From beae3cea178a0a93c25164e992e01c7b5b78e4d7 Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Sat, 12 Dec 2020 13:57:25 +0100
Subject: [PATCH 01/10] std: Improve sigaction interface

Add a smoke test to prevent regressions.
---
 lib/std/c.zig             |  6 ++---
 lib/std/os.zig            |  2 +-
 lib/std/os/bits/linux.zig |  6 ++---
 lib/std/os/linux.zig      | 47 ++++++++++++++++++++++-----------------
 lib/std/os/test.zig       | 30 +++++++++++++++++++++++++
 5 files changed, 64 insertions(+), 27 deletions(-)

diff --git a/lib/std/c.zig b/lib/std/c.zig
index 5ebbb9dd22..a8ac19053d 100644
--- a/lib/std/c.zig
+++ b/lib/std/c.zig
@@ -200,7 +200,7 @@ pub usingnamespace switch (builtin.os.tag) {
         pub extern "c" fn gettimeofday(noalias tv: ?*timeval, noalias tz: ?*timezone) c_int;
         pub extern "c" fn nanosleep(rqtp: *const timespec, rmtp: ?*timespec) c_int;
         pub extern "c" fn sched_yield() c_int;
-        pub extern "c" fn sigaction(sig: c_int, noalias act: *const Sigaction, noalias oact: ?*Sigaction) c_int;
+        pub extern "c" fn sigaction(sig: c_int, noalias act: ?*const Sigaction, noalias oact: ?*Sigaction) c_int;
         pub extern "c" fn sigprocmask(how: c_int, noalias set: ?*const sigset_t, noalias oset: ?*sigset_t) c_int;
         pub extern "c" fn socket(domain: c_uint, sock_type: c_uint, protocol: c_uint) c_int;
         pub extern "c" fn stat(noalias path: [*:0]const u8, noalias buf: *libc_stat) c_int;
@@ -215,7 +215,7 @@ pub usingnamespace switch (builtin.os.tag) {
         pub extern "c" fn gettimeofday(noalias tv: ?*timeval, noalias tz: ?*timezone) c_int;
         pub extern "c" fn nanosleep(rqtp: *const timespec, rmtp: ?*timespec) c_int;
         pub extern "c" fn sched_yield() c_int;
-        pub extern "c" fn sigaction(sig: c_int, noalias act: *const Sigaction, noalias oact: ?*Sigaction) c_int;
+        pub extern "c" fn sigaction(sig: c_int, noalias act: ?*const Sigaction, noalias oact: ?*Sigaction) c_int;
         pub extern "c" fn sigprocmask(how: c_int, noalias set: ?*const sigset_t, noalias oset: ?*sigset_t) c_int;
         pub extern "c" fn stat(noalias path: [*:0]const u8, noalias buf: *libc_stat) c_int;
     },
@@ -227,7 +227,7 @@ pub usingnamespace switch (builtin.os.tag) {
         pub extern "c" fn gettimeofday(noalias tv: ?*timeval, noalias tz: ?*timezone) c_int;
         pub extern "c" fn nanosleep(rqtp: *const timespec, rmtp: ?*timespec) c_int;
         pub extern "c" fn sched_yield() c_int;
-        pub extern "c" fn sigaction(sig: c_int, noalias act: *const Sigaction, noalias oact: ?*Sigaction) c_int;
+        pub extern "c" fn sigaction(sig: c_int, noalias act: ?*const Sigaction, noalias oact: ?*Sigaction) c_int;
         pub extern "c" fn sigprocmask(how: c_int, noalias set: ?*const sigset_t, noalias oset: ?*sigset_t) c_int;
         pub extern "c" fn socket(domain: c_uint, sock_type: c_uint, protocol: c_uint) c_int;
         pub extern "c" fn stat(noalias path: [*:0]const u8, noalias buf: *libc_stat) c_int;
diff --git a/lib/std/os.zig b/lib/std/os.zig
index e3afe90e5d..b385ffa19f 100644
--- a/lib/std/os.zig
+++ b/lib/std/os.zig
@@ -4592,7 +4592,7 @@ pub fn sigaltstack(ss: ?*stack_t, old_ss: ?*stack_t) SigaltstackError!void {
 }
 
 /// Examine and change a signal action.
-pub fn sigaction(sig: u6, act: *const Sigaction, oact: ?*Sigaction) void {
+pub fn sigaction(sig: u6, act: ?*const Sigaction, oact: ?*Sigaction) void {
     switch (errno(system.sigaction(sig, act, oact))) {
         0 => return,
         EFAULT => unreachable,
diff --git a/lib/std/os/bits/linux.zig b/lib/std/os/bits/linux.zig
index 6952ab7e0e..72621b7fee 100644
--- a/lib/std/os/bits/linux.zig
+++ b/lib/std/os/bits/linux.zig
@@ -867,13 +867,13 @@ pub const app_mask: sigset_t = [2]u32{ 0xfffffffc, 0x7fffffff } ++ [_]u32{0xffff
 pub const k_sigaction = if (is_mips)
     extern struct {
         flags: usize,
-        sigaction: ?fn (i32, *siginfo_t, ?*c_void) callconv(.C) void,
+        sigaction: ?fn (i32, *const siginfo_t, ?*const c_void) callconv(.C) void,
         mask: [4]u32,
         restorer: fn () callconv(.C) void,
     }
 else
     extern struct {
-        sigaction: ?fn (i32, *siginfo_t, ?*c_void) callconv(.C) void,
+        sigaction: ?fn (i32, *const siginfo_t, ?*const c_void) callconv(.C) void,
         flags: usize,
         restorer: fn () callconv(.C) void,
         mask: [2]u32,
@@ -881,7 +881,7 @@ else
 
