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f8861f5d | 1 | /* tc-bpf.c -- Assembler for the Linux eBPF. |
d87bef3a | 2 | Copyright (C) 2019-2023 Free Software Foundation, Inc. |
f8861f5d JM |
3 | Contributed by Oracle, Inc. |
4 | ||
5 | This file is part of GAS, the GNU Assembler. | |
6 | ||
7 | GAS is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 3, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GAS is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GAS; see the file COPYING. If not, write to | |
19 | the Free Software Foundation, 51 Franklin Street - Fifth Floor, | |
20 | Boston, MA 02110-1301, USA. */ | |
21 | ||
22 | #include "as.h" | |
23 | #include "subsegs.h" | |
24 | #include "symcat.h" | |
d218e7fe | 25 | #include "opcode/bpf.h" |
f8861f5d JM |
26 | #include "elf/common.h" |
27 | #include "elf/bpf.h" | |
28 | #include "dwarf2dbg.h" | |
d218e7fe | 29 | #include "libiberty.h" |
ff5a51b3 | 30 | #include <ctype.h> |
f8861f5d | 31 | |
d218e7fe JM |
32 | /* Data structure representing a parsed BPF instruction. */ |
33 | ||
34 | struct bpf_insn | |
35 | { | |
c2ca88d7 | 36 | enum bpf_insn_id id; |
d218e7fe JM |
37 | int size; /* Instruction size in bytes. */ |
38 | bpf_insn_word opcode; | |
39 | uint8_t dst; | |
40 | uint8_t src; | |
41 | expressionS offset16; | |
42 | expressionS imm32; | |
43 | expressionS imm64; | |
44 | expressionS disp16; | |
45 | expressionS disp32; | |
46 | ||
47 | unsigned int has_dst : 1; | |
48 | unsigned int has_src : 1; | |
49 | unsigned int has_offset16 : 1; | |
50 | unsigned int has_disp16 : 1; | |
51 | unsigned int has_disp32 : 1; | |
52 | unsigned int has_imm32 : 1; | |
53 | unsigned int has_imm64 : 1; | |
54 | }; | |
55 | ||
9d1e07bd | 56 | const char comment_chars[] = ";#"; |
ff5a51b3 | 57 | const char line_comment_chars[] = "#"; |
f8861f5d JM |
58 | const char line_separator_chars[] = "`"; |
59 | const char EXP_CHARS[] = "eE"; | |
60 | const char FLT_CHARS[] = "fFdD"; | |
61 | ||
1802aae8 JM |
62 | /* Like s_lcomm_internal in gas/read.c but the alignment string |
63 | is allowed to be optional. */ | |
64 | ||
65 | static symbolS * | |
66 | pe_lcomm_internal (int needs_align, symbolS *symbolP, addressT size) | |
67 | { | |
68 | addressT align = 0; | |
69 | ||
70 | SKIP_WHITESPACE (); | |
71 | ||
72 | if (needs_align | |
73 | && *input_line_pointer == ',') | |
74 | { | |
75 | align = parse_align (needs_align - 1); | |
76 | ||
77 | if (align == (addressT) -1) | |
78 | return NULL; | |
79 | } | |
80 | else | |
81 | { | |
82 | if (size >= 8) | |
83 | align = 3; | |
84 | else if (size >= 4) | |
85 | align = 2; | |
86 | else if (size >= 2) | |
87 | align = 1; | |
88 | else | |
89 | align = 0; | |
90 | } | |
91 | ||
92 | bss_alloc (symbolP, size, align); | |
93 | return symbolP; | |
94 | } | |
95 | ||
96 | static void | |
97 | pe_lcomm (int needs_align) | |
98 | { | |
99 | s_comm_internal (needs_align * 2, pe_lcomm_internal); | |
100 | } | |
101 | ||
f8861f5d JM |
102 | /* The target specific pseudo-ops which we support. */ |
103 | const pseudo_typeS md_pseudo_table[] = | |
104 | { | |
e0b989a6 JM |
105 | { "half", cons, 2 }, |
106 | { "word", cons, 4 }, | |
107 | { "dword", cons, 8 }, | |
1802aae8 | 108 | { "lcomm", pe_lcomm, 1 }, |
d0044bac | 109 | { NULL, NULL, 0 } |
f8861f5d JM |
110 | }; |
111 | ||
1802aae8 JM |
112 | \f |
113 | ||
f8861f5d JM |
114 | /* Command-line options processing. */ |
115 | ||
116 | enum options | |
117 | { | |
118 | OPTION_LITTLE_ENDIAN = OPTION_MD_BASE, | |
4449c81a | 119 | OPTION_BIG_ENDIAN, |
d218e7fe JM |
120 | OPTION_XBPF, |
121 | OPTION_DIALECT, | |
122 | OPTION_ISA_SPEC, | |
f8861f5d JM |
123 | }; |
124 | ||
125 | struct option md_longopts[] = | |
126 | { | |
127 | { "EL", no_argument, NULL, OPTION_LITTLE_ENDIAN }, | |
128 | { "EB", no_argument, NULL, OPTION_BIG_ENDIAN }, | |
4449c81a | 129 | { "mxbpf", no_argument, NULL, OPTION_XBPF }, |
d218e7fe JM |
130 | { "mdialect", required_argument, NULL, OPTION_DIALECT}, |
131 | { "misa-spec", required_argument, NULL, OPTION_ISA_SPEC}, | |
f8861f5d JM |
132 | { NULL, no_argument, NULL, 0 }, |
133 | }; | |
134 | ||
135 | size_t md_longopts_size = sizeof (md_longopts); | |
136 | ||
137 | const char * md_shortopts = ""; | |
138 | ||
d218e7fe JM |
139 | /* BPF supports little-endian and big-endian variants. The following |
140 | global records what endianness to use. It can be configured using | |
141 | command-line options. It defaults to the host endianness | |
142 | initialized in md_begin. */ | |
f8861f5d | 143 | |
f8861f5d | 144 | static int set_target_endian = 0; |
d218e7fe JM |
145 | extern int target_big_endian; |
146 | ||
147 | /* The ISA specification can be one of BPF_V1, BPF_V2, BPF_V3, BPF_V4 | |
148 | or BPF_XPBF. The ISA spec to use can be configured using | |
149 | command-line options. It defaults to the latest BPF spec. */ | |
150 | ||
151 | static int isa_spec = BPF_V4; | |
f8861f5d | 152 | |
d218e7fe JM |
153 | /* The assembler supports two different dialects: "normal" syntax and |
