Enum Expression 

pub enum Expression {
    Constant(u32),
    SymbolAddressIndex(u16),
    SectionAddressIndex(u16),
    Bank(u16),
    SectionOffset(u16),
    Offset(u16),
    SectionStart(u16),
    GroupStart(u16),
    GroupOffset(u16),
    Segment(u16),
    GroupOrg(u16),
    SectionEnd(u16),
    Equals(Box<Expression>, Box<Expression>),
    NotEquals(Box<Expression>, Box<Expression>),
    LTE(Box<Expression>, Box<Expression>),
    LessThan(Box<Expression>, Box<Expression>),
    GTE(Box<Expression>, Box<Expression>),
    GreaterThan(Box<Expression>, Box<Expression>),
    Add(Box<Expression>, Box<Expression>),
    Subtract(Box<Expression>, Box<Expression>),
    Multiply(Box<Expression>, Box<Expression>),
    Divide(Box<Expression>, Box<Expression>),
    And(Box<Expression>, Box<Expression>),
    Or(Box<Expression>, Box<Expression>),
    XOR(Box<Expression>, Box<Expression>),
    LeftShift(Box<Expression>, Box<Expression>),
    RightShift(Box<Expression>, Box<Expression>),
    Mod(Box<Expression>, Box<Expression>),
    Dashes(Box<Expression>, Box<Expression>),
    Revword(Box<Expression>, Box<Expression>),
    Check0(Box<Expression>, Box<Expression>),
    Check1(Box<Expression>, Box<Expression>),
    BitRange(Box<Expression>, Box<Expression>),
    ArshiftChk(Box<Expression>, Box<Expression>),
}

An expression used in relocations.

PSY-Q uses a sophisticated expression system for calculating relocated addresses. Expressions can be constants, symbol references, or complex arithmetic operations.

Each component of an expression has a unique on disk format. There are no synchronization points, or sizes encoded into the structure, so it is important that each type is explicitly modeled.

Linker expressions are similar, but not identical to assembler expressions and some built-in functions are available in both.

Example Expressions

• $1000 - Constant value 0x1000
• [5] - Address of symbol #5
• sectbase(2) - Base address of section #2
• (sectstart(1)+$100) - Section 1 start plus 0x100

Variants

Constant(u32)

A constant value.

$123D

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x0
1	u32	Value.

SymbolAddressIndex(u16)

Index of a symbol’s address.

[x]

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x2
1	u16	???

SectionAddressIndex(u16)

Base address of a section.

sectbase(x)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x4
1	u16	???

Bank(u16)

Untested

bank(x)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x6
1	u16	???

SectionOffset(u16)

Untested

sectof(x)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x8
1	u16	Section ID.

Offset(u16)

Untested

offs(x)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0xA
1	u16	???

SectionStart(u16)

Start address of a section.

sectstart(x)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0xC
1	u16	Section ID.

GroupStart(u16)

Untested

groupstart(x)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0xE
1	u16	Group ID.

GroupOffset(u16)

The offset of a group.

Untested

groupof(x)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x10
1	u16	Group ID.

Segment(u16)

Untested

seg(x)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x12
1	u16	???

GroupOrg(u16)

The ORG address of a group for a symbol.

grouporg(x)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x14
1	u16	Symbol ID.

SectionEnd(u16)

End address of a section.

sectend(X)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x16
1	u16	Section ID.

Equals(Box<Expression>, Box<Expression>)

Equality comparison.

(a=b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x20
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

NotEquals(Box<Expression>, Box<Expression>)

Inequality comparison.

(a<>b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x22
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

LTE(Box<Expression>, Box<Expression>)

Less than or equal.

(a<=b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x24
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

LessThan(Box<Expression>, Box<Expression>)

Less than.

(a<b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x26
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

GTE(Box<Expression>, Box<Expression>)

Greater than or equal.

(a>=b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x28
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

GreaterThan(Box<Expression>, Box<Expression>)

Greater than.

(a>b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x2A
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

Add(Box<Expression>, Box<Expression>)

Addition.

(a+b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x2C
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

Subtract(Box<Expression>, Box<Expression>)

Subtraction.

(a-b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x2E
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

Multiply(Box<Expression>, Box<Expression>)

Multiplication.

(a*b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x30
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

Divide(Box<Expression>, Box<Expression>)

Division.

(a/b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x32
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

And(Box<Expression>, Box<Expression>)

Bitwise AND.

(a&b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x34
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

Or(Box<Expression>, Box<Expression>)

Bitwise OR operator.

(a!b)

Instead of using the typical | (pipe) symbol, the default rendering of this operator is the ! (exclamation point/bang) symbol. In the assembler, the | symbol acts as an alias for !.

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x36
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

XOR(Box<Expression>, Box<Expression>)

Bitwise XOR.

(a^b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x38
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

LeftShift(Box<Expression>, Box<Expression>)

Left shift.

(a<<b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x3A
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

RightShift(Box<Expression>, Box<Expression>)

Right shift.

(a>>b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x3C
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

Mod(Box<Expression>, Box<Expression>)

Modulo.

(a%b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x3E
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

Dashes(Box<Expression>, Box<Expression>)

Dashes operator.

