shells/powershell: Microsoft's shell with support for .NET objects

Co-authored-by:	Felix Palmen <zirias@FreeBSD.org>
Co-authored-by:	Szczepan Ćwikliński <sec@thinkcode.pl>

1 files changed, 94 insertions, 0 deletions

diff --git a/shells/powershell/files/patch-src_powershell_Program.cs b/shells/powershell/files/patch-src_powershell_Program.cs
new file mode 100644
index 000000000000..ec1585be12ca
--- /dev/null
+++ b/shells/powershell/files/patch-src_powershell_Program.cs
@@ -0,0 +1,94 @@
+--- src/powershell/Program.cs.orig	2024-03-30 20:39:17 UTC
++++ src/powershell/Program.cs
+@@ -56,6 +56,13 @@ namespace Microsoft.PowerShell
+         private const int MACOS_KERN_ARGMAX = 8;
+         private const int MACOS_KERN_PROCARGS2 = 49;
+         private const int MACOS_PROC_PIDPATHINFO_MAXSIZE = 4096;
++
++        // FreeBSD p/Invoke constants
++        private const int FREEBSD_CTL_KERN = 1;
++        private const int FREEBSD_KERN_PROC = 14;
++        private const int FREEBSD_KERN_PROC_ARGS = 7;
++        private const int FREEBSD_KERN_PROC_PATHNAME = 12;
++        private const int FREEBSD_ENOMEM = 12;
+ #endif
+ 
+         /// <summary>
+@@ -125,7 +132,62 @@ namespace Microsoft.PowerShell
+                 ThrowOnFailure("exec", ExecPwshLogin(args, pwshPath, isMacOS: false));
+                 return;
+             }
++            else if (OperatingSystem.IsFreeBSD())
++            {
++                Span<int> fmib = stackalloc int[4];
++                int fmibLength = 4;
++                fmib[0] = FREEBSD_CTL_KERN;
++                fmib[1] = FREEBSD_KERN_PROC;
++                fmib[2] = FREEBSD_KERN_PROC_ARGS;
++                fmib[3] = -1;
+ 
++                int sz = 1;
++                unsafe
++                {
++                    fixed (int *mibptr = fmib)
++                    {
++                        ThrowOnFailure(nameof(procNameFirstByte), SysCtl(mibptr, fmibLength, &procNameFirstByte, &sz, IntPtr.Zero, 0), FREEBSD_ENOMEM);
++                    }
++                }
++
++                if (!IsLogin(procNameFirstByte, args))
++                {
++                    return;
++                }
++
++                fmib[2] = FREEBSD_KERN_PROC_PATHNAME;
++                int pathsz = 0;
++
++                unsafe
++                {
++                    fixed (int *mibptr = fmib)
++                    {
++                        ThrowOnFailure(nameof(pathsz), SysCtl(mibptr, fmibLength, (void *)null, &pathsz, IntPtr.Zero, 0));
++                    }
++                }
++
++                IntPtr execPathPtr = Marshal.AllocHGlobal(pathsz);
++                try
++                {
++                    unsafe
++                    {
++                        fixed (int *mibptr = fmib)
++                        {
++                            ThrowOnFailure(nameof(execPathPtr), SysCtl(mibptr, fmibLength, execPathPtr.ToPointer(), &pathsz, IntPtr.Zero, 0));
++                        }
++                    }
++                    string? execPath = Marshal.PtrToStringAnsi(execPathPtr);
++                    ArgumentNullException.ThrowIfNull(execPath);
++                    ThrowOnFailure("exec", ExecPwshLogin(args, execPath, isMacOS: false));
++                }
++                finally
++                {
++                    Marshal.FreeHGlobal(execPathPtr);
++                }
++
++                return;
++            }
++
+             // At this point, we are on macOS
+ 
+             // Set up the mib array and the query for process maximum args size
+@@ -417,11 +479,13 @@ namespace Microsoft.PowerShell
+         /// </summary>
+         /// <param name="call">The native call that was attempted.</param>
+         /// <param name="code">The exit code it returned.</param>
+-        private static void ThrowOnFailure(string call, int code)
++        /// <param name="ignore">Ignore this error, consider it success.</param>
++        private static void ThrowOnFailure(string call, int code, int ignore = 0)
+         {
+             if (code < 0)
+             {
+                 code = Marshal.GetLastWin32Error();
++                if (code == ignore) return;
+                 Console.Error.WriteLine($"Call to '{call}' failed with errno {code}");
+                 throw new StartupException(call, code);
+             }