154 | "pseudoc" syntax. The dialect to use can be configured using | |
155 | command-line options. */ | |
4449c81a | 156 | |
d218e7fe JM |
157 | enum target_asm_dialect |
158 | { | |
159 | DIALECT_NORMAL, | |
160 | DIALECT_PSEUDOC | |
161 | }; | |
162 | ||
163 | static int asm_dialect = DIALECT_NORMAL; | |
4449c81a | 164 | |
f8861f5d | 165 | int |
d218e7fe | 166 | md_parse_option (int c, const char * arg) |
f8861f5d JM |
167 | { |
168 | switch (c) | |
169 | { | |
170 | case OPTION_BIG_ENDIAN: | |
171 | set_target_endian = 1; | |
172 | target_big_endian = 1; | |
173 | break; | |
174 | case OPTION_LITTLE_ENDIAN: | |
d218e7fe | 175 | set_target_endian = 0; |
f8861f5d JM |
176 | target_big_endian = 0; |
177 | break; | |
d218e7fe JM |
178 | case OPTION_DIALECT: |
179 | if (strcmp (arg, "normal") == 0) | |
180 | asm_dialect = DIALECT_NORMAL; | |
181 | else if (strcmp (arg, "pseudoc") == 0) | |
182 | asm_dialect = DIALECT_PSEUDOC; | |
183 | else | |
184 | as_fatal (_("-mdialect=%s is not valid. Expected normal or pseudoc"), | |
185 | arg); | |
186 | break; | |
187 | case OPTION_ISA_SPEC: | |
188 | if (strcmp (arg, "v1") == 0) | |
189 | isa_spec = BPF_V1; | |
190 | else if (strcmp (arg, "v2") == 0) | |
191 | isa_spec = BPF_V2; | |
192 | else if (strcmp (arg, "v3") == 0) | |
193 | isa_spec = BPF_V3; | |
194 | else if (strcmp (arg, "v4") == 0) | |
195 | isa_spec = BPF_V4; | |
196 | else if (strcmp (arg, "xbpf") == 0) | |
197 | isa_spec = BPF_XBPF; | |
198 | else | |
199 | as_fatal (_("-misa-spec=%s is not valid. Expected v1, v2, v3, v4 o xbpf"), | |
200 | arg); | |
201 | break; | |
4449c81a | 202 | case OPTION_XBPF: |
d218e7fe JM |
203 | /* This is an alias for -misa-spec=xbpf. */ |
204 | isa_spec = BPF_XBPF; | |
4449c81a | 205 | break; |
f8861f5d JM |
206 | default: |
207 | return 0; | |
208 | } | |
209 | ||
210 | return 1; | |
211 | } | |
212 | ||
213 | void | |
214 | md_show_usage (FILE * stream) | |
215 | { | |
216 | fprintf (stream, _("\nBPF options:\n")); | |
217 | fprintf (stream, _("\ | |
d218e7fe JM |
218 | BPF options:\n\ |
219 | -EL generate code for a little endian machine\n\ | |
220 | -EB generate code for a big endian machine\n\ | |
221 | -mdialect=DIALECT set the assembly dialect (normal, pseudoc)\n\ | |
222 | -misa-spec set the BPF ISA spec (v1, v2, v3, v4, xbpf)\n\ | |
223 | -mxbpf alias for -misa-spec=xbpf\n")); | |
f8861f5d JM |
224 | } |
225 | ||
226 | \f | |
d218e7fe JM |
227 | /* This function is called once, at assembler startup time. This |
228 | should set up all the tables, etc that the MD part of the assembler | |
229 | needs. */ | |
ff5a51b3 | 230 | |
f8861f5d JM |
231 | void |
232 | md_begin (void) | |
233 | { | |
f8861f5d JM |
234 | /* If not specified in the command line, use the host |
235 | endianness. */ | |
236 | if (!set_target_endian) | |
237 | { | |
238 | #ifdef WORDS_BIGENDIAN | |
239 | target_big_endian = 1; | |
240 | #else | |
241 | target_big_endian = 0; | |
242 | #endif | |
243 | } | |
244 | ||
ff5a51b3 GM |
245 | /* Ensure that lines can begin with '*' in BPF store pseudoc instruction. */ |
246 | lex_type['*'] |= LEX_BEGIN_NAME; | |
247 | ||
f8861f5d JM |
248 | /* Set the machine type. */ |
249 | bfd_default_set_arch_mach (stdoutput, bfd_arch_bpf, bfd_mach_bpf); | |
250 | } | |
251 | ||
d218e7fe JM |
252 | /* Round up a section size to the appropriate boundary. */ |
253 | ||
f8861f5d JM |
254 | valueT |
255 | md_section_align (segT segment, valueT size) | |
256 | { | |
fd361982 | 257 | int align = bfd_section_alignment (segment); |
f8861f5d JM |
258 | |
259 | return ((size + (1 << align) - 1) & -(1 << align)); | |
260 | } | |
261 | ||
262 | \f | |
263 | /* Functions concerning relocs. */ | |
264 | ||
265 | /* The location from which a PC relative jump should be calculated, | |
266 | given a PC relative reloc. */ | |
267 | ||
268 | long | |
269 | md_pcrel_from_section (fixS *fixP, segT sec) | |
270 | { | |
271 | if (fixP->fx_addsy != (symbolS *) NULL | |
272 | && (! S_IS_DEFINED (fixP->fx_addsy) | |
273 | || (S_GET_SEGMENT (fixP->fx_addsy) != sec) | |
274 | || S_IS_EXTERNAL (fixP->fx_addsy) | |
275 | || S_IS_WEAK (fixP->fx_addsy))) | |
276 | { | |
277 | /* The symbol is undefined (or is defined but not in this section). | |
278 | Let the linker figure it out. */ | |
279 | return 0; | |
280 | } | |
281 | ||
282 | return fixP->fx_where + fixP->fx_frag->fr_address; | |
283 | } | |
284 | ||
285 | /* Write a value out to the object file, using the appropriate endianness. */ | |
286 | ||
287 | void | |
288 | md_number_to_chars (char * buf, valueT val, int n) | |
289 | { | |
290 | if (target_big_endian) | |
291 | number_to_chars_bigendian (buf, val, n); | |
292 | else | |
293 | number_to_chars_littleendian (buf, val, n); | |
294 | } | |
295 | ||
296 | arelent * | |
d218e7fe | 297 | tc_gen_reloc (asection *sec ATTRIBUTE_UNUSED, fixS *fixP) |
f8861f5d | 298 | { |
d218e7fe JM |
299 | bfd_reloc_code_real_type r_type = fixP->fx_r_type; |
300 | arelent *reloc; | |
f8861f5d | 301 | |
