Package jminusminus

Class JCompilationUnit

java.lang.Object

jminusminus.JAST

jminusminus.JCompilationUnit

class JCompilationUnit
extends JAST

The abstract syntax tree (AST) node representing a compilation unit, and so the root of the AST.

The AST is produced by the Parser. Once the AST has been built, three successive methods are invoked:

1. Method preAnalyze() is invoked for making a first pass at type analysis, recursively reaching down to the member headers for declaring types and member interfaces in the environment (contexts). preAnalyze() also creates a partial class file (in memory) for recording member header information.
2. Method analyze() is invoked for type-checking field initializations and method bodies, and determining the types of all expressions. A certain amount of tree surgery is also done here. And stack frame offsets are computed for method parameters and local variables.
3. Method codegen() is invoked for generating code for the compilation unit to a class file. For each type declaration, it instantiates a CLEmitter object (an abstraction of the class file) and then invokes methods on that CLEmitter for generating instructions. At the end of each type declaration, a method is invoked on the CLEmitter which writes the class out to the file system either as .class file or as a .s (SPIM) file. Of course, codegen() makes recursive calls down the tree, to the codegen methods at each node, for generating the appropriate instructions.

Field Summary

Fields inherited from class jminusminus.JAST

compilationUnit, line

Constructor Summary

Constructors

Constructor	Description
JCompilationUnit(String fileName, int line, TypeName packageName, ArrayList<TypeName> imports, ArrayList<JAST> typeDeclarations)	Constructs an AST node for a compilation unit.

Method Summary

Modifier and Type	Method	Description
JAST	analyze(Context context)	Performs semantic analysis on this AST and returns the (possibly modified) AST.
ArrayList<CLFile>	clFiles()	Returns the list of CLFile objects corresponding to the type declarations in this compilation unit.
void	codegen(CLEmitter output)	Performs code generation for this AST.
boolean	errorHasOccurred()	Returns true if a semantic error has occurred up to now, and false otherwise.
String	packageName()	Returns the package in which this compilation unit is defined.
void	preAnalyze()	Constructs a context for the compilation unit, initializing it with imported types.
void	reportSemanticError(int line, String message, Object... arguments)	Reports a semantic error.
void	toJSON(JSONElement json)	Stores information about this AST in JSON format.

Methods inherited from class jminusminus.JAST

line, partialCodegen, unescape

Methods inherited from class java.lang.Object

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

Constructor Details

JCompilationUnit

public JCompilationUnit(String fileName,
 int line,
 TypeName packageName,
 ArrayList<TypeName> imports,
 ArrayList<JAST> typeDeclarations)

Constructs an AST node for a compilation unit.

Parameters:

fileName - the name of the source file.

line - line in which the compilation unit occurs in the source file.

packageName - package name.

imports - a list of imports.

typeDeclarations - type declarations.

Method Details

packageName

public String packageName()

Returns the package in which this compilation unit is defined.

Returns:

the package in which this compilation unit is defined.

clFiles

public ArrayList<CLFile> clFiles()

Returns the list of CLFile objects corresponding to the type declarations in this compilation unit.

Returns:

the list of CLFile objects corresponding to the type declarations in this compilation unit.

errorHasOccurred

public boolean errorHasOccurred()

Returns true if a semantic error has occurred up to now, and false otherwise.

Returns:

true if a semantic error has occurred up to now, and false otherwise..

reportSemanticError

public void reportSemanticError(int line,
 String message,
 Object... arguments)

Reports a semantic error.

Parameters:

line - line in which the error occurred in the source file.

message - message identifying the error.

arguments - related values.

preAnalyze

public void preAnalyze()

Constructs a context for the compilation unit, initializing it with imported types. Then pre-analyzes the unit's type declarations, adding their types to the context.

analyze

public JAST analyze(Context context)

Performs semantic analysis on this AST and returns the (possibly modified) AST.

Specified by:

analyze in class JAST

Parameters:

context - the environment (scope) in which code is analyzed.

Returns:

the (possibly modified) AST.

codegen

public void codegen(CLEmitter output)

Performs code generation for this AST.

Specified by:

codegen in class JAST

Parameters:

output - the code emitter.

toJSON

public void toJSON(JSONElement json)

Stores information about this AST in JSON format.

Overrides:

toJSON in class JAST

Parameters:

json - the JSON emitter.