Test multiple starting rules

assets/parser.c.erb

@@ -695,11 +695,13 @@ typedef struct
 } state_value_t;
 
 /** Common AST node structure. */
-typedef struct
+typedef struct ASTNode_s
 {
     <%= @grammar.prefix %>position_t position;
     <%= @grammar.prefix %>position_t end_position;
-    void * fields[];
+    uint16_t n_fields;
+    uint8_t is_token;
+    struct ASTNode_s * fields[];
 } ASTNode;
 
 /** Parser shift table. */
@@ -922,6 +924,8 @@ static size_t check_reduce(size_t state_id, <%= @grammar.prefix %>token_t token)
  *
  * @param context
  *   Lexer/parser context structure.
+ * @start_state_id
+ *   ID of the state in which to start.
  *
  * @retval P_SUCCESS
  *   The parser successfully matched the input text. The parse result value
@@ -934,7 +938,7 @@ static size_t check_reduce(size_t state_id, <%= @grammar.prefix %>token_t token)
  * @reval P_UNEXPECTED_INPUT
  *   Input text does not match any lexer pattern.
  */
-size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
+static size_t parse_from(<%= @grammar.prefix %>context_t * context, size_t start_state_id)
 {
     <%= @grammar.prefix %>token_info_t token_info;
     <%= @grammar.prefix %>token_t token = INVALID_TOKEN_ID;
@@ -947,6 +951,7 @@ size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
 <% end %>
     state_values_stack_init(&statevalues);
     state_values_stack_push(&statevalues);
+    state_values_stack_index(&statevalues, -1)->state_id = start_state_id;
     size_t result;
     for (;;)
     {
@@ -972,7 +977,7 @@ size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
             {
                 /* Successful parse. */
 <% if @grammar.ast %>
-                context->parse_result = (<%= @grammar.ast_prefix %><%= @grammar.start_rule %><%= @grammar.ast_suffix %> *)state_values_stack_index(&statevalues, -1)->ast_node;
+                context->parse_result = state_values_stack_index(&statevalues, -1)->ast_node;
 <% else %>
                 context->parse_result = state_values_stack_index(&statevalues, -1)->pvalue;
 <% end %>
@@ -992,6 +997,8 @@ size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
                 <%= @grammar.ast_prefix %>Token<%= @grammar.ast_suffix %> * token_ast_node = (<%= @grammar.ast_prefix %>Token<%= @grammar.ast_suffix %> *)malloc(sizeof(<%= @grammar.ast_prefix %>Token<%= @grammar.ast_suffix %>));
                 token_ast_node->position = token_info.position;
                 token_ast_node->end_position = token_info.end_position;
+                token_ast_node->n_fields = 0u;
+                token_ast_node->is_token = 1u;
                 token_ast_node->token = token;
                 token_ast_node->pvalue = token_info.pvalue;
                 state_values_stack_index(&statevalues, -1)->ast_node = token_ast_node;
@@ -1028,31 +1035,30 @@ size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
             else if (parser_reduce_table[reduce_index].n_states > 0)
             {
                 size_t n_fields = parser_reduce_table[reduce_index].rule_set_node_field_array_size;
-                ASTNode * node = (ASTNode *)malloc(sizeof(ASTNode) + n_fields * sizeof(void *));
+                size_t bytes = sizeof(ASTNode) + n_fields * sizeof(void *);
+                ASTNode * node = (ASTNode *)malloc(bytes);
+                memset(node, 0, bytes);
                 node->position = INVALID_POSITION;
                 node->end_position = INVALID_POSITION;
-                for (size_t i = 0; i < n_fields; i++)
-                {
-                    node->fields[i] = NULL;
-                }
+                node->n_fields = n_fields;
                 if (parser_reduce_table[reduce_index].rule_set_node_field_index_map == NULL)
                 {
                     for (size_t i = 0; i < parser_reduce_table[reduce_index].n_states; i++)
                     {
-                        node->fields[i] = state_values_stack_index(&statevalues, -(int)parser_reduce_table[reduce_index].n_states + (int)i)->ast_node;
+                        node->fields[i] = (ASTNode *)state_values_stack_index(&statevalues, -(int)parser_reduce_table[reduce_index].n_states + (int)i)->ast_node;
                     }
                 }
                 else
                 {
                     for (size_t i = 0; i < parser_reduce_table[reduce_index].n_states; i++)
                     {
-                        node->fields[parser_reduce_table[reduce_index].rule_set_node_field_index_map[i]] = state_values_stack_index(&statevalues, -(int)parser_reduce_table[reduce_index].n_states + (int)i)->ast_node;
+                        node->fields[parser_reduce_table[reduce_index].rule_set_node_field_index_map[i]] = (ASTNode *)state_values_stack_index(&statevalues, -(int)parser_reduce_table[reduce_index].n_states + (int)i)->ast_node;
                     }
                 }
                 bool position_found = false;
                 for (size_t i = 0; i < n_fields; i++)
                 {
-                    ASTNode * child = (ASTNode *)node->fields[i];
+                    ASTNode * child = node->fields[i];
                     if ((child != NULL) && <%= @grammar.prefix %>position_valid(child->position))
                     {
                         if (!position_found)
@@ -1074,6 +1080,7 @@ size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
             memset(&reduced_parser_value2, 0, sizeof(reduced_parser_value2));
             if (parser_user_code(&reduced_parser_value2, parser_reduce_table[reduce_index].rule, &statevalues, parser_reduce_table[reduce_index].n_states, context) == P_USER_TERMINATED)
             {
+                state_values_stack_free(&statevalues);
                 return P_USER_TERMINATED;
             }
             reduced_parser_value = reduced_parser_value2;
@@ -1097,6 +1104,19 @@ size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
     return result;
 }
 
