Add SymbolicConstantsMach and its test

util/mach/mach_extensions.cc

Index: util/mach/mach_extensions.cc
diff --git a/util/mach/mach_extensions.cc b/util/mach/mach_extensions.cc
new file mode 100644
index 0000000000000000000000000000000000000000..8b2468db956c9cee2d15ed5ba4bc6c09942914e7
--- /dev/null
+++ b/util/mach/mach_extensions.cc
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+// Copyright 2014 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "util/mach/mach_extensions.h"
+
+#include <AvailabilityMacros.h>
+
+#include "util/mac/mac_util.h"
+
+namespace crashpad {
+
+exception_mask_t ExcMaskAll() {
+  // This is necessary because of the way that the kernel validates
+  // exception_mask_t arguments to
+  // {host,task,thread}_{get,set,swap}_exception_ports(). It is strict,
+  // rejecting attempts to operate on any bits that it does not recognize. See
+  // 10.9.4 xnu-2422.110.17/osfmk/mach/ipc_host.c and
+  // xnu-2422.110.17/osfmk/mach/ipc_tt.c.
+
+#if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_9
+  int mac_os_x_minor_version = MacOSXMinorVersion();
+#endif
+
+  // See 10.6.8 xnu-1504.15.3/osfmk/mach/exception_types.h. 10.7 uses the same
+  // definition as 10.6. See 10.7.5 xnu-1699.32.7/osfmk/mach/exception_types.h
+  //
+  // The 10.5 SDK actually defined EXC_MASK_ALL as including EXC_MASK_CRASH.
+  // Later SDKs removed EXC_MASK_CRASH from EXC_MASK_ALL, but placed it into a
+  // new constant, EXC_MASK_VALID. For consistent behavior, don’t include
+  // EXC_MASK_CRASH in the 10.5 EXC_MASK_ALL. Consumers that want EXC_MASK_ALL
+  // along with EXC_MASK_CRASH must use ExcMaskAll() | EXC_MASK_CRASH
+  // explicitly. 10.5 otherwise behaves identically to 10.6. See 10.5.8
+  // xnu-1228.15.4/osfmk/mach/exception_types.h.
+  const exception_mask_t kExcMaskAll_10_6 =
+      EXC_MASK_BAD_ACCESS | EXC_MASK_BAD_INSTRUCTION | EXC_MASK_ARITHMETIC |
+      EXC_MASK_EMULATION | EXC_MASK_SOFTWARE | EXC_MASK_BREAKPOINT |
+      EXC_MASK_SYSCALL | EXC_MASK_MACH_SYSCALL | EXC_MASK_RPC_ALERT |
+      EXC_MASK_MACHINE;
+#if MAC_OS_X_VERSION_MIN_REQUIRED <= MAC_OS_X_VERSION_10_7
+  if (mac_os_x_minor_version <= 7) {
+    return kExcMaskAll_10_6;
+  }
+#endif
+
+  // 10.8 added EXC_MASK_RESOURCE. See 10.8.5
+  // xnu-2050.48.11/osfmk/mach/exception_types.h.
+  const exception_mask_t kExcMaskAll_10_8 =
+      kExcMaskAll_10_6 | EXC_MASK_RESOURCE;
+#if MAC_OS_X_VERSION_MIN_REQUIRED <= MAC_OS_X_VERSION_10_8
+  if (mac_os_x_minor_version <= 8) {
+    return kExcMaskAll_10_8;
+  }
+#endif
+
+  // 10.9 added EXC_MASK_GUARD. See 10.9.4
+  // xnu-2422.110.17/osfmk/mach/exception_types.h.
+  const exception_mask_t kExcMaskAll_10_9 = kExcMaskAll_10_8 | EXC_MASK_GUARD;
+  return kExcMaskAll_10_9;
+}
+
+}  // namespace crashpad