cetus.hir

Class SymbolTools

java.lang.Object

cetus.hir.SymbolTools

public final class SymbolTools
extends java.lang.Object

SymbolTools provides tools for interfacing symbol tables and related searches.

Method Summary

Methods

Modifier and Type	Method and Description
static void	addSymbols(SymbolTable table, Declaration decl) Adds symbols to a symbol table and checks for duplicates.
static boolean	containsSpecifier(Symbol symbol, Specifier spec) Checks if the specified symbol object contains the given specifier.
static java.util.List<Symbol>	exprsToSymbols(java.util.List<Expression> exprs) Returns a list of symbols by taking symbol object out of the expressions in the given list.
static Declaration	findSymbol(SymbolTable table, IDExpression name) Searches for a symbol by name in the table.
static Declaration	findSymbol(SymbolTable table, java.lang.String sname) Searches for a symbol by String sname in the table.
static java.util.Set<Symbol>	getAccessedSymbols(Traversable t) Returns the set of symbols accessed in the traversable object.
static Identifier	getArrayTemp(Traversable where, java.util.List specs, ArraySpecifier aspec, java.lang.String name) Returns a new identifier derived from the given IR object, type list, array specifier and name.
static Identifier	getArrayTemp(Traversable where, java.util.List specs, java.util.List aspecs, java.lang.String name) Returns a new identifier derived from the given IR object, type list, array specifiers and name.
static ClassDeclaration	getClassDeclaration(Symbol symbol, Traversable tr) Returns the user-defined class declaration for the given symbol.
static java.util.List<Specifier>	getExactExpressionType(Expression e) Returns the exact type of the given expression, tracking all specifiers relevant to the expression.
static java.util.List	getExpressionType(Expression e) Returns a list of specifiers of the given expression.
static java.util.Set<Symbol>	getGlobalSymbols(Traversable t) Returns the set of Symbol objects that are global variables of the File scope
static java.util.Set<Symbol>	getLocalSymbols(Traversable t) Returns the set of symbols declared within the specified traversable object.
static java.util.List	getNativeSpecifiers(Traversable t, Symbol symbol) Returns C-native specifiers for the given symbol.
static NameID	getNewName(java.lang.String name, Traversable tr) Returns a new name id with the given name suggestion and scope.
static Identifier	getOrphanID(java.lang.String name) Returns an incomplete Identifier whose relevant symbol is not defined.
static java.util.Set<Symbol>	getParameterSymbols(Procedure proc) Returns the set of Symbol objects that are formal parameters of the given Procedure
static Identifier	getPointerTemp(Traversable where, Identifier refID) Returns a new, pointer-type identifier derived from the given IR object.
static Identifier	getPointerTemp(Traversable where, java.util.List specs, java.util.List pspecs, java.lang.String name) Returns a new, pointer-type identifier derived from the given IR object.
static Identifier	getPointerTemp(Traversable where, java.util.List specs, java.lang.String name) Returns a new, pointer-type identifier derived from the given IR object.
static java.util.Set<Symbol>	getSideEffectSymbols(FunctionCall fc)
static Symbol	getSymbolOf(Expression e) Returns the symbol of the expression if it represents an lvalue.
static Symbol	getSymbolOfName(java.lang.String name, Traversable tr) Returns the symbol object having the specified string name.
static java.util.Set<Symbol>	getSymbols(SymbolTable st) Returns the set of Symbol objects contained in the given SymbolTable object.
static Identifier	getTemp(Identifier id) Returns a new identifier derived from the given identifier.
static Identifier	getTemp(Identifier id, java.lang.String name) Returns a new identifier derived from the given identifier and name.
static Identifier	getTemp(Traversable where, Identifier id) Returns a new identifier derived from the given IR object and identifier.
static Identifier	getTemp(Traversable where, java.util.List specs, java.lang.String name) Returns a new identifier derived from the given IR object, type list, and name.
static Identifier	getTemp(Traversable where, Specifier spec, java.lang.String name) Returns a new identifier derived from the given IR object, type, and name.
static IDExpression	getUnusedID(SymbolTable table) Returns a randomly-generated name that is not found in the table.
static java.util.Set<Symbol>	getVariableSymbols(SymbolTable st) Returns the set of Symbol objects contained in the given SymbolTable object excluding Procedures.
static java.util.LinkedList	getVariableType(Expression e) Returns a list of specifiers of the expression.
static boolean	isArray(Symbol symbol) Checks if the symbol is an array variable.
static boolean	isFormal(Symbol symbol) Checks if the given symbol is declared as a formal variable.
static boolean	isFormal(Symbol symbol, Procedure proc) Checks if the given symbol is declared as a formal variable.
static boolean	isGlobal(Symbol symbol) Checks if the given symbol is declared as a global variable.
static boolean	isGlobal(Symbol symbol, Traversable t) Checks if the symbol is a global variable to the procedure containing the given traversable object.
static boolean	isInteger(java.util.List specifiers)
static boolean	isInteger(Symbol symbol) Checks if the symbol is an interger type variable.
static boolean	isLocal(Symbol symbol) Checks if the given symbol is declared as a local variable.
static boolean	isOrphan(Symbol symbol) Checks if the given symbol does not belong to the IR tree.
static boolean	isPointer(Expression e) Checks if the symbol is a pointer type variable.
static boolean	isPointer(Symbol symbol) Checks if the symbol is a pointer type variable.
static boolean	isPointerParameter(Symbol param) Checks if the given symbol is a parameter and a pointer-compatible symbol.
static boolean	isScalar(Symbol symbol) Checks if the symbol is a scalar variable.
static boolean	isStruct(Symbol symbol, Traversable tr) Checks if the given symbol is a user-defined struct type.
static void	linkSymbol(Traversable t) Makes links from all IDExpression objects in the program to their corresponding declarators while generating warnings if there is any undeclared variables or functions.
static void	setSymbolName(Symbol symbol, java.lang.String name, SymbolTable symtab) Renames the specified symbol within the given symbol table object.

