Changes to support OpenBSD. (apple#52)

* [cmake] Support amd64 architecture name.

On OpenBSD, "x86_64" is called "amd64", and therefore recognition of this
name is required for the cmake build.

* [cmake] Add missing file.

This is required since, for example, `Deque+Extras` requires
`_withContiguousStorageIfAvailable_SR14663`.

* ManagedBuffer.capacity is unavailable on OpenBSD.

ManagedBuffer requires nonstandard API to implement `capacity` and
subsequently is unavailable on OpenBSD. For portability, just use
`minimumCapacity` on this platform.

Author: 3405691582

Sources/DequeModule/CMakeLists.txt

@@ -12,6 +12,7 @@ add_library(DequeModule
   _DequeBufferHeader.swift
   _DequeSlot.swift
   _UnsafeWrappedBuffer.swift
+  Compatibility.swift
   Deque._Storage.swift
   Deque._UnsafeHandle.swift
   Deque.swift

Sources/DequeModule/Deque._Storage.swift

@@ -48,8 +48,13 @@ extension Deque._Storage {
   internal init(minimumCapacity: Int) {
     let object = _DequeBuffer<Element>.create(
       minimumCapacity: minimumCapacity,
-      makingHeaderWith: { object in
-        _DequeBufferHeader(capacity: object.capacity, count: 0, startSlot: .zero)
+      makingHeaderWith: {
+        #if os(OpenBSD)
+        let capacity = minimumCapacity
+        #else
+        let capacity = $0.capacity
+        #endif
+        return _DequeBufferHeader(capacity: capacity, count: 0, startSlot: .zero)
       })
     self.init(_buffer: _Buffer(unsafeBufferObject: object))
   }

Sources/DequeModule/Deque._UnsafeHandle.swift

@@ -298,8 +298,13 @@ extension Deque._UnsafeHandle {
     let object = _DequeBuffer<Element>.create(
       minimumCapacity: minimumCapacity,
       makingHeaderWith: {
-        _DequeBufferHeader(
-          capacity: $0.capacity,
+        #if os(OpenBSD)
+        let capacity = minimumCapacity
+        #else
+        let capacity = $0.capacity
+        #endif
+        return _DequeBufferHeader(
+          capacity: capacity,
           count: count,
           startSlot: .zero)
       })
@@ -327,8 +332,13 @@ extension Deque._UnsafeHandle {
     let object = _DequeBuffer<Element>.create(
       minimumCapacity: minimumCapacity,
       makingHeaderWith: {
-        _DequeBufferHeader(
-          capacity: $0.capacity,
+        #if os(OpenBSD)
+        let capacity = minimumCapacity
+        #else
+        let capacity = $0.capacity
+        #endif
+        return _DequeBufferHeader(
+          capacity: capacity,
           count: count,
           startSlot: .zero)
       })

cmake/modules/SwiftSupport.cmake

@@ -31,6 +31,8 @@ function(get_swift_host_arch result_var_name)
     set("${result_var_name}" "armv7" PARENT_SCOPE)
   elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "armv7-a")
     set("${result_var_name}" "armv7" PARENT_SCOPE)
+  elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "amd64")
+    set("${result_var_name}" "amd64" PARENT_SCOPE)
   elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "AMD64")
     set("${result_var_name}" "x86_64" PARENT_SCOPE)
   elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "IA64")