dbg.zig

const std = @import("std");
const builtin = @import("builtin");

pub fn main() !void {
    try dbg("{d}", 24);
}

fn dbg(comptime fmt: []const u8, x: anytype) !void {
    comptime std.debug.assert(builtin.mode == .Debug);

    const stderr = std.io.getStdErr().writer();
    const debug_info = try std.debug.getSelfDebugInfo();

    var it = std.debug.StackIterator.init(@returnAddress(), null);
    const address = it.next().?;

    const module = try debug_info.getModuleForAddress(address);

    const symbol_info = try module.getSymbolAtAddress(debug_info.allocator, address);
    defer symbol_info.deinit(debug_info.allocator);

    if (symbol_info.line_info) |li| {
        try stderr.print("[{s}:{d}:{d}]: ", .{ li.file_name, li.line, li.column });
    } else {
        try stderr.writeAll("[???:?:?]: ");
    }
    try stderr.print(fmt, .{x});
    try stderr.writeAll("\n");
}