requested changes to java.c, configure.ac, and internal state to cobl…

ChangeLog

@@ -1,3 +1,6 @@
+2024-06-12	Vedant Tewari <[email protected]>
+
+	* configure.ac: Add support for JNI (Java Native Interface)
 
 2023-02-25  Ron Norman <[email protected]> 
 

DEPENDENCIES

@@ -137,6 +137,19 @@ 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.
+
+    One of the following:
+
+  o Java Development Kit (JDK) 8 or later
+    https://openjdk.java.net/
+
+    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 +119,15 @@ 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.
+
+

cobc/codegen.c

@@ -146,6 +146,8 @@ 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;
+extern JavaVM *jvm;
+extern JNIEnv *env;
 static struct call_list		*func_call_cache = NULL;
 static struct static_call_list	*static_call_cache = NULL;
 static struct base_list		*base_cache = NULL;
@@ -387,6 +389,21 @@ lookup_source (const char *p)
 	return source_id++;
 }
 
+static void lookup_java_call(const char *p) {
+    struct call_list *clp;
+
+    for (clp = call_cache; clp; clp = clp->next) {
+        if (strcmp(p, clp->call_name) == 0) {
+            return;
+        }
+	}
+
+    clp = (struct call_list *)cob_malloc(sizeof(struct call_list));
+    clp->call_name = p;
+    clp->next = call_cache;
+    call_cache = clp;
+}
+
 static void
 lookup_call (const char *p)
 {
@@ -419,6 +436,24 @@ lookup_func_call (const char *p)
 	func_call_cache = clp;
 }
 
+static void
+lookup_java_call (const char *p)
+{
+	struct static_call_list *sclp;
+
+	for (sclp = static_call_cache; sclp; sclp = sclp->next) {
+		if (strcmp (p, sclp->call_name) == 0) {
+			return;
+		}
+	}
+	sclp = cobc_parse_malloc (sizeof (struct static_call_list));
+	sclp->call_name = p;
+	sclp->convention = convention;
+	sclp->return_type = return_type;
+	sclp->next = static_call_cache;
+	static_call_cache = sclp;
+}
+
 static void
 lookup_static_call (const char *p, int convention, int return_type)
 {
@@ -7070,7 +7105,7 @@ output_call (struct cb_call *p)
 		ret_ptr = 1;
 	}
 	system_call = NULL;
-
+	// check the name where it is translated, check if the string begins with java then encode the string differently
 #ifdef	_WIN32
 	if (p->convention & CB_CONV_STDCALL) {
 		convention = "_std";
@@ -7532,27 +7567,39 @@ output_call (struct cb_call *p)
 		if (name_is_literal_or_prototype) {
 			s = get_program_id_str (p->name);
 			name_str = cb_encode_program_id (s, 1, cb_fold_call);
-			lookup_call (name_str);
-			callname = s;
+#ifdef HAVE_JNI
+			/* Distinguishing lookup from call*/
+			if(strncmp("Java.", name, 6) == 0) {
+				void static_java_method = lookup_static_call(s + 6, p->argv[0], COB_RETURN_NULL);
+				cob_call_java(static_java_method);
+			} else {
+				// rest
+#endif	
+				// we need to use lookup_java_call instead (implement)
+				lookup_java_call (name_str);
+				callname = s;
 
-			output_line ("if (call_%s.funcvoid == NULL || cob_glob_ptr->cob_physical_cancel)", name_str);
-			output_block_open ();
-			output_prefix ();
+				output_line ("if (call_%s.funcvoid == NULL || cob_glob_ptr->cob_physical_cancel)", name_str);
+				output_block_open ();
+				output_prefix ();
 
-			nlp = find_nested_prog_with_id (name_str);
-			if (nlp) {
-				output ("call_%s.funcint = %s_%d__;",
-					name_str, name_str,
-					nlp->nested_prog->toplev_count);
-			} else {
-				output ("call_%s.funcvoid = ", name_str);
-				output ("cob_resolve_cobol (");
-				output_string ((const unsigned char *)s,
-						(int)strlen (s), 0);
-				output (", %d, %d);", cb_fold_call, !p->stmt1);
+				nlp = find_nested_prog_with_id (name_str);
+				if (nlp) {
+					output ("call_%s.funcint = %s_%d__;",
+						name_str, name_str,
+						nlp->nested_prog->toplev_count);
+				} else {
+					output ("call_%s.funcvoid = ", name_str);
+					output ("cob_resolve_cobol (");
+					output_string ((const unsigned char *)s,
+							(int)strlen (s), 0);
+					output (", %d, %d);", cb_fold_call, !p->stmt1);
+				}
+				output_newline ();
+				output_block_close ();
+#ifdef HAVE_JNI
 			}
-			output_newline ();
-			output_block_close ();
+#endif	
 		} else {
 			name_str = NULL;
 			needs_unifunc = 1;

configure.ac

@@ -468,6 +468,22 @@ AC_DEFUN([AC_PROG_CXX], [])
 AC_PROG_LN_S
 AC_PROG_INSTALL
 
+PRINT_VAR(JAVA_HOME)
+PRINT_VAR(JAVA)
+PRINT_VAR(JAVAC)
+PRINT_VAR(JAVAH)
+PRINT_VAR(JAR)
+PRINT_VAR(JNI_INCLUDES)
+
+AC_PATH_PROG(javahome,java, "/usr/bin")
+javahome=`dirname ${javahome}`
+echo "JAVAHOME=${javahome}"
+for each in `ls ${javahome}/include` ;do
+  if [ test -d ${javahome}/include/${each} ] ;then
+     javaos=${each}
+  fi;
+done;
+
 AC_PROG_MAKE_SET
 AC_LIB_RPATH
 
