org.stringtemplate.v4.compiler.CompiledST Maven / Gradle / Ivy
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StringTemplate is a java template engine for generating source code,
web pages, emails, or any other formatted text output.
StringTemplate is particularly good at multi-targeted code generators,
multiple site skins, and internationalization/localization.
It evolved over years of effort developing jGuru.com.
StringTemplate also powers the ANTLR 3 and 4 code generator. Its distinguishing characteristic
is that unlike other engines, it strictly enforces model-view separation.
Strict separation makes websites and code generators more flexible
and maintainable; it also provides an excellent defense against malicious
template authors.
/*
* [The "BSD license"]
* Copyright (c) 2011 Terence Parr
* 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.stringtemplate.v4.compiler;
import org.antlr.runtime.*;
import org.antlr.runtime.tree.CommonTree;
import org.stringtemplate.v4.*;
import org.stringtemplate.v4.misc.*;
import java.io.*;
import java.util.*;
/** The result of compiling an {@link ST}. Contains all the bytecode instructions,
* string table, bytecode address to source code map, and other bookkeeping
* info. It's the implementation of an ST you might say. All instances
* of the same template share a single implementation ({@link ST#impl} field).
*/
public class CompiledST implements Cloneable {
public String name;
/**
* Every template knows where it is relative to the group that loaded it.
* The prefix is the relative path from the root. {@code "/prefix/name"} is
* the fully qualified name of this template. All calls to
* {@link STGroup#getInstanceOf} calls must use fully qualified names. A
* {@code "/"} is added to the front if you don't specify one. Template
* references within template code, however, uses relative names, unless of
* course the name starts with {@code "/"}.
*
* This has nothing to do with the outer filesystem path to the group dir or
* group file.
*
* We set this as we load/compile the template.
*
* Always ends with {@code "/"}.
*/
public String prefix = "/";
/** The original, immutable pattern (not really used again after
* initial "compilation"). Useful for debugging. Even for
* subtemplates, this is entire overall template.
*/
public String template;
/** The token that begins template definition; could be {@code <@r>} of region. */
public Token templateDefStartToken;
/** Overall token stream for template (debug only). */
public TokenStream tokens;
/** How do we interpret syntax of template? (debug only) */
public CommonTree ast;
public Map formalArguments;
public boolean hasFormalArgs;
public int numberOfArgsWithDefaultValues;
/** A list of all regions and subtemplates. */
public List implicitlyDefinedTemplates;
/**
* The group that physically defines this {@link ST} definition. We use it
* to initiate interpretation via {@link ST#toString}. From there, it
* becomes field {@link Interpreter#group} and is fixed until rendering
* completes.
*/
public STGroup nativeGroup = STGroup.defaultGroup;
/** Does this template come from a {@code <@region>...<@end>} embedded in
* another template?
*/
public boolean isRegion;
/**
* If someone refs {@code <@r()>} in template t, an implicit
*
*
* {@code @t.r() ::= ""}
*
* is defined, but you can overwrite this def by defining your own. We need
* to prevent more than one manual def though. Between this var and
* {@link #isRegion} we can determine these cases.
*/
public ST.RegionType regionDefType;
public boolean isAnonSubtemplate; // {...}
public String[] strings; // string operands of instructions
public byte[] instrs; // byte-addressable code memory.
public int codeSize;
public Interval[] sourceMap; // maps IP to range in template pattern
public CompiledST() {
instrs = new byte[Compiler.TEMPLATE_INITIAL_CODE_SIZE];
sourceMap = new Interval[Compiler.TEMPLATE_INITIAL_CODE_SIZE];
template = "";
}
/**
* Cloning the {@link CompiledST} for an {@link ST} instance allows
* {@link ST#add} to be called safely during interpretation for templates
* that do not contain formal arguments.
*
* @return A copy of the current {@link CompiledST} instance. The copy is a
* shallow copy, with the exception of the {@link #formalArguments} field
* which is also cloned.
*
* @exception CloneNotSupportedException If the current instance cannot be
* cloned.
