Rust dbg replacements

Brainstorming
1

dbg in Rust is very useful for debugging, but it seems we can’t implement it in Zig, function below is the best solution I can think of, although works, less practical than rust’s.

fn dbg(v: anytype, loc: std.builtin.SourceLocation) @TypeOf(v) {
    std.debug.print("{s}:{d} {any}\n", .{ loc.file, loc.line, v });
    return v;
}

pub fn main() !void {
    const a: usize = 1;
    const b = dbg(a + 1, @src());
    std.debug.print("{d}\n", .{b});
}
2

You don’t need @src(). See: How to print caller's file&line number at runtime? - #2 by dimdin

2 Likes
3

Thanks a lot! This is the updated version of dbg:

pub fn dbg(v: anytype) @TypeOf(v) {
    const debug_info = std.debug.getSelfDebugInfo() catch return v;
    const address = @returnAddress();
    const module = debug_info.getModuleForAddress(address) catch return v;
    const symbol_info = module.getSymbolAtAddress(debug_info.allocator, address) catch return v;
    defer symbol_info.deinit(debug_info.allocator);

    const line, const column = if (symbol_info.line_info) |line_info|
        .{ line_info.line, line_info.column }
    else
        .{ 0, 0 };

    std.debug.print("[{s}:{d}:{d}] -> {any}\n", .{ symbol_info.symbol_name, line, column, v });

    return v;
}
6 Likes