com.tangosol.dev.compiler.java.Statement Maven / Gradle / Ivy
/*
* Copyright (c) 2000, 2020, Oracle and/or its affiliates.
*
* Licensed under the Universal Permissive License v 1.0 as shown at
* http://oss.oracle.com/licenses/upl.
*/
package com.tangosol.dev.compiler.java;
import com.tangosol.dev.assembler.CodeAttribute;
import com.tangosol.dev.assembler.Label;
import com.tangosol.dev.compiler.CompilerException;
import com.tangosol.dev.compiler.Context;
import com.tangosol.util.ErrorList;
import java.util.Map;
import java.util.Set;
import java.util.HashSet;
/**
* This class implements a Java statement language element.
*
* The differences between the default element and a statement are:
*
* 1) An element takes two sets of unassigned variables for its precompile;
* statements only use the first ("if true") set. (The other set is
* used only by expressions.) Due to this, statements have a
* 2) An element can "swap itself out" during its precompile; statements
* by convention do not.
* 3) Statements do not implement the compile method; it is implemented
* by the Statement class itself. Instead, statements implement the
* compileImpl method, which is wrapped by the compile method and
* takes the same parameters (and has the same return value).
*
* @version 1.00, 09/15/98
* @author Cameron Purdy
*/
public abstract class Statement
extends Element
{
// ----- construction ---------------------------------------------------
/**
* Construct a statement.
*
* @param stmt the statement within which this element exists
* @param token the first token making up the language element
*/
protected Statement(Statement outer, Token token)
{
super((outer == null || outer instanceof Block ? (Block) outer : outer.getBlock()), token);
this.outer = outer;
}
// ----- code generation ------------------------------------------------
/**
* For all statements, the actual compilation is performed by the
* compileImpl method. The compile method (final on Statement) is
* responsible only for the start and end labels and for handling
* the "forced completion" flag.
*
* @param ctx the compiler context
* @param code the assembler code attribute to compile to
* @param fReached true if this language element is reached (JLS 14.19)
* @param errlist the error list to log errors to
*
* @return true if the element can complete normally (JLS 14.1)
*
* @exception CompilerException thrown if an error occurs that should
* stop the compilation process
*/
protected final boolean compile(Context ctx, CodeAttribute code, boolean fReached, ErrorList errlist)
throws CompilerException
{
if (labelStart != null)
{
code.add(labelStart);
}
if (ctx.isDebug())
{
code.setLine(getStartToken().getLine() + 1);
}
// compile the actual operation of this statement
boolean fCompletes = compileImpl(ctx, code, fReached, errlist);
if (labelEnd != null)
{
code.add(labelEnd);
}
// this statement may believe it completes, or some statement (e.g.
// a break) within this statement may make this statement completable
return fCompletes || isCompletable();
}
/**
* Perform final optimizations and code generation.
*
* @param ctx the compiler context
* @param code the assembler code attribute to compile to
* @param fReached true if this language element is reached (JLS 14.19)
* @param errlist the error list to log errors to
*
* @return true if the element can complete normally (JLS 14.1)
*
* @exception CompilerException thrown if an error occurs that should
* stop the compilation process
*/
protected abstract boolean compileImpl(Context ctx, CodeAttribute code, boolean fReached, ErrorList errlist)
throws CompilerException;
// ----- accessors ------------------------------------------------------
/**
* Get the statement that contains this statement. All statements, except
* for the main block, are contained by other statements.
*
* @return the statement that contains this statement
*/
public Statement getOuterStatement()
{
return outer;
}
/**
* Set the statement that contains this statement.
*
* @param outer the statement that contains this statement
*/
public void setOuterStatement(Statement outer)
{
this.outer = outer;
}
/**
* Get the first inner statement, if any.
*
* @return the first inner statement
*/
public Statement getInnerStatement()
{
return inner;
}
/**
* Set the inner statement.