 /// Renamed from `sigaction` to `Sigaction` to avoid conflict with the syscall.
 pub const Sigaction = extern struct {
-    pub const sigaction_fn = fn (i32, *siginfo_t, ?*c_void) callconv(.C) void;
+    pub const sigaction_fn = fn (i32, *const siginfo_t, ?*const c_void) callconv(.C) void;
     sigaction: ?sigaction_fn,
     mask: sigset_t,
     flags: u32,
diff --git a/lib/std/os/linux.zig b/lib/std/os/linux.zig
index b669ed2436..956d92da36 100644
--- a/lib/std/os/linux.zig
+++ b/lib/std/os/linux.zig
@@ -857,35 +857,42 @@ pub fn sigprocmask(flags: u32, noalias set: ?*const sigset_t, noalias oldset: ?*
     return syscall4(.rt_sigprocmask, flags, @ptrToInt(set), @ptrToInt(oldset), NSIG / 8);
 }
 
-pub fn sigaction(sig: u6, noalias act: *const Sigaction, noalias oact: ?*Sigaction) usize {
+pub fn sigaction(sig: u6, noalias act: ?*const Sigaction, noalias oact: ?*Sigaction) usize {
     assert(sig >= 1);
     assert(sig != SIGKILL);
     assert(sig != SIGSTOP);
 
-    const restorer_fn = if ((act.flags & SA_SIGINFO) != 0) restore_rt else restore;
-    var ksa = k_sigaction{
-        .sigaction = act.sigaction,
-        .flags = act.flags | SA_RESTORER,
-        .mask = undefined,
-        .restorer = @ptrCast(fn () callconv(.C) void, restorer_fn),
-    };
-    var ksa_old: k_sigaction = undefined;
-    const ksa_mask_size = @sizeOf(@TypeOf(ksa_old.mask));
-    @memcpy(@ptrCast([*]u8, &ksa.mask), @ptrCast([*]const u8, &act.mask), ksa_mask_size);
+    var ksa: k_sigaction = undefined;
+    var oldksa: k_sigaction = undefined;
+    const mask_size = @sizeOf(@TypeOf(ksa.mask));
+
+    if (act) |new| {
+        const restorer_fn = if ((new.flags & SA_SIGINFO) != 0) restore_rt else restore;
+        ksa = k_sigaction{
+            .sigaction = new.sigaction,
+            .flags = new.flags | SA_RESTORER,
+            .mask = undefined,
+            .restorer = @ptrCast(fn () callconv(.C) void, restorer_fn),
+        };
+        @memcpy(@ptrCast([*]u8, &ksa.mask), @ptrCast([*]const u8, &new.mask), mask_size);
+    }
+
+    const ksa_arg = if (act != null) @ptrToInt(&ksa) else 0;
+    const oldksa_arg = if (oact != null) @ptrToInt(&oldksa) else 0;
+
     const result = switch (builtin.arch) {
         // The sparc version of rt_sigaction needs the restorer function to be passed as an argument too.
-        .sparc, .sparcv9 => syscall5(.rt_sigaction, sig, @ptrToInt(&ksa), @ptrToInt(&ksa_old), @ptrToInt(ksa.restorer), ksa_mask_size),
-        else => syscall4(.rt_sigaction, sig, @ptrToInt(&ksa), @ptrToInt(&ksa_old), ksa_mask_size),
+        .sparc, .sparcv9 => syscall5(.rt_sigaction, sig, ksa_arg, oldksa_arg, @ptrToInt(ksa.restorer), mask_size),
+        else => syscall4(.rt_sigaction, sig, ksa_arg, oldksa_arg, mask_size),
     };
-    const err = getErrno(result);
-    if (err != 0) {
-        return result;
-    }
+    if (getErrno(result) != 0) return result;
+
     if (oact) |old| {
-        old.sigaction = ksa_old.sigaction;
-        old.flags = @truncate(u32, ksa_old.flags);
-        @memcpy(@ptrCast([*]u8, &old.mask), @ptrCast([*]const u8, &ksa_old.mask), ksa_mask_size);
+        old.sigaction = oldksa.sigaction;
+        old.flags = @truncate(u32, oldksa.flags);
+        @memcpy(@ptrCast([*]u8, &old.mask), @ptrCast([*]const u8, &oldksa.mask), mask_size);
     }
+
     return 0;
 }
 
