//! Here we test our ELF linker for correctness and functionality.
//! Currently, we support linking x86_64 Linux, but in the future we
//! will progressively relax those to exercise more combinations.

pub fn testAll(b: *Build, build_opts: BuildOptions) *Step {
    _ = build_opts;
    const elf_step = b.step("test-elf", "Run ELF tests");

    const default_target = b.resolveTargetQuery(.{
        .cpu_arch = .x86_64, // TODO relax this once ELF linker is able to handle other archs
        .os_tag = .linux,
    });
    const x86_64_musl = b.resolveTargetQuery(.{
        .cpu_arch = .x86_64,
        .os_tag = .linux,
        .abi = .musl,
    });
    const x86_64_gnu = b.resolveTargetQuery(.{
        .cpu_arch = .x86_64,
        .os_tag = .linux,
        .abi = .gnu,
    });
    const aarch64_musl = b.resolveTargetQuery(.{
        .cpu_arch = .aarch64,
        .os_tag = .linux,
        .abi = .musl,
    });
    const riscv64_musl = b.resolveTargetQuery(.{
        .cpu_arch = .riscv64,
        .os_tag = .linux,
        .abi = .musl,
    });

    // Common tests
    for (&[_]std.Target.Cpu.Arch{
        .x86_64,
        .aarch64,
    }) |cpu_arch| {
        const musl_target = b.resolveTargetQuery(.{
            .cpu_arch = cpu_arch,
            .os_tag = .linux,
            .abi = .musl,
        });
        const gnu_target = b.resolveTargetQuery(.{
            .cpu_arch = cpu_arch,
            .os_tag = .linux,
            .abi = .gnu,
        });

        // Exercise linker in -r mode
        elf_step.dependOn(testEmitRelocatable(b, .{ .target = musl_target }));
        elf_step.dependOn(testRelocatableArchive(b, .{ .target = musl_target }));
        elf_step.dependOn(testRelocatableEhFrame(b, .{ .target = musl_target }));
        elf_step.dependOn(testRelocatableNoEhFrame(b, .{ .target = musl_target }));

        // Exercise linker in ar mode
        elf_step.dependOn(testEmitStaticLib(b, .{ .target = musl_target }));

        // Exercise linker with LLVM backend
        // musl tests
        elf_step.dependOn(testAbsSymbols(b, .{ .target = musl_target }));
        elf_step.dependOn(testCommonSymbols(b, .{ .target = musl_target }));
        elf_step.dependOn(testCommonSymbolsInArchive(b, .{ .target = musl_target }));
        elf_step.dependOn(testCommentString(b, .{ .target = musl_target }));
        elf_step.dependOn(testEmptyObject(b, .{ .target = musl_target }));
        elf_step.dependOn(testEntryPoint(b, .{ .target = musl_target }));
        elf_step.dependOn(testGcSections(b, .{ .target = musl_target }));
        elf_step.dependOn(testImageBase(b, .{ .target = musl_target }));
        elf_step.dependOn(testInitArrayOrder(b, .{ .target = musl_target }));
        elf_step.dependOn(testLargeAlignmentExe(b, .{ .target = musl_target }));
        // https://github.com/ziglang/zig/issues/17449
        // elf_step.dependOn(testLargeBss(b, .{ .target = musl_target }));
        elf_step.dependOn(testLinkingC(b, .{ .target = musl_target }));
        elf_step.dependOn(testLinkingCpp(b, .{ .target = musl_target }));
        elf_step.dependOn(testLinkingZig(b, .{ .target = musl_target }));
        elf_step.dependOn(testMergeStrings(b, .{ .target = musl_target }));
        elf_step.dependOn(testMergeStrings2(b, .{ .target = musl_target }));
        // https://github.com/ziglang/zig/issues/17451
        // elf_step.dependOn(testNoEhFrameHdr(b, .{ .target = musl_target }));
        elf_step.dependOn(testTlsStatic(b, .{ .target = musl_target }));
        elf_step.dependOn(testStrip(b, .{ .target = musl_target }));

        // glibc tests
        elf_step.dependOn(testAsNeeded(b, .{ .target = gnu_target }));
        // https://github.com/ziglang/zig/issues/17430
        // elf_step.dependOn(testCanonicalPlt(b, .{ .target = gnu_target }));
        elf_step.dependOn(testCommentString(b, .{ .target = gnu_target }));
        elf_step.dependOn(testCopyrel(b, .{ .target = gnu_target }));
        // https://github.com/ziglang/zig/issues/17430
        // elf_step.dependOn(testCopyrelAlias(b, .{ .target = gnu_target }));
        // https://github.com/ziglang/zig/issues/17430
        // elf_step.dependOn(testCopyrelAlignment(b, .{ .target = gnu_target }));
        elf_step.dependOn(testDsoPlt(b, .{ .target = gnu_target }));
        elf_step.dependOn(testDsoUndef(b, .{ .target = gnu_target }));
        elf_step.dependOn(testExportDynamic(b, .{ .target = gnu_target }));
        elf_step.dependOn(testExportSymbolsFromExe(b, .{ .target = gnu_target }));
        // https://github.com/ziglang/zig/issues/17430
        // elf_step.dependOn(testFuncAddress(b, .{ .target = gnu_target }));
        elf_step.dependOn(testHiddenWeakUndef(b, .{ .target = gnu_target }));
        elf_step.dependOn(testIFuncAlias(b, .{ .target = gnu_target }));
        // https://github.com/ziglang/zig/issues/17430
        // elf_step.dependOn(testIFuncDlopen(b, .{ .target = gnu_target }));
        elf_step.dependOn(testIFuncDso(b, .{ .target = gnu_target }));
        elf_step.dependOn(testIFuncDynamic(b, .{ .target = gnu_target }));
        elf_step.dependOn(testIFuncExport(b, .{ .target = gnu_target }));
        elf_step.dependOn(testIFuncFuncPtr(b, .{ .target = gnu_target }));
        elf_step.dependOn(testIFuncNoPlt(b, .{ .target = gnu_target }));
        // https://github.com/ziglang/zig/issues/17430 ??
        // elf_step.dependOn(testIFuncStatic(b, .{ .target = gnu_target }));
        // elf_step.dependOn(testIFuncStaticPie(b, .{ .target = gnu_target }));
        elf_step.dependOn(testInitArrayOrder(b, .{ .target = gnu_target }));
        elf_step.dependOn(testLargeAlignmentDso(b, .{ .target = gnu_target }));
        elf_step.dependOn(testLargeAlignmentExe(b, .{ .target = gnu_target }));
        elf_step.dependOn(testLargeBss(b, .{ .target = gnu_target }));
        elf_step.dependOn(testLinkOrder(b, .{ .target = gnu_target }));
        elf_step.dependOn(testLdScript(b, .{ .target = gnu_target }));
        elf_step.dependOn(testLdScriptPathError(b, .{ .target = gnu_target }));
        elf_step.dependOn(testLdScriptAllowUndefinedVersion(b, .{ .target = gnu_target, .use_lld = true }));
        elf_step.dependOn(testLdScriptDisallowUndefinedVersion(b, .{ .target = gnu_target, .use_lld = true }));
        // https://github.com/ziglang/zig/issues/17451
        // elf_step.dependOn(testNoEhFrameHdr(b, .{ .target = gnu_target }));
        elf_step.dependOn(testPie(b, .{ .target = gnu_target }));
        elf_step.dependOn(testPltGot(b, .{ .target = gnu_target }));
        elf_step.dependOn(testPreinitArray(b, .{ .target = gnu_target }));
        elf_step.dependOn(testSharedAbsSymbol(b, .{ .target = gnu_target }));
        elf_step.dependOn(testTlsDfStaticTls(b, .{ .target = gnu_target }));
        elf_step.dependOn(testTlsDso(b, .{ .target = gnu_target }));
        elf_step.dependOn(testTlsGd(b, .{ .target = gnu_target }));
        elf_step.dependOn(testTlsGdNoPlt(b, .{ .target = gnu_target }));
        elf_step.dependOn(testTlsGdToIe(b, .{ .target = gnu_target }));
        elf_step.dependOn(testTlsIe(b, .{ .target = gnu_target }));
        elf_step.dependOn(testTlsLargeAlignment(b, .{ .target = gnu_target }));
        elf_step.dependOn(testTlsLargeTbss(b, .{ .target = gnu_target }));
        elf_step.dependOn(testTlsLargeStaticImage(b, .{ .target = gnu_target }));
        elf_step.dependOn(testTlsLd(b, .{ .target = gnu_target }));
        elf_step.dependOn(testTlsLdDso(b, .{ .target = gnu_target }));
        elf_step.dependOn(testTlsLdNoPlt(b, .{ .target = gnu_target }));
        // https://github.com/ziglang/zig/issues/17430
        // elf_step.dependOn(testTlsNoPic(b, .{ .target = gnu_target }));
        elf_step.dependOn(testTlsOffsetAlignment(b, .{ .target = gnu_target }));
        elf_step.dependOn(testTlsPic(b, .{ .target = gnu_target }));
        elf_step.dependOn(testTlsSmallAlignment(b, .{ .target = gnu_target }));
        elf_step.dependOn(testUnknownFileTypeError(b, .{ .target = gnu_target }));
        elf_step.dependOn(testUnresolvedError(b, .{ .target = gnu_target }));
        elf_step.dependOn(testWeakExports(b, .{ .target = gnu_target }));
        elf_step.dependOn(testWeakUndefsDso(b, .{ .target = gnu_target }));
        elf_step.dependOn(testZNow(b, .{ .target = gnu_target }));
        elf_step.dependOn(testZStackSize(b, .{ .target = gnu_target }));
    }

    // x86_64 specific tests
    elf_step.dependOn(testMismatchedCpuArchitectureError(b, .{ .target = x86_64_musl }));
    elf_step.dependOn(testZText(b, .{ .target = x86_64_gnu }));

    // aarch64 specific tests
    elf_step.dependOn(testThunks(b, .{ .target = aarch64_musl }));

    // x86_64 self-hosted backend
    elf_step.dependOn(testCommentString(b, .{ .use_llvm = false, .target = default_target }));
    elf_step.dependOn(testCommentStringStaticLib(b, .{ .use_llvm = false, .target = default_target }));
    elf_step.dependOn(testEmitRelocatable(b, .{ .use_llvm = false, .target = x86_64_musl }));
    elf_step.dependOn(testEmitStaticLibZig(b, .{ .use_llvm = false, .target = x86_64_musl }));
    elf_step.dependOn(testGcSectionsZig(b, .{ .use_llvm = false, .target = default_target }));
    elf_step.dependOn(testLinkingObj(b, .{ .use_llvm = false, .target = default_target }));
    elf_step.dependOn(testLinkingStaticLib(b, .{ .use_llvm = false, .target = default_target }));
    elf_step.dependOn(testLinkingZig(b, .{ .use_llvm = false, .target = default_target }));
    elf_step.dependOn(testImportingDataDynamic(b, .{ .use_llvm = false, .target = x86_64_gnu }));
    elf_step.dependOn(testImportingDataStatic(b, .{ .use_llvm = false, .target = x86_64_musl }));

    // riscv64 linker backend is currently not complete enough to support more
    elf_step.dependOn(testLinkingC(b, .{ .target = riscv64_musl }));

    return elf_step;
}

fn testAbsSymbols(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "abs-symbols", opts);

    const obj = addObject(b, opts, .{
        .name = "obj",
        .asm_source_bytes =
        \\.globl foo
        \\foo = 0x800008
        \\
        ,
    });

    const exe = addExecutable(b, opts, .{
        .name = "test",
        .c_source_bytes =
        \\#include <signal.h>
        \\#include <stdio.h>
        \\#include <stdlib.h>
        \\#include <ucontext.h>
        \\#include <assert.h>
        \\void handler(int signum, siginfo_t *info, void *ptr) {
        \\  assert((size_t)info->si_addr == 0x800008);
        \\  exit(0);
        \\}
        \\extern int foo;
        \\int main() {
        \\  struct sigaction act;
        \\  act.sa_flags = SA_SIGINFO | SA_RESETHAND;
        \\  act.sa_sigaction = handler;
        \\  sigemptyset(&act.sa_mask);
        \\  sigaction(SIGSEGV, &act, 0);
        \\  foo = 5;
        \\  return 0;
        \\}
        ,
    });
    exe.addObject(obj);
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectExitCode(0);
    test_step.dependOn(&run.step);

    return test_step;
}

fn testAsNeeded(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "as-needed", opts);

    const main_o = addObject(b, opts, .{
        .name = "main",
        .c_source_bytes =
        \\#include <stdio.h>
        \\int baz();
        \\int main() {
        \\  printf("%d\n", baz());
        \\  return 0;
        \\}
        \\
        ,
    });
    main_o.linkLibC();

    const libfoo = addSharedLibrary(b, opts, .{ .name = "foo" });
    addCSourceBytes(libfoo, "int foo() { return 42; }", &.{});

    const libbar = addSharedLibrary(b, opts, .{ .name = "bar" });
    addCSourceBytes(libbar, "int bar() { return 42; }", &.{});

    const libbaz = addSharedLibrary(b, opts, .{ .name = "baz" });
    addCSourceBytes(libbaz,
        \\int foo();
        \\int baz() { return foo(); }
    , &.{});

    {
        const exe = addExecutable(b, opts, .{
            .name = "test",
        });
        exe.addObject(main_o);
        exe.linkSystemLibrary2("foo", .{ .needed = true });
        exe.addLibraryPath(libfoo.getEmittedBinDirectory());
        exe.addRPath(libfoo.getEmittedBinDirectory());
        exe.linkSystemLibrary2("bar", .{ .needed = true });
        exe.addLibraryPath(libbar.getEmittedBinDirectory());
        exe.addRPath(libbar.getEmittedBinDirectory());
        exe.linkSystemLibrary2("baz", .{ .needed = true });
        exe.addLibraryPath(libbaz.getEmittedBinDirectory());
        exe.addRPath(libbaz.getEmittedBinDirectory());
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("42\n");
        test_step.dependOn(&run.step);

        const check = exe.checkObject();
        check.checkInDynamicSection();
        check.checkExact("NEEDED libfoo.so");
        check.checkExact("NEEDED libbar.so");
        check.checkExact("NEEDED libbaz.so");
        test_step.dependOn(&check.step);
    }

