neovim/src/nlua0.zig

//! "nlua" is an abbreviation for nvim flavored lua, i e lua with the
//! extended standard library functionality added by nvim such as json, mpack
//! and libuv and a range of vim.* utility functions.
//!
//! nlua0 is an interpreter for the "bootstrap" lua code we need to run before
//! nvim can be built, in order to run lua scripts which process and generate
//! more .c code, which still need these extensions.
const std = @import("std");
const ziglua = @import("ziglua");
const options = @import("options");

const embedded_data = @import("embedded_data");

// these are common dependencies used by many generators
const hashy = @embedFile("gen/hashy.lua");
const c_grammar = @embedFile("gen/c_grammar.lua");

const Lua = ziglua.Lua;

extern "c" fn luaopen_mpack(ptr: *anyopaque) c_int;
extern "c" fn luaopen_lpeg(ptr: *anyopaque) c_int;
extern "c" fn luaopen_bit(ptr: *anyopaque) c_int;
extern "c" fn luaopen_luv(ptr: *anyopaque) c_int;

fn init_lua() !*Lua {
    // Initialize the Lua vm
    var lua = try Lua.init(std.heap.c_allocator);
    lua.openLibs();

    // this sets _G.vim by itself, so we don't need to
    try lua.loadBuffer(embedded_data.shared_module, "shared.lua");
    lua.call(.{ .results = 1 });

    try lua.loadBuffer(embedded_data.inspect_module, "inspect.lua");
    lua.call(.{ .results = 1 });
    lua.setField(-2, "inspect");

    try lua.loadBuffer(embedded_data.iter_module, "iter.lua");
    lua.call(.{ .results = 1 });
    lua.setField(-2, "iter");

    _ = try lua.getGlobal("package");
    _ = lua.getField(-1, "preload");
    try lua.loadBuffer(hashy, "hashy.lua"); // [package, preload, hashy]
    lua.setField(-2, "gen.hashy");
    try lua.loadBuffer(c_grammar, "c_grammar.lua"); // [package, preload, c_grammar]
    lua.setField(-2, "gen.c_grammar");
    lua.pop(2);

    const retval = luaopen_mpack(lua);
    if (retval != 1) return error.LoadError;
    _ = lua.getField(-1, "NIL"); // [vim, mpack, NIL]
    lua.setField(-3, "NIL"); // vim.NIL = mpack.NIL (wow BOB wow)
    lua.setField(-2, "mpack");

    const retval2 = luaopen_lpeg(lua);
    if (retval2 != 1) return error.LoadError;
    lua.setField(-3, "lpeg");

    const retval3 = luaopen_luv(lua);
    if (retval3 != 1) return error.LoadError;
    lua.setField(-3, "uv");

    lua.pop(2);

    if (!options.use_luajit) {
        lua.pop(luaopen_bit(lua));
    }
    return lua;
}

pub fn main(init: std.process.Init) !void {
    const args = init.minimal.args;

    const lua = try init_lua();
    defer lua.deinit();

    if (args.vector.len < 2) {
        std.debug.print("USAGE: nlua0 script.lua args...\n\n", .{});
        return;
    }
    lua.createTable(@intCast(args.vector.len - 2), 1);

    var iter = try init.minimal.args.iterateAllocator(init.arena.allocator());
    _ = iter.skip();
    var i: u32 = 0;
    var firstarg: [:0]const u8 = undefined;
    while (iter.next()) |val| : (i += 1) {
        _ = lua.pushString(val);
        if (i == 0) {
            firstarg = try lua.toString(-1); // preserved on lua heap..
        }
        lua.rawSetIndex(-2, @intCast(i));
    }
    lua.setGlobal("arg");

    _ = try lua.getGlobal("debug");
    _ = lua.getField(-1, "traceback");
    try lua.loadFile(firstarg);
    lua.protectedCall(.{ .msg_handler = -2 }) catch |e| {
        if (e == error.LuaRuntime) {
            const msg = try lua.toString(-1);
            std.debug.print("{s}\n", .{msg});
        }
        return e;
    };
}

fn do_ret1(lua: *Lua, str: [:0]const u8) !void {
    try lua.loadString(str);
    try lua.protectedCall(.{ .results = 1 });
}

test "simple test" {
    const lua = try init_lua();
    defer lua.deinit();

    try do_ret1(lua, "return vim.isarray({2,3})");
    try std.testing.expectEqual(true, lua.toBoolean(-1));
    lua.pop(1);

    try do_ret1(lua, "return vim.isarray({a=2,b=3})");
    try std.testing.expectEqual(false, lua.toBoolean(-1));
    lua.pop(1);

    try do_ret1(lua, "return vim.inspect(vim.mpack.decode('\\146\\42\\69'))");
    try std.testing.expectEqualStrings("{ 42, 69 }", try lua.toString(-1));
    lua.pop(1);

    try do_ret1(lua, "return require'bit'.band(7,12)");
    try std.testing.expectEqualStrings("4", try lua.toString(-1));
    lua.pop(1);
}