d218e7fe | 302 | reloc = XNEW (arelent); |
f8861f5d | 303 | |
d218e7fe JM |
304 | if (fixP->fx_pcrel) |
305 | { | |
306 | r_type = (r_type == BFD_RELOC_8 ? BFD_RELOC_8_PCREL | |
307 | : r_type == BFD_RELOC_16 ? BFD_RELOC_16_PCREL | |
308 | : r_type == BFD_RELOC_24 ? BFD_RELOC_24_PCREL | |
309 | : r_type == BFD_RELOC_32 ? BFD_RELOC_32_PCREL | |
310 | : r_type == BFD_RELOC_64 ? BFD_RELOC_64_PCREL | |
311 | : r_type); | |
312 | } | |
313 | ||
314 | reloc->howto = bfd_reloc_type_lookup (stdoutput, r_type); | |
315 | ||
316 | if (reloc->howto == (reloc_howto_type *) NULL) | |
f8861f5d | 317 | { |
d218e7fe JM |
318 | as_bad_where (fixP->fx_file, fixP->fx_line, |
319 | _("relocation is not supported")); | |
320 | return NULL; | |
f8861f5d | 321 | } |
d218e7fe JM |
322 | |
323 | //XXX gas_assert (!fixP->fx_pcrel == !reloc->howto->pc_relative); | |
324 | ||
325 | reloc->sym_ptr_ptr = XNEW (asymbol *); | |
326 | *reloc->sym_ptr_ptr = symbol_get_bfdsym (fixP->fx_addsy); | |
327 | ||
328 | /* Use fx_offset for these cases. */ | |
329 | if (fixP->fx_r_type == BFD_RELOC_VTABLE_ENTRY | |
330 | || fixP->fx_r_type == BFD_RELOC_VTABLE_INHERIT) | |
331 | reloc->addend = fixP->fx_offset; | |
332 | else | |
333 | reloc->addend = fixP->fx_addnumber; | |
334 | ||
335 | reloc->address = fixP->fx_frag->fr_address + fixP->fx_where; | |
336 | return reloc; | |
f8861f5d | 337 | } |
d218e7fe | 338 | |
f8861f5d JM |
339 | \f |
340 | /* *FRAGP has been relaxed to its final size, and now needs to have | |
341 | the bytes inside it modified to conform to the new size. | |
342 | ||
343 | Called after relaxation is finished. | |
344 | fragP->fr_type == rs_machine_dependent. | |
345 | fragP->fr_subtype is the subtype of what the address relaxed to. */ | |
346 | ||
347 | void | |
348 | md_convert_frag (bfd *abfd ATTRIBUTE_UNUSED, | |
349 | segT sec ATTRIBUTE_UNUSED, | |
350 | fragS *fragP ATTRIBUTE_UNUSED) | |
351 | { | |
352 | as_fatal (_("convert_frag called")); | |
353 | } | |
354 | ||
355 | int | |
356 | md_estimate_size_before_relax (fragS *fragP ATTRIBUTE_UNUSED, | |
357 | segT segment ATTRIBUTE_UNUSED) | |
358 | { | |
359 | as_fatal (_("estimate_size_before_relax called")); | |
360 | return 0; | |
361 | } | |
362 | ||
363 | \f | |
d218e7fe JM |
364 | /* Apply a fixS (fixup of an instruction or data that we didn't have |
365 | enough info to complete immediately) to the data in a frag. */ | |
366 | ||
f8861f5d | 367 | void |
d218e7fe | 368 | md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED) |
f8861f5d | 369 | { |
d218e7fe JM |
370 | char *where = fixP->fx_frag->fr_literal + fixP->fx_where; |
371 | ||
372 | switch (fixP->fx_r_type) | |
f8861f5d | 373 | { |
d218e7fe JM |
374 | case BFD_RELOC_BPF_DISP16: |
375 | /* Convert from bytes to number of 64-bit words to the target, | |
376 | minus one. */ | |
377 | *valP = (((long) (*valP)) - 8) / 8; | |
378 | break; | |
c2ca88d7 | 379 | case BFD_RELOC_BPF_DISPCALL32: |
d218e7fe | 380 | case BFD_RELOC_BPF_DISP32: |
d218e7fe JM |
381 | /* Convert from bytes to number of 64-bit words to the target, |
382 | minus one. */ | |
383 | *valP = (((long) (*valP)) - 8) / 8; | |
c2ca88d7 JM |
384 | |
385 | if (fixP->fx_r_type == BFD_RELOC_BPF_DISPCALL32) | |
386 | { | |
387 | /* eBPF supports two kind of CALL instructions: the so | |
388 | called pseudo calls ("bpf to bpf") and external calls | |
389 | ("bpf to kernel"). | |
390 | ||
391 | Both kind of calls use the same instruction (CALL). | |
392 | However, external calls are constructed by passing a | |
393 | constant argument to the instruction, whereas pseudo | |
394 | calls result from expressions involving symbols. In | |
395 | practice, instructions requiring a fixup are interpreted | |
396 | as pseudo-calls. If we are executing this code, this is | |
397 | a pseudo call. | |
398 | ||
399 | The kernel expects for pseudo-calls to be annotated by | |
400 | having BPF_PSEUDO_CALL in the SRC field of the | |
401 | instruction. But beware the infamous nibble-swapping of | |
402 | eBPF and take endianness into account here. | |
403 | ||
404 | Note that the CALL instruction has only one operand, so | |
405 | this code is executed only once per instruction. */ | |
406 | md_number_to_chars (where + 1, target_big_endian ? 0x01 : 0x10, 1); | |
407 | } | |
d218e7fe JM |
408 | break; |
409 | case BFD_RELOC_16_PCREL: | |
410 | /* Convert from bytes to number of 64-bit words to the target, | |
411 | minus one. */ | |
412 | *valP = (((long) (*valP)) - 8) / 8; | |
413 | break; | |
414 | default: | |
415 | break; | |
416 | } | |
f8861f5d | 417 | |
d218e7fe JM |
418 | if (fixP->fx_addsy == (symbolS *) NULL) |
419 | fixP->fx_done = 1; | |
420 | ||
421 | if (fixP->fx_done) | |
422 | { | |
423 | /* We're finished with this fixup. Install it because | |
424 | bfd_install_relocation won't be called to do it. */ | |
425 | switch (fixP->fx_r_type) | |
426 | { | |
427 | case BFD_RELOC_8: | |
428 | md_number_to_chars (where, *valP, 1); | |
429 | break; | |
430 | case BFD_RELOC_16: | |
