; | |
768a979c | 678 | value->u.reg = SYMBOL_REGISTER_OPS (var)->register_number (var, gdbarch); |
c906108c SS |
679 | break; |
680 | ||
681 | /* A lot like LOC_REF_ARG, but the pointer lives directly in a | |
2a2d4dc3 AS |
682 | register, not on the stack. Simpler than LOC_REGISTER |
683 | because it's just like any other case where the thing | |
684 | has a real address. */ | |
c906108c | 685 | case LOC_REGPARM_ADDR: |
768a979c | 686 | ax_reg (ax, SYMBOL_REGISTER_OPS (var)->register_number (var, gdbarch)); |
c906108c SS |
687 | value->kind = axs_lvalue_memory; |
688 | break; | |
689 | ||
690 | case LOC_UNRESOLVED: | |
691 | { | |
c5aa993b | 692 | struct minimal_symbol *msym |
3567439c | 693 | = lookup_minimal_symbol (SYMBOL_LINKAGE_NAME (var), NULL, NULL); |
c5aa993b | 694 | if (!msym) |
3d263c1d | 695 | error (_("Couldn't resolve symbol `%s'."), SYMBOL_PRINT_NAME (var)); |
c5aa993b | 696 | |
c906108c SS |
697 | /* Push the address of the variable. */ |
698 | ax_const_l (ax, SYMBOL_VALUE_ADDRESS (msym)); | |
699 | value->kind = axs_lvalue_memory; | |
700 | } | |
c5aa993b | 701 | break; |
c906108c | 702 | |
a55cc764 | 703 | case LOC_COMPUTED: |
a67af2b9 | 704 | /* FIXME: cagney/2004-01-26: It should be possible to |
768a979c | 705 | unconditionally call the SYMBOL_COMPUTED_OPS method when available. |
d3efc286 | 706 | Unfortunately DWARF 2 stores the frame-base (instead of the |
a67af2b9 AC |
707 | function) location in a function's symbol. Oops! For the |
708 | moment enable this when/where applicable. */ | |
505e835d | 709 | SYMBOL_COMPUTED_OPS (var)->tracepoint_var_ref (var, gdbarch, ax, value); |
a55cc764 DJ |
710 | break; |
711 | ||
c906108c | 712 | case LOC_OPTIMIZED_OUT: |
400c6af0 SS |
713 | /* Flag this, but don't say anything; leave it up to callers to |
714 | warn the user. */ | |
715 | value->optimized_out = 1; | |
c906108c SS |
716 | break; |
717 | ||
718 | default: | |
3d263c1d | 719 | error (_("Cannot find value of botched symbol `%s'."), |
de5ad195 | 720 | SYMBOL_PRINT_NAME (var)); |
c906108c SS |
721 | break; |
722 | } | |
723 | } | |
c5aa993b | 724 | \f |
c906108c SS |
725 | |
726 | ||
c906108c SS |
727 | /* Generating bytecode from GDB expressions: literals */ |
728 | ||
729 | static void | |
fba45db2 KB |
730 | gen_int_literal (struct agent_expr *ax, struct axs_value *value, LONGEST k, |
731 | struct type *type) | |
c906108c SS |
732 | { |
733 | ax_const_l (ax, k); | |
734 | value->kind = axs_rvalue; | |
648027cc | 735 | value->type = check_typedef (type); |
c906108c | 736 | } |
c5aa993b | 737 | \f |
c906108c SS |
738 | |
739 | ||
c906108c SS |
740 | /* Generating bytecode from GDB expressions: unary conversions, casts */ |
741 | ||
742 | /* Take what's on the top of the stack (as described by VALUE), and | |
743 | try to make an rvalue out of it. Signal an error if we can't do | |
744 | that. */ | |
745 | static void | |
fba45db2 | 746 | require_rvalue (struct agent_expr *ax, struct axs_value *value) |
c906108c | 747 | { |
3a96536b SS |
748 | /* Only deal with scalars, structs and such may be too large |
749 | to fit in a stack entry. */ | |
750 | value->type = check_typedef (value->type); | |
751 | if (TYPE_CODE (value->type) == TYPE_CODE_ARRAY | |
752 | || TYPE_CODE (value->type) == TYPE_CODE_STRUCT | |
753 | || TYPE_CODE (value->type) == TYPE_CODE_UNION | |
754 | || TYPE_CODE (value->type) == TYPE_CODE_FUNC) | |
1c40aa62 | 755 | error (_("Value not scalar: cannot be an rvalue.")); |
3a96536b | 756 | |
c906108c SS |
757 | switch (value->kind) |
758 | { | |
759 | case axs_rvalue: | |
760 | /* It's already an rvalue. */ | |
761 | break; | |
762 | ||
763 | case axs_lvalue_memory: | |
764 | /* The top of stack is the address of the object. Dereference. */ | |
765 | gen_fetch (ax, value->type); | |
766 | break; | |
767 | ||
768 | case axs_lvalue_register: | |
769 | /* There's nothing on the stack, but value->u.reg is the | |
770 | register number containing the value. | |
771 | ||
c5aa993b JM |
772 | When we add floating-point support, this is going to have to |
773 | change. What about SPARC register pairs, for example? */ | |
c906108c SS |
774 | ax_reg (ax, value->u.reg); |
775 | gen_extend (ax, value->type); | |
776 | break; | |
777 | } | |
778 | ||
779 | value->kind = axs_rvalue; | |
780 | } | |
781 | ||
782 | ||
783 | /* Assume the top of the stack is described by VALUE, and perform the | |
784 | usual unary conversions. This is motivated by ANSI 6.2.2, but of | |
785 | course GDB expressions are not ANSI; they're the mishmash union of | |
786 | a bunch of languages. Rah. | |
787 | ||
788 | NOTE! This function promises to produce an rvalue only when the | |
789 | incoming value is of an appropriate type. In other words, the | |
790 | consumer of the value this function produces may assume the value | |
791 | is an rvalue only after checking its type. | |
792 | ||
793 | The immediate issue is that if the user tries to use a structure or | |
794 | union as an operand of, say, the `+' operator, we don't want to try | |
795 | to convert that structure to an rvalue; require_rvalue will bomb on | |
796 | structs and unions. Rather, we want to simply pass the struct | |
797 | lvalue through unchanged, and let `+' raise an error. */ | |
798 | ||
799 | static void | |
f7c79c41 UW |
800 | gen_usual_unary (struct expression *exp, struct agent_expr *ax, |
801 | struct axs_value *value) | |
c906108c SS |
802 | { |
803 | /* We don't have to generate any code for the usual integral | |
804 | conversions, since values are always represented as full-width on | |
805 | the stack. Should we tweak the type? */ | |
806 | ||
807 | /* Some types require special handling. */ | |
0004e5a2 | 808 | switch (TYPE_CODE (value->type)) |
c906108c SS |
809 | { |
810 | /* Functions get converted to a pointer to the function. */ | |
811 | case TYPE_CODE_FUNC: | |
812 | value->type = lookup_pointer_type (value->type); | |
813 | value->kind = axs_rvalue; /* Should always be true, but just in case. */ | |
814 | break; | |
815 | ||
816 | /* Arrays get converted to a pointer to their first element, and | |
c5aa993b | 817 | are no longer an lvalue. */ |
c906108c SS |
818 | case TYPE_CODE_ARRAY: |
819 | { | |
820 | struct type *elements = TYPE_TARGET_TYPE (value->type); | |
821 | value->type = lookup_pointer_type (elements); | |
822 | value->kind = axs_rvalue; | |
823 | /* We don't need to generate any code; the address of the array | |
824 | is also the address of its first element. */ | |
825 | } | |
c5aa993b | 826 | break; |
c906108c | 827 | |
c5aa993b JM |
828 | /* Don't try to convert structures and unions to rvalues. Let the |
829 | consumer signal an error. */ | |
c906108c SS |
830 | case TYPE_CODE_STRUCT: |
831 | case TYPE_CODE_UNION: | |
832 | return; | |
833 | ||
3b11a015 | 834 | /* If the value is an enum or a bool, call it an integer. */ |
c906108c | 835 | case TYPE_CODE_ENUM: |
3b11a015 | 836 | case TYPE_CODE_BOOL: |
f7c79c41 | 837 | value->type = builtin_type (exp->gdbarch)->builtin_int; |
c906108c SS |
838 | break; |
839 | } | |
840 | ||
841 | /* If the value is an lvalue, dereference it. */ | |
842 | require_rvalue (ax, value); | |
843 | } | |
844 | ||
845 | ||
846 | /* Return non-zero iff the type TYPE1 is considered "wider" than the | |
847 | type TYPE2, according to the rules described in gen_usual_arithmetic. */ | |
848 | static int | |
fba45db2 | 849 | type_wider_than (struct type *type1, struct type *type2) |
c906108c SS |
850 | { |
851 | return (TYPE_LENGTH (type1) > TYPE_LENGTH (type2) | |
852 | || (TYPE_LENGTH (type1) == TYPE_LENGTH (type2) | |
853 | && TYPE_UNSIGNED (type1) | |
c5aa993b | 854 | && !TYPE_UNSIGNED (type2))); |
c906108c SS |
855 | } |
856 | ||
857 | ||
858 | /* Return the "wider" of the two types TYPE1 and TYPE2. */ | |
859 | static struct type * | |
fba45db2 | 860 | max_type (struct type *type1, struct type *type2) |
c906108c SS |
861 | { |
862 | return type_wider_than (type1, type2) ? type1 : type2; | |
863 | } | |
864 | ||
865 | ||
866 | /* Generate code to convert a scalar value of type FROM to type TO. */ | |
867 | static void | |
fba45db2 | 868 | gen_conversion (struct agent_expr *ax, struct type *from, struct type *to) |
c906108c SS |
869 | { |
870 | /* Perhaps there is a more graceful way to state these rules. */ | |
871 | ||
872 | /* If we're converting to a narrower type, then we need to clear out | |
873 | the upper bits. */ | |
874 | if (TYPE_LENGTH (to) < TYPE_LENGTH (from)) | |
875 | gen_extend (ax, from); | |
876 | ||
877 | /* If the two values have equal width, but different signednesses, | |
878 | then we need to extend. */ | |
879 | else if (TYPE_LENGTH (to) == TYPE_LENGTH (from)) | |
880 | { | |
881 | if (TYPE_UNSIGNED (from) != TYPE_UNSIGNED (to)) | |
882 | gen_extend (ax, to); | |
883 | } | |
884 | ||
885 | /* If we're converting to a wider type, and becoming unsigned, then | |
886 | we need to zero out any possible sign bits. */ | |
887 | else if (TYPE_LENGTH (to) > TYPE_LENGTH (from)) | |
888 | { | |
889 | if (TYPE_UNSIGNED (to)) | |
890 | gen_extend (ax, to); | |
891 | } | |
892 | } | |
893 | ||
894 | ||
895 | /* Return non-zero iff the type FROM will require any bytecodes to be | |
896 | emitted to be converted to the type TO. */ | |
897 | static int | |
fba45db2 | 898 | is_nontrivial_conversion (struct type *from, struct type *to) |
c906108c | 899 | { |
35c9c7ba | 900 | struct agent_expr *ax = new_agent_expr (NULL, 0); |
c906108c SS |
901 | int nontrivial; |
902 | ||
903 | /* Actually generate the code, and see if anything came out. At the | |
904 | moment, it would be trivial to replicate the code in | |
905 | gen_conversion here, but in the future, when we're supporting | |
