# Assemble a program, load it into a fresh machine and run it: the three
# steps every test of lib/rv32 and lib/cc takes.

from rv32.asm import assemble, Program
from rv32.sim import INSTR_BYTES, Machine, machine, run

STEP_LIMIT: Int = 10000000     # instructions before a run is cut off

#| The address of label `name` in an assembled program, or 0 when it has none.
def entry(p: Program, name: Str) -> Int {
    for k to len(p.labels) {
        if p.labels[k] == name {
            return p.addrs[k]
        }
    }
    return 0
}

#| Assemble `text`, start at `_start` (or address 0) and run until the
#| program exits or `limit` instructions have run.
def run_asm(text: Str, limit: Int) -> Machine {
    p = assemble(text)
    return run(machine(p.image, entry(p, "_start")), limit)
}

test "a program starts at _start and exits with a0" {
    text = "j _start\nli a0, 1\n_start: li a0, 7\nli a7, 93\necall\n"
    assert_true(entry(assemble(text), "_start") == 2 * INSTR_BYTES)
    m = run_asm(text, STEP_LIMIT)
    assert_true(m.halted)
    assert_true(m.exit_code == 7)
}

# SPDX-License-Identifier: MIT OR Apache-2.0
# SPDX-FileCopyrightText: 2026 The Viv authors