diff --git a/lib/std/os/test.zig b/lib/std/os/test.zig
index 81f9922d13..be0c718086 100644
--- a/lib/std/os/test.zig
+++ b/lib/std/os/test.zig
@@ -646,3 +646,33 @@ test "shutdown socket" {
     };
     os.closeSocket(sock);
 }
+
+var signal_test_failed = true;
+
+test "sigaction" {
+    if (builtin.os.tag == .wasi or builtin.os.tag == .windows)
+        return error.SkipZigTest;
+
+    const S = struct {
+        fn handler(sig: i32, info: *const os.siginfo_t, ctx_ptr: ?*const c_void) callconv(.C) void {
+            // Check that we received the correct signal.
+            signal_test_failed = info.signo == os.SIGUSR1;
+        }
+    };
+
+    var sa = os.Sigaction{
+        .sigaction = S.handler,
+        .mask = os.empty_sigset,
+        .flags = os.SA_RESETHAND,
+    };
+    var old_sa: os.Sigaction = undefined;
+    // Install the new signal handler.
+    os.sigaction(os.SIGUSR1, &sa, null);
+    // Check that we can read it back correctly.
+    os.sigaction(os.SIGUSR1, null, &old_sa);
+    testing.expectEqual(S.handler, old_sa.sigaction.?);
+    testing.expect((old_sa.flags & os.SA_RESETHAND) != 0);
+    // Invoke the handler.
+    try os.raise(os.SIGUSR1);
+    testing.expect(signal_test_failed == false);
+}

From 1d9b28403a1074cbbbd0605f07819136c9f96cdc Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Sat, 12 Dec 2020 15:34:26 +0100
Subject: [PATCH 02/10] std: Correct check in signal test

Ooops.
---
 lib/std/os/test.zig | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/std/os/test.zig b/lib/std/os/test.zig
index be0c718086..6c86f9322f 100644
--- a/lib/std/os/test.zig
+++ b/lib/std/os/test.zig
@@ -656,14 +656,15 @@ test "sigaction" {
     const S = struct {
         fn handler(sig: i32, info: *const os.siginfo_t, ctx_ptr: ?*const c_void) callconv(.C) void {
             // Check that we received the correct signal.
-            signal_test_failed = info.signo == os.SIGUSR1;
+            if (sig == os.SIGUSR1 and sig == info.signo)
+                signal_test_failed = false;
         }
     };
 
     var sa = os.Sigaction{
         .sigaction = S.handler,
         .mask = os.empty_sigset,
-        .flags = os.SA_RESETHAND,
+        .flags = os.SA_SIGINFO | os.SA_RESETHAND,
     };
     var old_sa: os.Sigaction = undefined;
     // Install the new signal handler.

From 629cc6cf285f60581f03b69ec8d012d2e370a029 Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Sat, 12 Dec 2020 16:44:10 +0100
Subject: [PATCH 03/10] std: Further siginfo refinements

* Define siginfo and sigaction for Darwin
* Define sigaction/handler union for maximum libc compatibility
* Minor correction to some type definitions
---
 lib/std/debug.zig             |  4 ++--
 lib/std/os/bits/darwin.zig    | 30 +++++++++++++++++++++----
 lib/std/os/bits/dragonfly.zig | 14 +++++++-----
 lib/std/os/bits/freebsd.zig   | 11 ++++++----
 lib/std/os/bits/linux.zig     | 41 ++++++++++++++++++++++-------------
 lib/std/os/bits/netbsd.zig    | 11 +++++++---
 lib/std/os/bits/openbsd.zig   | 11 +++++++---
 lib/std/os/linux.zig          |  6 ++---
 lib/std/os/test.zig           |  4 ++--
 9 files changed, 91 insertions(+), 41 deletions(-)

diff --git a/lib/std/debug.zig b/lib/std/debug.zig
index 4f0f44d1b7..be5635ee8f 100644
--- a/lib/std/debug.zig
+++ b/lib/std/debug.zig
@@ -1721,7 +1721,7 @@ pub fn attachSegfaultHandler() void {
         return;
     }
     var act = os.Sigaction{
-        .sigaction = handleSegfaultLinux,
+        .handler = .{ .sigaction = handleSegfaultLinux },
         .mask = os.empty_sigset,
         .flags = (os.SA_SIGINFO | os.SA_RESTART | os.SA_RESETHAND),
     };
@@ -1740,7 +1740,7 @@ fn resetSegfaultHandler() void {
         return;
     }
     var act = os.Sigaction{
-        .sigaction = os.SIG_DFL,
+        .handler = .{ .sigaction = os.SIG_DFL },
         .mask = os.empty_sigset,
         .flags = 0,
     };
diff --git a/lib/std/os/bits/darwin.zig b/lib/std/os/bits/darwin.zig
index 83ca09a9e1..a6dbff8453 100644
--- a/lib/std/os/bits/darwin.zig
+++ b/lib/std/os/bits/darwin.zig
@@ -124,13 +124,35 @@ pub const timespec = extern struct {
 };
 
 pub const sigset_t = u32;
-pub const empty_sigset = sigset_t(0);
+pub const empty_sigset: sigset_t = 0;
+
+pub const siginfo_t = extern struct {
+    signo: c_int,
+    errno: c_int,
+    code: c_int,
+    pid: pid_t,
+    uid: uid_t,
+    status: c_int,
+    addr: *c_void,
+    value: extern union {
+        int: c_int,
+        ptr: *c_void,
+    },
+    si_band: c_long,
+    _pad: [7]c_ulong,
+};
 