906 | floating point and the like, it may not be. Doing things this | |
907 | way allows this function to be independent of the logic in | |
908 | gen_conversion. */ | |
909 | gen_conversion (ax, from, to); | |
910 | nontrivial = ax->len > 0; | |
911 | free_agent_expr (ax); | |
912 | return nontrivial; | |
913 | } | |
914 | ||
915 | ||
916 | /* Generate code to perform the "usual arithmetic conversions" (ANSI C | |
917 | 6.2.1.5) for the two operands of an arithmetic operator. This | |
918 | effectively finds a "least upper bound" type for the two arguments, | |
919 | and promotes each argument to that type. *VALUE1 and *VALUE2 | |
920 | describe the values as they are passed in, and as they are left. */ | |
921 | static void | |
f7c79c41 UW |
922 | gen_usual_arithmetic (struct expression *exp, struct agent_expr *ax, |
923 | struct axs_value *value1, struct axs_value *value2) | |
c906108c SS |
924 | { |
925 | /* Do the usual binary conversions. */ | |
926 | if (TYPE_CODE (value1->type) == TYPE_CODE_INT | |
927 | && TYPE_CODE (value2->type) == TYPE_CODE_INT) | |
928 | { | |
929 | /* The ANSI integral promotions seem to work this way: Order the | |
c5aa993b JM |
930 | integer types by size, and then by signedness: an n-bit |
931 | unsigned type is considered "wider" than an n-bit signed | |
932 | type. Promote to the "wider" of the two types, and always | |
933 | promote at least to int. */ | |
f7c79c41 | 934 | struct type *target = max_type (builtin_type (exp->gdbarch)->builtin_int, |
c906108c SS |
935 | max_type (value1->type, value2->type)); |
936 | ||
937 | /* Deal with value2, on the top of the stack. */ | |
938 | gen_conversion (ax, value2->type, target); | |
939 | ||
940 | /* Deal with value1, not on the top of the stack. Don't | |
941 | generate the `swap' instructions if we're not actually going | |
942 | to do anything. */ | |
943 | if (is_nontrivial_conversion (value1->type, target)) | |
944 | { | |
945 | ax_simple (ax, aop_swap); | |
946 | gen_conversion (ax, value1->type, target); | |
947 | ax_simple (ax, aop_swap); | |
948 | } | |
949 | ||
648027cc | 950 | value1->type = value2->type = check_typedef (target); |
c906108c SS |
951 | } |
952 | } | |
953 | ||
954 | ||
955 | /* Generate code to perform the integral promotions (ANSI 6.2.1.1) on | |
956 | the value on the top of the stack, as described by VALUE. Assume | |
957 | the value has integral type. */ | |
958 | static void | |
f7c79c41 UW |
959 | gen_integral_promotions (struct expression *exp, struct agent_expr *ax, |
960 | struct axs_value *value) | |
c906108c | 961 | { |
f7c79c41 UW |
962 | const struct builtin_type *builtin = builtin_type (exp->gdbarch); |
963 | ||
964 | if (!type_wider_than (value->type, builtin->builtin_int)) | |
c906108c | 965 | { |
f7c79c41 UW |
966 | gen_conversion (ax, value->type, builtin->builtin_int); |
967 | value->type = builtin->builtin_int; | |
c906108c | 968 | } |
f7c79c41 | 969 | else if (!type_wider_than (value->type, builtin->builtin_unsigned_int)) |
c906108c | 970 | { |
f7c79c41 UW |
971 | gen_conversion (ax, value->type, builtin->builtin_unsigned_int); |
972 | value->type = builtin->builtin_unsigned_int; | |
c906108c SS |
973 | } |
974 | } | |
975 | ||
976 | ||
977 | /* Generate code for a cast to TYPE. */ | |
978 | static void | |
fba45db2 | 979 | gen_cast (struct agent_expr *ax, struct axs_value *value, struct type *type) |
c906108c SS |
980 | { |
981 | /* GCC does allow casts to yield lvalues, so this should be fixed | |
982 | before merging these changes into the trunk. */ | |
983 | require_rvalue (ax, value); | |
984 | /* Dereference typedefs. */ | |
985 | type = check_typedef (type); | |
986 | ||
0004e5a2 | 987 | switch (TYPE_CODE (type)) |
c906108c SS |
988 | { |
989 | case TYPE_CODE_PTR: | |
b97aedf3 | 990 | case TYPE_CODE_REF: |
c906108c SS |
991 | /* It's implementation-defined, and I'll bet this is what GCC |
992 | does. */ | |
993 | break; | |
994 | ||
995 | case TYPE_CODE_ARRAY: | |
996 | case TYPE_CODE_STRUCT: | |
997 | case TYPE_CODE_UNION: | |
998 | case TYPE_CODE_FUNC: | |
3d263c1d | 999 | error (_("Invalid type cast: intended type must be scalar.")); |
c906108c SS |
1000 | |
1001 | case TYPE_CODE_ENUM: | |
3b11a015 | 1002 | case TYPE_CODE_BOOL: |
c906108c SS |
1003 | /* We don't have to worry about the size of the value, because |
1004 | all our integral values are fully sign-extended, and when | |
1005 | casting pointers we can do anything we like. Is there any | |
74b35824 JB |
1006 | way for us to know what GCC actually does with a cast like |
1007 | this? */ | |
c906108c | 1008 | break; |
c5aa993b | 1009 | |
c906108c SS |
1010 | case TYPE_CODE_INT: |
1011 | gen_conversion (ax, value->type, type); | |
1012 | break; | |
1013 | ||
1014 | case TYPE_CODE_VOID: | |
1015 | /* We could pop the value, and rely on everyone else to check | |
c5aa993b JM |
1016 | the type and notice that this value doesn't occupy a stack |
1017 | slot. But for now, leave the value on the stack, and | |
1018 | preserve the "value == stack element" assumption. */ | |
c906108c SS |
1019 | break; |
1020 | ||
1021 | default: | |
3d263c1d | 1022 | error (_("Casts to requested type are not yet implemented.")); |
c906108c SS |
1023 | } |
1024 | ||
1025 | value->type = type; | |
1026 | } | |
c5aa993b | 1027 | \f |
c906108c SS |
1028 | |
1029 | ||
c906108c SS |
1030 | /* Generating bytecode from GDB expressions: arithmetic */ |
1031 | ||
1032 | /* Scale the integer on the top of the stack by the size of the target | |
1033 | of the pointer type TYPE. */ | |
1034 | static void | |
fba45db2 | 1035 | gen_scale (struct agent_expr *ax, enum agent_op op, struct type *type) |
c906108c SS |
1036 | { |
1037 | struct type *element = TYPE_TARGET_TYPE (type); | |
1038 | ||
0004e5a2 | 1039 | if (TYPE_LENGTH (element) != 1) |
c906108c | 1040 | { |
0004e5a2 | 1041 | ax_const_l (ax, TYPE_LENGTH (element)); |
c906108c SS |
1042 | ax_simple (ax, op); |
1043 | } | |
1044 | } | |
1045 | ||
1046 | ||
f7c79c41 | 1047 | /* Generate code for pointer arithmetic PTR + INT. */ |
c906108c | 1048 | static void |
f7c79c41 UW |
1049 | gen_ptradd (struct agent_expr *ax, struct axs_value *value, |
1050 | struct axs_value *value1, struct axs_value *value2) | |
c906108c | 1051 | { |
b97aedf3 | 1052 | gdb_assert (pointer_type (value1->type)); |
f7c79c41 | 1053 | gdb_assert (TYPE_CODE (value2->type) == TYPE_CODE_INT); |
c906108c | 1054 | |
f7c79c41 UW |
1055 | gen_scale (ax, aop_mul, value1->type); |
1056 | ax_simple (ax, aop_add); | |
1057 | gen_extend (ax, value1->type); /* Catch overflow. */ | |
1058 | value->type = value1->type; | |
1059 | value->kind = axs_rvalue; | |
1060 | } | |
c906108c | 1061 | |
c906108c | 1062 | |
f7c79c41 UW |
1063 | /* Generate code for pointer arithmetic PTR - INT. */ |
1064 | static void | |
1065 | gen_ptrsub (struct agent_expr *ax, struct axs_value *value, | |
1066 | struct axs_value *value1, struct axs_value *value2) | |
1067 | { | |
b97aedf3 | 1068 | gdb_assert (pointer_type (value1->type)); |
f7c79c41 | 1069 | gdb_assert (TYPE_CODE (value2->type) == TYPE_CODE_INT); |
c906108c | 1070 | |
f7c79c41 UW |
1071 | gen_scale (ax, aop_mul, value1->type); |
1072 | ax_simple (ax, aop_sub); | |
1073 | gen_extend (ax, value1->type); /* Catch overflow. */ | |
1074 | value->type = value1->type; | |
c906108c SS |
1075 | value->kind = axs_rvalue; |
1076 | } | |
1077 | ||
1078 | ||
f7c79c41 | 1079 | /* Generate code for pointer arithmetic PTR - PTR. */ |
c906108c | 1080 | static void |
f7c79c41 UW |
1081 | gen_ptrdiff (struct agent_expr *ax, struct axs_value *value, |
1082 | struct axs_value *value1, struct axs_value *value2, | |
1083 | struct type *result_type) | |
c906108c | 1084 | { |
b97aedf3 SS |
1085 | gdb_assert (pointer_type (value1->type)); |
1086 | gdb_assert (pointer_type (value2->type)); | |
c906108c | 1087 | |
f7c79c41 UW |
1088 | if (TYPE_LENGTH (TYPE_TARGET_TYPE (value1->type)) |
1089 | != TYPE_LENGTH (TYPE_TARGET_TYPE (value2->type))) | |
1090 | error (_("\ | |
c906108c | 1091 | First argument of `-' is a pointer, but second argument is neither\n\ |
3d263c1d | 1092 | an integer nor a pointer of the same type.")); |
c906108c | 1093 | |
f7c79c41 UW |
1094 | ax_simple (ax, aop_sub); |
1095 | gen_scale (ax, aop_div_unsigned, value1->type); | |
1096 | value->type = result_type; | |
c906108c SS |
1097 | value->kind = axs_rvalue; |
1098 | } | |
1099 | ||
3b11a015 SS |
1100 | static void |
1101 | gen_equal (struct agent_expr *ax, struct axs_value *value, | |
1102 | struct axs_value *value1, struct axs_value *value2, | |
1103 | struct type *result_type) | |
1104 | { | |
1105 | if (pointer_type (value1->type) || pointer_type (value2->type)) | |
1106 | ax_simple (ax, aop_equal); | |
1107 | else | |
1108 | gen_binop (ax, value, value1, value2, | |
1109 | aop_equal, aop_equal, 0, "equal"); | |
1110 | value->type = result_type; | |
1111 | value->kind = axs_rvalue; | |
1112 | } | |
1113 | ||
1114 | static void | |
1115 | gen_less (struct agent_expr *ax, struct axs_value *value, | |
1116 | struct axs_value *value1, struct axs_value *value2, | |
1117 | struct type *result_type) | |
1118 | { | |
1119 | if (pointer_type (value1->type) || pointer_type (value2->type)) | |
1120 | ax_simple (ax, aop_less_unsigned); | |
1121 | else | |
1122 | gen_binop (ax, value, value1, value2, | |
1123 | aop_less_signed, aop_less_unsigned, 0, "less than"); | |
1124 | value->type = result_type; | |
1125 | value->kind = axs_rvalue; | |
1126 | } | |
f7c79c41 | 1127 | |
c906108c SS |
1128 | /* Generate code for a binary operator that doesn't do pointer magic. |
1129 | We set VALUE to describe the result value; we assume VALUE1 and | |