    {
        const exe = addExecutable(b, opts, .{
            .name = "test",
        });
        exe.addObject(main_o);
        exe.linkSystemLibrary2("foo", .{ .needed = false });
        exe.addLibraryPath(libfoo.getEmittedBinDirectory());
        exe.addRPath(libfoo.getEmittedBinDirectory());
        exe.linkSystemLibrary2("bar", .{ .needed = false });
        exe.addLibraryPath(libbar.getEmittedBinDirectory());
        exe.addRPath(libbar.getEmittedBinDirectory());
        exe.linkSystemLibrary2("baz", .{ .needed = false });
        exe.addLibraryPath(libbaz.getEmittedBinDirectory());
        exe.addRPath(libbaz.getEmittedBinDirectory());
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("42\n");
        test_step.dependOn(&run.step);

        const check = exe.checkObject();
        check.checkInDynamicSection();
        check.checkNotPresent("NEEDED libbar.so");
        check.checkInDynamicSection();
        check.checkExact("NEEDED libfoo.so");
        check.checkExact("NEEDED libbaz.so");
        test_step.dependOn(&check.step);
    }

    return test_step;
}

fn testCanonicalPlt(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "canonical-plt", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "a" });
    addCSourceBytes(dso,
        \\void *foo() {
        \\  return foo;
        \\}
        \\void *bar() {
        \\  return bar;
        \\}
    , &.{});

    const b_o = addObject(b, opts, .{
        .name = "obj",
        .c_source_bytes =
        \\void *bar();
        \\void *baz() {
        \\  return bar;
        \\}
        \\
        ,
        .pic = true,
    });

    const main_o = addObject(b, opts, .{
        .name = "main",
        .c_source_bytes =
        \\#include <assert.h>
        \\void *foo();
        \\void *bar();
        \\void *baz();
        \\int main() {
        \\  assert(foo == foo());
        \\  assert(bar == bar());
        \\  assert(bar == baz());
        \\  return 0;
        \\}
        \\
        ,
        .pic = false,
    });
    main_o.linkLibC();

    const exe = addExecutable(b, opts, .{
        .name = "main",
    });
    exe.addObject(main_o);
    exe.addObject(b_o);
    exe.linkLibrary(dso);
    exe.linkLibC();
    exe.pie = false;

    const run = addRunArtifact(exe);
    run.expectExitCode(0);
    test_step.dependOn(&run.step);

    return test_step;
}

fn testCommentString(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "comment-string", opts);

    const exe = addExecutable(b, opts, .{ .name = "main", .zig_source_bytes = 
    \\pub fn main() void {}
    });

    const check = exe.checkObject();
    check.dumpSection(".comment");
    check.checkContains("zig");
    test_step.dependOn(&check.step);

    return test_step;
}

fn testCommentStringStaticLib(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "comment-string-static-lib", opts);

    const lib = addStaticLibrary(b, opts, .{ .name = "lib", .zig_source_bytes = 
    \\export fn foo() void {}
    });

    const check = lib.checkObject();
    check.dumpSection(".comment");
    check.checkContains("zig");
    test_step.dependOn(&check.step);

    return test_step;
}

fn testCommonSymbols(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "common-symbols", opts);

    const exe = addExecutable(b, opts, .{
        .name = "test",
    });
    addCSourceBytes(exe,
        \\int foo;
        \\int bar;
        \\int baz = 42;
    , &.{"-fcommon"});
    addCSourceBytes(exe,
        \\#include<stdio.h>
        \\int foo;
        \\int bar = 5;
        \\int baz;
        \\int main() {
        \\  printf("%d %d %d\n", foo, bar, baz);
        \\}
    , &.{"-fcommon"});
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("0 5 42\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testCommonSymbolsInArchive(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "common-symbols-in-archive", opts);

    const a_o = addObject(b, opts, .{
        .name = "a",
        .c_source_bytes =
        \\#include <stdio.h>
        \\int foo;
        \\int bar;
        \\extern int baz;
        \\__attribute__((weak)) int two();
        \\int main() {
        \\  printf("%d %d %d %d\n", foo, bar, baz, two ? two() : -1);
        \\}
        \\
        ,
        .c_source_flags = &.{"-fcommon"},
    });
    a_o.linkLibC();

    const b_o = addObject(b, opts, .{
        .name = "b",
        .c_source_bytes = "int foo = 5;",
        .c_source_flags = &.{"-fcommon"},
    });

    {
        const c_o = addObject(b, opts, .{
            .name = "c",
            .c_source_bytes =
            \\int bar;
            \\int two() { return 2; }
            \\
            ,
            .c_source_flags = &.{"-fcommon"},
        });

        const d_o = addObject(b, opts, .{
            .name = "d",
            .c_source_bytes = "int baz;",
            .c_source_flags = &.{"-fcommon"},
        });

        const lib = addStaticLibrary(b, opts, .{ .name = "lib" });
        lib.addObject(b_o);
        lib.addObject(c_o);
        lib.addObject(d_o);

        const exe = addExecutable(b, opts, .{
            .name = "test",
        });
        exe.addObject(a_o);
        exe.linkLibrary(lib);
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("5 0 0 -1\n");
        test_step.dependOn(&run.step);
    }

    {
        const e_o = addObject(b, opts, .{
            .name = "e",
            .c_source_bytes =
            \\int bar = 0;
            \\int baz = 7;
            \\int two() { return 2; }
            ,
            .c_source_flags = &.{"-fcommon"},
        });

        const lib = addStaticLibrary(b, opts, .{ .name = "lib" });
        lib.addObject(b_o);
        lib.addObject(e_o);

        const exe = addExecutable(b, opts, .{
            .name = "test",
        });
        exe.addObject(a_o);
        exe.linkLibrary(lib);
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("5 0 7 2\n");
        test_step.dependOn(&run.step);
    }

    return test_step;
}

fn testCopyrel(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "copyrel", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "a" });
    addCSourceBytes(dso,
        \\int foo = 3;
        \\int bar = 5;
    , &.{});

    const exe = addExecutable(b, opts, .{
        .name = "main",
        .c_source_bytes =
        \\#include<stdio.h>
        \\extern int foo, bar;
        \\int main() {
        \\  printf("%d %d\n", foo, bar);
        \\  return 0;
        \\}
        ,
    });
    exe.linkLibrary(dso);
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("3 5\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testCopyrelAlias(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "copyrel-alias", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "a" });
    addCSourceBytes(dso,
        \\int bruh = 31;
        \\int foo = 42;
        \\extern int bar __attribute__((alias("foo")));
        \\extern int baz __attribute__((alias("foo")));
    , &.{});

    const exe = addExecutable(b, opts, .{
        .name = "main",
        .pic = false,
    });
    addCSourceBytes(exe,
        \\#include<stdio.h>
        \\extern int foo;
        \\extern int *get_bar();
        \\int main() {
        \\  printf("%d %d %d\n", foo, *get_bar(), &foo == get_bar());
        \\  return 0;
        \\}
    , &.{});
    addCSourceBytes(exe,
        \\extern int bar;
        \\int *get_bar() { return &bar; }
    , &.{});
    exe.linkLibrary(dso);
    exe.linkLibC();
    exe.pie = false;

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("42 42 1\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testCopyrelAlignment(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "copyrel-alignment", opts);

    const a_so = addSharedLibrary(b, opts, .{ .name = "a" });
    addCSourceBytes(a_so, "__attribute__((aligned(32))) int foo = 5;", &.{});

    const b_so = addSharedLibrary(b, opts, .{ .name = "b" });
    addCSourceBytes(b_so, "__attribute__((aligned(8))) int foo = 5;", &.{});

    const c_so = addSharedLibrary(b, opts, .{ .name = "c" });
    addCSourceBytes(c_so, "__attribute__((aligned(256))) int foo = 5;", &.{});

    const obj = addObject(b, opts, .{
        .name = "main",
        .c_source_bytes =
        \\#include <stdio.h>
        \\extern int foo;
        \\int main() { printf("%d\n", foo); }
        \\
        ,
        .pic = false,
    });
    obj.linkLibC();

    const exp_stdout = "5\n";

    {
        const exe = addExecutable(b, opts, .{ .name = "main" });
        exe.addObject(obj);
        exe.linkLibrary(a_so);
        exe.linkLibC();
        exe.pie = false;

        const run = addRunArtifact(exe);
        run.expectStdOutEqual(exp_stdout);
        test_step.dependOn(&run.step);

        const check = exe.checkObject();
        check.checkInHeaders();
        check.checkExact("section headers");
        check.checkExact("name .copyrel");
        check.checkExact("addralign 20");
        test_step.dependOn(&check.step);
    }

    {
        const exe = addExecutable(b, opts, .{ .name = "main" });
        exe.addObject(obj);
        exe.linkLibrary(b_so);
        exe.linkLibC();
        exe.pie = false;

        const run = addRunArtifact(exe);
        run.expectStdOutEqual(exp_stdout);
        test_step.dependOn(&run.step);

        const check = exe.checkObject();
        check.checkInHeaders();
        check.checkExact("section headers");
        check.checkExact("name .copyrel");
        check.checkExact("addralign 8");
        test_step.dependOn(&check.step);
    }

    {
        const exe = addExecutable(b, opts, .{ .name = "main" });
        exe.addObject(obj);
        exe.linkLibrary(c_so);
        exe.linkLibC();
        exe.pie = false;

        const run = addRunArtifact(exe);
        run.expectStdOutEqual(exp_stdout);
        test_step.dependOn(&run.step);

        const check = exe.checkObject();
        check.checkInHeaders();
        check.checkExact("section headers");
        check.checkExact("name .copyrel");
        check.checkExact("addralign 100");
        test_step.dependOn(&check.step);
    }

    return test_step;
}

fn testDsoPlt(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "dso-plt", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "dso" });
    addCSourceBytes(dso,
        \\#include<stdio.h>
        \\void world() {
        \\  printf("world\n");
        \\}
        \\void real_hello() {
        \\  printf("Hello ");
        \\  world();
        \\}
        \\void hello() {
        \\  real_hello();
        \\}
    , &.{});
    dso.linkLibC();

    const exe = addExecutable(b, opts, .{ .name = "test" });
    addCSourceBytes(exe,
        \\#include<stdio.h>
        \\void world() {
        \\  printf("WORLD\n");
        \\}
        \\void hello();
        \\int main() {
        \\  hello();
        \\}
    , &.{});
    exe.linkLibrary(dso);
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("Hello WORLD\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testDsoUndef(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "dso-undef", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "dso" });
    addCSourceBytes(dso,
        \\extern int foo;
        \\int bar = 5;
        \\int baz() { return foo; }
    , &.{});
    dso.linkLibC();

    const obj = addObject(b, opts, .{
        .name = "obj",
        .c_source_bytes = "int foo = 3;",
    });

    const lib = addStaticLibrary(b, opts, .{ .name = "lib" });
    lib.addObject(obj);

    const exe = addExecutable(b, opts, .{ .name = "test" });
    exe.linkLibrary(dso);
    exe.linkLibrary(lib);
    addCSourceBytes(exe,
        \\extern int bar;
        \\int main() {
        \\  return bar - 5;
        \\}
    , &.{});
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectExitCode(0);
    test_step.dependOn(&run.step);

    const check = exe.checkObject();
    check.checkInDynamicSymtab();
    check.checkContains("foo");
    test_step.dependOn(&check.step);

    return test_step;
}

fn testEmitRelocatable(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "emit-relocatable", opts);

    const a_o = addObject(b, opts, .{ .name = "a", .zig_source_bytes = 
    \\const std = @import("std");
    \\extern var bar: i32;
    \\export fn foo() i32 {
    \\   return bar;
    \\}
    \\export fn printFoo() void {
    \\    std.debug.print("foo={d}\n", .{foo()});
    \\}
    });
    a_o.linkLibC();

    const b_o = addObject(b, opts, .{ .name = "b", .c_source_bytes = 
    \\#include <stdio.h>
    \\int bar = 42;
    \\void printBar() {
    \\  fprintf(stderr, "bar=%d\n", bar);
    \\}
    });
    b_o.linkLibC();

    const c_o = addObject(b, opts, .{ .name = "c" });
    c_o.addObject(a_o);
    c_o.addObject(b_o);

    const exe = addExecutable(b, opts, .{ .name = "test", .zig_source_bytes = 
    \\const std = @import("std");
    \\extern fn printFoo() void;
    \\extern fn printBar() void;
    \\pub fn main() void {
    \\    printFoo();
    \\    printBar();
    \\}
    });
    exe.addObject(c_o);
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdErrEqual(
        \\foo=42
        \\bar=42
        \\
    );
    test_step.dependOn(&run.step);

    return test_step;
}

fn testEmitStaticLib(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "emit-static-lib", opts);

    const obj1 = addObject(b, opts, .{
        .name = "obj1",
        .c_source_bytes =
        \\int foo = 0;
        \\int bar = 2;
        \\int fooBar() {
        \\  return foo + bar;
        \\}
        ,
    });

    const obj2 = addObject(b, opts, .{
        .name = "obj2",
        .c_source_bytes = "int tentative;",
        .c_source_flags = &.{"-fcommon"},
    });

    const obj3 = addObject(b, opts, .{
        .name = "a_very_long_file_name_so_that_it_ends_up_in_strtab",
        .zig_source_bytes =
        \\fn weakFoo() callconv(.C) usize {
        \\    return 42;
        \\}
        \\export var strongBar: usize = 100;
        \\comptime {
        \\    @export(weakFoo, .{ .name = "weakFoo", .linkage = .weak });
        \\    @export(strongBar, .{ .name = "strongBarAlias", .linkage = .strong });
        \\}
        ,
    });

    const lib = addStaticLibrary(b, opts, .{ .name = "lib" });
    lib.addObject(obj1);
    lib.addObject(obj2);
    lib.addObject(obj3);