*
* @first the inner statement
*/
protected void setInnerStatement(Statement inner)
{
this.inner = inner;
}
/**
* Get the next statement, if any.
*
* @return the next statement (after this one)
*/
public Statement getNextStatement()
{
return next;
}
/**
* Set the next statement.
*
* @first the next statement
*/
protected void setNextStatement(Statement next)
{
this.next = next;
}
/**
* Get the assembly label for this statement.
*
* @return the assembly label for this statement
*/
public Label getStartLabel()
{
if (labelStart == null)
{
labelStart = new Label();
}
return labelStart;
}
/**
* Get the assembly label for the loop continuation point of this
* statement.
*
* This is only applicable for the following:
*
* WhileStatement
* DoStatement
* ForStatement
*
* @return the assembly label trailing this statement
*/
public Label getContinuationLabel()
{
if (labelCont == null)
{
labelCont = new Label();
}
return labelCont;
}
/**
* Get the assembly label for the next statement.
*
* @return the assembly label trailing this statement
*/
public Label getEndLabel()
{
if (labelEnd == null)
{
labelEnd = new Label();
}
return labelEnd;
}
/**
* Determine if this statement completes normally even if it appears
* to complete abruptly. (Value is only meaningful after the inner
* statements have been pre-compiled.)
*
* This is only applicable for the following:
*
* LabelStatement
* SwitchStatement
* WhileStatement
* DoStatement
* ForStatement
*
* @return true if an inner statement causes this statement to complete
* normally
*/
protected boolean isCompletable()
{
return fCompletable;
}
/**
* Force this statement to complete normally.
*
* This is only applicable for the following:
*
* LabelStatement
* SwitchStatement
* WhileStatement
* DoStatement
* ForStatement
*
* @param fCompletable true if this statement completes normally as a
* result of an inner
*/
protected void setCompletable(boolean fCompletable)
{
this.fCompletable = fCompletable;
}
/**
* Add the passed unassigned variables from a BreakStatement to the
* set of unassigned variables for this statement.
*
* This is only applicable for the following:
*
* LabelStatement
* SwitchStatement
* WhileStatement
* DoStatement
* ForStatement
*
* @param setVars the set of unassigned vars at the BreakStatement
*/
protected void addBreakUVars(Set setVars)
{
getBreakUVars().addAll(setVars);
}
/**
* Get the (union) set of all unassigned variables from each break.
*
* This is only applicable for the following:
*
* LabelStatement
* SwitchStatement
* WhileStatement
* DoStatement
* ForStatement
*
* @return a set of variables which is the union of all sets of
* unassigned variables for each break statement which
* completes this statement
*/
protected Set getBreakUVars()
{
Set setVars = this.setBreakUVars;
if (setVars == null)
{
this.setBreakUVars = setVars = new HashSet();
}
return setVars;
}
/**
* Add the passed unassigned variables from a ContinueStatement to the
* set of unassigned variables for this statement.
*
* This is only applicable for the following:
*
* LabelStatement
* WhileStatement
* DoStatement
* ForStatement
*
* @param setVars the set of unassigned vars at the ContinueStatement
*/
protected void addContinueUVars(Set setVars)
{
getContinueUVars().addAll(setVars);
}
/**
* Get the (union) set of all unassigned variables from each continue.
*
* This is only applicable for the following:
*
* LabelStatement
* WhileStatement
* DoStatement
* ForStatement
*
* @return a set of variables which is the union of all sets of
* unassigned variables for each Continue statement which
* completes this statement
*/
protected Set getContinueUVars()
{
Set setVars = this.setContinueUVars;
if (setVars == null)
{
this.setContinueUVars = setVars = new HashSet();
}
return setVars;
}
/**
* Add the passed assigned final variables from a BreakStatement to the
* set of assigned variables for this statement.
