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 __attribute__((visibility("hidden")))
38 int filter_parser_debug = 0;
40 __attribute__((visibility("hidden")))
41 int yyparse(struct filter_parser_ctx *parser_ctx);
42 __attribute__((visibility("hidden")))
43 int yylex(union YYSTYPE *yyval, struct filter_parser_ctx *parser_ctx);
44 __attribute__((visibility("hidden")))
45 int yylex_init_extra(struct filter_parser_ctx *parser_ctx, yyscan_t * ptr_yy_globals);
46 __attribute__((visibility("hidden")))
47 int yylex_destroy(yyscan_t yyparser_ctx);
48 __attribute__((visibility("hidden")))
49 void yyrestart(FILE * in_str, yyscan_t parser_ctx);
52 struct cds_list_head gc;
57 static const char *node_type_to_str[] = {
58 [ NODE_UNKNOWN ] = "NODE_UNKNOWN",
59 [ NODE_ROOT ] = "NODE_ROOT",
60 [ NODE_EXPRESSION ] = "NODE_EXPRESSION",
61 [ NODE_OP ] = "NODE_OP",
62 [ NODE_UNARY_OP ] = "NODE_UNARY_OP",
65 __attribute__((visibility("hidden")))
66 const char *node_type(struct filter_node *node)
68 if (node->type < NR_NODE_TYPES)
69 return node_type_to_str[node->type];
74 static struct gc_string *gc_string_alloc(struct filter_parser_ctx *parser_ctx,
77 struct gc_string *gstr;
80 /* TODO: could be faster with find first bit or glib Gstring */
81 /* sizeof long to account for malloc header (int or long ?) */
82 for (alloclen = 8; alloclen < sizeof(long) + sizeof(*gstr) + len;
85 gstr = malloc(alloclen);
86 cds_list_add(&gstr->gc, &parser_ctx->allocated_strings);
87 gstr->alloclen = alloclen;
92 * note: never use gc_string_append on a string that has external references.
93 * gsrc will be garbage collected immediately, and gstr might be.
94 * Should only be used to append characters to a string literal or constant.
96 __attribute__((visibility("hidden")))
97 struct gc_string *gc_string_append(struct filter_parser_ctx *parser_ctx,
98 struct gc_string *gstr,
99 struct gc_string *gsrc)
101 size_t newlen = strlen(gsrc->s) + strlen(gstr->s) + 1;
104 /* TODO: could be faster with find first bit or glib Gstring */
105 /* sizeof long to account for malloc header (int or long ?) */
106 for (alloclen = 8; alloclen < sizeof(long) + sizeof(*gstr) + newlen;
109 if (alloclen > gstr->alloclen) {
110 struct gc_string *newgstr;
112 newgstr = gc_string_alloc(parser_ctx, newlen);
113 strcpy(newgstr->s, gstr->s);
114 strcat(newgstr->s, gsrc->s);
115 cds_list_del(&gstr->gc);
119 strcat(gstr->s, gsrc->s);
121 cds_list_del(&gsrc->gc);
126 __attribute__((visibility("hidden")))
127 void setstring(struct filter_parser_ctx *parser_ctx, YYSTYPE *lvalp, const char *src)
129 lvalp->gs = gc_string_alloc(parser_ctx, strlen(src) + 1);
130 strcpy(lvalp->gs->s, src);
133 static struct filter_node *make_node(struct filter_parser_ctx *scanner,
136 struct filter_ast *ast = filter_parser_get_ast(scanner);
137 struct filter_node *node;
139 node = malloc(sizeof(*node));
142 memset(node, 0, sizeof(*node));
144 cds_list_add(&node->gc, &ast->allocated_nodes);
148 fprintf(stderr, "[error] %s: trying to create root node\n", __func__);
151 case NODE_EXPRESSION:
160 fprintf(stderr, "[error] %s: unknown node type %d\n", __func__,
168 static struct filter_node *make_op_node(struct filter_parser_ctx *scanner,
170 struct filter_node *lchild,
171 struct filter_node *rchild)
173 struct filter_ast *ast = filter_parser_get_ast(scanner);
174 struct filter_node *node;
176 node = malloc(sizeof(*node));
179 memset(node, 0, sizeof(*node));
180 node->type = NODE_OP;
181 cds_list_add(&node->gc, &ast->allocated_nodes);
182 node->u.op.type = type;
183 node->u.op.lchild = lchild;
184 node->u.op.rchild = rchild;
188 __attribute__((visibility("hidden")))
189 void yyerror(struct filter_parser_ctx *parser_ctx, const char *str)
191 fprintf(stderr, "error %s\n", str);
194 __attribute__((visibility("hidden")))
200 #define parse_error(parser_ctx, str) \
202 yyerror(parser_ctx, YY_("parse error: " str "\n")); \
206 static void free_strings(struct cds_list_head *list)
208 struct gc_string *gstr, *tmp;
210 cds_list_for_each_entry_safe(gstr, tmp, list, gc)
214 static struct filter_ast *filter_ast_alloc(void)
216 struct filter_ast *ast;
218 ast = malloc(sizeof(*ast));
221 memset(ast, 0, sizeof(*ast));
222 CDS_INIT_LIST_HEAD(&ast->allocated_nodes);
223 ast->root.type = NODE_ROOT;
227 static void filter_ast_free(struct filter_ast *ast)
229 struct filter_node *node, *tmp;
231 cds_list_for_each_entry_safe(node, tmp, &ast->allocated_nodes, gc)
236 __attribute__((visibility("hidden")))
237 int filter_parser_ctx_append_ast(struct filter_parser_ctx *parser_ctx)
239 return yyparse(parser_ctx);
242 __attribute__((visibility("hidden")))
243 struct filter_parser_ctx *filter_parser_ctx_alloc(FILE *input)
245 struct filter_parser_ctx *parser_ctx;
248 yydebug = filter_parser_debug;
250 parser_ctx = malloc(sizeof(*parser_ctx));
253 memset(parser_ctx, 0, sizeof(*parser_ctx));
255 ret = yylex_init_extra(parser_ctx, &parser_ctx->scanner);
257 fprintf(stderr, "yylex_init error\n");
258 goto cleanup_parser_ctx;
260 /* Start processing new stream */
261 yyrestart(input, parser_ctx->scanner);
263 parser_ctx->ast = filter_ast_alloc();
264 if (!parser_ctx->ast)
266 CDS_INIT_LIST_HEAD(&parser_ctx->allocated_strings);
269 fprintf(stdout, "parser_ctx input is a%s.\n",
270 isatty(fileno(input)) ? "n interactive tty" :
271 " noninteractive file");
276 ret = yylex_destroy(parser_ctx->scanner);
278 fprintf(stderr, "yylex_destroy error\n");
284 __attribute__((visibility("hidden")))
285 void filter_parser_ctx_free(struct filter_parser_ctx *parser_ctx)
289 free_strings(&parser_ctx->allocated_strings);
290 filter_ast_free(parser_ctx->ast);
291 ret = yylex_destroy(parser_ctx->scanner);
293 fprintf(stderr, "yylex_destroy error\n");
301 %parse-param {struct filter_parser_ctx *parser_ctx}
302 %lex-param {struct filter_parser_ctx *parser_ctx}
303 %start translation_unit
304 %token CHARACTER_CONSTANT_START SQUOTE STRING_LITERAL_START DQUOTE
305 %token ESCSEQ CHAR_STRING_TOKEN
306 %token DECIMAL_CONSTANT OCTAL_CONSTANT HEXADECIMAL_CONSTANT FLOAT_CONSTANT
307 %token LSBRAC RSBRAC LPAREN RPAREN LBRAC RBRAC RARROW
