add behavior test for resolved alignment issue

std.zig.Server: remove workaround for fixed issue closes #14904 Note the C backend is not passing the new test.
ziglang · Aug 1, 2023 · 88e3a26 · 88e3a26
1 parent e84cda0
commit 88e3a26
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Showing 2 changed files with 25 additions and 14 deletions.
diff --git a/lib/std/zig/Server.zig b/lib/std/zig/Server.zig
@@ -104,9 +104,9 @@ pub fn receiveMessage(s: *Server) !InMessage.Header {
         const buf = fifo.readableSlice(0);
         assert(fifo.readableLength() == buf.len);
         if (buf.len >= @sizeOf(Header)) {
-            // workaround for https://github.com/ziglang/zig/issues/14904
-            const bytes_len = bswap_and_workaround_u32(buf[4..][0..4]);
-            const tag = bswap_and_workaround_tag(buf[0..][0..4]);
+            const header: *align(1) const Header = @ptrCast(buf[0..@sizeOf(Header)]);
+            const bytes_len = bswap(header.bytes_len);
+            const tag = bswap(header.tag);
 
             if (buf.len - @sizeOf(Header) >= bytes_len) {
                 fifo.discard(@sizeOf(Header));
@@ -278,17 +278,6 @@ fn bswap_u32_array(slice: []u32) void {
     for (slice) |*elem| elem.* = @byteSwap(elem.*);
 }
 
-/// workaround for https://github.com/ziglang/zig/issues/14904
-fn bswap_and_workaround_u32(bytes_ptr: *const [4]u8) u32 {
-    return std.mem.readIntLittle(u32, bytes_ptr);
-}
-
-/// workaround for https://github.com/ziglang/zig/issues/14904
-fn bswap_and_workaround_tag(bytes_ptr: *const [4]u8) InMessage.Tag {
-    const int = std.mem.readIntLittle(u32, bytes_ptr);
-    return @as(InMessage.Tag, @enumFromInt(int));
-}
-
 const OutMessage = std.zig.Server.Message;
 const InMessage = std.zig.Client.Message;
 

diff --git a/test/behavior/align.zig b/test/behavior/align.zig
@@ -593,3 +593,25 @@ test "alignment of slice element" {
     const a: []align(1024) const u8 = undefined;
     try expect(@TypeOf(&a[0]) == *align(1024) const u8);
 }
+
+test "sub-aligned pointer field access" {
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
+
+    // Originally reported at https://github.com/ziglang/zig/issues/14904
+
+    const Header = extern struct {
+        tag: u32,
+        bytes_len: u32,
+    };
+    var buf: [9]u8 align(4) = .{ 1, 2, 3, 4, 5, 6, 7, 8, 9 };
+    const ptr: *align(1) Header = @ptrCast(buf[1..][0..8]);
+    const x = ptr.bytes_len;
+    switch (builtin.cpu.arch.endian()) {
+        .Big => try expect(x == 0x06070809),
+        .Little => try expect(x == 0x09080706),
+    }
+}