 /// Renamed from `sigaction` to `Sigaction` to avoid conflict with function name.
 pub const Sigaction = extern struct {
-    handler: fn (c_int) callconv(.C) void,
-    sa_mask: sigset_t,
-    sa_flags: c_int,
+    pub const handler_fn = fn (c_int) callconv(.C) void;
+    pub const sigaction_fn = fn (c_int, *const siginfo_t, ?*const c_void) callconv(.C) void;
+
+    handler: extern union {
+        handler: ?handler_fn,
+        sigaction: ?sigaction_fn,
+    },
+    mask: sigset_t,
+    flags: c_uint,
 };
 
 pub const dirent = extern struct {
diff --git a/lib/std/os/bits/dragonfly.zig b/lib/std/os/bits/dragonfly.zig
index 2fd9e39c7b..61b6b9f363 100644
--- a/lib/std/os/bits/dragonfly.zig
+++ b/lib/std/os/bits/dragonfly.zig
@@ -530,12 +530,16 @@ pub const sigset_t = extern struct {
 };
 pub const sig_atomic_t = c_int;
 pub const Sigaction = extern struct {
-    __sigaction_u: extern union {
-        __sa_handler: ?fn (c_int) callconv(.C) void,
-        __sa_sigaction: ?fn (c_int, [*c]siginfo_t, ?*c_void) callconv(.C) void,
+    pub const handler_fn = fn (c_int) callconv(.C) void;
+    pub const sigaction_fn = fn (c_int, *const siginfo_t, ?*const c_void) callconv(.C) void;
+
+    /// signal handler
+    handler: extern union {
+        handler: ?handler_fn,
+        sigaction: ?sigaction_fn,
     },
-    sa_flags: c_int,
-    sa_mask: sigset_t,
+    flags: c_uint,
+    mask: sigset_t,
 };
 pub const sig_t = [*c]fn (c_int) callconv(.C) void;
 
diff --git a/lib/std/os/bits/freebsd.zig b/lib/std/os/bits/freebsd.zig
index 5dce94bd90..feac7b354a 100644
--- a/lib/std/os/bits/freebsd.zig
+++ b/lib/std/os/bits/freebsd.zig
@@ -742,14 +742,17 @@ pub const SIG_IGN = @intToPtr(fn (i32) callconv(.C) void, 1);
 
 /// Renamed from `sigaction` to `Sigaction` to avoid conflict with the syscall.
 pub const Sigaction = extern struct {
+    pub const handler_fn = fn (c_int) callconv(.C) void;
+    pub const sigaction_fn = fn (c_int, *const siginfo_t, ?*const c_void) callconv(.C) void;
+
     /// signal handler
-    __sigaction_u: extern union {
-        __sa_handler: fn (i32) callconv(.C) void,
-        __sa_sigaction: fn (i32, *__siginfo, usize) callconv(.C) void,
+    handler: extern union {
+        handler: ?handler_fn,
+        sigaction: ?sigaction_fn,
     },
 
     /// see signal options
-    sa_flags: u32,
+    sa_flags: c_uint,
 
     /// signal mask to apply
     sa_mask: sigset_t,
diff --git a/lib/std/os/bits/linux.zig b/lib/std/os/bits/linux.zig
index 72621b7fee..e86a08e861 100644
--- a/lib/std/os/bits/linux.zig
+++ b/lib/std/os/bits/linux.zig
@@ -864,27 +864,38 @@ pub const sigset_t = [1024 / 32]u32;
 pub const all_mask: sigset_t = [_]u32{0xffffffff} ** sigset_t.len;
 pub const app_mask: sigset_t = [2]u32{ 0xfffffffc, 0x7fffffff } ++ [_]u32{0xffffffff} ** 30;
 
-pub const k_sigaction = if (is_mips)
-    extern struct {
-        flags: usize,
-        sigaction: ?fn (i32, *const siginfo_t, ?*const c_void) callconv(.C) void,
-        mask: [4]u32,
+pub const k_sigaction = switch (builtin.arch) {
+    .mips, .mipsel => extern struct {
+        flags: c_uint,
+        handler: ?fn (c_int) callconv(.C) void,
+        mask: [4]c_ulong,
         restorer: fn () callconv(.C) void,
-    }
-else
-    extern struct {
-        sigaction: ?fn (i32, *const siginfo_t, ?*const c_void) callconv(.C) void,
-        flags: usize,
+    },
+    .mips64, .mips64el => extern struct {
+        flags: c_uint,
+        handler: ?fn (c_int) callconv(.C) void,
+        mask: [2]c_ulong,
         restorer: fn () callconv(.C) void,
-        mask: [2]u32,
-    };
+    },
+    else => extern struct {
+        handler: ?fn (c_int) callconv(.C) void,
+        flags: c_ulong,
+        restorer: fn () callconv(.C) void,
+        mask: [2]c_uint,
+    },
+};
 
