- implemented local labels

[r21936]

diff --git a/ast.c b/ast.c
index cfcd011..fac1ca5 100644 (file)
--- a/ast.c
+++ b/ast.c
@@ -999,21 +999,38 @@ static void print_declaration_statement(
                const declaration_statement_t *statement)
 {
        bool first = true;
-       for (declaration_t *declaration = statement->declarations_begin;
-            declaration != statement->declarations_end->next;
-            declaration = declaration->next) {
-               if (declaration->storage_class == STORAGE_CLASS_ENUM_ENTRY)
-                       continue;
-               if (declaration->implicit)
-                       continue;
-
-               if (!first) {
-                       print_indent();
-               } else {
-                       first = false;
+       declaration_t *declaration = statement->declarations_begin;
+
+       if (declaration->namespc == NAMESPACE_LOCAL_LABEL) {
+               fputs("__label__ ", out);
+               for (;
+                       declaration != statement->declarations_end->next;
+                       declaration = declaration->next) {
+                       if (!first) {
+                               fputs(", ", out);
+                       } else {
+                               first = false;
+                       }
+                       fputs(declaration->symbol->string, out);
+               }
+               fputs(";\n", out);
+       } else {
+               for (;
+                        declaration != statement->declarations_end->next;
+                        declaration = declaration->next) {
+                       if (declaration->storage_class == STORAGE_CLASS_ENUM_ENTRY)
+                               continue;
+                       if (declaration->implicit)
+                               continue;
+
+                       if (!first) {
+                               print_indent();
+                       } else {
+                               first = false;
+                       }
+                       print_declaration(declaration);
+                       fputc('\n', out);
                }
-               print_declaration(declaration);
-               fputc('\n', out);
        }
 }
 
@@ -1445,11 +1462,11 @@ void print_expression(const expression_t *expression) {
  */
 void print_declaration(const declaration_t *declaration)
 {
-       if(declaration->namespc != NAMESPACE_NORMAL &&
-                       declaration->symbol == NULL)
+       if (declaration->namespc != NAMESPACE_NORMAL &&
+           declaration->symbol == NULL)
                return;
 
-       switch(declaration->namespc) {
+       switch (declaration->namespc) {
        case NAMESPACE_NORMAL:
                print_normal_declaration(declaration);
                break;

diff --git a/ast2firm.c b/ast2firm.c
index afa595f..670c483 100644 (file)
--- a/ast2firm.c
+++ b/ast2firm.c
@@ -2956,7 +2956,7 @@ static ir_node *builtin_prefetch_to_firm(
 
 static ir_node *get_label_block(declaration_t *label)
 {
-       assert(label->namespc == NAMESPACE_LABEL);
+       assert(label->namespc == NAMESPACE_LABEL || label->namespc == NAMESPACE_LOCAL_LABEL);
 
        if (label->declaration_kind == DECLARATION_KIND_LABEL_BLOCK) {
                return label->v.block;

diff --git a/ast_t.h b/ast_t.h
index 3848373..446c923 100644 (file)
--- a/ast_t.h
+++ b/ast_t.h
@@ -389,6 +389,7 @@ typedef enum namespace_t {
        NAMESPACE_UNION,
        NAMESPACE_ENUM,
        NAMESPACE_LABEL,
+       NAMESPACE_LOCAL_LABEL
 } namespace_t;
 
 typedef enum initializer_kind_t {

diff --git a/parser.c b/parser.c
index 240c92a..d25c44f 100644 (file)
--- a/parser.c
+++ b/parser.c
@@ -110,6 +110,7 @@ static token_t             lookahead_buffer[MAX_LOOKAHEAD];
 static int                 lookahead_bufpos;
 static stack_entry_t      *environment_stack = NULL;
 static stack_entry_t      *label_stack       = NULL;
+static stack_entry_t      *local_label_stack = NULL;
 static scope_t            *global_scope      = NULL;
 static scope_t            *scope             = NULL;
 static declaration_t      *last_declaration  = NULL;
@@ -480,13 +481,21 @@ static size_t environment_top(void)
 }
 
 /**
- * Returns the index of the top element of the label stack.
+ * Returns the index of the top element of the global label stack.
  */
 static size_t label_top(void)
 {
        return ARR_LEN(label_stack);
 }
 
