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 static void print_token(FILE *fp, int type, YYSTYPE value);
  15
  16 #define YYLEX_PARAM parser->scanner
  17 #define YYPRINT(f, t, v) print_token(f, t, v)
  18
  19 static void yyerror(struct grub2_parser *, char const *s);
  20 %}
  21
  22 %union {
  23         struct grub2_word       *word;
  24         struct grub2_argv       *argv;
  25         struct grub2_statement  *statement;
  26         struct grub2_statements *statements;
  27 }
  28
  29 /* reserved words */
  30 %token  TOKEN_LDSQBRACKET       "[["
  31 %token  TOKEN_RDSQBRACKET       "]]"
  32 %token  TOKEN_CASE              "case"
  33 %token  TOKEN_DO                "do"
  34 %token  TOKEN_DONE              "done"
  35 %token  TOKEN_ELIF              "elif"
  36 %token  TOKEN_ELSE              "else"
  37 %token  TOKEN_ESAC              "esac"
  38 %token  TOKEN_FI                "fi"
  39 %token  TOKEN_FOR               "for"
  40 %token  TOKEN_FUNCTION          "function"
  41 %token  TOKEN_IF                "if"
  42 %token  TOKEN_IN                "in"
  43 %token  TOKEN_MENUENTRY         "menuentry"
  44 %token  TOKEN_SELECT            "select"
  45 %token  TOKEN_SUBMENU           "submenu"
  46 %token  TOKEN_THEN              "then"
  47 %token  TOKEN_TIME              "time"
  48 %token  TOKEN_UTIL              "until"
  49 %token  TOKEN_WHILE             "while"
  50
  51 %type <statement>       statement
  52 %type <statements>      statements
  53 %type <statement>       conditional
  54 %type <statement>       elif
  55 %type <statements>      elifs
  56 %type <argv>            words
  57 %type <word>            word
  58
  59 /* syntax */
  60 %token  TOKEN_EOL
  61 %token  TOKEN_DELIM
  62 %token  <word> TOKEN_WORD
  63 %token  TOKEN_EOF 0
  64
  65 %start  script
  66 %debug
  67
  68 %%
  69
  70 script: statements {
  71                 parser->script->statements = $1;
  72         }
  73
  74 eol:    TOKEN_EOL | TOKEN_EOF;
  75
  76 statements: /* empty */ {
  77                 $$ = create_statements(parser);
  78         }
  79         | statements statement eol {
  80                 statement_append($1, $2);
  81                 $$ = $1;
  82         }
  83         | statements TOKEN_EOL {
  84                 $$ = $1;
  85         }
  86
  87 conditional: statement TOKEN_EOL "then" TOKEN_EOL statements {
  88                 $$ = create_statement_conditional(parser, $1, $5);
  89         }
  90
  91 elif: "elif" TOKEN_DELIM conditional {
  92                 $$ = $3;
  93       }
  94
  95 elifs: /* empty */ {
  96                 $$ = create_statements(parser);
  97         }
  98         | elifs elif {
  99                 statement_append($1, $2);
 100                 $$ = $1;
 101         }
 102
 103 statement:
 104         words {
 105                    $$ = create_statement_simple(parser, $1);
 106         }
 107         | '{' statements '}' {
 108                 $$ = create_statement_block(parser, $2);
 109         }
 110         | "if" TOKEN_DELIM conditional elifs "fi" {
 111                 $$ = create_statement_if(parser, $3, $4, NULL);
 112         }
 113         | "if" TOKEN_DELIM conditional
 114                 elifs
 115                 "else" TOKEN_EOL
 116                 statements
 117                 "fi" {
 118                 $$ = create_statement_if(parser, $3, $4, $7);
 119         }
 120         | "function" TOKEN_DELIM word TOKEN_DELIM '{' statements '}' {
 121                 $$ = create_statement_function(parser, $3, $6);
 122         }
 123         | "menuentry" TOKEN_DELIM words TOKEN_DELIM
 124                 '{' statements '}' {
 125                 $$ = create_statement_menuentry(parser, $3, $6);
 126         }
 127         | "submenu" TOKEN_DELIM words TOKEN_DELIM
 128                 '{' statements '}' {
 129                 /* we just flatten everything */
 130                 $$ = create_statement_block(parser, $6);
 131         }
 132
 133 words:  word {
 134                 $$ = create_argv(parser);
 135                 argv_append($$, $1);
 136         }
 137         | words TOKEN_DELIM word {
 138                 argv_append($1, $3);
 139                 $$ = $1;
 140         }
 141
 142 word:   TOKEN_WORD
 143         | word TOKEN_WORD {
 144                 word_append($1, $2);
 145                 $$ = $1;
 146         }
 147
 148 %%
 149 void yyerror(struct grub2_parser *parser, char const *s)
 150 {
 151         fprintf(stderr, "%d: error: %s '%s'\n",
 152                         yyget_lineno(parser->scanner),
 153                         s, yyget_text(parser->scanner));
 154 }
 155
 156 static void print_token(FILE *fp, int type, YYSTYPE value)
 157 {
 158         if (type != TOKEN_WORD)
 159                 return;
 160         fprintf(fp, "%s", value.word->text);
 161 }
 162
 163 struct grub2_statements *create_statements(struct grub2_parser *parser)
 164 {
 165         struct grub2_statements *stmts = talloc(parser,
 166                         struct grub2_statements);
 167         list_init(&stmts->list);
 168         return stmts;
 169 }
 170
 171 struct grub2_statement *create_statement_simple(struct grub2_parser *parser,
 172                 struct grub2_argv *argv)
 173 {
