Prism Bytecode File Structure

The following documentation outlines the structure of the bytecode file used by our Prism programming language. This structure is crucial for understanding how the source code is represented by the compiler and executed by the Prism virtual machine.

Header

The Prism bytecode file begins with a header containing essential information for interpreting the bytecode. Key components of the header include:

Magic Number: A magic number identifying the file as Prism bytecode. This number is "0x505249534D", corresponding to "PRISM" in ASCII.

Format Version: A version number indicating the bytecode file format version. Currently, we are at version 1.0.

Code Section

The code section in the Prism bytecode file contains the instructions to be executed. Each instruction is represented by an opcode, possibly followed by operands. The Code section is divided into three subsections:

Frame: This part contains a list of instructions for each function defined in the source code.

Labels: The instruction lists at this level correspond to actions to be taken in control structures such as "if" or "while".

Main Instructions: This section represents the instructions of the main function in the source code.

Here's a simple example to illustrate the structure :

Header

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Frame

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Labels

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Main instructions

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Opcodes for Builtins

Opcode	Builtins	Description
0x00	Add	Performs addition
0x01	Sub	Performs subtraction
0x02	Mul	Performs multiplication
0x03	Div	Performs division
0x04	Eq	Checks for equality
0x05	Less	Checks if the first value is less than the second

Opcodes for Values

Opcode	Values	Description
0x06	Integer	Represents an integer value
0x07	Boolean	Represents a boolean value
0x08	Op	Represents a built-in operation (addition, subtraction, etc.)
0x09	Function	Represents a function
0x0A	Symbol	Represents a symbol (variable name)

Opcodes for Instructions

Opcode	Mnemonic	Description
0x0B	SysCall	Applies the built-in function on the stack
0x0C	RetValue	Returns the value at the top of the stack and terminates execution
0x0D	PushArg	Pushes the value into the arguments queue
0x0E	PushValue	Adds a new value to the top of the stack
0x0F	PushFunc	Pushes the position of a function onto the stack and adds corresponding instructions
0x10	Loop	Adds instructions from Labels when the loop condition is true
0x11	LoadArg	Finds the index in the queue and pushes it onto the stack
0x12	LoadName	Pushes into the stack the value associated with the name
0x13	StoreValue	Adds the name to the environment
0x14	JumpIfTrue	Adds instructions from Labels when the condition is true
0x15	JumpIfFalse	Adds instructions from Labels when the condition is false