@@ -480,9 +496,34 @@ dnl AC_CHECK_HEADERS([stdint.h whcar.h malloc.h])
 # mandatory:
 AC_CHECK_HEADERS([sys/types.h signal.h stddef.h], [],
 	[AC_MSG_ERROR([mandatory header could not be found or included])])
+AC_CHECK_HEADERS([jni.h], [have_jni=yes],
+  [AC_MSG_ERROR([jni.h is required but could not be found])])
+AC_CHECK_HEADERS([jni_md.h], [],
+  [AC_MSG_ERROR([jni_md.h is required but could not be found])])
 # optional:
 AC_CHECK_HEADERS([sys/time.h locale.h fcntl.h dlfcn.h sys/wait.h sys/sysmacros.h])
-
+AC_ARG_VAR([JAVA_HOME], [Java Runtime Environment (JRE) location])
+AC_ARG_ENABLE([java],
+              [AC_HELP_STRING([--disable-java],
+                              [disable Java Interoperatibility])])
+case $target_cpu in
+     x86_64) JVM_ARCH=amd64 ;;
+     i?86)   JVM_ARCH=i386 ;;
+     *)      JVM_ARCH=$target_cpu ;;
+esac
+AC_SUBST([JVM_ARCH])
+AS_IF([test X$enable_java_feature != Xno],
+	[AS_IF([test X$have_jni != Xyes],
+		[AC_MSG_FAILURE([The Java Native Interface is required for Java feature.])])
+	AS_IF([test -z "$JAVA_HOME"],
+	[AC_MSG_WARN([JAVA_HOME has not been set.  JAVA_HOME must be set at run time to locate libjvm.])],
+	[save_LDFLAGS=$LDFLAGS
+	LDFLAGS="-L$JAVA_HOME/lib/$JVM_ARCH/client -L$JAVA_HOME/lib/$JVM_ARCH/server $LDFLAGS"
+	AC_CHECK_LIB([jvm], [JNI_CreateJavaVM], [LIBS=$LIBS],
+				[AC_MSG_WARN([no libjvm found at JAVA_HOME])])
+	AC_DEFINE([WITH_JNI], [1])
+	LDFLAGS=$save_LDFLAGS
+])])
 
 # Checks for typedefs, structures, and compiler characteristics.
 AC_C_CONST

libcob/ChangeLog

@@ -1,3 +1,8 @@
+2024-06-12	Vedant Tewari <[email protected]>
+
+    * Makefile.am: Updated to include JNI-related files.
+    * coblocal.h: Added internal state for JNI support.
+    * java.c: Implemented JNI support for GnuCOBOL.
 
 2023-06-02  Simon Sobisch <[email protected]>
 

libcob/Makefile.am

@@ -19,6 +19,12 @@
 # You should have received a copy of the GNU General Public License
 # along with GnuCOBOL.  If not, see <https://www.gnu.org/licenses/>.
 
+lib_LTLIBRARIES = libcob.la
+libcob_la_SOURCES = common.c move.c numeric.c strings.c \
+	fileio.c call.c intrinsic.c termio.c screenio.c reportio.c cobgetopt.c \
+	java.c \
+	mlio.c coblocal.h cconv.c system.def profiling.c
+
 if LOCAL_CJSON
 nodist_libcob_la_SOURCES = cJSON.c
 DISTCLEANFILES = cJSON.c cJSON.h

libcob/coblocal.h

@@ -1,6 +1,6 @@
 /*
    Copyright (C) 2007-2012, 2014-2022 Free Software Foundation, Inc.
-   Written by Roger While, Simon Sobisch, Ron Norman
+   Written by Roger While, Simon Sobisch, Ron Norman, Vedant Tewari
 
    This file is part of GnuCOBOL.
 
@@ -449,6 +449,18 @@ COB_HIDDEN const char	*cob_get_last_exception_name	(void);
 COB_EXPIMP void		cob_field_to_string	(const cob_field *, void *,
 						 const size_t);
 COB_HIDDEN void		cob_parameter_check	(const char *, const int);
+COB_HIDDEN char*        cob_get_strerror (void);
+
+enum cob_case_modifier {
+	CCM_NONE,
+	CCM_LOWER,
+	CCM_UPPER,
+	CCM_LOWER_LOCALE,
+	CCM_UPPER_LOCALE
+};
+
+COB_HIDDEN int		cob_field_to_string	(const cob_field *, void *,
+						 const size_t, const enum cob_case_modifier target_case);
 
 COB_HIDDEN cob_settings *cob_get_settings_ptr	(void);
 

libcob/common.h

@@ -1294,6 +1294,17 @@ struct cob_call_struct {
 	cob_call_union		cob_cstr_cancel;	/* Cancel entry */
 };
 
+#ifdef HAVE_JNI
+typedef struct __cob_java_static_method {
+	jclass cls;
+	jmethodID mid;
+} cob_java_handle;
+
+COB_EXPIMP cob_java_handle* cob_resolve_java (const char* class_name, const char* method_name, 
+const char *type_signature);
+COB_EXPIMP int cob_call_java (const cob_java_handle* nargs);
+#endif
+
 /* Screen structure */
 typedef struct __cob_screen {
 	struct __cob_screen	*next;		/* Pointer to next */