Methods inherited from class java.lang.Object

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

Method Detail

linkSymbol

public static void linkSymbol(Traversable t)

Makes links from all IDExpression objects in the program to their corresponding declarators while generating warnings if there is any undeclared variables or functions. This method is called with the whole program, before any Cetus passes by default and provides a short cut to the declaration point, which enables faster access to the declaration when necessary. Pass writers can call this routine after changing a certain part of the program, e.g., a specific program section within a scope, to reflect the change due to new insertion of declaration.

Parameters:

t - the input cetus IR.

isGlobal

public static boolean isGlobal(Symbol symbol)

Checks if the given symbol is declared as a global variable.

Parameters:

symbol - the symbol of the variable.

Returns:

true if the variable is global.

isLocal

public static boolean isLocal(Symbol symbol)

Checks if the given symbol is declared as a local variable. This checking should be made along with other types of checking since the formal parameters are not part of the IR tree.

Parameters:

symbol - the symbol of the variable.

Returns:

true if the variable is local.

isOrphan

public static boolean isOrphan(Symbol symbol)

Checks if the given symbol does not belong to the IR tree. There can be two types of orphan symbol -- 1) formal parameters, 2) other temporary variables not in the tree.

Parameters:

symbol - the symbol of the variable.

Returns:

true if the variable is orphan.

isFormal

public static boolean isFormal(Symbol symbol,
               Procedure proc)

Checks if the given symbol is declared as a formal variable. This utility function is using a weak point of the current IR hierarchy; formal parameters are not part of the IR tree but just a satellite data of a procedure object.

Parameters:

symbol - the symbol of the variable.

Returns:

true if the variable is formal.

isFormal

public static boolean isFormal(Symbol symbol)

Checks if the given symbol is declared as a formal variable.

