5 * LTTng filter expression parser
7 * Copyright 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
9 * This library is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU Lesser General Public License, version 2.1 only,
11 * as published by the Free Software Foundation.
13 * This library 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 GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public License
19 * along with this library; if not, write to the Free Software Foundation,
20 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 * Grammar inspired from http://www.quut.com/c/ANSI-C-grammar-y.html
32 #include "filter-ast.h"
33 #include "filter-parser.h"
35 __attribute__((visibility("hidden")))
37 int filter_parser_debug = 0;
39 __attribute__((visibility("hidden")))
40 int yyparse(struct filter_parser_ctx *parser_ctx);
41 __attribute__((visibility("hidden")))
42 int yylex(union YYSTYPE *yyval, struct filter_parser_ctx *parser_ctx);
43 __attribute__((visibility("hidden")))
44 int yylex_init_extra(struct filter_parser_ctx *parser_ctx, yyscan_t * ptr_yy_globals);
45 __attribute__((visibility("hidden")))
46 int yylex_destroy(yyscan_t yyparser_ctx);
47 __attribute__((visibility("hidden")))
48 void yyrestart(FILE * in_str, yyscan_t parser_ctx);
51 struct cds_list_head gc;
56 static const char *node_type_to_str[] = {
57 [ NODE_UNKNOWN ] = "NODE_UNKNOWN",
58 [ NODE_ROOT ] = "NODE_ROOT",
59 [ NODE_EXPRESSION ] = "NODE_EXPRESSION",
60 [ NODE_OP ] = "NODE_OP",
61 [ NODE_UNARY_OP ] = "NODE_UNARY_OP",
64 __attribute__((visibility("hidden")))
65 const char *node_type(struct filter_node *node)
67 if (node->type < NR_NODE_TYPES)
68 return node_type_to_str[node->type];
73 static struct gc_string *gc_string_alloc(struct filter_parser_ctx *parser_ctx,
76 struct gc_string *gstr;
79 /* TODO: could be faster with find first bit or glib Gstring */
80 /* sizeof long to account for malloc header (int or long ?) */
81 for (alloclen = 8; alloclen < sizeof(long) + sizeof(*gstr) + len;
84 gstr = malloc(alloclen);
85 cds_list_add(&gstr->gc, &parser_ctx->allocated_strings);
86 gstr->alloclen = alloclen;
91 * note: never use gc_string_append on a string that has external references.
92 * gsrc will be garbage collected immediately, and gstr might be.
93 * Should only be used to append characters to a string literal or constant.
95 __attribute__((visibility("hidden")))
96 struct gc_string *gc_string_append(struct filter_parser_ctx *parser_ctx,
97 struct gc_string *gstr,
98 struct gc_string *gsrc)
100 size_t newlen = strlen(gsrc->s) + strlen(gstr->s) + 1;
103 /* TODO: could be faster with find first bit or glib Gstring */
104 /* sizeof long to account for malloc header (int or long ?) */
105 for (alloclen = 8; alloclen < sizeof(long) + sizeof(*gstr) + newlen;
108 if (alloclen > gstr->alloclen) {
109 struct gc_string *newgstr;
111 newgstr = gc_string_alloc(parser_ctx, newlen);
112 strcpy(newgstr->s, gstr->s);
113 strcat(newgstr->s, gsrc->s);
114 cds_list_del(&gstr->gc);
118 strcat(gstr->s, gsrc->s);
120 cds_list_del(&gsrc->gc);
125 __attribute__((visibility("hidden")))
