OpenBSD 7.8 will require OpaquePointer for FILE.

OpenBSD 7.8 snapshots hide the type information for FILE. Therefore, the
types for the standard stdio streams should (regrettably) be
OpaquePointer, due to the well-discussed issue of losing type information
for forward-declared C types.

We explicitly drop to void * in the LibcOverlayShims for backwards
compatibility, since OpenBSD 7.8 is not yet released.

However, because SwiftReflectionTest uses libc FILE functions like
fwrite and fflush directly, this means that building this on 7.7 will
still fail because types will mismatch. Instead of adding extra shims,
let's just skip building SwiftReflectionTest on 7.7.

Author: 3405691582

stdlib/private/CMakeLists.txt

@@ -30,7 +30,10 @@ if(SWIFT_BUILD_SDK_OVERLAY
   endif()
   # Currently SwiftReflectionTest cannot be built on Windows, due to
   # dependencies on POSIX symbols
-  if (SWIFT_INCLUDE_TESTS AND (NOT CMAKE_SYSTEM_NAME STREQUAL "Windows"))
+  if (SWIFT_INCLUDE_TESTS
+      AND NOT CMAKE_SYSTEM_NAME STREQUAL "Windows"
+      AND NOT (CMAKE_SYSTEM_NAME STREQUAL "OpenBSD"
+               AND CMAKE_SYSTEM_VERSION VERSION_LESS "7.8"))
     add_subdirectory(SwiftReflectionTest)
   endif()
 endif()

stdlib/public/Platform/Platform.swift

@@ -74,9 +74,9 @@ public func snprintf(ptr: UnsafeMutablePointer<Int8>, _ len: Int, _ format: Unsa
 #endif
 
 #elseif os(OpenBSD)
-public var stdin: UnsafeMutablePointer<FILE> { return _swift_stdlib_stdin() }
-public var stdout: UnsafeMutablePointer<FILE> { return _swift_stdlib_stdout() }
-public var stderr: UnsafeMutablePointer<FILE> { return _swift_stdlib_stderr() }
+public var stdin: OpaquePointer { return OpaquePointer(_swift_stdlib_stdin()) }
+public var stdout: OpaquePointer { return OpaquePointer(_swift_stdlib_stdout()) }
+public var stderr: OpaquePointer { return OpaquePointer(_swift_stdlib_stderr()) }
 #elseif os(Windows)
 public var stdin: UnsafeMutablePointer<FILE> {
   return unsafe __acrt_iob_func(0)

stdlib/public/SwiftShims/swift/shims/LibcOverlayShims.h

@@ -121,15 +121,15 @@ int static inline _swift_stdlib_openat(int fd, const char *path, int oflag,
 #endif
 
 #if defined(__OpenBSD__)
-static inline FILE *_swift_stdlib_stdin(void) {
+static inline void *_swift_stdlib_stdin(void) {
   return stdin;
 }
 
-static inline FILE *_swift_stdlib_stdout(void) {
+static inline void *_swift_stdlib_stdout(void) {
   return stdout;
 }
 
-static inline FILE *_swift_stdlib_stderr(void) {
+static inline void *_swift_stdlib_stderr(void) {
   return stderr;
 }
 #endif