Commit | Line | Data |
---|---|---|
1bac305b AC |
1 | /* GDB-specific functions for operating on agent expressions. |
2 | ||
0fb0cc75 | 3 | Copyright (C) 1998, 1999, 2000, 2001, 2003, 2007, 2008, 2009 |
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" | |
25 | #include "value.h" | |
26 | #include "expression.h" | |
27 | #include "command.h" | |
28 | #include "gdbcmd.h" | |
29 | #include "frame.h" | |
30 | #include "target.h" | |
31 | #include "ax.h" | |
32 | #include "ax-gdb.h" | |
309367d4 | 33 | #include "gdb_string.h" |
fe898f56 | 34 | #include "block.h" |
7b83296f | 35 | #include "regcache.h" |
029a67e4 | 36 | #include "user-regs.h" |
f7c79c41 | 37 | #include "language.h" |
6c228b9c | 38 | #include "dictionary.h" |
f61e138d | 39 | #include "tracepoint.h" |
c906108c | 40 | |
6426a772 JM |
41 | /* To make sense of this file, you should read doc/agentexpr.texi. |
42 | Then look at the types and enums in ax-gdb.h. For the code itself, | |
43 | look at gen_expr, towards the bottom; that's the main function that | |
44 | looks at the GDB expressions and calls everything else to generate | |
45 | code. | |
c906108c SS |
46 | |
47 | I'm beginning to wonder whether it wouldn't be nicer to internally | |
48 | generate trees, with types, and then spit out the bytecode in | |
49 | linear form afterwards; we could generate fewer `swap', `ext', and | |
50 | `zero_ext' bytecodes that way; it would make good constant folding | |
51 | easier, too. But at the moment, I think we should be willing to | |
52 | pay for the simplicity of this code with less-than-optimal bytecode | |
53 | strings. | |
54 | ||
c5aa993b JM |
55 | Remember, "GBD" stands for "Great Britain, Dammit!" So be careful. */ |
56 | \f | |
c906108c SS |
57 | |
58 | ||
c906108c SS |
59 | /* Prototypes for local functions. */ |
60 | ||
61 | /* There's a standard order to the arguments of these functions: | |
62 | union exp_element ** --- pointer into expression | |
63 | struct agent_expr * --- agent expression buffer to generate code into | |
64 | struct axs_value * --- describes value left on top of stack */ | |
c5aa993b | 65 | |
a14ed312 KB |
66 | static struct value *const_var_ref (struct symbol *var); |
67 | static struct value *const_expr (union exp_element **pc); | |
68 | static struct value *maybe_const_expr (union exp_element **pc); | |
69 | ||
70 | static void gen_traced_pop (struct agent_expr *, struct axs_value *); | |
71 | ||
72 | static void gen_sign_extend (struct agent_expr *, struct type *); | |
73 | static void gen_extend (struct agent_expr *, struct type *); | |
74 | static void gen_fetch (struct agent_expr *, struct type *); | |
75 | static void gen_left_shift (struct agent_expr *, int); | |
76 | ||
77 | ||
f7c79c41 UW |
78 | static void gen_frame_args_address (struct gdbarch *, struct agent_expr *); |
79 | static void gen_frame_locals_address (struct gdbarch *, struct agent_expr *); | |
a14ed312 KB |
80 | static void gen_offset (struct agent_expr *ax, int offset); |
81 | static void gen_sym_offset (struct agent_expr *, struct symbol *); | |
f7c79c41 | 82 | static void gen_var_ref (struct gdbarch *, struct agent_expr *ax, |
a14ed312 KB |
83 | struct axs_value *value, struct symbol *var); |
84 | ||
85 | ||
86 | static void gen_int_literal (struct agent_expr *ax, | |
87 | struct axs_value *value, | |
88 | LONGEST k, struct type *type); | |
89 | ||
90 | ||
91 | static void require_rvalue (struct agent_expr *ax, struct axs_value *value); | |
f7c79c41 UW |
92 | static void gen_usual_unary (struct expression *exp, struct agent_expr *ax, |
93 | struct axs_value *value); | |
a14ed312 KB |
94 | static int type_wider_than (struct type *type1, struct type *type2); |
95 | static struct type *max_type (struct type *type1, struct type *type2); | |
96 | static void gen_conversion (struct agent_expr *ax, | |
97 | struct type *from, struct type *to); | |
98 | static int is_nontrivial_conversion (struct type *from, struct type *to); | |
f7c79c41 UW |
99 | static void gen_usual_arithmetic (struct expression *exp, |
100 | struct agent_expr *ax, | |
a14ed312 KB |
101 | struct axs_value *value1, |
102 | struct axs_value *value2); | |
f7c79c41 UW |
103 | static void gen_integral_promotions (struct expression *exp, |
104 | struct agent_expr *ax, | |
a14ed312 KB |
105 | struct axs_value *value); |
106 | static void gen_cast (struct agent_expr *ax, | |
107 | struct axs_value *value, struct type *type); | |
108 | static void gen_scale (struct agent_expr *ax, | |
109 | enum agent_op op, struct type *type); | |
f7c79c41 UW |
110 | static void gen_ptradd (struct agent_expr *ax, struct axs_value *value, |
111 | struct axs_value *value1, struct axs_value *value2); | |
112 | static void gen_ptrsub (struct agent_expr *ax, struct axs_value *value, | |
113 | struct axs_value *value1, struct axs_value *value2); | |
114 | static void gen_ptrdiff (struct agent_expr *ax, struct axs_value *value, | |
115 | struct axs_value *value1, struct axs_value *value2, | |
116 | struct type *result_type); | |
a14ed312 KB |
117 | static void gen_binop (struct agent_expr *ax, |
118 | struct axs_value *value, | |
119 | struct axs_value *value1, | |
120 | struct axs_value *value2, | |
121 | enum agent_op op, | |
122 | enum agent_op op_unsigned, int may_carry, char *name); | |
f7c79c41 UW |
123 | static void gen_logical_not (struct agent_expr *ax, struct axs_value *value, |
124 | struct type *result_type); | |
a14ed312 KB |
125 | static void gen_complement (struct agent_expr *ax, struct axs_value *value); |
126 | static void gen_deref (struct agent_expr *, struct axs_value *); | |
127 | static void gen_address_of (struct agent_expr *, struct axs_value *); | |
128 | static int find_field (struct type *type, char *name); | |
505e835d | 129 | static void gen_bitfield_ref (struct expression *exp, struct agent_expr *ax, |
a14ed312 KB |
130 | struct axs_value *value, |
131 | struct type *type, int start, int end); | |
505e835d | 132 | static void gen_struct_ref (struct expression *exp, struct agent_expr *ax, |
a14ed312 KB |
133 | struct axs_value *value, |
134 | char *field, | |
135 | char *operator_name, char *operand_name); | |
f7c79c41 | 136 | static void gen_repeat (struct expression *exp, union exp_element **pc, |
a14ed312 | 137 | struct agent_expr *ax, struct axs_value *value); |
f7c79c41 UW |
138 | static void gen_sizeof (struct expression *exp, union exp_element **pc, |
139 | struct agent_expr *ax, struct axs_value *value, | |
140 | struct type *size_type); | |
141 | static void gen_expr (struct expression *exp, union exp_element **pc, | |
a14ed312 | 142 | struct agent_expr *ax, struct axs_value *value); |
f61e138d SS |
143 | static void gen_expr_binop_rest (struct expression *exp, |
144 | enum exp_opcode op, union exp_element **pc, | |
145 | struct agent_expr *ax, | |
146 | struct axs_value *value, | |
147 | struct axs_value *value1, | |
148 | struct axs_value *value2); | |
c5aa993b | 149 | |
a14ed312 | 150 | static void agent_command (char *exp, int from_tty); |
c906108c | 151 | \f |
c5aa993b | 152 | |
c906108c SS |
153 | /* Detecting constant expressions. */ |
154 | ||
155 | /* If the variable reference at *PC is a constant, return its value. | |
156 | Otherwise, return zero. | |
157 | ||
158 | Hey, Wally! How can a variable reference be a constant? | |
159 | ||
160 | Well, Beav, this function really handles the OP_VAR_VALUE operator, | |
161 | not specifically variable references. GDB uses OP_VAR_VALUE to | |
162 | refer to any kind of symbolic reference: function names, enum | |
163 | elements, and goto labels are all handled through the OP_VAR_VALUE | |
164 | operator, even though they're constants. It makes sense given the | |
165 | situation. | |
166 | ||
167 | Gee, Wally, don'cha wonder sometimes if data representations that | |
168 | subvert commonly accepted definitions of terms in favor of heavily | |
169 | context-specific interpretations are really just a tool of the | |
170 | programming hegemony to preserve their power and exclude the | |
171 | proletariat? */ | |
172 | ||
173 | static struct value * | |
fba45db2 | 174 | const_var_ref (struct symbol *var) |
c906108c SS |
175 | { |
176 | struct type *type = SYMBOL_TYPE (var); | |
177 | ||
178 | switch (SYMBOL_CLASS (var)) | |
179 | { | |
180 | case LOC_CONST: | |
181 | return value_from_longest (type, (LONGEST) SYMBOL_VALUE (var)); | |
182 | ||
183 | case LOC_LABEL: | |
4478b372 | 184 | return value_from_pointer (type, (CORE_ADDR) SYMBOL_VALUE_ADDRESS (var)); |
c906108c SS |
185 | |
186 | default: | |
187 | return 0; | |
188 | } | |
189 | } | |
190 | ||
191 | ||
192 | /* If the expression starting at *PC has a constant value, return it. | |
193 | Otherwise, return zero. If we return a value, then *PC will be | |
194 | advanced to the end of it. If we return zero, *PC could be | |
195 | anywhere. */ | |
196 | static struct value * | |
fba45db2 | 197 | const_expr (union exp_element **pc) |
c906108c SS |
198 | { |
199 | enum exp_opcode op = (*pc)->opcode; | |
200 | struct value *v1; | |
201 | ||
202 | switch (op) | |
203 | { | |
204 | case OP_LONG: | |
205 | { | |
206 | struct type *type = (*pc)[1].type; | |
207 | LONGEST k = (*pc)[2].longconst; | |
208 | (*pc) += 4; | |
209 | return value_from_longest (type, k); | |
210 | } | |
211 | ||
212 | case OP_VAR_VALUE: | |
213 | { | |
214 | struct value *v = const_var_ref ((*pc)[2].symbol); | |
215 | (*pc) += 4; | |
216 | return v; | |
217 | } | |
218 | ||
c5aa993b | 219 | /* We could add more operators in here. */ |
c906108c SS |
220 | |
221 | case UNOP_NEG: | |
222 | (*pc)++; | |
223 | v1 = const_expr (pc); | |
224 | if (v1) | |
225 | return value_neg (v1); | |
226 | else | |
227 | return 0; | |
228 | ||
229 | default: | |
230 | return 0; | |
231 | } | |
232 | } | |
233 | ||
234 | ||
235 | /* Like const_expr, but guarantee also that *PC is undisturbed if the | |
236 | expression is not constant. */ | |
237 | static struct value * | |
fba45db2 | 238 | maybe_const_expr (union exp_element **pc) |
c906108c SS |
239 | { |
240 | union exp_element *tentative_pc = *pc; | |
241 | struct value *v = const_expr (&tentative_pc); | |
242 | ||
243 | /* If we got a value, then update the real PC. */ | |
244 | if (v) | |
245 | *pc = tentative_pc; | |
c5aa993b | 246 | |
c906108c SS |
247 | return v; |
248 | } | |
c906108c | 249 | \f |
c5aa993b | 250 | |
c906108c SS |
251 | /* Generating bytecode from GDB expressions: general assumptions */ |
252 | ||
253 | /* Here are a few general assumptions made throughout the code; if you | |
254 | want to make a change that contradicts one of these, then you'd | |
255 | better scan things pretty thoroughly. | |
256 | ||
257 | - We assume that all values occupy one stack element. For example, | |
c5aa993b JM |
258 | sometimes we'll swap to get at the left argument to a binary |
259 | operator. If we decide that void values should occupy no stack | |
260 | elements, or that synthetic arrays (whose size is determined at | |
261 | run time, created by the `@' operator) should occupy two stack | |
262 | elements (address and length), then this will cause trouble. | |
c906108c SS |
263 | |
264 | - We assume the stack elements are infinitely wide, and that we | |
c5aa993b JM |
265 | don't have to worry what happens if the user requests an |
