discover/grub2: Create 'conditional' statements

Rather than holding the condition and conditional-statements in struct
grub2_statment_if, create a new conditional type that contains these. We
can then use this to implement elif statements.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

diff --git a/discover/grub2/grub2.h b/discover/grub2/grub2.h
index 5b83fad5d05f38503fd755207de96b8955d800cd..7f4a8345e666ff7ac78012320610ed07fdfe9c76 100644 (file)
--- a/discover/grub2/grub2.h
+++ b/discover/grub2/grub2.h
@@ -43,6 +43,7 @@ struct grub2_statement {
                STMT_TYPE_MENUENTRY,
                STMT_TYPE_IF,
                STMT_TYPE_BLOCK,
                STMT_TYPE_MENUENTRY,
                STMT_TYPE_IF,
                STMT_TYPE_BLOCK,

+               STMT_TYPE_CONDITIONAL,

        } type;
        int                     (*exec)(struct grub2_script *,
                                        struct grub2_statement *);
        } type;
        int                     (*exec)(struct grub2_script *,
                                        struct grub2_statement *);


@@ -59,11 +60,16 @@ struct grub2_statement_menuentry {
        struct grub2_statements *statements;
 };
 
        struct grub2_statements *statements;
 };
 

-struct grub2_statement_if {
+struct grub2_statement_conditional {

        struct grub2_statement  st;
        struct grub2_statement  *condition;
        struct grub2_statement  st;
        struct grub2_statement  *condition;

-       struct grub2_statements *true_case;
-       struct grub2_statements *false_case;
+       struct grub2_statements *statements;
+};
+
+struct grub2_statement_if {
+       struct grub2_statement  st;
+       struct grub2_statement  *conditional;
+       struct grub2_statements *else_case;

 };
 
 struct grub2_statement_block {
 };
 
 struct grub2_statement_block {


@@ -102,10 +108,13 @@ struct grub2_statement *create_statement_simple(struct grub2_parser *parser,
 struct grub2_statement *create_statement_menuentry(struct grub2_parser *parser,
                struct grub2_argv *argv, struct grub2_statements *stmts);
 
 struct grub2_statement *create_statement_menuentry(struct grub2_parser *parser,
                struct grub2_argv *argv, struct grub2_statements *stmts);
 

+struct grub2_statement *create_statement_conditional(
+               struct grub2_parser *parser, struct grub2_statement *condition,
+               struct grub2_statements *statements);
+

 struct grub2_statement *create_statement_if(struct grub2_parser *parser,
 struct grub2_statement *create_statement_if(struct grub2_parser *parser,

-               struct grub2_statement *condition,
-               struct grub2_statements *true_case,
-               struct grub2_statements *false_case);
+               struct grub2_statement *conditional,
+               struct grub2_statements *else_case);

 
 struct grub2_statement *create_statement_block(struct grub2_parser *parser,
                struct grub2_statements *stmts);
 
 struct grub2_statement *create_statement_block(struct grub2_parser *parser,
                struct grub2_statements *stmts);

diff --git a/discover/grub2/parser.y b/discover/grub2/parser.y
index 0540ff3c088b768f106d945d8f1e86ee7660d0e3..52dac9c7b27ee28d804010f3233279988205acd9 100644 (file)
--- a/discover/grub2/parser.y
+++ b/discover/grub2/parser.y
@@ -47,6 +47,7 @@ static void yyerror(struct grub2_parser *, char const *s);
 
 %type <statement>      statement
 %type <statements>     statements
 
 %type <statement>      statement
 %type <statements>     statements

+%type <statement>      conditional

 %type <argv>           words
 %type <word>           word
 
 %type <argv>           words
 %type <word>           word
 


@@ -75,6 +76,10 @@ statements: /* empty */ {
                $$ = $1;
        }
 
                $$ = $1;
        }
 

+conditional: statement TOKEN_EOL "then" TOKEN_EOL statements {
+               $$ = create_statement_conditional(parser, $1, $5);
+       }
+

 statement:
        words {
                   $$ = create_statement_simple(parser, $1);
 statement:
        words {
                   $$ = create_statement_simple(parser, $1);


@@ -82,19 +87,14 @@ statement:
        | '{' statements '}' {
                $$ = create_statement_block(parser, $2);
        }
        | '{' statements '}' {
                $$ = create_statement_block(parser, $2);
        }

-       | "if" TOKEN_DELIM statement
-               "then" TOKEN_EOL
-               statements
-               "fi" {
-               $$ = create_statement_if(parser, $3, $6, NULL);
+       | "if" TOKEN_DELIM conditional "fi" {
+               $$ = create_statement_if(parser, $3, NULL);

        }
        }

-       | "if" TOKEN_DELIM statement
-               "then" TOKEN_EOL
-               statements
+       | "if" TOKEN_DELIM conditional

