git.ozlabs.org Git - petitboot/blob - discover/grub2/parser.y

   1
   2 %pure-parser
   3 %lex-param { yyscan_t scanner }
   4 %parse-param { struct grub2_parser *parser }
   5 %error-verbose
   6
   7 %{
   8 #include <talloc/talloc.h>
   9
  10 #include "grub2.h"
  11 #include "parser.h"
  12 #include "lexer.h"
  13
  14 #define YYLEX_PARAM parser->scanner
  15
  16 static void yyerror(struct grub2_parser *, char const *s);
  17 %}
  18
  19 %union {
  20         struct grub2_word       *word;
  21         struct grub2_argv       *argv;
  22         struct grub2_statement  *statement;
  23         struct grub2_statements *statements;
  24 }
  25
  26 /* reserved words */
  27 %token  TOKEN_LDSQBRACKET       "[["
  28 %token  TOKEN_RDSQBRACKET       "]]"
  29 %token  TOKEN_CASE              "case"
  30 %token  TOKEN_DO                "do"
  31 %token  TOKEN_DONE              "done"
  32 %token  TOKEN_ELIF              "elif"
  33 %token  TOKEN_ELSE              "else"
  34 %token  TOKEN_ESAC              "esac"
  35 %token  TOKEN_FI                "fi"
  36 %token  TOKEN_FOR               "for"
  37 %token  TOKEN_FUNCTION          "function"
  38 %token  TOKEN_IF                "if"
  39 %token  TOKEN_IN                "in"
  40 %token  TOKEN_MENUENTRY         "menuentry"
  41 %token  TOKEN_SELECT            "select"
  42 %token  TOKEN_THEN              "then"
  43 %token  TOKEN_TIME              "time"
  44 %token  TOKEN_UTIL              "until"
  45 %token  TOKEN_WHILE             "while"
  46
  47 %type <statement>       statement
  48 %type <statements>      statements
  49 %type <argv>            words
  50 %type <word>            word
  51
  52 /* syntax */
  53 %token  TOKEN_EOL
  54 %token  TOKEN_DELIM
  55 %token  <word> TOKEN_WORD
  56
  57 %start  script
  58 %debug
  59
  60 %%
  61
  62 script: statements {
  63                 parser->script->statements = $1;
  64         }
  65
  66 statements: statement {
  67                 $$ = create_statements(parser);
  68                 statement_append($$, $1);
  69         }
  70         | statements statement {
  71                 statement_append($1, $2);
  72                 $$ = $1;
  73         }
  74
  75 statement: TOKEN_EOL {
  76                 $$ = NULL;
  77         }
  78         | words TOKEN_EOL {
  79                    $$ = create_statement_simple(parser, $1);
  80         }
  81         | '{' statements '}' {
  82                 $$ = create_statement_block(parser, $2);
  83         }
  84         | "if" TOKEN_DELIM statement
  85                 "then" TOKEN_EOL
  86                 statements
  87                 "fi" TOKEN_EOL {
  88                 $$ = create_statement_if(parser, $3, $6, NULL);
  89         }
  90         | "if" TOKEN_DELIM statement
  91                 "then" TOKEN_EOL
  92                 statements
  93                 "else" TOKEN_EOL
  94                 statements
  95                 "fi" TOKEN_EOL {
  96                 $$ = create_statement_if(parser, $3, $6, $9);
  97         }
  98         | "menuentry" TOKEN_DELIM words TOKEN_DELIM
  99                 '{' statements '}'
 100                 TOKEN_EOL {
 101                 $$ = create_statement_menuentry(parser, $3, $6);
 102         }
 103
 104 words:  word {
 105                 $$ = create_argv(parser);
 106                 argv_append($$, $1);
 107         }
 108         | words TOKEN_DELIM word {
 109                 argv_append($1, $3);
 110                 $$ = $1;
 111         }
 112
 113 word:   TOKEN_WORD
 114         | word TOKEN_WORD {
 115                 word_append($1, $2);
 116                 $$ = $1;
 117         }
 118
 119 %%
 120 void yyerror(struct grub2_parser *parser, char const *s)
 121 {
 122         fprintf(stderr, "%d: error: %s '%s'\n",
 123                         yyget_lineno(parser->scanner),
 124                         s, yyget_text(parser->scanner));
 125 }
 126
 127 struct grub2_statements *create_statements(struct grub2_parser *parser)
 128 {
 129         struct grub2_statements *stmts = talloc(parser,
 130                         struct grub2_statements);
 131         list_init(&stmts->list);
 132         return stmts;
 133 }
 134
 135 struct grub2_statement *create_statement_simple(struct grub2_parser *parser,