*/
@Override
public CompiledST clone() throws CloneNotSupportedException {
CompiledST clone = (CompiledST)super.clone();
if (formalArguments != null) {
formalArguments = Collections.synchronizedMap(new LinkedHashMap(formalArguments));
}
return clone;
}
public void addImplicitlyDefinedTemplate(CompiledST sub) {
sub.prefix = this.prefix;
if ( sub.name.charAt(0)!='/' ) sub.name = sub.prefix+sub.name;
if ( implicitlyDefinedTemplates == null ) {
implicitlyDefinedTemplates = new ArrayList();
}
implicitlyDefinedTemplates.add(sub);
}
public void defineArgDefaultValueTemplates(STGroup group) {
if ( formalArguments==null ) return;
for (String a : formalArguments.keySet()) {
FormalArgument fa = formalArguments.get(a);
if ( fa.defaultValueToken!=null ) {
numberOfArgsWithDefaultValues++;
switch (fa.defaultValueToken.getType()) {
case GroupParser.ANONYMOUS_TEMPLATE:
String argSTname = fa.name + "_default_value";
Compiler c2 = new Compiler(group);
String defArgTemplate =
Misc.strip(fa.defaultValueToken.getText(), 1);
fa.compiledDefaultValue =
c2.compile(group.getFileName(), argSTname, null,
defArgTemplate, fa.defaultValueToken);
fa.compiledDefaultValue.name = argSTname;
fa.compiledDefaultValue.defineImplicitlyDefinedTemplates(group);
break;
case GroupParser.STRING:
fa.defaultValue = Misc.strip(fa.defaultValueToken.getText(), 1);
break;
case GroupParser.LBRACK:
fa.defaultValue = Collections.emptyList();
break;
case GroupParser.TRUE:
case GroupParser.FALSE:
fa.defaultValue = fa.defaultValueToken.getType()==GroupParser.TRUE;
break;
default:
throw new UnsupportedOperationException("Unexpected default value token type.");
}
}
}
}
public void defineFormalArgs(List args) {
hasFormalArgs = true; // even if no args; it's formally defined
if ( args == null ) formalArguments = null;
else for (FormalArgument a : args) addArg(a);
}
/** Used by {@link ST#add} to add args one by one without turning on full formal args definition signal. */
public void addArg(FormalArgument a) {
if ( formalArguments==null ) {
formalArguments = Collections.synchronizedMap(new LinkedHashMap());
}
else if (formalArguments.containsKey(a.name)) {
throw new IllegalArgumentException(String.format("Formal argument %s already exists.", a.name));
}
a.index = formalArguments.size();
formalArguments.put(a.name, a);
}
public void defineImplicitlyDefinedTemplates(STGroup group) {
if ( implicitlyDefinedTemplates !=null ) {
for (CompiledST sub : implicitlyDefinedTemplates) {
group.rawDefineTemplate(sub.name, sub, sub.templateDefStartToken);
sub.defineImplicitlyDefinedTemplates(group);
}
}
}
public String getTemplateSource() {
Interval r = getTemplateRange();
return template.substring(r.a, r.b+1);
}
public Interval getTemplateRange() {
if ( isAnonSubtemplate ) {
int start = Integer.MAX_VALUE;
int stop = Integer.MIN_VALUE;
for (Interval interval : sourceMap) {
if (interval == null) {
continue;
}
start = Math.min(start, interval.a);
stop = Math.max(stop, interval.b);
}
if (start <= stop + 1) {
return new Interval(start, stop);
}
}
return new Interval(0, template.length()-1);
}
public String instrs() {
BytecodeDisassembler dis = new BytecodeDisassembler(this);
return dis.instrs();
}
public void dump() {
BytecodeDisassembler dis = new BytecodeDisassembler(this);
System.out.println(name+":");
System.out.println(dis.disassemble());
System.out.println("Strings:");
System.out.println(dis.strings());
System.out.println("Bytecode to template map:");
System.out.println(dis.sourceMap());
}
public String disasm() {
BytecodeDisassembler dis = new BytecodeDisassembler(this);
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
pw.println(dis.disassemble());
pw.println("Strings:");
pw.println(dis.strings());
pw.println("Bytecode to template map:");
pw.println(dis.sourceMap());
pw.close();
return sw.toString();
}
}