 /// Renamed from `sigaction` to `Sigaction` to avoid conflict with the syscall.
 pub const Sigaction = extern struct {
-    pub const sigaction_fn = fn (i32, *const siginfo_t, ?*const c_void) callconv(.C) void;
-    sigaction: ?sigaction_fn,
+    pub const handler_fn = fn (c_int) callconv(.C) void;
+    pub const sigaction_fn = fn (c_int, *const siginfo_t, ?*const c_void) callconv(.C) void;
+
+    handler: extern union {
+        handler: ?handler_fn,
+        sigaction: ?sigaction_fn,
+    },
     mask: sigset_t,
-    flags: u32,
+    flags: c_uint,
     restorer: ?fn () callconv(.C) void = null,
 };
 
diff --git a/lib/std/os/bits/netbsd.zig b/lib/std/os/bits/netbsd.zig
index 0f4b6b60fa..316bf3cda2 100644
--- a/lib/std/os/bits/netbsd.zig
+++ b/lib/std/os/bits/netbsd.zig
@@ -716,13 +716,18 @@ pub const SIG_IGN = @intToPtr(?Sigaction.sigaction_fn, 1);
 
 /// Renamed from `sigaction` to `Sigaction` to avoid conflict with the syscall.
 pub const Sigaction = extern struct {
-    pub const sigaction_fn = fn (i32, *siginfo_t, ?*c_void) callconv(.C) void;
+    pub const handler_fn = fn (c_int) callconv(.C) void;
+    pub const sigaction_fn = fn (c_int, *const siginfo_t, ?*const c_void) callconv(.C) void;
+
     /// signal handler
-    sigaction: ?sigaction_fn,
+    handler: extern union {
+        handler: ?handler_fn,
+        sigaction: ?sigaction_fn,
+    },
     /// signal mask to apply
     mask: sigset_t,
     /// signal options
-    flags: u32,
+    flags: c_uint,
 };
 
 pub const sigval_t = extern union {
diff --git a/lib/std/os/bits/openbsd.zig b/lib/std/os/bits/openbsd.zig
index c85a476e02..8b28c0bffd 100644
--- a/lib/std/os/bits/openbsd.zig
+++ b/lib/std/os/bits/openbsd.zig
@@ -753,13 +753,18 @@ pub const SIG_IGN = @intToPtr(?Sigaction.sigaction_fn, 1);
 
 /// Renamed from `sigaction` to `Sigaction` to avoid conflict with the syscall.
 pub const Sigaction = extern struct {
-    pub const sigaction_fn = fn (c_int, *siginfo_t, ?*c_void) callconv(.C) void;
+    pub const handler_fn = fn (c_int) callconv(.C) void;
+    pub const sigaction_fn = fn (c_int, *const siginfo_t, ?*const c_void) callconv(.C) void;
+
     /// signal handler
-    sigaction: ?sigaction_fn,
+    handler: extern union {
+        handler: ?handler_fn,
+        sigaction: ?sigaction_fn,
+    },
     /// signal mask to apply
     mask: sigset_t,
     /// signal options
-    flags: c_int,
+    flags: c_uint,
 };
 
 pub const sigval = extern union {
diff --git a/lib/std/os/linux.zig b/lib/std/os/linux.zig
index 956d92da36..f840f6a255 100644
--- a/lib/std/os/linux.zig
+++ b/lib/std/os/linux.zig
@@ -869,7 +869,7 @@ pub fn sigaction(sig: u6, noalias act: ?*const Sigaction, noalias oact: ?*Sigact
     if (act) |new| {
         const restorer_fn = if ((new.flags & SA_SIGINFO) != 0) restore_rt else restore;
         ksa = k_sigaction{
-            .sigaction = new.sigaction,
+            .handler = new.handler.handler,
             .flags = new.flags | SA_RESTORER,
             .mask = undefined,
             .restorer = @ptrCast(fn () callconv(.C) void, restorer_fn),
@@ -888,8 +888,8 @@ pub fn sigaction(sig: u6, noalias act: ?*const Sigaction, noalias oact: ?*Sigact
     if (getErrno(result) != 0) return result;
 
     if (oact) |old| {
-        old.sigaction = oldksa.sigaction;
-        old.flags = @truncate(u32, oldksa.flags);
+        old.handler.handler = oldksa.handler;
+        old.flags = @truncate(c_uint, oldksa.flags);
         @memcpy(@ptrCast([*]u8, &old.mask), @ptrCast([*]const u8, &oldksa.mask), mask_size);
     }
 
diff --git a/lib/std/os/test.zig b/lib/std/os/test.zig
index 6c86f9322f..bbc6c968f1 100644
--- a/lib/std/os/test.zig
+++ b/lib/std/os/test.zig
@@ -662,7 +662,7 @@ test "sigaction" {
     };
 
     var sa = os.Sigaction{
-        .sigaction = S.handler,
+        .handler = .{ .sigaction = S.handler },
         .mask = os.empty_sigset,
         .flags = os.SA_SIGINFO | os.SA_RESETHAND,
     };
@@ -671,7 +671,7 @@ test "sigaction" {
     os.sigaction(os.SIGUSR1, &sa, null);
     // Check that we can read it back correctly.
     os.sigaction(os.SIGUSR1, null, &old_sa);
-    testing.expectEqual(S.handler, old_sa.sigaction.?);
+    testing.expectEqual(S.handler, old_sa.handler.sigaction.?);
     testing.expect((old_sa.flags & os.SA_RESETHAND) != 0);
     // Invoke the handler.
     try os.raise(os.SIGUSR1);

From fc70db5ab5ab252471cf35acd48dc8dea0b0870d Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Sun, 13 Dec 2020 19:17:04 +0100
Subject: [PATCH 04/10] std: Fixes for siginfo test on macos

Xnu's sigaction() only supports fetching a limited set of sa_flags, test
SA_SIGINFO instead of SA_RESETHAND as that's supported everywhere.