126 void setstring(struct filter_parser_ctx *parser_ctx, YYSTYPE *lvalp, const char *src)
128 lvalp->gs = gc_string_alloc(parser_ctx, strlen(src) + 1);
129 strcpy(lvalp->gs->s, src);
132 static struct filter_node *make_node(struct filter_parser_ctx *scanner,
135 struct filter_ast *ast = filter_parser_get_ast(scanner);
136 struct filter_node *node;
138 node = malloc(sizeof(*node));
141 memset(node, 0, sizeof(*node));
143 cds_list_add(&node->gc, &ast->allocated_nodes);
147 fprintf(stderr, "[error] %s: trying to create root node\n", __func__);
150 case NODE_EXPRESSION:
159 fprintf(stderr, "[error] %s: unknown node type %d\n", __func__,
167 static struct filter_node *make_op_node(struct filter_parser_ctx *scanner,
169 struct filter_node *lchild,
170 struct filter_node *rchild)
172 struct filter_ast *ast = filter_parser_get_ast(scanner);
173 struct filter_node *node;
175 node = malloc(sizeof(*node));
178 memset(node, 0, sizeof(*node));
179 node->type = NODE_OP;
180 cds_list_add(&node->gc, &ast->allocated_nodes);
181 node->u.op.type = type;
182 node->u.op.lchild = lchild;
183 node->u.op.rchild = rchild;
187 __attribute__((visibility("hidden")))
188 void yyerror(struct filter_parser_ctx *parser_ctx, const char *str)
190 fprintf(stderr, "error %s\n", str);
193 __attribute__((visibility("hidden")))
199 #define parse_error(parser_ctx, str) \
201 yyerror(parser_ctx, YY_("parse error: " str "\n")); \
205 static void free_strings(struct cds_list_head *list)
207 struct gc_string *gstr, *tmp;
209 cds_list_for_each_entry_safe(gstr, tmp, list, gc)
213 static struct filter_ast *filter_ast_alloc(void)
215 struct filter_ast *ast;
217 ast = malloc(sizeof(*ast));
220 memset(ast, 0, sizeof(*ast));
221 CDS_INIT_LIST_HEAD(&ast->allocated_nodes);
222 ast->root.type = NODE_ROOT;
226 static void filter_ast_free(struct filter_ast *ast)
228 struct filter_node *node, *tmp;
230 cds_list_for_each_entry_safe(node, tmp, &ast->allocated_nodes, gc)
234 int filter_parser_ctx_append_ast(struct filter_parser_ctx *parser_ctx)
236 return yyparse(parser_ctx);
239 struct filter_parser_ctx *filter_parser_ctx_alloc(FILE *input)
241 struct filter_parser_ctx *parser_ctx;
244 yydebug = filter_parser_debug;
246 parser_ctx = malloc(sizeof(*parser_ctx));
249 memset(parser_ctx, 0, sizeof(*parser_ctx));
251 ret = yylex_init_extra(parser_ctx, &parser_ctx->scanner);
253 fprintf(stderr, "yylex_init error\n");
254 goto cleanup_parser_ctx;
256 /* Start processing new stream */
257 yyrestart(input, parser_ctx->scanner);
259 parser_ctx->ast = filter_ast_alloc();
260 if (!parser_ctx->ast)
262 CDS_INIT_LIST_HEAD(&parser_ctx->allocated_strings);
265 fprintf(stdout, "parser_ctx input is a%s.\n",
266 isatty(fileno(input)) ? "n interactive tty" :
267 " noninteractive file");
272 ret = yylex_destroy(parser_ctx->scanner);
274 fprintf(stderr, "yylex_destroy error\n");
280 void filter_parser_ctx_free(struct filter_parser_ctx *parser_ctx)
284 free_strings(&parser_ctx->allocated_strings);
285 filter_ast_free(parser_ctx->ast);
286 ret = yylex_destroy(parser_ctx->scanner);
288 fprintf(stderr, "yylex_destroy error\n");
296 %parse-param {struct filter_parser_ctx *parser_ctx}
297 %lex-param {struct filter_parser_ctx *parser_ctx}
