Package com.ibm.wala.ssa

Class SymbolTable

java.lang.Object
com.ibm.wala.ssa.SymbolTable
All Implemented Interfaces:
Cloneable
public class SymbolTable extends Object implements Cloneable
A symbol table which associates information with each variable (value number) in an SSA IR.

By convention, symbol numbers start at 1 ... the "this" parameter will be symbol number 1 in a virtual method.

This class is used heavily during SSA construction by SSABuilder.

  • Constructor Details

    • SymbolTable

      public SymbolTable(int numberOfParameters)
      Parameters:
      numberOfParameters - in the IR .. should be ir.getNumberOfParameters()

  • Method Details

    • newSymbol

      public int newSymbol()
      Method newSymbol.
      Returns:
      int

    • setConstantValue

      public void setConstantValue(int vn, ConstantValue val)

    • setDefaultValue

      public void setDefaultValue(int vn, Object defaultValue)
      Set the default value for a value number. The notion of a default value is for use by languages that do not require variables to be defined before they are used. In this situation, SSA conversion can fail since it depends on the assumption that values are always defined when used. The default value is the constant to be used in cases when a given value is used without having been defined. Currently, this is used only by CAst front ends for languages with this "feature".

    • getDefaultValue

      public int getDefaultValue(int vn)

    • getNullConstant

      public int getNullConstant()

    • getConstant

      public int getConstant(boolean b)

    • getConstant

      public int getConstant(int i)

    • getConstant

      public int getConstant(long l)

    • getConstant

      public int getConstant(float f)

    • getConstant

      public int getConstant(double d)

    • getOtherConstant

      public int getOtherConstant(Object v)

    • getConstant

      public int getConstant(String s)

    • getParameter

      public int getParameter(int i) throws IllegalArgumentException
      Return the value number of the ith parameter

      By convention, for a non-static method, the 0th parameter is 'this'

      Throws:
      IllegalArgumentException

    • ensureSymbol

      public void ensureSymbol(int i)
      ensure that the symbol table has allocated space for the particular value number
      Parameters:
      i - a value number

    • getValueString

      public String getValueString(int valueNumber)

    • isConstant

      public boolean isConstant(int v)

    • isZero

      public boolean isZero(int v)

    • isOne

      public boolean isOne(int v)

    • isTrue

      public boolean isTrue(int v)

    • isZeroOrFalse

      public boolean isZeroOrFalse(int v)

    • isOneOrTrue

      public boolean isOneOrTrue(int v)

    • isFalse

      public boolean isFalse(int v)

    • isBooleanOrZeroOneConstant

      public boolean isBooleanOrZeroOneConstant(int v)

    • isBooleanConstant

      public boolean isBooleanConstant(int v)

    • isIntegerConstant

      public boolean isIntegerConstant(int v)

    • isLongConstant

      public boolean isLongConstant(int v)

    • isFloatConstant

      public boolean isFloatConstant(int v)

    • isDoubleConstant

      public boolean isDoubleConstant(int v)

    • isNumberConstant

      public boolean isNumberConstant(int v)

    • isStringConstant

      public boolean isStringConstant(int v)

    • isNullConstant

      public boolean isNullConstant(int v)

    • newPhi

      public int newPhi(int[] rhs) throws IllegalArgumentException
      Throws:
      IllegalArgumentException - if rhs is null

    • getPhiValue

      public PhiValue getPhiValue(int valueNumber)
      Return the PhiValue that is associated with a given value number

    • getMaxValueNumber

      public int getMaxValueNumber()

    • getParameterValueNumbers

      public int[] getParameterValueNumbers()

    • getNumberOfParameters

      public int getNumberOfParameters()

    • getStringValue

      public String getStringValue(int v) throws IllegalArgumentException
      Throws:
      IllegalArgumentException

    • getFloatValue

      public float getFloatValue(int v) throws IllegalArgumentException
      Throws:
      IllegalArgumentException

    • getDoubleValue

      public double getDoubleValue(int v) throws IllegalArgumentException
      Throws:
      IllegalArgumentException

    • getIntValue

      public int getIntValue(int v) throws IllegalArgumentException
      Throws:
      IllegalArgumentException

    • getLongValue

      public long getLongValue(int v) throws IllegalArgumentException
      Throws:
      IllegalArgumentException

    • getConstantValue

      public Object getConstantValue(int v) throws IllegalArgumentException
      Throws:
      IllegalArgumentException

    • getValue

      public Value getValue(int valueNumber)
      Returns:
      the Value object for given value number or null if we have no special information about the value

    • isParameter

      public boolean isParameter(int valueNumber)
      Returns:
      true iff this valueNumber is a parameter

    • copy

      public SymbolTable copy()