Improving the code generator and updating targets

CHANGELOG.md

@@ -6,16 +6,17 @@ This file is used to document any relevant changes done to UniCC.
 
 Released on: Not released yet.
 
+- Code generator does not emit action code when the action is empty.
 - New command-line parameter "-l" or "--language" to specify a target language
   via command-line. This is useful when a grammar only contains AST definitions,
-  which allows to render in any target.
+  which allows to render and run it in any target.
 - Abstract syntax tree generation support:
   - Drafting an abstract syntax tree definition syntax for the grammar language,
-    by using the "=" operator.
-  - See examples/expr.ast.par for an example working with C and Python
+    by using the operators "=" and ":=". See examples/expr.ast.par for an
+    example working under both C and Python without any modifications.
   - C and Python parser targets extended to construct abstract syntax tree
     data structures dynamically.
-  - These are first attempts for an upcoming UniCC v2, where the targets shall
+  - These are first changes for an upcoming UniCC v2, where the targets shall
     be re-used with only few improvements.
 - Fixed several bugs in the Python target on insensitive mode.
 - Additionally allow ":" in case of "->" in grammar definitions.
@@ -24,7 +25,7 @@ Released on: Not released yet.
 
 ## v1.2
 
-Released on: December 7, 2017
+Released on: November 7, 2017
 
 - Started an (yet incomplete) new standard template to provide parser generation
   support for the Python programming language (targets/python.tlt).

build.c

@@ -1238,10 +1238,6 @@ void build_code( PARSER* parser )
 	{
 		p = (PROD*)plist_access( e );
 
-		actions = pstrcatstr( actions, pstrrender( gen->action_start,
-			GEN_WILD_PREFIX "production-number", int_to_str( p->id ), TRUE,
-				(char*)NULL ), TRUE );
-
 		/* Select the semantic code to be processed! */
 		act = (char*)NULL;
 
@@ -1268,8 +1264,14 @@ void build_code( PARSER* parser )
 			act = (char*)NULL;
 		}
 
-		if( act )
+		if( act && *act )
 		{
+			/* Generate action start */
+			actions = pstrcatstr( actions, pstrrender( gen->action_start,
+				GEN_WILD_PREFIX "production-number", int_to_str( p->id ), TRUE,
+					(char*)NULL ), TRUE );
+
+			/* Generate code localization */
 			if( gen->code_localization && p->code_at > 0 )
 			{
 				actions = pstrcatstr( actions,
@@ -1280,13 +1282,15 @@ void build_code( PARSER* parser )
 					TRUE );
 			}
 
+			/* Generate the action code */
 			act = build_action( parser, gen, p, act, is_default_code );
 			actions = pstrcatstr( actions, act, TRUE );
-		}
 
-		actions = pstrcatstr( actions, pstrrender( gen->action_end,
-			GEN_WILD_PREFIX "production-number", int_to_str( p->id ), TRUE,
-				(char*)NULL ), TRUE );
+			/* Generate the action end */
+			actions = pstrcatstr( actions, pstrrender( gen->action_end,
+				GEN_WILD_PREFIX "production-number", int_to_str( p->id ), TRUE,
+					(char*)NULL ), TRUE );
+		}
 
 		/* Generate production information table */
 		productions = pstrcatstr( productions, pstrrender(

parse.c

@@ -1,5 +1,5 @@
 /*
-	Parser module generated from parse.par.
+	Parser module generated by unicc from parse.par.
 	DO NOT EDIT THIS FILE MANUALLY, IT WILL GO AWAY!
 */
 
@@ -3863,21 +3863,6 @@ int _parse( _pcb* pcb )
 	reset_strbuf();
 						strbuf_append( ( ( pcb->tos - 0 )->value.value_5 ) );
 
-					;
-				}				break;
-					case 159:
-				{
-
-					;
-				}				break;
-					case 160:
-				{
-
-					;
-				}				break;
-					case 161:
-				{
-
 					;
 				}				break;
 					case 162:
@@ -3905,11 +3890,6 @@ int _parse( _pcb* pcb )
 				{
 					 pcb->ret.value_5 = 0; 
 					;
-				}				break;
-					case 167:
-				{
-
-					;
 				}				break;
 					case 168:
 				{
@@ -3956,31 +3936,6 @@ int _parse( _pcb* pcb )
 				{
 					 pcb->ret.value_5 = ( ( pcb->tos - 1 )->value.value_5 ); 
 					;
-				}				break;
-					case 176:
-				{
-
-					;
-				}				break;
-					case 177:
-				{
-
-					;
-				}				break;
-					case 178:
-				{
-
-					;
-				}				break;
-					case 179:
-				{
-
-					;
-				}				break;
-					case 180:
-				{
-
-					;
 				}				break;
 					case 181:
 				{

parse.h

@@ -1,5 +1,5 @@
 /*
-	Parser header generated from parse.par.
+	Parser header generated by unicc from parse.par.
 	DO NOT EDIT THIS FILE MANUALLY, IT WILL GO AWAY!
 */
 

targets/C.source/STDTPL.xml

@@ -66,6 +66,14 @@ the UniCC Standard C Parser Template.
 	<!-- Escape double quotation marks -->
 	<escape-sequence for="&#x22;" do="\&#x22;" />
 
+	<!--
+	****************************************************************************
+	The unset value
+	****************************************************************************
+	This defines the value that stands for Nothing, Empty, Unset, 0.
+	-->
+	<null-value>NULL</null-value>
+
 	<!--
 	****************************************************************************
 	Value-stack templates
@@ -746,7 +754,7 @@ the UniCC Standard C Parser Template.
 	the filename-attribute of the file-tag, to generate adequate filenames.
 	-->
 	<file filename="@@basename.c">/*
-	Parser module generated from @@filename.
+	Parser module generated by unicc from @@filename.
 	DO NOT EDIT THIS FILE MANUALLY, IT WILL GO AWAY!
 */
 
@@ -796,7 +804,7 @@ the UniCC Standard C Parser Template.
 