266 | operation that is wider than the actual interpreter's stack. | |
267 | That is, it's up to the interpreter to handle directly all the | |
268 | integer widths the user has access to. (Woe betide the language | |
269 | with bignums!) | |
c906108c SS |
270 | |
271 | - We don't support side effects. Thus, we don't have to worry about | |
c5aa993b | 272 | GCC's generalized lvalues, function calls, etc. |
c906108c SS |
273 | |
274 | - We don't support floating point. Many places where we switch on | |
c5aa993b JM |
275 | some type don't bother to include cases for floating point; there |
276 | may be even more subtle ways this assumption exists. For | |
277 | example, the arguments to % must be integers. | |
c906108c SS |
278 | |
279 | - We assume all subexpressions have a static, unchanging type. If | |
c5aa993b JM |
280 | we tried to support convenience variables, this would be a |
281 | problem. | |
c906108c SS |
282 | |
283 | - All values on the stack should always be fully zero- or | |
c5aa993b JM |
284 | sign-extended. |
285 | ||
286 | (I wasn't sure whether to choose this or its opposite --- that | |
287 | only addresses are assumed extended --- but it turns out that | |
288 | neither convention completely eliminates spurious extend | |
289 | operations (if everything is always extended, then you have to | |
290 | extend after add, because it could overflow; if nothing is | |
291 | extended, then you end up producing extends whenever you change | |
292 | sizes), and this is simpler.) */ | |
c906108c | 293 | \f |
c5aa993b | 294 | |
c906108c SS |
295 | /* Generating bytecode from GDB expressions: the `trace' kludge */ |
296 | ||
297 | /* The compiler in this file is a general-purpose mechanism for | |
298 | translating GDB expressions into bytecode. One ought to be able to | |
299 | find a million and one uses for it. | |
300 | ||
301 | However, at the moment it is HOPELESSLY BRAIN-DAMAGED for the sake | |
302 | of expediency. Let he who is without sin cast the first stone. | |
303 | ||
304 | For the data tracing facility, we need to insert `trace' bytecodes | |
305 | before each data fetch; this records all the memory that the | |
306 | expression touches in the course of evaluation, so that memory will | |
307 | be available when the user later tries to evaluate the expression | |
308 | in GDB. | |
309 | ||
310 | This should be done (I think) in a post-processing pass, that walks | |
311 | an arbitrary agent expression and inserts `trace' operations at the | |
312 | appropriate points. But it's much faster to just hack them | |
313 | directly into the code. And since we're in a crunch, that's what | |
314 | I've done. | |
315 | ||
316 | Setting the flag trace_kludge to non-zero enables the code that | |
317 | emits the trace bytecodes at the appropriate points. */ | |
318 | static int trace_kludge; | |
319 | ||
320 | /* Trace the lvalue on the stack, if it needs it. In either case, pop | |
321 | the value. Useful on the left side of a comma, and at the end of | |
322 | an expression being used for tracing. */ | |
323 | static void | |
fba45db2 | 324 | gen_traced_pop (struct agent_expr *ax, struct axs_value *value) |
c906108c SS |
325 | { |
326 | if (trace_kludge) | |
327 | switch (value->kind) | |
328 | { | |
329 | case axs_rvalue: | |
330 | /* We don't trace rvalues, just the lvalues necessary to | |
c5aa993b | 331 | produce them. So just dispose of this value. */ |
c906108c SS |
332 | ax_simple (ax, aop_pop); |
333 | break; | |
334 | ||
335 | case axs_lvalue_memory: | |
336 | { | |
648027cc | 337 | int length = TYPE_LENGTH (check_typedef (value->type)); |
c906108c SS |
338 | |
339 | /* There's no point in trying to use a trace_quick bytecode | |
340 | here, since "trace_quick SIZE pop" is three bytes, whereas | |
341 | "const8 SIZE trace" is also three bytes, does the same | |
342 | thing, and the simplest code which generates that will also | |
343 | work correctly for objects with large sizes. */ | |
344 | ax_const_l (ax, length); | |
345 | ax_simple (ax, aop_trace); | |
346 | } | |
c5aa993b | 347 | break; |
c906108c SS |
348 | |
349 | case axs_lvalue_register: | |
350 | /* We need to mention the register somewhere in the bytecode, | |
351 | so ax_reqs will pick it up and add it to the mask of | |
352 | registers used. */ | |
353 | ax_reg (ax, value->u.reg); | |
354 | ax_simple (ax, aop_pop); | |
355 | break; | |
356 | } | |
357 | else | |
358 | /* If we're not tracing, just pop the value. */ | |
359 | ax_simple (ax, aop_pop); | |
360 | } | |
c5aa993b | 361 | \f |
c906108c SS |
362 | |
363 | ||
c906108c SS |
364 | /* Generating bytecode from GDB expressions: helper functions */ |
365 | ||
366 | /* Assume that the lower bits of the top of the stack is a value of | |
367 | type TYPE, and the upper bits are zero. Sign-extend if necessary. */ | |
368 | static void | |
fba45db2 | 369 | gen_sign_extend (struct agent_expr *ax, struct type *type) |
c906108c SS |
370 | { |
371 | /* Do we need to sign-extend this? */ | |
c5aa993b | 372 | if (!TYPE_UNSIGNED (type)) |
0004e5a2 | 373 | ax_ext (ax, TYPE_LENGTH (type) * TARGET_CHAR_BIT); |
c906108c SS |
374 | } |
375 | ||
376 | ||
377 | /* Assume the lower bits of the top of the stack hold a value of type | |
378 | TYPE, and the upper bits are garbage. Sign-extend or truncate as | |
379 | needed. */ | |
380 | static void | |
fba45db2 | 381 | gen_extend (struct agent_expr *ax, struct type *type) |
c906108c | 382 | { |
0004e5a2 | 383 | int bits = TYPE_LENGTH (type) * TARGET_CHAR_BIT; |
c906108c SS |
384 | /* I just had to. */ |
385 | ((TYPE_UNSIGNED (type) ? ax_zero_ext : ax_ext) (ax, bits)); | |
386 | } | |
387 | ||
388 | ||
389 | /* Assume that the top of the stack contains a value of type "pointer | |
390 | to TYPE"; generate code to fetch its value. Note that TYPE is the | |
391 | target type, not the pointer type. */ | |
392 | static void | |
fba45db2 | 393 | gen_fetch (struct agent_expr *ax, struct type *type) |
c906108c SS |
394 | { |
395 | if (trace_kludge) | |
396 | { | |
397 | /* Record the area of memory we're about to fetch. */ | |
398 | ax_trace_quick (ax, TYPE_LENGTH (type)); | |
399 | } | |
400 | ||
0004e5a2 | 401 | switch (TYPE_CODE (type)) |
c906108c SS |
402 | { |
403 | case TYPE_CODE_PTR: | |
404 | case TYPE_CODE_ENUM: | |
405 | case TYPE_CODE_INT: | |
406 | case TYPE_CODE_CHAR: | |
407 | /* It's a scalar value, so we know how to dereference it. How | |
408 | many bytes long is it? */ | |
0004e5a2 | 409 | switch (TYPE_LENGTH (type)) |
c906108c | 410 | { |
c5aa993b JM |
411 | case 8 / TARGET_CHAR_BIT: |
412 | ax_simple (ax, aop_ref8); | |
413 | break; | |
414 | case 16 / TARGET_CHAR_BIT: | |
415 | ax_simple (ax, aop_ref16); | |
416 | break; | |
417 | case 32 / TARGET_CHAR_BIT: | |
418 | ax_simple (ax, aop_ref32); | |
419 | break; | |
420 | case 64 / TARGET_CHAR_BIT: | |
421 | ax_simple (ax, aop_ref64); | |
422 | break; | |
c906108c SS |
423 | |
424 | /* Either our caller shouldn't have asked us to dereference | |
425 | that pointer (other code's fault), or we're not | |
426 | implementing something we should be (this code's fault). | |
427 | In any case, it's a bug the user shouldn't see. */ | |
428 | default: | |
8e65ff28 | 429 | internal_error (__FILE__, __LINE__, |
3d263c1d | 430 | _("gen_fetch: strange size")); |
c906108c SS |
431 | } |
432 | ||
433 | gen_sign_extend (ax, type); | |
434 | break; | |
435 | ||
436 | default: | |
437 | /* Either our caller shouldn't have asked us to dereference that | |
c5aa993b JM |
438 | pointer (other code's fault), or we're not implementing |
439 | something we should be (this code's fault). In any case, | |
440 | it's a bug the user shouldn't see. */ | |
8e65ff28 | 441 | internal_error (__FILE__, __LINE__, |
3d263c1d | 442 | _("gen_fetch: bad type code")); |
c906108c SS |
443 | } |
444 | } | |
445 | ||
446 | ||
447 | /* Generate code to left shift the top of the stack by DISTANCE bits, or | |
448 | right shift it by -DISTANCE bits if DISTANCE < 0. This generates | |
449 | unsigned (logical) right shifts. */ | |
450 | static void | |
fba45db2 | 451 | gen_left_shift (struct agent_expr *ax, int distance) |
c906108c SS |
452 | { |
453 | if (distance > 0) | |
454 | { | |
455 | ax_const_l (ax, distance); | |
456 | ax_simple (ax, aop_lsh); | |
457 | } | |
458 | else if (distance < 0) | |
459 | { | |
460 | ax_const_l (ax, -distance); | |
461 | ax_simple (ax, aop_rsh_unsigned); | |
462 | } | |
463 | } | |
c5aa993b | 464 | \f |
c906108c SS |
465 | |
466 | ||
c906108c SS |
467 | /* Generating bytecode from GDB expressions: symbol references */ |
468 | ||
469 | /* Generate code to push the base address of the argument portion of | |
470 | the top stack frame. */ | |
471 | static void | |
f7c79c41 | 472 | gen_frame_args_address (struct gdbarch *gdbarch, struct agent_expr *ax) |
c906108c | 473 | { |
39d4ef09 AC |
474 | int frame_reg; |
475 | LONGEST frame_offset; | |
c906108c | 476 | |
f7c79c41 | 477 | gdbarch_virtual_frame_pointer (gdbarch, |
c7bb205c | 478 | ax->scope, &frame_reg, &frame_offset); |
c5aa993b | 479 | ax_reg (ax, frame_reg); |
c906108c SS |
480 | gen_offset (ax, frame_offset); |
481 | } | |
482 | ||
483 | ||
484 | /* Generate code to push the base address of the locals portion of the | |
485 | top stack frame. */ | |
486 | static void | |
f7c79c41 | 487 | gen_frame_locals_address (struct gdbarch *gdbarch, struct agent_expr *ax) |
c906108c | 488 | { |
39d4ef09 AC |
489 | int frame_reg; |
490 | LONGEST frame_offset; | |
c906108c | 491 | |
f7c79c41 | 492 | gdbarch_virtual_frame_pointer (gdbarch, |
c7bb205c | 493 | ax->scope, &frame_reg, &frame_offset); |
c5aa993b | 494 | ax_reg (ax, frame_reg); |
c906108c SS |
495 | gen_offset (ax, frame_offset); |
496 | } | |
497 | ||
498 | ||
499 | /* Generate code to add OFFSET to the top of the stack. Try to | |
500 | generate short and readable code. We use this for getting to | |
501 | variables on the stack, and structure members. If we were | |
502 | programming in ML, it would be clearer why these are the same | |
503 | thing. */ | |
504 | static void | |
fba45db2 | 505 | gen_offset (struct agent_expr *ax, int offset) |
c906108c SS |
506 | { |
507 | /* It would suffice to simply push the offset and add it, but this | |
508 | makes it easier to read positive and negative offsets in the | |
509 | bytecode. */ | |
510 | if (offset > 0) | |
511 | { | |
512 | ax_const_l (ax, offset); | |
513 | ax_simple (ax, aop_add); | |
514 | } | |
515 | else if (offset < 0) | |
516 | { | |
517 | ax_const_l (ax, -offset); | |
518 | ax_simple (ax, aop_sub); | |
519 | } | |
520 | } | |
521 | ||
522 | ||
523 | /* In many cases, a symbol's value is the offset from some other | |
524 | address (stack frame, base register, etc.) Generate code to add | |
525 | VAR's value to the top of the stack. */ | |
526 | static void | |
fba45db2 | 527 | gen_sym_offset (struct agent_expr *ax, struct symbol *var) |
c906108c SS |
528 | { |
529 | gen_offset (ax, SYMBOL_VALUE (var)); | |
530 | } | |
531 | ||
532 | ||
533 | /* Generate code for a variable reference to AX. The variable is the | |
534 | symbol VAR. Set VALUE to describe the result. */ | |
535 | ||
536 | static void | |
f7c79c41 UW |
537 | gen_var_ref (struct gdbarch *gdbarch, struct agent_expr *ax, |