+size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
+{
+    return parse_from(context, 0u);
+}
+
+<% @grammar.start_rules.each_with_index do |start_rule, i| %>
+
+size_t <%= @grammar.prefix %>parse_<%= start_rule %>(<%= @grammar.prefix %>context_t * context)
+{
+    return parse_from(context, <%= i %>u);
+}
+<% end %>
+
 /**
  * Get the parse result value.
  *
@@ -1106,17 +1126,28 @@ size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
  * @return Parse result value.
  */
 <% if @grammar.ast %>
-<%= @grammar.ast_prefix %><%= @grammar.start_rule %><%= @grammar.ast_suffix %> * <%= @grammar.prefix %>result(<%= @grammar.prefix %>context_t * context)
+<%= @grammar.ast_prefix %><%= @grammar.start_rules[0] %><%= @grammar.ast_suffix %> * <%= @grammar.prefix %>result(<%= @grammar.prefix %>context_t * context)
+{
+    return (<%= @grammar.ast_prefix %><%= @grammar.start_rules[0] %><%= @grammar.ast_suffix %> *) context->parse_result;
+}
+<%   @grammar.start_rules.each_with_index do |start_rule, i| %>
+<%= @grammar.ast_prefix %><%= start_rule %><%= @grammar.ast_suffix %> * <%= @grammar.prefix %>result_<%= start_rule %>(<%= @grammar.prefix %>context_t * context)
+{
+    return (<%= @grammar.ast_prefix %><%= start_rule %><%= @grammar.ast_suffix %> *) context->parse_result;
+}
+<%   end %>
 <% else %>
 <%= start_rule_type[1] %> <%= @grammar.prefix %>result(<%= @grammar.prefix %>context_t * context)
-<% end %>
 {
-<% if @grammar.ast %>
-    return context->parse_result;
-<% else %>
     return context->parse_result.v_<%= start_rule_type[0] %>;
-<% end %>
 }
+<%   @grammar.start_rules.each_with_index do |start_rule, i| %>
+<%= start_rule_type(i)[1] %> <%= @grammar.prefix %>result_<%= start_rule %>(<%= @grammar.prefix %>context_t * context)
+{
+    return context->parse_result.v_<%= start_rule_type(i)[0] %>;
+}
+<%   end %>
+<% end %>
 
 /**
  * Get the current text input position.
@@ -1153,3 +1184,45 @@ size_t <%= @grammar.prefix %>user_terminate_code(<%= @grammar.prefix %>context_t
 {
     return context->token;
 }
+<% if @grammar.ast %>
+
+static void free_ast_node(ASTNode * node)
+{
+    if (node->is_token)
+    {
+<%   if @grammar.free_token_node %>
+        <%= @grammar.free_token_node %>((<%= @grammar.ast_prefix %>Token<%= @grammar.ast_suffix %> *) node);
+<%   end %>
+        /* TODO: free value_t */
+    }
+    else if (node->n_fields > 0u)
+    {
+        for (size_t i = 0u; i < node->n_fields; i++)
+        {
+            if (node->fields[i] != NULL)
+            {
+                free_ast_node(node->fields[i]);
+            }
+        }
+    }
+    free(node);
+}
+
+/**
+ * Free all AST node memory.
+ */
+void <%= @grammar.prefix %>free_ast(<%= @grammar.ast_prefix %><%= @grammar.start_rules[0] %><%= @grammar.ast_suffix %> * ast)
+{
+    free_ast_node((ASTNode *)ast);
+}
+<%   @grammar.start_rules.each_with_index do |start_rule, i| %>
+
+/**
+ * Free all AST node memory.
+ */
+void <%= @grammar.prefix %>free_ast_<%= start_rule %>(<%= @grammar.ast_prefix %><%= start_rule %><%= @grammar.ast_suffix %> * ast)
+{
+    free_ast_node((ASTNode *)ast);
+}
+<%   end %>
+<% end %>

assets/parser.d.erb

@@ -173,7 +173,7 @@ public struct <%= @grammar.prefix %>context_t
 
     /** Parse result value. */
 <% if @grammar.ast %>
-    <%= @grammar.ast_prefix %><%= @grammar.start_rule %><%= @grammar.ast_suffix %> * parse_result;
+    void * parse_result;
 <% else %>
     <%= @grammar.prefix %>value_t parse_result;
 <% end %>
@@ -985,6 +985,8 @@ private size_t check_reduce(size_t state_id, <%= @grammar.prefix %>token_t token
  *
  * @param context
  *   Lexer/parser context structure.
+ * @start_state_id
+ *   ID of the state in which to start.
  *
  * @retval P_SUCCESS
  *   The parser successfully matched the input text. The parse result value
@@ -997,11 +999,12 @@ private size_t check_reduce(size_t state_id, <%= @grammar.prefix %>token_t token
  * @reval P_UNEXPECTED_INPUT
  *   Input text does not match any lexer pattern.
  */
-public size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
+private size_t parse_from(<%= @grammar.prefix %>context_t * context, size_t start_state_id)
 {
     <%= @grammar.prefix %>token_info_t token_info;
     <%= @grammar.prefix %>token_t token = INVALID_TOKEN_ID;
     state_value_t[] statevalues = new state_value_t[](1);
+    statevalues[0].state_id = start_state_id;
     size_t reduced_rule_set = INVALID_ID;
 <% if @grammar.ast %>
     void * reduced_parser_node;
@@ -1031,7 +1034,7 @@ public size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * cont
             {
                 /* Successful parse. */
 <% if @grammar.ast %>
-                context.parse_result = cast(<%= @grammar.ast_prefix %><%= @grammar.start_rule %><%= @grammar.ast_suffix %> *)statevalues[$-1].ast_node;
+                context.parse_result = statevalues[$-1].ast_node;
 <% else %>
                 context.parse_result = statevalues[$-1].pvalue;
 <% end %>
@@ -1147,6 +1150,19 @@ public size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * cont
     }
 }
 
