tiny.profiling.code_layout

1const std = @import("std");2const capture = @import("capture");3const pretty = @import("pretty");4const pretty_usage = @import("pretty_usage");5const sys = @import("sys");67const pretty_json = pretty.json;8const max_image_bytes = 512 * 1024 * 1024;910pub const Image = struct {11    path: []const u8,12    fingerprint: capture.code_layout.Fingerprint,13};1415pub const Report = struct {16    images: []const Image,17    distinct_code_digests: usize,1819    pub fn variationObserved(self: Report) bool {20        return self.distinct_code_digests > 1;21    }22};2324const Options = struct {25    paths: []const []const u8,26    json: bool,27};2829pub fn run(allocator: std.mem.Allocator, args: []const []const u8) !u8 {30    const options = try parseArgs(allocator, args);31    const report = try inspect(allocator, options.paths);32    if (options.json) {33        try writeJson(report);34    } else {35        try writeText(allocator, report);36    }37    return 0;38}3940pub fn inspect(allocator: std.mem.Allocator, paths: []const []const u8) !Report {41    var images: std.ArrayList(Image) = .empty;42    for (paths) |path| {43        const fingerprint = fingerprint: {44            const bytes = try sys.fs.readFileAlloc(allocator, path, max_image_bytes);45            defer allocator.free(bytes);46            break :fingerprint try capture.code_layout.fingerprintElf(allocator, bytes);47        };48        try images.append(allocator, .{49            .path = path,50            .fingerprint = fingerprint,51        });52    }53    const owned = try images.toOwnedSlice(allocator);54    return .{55        .images = owned,56        .distinct_code_digests = distinctDigestCount(owned),57    };58}5960fn parseArgs(allocator: std.mem.Allocator, args: []const []const u8) !Options {61    var paths: std.ArrayList([]const u8) = .empty;62    var json = false;63    for (args) |arg| {64        if (std.mem.eql(u8, arg, "--json")) {65            json = true;66        } else if (std.mem.startsWith(u8, arg, "-")) {67            return error.UnknownArgument;68        } else {69            try paths.append(allocator, arg);70        }71    }72    if (paths.items.len == 0) return error.MissingImagePath;73    return .{ .paths = try paths.toOwnedSlice(allocator), .json = json };74}7576fn distinctDigestCount(images: []const Image) usize {77    var distinct: usize = 0;78    for (images, 0..) |image, index| {79        var seen = false;80        for (images[0..index]) |prior| {81            if (std.mem.eql(u8, &image.fingerprint.digest, &prior.fingerprint.digest)) {82                seen = true;83                break;84            }85        }86        if (!seen) distinct += 1;87    }88    return distinct;89}9091fn writeText(allocator: std.mem.Allocator, report: Report) !void {92    const terminal = pretty_usage.Terminal.stdout(allocator, .{});93    try terminal.writeTextFmt("code layout: {d} image(s), {d} distinct code digest(s), variation {s}\n", .{94        report.images.len,95        report.distinct_code_digests,96        if (report.variationObserved()) "observed" else "not observed",97    });98    for (report.images) |image| {99        const hex = image.fingerprint.hex();100        try terminal.writeTextFmt("  {s}  {s}  {d} section(s), {d} byte(s), 0x{x}-0x{x}\n", .{101            hex,102            image.path,103            image.fingerprint.executable_sections,104            image.fingerprint.executable_bytes,105            image.fingerprint.first_address,106            image.fingerprint.last_address_end,107        });108    }109}110111fn writeJson(report: Report) !void {112    var buffer: [8192]u8 = undefined;113    var file_writer = sys.stdio.stdout().writer(std.Options.debug_io, &buffer);114    defer file_writer.interface.flush() catch {};115    var out = pretty_json.Writer.init(&file_writer.interface, .minified);116    try out.beginObject();117    try out.objectField("schema");118    try out.write(capture.code_layout.schema);119    try out.objectField("input_count");120    try out.write(report.images.len);121    try out.objectField("distinct_code_digests");122    try out.write(report.distinct_code_digests);123    try out.objectField("code_variation_observed");124    try out.write(report.variationObserved());125    try out.objectField("images");126    try out.beginArray();127    for (report.images) |image| {128        const hex = image.fingerprint.hex();129        try out.beginObject();130        try out.objectField("path");131        try out.write(image.path);132        try out.objectField("format");133        try out.write("elf");134        try out.objectField("code_digest_sha256");135        try out.write(&hex);136        try out.objectField("executable_sections");137        try out.write(image.fingerprint.executable_sections);138        try out.objectField("executable_bytes");139        try out.write(image.fingerprint.executable_bytes);140        try out.objectField("first_address");141        try out.write(image.fingerprint.first_address);142        try out.objectField("last_address_end");143        try out.write(image.fingerprint.last_address_end);144        try out.endObject();145    }146    try out.endArray();147    try out.endObject();148    try file_writer.interface.writeByte('\n');149}150151test "code layout CLI parses image paths" {152    var arena_state = std.heap.ArenaAllocator.init(std.testing.allocator);153    defer arena_state.deinit();154    const options = try parseArgs(arena_state.allocator(), &.{ "first", "--json", "second" });155    try std.testing.expect(options.json);156    try std.testing.expectEqual(@as(usize, 2), options.paths.len);157    try std.testing.expectEqualStrings("first", options.paths[0]);158    try std.testing.expectEqualStrings("second", options.paths[1]);159    try std.testing.expectError(error.MissingImagePath, parseArgs(arena_state.allocator(), &.{"--json"}));160}

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