(a---b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x40
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

Revword(Box<Expression>, Box<Expression>)

Reverse word.

(a-revword-b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x42
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

Check0(Box<Expression>, Box<Expression>)

Check0.

(a-check0-b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x44
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

Check1(Box<Expression>, Box<Expression>)

Check1.

(a-check1-b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x46
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

BitRange(Box<Expression>, Box<Expression>)

Bit range extraction.

(a-bitrange-b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x48
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

ArshiftChk(Box<Expression>, Box<Expression>)

Arithmetic shift with check.

(a-arshift_chk-b)

Structure on Disk

Offset	Type	Description
0	u8	Magic: 0x4A
1	Expression	Left Expression.
sizeof(left_expression) + 1	Expression	Right Expression.

Trait Implementations

impl BinRead for Expression

type Args<'__binrw_generated_args_lifetime> = ()

The type used for the args parameter of read_args() and read_options().

fn read_options<R: Read + Seek>( __binrw_generated_var_reader: &mut R, __binrw_generated_var_endian: Endian, __binrw_generated_var_arguments: Self::Args<'_>, ) -> BinResult<Self>

Read Self from the reader using the given Endian and arguments.

fn read<R>(reader: &mut R) -> Result<Self, Error>

where R: Read + Seek, Self: ReadEndian, Self::Args<'a>: for<'a> Required,

Read Self from the reader using default arguments.

fn read_be<R>(reader: &mut R) -> Result<Self, Error>

where R: Read + Seek, Self::Args<'a>: for<'a> Required,

Read Self from the reader using default arguments and assuming big-endian byte order.

fn read_le<R>(reader: &mut R) -> Result<Self, Error>

where R: Read + Seek, Self::Args<'a>: for<'a> Required,

Read Self from the reader using default arguments and assuming little-endian byte order.

fn read_ne<R>(reader: &mut R) -> Result<Self, Error>

where R: Read + Seek, Self::Args<'a>: for<'a> Required,

Read T from the reader assuming native-endian byte order.

fn read_args<R>(reader: &mut R, args: Self::Args<'_>) -> Result<Self, Error>

where R: Read + Seek, Self: ReadEndian,

Read Self from the reader using the given arguments.

fn read_be_args<R>(reader: &mut R, args: Self::Args<'_>) -> Result<Self, Error>

where R: Read + Seek,

Read Self from the reader, assuming big-endian byte order, using the given arguments.

fn read_le_args<R>(reader: &mut R, args: Self::Args<'_>) -> Result<Self, Error>

where R: Read + Seek,

Read Self from the reader, assuming little-endian byte order, using the given arguments.

fn read_ne_args<R>(reader: &mut R, args: Self::Args<'_>) -> Result<Self, Error>

where R: Read + Seek,

Read T from the reader, assuming native-endian byte order, using the given arguments.

impl BinWrite for Expression

type Args<'__binrw_generated_args_lifetime> = ()

The type used for the args parameter of write_args() and write_options().

fn write_options<W: Write + Seek>( &self, __binrw_generated_var_writer: &mut W, __binrw_generated_var_endian: Endian, __binrw_generated_var_arguments: Self::Args<'_>, ) -> BinResult<()>

Write Self to the writer using the given Endian and arguments.

fn write<W>(&self, writer: &mut W) -> Result<(), Error>

where W: Write + Seek, Self: WriteEndian, Self::Args<'a>: for<'a> Required,

Write Self to the writer using default arguments.

fn write_be<W>(&self, writer: &mut W) -> Result<(), Error>

where W: Write + Seek, Self::Args<'a>: for<'a> Required,

Write Self to the writer assuming big-endian byte order.

fn write_le<W>(&self, writer: &mut W) -> Result<(), Error>

where W: Write + Seek, Self::Args<'a>: for<'a> Required,

Write Self to the writer assuming little-endian byte order.

fn write_ne<W>(&self, writer: &mut W) -> Result<(), Error>

where W: Write + Seek, Self::Args<'a>: for<'a> Required,

Write Self to the writer assuming native-endian byte order.

fn write_args<W>( &self, writer: &mut W, args: Self::Args<'_>, ) -> Result<(), Error>

where W: Write + Seek, Self: WriteEndian,

Write Self to the writer using the given arguments.

fn write_be_args<W>( &self, writer: &mut W, args: Self::Args<'_>, ) -> Result<(), Error>

where W: Write + Seek,

Write Self to the writer, assuming big-endian byte order, using the given arguments.

fn write_le_args<W>( &self, writer: &mut W, args: Self::Args<'_>, ) -> Result<(), Error>

where W: Write + Seek,

Write Self to the writer, assuming little-endian byte order, using the given arguments.

fn write_ne_args<W>( &self, writer: &mut W, args: Self::Args<'_>, ) -> Result<(), Error>

where W: Write + Seek,

Write Self to the writer, assuming native-endian byte order, using the given arguments.

impl Clone for Expression

fn clone(&self) -> Expression

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Expression

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for Expression

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for Expression

fn eq(&self, other: &Expression) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl ReadEndian for Expression

const ENDIAN: EndianKind

The endianness of the type.

impl WriteEndian for Expression

const ENDIAN: EndianKind

The endianness of the type.

impl StructuralPartialEq for Expression