tiny.tldr.formats.dispatch

1const std = @import("std");2const root = @import("../root.zig");34const coff = @import("coff.zig");5const elf = @import("elf/root.zig");6const macho = @import("macho.zig");78const elf_object = elf.object;910pub fn parseObject(11    allocator: std.mem.Allocator,12    input: root.Input,13) root.Error!root.Object {14    return switch (try detectObjectFormat(input.bytes)) {15        .elf => try elf.parseObjectMetadata(allocator, input),16        .coff => try coff.parseObjectMetadata(allocator, input.bytes),17        .macho => try macho.parseObjectMetadata(allocator, input.bytes),18        .wasm => error.UnsupportedFormat,19    };20}2122pub fn detectObjectFormat(bytes: []const u8) root.Error!root.model.ObjectFormat {23    if (bytes.len >= 4 and std.mem.eql(u8, bytes[0..4], std.elf.MAGIC)) return .elf;24    if (isMachO(bytes)) return .macho;25    if (coff.isObject(bytes)) return .coff;26    return error.UnsupportedFormat;27}2829pub fn validateInputFormats(inputs: []const root.Input, options: root.LinkOptions) root.Error!void {30    for (inputs) |input| {31        if (root.archive.isArchive(input.bytes)) continue;32        const input_format = try detectObjectFormat(input.bytes);33        if (input_format == options.target.object_format) continue;34        if (options.diagnostics) |diagnostics| {35            diagnostics.recordUnsupportedInputFormat(36                input.name,37                input_format,38                options.target.object_format,39            );40        }41        return error.UnsupportedFormat;42    }43}4445fn isMachO(bytes: []const u8) bool {46    if (bytes.len < 4) return false;47    return switch (std.mem.readInt(u32, bytes[0..4], .little)) {48        std.macho.MH_MAGIC,49        std.macho.MH_CIGAM,50        std.macho.MH_MAGIC_64,51        std.macho.MH_CIGAM_64,52        std.macho.FAT_MAGIC,53        std.macho.FAT_CIGAM,54        std.macho.FAT_MAGIC_64,55        std.macho.FAT_CIGAM_64,56        => true,57        else => false,58    };59}6061test "object format detection recognizes supported object containers" {62    var coff_header = @as([@sizeOf(std.coff.Header)]u8, @splat(0));63    std.mem.writeInt(u16, coff_header[0..2], @backingInt(std.coff.IMAGE.FILE.MACHINE.AMD64), .little);6465    try std.testing.expectEqual(root.model.ObjectFormat.elf, try detectObjectFormat(std.elf.MAGIC ++ "rest"));66    try std.testing.expectEqual(root.model.ObjectFormat.coff, try detectObjectFormat(&coff_header));67    try std.testing.expectError(error.UnsupportedFormat, detectObjectFormat("not an object"));68}6970test "object format detection recognizes Mach-O container magics" {71    const macho_magics = [_]u32{72        std.macho.MH_MAGIC,73        std.macho.MH_CIGAM,74        std.macho.MH_MAGIC_64,75        std.macho.MH_CIGAM_64,76        std.macho.FAT_MAGIC,77        std.macho.FAT_CIGAM,78        std.macho.FAT_MAGIC_64,79        std.macho.FAT_CIGAM_64,80    };8182    for (macho_magics) |magic| {83        var header: [4]u8 = undefined;84        std.mem.writeInt(u32, &header, magic, .little);85        try std.testing.expectEqual(root.model.ObjectFormat.macho, try detectObjectFormat(&header));86    }87}8889test "object parser dispatches ELF metadata" {90    const allocator = std.testing.allocator;91    const text = [_]u8{0xc3};92    const text_index: u16 = 1;93    const bytes = try elf_object.build(allocator, .{94        .sections = &.{elf_object.Section.progbits(".text", &text, std.elf.SHF_EXECINSTR, 16)},95        .symbols = &.{96            elf_object.Symbol.section(text_index),97            elf_object.Symbol.function("_start", text_index, 0, text.len),98        },99    });100    defer allocator.free(bytes);101102    var parsed = try parseObject(allocator, .{ .name = "start.o", .bytes = bytes });103    defer parsed.deinit(allocator);104105    try std.testing.expectEqual(root.model.ObjectFormat.elf, parsed.target.object_format);106    try std.testing.expect(parsed.sections.len > text_index);107    try std.testing.expectEqualStrings(".text", parsed.sections[text_index].name);108    try std.testing.expectEqual(@as(u64, 16), parsed.sections[text_index].alignment);109    for (parsed.symbols) |symbol| {110        if (std.mem.eql(u8, symbol.name, "_start")) {111            try std.testing.expect(symbol.external);112            try std.testing.expect(!symbol.undefined);113            return;114        }115    }116    return error.MissingEntrySymbol;117}

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