+public size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
+{
+    return parse_from(context, 0u);
+}
+
+<% @grammar.start_rules.each_with_index do |start_rule, i| %>
+
+public size_t <%= @grammar.prefix %>parse_<%= start_rule %>(<%= @grammar.prefix %>context_t * context)
+{
+    return parse_from(context, <%= i %>u);
+}
+<% end %>
+
 /**
  * Get the parse result value.
  *
@@ -1156,17 +1172,28 @@ public size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * cont
  * @return Parse result value.
  */
 <% if @grammar.ast %>
-public <%= @grammar.ast_prefix %><%= @grammar.start_rule %><%= @grammar.ast_suffix %> * <%= @grammar.prefix %>result(<%= @grammar.prefix %>context_t * context)
+public <%= @grammar.ast_prefix %><%= @grammar.start_rules[0] %><%= @grammar.ast_suffix %> * <%= @grammar.prefix %>result(<%= @grammar.prefix %>context_t * context)
+{
+    return cast(<%= @grammar.ast_prefix %><%= @grammar.start_rules[0] %><%= @grammar.ast_suffix %> *)context.parse_result;
+}
+<%   @grammar.start_rules.each_with_index do |start_rule, i| %>
+public <%= @grammar.ast_prefix %><%= start_rule %><%= @grammar.ast_suffix %> * <%= @grammar.prefix %>result_<%= start_rule %>(<%= @grammar.prefix %>context_t * context)
+{
+    return cast(<%= @grammar.ast_prefix %><%= start_rule %><%= @grammar.ast_suffix %> *)context.parse_result;
+}
+<%   end %>
 <% else %>
 public <%= start_rule_type[1] %> <%= @grammar.prefix %>result(<%= @grammar.prefix %>context_t * context)
-<% end %>
 {
-<% if @grammar.ast %>
-    return context.parse_result;
-<% else %>
     return context.parse_result.v_<%= start_rule_type[0] %>;
-<% end %>
 }
+<%   @grammar.start_rules.each_with_index do |start_rule, i| %>
+public <%= start_rule_type(i)[1] %> <%= @grammar.prefix %>result_<%= start_rule %>(<%= @grammar.prefix %>context_t * context)
+{
+    return context.parse_result.v_<%= start_rule_type(i)[0] %>;
+}
+<%   end %>
+<% end %>
 
 /**
  * Get the current text input position.

assets/parser.h.erb

@@ -75,9 +75,11 @@ typedef union
 /** AST node types. @{ */
 typedef struct <%= @grammar.ast_prefix %>Token<%= @grammar.ast_suffix %>
 {
-    /* ASTNode fields must be present in the same order here. */
+    <% # ASTNode fields must be present in the same order here. # %>
     <%= @grammar.prefix %>position_t position;
     <%= @grammar.prefix %>position_t end_position;
+    uint16_t n_fields;
+    uint8_t is_token;
     <%= @grammar.prefix %>token_t token;
     <%= @grammar.prefix %>value_t pvalue;
 } <%= @grammar.ast_prefix %>Token<%= @grammar.ast_suffix %>;
@@ -93,8 +95,11 @@ struct <%= name %>;
 <%     next if rule_set.optional? %>
 typedef struct <%= @grammar.ast_prefix %><%= name %><%= @grammar.ast_suffix %>
 {
+    <% # ASTNode fields must be present in the same order here. # %>
     <%= @grammar.prefix %>position_t position;
     <%= @grammar.prefix %>position_t end_position;
+    uint16_t n_fields;
+    uint8_t is_token;
 <%     rule_set.ast_fields.each do |fields| %>
     union
     {
@@ -157,7 +162,7 @@ typedef struct
 
     /** Parse result value. */
 <% if @grammar.ast %>
-    <%= @grammar.ast_prefix %><%= @grammar.start_rule %><%= @grammar.ast_suffix %> * parse_result;
+    void * parse_result;
 <% else %>
     <%= @grammar.prefix %>value_t parse_result;
 <% end %>
@@ -184,11 +189,27 @@ size_t <%= @grammar.prefix %>decode_code_point(uint8_t const * input, size_t inp
 size_t <%= @grammar.prefix %>lex(<%= @grammar.prefix %>context_t * context, <%= @grammar.prefix %>token_info_t * out_token_info);
 
 size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context);
+<%   @grammar.start_rules.each_with_index do |start_rule, i| %>
+size_t <%= @grammar.prefix %>parse_<%= start_rule %>(<%= @grammar.prefix %>context_t * context);
+<%   end %>
 
 <% if @grammar.ast %>
-<%= @grammar.ast_prefix %><%= @grammar.start_rule %><%= @grammar.ast_suffix %> * <%= @grammar.prefix %>result(<%= @grammar.prefix %>context_t * context);
+<%= @grammar.ast_prefix %><%= @grammar.start_rules[0] %><%= @grammar.ast_suffix %> * <%= @grammar.prefix %>result(<%= @grammar.prefix %>context_t * context);
+<%   @grammar.start_rules.each_with_index do |start_rule, i| %>
+<%= @grammar.ast_prefix %><%= start_rule %><%= @grammar.ast_suffix %> * <%= @grammar.prefix %>result_<%= start_rule %>(<%= @grammar.prefix %>context_t * context);
+<%   end %>
 <% else %>
 <%= start_rule_type[1] %> <%= @grammar.prefix %>result(<%= @grammar.prefix %>context_t * context);
+<%   @grammar.start_rules.each_with_index do |start_rule, i| %>
+<%= start_rule_type(i)[1] %> <%= @grammar.prefix %>result_<%= start_rule %>(<%= @grammar.prefix %>context_t * context);
+<%   end %>
+<% end %>
+
+<% if @grammar.ast %>
+void <%= @grammar.prefix %>free_ast(<%= @grammar.ast_prefix %><%= @grammar.start_rules[0] %><%= @grammar.ast_suffix %> * ast);
+<%   @grammar.start_rules.each_with_index do |start_rule, i| %>
+void <%= @grammar.prefix %>free_ast_<%= start_rule %>(<%= @grammar.ast_prefix %><%= start_rule %><%= @grammar.ast_suffix %> * ast);
+<%   end %>
 <% end %>
 
 <%= @grammar.prefix %>position_t <%= @grammar.prefix %>position(<%= @grammar.prefix %>context_t * context);

doc/user_guide.md

@@ -326,6 +326,36 @@ assert(itemsmore.pItem.pItem.pItem !is null);
 assert(itemsmore.pItem.pItem.pItem.pToken1 !is null);
 ```
 
+## Freeing user-allocated memory in token node `pvalue`: the `free_token_node` statement
+
+If user lexer code block allocates memory to store in a token node's `pvalue`,
+the `free_token_node` grammar statement can be used to specify the name of a
+function which will be called during the `p_free_ast()` call to free the memory
+associated with a token node.
+
+Example:
+
+```
+<<
+static void free_token(Token * token)
+{
+    free(token->pvalue);
+}
+>>
+ast;
+free_token_node free_token;
+ptype int *;
+token a <<
+  $$ = (int *)malloc(sizeof(int));
+  *$$ = 1;
+>>
+token b <<
+  $$ = (int *)malloc(sizeof(int));
+  *$$ = 2;
+>>
+Start -> a:a b:b;
+```
+
 ##> Specifying tokens - the `token` statement
 
 The `token` statement allows defining a lexer token and a pattern to match that
@@ -708,6 +738,22 @@ Example:
 start MyStartRule;
 ```
 