Add another check to make sure SA_RESETHAND works.

Co-authored-by: Jakub Konka <kubkon@jakubkonka.com>
---
 lib/std/os/bits/darwin.zig | 5 +++++
 lib/std/os/test.zig        | 5 ++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/lib/std/os/bits/darwin.zig b/lib/std/os/bits/darwin.zig
index a6dbff8453..8bd40ed9a3 100644
--- a/lib/std/os/bits/darwin.zig
+++ b/lib/std/os/bits/darwin.zig
@@ -126,6 +126,11 @@ pub const timespec = extern struct {
 pub const sigset_t = u32;
 pub const empty_sigset: sigset_t = 0;
 
+pub const SIG_ERR = @intToPtr(?Sigaction.sigaction_fn, maxInt(usize));
+pub const SIG_DFL = @intToPtr(?Sigaction.sigaction_fn, 0);
+pub const SIG_IGN = @intToPtr(?Sigaction.sigaction_fn, 1);
+pub const SIG_HOLD = @intToPtr(?Sigaction.sigaction_fn, 5);
+
 pub const siginfo_t = extern struct {
     signo: c_int,
     errno: c_int,
diff --git a/lib/std/os/test.zig b/lib/std/os/test.zig
index bbc6c968f1..59116e1bbd 100644
--- a/lib/std/os/test.zig
+++ b/lib/std/os/test.zig
@@ -672,8 +672,11 @@ test "sigaction" {
     // Check that we can read it back correctly.
     os.sigaction(os.SIGUSR1, null, &old_sa);
     testing.expectEqual(S.handler, old_sa.handler.sigaction.?);
-    testing.expect((old_sa.flags & os.SA_RESETHAND) != 0);
+    testing.expect((old_sa.flags & os.SA_SIGINFO) != 0);
     // Invoke the handler.
     try os.raise(os.SIGUSR1);
     testing.expect(signal_test_failed == false);
+    // Check if the handler has been correctly reset to SIG_DFL
+    os.sigaction(os.SIGUSR1, null, &old_sa);
+    testing.expectEqual(os.SIG_DFL, old_sa.handler.sigaction);
 }

From 3375a580be51210115d43b9b76ecf8beef0d46dd Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Sun, 13 Dec 2020 19:28:38 +0100
Subject: [PATCH 05/10] std: Update more siginfo bits for BSDs

---
 lib/std/os/bits/netbsd.zig  |  4 ++++
 lib/std/os/bits/openbsd.zig | 18 ++++++++++++------
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/lib/std/os/bits/netbsd.zig b/lib/std/os/bits/netbsd.zig
index 316bf3cda2..be25284b73 100644
--- a/lib/std/os/bits/netbsd.zig
+++ b/lib/std/os/bits/netbsd.zig
@@ -805,6 +805,10 @@ pub const sigset_t = extern struct {
     __bits: [_SIG_WORDS]u32,
 };
 
+pub const SIG_ERR = @intToPtr(?Sigaction.sigaction_fn, maxInt(usize));
+pub const SIG_DFL = @intToPtr(?Sigaction.sigaction_fn, 0);
+pub const SIG_IGN = @intToPtr(?Sigaction.sigaction_fn, 1);
+
 pub const empty_sigset = sigset_t{ .__bits = [_]u32{0} ** _SIG_WORDS };
 
 // XXX x86_64 specific
diff --git a/lib/std/os/bits/openbsd.zig b/lib/std/os/bits/openbsd.zig
index 8b28c0bffd..9e7b8aa399 100644
--- a/lib/std/os/bits/openbsd.zig
+++ b/lib/std/os/bits/openbsd.zig
@@ -773,11 +773,6 @@ pub const sigval = extern union {
 };
 
 pub const siginfo_t = extern union {
-    pad: [128]u8,
-    info: _ksiginfo,
-};
-
-pub const _ksiginfo = extern struct {
     signo: c_int,
     code: c_int,
     errno: c_int,
@@ -794,11 +789,22 @@ pub const _ksiginfo = extern struct {
             addr: ?*c_void,
             trapno: c_int,
         },
+        __pad: [128 - 3 * @sizeOf(c_int)]u8,
     } align(@sizeOf(usize)),
 };
 
+comptime {
+    std.debug.assert(@sizeOf(siginfo_t) == 128);
+}
+
 pub const sigset_t = c_uint;
-pub const empty_sigset = sigset_t(0);
+pub const empty_sigset: sigset_t = 0;
+
+pub const SIG_ERR = @intToPtr(?Sigaction.sigaction_fn, maxInt(usize));
+pub const SIG_DFL = @intToPtr(?Sigaction.sigaction_fn, 0);
+pub const SIG_IGN = @intToPtr(?Sigaction.sigaction_fn, 1);
+pub const SIG_CATCH = @intToPtr(?Sigaction.sigaction_fn, 2);
+pub const SIG_HOLD = @intToPtr(?Sigaction.sigaction_fn, 3);
 
 pub const EPERM = 1; // Operation not permitted
 pub const ENOENT = 2; // No such file or directory