    const check = lib.checkObject();
    check.checkInArchiveSymtab();
    check.checkExactPath("in object", obj1.getEmittedBin());
    check.checkExact("foo");
    check.checkInArchiveSymtab();
    check.checkExactPath("in object", obj1.getEmittedBin());
    check.checkExact("bar");
    check.checkInArchiveSymtab();
    check.checkExactPath("in object", obj1.getEmittedBin());
    check.checkExact("fooBar");
    check.checkInArchiveSymtab();
    check.checkExactPath("in object", obj2.getEmittedBin());
    check.checkExact("tentative");
    check.checkInArchiveSymtab();
    check.checkExactPath("in object", obj3.getEmittedBin());
    check.checkExact("weakFoo");
    check.checkInArchiveSymtab();
    check.checkExactPath("in object", obj3.getEmittedBin());
    check.checkExact("strongBar");
    check.checkInArchiveSymtab();
    check.checkExactPath("in object", obj3.getEmittedBin());
    check.checkExact("strongBarAlias");
    test_step.dependOn(&check.step);

    return test_step;
}

fn testEmitStaticLibZig(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "emit-static-lib-zig", opts);

    const obj1 = addObject(b, opts, .{
        .name = "obj1",
        .zig_source_bytes =
        \\export var foo: i32 = 42;
        \\export var bar: i32 = 2;
        ,
    });

    const lib = addStaticLibrary(b, opts, .{
        .name = "lib",
        .zig_source_bytes =
        \\extern var foo: i32;
        \\extern var bar: i32;
        \\export fn fooBar() i32 {
        \\  return foo + bar;
        \\}
        ,
    });
    lib.addObject(obj1);

    const exe = addExecutable(b, opts, .{
        .name = "test",
        .zig_source_bytes =
        \\const std = @import("std");
        \\extern fn fooBar() i32;
        \\pub fn main() void {
        \\  std.debug.print("{d}", .{fooBar()});
        \\}
        ,
    });
    exe.linkLibrary(lib);

    const run = addRunArtifact(exe);
    run.expectStdErrEqual("44");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testEmptyObject(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "empty-object", opts);

    const exe = addExecutable(b, opts, .{ .name = "test" });
    addCSourceBytes(exe, "int main() { return 0; }", &.{});
    addCSourceBytes(exe, "", &.{});
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectExitCode(0);
    test_step.dependOn(&run.step);

    return test_step;
}

fn testEntryPoint(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "entry-point", opts);

    const a_o = addObject(b, opts, .{
        .name = "a",
        .asm_source_bytes =
        \\.globl foo, bar
        \\foo = 0x1000
        \\bar = 0x2000
        \\
        ,
    });

    const b_o = addObject(b, opts, .{
        .name = "b",
        .c_source_bytes = "int main() { return 0; }",
    });

    {
        const exe = addExecutable(b, opts, .{ .name = "main" });
        exe.addObject(a_o);
        exe.addObject(b_o);
        exe.entry = .{ .symbol_name = "foo" };

        const check = exe.checkObject();
        check.checkInHeaders();
        check.checkExact("header");
        check.checkExact("entry 1000");
        test_step.dependOn(&check.step);
    }

    {
        // TODO looks like not assigning a unique name to this executable will
        // cause an artifact collision taking the cached executable from the above
        // step instead of generating a new one.
        const exe = addExecutable(b, opts, .{ .name = "other" });
        exe.addObject(a_o);
        exe.addObject(b_o);
        exe.entry = .{ .symbol_name = "bar" };

        const check = exe.checkObject();
        check.checkInHeaders();
        check.checkExact("header");
        check.checkExact("entry 2000");
        test_step.dependOn(&check.step);
    }

    return test_step;
}

fn testExportDynamic(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "export-dynamic", opts);

    const obj = addObject(b, opts, .{
        .name = "obj",
        .asm_source_bytes =
        \\.text
        \\  .globl foo
        \\  .hidden foo
        \\foo:
        \\  nop
        \\  .globl bar
        \\bar:
        \\  nop
        \\  .globl _start
        \\_start:
        \\  nop
        \\
        ,
    });

    const dso = addSharedLibrary(b, opts, .{ .name = "a" });
    addCSourceBytes(dso, "int baz = 10;", &.{});

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\extern int baz;
        \\int callBaz() {
        \\  return baz;
        \\}
    , &.{});
    exe.addObject(obj);
    exe.linkLibrary(dso);
    exe.rdynamic = true;

    const check = exe.checkObject();
    check.checkInDynamicSymtab();
    check.checkContains("bar");
    check.checkInDynamicSymtab();
    check.checkContains("_start");
    test_step.dependOn(&check.step);

    return test_step;
}

fn testExportSymbolsFromExe(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "export-symbols-from-exe", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "a" });
    addCSourceBytes(dso,
        \\void expfn1();
        \\void expfn2() {}
        \\
        \\void foo() {
        \\  expfn1();
        \\}
    , &.{});

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\void expfn1() {}
        \\void expfn2() {}
        \\void foo();
        \\
        \\int main() {
        \\  expfn1();
        \\  expfn2();
        \\  foo();
        \\}
    , &.{});
    exe.linkLibrary(dso);
    exe.linkLibC();

    const check = exe.checkObject();
    check.checkInDynamicSymtab();
    check.checkContains("expfn2");
    check.checkInDynamicSymtab();
    check.checkContains("expfn1");
    test_step.dependOn(&check.step);

    return test_step;
}

fn testFuncAddress(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "func-address", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "a" });
    addCSourceBytes(dso, "void fn() {}", &.{});

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\#include <assert.h>
        \\typedef void Func();
        \\void fn();
        \\Func *const ptr = fn;
        \\int main() {
        \\  assert(fn == ptr);
        \\}
    , &.{});
    exe.linkLibrary(dso);
    exe.root_module.pic = false;
    exe.pie = false;

    const run = addRunArtifact(exe);
    run.expectExitCode(0);
    test_step.dependOn(&run.step);

    return test_step;
}

fn testGcSections(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "gc-sections", opts);

    const obj = addObject(b, opts, .{
        .name = "obj",
        .cpp_source_bytes =
        \\#include <stdio.h>
        \\int two() { return 2; }
        \\int live_var1 = 1;
        \\int live_var2 = two();
        \\int dead_var1 = 3;
        \\int dead_var2 = 4;
        \\void live_fn1() {}
        \\void live_fn2() { live_fn1(); }
        \\void dead_fn1() {}
        \\void dead_fn2() { dead_fn1(); }
        \\int main() {
        \\  printf("%d %d\n", live_var1, live_var2);
        \\  live_fn2();
        \\}
        ,
    });
    obj.link_function_sections = true;
    obj.link_data_sections = true;
    obj.linkLibC();
    obj.linkLibCpp();

    {
        const exe = addExecutable(b, opts, .{ .name = "test" });
        exe.addObject(obj);
        exe.link_gc_sections = false;
        exe.linkLibC();
        exe.linkLibCpp();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("1 2\n");
        test_step.dependOn(&run.step);

        const check = exe.checkObject();
        check.checkInSymtab();
        check.checkContains("live_var1");
        check.checkInSymtab();
        check.checkContains("live_var2");
        check.checkInSymtab();
        check.checkContains("dead_var1");
        check.checkInSymtab();
        check.checkContains("dead_var2");
        check.checkInSymtab();
        check.checkContains("live_fn1");
        check.checkInSymtab();
        check.checkContains("live_fn2");
        check.checkInSymtab();
        check.checkContains("dead_fn1");
        check.checkInSymtab();
        check.checkContains("dead_fn2");
        test_step.dependOn(&check.step);
    }

    {
        const exe = addExecutable(b, opts, .{ .name = "test" });
        exe.addObject(obj);
        exe.link_gc_sections = true;
        exe.linkLibC();
        exe.linkLibCpp();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("1 2\n");
        test_step.dependOn(&run.step);

        const check = exe.checkObject();
        check.checkInSymtab();
        check.checkContains("live_var1");
        check.checkInSymtab();
        check.checkContains("live_var2");
        check.checkInSymtab();
        check.checkNotPresent("dead_var1");
        check.checkInSymtab();
        check.checkNotPresent("dead_var2");
        check.checkInSymtab();
        check.checkContains("live_fn1");
        check.checkInSymtab();
        check.checkContains("live_fn2");
        check.checkInSymtab();
        check.checkNotPresent("dead_fn1");
        check.checkInSymtab();
        check.checkNotPresent("dead_fn2");
        test_step.dependOn(&check.step);
    }

    return test_step;
}

fn testGcSectionsZig(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "gc-sections-zig", opts);

    const obj = addObject(b, .{
        .target = opts.target,
        .use_llvm = true,
    }, .{
        .name = "obj",
        .c_source_bytes =
        \\int live_var1 = 1;
        \\int live_var2 = 2;
        \\int dead_var1 = 3;
        \\int dead_var2 = 4;
        \\void live_fn1() {}
        \\void live_fn2() { live_fn1(); }
        \\void dead_fn1() {}
        \\void dead_fn2() { dead_fn1(); }
        ,
    });
    obj.link_function_sections = true;
    obj.link_data_sections = true;

    {
        const exe = addExecutable(b, opts, .{
            .name = "test1",
            .zig_source_bytes =
            \\const std = @import("std");
            \\extern var live_var1: i32;
            \\extern var live_var2: i32;
            \\extern fn live_fn2() void;
            \\pub fn main() void {
            \\    const stdout = std.io.getStdOut();
            \\    stdout.writer().print("{d} {d}\n", .{ live_var1, live_var2 }) catch unreachable;
            \\    live_fn2();
            \\}
            ,
        });
        exe.addObject(obj);
        exe.link_gc_sections = false;

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("1 2\n");
        test_step.dependOn(&run.step);

        const check = exe.checkObject();
        check.checkInSymtab();
        check.checkContains("live_var1");
        check.checkInSymtab();
        check.checkContains("live_var2");
        check.checkInSymtab();
        check.checkContains("dead_var1");
        check.checkInSymtab();
        check.checkContains("dead_var2");
        check.checkInSymtab();
        check.checkContains("live_fn1");
        check.checkInSymtab();
        check.checkContains("live_fn2");
        check.checkInSymtab();
        check.checkContains("dead_fn1");
        check.checkInSymtab();
        check.checkContains("dead_fn2");
        test_step.dependOn(&check.step);
    }

    {
        const exe = addExecutable(b, opts, .{
            .name = "test2",
            .zig_source_bytes =
            \\const std = @import("std");
            \\extern var live_var1: i32;
            \\extern var live_var2: i32;
            \\extern fn live_fn2() void;
            \\pub fn main() void {
            \\    const stdout = std.io.getStdOut();
            \\    stdout.writer().print("{d} {d}\n", .{ live_var1, live_var2 }) catch unreachable;
            \\    live_fn2();
            \\}
            ,
        });
        exe.addObject(obj);
        exe.link_gc_sections = true;

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("1 2\n");
        test_step.dependOn(&run.step);

        const check = exe.checkObject();
        check.checkInSymtab();
        check.checkContains("live_var1");
        check.checkInSymtab();
        check.checkContains("live_var2");
        check.checkInSymtab();
        check.checkNotPresent("dead_var1");
        check.checkInSymtab();
        check.checkNotPresent("dead_var2");
        check.checkInSymtab();
        check.checkContains("live_fn1");
        check.checkInSymtab();
        check.checkContains("live_fn2");
        check.checkInSymtab();
        check.checkNotPresent("dead_fn1");
        check.checkInSymtab();
        check.checkNotPresent("dead_fn2");
        test_step.dependOn(&check.step);
    }

    return test_step;
}

fn testHiddenWeakUndef(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "hidden-weak-undef", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "a" });
    addCSourceBytes(dso,
        \\__attribute__((weak, visibility("hidden"))) void foo();
        \\void bar() { foo(); }
    , &.{});

    const check = dso.checkObject();
    check.checkInDynamicSymtab();
    check.checkNotPresent("foo");
    check.checkInDynamicSymtab();
    check.checkContains("bar");
    test_step.dependOn(&check.step);

    return test_step;
}

fn testIFuncAlias(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "ifunc-alias", opts);

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\#include <assert.h>
        \\void foo() {}
        \\int bar() __attribute__((ifunc("resolve_bar")));
        \\void *resolve_bar() { return foo; }
        \\void *bar2 = bar;
        \\int main() {
        \\  assert(bar == bar2);
        \\}
    , &.{});
    exe.root_module.pic = true;
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectExitCode(0);
    test_step.dependOn(&run.step);

    return test_step;
}

fn testIFuncDlopen(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "ifunc-dlopen", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "a" });
    addCSourceBytes(dso,
        \\__attribute__((ifunc("resolve_foo")))
        \\void foo(void);
        \\static void real_foo(void) {
        \\}
        \\typedef void Func();
        \\static Func *resolve_foo(void) {
        \\  return real_foo;
        \\}
    , &.{});

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\#include <dlfcn.h>
        \\#include <assert.h>
        \\#include <stdlib.h>
        \\typedef void Func();
        \\void foo(void);
        \\int main() {
        \\  void *handle = dlopen(NULL, RTLD_NOW);
        \\  Func *p = dlsym(handle, "foo");
        \\
        \\  foo();
        \\  p();
        \\  assert(foo == p);
        \\}
    , &.{});
    exe.linkLibrary(dso);
    exe.linkLibC();
    exe.linkSystemLibrary2("dl", .{});
    exe.root_module.pic = false;
    exe.pie = false;

    const run = addRunArtifact(exe);
    run.expectExitCode(0);
    test_step.dependOn(&run.step);

    return test_step;
}

fn testIFuncDso(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "ifunc-dso", opts);

    const dso = addSharedLibrary(b, opts, .{
        .name = "a",
        .c_source_bytes =
        \\#include<stdio.h>
        \\__attribute__((ifunc("resolve_foobar")))
        \\void foobar(void);
        \\static void real_foobar(void) {
        \\  printf("Hello world\n");
        \\}
        \\typedef void Func();
        \\static Func *resolve_foobar(void) {
        \\  return real_foobar;
        \\}
        ,
    });
    dso.linkLibC();

    const exe = addExecutable(b, opts, .{
        .name = "main",
        .c_source_bytes =
        \\void foobar(void);
        \\int main() {
        \\  foobar();
        \\}
        ,
    });
    exe.linkLibrary(dso);

