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The ANTLR 4 grammar compiler.
/*
* [The "BSD license"]
* Copyright (c) 2012 Terence Parr
* Copyright (c) 2012 Sam Harwell
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.antlr.v4.codegen;
import org.antlr.v4.Tool;
import org.antlr.v4.codegen.model.ModelElement;
import org.antlr.v4.codegen.model.OutputModelObject;
import org.antlr.v4.tool.ErrorType;
import org.stringtemplate.v4.ST;
import org.stringtemplate.v4.STGroup;
import org.stringtemplate.v4.compiler.FormalArgument;
import java.lang.reflect.Field;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
/** Convert an output model tree to template hierarchy by walking
* the output model. Each output model object has a corresponding template
* of the same name. An output model object can have nested objects.
* We identify those nested objects by the list of arguments in the template
* definition. For example, here is the definition of the parser template:
*
* Parser(parser, scopes, funcs) ::= <<...>>
*
* The first template argument is always the output model object from which
* this walker will create the template. Any other arguments identify
* the field names within the output model object of nested model objects.
* So, in this case, template Parser is saying that output model object
* Parser has two fields the walker should chase called a scopes and funcs.
*
* This simple mechanism means we don't have to include code in every
* output model object that says how to create the corresponding template.
*/
public class OutputModelWalker {
Tool tool;
STGroup templates;
public OutputModelWalker(Tool tool,
STGroup templates)
{
this.tool = tool;
this.templates = templates;
}
public ST walk(OutputModelObject omo) {
// CREATE TEMPLATE FOR THIS OUTPUT OBJECT
Class cl = omo.getClass();
String templateName = cl.getSimpleName();
if ( templateName == null ) {
tool.errMgr.toolError(ErrorType.NO_MODEL_TO_TEMPLATE_MAPPING, cl.getSimpleName());
return new ST("["+templateName+" invalid]");
}
ST st = templates.getInstanceOf(templateName);
if ( st == null ) {
tool.errMgr.toolError(ErrorType.CODE_GEN_TEMPLATES_INCOMPLETE, templateName);
return new ST("["+templateName+" invalid]");
}
if ( st.impl.formalArguments == null ) {
tool.errMgr.toolError(ErrorType.CODE_TEMPLATE_ARG_ISSUE, templateName, "");
return st;
}
Map formalArgs = st.impl.formalArguments;
// PASS IN OUTPUT MODEL OBJECT TO TEMPLATE AS FIRST ARG
Set argNames = formalArgs.keySet();
Iterator arg_it = argNames.iterator();
String modelArgName = arg_it.next(); // ordered so this is first arg
st.add(modelArgName, omo);
// COMPUTE STs FOR EACH NESTED MODEL OBJECT MARKED WITH @ModelElement AND MAKE ST ATTRIBUTE
Set usedFieldNames = new HashSet();
Field fields[] = cl.getFields();
for (Field fi : fields) {
ModelElement annotation = fi.getAnnotation(ModelElement.class);
if (annotation == null) {
continue;
}
String fieldName = fi.getName();
if (!usedFieldNames.add(fieldName)) {
tool.errMgr.toolError(ErrorType.INTERNAL_ERROR, "Model object " + omo.getClass().getSimpleName() + " has multiple fields named '" + fieldName + "'");
continue;
}
// Just don't set @ModelElement fields w/o formal arg in target ST
if ( formalArgs.get(fieldName)==null ) continue;
try {
Object o = fi.get(omo);
if ( o instanceof OutputModelObject ) { // SINGLE MODEL OBJECT?
OutputModelObject nestedOmo = (OutputModelObject)o;
ST nestedST = walk(nestedOmo);
// System.out.println("set ModelElement "+fieldName+"="+nestedST+" in "+templateName);
st.add(fieldName, nestedST);
}
else if ( o instanceof Collection || o instanceof OutputModelObject[] ) {
// LIST OF MODEL OBJECTS?
if ( o instanceof OutputModelObject[] ) {
o = Arrays.asList((OutputModelObject[])o);
}
Collection nestedOmos = (Collection)o;
for (Object nestedOmo : nestedOmos) {
if ( nestedOmo==null ) continue;
ST nestedST = walk((OutputModelObject)nestedOmo);
// System.out.println("set ModelElement "+fieldName+"="+nestedST+" in "+templateName);
st.add(fieldName, nestedST);
}
}
else if ( o instanceof Map ) {
Map nestedOmoMap = (Map)o;
Map m = new HashMap();
for (Map.Entry entry : nestedOmoMap.entrySet()) {
ST nestedST = walk((OutputModelObject)entry.getValue());
// System.out.println("set ModelElement "+fieldName+"="+nestedST+" in "+templateName);
m.put(entry.getKey(), nestedST);
}
st.add(fieldName, m);
}
else if ( o!=null ) {
tool.errMgr.toolError(ErrorType.INTERNAL_ERROR, "not recognized nested model element: "+fieldName);
}
}
catch (IllegalAccessException iae) {
tool.errMgr.toolError(ErrorType.CODE_TEMPLATE_ARG_ISSUE, templateName, fieldName);
}
}
//st.impl.dump();
return st;
}
}