538 | struct axs_value *value, struct symbol *var) | |
c906108c SS |
539 | { |
540 | /* Dereference any typedefs. */ | |
541 | value->type = check_typedef (SYMBOL_TYPE (var)); | |
542 | ||
543 | /* I'm imitating the code in read_var_value. */ | |
544 | switch (SYMBOL_CLASS (var)) | |
545 | { | |
546 | case LOC_CONST: /* A constant, like an enum value. */ | |
547 | ax_const_l (ax, (LONGEST) SYMBOL_VALUE (var)); | |
548 | value->kind = axs_rvalue; | |
549 | break; | |
550 | ||
551 | case LOC_LABEL: /* A goto label, being used as a value. */ | |
552 | ax_const_l (ax, (LONGEST) SYMBOL_VALUE_ADDRESS (var)); | |
553 | value->kind = axs_rvalue; | |
554 | break; | |
555 | ||
556 | case LOC_CONST_BYTES: | |
8e65ff28 | 557 | internal_error (__FILE__, __LINE__, |
3d263c1d | 558 | _("gen_var_ref: LOC_CONST_BYTES symbols are not supported")); |
c906108c SS |
559 | |
560 | /* Variable at a fixed location in memory. Easy. */ | |
561 | case LOC_STATIC: | |
562 | /* Push the address of the variable. */ | |
563 | ax_const_l (ax, SYMBOL_VALUE_ADDRESS (var)); | |
564 | value->kind = axs_lvalue_memory; | |
565 | break; | |
566 | ||
567 | case LOC_ARG: /* var lives in argument area of frame */ | |
f7c79c41 | 568 | gen_frame_args_address (gdbarch, ax); |
c906108c SS |
569 | gen_sym_offset (ax, var); |
570 | value->kind = axs_lvalue_memory; | |
571 | break; | |
572 | ||
573 | case LOC_REF_ARG: /* As above, but the frame slot really | |
574 | holds the address of the variable. */ | |
f7c79c41 | 575 | gen_frame_args_address (gdbarch, ax); |
c906108c SS |
576 | gen_sym_offset (ax, var); |
577 | /* Don't assume any particular pointer size. */ | |
f7c79c41 | 578 | gen_fetch (ax, builtin_type (gdbarch)->builtin_data_ptr); |
c906108c SS |
579 | value->kind = axs_lvalue_memory; |
580 | break; | |
581 | ||
582 | case LOC_LOCAL: /* var lives in locals area of frame */ | |
f7c79c41 | 583 | gen_frame_locals_address (gdbarch, ax); |
c906108c SS |
584 | gen_sym_offset (ax, var); |
585 | value->kind = axs_lvalue_memory; | |
586 | break; | |
587 | ||
c906108c | 588 | case LOC_TYPEDEF: |
3d263c1d | 589 | error (_("Cannot compute value of typedef `%s'."), |
de5ad195 | 590 | SYMBOL_PRINT_NAME (var)); |
c906108c SS |
591 | break; |
592 | ||
593 | case LOC_BLOCK: | |
594 | ax_const_l (ax, BLOCK_START (SYMBOL_BLOCK_VALUE (var))); | |
595 | value->kind = axs_rvalue; | |
596 | break; | |
597 | ||
598 | case LOC_REGISTER: | |
c906108c SS |
599 | /* Don't generate any code at all; in the process of treating |
600 | this as an lvalue or rvalue, the caller will generate the | |
601 | right code. */ | |
602 | value->kind = axs_lvalue_register; | |
768a979c | 603 | value->u.reg = SYMBOL_REGISTER_OPS (var)->register_number (var, gdbarch); |
c906108c SS |
604 | break; |
605 | ||
606 | /* A lot like LOC_REF_ARG, but the pointer lives directly in a | |
2a2d4dc3 AS |
607 | register, not on the stack. Simpler than LOC_REGISTER |
608 | because it's just like any other case where the thing | |
609 | has a real address. */ | |
c906108c | 610 | case LOC_REGPARM_ADDR: |
768a979c | 611 | ax_reg (ax, SYMBOL_REGISTER_OPS (var)->register_number (var, gdbarch)); |
c906108c SS |
612 | value->kind = axs_lvalue_memory; |
613 | break; | |
614 | ||
615 | case LOC_UNRESOLVED: | |
616 | { | |
c5aa993b | 617 | struct minimal_symbol *msym |
3567439c | 618 | = lookup_minimal_symbol (SYMBOL_LINKAGE_NAME (var), NULL, NULL); |
c5aa993b | 619 | if (!msym) |
3d263c1d | 620 | error (_("Couldn't resolve symbol `%s'."), SYMBOL_PRINT_NAME (var)); |
c5aa993b | 621 | |
c906108c SS |
622 | /* Push the address of the variable. */ |
623 | ax_const_l (ax, SYMBOL_VALUE_ADDRESS (msym)); | |
624 | value->kind = axs_lvalue_memory; | |
625 | } | |
c5aa993b | 626 | break; |
c906108c | 627 | |
a55cc764 | 628 | case LOC_COMPUTED: |
a67af2b9 | 629 | /* FIXME: cagney/2004-01-26: It should be possible to |
768a979c | 630 | unconditionally call the SYMBOL_COMPUTED_OPS method when available. |
d3efc286 | 631 | Unfortunately DWARF 2 stores the frame-base (instead of the |
a67af2b9 AC |
632 | function) location in a function's symbol. Oops! For the |
633 | moment enable this when/where applicable. */ | |
505e835d | 634 | SYMBOL_COMPUTED_OPS (var)->tracepoint_var_ref (var, gdbarch, ax, value); |
a55cc764 DJ |
635 | break; |
636 | ||
c906108c | 637 | case LOC_OPTIMIZED_OUT: |
3d263c1d | 638 | error (_("The variable `%s' has been optimized out."), |
de5ad195 | 639 | SYMBOL_PRINT_NAME (var)); |
c906108c SS |
640 | break; |
641 | ||
642 | default: | |
3d263c1d | 643 | error (_("Cannot find value of botched symbol `%s'."), |
de5ad195 | 644 | SYMBOL_PRINT_NAME (var)); |
c906108c SS |
645 | break; |
646 | } | |
647 | } | |
c5aa993b | 648 | \f |
c906108c SS |
649 | |
650 | ||
c906108c SS |
651 | /* Generating bytecode from GDB expressions: literals */ |
652 | ||
653 | static void | |
fba45db2 KB |
654 | gen_int_literal (struct agent_expr *ax, struct axs_value *value, LONGEST k, |
655 | struct type *type) | |
c906108c SS |
656 | { |
657 | ax_const_l (ax, k); | |
658 | value->kind = axs_rvalue; | |
648027cc | 659 | value->type = check_typedef (type); |
c906108c | 660 | } |
c5aa993b | 661 | \f |
c906108c SS |
662 | |
663 | ||
c906108c SS |
664 | /* Generating bytecode from GDB expressions: unary conversions, casts */ |
665 | ||
666 | /* Take what's on the top of the stack (as described by VALUE), and | |
667 | try to make an rvalue out of it. Signal an error if we can't do | |
668 | that. */ | |
669 | static void | |
fba45db2 | 670 | require_rvalue (struct agent_expr *ax, struct axs_value *value) |
c906108c SS |
671 | { |
672 | switch (value->kind) | |
673 | { | |
674 | case axs_rvalue: | |
675 | /* It's already an rvalue. */ | |
676 | break; | |
677 | ||
678 | case axs_lvalue_memory: | |
679 | /* The top of stack is the address of the object. Dereference. */ | |
680 | gen_fetch (ax, value->type); | |
681 | break; | |
682 | ||
683 | case axs_lvalue_register: | |
684 | /* There's nothing on the stack, but value->u.reg is the | |
685 | register number containing the value. | |
686 | ||
c5aa993b JM |
687 | When we add floating-point support, this is going to have to |
688 | change. What about SPARC register pairs, for example? */ | |
c906108c SS |
689 | ax_reg (ax, value->u.reg); |
690 | gen_extend (ax, value->type); | |
691 | break; | |
692 | } | |
693 | ||
694 | value->kind = axs_rvalue; | |
695 | } | |
696 | ||
697 | ||
698 | /* Assume the top of the stack is described by VALUE, and perform the | |
699 | usual unary conversions. This is motivated by ANSI 6.2.2, but of | |
700 | course GDB expressions are not ANSI; they're the mishmash union of | |
701 | a bunch of languages. Rah. | |
702 | ||
703 | NOTE! This function promises to produce an rvalue only when the | |
704 | incoming value is of an appropriate type. In other words, the | |
705 | consumer of the value this function produces may assume the value | |
706 | is an rvalue only after checking its type. | |
707 | ||
708 | The immediate issue is that if the user tries to use a structure or | |
709 | union as an operand of, say, the `+' operator, we don't want to try | |
710 | to convert that structure to an rvalue; require_rvalue will bomb on | |
711 | structs and unions. Rather, we want to simply pass the struct | |
712 | lvalue through unchanged, and let `+' raise an error. */ | |
713 | ||
714 | static void | |
f7c79c41 UW |
715 | gen_usual_unary (struct expression *exp, struct agent_expr *ax, |
716 | struct axs_value *value) | |
c906108c SS |
717 | { |
718 | /* We don't have to generate any code for the usual integral | |
719 | conversions, since values are always represented as full-width on | |
720 | the stack. Should we tweak the type? */ | |
721 | ||
722 | /* Some types require special handling. */ | |
0004e5a2 | 723 | switch (TYPE_CODE (value->type)) |
c906108c SS |
724 | { |
725 | /* Functions get converted to a pointer to the function. */ | |
726 | case TYPE_CODE_FUNC: | |
727 | value->type = lookup_pointer_type (value->type); | |
728 | value->kind = axs_rvalue; /* Should always be true, but just in case. */ | |
729 | break; | |
730 | ||
731 | /* Arrays get converted to a pointer to their first element, and | |
c5aa993b | 732 | are no longer an lvalue. */ |
c906108c SS |
733 | case TYPE_CODE_ARRAY: |
734 | { | |
735 | struct type *elements = TYPE_TARGET_TYPE (value->type); | |
736 | value->type = lookup_pointer_type (elements); | |
737 | value->kind = axs_rvalue; | |
738 | /* We don't need to generate any code; the address of the array | |
739 | is also the address of its first element. */ | |
740 | } | |
c5aa993b | 741 | break; |
c906108c | 742 | |
c5aa993b JM |
743 | /* Don't try to convert structures and unions to rvalues. Let the |
744 | consumer signal an error. */ | |
c906108c SS |
745 | case TYPE_CODE_STRUCT: |
746 | case TYPE_CODE_UNION: | |
747 | return; | |
748 | ||
749 | /* If the value is an enum, call it an integer. */ | |
750 | case TYPE_CODE_ENUM: | |
f7c79c41 | 751 | value->type = builtin_type (exp->gdbarch)->builtin_int; |
c906108c SS |
752 | break; |
753 | } | |
754 | ||
755 | /* If the value is an lvalue, dereference it. */ | |
756 | require_rvalue (ax, value); | |
757 | } | |
758 | ||
759 | ||
760 | /* Return non-zero iff the type TYPE1 is considered "wider" than the | |
761 | type TYPE2, according to the rules described in gen_usual_arithmetic. */ | |
762 | static int | |
fba45db2 | 763 | type_wider_than (struct type *type1, struct type *type2) |
c906108c SS |
764 | { |
765 | return (TYPE_LENGTH (type1) > TYPE_LENGTH (type2) | |
766 | || (TYPE_LENGTH (type1) == TYPE_LENGTH (type2) | |
767 | && TYPE_UNSIGNED (type1) | |
c5aa993b | 768 | && !TYPE_UNSIGNED (type2))); |
c906108c SS |
769 | } |
770 | ||
771 | ||
772 | /* Return the "wider" of the two types TYPE1 and TYPE2. */ | |
773 | static struct type * | |
fba45db2 | 774 | max_type (struct type *type1, struct type *type2) |
c906108c SS |
775 | { |
776 | return type_wider_than (type1, type2) ? type1 : type2; | |
777 | } | |
778 | ||
779 | ||
780 | /* Generate code to convert a scalar value of type FROM to type TO. */ | |
781 | static void | |
fba45db2 | 782 | gen_conversion (struct agent_expr *ax, struct type *from, struct type *to) |
c906108c SS |
783 | { |
784 | /* Perhaps there is a more graceful way to state these rules. */ | |
785 | ||
786 | /* If we're converting to a narrower type, then we need to clear out | |
787 | the upper bits. */ | |
788 | if (TYPE_LENGTH (to) < TYPE_LENGTH (from)) | |
789 | gen_extend (ax, from); | |
790 | ||
791 | /* If the two values have equal width, but different signednesses, | |
792 | then we need to extend. */ | |
793 | else if (TYPE_LENGTH (to) == TYPE_LENGTH (from)) | |
794 | { | |
795 | if (TYPE_UNSIGNED (from) != TYPE_UNSIGNED (to)) | |
796 | gen_extend (ax, to); | |
797 | } | |
798 | ||
799 | /* If we're converting to a wider type, and becoming unsigned, then | |
800 | we need to zero out any possible sign bits. */ | |
801 | else if (TYPE_LENGTH (to) > TYPE_LENGTH (from)) | |
802 | { | |
803 | if (TYPE_UNSIGNED (to)) | |
804 | gen_extend (ax, to); | |
805 | } | |
806 | } | |
807 | ||
808 | ||
809 | /* Return non-zero iff the type FROM will require any bytecodes to be | |
810 | emitted to be converted to the type TO. */ | |
