Add native method to query Mach-O SDK version at runtime

bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/library/os_custom.c

@@ -15,6 +15,8 @@
 #include "swt.h"
 #include "os_structs.h"
 #include "os_stats.h"
+#include <mach-o/loader.h>
+#include <crt_externs.h>
 
 #define OS_NATIVE(func) Java_org_eclipse_swt_internal_cocoa_OS_##func
 
@@ -150,3 +152,26 @@ JNIEXPORT jlong JNICALL OS_NATIVE(beginSheetModalForWindow)
 }
 #endif
 
+#ifndef NO_getMachOSDKVersion
+JNIEXPORT jint JNICALL OS_NATIVE(getMachOSDKVersion)
+	(JNIEnv *env, jclass that)
+{
+	jint rc = 0;
+	OS_NATIVE_ENTER(env, that, getMachOSDKVersion_FUNC);
+	const struct mach_header_64 *header = (const struct mach_header_64 *)_NSGetMachExecuteHeader();
+	const uint8_t *ptr = (const uint8_t *)header + sizeof(struct mach_header_64);
+	for (uint32_t i = 0; i < header->ncmds; i++) {
+		const struct load_command *lc = (const struct load_command *)ptr;
+		if (lc->cmd == LC_BUILD_VERSION) {
+			const struct build_version_command *bv = (const struct build_version_command *)ptr;
+			uint32_t sdk = bv->sdk;
+			rc = (jint)(((sdk >> 16) & 0xff) << 16) | (((sdk >> 8) & 0xff) << 8) | (sdk & 0xff);
+			break;
+		}
+		ptr += lc->cmdsize;
+	}
+	OS_NATIVE_EXIT(env, that, getMachOSDKVersion_FUNC);
+	return rc;
+}
+#endif
+

bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/library/os_stats.h

@@ -369,6 +369,7 @@ typedef enum {
 	class_1getMethodImplementation_FUNC,
 	class_1getName_FUNC,
 	class_1getSuperclass_FUNC,
+	getMachOSDKVersion_FUNC,
 	getpid_FUNC,
 	instrumentObjcMessageSends_FUNC,
 	isFlipped_1CALLBACK_FUNC,

bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/OS.java

@@ -38,6 +38,18 @@ public static int VERSION (int major, int minor, int bugfix) {
 		return (major << 16) + (minor << 8) + bugfix;
 	}
 
+	public static int VERSION_MAJOR (int version) {
+		return (version >>> 16) & 0xFF;
+	}
+
+	public static int VERSION_MINOR (int version) {
+		return (version >>> 8) & 0xFF;
+	}
+
+	public static int VERSION_BUGFIX (int version) {
+		return version & 0xFF;
+	}
+
 	public static final boolean IS_X86_64 = System.getProperty("os.arch").equals("x86_64"); //$NON-NLS-1$
 
 	/*
@@ -336,6 +348,14 @@ public static boolean isSystemDarkAppearance() {
 
 public static final native int getpid();
 
+/**
+ * Returns the SDK version from LC_BUILD_VERSION in the main executable's
+ * Mach-O header, encoded as {@code (major << 16) + (minor << 8) + bugfix}.
+ * Returns 0 if LC_BUILD_VERSION is not found.
+ * @method flags=no_gen
+ */
+public static final native int getMachOSDKVersion();
+
 public static final native void call(long proc, long id, long sel);
 
 /** QuickDraw calls */