+Multiple start rules can be specified, either with multiple `start` statements
+or one `start` statement listing multiple start rules.
+Example:
+
+```
+start Module ModuleItem Statement Expression;
+```
+
+When multiple start rules are specified, multiple `p_parse_*()` functions,
+`p_result_*()`, and `p_free_ast_*()` functions (in AST mode) are generated.
+A default `p_parse()`, `p_result()`, `p_free_ast()` are generated corresponding
+to the first start rule.
+Additionally, each start rule causes the generation of another version of each
+of these functions, for example `p_parse_Statement()`, `p_result_Statement()`,
+and `p_free_ast_Statement()`.
+
 ##> Specifying the parser module name - the `module` statement
 
 The `module` statement can be used to specify the module name for a generated
@@ -988,6 +1034,16 @@ p_context_init(&context, input, input_length);
 size_t result = p_parse(&context);
 ```
 
+When multiple start rules are specified, a separate parse function is generated
+for each which starts parsing at the given rule.
+For example, if `Statement` is specified as a start rule:
+
+```
+size_t result = p_parse_Statement(&context);
+```
+
+In this case, the parser will start parsing with the `Statement` rule.
+
 ### `p_position_valid`
 
 The `p_position_valid()` function is only generated for C targets.
@@ -1026,6 +1082,23 @@ if (p_parse(&context) == P_SUCCESS)
 If AST generation mode is active, then the `p_result()` function returns a
 `Start *` pointing to the `Start` AST structure.
 
+When multiple start rules are specified, a separate result function is generated
+for each which returns the parse result for the corresponding rule.
+For example, if `Statement` is specified as a start rule:
+
+```
+p_context_t context;
+p_context_init(&context, input, input_length);
+size_t result = p_parse(&context);
+if (p_parse_Statement(&context) == P_SUCCESS)
+{
+    result = p_result_Statement(&context);
+}
+```
+
+In this case, the parser will start parsing with the `Statement` rule and the
+parse result from the `Statement` rule will be returned.
+
 ### `p_position`
 
 The `p_position()` function can be used to retrieve the parser position where
@@ -1098,6 +1171,31 @@ assert(code_point == 0x1F9E1u);
 assert(code_point_length == 4u);
 ```
 
+### `p_free_ast`
+
+The `p_free_ast()` function can be used to free the memory used by the AST.
+It should be passed the same value that is returned by `p_result()`.
+
+The `p_free_ast()` function is only available for C/C++ output targets.
+
+Note that if any lexer user code block allocates memory to store in a token's
+`pvalue`, in order to properly free this memory a `free_token_node` function
+should be specified in the grammar file.
+If specified, the `free_token_node` function will be called during the
+`p_free_ast()` process to allow user code to free any memory associated with
+a token node's `pvalue`.
+
+When multiple start rules are specified, a separate `p_free_ast` function is
+generated for each which frees the AST resulting from parsing the given rule.
+For example, if `Statement` is specified as a start rule:
+
+```
+p_free_ast_Statement(statement_ast);
+```
+
+In this case, Propane will free a `Statement` AST structure returned by the
+`p_parse_Statement(&context)` function.
+
 ##> Data
 
 ### `p_token_names`

lib/propane/generator.rb

@@ -71,12 +71,15 @@ class Propane
         end
         tokens_by_name[token.name] = token
       end
-      # Check for user start rule.
-      unless @grammar.rules.find {|rule| rule.name == @grammar.start_rule}
-        raise Error.new("Start rule `#{@grammar.start_rule}` not found")
+      # Create real start rule(s).
+      real_start_rules = @grammar.start_rules.map do |start_rule|
+        unless @grammar.rules.find {|rule| rule.name == start_rule}
+          raise Error.new("Start rule `#{start_rule}` not found")
+        end
+        Rule.new("$#{start_rule}", [start_rule, "$EOF"], nil, nil, nil)
       end
-      # Add "real" start rule.
-      @grammar.rules.unshift(Rule.new("$Start", [@grammar.start_rule, "$EOF"], nil, nil, nil))
+      # Add real start rules before user-given rules.
+      @grammar.rules = real_start_rules + @grammar.rules
       # Generate and add rules for optional components.
       generate_optional_component_rules!(tokens_by_name)
       # Build rule sets.
@@ -332,9 +335,9 @@ class Propane
     #
     # @return [Array<String>]
     #   Start rule parser value type name and type string.
-    def start_rule_type
+    def start_rule_type(start_rule_index = 0)
       start_rule = @grammar.rules.find do |rule|
-        rule.name == @grammar.start_rule
+        rule.name == @grammar.start_rules[start_rule_index]
       end
       [start_rule.ptypename, @grammar.ptypes[start_rule.ptypename]]
     end

lib/propane/grammar.rb

@@ -8,10 +8,11 @@ class Propane
     attr_reader :ast
     attr_reader :ast_prefix
     attr_reader :ast_suffix
+    attr_reader :free_token_node
     attr_reader :modulename
     attr_reader :patterns
-    attr_reader :rules
-    attr_reader :start_rule
+    attr_accessor :rules
+    attr_reader :start_rules
     attr_reader :tokens
     attr_reader :code_blocks
     attr_reader :ptypes
@@ -19,7 +20,7 @@ class Propane
 
     def initialize(input)
       @patterns = []
-      @start_rule = "Start"
+      @start_rules = []
       @tokens = []
       @rules = []
       @code_blocks = {}
@@ -32,7 +33,9 @@ class Propane
       @ast = false
       @ast_prefix = ""
       @ast_suffix = ""
+      @free_token_node = nil
       parse_grammar!
+      @start_rules << "Start" if @start_rules.empty?
     end
 
     def ptype
@@ -62,6 +65,7 @@ class Propane
       elsif parse_ast_statement!
       elsif parse_ast_prefix_statement!
       elsif parse_ast_suffix_statement!
+      elsif parse_free_token_node_statement!
       elsif parse_module_statement!
       elsif parse_ptype_statement!
       elsif parse_pattern_statement!
@@ -112,6 +116,12 @@ class Propane
       end
     end
 
