lib/cc/driver.viv

# The compiler driver: C source to assembly, and C source to a finished
# run on the simulator.
#
#     source --lexer--> tokens --parser--> tree --checks--> tree
#            --codegen--> assembly
#            --assembler--> machine code --simulator--> exit code, output

from cc.lexer import tokenize
from cc.parser import parse
from cc.types import check_program
from cc.codegen import codegen
from rv32.sim import Machine
from rv32.system import run_asm

RUN_LIMIT: Int = 20000000      # instructions before a run is cut off

#| The RV32IM assembly for a C program.
def compile(src: Str) -> Str {
    #: lex: split the source text into tokens
    tokens = tokenize(src)
    #: parse: build the syntax tree from the tokens
    tree = parse(tokens)
    #: check: every called function exists and gets its number of
    #: arguments, none is defined twice, and there is a main
    checked = check_program(tree)
    #: emit: the RISC-V assembly for the checked tree
    return codegen(checked)
}

#| Compile, assemble and run a C program; the machine when it stopped.
def run_c(src: Str) -> Machine {
    return run_asm(compile(src), RUN_LIMIT)
}

test "a C program compiles, runs and exits with main's value" {
    m = run_c("int main() { return 6 * 7; }")
    assert_true(m.halted)
    assert_true(m.exit_code == 42)
    assert_true(m.output == "")
}

# SPDX-License-Identifier: MIT
# SPDX-FileCopyrightText: 2019 Rui Ueyama
# SPDX-FileCopyrightText: 2026 The Viv authors