431 | md_number_to_chars (where, *valP, 2); | |
432 | break; | |
433 | case BFD_RELOC_32: | |
434 | md_number_to_chars (where, *valP, 4); | |
435 | break; | |
436 | case BFD_RELOC_64: | |
437 | md_number_to_chars (where, *valP, 8); | |
438 | break; | |
439 | case BFD_RELOC_BPF_DISP16: | |
440 | md_number_to_chars (where + 2, (uint16_t) *valP, 2); | |
f8861f5d | 441 | break; |
d218e7fe | 442 | case BFD_RELOC_BPF_DISP32: |
c2ca88d7 | 443 | case BFD_RELOC_BPF_DISPCALL32: |
d218e7fe | 444 | md_number_to_chars (where + 4, (uint32_t) *valP, 4); |
f8861f5d | 445 | break; |
d218e7fe JM |
446 | case BFD_RELOC_16_PCREL: |
447 | md_number_to_chars (where + 2, (uint32_t) *valP, 2); | |
448 | break; | |
449 | default: | |
450 | as_bad_where (fixP->fx_file, fixP->fx_line, | |
451 | _("internal error: can't install fix for reloc type %d (`%s')"), | |
452 | fixP->fx_r_type, bfd_get_reloc_code_name (fixP->fx_r_type)); | |
453 | break; | |
454 | } | |
f8861f5d JM |
455 | } |
456 | ||
d218e7fe JM |
457 | /* Tuck `value' away for use by tc_gen_reloc. |
458 | See the comment describing fx_addnumber in write.h. | |
459 | This field is misnamed (or misused :-). */ | |
460 | fixP->fx_addnumber = *valP; | |
f8861f5d JM |
461 | } |
462 | ||
d218e7fe JM |
463 | /* Parse an operand expression. Returns the first character that is |
464 | not part of the expression, or NULL in case of parse error. | |
ff5a51b3 | 465 | |
d218e7fe | 466 | See md_operand below to see how exp_parse_failed is used. */ |
ff5a51b3 | 467 | |
d218e7fe | 468 | static int exp_parse_failed = 0; |
ff5a51b3 GM |
469 | |
470 | static char * | |
d218e7fe | 471 | parse_expression (char *s, expressionS *exp) |
ff5a51b3 | 472 | { |
d218e7fe JM |
473 | char *saved_input_line_pointer = input_line_pointer; |
474 | char *saved_s = s; | |
ff5a51b3 | 475 | |
d218e7fe JM |
476 | exp_parse_failed = 0; |
477 | input_line_pointer = s; | |
478 | expression (exp); | |
479 | s = input_line_pointer; | |
480 | input_line_pointer = saved_input_line_pointer; | |
ff5a51b3 | 481 | |
d218e7fe JM |
482 | switch (exp->X_op == O_absent || exp_parse_failed) |
483 | return NULL; | |
ff5a51b3 | 484 | |
d218e7fe JM |
485 | /* The expression parser may consume trailing whitespaces. We have |
486 | to undo that since the instruction templates may be expecting | |
487 | these whitespaces. */ | |
488 | { | |
489 | char *p; | |
490 | for (p = s - 1; p >= saved_s && *p == ' '; --p) | |
491 | --s; | |
492 | } | |
ff5a51b3 | 493 | |
d218e7fe | 494 | return s; |
ff5a51b3 GM |
495 | } |
496 | ||
d218e7fe JM |
497 | /* Parse a BPF register name and return the corresponding register |
498 | number. Return NULL in case of parse error, or a pointer to the | |
499 | first character in S that is not part of the register name. */ | |
ff5a51b3 | 500 | |
d218e7fe JM |
501 | static char * |
502 | parse_bpf_register (char *s, char rw, uint8_t *regno) | |
ff5a51b3 | 503 | { |
d218e7fe | 504 | if (asm_dialect == DIALECT_NORMAL) |
ff5a51b3 | 505 | { |
d218e7fe JM |
506 | rw = 'r'; |
507 | if (*s != '%') | |
508 | return NULL; | |
509 | s += 1; | |
ff5a51b3 | 510 | |
d218e7fe JM |
511 | if (*s == 'f' && *(s + 1) == 'p') |
512 | { | |
513 | *regno = 10; | |
514 | s += 2; | |
515 | return s; | |
516 | } | |
517 | } | |
ff5a51b3 | 518 | |
d218e7fe JM |
519 | if (*s != rw) |
520 | return NULL; | |
521 | s += 1; | |
ff5a51b3 | 522 | |
d218e7fe JM |
523 | if (*s == '1') |
524 | { | |
525 | if (*(s + 1) == '0') | |
526 | { | |
527 | *regno = 10; | |
528 | s += 2; | |
529 | } | |
530 | else | |
531 | { | |
532 | *regno = 1; | |
533 | s += 1; | |
534 | } | |
535 | } | |
536 | else if (*s >= '0' && *s <= '9') | |
537 | { | |
538 | *regno = *s - '0'; | |
539 | s += 1; | |
540 | } | |
ff5a51b3 | 541 | |
d218e7fe | 542 | return s; |
ff5a51b3 GM |
543 | } |
544 | ||
d218e7fe | 545 | /* Collect a parse error message. */ |
ff5a51b3 | 546 | |
d218e7fe JM |
547 | static int partial_match_length = 0; |
548 | static char *errmsg = NULL; | |
ff5a51b3 | 549 | |
d218e7fe JM |
550 | static void |
551 | parse_error (int length, const char *fmt, ...) | |
ff5a51b3 | 552 | { |
d218e7fe | 553 | if (length > partial_match_length) |
ff5a51b3 | 554 | { |
d218e7fe | 555 | va_list args; |
ff5a51b3 | 556 | |
d218e7fe JM |
557 | free (errmsg); |
558 | va_start (args, fmt); | |
559 | errmsg = xvasprintf (fmt, args); | |
560 | va_end (args); | |
561 | partial_match_length = length; | |
ff5a51b3 | 562 | } |
ff5a51b3 GM |
563 | } |
564 | ||
d218e7fe JM |
565 | /* Assemble a machine instruction in STR and emit the frags/bytes it |
566 | assembles to. */ | |
ff5a51b3 | 567 | |
d218e7fe JM |
568 | void |
569 | md_assemble (char *str ATTRIBUTE_UNUSED) | |
ff5a51b3 | 570 | { |
d218e7fe JM |
571 | /* There are two different syntaxes that can be used to write BPF |
572 | instructions. One is very conventional and like any other | |
573 | assembly language where each instruction is conformed by an | |
574 | instruction mnemonic followed by its operands. This is what we | |
