from numba import compiler, typing
from numba.targets import cpu
from numba import types
from numba.targets.registry import cpu_target
from numba import config
from numba.annotations import type_annotations
from numba.ir_utils import copy_propagate, apply_copy_propagate, get_name_var_table, remove_dels, remove_dead
from numba import ir
from numba import unittest_support as unittest

def test_will_propagate(b, z, w):
    x = 3
    if b > 0:
        y = z + w
    else:
        y = 0
    a = 2 * x
    return a < b

def null_func(a,b,c):
    False

def findLhsAssign(func_ir, var):
    for label, block in func_ir.blocks.items():
        for i, inst in enumerate(block.body):
            if isinstance(inst, ir.Assign) and inst.target.name==var:
                return True

    return False

class TestRemoveDead(unittest.TestCase):
    def test1(self):
        typingctx = typing.Context()
        targetctx = cpu.CPUContext(typingctx)
        test_ir = compiler.run_frontend(test_will_propagate)
        #print("Num blocks = ", len(test_ir.blocks))
        #print(test_ir.dump())
        with cpu_target.nested_context(typingctx, targetctx):
            typingctx.refresh()
            targetctx.refresh()
            args = (types.int64, types.int64, types.int64)
            typemap, return_type, calltypes = compiler.type_inference_stage(typingctx, test_ir, args, None)
            #print("typemap = ", typemap)
            #print("return_type = ", return_type)
            type_annotation = type_annotations.TypeAnnotation(
                func_ir=test_ir,
                typemap=typemap,
                calltypes=calltypes,
                lifted=(),
                lifted_from=None,
                args=args,
                return_type=return_type,
                html_output=config.HTML)
            remove_dels(test_ir.blocks)
            in_cps, out_cps = copy_propagate(test_ir.blocks, typemap)
            #print("in_cps = ", in_cps)
            #print("out_cps = ", out_cps)
            apply_copy_propagate(test_ir.blocks, in_cps, get_name_var_table(test_ir.blocks), null_func, None, typemap, calltypes)
            #print(test_ir.dump())

            #print("findAssign = ", findAssign(test_ir, "x"))
            remove_dead(test_ir.blocks, test_ir.arg_names)
            #print(test_ir.dump())
            self.assertFalse(findLhsAssign(test_ir, "x"))

if __name__ == "__main__":
    unittest.main()

Add test for dead code removal.
Add test for dead code removal.
