Merge pull request #13418 from ryanschneider/signal-alignment-13216

std.os: fix alignment of Sigaction.handler_fn

lib/std/c/darwin.zig

@@ -918,7 +918,7 @@ pub const siginfo_t = extern struct {
 
 /// Renamed from `sigaction` to `Sigaction` to avoid conflict with function name.
 pub const Sigaction = extern struct {
-    pub const handler_fn = std.meta.FnPtr(fn (c_int) callconv(.C) void);
+    pub const handler_fn = std.meta.FnPtr(fn (c_int) align(1) callconv(.C) void);
     pub const sigaction_fn = std.meta.FnPtr(fn (c_int, *const siginfo_t, ?*const anyopaque) callconv(.C) void);
 
     handler: extern union {

lib/std/c/dragonfly.zig

@@ -681,7 +681,7 @@ pub const empty_sigset = sigset_t{ .__bits = [_]c_uint{0} ** _SIG_WORDS };
 pub const sig_atomic_t = c_int;
 
 pub const Sigaction = extern struct {
-    pub const handler_fn = std.meta.FnPtr(fn (c_int) callconv(.C) void);
+    pub const handler_fn = std.meta.FnPtr(fn (c_int) align(1) callconv(.C) void);
     pub const sigaction_fn = std.meta.FnPtr(fn (c_int, *const siginfo_t, ?*const anyopaque) callconv(.C) void);
 
     /// signal handler

lib/std/c/freebsd.zig

@@ -1197,7 +1197,7 @@ const NSIG = 32;
 
 /// Renamed from `sigaction` to `Sigaction` to avoid conflict with the syscall.
 pub const Sigaction = extern struct {
-    pub const handler_fn = std.meta.FnPtr(fn (c_int) callconv(.C) void);
+    pub const handler_fn = std.meta.FnPtr(fn (c_int) align(1) callconv(.C) void);
     pub const sigaction_fn = std.meta.FnPtr(fn (c_int, *const siginfo_t, ?*const anyopaque) callconv(.C) void);
 
     /// signal handler

lib/std/c/haiku.zig

@@ -742,7 +742,7 @@ const NSIG = 32;
 
 /// Renamed from `sigaction` to `Sigaction` to avoid conflict with the syscall.
 pub const Sigaction = extern struct {
-    pub const handler_fn = std.meta.FnPtr(fn (i32) callconv(.C) void);
+    pub const handler_fn = std.meta.FnPtr(fn (i32) align(1) callconv(.C) void);
 
     /// signal handler
     __sigaction_u: extern union {

lib/std/c/netbsd.zig

@@ -971,7 +971,7 @@ pub const SIG = struct {
 
 /// Renamed from `sigaction` to `Sigaction` to avoid conflict with the syscall.
 pub const Sigaction = extern struct {
-    pub const handler_fn = std.meta.FnPtr(fn (c_int) callconv(.C) void);
+    pub const handler_fn = std.meta.FnPtr(fn (c_int) align(1) callconv(.C) void);
     pub const sigaction_fn = std.meta.FnPtr(fn (c_int, *const siginfo_t, ?*const anyopaque) callconv(.C) void);
 
     /// signal handler

lib/std/c/openbsd.zig

@@ -1026,7 +1026,7 @@ pub const SIG = struct {
 
 /// Renamed from `sigaction` to `Sigaction` to avoid conflict with the syscall.
 pub const Sigaction = extern struct {
-    pub const handler_fn = std.meta.FnPtr(fn (c_int) callconv(.C) void);
+    pub const handler_fn = std.meta.FnPtr(fn (c_int) align(1) callconv(.C) void);
     pub const sigaction_fn = std.meta.FnPtr(fn (c_int, *const siginfo_t, ?*const anyopaque) callconv(.C) void);
 
     /// signal handler

lib/std/c/solaris.zig

@@ -952,7 +952,7 @@ pub const SIG = struct {
 
 /// Renamed from `sigaction` to `Sigaction` to avoid conflict with the syscall.
 pub const Sigaction = extern struct {
-    pub const handler_fn = std.meta.FnPtr(fn (c_int) callconv(.C) void);
+    pub const handler_fn = std.meta.FnPtr(fn (c_int) align(1) callconv(.C) void);
     pub const sigaction_fn = std.meta.FnPtr(fn (c_int, *const siginfo_t, ?*const anyopaque) callconv(.C) void);
 