+/**
+ * Returns the index of the top element of the local label stack.
+ */
+static size_t local_label_top(void)
+{
+       return ARR_LEN(local_label_stack);
+}
+
 /**
  * Return the next token.
  */
@@ -765,6 +774,11 @@ static void stack_push(stack_entry_t **stack_ptr, declaration_t *declaration)
        ARR_APP1(stack_entry_t, *stack_ptr, entry);
 }
 
+/**
+ * Push a declaration on the environment stack.
+ *
+ * @param declaration  the declaration
+ */
 static void environment_push(declaration_t *declaration)
 {
        assert(declaration->source_position.input_name != NULL);
@@ -773,7 +787,7 @@ static void environment_push(declaration_t *declaration)
 }
 
 /**
- * Push a declaration of the label stack.
+ * Push a declaration on the global label stack.
  *
  * @param declaration  the declaration
  */
@@ -783,6 +797,17 @@ static void label_push(declaration_t *declaration)
        stack_push(&label_stack, declaration);
 }
 
+/**
+ * Push a declaration of the local label stack.
+ *
+ * @param declaration  the declaration
+ */
+static void local_label_push(declaration_t *declaration)
+{
+       assert(declaration->parent_scope != NULL);
+       stack_push(&local_label_stack, declaration);
+}
+
 /**
  * pops symbols from the environment stack until @p new_top is the top element
  */
@@ -833,13 +858,19 @@ static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
        ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 }
 
+/**
+ * Pop all entries from the environment stack until the new_top
+ * is reached.
+ *
+ * @param new_top  the new stack top
+ */
 static void environment_pop_to(size_t new_top)
 {
        stack_pop_to(&environment_stack, new_top);
 }
 
 /**
- * Pop all entries on the label stack until the new_top
+ * Pop all entries from the global label stack until the new_top
  * is reached.
  *
  * @param new_top  the new stack top
@@ -849,6 +880,18 @@ static void label_pop_to(size_t new_top)
        stack_pop_to(&label_stack, new_top);
 }
 
+/**
+ * Pop all entries from the local label stack until the new_top
+ * is reached.
+ *
+ * @param new_top  the new stack top
+ */
+static void local_label_pop_to(size_t new_top)
+{
+       stack_pop_to(&local_label_stack, new_top);
+}
+
+
 static int get_akind_rank(atomic_type_kind_t akind)
 {
        return (int) akind;
@@ -6613,8 +6656,17 @@ end_error:
  */
 static declaration_t *get_label(symbol_t *symbol)
 {
-       declaration_t *candidate = get_declaration(symbol, NAMESPACE_LABEL);
+       declaration_t *candidate;
        assert(current_function != NULL);
+
+       candidate = get_declaration(symbol, NAMESPACE_LOCAL_LABEL);
+       /* if we found a local label, we already created the declaration */
+       if (candidate != NULL) {
+               assert(candidate->parent_scope == scope);
+               return candidate;
+       }
+
+       candidate = get_declaration(symbol, NAMESPACE_LABEL);
        /* if we found a label in the same function, then we already created the
         * declaration */
        if (candidate != NULL
@@ -8712,9 +8764,9 @@ static statement_t *parse_label_statement(void)
 
        PUSH_PARENT(statement);
 
-       /* if source position is already set then the label is defined twice,
-        * otherwise it was just mentioned in a goto so far */
-       if (label->source_position.input_name != NULL) {
+       /* if statement is already set then the label is defined twice,
+        * otherwise it was just mentioned in a goto/local label declaration so far */
+       if (label->init.statement != NULL) {
                errorf(HERE, "duplicate label '%Y' (declared %P)",
                       symbol, &label->source_position);
        } else {
@@ -9130,7 +9182,7 @@ end_error:
 /**
  * Parse a __leave statement.
  */
-static statement_t *parse_leave(void)
+static statement_t *parse_leave_statement(void)
 {
        if (current_try == NULL) {
                errorf(HERE, "__leave statement not within __try");
@@ -9358,6 +9410,54 @@ static statement_t *parse_empty_statement(void)
        return statement;
 }
 