308 %token STAR PLUS MINUS
309 %token MOD_OP DIV_OP RIGHT_OP LEFT_OP
310 %token EQ_OP NE_OP LE_OP GE_OP LT_OP GT_OP AND_OP OR_OP NOT_OP
311 %token ASSIGN COLON SEMICOLON DOTDOTDOT DOT EQUAL COMMA
312 %token XOR_BIN AND_BIN OR_BIN NOT_BIN
314 %token <gs> IDENTIFIER
320 struct gc_string *gs;
321 struct filter_node *n;
324 %type <gs> s_char s_char_sequence c_char c_char_sequence
326 %type <n> primary_expression
327 %type <n> postfix_expression
328 %type <n> unary_expression
329 %type <n> unary_operator
330 %type <n> multiplicative_expression
331 %type <n> additive_expression
332 %type <n> shift_expression
333 %type <n> relational_expression
334 %type <n> equality_expression
335 %type <n> and_expression
336 %type <n> exclusive_or_expression
337 %type <n> inclusive_or_expression
338 %type <n> logical_and_expression
339 %type <n> logical_or_expression
350 | c_char_sequence c_char
351 { $$ = gc_string_append(parser_ctx, $1, $2); }
359 parse_error(parser_ctx, "escape sequences not supported yet");
363 /* 1.6 String literals */
368 | s_char_sequence s_char
369 { $$ = gc_string_append(parser_ctx, $1, $2); }
377 parse_error(parser_ctx, "escape sequences not supported yet");
384 $$ = make_node(parser_ctx, NODE_EXPRESSION);
385 $$->u.expression.type = AST_EXP_IDENTIFIER;
386 $$->u.expression.u.identifier = yylval.gs->s;
390 $$ = make_node(parser_ctx, NODE_EXPRESSION);
391 $$->u.expression.type = AST_EXP_CONSTANT;
392 sscanf(yylval.gs->s, "%" PRIu64,
393 &$$->u.expression.u.constant);
397 $$ = make_node(parser_ctx, NODE_EXPRESSION);
398 $$->u.expression.type = AST_EXP_CONSTANT;
399 sscanf(yylval.gs->s, "0%" PRIo64,
400 &$$->u.expression.u.constant);
402 | HEXADECIMAL_CONSTANT
404 $$ = make_node(parser_ctx, NODE_EXPRESSION);
405 $$->u.expression.type = AST_EXP_CONSTANT;
406 sscanf(yylval.gs->s, "0x%" PRIx64,
407 &$$->u.expression.u.constant);
411 $$ = make_node(parser_ctx, NODE_EXPRESSION);
412 $$->u.expression.type = AST_EXP_FLOAT_CONSTANT;
413 sscanf(yylval.gs->s, "%lg",
414 &$$->u.expression.u.float_constant);
416 | STRING_LITERAL_START DQUOTE
418 $$ = make_node(parser_ctx, NODE_EXPRESSION);
419 $$->u.expression.type = AST_EXP_STRING;
420 $$->u.expression.u.string = "";
422 | STRING_LITERAL_START s_char_sequence DQUOTE
424 $$ = make_node(parser_ctx, NODE_EXPRESSION);
425 $$->u.expression.type = AST_EXP_STRING;
426 $$->u.expression.u.string = $2->s;
428 | CHARACTER_CONSTANT_START c_char_sequence SQUOTE
430 $$ = make_node(parser_ctx, NODE_EXPRESSION);
431 $$->u.expression.type = AST_EXP_STRING;
432 $$->u.expression.u.string = $2->s;
434 | LPAREN expression RPAREN
436 $$ = make_node(parser_ctx, NODE_EXPRESSION);
437 $$->u.expression.type = AST_EXP_NESTED;
438 $$->u.expression.u.child = $2;
445 | postfix_expression DOT IDENTIFIER
447 $$ = make_node(parser_ctx, NODE_EXPRESSION);
448 $$->u.expression.type = AST_EXP_IDENTIFIER;
449 $$->u.expression.post_op = AST_LINK_DOT;
450 $$->u.expression.u.identifier = $3->s;
451 $$->u.expression.prev = $1;
453 | postfix_expression RARROW IDENTIFIER