575 | call the "normal" syntax. The other syntax tries to look like C | |
576 | statements. We have to support both syntaxes in this assembler. | |
577 | ||
578 | One of the many nuisances introduced by this eccentricity is that | |
579 | in the pseudo-c syntax it is not possible to hash the opcodes | |
580 | table by instruction mnemonic, because there is none. So we have | |
581 | no other choice than to try to parse all instruction opcodes | |
582 | until one matches. This is slow. | |
583 | ||
584 | Another problem is that emitting detailed diagnostics becomes | |
585 | tricky, since the lack of mnemonic means it is not clear what | |
586 | instruction was intended by the user, and we cannot emit | |
587 | diagnostics for every attempted template. So if an instruction | |
588 | is not parsed, we report the diagnostic corresponding to the | |
589 | partially parsed instruction that was matched further. */ | |
590 | ||
591 | unsigned int idx = 0; | |
592 | struct bpf_insn insn; | |
593 | const struct bpf_opcode *opcode; | |
594 | ||
595 | /* Initialize the global diagnostic variables. See the parse_error | |
596 | function above. */ | |
597 | partial_match_length = 0; | |
598 | errmsg = NULL; | |
599 | ||
600 | #define PARSE_ERROR(...) parse_error (s - str, __VA_ARGS__) | |
601 | ||
602 | while ((opcode = bpf_get_opcode (idx++)) != NULL) | |
ff5a51b3 | 603 | { |
d218e7fe JM |
604 | const char *p; |
605 | char *s; | |
606 | const char *template | |
607 | = (asm_dialect == DIALECT_PSEUDOC ? opcode->pseudoc : opcode->normal); | |
608 | ||
609 | /* Do not try to match opcodes with a higher version than the | |
610 | selected ISA spec. */ | |
611 | if (opcode->version > isa_spec) | |
612 | continue; | |
613 | ||
614 | memset (&insn, 0, sizeof (struct bpf_insn)); | |
615 | insn.size = 8; | |
616 | for (s = str, p = template; *p != '\0';) | |
617 | { | |
618 | if (*p == ' ') | |
619 | { | |
620 | /* Expect zero or more spaces. */ | |
621 | while (*s != '\0' && (*s == ' ' || *s == '\t')) | |
622 | s += 1; | |
623 | p += 1; | |
624 | } | |
625 | else if (*p == '%') | |
626 | { | |
627 | if (*(p + 1) == '%') | |
628 | { | |
629 | if (*s != '%') | |
630 | { | |
631 | PARSE_ERROR ("expected '%%'"); | |
632 | break; | |
633 | } | |
634 | p += 2; | |
635 | s += 1; | |
636 | } | |
637 | else if (*(p + 1) == 'w') | |
638 | { | |
639 | /* Expect zero or more spaces. */ | |
640 | while (*s != '\0' && (*s == ' ' || *s == '\t')) | |
641 | s += 1; | |
642 | p += 2; | |
643 | } | |
644 | else if (*(p + 1) == 'W') | |
645 | { | |
646 | /* Expect one or more spaces. */ | |
647 | if (*s != ' ' && *s != '\t') | |
648 | { | |
649 | PARSE_ERROR ("expected white space, got '%s'", | |
650 | s); | |
651 | break; | |
652 | } | |
653 | while (*s != '\0' && (*s == ' ' || *s == '\t')) | |
654 | s += 1; | |
655 | p += 2; | |
656 | } | |
657 | else if (strncmp (p, "%dr", 3) == 0) | |
658 | { | |
659 | uint8_t regno; | |
660 | char *news = parse_bpf_register (s, 'r', ®no); | |
661 | ||
662 | if (news == NULL || (insn.has_dst && regno != insn.dst)) | |
663 | { | |
664 | if (news != NULL) | |
665 | PARSE_ERROR ("expected register r%d, got r%d", | |
666 | insn.dst, regno); | |
667 | else | |
668 | PARSE_ERROR ("expected register name, got '%s'", s); | |
669 | break; | |
670 | } | |
671 | s = news; | |
672 | insn.dst = regno; | |
673 | insn.has_dst = 1; | |
674 | p += 3; | |
675 | } | |
676 | else if (strncmp (p, "%sr", 3) == 0) | |
677 | { | |
678 | uint8_t regno; | |
679 | char *news = parse_bpf_register (s, 'r', ®no); | |
680 | ||
681 | if (news == NULL || (insn.has_src && regno != insn.src)) | |
682 | { | |
683 | if (news != NULL) | |
684 | PARSE_ERROR ("expected register r%d, got r%d", | |
685 | insn.dst, regno); | |
686 | else | |
687 | PARSE_ERROR ("expected register name, got '%s'", s); | |
688 | break; | |
689 | } | |
690 | s = news; | |
691 | insn.src = regno; | |
692 | insn.has_src = 1; | |
693 | p += 3; | |
694 | } | |
695 | else if (strncmp (p, "%dw", 3) == 0) | |
696 | { | |
697 | uint8_t regno; | |
698 | char *news = parse_bpf_register (s, 'w', ®no); | |
699 | ||
700 | if (news == NULL || (insn.has_dst && regno != insn.dst)) | |
701 | { | |
702 | if (news != NULL) | |
703 | PARSE_ERROR ("expected register r%d, got r%d", | |
704 | insn.dst, regno); | |
705 | else | |
706 | PARSE_ERROR ("expected register name, got '%s'", s); | |
707 | break; | |
708 | } | |
709 | s = news; | |
710 | insn.dst = regno; | |
711 | insn.has_dst = 1; | |
712 | p += 3; | |
713 | } | |
714 | else if (strncmp (p, "%sw", 3) == 0) | |
715 | { | |
716 | uint8_t regno; | |
717 | char *news = parse_bpf_register (s, 'w', ®no); | |
718 | ||
719 | if (news == NULL || (insn.has_src && regno != insn.src)) | |
720 | { | |
721 | if (news != NULL) | |
722 | PARSE_ERROR ("expected register r%d, got r%d", | |
723 | insn.dst, regno); | |
724 | else | |
725 | PARSE_ERROR ("expected register name, got '%s'", s); | |
726 | break; | |
727 | } | |
728 | s = news; | |
729 | insn.src = regno; | |
730 | insn.has_src = 1; | |