Parameters:

symbol - the symbol to be checked.

Returns:

true if the symbol represents a formal parameter, false otherwise.

exprsToSymbols

public static java.util.List<Symbol> exprsToSymbols(java.util.List<Expression> exprs)

Returns a list of symbols by taking symbol object out of the expressions in the given list.

Parameters:

exprs - the list of requested expressions.

Returns:

the list of symbols that represent each expression.

isPointerParameter

public static boolean isPointerParameter(Symbol param)

Checks if the given symbol is a parameter and a pointer-compatible symbol. Any array declarator is a pointer-compatible symbol.

Parameters:

param - the parameter symbol to be checked.

Returns:

true if param is pointer-compatible.

getNativeSpecifiers

public static java.util.List getNativeSpecifiers(Traversable t,
                                 Symbol symbol)

Returns C-native specifiers for the given symbol.

Parameters:

t - the traversable object where search starts from.

symbol - the symbol object of interest.

Returns:

the list of resolved specifiers without any user specifiers.

isStruct

public static boolean isStruct(Symbol symbol,
               Traversable tr)

Checks if the given symbol is a user-defined struct type. Notice that the first parameter symbol should exist as a traversable object.

Parameters:

symbol - the symbol object to be checked.

tr - the traversable object to be searched.

getClassDeclaration

public static ClassDeclaration getClassDeclaration(Symbol symbol,
                                   Traversable tr)

Returns the user-defined class declaration for the given symbol. Notice that it does not deferentiate "a" and "*a".

Parameters:

symbol - the symbol object to be checked.

tr - the traversable object to be searched.

getOrphanID

public static Identifier getOrphanID(java.lang.String name)

Returns an incomplete Identifier whose relevant symbol is not defined. This method is equivalent to the constructor of Identifier with a raw string name, which is now hidden to external world.

addSymbols

public static void addSymbols(SymbolTable table,
              Declaration decl)

Adds symbols to a symbol table and checks for duplicates.

Parameters:

table - The symbol table to add the symbols to.

decl - The declaration of the symbols. symbols in the table.

findSymbol

public static Declaration findSymbol(SymbolTable table,
                     IDExpression name)

Searches for a symbol by name in the table. If the symbol is not in the table, then parent tables will be searched.

Parameters:

table - The initial table to search.

name - The name of the symbol to locate.

Returns:

a Declaration if the symbol is found, or null if it is not found. The Declaration may contain multiple declarators, of which name will be one, unless the SingleDeclarator pass has been run on the program.

getUnusedID

public static IDExpression getUnusedID(SymbolTable table)

Returns a randomly-generated name that is not found in the table.

Parameters:

table - The table to search.

Returns:

a unique name.

getTemp

public static Identifier getTemp(Identifier id)

Returns a new identifier derived from the given identifier. This method internally calls getTemp(Identifier, String).

Parameters:

id - the identifier from which type and scope are derived.

Returns:

the new identifier.

getTemp

public static Identifier getTemp(Traversable where,
                 Identifier id)

Returns a new identifier derived from the given IR object and identifier. This method internally calls getTemp(Traversable, List, String).

Parameters:

where - the IR object from which scope is derived.

id - the identifier from which type is derived.

Returns:

the new identifier.

getTemp

public static Identifier getTemp(Identifier id,
                 java.lang.String name)

Returns a new identifier derived from the given identifier and name. This method internally calls getTemp(Traversable, List, String).

Parameters:

id - the identifier from which scope is derived.

name - the string from which name is derived.

Returns:

the new identifier.

getTemp

public static Identifier getTemp(Traversable where,
                 Specifier spec,
                 java.lang.String name)

Returns a new identifier derived from the given IR object, type, and name. This method internally calls getTemp(Traversable, List, String).

Parameters:

where - the IR object from which scope is derived.

spec - the type specifier.

name - the string from which name is derived.