 </file>
 <file filename="@@basename.h">/*
-	Parser header generated from @@filename.
+	Parser header generated by unicc from @@filename.
 	DO NOT EDIT THIS FILE MANUALLY, IT WILL GO AWAY!
 */
 

targets/c.tlt

@@ -66,6 +66,14 @@ the UniCC Standard C Parser Template.
 	<!-- Escape double quotation marks -->
 	<escape-sequence for="&#x22;" do="\&#x22;" />
 
+	<!--
+	****************************************************************************
+	The unset value
+	****************************************************************************
+	This defines the value that stands for Nothing, Empty, Unset, 0.
+	-->
+	<null-value>NULL</null-value>
+
 	<!--
 	****************************************************************************
 	Value-stack templates
@@ -746,7 +754,7 @@ the UniCC Standard C Parser Template.
 	the filename-attribute of the file-tag, to generate adequate filenames.
 	-->
 	<file filename="@@basename.c">/*
-	Parser module generated from @@filename.
+	Parser module generated by unicc from @@filename.
 	DO NOT EDIT THIS FILE MANUALLY, IT WILL GO AWAY!
 */
 
@@ -2109,7 +2117,7 @@ int main( int argc, char** argv )
 
 </file>
 <file filename="@@basename.h">/*
-	Parser header generated from @@filename.
+	Parser header generated by unicc from @@filename.
 	DO NOT EDIT THIS FILE MANUALLY, IT WILL GO AWAY!
 */
 

targets/python.tlt

@@ -2,6 +2,7 @@
 <generator name="Python" long-name="UniCC Standard Python Template" version="0.3">
 	<escape-sequence for="\" do="\\" />
 	<escape-sequence for="&#x22;" do="\&#x22;" />
+	<null-value>None</null-value>
 	<code_localization />
 
 	<vstack_def_type>any</vstack_def_type>
@@ -21,7 +22,7 @@
 
 	<action_set_lhs>pcb.lhs = @@sym</action_set_lhs>
 
-	<scan_action_start>&#x09;def _scan_action_@@symbol-number(self, shift = True):&#x0A;&#x09;&#x09;</scan_action_start>
+	<scan_action_start>&#x09;def _scan_action_@@symbol-number(self, pcb, shift = True):&#x0A;&#x09;&#x09;</scan_action_start>
 	<scan_action_end>&#x0A;&#x09;&#x09;return&#x0A;&#x0A;</scan_action_end>
 	<scan_action_begin_offset>pcb.buf</scan_action_begin_offset>
 	<scan_action_end_offset>pcb.length</scan_action_end_offset>
@@ -94,6 +95,8 @@
 	<file filename="@@basename.py">#!/usr/bin/python
 #-*- coding: utf-8 -*-
 
+# Parser module generated by unicc from @@filename.
+# DO NOT EDIT THIS FILE MANUALLY, IT WILL GO AWAY!
 @@prologue
 
 class @@prefixNode(object):
@@ -200,6 +203,12 @@ class @@prefixParser(object):
 @@dfa-accept
 	)
 
+	# Parsing actions
+@@scan_actions
+@@actions
+
+	# Parsing algorithm
+
 	def _get_act(self, pcb):
 		# Get action table entry
 
@@ -351,9 +360,6 @@ class @@prefixParser(object):
 
 		return pcb.sym &gt; -1
 
-@@scan_actions
-@@actions
-
 	def parse(self, s = None):
 		if s is None:
 			try:
@@ -393,7 +399,9 @@ class @@prefixParser(object):
 				pcb.stack.append(pcb.tos)
 
 				# Execute scanner actions, if existing.
-				#fn = getattr(self, "scan_action_%d" % pcb.sym)()
+				scan_fn = getattr(self, "_scan_action_%d" % pcb.sym, None)
+				if scan_fn:
+					scan_fn(pcb)
 
 				pcb.tos.state = -1 if pcb.act &amp; self._REDUCE else pcb.idx
 				pcb.tos.symbol = self._symbols[pcb.sym]
@@ -420,7 +428,9 @@ class @@prefixParser(object):
 
 				# Call reduce function
 				#print("CALL", "_reduce_action_%d" % pcb.idx)
-				getattr(self, "_reduce_action_%d" % pcb.idx)(pcb)
+				reduce_fn = getattr(self, "_reduce_action_%d" % pcb.idx, None)
+				if reduce_fn:
+					reduce_fn(pcb)
 
 				# Drop right-hand side
 				cnodes = None