811 | static int | |
fba45db2 | 812 | is_nontrivial_conversion (struct type *from, struct type *to) |
c906108c SS |
813 | { |
814 | struct agent_expr *ax = new_agent_expr (0); | |
815 | int nontrivial; | |
816 | ||
817 | /* Actually generate the code, and see if anything came out. At the | |
818 | moment, it would be trivial to replicate the code in | |
819 | gen_conversion here, but in the future, when we're supporting | |
820 | floating point and the like, it may not be. Doing things this | |
821 | way allows this function to be independent of the logic in | |
822 | gen_conversion. */ | |
823 | gen_conversion (ax, from, to); | |
824 | nontrivial = ax->len > 0; | |
825 | free_agent_expr (ax); | |
826 | return nontrivial; | |
827 | } | |
828 | ||
829 | ||
830 | /* Generate code to perform the "usual arithmetic conversions" (ANSI C | |
831 | 6.2.1.5) for the two operands of an arithmetic operator. This | |
832 | effectively finds a "least upper bound" type for the two arguments, | |
833 | and promotes each argument to that type. *VALUE1 and *VALUE2 | |
834 | describe the values as they are passed in, and as they are left. */ | |
835 | static void | |
f7c79c41 UW |
836 | gen_usual_arithmetic (struct expression *exp, struct agent_expr *ax, |
837 | struct axs_value *value1, struct axs_value *value2) | |
c906108c SS |
838 | { |
839 | /* Do the usual binary conversions. */ | |
840 | if (TYPE_CODE (value1->type) == TYPE_CODE_INT | |
841 | && TYPE_CODE (value2->type) == TYPE_CODE_INT) | |
842 | { | |
843 | /* The ANSI integral promotions seem to work this way: Order the | |
c5aa993b JM |
844 | integer types by size, and then by signedness: an n-bit |
845 | unsigned type is considered "wider" than an n-bit signed | |
846 | type. Promote to the "wider" of the two types, and always | |
847 | promote at least to int. */ | |
f7c79c41 | 848 | struct type *target = max_type (builtin_type (exp->gdbarch)->builtin_int, |
c906108c SS |
849 | max_type (value1->type, value2->type)); |
850 | ||
851 | /* Deal with value2, on the top of the stack. */ | |
852 | gen_conversion (ax, value2->type, target); | |
853 | ||
854 | /* Deal with value1, not on the top of the stack. Don't | |
855 | generate the `swap' instructions if we're not actually going | |
856 | to do anything. */ | |
857 | if (is_nontrivial_conversion (value1->type, target)) | |
858 | { | |
859 | ax_simple (ax, aop_swap); | |
860 | gen_conversion (ax, value1->type, target); | |
861 | ax_simple (ax, aop_swap); | |
862 | } | |
863 | ||
648027cc | 864 | value1->type = value2->type = check_typedef (target); |
c906108c SS |
865 | } |
866 | } | |
867 | ||
868 | ||
869 | /* Generate code to perform the integral promotions (ANSI 6.2.1.1) on | |
870 | the value on the top of the stack, as described by VALUE. Assume | |
871 | the value has integral type. */ | |
872 | static void | |
f7c79c41 UW |
873 | gen_integral_promotions (struct expression *exp, struct agent_expr *ax, |
874 | struct axs_value *value) | |
c906108c | 875 | { |
f7c79c41 UW |
876 | const struct builtin_type *builtin = builtin_type (exp->gdbarch); |
877 | ||
878 | if (!type_wider_than (value->type, builtin->builtin_int)) | |
c906108c | 879 | { |
f7c79c41 UW |
880 | gen_conversion (ax, value->type, builtin->builtin_int); |
881 | value->type = builtin->builtin_int; | |
c906108c | 882 | } |
f7c79c41 | 883 | else if (!type_wider_than (value->type, builtin->builtin_unsigned_int)) |
c906108c | 884 | { |
f7c79c41 UW |
885 | gen_conversion (ax, value->type, builtin->builtin_unsigned_int); |
886 | value->type = builtin->builtin_unsigned_int; | |
c906108c SS |
887 | } |
888 | } | |
889 | ||
890 | ||
891 | /* Generate code for a cast to TYPE. */ | |
892 | static void | |
fba45db2 | 893 | gen_cast (struct agent_expr *ax, struct axs_value *value, struct type *type) |
c906108c SS |
894 | { |
895 | /* GCC does allow casts to yield lvalues, so this should be fixed | |
896 | before merging these changes into the trunk. */ | |
897 | require_rvalue (ax, value); | |
898 | /* Dereference typedefs. */ | |
899 | type = check_typedef (type); | |
900 | ||
0004e5a2 | 901 | switch (TYPE_CODE (type)) |
c906108c SS |
902 | { |
903 | case TYPE_CODE_PTR: | |
904 | /* It's implementation-defined, and I'll bet this is what GCC | |
905 | does. */ | |
906 | break; | |
907 | ||
908 | case TYPE_CODE_ARRAY: | |
909 | case TYPE_CODE_STRUCT: | |
910 | case TYPE_CODE_UNION: | |
911 | case TYPE_CODE_FUNC: | |
3d263c1d | 912 | error (_("Invalid type cast: intended type must be scalar.")); |
c906108c SS |
913 | |
914 | case TYPE_CODE_ENUM: | |
915 | /* We don't have to worry about the size of the value, because | |
916 | all our integral values are fully sign-extended, and when | |
917 | casting pointers we can do anything we like. Is there any | |
74b35824 JB |
918 | way for us to know what GCC actually does with a cast like |
919 | this? */ | |
c906108c | 920 | break; |
c5aa993b | 921 | |
c906108c SS |
922 | case TYPE_CODE_INT: |
923 | gen_conversion (ax, value->type, type); | |
924 | break; | |
925 | ||
926 | case TYPE_CODE_VOID: | |
927 | /* We could pop the value, and rely on everyone else to check | |
c5aa993b JM |
928 | the type and notice that this value doesn't occupy a stack |
929 | slot. But for now, leave the value on the stack, and | |
930 | preserve the "value == stack element" assumption. */ | |
c906108c SS |
931 | break; |
932 | ||
933 | default: | |
3d263c1d | 934 | error (_("Casts to requested type are not yet implemented.")); |
c906108c SS |
935 | } |
936 | ||
937 | value->type = type; | |
938 | } | |
c5aa993b | 939 | \f |
c906108c SS |
940 | |
941 | ||
c906108c SS |
942 | /* Generating bytecode from GDB expressions: arithmetic */ |
943 | ||
944 | /* Scale the integer on the top of the stack by the size of the target | |
945 | of the pointer type TYPE. */ | |
946 | static void | |
fba45db2 | 947 | gen_scale (struct agent_expr *ax, enum agent_op op, struct type *type) |
c906108c SS |
948 | { |
949 | struct type *element = TYPE_TARGET_TYPE (type); | |
950 | ||
0004e5a2 | 951 | if (TYPE_LENGTH (element) != 1) |
c906108c | 952 | { |
0004e5a2 | 953 | ax_const_l (ax, TYPE_LENGTH (element)); |
c906108c SS |
954 | ax_simple (ax, op); |
955 | } | |
956 | } | |
957 | ||
958 | ||
f7c79c41 | 959 | /* Generate code for pointer arithmetic PTR + INT. */ |
c906108c | 960 | static void |
f7c79c41 UW |
961 | gen_ptradd (struct agent_expr *ax, struct axs_value *value, |
962 | struct axs_value *value1, struct axs_value *value2) | |
c906108c | 963 | { |
f7c79c41 UW |
964 | gdb_assert (TYPE_CODE (value1->type) == TYPE_CODE_PTR); |
965 | gdb_assert (TYPE_CODE (value2->type) == TYPE_CODE_INT); | |
c906108c | 966 | |
f7c79c41 UW |
967 | gen_scale (ax, aop_mul, value1->type); |
968 | ax_simple (ax, aop_add); | |
969 | gen_extend (ax, value1->type); /* Catch overflow. */ | |
970 | value->type = value1->type; | |
971 | value->kind = axs_rvalue; | |
972 | } | |
c906108c | 973 | |
c906108c | 974 | |
f7c79c41 UW |
975 | /* Generate code for pointer arithmetic PTR - INT. */ |
976 | static void | |
977 | gen_ptrsub (struct agent_expr *ax, struct axs_value *value, | |
978 | struct axs_value *value1, struct axs_value *value2) | |
979 | { | |
980 | gdb_assert (TYPE_CODE (value1->type) == TYPE_CODE_PTR); | |
981 | gdb_assert (TYPE_CODE (value2->type) == TYPE_CODE_INT); | |
c906108c | 982 | |
f7c79c41 UW |
983 | gen_scale (ax, aop_mul, value1->type); |
984 | ax_simple (ax, aop_sub); | |
985 | gen_extend (ax, value1->type); /* Catch overflow. */ | |
986 | value->type = value1->type; | |
c906108c SS |
987 | value->kind = axs_rvalue; |
988 | } | |
989 | ||
990 | ||
f7c79c41 | 991 | /* Generate code for pointer arithmetic PTR - PTR. */ |
c906108c | 992 | static void |
f7c79c41 UW |
993 | gen_ptrdiff (struct agent_expr *ax, struct axs_value *value, |
994 | struct axs_value *value1, struct axs_value *value2, | |
995 | struct type *result_type) | |
c906108c | 996 | { |
f7c79c41 UW |
997 | gdb_assert (TYPE_CODE (value1->type) == TYPE_CODE_PTR); |
998 | gdb_assert (TYPE_CODE (value2->type) == TYPE_CODE_PTR); | |
c906108c | 999 | |
f7c79c41 UW |
1000 | if (TYPE_LENGTH (TYPE_TARGET_TYPE (value1->type)) |
1001 | != TYPE_LENGTH (TYPE_TARGET_TYPE (value2->type))) | |
1002 | error (_("\ | |
c906108c | 1003 | First argument of `-' is a pointer, but second argument is neither\n\ |
3d263c1d | 1004 | an integer nor a pointer of the same type.")); |
c906108c | 1005 | |
f7c79c41 UW |
1006 | ax_simple (ax, aop_sub); |
1007 | gen_scale (ax, aop_div_unsigned, value1->type); | |
1008 | value->type = result_type; | |
c906108c SS |
1009 | value->kind = axs_rvalue; |
1010 | } | |
1011 | ||
f7c79c41 | 1012 | |
c906108c SS |
1013 | /* Generate code for a binary operator that doesn't do pointer magic. |
1014 | We set VALUE to describe the result value; we assume VALUE1 and | |
1015 | VALUE2 describe the two operands, and that they've undergone the | |
1016 | usual binary conversions. MAY_CARRY should be non-zero iff the | |
1017 | result needs to be extended. NAME is the English name of the | |
1018 | operator, used in error messages */ | |
1019 | static void | |
fba45db2 KB |
1020 | gen_binop (struct agent_expr *ax, struct axs_value *value, |
1021 | struct axs_value *value1, struct axs_value *value2, enum agent_op op, | |
1022 | enum agent_op op_unsigned, int may_carry, char *name) | |
c906108c SS |
1023 | { |
1024 | /* We only handle INT op INT. */ | |
0004e5a2 DJ |
1025 | if ((TYPE_CODE (value1->type) != TYPE_CODE_INT) |
1026 | || (TYPE_CODE (value2->type) != TYPE_CODE_INT)) | |
3d263c1d | 1027 | error (_("Invalid combination of types in %s."), name); |
c5aa993b | 1028 | |
c906108c SS |
1029 | ax_simple (ax, |
1030 | TYPE_UNSIGNED (value1->type) ? op_unsigned : op); | |
1031 | if (may_carry) | |
c5aa993b | 1032 | gen_extend (ax, value1->type); /* catch overflow */ |
c906108c SS |
1033 | value->type = value1->type; |
1034 | value->kind = axs_rvalue; | |
1035 | } | |
1036 | ||
1037 | ||
1038 | static void | |
f7c79c41 UW |
1039 | gen_logical_not (struct agent_expr *ax, struct axs_value *value, |
1040 | struct type *result_type) | |
c906108c SS |
1041 | { |
1042 | if (TYPE_CODE (value->type) != TYPE_CODE_INT | |
1043 | && TYPE_CODE (value->type) != TYPE_CODE_PTR) | |
3d263c1d | 1044 | error (_("Invalid type of operand to `!'.")); |
c906108c | 1045 | |
c906108c | 1046 | ax_simple (ax, aop_log_not); |
f7c79c41 | 1047 | value->type = result_type; |
c906108c SS |
1048 | } |
1049 | ||
1050 | ||
1051 | static void | |
fba45db2 | 1052 | gen_complement (struct agent_expr *ax, struct axs_value *value) |
c906108c SS |
1053 | { |
1054 | if (TYPE_CODE (value->type) != TYPE_CODE_INT) | |
3d263c1d | 1055 | error (_("Invalid type of operand to `~'.")); |
c906108c | 1056 | |
c906108c SS |
1057 | ax_simple (ax, aop_bit_not); |
1058 | gen_extend (ax, value->type); | |
1059 | } | |
c5aa993b | 1060 | \f |
c906108c SS |
1061 | |
1062 | ||
c906108c SS |
1063 | /* Generating bytecode from GDB expressions: * & . -> @ sizeof */ |
1064 | ||
1065 | /* Dereference the value on the top of the stack. */ | |
1066 | static void | |
fba45db2 | 1067 | gen_deref (struct agent_expr *ax, struct axs_value *value) |
c906108c SS |
1068 | { |
1069 | /* The caller should check the type, because several operators use | |