                "else" TOKEN_EOL
                statements
                "fi" {
                "else" TOKEN_EOL
                statements
                "fi" {

-               $$ = create_statement_if(parser, $3, $6, $9);
+               $$ = create_statement_if(parser, $3, $6);

        }
        | "function" TOKEN_DELIM word TOKEN_DELIM '{' statements '}' {
                $$ = create_statement_function(parser, $3, $6);
        }
        | "function" TOKEN_DELIM word TOKEN_DELIM '{' statements '}' {
                $$ = create_statement_function(parser, $3, $6);


@@ -163,18 +163,29 @@ struct grub2_statement *create_statement_menuentry(struct grub2_parser *parser,
        return &stmt->st;
 }
 
        return &stmt->st;
 }
 

-struct grub2_statement *create_statement_if(struct grub2_parser *parser,
+struct grub2_statement *create_statement_conditional(
+               struct grub2_parser *parser,

                struct grub2_statement *condition,
                struct grub2_statement *condition,

-               struct grub2_statements *true_case,
-               struct grub2_statements *false_case)
+               struct grub2_statements *statements)
+{
+       struct grub2_statement_conditional *stmt =
+               talloc(parser, struct grub2_statement_conditional);
+       stmt->st.type = STMT_TYPE_CONDITIONAL;
+       stmt->condition = condition;
+       stmt->statements = statements;
+       return &stmt->st;
+}
+
+struct grub2_statement *create_statement_if(struct grub2_parser *parser,
+               struct grub2_statement *conditional,
+               struct grub2_statements *else_case)

 {
        struct grub2_statement_if *stmt =
                talloc(parser, struct grub2_statement_if);
        stmt->st.type = STMT_TYPE_IF;
        stmt->st.exec = statement_if_execute;
 {
        struct grub2_statement_if *stmt =
                talloc(parser, struct grub2_statement_if);
        stmt->st.type = STMT_TYPE_IF;
        stmt->st.exec = statement_if_execute;

-       stmt->condition = condition;
-       stmt->true_case = true_case;
-       stmt->false_case = false_case;
+       stmt->conditional = conditional;
+       stmt->else_case = else_case;

        return &stmt->st;
 }
 
        return &stmt->st;
 }
 

diff --git a/discover/grub2/script.c b/discover/grub2/script.c
index 9c087373ac0454524308fa6da5370a0b86b69cc5..c0d6e1a4e4a31affa291713b0351f816ac16afed 100644 (file)
--- a/discover/grub2/script.c
+++ b/discover/grub2/script.c
@@ -15,6 +15,8 @@
        container_of(stmt, struct grub2_statement_menuentry, st)
 #define to_stmt_function(stmt) \
        container_of(stmt, struct grub2_statement_function, st)
        container_of(stmt, struct grub2_statement_menuentry, st)
 #define to_stmt_function(stmt) \
        container_of(stmt, struct grub2_statement_function, st)

+#define to_stmt_conditional(stmt) \
+       container_of(stmt, struct grub2_statement_conditional, st)

 
 struct env_entry {
        const char              *name;
 
 struct env_entry {
        const char              *name;


@@ -252,24 +254,36 @@ int statement_simple_execute(struct grub2_script *script,
        return rc;
 }
 
        return rc;
 }
 

+/* returns 0 if the statement was executed, 1 otherwise */
+static int statement_conditional_execute(struct grub2_script *script,
+               struct grub2_statement *statement, bool *executed)
+{
+       struct grub2_statement_conditional *st = to_stmt_conditional(statement);
+       int rc;
+
+       rc = st->condition->exec(script, st->condition);
+       *executed = (!rc);
+       if (*executed)
+               rc = statements_execute(script, st->statements);
+
+       return rc;
+}
+

 int statement_if_execute(struct grub2_script *script,
                struct grub2_statement *statement)
 {
        struct grub2_statement_if *st = to_stmt_if(statement);
 int statement_if_execute(struct grub2_script *script,
                struct grub2_statement *statement)
 {
        struct grub2_statement_if *st = to_stmt_if(statement);

-       struct grub2_statements *case_stmts;
+       struct grub2_statement *conditional;
+       bool executed;

        int rc;
 
        int rc;
 

-       rc = st->condition->exec(script, st->condition);
+       conditional = st->conditional;

 
 

-       if (rc == 0)
-               case_stmts = st->true_case;
-       else
-               case_stmts = st->false_case;
+       rc = statement_conditional_execute(script,
+                       conditional, &executed);

 
 

-       if (case_stmts)
-               statements_execute(script, case_stmts);
-       else
-               rc = 0;
+       if (!executed && st->else_case)
+               rc = statements_execute(script, st->else_case);

 
        return rc;
 }
 
        return rc;
 }