731 | p += 3; | |
732 | } | |
733 | else if (strncmp (p, "%i32", 4) == 0 | |
734 | || strncmp (p, "%I32", 4) == 0) | |
735 | { | |
736 | if (p[1] == 'I') | |
737 | { | |
738 | while (*s == ' ' || *s == '\t') | |
739 | s += 1; | |
740 | if (*s != '+' && *s != '-') | |
741 | { | |
742 | PARSE_ERROR ("expected `+' or `-', got `%c'", *s); | |
743 | break; | |
744 | } | |
745 | } | |
746 | ||
747 | s = parse_expression (s, &insn.imm32); | |
748 | if (s == NULL) | |
749 | { | |
750 | PARSE_ERROR ("expected signed 32-bit immediate"); | |
751 | break; | |
752 | } | |
753 | insn.has_imm32 = 1; | |
754 | p += 4; | |
755 | } | |
756 | else if (strncmp (p, "%o16", 4) == 0) | |
757 | { | |
758 | while (*s == ' ' || *s == '\t') | |
759 | s += 1; | |
760 | if (*s != '+' && *s != '-') | |
761 | { | |
762 | PARSE_ERROR ("expected `+' or `-', got `%c'", *s); | |
763 | break; | |
764 | } | |
765 | ||
766 | s = parse_expression (s, &insn.offset16); | |
767 | if (s == NULL) | |
768 | { | |
769 | PARSE_ERROR ("expected signed 16-bit offset"); | |
770 | break; | |
771 | } | |
772 | insn.has_offset16 = 1; | |
773 | p += 4; | |
774 | } | |
775 | else if (strncmp (p, "%d16", 4) == 0) | |
776 | { | |
777 | s = parse_expression (s, &insn.disp16); | |
778 | if (s == NULL) | |
779 | { | |
780 | PARSE_ERROR ("expected signed 16-bit displacement"); | |
781 | break; | |
782 | } | |
783 | insn.has_disp16 = 1; | |
784 | p += 4; | |
785 | } | |
786 | else if (strncmp (p, "%d32", 4) == 0) | |
787 | { | |
788 | s = parse_expression (s, &insn.disp32); | |
789 | if (s == NULL) | |
790 | { | |
791 | PARSE_ERROR ("expected signed 32-bit displacement"); | |
792 | break; | |
793 | } | |
794 | insn.has_disp32 = 1; | |
795 | p += 4; | |
796 | } | |
797 | else if (strncmp (p, "%i64", 4) == 0) | |
798 | { | |
799 | s = parse_expression (s, &insn.imm64); | |
800 | if (s == NULL) | |
801 | { | |
802 | PARSE_ERROR ("expected signed 64-bit immediate"); | |
803 | break; | |
804 | } | |
805 | insn.has_imm64 = 1; | |
806 | insn.size = 16; | |
807 | p += 4; | |
808 | } | |
809 | else | |
810 | as_fatal (_("invalid %%-tag in BPF opcode '%s'\n"), template); | |
811 | } | |
812 | else | |
813 | { | |
814 | /* Match a literal character. */ | |
815 | if (*s != *p) | |
816 | { | |
817 | if (*s == '\0') | |
818 | PARSE_ERROR ("expected '%c'", *p); | |
819 | else if (*s == '%') | |
820 | { | |
821 | /* This is to workaround a bug in as_bad. */ | |
822 | char tmp[3]; | |
823 | ||
824 | tmp[0] = '%'; | |
825 | tmp[1] = '%'; | |
826 | tmp[2] = '\0'; | |
827 | ||
828 | PARSE_ERROR ("expected '%c', got '%s'", *p, tmp); | |
829 | } | |
830 | else | |
831 | PARSE_ERROR ("expected '%c', got '%c'", *p, *s); | |
832 | break; | |
833 | } | |
834 | p += 1; | |
835 | s += 1; | |
836 | } | |
837 | } | |
ff5a51b3 | 838 | |
d218e7fe JM |
839 | if (*p == '\0') |
840 | { | |
841 | /* Allow white spaces at the end of the line. */ | |
842 | while (*s != '\0' && (*s == ' ' || *s == '\t')) | |
843 | s += 1; | |
844 | if (*s == '\0') | |
845 | /* We parsed an instruction successfully. */ | |
846 | break; | |
847 | PARSE_ERROR ("extra junk at end of line"); | |
848 | } | |
849 | } | |
ff5a51b3 | 850 | |
d218e7fe JM |
851 | if (opcode == NULL) |
852 | { | |
853 | as_bad (_("unrecognized instruction `%s'"), str); | |
854 | if (errmsg != NULL) | |
855 | { | |
fafcbd14 | 856 | as_bad ("%s", errmsg); |
d218e7fe JM |
857 | free (errmsg); |
858 | } | |
ff5a51b3 | 859 | |
d218e7fe JM |
860 | return; |
861 | } | |
c2ca88d7 | 862 | insn.id = opcode->id; |
d218e7fe | 863 | insn.opcode = opcode->opcode; |
ff5a51b3 | 864 | |
d218e7fe | 865 | #undef PARSE_ERROR |
ff5a51b3 | 866 | |
d218e7fe JM |
867 | /* Generate the frags and fixups for the parsed instruction. */ |
868 | { | |
869 | char *this_frag = frag_more (insn.size); | |
870 | char bytes[16]; | |
871 | uint8_t src, dst; | |
872 | int i; | |
873 | ||
874 | /* Zero all the bytes. */ | |
875 | memset (bytes, 0, 16); | |
876 | ||
877 | /* First encode the opcodes. Note that we have to handle the | |
878 | endianness groups of the BPF instructions: 8 | 4 | 4 | 16 | | |
879 | 32. */ | |
880 | if (target_big_endian) | |
881 | { | |
882 | /* code */ | |
883 | bytes[0] = (insn.opcode >> 56) & 0xff; | |
884 | /* regs */ | |
885 | bytes[1] = (insn.opcode >> 48) & 0xff; | |
886 | /* offset16 */ | |
887 | bytes[2] = (insn.opcode >> 40) & 0xff; | |
888 | bytes[3] = (insn.opcode >> 32) & 0xff; | |
889 | /* imm32 */ | |
890 | bytes[4] = (insn.opcode >> 24) & 0xff; | |
891 | bytes[5] = (insn.opcode >> 16) & 0xff; | |
892 | bytes[6] = (insn.opcode >> 8) & 0xff; | |
893 | bytes[7] = insn.opcode & 0xff; | |
894 | } | |
895 | else | |
896 | { | |
897 | /* code */ | |
898 | bytes[0] = (insn.opcode >> 56) & 0xff; | |
899 | /* regs */ | |
900 | bytes[1] = (((((insn.opcode >> 48) & 0xff) & 0xf) << 4) | |
901 | | (((insn.opcode >> 48) & 0xff) & 0xf)); | |
902 | /* offset16 */ | |
903 | bytes[3] = (insn.opcode >> 40) & 0xff; | |
904 | bytes[2] = (insn.opcode >> 32) & 0xff; | |
905 | /* imm32 */ | |