455 $$ = make_node(parser_ctx, NODE_EXPRESSION);
456 $$->u.expression.type = AST_EXP_IDENTIFIER;
457 $$->u.expression.post_op = AST_LINK_RARROW;
458 $$->u.expression.u.identifier = $3->s;
459 $$->u.expression.prev = $1;
466 | unary_operator unary_expression
469 $$->u.unary_op.child = $2;
476 $$ = make_node(parser_ctx, NODE_UNARY_OP);
477 $$->u.unary_op.type = AST_UNARY_PLUS;
481 $$ = make_node(parser_ctx, NODE_UNARY_OP);
482 $$->u.unary_op.type = AST_UNARY_MINUS;
486 $$ = make_node(parser_ctx, NODE_UNARY_OP);
487 $$->u.unary_op.type = AST_UNARY_NOT;
491 $$ = make_node(parser_ctx, NODE_UNARY_OP);
492 $$->u.unary_op.type = AST_UNARY_BIN_NOT;
496 multiplicative_expression
499 | multiplicative_expression STAR unary_expression
501 $$ = make_op_node(parser_ctx, AST_OP_MUL, $1, $3);
503 | multiplicative_expression DIV_OP unary_expression
505 $$ = make_op_node(parser_ctx, AST_OP_DIV, $1, $3);
507 | multiplicative_expression MOD_OP unary_expression
509 $$ = make_op_node(parser_ctx, AST_OP_MOD, $1, $3);
514 : multiplicative_expression
516 | additive_expression PLUS multiplicative_expression
518 $$ = make_op_node(parser_ctx, AST_OP_PLUS, $1, $3);
520 | additive_expression MINUS multiplicative_expression
522 $$ = make_op_node(parser_ctx, AST_OP_MINUS, $1, $3);
527 : additive_expression
529 | shift_expression LEFT_OP additive_expression
531 $$ = make_op_node(parser_ctx, AST_OP_LSHIFT, $1, $3);
533 | shift_expression RIGHT_OP additive_expression
535 $$ = make_op_node(parser_ctx, AST_OP_RSHIFT, $1, $3);
539 relational_expression
542 | relational_expression LT_OP shift_expression
544 $$ = make_op_node(parser_ctx, AST_OP_LT, $1, $3);
546 | relational_expression GT_OP shift_expression
548 $$ = make_op_node(parser_ctx, AST_OP_GT, $1, $3);
550 | relational_expression LE_OP shift_expression
552 $$ = make_op_node(parser_ctx, AST_OP_LE, $1, $3);
554 | relational_expression GE_OP shift_expression
556 $$ = make_op_node(parser_ctx, AST_OP_GE, $1, $3);
561 : relational_expression
563 | equality_expression EQ_OP relational_expression
565 $$ = make_op_node(parser_ctx, AST_OP_EQ, $1, $3);
567 | equality_expression NE_OP relational_expression
569 $$ = make_op_node(parser_ctx, AST_OP_NE, $1, $3);
574 : equality_expression
576 | and_expression AND_BIN equality_expression
578 $$ = make_op_node(parser_ctx, AST_OP_BIN_AND, $1, $3);
582 exclusive_or_expression
585 | exclusive_or_expression XOR_BIN and_expression
587 $$ = make_op_node(parser_ctx, AST_OP_BIN_XOR, $1, $3);
591 inclusive_or_expression
592 : exclusive_or_expression
594 | inclusive_or_expression OR_BIN exclusive_or_expression
596 $$ = make_op_node(parser_ctx, AST_OP_BIN_OR, $1, $3);
600 logical_and_expression
601 : inclusive_or_expression
603 | logical_and_expression AND_OP inclusive_or_expression
605 $$ = make_op_node(parser_ctx, AST_OP_AND, $1, $3);
609 logical_or_expression
610 : logical_and_expression
612 | logical_or_expression OR_OP logical_and_expression
614 $$ = make_op_node(parser_ctx, AST_OP_OR, $1, $3);
619 : logical_or_expression
626 parser_ctx->ast->root.u.root.child = $1;