     /// signal options

lib/std/os/linux.zig

@@ -3130,7 +3130,7 @@ pub const all_mask: sigset_t = [_]u32{0xffffffff} ** @typeInfo(sigset_t).Array.l
 pub const app_mask: sigset_t = [2]u32{ 0xfffffffc, 0x7fffffff } ++ [_]u32{0xffffffff} ** 30;
 
 const k_sigaction_funcs = struct {
-    const handler = ?std.meta.FnPtr(fn (c_int) callconv(.C) void);
+    const handler = ?std.meta.FnPtr(fn (c_int) align(1) callconv(.C) void);
     const restorer = std.meta.FnPtr(fn () callconv(.C) void);
 };
 
@@ -3157,7 +3157,7 @@ pub const k_sigaction = switch (native_arch) {
 
 /// Renamed from `sigaction` to `Sigaction` to avoid conflict with the syscall.
 pub const Sigaction = extern struct {
-    pub const handler_fn = std.meta.FnPtr(fn (c_int) callconv(.C) void);
+    pub const handler_fn = std.meta.FnPtr(fn (c_int) align(1) callconv(.C) void);
     pub const sigaction_fn = std.meta.FnPtr(fn (c_int, *const siginfo_t, ?*const anyopaque) callconv(.C) void);
 
     handler: extern union {

lib/std/os/test.zig

@@ -739,8 +739,6 @@ test "shutdown socket" {
     os.closeSocket(sock);
 }
 
-var signal_test_failed = true;
-
 test "sigaction" {
     if (native_os == .wasi or native_os == .windows)
         return error.SkipZigTest;
@@ -750,17 +748,19 @@ test "sigaction" {
         return error.SkipZigTest;
 
     const S = struct {
+        var handler_called_count: u32 = 0;
+
         fn handler(sig: i32, info: *const os.siginfo_t, ctx_ptr: ?*const anyopaque) callconv(.C) void {
             _ = ctx_ptr;
             // Check that we received the correct signal.
             switch (native_os) {
                 .netbsd => {
                     if (sig == os.SIG.USR1 and sig == info.info.signo)
-                        signal_test_failed = false;
+                        handler_called_count += 1;
                 },
                 else => {
                     if (sig == os.SIG.USR1 and sig == info.signo)
-                        signal_test_failed = false;
+                        handler_called_count += 1;
                 },
             }
         }
@@ -774,18 +774,41 @@ test "sigaction" {
         .flags = os.SA.SIGINFO | os.SA.RESETHAND,
     };
     var old_sa: os.Sigaction = undefined;
+
     // Install the new signal handler.
     try os.sigaction(os.SIG.USR1, &sa, null);
+
     // Check that we can read it back correctly.
     try os.sigaction(os.SIG.USR1, null, &old_sa);
     try testing.expectEqual(actual_handler, old_sa.handler.sigaction.?);
     try testing.expect((old_sa.flags & os.SA.SIGINFO) != 0);
+
     // Invoke the handler.
     try os.raise(os.SIG.USR1);
-    try testing.expect(signal_test_failed == false);
+    try testing.expect(S.handler_called_count == 1);
-    // Check if the handler has been correctly reset to SIG_DFL
+
+    // Check if passing RESETHAND correctly reset the handler to SIG_DFL
     try os.sigaction(os.SIG.USR1, null, &old_sa);
     try testing.expectEqual(os.SIG.DFL, old_sa.handler.handler);
+
+    // Reinstall the signal w/o RESETHAND and re-raise
+    sa.flags = os.SA.SIGINFO;
+    try os.sigaction(os.SIG.USR1, &sa, null);
+    try os.raise(os.SIG.USR1);
+    try testing.expect(S.handler_called_count == 2);
+
+    // Now set the signal to ignored
+    sa.handler = .{ .handler = os.SIG.IGN };
+    sa.flags = 0;
+    try os.sigaction(os.SIG.USR1, &sa, null);
+
+    // Re-raise to ensure handler is actually ignored
+    try os.raise(os.SIG.USR1);
+    try testing.expect(S.handler_called_count == 2);
+
+    // Ensure that ignored state is returned when querying
+    try os.sigaction(os.SIG.USR1, null, &old_sa);
+    try testing.expectEqual(os.SIG.IGN, old_sa.handler.handler.?);
 }
 
 test "dup & dup2" {