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("Hello world\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testIFuncDynamic(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "ifunc-dynamic", opts);

    const main_c =
        \\#include <stdio.h>
        \\__attribute__((ifunc("resolve_foobar")))
        \\static void foobar(void);
        \\static void real_foobar(void) {
        \\  printf("Hello world\n");
        \\}
        \\typedef void Func();
        \\static Func *resolve_foobar(void) {
        \\  return real_foobar;
        \\}
        \\int main() {
        \\  foobar();
        \\}
    ;

    {
        const exe = addExecutable(b, opts, .{ .name = "main" });
        addCSourceBytes(exe, main_c, &.{});
        exe.linkLibC();
        exe.link_z_lazy = true;

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("Hello world\n");
        test_step.dependOn(&run.step);
    }
    {
        const exe = addExecutable(b, opts, .{ .name = "other" });
        addCSourceBytes(exe, main_c, &.{});
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("Hello world\n");
        test_step.dependOn(&run.step);
    }

    return test_step;
}

fn testIFuncExport(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "ifunc-export", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "a" });
    addCSourceBytes(dso,
        \\#include <stdio.h>
        \\__attribute__((ifunc("resolve_foobar")))
        \\void foobar(void);
        \\void real_foobar(void) {
        \\  printf("Hello world\n");
        \\}
        \\typedef void Func();
        \\Func *resolve_foobar(void) {
        \\  return real_foobar;
        \\}
    , &.{});
    dso.linkLibC();

    const check = dso.checkObject();
    check.checkInDynamicSymtab();
    check.checkContains("IFUNC GLOBAL DEFAULT foobar");
    test_step.dependOn(&check.step);

    return test_step;
}

fn testIFuncFuncPtr(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "ifunc-func-ptr", opts);

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\typedef int Fn();
        \\int foo() __attribute__((ifunc("resolve_foo")));
        \\int real_foo() { return 3; }
        \\Fn *resolve_foo(void) {
        \\  return real_foo;
        \\}
    , &.{});
    addCSourceBytes(exe,
        \\typedef int Fn();
        \\int foo();
        \\Fn *get_foo() { return foo; }
    , &.{});
    addCSourceBytes(exe,
        \\#include <stdio.h>
        \\typedef int Fn();
        \\Fn *get_foo();
        \\int main() {
        \\  Fn *f = get_foo();
        \\  printf("%d\n", f());
        \\}
    , &.{});
    exe.root_module.pic = true;
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("3\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testIFuncNoPlt(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "ifunc-noplt", opts);

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\#include <stdio.h>
        \\__attribute__((ifunc("resolve_foo")))
        \\void foo(void);
        \\void hello(void) {
        \\  printf("Hello world\n");
        \\}
        \\typedef void Fn();
        \\Fn *resolve_foo(void) {
        \\  return hello;
        \\}
        \\int main() {
        \\  foo();
        \\}
    , &.{"-fno-plt"});
    exe.root_module.pic = true;
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("Hello world\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testIFuncStatic(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "ifunc-static", opts);

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\#include <stdio.h>
        \\void foo() __attribute__((ifunc("resolve_foo")));
        \\void hello() {
        \\  printf("Hello world\n");
        \\}
        \\void *resolve_foo() {
        \\  return hello;
        \\}
        \\int main() {
        \\  foo();
        \\  return 0;
        \\}
    , &.{});
    exe.linkLibC();
    exe.linkage = .static;

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("Hello world\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testIFuncStaticPie(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "ifunc-static-pie", opts);

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\#include <stdio.h>
        \\void foo() __attribute__((ifunc("resolve_foo")));
        \\void hello() {
        \\  printf("Hello world\n");
        \\}
        \\void *resolve_foo() {
        \\  return hello;
        \\}
        \\int main() {
        \\  foo();
        \\  return 0;
        \\}
    , &.{});
    exe.linkage = .static;
    exe.root_module.pic = true;
    exe.pie = true;
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("Hello world\n");
    test_step.dependOn(&run.step);

    const check = exe.checkObject();
    check.checkInHeaders();
    check.checkExact("header");
    check.checkExact("type DYN");
    check.checkInHeaders();
    check.checkExact("section headers");
    check.checkExact("name .dynamic");
    check.checkInHeaders();
    check.checkExact("section headers");
    check.checkNotPresent("name .interp");
    test_step.dependOn(&check.step);

    return test_step;
}

fn testImageBase(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "image-base", opts);

    {
        const exe = addExecutable(b, opts, .{ .name = "main1" });
        addCSourceBytes(exe,
            \\#include <stdio.h>
            \\int main() {
            \\  printf("Hello World!\n");
            \\  return 0;
            \\}
        , &.{});
        exe.linkLibC();
        exe.image_base = 0x8000000;

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("Hello World!\n");
        test_step.dependOn(&run.step);

        const check = exe.checkObject();
        check.checkInHeaders();
        check.checkExact("header");
        check.checkExtract("entry {addr}");
        check.checkComputeCompare("addr", .{ .op = .gte, .value = .{ .literal = 0x8000000 } });
        test_step.dependOn(&check.step);
    }

    {
        const exe = addExecutable(b, opts, .{ .name = "main2" });
        addCSourceBytes(exe, "void _start() {}", &.{});
        exe.image_base = 0xffffffff8000000;

        const check = exe.checkObject();
        check.checkInHeaders();
        check.checkExact("header");
        check.checkExtract("entry {addr}");
        check.checkComputeCompare("addr", .{ .op = .gte, .value = .{ .literal = 0xffffffff8000000 } });
        test_step.dependOn(&check.step);
    }

    return test_step;
}

fn testImportingDataDynamic(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "importing-data-dynamic", opts);

    const dso = addSharedLibrary(b, .{
        .target = opts.target,
        .optimize = opts.optimize,
        .use_llvm = true,
    }, .{
        .name = "a",
        .c_source_bytes = "int foo = 42;",
    });

    const main = addExecutable(b, opts, .{
        .name = "main",
        .zig_source_bytes =
        \\extern var foo: i32;
        \\pub fn main() void {
        \\    @import("std").debug.print("{d}\n", .{foo});
        \\}
        ,
        .strip = true, // TODO temp hack
    });
    main.pie = true;
    main.linkLibrary(dso);
    main.linkLibC();

    const run = addRunArtifact(main);
    run.expectStdErrEqual("42\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testImportingDataStatic(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "importing-data-static", opts);

    const obj = addObject(b, .{
        .target = opts.target,
        .optimize = opts.optimize,
        .use_llvm = true,
    }, .{
        .name = "a",
        .c_source_bytes = "int foo = 42;",
    });

    const lib = addStaticLibrary(b, .{
        .target = opts.target,
        .optimize = opts.optimize,
        .use_llvm = true,
    }, .{
        .name = "a",
    });
    lib.addObject(obj);

    const main = addExecutable(b, opts, .{
        .name = "main",
        .zig_source_bytes =
        \\extern var foo: i32;
        \\pub fn main() void {
        \\    @import("std").debug.print("{d}\n", .{foo});
        \\}
        ,
        .strip = true, // TODO temp hack
    });
    main.linkLibrary(lib);
    main.linkLibC();

    const run = addRunArtifact(main);
    run.expectStdErrEqual("42\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testInitArrayOrder(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "init-array-order", opts);

    const a_o = addObject(b, opts, .{
        .name = "a",
        .c_source_bytes =
        \\#include <stdio.h>
        \\__attribute__((constructor(10000))) void init4() { printf("1"); }
        ,
    });
    a_o.linkLibC();

    const b_o = addObject(b, opts, .{
        .name = "b",
        .c_source_bytes =
        \\#include <stdio.h>
        \\__attribute__((constructor(1000))) void init3() { printf("2"); }
        ,
    });
    b_o.linkLibC();

    const c_o = addObject(b, opts, .{
        .name = "c",
        .c_source_bytes =
        \\#include <stdio.h>
        \\__attribute__((constructor)) void init1() { printf("3"); }
        ,
    });
    c_o.linkLibC();

    const d_o = addObject(b, opts, .{
        .name = "d",
        .c_source_bytes =
        \\#include <stdio.h>
        \\__attribute__((constructor)) void init2() { printf("4"); }
        ,
    });
    d_o.linkLibC();

    const e_o = addObject(b, opts, .{
        .name = "e",
        .c_source_bytes =
        \\#include <stdio.h>
        \\__attribute__((destructor(10000))) void fini4() { printf("5"); }
        ,
    });
    e_o.linkLibC();

    const f_o = addObject(b, opts, .{
        .name = "f",
        .c_source_bytes =
        \\#include <stdio.h>
        \\__attribute__((destructor(1000))) void fini3() { printf("6"); }
        ,
    });
    f_o.linkLibC();

    const g_o = addObject(b, opts, .{
        .name = "g",
        .c_source_bytes =
        \\#include <stdio.h>
        \\__attribute__((destructor)) void fini1() { printf("7"); }
        ,
    });
    g_o.linkLibC();

    const h_o = addObject(b, opts, .{ .name = "h", .c_source_bytes = 
    \\#include <stdio.h>
    \\__attribute__((destructor)) void fini2() { printf("8"); }
    });
    h_o.linkLibC();

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe, "int main() { return 0; }", &.{});
    exe.addObject(a_o);
    exe.addObject(b_o);
    exe.addObject(c_o);
    exe.addObject(d_o);
    exe.addObject(e_o);
    exe.addObject(f_o);
    exe.addObject(g_o);
    exe.addObject(h_o);

    if (opts.target.result.isGnuLibC()) {
        // TODO I think we need to clarify our use of `-fPIC -fPIE` flags for different targets
        exe.pie = true;
    }

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("21348756");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testLargeAlignmentDso(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "large-alignment-dso", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "dso" });
    addCSourceBytes(dso,
        \\#include <stdio.h>
        \\#include <stdint.h>
        \\void hello() __attribute__((aligned(32768), section(".hello")));
        \\void world() __attribute__((aligned(32768), section(".world")));
        \\void hello() {
        \\  printf("Hello");
        \\}
        \\void world() {
        \\  printf(" world");
        \\}
        \\void greet() {
        \\  hello();
        \\  world();
        \\}
    , &.{});
    dso.link_function_sections = true;
    dso.linkLibC();

    const check = dso.checkObject();
    check.checkInSymtab();
    check.checkExtract("{addr1} {size1} {shndx1} FUNC GLOBAL DEFAULT hello");
    check.checkInSymtab();
    check.checkExtract("{addr2} {size2} {shndx2} FUNC GLOBAL DEFAULT world");
    check.checkComputeCompare("addr1 16 %", .{ .op = .eq, .value = .{ .literal = 0 } });
    check.checkComputeCompare("addr2 16 %", .{ .op = .eq, .value = .{ .literal = 0 } });
    test_step.dependOn(&check.step);

    const exe = addExecutable(b, opts, .{ .name = "test" });
    addCSourceBytes(exe,
        \\void greet();
        \\int main() { greet(); }
    , &.{});
    exe.linkLibrary(dso);
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("Hello world");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testLargeAlignmentExe(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "large-alignment-exe", opts);

    const exe = addExecutable(b, opts, .{ .name = "test" });
    addCSourceBytes(exe,
        \\#include <stdio.h>
        \\#include <stdint.h>
        \\
        \\void hello() __attribute__((aligned(32768), section(".hello")));
        \\void world() __attribute__((aligned(32768), section(".world")));
        \\
        \\void hello() {
        \\  printf("Hello");
        \\}
        \\
        \\void world() {
        \\  printf(" world");
        \\}
        \\
        \\int main() {
        \\  hello();
        \\  world();
        \\}
    , &.{});
    exe.link_function_sections = true;
    exe.linkLibC();

    const check = exe.checkObject();
    check.checkInSymtab();
    check.checkExtract("{addr1} {size1} {shndx1} FUNC LOCAL DEFAULT hello");
    check.checkInSymtab();
    check.checkExtract("{addr2} {size2} {shndx2} FUNC LOCAL DEFAULT world");
    check.checkComputeCompare("addr1 16 %", .{ .op = .eq, .value = .{ .literal = 0 } });
    check.checkComputeCompare("addr2 16 %", .{ .op = .eq, .value = .{ .literal = 0 } });
    test_step.dependOn(&check.step);

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("Hello world");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testLargeBss(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "large-bss", opts);

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\char arr[0x100000000];
        \\int main() {
        \\  return arr[2000];
        \\}
    , &.{});
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectExitCode(0);
    test_step.dependOn(&run.step);

    return test_step;
}

fn testLinkOrder(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "link-order", opts);

    const obj = addObject(b, opts, .{
        .name = "obj",
        .c_source_bytes = "void foo() {}",
        .pic = true,
    });

    const dso = addSharedLibrary(b, opts, .{ .name = "a" });
    dso.addObject(obj);

    const lib = addStaticLibrary(b, opts, .{ .name = "b" });
    lib.addObject(obj);

    const main_o = addObject(b, opts, .{
        .name = "main",
        .c_source_bytes =
        \\void foo();
        \\int main() {
        \\  foo();
        \\}
        ,
    });

    // https://github.com/ziglang/zig/issues/17450
    // {
    //     const exe = addExecutable(b, opts, .{ .name = "main1"});
    //     exe.addObject(main_o);
    //     exe.linkSystemLibrary2("a", .{});
    //     exe.addLibraryPath(dso.getEmittedBinDirectory());
    //     exe.addRPath(dso.getEmittedBinDirectory());
    //     exe.linkSystemLibrary2("b", .{});
    //     exe.addLibraryPath(lib.getEmittedBinDirectory());
    //     exe.addRPath(lib.getEmittedBinDirectory());
    //     exe.linkLibC();

    //     const check = exe.checkObject();
    //     check.checkInDynamicSection();
    //     check.checkContains("libb.so");
    //     test_step.dependOn(&check.step);
    // }