From 3a759fdb17d034cef1699774a098edeff5fc47bc Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Sun, 13 Dec 2020 19:34:51 +0100
Subject: [PATCH 06/10] Disable sigaction test on i386 because of #7427

---
 lib/std/os/test.zig | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/std/os/test.zig b/lib/std/os/test.zig
index 59116e1bbd..8ad172679b 100644
--- a/lib/std/os/test.zig
+++ b/lib/std/os/test.zig
@@ -653,6 +653,10 @@ test "sigaction" {
     if (builtin.os.tag == .wasi or builtin.os.tag == .windows)
         return error.SkipZigTest;
 
+    // https://github.com/ziglang/zig/issues/7427
+    if (builtin.os.tag == .linux and builtin.arch == .i386)
+        return error.SkipZigTest;
+
     const S = struct {
         fn handler(sig: i32, info: *const os.siginfo_t, ctx_ptr: ?*const c_void) callconv(.C) void {
             // Check that we received the correct signal.

From 75159229075a2932beec44d46bf6850d2e585d3c Mon Sep 17 00:00:00 2001
From: Alex Cameron <ascottcameron@gmail.com>
Date: Sat, 12 Dec 2020 05:30:06 +0000
Subject: [PATCH 07/10] Fix Sigaction struct on FreeBSD.

---
 lib/std/os/bits/freebsd.zig | 39 +++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/lib/std/os/bits/freebsd.zig b/lib/std/os/bits/freebsd.zig
index feac7b354a..3a71218b37 100644
--- a/lib/std/os/bits/freebsd.zig
+++ b/lib/std/os/bits/freebsd.zig
@@ -758,6 +758,43 @@ pub const Sigaction = extern struct {
     sa_mask: sigset_t,
 };
 
+pub const __siginfo = extern struct {
+    si_signo: c_int,
+    si_errno: c_int,
+    si_code: c_int,
+    si_pid: pid_t,
+    si_uid: uid_t,
+    si_status: c_int,
+    si_addr: ?*c_void,
+    si_value: sigval,
+    _reason: extern union {
+        _fault: extern struct {
+            _trapno: c_int,
+        },
+        _timer: extern struct {
+            _timerid: c_int,
+            _overrun: c_int,
+        },
+        _mesgq: extern struct {
+            _mqd: c_int,
+        },
+        _poll: extern struct {
+            _band: c_long,
+        },
+        __spare__: extern struct {
+            __spare1__: c_long,
+            __spare2__: [7]c_int,
+        },
+    },
+};
+
+pub const sigval = extern union {
+    sival_int: c_int,
+    sival_ptr: ?*c_void,
+    sigval_int: c_int,
+    sigval_ptr: ?*c_void,
+};
+
 pub const _SIG_WORDS = 4;
 pub const _SIG_MAXSIG = 128;
 
@@ -778,6 +815,8 @@ pub const sigset_t = extern struct {
     __bits: [_SIG_WORDS]u32,
 };
 
+pub const empty_sigset = sigset_t{ .__bits = [_]u32{0} ** _SIG_WORDS };
+
 pub const EPERM = 1; // Operation not permitted
 pub const ENOENT = 2; // No such file or directory
 pub const ESRCH = 3; // No such process

From 97ba3d9a6604a4ac4a92891beb19ec5889bd15ac Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Sun, 13 Dec 2020 19:45:11 +0100
Subject: [PATCH 08/10] std: Drop struct prefixes in FreeBSD siginfo

I'm not sure this prefix-free style is a good idea, but let's roll with
it for the moment.
---
 lib/std/os/bits/freebsd.zig | 54 ++++++++++++++++++-------------------
 1 file changed, 26 insertions(+), 28 deletions(-)

diff --git a/lib/std/os/bits/freebsd.zig b/lib/std/os/bits/freebsd.zig
index 3a71218b37..e7cfc2a784 100644
--- a/lib/std/os/bits/freebsd.zig
+++ b/lib/std/os/bits/freebsd.zig
@@ -752,47 +752,45 @@ pub const Sigaction = extern struct {
     },
 
     /// see signal options
-    sa_flags: c_uint,
+    flags: c_uint,
 
     /// signal mask to apply
-    sa_mask: sigset_t,
+    mask: sigset_t,
 };
 
