Initial Handling of Non-Void Java Method Calls in GnuCOBOL

ChangeLog

@@ -1,5 +1,11 @@
+
+2024-07-12  Vedant Tewari <[email protected]>
 
-2023-02-25  Ron Norman <[email protected]> 
+	* ax_prog_java.m4: Added macro for jni check
+	* ax_jni_include_dir.m4: Added macro for jni check
+    	* configure.ac: added support for Java interoperability through JNI
+
+2023-02-25  Ron Norman <[email protected]>
 
 	* configure.ac: Add check for  sys/time.h
 

DEPENDENCIES

@@ -137,6 +137,21 @@ The following libraries ARE required WHEN :
 
     JSON-C is distributed under Expat License.
 
+5) JNI (Java Native Interface) support is used
+
+    BOTH runtime AND development components required.
+
+    Java Development Kit (JDK) 8 or later
+
+    https://openjdk.org/
+
+    The JDK is distributed under various open-source licenses depending
+    on the vendor and version. Common licenses include the GNU General
+    Public License (GPL) and the Oracle Binary Code License Agreement.
+
+    To enable JNI support, ensure that the JDK is installed on your system,
+    and set the appropriate environment variables (e.g., JAVA_HOME) to point
+    to the JDK installation directory.
 
 See HACKING if you wish to hack the GnuCOBOL source or build directly
 from version control as this includes the list of additional tools

DEPENDENCIES.md

@@ -119,3 +119,13 @@ Support for GENERATE JSON is provided by *one* of the following:
 
     JSON-C is distributed under Expat License.
 
+JNI Support
+------------
+
+Support for JNI (Java Native Interface) is provided by:
+
+* [Java Development Kit (JDK)](https://openjdk.java.net/) 8 or later.
+
+    The JDK is distributed under various open-source licenses depending on the vendor and version. Common licenses include the GNU General Public License (GPL) and the Oracle Binary Code License Agreement.
+
+To enable JNI support, ensure that the JDK is installed on your system, and set the appropriate environment variables (e.g., JAVA_HOME) to point to the JDK installation directory.

NEWS

@@ -20,7 +20,7 @@ NEWS - user visible changes				-*- outline -*-
 
 
 * New GnuCOBOL features
-
+** Initial support for Java interoperability through JNI (new optional dependency JDK)
 ** file handling: added backends for ODBC (so far PostgrSQL, MySQL, SQLite,
    MSSQL) and OCI, along with new directory COB_SCHEMA_DIR containing the
    necessary internal schema files to match the file definition to the

cobc/ChangeLog

@@ -1,4 +1,8 @@
 
+2024-08-14  Nicolas Berthier <[email protected]>
+
+	* cobc.c (cobc_print_info): added note for Java interoperability
+
 2024-08-04  David Declerck <[email protected]>
 
 	Adjustments to merge 2022-12-21:

cobc/cobc.c

@@ -2620,6 +2620,12 @@ cobc_print_info (void)
 
 	cobc_var_print (_("JSON library"),		_(WITH_JSON), 0);
 
+#ifdef WITH_JNI
+	cobc_var_print (_("Java interoperability"),	_("enabled"), 0);
+#else
+	cobc_var_print (_("Java interoperability"),	_("disabled"), 0);
+#endif
+
 #ifdef COB_DEBUG_LOG
 	cobc_var_print ("DEBUG_LOG",		_("enabled"), 0);
 #endif

cobc/codegen.c

@@ -1,7 +1,7 @@
 /*
    Copyright (C) 2003-2024 Free Software Foundation, Inc.
    Written by Keisuke Nishida, Roger While, Ron Norman, Simon Sobisch,
-   Edward Hart
+   Edward Hart, Vedant Tewari
 
    This file is part of GnuCOBOL.
 