    {
        const exe = addExecutable(b, opts, .{ .name = "main2" });
        exe.addObject(main_o);
        exe.linkSystemLibrary2("b", .{});
        exe.addLibraryPath(lib.getEmittedBinDirectory());
        exe.addRPath(lib.getEmittedBinDirectory());
        exe.linkSystemLibrary2("a", .{});
        exe.addLibraryPath(dso.getEmittedBinDirectory());
        exe.addRPath(dso.getEmittedBinDirectory());
        exe.linkLibC();

        const check = exe.checkObject();
        check.checkInDynamicSection();
        check.checkNotPresent("libb.so");
        test_step.dependOn(&check.step);
    }

    return test_step;
}

fn testLdScript(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "ld-script", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "bar" });
    addCSourceBytes(dso, "int foo() { return 42; }", &.{});

    const scripts = WriteFile.create(b);
    _ = scripts.add("liba.so", "INPUT(libfoo.so)");
    _ = scripts.add("libfoo.so", "GROUP(AS_NEEDED(-lbar))");

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\int foo();
        \\int main() {
        \\  return foo() - 42;
        \\}
    , &.{});
    exe.linkSystemLibrary2("a", .{});
    exe.addLibraryPath(scripts.getDirectory());
    exe.addLibraryPath(dso.getEmittedBinDirectory());
    exe.addRPath(dso.getEmittedBinDirectory());
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectExitCode(0);
    test_step.dependOn(&run.step);

    return test_step;
}

fn testLdScriptPathError(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "ld-script-path-error", opts);

    const scripts = WriteFile.create(b);
    _ = scripts.add("liba.so", "INPUT(libfoo.so)");

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe, "int main() { return 0; }", &.{});
    exe.linkSystemLibrary2("a", .{});
    exe.addLibraryPath(scripts.getDirectory());
    exe.linkLibC();

    expectLinkErrors(
        exe,
        test_step,
        .{
            .contains = "error: missing library dependency: GNU ld script '/?/liba.so' requires 'libfoo.so', but file not found",
        },
    );

    return test_step;
}

fn testLdScriptAllowUndefinedVersion(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "ld-script-allow-undefined-version", opts);

    const so = addSharedLibrary(b, opts, .{
        .name = "add",
        .zig_source_bytes =
        \\export fn add(a: i32, b: i32) i32 {
        \\    return a + b;
        \\}
        ,
    });
    const ld = b.addWriteFiles().add("add.ld", "VERSION { ADD_1.0 { global: add; sub; local: *; }; }");
    so.setLinkerScript(ld);
    so.linker_allow_undefined_version = true;

    const exe = addExecutable(b, opts, .{
        .name = "main",
        .zig_source_bytes =
        \\const std = @import("std");
        \\extern fn add(a: i32, b: i32) i32;
        \\pub fn main() void {
        \\    std.debug.print("{d}\n", .{add(1, 2)});
        \\}
        ,
    });
    exe.linkLibrary(so);
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdErrEqual("3\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testLdScriptDisallowUndefinedVersion(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "ld-script-disallow-undefined-version", opts);

    const so = addSharedLibrary(b, opts, .{
        .name = "add",
        .zig_source_bytes =
        \\export fn add(a: i32, b: i32) i32 {
        \\    return a + b;
        \\}
        ,
    });
    const ld = b.addWriteFiles().add("add.ld", "VERSION { ADD_1.0 { global: add; sub; local: *; }; }");
    so.setLinkerScript(ld);
    so.linker_allow_undefined_version = false;

    expectLinkErrors(
        so,
        test_step,
        .{
            .contains = "error: ld.lld: version script assignment of 'ADD_1.0' to symbol 'sub' failed: symbol not defined",
        },
    );

    return test_step;
}

fn testMismatchedCpuArchitectureError(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "mismatched-cpu-architecture-error", opts);

    const obj = addObject(b, .{
        .target = b.resolveTargetQuery(.{ .cpu_arch = .aarch64, .os_tag = .linux, .abi = .gnu }),
    }, .{
        .name = "a",
        .c_source_bytes = "int foo;",
        .strip = true,
    });

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\extern int foo;
        \\int main() {
        \\  return foo;
        \\}
    , &.{});
    exe.addObject(obj);
    exe.linkLibC();

    expectLinkErrors(exe, test_step, .{ .exact = &.{
        "invalid cpu architecture: aarch64",
        "note: while parsing /?/a.o",
    } });

    return test_step;
}

fn testLinkingC(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "linking-c", opts);

    const exe = addExecutable(b, opts, .{ .name = "test" });
    addCSourceBytes(exe,
        \\#include <stdio.h>
        \\int main() {
        \\  printf("Hello World!\n");
        \\  return 0;
        \\}
    , &.{});
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("Hello World!\n");
    test_step.dependOn(&run.step);

    const check = exe.checkObject();
    check.checkInHeaders();
    check.checkExact("header");
    check.checkExact("type EXEC");
    check.checkInHeaders();
    check.checkExact("section headers");
    check.checkNotPresent("name .dynamic");
    test_step.dependOn(&check.step);

    return test_step;
}

fn testLinkingCpp(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "linking-cpp", opts);

    const exe = addExecutable(b, opts, .{ .name = "test" });
    addCppSourceBytes(exe,
        \\#include <iostream>
        \\int main() {
        \\  std::cout << "Hello World!" << std::endl;
        \\  return 0;
        \\}
    , &.{});
    exe.linkLibC();
    exe.linkLibCpp();

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("Hello World!\n");
    test_step.dependOn(&run.step);

    const check = exe.checkObject();
    check.checkInHeaders();
    check.checkExact("header");
    check.checkExact("type EXEC");
    check.checkInHeaders();
    check.checkExact("section headers");
    check.checkNotPresent("name .dynamic");
    test_step.dependOn(&check.step);

    return test_step;
}

fn testLinkingObj(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "linking-obj", opts);

    const obj = addObject(b, opts, .{
        .name = "aobj",
        .zig_source_bytes =
        \\extern var mod: usize;
        \\export fn callMe() usize {
        \\    return me * mod;
        \\}
        \\var me: usize = 42;
        ,
    });

    const exe = addExecutable(b, opts, .{
        .name = "testobj",
        .zig_source_bytes =
        \\const std = @import("std");
        \\extern fn callMe() usize;
        \\export var mod: usize = 2;
        \\pub fn main() void {
        \\    std.debug.print("{d}\n", .{callMe()});
        \\}
        ,
    });
    exe.addObject(obj);

    const run = addRunArtifact(exe);
    run.expectStdErrEqual("84\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testLinkingStaticLib(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "linking-static-lib", opts);

    const obj = addObject(b, opts, .{
        .name = "bobj",
        .zig_source_bytes = "export var bar: i32 = -42;",
    });

    const lib = addStaticLibrary(b, opts, .{
        .name = "alib",
        .zig_source_bytes =
        \\export fn foo() i32 {
        \\    return 42;
        \\}
        ,
    });
    lib.addObject(obj);

    const exe = addExecutable(b, opts, .{
        .name = "testlib",
        .zig_source_bytes =
        \\const std = @import("std");
        \\extern fn foo() i32;
        \\extern var bar: i32;
        \\pub fn main() void {
        \\    std.debug.print("{d}\n", .{foo() + bar});
        \\}
        ,
    });
    exe.linkLibrary(lib);

    const run = addRunArtifact(exe);
    run.expectStdErrEqual("0\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testLinkingZig(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "linking-zig-static", opts);

    const exe = addExecutable(b, opts, .{
        .name = "test",
        .zig_source_bytes =
        \\pub fn main() void {
        \\    @import("std").debug.print("Hello World!\n", .{});
        \\}
        ,
    });

    const run = addRunArtifact(exe);
    run.expectStdErrEqual("Hello World!\n");
    test_step.dependOn(&run.step);

    const check = exe.checkObject();
    check.checkInHeaders();
    check.checkExact("header");
    check.checkExact("type EXEC");
    check.checkInHeaders();
    check.checkExact("section headers");
    check.checkNotPresent("name .dynamic");
    test_step.dependOn(&check.step);

    return test_step;
}

// Adapted from https://github.com/rui314/mold/blob/main/test/elf/mergeable-strings.sh
fn testMergeStrings(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "merge-strings", opts);

    const obj1 = addObject(b, opts, .{ .name = "a.o" });
    addCSourceBytes(obj1,
        \\#include <uchar.h>
        \\#include <wchar.h>
        \\char *cstr1 = "foo";
        \\wchar_t *wide1 = L"foo";
        \\char16_t *utf16_1 = u"foo";
        \\char32_t *utf32_1 = U"foo";
    , &.{"-O2"});
    obj1.linkLibC();

    const obj2 = addObject(b, opts, .{ .name = "b.o" });
    addCSourceBytes(obj2,
        \\#include <stdio.h>
        \\#include <assert.h>
        \\#include <uchar.h>
        \\#include <wchar.h>
        \\extern char *cstr1;
        \\extern wchar_t *wide1;
        \\extern char16_t *utf16_1;
        \\extern char32_t *utf32_1;
        \\char *cstr2 = "foo";
        \\wchar_t *wide2 = L"foo";
        \\char16_t *utf16_2 = u"foo";
        \\char32_t *utf32_2 = U"foo";
        \\int main() {
        \\ printf("%p %p %p %p %p %p %p %p\n",
        \\ cstr1, cstr2, wide1, wide2, utf16_1, utf16_2, utf32_1, utf32_2);
        \\  assert((void*)cstr1 ==   (void*)cstr2);
        \\  assert((void*)wide1 ==   (void*)wide2);
        \\  assert((void*)utf16_1 == (void*)utf16_2);
        \\  assert((void*)utf32_1 == (void*)utf32_2);
        \\  assert((void*)wide1 ==   (void*)utf32_1);
        \\  assert((void*)cstr1 !=   (void*)wide1);
        \\  assert((void*)cstr1 !=   (void*)utf32_1);
        \\  assert((void*)wide1 !=   (void*)utf16_1);
        \\}
    , &.{"-O2"});
    obj2.linkLibC();

    const exe = addExecutable(b, opts, .{ .name = "main" });
    exe.addObject(obj1);
    exe.addObject(obj2);
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectExitCode(0);
    test_step.dependOn(&run.step);

    return test_step;
}

fn testMergeStrings2(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "merge-strings2", opts);

    const obj1 = addObject(b, opts, .{ .name = "a", .zig_source_bytes = 
    \\const std = @import("std");
    \\export fn foo() void {
    \\    var arr: [5:0]u16 = [_:0]u16{ 1, 2, 3, 4, 5 };
    \\    const slice = std.mem.sliceTo(&arr, 3);
    \\    std.testing.expectEqualSlices(u16, arr[0..2], slice) catch unreachable;
    \\}
    });

    const obj2 = addObject(b, opts, .{ .name = "b", .zig_source_bytes = 
    \\const std = @import("std");
    \\extern fn foo() void;
    \\pub fn main() void {
    \\    foo();
    \\    var arr: [5:0]u16 = [_:0]u16{ 5, 4, 3, 2, 1 };
    \\    const slice = std.mem.sliceTo(&arr, 3);
    \\    std.testing.expectEqualSlices(u16, arr[0..2], slice) catch unreachable;
    \\}
    });

    {
        const exe = addExecutable(b, opts, .{ .name = "main1" });
        exe.addObject(obj1);
        exe.addObject(obj2);

        const run = addRunArtifact(exe);
        run.expectExitCode(0);
        test_step.dependOn(&run.step);

        const check = exe.checkObject();
        check.dumpSection(".rodata.str");
        check.checkContains("\x01\x00\x02\x00\x03\x00\x04\x00\x05\x00\x00\x00");
        check.dumpSection(".rodata.str");
        check.checkContains("\x05\x00\x04\x00\x03\x00\x02\x00\x01\x00\x00\x00");
        test_step.dependOn(&check.step);
    }

    {
        const obj3 = addObject(b, opts, .{ .name = "c" });
        obj3.addObject(obj1);
        obj3.addObject(obj2);

        const exe = addExecutable(b, opts, .{ .name = "main2" });
        exe.addObject(obj3);

        const run = addRunArtifact(exe);
        run.expectExitCode(0);
        test_step.dependOn(&run.step);

        const check = exe.checkObject();
        check.dumpSection(".rodata.str");
        check.checkContains("\x01\x00\x02\x00\x03\x00\x04\x00\x05\x00\x00\x00");
        check.dumpSection(".rodata.str");
        check.checkContains("\x05\x00\x04\x00\x03\x00\x02\x00\x01\x00\x00\x00");
        test_step.dependOn(&check.step);
    }

    return test_step;
}

fn testNoEhFrameHdr(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "no-eh-frame-hdr", opts);

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe, "int main() { return 0; }", &.{});
    exe.link_eh_frame_hdr = false;
    exe.linkLibC();

    const check = exe.checkObject();
    check.checkInHeaders();
    check.checkExact("section headers");
    check.checkNotPresent("name .eh_frame_hdr");
    test_step.dependOn(&check.step);

    return test_step;
}

fn testPie(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "hello-pie", opts);

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\#include <stdio.h>
        \\int main() {
        \\  printf("Hello!\n");
        \\  return 0;
        \\}
    , &.{});
    exe.linkLibC();
    exe.root_module.pic = true;
    exe.pie = true;

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("Hello!\n");
    test_step.dependOn(&run.step);

    const check = exe.checkObject();
    check.checkInHeaders();
    check.checkExact("header");
    check.checkExact("type DYN");
    check.checkInHeaders();
    check.checkExact("section headers");
    check.checkExact("name .dynamic");
    test_step.dependOn(&check.step);

    return test_step;
}

fn testPltGot(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "plt-got", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "a" });
    addCSourceBytes(dso,
        \\#include <stdio.h>
        \\void ignore(void *foo) {}
        \\void hello() {
        \\  printf("Hello world\n");
        \\}
    , &.{});
    dso.linkLibC();