1070 | this, and we don't know what error message to generate. */ | |
0004e5a2 | 1071 | if (TYPE_CODE (value->type) != TYPE_CODE_PTR) |
8e65ff28 | 1072 | internal_error (__FILE__, __LINE__, |
3d263c1d | 1073 | _("gen_deref: expected a pointer")); |
c906108c SS |
1074 | |
1075 | /* We've got an rvalue now, which is a pointer. We want to yield an | |
1076 | lvalue, whose address is exactly that pointer. So we don't | |
1077 | actually emit any code; we just change the type from "Pointer to | |
1078 | T" to "T", and mark the value as an lvalue in memory. Leave it | |
1079 | to the consumer to actually dereference it. */ | |
1080 | value->type = check_typedef (TYPE_TARGET_TYPE (value->type)); | |
0004e5a2 | 1081 | value->kind = ((TYPE_CODE (value->type) == TYPE_CODE_FUNC) |
c906108c SS |
1082 | ? axs_rvalue : axs_lvalue_memory); |
1083 | } | |
1084 | ||
1085 | ||
1086 | /* Produce the address of the lvalue on the top of the stack. */ | |
1087 | static void | |
fba45db2 | 1088 | gen_address_of (struct agent_expr *ax, struct axs_value *value) |
c906108c SS |
1089 | { |
1090 | /* Special case for taking the address of a function. The ANSI | |
1091 | standard describes this as a special case, too, so this | |
1092 | arrangement is not without motivation. */ | |
0004e5a2 | 1093 | if (TYPE_CODE (value->type) == TYPE_CODE_FUNC) |
c906108c SS |
1094 | /* The value's already an rvalue on the stack, so we just need to |
1095 | change the type. */ | |
1096 | value->type = lookup_pointer_type (value->type); | |
1097 | else | |
1098 | switch (value->kind) | |
1099 | { | |
1100 | case axs_rvalue: | |
3d263c1d | 1101 | error (_("Operand of `&' is an rvalue, which has no address.")); |
c906108c SS |
1102 | |
1103 | case axs_lvalue_register: | |
3d263c1d | 1104 | error (_("Operand of `&' is in a register, and has no address.")); |
c906108c SS |
1105 | |
1106 | case axs_lvalue_memory: | |
1107 | value->kind = axs_rvalue; | |
1108 | value->type = lookup_pointer_type (value->type); | |
1109 | break; | |
1110 | } | |
1111 | } | |
1112 | ||
1113 | ||
1114 | /* A lot of this stuff will have to change to support C++. But we're | |
1115 | not going to deal with that at the moment. */ | |
1116 | ||
1117 | /* Find the field in the structure type TYPE named NAME, and return | |
1118 | its index in TYPE's field array. */ | |
1119 | static int | |
fba45db2 | 1120 | find_field (struct type *type, char *name) |
c906108c SS |
1121 | { |
1122 | int i; | |
1123 | ||
1124 | CHECK_TYPEDEF (type); | |
1125 | ||
1126 | /* Make sure this isn't C++. */ | |
1127 | if (TYPE_N_BASECLASSES (type) != 0) | |
8e65ff28 | 1128 | internal_error (__FILE__, __LINE__, |
3d263c1d | 1129 | _("find_field: derived classes supported")); |
c906108c SS |
1130 | |
1131 | for (i = 0; i < TYPE_NFIELDS (type); i++) | |
1132 | { | |
1133 | char *this_name = TYPE_FIELD_NAME (type, i); | |
1134 | ||
747f3d18 MS |
1135 | if (this_name) |
1136 | { | |
1137 | if (strcmp (name, this_name) == 0) | |
1138 | return i; | |
c906108c | 1139 | |
747f3d18 MS |
1140 | if (this_name[0] == '\0') |
1141 | internal_error (__FILE__, __LINE__, | |
1142 | _("find_field: anonymous unions not supported")); | |
1143 | } | |
c906108c SS |
1144 | } |
1145 | ||
3d263c1d | 1146 | error (_("Couldn't find member named `%s' in struct/union `%s'"), |
7495dfdb | 1147 | name, TYPE_TAG_NAME (type)); |
c906108c SS |
1148 | |
1149 | return 0; | |
1150 | } | |
1151 | ||
1152 | ||
1153 | /* Generate code to push the value of a bitfield of a structure whose | |
1154 | address is on the top of the stack. START and END give the | |
1155 | starting and one-past-ending *bit* numbers of the field within the | |
1156 | structure. */ | |
1157 | static void | |
505e835d UW |
1158 | gen_bitfield_ref (struct expression *exp, struct agent_expr *ax, |
1159 | struct axs_value *value, struct type *type, | |
1160 | int start, int end) | |
c906108c SS |
1161 | { |
1162 | /* Note that ops[i] fetches 8 << i bits. */ | |
1163 | static enum agent_op ops[] | |
c5aa993b JM |
1164 | = |
1165 | {aop_ref8, aop_ref16, aop_ref32, aop_ref64}; | |
c906108c SS |
1166 | static int num_ops = (sizeof (ops) / sizeof (ops[0])); |
1167 | ||
1168 | /* We don't want to touch any byte that the bitfield doesn't | |
1169 | actually occupy; we shouldn't make any accesses we're not | |
1170 | explicitly permitted to. We rely here on the fact that the | |
1171 | bytecode `ref' operators work on unaligned addresses. | |
1172 | ||
1173 | It takes some fancy footwork to get the stack to work the way | |
1174 | we'd like. Say we're retrieving a bitfield that requires three | |
1175 | fetches. Initially, the stack just contains the address: | |
c5aa993b | 1176 | addr |
c906108c | 1177 | For the first fetch, we duplicate the address |
c5aa993b | 1178 | addr addr |
c906108c SS |
1179 | then add the byte offset, do the fetch, and shift and mask as |
1180 | needed, yielding a fragment of the value, properly aligned for | |
1181 | the final bitwise or: | |
c5aa993b | 1182 | addr frag1 |
c906108c | 1183 | then we swap, and repeat the process: |
c5aa993b JM |
1184 | frag1 addr --- address on top |
1185 | frag1 addr addr --- duplicate it | |
1186 | frag1 addr frag2 --- get second fragment | |
1187 | frag1 frag2 addr --- swap again | |
1188 | frag1 frag2 frag3 --- get third fragment | |
c906108c SS |
1189 | Notice that, since the third fragment is the last one, we don't |
1190 | bother duplicating the address this time. Now we have all the | |
1191 | fragments on the stack, and we can simply `or' them together, | |
1192 | yielding the final value of the bitfield. */ | |
1193 | ||
1194 | /* The first and one-after-last bits in the field, but rounded down | |
1195 | and up to byte boundaries. */ | |
1196 | int bound_start = (start / TARGET_CHAR_BIT) * TARGET_CHAR_BIT; | |
c5aa993b JM |
1197 | int bound_end = (((end + TARGET_CHAR_BIT - 1) |
1198 | / TARGET_CHAR_BIT) | |
1199 | * TARGET_CHAR_BIT); | |
c906108c SS |
1200 | |
1201 | /* current bit offset within the structure */ | |
1202 | int offset; | |
1203 | ||
1204 | /* The index in ops of the opcode we're considering. */ | |
1205 | int op; | |
1206 | ||
1207 | /* The number of fragments we generated in the process. Probably | |
1208 | equal to the number of `one' bits in bytesize, but who cares? */ | |
1209 | int fragment_count; | |
1210 | ||
1211 | /* Dereference any typedefs. */ | |
1212 | type = check_typedef (type); | |
1213 | ||
1214 | /* Can we fetch the number of bits requested at all? */ | |
1215 | if ((end - start) > ((1 << num_ops) * 8)) | |
8e65ff28 | 1216 | internal_error (__FILE__, __LINE__, |
3d263c1d | 1217 | _("gen_bitfield_ref: bitfield too wide")); |
c906108c SS |
1218 | |
1219 | /* Note that we know here that we only need to try each opcode once. | |
1220 | That may not be true on machines with weird byte sizes. */ | |
1221 | offset = bound_start; | |
1222 | fragment_count = 0; | |
1223 | for (op = num_ops - 1; op >= 0; op--) | |
1224 | { | |
1225 | /* number of bits that ops[op] would fetch */ | |
1226 | int op_size = 8 << op; | |
1227 | ||
1228 | /* The stack at this point, from bottom to top, contains zero or | |
c5aa993b JM |
1229 | more fragments, then the address. */ |
1230 | ||
c906108c SS |
1231 | /* Does this fetch fit within the bitfield? */ |
1232 | if (offset + op_size <= bound_end) | |
1233 | { | |
1234 | /* Is this the last fragment? */ | |
1235 | int last_frag = (offset + op_size == bound_end); | |
1236 | ||
c5aa993b JM |
1237 | if (!last_frag) |
1238 | ax_simple (ax, aop_dup); /* keep a copy of the address */ | |
1239 | ||
c906108c SS |
1240 | /* Add the offset. */ |
1241 | gen_offset (ax, offset / TARGET_CHAR_BIT); | |
1242 | ||
1243 | if (trace_kludge) | |
1244 | { | |
1245 | /* Record the area of memory we're about to fetch. */ | |
1246 | ax_trace_quick (ax, op_size / TARGET_CHAR_BIT); | |
1247 | } | |
1248 | ||
1249 | /* Perform the fetch. */ | |
1250 | ax_simple (ax, ops[op]); | |
c5aa993b JM |
1251 | |
1252 | /* Shift the bits we have to their proper position. | |
c906108c SS |
1253 | gen_left_shift will generate right shifts when the operand |
1254 | is negative. | |
1255 | ||
c5aa993b JM |
1256 | A big-endian field diagram to ponder: |
1257 | byte 0 byte 1 byte 2 byte 3 byte 4 byte 5 byte 6 byte 7 | |
1258 | +------++------++------++------++------++------++------++------+ | |
1259 | xxxxAAAAAAAAAAAAAAAAAAAAAAAAAAAABBBBBBBBBBBBBBBBCCCCCxxxxxxxxxxx | |
1260 | ^ ^ ^ ^ | |
1261 | bit number 16 32 48 53 | |
c906108c SS |
1262 | These are bit numbers as supplied by GDB. Note that the |
1263 | bit numbers run from right to left once you've fetched the | |
1264 | value! | |
1265 | ||
c5aa993b JM |
1266 | A little-endian field diagram to ponder: |
1267 | byte 7 byte 6 byte 5 byte 4 byte 3 byte 2 byte 1 byte 0 | |
1268 | +------++------++------++------++------++------++------++------+ | |
1269 | xxxxxxxxxxxAAAAABBBBBBBBBBBBBBBBCCCCCCCCCCCCCCCCCCCCCCCCCCCCxxxx | |
1270 | ^ ^ ^ ^ ^ | |
1271 | bit number 48 32 16 4 0 | |
1272 | ||
1273 | In both cases, the most significant end is on the left | |
1274 | (i.e. normal numeric writing order), which means that you | |
1275 | don't go crazy thinking about `left' and `right' shifts. | |
1276 | ||
1277 | We don't have to worry about masking yet: | |
1278 | - If they contain garbage off the least significant end, then we | |
1279 | must be looking at the low end of the field, and the right | |
1280 | shift will wipe them out. | |
1281 | - If they contain garbage off the most significant end, then we | |
1282 | must be looking at the most significant end of the word, and | |
1283 | the sign/zero extension will wipe them out. | |
1284 | - If we're in the interior of the word, then there is no garbage | |
1285 | on either end, because the ref operators zero-extend. */ | |
505e835d | 1286 | if (gdbarch_byte_order (exp->gdbarch) == BFD_ENDIAN_BIG) |
c906108c | 1287 | gen_left_shift (ax, end - (offset + op_size)); |
c5aa993b | 1288 | else |
c906108c SS |
1289 | gen_left_shift (ax, offset - start); |
1290 | ||
c5aa993b | 1291 | if (!last_frag) |
c906108c SS |
1292 | /* Bring the copy of the address up to the top. */ |
1293 | ax_simple (ax, aop_swap); | |
1294 | ||
1295 | offset += op_size; | |
1296 | fragment_count++; | |
1297 | } | |
1298 | } | |
1299 | ||
1300 | /* Generate enough bitwise `or' operations to combine all the | |
1301 | fragments we left on the stack. */ | |
1302 | while (fragment_count-- > 1) | |
1303 | ax_simple (ax, aop_bit_or); | |
1304 | ||
1305 | /* Sign- or zero-extend the value as appropriate. */ | |
1306 | ((TYPE_UNSIGNED (type) ? ax_zero_ext : ax_ext) (ax, end - start)); | |
1307 | ||
1308 | /* This is *not* an lvalue. Ugh. */ | |
1309 | value->kind = axs_rvalue; | |
1310 | value->type = type; | |
1311 | } | |
1312 | ||
1313 | ||
1314 | /* Generate code to reference the member named FIELD of a structure or | |
1315 | union. The top of the stack, as described by VALUE, should have | |
1316 | type (pointer to a)* struct/union. OPERATOR_NAME is the name of | |
1317 | the operator being compiled, and OPERAND_NAME is the kind of thing | |
1318 | it operates on; we use them in error messages. */ | |
1319 | static void | |
505e835d UW |
1320 | gen_struct_ref (struct expression *exp, struct agent_expr *ax, |
