- added check for multiple default labels

- added check for undefined goto labels

[r18696]

diff --git a/ast_t.h b/ast_t.h
index 79418c5..daceed6 100644 (file)
--- a/ast_t.h
+++ b/ast_t.h
@@ -483,6 +483,7 @@ struct switch_statement_t {
 struct goto_statement_t {
        statement_base_t  statement;
        declaration_t    *label;
+       goto_statement_t *next; /**< link all goto statements in a function */
 };
 
 struct case_label_statement_t {

diff --git a/parser.c b/parser.c
index bac60ce..7fd54f4 100644 (file)
--- a/parser.c
+++ b/parser.c
@@ -50,6 +50,7 @@ static declaration_t      *last_declaration  = NULL;
 static declaration_t      *current_function  = NULL;
 static switch_statement_t *current_switch    = NULL;
 static statement_t        *current_loop      = NULL;
+static goto_statement_t   *goto_list         = NULL;
 static struct obstack  temp_obst;
 
 /** The current source position. */
@@ -2694,6 +2695,26 @@ static void parse_kr_declaration_list(declaration_t *declaration)
        declaration->type = type;
 }
 
+/**
+ * Check if all labels are defined in the current function.
+ */
+static void check_for_missing_labels(void)
+{
+       const goto_statement_t *goto_statement, *next;
+
+       for (goto_statement = goto_list;
+            goto_statement != NULL;
+            goto_statement = next) {
+                const declaration_t *label = goto_statement->label;
+
+                if (label->source_position.input_name == NULL) {
+                        errorf(goto_statement->statement.source_position,
+                                "label '%Y' used but not defined", label->symbol);
+                }
+       }
+       goto_list = NULL;
+}
+
 static void parse_external_declaration(void)
 {
        /* function-definitions and declarations both start with declaration
@@ -2787,6 +2808,7 @@ static void parse_external_declaration(void)
                current_function                    = declaration;
 
                declaration->init.statement = parse_compound_statement();
+               check_for_missing_labels();
 
                assert(current_function == declaration);
                current_function = old_current_function;
@@ -4858,23 +4880,44 @@ static statement_t *parse_case_statement(void)
 
        expect(':');
 
-       if (current_switch != NULL) {
-               /* link all cases into the switch statement */
-               if (current_switch->last_case == NULL) {
-                       current_switch->first_case =
-                       current_switch->last_case  = &statement->case_label;
+       if (! is_constant_expression(statement->case_label.expression)) {
+               errorf(statement->base.source_position,
+                       "case label does not reduce to an integer constant");
+       } else {
+               /* TODO: check if the case label is already known */
+               if (current_switch != NULL) {
+                       /* link all cases into the switch statement */
+                       if (current_switch->last_case == NULL) {
+                               current_switch->first_case =
+                               current_switch->last_case  = &statement->case_label;
+                       } else {
+                               current_switch->last_case->next = &statement->case_label;
+                       }
                } else {
-                       current_switch->last_case->next = &statement->case_label;
+                       errorf(statement->base.source_position,
+                               "case label not within a switch statement");
                }
-       } else {
-               errorf(statement->base.source_position,
-                       "case label not within a switch statement");
        }
        statement->case_label.label_statement = parse_statement();
 
        return statement;
 }
 
+/**
+ * Finds an existing default label of a switch statement.
+ */
+static case_label_statement_t *
+find_default_label(const switch_statement_t *statement)
+{
+       for (case_label_statement_t *label = statement->first_case;
+            label != NULL;
+                label = label->next) {
+               if (label->expression == NULL)
+                       return label;
+       }
+       return NULL;
+}
+
 /**
  * Parse a default statement.
  */
@@ -4888,12 +4931,19 @@ static statement_t *parse_default_statement(void)
 
        expect(':');
        if (current_switch != NULL) {
-               /* link all cases into the switch statement */
-               if (current_switch->last_case == NULL) {
-                       current_switch->first_case =
-                               current_switch->last_case  = &statement->case_label;
+               const case_label_statement_t *def_label = find_default_label(current_switch);
+               if (def_label != NULL) {
+                       errorf(HERE, "multiple default labels in one switch");
+                       errorf(def_label->statement.source_position,
+                               "this is the first default label");
                } else {
-                       current_switch->last_case->next = &statement->case_label;
+                       /* link all cases into the switch statement */
+                       if (current_switch->last_case == NULL) {
+                               current_switch->first_case =
+                                       current_switch->last_case  = &statement->case_label;
+                       } else {
+                               current_switch->last_case->next = &statement->case_label;
+                       }
                }
        } else {
                errorf(statement->base.source_position,
@@ -5142,6 +5192,10 @@ static statement_t *parse_goto(void)
 
        statement->label = label;
 
+       /* remember the goto's in a list for later checking */
+       statement->next = goto_list;
+       goto_list       = statement;
+
        expect(';');
 
        return (statement_t*) statement;