1130 | VALUE2 describe the two operands, and that they've undergone the | |
1131 | usual binary conversions. MAY_CARRY should be non-zero iff the | |
1132 | result needs to be extended. NAME is the English name of the | |
1133 | operator, used in error messages */ | |
1134 | static void | |
fba45db2 KB |
1135 | gen_binop (struct agent_expr *ax, struct axs_value *value, |
1136 | struct axs_value *value1, struct axs_value *value2, enum agent_op op, | |
1137 | enum agent_op op_unsigned, int may_carry, char *name) | |
c906108c SS |
1138 | { |
1139 | /* We only handle INT op INT. */ | |
0004e5a2 DJ |
1140 | if ((TYPE_CODE (value1->type) != TYPE_CODE_INT) |
1141 | || (TYPE_CODE (value2->type) != TYPE_CODE_INT)) | |
3d263c1d | 1142 | error (_("Invalid combination of types in %s."), name); |
c5aa993b | 1143 | |
c906108c SS |
1144 | ax_simple (ax, |
1145 | TYPE_UNSIGNED (value1->type) ? op_unsigned : op); | |
1146 | if (may_carry) | |
c5aa993b | 1147 | gen_extend (ax, value1->type); /* catch overflow */ |
c906108c SS |
1148 | value->type = value1->type; |
1149 | value->kind = axs_rvalue; | |
1150 | } | |
1151 | ||
1152 | ||
1153 | static void | |
f7c79c41 UW |
1154 | gen_logical_not (struct agent_expr *ax, struct axs_value *value, |
1155 | struct type *result_type) | |
c906108c SS |
1156 | { |
1157 | if (TYPE_CODE (value->type) != TYPE_CODE_INT | |
1158 | && TYPE_CODE (value->type) != TYPE_CODE_PTR) | |
3d263c1d | 1159 | error (_("Invalid type of operand to `!'.")); |
c906108c | 1160 | |
c906108c | 1161 | ax_simple (ax, aop_log_not); |
f7c79c41 | 1162 | value->type = result_type; |
c906108c SS |
1163 | } |
1164 | ||
1165 | ||
1166 | static void | |
fba45db2 | 1167 | gen_complement (struct agent_expr *ax, struct axs_value *value) |
c906108c SS |
1168 | { |
1169 | if (TYPE_CODE (value->type) != TYPE_CODE_INT) | |
3d263c1d | 1170 | error (_("Invalid type of operand to `~'.")); |
c906108c | 1171 | |
c906108c SS |
1172 | ax_simple (ax, aop_bit_not); |
1173 | gen_extend (ax, value->type); | |
1174 | } | |
c5aa993b | 1175 | \f |
c906108c SS |
1176 | |
1177 | ||
c906108c SS |
1178 | /* Generating bytecode from GDB expressions: * & . -> @ sizeof */ |
1179 | ||
1180 | /* Dereference the value on the top of the stack. */ | |
1181 | static void | |
fba45db2 | 1182 | gen_deref (struct agent_expr *ax, struct axs_value *value) |
c906108c SS |
1183 | { |
1184 | /* The caller should check the type, because several operators use | |
1185 | this, and we don't know what error message to generate. */ | |
b97aedf3 | 1186 | if (!pointer_type (value->type)) |
8e65ff28 | 1187 | internal_error (__FILE__, __LINE__, |
3d263c1d | 1188 | _("gen_deref: expected a pointer")); |
c906108c SS |
1189 | |
1190 | /* We've got an rvalue now, which is a pointer. We want to yield an | |
1191 | lvalue, whose address is exactly that pointer. So we don't | |
1192 | actually emit any code; we just change the type from "Pointer to | |
1193 | T" to "T", and mark the value as an lvalue in memory. Leave it | |
1194 | to the consumer to actually dereference it. */ | |
1195 | value->type = check_typedef (TYPE_TARGET_TYPE (value->type)); | |
b1028c8e PA |
1196 | if (TYPE_CODE (value->type) == TYPE_CODE_VOID) |
1197 | error (_("Attempt to dereference a generic pointer.")); | |
0004e5a2 | 1198 | value->kind = ((TYPE_CODE (value->type) == TYPE_CODE_FUNC) |
c906108c SS |
1199 | ? axs_rvalue : axs_lvalue_memory); |
1200 | } | |
1201 | ||
1202 | ||
1203 | /* Produce the address of the lvalue on the top of the stack. */ | |
1204 | static void | |
fba45db2 | 1205 | gen_address_of (struct agent_expr *ax, struct axs_value *value) |
c906108c SS |
1206 | { |
1207 | /* Special case for taking the address of a function. The ANSI | |
1208 | standard describes this as a special case, too, so this | |
1209 | arrangement is not without motivation. */ | |
0004e5a2 | 1210 | if (TYPE_CODE (value->type) == TYPE_CODE_FUNC) |
c906108c SS |
1211 | /* The value's already an rvalue on the stack, so we just need to |
1212 | change the type. */ | |
1213 | value->type = lookup_pointer_type (value->type); | |
1214 | else | |
1215 | switch (value->kind) | |
1216 | { | |
1217 | case axs_rvalue: | |
3d263c1d | 1218 | error (_("Operand of `&' is an rvalue, which has no address.")); |
c906108c SS |
1219 | |
1220 | case axs_lvalue_register: | |
3d263c1d | 1221 | error (_("Operand of `&' is in a register, and has no address.")); |
c906108c SS |
1222 | |
1223 | case axs_lvalue_memory: | |
1224 | value->kind = axs_rvalue; | |
1225 | value->type = lookup_pointer_type (value->type); | |
1226 | break; | |
1227 | } | |
1228 | } | |
1229 | ||
c906108c SS |
1230 | /* Generate code to push the value of a bitfield of a structure whose |
1231 | address is on the top of the stack. START and END give the | |
1232 | starting and one-past-ending *bit* numbers of the field within the | |
1233 | structure. */ | |
1234 | static void | |
505e835d UW |
1235 | gen_bitfield_ref (struct expression *exp, struct agent_expr *ax, |
1236 | struct axs_value *value, struct type *type, | |
1237 | int start, int end) | |
c906108c SS |
1238 | { |
1239 | /* Note that ops[i] fetches 8 << i bits. */ | |
1240 | static enum agent_op ops[] | |
c5aa993b JM |
1241 | = |
1242 | {aop_ref8, aop_ref16, aop_ref32, aop_ref64}; | |
c906108c SS |
1243 | static int num_ops = (sizeof (ops) / sizeof (ops[0])); |
1244 | ||
1245 | /* We don't want to touch any byte that the bitfield doesn't | |
1246 | actually occupy; we shouldn't make any accesses we're not | |
1247 | explicitly permitted to. We rely here on the fact that the | |
1248 | bytecode `ref' operators work on unaligned addresses. | |
1249 | ||
1250 | It takes some fancy footwork to get the stack to work the way | |
1251 | we'd like. Say we're retrieving a bitfield that requires three | |
1252 | fetches. Initially, the stack just contains the address: | |
c5aa993b | 1253 | addr |
c906108c | 1254 | For the first fetch, we duplicate the address |
c5aa993b | 1255 | addr addr |
c906108c SS |
1256 | then add the byte offset, do the fetch, and shift and mask as |
1257 | needed, yielding a fragment of the value, properly aligned for | |
1258 | the final bitwise or: | |
c5aa993b | 1259 | addr frag1 |
c906108c | 1260 | then we swap, and repeat the process: |
c5aa993b JM |
1261 | frag1 addr --- address on top |
1262 | frag1 addr addr --- duplicate it | |
1263 | frag1 addr frag2 --- get second fragment | |
1264 | frag1 frag2 addr --- swap again | |
1265 | frag1 frag2 frag3 --- get third fragment | |
c906108c SS |
1266 | Notice that, since the third fragment is the last one, we don't |
1267 | bother duplicating the address this time. Now we have all the | |
1268 | fragments on the stack, and we can simply `or' them together, | |
1269 | yielding the final value of the bitfield. */ | |
1270 | ||
1271 | /* The first and one-after-last bits in the field, but rounded down | |
1272 | and up to byte boundaries. */ | |
1273 | int bound_start = (start / TARGET_CHAR_BIT) * TARGET_CHAR_BIT; | |
c5aa993b JM |
1274 | int bound_end = (((end + TARGET_CHAR_BIT - 1) |
1275 | / TARGET_CHAR_BIT) | |
1276 | * TARGET_CHAR_BIT); | |
c906108c SS |
1277 | |
1278 | /* current bit offset within the structure */ | |
1279 | int offset; | |
1280 | ||
1281 | /* The index in ops of the opcode we're considering. */ | |
1282 | int op; | |
1283 | ||
1284 | /* The number of fragments we generated in the process. Probably | |
1285 | equal to the number of `one' bits in bytesize, but who cares? */ | |
1286 | int fragment_count; | |
1287 | ||
1288 | /* Dereference any typedefs. */ | |
1289 | type = check_typedef (type); | |
1290 | ||
1291 | /* Can we fetch the number of bits requested at all? */ | |
1292 | if ((end - start) > ((1 << num_ops) * 8)) | |
8e65ff28 | 1293 | internal_error (__FILE__, __LINE__, |
3d263c1d | 1294 | _("gen_bitfield_ref: bitfield too wide")); |
c906108c SS |
1295 | |
1296 | /* Note that we know here that we only need to try each opcode once. | |
1297 | That may not be true on machines with weird byte sizes. */ | |
1298 | offset = bound_start; | |
1299 | fragment_count = 0; | |
1300 | for (op = num_ops - 1; op >= 0; op--) | |
1301 | { | |
1302 | /* number of bits that ops[op] would fetch */ | |
1303 | int op_size = 8 << op; | |
1304 | ||
1305 | /* The stack at this point, from bottom to top, contains zero or | |
c5aa993b JM |
1306 | more fragments, then the address. */ |
1307 | ||
c906108c SS |
1308 | /* Does this fetch fit within the bitfield? */ |
1309 | if (offset + op_size <= bound_end) | |
1310 | { | |
1311 | /* Is this the last fragment? */ | |
1312 | int last_frag = (offset + op_size == bound_end); | |
1313 | ||
c5aa993b JM |
1314 | if (!last_frag) |
1315 | ax_simple (ax, aop_dup); /* keep a copy of the address */ | |
1316 | ||
c906108c SS |
1317 | /* Add the offset. */ |
1318 | gen_offset (ax, offset / TARGET_CHAR_BIT); | |
1319 | ||
1320 | if (trace_kludge) | |
1321 | { | |
1322 | /* Record the area of memory we're about to fetch. */ | |
1323 | ax_trace_quick (ax, op_size / TARGET_CHAR_BIT); | |
1324 | } | |
1325 | ||
1326 | /* Perform the fetch. */ | |
1327 | ax_simple (ax, ops[op]); | |
c5aa993b JM |
1328 | |
1329 | /* Shift the bits we have to their proper position. | |
c906108c SS |
1330 | gen_left_shift will generate right shifts when the operand |
1331 | is negative. | |
1332 | ||
c5aa993b JM |
1333 | A big-endian field diagram to ponder: |
1334 | byte 0 byte 1 byte 2 byte 3 byte 4 byte 5 byte 6 byte 7 | |
1335 | +------++------++------++------++------++------++------++------+ | |
1336 | xxxxAAAAAAAAAAAAAAAAAAAAAAAAAAAABBBBBBBBBBBBBBBBCCCCCxxxxxxxxxxx | |
1337 | ^ ^ ^ ^ | |