-pub const __siginfo = extern struct {
-    si_signo: c_int,
-    si_errno: c_int,
-    si_code: c_int,
-    si_pid: pid_t,
-    si_uid: uid_t,
-    si_status: c_int,
-    si_addr: ?*c_void,
-    si_value: sigval,
-    _reason: extern union {
-        _fault: extern struct {
-            _trapno: c_int,
+pub const siginfo_t = extern struct {
+    signo: c_int,
+    errno: c_int,
+    code: c_int,
+    pid: pid_t,
+    uid: uid_t,
+    status: c_int,
+    addr: ?*c_void,
+    value: sigval,
+    reason: extern union {
+        fault: extern struct {
+            trapno: c_int,
         },
-        _timer: extern struct {
-            _timerid: c_int,
-            _overrun: c_int,
+        timer: extern struct {
+            timerid: c_int,
+            overrun: c_int,
         },
-        _mesgq: extern struct {
-            _mqd: c_int,
+        mesgq: extern struct {
+            mqd: c_int,
         },
-        _poll: extern struct {
-            _band: c_long,
+        poll: extern struct {
+            band: c_long,
         },
-        __spare__: extern struct {
-            __spare1__: c_long,
-            __spare2__: [7]c_int,
+        spare: extern struct {
+            spare1: c_long,
+            spare2: [7]c_int,
         },
     },
 };
 
 pub const sigval = extern union {
-    sival_int: c_int,
-    sival_ptr: ?*c_void,
-    sigval_int: c_int,
-    sigval_ptr: ?*c_void,
+    int: c_int,
+    ptr: ?*c_void,
 };
 
 pub const _SIG_WORDS = 4;

From bb72b0e800518863f4bd7fc459fedb7f90d8e9e5 Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Sun, 13 Dec 2020 20:36:34 +0100
Subject: [PATCH 09/10] Fix compilation error on FreeBSD

---
 lib/std/os/bits/freebsd.zig | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/std/os/bits/freebsd.zig b/lib/std/os/bits/freebsd.zig
index e7cfc2a784..6378dcaf8d 100644
--- a/lib/std/os/bits/freebsd.zig
+++ b/lib/std/os/bits/freebsd.zig
@@ -736,9 +736,9 @@ pub const winsize = extern struct {
 
 const NSIG = 32;
 
-pub const SIG_ERR = @intToPtr(fn (i32) callconv(.C) void, maxInt(usize));
-pub const SIG_DFL = @intToPtr(fn (i32) callconv(.C) void, 0);
-pub const SIG_IGN = @intToPtr(fn (i32) callconv(.C) void, 1);
+pub const SIG_ERR = @intToPtr(?Sigaction.sigaction_fn, maxInt(usize));
+pub const SIG_DFL = @intToPtr(?Sigaction.sigaction_fn, 0);
+pub const SIG_IGN = @intToPtr(?Sigaction.sigaction_fn, 1);
 
 /// Renamed from `sigaction` to `Sigaction` to avoid conflict with the syscall.
 pub const Sigaction = extern struct {

From d9e9390550e8290c1959ad2a8940e94d56f3ae1e Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Sun, 13 Dec 2020 20:36:47 +0100
Subject: [PATCH 10/10] Fix compilation error on OpenBSD

---
 lib/std/os/bits/openbsd.zig | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/lib/std/os/bits/openbsd.zig b/lib/std/os/bits/openbsd.zig
index 9e7b8aa399..5a2d929d03 100644
--- a/lib/std/os/bits/openbsd.zig
+++ b/lib/std/os/bits/openbsd.zig
@@ -750,6 +750,8 @@ const NSIG = 33;
 pub const SIG_ERR = @intToPtr(?Sigaction.sigaction_fn, maxInt(usize));
 pub const SIG_DFL = @intToPtr(?Sigaction.sigaction_fn, 0);
 pub const SIG_IGN = @intToPtr(?Sigaction.sigaction_fn, 1);
+pub const SIG_CATCH = @intToPtr(?Sigaction.sigaction_fn, 2);
+pub const SIG_HOLD = @intToPtr(?Sigaction.sigaction_fn, 3);
 
 /// Renamed from `sigaction` to `Sigaction` to avoid conflict with the syscall.
 pub const Sigaction = extern struct {
@@ -772,7 +774,7 @@ pub const sigval = extern union {
     ptr: ?*c_void,
 };
 
-pub const siginfo_t = extern union {
+pub const siginfo_t = extern struct {
     signo: c_int,
     code: c_int,
     errno: c_int,
@@ -790,22 +792,20 @@ pub const siginfo_t = extern union {
             trapno: c_int,
         },
         __pad: [128 - 3 * @sizeOf(c_int)]u8,
-    } align(@sizeOf(usize)),
+    },
 };
 
 comptime {
-    std.debug.assert(@sizeOf(siginfo_t) == 128);
+    if (@sizeOf(usize) == 4)
+        std.debug.assert(@sizeOf(siginfo_t) == 128)
+    else
+    // Take into account the padding between errno and data fields.
+        std.debug.assert(@sizeOf(siginfo_t) == 136);
 }
 
 pub const sigset_t = c_uint;
 pub const empty_sigset: sigset_t = 0;
 
-pub const SIG_ERR = @intToPtr(?Sigaction.sigaction_fn, maxInt(usize));
-pub const SIG_DFL = @intToPtr(?Sigaction.sigaction_fn, 0);
-pub const SIG_IGN = @intToPtr(?Sigaction.sigaction_fn, 1);
-pub const SIG_CATCH = @intToPtr(?Sigaction.sigaction_fn, 2);
-pub const SIG_HOLD = @intToPtr(?Sigaction.sigaction_fn, 3);
-
 pub const EPERM = 1; // Operation not permitted
 pub const ENOENT = 2; // No such file or directory
 pub const ESRCH = 3; // No such process