+static statement_t *parse_local_label_declaration(void) {
+       statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
+       statement->base.source_position = token.source_position;
+
+       eat(T___label__);
+
+       declaration_t *begin = NULL, *end = NULL;
+
+       while (true) {
+               if (token.type != T_IDENTIFIER) {
+                       parse_error_expected("while parsing local label declaration",
+                               T_IDENTIFIER, NULL);
+                       goto end_error;
+               }
+               symbol_t      *symbol      = token.v.symbol;
+               declaration_t *declaration = get_declaration(symbol, NAMESPACE_LOCAL_LABEL);
+               if (declaration != NULL) {
+                       errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition at %P)",
+                               symbol, &declaration->source_position);
+               } else {
+                       declaration = allocate_declaration_zero();
+                       declaration->namespc         = NAMESPACE_LOCAL_LABEL;
+                       declaration->source_position = token.source_position;
+                       declaration->symbol          = symbol;
+                       declaration->parent_scope    = scope;
+                       declaration->init.statement  = NULL;
+
+                       if (end != NULL)
+                               end->next = declaration;
+                       end = declaration;
+                       if (begin == NULL)
+                               begin = declaration;
+
+                       local_label_push(declaration);
+               }
+               next_token();
+
+               if (token.type != ',')
+                       break;
+               next_token();
+       }
+       eat(';');
+end_error:
+       statement->declaration.declarations_begin = begin;
+       statement->declaration.declarations_end   = end;
+       return statement;
+}
+
 /**
  * Parse a statement.
  * There's also parse_statement() which additionally checks for
@@ -9403,9 +9503,13 @@ static statement_t *intern_parse_statement(void)
                statement = parse_declaration_statement();
                break;
 
+       case T___label__:
+               statement = parse_local_label_declaration();
+               break;
+
        case ';':        statement = parse_empty_statement();         break;
        case '{':        statement = parse_compound_statement(false); break;
-       case T___leave:  statement = parse_leave();                   break;
+       case T___leave:  statement = parse_leave_statement();                   break;
        case T___try:    statement = parse_ms_try_statment();         break;
        case T_asm:      statement = parse_asm_statement();           break;
        case T_break:    statement = parse_break();                   break;
@@ -9464,6 +9568,7 @@ static statement_t *parse_compound_statement(bool inside_expression_statement)
        add_anchor_token('}');
 
        int      top        = environment_top();
+       int      top_local  = local_label_top();
        scope_t *last_scope = scope;
        set_scope(&statement->compound.scope);
 
@@ -9526,6 +9631,7 @@ end_error:
        assert(scope == &statement->compound.scope);
        set_scope(last_scope);
        environment_pop_to(top);
+       local_label_pop_to(top_local);
 
        POP_PARENT;
        return statement;
@@ -9652,6 +9758,7 @@ void start_parsing(void)
 {
        environment_stack = NEW_ARR_F(stack_entry_t, 0);
        label_stack       = NEW_ARR_F(stack_entry_t, 0);
+       local_label_stack = NEW_ARR_F(stack_entry_t, 0);
        diagnostic_count  = 0;
        error_count       = 0;
        warning_count     = 0;
@@ -9683,6 +9790,7 @@ translation_unit_t *finish_parsing(void)
 
        DEL_ARR_F(environment_stack);
        DEL_ARR_F(label_stack);
+       DEL_ARR_F(local_label_stack);
 
        translation_unit_t *result = unit;
        unit = NULL;
@@ -9692,7 +9800,7 @@ translation_unit_t *finish_parsing(void)
 void parse(void)
 {
        lookahead_bufpos = 0;
-       for(int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
+       for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
                next_token();
        }
        parse_translation_unit();

diff --git a/parsetest/gnu99/local_label.c b/parsetest/gnu99/local_label.c
index 07ab369..d297634 100644 (file)
--- a/parsetest/gnu99/local_label.c
+++ b/parsetest/gnu99/local_label.c
@@ -5,6 +5,7 @@ int test(int a, int b) {
       goto label;
     b = 1;
 label:
+label2:
     ++b;
   }
   if (a) {
@@ -13,6 +14,7 @@ label:
       goto label;
     b = 1;
 label:
+label2:
     ++b;
   }
   return b;