 174         struct grub2_statement_simple *stmt =
 175                 talloc(parser, struct grub2_statement_simple);
 176         stmt->st.type = STMT_TYPE_SIMPLE;
 177         stmt->st.exec = statement_simple_execute;
 178         stmt->argv = argv;
 179         return &stmt->st;
 180 }
 181
 182 struct grub2_statement *create_statement_menuentry(struct grub2_parser *parser,
 183                 struct grub2_argv *argv, struct grub2_statements *stmts)
 184 {
 185         struct grub2_statement_menuentry *stmt =
 186                 talloc(parser, struct grub2_statement_menuentry);
 187         stmt->st.type = STMT_TYPE_MENUENTRY;
 188         stmt->st.exec = statement_menuentry_execute;
 189         stmt->argv = argv;
 190         stmt->statements = stmts;
 191         return &stmt->st;
 192 }
 193
 194 struct grub2_statement *create_statement_conditional(
 195                 struct grub2_parser *parser,
 196                 struct grub2_statement *condition,
 197                 struct grub2_statements *statements)
 198 {
 199         struct grub2_statement_conditional *stmt =
 200                 talloc(parser, struct grub2_statement_conditional);
 201         stmt->st.type = STMT_TYPE_CONDITIONAL;
 202         stmt->condition = condition;
 203         stmt->statements = statements;
 204         return &stmt->st;
 205 }
 206
 207 struct grub2_statement *create_statement_if(struct grub2_parser *parser,
 208                 struct grub2_statement *conditional,
 209                 struct grub2_statements *elifs,
 210                 struct grub2_statements *else_case)
 211 {
 212         struct grub2_statement_if *stmt =
 213                 talloc(parser, struct grub2_statement_if);
 214
 215         list_add(&elifs->list, &conditional->list);
 216
 217         stmt->st.type = STMT_TYPE_IF;
 218         stmt->st.exec = statement_if_execute;
 219         stmt->conditionals = elifs;
 220         stmt->else_case = else_case;
 221         return &stmt->st;
 222 }
 223
 224 struct grub2_statement *create_statement_block(struct grub2_parser *parser,
 225                 struct grub2_statements *stmts)
 226 {
 227         struct grub2_statement_block *stmt =
 228                 talloc(parser, struct grub2_statement_block);
 229         stmt->st.type = STMT_TYPE_BLOCK;
 230         stmt->st.exec = statement_block_execute;
 231         stmt->statements = stmts;
 232         return &stmt->st;
 233 }
 234
 235 struct grub2_statement *create_statement_function(struct grub2_parser *parser,
 236                 struct grub2_word *name, struct grub2_statements *body)
 237 {
 238         struct grub2_statement_function *stmt =
 239                 talloc(parser, struct grub2_statement_function);
 240         stmt->st.exec = statement_function_execute;
 241         stmt->name = name;
 242         stmt->body = body;
 243         return &stmt->st;
 244 }
 245
 246 void statement_append(struct grub2_statements *stmts,
 247                 struct grub2_statement *stmt)
 248 {
 249         if (!stmt)
 250                 return;
 251         list_add_tail(&stmts->list, &stmt->list);
 252 }
 253
 254 struct grub2_word *create_word_text(struct grub2_parser *parser,
 255                 const char *text)
 256 {
 257         struct grub2_word *word = talloc(parser, struct grub2_word);
 258         word->type = GRUB2_WORD_TEXT;
 259         word->split = false;
 260         word->text = talloc_strdup(word, text);
 261         word->next = NULL;
 262         word->last = word;
 263         return word;
 264 }
 265
 266 struct grub2_word *create_word_var(struct grub2_parser *parser,
 267                 const char *name, bool split)
 268 {
 269         struct grub2_word *word = talloc(parser, struct grub2_word);
 270         word->type = GRUB2_WORD_VAR;
 271         word->name = talloc_strdup(word, name);
 272         word->split = split;
 273         word->next = NULL;
 274         word->last = word;
 275         return word;
 276 }
 277
 278 struct grub2_argv *create_argv(struct grub2_parser *parser)
 279 {
 280         struct grub2_argv *argv = talloc(parser, struct grub2_argv);
 281         list_init(&argv->words);
 282         return argv;
 283 }
 284
 285 void argv_append(struct grub2_argv *argv, struct grub2_word *word)
 286 {
 287         list_add_tail(&argv->words, &word->argv_list);
 288 }
 289
 290 void word_append(struct grub2_word *w1, struct grub2_word *w2)
 291 {
 292         w1->last->next = w2;
 293         w1->last = w2;
 294 }
 295
 296 struct grub2_parser *grub2_parser_create(struct discover_context *ctx)
 297 {
 298         struct grub2_parser *parser;
 299
 300         parser = talloc(ctx, struct grub2_parser);
 301         yylex_init_extra(parser, &parser->scanner);
 302         parser->script = create_script(parser, ctx);
 303
 304         return parser;
 305 }
 306
 307 void grub2_parser_parse(struct grub2_parser *parser, char *buf, int len)
 308 {
 309         YY_BUFFER_STATE bufstate;
 310         int rc;
 311
 312         bufstate = yy_scan_bytes(buf, len - 1, parser->scanner);
 313
 314         rc = yyparse(parser);
 315
 316         yy_delete_buffer(bufstate, parser->scanner);
 317
 318         if (!rc)
 319                 script_execute(parser->script);
 320 }
 321