ios: Provide a copy of mach_exc.defs and run mig on it

This updates (and corrects) 8dbbaff2e1a5, which added exc.defs, by
adding mach_exc.defs too.

The difference betwen the exc and mach_exc subsystems is that the |code|
parameter is int[] in exc and int64_t[] in mach_exc. Many exceptions
carry the exception address in code[1], and a 32-bit int results in the
exception address being truncated in exc. No information is lost in
mach_exc, where a 64-bit int64_t is used.

In 8dbbaff2e1a5, I misremembered the type of the |code| parameter as a
type derived from uintptr_t, such as vm_address_t, an integer as wide as
a pointer. I was wrong, and mach_exc is necessary. I also noted that
Apple normally forbids mach_-prefixed interfaces in favor of the
prefix-less ones for the reasons I mentioned, and that, all else being
equal, it was desirable to adhere to the spirit of that convention.
Because neither exc nor mach_exc are available in the SDK, it’s moot
from a technical perspective, as we need to provide our own stubs either
way.

Bug: crashpad:31
Change-Id: Ied1be470e653b2bead1a283cb8b9283d210c328d
Reviewed-on: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/2159286
Reviewed-by: Justin Cohen <justincohen@chromium.org>
Commit-Queue: Mark Mentovai <mark@chromium.org>

third_party/xnu/README.crashpad

@@ -17,6 +17,6 @@ Local Modifications:
    <mach/vm_prot.h> have been retained but these headers have not been provided.
    External headers must be made available to provide the cpu_type_t,
    cpu_subtype_t, and vm_prot_t types.
- - osfmk/mach/exc.defs is present, to fill in for <mach/exc.defs> on iOS, where
+ - osfmk/mach/exc.defs and osfmk/mach/mach_exc.defs are present, to fill in
-   it is missing.
+   for <mach/exc.defs> and <mach/mach_exc.defs> on iOS, where they are missing.
  - Anything not listed above is omitted.

third_party/xnu/osfmk/mach/mach_exc.defs

@@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2006 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ * 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ * 
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ * 
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ */
+/*
+ * @OSF_COPYRIGHT@
+ */
+/* 
+ * Mach Operating System
+ * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
+ * All Rights Reserved.
+ * 
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ * 
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ * 
+ * Carnegie Mellon requests users of this software to return to
+ * 
+ *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
+ *  School of Computer Science
+ *  Carnegie Mellon University
+ *  Pittsburgh PA 15213-3890
+ * 
+ * any improvements or extensions that they make and grant Carnegie Mellon
+ * the rights to redistribute these changes.
+ */
+/*
+ */
+/*
+ * Abstract:
+ *	MiG definitions file for Mach exception interface.
+ */
+
+subsystem
+#if	KERNEL_USER
+	  KernelUser
+#endif
+#if	KERNEL_SERVER
+	  KernelServer
+#endif	/* KERNEL_SERVER */
+
+		     mach_exc 2405;
+
+#include <mach/std_types.defs>
+#include <mach/mach_types.defs>
+
+ServerPrefix catch_;
+
+type mach_exception_data_t	= array[*:2] of int64_t;
+type exception_type_t		= int;
+
+routine		mach_exception_raise(
+			exception_port	: mach_port_t;
+			thread		: mach_port_t;
+			task		: mach_port_t;
+			exception	: exception_type_t;
+			code		: mach_exception_data_t
+#if MACH_EXC_SERVER_SECTOKEN
+ ;
+ ServerSecToken stoken	: security_token_t
+#endif
+#if MACH_EXC_SERVER_AUDITTOKEN
+ ;
+ ServerAuditToken atoken: audit_token_t
+#endif
+			);
+
+routine		mach_exception_raise_state(
+			exception_port	: mach_port_t;
+			exception	: exception_type_t;
+			code		: mach_exception_data_t, const;
+		  inout flavor		: int;
+			old_state	: thread_state_t, const;
+		    out new_state	: thread_state_t
+#if MACH_EXC_SERVER_SECTOKEN
+ ;
+ ServerSecToken stoken	: security_token_t
+#endif
+#if MACH_EXC_SERVER_AUDITTOKEN
+ ;
+ ServerAuditToken atoken: audit_token_t
+#endif
+			);
+
+routine		mach_exception_raise_state_identity(
+			exception_port  : mach_port_t;
+			thread          : mach_port_t;
+			task            : mach_port_t;
+			exception       : exception_type_t;
+			code            : mach_exception_data_t;
+		  inout flavor          : int;
+			old_state       : thread_state_t;
+		    out new_state       : thread_state_t
+#if MACH_EXC_SERVER_SECTOKEN
+ ;
+ ServerSecToken stoken	: security_token_t
+#endif
+#if MACH_EXC_SERVER_AUDITTOKEN
+ ;
+ ServerAuditToken atoken: audit_token_t
+#endif
+			);
+
+/* vim: set ft=c : */

util/BUILD.gn

@@ -42,7 +42,10 @@ if (crashpad_is_mac || crashpad_is_ios) {
         "mach/child_port.defs",
       ]
     } else if (crashpad_is_ios) {
-      sources = [ "../third_party/xnu/osfmk/mach/exc.defs" ]
+      sources = [
+        "../third_party/xnu/osfmk/mach/exc.defs",
+        "../third_party/xnu/osfmk/mach/mach_exc.defs",
+      ]
     }
 
     outputs = [