1321 | struct axs_value *value, char *field, | |
fba45db2 | 1322 | char *operator_name, char *operand_name) |
c906108c SS |
1323 | { |
1324 | struct type *type; | |
1325 | int i; | |
1326 | ||
1327 | /* Follow pointers until we reach a non-pointer. These aren't the C | |
1328 | semantics, but they're what the normal GDB evaluator does, so we | |
1329 | should at least be consistent. */ | |
0004e5a2 | 1330 | while (TYPE_CODE (value->type) == TYPE_CODE_PTR) |
c906108c | 1331 | { |
f7c79c41 | 1332 | require_rvalue (ax, value); |
c906108c SS |
1333 | gen_deref (ax, value); |
1334 | } | |
e8860ec2 | 1335 | type = check_typedef (value->type); |
c906108c SS |
1336 | |
1337 | /* This must yield a structure or a union. */ | |
1338 | if (TYPE_CODE (type) != TYPE_CODE_STRUCT | |
1339 | && TYPE_CODE (type) != TYPE_CODE_UNION) | |
3d263c1d | 1340 | error (_("The left operand of `%s' is not a %s."), |
c906108c SS |
1341 | operator_name, operand_name); |
1342 | ||
1343 | /* And it must be in memory; we don't deal with structure rvalues, | |
1344 | or structures living in registers. */ | |
1345 | if (value->kind != axs_lvalue_memory) | |
3d263c1d | 1346 | error (_("Structure does not live in memory.")); |
c906108c SS |
1347 | |
1348 | i = find_field (type, field); | |
c5aa993b | 1349 | |
c906108c SS |
1350 | /* Is this a bitfield? */ |
1351 | if (TYPE_FIELD_PACKED (type, i)) | |
505e835d | 1352 | gen_bitfield_ref (exp, ax, value, TYPE_FIELD_TYPE (type, i), |
c906108c SS |
1353 | TYPE_FIELD_BITPOS (type, i), |
1354 | (TYPE_FIELD_BITPOS (type, i) | |
1355 | + TYPE_FIELD_BITSIZE (type, i))); | |
1356 | else | |
1357 | { | |
1358 | gen_offset (ax, TYPE_FIELD_BITPOS (type, i) / TARGET_CHAR_BIT); | |
1359 | value->kind = axs_lvalue_memory; | |
1360 | value->type = TYPE_FIELD_TYPE (type, i); | |
1361 | } | |
1362 | } | |
1363 | ||
1364 | ||
1365 | /* Generate code for GDB's magical `repeat' operator. | |
1366 | LVALUE @ INT creates an array INT elements long, and whose elements | |
1367 | have the same type as LVALUE, located in memory so that LVALUE is | |
1368 | its first element. For example, argv[0]@argc gives you the array | |
1369 | of command-line arguments. | |
1370 | ||
1371 | Unfortunately, because we have to know the types before we actually | |
1372 | have a value for the expression, we can't implement this perfectly | |
1373 | without changing the type system, having values that occupy two | |
1374 | stack slots, doing weird things with sizeof, etc. So we require | |
1375 | the right operand to be a constant expression. */ | |
1376 | static void | |
f7c79c41 UW |
1377 | gen_repeat (struct expression *exp, union exp_element **pc, |
1378 | struct agent_expr *ax, struct axs_value *value) | |
c906108c SS |
1379 | { |
1380 | struct axs_value value1; | |
1381 | /* We don't want to turn this into an rvalue, so no conversions | |
1382 | here. */ | |
f7c79c41 | 1383 | gen_expr (exp, pc, ax, &value1); |
c906108c | 1384 | if (value1.kind != axs_lvalue_memory) |
3d263c1d | 1385 | error (_("Left operand of `@' must be an object in memory.")); |
c906108c SS |
1386 | |
1387 | /* Evaluate the length; it had better be a constant. */ | |
1388 | { | |
1389 | struct value *v = const_expr (pc); | |
1390 | int length; | |
1391 | ||
c5aa993b | 1392 | if (!v) |
3d263c1d | 1393 | error (_("Right operand of `@' must be a constant, in agent expressions.")); |
04624583 | 1394 | if (TYPE_CODE (value_type (v)) != TYPE_CODE_INT) |
3d263c1d | 1395 | error (_("Right operand of `@' must be an integer.")); |
c906108c SS |
1396 | length = value_as_long (v); |
1397 | if (length <= 0) | |
3d263c1d | 1398 | error (_("Right operand of `@' must be positive.")); |
c906108c SS |
1399 | |
1400 | /* The top of the stack is already the address of the object, so | |
1401 | all we need to do is frob the type of the lvalue. */ | |
1402 | { | |
1403 | /* FIXME-type-allocation: need a way to free this type when we are | |
c5aa993b | 1404 | done with it. */ |
e3506a9f UW |
1405 | struct type *array |
1406 | = lookup_array_range_type (value1.type, 0, length - 1); | |
c906108c SS |
1407 | |
1408 | value->kind = axs_lvalue_memory; | |
1409 | value->type = array; | |
1410 | } | |
1411 | } | |
1412 | } | |
1413 | ||
1414 | ||
1415 | /* Emit code for the `sizeof' operator. | |
1416 | *PC should point at the start of the operand expression; we advance it | |
1417 | to the first instruction after the operand. */ | |
1418 | static void | |
f7c79c41 UW |
1419 | gen_sizeof (struct expression *exp, union exp_element **pc, |
1420 | struct agent_expr *ax, struct axs_value *value, | |
1421 | struct type *size_type) | |
c906108c SS |
1422 | { |
1423 | /* We don't care about the value of the operand expression; we only | |
1424 | care about its type. However, in the current arrangement, the | |
1425 | only way to find an expression's type is to generate code for it. | |
1426 | So we generate code for the operand, and then throw it away, | |
1427 | replacing it with code that simply pushes its size. */ | |
1428 | int start = ax->len; | |
f7c79c41 | 1429 | gen_expr (exp, pc, ax, value); |
c906108c SS |
1430 | |
1431 | /* Throw away the code we just generated. */ | |
1432 | ax->len = start; | |
c5aa993b | 1433 | |
c906108c SS |
1434 | ax_const_l (ax, TYPE_LENGTH (value->type)); |
1435 | value->kind = axs_rvalue; | |
f7c79c41 | 1436 | value->type = size_type; |
c906108c | 1437 | } |
c906108c | 1438 | \f |
c5aa993b | 1439 | |
c906108c SS |
1440 | /* Generating bytecode from GDB expressions: general recursive thingy */ |
1441 | ||
3d263c1d | 1442 | /* XXX: i18n */ |
c906108c SS |
1443 | /* A gen_expr function written by a Gen-X'er guy. |
1444 | Append code for the subexpression of EXPR starting at *POS_P to AX. */ | |
1445 | static void | |
f7c79c41 UW |
1446 | gen_expr (struct expression *exp, union exp_element **pc, |
1447 | struct agent_expr *ax, struct axs_value *value) | |
c906108c SS |
1448 | { |
1449 | /* Used to hold the descriptions of operand expressions. */ | |
09d559e4 | 1450 | struct axs_value value1, value2, value3; |
f61e138d | 1451 | enum exp_opcode op = (*pc)[0].opcode, op2; |
09d559e4 | 1452 | int if1, go1, if2, go2, end; |
c906108c SS |
1453 | |
1454 | /* If we're looking at a constant expression, just push its value. */ | |
1455 | { | |
1456 | struct value *v = maybe_const_expr (pc); | |
c5aa993b | 1457 | |
c906108c SS |
1458 | if (v) |
1459 | { | |
1460 | ax_const_l (ax, value_as_long (v)); | |
1461 | value->kind = axs_rvalue; | |
df407dfe | 1462 | value->type = check_typedef (value_type (v)); |
c906108c SS |
1463 | return; |
1464 | } | |
1465 | } | |
1466 | ||
1467 | /* Otherwise, go ahead and generate code for it. */ | |
1468 | switch (op) | |
1469 | { | |
1470 | /* Binary arithmetic operators. */ | |
1471 | case BINOP_ADD: | |
1472 | case BINOP_SUB: | |
1473 | case BINOP_MUL: | |
1474 | case BINOP_DIV: | |
1475 | case BINOP_REM: | |
1476 | case BINOP_SUBSCRIPT: | |
1477 | case BINOP_BITWISE_AND: | |
1478 | case BINOP_BITWISE_IOR: | |
1479 | case BINOP_BITWISE_XOR: | |
782b2b07 SS |
1480 | case BINOP_EQUAL: |
1481 | case BINOP_NOTEQUAL: | |
1482 | case BINOP_LESS: | |
1483 | case BINOP_GTR: | |
1484 | case BINOP_LEQ: | |
1485 | case BINOP_GEQ: | |
c906108c | 1486 | (*pc)++; |
f7c79c41 UW |
1487 | gen_expr (exp, pc, ax, &value1); |
1488 | gen_usual_unary (exp, ax, &value1); | |
f61e138d SS |
1489 | gen_expr_binop_rest (exp, op, pc, ax, value, &value1, &value2); |
1490 | break; | |
1491 | ||
09d559e4 SS |
1492 | case BINOP_LOGICAL_AND: |
1493 | (*pc)++; | |
1494 | /* Generate the obvious sequence of tests and jumps. */ | |
1495 | gen_expr (exp, pc, ax, &value1); | |
1496 | gen_usual_unary (exp, ax, &value1); | |
1497 | if1 = ax_goto (ax, aop_if_goto); | |
1498 | go1 = ax_goto (ax, aop_goto); | |
1499 | ax_label (ax, if1, ax->len); | |
1500 | gen_expr (exp, pc, ax, &value2); | |
1501 | gen_usual_unary (exp, ax, &value2); | |
1502 | if2 = ax_goto (ax, aop_if_goto); | |
1503 | go2 = ax_goto (ax, aop_goto); | |
1504 | ax_label (ax, if2, ax->len); | |
1505 | ax_const_l (ax, 1); | |
1506 | end = ax_goto (ax, aop_goto); | |
1507 | ax_label (ax, go1, ax->len); | |
1508 | ax_label (ax, go2, ax->len); | |
1509 | ax_const_l (ax, 0); | |
1510 | ax_label (ax, end, ax->len); | |
1511 | value->kind = axs_rvalue; | |
1512 | value->type = language_bool_type (exp->language_defn, exp->gdbarch); | |
1513 | break; | |
1514 | ||
1515 | case BINOP_LOGICAL_OR: | |
1516 | (*pc)++; | |
1517 | /* Generate the obvious sequence of tests and jumps. */ | |
1518 | gen_expr (exp, pc, ax, &value1); | |
1519 | gen_usual_unary (exp, ax, &value1); | |
1520 | if1 = ax_goto (ax, aop_if_goto); | |
1521 | gen_expr (exp, pc, ax, &value2); | |
1522 | gen_usual_unary (exp, ax, &value2); | |
1523 | if2 = ax_goto (ax, aop_if_goto); | |
1524 | ax_const_l (ax, 0); | |
1525 | end = ax_goto (ax, aop_goto); | |
1526 | ax_label (ax, if1, ax->len); | |
1527 | ax_label (ax, if2, ax->len); | |
1528 | ax_const_l (ax, 1); | |
1529 | ax_label (ax, end, ax->len); | |
1530 | value->kind = axs_rvalue; | |
1531 | value->type = language_bool_type (exp->language_defn, exp->gdbarch); | |
1532 | break; | |
1533 | ||
1534 | case TERNOP_COND: | |
1535 | (*pc)++; | |
1536 | gen_expr (exp, pc, ax, &value1); | |
1537 | gen_usual_unary (exp, ax, &value1); | |
1538 | /* For (A ? B : C), it's easiest to generate subexpression | |
1539 | bytecodes in order, but if_goto jumps on true, so we invert | |
1540 | the sense of A. Then we can do B by dropping through, and | |
1541 | jump to do C. */ | |
1542 | gen_logical_not (ax, &value1, | |
1543 | language_bool_type (exp->language_defn, exp->gdbarch)); | |
1544 | if1 = ax_goto (ax, aop_if_goto); | |
1545 | gen_expr (exp, pc, ax, &value2); | |
1546 | gen_usual_unary (exp, ax, &value2); | |
1547 | end = ax_goto (ax, aop_goto); | |
1548 | ax_label (ax, if1, ax->len); | |
1549 | gen_expr (exp, pc, ax, &value3); | |
1550 | gen_usual_unary (exp, ax, &value3); | |
1551 | ax_label (ax, end, ax->len); | |
1552 | /* This is arbitary - what if B and C are incompatible types? */ | |
1553 | value->type = value2.type; | |
1554 | value->kind = value2.kind; | |
1555 | break; | |
1556 | ||
f61e138d SS |
1557 | case BINOP_ASSIGN: |
1558 | (*pc)++; | |
1559 | if ((*pc)[0].opcode == OP_INTERNALVAR) | |
c906108c | 1560 | { |
f61e138d SS |
1561 | char *name = internalvar_name ((*pc)[1].internalvar); |
1562 | struct trace_state_variable *tsv; | |
1563 | (*pc) += 3; | |
1564 | gen_expr (exp, pc, ax, value); | |
1565 | tsv = find_trace_state_variable (name); | |
1566 | if (tsv) | |
f7c79c41 | 1567 | { |
f61e138d SS |
1568 | ax_tsv (ax, aop_setv, tsv->number); |
1569 | if (trace_kludge) | |
1570 | ax_tsv (ax, aop_tracev, tsv->number); | |
f7c79c41 | 1571 | } |
f7c79c41 | 1572 | else |
f61e138d SS |
1573 | error (_("$%s is not a trace state variable, may not assign to it"), name); |
1574 | } | |
1575 | else | |
1576 | error (_("May only assign to trace state variables")); | |
1577 | break; | |
782b2b07 | 1578 | |
f61e138d SS |
1579 | case BINOP_ASSIGN_MODIFY: |
1580 | (*pc)++; | |
1581 | op2 = (*pc)[0].opcode; | |
1582 | (*pc)++; | |
1583 | (*pc)++; | |
1584 | if ((*pc)[0].opcode == OP_INTERNALVAR) | |
1585 | { | |
1586 | char *name = internalvar_name ((*pc)[1].internalvar); | |
