Package ghidra.program.disassemble

Class DisassemblerContextImpl

  • All Implemented Interfaces:
    DisassemblerContext, ProcessorContext, ProcessorContextView
    public class DisassemblerContextImpl
extends java.lang.Object
implements DisassemblerContext
    Maintains processor state information during disassembly and analysis. Tracks register state associated with instruction flows. Within this context, a flow is defined as a contiguous range of instructions. Also, this context provides storage for context states at future flow addresses, which will be used when subsequent flowTo(Address) or flowStart(Address) calls are made with those addresses.

    • Constructor Detail

      • DisassemblerContextImpl

        public DisassemblerContextImpl​(ProgramContext programContext)
        Constructor for DisassemblerContext.
        Parameters:
        programContext - contains the values for registers at specific addresses store in the program.

    • Method Detail

      • copyToFutureFlowState

        public RegisterValue copyToFutureFlowState​(Address address)
        Saves the current processor state for when this context flows to the given address. Use this method if keeping separate flows from different flow from addresses is not important.
        Parameters:
        address - the address at which to save the current processor state.
        Returns:
        context register value which was copied

      • copyToFutureFlowState

        public RegisterValue copyToFutureFlowState​(Address fromAddr,
                                           Address destAddr)
        Saves the current processor state flowing from the fromAddr, for when this context flows to the given address.
        Parameters:
        fromAddr - the address from which this flow originates.
        destAddr - the address at which to save the current processor state.
        Returns:
        context register value which was copied

      • mergeToFutureFlowState

        public java.util.ArrayList<RegisterValue> mergeToFutureFlowState​(Address address)
        Saves the current processor state for when this context is later used at the given address. If the address already has a value, return the value on a collision list! Use this method if keeping separate flows from different flow from addresses is not important.
        Parameters:
        address - the address at which to save the current processor state.

      • mergeToFutureFlowState

        public java.util.ArrayList<RegisterValue> mergeToFutureFlowState​(Address fromAddr,
                                                                 Address destAddr)
        Saves the current processor state flowing from the fromAddr to the destAddr for when this context is later used. If the address already has a value, return the value on a collision list!
        Parameters:
        fromAddr - the address from which this flow originated
        destAddr - the address at which to save the current processor state.

      • flowAbort

        public void flowAbort()
        Terminate active flow while preserving any accumulated future context. Any context commits resulting from a flowToAddress or flowEnd will be unaffected.

      • flowStart

        public void flowStart​(Address address)
        Starts a new flow. Initializes the current state for all registers using any future flow state that has been set. Use this method if keeping separate flows from different flow from addresses is not important.
        Parameters:
        address - the starting address of a new instruction flow.
        Throws:
        java.lang.IllegalStateException - if a previous flow was not ended.

      • flowStart

        public void flowStart​(Address fromAddr,
                      Address toAddr)
        Starts a new flow from an address to the new start. Initializes the current state for all registers using any future flow state that has been set flowing from the fromAddr.
        Parameters:
        fromAddr - address that this flow is flowing from.
        toAddr - the starting address of a new instruction flow.
        Throws:
        java.lang.IllegalStateException - if a previous flow was not ended.

      • getFlowContextValue

        public RegisterValue getFlowContextValue​(Address destAddr,
                                         boolean isFallThrough)
        Get flowed context value at arbitrary destination address without affecting state. Use this method if keeping separate flows from different flow from addresses is not important.
        Parameters:
        destAddr -
        isFallThrough -
        Returns:

      • getFlowContextValue

        public RegisterValue getFlowContextValue​(Address fromAddr,
                                         Address destAddr,
                                         boolean isFallThrough)
        Get flowed context value at a destination address, that has been flowed from the fromAddr, without affecting state.
        Parameters:
        fromAddr - address that this flow is flowing from.
        toAddr - the starting address of a new instruction flow.
        Throws:
        java.lang.IllegalStateException - if a previous flow was not ended.

      • flowToAddress

        public void flowToAddress​(Address address)
        Continues the current flow at the given address. Checks for register values that have been stored in the future flow state. If any registers have saved future state, the current state for all registers is written to the program context upto the specified address(exclusive). The future flow state values are then loaded into the current context. Use this method if keeping separate flows from different flow from addresses is not important.
        Parameters:
        address - the address to flow to.
        Throws:
        java.lang.IllegalStateException - if no flow was started.

      • flowToAddress

        public void flowToAddress​(Address fromAddr,
                          Address destAddr)
        Continues the current flow from an address to the given address. Checks for register values that have been stored in the future flow state. If any registers have saved future state, the current state for all registers is written to the program context upto the specified address(exclusive). The future flow state values are then loaded into the current context.
        Parameters:
        fromAddr - address that this flow is flowing from.
        toAddr - the starting address of a new instruction flow.
        Throws:
        java.lang.IllegalStateException - if a previous flow was not ended.

      • flowEnd

        public void flowEnd​(Address maxAddress)
        Ends the current flow. Unsaved register values will be saved up to and including max address.
        Parameters:
        maxAddress - the maximum address of an instruction flow. If maxAddress is null, or the current flow address has already advanced beyond maxAddress, then no save is performed.
        Throws:
        java.lang.IllegalStateException - if a flow has not been started.

      • setValue

        public void setValue​(Register register,
                     Address address,
                     java.math.BigInteger newValue)
        Sets the value for the given register to be used when the flow advances to the given address using either the flowTo() or flowStart() methods. The new value has precedence over any existing value. Use this method if keeping separate flows from different flow from addresses is not important.
        Parameters:
        register - the register for which the value is to be saved.
        address - the future flow address to save the value.
        newValue - the value to save for future flow.