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\void ignore(void *);
        \\int hello();
        \\void foo() { ignore(hello); }
        \\int main() { hello(); }
    , &.{});
    exe.linkLibrary(dso);
    exe.root_module.pic = true;
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("Hello world\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testPreinitArray(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "preinit-array", opts);

    {
        const obj = addObject(b, opts, .{
            .name = "obj",
            .c_source_bytes = "void _start() {}",
        });

        const exe = addExecutable(b, opts, .{ .name = "main1" });
        exe.addObject(obj);

        const check = exe.checkObject();
        check.checkInDynamicSection();
        check.checkNotPresent("PREINIT_ARRAY");
    }

    {
        const exe = addExecutable(b, opts, .{ .name = "main2" });
        addCSourceBytes(exe,
            \\void preinit_fn() {}
            \\int main() {}
            \\__attribute__((section(".preinit_array")))
            \\void *preinit[] = { preinit_fn };
        , &.{});
        exe.linkLibC();

        const check = exe.checkObject();
        check.checkInDynamicSection();
        check.checkContains("PREINIT_ARRAY");
    }

    return test_step;
}

fn testRelocatableArchive(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "relocatable-archive", opts);

    const obj1 = addObject(b, opts, .{
        .name = "obj1",
        .c_source_bytes =
        \\void bar();
        \\void foo() {
        \\  bar();
        \\}
        ,
    });

    const obj2 = addObject(b, opts, .{
        .name = "obj2",
        .c_source_bytes =
        \\void bar() {}
        ,
    });

    const obj3 = addObject(b, opts, .{
        .name = "obj3",
        .c_source_bytes =
        \\void baz();
        ,
    });

    const obj4 = addObject(b, opts, .{
        .name = "obj4",
        .c_source_bytes =
        \\void foo();
        \\int main() {
        \\  foo();
        \\}
        ,
    });

    const lib = addStaticLibrary(b, opts, .{ .name = "lib" });
    lib.addObject(obj1);
    lib.addObject(obj2);
    lib.addObject(obj3);

    const obj5 = addObject(b, opts, .{
        .name = "obj5",
    });
    obj5.addObject(obj4);
    obj5.linkLibrary(lib);

    const check = obj5.checkObject();
    check.checkInSymtab();
    check.checkContains("foo");
    check.checkInSymtab();
    check.checkContains("bar");
    check.checkInSymtab();
    check.checkNotPresent("baz");
    test_step.dependOn(&check.step);

    return test_step;
}

fn testRelocatableEhFrame(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "relocatable-eh-frame", opts);

    {
        const obj = addObject(b, opts, .{
            .name = "obj1",
            .cpp_source_bytes =
            \\#include <stdexcept>
            \\int try_me() {
            \\  throw std::runtime_error("Oh no!");
            \\}
            ,
        });
        addCppSourceBytes(obj,
            \\extern int try_me();
            \\int try_again() {
            \\  return try_me();
            \\}
        , &.{});
        obj.linkLibCpp();

        const exe = addExecutable(b, opts, .{ .name = "test1" });
        addCppSourceBytes(exe,
            \\#include <iostream>
            \\#include <stdexcept>
            \\extern int try_again();
            \\int main() {
            \\  try {
            \\    try_again();
            \\  } catch (const std::exception &e) {
            \\    std::cout << "exception=" << e.what();
            \\  }
            \\  return 0;
            \\}
        , &.{});
        exe.addObject(obj);
        exe.linkLibCpp();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("exception=Oh no!");
        test_step.dependOn(&run.step);
    }

    {
        // Let's make the object file COMDAT group heavy!
        const obj = addObject(b, opts, .{
            .name = "obj2",
            .cpp_source_bytes =
            \\#include <stdexcept>
            \\int try_me() {
            \\  throw std::runtime_error("Oh no!");
            \\}
            ,
        });
        addCppSourceBytes(obj,
            \\extern int try_me();
            \\int try_again() {
            \\  return try_me();
            \\}
        , &.{});
        addCppSourceBytes(obj,
            \\#include <iostream>
            \\#include <stdexcept>
            \\extern int try_again();
            \\int main() {
            \\  try {
            \\    try_again();
            \\  } catch (const std::exception &e) {
            \\    std::cout << "exception=" << e.what();
            \\  }
            \\  return 0;
            \\}
        , &.{});
        obj.linkLibCpp();

        const exe = addExecutable(b, opts, .{ .name = "test2" });
        exe.addObject(obj);
        exe.linkLibCpp();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("exception=Oh no!");
        test_step.dependOn(&run.step);
    }

    return test_step;
}

// Adapted from https://github.com/rui314/mold/blob/main/test/elf/relocatable-mergeable-sections.sh
fn testRelocatableMergeStrings(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "relocatable-merge-strings", opts);

    const obj1 = addObject(b, opts, .{ .name = "a", .asm_source_bytes = 
    \\.section .rodata.str1.1,"aMS",@progbits,1
    \\val1:
    \\.ascii "Hello \0"
    \\.section .rodata.str1.1,"aMS",@progbits,1
    \\val5:
    \\.ascii "World \0"
    \\.section .rodata.str1.1,"aMS",@progbits,1
    \\val7:
    \\.ascii "Hello \0"
    });

    const obj2 = addObject(b, opts, .{ .name = "b" });
    obj2.addObject(obj1);

    const check = obj2.checkObject();
    check.dumpSection(".rodata.str1.1");
    check.checkExact("Hello \x00World \x00");
    test_step.dependOn(&check.step);

    return test_step;
}

fn testRelocatableNoEhFrame(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "relocatable-no-eh-frame", opts);

    const obj1 = addObject(b, opts, .{
        .name = "obj1",
        .c_source_bytes = "int bar() { return 42; }",
        .c_source_flags = &.{
            "-fno-unwind-tables",
            "-fno-asynchronous-unwind-tables",
        },
    });

    const obj2 = addObject(b, opts, .{
        .name = "obj2",
    });
    obj2.addObject(obj1);

    const check1 = obj1.checkObject();
    check1.checkInHeaders();
    check1.checkExact("section headers");
    check1.checkNotPresent(".eh_frame");
    test_step.dependOn(&check1.step);

    const check2 = obj2.checkObject();
    check2.checkInHeaders();
    check2.checkExact("section headers");
    check2.checkNotPresent(".eh_frame");
    test_step.dependOn(&check2.step);

    return test_step;
}

fn testSharedAbsSymbol(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "shared-abs-symbol", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "a" });
    addAsmSourceBytes(dso,
        \\.globl foo
        \\foo = 3;
    );

    const obj = addObject(b, opts, .{
        .name = "obj",
        .c_source_bytes =
        \\#include <stdio.h>
        \\extern char foo;
        \\int main() { printf("foo=%p\n", &foo); }
        ,
        .pic = true,
    });
    obj.linkLibC();

    {
        const exe = addExecutable(b, opts, .{ .name = "main1" });
        exe.addObject(obj);
        exe.linkLibrary(dso);
        exe.pie = true;

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("foo=0x3\n");
        test_step.dependOn(&run.step);

        const check = exe.checkObject();
        check.checkInHeaders();
        check.checkExact("header");
        check.checkExact("type DYN");
        // TODO fix/improve in CheckObject
        // check.checkInSymtab();
        // check.checkNotPresent("foo");
        test_step.dependOn(&check.step);
    }

    // https://github.com/ziglang/zig/issues/17430
    // {
    //     const exe = addExecutable(b, opts, .{ .name = "main2"});
    //     exe.addObject(obj);
    //     exe.linkLibrary(dso);
    //     exe.pie = false;

    //     const run = addRunArtifact(exe);
    //     run.expectStdOutEqual("foo=0x3\n");
    //     test_step.dependOn(&run.step);

    //     const check = exe.checkObject();
    //     check.checkInHeaders();
    //     check.checkExact("header");
    //     check.checkExact("type EXEC");
    //     // TODO fix/improve in CheckObject
    //     // check.checkInSymtab();
    //     // check.checkNotPresent("foo");
    //     test_step.dependOn(&check.step);
    // }

    return test_step;
}

fn testStrip(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "strip", opts);

    const obj = addObject(b, opts, .{
        .name = "obj",
        .c_source_bytes =
        \\#include <stdio.h>
        \\int main() {
        \\  printf("Hello!\n");
        \\  return 0;
        \\}
        ,
    });
    obj.linkLibC();

    {
        const exe = addExecutable(b, opts, .{ .name = "main1" });
        exe.addObject(obj);
        exe.root_module.strip = false;
        exe.linkLibC();

        const check = exe.checkObject();
        check.checkInHeaders();
        check.checkExact("section headers");
        check.checkExact("name .debug_info");
        test_step.dependOn(&check.step);
    }

    {
        const exe = addExecutable(b, opts, .{ .name = "main2" });
        exe.addObject(obj);
        exe.root_module.strip = true;
        exe.linkLibC();

        const check = exe.checkObject();
        check.checkInHeaders();
        check.checkExact("section headers");
        check.checkNotPresent("name .debug_info");
        test_step.dependOn(&check.step);
    }

    return test_step;
}

fn testThunks(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "thunks", opts);

    const src =
        \\#include <stdio.h>
        \\__attribute__((aligned(0x8000000))) int bar() {
        \\  return 42;
        \\}
        \\int foobar();
        \\int foo() {
        \\  return bar() - foobar();
        \\}
        \\__attribute__((aligned(0x8000000))) int foobar() {
        \\  return 42;
        \\}
        \\int main() {
        \\  printf("bar=%d, foo=%d, foobar=%d", bar(), foo(), foobar());
        \\  return foo();
        \\}
    ;

    {
        const exe = addExecutable(b, opts, .{ .name = "main", .c_source_bytes = src });
        exe.link_function_sections = true;
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("bar=42, foo=0, foobar=42");
        run.expectExitCode(0);
        test_step.dependOn(&run.step);
    }

    {
        const exe = addExecutable(b, opts, .{ .name = "main2", .c_source_bytes = src });
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("bar=42, foo=0, foobar=42");
        run.expectExitCode(0);
        test_step.dependOn(&run.step);
    }

    return test_step;
}

fn testTlsDfStaticTls(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "tls-df-static-tls", opts);

    const obj = addObject(b, opts, .{
        .name = "obj",
        .c_source_bytes =
        \\static _Thread_local int foo = 5;
        \\void mutate() { ++foo; }
        \\int bar() { return foo; }
        ,
        .c_source_flags = &.{"-ftls-model=initial-exec"},
        .pic = true,
    });

    {
        const dso = addSharedLibrary(b, opts, .{ .name = "a" });
        dso.addObject(obj);
        // dso.link_relax = true;

        const check = dso.checkObject();
        check.checkInDynamicSection();
        check.checkContains("STATIC_TLS");
        test_step.dependOn(&check.step);
    }

    // TODO add -Wl,--no-relax
    // {
    //     const dso = addSharedLibrary(b, opts, .{ .name = "a"});
    //     dso.addObject(obj);
    //     dso.link_relax = false;

    //     const check = dso.checkObject();
    //     check.checkInDynamicSection();
    //     check.checkContains("STATIC_TLS");
    //     test_step.dependOn(&check.step);
    // }

    return test_step;
}

fn testTlsDso(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "tls-dso", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "a" });
    addCSourceBytes(dso,
        \\extern _Thread_local int foo;
        \\_Thread_local int bar;
        \\int get_foo1() { return foo; }
        \\int get_bar1() { return bar; }
    , &.{});

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\#include <stdio.h>
        \\_Thread_local int foo;
        \\extern _Thread_local int bar;
        \\int get_foo1();
        \\int get_bar1();
        \\int get_foo2() { return foo; }
        \\int get_bar2() { return bar; }
        \\int main() {
        \\  foo = 5;
        \\  bar = 3;
        \\  printf("%d %d %d %d %d %d\n",
        \\         foo, bar,
        \\         get_foo1(), get_bar1(),
        \\         get_foo2(), get_bar2());
        \\  return 0;
        \\}
    , &.{});
    exe.linkLibrary(dso);
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("5 3 5 3 5 3\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testTlsGd(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "tls-gd", opts);

    const main_o = addObject(b, opts, .{
        .name = "main",
        .c_source_bytes =
        \\#include <stdio.h>
        \\__attribute__((tls_model("global-dynamic"))) static _Thread_local int x1 = 1;
        \\__attribute__((tls_model("global-dynamic"))) static _Thread_local int x2;
        \\__attribute__((tls_model("global-dynamic"))) extern _Thread_local int x3;
        \\__attribute__((tls_model("global-dynamic"))) extern _Thread_local int x4;
        \\int get_x5();
        \\int get_x6();
        \\int main() {
        \\  x2 = 2;
        \\  printf("%d %d %d %d %d %d\n", x1, x2, x3, x4, get_x5(), get_x6());
        \\  return 0;
        \\}
        ,
        .pic = true,
    });
    main_o.linkLibC();

    const a_o = addObject(b, opts, .{
        .name = "a",
        .c_source_bytes =
        \\__attribute__((tls_model("global-dynamic"))) _Thread_local int x3 = 3;
        \\__attribute__((tls_model("global-dynamic"))) static _Thread_local int x5 = 5;
        \\int get_x5() { return x5; }
        ,
        .pic = true,
    });

    const b_o = addObject(b, opts, .{
        .name = "b",
        .c_source_bytes =
        \\__attribute__((tls_model("global-dynamic"))) _Thread_local int x4 = 4;
        \\__attribute__((tls_model("global-dynamic"))) static _Thread_local int x6 = 6;
        \\int get_x6() { return x6; }
        ,
        .pic = true,
    });

    const exp_stdout = "1 2 3 4 5 6\n";

    const dso1 = addSharedLibrary(b, opts, .{ .name = "a" });
    dso1.addObject(a_o);

    const dso2 = addSharedLibrary(b, opts, .{ .name = "b" });
    dso2.addObject(b_o);
    // dso2.link_relax = false; // TODO

    {
        const exe = addExecutable(b, opts, .{ .name = "main1" });
        exe.addObject(main_o);
        exe.linkLibrary(dso1);
        exe.linkLibrary(dso2);

        const run = addRunArtifact(exe);
        run.expectStdOutEqual(exp_stdout);
        test_step.dependOn(&run.step);
    }