*
* This is only applicable for the following:
*
* LabelStatement
* SwitchStatement
* WhileStatement
* DoStatement
* ForStatement
*
* @param setVars the set of assigned final vars at the BreakStatement
*/
protected void addBreakFVars(Set setVars)
{
getBreakFVars().addAll(setVars);
}
/**
* Get the (union) set of all assigned final variables from each break.
*
* This is only applicable for the following:
*
* LabelStatement
* SwitchStatement
* WhileStatement
* DoStatement
* ForStatement
*
* @return a set of variables which is the union of all sets of
* assigned final variables for each break statement which
* completes this statement
*/
protected Set getBreakFVars()
{
Set setVars = this.setBreakFVars;
if (setVars == null)
{
this.setBreakFVars = setVars = new HashSet();
}
return setVars;
}
/**
* Add the passed assigned final variables from a ContinueStatement to
* the set of assigned final variables for this statement.
*
* This is only applicable for the following:
*
* LabelStatement
* WhileStatement
* DoStatement
* ForStatement
*
* @param setVars the set of assigned final vars at the ContinueStatement
*/
protected void addContinueFVars(Set setVars)
{
getContinueFVars().addAll(setVars);
}
/**
* Get the (union) set of all assigned final variables from each continue.
*
* This is only applicable for the following:
*
* LabelStatement
* WhileStatement
* DoStatement
* ForStatement
*
* @return a set of variables which is the union of all sets of
* assigned final variables for each Continue statement which
* completes this statement
*/
protected Set getContinueFVars()
{
Set setVars = this.setContinueFVars;
if (setVars == null)
{
this.setContinueFVars = setVars = new HashSet();
}
return setVars;
}
// ----- error logging --------------------------------------------------
/**
* Error: Statement is not reachable.
*
* @param errlist the error list to log errors to
*
* @exception CompilerException thrown if an error occurs that should
* stop the compilation process
*/
protected void notReached(ErrorList errlist)
throws CompilerException
{
logError(ERROR, STMT_NOT_REACHED, null, errlist);
}
// ----- Element methods ------------------------------------------------
/**
* Print the statement information.
*
* @param sIndent
*/
public void print(String sIndent)
{
out(sIndent + toString());
if (inner != null)
{
out(sIndent + " Inner Statements:");
inner.printList(sIndent + " ");
}
}
/**
* Print this statement and the list of statements following this statement.
*
* @param sIndent
*/
public void printList(String sIndent)
{
for (Statement stmt = this; stmt != null; stmt = stmt.next)
{
stmt.print(sIndent);
}
}
// ----- data members ---------------------------------------------------
/**
* The class name.
*/
private static final String CLASS = "Statement";
/**
* The statement within which this statement exists
*/
private Statement outer;
/**
* The statement within which this statement exists
*/
private Statement inner;
/**
* Supports a linked list of statements within a block.
*/
private Statement next;
/**
* The location of this statement in the assembly.
*/
private Label labelStart;
/**
* The location of the continuation point of this statement in the
* assembly.
*/
private Label labelCont;
/**
* The location of the next statement in the assembly.
*/
private Label labelEnd;
/**
* LabelStatement, SwitchStatement, WhileStatement, DoStatement, and
* ForStatement may complete normally due to a reachable break within
* them.
*/
private boolean fCompletable;
/**
* LabelStatement, SwitchStatement, WhileStatement, DoStatement, and
* ForStatement collect all unassigned variables from each continue.
*/
private Set setContinueUVars;
/**
* LabelStatement, SwitchStatement, WhileStatement, DoStatement, and
* ForStatement collect all unassigned variables from each break.
*/
private Set setBreakUVars;
/**
* LabelStatement, SwitchStatement, WhileStatement, DoStatement, and
* ForStatement collect all assigned final variables from each continue.
*/
private Set setContinueFVars;
/**
* LabelStatement, SwitchStatement, WhileStatement, DoStatement, and
* ForStatement collect all assigned final variables from each break.
*/
private Set setBreakFVars;
}
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