1338 | bit number 16 32 48 53 | |
c906108c SS |
1339 | These are bit numbers as supplied by GDB. Note that the |
1340 | bit numbers run from right to left once you've fetched the | |
1341 | value! | |
1342 | ||
c5aa993b JM |
1343 | A little-endian field diagram to ponder: |
1344 | byte 7 byte 6 byte 5 byte 4 byte 3 byte 2 byte 1 byte 0 | |
1345 | +------++------++------++------++------++------++------++------+ | |
1346 | xxxxxxxxxxxAAAAABBBBBBBBBBBBBBBBCCCCCCCCCCCCCCCCCCCCCCCCCCCCxxxx | |
1347 | ^ ^ ^ ^ ^ | |
1348 | bit number 48 32 16 4 0 | |
1349 | ||
1350 | In both cases, the most significant end is on the left | |
1351 | (i.e. normal numeric writing order), which means that you | |
1352 | don't go crazy thinking about `left' and `right' shifts. | |
1353 | ||
1354 | We don't have to worry about masking yet: | |
1355 | - If they contain garbage off the least significant end, then we | |
1356 | must be looking at the low end of the field, and the right | |
1357 | shift will wipe them out. | |
1358 | - If they contain garbage off the most significant end, then we | |
1359 | must be looking at the most significant end of the word, and | |
1360 | the sign/zero extension will wipe them out. | |
1361 | - If we're in the interior of the word, then there is no garbage | |
1362 | on either end, because the ref operators zero-extend. */ | |
505e835d | 1363 | if (gdbarch_byte_order (exp->gdbarch) == BFD_ENDIAN_BIG) |
c906108c | 1364 | gen_left_shift (ax, end - (offset + op_size)); |
c5aa993b | 1365 | else |
c906108c SS |
1366 | gen_left_shift (ax, offset - start); |
1367 | ||
c5aa993b | 1368 | if (!last_frag) |
c906108c SS |
1369 | /* Bring the copy of the address up to the top. */ |
1370 | ax_simple (ax, aop_swap); | |
1371 | ||
1372 | offset += op_size; | |
1373 | fragment_count++; | |
1374 | } | |
1375 | } | |
1376 | ||
1377 | /* Generate enough bitwise `or' operations to combine all the | |
1378 | fragments we left on the stack. */ | |
1379 | while (fragment_count-- > 1) | |
1380 | ax_simple (ax, aop_bit_or); | |
1381 | ||
1382 | /* Sign- or zero-extend the value as appropriate. */ | |
1383 | ((TYPE_UNSIGNED (type) ? ax_zero_ext : ax_ext) (ax, end - start)); | |
1384 | ||
1385 | /* This is *not* an lvalue. Ugh. */ | |
1386 | value->kind = axs_rvalue; | |
1387 | value->type = type; | |
1388 | } | |
1389 | ||
b6e7192f SS |
1390 | /* Generate bytecodes for field number FIELDNO of type TYPE. OFFSET |
1391 | is an accumulated offset (in bytes), will be nonzero for objects | |
1392 | embedded in other objects, like C++ base classes. Behavior should | |
1393 | generally follow value_primitive_field. */ | |
1394 | ||
1395 | static void | |
1396 | gen_primitive_field (struct expression *exp, | |
1397 | struct agent_expr *ax, struct axs_value *value, | |
1398 | int offset, int fieldno, struct type *type) | |
1399 | { | |
1400 | /* Is this a bitfield? */ | |
1401 | if (TYPE_FIELD_PACKED (type, fieldno)) | |
1402 | gen_bitfield_ref (exp, ax, value, TYPE_FIELD_TYPE (type, fieldno), | |
1403 | (offset * TARGET_CHAR_BIT | |
1404 | + TYPE_FIELD_BITPOS (type, fieldno)), | |
1405 | (offset * TARGET_CHAR_BIT | |
1406 | + TYPE_FIELD_BITPOS (type, fieldno) | |
1407 | + TYPE_FIELD_BITSIZE (type, fieldno))); | |
1408 | else | |
1409 | { | |
1410 | gen_offset (ax, offset | |
1411 | + TYPE_FIELD_BITPOS (type, fieldno) / TARGET_CHAR_BIT); | |
1412 | value->kind = axs_lvalue_memory; | |
1413 | value->type = TYPE_FIELD_TYPE (type, fieldno); | |
1414 | } | |
1415 | } | |
1416 | ||
1417 | /* Search for the given field in either the given type or one of its | |
1418 | base classes. Return 1 if found, 0 if not. */ | |
1419 | ||
1420 | static int | |
1421 | gen_struct_ref_recursive (struct expression *exp, struct agent_expr *ax, | |
1422 | struct axs_value *value, | |
1423 | char *field, int offset, struct type *type) | |
1424 | { | |
1425 | int i, rslt; | |
1426 | int nbases = TYPE_N_BASECLASSES (type); | |
1427 | ||
1428 | CHECK_TYPEDEF (type); | |
1429 | ||
1430 | for (i = TYPE_NFIELDS (type) - 1; i >= nbases; i--) | |
1431 | { | |
1432 | char *this_name = TYPE_FIELD_NAME (type, i); | |
1433 | ||
1434 | if (this_name) | |
1435 | { | |
1436 | if (strcmp (field, this_name) == 0) | |
1437 | { | |
1438 | /* Note that bytecodes for the struct's base (aka | |
1439 | "this") will have been generated already, which will | |
1440 | be unnecessary but not harmful if the static field is | |
1441 | being handled as a global. */ | |
1442 | if (field_is_static (&TYPE_FIELD (type, i))) | |
1443 | { | |
400c6af0 SS |
1444 | gen_static_field (exp->gdbarch, ax, value, type, i); |
1445 | if (value->optimized_out) | |
1446 | error (_("static field `%s' has been optimized out, cannot use"), | |
1447 | field); | |
b6e7192f SS |
1448 | return 1; |
1449 | } | |
1450 | ||
1451 | gen_primitive_field (exp, ax, value, offset, i, type); | |
1452 | return 1; | |
1453 | } | |
1454 | #if 0 /* is this right? */ | |
1455 | if (this_name[0] == '\0') | |
1456 | internal_error (__FILE__, __LINE__, | |
1457 | _("find_field: anonymous unions not supported")); | |
1458 | #endif | |
1459 | } | |
1460 | } | |
1461 | ||
1462 | /* Now scan through base classes recursively. */ | |
1463 | for (i = 0; i < nbases; i++) | |
1464 | { | |
1465 | struct type *basetype = check_typedef (TYPE_BASECLASS (type, i)); | |
1466 | ||
1467 | rslt = gen_struct_ref_recursive (exp, ax, value, field, | |
1468 | offset + TYPE_BASECLASS_BITPOS (type, i) / TARGET_CHAR_BIT, | |
1469 | basetype); | |
1470 | if (rslt) | |
1471 | return 1; | |
1472 | } | |
1473 | ||
1474 | /* Not found anywhere, flag so caller can complain. */ | |
1475 | return 0; | |
1476 | } | |
c906108c SS |
1477 | |
1478 | /* Generate code to reference the member named FIELD of a structure or | |
1479 | union. The top of the stack, as described by VALUE, should have | |
1480 | type (pointer to a)* struct/union. OPERATOR_NAME is the name of | |
1481 | the operator being compiled, and OPERAND_NAME is the kind of thing | |
1482 | it operates on; we use them in error messages. */ | |
1483 | static void | |
505e835d UW |
1484 | gen_struct_ref (struct expression *exp, struct agent_expr *ax, |
1485 | struct axs_value *value, char *field, | |
fba45db2 | 1486 | char *operator_name, char *operand_name) |
c906108c SS |
1487 | { |
1488 | struct type *type; | |
b6e7192f | 1489 | int found; |
c906108c SS |
1490 | |
1491 | /* Follow pointers until we reach a non-pointer. These aren't the C | |
1492 | semantics, but they're what the normal GDB evaluator does, so we | |
1493 | should at least be consistent. */ | |
b97aedf3 | 1494 | while (pointer_type (value->type)) |
c906108c | 1495 | { |
f7c79c41 | 1496 | require_rvalue (ax, value); |
c906108c SS |
1497 | gen_deref (ax, value); |
1498 | } | |
e8860ec2 | 1499 | type = check_typedef (value->type); |
c906108c SS |
1500 | |
1501 | /* This must yield a structure or a union. */ | |
1502 | if (TYPE_CODE (type) != TYPE_CODE_STRUCT | |
1503 | && TYPE_CODE (type) != TYPE_CODE_UNION) | |
3d263c1d | 1504 | error (_("The left operand of `%s' is not a %s."), |
c906108c SS |
1505 | operator_name, operand_name); |
1506 | ||
1507 | /* And it must be in memory; we don't deal with structure rvalues, | |
1508 | or structures living in registers. */ | |
1509 | if (value->kind != axs_lvalue_memory) | |
3d263c1d | 1510 | error (_("Structure does not live in memory.")); |
c906108c | 1511 | |
b6e7192f SS |
1512 | /* Search through fields and base classes recursively. */ |
1513 | found = gen_struct_ref_recursive (exp, ax, value, field, 0, type); | |
1514 | ||
1515 | if (!found) | |
1516 | error (_("Couldn't find member named `%s' in struct/union/class `%s'"), | |
1517 | field, TYPE_TAG_NAME (type)); | |
1518 | } | |
c5aa993b | 1519 | |
b6e7192f SS |
1520 | static int |
1521 | gen_namespace_elt (struct expression *exp, | |
1522 | struct agent_expr *ax, struct axs_value *value, | |
1523 | const struct type *curtype, char *name); | |
1524 | static int | |
1525 | gen_maybe_namespace_elt (struct expression *exp, | |
1526 | struct agent_expr *ax, struct axs_value *value, | |
1527 | const struct type *curtype, char *name); | |
1528 | ||
1529 | static void | |
400c6af0 | 1530 | gen_static_field (struct gdbarch *gdbarch, |
b6e7192f SS |
1531 | struct agent_expr *ax, struct axs_value *value, |
1532 | struct type *type, int fieldno) | |
1533 | { | |
1534 | if (TYPE_FIELD_LOC_KIND (type, fieldno) == FIELD_LOC_KIND_PHYSADDR) | |
c906108c | 1535 | { |
b6e7192f | 1536 | ax_const_l (ax, TYPE_FIELD_STATIC_PHYSADDR (type, fieldno)); |
c906108c | 1537 | value->kind = axs_lvalue_memory; |
b6e7192f | 1538 | value->type = TYPE_FIELD_TYPE (type, fieldno); |
400c6af0 | 1539 | value->optimized_out = 0; |
b6e7192f SS |
1540 | } |
1541 | else | |
1542 | { | |
1543 | char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno); | |
1544 | struct symbol *sym = lookup_symbol (phys_name, 0, VAR_DOMAIN, 0); | |
b6e7192f | 1545 | |
400c6af0 SS |
1546 | if (sym) |
1547 | { | |
1548 | gen_var_ref (gdbarch, ax, value, sym); | |
1549 | ||
1550 | /* Don't error if the value was optimized out, we may be | |
1551 | scanning all static fields and just want to pass over this | |
1552 | and continue with the rest. */ | |
1553 | } | |
1554 | else | |
1555 | { | |
1556 | /* Silently assume this was optimized out; class printing | |
1557 | will let the user know why the data is missing. */ | |
1558 | value->optimized_out = 1; | |
1559 | } | |
b6e7192f SS |
1560 | } |
1561 | } | |
1562 | ||
1563 | static int | |
1564 | gen_struct_elt_for_reference (struct expression *exp, | |
1565 | struct agent_expr *ax, struct axs_value *value, | |
1566 | struct type *type, char *fieldname) | |