Returns:

the new identifier.

getTemp

public static Identifier getTemp(Traversable where,
                 java.util.List specs,
                 java.lang.String name)

Returns a new identifier derived from the given IR object, type list, and name. This method internally calls getArrayTemp(Traversable, List, List, String).

Parameters:

where - the IR object from which scope is derived.

specs - the type specifiers.

name - the string from which name is derived.

Returns:

the new identifier.

getArrayTemp

public static Identifier getArrayTemp(Traversable where,
                      java.util.List specs,
                      ArraySpecifier aspec,
                      java.lang.String name)

Returns a new identifier derived from the given IR object, type list, array specifier and name. This method internally calls getArrayTemp(Traversable, List, List, String).

Parameters:

where - the IR object from which scope is derived.

specs - the type specifiers.

aspec - the array specifier.

name - the string from which name is derived.

Returns:

the new identifier.

getArrayTemp

public static Identifier getArrayTemp(Traversable where,
                      java.util.List specs,
                      java.util.List aspecs,
                      java.lang.String name)

Returns a new identifier derived from the given IR object, type list, array specifiers and name. If specs contains any pointer specifiers, they are automatically separated and inserted into the list of specifiers that belong to the new VariableDeclarator object.

Parameters:

where - the IR object from which scope is derived.

specs - the type specifiers.

aspecs - the array specifier.

name - the string from which name is derived.

Returns:

the new identifier.

getPointerTemp

public static Identifier getPointerTemp(Traversable where,
                        Identifier refID)

Returns a new, pointer-type identifier derived from the given IR object.

Parameters:

where - the IR object from which scope is derived.

refID - the identifier from which type and name are derived.

Returns:

the new pointer-type identifier.

getPointerTemp

public static Identifier getPointerTemp(Traversable where,
                        java.util.List specs,
                        java.lang.String name)

Returns a new, pointer-type identifier derived from the given IR object.

Parameters:

where - the IR object from which scope is derived.

specs - the type specifiers.

name - the string from which name is derived.

Returns:

the new pointer-type identifier.

getPointerTemp

public static Identifier getPointerTemp(Traversable where,
                        java.util.List specs,
                        java.util.List pspecs,
                        java.lang.String name)

Returns a new, pointer-type identifier derived from the given IR object.

Parameters:

where - the IR object from which scope is derived.

specs - the type specifiers.

pspecs - the pointer-type specifiers.

name - the string from which name is derived.

Returns:

the new pointer-type identifier.

getNewName

public static NameID getNewName(java.lang.String name,
                Traversable tr)

Returns a new name id with the given name suggestion and scope.

Parameters:

name - the name suggestion given by user.

tr - the traversable object which scope is derived from.

getSymbols

public static java.util.Set<Symbol> getSymbols(SymbolTable st)

Returns the set of Symbol objects contained in the given SymbolTable object.

Parameters:

st - the symbol table being searched.

Returns:

the set of symbols.

getVariableSymbols

public static java.util.Set<Symbol> getVariableSymbols(SymbolTable st)

Returns the set of Symbol objects contained in the given SymbolTable object excluding Procedures.

Parameters:

st - the symbol table being searched.

Returns:

the set of symbols.

getGlobalSymbols

public static java.util.Set<Symbol> getGlobalSymbols(Traversable t)

Returns the set of Symbol objects that are global variables of the File scope

getParameterSymbols

public static java.util.Set<Symbol> getParameterSymbols(Procedure proc)

Returns the set of Symbol objects that are formal parameters of the given Procedure

getSideEffectSymbols

public static java.util.Set<Symbol> getSideEffectSymbols(FunctionCall fc)

getAccessedSymbols

public static java.util.Set<Symbol> getAccessedSymbols(Traversable t)

Returns the set of symbols accessed in the traversable object.

Parameters:

t - the traversable object.