+    def parse_free_token_node_statement!
+      if md = consume!(/free_token_node\s+(\w+)\s*;/)
+        @free_token_node = md[1]
+      end
+    end
+
     def parse_module_statement!
       if consume!(/module\s+/)
         md = consume!(/([\w.]+)\s*/, "expected module name")
@@ -232,8 +242,11 @@ class Propane
     end
 
     def parse_start_statement!
-      if md = consume!(/start\s+(\w+)\s*;/)
-        @start_rule = md[1]
+      if md = consume!(/start\s+([\w\s]*);/)
+        start_rules = md[1].split(/\s+/).map(&:strip)
+        start_rules.each do |start_rule|
+          @start_rules << start_rule unless @start_rules.include?(start_rule)
+        end
       end
     end
 

lib/propane/parser.rb

@@ -16,11 +16,20 @@ class Propane
       @warnings = Set.new
       @errors = Set.new
       @options = options
-      start_item = Item.new(grammar.rules.first, 0)
-      eval_item_sets = Set[ItemSet.new([start_item])]
+      start_items = grammar.rules[0...grammar.start_rules.length].map do |start_rule|
+        Item.new(start_rule, 0)
+      end
+      start_item_sets = start_items.map {|item| ItemSet.new([item])}
+      eval_item_sets = Set[*start_item_sets]
 
       while eval_item_sets.size > 0
-        item_set = eval_item_sets.first
+        item_set =
+          if start_item_sets.size > 0
+            # Ensure we evaluate start_item_sets first in order
+            start_item_sets.slice!(0)
+          else
+            eval_item_sets.first
+          end
         eval_item_sets.delete(item_set)
         unless @item_sets_set.include?(item_set)
           item_set.id = @item_sets.size

spec/propane_spec.rb

@@ -78,9 +78,9 @@ EOF
     end
     case options[:language]
     when "c"
-      command = [*%w[gcc -Wall -o spec/run/testparser -Ispec -Ispec/run], *parsers, *test_files, "spec/testutils.c", "-lm"]
+      command = [*%w[gcc -g -Wall -o spec/run/testparser -Ispec -Ispec/run], *parsers, *test_files, "spec/testutils.c", "-lm"]
     when "cpp"
-      command = [*%w[g++ -x c++ -Wall -o spec/run/testparser -Ispec -Ispec/run], *parsers, *test_files, "spec/testutils.c", "-lm"]
+      command = [*%w[g++ -g -x c++ -Wall -o spec/run/testparser -Ispec -Ispec/run], *parsers, *test_files, "spec/testutils.c", "-lm"]
     when "d"
       command = [*%w[ldc2 -g --unittest -of spec/run/testparser -Ispec], *parsers, *test_files, "spec/testutils.d"]
     end
@@ -88,12 +88,24 @@ EOF
     expect(result).to be_truthy
   end
 
-  def run_test
+  def run_test(options)
     stdout, stderr, status = Open3.capture3("spec/run/testparser")
     File.binwrite("spec/run/.stderr", stderr)
     File.binwrite("spec/run/.stdout", stdout)
     stderr.sub!(/^.*modules passed unittests\n/, "")
-    Results.new(stdout, stderr, status)
+    results = Results.new(stdout, stderr, status)
+    if %w[c cpp].include?(options[:language])
+      stdout, stderr, status = Open3.capture3("valgrind --leak-check=full --show-leak-kinds=all --track-origins=yes --verbose spec/run/testparser")
+      vgout = stdout + stderr
+      File.binwrite("spec/run/.vgout", vgout)
+      vgout.scan(/lost: (\d+) bytes/) do |match|
+        bytes = $1.to_i
+        if bytes > 0
+          raise "Valgrind detected memory leak"
+        end
+      end
+    end
+    results
   end
 
   def lines(str)
@@ -286,7 +298,7 @@ Foo -> plus <<>>
 EOF
         run_propane(language: language)
         compile("spec/test_lexer.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -324,7 +336,7 @@ EOF
         end
         run_propane(language: language)
         compile("spec/test_lexer_unknown_character.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -418,7 +430,7 @@ EOF
         end
         run_propane(language: language)
         compile("spec/test_basic_math_grammar.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -444,7 +456,7 @@ R2 -> a b;
 EOF
         run_propane(language: language)
         compile("spec/test_parser_identical_rules_lookahead.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.status).to eq 0
       end
 
@@ -459,7 +471,7 @@ R1 -> b;
 EOF
         run_propane(language: language)
         compile("spec/test_parser_rule_from_multiple_states.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.status).to eq 0
       end
 
