parser.y

   1 /*
   2  * Copyright (C) 2013-2014 Jo-Philipp Wich <jow@openwrt.org>
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 %token_type {struct jp_opcode *}
  18 %extra_argument {struct jp_state *s}
  19
  20 %left T_AND.
  21 %left T_OR.
  22 %left T_UNION.
  23 %nonassoc T_EQ T_NE T_GT T_GE T_LT T_LE.
  24 %right T_NOT.
  25
  26 %include {
  27 #include <assert.h>
  28 #include <stddef.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31
  32 #include "ast.h"
  33 #include "lexer.h"
  34 #include "parser.h"
  35
  36 #define alloc_op(type, num, str, ...) \
  37         jp_alloc_op(s, type, num, str, ##__VA_ARGS__, NULL)
  38
  39 }
  40
  41 %syntax_error {
  42         int n = sizeof(tokennames) / sizeof(tokennames[0]);
  43         int l = strlen("Expecting ");
  44         int c = 0;
  45         int i;
  46
  47         for (i = 0; i < n; i++)
  48         {
  49                 if (yy_find_shift_action(yypParser, (YYCODETYPE)i) < YYNSTATE + YYNRULE)
  50                         l += strlen(tokennames[i]) + 4;
  51         }
  52
  53         s->error = malloc(l);
  54
  55         if (s->error)
  56         {
  57                 s->erroff = s->off;
  58                 strcpy(s->error, "Expecting ");
  59
  60                 for (i = 0; i < n; i++)
  61                 {
  62                         if (yy_find_shift_action(yypParser, (YYCODETYPE)i) < YYNSTATE + YYNRULE)
  63                         {
  64                                 if (c++)
  65                                         strcat(s->error, " or ");
  66
  67                                 strcat(s->error, tokennames[i]);
  68                         }
  69                 }
  70         }
  71 }
  72
  73
  74 input ::= expr(A).                                                                      { s->path = A; }
  75
  76 expr(A) ::= T_LABEL(B) T_EQ path(C).                            { A = B; B->down = C; }
  77 expr(A) ::= path(B).                                                            { A = B; }
  78
  79 path(A) ::= T_ROOT segments(B).                                         { A = alloc_op(T_ROOT, 0, NULL, B); }
  80 path(A) ::= T_THIS segments(B).                                         { A = alloc_op(T_THIS, 0, NULL, B); }
  81
  82 segments(A) ::= segments(B) segment(C).                         { A = append_op(B, C); }
  83 segments(A) ::= segment(B).                                                     { A = B; }
  84
  85 segment(A) ::= T_DOT T_LABEL(B).                                        { A = B; }
  86 segment(A) ::= T_DOT T_WILDCARD(B).                                     { A = B; }
  87 segment(A) ::= T_BROPEN union_exps(B) T_BRCLOSE.        { A = B; }
  88
  89 union_exps(A) ::= union_exp(B).                                         { A = B->sibling ? alloc_op(T_UNION, 0, NULL, B) : B; }
  90
  91 union_exp(A) ::= union_exp(B) T_UNION or_exps(C).       { A = append_op(B, C); }
  92 union_exp(A) ::= or_exps(B).                                            { A = B; }
  93
  94 or_exps(A) ::= or_exp(B).                                                       { A = B->sibling ? alloc_op(T_OR, 0, NULL, B) : B; }
  95
  96 or_exp(A) ::= or_exp(B) T_OR and_exps(C).                       { A = append_op(B, C); }
  97 or_exp(A) ::= and_exps(B).                                                      { A = B; }
  98
  99 and_exps(A) ::= and_exp(B).                                                     { A = B->sibling ? alloc_op(T_AND, 0, NULL, B) : B; }
 100
 101 and_exp(A) ::= and_exp(B) T_AND cmp_exp(C).                     { A = append_op(B, C); }
 102 and_exp(A) ::= cmp_exp(B).                                                      { A = B; }
 103
 104 cmp_exp(A) ::= unary_exp(B) T_LT unary_exp(C).          { A = alloc_op(T_LT, 0, NULL, B, C); }
 105 cmp_exp(A) ::= unary_exp(B) T_LE unary_exp(C).          { A = alloc_op(T_LE, 0, NULL, B, C); }
 106 cmp_exp(A) ::= unary_exp(B) T_GT unary_exp(C).          { A = alloc_op(T_GT, 0, NULL, B, C); }
 107 cmp_exp(A) ::= unary_exp(B) T_GE unary_exp(C).          { A = alloc_op(T_GE, 0, NULL, B, C); }
 108 cmp_exp(A) ::= unary_exp(B) T_EQ unary_exp(C).          { A = alloc_op(T_EQ, 0, NULL, B, C); }
 109 cmp_exp(A) ::= unary_exp(B) T_NE unary_exp(C).          { A = alloc_op(T_NE, 0, NULL, B, C); }
 110 cmp_exp(A) ::= unary_exp(B).                                            { A = B; }
 111
 112 unary_exp(A) ::= T_BOOL(B).                                                     { A = B; }
 113 unary_exp(A) ::= T_NUMBER(B).                                           { A = B; }
 114 unary_exp(A) ::= T_STRING(B).                                           { A = B; }
 115 unary_exp(A) ::= T_WILDCARD(B).                                         { A = B; }
 116 unary_exp(A) ::= T_POPEN or_exps(B) T_PCLOSE.           { A = B; }
 117 unary_exp(A) ::= T_NOT unary_exp(B).                            { A = alloc_op(T_NOT, 0, NULL, B); }
 118 unary_exp(A) ::= path(B).                                                       { A = B; }