    {
        const exe = addExecutable(b, opts, .{ .name = "main2" });
        exe.addObject(main_o);
        // exe.link_relax = false; // TODO
        exe.linkLibrary(dso1);
        exe.linkLibrary(dso2);

        const run = addRunArtifact(exe);
        run.expectStdOutEqual(exp_stdout);
        test_step.dependOn(&run.step);
    }

    // https://github.com/ziglang/zig/issues/17430 ??
    // {
    //     const exe = addExecutable(b, opts, .{ .name = "main3"});
    //     exe.addObject(main_o);
    //     exe.linkLibrary(dso1);
    //     exe.linkLibrary(dso2);
    //     exe.linkage = .static;

    //     const run = addRunArtifact(exe);
    //     run.expectStdOutEqual(exp_stdout);
    //     test_step.dependOn(&run.step);
    // }

    // {
    //     const exe = addExecutable(b, opts, .{ .name = "main4"});
    //     exe.addObject(main_o);
    //     // exe.link_relax = false; // TODO
    //     exe.linkLibrary(dso1);
    //     exe.linkLibrary(dso2);
    //     exe.linkage = .static;

    //     const run = addRunArtifact(exe);
    //     run.expectStdOutEqual(exp_stdout);
    //     test_step.dependOn(&run.step);
    // }

    return test_step;
}

fn testTlsGdNoPlt(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "tls-gd-no-plt", opts);

    const obj = addObject(b, opts, .{
        .name = "obj",
        .c_source_bytes =
        \\#include <stdio.h>
        \\__attribute__((tls_model("global-dynamic"))) static _Thread_local int x1 = 1;
        \\__attribute__((tls_model("global-dynamic"))) static _Thread_local int x2;
        \\__attribute__((tls_model("global-dynamic"))) extern _Thread_local int x3;
        \\__attribute__((tls_model("global-dynamic"))) extern _Thread_local int x4;
        \\int get_x5();
        \\int get_x6();
        \\int main() {
        \\  x2 = 2;
        \\
        \\  printf("%d %d %d %d %d %d\n", x1, x2, x3, x4, get_x5(), get_x6());
        \\  return 0;
        \\}
        ,
        .c_source_flags = &.{"-fno-plt"},
        .pic = true,
    });
    obj.linkLibC();

    const a_so = addSharedLibrary(b, opts, .{ .name = "a" });
    addCSourceBytes(a_so,
        \\__attribute__((tls_model("global-dynamic"))) _Thread_local int x3 = 3;
        \\__attribute__((tls_model("global-dynamic"))) static _Thread_local int x5 = 5;
        \\int get_x5() { return x5; }
    , &.{"-fno-plt"});

    const b_so = addSharedLibrary(b, opts, .{ .name = "b" });
    addCSourceBytes(b_so,
        \\__attribute__((tls_model("global-dynamic"))) _Thread_local int x4 = 4;
        \\__attribute__((tls_model("global-dynamic"))) static _Thread_local int x6 = 6;
        \\int get_x6() { return x6; }
    , &.{"-fno-plt"});
    // b_so.link_relax = false; // TODO

    {
        const exe = addExecutable(b, opts, .{ .name = "main1" });
        exe.addObject(obj);
        exe.linkLibrary(a_so);
        exe.linkLibrary(b_so);
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("1 2 3 4 5 6\n");
        test_step.dependOn(&run.step);
    }

    {
        const exe = addExecutable(b, opts, .{ .name = "main2" });
        exe.addObject(obj);
        exe.linkLibrary(a_so);
        exe.linkLibrary(b_so);
        exe.linkLibC();
        // exe.link_relax = false; // TODO

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("1 2 3 4 5 6\n");
        test_step.dependOn(&run.step);
    }

    return test_step;
}

fn testTlsGdToIe(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "tls-gd-to-ie", opts);

    const a_o = addObject(b, opts, .{
        .name = "a",
        .c_source_bytes =
        \\#include <stdio.h>
        \\__attribute__((tls_model("global-dynamic"))) static _Thread_local int x1 = 1;
        \\__attribute__((tls_model("global-dynamic"))) _Thread_local int x2 = 2;
        \\__attribute__((tls_model("global-dynamic"))) _Thread_local int x3;
        \\int foo() {
        \\  x3 = 3;
        \\
        \\  printf("%d %d %d\n", x1, x2, x3);
        \\  return 0;
        \\}
        ,
        .pic = true,
    });
    a_o.linkLibC();

    const b_o = addObject(b, opts, .{
        .name = "b",
        .c_source_bytes =
        \\int foo();
        \\int main() { foo(); }
        ,
        .pic = true,
    });

    {
        const dso = addSharedLibrary(b, opts, .{ .name = "a1" });
        dso.addObject(a_o);

        const exe = addExecutable(b, opts, .{ .name = "main1" });
        exe.addObject(b_o);
        exe.linkLibrary(dso);
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("1 2 3\n");
        test_step.dependOn(&run.step);
    }

    {
        const dso = addSharedLibrary(b, opts, .{ .name = "a2" });
        dso.addObject(a_o);
        // dso.link_relax = false; // TODO

        const exe = addExecutable(b, opts, .{ .name = "main2" });
        exe.addObject(b_o);
        exe.linkLibrary(dso);
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("1 2 3\n");
        test_step.dependOn(&run.step);
    }

    // {
    //     const dso = addSharedLibrary(b, opts, .{ .name = "a"});
    //     dso.addObject(a_o);
    //     dso.link_z_nodlopen = true;

    //     const exe = addExecutable(b, opts, .{ .name = "main"});
    //     exe.addObject(b_o);
    //     exe.linkLibrary(dso);

    //     const run = addRunArtifact(exe);
    //     run.expectStdOutEqual("1 2 3\n");
    //     test_step.dependOn(&run.step);
    // }

    // {
    //     const dso = addSharedLibrary(b, opts, .{ .name = "a"});
    //     dso.addObject(a_o);
    //     dso.link_relax = false;
    //     dso.link_z_nodlopen = true;

    //     const exe = addExecutable(b, opts, .{ .name = "main"});
    //     exe.addObject(b_o);
    //     exe.linkLibrary(dso);

    //     const run = addRunArtifact(exe);
    //     run.expectStdOutEqual("1 2 3\n");
    //     test_step.dependOn(&run.step);
    // }

    return test_step;
}

fn testTlsIe(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "tls-ie", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "a" });
    addCSourceBytes(dso,
        \\#include <stdio.h>
        \\__attribute__((tls_model("initial-exec"))) static _Thread_local int foo;
        \\__attribute__((tls_model("initial-exec"))) static _Thread_local int bar;
        \\void set() {
        \\  foo = 3;
        \\  bar = 5;
        \\}
        \\void print() {
        \\  printf("%d %d ", foo, bar);
        \\}
    , &.{});
    dso.linkLibC();

    const main_o = addObject(b, opts, .{
        .name = "main",
        .c_source_bytes =
        \\#include <stdio.h>
        \\_Thread_local int baz;
        \\void set();
        \\void print();
        \\int main() {
        \\  baz = 7;
        \\  print();
        \\  set();
        \\  print();
        \\  printf("%d\n", baz);
        \\}
        ,
    });
    main_o.linkLibC();

    const exp_stdout = "0 0 3 5 7\n";

    {
        const exe = addExecutable(b, opts, .{ .name = "main1" });
        exe.addObject(main_o);
        exe.linkLibrary(dso);
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual(exp_stdout);
        test_step.dependOn(&run.step);
    }

    {
        const exe = addExecutable(b, opts, .{ .name = "main2" });
        exe.addObject(main_o);
        exe.linkLibrary(dso);
        exe.linkLibC();
        // exe.link_relax = false; // TODO

        const run = addRunArtifact(exe);
        run.expectStdOutEqual(exp_stdout);
        test_step.dependOn(&run.step);
    }

    return test_step;
}

fn testTlsLargeAlignment(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "tls-large-alignment", opts);

    const a_o = addObject(b, opts, .{
        .name = "a",
        .c_source_bytes =
        \\__attribute__((section(".tdata1")))
        \\_Thread_local int x = 42;
        ,
        .c_source_flags = &.{"-std=c11"},
        .pic = true,
    });

    const b_o = addObject(b, opts, .{
        .name = "b",
        .c_source_bytes =
        \\__attribute__((section(".tdata2")))
        \\_Alignas(256) _Thread_local int y[] = { 1, 2, 3 };
        ,
        .c_source_flags = &.{"-std=c11"},
        .pic = true,
    });

    const c_o = addObject(b, opts, .{
        .name = "c",
        .c_source_bytes =
        \\#include <stdio.h>
        \\extern _Thread_local int x;
        \\extern _Thread_local int y[];
        \\int main() {
        \\  printf("%d %d %d %d\n", x, y[0], y[1], y[2]);
        \\}
        ,
        .pic = true,
    });
    c_o.linkLibC();

    {
        const dso = addSharedLibrary(b, opts, .{ .name = "a" });
        dso.addObject(a_o);
        dso.addObject(b_o);

        const exe = addExecutable(b, opts, .{ .name = "main" });
        exe.addObject(c_o);
        exe.linkLibrary(dso);
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("42 1 2 3\n");
        test_step.dependOn(&run.step);
    }

    {
        const exe = addExecutable(b, opts, .{ .name = "main" });
        exe.addObject(a_o);
        exe.addObject(b_o);
        exe.addObject(c_o);
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("42 1 2 3\n");
        test_step.dependOn(&run.step);
    }

    return test_step;
}

fn testTlsLargeTbss(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "tls-large-tbss", opts);

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addAsmSourceBytes(exe,
        \\.globl x, y
        \\.section .tbss,"awT",@nobits
        \\x:
        \\.zero 1024
        \\.section .tcommon,"awT",@nobits
        \\y:
        \\.zero 1024
    );
    addCSourceBytes(exe,
        \\#include <stdio.h>
        \\extern _Thread_local char x[1024000];
        \\extern _Thread_local char y[1024000];
        \\int main() {
        \\  x[0] = 3;
        \\  x[1023] = 5;
        \\  printf("%d %d %d %d %d %d\n", x[0], x[1], x[1023], y[0], y[1], y[1023]);
        \\}
    , &.{});
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("3 0 5 0 0 0\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testTlsLargeStaticImage(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "tls-large-static-image", opts);

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe, "_Thread_local int x[] = { 1, 2, 3, [10000] = 5 };", &.{});
    addCSourceBytes(exe,
        \\#include <stdio.h>
        \\extern _Thread_local int x[];
        \\int main() {
        \\  printf("%d %d %d %d %d\n", x[0], x[1], x[2], x[3], x[10000]);
        \\}
    , &.{});
    exe.root_module.pic = true;
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("1 2 3 0 5\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testTlsLd(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "tls-ld", opts);

    const main_o = addObject(b, opts, .{
        .name = "main",
        .c_source_bytes =
        \\#include <stdio.h>
        \\extern _Thread_local int foo;
        \\static _Thread_local int bar;
        \\int *get_foo_addr() { return &foo; }
        \\int *get_bar_addr() { return &bar; }
        \\int main() {
        \\  bar = 5;
        \\  printf("%d %d %d %d\n", *get_foo_addr(), *get_bar_addr(), foo, bar);
        \\  return 0;
        \\}
        ,
        .c_source_flags = &.{"-ftls-model=local-dynamic"},
        .pic = true,
    });
    main_o.linkLibC();

    const a_o = addObject(b, opts, .{
        .name = "a",
        .c_source_bytes = "_Thread_local int foo = 3;",
        .c_source_flags = &.{"-ftls-model=local-dynamic"},
        .pic = true,
    });

    const exp_stdout = "3 5 3 5\n";

    {
        const exe = addExecutable(b, opts, .{ .name = "main1" });
        exe.addObject(main_o);
        exe.addObject(a_o);
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual(exp_stdout);
        test_step.dependOn(&run.step);
    }

    {
        const exe = addExecutable(b, opts, .{ .name = "main2" });
        exe.addObject(main_o);
        exe.addObject(a_o);
        exe.linkLibC();
        // exe.link_relax = false; // TODO

        const run = addRunArtifact(exe);
        run.expectStdOutEqual(exp_stdout);
        test_step.dependOn(&run.step);
    }

    return test_step;
}

fn testTlsLdDso(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "tls-ld-dso", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "a" });
    addCSourceBytes(dso,
        \\static _Thread_local int def, def1;
        \\int f0() { return ++def; }
        \\int f1() { return ++def1 + def; }
    , &.{"-ftls-model=local-dynamic"});

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\#include <stdio.h>
        \\extern int f0();
        \\extern int f1();
        \\int main() {
        \\  int x = f0();
        \\  int y = f1();
        \\  printf("%d %d\n", x, y);
        \\  return 0;
        \\}
    , &.{});
    exe.linkLibrary(dso);
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("1 2\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testTlsLdNoPlt(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "tls-ld-no-plt", opts);

    const a_o = addObject(b, opts, .{
        .name = "a",
        .c_source_bytes =
        \\#include <stdio.h>
        \\extern _Thread_local int foo;
        \\static _Thread_local int bar;
        \\int *get_foo_addr() { return &foo; }
        \\int *get_bar_addr() { return &bar; }
        \\int main() {
        \\  bar = 5;
        \\
        \\  printf("%d %d %d %d\n", *get_foo_addr(), *get_bar_addr(), foo, bar);
        \\  return 0;
        \\}
        ,
        .c_source_flags = &.{ "-ftls-model=local-dynamic", "-fno-plt" },
        .pic = true,
    });
    a_o.linkLibC();

    const b_o = addObject(b, opts, .{
        .name = "b",
        .c_source_bytes = "_Thread_local int foo = 3;",
        .c_source_flags = &.{ "-ftls-model=local-dynamic", "-fno-plt" },
        .pic = true,
    });

    {
        const exe = addExecutable(b, opts, .{ .name = "main1" });
        exe.addObject(a_o);
        exe.addObject(b_o);
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("3 5 3 5\n");
        test_step.dependOn(&run.step);
    }