@@ -494,7 +506,7 @@ EOF
         end
         run_propane(language: language)
         compile("spec/test_user_code.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.status).to eq 0
         verify_lines(results.stdout, [
           "abc!",
@@ -530,7 +542,7 @@ EOF
         end
         run_propane(language: language)
         compile("spec/test_pattern.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.status).to eq 0
         verify_lines(results.stdout, [
           "def!",
@@ -572,7 +584,7 @@ EOF
         end
         run_propane(language: language)
         compile("spec/test_return_token_from_pattern.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.status).to eq 0
         verify_lines(results.stdout, [
           "def!",
@@ -630,7 +642,7 @@ EOF
         end
         run_propane(language: language)
         compile("spec/test_lexer_modes.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.status).to eq 0
         verify_lines(results.stdout, [
           "begin string mode",
@@ -688,7 +700,7 @@ EOF
         end
         run_propane(language: language)
         compile("spec/test_lexer_multiple_modes.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.status).to eq 0
         verify_lines(results.stdout, [
           "ident: d",
@@ -725,7 +737,7 @@ EOF
         end
         run_propane(language: language)
         compile("spec/test_parser_rule_user_code.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.status).to eq 0
         verify_lines(results.stdout, [
           "A!",
@@ -744,7 +756,7 @@ As -> As a << $$ = $1 + 1u; >>
 EOF
         run_propane(language: language)
         compile("spec/test_parsing_lists.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.status).to eq 0
         expect(results.stderr).to eq ""
       end
@@ -798,7 +810,7 @@ EOF
         end
         run_propane(language: language)
         compile("spec/test_lexer_match_text.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.status).to eq 0
         verify_lines(results.stdout, [
           "Matched token is identifier_123",
@@ -831,7 +843,7 @@ EOF
         end
         run_propane(language: language)
         compile("spec/test_lexer_result_value.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -846,7 +858,7 @@ Start -> a num;
 EOF
         run_propane(language: language)
         compile("spec/test_error_positions.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -875,7 +887,7 @@ Start -> b c b;
 EOF
         run_propane(name: "myp2", language: language)
         compile("spec/test_multiple_parsers.#{language}", parsers: %w[myp1 myp2], language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -894,7 +906,7 @@ Any -> c;
 EOF
         run_propane(language: language)
         compile("spec/test_user_terminate_lexer.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -912,7 +924,7 @@ Any -> ;
 EOF
         run_propane(language: language)
         compile("spec/test_user_terminate.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -956,7 +968,7 @@ EOF
         end
         run_propane(language: language)
         compile("spec/test_match_backslashes.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
         verify_lines(results.stdout, [
@@ -1021,7 +1033,7 @@ Two -> two;
 EOF
         run_propane(language: language)
         compile("spec/test_ast.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -1065,7 +1077,7 @@ Two -> two;
 EOF
         run_propane(language: language)
         compile("spec/test_ast_ps.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -1139,7 +1151,7 @@ EOF
         end
         run_propane(language: language)
         compile("spec/test_optional_rule_component.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
         verify_lines(results.stdout, [
@@ -1191,7 +1203,7 @@ EOF
         end
         run_propane(language: language)
         compile("spec/test_optional_rule_component_ast.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -1232,7 +1244,7 @@ EOF
         end
         run_propane(language: language)
         compile("spec/test_named_optional_rule_component_ast.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -1252,7 +1264,7 @@ T -> c;
 EOF
         run_propane(language: language)
         compile("spec/test_ast_token_positions.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -1272,7 +1284,7 @@ A -> bb? c?;
 EOF
         run_propane(language: language)
         compile("spec/test_ast_invalid_positions.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -1292,7 +1304,7 @@ T -> c;
 EOF
         run_propane(language: language)
         compile("spec/test_ast_field_aliases.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -1315,7 +1327,7 @@ T -> c;
 EOF
         run_propane(language: language)
         compile("spec/test_ast_field_aliases.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -1342,7 +1354,7 @@ EOF
 #include <stdio.h>
 #include <string.h>
 >>
-ptype char const *;
+ptype char *;
 token id /[a-zA-Z_][a-zA-Z0-9_]*/ <<
   char * s = (char *)malloc(match_length + 1);
   strncpy(s, (char const *)match, match_length);
@@ -1353,12 +1365,14 @@ drop /\\s+/;
 Start -> id:first id:second <<
   printf("first is %s\\n", ${first});
   printf("second is %s\\n", ${second});
+  free(${first});
+  free(${second});
 >>
 EOF
         end
         run_propane(language: language)
         compile("spec/test_field_aliases.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
         expect(results.stdout).to match /first is foo1.*second is bar2/m
@@ -1389,7 +1403,7 @@ EOF
 #include <stdio.h>
 #include <string.h>
 >>
-ptype char const *;
+ptype char *;
 token id /[a-zA-Z_][a-zA-Z0-9_]*/ <<
   char * s = (char *)malloc(match_length + 1);
   strncpy(s, (char const *)match, match_length);
@@ -1402,13 +1416,15 @@ Start -> Foo;
 Start -> id:first id:second <<
   printf("first is %s\\n", ${first});
   printf("second is %s\\n", ${second});
+  free(${first});
+  free(${second});
 >>
 Foo -> ;
 EOF
         end
         run_propane(language: language)
         compile("spec/test_field_aliases.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
         expect(results.stdout).to match /first is foo1.*second is bar2/m
@@ -1419,10 +1435,81 @@ EOF
         write_grammar(File.read("spec/ast_node_memory_remains.#{ext}.propane"))
         run_propane(language: language)
         compile("spec/test_ast_node_memory_remains.#{language}", language: language)
-        results = run_test
+        results = run_test(language: language)
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
+
+      it "allows multiple starting rules" do
+    write_grammar <<EOF
+ptype int;
+token a << $$ = 1; >>
+token b << $$ = 2; >>
+token c << $$ = 3; >>
+Start -> a b R;
+Start -> Bs:bs << $$ = $1; >>
+R -> c:c << $$ = $1; >>
+Bs -> << $$ = 0; >>
+Bs -> b:b Bs:bs << $$ = $1 + $2; >>
+start Start R Bs;
+EOF
+        run_propane(language: language)
+        compile("spec/test_starting_rules.#{language}", language: language)
+        results = run_test(language: language)
+        expect(results.stderr).to eq ""
+        expect(results.status).to eq 0
+      end
+
+      it "allows multiple starting rules in AST mode" do
+    write_grammar <<EOF
+ast;
+ptype int;
+token a << $$ = 1; >>
+token b << $$ = 2; >>
+token c << $$ = 3; >>
+Start -> a b R;
+Start -> Bs:bs;
+R -> c:c;
+Bs -> ;
+Bs -> b:b Bs:bs;
+start Start R Bs;
+EOF
+        run_propane(language: language)
+        compile("spec/test_starting_rules_ast.#{language}", language: language)
+        results = run_test(language: language)
+        expect(results.stderr).to eq ""
+        expect(results.status).to eq 0
+      end
+
+      if %w[c cpp].include?(language)
+        it "allows a user function to free token node memory in AST mode" do
+    write_grammar <<EOF
+<<
+static void free_token(Token * token)
+{
+    free(token->pvalue);
+}
+>>
+ast;
+free_token_node free_token;
+ptype int *;
+token a <<
+  $$ = (int *)malloc(sizeof(int));
+  *$$ = 1;
+>>
+token b <<
+  $$ = (int *)malloc(sizeof(int));
+  *$$ = 2;
+>>
+Start -> a:a b:b;
+EOF
+          run_propane(language: language)
+          compile("spec/test_free_ast_token_node_memory.#{language}", language: language)
+          results = run_test(language: language)
+          expect(results.stderr).to eq ""
+          expect(results.status).to eq 0
+        end
+      end
     end
   end
 end

spec/test_ast.c

@@ -33,12 +33,16 @@ int main()
     assert_eq(22, itemsmore->pItem->pToken1->pvalue);
     assert(itemsmore->pItemsMore == NULL);
 
