jminusminus

Class JInstanceOfOp

java.lang.Object

jminusminus.JAST

jminusminus.JStatement

jminusminus.JExpression

jminusminus.JInstanceOfOp

 class JInstanceOfOp
extends JExpression

The AST node for an instanceof expression, having two arguments: an expression and a reference type.

Field Summary

Fields inherited from class jminusminus.JExpression

isStatementExpression, type

Fields inherited from class jminusminus.JAST

compilationUnit, line

Constructor Summary

Constructors

Constructor and Description
JInstanceOfOp(int line, JExpression expr, Type typeSpec) Construct an AST node for an instanceof expression given its line number, the relational expression and reference type.

Method Summary

Methods

Modifier and Type	Method and Description
JInstanceOfOp	analyze(Context context) Analysis of an instanceof operation requires analyzing the expression to be tested, resolving the type was are testing for, and determining if the test is legal, or if the answer can be determined at compile time.
void	codegen(CLEmitter output) Generate code for the type test.
void	codegen(CLEmitter output, String targetLabel, boolean onTrue) Short-circuiting branching for instanceof.
void	writeToStdOut(PrettyPrinter p) Write the information pertaining to this AST to STDOUT.

Methods inherited from class jminusminus.JExpression

isStatementExpression, type

Methods inherited from class jminusminus.JAST

line, partialCodegen

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

JInstanceOfOp

public JInstanceOfOp(int line,
             JExpression expr,
             Type typeSpec)

Construct an AST node for an instanceof expression given its line number, the relational expression and reference type.

Parameters:

line - the line in which the instanceof expression occurs in the source file.

expr - the expression denoting the value to be tested.

typeSpec - the reference type we are testing for.

Method Detail

analyze

public JInstanceOfOp analyze(Context context)

Analysis of an instanceof operation requires analyzing the expression to be tested, resolving the type was are testing for, and determining if the test is legal, or if the answer can be determined at compile time.

Specified by:

analyze in class JExpression

Parameters:

context - context in which names are resolved.

Returns:

the analyzed (and possibly rewritten) AST subtree.

codegen

public void codegen(CLEmitter output)

Generate code for the type test.

Specified by:

codegen in class JAST

Parameters:

output - the code emitter (basically an abstraction for producing the .class file).

codegen

public void codegen(CLEmitter output,
           String targetLabel,
           boolean onTrue)

Short-circuiting branching for instanceof.

Overrides:

codegen in class JExpression

Parameters:

output - code emitter.

targetLabel - the label to which we should branch.

onTrue - do we branch on true?

writeToStdOut

public void writeToStdOut(PrettyPrinter p)

Description copied from class: JAST

Write the information pertaining to this AST to STDOUT.

Specified by:

writeToStdOut in class JAST

Parameters:

p - for pretty printing with indentation.