tiny.sys.backtrace

1const std = @import("std");2const capabilities = @import("capabilities.zig");34pub const required_capabilities = capabilities.pure();56pub fn supportsCapture() bool {7    return std.options.allow_stack_tracing and pointerStorageMatchesAddress();8}910pub fn capture(buffer: []?*anyopaque) usize {11    if (buffer.len == 0) return 0;12    if (!supportsCapture()) return 0;13    const addresses: []usize = @as([*]usize, @ptrCast(@alignCast(buffer.ptr)))[0..buffer.len];14    const trace = std.debug.captureCurrentStackTrace(.{}, addresses);15    for (trace.return_addresses, 0..) |address, index| {16        buffer[index] = @ptrFromInt(address);17    }18    return trace.return_addresses.len;19}2021fn pointerStorageMatchesAddress() bool {22    return @sizeOf(?*anyopaque) == @sizeOf(usize) and @alignOf(?*anyopaque) >= @alignOf(usize);23}2425test "backtrace capture support is queryable" {26    _ = supportsCapture();27}2829test "backtrace capture tolerates empty buffers" {30    try std.testing.expectEqual(@as(usize, 0), capture(&.{}));31}3233test "backtrace capture fits caller buffer" {34    var buffer = @as([16]?*anyopaque, @splat(null));35    const count = capture(&buffer);3637    try std.testing.expect(count <= buffer.len);38    if (count > 0) {39        try std.testing.expect(buffer[0] != null);40    }41}

1pub const backtrace = @import("backtrace.zig");