+    p_free_ast(start);
+
     input = "";
     p_context_init(&context, (uint8_t const *)input, strlen(input));
     assert_eq(P_SUCCESS, p_parse(&context));
     start = p_result(&context);
     assert(start->pItems == NULL);
 
+    p_free_ast(start);
+
     input = "2 1";
     p_context_init(&context, (uint8_t const *)input, strlen(input));
     assert_eq(P_SUCCESS, p_parse(&context));
@@ -51,5 +55,7 @@ int main()
     assert(start->pItems->pItem->pDual->pTwo2 == NULL);
     assert(start->pItems->pItem->pDual->pOne1 == NULL);
 
+    p_free_ast(start);
+
     return 0;
 }

spec/test_ast_field_aliases.c

@@ -15,5 +15,7 @@ int main()
     assert_eq(TOKEN_b, start->second->pToken->token);
     assert_eq(TOKEN_c, start->third->pToken->token);
 
+    p_free_ast(start);
+
     return 0;
 }

spec/test_ast_invalid_positions.c

@@ -30,6 +30,8 @@ int main()
     assert_eq(3, start->end_position.row);
     assert_eq(8, start->end_position.col);
 
+    p_free_ast(start);
+
     input = "a\nbb";
     p_context_init(&context, (uint8_t const *)input, strlen(input));
     assert(p_parse(&context) == P_SUCCESS);
@@ -54,6 +56,8 @@ int main()
     assert_eq(2, start->end_position.row);
     assert_eq(2, start->end_position.col);
 
+    p_free_ast(start);
+
     input = "a\nc\nc";
     p_context_init(&context, (uint8_t const *)input, strlen(input));
     assert(p_parse(&context) == P_SUCCESS);
@@ -78,6 +82,8 @@ int main()
     assert_eq(3, start->end_position.row);
     assert_eq(1, start->end_position.col);
 
+    p_free_ast(start);
+
     input = "a";
     p_context_init(&context, (uint8_t const *)input, strlen(input));
     assert(p_parse(&context) == P_SUCCESS);
@@ -98,5 +104,7 @@ int main()
     assert_eq(1, start->end_position.row);
     assert_eq(1, start->end_position.col);
 
+    p_free_ast(start);
+
     return 0;
 }

spec/test_ast_node_memory_remains.c

@@ -411,5 +411,8 @@ int main(int argc, char * argv[])
         }
     }
 
+    free(pfds);
+    p_free_ast(pmod);
+
     return 0;
 }

spec/test_ast_ps.c

@@ -33,12 +33,16 @@ int main()
     assert_eq(22, itemsmore->pItem->pToken1->pvalue);
     assert(itemsmore->pItemsMore == NULL);
 
+    p_free_ast(start);
+
     input = "";
     p_context_init(&context, (uint8_t const *)input, strlen(input));
     assert_eq(P_SUCCESS, p_parse(&context));
     start = p_result(&context);
     assert(start->pItems == NULL);
 
+    p_free_ast(start);
+
     input = "2 1";
     p_context_init(&context, (uint8_t const *)input, strlen(input));
     assert_eq(P_SUCCESS, p_parse(&context));
@@ -51,5 +55,7 @@ int main()
     assert(start->pItems->pItem->pDual->pTwo2 == NULL);
     assert(start->pItems->pItem->pDual->pOne1 == NULL);
 
+    p_free_ast(start);
+
     return 0;
 }

spec/test_ast_token_positions.c

@@ -43,6 +43,8 @@ int main()
     assert_eq(1, start->end_position.row);
     assert_eq(6, start->end_position.col);
 
+    p_free_ast(start);
+
     input = "\n\n  bb\nc\ncc\n\n     a";
     p_context_init(&context, (uint8_t const *)input, strlen(input));
     assert(p_parse(&context) == P_SUCCESS);
@@ -80,5 +82,7 @@ int main()
     assert_eq(7, start->end_position.row);
     assert_eq(6, start->end_position.col);
 
+    p_free_ast(start);
+
     return 0;
 }

spec/test_free_ast_token_node_memory.c

@@ -0,0 +1,19 @@
+#include "testparser.h"
+#include <assert.h>
+#include <string.h>
+#include "testutils.h"
+
+int main()
+{
+    char const * input = "ab";
+    p_context_t context;
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert_eq(P_SUCCESS, p_parse(&context));
+    Start * start = p_result(&context);
+    assert(start->a != NULL);
+    assert(*start->a->pvalue == 1);
+    assert(start->b != NULL);
+    assert(*start->b->pvalue == 2);
+
+    p_free_ast(start);
+}

spec/test_named_optional_rule_component_ast.c

@@ -17,6 +17,8 @@ int main()
     assert(start->pR == NULL);
     assert(start->r == NULL);
 
+    p_free_ast(start);
+
     input = "abcd";
     p_context_init(&context, (uint8_t const *)input, strlen(input));
     assert(p_parse(&context) == P_SUCCESS);
@@ -31,6 +33,8 @@ int main()
     assert(start->pR == start->r);
     assert_eq(TOKEN_c, start->pR->pToken1->token);
 
+    p_free_ast(start);
+
     input = "bdc";
     p_context_init(&context, (uint8_t const *)input, strlen(input));
     assert(p_parse(&context) == P_SUCCESS);
@@ -40,6 +44,8 @@ int main()
     assert(start->r != NULL);
     assert_eq(TOKEN_d, start->pR->pToken1->token);
 
