Commit f7f88787165e8417fa524f0781f6cd139864f12b | zig

author	Andrew Kelley <andrew@ziglang.org> 2025-01-14 19:03:10-08:00
committer	Andrew Kelley <andrew@ziglang.org> 2025-01-15 15:11:36-08:00
log	f7f88787165e8417fa524f0781f6cd139864f12b
tree	dfcf260df3c87edb9173d8c7009930c0ceb63531
parent	9143575ec309526f350f7f7969d76b4869a54fc7

wasm linker: correct export visibility logic

exports are hidden unless protected or rdynamic or explicitly asked for,
matching master branch

2 files changed, 26 insertions(+), 9 deletions(-)

src
- link
  - Wasm.zig
  - Wasm
    Flush.zig

src/link/Wasm.zig+13

...	@@ -4674,3 +4674,16 @@ fn resolveFunctionSynthetic(	...	@@ -4674,3 +4674,16 @@ fn resolveFunctionSynthetic(
4674	});	4674	});
4675	}	4675	}
4676	}	4676	}
		4677
		4678	pub fn addFunction(
		4679	wasm: *Wasm,
		4680	resolution: FunctionImport.Resolution,
		4681	params: []const std.wasm.Valtype,
		4682	returns: []const std.wasm.Valtype,
		4683	) Allocator.Error!void {
		4684	wasm.functions.putAssumeCapacity(resolution, {});
		4685	_ = try wasm.addFuncType(.{
		4686	.params = try wasm.internValtypeList(params),
		4687	.returns = try wasm.internValtypeList(returns),
		4688	});
		4689	}

src/link/Wasm/Flush.zig+13-9

 @@ -168,11 +168,17 @@ pub fn finish(f: *Flush, wasm: *Wasm) !void {
             if (ip.isFunctionType(ip.getNav(nav_export.nav_index).typeOf(ip))) {
                 log.debug("flush export '{s}' nav={d}", .{ nav_export.name.slice(wasm), nav_export.nav_index });
                 const function_index = Wasm.FunctionIndex.fromIpNav(wasm, nav_export.nav_index).?;
-                switch (export_index.ptr(zcu).opts.visibility) {
+                const explicit = f.missing_exports.swapRemove(nav_export.name);
-                    .default, .protected => try wasm.function_exports.put(gpa, nav_export.name, function_index),
+                const is_hidden = !explicit and switch (export_index.ptr(zcu).opts.visibility) {
-                    .hidden => try wasm.hidden_function_exports.put(gpa, nav_export.name, function_index),
+                    .protected => false,
+                    .hidden => true,
+                    .default => !comp.config.rdynamic,
+                };
+                if (is_hidden) {
+                    try wasm.hidden_function_exports.put(gpa, nav_export.name, function_index);
+                } else {
+                    try wasm.function_exports.put(gpa, nav_export.name, function_index);
                 }
-                _ = f.missing_exports.swapRemove(nav_export.name);
                 _ = f.function_imports.swapRemove(nav_export.name);
                 if (nav_export.name.toOptional() == entry_name)
 @@ -281,9 +287,7 @@ pub fn finish(f: *Flush, wasm: *Wasm) !void {
     // We also initialize bss segments (using memory.fill) as part of this
     // function.
     if (wasm.any_passive_inits) {
-        wasm.functions.putAssumeCapacity(.__wasm_init_memory, {});
+        try wasm.addFunction(.__wasm_init_memory, &.{}, &.{});
-        const empty = try wasm.internValtypeList(&.{});
-        _ = try wasm.addFuncType(.{ .params = empty, .returns = empty });
     }
     // When we have TLS GOT entries and shared memory is enabled,
 @@ -291,8 +295,8 @@ pub fn finish(f: *Flush, wasm: *Wasm) !void {
     if (shared_memory) {
         // This logic that checks `any_tls_relocs` is missing the part where it
         // also notices threadlocal globals from Zcu code.
-        if (wasm.any_tls_relocs) wasm.functions.putAssumeCapacity(.__wasm_apply_global_tls_relocs, {});
+        if (wasm.any_tls_relocs) try wasm.addFunction(.__wasm_apply_global_tls_relocs, &.{}, &.{});
-        wasm.functions.putAssumeCapacity(.__wasm_init_tls, {});
+        try wasm.addFunction(.__wasm_init_tls, &.{.i32}, &.{});
     }
     try wasm.tables.ensureUnusedCapacity(gpa, 1);