298 %start translation_unit
299 %token CHARACTER_CONSTANT_START SQUOTE STRING_LITERAL_START DQUOTE
300 %token ESCSEQ CHAR_STRING_TOKEN
301 %token DECIMAL_CONSTANT OCTAL_CONSTANT HEXADECIMAL_CONSTANT FLOAT_CONSTANT
302 %token LSBRAC RSBRAC LPAREN RPAREN LBRAC RBRAC RARROW
303 %token STAR PLUS MINUS
304 %token MOD_OP DIV_OP RIGHT_OP LEFT_OP
305 %token EQ_OP NE_OP LE_OP GE_OP LT_OP GT_OP AND_OP OR_OP NOT_OP
306 %token ASSIGN COLON SEMICOLON DOTDOTDOT DOT EQUAL COMMA
307 %token XOR_BIN AND_BIN OR_BIN NOT_BIN
309 %token <gs> IDENTIFIER
315 struct gc_string *gs;
316 struct filter_node *n;
319 %type <gs> s_char s_char_sequence c_char c_char_sequence
321 %type <n> primary_expression
322 %type <n> postfix_expression
323 %type <n> unary_expression
324 %type <n> unary_operator
325 %type <n> multiplicative_expression
326 %type <n> additive_expression
327 %type <n> shift_expression
328 %type <n> relational_expression
329 %type <n> equality_expression
330 %type <n> and_expression
331 %type <n> exclusive_or_expression
332 %type <n> inclusive_or_expression
333 %type <n> logical_and_expression
334 %type <n> logical_or_expression
345 | c_char_sequence c_char
346 { $$ = gc_string_append(parser_ctx, $1, $2); }
354 parse_error(parser_ctx, "escape sequences not supported yet");
358 /* 1.6 String literals */
363 | s_char_sequence s_char
364 { $$ = gc_string_append(parser_ctx, $1, $2); }
372 parse_error(parser_ctx, "escape sequences not supported yet");
379 $$ = make_node(parser_ctx, NODE_EXPRESSION);
380 $$->u.expression.type = AST_EXP_IDENTIFIER;
381 $$->u.expression.u.identifier = yylval.gs->s;
385 $$ = make_node(parser_ctx, NODE_EXPRESSION);
386 $$->u.expression.type = AST_EXP_CONSTANT;
387 sscanf(yylval.gs->s, "%" PRIu64,
388 &$$->u.expression.u.constant);
392 $$ = make_node(parser_ctx, NODE_EXPRESSION);
393 $$->u.expression.type = AST_EXP_CONSTANT;
394 sscanf(yylval.gs->s, "0%" PRIo64,
395 &$$->u.expression.u.constant);
397 | HEXADECIMAL_CONSTANT
399 $$ = make_node(parser_ctx, NODE_EXPRESSION);
400 $$->u.expression.type = AST_EXP_CONSTANT;
401 sscanf(yylval.gs->s, "0x%" PRIx64,
402 &$$->u.expression.u.constant);
406 $$ = make_node(parser_ctx, NODE_EXPRESSION);
407 $$->u.expression.type = AST_EXP_FLOAT_CONSTANT;
408 sscanf(yylval.gs->s, "%lg",
409 &$$->u.expression.u.float_constant);
411 | STRING_LITERAL_START DQUOTE
413 $$ = make_node(parser_ctx, NODE_EXPRESSION);
414 $$->u.expression.type = AST_EXP_STRING;
415 $$->u.expression.u.string = "";
417 | STRING_LITERAL_START s_char_sequence DQUOTE
419 $$ = make_node(parser_ctx, NODE_EXPRESSION);
420 $$->u.expression.type = AST_EXP_STRING;
421 $$->u.expression.u.string = $2->s;
423 | CHARACTER_CONSTANT_START c_char_sequence SQUOTE
425 $$ = make_node(parser_ctx, NODE_EXPRESSION);
426 $$->u.expression.type = AST_EXP_STRING;
427 $$->u.expression.u.string = $2->s;
429 | LPAREN expression RPAREN
431 $$ = make_node(parser_ctx, NODE_EXPRESSION);
432 $$->u.expression.type = AST_EXP_NESTED;
433 $$->u.expression.u.child = $2;
440 | postfix_expression DOT IDENTIFIER
442 $$ = make_node(parser_ctx, NODE_EXPRESSION);
443 $$->u.expression.type = AST_EXP_IDENTIFIER;
