[gcc(refs/users/iains/heads/d-for-darwin)] libphobos: Fix mcontext_t definitions for Darwin

[Iain D Sandoe <iains@gcc.gnu.org>]

https://gcc.gnu.org/g:16f6a362abf9b3f61fc8b62d2be79a39eda558ec

commit 16f6a362abf9b3f61fc8b62d2be79a39eda558ec
Author: Iain Buclaw <ibuclaw@gdcproject.org>
Date:   Mon Dec 7 15:42:09 2020 +0100

    libphobos: Fix mcontext_t definitions for Darwin

Diff:
---
 libphobos/libdruntime/core/sys/posix/ucontext.d | 119 ++++++++++++++++++++++--
 libphobos/src/std/datetime/package.d            |  15 +--
 2 files changed, 114 insertions(+), 20 deletions(-)

diff --git a/libphobos/libdruntime/core/sys/posix/ucontext.d b/libphobos/libdruntime/core/sys/posix/ucontext.d
index ef74771a50d..9400edd11f2 100644
--- a/libphobos/libdruntime/core/sys/posix/ucontext.d
+++ b/libphobos/libdruntime/core/sys/posix/ucontext.d
@@ -920,16 +920,121 @@ else version (CRuntime_Musl)
 }
 else version (Darwin)
 {
-    alias mcontext_t = void;
+    private
+    {
+        version (X86_Any)
+        {
+            struct __darwin_mmst_reg
+            {
+                char[10] __mmst_reg;
+                char[6] __mmst_rsrv;
+            }
+
+            struct __darwin_xmm_reg
+            {
+                char[16] __xmm_reg;
+            }
+
+            struct __darwin_exception_state
+            {
+                uint __trapno;
+                uint __err;
+                version (X86_64)
+                    ulong __faultvaddr;
+                else
+                    uint __faultvaddr;
+            }
+
+            struct __darwin_thread_state
+            {
+                version (X86_64)
+                    ulong[21] __regs;
+                else
+                    uint[16] __regs;
+            }
+
+            struct __darwin_float_state
+            {
+                int[2] __fpu_reserved;
+                ushort __fpu_fcw;
+                ushort __fpu_fsw;
+                uint[7] __fpu_regs;
+                __darwin_mmst_reg[8] __fpu_stmm;
+                version (X86_64)
+                {
+                    __darwin_xmm_reg[16] __fpu_xmm;
+                    char[6*16] __fpu_rsrv4;
+                }
+                else
+                {
+                    __darwin_xmm_reg[8] __fpu_xmm;
+                    char[14*16] __fpu_rsrv4;
+                }
+                int __fpu_reserved1;
+            }
+
+            struct __darwin_mcontext
+            {
+                __darwin_exception_state __es;
+                __darwin_thread_state __ss;
+                __darwin_float_state __fs;
+            }
+        }
+        else version (PPC_Any)
+        {
+            struct __darwin_exception_state
+            {
+                uint __dar;
+                uint __dsisr;
+                uint __exception;
+                uint __pad0;
+                uint[4] __pad1;
+            }
+
+            struct __darwin_thread_state
+            {
+                uint[40] __regs;
+            }
+
+            struct __darwin_float_state
+            {
+                double[32] __fpregs;
+                uint __fpscr_pad;
+                uint __fpscr;
+            }
+
+            struct __darwin_vector_state
+            {
+                uint[32][4] __save_vr;
+                uint[4] __save_vscr;
+                uint[4] __save_pad5;
+                uint __save_vrvalid;
+                uint[7] __save_pad6;
+            }
+
+            struct __darwin_mcontext
+            {
+                __darwin_exception_state __es;
+                __darwin_thread_state __ss;
+                __darwin_float_state __fs;
+                __darwin_vector_state __vs;
+            }
+        }
+        else
+            static assert(false, "mcontext_t unimplemented for this platform.");
+    }
+
+    alias mcontext_t = __darwin_mcontext*;
 
     struct ucontext
     {
-        int         uc_onstack;
-        sigset_t    uc_sigmask;
-        stack_t     uc_stack;
-        ucontext*   uc_link;
-        size_t      uc_mcsize;
-        mcontext_t* uc_mcontext;
+        int                uc_onstack;
+        sigset_t           uc_sigmask;
+        stack_t            uc_stack;
+        ucontext*          uc_link;
+        size_t             uc_mcsize;
+        __darwin_mcontext* uc_mcontext;
+        __darwin_mcontext  __mcontext_data;
     }
 
     alias ucontext_t = ucontext;
diff --git a/libphobos/src/std/datetime/package.d b/libphobos/src/std/datetime/package.d
index 976d06ddb79..a5fd03d39e9 100644
--- a/libphobos/src/std/datetime/package.d
+++ b/libphobos/src/std/datetime/package.d
@@ -115,7 +115,6 @@ public import std.datetime.interval;
 public import std.datetime.systime;
 public import std.datetime.timezone;
 
-import core.exception : AssertError;
 import std.functional : unaryFun;
 import std.traits;
 import std.typecons : Flag, Yes, No;
@@ -267,12 +266,7 @@ public:
         StopWatch sw;
         sw.start();
         auto t1 = sw.peek();
-        bool doublestart = true;
-        try
-            sw.start();
-        catch (AssertError e)
-            doublestart = false;
-        assert(!doublestart);
+        assert(sw._flagStarted);
         sw.stop();
         assert((t1 - sw.peek()).to!("seconds", real)() <= 0);
     }
@@ -294,12 +288,7 @@ public:
         sw.start();
         sw.stop();
         auto t1 = sw.peek();
-        bool doublestop = true;
-        try
-            sw.stop();
-        catch (AssertError e)
-            doublestop = false;
-        assert(!doublestop);
+        assert(!sw._flagStarted);
         assert((t1 - sw.peek()).to!("seconds", real)() == 0);
     }