1587 | struct trace_state_variable *tsv; | |
1588 | (*pc) += 3; | |
1589 | tsv = find_trace_state_variable (name); | |
1590 | if (tsv) | |
1591 | { | |
1592 | /* The tsv will be the left half of the binary operation. */ | |
1593 | ax_tsv (ax, aop_getv, tsv->number); | |
1594 | if (trace_kludge) | |
1595 | ax_tsv (ax, aop_tracev, tsv->number); | |
1596 | /* Trace state variables are always 64-bit integers. */ | |
1597 | value1.kind = axs_rvalue; | |
1598 | value1.type = builtin_type (exp->gdbarch)->builtin_long_long; | |
1599 | /* Now do right half of expression. */ | |
1600 | gen_expr_binop_rest (exp, op2, pc, ax, value, &value1, &value2); | |
1601 | /* We have a result of the binary op, set the tsv. */ | |
1602 | ax_tsv (ax, aop_setv, tsv->number); | |
1603 | if (trace_kludge) | |
1604 | ax_tsv (ax, aop_tracev, tsv->number); | |
1605 | } | |
1606 | else | |
1607 | error (_("$%s is not a trace state variable, may not assign to it"), name); | |
c906108c | 1608 | } |
f61e138d SS |
1609 | else |
1610 | error (_("May only assign to trace state variables")); | |
c906108c SS |
1611 | break; |
1612 | ||
1613 | /* Note that we need to be a little subtle about generating code | |
c5aa993b JM |
1614 | for comma. In C, we can do some optimizations here because |
1615 | we know the left operand is only being evaluated for effect. | |
1616 | However, if the tracing kludge is in effect, then we always | |
1617 | need to evaluate the left hand side fully, so that all the | |
1618 | variables it mentions get traced. */ | |
c906108c SS |
1619 | case BINOP_COMMA: |
1620 | (*pc)++; | |
f7c79c41 | 1621 | gen_expr (exp, pc, ax, &value1); |
c906108c | 1622 | /* Don't just dispose of the left operand. We might be tracing, |
c5aa993b JM |
1623 | in which case we want to emit code to trace it if it's an |
1624 | lvalue. */ | |
c906108c | 1625 | gen_traced_pop (ax, &value1); |
f7c79c41 | 1626 | gen_expr (exp, pc, ax, value); |
c906108c SS |
1627 | /* It's the consumer's responsibility to trace the right operand. */ |
1628 | break; | |
c5aa993b | 1629 | |
c906108c SS |
1630 | case OP_LONG: /* some integer constant */ |
1631 | { | |
1632 | struct type *type = (*pc)[1].type; | |
1633 | LONGEST k = (*pc)[2].longconst; | |
1634 | (*pc) += 4; | |
1635 | gen_int_literal (ax, value, k, type); | |
1636 | } | |
c5aa993b | 1637 | break; |
c906108c SS |
1638 | |
1639 | case OP_VAR_VALUE: | |
f7c79c41 | 1640 | gen_var_ref (exp->gdbarch, ax, value, (*pc)[2].symbol); |
c906108c SS |
1641 | (*pc) += 4; |
1642 | break; | |
1643 | ||
1644 | case OP_REGISTER: | |
1645 | { | |
67f3407f DJ |
1646 | const char *name = &(*pc)[2].string; |
1647 | int reg; | |
1648 | (*pc) += 4 + BYTES_TO_EXP_ELEM ((*pc)[1].longconst + 1); | |
f7c79c41 | 1649 | reg = user_reg_map_name_to_regnum (exp->gdbarch, name, strlen (name)); |
67f3407f DJ |
1650 | if (reg == -1) |
1651 | internal_error (__FILE__, __LINE__, | |
1652 | _("Register $%s not available"), name); | |
f7c79c41 | 1653 | if (reg >= gdbarch_num_regs (exp->gdbarch)) |
02e4669d JB |
1654 | error (_("'%s' is a pseudo-register; " |
1655 | "GDB cannot yet trace pseudoregister contents."), | |
1656 | name); | |
c906108c SS |
1657 | value->kind = axs_lvalue_register; |
1658 | value->u.reg = reg; | |
f7c79c41 | 1659 | value->type = register_type (exp->gdbarch, reg); |
c906108c | 1660 | } |
c5aa993b | 1661 | break; |
c906108c SS |
1662 | |
1663 | case OP_INTERNALVAR: | |
f61e138d SS |
1664 | { |
1665 | const char *name = internalvar_name ((*pc)[1].internalvar); | |
1666 | struct trace_state_variable *tsv; | |
1667 | (*pc) += 3; | |
1668 | tsv = find_trace_state_variable (name); | |
1669 | if (tsv) | |
1670 | { | |
1671 | ax_tsv (ax, aop_getv, tsv->number); | |
1672 | if (trace_kludge) | |
1673 | ax_tsv (ax, aop_tracev, tsv->number); | |
1674 | /* Trace state variables are always 64-bit integers. */ | |
1675 | value->kind = axs_rvalue; | |
1676 | value->type = builtin_type (exp->gdbarch)->builtin_long_long; | |
1677 | } | |
1678 | else | |
1679 | error (_("$%s is not a trace state variable; GDB agent expressions cannot use convenience variables."), name); | |
1680 | } | |
1681 | break; | |
c906108c | 1682 | |
c5aa993b | 1683 | /* Weirdo operator: see comments for gen_repeat for details. */ |
c906108c SS |
1684 | case BINOP_REPEAT: |
1685 | /* Note that gen_repeat handles its own argument evaluation. */ | |
1686 | (*pc)++; | |
f7c79c41 | 1687 | gen_repeat (exp, pc, ax, value); |
c906108c SS |
1688 | break; |
1689 | ||
1690 | case UNOP_CAST: | |
1691 | { | |
1692 | struct type *type = (*pc)[1].type; | |
1693 | (*pc) += 3; | |
f7c79c41 | 1694 | gen_expr (exp, pc, ax, value); |
c906108c SS |
1695 | gen_cast (ax, value, type); |
1696 | } | |
c5aa993b | 1697 | break; |
c906108c SS |
1698 | |
1699 | case UNOP_MEMVAL: | |
1700 | { | |
1701 | struct type *type = check_typedef ((*pc)[1].type); | |
1702 | (*pc) += 3; | |
f7c79c41 | 1703 | gen_expr (exp, pc, ax, value); |
c906108c SS |
1704 | /* I'm not sure I understand UNOP_MEMVAL entirely. I think |
1705 | it's just a hack for dealing with minsyms; you take some | |
1706 | integer constant, pretend it's the address of an lvalue of | |
1707 | the given type, and dereference it. */ | |
1708 | if (value->kind != axs_rvalue) | |
1709 | /* This would be weird. */ | |
8e65ff28 | 1710 | internal_error (__FILE__, __LINE__, |
3d263c1d | 1711 | _("gen_expr: OP_MEMVAL operand isn't an rvalue???")); |
c906108c SS |
1712 | value->type = type; |
1713 | value->kind = axs_lvalue_memory; | |
1714 | } | |
c5aa993b | 1715 | break; |
c906108c | 1716 | |
36e9969c NS |
1717 | case UNOP_PLUS: |
1718 | (*pc)++; | |
1719 | /* + FOO is equivalent to 0 + FOO, which can be optimized. */ | |
f7c79c41 UW |
1720 | gen_expr (exp, pc, ax, value); |
1721 | gen_usual_unary (exp, ax, value); | |
36e9969c NS |
1722 | break; |
1723 | ||
c906108c SS |
1724 | case UNOP_NEG: |
1725 | (*pc)++; | |
1726 | /* -FOO is equivalent to 0 - FOO. */ | |
22601c15 UW |
1727 | gen_int_literal (ax, &value1, 0, |
1728 | builtin_type (exp->gdbarch)->builtin_int); | |
f7c79c41 UW |
1729 | gen_usual_unary (exp, ax, &value1); /* shouldn't do much */ |
1730 | gen_expr (exp, pc, ax, &value2); | |
1731 | gen_usual_unary (exp, ax, &value2); | |
1732 | gen_usual_arithmetic (exp, ax, &value1, &value2); | |
1733 | gen_binop (ax, value, &value1, &value2, aop_sub, aop_sub, 1, "negation"); | |
c906108c SS |
1734 | break; |
1735 | ||
1736 | case UNOP_LOGICAL_NOT: | |
1737 | (*pc)++; | |
f7c79c41 UW |
1738 | gen_expr (exp, pc, ax, value); |
1739 | gen_usual_unary (exp, ax, value); | |
1740 | gen_logical_not (ax, value, | |
1741 | language_bool_type (exp->language_defn, exp->gdbarch)); | |
c906108c SS |
1742 | break; |
1743 | ||
1744 | case UNOP_COMPLEMENT: | |
1745 | (*pc)++; | |
f7c79c41 UW |
1746 | gen_expr (exp, pc, ax, value); |
1747 | gen_usual_unary (exp, ax, value); | |
1748 | gen_integral_promotions (exp, ax, value); | |
c906108c SS |
1749 | gen_complement (ax, value); |
1750 | break; | |
1751 | ||
1752 | case UNOP_IND: | |
1753 | (*pc)++; | |
f7c79c41 UW |
1754 | gen_expr (exp, pc, ax, value); |
1755 | gen_usual_unary (exp, ax, value); | |
c906108c | 1756 | if (TYPE_CODE (value->type) != TYPE_CODE_PTR) |
3d263c1d | 1757 | error (_("Argument of unary `*' is not a pointer.")); |
c906108c SS |
1758 | gen_deref (ax, value); |
1759 | break; | |
1760 | ||
1761 | case UNOP_ADDR: | |
1762 | (*pc)++; | |
f7c79c41 | 1763 | gen_expr (exp, pc, ax, value); |
c906108c SS |
1764 | gen_address_of (ax, value); |
1765 | break; | |
1766 | ||
1767 | case UNOP_SIZEOF: | |
1768 | (*pc)++; | |
1769 | /* Notice that gen_sizeof handles its own operand, unlike most | |
c5aa993b JM |
1770 | of the other unary operator functions. This is because we |
1771 | have to throw away the code we generate. */ | |
f7c79c41 UW |
1772 | gen_sizeof (exp, pc, ax, value, |
1773 | builtin_type (exp->gdbarch)->builtin_int); | |
c906108c SS |
1774 | break; |
1775 | ||
1776 | case STRUCTOP_STRUCT: | |
1777 | case STRUCTOP_PTR: | |
1778 | { | |
1779 | int length = (*pc)[1].longconst; | |
1780 | char *name = &(*pc)[2].string; | |
1781 | ||
1782 | (*pc) += 4 + BYTES_TO_EXP_ELEM (length + 1); | |
f7c79c41 | 1783 | gen_expr (exp, pc, ax, value); |
c906108c | 1784 | if (op == STRUCTOP_STRUCT) |
505e835d | 1785 | gen_struct_ref (exp, ax, value, name, ".", "structure or union"); |
c906108c | 1786 | else if (op == STRUCTOP_PTR) |
505e835d | 1787 | gen_struct_ref (exp, ax, value, name, "->", |
c906108c SS |
1788 | "pointer to a structure or union"); |
1789 | else | |
1790 | /* If this `if' chain doesn't handle it, then the case list | |
c5aa993b | 1791 | shouldn't mention it, and we shouldn't be here. */ |
8e65ff28 | 1792 | internal_error (__FILE__, __LINE__, |
3d263c1d | 1793 | _("gen_expr: unhandled struct case")); |
c906108c | 1794 | } |
c5aa993b | 1795 | break; |
c906108c | 1796 | |
6c228b9c SS |
1797 | case OP_THIS: |
1798 | { | |
6a0fc12f | 1799 | char *this_name; |
6c228b9c SS |
1800 | struct symbol *func, *sym; |
1801 | struct block *b; | |
1802 | ||
6a0fc12f PA |
1803 | func = block_linkage_function (block_for_pc (ax->scope)); |
1804 | this_name = language_def (SYMBOL_LANGUAGE (func))->la_name_of_this; | |
6c228b9c | 1805 | b = SYMBOL_BLOCK_VALUE (func); |
6c228b9c SS |
1806 | |
1807 | /* Calling lookup_block_symbol is necessary to get the LOC_REGISTER | |
1808 | symbol instead of the LOC_ARG one (if both exist). */ | |
6a0fc12f | 1809 | sym = lookup_block_symbol (b, this_name, NULL, VAR_DOMAIN); |
6c228b9c | 1810 | if (!sym) |
6a0fc12f | 1811 | error (_("no `%s' found"), this_name); |
6c228b9c SS |
1812 | |
1813 | gen_var_ref (exp->gdbarch, ax, value, sym); | |
1814 | (*pc) += 2; | |
1815 | } | |
1816 | break; | |
1817 | ||
c906108c | 1818 | case OP_TYPE: |
3d263c1d | 1819 | error (_("Attempt to use a type name as an expression.")); |
c906108c SS |
1820 | |
1821 | default: | |
3d263c1d | 1822 | error (_("Unsupported operator in expression.")); |
c906108c SS |
1823 | } |
1824 | } | |
f61e138d SS |
1825 | |
1826 | /* This handles the middle-to-right-side of code generation for binary | |
1827 | expressions, which is shared between regular binary operations and | |
1828 | assign-modify (+= and friends) expressions. */ | |
1829 | ||
1830 | static void | |
1831 | gen_expr_binop_rest (struct expression *exp, | |
1832 | enum exp_opcode op, union exp_element **pc, | |
1833 | struct agent_expr *ax, struct axs_value *value, | |
1834 | struct axs_value *value1, struct axs_value *value2) | |
1835 | { | |
1836 | gen_expr (exp, pc, ax, value2); | |
1837 | gen_usual_unary (exp, ax, value2); | |
1838 | gen_usual_arithmetic (exp, ax, value1, value2); | |
1839 | switch (op) | |
1840 | { | |
1841 | case BINOP_ADD: | |
1842 | if (TYPE_CODE (value1->type) == TYPE_CODE_INT | |
1843 | && TYPE_CODE (value2->type) == TYPE_CODE_PTR) | |
1844 | { | |
1845 | /* Swap the values and proceed normally. */ | |
1846 | ax_simple (ax, aop_swap); | |
1847 | gen_ptradd (ax, value, value2, value1); | |
1848 | } | |
1849 | else if (TYPE_CODE (value1->type) == TYPE_CODE_PTR | |
1850 | && TYPE_CODE (value2->type) == TYPE_CODE_INT) | |
1851 | gen_ptradd (ax, value, value1, value2); | |
1852 | else | |
1853 | gen_binop (ax, value, value1, value2, | |
1854 | aop_add, aop_add, 1, "addition"); | |