    {
        const exe = addExecutable(b, opts, .{ .name = "main2" });
        exe.addObject(a_o);
        exe.addObject(b_o);
        exe.linkLibC();
        // exe.link_relax = false; // TODO

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("3 5 3 5\n");
        test_step.dependOn(&run.step);
    }

    return test_step;
}

fn testTlsNoPic(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "tls-no-pic", opts);

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\#include <stdio.h>
        \\__attribute__((tls_model("global-dynamic"))) extern _Thread_local int foo;
        \\__attribute__((tls_model("global-dynamic"))) static _Thread_local int bar;
        \\int *get_foo_addr() { return &foo; }
        \\int *get_bar_addr() { return &bar; }
        \\int main() {
        \\  foo = 3;
        \\  bar = 5;
        \\
        \\  printf("%d %d %d %d\n", *get_foo_addr(), *get_bar_addr(), foo, bar);
        \\  return 0;
        \\}
    , .{});
    addCSourceBytes(exe,
        \\__attribute__((tls_model("global-dynamic"))) _Thread_local int foo;
    , &.{});
    exe.root_module.pic = false;
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("3 5 3 5\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testTlsOffsetAlignment(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "tls-offset-alignment", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "a" });
    addCSourceBytes(dso,
        \\#include <assert.h>
        \\#include <stdlib.h>
        \\
        \\// .tdata
        \\_Thread_local int x = 42;
        \\// .tbss
        \\__attribute__ ((aligned(64)))
        \\_Thread_local int y = 0;
        \\
        \\void *verify(void *unused) {
        \\  assert((unsigned long)(&y) % 64 == 0);
        \\  return NULL;
        \\}
    , &.{});
    dso.linkLibC();

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\#include <pthread.h>
        \\#include <dlfcn.h>
        \\#include <assert.h>
        \\void *(*verify)(void *);
        \\
        \\int main() {
        \\  void *handle = dlopen("liba.so", RTLD_NOW);
        \\  assert(handle);
        \\  *(void**)(&verify) = dlsym(handle, "verify");
        \\  assert(verify);
        \\
        \\  pthread_t thread;
        \\
        \\  verify(NULL);
        \\
        \\  pthread_create(&thread, NULL, verify, NULL);
        \\  pthread_join(thread, NULL);
        \\}
    , &.{});
    exe.addRPath(dso.getEmittedBinDirectory());
    exe.linkLibC();
    exe.root_module.pic = true;

    const run = addRunArtifact(exe);
    run.expectExitCode(0);
    test_step.dependOn(&run.step);

    return test_step;
}

fn testTlsPic(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "tls-pic", opts);

    const obj = addObject(b, opts, .{
        .name = "obj",
        .c_source_bytes =
        \\#include <stdio.h>
        \\__attribute__((tls_model("global-dynamic"))) extern _Thread_local int foo;
        \\__attribute__((tls_model("global-dynamic"))) static _Thread_local int bar;
        \\int *get_foo_addr() { return &foo; }
        \\int *get_bar_addr() { return &bar; }
        \\int main() {
        \\  bar = 5;
        \\
        \\  printf("%d %d %d %d\n", *get_foo_addr(), *get_bar_addr(), foo, bar);
        \\  return 0;
        \\}
        ,
        .pic = true,
    });
    obj.linkLibC();

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\__attribute__((tls_model("global-dynamic"))) _Thread_local int foo = 3;
    , &.{});
    exe.addObject(obj);
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("3 5 3 5\n");
    test_step.dependOn(&run.step);

    return test_step;
}

fn testTlsSmallAlignment(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "tls-small-alignment", opts);

    const a_o = addObject(b, opts, .{
        .name = "a",
        .asm_source_bytes =
        \\.text
        \\.byte 0
        \\
        ,
        .pic = true,
    });

    const b_o = addObject(b, opts, .{
        .name = "b",
        .c_source_bytes = "_Thread_local char x = 42;",
        .c_source_flags = &.{"-std=c11"},
        .pic = true,
    });

    const c_o = addObject(b, opts, .{
        .name = "c",
        .c_source_bytes =
        \\#include <stdio.h>
        \\extern _Thread_local char x;
        \\int main() {
        \\  printf("%d\n", x);
        \\}
        ,
        .pic = true,
    });
    c_o.linkLibC();

    {
        const exe = addExecutable(b, opts, .{ .name = "main" });
        exe.addObject(a_o);
        exe.addObject(b_o);
        exe.addObject(c_o);
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("42\n");
        test_step.dependOn(&run.step);
    }

    {
        const dso = addSharedLibrary(b, opts, .{ .name = "a" });
        dso.addObject(a_o);
        dso.addObject(b_o);

        const exe = addExecutable(b, opts, .{ .name = "main" });
        exe.addObject(c_o);
        exe.linkLibrary(dso);
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("42\n");
        test_step.dependOn(&run.step);
    }

    return test_step;
}

fn testTlsStatic(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "tls-static", opts);

    const exe = addExecutable(b, opts, .{ .name = "test" });
    addCSourceBytes(exe,
        \\#include <stdio.h>
        \\_Thread_local int a = 10;
        \\_Thread_local int b;
        \\_Thread_local char c = 'a';
        \\int main(int argc, char* argv[]) {
        \\  printf("%d %d %c\n", a, b, c);
        \\  a += 1;
        \\  b += 1;
        \\  c += 1;
        \\  printf("%d %d %c\n", a, b, c);
        \\  return 0;
        \\}
    , &.{});
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdOutEqual(
        \\10 0 a
        \\11 1 b
        \\
    );
    test_step.dependOn(&run.step);

    return test_step;
}

fn testUnknownFileTypeError(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "unknown-file-type-error", opts);

    const dylib = addSharedLibrary(b, .{
        .target = b.resolveTargetQuery(.{ .cpu_arch = .x86_64, .os_tag = .macos }),
    }, .{
        .name = "a",
        .zig_source_bytes = "export var foo: i32 = 0;",
    });

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\extern int foo;
        \\int main() {
        \\  return foo;
        \\}
    , &.{});
    exe.linkLibrary(dylib);
    exe.linkLibC();

    // TODO: improve the test harness to be able to selectively match lines in error output
    // while avoiding jankiness
    // expectLinkErrors(exe, test_step, .{ .exact = &.{
    //     "error: invalid token in LD script: '\\x00\\x00\\x00\\x0c\\x00\\x00\\x00/usr/lib/dyld\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x0d' (0:989)",
    //     "note: while parsing /?/liba.dylib",
    //     "error: unexpected error: parsing input file failed with error InvalidLdScript",
    //     "note: while parsing /?/liba.dylib",
    // } });
    expectLinkErrors(exe, test_step, .{
        .contains = "error: unexpected error: parsing input file failed with error InvalidLdScript",
    });

    return test_step;
}

fn testUnresolvedError(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "unresolved-error", opts);

    const obj1 = addObject(b, opts, .{
        .name = "a",
        .c_source_bytes =
        \\#include <stdio.h>
        \\int foo();
        \\int bar() {
        \\  return foo() + 1;
        \\}
        ,
        .c_source_flags = &.{"-ffunction-sections"},
    });
    obj1.linkLibC();

    const obj2 = addObject(b, opts, .{
        .name = "b",
        .c_source_bytes =
        \\#include <stdio.h>
        \\int foo();
        \\int bar();
        \\int main() {
        \\  return foo() + bar();
        \\}
        ,
        .c_source_flags = &.{"-ffunction-sections"},
    });
    obj2.linkLibC();

    const exe = addExecutable(b, opts, .{ .name = "main" });
    exe.addObject(obj1);
    exe.addObject(obj2);
    exe.linkLibC();

    expectLinkErrors(exe, test_step, .{ .exact = &.{
        "error: undefined symbol: foo",
        "note: referenced by /?/a.o:.text.bar",
        "note: referenced by /?/b.o:.text.main",
    } });

    return test_step;
}

fn testWeakExports(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "weak-exports", opts);

    const obj = addObject(b, opts, .{
        .name = "obj",
        .c_source_bytes =
        \\#include <stdio.h>
        \\__attribute__((weak)) int foo();
        \\int main() {
        \\  printf("%d\n", foo ? foo() : 3);
        \\}
        ,
        .pic = true,
    });
    obj.linkLibC();

    {
        const dso = addSharedLibrary(b, opts, .{ .name = "a" });
        dso.addObject(obj);
        dso.linkLibC();

        const check = dso.checkObject();
        check.checkInDynamicSymtab();
        check.checkContains("UND NOTYPE WEAK DEFAULT foo");
        test_step.dependOn(&check.step);
    }

    {
        const exe = addExecutable(b, opts, .{ .name = "main" });
        exe.addObject(obj);
        exe.linkLibC();

        const check = exe.checkObject();
        check.checkInDynamicSymtab();
        check.checkNotPresent("UND NOTYPE WEAK DEFAULT foo");
        test_step.dependOn(&check.step);

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("3\n");
        test_step.dependOn(&run.step);
    }

    return test_step;
}

fn testWeakUndefsDso(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "weak-undef-dso", opts);

    const dso = addSharedLibrary(b, opts, .{ .name = "a" });
    addCSourceBytes(dso,
        \\__attribute__((weak)) int foo();
        \\int bar() { return foo ? foo() : -1; }
    , &.{});

    {
        const exe = addExecutable(b, opts, .{ .name = "main" });
        addCSourceBytes(exe,
            \\#include <stdio.h>
            \\int bar();
            \\int main() { printf("bar=%d\n", bar()); }
        , &.{});
        exe.linkLibrary(dso);
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("bar=-1\n");
        test_step.dependOn(&run.step);
    }

    {
        const exe = addExecutable(b, opts, .{ .name = "main" });
        addCSourceBytes(exe,
            \\#include <stdio.h>
            \\int foo() { return 5; }
            \\int bar();
            \\int main() { printf("bar=%d\n", bar()); }
        , &.{});
        exe.linkLibrary(dso);
        exe.linkLibC();

        const run = addRunArtifact(exe);
        run.expectStdOutEqual("bar=5\n");
        test_step.dependOn(&run.step);
    }

    return test_step;
}

fn testZNow(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "z-now", opts);

    const obj = addObject(b, opts, .{
        .name = "obj",
        .c_source_bytes = "int main() { return 0; }",
        .pic = true,
    });

    {
        const dso = addSharedLibrary(b, opts, .{ .name = "a" });
        dso.addObject(obj);

        const check = dso.checkObject();
        check.checkInDynamicSection();
        check.checkContains("NOW");
        test_step.dependOn(&check.step);
    }

    {
        const dso = addSharedLibrary(b, opts, .{ .name = "a" });
        dso.addObject(obj);
        dso.link_z_lazy = true;

        const check = dso.checkObject();
        check.checkInDynamicSection();
        check.checkNotPresent("NOW");
        test_step.dependOn(&check.step);
    }

    return test_step;
}

fn testZStackSize(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "z-stack-size", opts);

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe, "int main() { return 0; }", &.{});
    exe.stack_size = 0x800000;
    exe.linkLibC();

    const check = exe.checkObject();
    check.checkInHeaders();
    check.checkExact("program headers");
    check.checkExact("type GNU_STACK");
    check.checkExact("memsz 800000");
    test_step.dependOn(&check.step);

    return test_step;
}

fn testZText(b: *Build, opts: Options) *Step {
    const test_step = addTestStep(b, "z-text", opts);

    // Previously, following mold, this test tested text relocs present in a PIE executable.
    // However, as we want to cover musl AND glibc, it is now modified to test presence of
    // text relocs in a DSO which is then linked with an executable.
    // According to Rich and this thread https://www.openwall.com/lists/musl/2020/09/25/4
    // musl supports only a very limited number of text relocations and only in DSOs (and
    // rightly so!).

    const a_o = addObject(b, opts, .{
        .name = "a",
        .asm_source_bytes =
        \\.globl fn1
        \\fn1:
        \\  sub $8, %rsp
        \\  movabs ptr, %rax
        \\  call *%rax
        \\  add $8, %rsp
        \\  ret
        \\
        ,
    });

    const b_o = addObject(b, opts, .{
        .name = "b",
        .c_source_bytes =
        \\int fn1();
        \\int fn2() {
        \\  return 3;
        \\}
        \\void *ptr = fn2;
        \\int fnn() {
        \\  return fn1();
        \\}
        ,
        .pic = true,
    });

    const dso = addSharedLibrary(b, opts, .{ .name = "a" });
    dso.addObject(a_o);
    dso.addObject(b_o);
    dso.link_z_notext = true;

    const exe = addExecutable(b, opts, .{ .name = "main" });
    addCSourceBytes(exe,
        \\#include <stdio.h>
        \\int fnn();
        \\int main() {
        \\  printf("%d\n", fnn());
        \\}
    , &.{});
    exe.linkLibrary(dso);
    exe.linkLibC();

    const run = addRunArtifact(exe);
    run.expectStdOutEqual("3\n");
    test_step.dependOn(&run.step);

    // Check for DT_TEXTREL in a DSO
    const check = dso.checkObject();
    check.checkInDynamicSection();
    // check.checkExact("TEXTREL 0"); // TODO fix in CheckObject parser
    check.checkContains("FLAGS TEXTREL");
    test_step.dependOn(&check.step);

    return test_step;
}

fn addTestStep(b: *Build, comptime prefix: []const u8, opts: Options) *Step {
    return link.addTestStep(b, "elf-" ++ prefix, opts);
}

const addAsmSourceBytes = link.addAsmSourceBytes;
const addCSourceBytes = link.addCSourceBytes;
const addCppSourceBytes = link.addCppSourceBytes;
const addExecutable = link.addExecutable;
const addObject = link.addObject;
const addRunArtifact = link.addRunArtifact;
const addSharedLibrary = link.addSharedLibrary;
const addStaticLibrary = link.addStaticLibrary;
const expectLinkErrors = link.expectLinkErrors;
const link = @import("link.zig");
const std = @import("std");

const Build = std.Build;
const BuildOptions = link.BuildOptions;
const Options = link.Options;
const Step = Build.Step;
const WriteFile = Step.WriteFile;