      • setValue

        public void setValue​(Register register,
                     Address fromAddr,
                     Address toAddr,
                     java.math.BigInteger newValue)
        Sets the value for the given register to be used when the flow advances to the given address using either the flowTo() or flowStart() methods. The new value has precedence over any existing value.
        Parameters:
        register - the register for which the value is to be saved.
        fromAddr - the address from which this flow originated
        toAddr - the future flow address to save the value.
        newValue - the value to save for future flow.

      • setFutureRegisterValue

        public void setFutureRegisterValue​(Address address,
                                   RegisterValue value)
        Description copied from interface: DisassemblerContext
        Combines value with any previously saved future register value at address or any value stored in the program if there is no previously saved future value. Use this method when multiple flows to the same address don't matter or the flowing from address is unknown. When value has conflicting bits with the previously saved value, value will take precedence. If the register value is the value for the processor context register and a previously saved value does not exist, the user saved values in the stored context of the program will be used as existing value.
        Specified by:
        setFutureRegisterValue in interface DisassemblerContext
        Parameters:
        address - the address to store the register value
        value - the register value to store at the address

      • setFutureRegisterValue

        public void setFutureRegisterValue​(Address fromAddr,
                                   Address toAddr,
                                   RegisterValue value)
        Description copied from interface: DisassemblerContext
        Combines value with any previously saved future register value at fromAddr/toAddr or any value stored in the program if there is no previously saved future value. When value has conflicting bits with the previously saved value, value will take precedence. If the register value is the value for the processor context register and a previously saved value does not exist, the user saved values in the stored context of the program will be used as existing value.
        Specified by:
        setFutureRegisterValue in interface DisassemblerContext
        Parameters:
        fromAddr - the address this value if flowing from
        toAddr - the address to store the register value
        value - the register value to store at the address

      • getAddress

        public Address getAddress()
        Returns the current flow address for this context.

      • setContextRegisterValue

        public void setContextRegisterValue​(RegisterValue value,
                                    Address address)
        Modify the current context register value at the specified address. If current disassembly flow address equals specified address the current disassembly context will be changed, otherwise the future flow state will be changed. This differs from setValue(Register, Address, BigInteger) in that is can affect the current context state at the current address in a non-delayed fashion. Use this method if keeping separate flows from different flow from addresses is not important.
        Parameters:
        value - register value
        address - disassembly address

      • setContextRegisterValue

        public void setContextRegisterValue​(RegisterValue value,
                                    Address fromAddr,
                                    Address toAddr)
        Modify the current context register value at the specified address. If current disassembly toAddr address equals specified address the current disassembly context will be changed, otherwise the future flow state flowing from the fromAddr will be changed. This differs from setValue(Register, Address, BigInteger) in that is can affect the current context state at the current address in a non-delayed fashion.
        Parameters:
        value - register value
        address - disassembly address
        fromAddr - the address from which this flow originated
        toAddr - the future flow address to save the value.

      • getValue

        public java.math.BigInteger getValue​(Register register,
                                     Address address,
                                     boolean signed)
        Returns the future register value at the specified address. If no future value is stored, it will return the value stored in the program. Use this method if keeping separate flows from different flow from addresses is not important.
        Parameters:
        register - the register to get a value for.
        address - the address at which to get a value.
        signed - if true, interpret the value as signed.
        Returns:
        the value of the register at the location, or null if a full value is not established.

      • getValue

        public java.math.BigInteger getValue​(Register register,
                                     Address fromAddr,
                                     Address toAddr,
                                     boolean signed)
        Returns the future register value at the specified address that occured because of a flow from the fromAddr. If no future value is stored, it will return the value stored in the program.
        Parameters:
        value - register value
        fromAddr - the address from which this flow originated
        toAddr - the future flow address to save the value.
        signed - if true, interpret the value as signed.
        Returns:
        the value of the register at the location, or null if a full value is not established.

      • getRegisterValue

        public RegisterValue getRegisterValue​(Register register,
                                      Address address)
        Returns the future RegisterValue at the specified address. If no future value is stored, it will return the value stored in the program. The value returned may not have a complete value for the requested register. Use this method if keeping separate flows from different flow from addresses is not important.
        Parameters:
        register - the register to get a value for.
        address - the address at which to get a value.
        signed - if true, interpret the value as signed.
        Returns:
        a RegisterValue object if one has been stored in the future flow or the program. The RegisterValue object may have a "no value" state for the bits specified by the given register. Also, null may be returned if no value have been stored.

      • getRegisterValue

        public RegisterValue getRegisterValue​(Register register,
                                      Address fromAddr,
                                      Address destAddr)
        Returns the future RegisterValue at the specified address that occured because of a flow from the fromAddr. If no future value is stored, it will return the value stored in the program. The value returned may not have a complete value for the requested register.
        Parameters:
        register - the register to get a value for.
        fromAddr - the address from which the flow originated
        destAddr - the address at which to get a value.
        signed - if true, interpret the value as signed.
        Returns:
        a RegisterValue object if one has been stored in the future flow or the program. The RegisterValue object may have a "no value" state for the bits specified by the given register. Also, null may be returned if no value have been stored.

      • getKnownFlowToAddresses

        public Address[] getKnownFlowToAddresses​(Address toAddr)
        Returns an array of locations that have values that will flow to this location
        Parameters:
        toAddr - address that is the target of a flow to
        Returns:
        and array of known address flows to this location

      • isFlowActive

        public boolean isFlowActive()
        Returns true if a flow has been started and not yet ended.
        Returns:
        true if a flow has been started and not yet ended.