906 | bytes[7] = (insn.opcode >> 24) & 0xff; | |
907 | bytes[6] = (insn.opcode >> 16) & 0xff; | |
908 | bytes[5] = (insn.opcode >> 8) & 0xff; | |
909 | bytes[4] = insn.opcode & 0xff; | |
910 | } | |
ff5a51b3 | 911 | |
d218e7fe JM |
912 | /* Now the registers. */ |
913 | src = insn.has_src ? insn.src : 0; | |
914 | dst = insn.has_dst ? insn.dst : 0; | |
ff5a51b3 | 915 | |
d218e7fe JM |
916 | if (target_big_endian) |
917 | bytes[1] = ((dst & 0xf) << 4) | (src & 0xf); | |
918 | else | |
919 | bytes[1] = ((src & 0xf) << 4) | (dst & 0xf); | |
ff5a51b3 | 920 | |
d218e7fe JM |
921 | /* Now the immediates. */ |
922 | if (insn.has_imm64) | |
923 | { | |
924 | switch (insn.imm64.X_op) | |
925 | { | |
926 | case O_constant: | |
927 | { | |
928 | uint64_t imm64 = insn.imm64.X_add_number; | |
929 | ||
930 | if (target_big_endian) | |
931 | { | |
932 | bytes[12] = (imm64 >> 56) & 0xff; | |
933 | bytes[13] = (imm64 >> 48) & 0xff; | |
934 | bytes[14] = (imm64 >> 40) & 0xff; | |
935 | bytes[15] = (imm64 >> 32) & 0xff; | |
936 | bytes[4] = (imm64 >> 24) & 0xff; | |
937 | bytes[5] = (imm64 >> 16) & 0xff; | |
938 | bytes[6] = (imm64 >> 8) & 0xff; | |
939 | bytes[7] = imm64 & 0xff; | |
940 | } | |
941 | else | |
942 | { | |
943 | bytes[15] = (imm64 >> 56) & 0xff; | |
944 | bytes[14] = (imm64 >> 48) & 0xff; | |
945 | bytes[13] = (imm64 >> 40) & 0xff; | |
946 | bytes[12] = (imm64 >> 32) & 0xff; | |
947 | bytes[7] = (imm64 >> 24) & 0xff; | |
948 | bytes[6] = (imm64 >> 16) & 0xff; | |
949 | bytes[5] = (imm64 >> 8) & 0xff; | |
950 | bytes[4] = imm64 & 0xff; | |
951 | } | |
952 | break; | |
953 | } | |
954 | case O_symbol: | |
955 | case O_subtract: | |
956 | case O_add: | |
957 | { | |
958 | reloc_howto_type *reloc_howto; | |
959 | int size; | |
960 | ||
961 | reloc_howto = bfd_reloc_type_lookup (stdoutput, BFD_RELOC_BPF_64); | |
962 | if (!reloc_howto) | |
963 | abort (); | |
964 | ||
965 | size = bfd_get_reloc_size (reloc_howto); | |
966 | ||
967 | fix_new_exp (frag_now, this_frag - frag_now->fr_literal, | |
968 | size, &insn.imm64, reloc_howto->pc_relative, | |
969 | BFD_RELOC_BPF_64); | |
970 | break; | |
971 | } | |
972 | default: | |
973 | abort (); | |
974 | } | |
975 | } | |
ff5a51b3 | 976 | |
d218e7fe JM |
977 | if (insn.has_imm32) |
978 | { | |
979 | switch (insn.imm32.X_op) | |
980 | { | |
981 | case O_constant: | |
982 | { | |
983 | uint32_t imm32 = insn.imm32.X_add_number; | |
984 | ||
985 | if (target_big_endian) | |
986 | { | |
987 | bytes[4] = (imm32 >> 24) & 0xff; | |
988 | bytes[5] = (imm32 >> 16) & 0xff; | |
989 | bytes[6] = (imm32 >> 8) & 0xff; | |
990 | bytes[7] = imm32 & 0xff; | |
991 | } | |
992 | else | |
993 | { | |
994 | bytes[7] = (imm32 >> 24) & 0xff; | |
995 | bytes[6] = (imm32 >> 16) & 0xff; | |
996 | bytes[5] = (imm32 >> 8) & 0xff; | |
997 | bytes[4] = imm32 & 0xff; | |
998 | } | |
999 | break; | |
1000 | } | |
1001 | case O_symbol: | |
1002 | case O_subtract: | |
1003 | case O_add: | |
1004 | case O_uminus: | |
1005 | { | |
1006 | reloc_howto_type *reloc_howto; | |
1007 | int size; | |
1008 | ||
1009 | reloc_howto = bfd_reloc_type_lookup (stdoutput, BFD_RELOC_32); | |
1010 | if (!reloc_howto) | |
1011 | abort (); | |
1012 | ||
1013 | size = bfd_get_reloc_size (reloc_howto); | |
1014 | ||
1015 | fix_new_exp (frag_now, this_frag - frag_now->fr_literal + 4, | |
1016 | size, &insn.imm32, reloc_howto->pc_relative, | |
1017 | BFD_RELOC_32); | |
1018 | break; | |
1019 | } | |
1020 | default: | |
1021 | abort (); | |
1022 | } | |
1023 | } | |
ff5a51b3 | 1024 | |
d218e7fe JM |
1025 | if (insn.has_disp32) |
1026 | { | |
1027 | switch (insn.disp32.X_op) | |
1028 | { | |
1029 | case O_constant: | |
1030 | { | |
1031 | uint32_t disp32 = insn.disp32.X_add_number; | |
1032 | ||
1033 | if (target_big_endian) | |
1034 | { | |
1035 | bytes[4] = (disp32 >> 24) & 0xff; | |
1036 | bytes[5] = (disp32 >> 16) & 0xff; | |
1037 | bytes[6] = (disp32 >> 8) & 0xff; | |
1038 | bytes[7] = disp32 & 0xff; | |
1039 | } | |
1040 | else | |
1041 | { | |
1042 | bytes[7] = (disp32 >> 24) & 0xff; | |
1043 | bytes[6] = (disp32 >> 16) & 0xff; | |
1044 | bytes[5] = (disp32 >> 8) & 0xff; | |
1045 | bytes[4] = disp32 & 0xff; | |
1046 | } | |
1047 | break; | |
1048 | } | |
1049 | case O_symbol: | |
1050 | case O_subtract: | |
1051 | case O_add: | |
1052 | { | |
1053 | reloc_howto_type *reloc_howto; | |
1054 | int size; | |
c2ca88d7 JM |
1055 | unsigned int bfd_reloc |
1056 | = (insn.id == BPF_INSN_CALL | |
1057 | ? BFD_RELOC_BPF_DISPCALL32 | |
1058 | : BFD_RELOC_BPF_DISP32); | |
d218e7fe | 1059 | |
c2ca88d7 | 1060 | reloc_howto = bfd_reloc_type_lookup (stdoutput, bfd_reloc); |
d218e7fe JM |
1061 | if (!reloc_howto) |
1062 | abort (); | |
1063 | ||
1064 | size = bfd_get_reloc_size (reloc_howto); | |
1065 | ||
1066 | fix_new_exp (frag_now, this_frag - frag_now->fr_literal, | |
1067 | size, &insn.disp32, reloc_howto->pc_relative, | |
c2ca88d7 | 1068 | bfd_reloc); |
d218e7fe JM |
1069 | break; |
1070 | } | |
1071 | default: | |
1072 | abort (); | |
1073 | } | |