1855 | break; | |
1856 | case BINOP_SUB: | |
1857 | if (TYPE_CODE (value1->type) == TYPE_CODE_PTR | |
1858 | && TYPE_CODE (value2->type) == TYPE_CODE_INT) | |
1859 | gen_ptrsub (ax,value, value1, value2); | |
1860 | else if (TYPE_CODE (value1->type) == TYPE_CODE_PTR | |
1861 | && TYPE_CODE (value2->type) == TYPE_CODE_PTR) | |
1862 | /* FIXME --- result type should be ptrdiff_t */ | |
1863 | gen_ptrdiff (ax, value, value1, value2, | |
1864 | builtin_type (exp->gdbarch)->builtin_long); | |
1865 | else | |
1866 | gen_binop (ax, value, value1, value2, | |
1867 | aop_sub, aop_sub, 1, "subtraction"); | |
1868 | break; | |
1869 | case BINOP_MUL: | |
1870 | gen_binop (ax, value, value1, value2, | |
1871 | aop_mul, aop_mul, 1, "multiplication"); | |
1872 | break; | |
1873 | case BINOP_DIV: | |
1874 | gen_binop (ax, value, value1, value2, | |
1875 | aop_div_signed, aop_div_unsigned, 1, "division"); | |
1876 | break; | |
1877 | case BINOP_REM: | |
1878 | gen_binop (ax, value, value1, value2, | |
1879 | aop_rem_signed, aop_rem_unsigned, 1, "remainder"); | |
1880 | break; | |
1881 | case BINOP_SUBSCRIPT: | |
1882 | gen_ptradd (ax, value, value1, value2); | |
1883 | if (TYPE_CODE (value->type) != TYPE_CODE_PTR) | |
1884 | error (_("Invalid combination of types in array subscripting.")); | |
1885 | gen_deref (ax, value); | |
1886 | break; | |
1887 | case BINOP_BITWISE_AND: | |
1888 | gen_binop (ax, value, value1, value2, | |
1889 | aop_bit_and, aop_bit_and, 0, "bitwise and"); | |
1890 | break; | |
1891 | ||
1892 | case BINOP_BITWISE_IOR: | |
1893 | gen_binop (ax, value, value1, value2, | |
1894 | aop_bit_or, aop_bit_or, 0, "bitwise or"); | |
1895 | break; | |
1896 | ||
1897 | case BINOP_BITWISE_XOR: | |
1898 | gen_binop (ax, value, value1, value2, | |
1899 | aop_bit_xor, aop_bit_xor, 0, "bitwise exclusive-or"); | |
1900 | break; | |
1901 | ||
1902 | case BINOP_EQUAL: | |
1903 | gen_binop (ax, value, value1, value2, | |
1904 | aop_equal, aop_equal, 0, "equal"); | |
1905 | break; | |
1906 | ||
1907 | case BINOP_NOTEQUAL: | |
1908 | gen_binop (ax, value, value1, value2, | |
1909 | aop_equal, aop_equal, 0, "equal"); | |
1910 | gen_logical_not (ax, value, | |
1911 | language_bool_type (exp->language_defn, | |
1912 | exp->gdbarch)); | |
1913 | break; | |
1914 | ||
1915 | case BINOP_LESS: | |
1916 | gen_binop (ax, value, value1, value2, | |
1917 | aop_less_signed, aop_less_unsigned, 0, "less than"); | |
1918 | break; | |
1919 | ||
1920 | case BINOP_GTR: | |
1921 | ax_simple (ax, aop_swap); | |
1922 | gen_binop (ax, value, value1, value2, | |
1923 | aop_less_signed, aop_less_unsigned, 0, "less than"); | |
1924 | break; | |
1925 | ||
1926 | case BINOP_LEQ: | |
1927 | ax_simple (ax, aop_swap); | |
1928 | gen_binop (ax, value, value1, value2, | |
1929 | aop_less_signed, aop_less_unsigned, 0, "less than"); | |
1930 | gen_logical_not (ax, value, | |
1931 | language_bool_type (exp->language_defn, | |
1932 | exp->gdbarch)); | |
1933 | break; | |
1934 | ||
1935 | case BINOP_GEQ: | |
1936 | gen_binop (ax, value, value1, value2, | |
1937 | aop_less_signed, aop_less_unsigned, 0, "less than"); | |
1938 | gen_logical_not (ax, value, | |
1939 | language_bool_type (exp->language_defn, | |
1940 | exp->gdbarch)); | |
1941 | break; | |
1942 | ||
1943 | default: | |
1944 | /* We should only list operators in the outer case statement | |
1945 | that we actually handle in the inner case statement. */ | |
1946 | internal_error (__FILE__, __LINE__, | |
1947 | _("gen_expr: op case sets don't match")); | |
1948 | } | |
1949 | } | |
c906108c | 1950 | \f |
c5aa993b | 1951 | |
0936ad1d SS |
1952 | /* Given a single variable and a scope, generate bytecodes to trace |
1953 | its value. This is for use in situations where we have only a | |
1954 | variable's name, and no parsed expression; for instance, when the | |
1955 | name comes from a list of local variables of a function. */ | |
1956 | ||
1957 | struct agent_expr * | |
1958 | gen_trace_for_var (CORE_ADDR scope, struct symbol *var) | |
1959 | { | |
1960 | struct cleanup *old_chain = 0; | |
1961 | struct agent_expr *ax = new_agent_expr (scope); | |
1962 | struct axs_value value; | |
1963 | ||
1964 | old_chain = make_cleanup_free_agent_expr (ax); | |
1965 | ||
1966 | trace_kludge = 1; | |
1967 | gen_var_ref (NULL, ax, &value, var); | |
1968 | ||
1969 | /* Make sure we record the final object, and get rid of it. */ | |
1970 | gen_traced_pop (ax, &value); | |
1971 | ||
1972 | /* Oh, and terminate. */ | |
1973 | ax_simple (ax, aop_end); | |
1974 | ||
1975 | /* We have successfully built the agent expr, so cancel the cleanup | |
1976 | request. If we add more cleanups that we always want done, this | |
1977 | will have to get more complicated. */ | |
1978 | discard_cleanups (old_chain); | |
1979 | return ax; | |
1980 | } | |
c5aa993b | 1981 | |
c906108c SS |
1982 | /* Generating bytecode from GDB expressions: driver */ |
1983 | ||
c906108c SS |
1984 | /* Given a GDB expression EXPR, return bytecode to trace its value. |
1985 | The result will use the `trace' and `trace_quick' bytecodes to | |
1986 | record the value of all memory touched by the expression. The | |
1987 | caller can then use the ax_reqs function to discover which | |
1988 | registers it relies upon. */ | |
1989 | struct agent_expr * | |
fba45db2 | 1990 | gen_trace_for_expr (CORE_ADDR scope, struct expression *expr) |
c906108c SS |
1991 | { |
1992 | struct cleanup *old_chain = 0; | |
1993 | struct agent_expr *ax = new_agent_expr (scope); | |
1994 | union exp_element *pc; | |
1995 | struct axs_value value; | |
1996 | ||
f23d52e0 | 1997 | old_chain = make_cleanup_free_agent_expr (ax); |
c906108c SS |
1998 | |
1999 | pc = expr->elts; | |
2000 | trace_kludge = 1; | |
f7c79c41 | 2001 | gen_expr (expr, &pc, ax, &value); |
c906108c SS |
2002 | |
2003 | /* Make sure we record the final object, and get rid of it. */ | |
2004 | gen_traced_pop (ax, &value); | |
2005 | ||
2006 | /* Oh, and terminate. */ | |
2007 | ax_simple (ax, aop_end); | |
2008 | ||
2009 | /* We have successfully built the agent expr, so cancel the cleanup | |
2010 | request. If we add more cleanups that we always want done, this | |
2011 | will have to get more complicated. */ | |
2012 | discard_cleanups (old_chain); | |
2013 | return ax; | |
2014 | } | |
c906108c | 2015 | |
782b2b07 SS |
2016 | /* Given a GDB expression EXPR, return a bytecode sequence that will |
2017 | evaluate and return a result. The bytecodes will do a direct | |
2018 | evaluation, using the current data on the target, rather than | |
2019 | recording blocks of memory and registers for later use, as | |
2020 | gen_trace_for_expr does. The generated bytecode sequence leaves | |
2021 | the result of expression evaluation on the top of the stack. */ | |
2022 | ||
2023 | struct agent_expr * | |
2024 | gen_eval_for_expr (CORE_ADDR scope, struct expression *expr) | |
2025 | { | |
2026 | struct cleanup *old_chain = 0; | |
2027 | struct agent_expr *ax = new_agent_expr (scope); | |
2028 | union exp_element *pc; | |
2029 | struct axs_value value; | |
2030 | ||
2031 | old_chain = make_cleanup_free_agent_expr (ax); | |
2032 | ||
2033 | pc = expr->elts; | |
2034 | trace_kludge = 0; | |
2035 | gen_expr (expr, &pc, ax, &value); | |
2036 | ||
2037 | /* Oh, and terminate. */ | |
2038 | ax_simple (ax, aop_end); | |
2039 | ||
2040 | /* We have successfully built the agent expr, so cancel the cleanup | |
2041 | request. If we add more cleanups that we always want done, this | |
2042 | will have to get more complicated. */ | |
2043 | discard_cleanups (old_chain); | |
2044 | return ax; | |
2045 | } | |
2046 | ||
c906108c | 2047 | static void |
fba45db2 | 2048 | agent_command (char *exp, int from_tty) |
c906108c SS |
2049 | { |
2050 | struct cleanup *old_chain = 0; | |
2051 | struct expression *expr; | |
2052 | struct agent_expr *agent; | |
6426a772 | 2053 | struct frame_info *fi = get_current_frame (); /* need current scope */ |
c906108c SS |
2054 | |
2055 | /* We don't deal with overlay debugging at the moment. We need to | |
2056 | think more carefully about this. If you copy this code into | |
2057 | another command, change the error message; the user shouldn't | |
2058 | have to know anything about agent expressions. */ | |
2059 | if (overlay_debugging) | |
3d263c1d | 2060 | error (_("GDB can't do agent expression translation with overlays.")); |
c906108c SS |
2061 | |
2062 | if (exp == 0) | |
3d263c1d | 2063 | error_no_arg (_("expression to translate")); |
c5aa993b | 2064 | |
c906108c | 2065 | expr = parse_expression (exp); |
c13c43fd | 2066 | old_chain = make_cleanup (free_current_contents, &expr); |
bdd78e62 | 2067 | agent = gen_trace_for_expr (get_frame_pc (fi), expr); |
f23d52e0 | 2068 | make_cleanup_free_agent_expr (agent); |
c906108c | 2069 | ax_print (gdb_stdout, agent); |
085dd6e6 JM |
2070 | |
2071 | /* It would be nice to call ax_reqs here to gather some general info | |
2072 | about the expression, and then print out the result. */ | |
c906108c SS |
2073 | |
2074 | do_cleanups (old_chain); | |
2075 | dont_repeat (); | |
2076 | } | |
782b2b07 SS |
2077 | |
2078 | /* Parse the given expression, compile it into an agent expression | |
2079 | that does direct evaluation, and display the resulting | |
2080 | expression. */ | |
2081 | ||
2082 | static void | |
2083 | agent_eval_command (char *exp, int from_tty) | |
2084 | { | |
2085 | struct cleanup *old_chain = 0; | |
2086 | struct expression *expr; | |
2087 | struct agent_expr *agent; | |
2088 | struct frame_info *fi = get_current_frame (); /* need current scope */ | |
2089 | ||
2090 | /* We don't deal with overlay debugging at the moment. We need to | |
2091 | think more carefully about this. If you copy this code into | |
2092 | another command, change the error message; the user shouldn't | |
2093 | have to know anything about agent expressions. */ | |
2094 | if (overlay_debugging) | |
2095 | error (_("GDB can't do agent expression translation with overlays.")); | |
2096 | ||
2097 | if (exp == 0) | |
2098 | error_no_arg (_("expression to translate")); | |
2099 | ||
2100 | expr = parse_expression (exp); | |
2101 | old_chain = make_cleanup (free_current_contents, &expr); | |
2102 | agent = gen_eval_for_expr (get_frame_pc (fi), expr); | |
2103 | make_cleanup_free_agent_expr (agent); | |
2104 | ax_print (gdb_stdout, agent); | |
2105 | ||
2106 | /* It would be nice to call ax_reqs here to gather some general info | |
2107 | about the expression, and then print out the result. */ | |
2108 | ||
2109 | do_cleanups (old_chain); | |
2110 | dont_repeat (); | |
2111 | } | |
c906108c | 2112 | \f |
c5aa993b | 2113 | |
c906108c SS |
2114 | /* Initialization code. */ |
2115 | ||
a14ed312 | 2116 | void _initialize_ax_gdb (void); |
c906108c | 2117 | void |
fba45db2 | 2118 | _initialize_ax_gdb (void) |
c906108c | 2119 | { |
c906108c | 2120 | add_cmd ("agent", class_maintenance, agent_command, |
782b2b07 SS |
2121 | _("Translate an expression into remote agent bytecode for tracing."), |
2122 | &maintenancelist); | |
2123 | ||
2124 | add_cmd ("agent-eval", class_maintenance, agent_eval_command, | |
2125 | _("Translate an expression into remote agent bytecode for evaluation."), | |
c906108c SS |
2126 | &maintenancelist); |
2127 | } |