discover/grub2: Allow empty statements

[petitboot] / discover / grub2 / parser.y

diff --git a/discover/grub2/parser.y b/discover/grub2/parser.y
index 2b229b80598ae63488bd17b0810f0d7f89e26198..0540ff3c088b768f106d945d8f1e86ee7660d0e3 100644 (file)
--- a/discover/grub2/parser.y
+++ b/discover/grub2/parser.y
@@ -2,6 +2,7 @@
 %pure-parser
 %lex-param { yyscan_t scanner }
 %parse-param { struct grub2_parser *parser }
+%error-verbose
 
 %{
 #include <talloc/talloc.h>
@@ -29,6 +30,7 @@ static void yyerror(struct grub2_parser *, char const *s);
 %token TOKEN_DO                "do"
 %token TOKEN_DONE              "done"
 %token TOKEN_ELIF              "elif"
+%token TOKEN_ELSE              "else"
 %token TOKEN_ESAC              "esac"
 %token TOKEN_FI                "fi"
 %token TOKEN_FOR               "for"
@@ -37,6 +39,7 @@ static void yyerror(struct grub2_parser *, char const *s);
 %token TOKEN_IN                "in"
 %token TOKEN_MENUENTRY         "menuentry"
 %token TOKEN_SELECT            "select"
+%token TOKEN_SUBMENU           "submenu"
 %token TOKEN_THEN              "then"
 %token TOKEN_TIME              "time"
 %token TOKEN_UTIL              "until"
@@ -57,23 +60,23 @@ static void yyerror(struct grub2_parser *, char const *s);
 
 %%
 
-script: statements {
+script:        statements {
                parser->script->statements = $1;
        }
 
-statements: statement {
+statements: /* empty */ {
                $$ = create_statements(parser);
-               statement_append($$, $1);
        }
-       | statements statement {
+       | statements statement TOKEN_EOL {
                statement_append($1, $2);
                $$ = $1;
        }
-
-statement: TOKEN_EOL {
-               $$ = NULL;
+       | statements TOKEN_EOL {
+               $$ = $1;
        }
-       | words TOKEN_EOL {
+
+statement:
+       words {
                   $$ = create_statement_simple(parser, $1);
        }
        | '{' statements '}' {
@@ -82,14 +85,29 @@ statement: TOKEN_EOL {
        | "if" TOKEN_DELIM statement
                "then" TOKEN_EOL
                statements
-               "fi" TOKEN_EOL {
+               "fi" {
                $$ = create_statement_if(parser, $3, $6, NULL);
        }
+       | "if" TOKEN_DELIM statement
+               "then" TOKEN_EOL
+               statements
+               "else" TOKEN_EOL
+               statements
+               "fi" {
+               $$ = create_statement_if(parser, $3, $6, $9);
+       }
+       | "function" TOKEN_DELIM word TOKEN_DELIM '{' statements '}' {
+               $$ = create_statement_function(parser, $3, $6);
+       }
        | "menuentry" TOKEN_DELIM words TOKEN_DELIM
-               '{' statements '}'
-               TOKEN_EOL {
+               '{' statements '}' {
                $$ = create_statement_menuentry(parser, $3, $6);
        }
+       | "submenu" TOKEN_DELIM words TOKEN_DELIM
+               '{' statements '}' {
+               /* we just flatten everything */
+               $$ = create_statement_block(parser, $6);
+       }
 
 words: word {
                $$ = create_argv(parser);
@@ -171,6 +189,17 @@ struct grub2_statement *create_statement_block(struct grub2_parser *parser,
        return &stmt->st;
 }
 
+struct grub2_statement *create_statement_function(struct grub2_parser *parser,
+               struct grub2_word *name, struct grub2_statements *body)
+{
+       struct grub2_statement_function *stmt =
+               talloc(parser, struct grub2_statement_function);
+       stmt->st.exec = statement_function_execute;
+       stmt->name = name;
+       stmt->body = body;
+       return &stmt->st;
+}
+
 void statement_append(struct grub2_statements *stmts,
                struct grub2_statement *stmt)
 {
@@ -235,13 +264,15 @@ struct grub2_parser *grub2_parser_create(struct discover_context *ctx)
 void grub2_parser_parse(struct grub2_parser *parser, char *buf, int len)
 {
        YY_BUFFER_STATE bufstate;
+       int rc;
 
        bufstate = yy_scan_bytes(buf, len - 1, parser->scanner);
 
-       yyparse(parser);
+       rc = yyparse(parser);
 
        yy_delete_buffer(bufstate, parser->scanner);
 
-       script_execute(parser->script);
+       if (!rc)
+               script_execute(parser->script);
 }