@@ -147,6 +147,7 @@ static struct literal_list	*literal_cache = NULL;
 static struct field_list	*field_cache = NULL;
 static struct field_list	*local_field_cache = NULL;
 static struct call_list		*call_cache = NULL;
+static struct call_list	*call_java_cache = NULL;
 static struct call_list		*func_call_cache = NULL;
 static struct static_call_list	*static_call_cache = NULL;
 static struct base_list		*base_cache = NULL;
@@ -395,6 +396,22 @@ lookup_source (const char *p)
 	return source_id++;
 }
 
+static void
+lookup_java_call(const char *p)
+{
+	struct call_list *clp;
+
+	for (clp = call_java_cache; clp; clp = clp->next) {
+		if (strcmp (p, clp->call_name) == 0) {
+			return;
+		}
+	}
+	clp = cobc_parse_malloc (sizeof (struct call_list));
+	clp->call_name = p;
+	clp->next = call_java_cache;
+	call_java_cache = clp;
+}
+
 static void
 lookup_call (const char *p)
 {
@@ -1978,6 +1995,11 @@ output_call_cache (void)
 		output_local ("static cob_call_union\tcall_%s;\n",
 			      call->call_name);
 	}
+	call_java_cache = call_list_reverse (call_java_cache);
+	for (call = call_java_cache; call; call = call->next) {
+		output_local ("static cob_java_handle*\tcall_java_%s;\n",
+			      call->call_name);
+	}
 	func_call_cache = call_list_reverse (func_call_cache);
 	for (call = func_call_cache; call; call = call->next) {
 		output_local ("static cob_call_union\tfunc_%s;\n",
@@ -7068,6 +7090,132 @@ output_field_constant (cb_tree x, int n, const char *flagname)
 	output_newline ();
 }
 