 136                 struct grub2_argv *argv)
 137 {
 138         struct grub2_statement_simple *stmt =
 139                 talloc(parser, struct grub2_statement_simple);
 140         stmt->st.type = STMT_TYPE_SIMPLE;
 141         stmt->st.exec = statement_simple_execute;
 142         stmt->argv = argv;
 143         return &stmt->st;
 144 }
 145
 146 struct grub2_statement *create_statement_menuentry(struct grub2_parser *parser,
 147                 struct grub2_argv *argv, struct grub2_statements *stmts)
 148 {
 149         struct grub2_statement_menuentry *stmt =
 150                 talloc(parser, struct grub2_statement_menuentry);
 151         stmt->st.type = STMT_TYPE_MENUENTRY;
 152         stmt->st.exec = statement_menuentry_execute;
 153         stmt->argv = argv;
 154         stmt->statements = stmts;
 155         return &stmt->st;
 156 }
 157
 158 struct grub2_statement *create_statement_if(struct grub2_parser *parser,
 159                 struct grub2_statement *condition,
 160                 struct grub2_statements *true_case,
 161                 struct grub2_statements *false_case)
 162 {
 163         struct grub2_statement_if *stmt =
 164                 talloc(parser, struct grub2_statement_if);
 165         stmt->st.type = STMT_TYPE_IF;
 166         stmt->st.exec = statement_if_execute;
 167         stmt->condition = condition;
 168         stmt->true_case = true_case;
 169         stmt->false_case = false_case;
 170         return &stmt->st;
 171 }
 172
 173 struct grub2_statement *create_statement_block(struct grub2_parser *parser,
 174                 struct grub2_statements *stmts)
 175 {
 176         struct grub2_statement_block *stmt =
 177                 talloc(parser, struct grub2_statement_block);
 178         stmt->st.type = STMT_TYPE_BLOCK;
 179         stmt->st.exec = NULL;
 180         stmt->statements = stmts;
 181         return &stmt->st;
 182 }
 183
 184 void statement_append(struct grub2_statements *stmts,
 185                 struct grub2_statement *stmt)
 186 {
 187         if (!stmt)
 188                 return;
 189         list_add_tail(&stmts->list, &stmt->list);
 190 }
 191
 192 struct grub2_word *create_word_text(struct grub2_parser *parser,
 193                 const char *text)
 194 {
 195         struct grub2_word *word = talloc(parser, struct grub2_word);
 196         word->type = GRUB2_WORD_TEXT;
 197         word->split = false;
 198         word->text = talloc_strdup(word, text);
 199         word->next = NULL;
 200         word->last = word;
 201         return word;
 202 }
 203
 204 struct grub2_word *create_word_var(struct grub2_parser *parser,
 205                 const char *name, bool split)
 206 {
 207         struct grub2_word *word = talloc(parser, struct grub2_word);
 208         word->type = GRUB2_WORD_VAR;
 209         word->name = talloc_strdup(word, name);
 210         word->split = split;
 211         word->next = NULL;
 212         word->last = word;
 213         return word;
 214 }
 215
 216 struct grub2_argv *create_argv(struct grub2_parser *parser)
 217 {
 218         struct grub2_argv *argv = talloc(parser, struct grub2_argv);
 219         list_init(&argv->words);
 220         return argv;
 221 }
 222
 223 void argv_append(struct grub2_argv *argv, struct grub2_word *word)
 224 {
 225         list_add_tail(&argv->words, &word->argv_list);
 226 }
 227
 228 void word_append(struct grub2_word *w1, struct grub2_word *w2)
 229 {
 230         w1->last->next = w2;
 231         w1->last = w2;
 232 }
 233
 234 struct grub2_parser *grub2_parser_create(struct discover_context *ctx)
 235 {
 236         struct grub2_parser *parser;
 237
 238         parser = talloc(ctx, struct grub2_parser);
 239         yylex_init_extra(parser, &parser->scanner);
 240         parser->script = create_script(parser, ctx);
 241
 242         return parser;
 243 }
 244
 245 void grub2_parser_parse(struct grub2_parser *parser, char *buf, int len)
 246 {
 247         YY_BUFFER_STATE bufstate;
 248         int rc;
 249
 250         bufstate = yy_scan_bytes(buf, len - 1, parser->scanner);
 251
 252         rc = yyparse(parser);
 253
 254         yy_delete_buffer(bufstate, parser->scanner);
 255
 256         if (!rc)
 257                 script_execute(parser->script);
 258 }
 259