1567 | { | |
1568 | struct type *t = type; | |
1569 | int i; | |
b6e7192f SS |
1570 | |
1571 | if (TYPE_CODE (t) != TYPE_CODE_STRUCT | |
1572 | && TYPE_CODE (t) != TYPE_CODE_UNION) | |
1573 | internal_error (__FILE__, __LINE__, | |
1574 | _("non-aggregate type to gen_struct_elt_for_reference")); | |
1575 | ||
1576 | for (i = TYPE_NFIELDS (t) - 1; i >= TYPE_N_BASECLASSES (t); i--) | |
1577 | { | |
1578 | char *t_field_name = TYPE_FIELD_NAME (t, i); | |
1579 | ||
1580 | if (t_field_name && strcmp (t_field_name, fieldname) == 0) | |
1581 | { | |
1582 | if (field_is_static (&TYPE_FIELD (t, i))) | |
1583 | { | |
400c6af0 SS |
1584 | gen_static_field (exp->gdbarch, ax, value, t, i); |
1585 | if (value->optimized_out) | |
1586 | error (_("static field `%s' has been optimized out, cannot use"), | |
1587 | fieldname); | |
b6e7192f SS |
1588 | return 1; |
1589 | } | |
1590 | if (TYPE_FIELD_PACKED (t, i)) | |
1591 | error (_("pointers to bitfield members not allowed")); | |
1592 | ||
1593 | /* FIXME we need a way to do "want_address" equivalent */ | |
1594 | ||
1595 | error (_("Cannot reference non-static field \"%s\""), fieldname); | |
1596 | } | |
c906108c | 1597 | } |
b6e7192f SS |
1598 | |
1599 | /* FIXME add other scoped-reference cases here */ | |
1600 | ||
1601 | /* Do a last-ditch lookup. */ | |
1602 | return gen_maybe_namespace_elt (exp, ax, value, type, fieldname); | |
c906108c SS |
1603 | } |
1604 | ||
b6e7192f SS |
1605 | /* C++: Return the member NAME of the namespace given by the type |
1606 | CURTYPE. */ | |
1607 | ||
1608 | static int | |
1609 | gen_namespace_elt (struct expression *exp, | |
1610 | struct agent_expr *ax, struct axs_value *value, | |
1611 | const struct type *curtype, char *name) | |
1612 | { | |
1613 | int found = gen_maybe_namespace_elt (exp, ax, value, curtype, name); | |
1614 | ||
1615 | if (!found) | |
1616 | error (_("No symbol \"%s\" in namespace \"%s\"."), | |
1617 | name, TYPE_TAG_NAME (curtype)); | |
1618 | ||
1619 | return found; | |
1620 | } | |
1621 | ||
1622 | /* A helper function used by value_namespace_elt and | |
1623 | value_struct_elt_for_reference. It looks up NAME inside the | |
1624 | context CURTYPE; this works if CURTYPE is a namespace or if CURTYPE | |
1625 | is a class and NAME refers to a type in CURTYPE itself (as opposed | |
1626 | to, say, some base class of CURTYPE). */ | |
1627 | ||
1628 | static int | |
1629 | gen_maybe_namespace_elt (struct expression *exp, | |
1630 | struct agent_expr *ax, struct axs_value *value, | |
1631 | const struct type *curtype, char *name) | |
1632 | { | |
1633 | const char *namespace_name = TYPE_TAG_NAME (curtype); | |
1634 | struct symbol *sym; | |
1635 | ||
1636 | sym = cp_lookup_symbol_namespace (namespace_name, name, | |
1637 | block_for_pc (ax->scope), | |
ac0cd78b | 1638 | VAR_DOMAIN); |
b6e7192f SS |
1639 | |
1640 | if (sym == NULL) | |
1641 | return 0; | |
1642 | ||
1643 | gen_var_ref (exp->gdbarch, ax, value, sym); | |
1644 | ||
400c6af0 SS |
1645 | if (value->optimized_out) |
1646 | error (_("`%s' has been optimized out, cannot use"), | |
1647 | SYMBOL_PRINT_NAME (sym)); | |
1648 | ||
b6e7192f SS |
1649 | return 1; |
1650 | } | |
1651 | ||
1652 | ||
1653 | static int | |
1654 | gen_aggregate_elt_ref (struct expression *exp, | |
1655 | struct agent_expr *ax, struct axs_value *value, | |
1656 | struct type *type, char *field, | |
1657 | char *operator_name, char *operand_name) | |
1658 | { | |
1659 | switch (TYPE_CODE (type)) | |
1660 | { | |
1661 | case TYPE_CODE_STRUCT: | |
1662 | case TYPE_CODE_UNION: | |
1663 | return gen_struct_elt_for_reference (exp, ax, value, type, field); | |
1664 | break; | |
1665 | case TYPE_CODE_NAMESPACE: | |
1666 | return gen_namespace_elt (exp, ax, value, type, field); | |
1667 | break; | |
1668 | default: | |
1669 | internal_error (__FILE__, __LINE__, | |
1670 | _("non-aggregate type in gen_aggregate_elt_ref")); | |
1671 | } | |
1672 | ||
1673 | return 0; | |
1674 | } | |
c906108c SS |
1675 | |
1676 | /* Generate code for GDB's magical `repeat' operator. | |
1677 | LVALUE @ INT creates an array INT elements long, and whose elements | |
1678 | have the same type as LVALUE, located in memory so that LVALUE is | |
1679 | its first element. For example, argv[0]@argc gives you the array | |
1680 | of command-line arguments. | |
1681 | ||
1682 | Unfortunately, because we have to know the types before we actually | |
1683 | have a value for the expression, we can't implement this perfectly | |
1684 | without changing the type system, having values that occupy two | |
1685 | stack slots, doing weird things with sizeof, etc. So we require | |
1686 | the right operand to be a constant expression. */ | |
1687 | static void | |
f7c79c41 UW |
1688 | gen_repeat (struct expression *exp, union exp_element **pc, |
1689 | struct agent_expr *ax, struct axs_value *value) | |
c906108c SS |
1690 | { |
1691 | struct axs_value value1; | |
1692 | /* We don't want to turn this into an rvalue, so no conversions | |
1693 | here. */ | |
f7c79c41 | 1694 | gen_expr (exp, pc, ax, &value1); |
c906108c | 1695 | if (value1.kind != axs_lvalue_memory) |
3d263c1d | 1696 | error (_("Left operand of `@' must be an object in memory.")); |
c906108c SS |
1697 | |
1698 | /* Evaluate the length; it had better be a constant. */ | |
1699 | { | |
1700 | struct value *v = const_expr (pc); | |
1701 | int length; | |
1702 | ||
c5aa993b | 1703 | if (!v) |
3d263c1d | 1704 | error (_("Right operand of `@' must be a constant, in agent expressions.")); |
04624583 | 1705 | if (TYPE_CODE (value_type (v)) != TYPE_CODE_INT) |
3d263c1d | 1706 | error (_("Right operand of `@' must be an integer.")); |
c906108c SS |
1707 | length = value_as_long (v); |
1708 | if (length <= 0) | |
3d263c1d | 1709 | error (_("Right operand of `@' must be positive.")); |
c906108c SS |
1710 | |
1711 | /* The top of the stack is already the address of the object, so | |
1712 | all we need to do is frob the type of the lvalue. */ | |
1713 | { | |
1714 | /* FIXME-type-allocation: need a way to free this type when we are | |
c5aa993b | 1715 | done with it. */ |
e3506a9f UW |
1716 | struct type *array |
1717 | = lookup_array_range_type (value1.type, 0, length - 1); | |
c906108c SS |
1718 | |
1719 | value->kind = axs_lvalue_memory; | |
1720 | value->type = array; | |
1721 | } | |
1722 | } | |
1723 | } | |
1724 | ||
1725 | ||
1726 | /* Emit code for the `sizeof' operator. | |
1727 | *PC should point at the start of the operand expression; we advance it | |
1728 | to the first instruction after the operand. */ | |
1729 | static void | |
f7c79c41 UW |
1730 | gen_sizeof (struct expression *exp, union exp_element **pc, |
1731 | struct agent_expr *ax, struct axs_value *value, | |
1732 | struct type *size_type) | |
c906108c SS |
1733 | { |
1734 | /* We don't care about the value of the operand expression; we only | |
1735 | care about its type. However, in the current arrangement, the | |
1736 | only way to find an expression's type is to generate code for it. | |
1737 | So we generate code for the operand, and then throw it away, | |
1738 | replacing it with code that simply pushes its size. */ | |
1739 | int start = ax->len; | |
f7c79c41 | 1740 | gen_expr (exp, pc, ax, value); |
c906108c SS |
1741 | |
1742 | /* Throw away the code we just generated. */ | |
1743 | ax->len = start; | |
c5aa993b | 1744 | |
c906108c SS |
1745 | ax_const_l (ax, TYPE_LENGTH (value->type)); |
1746 | value->kind = axs_rvalue; | |
f7c79c41 | 1747 | value->type = size_type; |
c906108c | 1748 | } |
c906108c | 1749 | \f |
c5aa993b | 1750 | |
c906108c SS |
1751 | /* Generating bytecode from GDB expressions: general recursive thingy */ |
1752 | ||
3d263c1d | 1753 | /* XXX: i18n */ |
c906108c SS |
1754 | /* A gen_expr function written by a Gen-X'er guy. |
1755 | Append code for the subexpression of EXPR starting at *POS_P to AX. */ | |
1756 | static void | |
f7c79c41 UW |
1757 | gen_expr (struct expression *exp, union exp_element **pc, |
1758 | struct agent_expr *ax, struct axs_value *value) | |
c906108c SS |
1759 | { |
1760 | /* Used to hold the descriptions of operand expressions. */ | |
09d559e4 | 1761 | struct axs_value value1, value2, value3; |
f61e138d | 1762 | enum exp_opcode op = (*pc)[0].opcode, op2; |
09d559e4 | 1763 | int if1, go1, if2, go2, end; |
3b11a015 | 1764 | struct type *int_type = builtin_type (exp->gdbarch)->builtin_int; |
c906108c SS |
1765 | |
1766 | /* If we're looking at a constant expression, just push its value. */ | |
1767 | { | |
1768 | struct value *v = maybe_const_expr (pc); | |
c5aa993b | 1769 | |
c906108c SS |
1770 | if (v) |
1771 | { | |
1772 | ax_const_l (ax, value_as_long (v)); | |
1773 | value->kind = axs_rvalue; | |
df407dfe | 1774 | value->type = check_typedef (value_type (v)); |
c906108c SS |
1775 | return; |
1776 | } | |
1777 | } | |
1778 | ||
1779 | /* Otherwise, go ahead and generate code for it. */ | |
1780 | switch (op) | |
1781 | { | |
1782 | /* Binary arithmetic operators. */ | |
1783 | case BINOP_ADD: | |
1784 | case BINOP_SUB: | |
1785 | case BINOP_MUL: | |
1786 | case BINOP_DIV: | |
1787 | case BINOP_REM: | |
948103cf SS |
1788 | case BINOP_LSH: |
1789 | case BINOP_RSH: | |
c906108c SS |
1790 | case BINOP_SUBSCRIPT: |
1791 | case BINOP_BITWISE_AND: | |
1792 | case BINOP_BITWISE_IOR: | |
1793 | case BINOP_BITWISE_XOR: | |
782b2b07 SS |
1794 | case BINOP_EQUAL: |
1795 | case BINOP_NOTEQUAL: | |
1796 | case BINOP_LESS: | |
1797 | case BINOP_GTR: | |
1798 | case BINOP_LEQ: | |
1799 | case BINOP_GEQ: | |
c906108c | 1800 | (*pc)++; |
f7c79c41 UW |
1801 | gen_expr (exp, pc, ax, &value1); |
1802 | gen_usual_unary (exp, ax, &value1); | |
f61e138d SS |
