Commit 8aab222ffbde5bfc141b23b2553b2887cf1a3ae3 | zig

author	Matthew Lugg <mlugg@mlugg.co.uk> 2025-05-15 13:15:23+01:00
committer	Matthew Lugg <mlugg@mlugg.co.uk> 2025-06-17 15:33:50+01:00
log	8aab222ffbde5bfc141b23b2553b2887cf1a3ae3
tree	9b8afec613ed127e6f44d665c54e27c1edf24e14
parent	561fdd0ed3d93a373f126f4df01caf813ad32fec

Compilation: add missing link file options to cache manifest

Also add a standalone test which covers the `-fentry` case. It does this
by performing two reproducible compilations which are identical other
than having different entry points, and checking whether the emitted
binaries are identical (they should *not* be).

Resolves: #23869

5 files changed, 88 insertions(+), 0 deletions(-)

src
- Compilation.zig
test
- standalone
  - build.zig.zon
  - entry_point
    build.zig
    check_differ.zig
    main.zig

src/Compilation.zig+15

 @@ -3233,6 +3233,13 @@ fn addNonIncrementalStuffToCacheManifest(
     man.hash.addOptional(opts.allow_shlib_undefined);
     man.hash.add(opts.bind_global_refs_locally);
+    const EntryTag = @typeInfo(link.File.OpenOptions.Entry).@"union".tag_type.?;
+    man.hash.add(@as(EntryTag, opts.entry));
+    switch (opts.entry) {
+        .default, .disabled, .enabled => {},
+        .named => |name| man.hash.addBytes(name),
+    }
     // ELF specific stuff
     man.hash.add(opts.z_nodelete);
     man.hash.add(opts.z_notext);
 @@ -3254,6 +3261,9 @@ fn addNonIncrementalStuffToCacheManifest(
     man.hash.addOptional(opts.max_memory);
     man.hash.addOptional(opts.global_base);
     man.hash.addListOfBytes(opts.export_symbol_names);
+    man.hash.add(opts.import_symbols);
+    man.hash.add(opts.import_table);
+    man.hash.add(opts.export_table);
     // Mach-O specific stuff
     try link.File.MachO.hashAddFrameworks(man, opts.frameworks);
 @@ -3264,6 +3274,9 @@ fn addNonIncrementalStuffToCacheManifest(
     man.hash.add(opts.dead_strip_dylibs);
     man.hash.add(opts.force_load_objc);
     man.hash.add(opts.discard_local_symbols);
+    man.hash.addOptional(opts.compatibility_version);
+    man.hash.addOptionalBytes(opts.install_name);
+    man.hash.addOptional(opts.darwin_sdk_layout);
     // COFF specific stuff
     man.hash.addOptional(opts.subsystem);
 @@ -3272,6 +3285,8 @@ fn addNonIncrementalStuffToCacheManifest(
     man.hash.add(opts.dynamicbase);
     man.hash.addOptional(opts.major_subsystem_version);
     man.hash.addOptional(opts.minor_subsystem_version);
+    man.hash.addOptionalBytes(opts.pdb_source_path);
+    man.hash.addOptionalBytes(opts.module_definition_file);
 }
 fn emitFromCObject(

test/standalone/build.zig.zon+3

 @@ -201,6 +201,9 @@
         .config_header = .{
             .path = "config_header",
         },
+        .entry_point = .{
+            .path = "entry_point",
+        },
     },
     .paths = .{
         "build.zig",

test/standalone/entry_point/build.zig created+46

...	@@ -0,0 +1,46 @@
1	pub fn build(b: *std.Build) !void {
2	const mod = b.createModule(.{
3	// Setting the entry point doesn't work properly on all targets right now. Since we're
4	// really just trying to make sure that the compiler frontend respects `-fentry` and
5	// includes it in the cache manifest, just test for a target where it works.
6	.target = b.resolveTargetQuery(try .parse(.{
7	.arch_os_abi = "x86_64-linux",
8	})),
9	.optimize = .ReleaseFast, // non-Debug build for reproducible output
10	.root_source_file = b.path("main.zig"),
11	});
12
13	const exe_foo = b.addExecutable(.{
14	.name = "the_exe", // same name for reproducible output
15	.root_module = mod,
16	});
17	exe_foo.entry = .{ .symbol_name = "foo" };
18	const exe_bar = b.addExecutable(.{
19	.name = "the_exe", // same name for reproducible output
20	.root_module = mod,
21	});
22	exe_bar.entry = .{ .symbol_name = "bar" };
23
24	// Despite the output binary being reproducible, the `entry` differed, so the emitted binaries
25	// should be different. But the two compilations are otherwise identical, so if `entry` isn't
26	// being respected properly, we will see identical binaries.
27
28	const check_differ_exe = b.addExecutable(.{
29	.name = "check_differ",
30	.root_module = b.createModule(.{
31	.target = b.graph.host,
32	.optimize = .Debug,
33	.root_source_file = b.path("check_differ.zig"),
34	}),
35	});
36
37	const diff_cmd = b.addRunArtifact(check_differ_exe);
38	diff_cmd.addFileArg(exe_foo.getEmittedBin());
39	diff_cmd.addFileArg(exe_bar.getEmittedBin());
40	diff_cmd.expectExitCode(0);
41
42	const test_step = b.step("test", "Test it");
43	b.default_step = test_step;
44	test_step.dependOn(&diff_cmd.step);
45	}
46	const std = @import("std");

test/standalone/entry_point/check_differ.zig created+17

...	@@ -0,0 +1,17 @@
1	pub fn main() !void {
2	var arena_state: std.heap.ArenaAllocator = .init(std.heap.page_allocator);
3	defer arena_state.deinit();
4	const arena = arena_state.allocator();
5
6	const args = try std.process.argsAlloc(arena);
7	if (args.len != 3) return error.BadUsage; // usage: 'check_differ <path a> <path b>'
8
9	const contents_1 = try std.fs.cwd().readFileAlloc(arena, args[1], 1024 * 1024 * 64); // 64 MiB ought to be plenty
10	const contents_2 = try std.fs.cwd().readFileAlloc(arena, args[2], 1024 * 1024 * 64); // 64 MiB ought to be plenty
11
12	if (std.mem.eql(u8, contents_1, contents_2)) {
13	return error.FilesMatch;
14	}
15	// success, files differ
16	}
17	const std = @import("std");

test/standalone/entry_point/main.zig created+7

...	@@ -0,0 +1,7 @@
1	pub const _start = {};
2	export fn foo() u32 {
3	return 123;
4	}
5	export fn bar() u32 {
6	return 456;
7	}