8368877: Generate Jextract bindings for Kqueue

Reviewed-by: alanb, aefimov

Author: Darragh Clarke

src/java.base/macosx/classes/jdk/internal/ffi/generated/errno/errno_h$shared.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2025, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+// Generated by jextract
+
+package jdk.internal.ffi.generated.errno;
+
+import java.lang.foreign.*;
+import java.lang.invoke.*;
+import java.util.*;
+import java.util.stream.*;
+
+import static java.lang.foreign.ValueLayout.*;
+
+@SuppressWarnings("restricted")
+public class errno_h$shared {
+
+    errno_h$shared() {
+        // Should not be called directly
+    }
+
+    public static final OfBoolean C_BOOL = (OfBoolean) Linker.nativeLinker().canonicalLayouts().get("bool");
+    public static final OfByte C_CHAR =(OfByte)Linker.nativeLinker().canonicalLayouts().get("char");
+    public static final OfShort C_SHORT = (OfShort) Linker.nativeLinker().canonicalLayouts().get("short");
+    public static final OfInt C_INT = (OfInt) Linker.nativeLinker().canonicalLayouts().get("int");
+    public static final OfLong C_LONG_LONG = (OfLong) Linker.nativeLinker().canonicalLayouts().get("long long");
+    public static final OfFloat C_FLOAT = (OfFloat) Linker.nativeLinker().canonicalLayouts().get("float");
+    public static final OfDouble C_DOUBLE = (OfDouble) Linker.nativeLinker().canonicalLayouts().get("double");
+    public static final AddressLayout C_POINTER = ((AddressLayout) Linker.nativeLinker().canonicalLayouts().get("void*"))
+            .withTargetLayout(MemoryLayout.sequenceLayout(Long.MAX_VALUE, C_CHAR));
+    public static final OfLong C_LONG = (OfLong) Linker.nativeLinker().canonicalLayouts().get("long");
+
+    static final boolean TRACE_DOWNCALLS = Boolean.getBoolean("jextract.trace.downcalls");
+
+    static void traceDowncall(String name, Object... args) {
+         String traceArgs = Arrays.stream(args)
+                       .map(Object::toString)
+                       .collect(Collectors.joining(", "));
+         System.out.printf("%s(%s)\n", name, traceArgs);
+    }
+
+    static MethodHandle upcallHandle(Class<?> fi, String name, FunctionDescriptor fdesc) {
+        try {
+            return MethodHandles.lookup().findVirtual(fi, name, fdesc.toMethodType());
+        } catch (ReflectiveOperationException ex) {
+            throw new AssertionError(ex);
+        }
+    }
+
+    static MemoryLayout align(MemoryLayout layout, long align) {
+        return switch (layout) {
+            case PaddingLayout p -> p;
+            case ValueLayout v -> v.withByteAlignment(align);
+            case GroupLayout g -> {
+                MemoryLayout[] alignedMembers = g.memberLayouts().stream()
+                        .map(m -> align(m, align)).toArray(MemoryLayout[]::new);
+                yield g instanceof StructLayout ?
+                        MemoryLayout.structLayout(alignedMembers) : MemoryLayout.unionLayout(alignedMembers);
+            }
+            case SequenceLayout s -> MemoryLayout.sequenceLayout(s.elementCount(), align(s.elementLayout(), align));
+        };
+    }
+}

src/java.base/macosx/classes/jdk/internal/ffi/generated/errno/errno_h.java

@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2024, 2025, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+// Generated by jextract
+
+package jdk.internal.ffi.generated.errno;
+
+import java.lang.foreign.*;
+import java.lang.invoke.*;
+
+@SuppressWarnings("restricted")
+public class errno_h extends errno_h$shared {
+
+    errno_h() {
+        // Should not be called directly
+    }
+
+    static final Arena LIBRARY_ARENA = Arena.ofAuto();
+
+    static final SymbolLookup SYMBOL_LOOKUP = SymbolLookup.loaderLookup()
+            .or(Linker.nativeLinker().defaultLookup());
+
+    private static final int EINTR = (int)4L;
+    /**
+     * {@snippet lang=c :
+     * #define EINTR 4
+     * }
+     */
+    public static int EINTR() {
+        return EINTR;
+    }
+
+    private static class strerror_r {
+        public static final FunctionDescriptor DESC = FunctionDescriptor.of(
+                C_INT,
+                C_INT,
+                C_POINTER,
+                C_LONG
+        );
+
+        public static final MemorySegment ADDR = SYMBOL_LOOKUP.findOrThrow("strerror_r");
+
+        public static final MethodHandle HANDLE = Linker.nativeLinker().downcallHandle(ADDR, DESC);
+    }
+
+    /**
+     * Function descriptor for:
+     * {@snippet lang=c :
+     * int strerror_r(int __errnum, char *__strerrbuf, size_t __buflen)
+     * }
+     */
+    public static FunctionDescriptor strerror_r$descriptor() {
+        return strerror_r.DESC;
+    }
+
+    /**
+     * Downcall method handle for:
+     * {@snippet lang=c :
+     * int strerror_r(int __errnum, char *__strerrbuf, size_t __buflen)
+     * }
+     */
+    public static MethodHandle strerror_r$handle() {
+        return strerror_r.HANDLE;
+    }
+
+    /**
+     * Address for:
+     * {@snippet lang=c :
+     * int strerror_r(int __errnum, char *__strerrbuf, size_t __buflen)
+     * }
+     */
+    public static MemorySegment strerror_r$address() {
+        return strerror_r.ADDR;
+    }
+
+    /**
+     * {@snippet lang=c :
+     * int strerror_r(int __errnum, char *__strerrbuf, size_t __buflen)
+     * }
+     */
+    public static int strerror_r(int __errnum, MemorySegment __strerrbuf, long __buflen) {
+        var mh$ = strerror_r.HANDLE;
+        try {
+            if (TRACE_DOWNCALLS) {
+                traceDowncall("strerror_r", __errnum, __strerrbuf, __buflen);
+            }
+            return (int)mh$.invokeExact(__errnum, __strerrbuf, __buflen);
+        } catch (Error | RuntimeException ex) {
+           throw ex;
+        } catch (Throwable ex$) {
+           throw new AssertionError("should not reach here", ex$);
+        }
+    }
+}

src/java.base/macosx/classes/jdk/internal/ffi/generated/errno/package-info.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2024, 2025, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * Defines native structures for errno APIs.
+ * Generated with the following jextract command:
+ * {@snippet lang = "Shell Script":
+ *
+ * HEADER_NAME=errno.h
+ * echo "#include <errno.h>" > $HEADER_NAME
+ * echo "#include <string.h>" >> $HEADER_NAME
+ *
+ * jextract --target-package jdk.internal.ffi.generated.errno \
+ *    --include-constant EINTR \
+ *    --include-function strerror_r \
+ *    $HEADER_NAME
+ * }
+ *
+ */
+
+package jdk.internal.ffi.generated.errno;