444 $$->u.expression.post_op = AST_LINK_DOT;
445 $$->u.expression.u.identifier = $3->s;
446 $$->u.expression.prev = $1;
448 | postfix_expression RARROW IDENTIFIER
450 $$ = make_node(parser_ctx, NODE_EXPRESSION);
451 $$->u.expression.type = AST_EXP_IDENTIFIER;
452 $$->u.expression.post_op = AST_LINK_RARROW;
453 $$->u.expression.u.identifier = $3->s;
454 $$->u.expression.prev = $1;
461 | unary_operator unary_expression
464 $$->u.unary_op.child = $2;
471 $$ = make_node(parser_ctx, NODE_UNARY_OP);
472 $$->u.unary_op.type = AST_UNARY_PLUS;
476 $$ = make_node(parser_ctx, NODE_UNARY_OP);
477 $$->u.unary_op.type = AST_UNARY_MINUS;
481 $$ = make_node(parser_ctx, NODE_UNARY_OP);
482 $$->u.unary_op.type = AST_UNARY_NOT;
486 multiplicative_expression
489 | multiplicative_expression STAR unary_expression
491 $$ = make_op_node(parser_ctx, AST_OP_MUL, $1, $3);
493 | multiplicative_expression DIV_OP unary_expression
495 $$ = make_op_node(parser_ctx, AST_OP_DIV, $1, $3);
497 | multiplicative_expression MOD_OP unary_expression
499 $$ = make_op_node(parser_ctx, AST_OP_MOD, $1, $3);
504 : multiplicative_expression
506 | additive_expression PLUS multiplicative_expression
508 $$ = make_op_node(parser_ctx, AST_OP_PLUS, $1, $3);
510 | additive_expression MINUS multiplicative_expression
512 $$ = make_op_node(parser_ctx, AST_OP_MINUS, $1, $3);
517 : additive_expression
519 | shift_expression LEFT_OP additive_expression
521 $$ = make_op_node(parser_ctx, AST_OP_LSHIFT, $1, $3);
523 | shift_expression RIGHT_OP additive_expression
525 $$ = make_op_node(parser_ctx, AST_OP_RSHIFT, $1, $3);
529 relational_expression
532 | relational_expression LT_OP shift_expression
534 $$ = make_op_node(parser_ctx, AST_OP_LT, $1, $3);
536 | relational_expression GT_OP shift_expression
538 $$ = make_op_node(parser_ctx, AST_OP_GT, $1, $3);
540 | relational_expression LE_OP shift_expression
542 $$ = make_op_node(parser_ctx, AST_OP_LE, $1, $3);
544 | relational_expression GE_OP shift_expression
546 $$ = make_op_node(parser_ctx, AST_OP_GE, $1, $3);
551 : relational_expression
553 | equality_expression EQ_OP relational_expression
555 $$ = make_op_node(parser_ctx, AST_OP_EQ, $1, $3);
557 | equality_expression NE_OP relational_expression
559 $$ = make_op_node(parser_ctx, AST_OP_NE, $1, $3);
564 : equality_expression
566 | and_expression AND_BIN equality_expression
568 $$ = make_op_node(parser_ctx, AST_OP_BIN_AND, $1, $3);
572 exclusive_or_expression
575 | exclusive_or_expression XOR_BIN and_expression
577 $$ = make_op_node(parser_ctx, AST_OP_BIN_XOR, $1, $3);
581 inclusive_or_expression
582 : exclusive_or_expression
584 | inclusive_or_expression OR_BIN exclusive_or_expression
586 $$ = make_op_node(parser_ctx, AST_OP_BIN_OR, $1, $3);
590 logical_and_expression
591 : inclusive_or_expression
593 | logical_and_expression AND_OP inclusive_or_expression
595 $$ = make_op_node(parser_ctx, AST_OP_AND, $1, $3);
599 logical_or_expression
600 : logical_and_expression
602 | logical_or_expression OR_OP logical_and_expression
604 $$ = make_op_node(parser_ctx, AST_OP_OR, $1, $3);
609 : logical_or_expression
616 parser_ctx->ast->root.u.root.child = $1;