1803 | gen_expr_binop_rest (exp, op, pc, ax, value, &value1, &value2); |
1804 | break; | |
1805 | ||
09d559e4 SS |
1806 | case BINOP_LOGICAL_AND: |
1807 | (*pc)++; | |
1808 | /* Generate the obvious sequence of tests and jumps. */ | |
1809 | gen_expr (exp, pc, ax, &value1); | |
1810 | gen_usual_unary (exp, ax, &value1); | |
1811 | if1 = ax_goto (ax, aop_if_goto); | |
1812 | go1 = ax_goto (ax, aop_goto); | |
1813 | ax_label (ax, if1, ax->len); | |
1814 | gen_expr (exp, pc, ax, &value2); | |
1815 | gen_usual_unary (exp, ax, &value2); | |
1816 | if2 = ax_goto (ax, aop_if_goto); | |
1817 | go2 = ax_goto (ax, aop_goto); | |
1818 | ax_label (ax, if2, ax->len); | |
1819 | ax_const_l (ax, 1); | |
1820 | end = ax_goto (ax, aop_goto); | |
1821 | ax_label (ax, go1, ax->len); | |
1822 | ax_label (ax, go2, ax->len); | |
1823 | ax_const_l (ax, 0); | |
1824 | ax_label (ax, end, ax->len); | |
1825 | value->kind = axs_rvalue; | |
3b11a015 | 1826 | value->type = int_type; |
09d559e4 SS |
1827 | break; |
1828 | ||
1829 | case BINOP_LOGICAL_OR: | |
1830 | (*pc)++; | |
1831 | /* Generate the obvious sequence of tests and jumps. */ | |
1832 | gen_expr (exp, pc, ax, &value1); | |
1833 | gen_usual_unary (exp, ax, &value1); | |
1834 | if1 = ax_goto (ax, aop_if_goto); | |
1835 | gen_expr (exp, pc, ax, &value2); | |
1836 | gen_usual_unary (exp, ax, &value2); | |
1837 | if2 = ax_goto (ax, aop_if_goto); | |
1838 | ax_const_l (ax, 0); | |
1839 | end = ax_goto (ax, aop_goto); | |
1840 | ax_label (ax, if1, ax->len); | |
1841 | ax_label (ax, if2, ax->len); | |
1842 | ax_const_l (ax, 1); | |
1843 | ax_label (ax, end, ax->len); | |
1844 | value->kind = axs_rvalue; | |
3b11a015 | 1845 | value->type = int_type; |
09d559e4 SS |
1846 | break; |
1847 | ||
1848 | case TERNOP_COND: | |
1849 | (*pc)++; | |
1850 | gen_expr (exp, pc, ax, &value1); | |
1851 | gen_usual_unary (exp, ax, &value1); | |
1852 | /* For (A ? B : C), it's easiest to generate subexpression | |
1853 | bytecodes in order, but if_goto jumps on true, so we invert | |
1854 | the sense of A. Then we can do B by dropping through, and | |
1855 | jump to do C. */ | |
3b11a015 | 1856 | gen_logical_not (ax, &value1, int_type); |
09d559e4 SS |
1857 | if1 = ax_goto (ax, aop_if_goto); |
1858 | gen_expr (exp, pc, ax, &value2); | |
1859 | gen_usual_unary (exp, ax, &value2); | |
1860 | end = ax_goto (ax, aop_goto); | |
1861 | ax_label (ax, if1, ax->len); | |
1862 | gen_expr (exp, pc, ax, &value3); | |
1863 | gen_usual_unary (exp, ax, &value3); | |
1864 | ax_label (ax, end, ax->len); | |
1865 | /* This is arbitary - what if B and C are incompatible types? */ | |
1866 | value->type = value2.type; | |
1867 | value->kind = value2.kind; | |
1868 | break; | |
1869 | ||
f61e138d SS |
1870 | case BINOP_ASSIGN: |
1871 | (*pc)++; | |
1872 | if ((*pc)[0].opcode == OP_INTERNALVAR) | |
c906108c | 1873 | { |
f61e138d SS |
1874 | char *name = internalvar_name ((*pc)[1].internalvar); |
1875 | struct trace_state_variable *tsv; | |
1876 | (*pc) += 3; | |
1877 | gen_expr (exp, pc, ax, value); | |
1878 | tsv = find_trace_state_variable (name); | |
1879 | if (tsv) | |
f7c79c41 | 1880 | { |
f61e138d SS |
1881 | ax_tsv (ax, aop_setv, tsv->number); |
1882 | if (trace_kludge) | |
1883 | ax_tsv (ax, aop_tracev, tsv->number); | |
f7c79c41 | 1884 | } |
f7c79c41 | 1885 | else |
f61e138d SS |
1886 | error (_("$%s is not a trace state variable, may not assign to it"), name); |
1887 | } | |
1888 | else | |
1889 | error (_("May only assign to trace state variables")); | |
1890 | break; | |
782b2b07 | 1891 | |
f61e138d SS |
1892 | case BINOP_ASSIGN_MODIFY: |
1893 | (*pc)++; | |
1894 | op2 = (*pc)[0].opcode; | |
1895 | (*pc)++; | |
1896 | (*pc)++; | |
1897 | if ((*pc)[0].opcode == OP_INTERNALVAR) | |
1898 | { | |
1899 | char *name = internalvar_name ((*pc)[1].internalvar); | |
1900 | struct trace_state_variable *tsv; | |
1901 | (*pc) += 3; | |
1902 | tsv = find_trace_state_variable (name); | |
1903 | if (tsv) | |
1904 | { | |
1905 | /* The tsv will be the left half of the binary operation. */ | |
1906 | ax_tsv (ax, aop_getv, tsv->number); | |
1907 | if (trace_kludge) | |
1908 | ax_tsv (ax, aop_tracev, tsv->number); | |
1909 | /* Trace state variables are always 64-bit integers. */ | |
1910 | value1.kind = axs_rvalue; | |
1911 | value1.type = builtin_type (exp->gdbarch)->builtin_long_long; | |
1912 | /* Now do right half of expression. */ | |
1913 | gen_expr_binop_rest (exp, op2, pc, ax, value, &value1, &value2); | |
1914 | /* We have a result of the binary op, set the tsv. */ | |
1915 | ax_tsv (ax, aop_setv, tsv->number); | |
1916 | if (trace_kludge) | |
1917 | ax_tsv (ax, aop_tracev, tsv->number); | |
1918 | } | |
1919 | else | |
1920 | error (_("$%s is not a trace state variable, may not assign to it"), name); | |
c906108c | 1921 | } |
f61e138d SS |
1922 | else |
1923 | error (_("May only assign to trace state variables")); | |
c906108c SS |
1924 | break; |
1925 | ||
1926 | /* Note that we need to be a little subtle about generating code | |
c5aa993b JM |
1927 | for comma. In C, we can do some optimizations here because |
1928 | we know the left operand is only being evaluated for effect. | |
1929 | However, if the tracing kludge is in effect, then we always | |
1930 | need to evaluate the left hand side fully, so that all the | |
1931 | variables it mentions get traced. */ | |
c906108c SS |
1932 | case BINOP_COMMA: |
1933 | (*pc)++; | |
f7c79c41 | 1934 | gen_expr (exp, pc, ax, &value1); |
c906108c | 1935 | /* Don't just dispose of the left operand. We might be tracing, |
c5aa993b JM |
1936 | in which case we want to emit code to trace it if it's an |
1937 | lvalue. */ | |
400c6af0 | 1938 | gen_traced_pop (exp->gdbarch, ax, &value1); |
f7c79c41 | 1939 | gen_expr (exp, pc, ax, value); |
c906108c SS |
1940 | /* It's the consumer's responsibility to trace the right operand. */ |
1941 | break; | |
c5aa993b | 1942 | |
c906108c SS |
1943 | case OP_LONG: /* some integer constant */ |
1944 | { | |
1945 | struct type *type = (*pc)[1].type; | |
1946 | LONGEST k = (*pc)[2].longconst; | |
1947 | (*pc) += 4; | |
1948 | gen_int_literal (ax, value, k, type); | |
1949 | } | |
c5aa993b | 1950 | break; |
c906108c SS |
1951 | |
1952 | case OP_VAR_VALUE: | |
f7c79c41 | 1953 | gen_var_ref (exp->gdbarch, ax, value, (*pc)[2].symbol); |
400c6af0 SS |
1954 | |
1955 | if (value->optimized_out) | |
1956 | error (_("`%s' has been optimized out, cannot use"), | |
1957 | SYMBOL_PRINT_NAME ((*pc)[2].symbol)); | |
1958 | ||
c906108c SS |
1959 | (*pc) += 4; |
1960 | break; | |
1961 | ||
1962 | case OP_REGISTER: | |
1963 | { | |
67f3407f DJ |
1964 | const char *name = &(*pc)[2].string; |
1965 | int reg; | |
1966 | (*pc) += 4 + BYTES_TO_EXP_ELEM ((*pc)[1].longconst + 1); | |
f7c79c41 | 1967 | reg = user_reg_map_name_to_regnum (exp->gdbarch, name, strlen (name)); |
67f3407f DJ |
1968 | if (reg == -1) |
1969 | internal_error (__FILE__, __LINE__, | |
1970 | _("Register $%s not available"), name); | |
f7c79c41 | 1971 | if (reg >= gdbarch_num_regs (exp->gdbarch)) |
02e4669d JB |
1972 | error (_("'%s' is a pseudo-register; " |
1973 | "GDB cannot yet trace pseudoregister contents."), | |
1974 | name); | |
c906108c SS |
1975 | value->kind = axs_lvalue_register; |
1976 | value->u.reg = reg; | |
f7c79c41 | 1977 | value->type = register_type (exp->gdbarch, reg); |
c906108c | 1978 | } |
c5aa993b | 1979 | break; |
c906108c SS |
1980 | |
1981 | case OP_INTERNALVAR: | |
f61e138d SS |
1982 | { |
1983 | const char *name = internalvar_name ((*pc)[1].internalvar); | |
1984 | struct trace_state_variable *tsv; | |
1985 | (*pc) += 3; | |
1986 | tsv = find_trace_state_variable (name); | |
1987 | if (tsv) | |
1988 | { | |
1989 | ax_tsv (ax, aop_getv, tsv->number); | |
1990 | if (trace_kludge) | |
1991 | ax_tsv (ax, aop_tracev, tsv->number); | |
1992 | /* Trace state variables are always 64-bit integers. */ | |
1993 | value->kind = axs_rvalue; | |
1994 | value->type = builtin_type (exp->gdbarch)->builtin_long_long; | |
1995 | } | |
1996 | else | |
1997 | error (_("$%s is not a trace state variable; GDB agent expressions cannot use convenience variables."), name); | |
1998 | } | |
1999 | break; | |
c906108c | 2000 | |
c5aa993b | 2001 | /* Weirdo operator: see comments for gen_repeat for details. */ |
c906108c SS |
2002 | case BINOP_REPEAT: |
2003 | /* Note that gen_repeat handles its own argument evaluation. */ | |
2004 | (*pc)++; | |
f7c79c41 | 2005 | gen_repeat (exp, pc, ax, value); |
c906108c SS |
2006 | break; |
2007 | ||
2008 | case UNOP_CAST: | |
2009 | { | |
2010 | struct type *type = (*pc)[1].type; | |
2011 | (*pc) += 3; | |
f7c79c41 | 2012 | gen_expr (exp, pc, ax, value); |
c906108c SS |
2013 | gen_cast (ax, value, type); |
2014 | } | |
c5aa993b | 2015 | break; |
c906108c SS |
2016 | |
2017 | case UNOP_MEMVAL: | |
2018 | { | |
2019 | struct type *type = check_typedef ((*pc)[1].type); | |
2020 | (*pc) += 3; | |
f7c79c41 | 2021 | gen_expr (exp, pc, ax, value); |
c906108c SS |
2022 | /* I'm not sure I understand UNOP_MEMVAL entirely. I think |
2023 | it's just a hack for dealing with minsyms; you take some | |
2024 | integer constant, pretend it's the address of an lvalue of | |
2025 | the given type, and dereference it. */ | |
2026 | if (value->kind != axs_rvalue) | |
2027 | /* This would be weird. */ | |
8e65ff28 | 2028 | internal_error (__FILE__, __LINE__, |
3d263c1d | 2029 | _("gen_expr: OP_MEMVAL operand isn't an rvalue???")); |
c906108c SS |
2030 | value->type = type; |
2031 | value->kind = axs_lvalue_memory; | |
2032 | } | |
c5aa993b | 2033 | break; |
c906108c | 2034 | |
36e9969c NS |
2035 | case UNOP_PLUS: |
2036 | (*pc)++; | |
2037 | /* + FOO is equivalent to 0 + FOO, which can be optimized. */ | |