+static void
+output_java_call (struct cb_call *p)
+{
+	char* full_name = (char *)CB_LITERAL(p->name)->data; /* Assume java.prefix (enforced in `parser.y`, rule `call_body`)*/
+	char* class_and_method_name = full_name + 5;
+	char *last_dot;
+	char *method_name;
+	const char *class_name;
+	char method_signature[256] = "(";
+	char* mangled;
+	struct cb_tree *ptr;
+
+	mangled = strdup(class_and_method_name);
+	for (size_t i = 0; i < strlen(mangled) + 1; i++) {
+		mangled[i] = (mangled[i] == '.') ? '_' : mangled[i];
+	}
+
+	last_dot = strrchr(class_and_method_name, '.');
+	if (last_dot == NULL) {
+		cobc_err_msg (_("malformed call '%s' to a Java method"), class_and_method_name);
+		COBC_ABORT ();
+	}
+
+	*last_dot = '\0';
+	method_name = last_dot + 1;
+	class_name = class_and_method_name;
+
+    for(ptr = p->args; ptr != NULL; ptr = ptr->next) {
+        switch(CB_TREE_TAG(ptr)) {
+            case CB_TAG_INTEGER:
+                strcat(method_signature, "I"); 
+                break;
+            case CB_TAG_LONG:
+                strcat(method_signature, "J");
+                break;
+            case CB_TAG_FLOAT:
+                strcat(method_signature, "F");
+                break;
+            case CB_TAG_DOUBLE:
+                strcat(method_signature, "D"); 
+                break;
+            case CB_TAG_BOOLEAN:
+                strcat(method_signature, "Z");
+                break;
+            case CB_TAG_BYTE:
+                strcat(method_signature, "B");
+                break;
+            case CB_TAG_SHORT:
+                strcat(method_signature, "S");
+                break;
+            case CB_TAG_CHAR:
+                strcat(method_signature, "C"); 
+                break;
+            case CB_TAG_STRING:
+                strcat(method_signature, "Ljava/lang/String;"); 
+                break;
+            case CB_TAG_OBJECT: 
+                strcat(method_signature, "Ljava/lang/Object;"); 
+                break;
+            case CB_TAG_LITERAL:
+                if(CB_TREE_CATEGORY(ptr) == CB_CATEGORY_NUMERIC) {
+                    strcat(method_signature, "I"); 
+                } else if(CB_TREE_CATEGORY(ptr) == CB_CATEGORY_ALPHANUMERIC) {
+                    strcat(method_signature, "Ljava/lang/String;");
+                }
+                break;
+            case CB_TAG_ARRAY:
+                switch(CB_TREE_TAG(CB_TREE(ptr)->next)) {
+                    case CB_TAG_INTEGER:
+                        strcat(method_signature, "[I"); 
+                        break;
+                    case CB_TAG_LONG:
+                        strcat(method_signature, "[J"); 
+                        break;
+                    case CB_TAG_FLOAT:
+                        strcat(method_signature, "[F"); 
+                        break;
+                    case CB_TAG_DOUBLE:
+                        strcat(method_signature, "[D");
+                        break;
+                    case CB_TAG_BOOLEAN:
+                        strcat(method_signature, "[Z"); 
+                        break;
+                    case CB_TAG_BYTE:
+                        strcat(method_signature, "[B"); 
+                        break;
+                    case CB_TAG_SHORT:
+                        strcat(method_signature, "[S"); 
+                        break;
+                    case CB_TAG_CHAR:
+                        strcat(method_signature, "[C");
+                        break;
+                    case CB_TAG_STRING:
+                        strcat(method_signature, "[Ljava/lang/String;"); 
+                        break;
+                    case CB_TAG_OBJECT:
+                        strcat(method_signature, "[Ljava/lang/Object;"); 
+                        break;
+                    default:
+                        cobc_err_msg(_("Unsupported array type in Java method call"));
+                        COBC_ABORT();
+                }
+                break;
+            default:
+                cobc_err_msg(_("Unsupported argument type in Java method call"));
+                COBC_ABORT();
+        }
+    }
+
+	strcat(method_signature, ")V");
+
+	lookup_java_call(mangled);
+	output_line("if (call_java_%s == NULL)", mangled);
+	output_block_open();
+
+	output_prefix();
+	output_line("call_java_%s = ", mangled);
+	output("cob_resolve_java(\"%s\", \"%s\", \"()V\");", class_name, method_name, method_signature);
+	output_newline ();
+	output_prefix ();
+	output_line("cob_call_java(call_java_%s);\n", mangled);
+	output_newline();
+	output_block_close();
+	cobc_free(mangled);
+}
+
 static void
 output_call (struct cb_call *p)
 {
@@ -7097,6 +7245,11 @@ output_call (struct cb_call *p)
 	}
 	system_call = NULL;
 
+	if (p->convention & CB_CONV_JAVA) {
+		output_java_call(p);
+		return;
+	}
+
 #ifdef	_WIN32
 	if (p->convention & CB_CONV_STDCALL) {
 		convention = "_std";

cobc/parser.y

@@ -12253,6 +12253,11 @@ call_body:
 
 	/* Check parameter conformance, if we can work out what is being called. */
 	if (CB_LITERAL_P ($3)) {
+		/* Check for "Java." prefix and set call convention */
+		char* s = (char *)CB_LITERAL ($3)->data;
+	        if (strncasecmp("Java.", s, 5) == 0) {
+		        call_conv = CB_CONV_JAVA;
+                }
 		cb_check_conformance ($3, $7, $8);
 	} else if (CB_REFERENCE_P ($3)) {
 		cb_tree	ref = cb_ref ($3);

cobc/tree.h

@@ -199,6 +199,7 @@ enum cb_tag {
 #define CB_CONV_THUNK_16	(1 << 5)
 #define CB_CONV_STDCALL		(1 << 6)
 #define CB_CONV_COBOL	(1 << 15)
+#define CB_CONV_JAVA    (1 << 16)
 #define CB_CONV_C	(0)
 #define CB_CONV_PASCAL	(CB_CONV_L_TO_R | CB_CONV_CALLEE_STACK)