8254231: Implementation of Foreign Linker API (Incubator)

Reviewed-by: coleenp, ihse, dholmes, vlivanov

src/java.base/share/native/libjava/NativeLibraries.c

@@ -246,6 +246,29 @@ Java_jdk_internal_loader_NativeLibraries_findEntry0
     return res;
 }
 
+/*
+ * Class:     jdk_internal_loader_NativeLibraries
+ * Method:    findEntryInProcess
+ * Signature: (Ljava/lang/String;)J
+ */
+JNIEXPORT jlong JNICALL
+Java_jdk_internal_loader_NativeLibraries_findEntryInProcess
+  (JNIEnv *env, jclass cls, jstring name)
+{
+    const char *cname;
+    jlong res;
+
+    if (!initIDs(env))
+        return jlong_zero;
+
+    cname = (*env)->GetStringUTFChars(env, name, 0);
+    if (cname == 0)
+        return jlong_zero;
+    res = ptr_to_jlong(findEntryInProcess(cname));
+    (*env)->ReleaseStringUTFChars(env, name, cname);
+    return res;
+}
+
 /*
  * Class:     jdk_internal_loader_NativeLibraries
  * Method:    findBuiltinLib

src/java.base/share/native/libjava/jni_util.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2020, 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
@@ -333,6 +333,8 @@ JNIEXPORT void InitializeEncoding(JNIEnv *env, const char *name);
 
 void* getProcessHandle();
 
+void* findEntryInProcess(const char* name);
+
 void buildJniFunctionName(const char *sym, const char *cname,
                           char *jniEntryName);