nuttx.zig

//! LVGL Functions specific to Apache NuttX RTOS
//! https://lupyuen.github.io/articles/lvgl4

/// Import the Zig Standard Library
const std = @import("std");
const builtin = @import("builtin");

///////////////////////////////////////////////////////////////////////////////
//  Panic Handler

/// Called by Zig when it hits a Panic. We print the Panic Message, Stack Trace and halt. See
/// https://andrewkelley.me/post/zig-stack-traces-kernel-panic-bare-bones-os.html
/// https://github.com/ziglang/zig/blob/master/lib/std/builtin.zig#L763-L847
pub fn panic(message: []const u8, _stack_trace: ?*std.builtin.StackTrace) noreturn {
    // Print the Panic Message
    _ = _stack_trace;
    _ = puts("\n!ZIG PANIC!");
    _ = puts(@ptrCast([*c]const u8, message));

    // Print the Stack Trace
    _ = puts("Stack Trace:");
    var it = std.debug.StackIterator.init(@returnAddress(), null);
    while (it.next()) |return_address| {
        _ = printf("%p\n", return_address);
    }

    // Halt
    while (true) {}
}

///////////////////////////////////////////////////////////////////////////////
//  Logging

/// Called by Zig for `std.log.debug`, `std.log.info`, `std.log.err`, ...
/// https://gist.github.com/leecannon/d6f5d7e5af5881c466161270347ce84d
pub fn log(
    comptime _message_level: std.log.Level,
    comptime _scope: @Type(.EnumLiteral),
    comptime format: []const u8,
    args: anytype,
) void {
    _ = _message_level;
    _ = _scope;

    // Format the message
    var buf: [100]u8 = undefined; // Limit to 100 chars
    var slice = std.fmt.bufPrint(&buf, format, args) catch {
        _ = puts("*** log error: buf too small");
        return;
    };

    // Terminate the formatted message with a null
    var buf2: [buf.len + 1:0]u8 = undefined;
    std.mem.copy(u8, buf2[0..slice.len], slice[0..slice.len]);
    buf2[slice.len] = 0;

    // Print the formatted message
    _ = puts(&buf2);
}

///////////////////////////////////////////////////////////////////////////////
//  Imported Functions and Variables

/// For safety, we import these functions ourselves to enforce Null-Terminated Strings.
/// We changed `[*c]const u8` to `[*:0]const u8`
extern fn printf(format: [*:0]const u8, ...) c_int;
extern fn puts(str: [*:0]const u8) c_int;

/// Aliases for Zig Standard Library
const assert = std.debug.assert;
const debug = std.log.debug;