+    p_free_ast(start);
+
     return 0;
 }
 

spec/test_optional_rule_component_ast.c

@@ -16,6 +16,8 @@ int main()
     assert(start->pR3 == NULL);
     assert(start->pR == NULL);
 
+    p_free_ast(start);
+
     input = "abcd";
     p_context_init(&context, (uint8_t const *)input, strlen(input));
     assert(p_parse(&context) == P_SUCCESS);
@@ -28,6 +30,8 @@ int main()
     assert(start->pR == start->pR3);
     assert_eq(TOKEN_c, start->pR->pToken1->token);
 
+    p_free_ast(start);
+
     input = "bdc";
     p_context_init(&context, (uint8_t const *)input, strlen(input));
     assert(p_parse(&context) == P_SUCCESS);
@@ -37,6 +41,8 @@ int main()
     assert(start->pR != NULL);
     assert_eq(TOKEN_d, start->pR->pToken1->token);
 
+    p_free_ast(start);
+
     return 0;
 }
 

spec/test_start_rule_ast.c

@@ -13,5 +13,7 @@ int main()
     assert(top->pToken != NULL);
     assert_eq(TOKEN_hi, top->pToken->token);
 
+    p_free_ast(top);
+
     return 0;
 }

spec/test_starting_rules.c

@@ -0,0 +1,27 @@
+#include "testparser.h"
+#include <assert.h>
+#include <string.h>
+#include "testutils.h"
+
+int main()
+{
+    char const * input = "bbbb";
+    p_context_t context;
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+    int result = p_result(&context);
+    assert_eq(8, result);
+
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse_Bs(&context) == P_SUCCESS);
+    result = p_result_Bs(&context);
+    assert_eq(8, result);
+
+    input = "c";
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse_R(&context) == P_SUCCESS);
+    result = p_result_R(&context);
+    assert_eq(3, result);
+
+    return 0;
+}

spec/test_starting_rules.d

@@ -0,0 +1,29 @@
+import testparser;
+import std.stdio;
+import testutils;
+
+int main()
+{
+    return 0;
+}
+
+unittest
+{
+    string input = "bbbb";
+    p_context_t context;
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+    int result = p_result(&context);
+    assert(result == 8);
+
+    p_context_init(&context, input);
+    assert(p_parse_Bs(&context) == P_SUCCESS);
+    result = p_result_Bs(&context);
+    assert(result == 8);
+
+    input = "c";
+    p_context_init(&context, input);
+    assert(p_parse_R(&context) == P_SUCCESS);
+    result = p_result_R(&context);
+    assert(result == 3);
+}

spec/test_starting_rules_ast.c

@@ -0,0 +1,37 @@
+#include "testparser.h"
+#include <assert.h>
+#include <string.h>
+#include "testutils.h"
+
+int main()
+{
+    char const * input = "bbbb";
+    p_context_t context;
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+    Start * start = p_result(&context);
+    assert_not_null(start->bs);
+    assert_not_null(start->bs->b);
+    assert_not_null(start->bs->bs->b);
+    assert_not_null(start->bs->bs->bs->b);
+    assert_not_null(start->bs->bs->bs->bs->b);
+    p_free_ast(start);
+
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse_Bs(&context) == P_SUCCESS);
+    Bs * bs = p_result_Bs(&context);
+    assert_not_null(bs->b);
+    assert_not_null(bs->bs->b);
+    assert_not_null(bs->bs->bs->b);
+    assert_not_null(bs->bs->bs->bs->b);
+    p_free_ast_Bs(bs);
+
+    input = "c";
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse_R(&context) == P_SUCCESS);
+    R * r = p_result_R(&context);
+    assert_not_null(r->c);
+    p_free_ast_R(r);
+
+    return 0;
+}

spec/test_starting_rules_ast.d

@@ -0,0 +1,36 @@
+import testparser;
+import std.stdio;
+import testutils;
+
+int main()
+{
+    return 0;
+}
+
+unittest
+{
+    string input = "bbbb";
+    p_context_t context;
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+    Start * start = p_result(&context);
+    assert(start.bs);
+    assert(start.bs.b);
+    assert(start.bs.bs.b);
+    assert(start.bs.bs.bs.b);
+    assert(start.bs.bs.bs.bs.b);
+
+    p_context_init(&context, input);
+    assert(p_parse_Bs(&context) == P_SUCCESS);
+    Bs * bs = p_result_Bs(&context);
+    assert(bs.b);
+    assert(bs.bs.b);
+    assert(bs.bs.bs.b);
+    assert(bs.bs.bs.bs.b);
+
+    input = "c";
+    p_context_init(&context, input);
+    assert(p_parse_R(&context) == P_SUCCESS);
+    R * r = p_result_R(&context);
+    assert(r.c);
+}

spec/testutils.c

@@ -14,6 +14,24 @@ void assert_eq_size_t_i(size_t expected, size_t actual, char const * file, size_
     }
 }
 
+void assert_ne_size_t_i(size_t expected, size_t actual, char const * file, size_t line)
+{
+    if (expected == actual)
+    {
+        fprintf(stderr, "%s:%lu: expected not %lu, got %lu\n", file, line, expected, actual);
+        assert(false);
+    }
+}
+
+void assert_not_null_i(void * ptr, char const * file, size_t line)
+{
+    if (ptr == NULL)
+    {
+        fprintf(stderr, "%s:%lu: expected not NULL\n", file, line);
+        assert(false);
+    }
+}
+
 void str_init(str_t * str, char const * cs)
 {
     size_t length = strlen(cs);

spec/testutils.h

@@ -5,6 +5,16 @@ void assert_eq_size_t_i(size_t expected, size_t actual, char const * file, size_
 #define assert_eq(expected, actual) \
     assert_eq_size_t_i(expected, actual, __FILE__, __LINE__)
 
+void assert_ne_size_t_i(size_t expected, size_t actual, char const * file, size_t line);
+
+#define assert_ne(expected, actual) \
+    assert_ne_size_t_i(expected, actual, __FILE__, __LINE__)
+
+void assert_not_null_i(void * ptr, char const * file, size_t line);
+
+#define assert_not_null(ptr) \
+    assert_not_null_i(ptr, __FILE__, __LINE__)
+
 typedef struct
 {
     char * cs;