Returns:

the set of symbols.

getLocalSymbols

public static java.util.Set<Symbol> getLocalSymbols(Traversable t)

Returns the set of symbols declared within the specified traversable object.

Parameters:

t - the traversable object.

Returns:

the set of such symbols.

getSymbolOfName

public static Symbol getSymbolOfName(java.lang.String name,
                     Traversable tr)

Returns the symbol object having the specified string name.

Parameters:

name - the name to be searched for.

tr - the IR location where searching starts.

Returns:

the symbol object.

getSymbolOf

public static Symbol getSymbolOf(Expression e)

Returns the symbol of the expression if it represents an lvalue.

Parameters:

e - the input expression.

Returns:

the corresponding symbol object.

isGlobal

public static boolean isGlobal(Symbol symbol,
               Traversable t)

Checks if the symbol is a global variable to the procedure containing the given traversable object.

Parameters:

symbol - The symbol object

t - The traversable object

Returns:

true if it is global, false otherwise

isScalar

public static boolean isScalar(Symbol symbol)

Checks if the symbol is a scalar variable.

Parameters:

symbol - The symbol

Returns:

true if it is a scalar variable, false otherwise

isArray

public static boolean isArray(Symbol symbol)

Checks if the symbol is an array variable.

Parameters:

symbol - The symbol

Returns:

true if it is an array variable, false otherwise

isPointer

public static boolean isPointer(Symbol symbol)

Checks if the symbol is a pointer type variable.

Parameters:

symbol - The symbol

Returns:

true if it is a pointer type variable, false otherwise

isPointer

public static boolean isPointer(Expression e)

Checks if the symbol is a pointer type variable. The input expression should represent a variable. Otherwise it will return true.

Parameters:

e - the expression to be tested.

isInteger

public static boolean isInteger(Symbol symbol)

Checks if the symbol is an interger type variable.

Parameters:

symbol - the symbol.

Returns:

true if it is an integer type variable, false otherwise.

isInteger

public static boolean isInteger(java.util.List specifiers)

getExactExpressionType

public static java.util.List<Specifier> getExactExpressionType(Expression e)

Returns the exact type of the given expression, tracking all specifiers relevant to the expression. For example, the returned list contains the type specifiers and array specifiers for an identifier declared as an array type.

Parameters:

e - the expression to be examined.

Returns:

the type of the expression.

getExpressionType

public static java.util.List getExpressionType(Expression e)

Returns a list of specifiers of the given expression.

Parameters:

e - the given expression.

Returns:

the list of specifiers.

findSymbol

public static Declaration findSymbol(SymbolTable table,
                     java.lang.String sname)

Searches for a symbol by String sname in the table. If the symbol is not in the table, then parent tables will be searched breadth-first. If multiple symbols have the same String name, the first one found during the search will be returned.

Parameters:

table - The initial table to search.

sname - The String name of the symbol (Symbol.getSymbolName()) to locate.

Returns:

a Declaration if the symbol is found, or null if it is not found. The Declaration may contain multiple declarators, of which sname will be one, unless the SingleDeclarator pass has been run on the program.

getVariableType

public static java.util.LinkedList getVariableType(Expression e)

Returns a list of specifiers of the expression.

setSymbolName

public static void setSymbolName(Symbol symbol,
                 java.lang.String name,
                 SymbolTable symtab)

Renames the specified symbol within the given symbol table object.

Parameters:

symbol - the symbol object to be renamed.

name - the new name of the specified symbol.

symtab - the symbol table object that contains symbol.

containsSpecifier

public static boolean containsSpecifier(Symbol symbol,
                        Specifier spec)

Checks if the specified symbol object contains the given specifier. This functionality can also be provided through Symbol.getTypeSpecifiers() or Symbol.getArraySpecifiers() but they consume extra memory for the returned list.

Parameters:

symbol - the symbol to be checked.

spec - the specifier to be searched for.

Returns:

true if a matching specifier is found.