f7c79c41 UW |
2038 | gen_expr (exp, pc, ax, value); |
2039 | gen_usual_unary (exp, ax, value); | |
36e9969c NS |
2040 | break; |
2041 | ||
c906108c SS |
2042 | case UNOP_NEG: |
2043 | (*pc)++; | |
2044 | /* -FOO is equivalent to 0 - FOO. */ | |
22601c15 UW |
2045 | gen_int_literal (ax, &value1, 0, |
2046 | builtin_type (exp->gdbarch)->builtin_int); | |
f7c79c41 UW |
2047 | gen_usual_unary (exp, ax, &value1); /* shouldn't do much */ |
2048 | gen_expr (exp, pc, ax, &value2); | |
2049 | gen_usual_unary (exp, ax, &value2); | |
2050 | gen_usual_arithmetic (exp, ax, &value1, &value2); | |
2051 | gen_binop (ax, value, &value1, &value2, aop_sub, aop_sub, 1, "negation"); | |
c906108c SS |
2052 | break; |
2053 | ||
2054 | case UNOP_LOGICAL_NOT: | |
2055 | (*pc)++; | |
f7c79c41 UW |
2056 | gen_expr (exp, pc, ax, value); |
2057 | gen_usual_unary (exp, ax, value); | |
3b11a015 | 2058 | gen_logical_not (ax, value, int_type); |
c906108c SS |
2059 | break; |
2060 | ||
2061 | case UNOP_COMPLEMENT: | |
2062 | (*pc)++; | |
f7c79c41 UW |
2063 | gen_expr (exp, pc, ax, value); |
2064 | gen_usual_unary (exp, ax, value); | |
2065 | gen_integral_promotions (exp, ax, value); | |
c906108c SS |
2066 | gen_complement (ax, value); |
2067 | break; | |
2068 | ||
2069 | case UNOP_IND: | |
2070 | (*pc)++; | |
f7c79c41 UW |
2071 | gen_expr (exp, pc, ax, value); |
2072 | gen_usual_unary (exp, ax, value); | |
b97aedf3 | 2073 | if (!pointer_type (value->type)) |
3d263c1d | 2074 | error (_("Argument of unary `*' is not a pointer.")); |
c906108c SS |
2075 | gen_deref (ax, value); |
2076 | break; | |
2077 | ||
2078 | case UNOP_ADDR: | |
2079 | (*pc)++; | |
f7c79c41 | 2080 | gen_expr (exp, pc, ax, value); |
c906108c SS |
2081 | gen_address_of (ax, value); |
2082 | break; | |
2083 | ||
2084 | case UNOP_SIZEOF: | |
2085 | (*pc)++; | |
2086 | /* Notice that gen_sizeof handles its own operand, unlike most | |
c5aa993b JM |
2087 | of the other unary operator functions. This is because we |
2088 | have to throw away the code we generate. */ | |
f7c79c41 UW |
2089 | gen_sizeof (exp, pc, ax, value, |
2090 | builtin_type (exp->gdbarch)->builtin_int); | |
c906108c SS |
2091 | break; |
2092 | ||
2093 | case STRUCTOP_STRUCT: | |
2094 | case STRUCTOP_PTR: | |
2095 | { | |
2096 | int length = (*pc)[1].longconst; | |
2097 | char *name = &(*pc)[2].string; | |
2098 | ||
2099 | (*pc) += 4 + BYTES_TO_EXP_ELEM (length + 1); | |
f7c79c41 | 2100 | gen_expr (exp, pc, ax, value); |
c906108c | 2101 | if (op == STRUCTOP_STRUCT) |
505e835d | 2102 | gen_struct_ref (exp, ax, value, name, ".", "structure or union"); |
c906108c | 2103 | else if (op == STRUCTOP_PTR) |
505e835d | 2104 | gen_struct_ref (exp, ax, value, name, "->", |
c906108c SS |
2105 | "pointer to a structure or union"); |
2106 | else | |
2107 | /* If this `if' chain doesn't handle it, then the case list | |
c5aa993b | 2108 | shouldn't mention it, and we shouldn't be here. */ |
8e65ff28 | 2109 | internal_error (__FILE__, __LINE__, |
3d263c1d | 2110 | _("gen_expr: unhandled struct case")); |
c906108c | 2111 | } |
c5aa993b | 2112 | break; |
c906108c | 2113 | |
6c228b9c SS |
2114 | case OP_THIS: |
2115 | { | |
6a0fc12f | 2116 | char *this_name; |
6c228b9c SS |
2117 | struct symbol *func, *sym; |
2118 | struct block *b; | |
2119 | ||
6a0fc12f PA |
2120 | func = block_linkage_function (block_for_pc (ax->scope)); |
2121 | this_name = language_def (SYMBOL_LANGUAGE (func))->la_name_of_this; | |
6c228b9c | 2122 | b = SYMBOL_BLOCK_VALUE (func); |
6c228b9c SS |
2123 | |
2124 | /* Calling lookup_block_symbol is necessary to get the LOC_REGISTER | |
2125 | symbol instead of the LOC_ARG one (if both exist). */ | |
94af9270 | 2126 | sym = lookup_block_symbol (b, this_name, VAR_DOMAIN); |
6c228b9c | 2127 | if (!sym) |
6a0fc12f | 2128 | error (_("no `%s' found"), this_name); |
6c228b9c SS |
2129 | |
2130 | gen_var_ref (exp->gdbarch, ax, value, sym); | |
400c6af0 SS |
2131 | |
2132 | if (value->optimized_out) | |
2133 | error (_("`%s' has been optimized out, cannot use"), | |
2134 | SYMBOL_PRINT_NAME (sym)); | |
2135 | ||
6c228b9c SS |
2136 | (*pc) += 2; |
2137 | } | |
2138 | break; | |
2139 | ||
b6e7192f SS |
2140 | case OP_SCOPE: |
2141 | { | |
2142 | struct type *type = (*pc)[1].type; | |
2143 | int length = longest_to_int ((*pc)[2].longconst); | |
2144 | char *name = &(*pc)[3].string; | |
2145 | int found; | |
2146 | ||
2147 | found = gen_aggregate_elt_ref (exp, ax, value, type, name, | |
2148 | "?", "??"); | |
2149 | if (!found) | |
2150 | error (_("There is no field named %s"), name); | |
2151 | (*pc) += 5 + BYTES_TO_EXP_ELEM (length + 1); | |
2152 | } | |
2153 | break; | |
2154 | ||
c906108c | 2155 | case OP_TYPE: |
3d263c1d | 2156 | error (_("Attempt to use a type name as an expression.")); |
c906108c SS |
2157 | |
2158 | default: | |
b6e7192f SS |
2159 | error (_("Unsupported operator %s (%d) in expression."), |
2160 | op_string (op), op); | |
c906108c SS |
2161 | } |
2162 | } | |
f61e138d SS |
2163 | |
2164 | /* This handles the middle-to-right-side of code generation for binary | |
2165 | expressions, which is shared between regular binary operations and | |
2166 | assign-modify (+= and friends) expressions. */ | |
2167 | ||
2168 | static void | |
2169 | gen_expr_binop_rest (struct expression *exp, | |
2170 | enum exp_opcode op, union exp_element **pc, | |
2171 | struct agent_expr *ax, struct axs_value *value, | |
2172 | struct axs_value *value1, struct axs_value *value2) | |
2173 | { | |
3b11a015 SS |
2174 | struct type *int_type = builtin_type (exp->gdbarch)->builtin_int; |
2175 | ||
f61e138d SS |
2176 | gen_expr (exp, pc, ax, value2); |
2177 | gen_usual_unary (exp, ax, value2); | |
2178 | gen_usual_arithmetic (exp, ax, value1, value2); | |
2179 | switch (op) | |
2180 | { | |
2181 | case BINOP_ADD: | |
2182 | if (TYPE_CODE (value1->type) == TYPE_CODE_INT | |
b97aedf3 | 2183 | && pointer_type (value2->type)) |
f61e138d SS |
2184 | { |
2185 | /* Swap the values and proceed normally. */ | |
2186 | ax_simple (ax, aop_swap); | |
2187 | gen_ptradd (ax, value, value2, value1); | |
2188 | } | |
b97aedf3 | 2189 | else if (pointer_type (value1->type) |
f61e138d SS |
2190 | && TYPE_CODE (value2->type) == TYPE_CODE_INT) |
2191 | gen_ptradd (ax, value, value1, value2); | |
2192 | else | |
2193 | gen_binop (ax, value, value1, value2, | |
2194 | aop_add, aop_add, 1, "addition"); | |
2195 | break; | |
2196 | case BINOP_SUB: | |
b97aedf3 | 2197 | if (pointer_type (value1->type) |
f61e138d SS |
2198 | && TYPE_CODE (value2->type) == TYPE_CODE_INT) |
2199 | gen_ptrsub (ax,value, value1, value2); | |
b97aedf3 SS |
2200 | else if (pointer_type (value1->type) |
2201 | && pointer_type (value2->type)) | |
f61e138d SS |
2202 | /* FIXME --- result type should be ptrdiff_t */ |
2203 | gen_ptrdiff (ax, value, value1, value2, | |
2204 | builtin_type (exp->gdbarch)->builtin_long); | |
2205 | else | |
2206 | gen_binop (ax, value, value1, value2, | |
2207 | aop_sub, aop_sub, 1, "subtraction"); | |
2208 | break; | |
2209 | case BINOP_MUL: | |
2210 | gen_binop (ax, value, value1, value2, | |
2211 | aop_mul, aop_mul, 1, "multiplication"); | |
2212 | break; | |
2213 | case BINOP_DIV: | |
2214 | gen_binop (ax, value, value1, value2, | |
2215 | aop_div_signed, aop_div_unsigned, 1, "division"); | |
2216 | break; | |
2217 | case BINOP_REM: | |
2218 | gen_binop (ax, value, value1, value2, | |
2219 | aop_rem_signed, aop_rem_unsigned, 1, "remainder"); | |
2220 | break; | |
948103cf SS |
2221 | case BINOP_LSH: |
2222 | gen_binop (ax, value, value1, value2, | |
2223 | aop_lsh, aop_lsh, 1, "left shift"); | |
2224 | break; | |
2225 | case BINOP_RSH: | |
2226 | gen_binop (ax, value, value1, value2, | |
2227 | aop_rsh_signed, aop_rsh_unsigned, 1, "right shift"); | |
2228 | break; | |
f61e138d | 2229 | case BINOP_SUBSCRIPT: |
be636754 PA |
2230 | { |
2231 | struct type *type; | |
2232 | ||
2233 | if (binop_types_user_defined_p (op, value1->type, value2->type)) | |
2234 | { | |
2235 | error (_("\ | |
2236 | cannot subscript requested type: cannot call user defined functions")); | |
2237 | } | |
2238 | else | |
2239 | { | |
2240 | /* If the user attempts to subscript something that is not | |
2241 | an array or pointer type (like a plain int variable for | |
2242 | example), then report this as an error. */ | |
2243 | type = check_typedef (value1->type); | |
2244 | if (TYPE_CODE (type) != TYPE_CODE_ARRAY | |
2245 | && TYPE_CODE (type) != TYPE_CODE_PTR) | |
2246 | { | |
2247 | if (TYPE_NAME (type)) | |
2248 | error (_("cannot subscript something of type `%s'"), | |
2249 | TYPE_NAME (type)); | |
2250 | else | |
2251 | error (_("cannot subscript requested type")); | |
2252 | } | |
2253 | } | |
2254 | ||
5d5b640e PA |
2255 | if (!is_integral_type (value2->type)) |
2256 | error (_("Argument to arithmetic operation not a number or boolean.")); | |
2257 | ||
be636754 PA |
2258 | gen_ptradd (ax, value, value1, value2); |
2259 | gen_deref (ax, value); | |
2260 | break; | |
2261 | } | |
f61e138d SS |
2262 | case BINOP_BITWISE_AND: |
2263 | gen_binop (ax, value, value1, value2, | |
2264 | aop_bit_and, aop_bit_and, 0, "bitwise and"); | |
2265 | break; | |
2266 | ||
2267 | case BINOP_BITWISE_IOR: | |
2268 | gen_binop (ax, value, value1, value2, | |
2269 | aop_bit_or, aop_bit_or, 0, "bitwise or"); | |
2270 | break; | |
2271 | ||
2272 | case BINOP_BITWISE_XOR: | |
2273 | gen_binop (ax, value, value1, value2, | |
2274 | aop_bit_xor, aop_bit_xor, 0, "bitwise exclusive-or"); | |
2275 | break; | |
2276 | ||
2277 | case BINOP_EQUAL: | |
3b11a015 | 2278 | gen_equal (ax, value, value1, value2, int_type); |
f61e138d SS |
2279 | break; |
2280 | ||