1074 | } | |
ff5a51b3 | 1075 | |
d218e7fe JM |
1076 | if (insn.has_offset16) |
1077 | { | |
1078 | switch (insn.offset16.X_op) | |
1079 | { | |
1080 | case O_constant: | |
1081 | { | |
1082 | uint32_t offset16 = insn.offset16.X_add_number; | |
1083 | ||
1084 | if (target_big_endian) | |
1085 | { | |
1086 | bytes[2] = (offset16 >> 8) & 0xff; | |
1087 | bytes[3] = offset16 & 0xff; | |
1088 | } | |
1089 | else | |
1090 | { | |
1091 | bytes[3] = (offset16 >> 8) & 0xff; | |
1092 | bytes[2] = offset16 & 0xff; | |
1093 | } | |
1094 | break; | |
1095 | } | |
1096 | case O_symbol: | |
1097 | case O_subtract: | |
1098 | case O_add: | |
1099 | { | |
1100 | reloc_howto_type *reloc_howto; | |
1101 | int size; | |
1102 | ||
1103 | reloc_howto = bfd_reloc_type_lookup (stdoutput, BFD_RELOC_BPF_DISP16); | |
1104 | if (!reloc_howto) | |
1105 | abort (); | |
1106 | ||
1107 | size = bfd_get_reloc_size (reloc_howto); | |
1108 | ||
1109 | fix_new_exp (frag_now, this_frag - frag_now->fr_literal, | |
1110 | size, &insn.offset16, reloc_howto->pc_relative, | |
1111 | BFD_RELOC_BPF_DISP16); | |
1112 | break; | |
1113 | } | |
1114 | default: | |
1115 | abort (); | |
1116 | } | |
1117 | } | |
ff5a51b3 | 1118 | |
d218e7fe JM |
1119 | if (insn.has_disp16) |
1120 | { | |
1121 | switch (insn.disp16.X_op) | |
1122 | { | |
1123 | case O_constant: | |
1124 | { | |
1125 | uint32_t disp16 = insn.disp16.X_add_number; | |
1126 | ||
1127 | if (target_big_endian) | |
1128 | { | |
1129 | bytes[2] = (disp16 >> 8) & 0xff; | |
1130 | bytes[3] = disp16 & 0xff; | |
1131 | } | |
1132 | else | |
1133 | { | |
1134 | bytes[3] = (disp16 >> 8) & 0xff; | |
1135 | bytes[2] = disp16 & 0xff; | |
1136 | } | |
1137 | break; | |
1138 | } | |
1139 | case O_symbol: | |
1140 | case O_subtract: | |
1141 | case O_add: | |
1142 | { | |
1143 | reloc_howto_type *reloc_howto; | |
1144 | int size; | |
1145 | ||
1146 | reloc_howto = bfd_reloc_type_lookup (stdoutput, BFD_RELOC_BPF_DISP16); | |
1147 | if (!reloc_howto) | |
1148 | abort (); | |
1149 | ||
1150 | size = bfd_get_reloc_size (reloc_howto); | |
1151 | ||
1152 | fix_new_exp (frag_now, this_frag - frag_now->fr_literal, | |
1153 | size, &insn.disp16, reloc_howto->pc_relative, | |
1154 | BFD_RELOC_BPF_DISP16); | |
1155 | break; | |
1156 | } | |
1157 | default: | |
1158 | abort (); | |
1159 | } | |
1160 | } | |
ff5a51b3 | 1161 | |
d218e7fe JM |
1162 | /* Emit bytes. */ |
1163 | for (i = 0; i < insn.size; ++i) | |
1164 | { | |
1165 | md_number_to_chars (this_frag, (valueT) bytes[i], 1); | |
1166 | this_frag += 1; | |
1167 | } | |
1168 | } | |
ff5a51b3 | 1169 | |
d218e7fe JM |
1170 | /* Emit DWARF2 debugging information. */ |
1171 | dwarf2_emit_insn (insn.size); | |
ff5a51b3 GM |
1172 | } |
1173 | ||
d218e7fe | 1174 | /* Parse an operand that is machine-specific. */ |
f8861f5d JM |
1175 | |
1176 | void | |
1177 | md_operand (expressionS *expressionP) | |
1178 | { | |
d218e7fe JM |
1179 | /* If this hook is invoked it means GAS failed to parse a generic |
1180 | expression. We should inhibit the as_bad in expr.c, so we can fail | |
1181 | while parsing instruction alternatives. To do that, we change the | |
1182 | expression to not have an O_absent. But then we also need to set | |
1183 | exp_parse_failed to parse_expression above does the right thing. */ | |
1184 | ++input_line_pointer; | |
1185 | expressionP->X_op = O_constant; | |
1186 | expressionP->X_add_number = 0; | |
1187 | exp_parse_failed = 1; | |
f8861f5d JM |
1188 | } |
1189 | ||
f8861f5d JM |
1190 | symbolS * |
1191 | md_undefined_symbol (char *name ATTRIBUTE_UNUSED) | |
1192 | { | |
1193 | return NULL; | |
1194 | } | |
1195 | ||
1196 | \f | |
1197 | /* Turn a string in input_line_pointer into a floating point constant | |
1198 | of type TYPE, and store the appropriate bytes in *LITP. The number | |
1199 | of LITTLENUMS emitted is stored in *SIZEP. An error message is | |
1200 | returned, or NULL on OK. */ | |
1201 | ||
1202 | const char * | |
1203 | md_atof (int type, char *litP, int *sizeP) | |
1204 | { | |
5b7c81bd | 1205 | return ieee_md_atof (type, litP, sizeP, false); |
f8861f5d | 1206 | } |
d218e7fe JM |
1207 | |
1208 | \f | |
1209 | /* Determine whether the equal sign in the given string corresponds to | |
1210 | a BPF instruction, i.e. when it is not to be considered a symbol | |
1211 | assignment. */ | |
1212 | ||
1213 | bool | |
1214 | bpf_tc_equal_in_insn (int c ATTRIBUTE_UNUSED, char *str ATTRIBUTE_UNUSED) | |
1215 | { | |
1216 | uint8_t regno; | |
1217 | ||
1218 | /* Only pseudo-c instructions can have equal signs, and of these, | |
1219 | all that could be confused with a symbol assignment all start | |
1220 | with a register name. */ | |
1221 | if (asm_dialect == DIALECT_PSEUDOC) | |
1222 | { | |
1223 | char *w = parse_bpf_register (str, 'w', ®no); | |
1224 | char *r = parse_bpf_register (str, 'r', ®no); | |
1225 | ||
1226 | if ((w != NULL && *w == '\0') | |
1227 | || (r != NULL && *r == '\0')) | |
1228 | return 1; | |
1229 | } | |
1230 | ||
1231 | return 0; | |
1232 | } |