verify

Documentation

Overview

Package verify contains a symbolic verifier to check if registers are allocated correctly

Index

• Variables
• func Verify(fn *ir.Func) []error

Variables

var ErrIllegalAssignment = errors.New("illegal register assignment in two operand instruction")

var ErrMissingCopy = errors.New("missing copy of block parameter")

var ErrNoRegAssigned = errors.New("no register assigned to a variable")

var ErrWrongValueInReg = errors.New("attempt to read wrong value from register")

Functions

func Verify

func Verify(fn *ir.Func) []error

Verify executes the function symbolically, tracking which values are in which registers. Each block is executed with each permutation of input values, which are hashed to ensure the block isn't executed twice with the same input parameters, so that it will eventually halt.

This verifier tries not to rely on liveness analysis and tries to execute the code from the beginning to the end in order to be very different from the way the register allocator works, thus increasing the likelihood of catching bugs.

This verifier wasn't really designed to be fast, since it probably won't need to run in production. It's mainly for catching bugs in tests / development. But if tests end up slow, this could be optimized.