2281 | case BINOP_NOTEQUAL: | |
3b11a015 SS |
2282 | gen_equal (ax, value, value1, value2, int_type); |
2283 | gen_logical_not (ax, value, int_type); | |
f61e138d SS |
2284 | break; |
2285 | ||
2286 | case BINOP_LESS: | |
3b11a015 | 2287 | gen_less (ax, value, value1, value2, int_type); |
f61e138d SS |
2288 | break; |
2289 | ||
2290 | case BINOP_GTR: | |
2291 | ax_simple (ax, aop_swap); | |
3b11a015 | 2292 | gen_less (ax, value, value1, value2, int_type); |
f61e138d SS |
2293 | break; |
2294 | ||
2295 | case BINOP_LEQ: | |
2296 | ax_simple (ax, aop_swap); | |
3b11a015 SS |
2297 | gen_less (ax, value, value1, value2, int_type); |
2298 | gen_logical_not (ax, value, int_type); | |
f61e138d SS |
2299 | break; |
2300 | ||
2301 | case BINOP_GEQ: | |
3b11a015 SS |
2302 | gen_less (ax, value, value1, value2, int_type); |
2303 | gen_logical_not (ax, value, int_type); | |
f61e138d SS |
2304 | break; |
2305 | ||
2306 | default: | |
2307 | /* We should only list operators in the outer case statement | |
2308 | that we actually handle in the inner case statement. */ | |
2309 | internal_error (__FILE__, __LINE__, | |
2310 | _("gen_expr: op case sets don't match")); | |
2311 | } | |
2312 | } | |
c906108c | 2313 | \f |
c5aa993b | 2314 | |
0936ad1d SS |
2315 | /* Given a single variable and a scope, generate bytecodes to trace |
2316 | its value. This is for use in situations where we have only a | |
2317 | variable's name, and no parsed expression; for instance, when the | |
2318 | name comes from a list of local variables of a function. */ | |
2319 | ||
2320 | struct agent_expr * | |
400c6af0 SS |
2321 | gen_trace_for_var (CORE_ADDR scope, struct gdbarch *gdbarch, |
2322 | struct symbol *var) | |
0936ad1d SS |
2323 | { |
2324 | struct cleanup *old_chain = 0; | |
35c9c7ba | 2325 | struct agent_expr *ax = new_agent_expr (gdbarch, scope); |
0936ad1d SS |
2326 | struct axs_value value; |
2327 | ||
2328 | old_chain = make_cleanup_free_agent_expr (ax); | |
2329 | ||
2330 | trace_kludge = 1; | |
400c6af0 SS |
2331 | gen_var_ref (gdbarch, ax, &value, var); |
2332 | ||
2333 | /* If there is no actual variable to trace, flag it by returning | |
2334 | an empty agent expression. */ | |
2335 | if (value.optimized_out) | |
2336 | { | |
2337 | do_cleanups (old_chain); | |
2338 | return NULL; | |
2339 | } | |
0936ad1d SS |
2340 | |
2341 | /* Make sure we record the final object, and get rid of it. */ | |
400c6af0 | 2342 | gen_traced_pop (gdbarch, ax, &value); |
0936ad1d SS |
2343 | |
2344 | /* Oh, and terminate. */ | |
2345 | ax_simple (ax, aop_end); | |
2346 | ||
2347 | /* We have successfully built the agent expr, so cancel the cleanup | |
2348 | request. If we add more cleanups that we always want done, this | |
2349 | will have to get more complicated. */ | |
2350 | discard_cleanups (old_chain); | |
2351 | return ax; | |
2352 | } | |
c5aa993b | 2353 | |
c906108c SS |
2354 | /* Generating bytecode from GDB expressions: driver */ |
2355 | ||
c906108c SS |
2356 | /* Given a GDB expression EXPR, return bytecode to trace its value. |
2357 | The result will use the `trace' and `trace_quick' bytecodes to | |
2358 | record the value of all memory touched by the expression. The | |
2359 | caller can then use the ax_reqs function to discover which | |
2360 | registers it relies upon. */ | |
2361 | struct agent_expr * | |
fba45db2 | 2362 | gen_trace_for_expr (CORE_ADDR scope, struct expression *expr) |
c906108c SS |
2363 | { |
2364 | struct cleanup *old_chain = 0; | |
35c9c7ba | 2365 | struct agent_expr *ax = new_agent_expr (expr->gdbarch, scope); |
c906108c SS |
2366 | union exp_element *pc; |
2367 | struct axs_value value; | |
2368 | ||
f23d52e0 | 2369 | old_chain = make_cleanup_free_agent_expr (ax); |
c906108c SS |
2370 | |
2371 | pc = expr->elts; | |
2372 | trace_kludge = 1; | |
35c9c7ba | 2373 | value.optimized_out = 0; |
f7c79c41 | 2374 | gen_expr (expr, &pc, ax, &value); |
c906108c SS |
2375 | |
2376 | /* Make sure we record the final object, and get rid of it. */ | |
400c6af0 | 2377 | gen_traced_pop (expr->gdbarch, ax, &value); |
c906108c SS |
2378 | |
2379 | /* Oh, and terminate. */ | |
2380 | ax_simple (ax, aop_end); | |
2381 | ||
2382 | /* We have successfully built the agent expr, so cancel the cleanup | |
2383 | request. If we add more cleanups that we always want done, this | |
2384 | will have to get more complicated. */ | |
2385 | discard_cleanups (old_chain); | |
2386 | return ax; | |
2387 | } | |
c906108c | 2388 | |
782b2b07 SS |
2389 | /* Given a GDB expression EXPR, return a bytecode sequence that will |
2390 | evaluate and return a result. The bytecodes will do a direct | |
2391 | evaluation, using the current data on the target, rather than | |
2392 | recording blocks of memory and registers for later use, as | |
2393 | gen_trace_for_expr does. The generated bytecode sequence leaves | |
2394 | the result of expression evaluation on the top of the stack. */ | |
2395 | ||
2396 | struct agent_expr * | |
2397 | gen_eval_for_expr (CORE_ADDR scope, struct expression *expr) | |
2398 | { | |
2399 | struct cleanup *old_chain = 0; | |
35c9c7ba | 2400 | struct agent_expr *ax = new_agent_expr (expr->gdbarch, scope); |
782b2b07 SS |
2401 | union exp_element *pc; |
2402 | struct axs_value value; | |
2403 | ||
2404 | old_chain = make_cleanup_free_agent_expr (ax); | |
2405 | ||
2406 | pc = expr->elts; | |
2407 | trace_kludge = 0; | |
35c9c7ba | 2408 | value.optimized_out = 0; |
782b2b07 SS |
2409 | gen_expr (expr, &pc, ax, &value); |
2410 | ||
35c9c7ba SS |
2411 | require_rvalue (ax, &value); |
2412 | ||
782b2b07 SS |
2413 | /* Oh, and terminate. */ |
2414 | ax_simple (ax, aop_end); | |
2415 | ||
2416 | /* We have successfully built the agent expr, so cancel the cleanup | |
2417 | request. If we add more cleanups that we always want done, this | |
2418 | will have to get more complicated. */ | |
2419 | discard_cleanups (old_chain); | |
2420 | return ax; | |
2421 | } | |
2422 | ||
c906108c | 2423 | static void |
fba45db2 | 2424 | agent_command (char *exp, int from_tty) |
c906108c SS |
2425 | { |
2426 | struct cleanup *old_chain = 0; | |
2427 | struct expression *expr; | |
2428 | struct agent_expr *agent; | |
6426a772 | 2429 | struct frame_info *fi = get_current_frame (); /* need current scope */ |
c906108c SS |
2430 | |
2431 | /* We don't deal with overlay debugging at the moment. We need to | |
2432 | think more carefully about this. If you copy this code into | |
2433 | another command, change the error message; the user shouldn't | |
2434 | have to know anything about agent expressions. */ | |
2435 | if (overlay_debugging) | |
3d263c1d | 2436 | error (_("GDB can't do agent expression translation with overlays.")); |
c906108c SS |
2437 | |
2438 | if (exp == 0) | |
3d263c1d | 2439 | error_no_arg (_("expression to translate")); |
c5aa993b | 2440 | |
c906108c | 2441 | expr = parse_expression (exp); |
c13c43fd | 2442 | old_chain = make_cleanup (free_current_contents, &expr); |
bdd78e62 | 2443 | agent = gen_trace_for_expr (get_frame_pc (fi), expr); |
f23d52e0 | 2444 | make_cleanup_free_agent_expr (agent); |
35c9c7ba | 2445 | ax_reqs (agent); |
c906108c | 2446 | ax_print (gdb_stdout, agent); |
085dd6e6 JM |
2447 | |
2448 | /* It would be nice to call ax_reqs here to gather some general info | |
2449 | about the expression, and then print out the result. */ | |
c906108c SS |
2450 | |
2451 | do_cleanups (old_chain); | |
2452 | dont_repeat (); | |
2453 | } | |
782b2b07 SS |
2454 | |
2455 | /* Parse the given expression, compile it into an agent expression | |
2456 | that does direct evaluation, and display the resulting | |
2457 | expression. */ | |
2458 | ||
2459 | static void | |
2460 | agent_eval_command (char *exp, int from_tty) | |
2461 | { | |
2462 | struct cleanup *old_chain = 0; | |
2463 | struct expression *expr; | |
2464 | struct agent_expr *agent; | |
2465 | struct frame_info *fi = get_current_frame (); /* need current scope */ | |
2466 | ||
2467 | /* We don't deal with overlay debugging at the moment. We need to | |
2468 | think more carefully about this. If you copy this code into | |
2469 | another command, change the error message; the user shouldn't | |
2470 | have to know anything about agent expressions. */ | |
2471 | if (overlay_debugging) | |
2472 | error (_("GDB can't do agent expression translation with overlays.")); | |
2473 | ||
2474 | if (exp == 0) | |
2475 | error_no_arg (_("expression to translate")); | |
2476 | ||
2477 | expr = parse_expression (exp); | |
2478 | old_chain = make_cleanup (free_current_contents, &expr); | |
2479 | agent = gen_eval_for_expr (get_frame_pc (fi), expr); | |
2480 | make_cleanup_free_agent_expr (agent); | |
35c9c7ba | 2481 | ax_reqs (agent); |
782b2b07 SS |
2482 | ax_print (gdb_stdout, agent); |
2483 | ||
2484 | /* It would be nice to call ax_reqs here to gather some general info | |
2485 | about the expression, and then print out the result. */ | |
2486 | ||
2487 | do_cleanups (old_chain); | |
2488 | dont_repeat (); | |
2489 | } | |
c906108c | 2490 | \f |
c5aa993b | 2491 | |
c906108c SS |
2492 | /* Initialization code. */ |
2493 | ||
a14ed312 | 2494 | void _initialize_ax_gdb (void); |
c906108c | 2495 | void |
fba45db2 | 2496 | _initialize_ax_gdb (void) |
c906108c | 2497 | { |
c906108c | 2498 | add_cmd ("agent", class_maintenance, agent_command, |
782b2b07 SS |
2499 | _("Translate an expression into remote agent bytecode for tracing."), |
2500 | &maintenancelist); | |
2501 | ||
2502 | add_cmd ("agent-eval", class_maintenance, agent_eval_command, | |
2503 | _("Translate an expression into remote agent bytecode for evaluation."), | |
c906108c SS |
2504 | &maintenancelist); |
2505 | } |