Merge pull request #22 from ChengJin01/ffi_inline_libc_func_jdk20

[FFI]Inline the missing libc functions for symbol lookup on AIX

closed/src/java.base/aix/native/libsyslookup/syslookup.c

@@ -0,0 +1,37 @@
+/*
+ * ===========================================================================
+ * (c) Copyright IBM Corp. 2023, 2023 All Rights Reserved
+ * ===========================================================================
+ *
+ * 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.
+ *
+ * IBM designates this particular file as subject to the "Classpath" exception
+ * as provided by IBM 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, see <http://www.gnu.org/licenses/>.
+ *
+ * ===========================================================================
+ */
+
+#include <fstab.h>
+#include <setjmp.h>
+#include <string.h>
+#include <strings.h>
+
+/* The function list inlines the libc functions which
+ * are missing in loading the default library.
+ */
+__attribute__((visibility("default"))) void* funcs[] = {
+		&bcopy, &endfsent, &getfsent, &getfsfile, &getfsspec, &longjmp,
+		&memcpy, &memmove, &setfsent, &setjmp, &siglongjmp, &strcat,
+		&strcpy, &strncat, &strncpy
+};

src/java.base/share/classes/jdk/internal/foreign/SystemLookup.java

@@ -85,14 +85,27 @@ private static SymbolLookup makeAixLookup() {
         NativeLibrary lib = NativeLibraries.defaultLibrary;
         return name -> {
             Objects.requireNonNull(name);
-            try {
-                long addr = lib.lookup(name);
-                return (addr == 0) ?
-                        Optional.empty() :
-                        Optional.of(MemorySegment.ofAddress(addr, 0, SegmentScope.global()));
-            } catch (NoSuchMethodException e) {
-                return Optional.empty();
+            MemorySegment funcAddr = null;
+            AixFuncSymbols symbol = AixFuncSymbols.valueOfOrNull(name);
+            if (symbol == null) {
+                try {
+                    /* Look up the libc functions in the default library. */
+                    funcAddr = MemorySegment.ofAddress(lib.lookup(name));
+                } catch (NoSuchMethodException e) {
+                    return Optional.empty();
+                }
+            } else {
+                /* Directly load the specified library with the libc functions
+                 * missing in the default library.
+                 */
+                SymbolLookup funcsLibLookup =
+                        libLookup(libs -> libs.load(jdkLibraryPath("syslookup")));
+                MemorySegment funcs = MemorySegment.ofAddress(funcsLibLookup.find("funcs").orElseThrow().address(),
+                    ADDRESS.byteSize() * AixFuncSymbols.values().length, SegmentScope.global());
+                funcAddr = funcs.getAtIndex(ADDRESS, symbol.ordinal());
             }
+
+            return Optional.of(MemorySegment.ofAddress(funcAddr.address(), 0L, SegmentScope.global()));
         };
     }
 
@@ -231,4 +244,20 @@ static WindowsFallbackSymbols valueOfOrNull(String name) {
             }
         }
     }
+
+    /* Inlined libc function symbols missing in the default library. */
+    public enum AixFuncSymbols {
+        bcopy, endfsent, getfsent, getfsfile, getfsspec, longjmp,
+        memcpy, memmove, setfsent, setjmp, siglongjmp, strcat,
+        strcpy, strncat, strncpy
+        ;
+
+        static AixFuncSymbols valueOfOrNull(String name) {
+            try {
+                return valueOf(name);
+            } catch (IllegalArgumentException e) {
+                return null;
+            }
+        }
+    }
 }