Increase maximum supported fixed args on varargs calls from 3 to 255

java-native-access · Feb 19, 2023 · b05eb35 · b05eb35
1 parent 54fc662
commit b05eb35
Show file tree

Hide file tree

Showing 3 changed files with 33 additions and 3 deletions.
diff --git a/native/testlib.c b/native/testlib.c
@@ -908,6 +908,19 @@ addVarArgs(const char *fmt, ...) {
   return sum;
 }
 
+EXPORT int32_t
+addSeveralFixedArgsAndVarArgs(int a, int b, int c, int d, int n_varargs, ...) {
+  va_list ap;
+  int32_t sum = a + b + c + d;
+  va_start(ap, n_varargs);
+
+  for (int i = 0; i < n_varargs; i++) {
+    sum += va_arg(ap, int32_t);
+  }
+  va_end(ap);
+  return sum;
+}
+
 EXPORT void
 modifyStructureVarArgs(const char* fmt, ...) {
   struct _ss {

diff --git a/src/com/sun/jna/Function.java b/src/com/sun/jna/Function.java
@@ -76,9 +76,9 @@ public interface PostCallRead {
     /** Whether to throw an exception if last error is non-zero after call. */
     @java.lang.annotation.Native
     public static final int THROW_LAST_ERROR = 0x40;
-    /** Mask for number of fixed args (1-3) for varargs calls. */
+    /** Mask for number of fixed args (max 255) for varargs calls. */
     @java.lang.annotation.Native
-    public static final int USE_VARARGS = 0x180;
+    public static final int USE_VARARGS = 0x7F80;
 
     static final Integer INTEGER_TRUE = Integer.valueOf(-1);
     static final Integer INTEGER_FALSE = Integer.valueOf(0);
@@ -410,7 +410,7 @@ Object invoke(Object[] args, Class<?> returnType, boolean allowObjects) {
     /* @see NativeLibrary#NativeLibrary(String,String,long,Map) implementation */
     Object invoke(Object[] args, Class<?> returnType, boolean allowObjects, int fixedArgs) {
         Object result = null;
-        int callFlags = this.callFlags | ((fixedArgs & 0x3) << 7);
+        int callFlags = this.callFlags | ((fixedArgs & 0xFF) << 7);
         if (returnType == null || returnType==void.class || returnType==Void.class) {
             Native.invokeVoid(this, this.peer, callFlags, args);
             result = null;

diff --git a/test/com/sun/jna/VarArgsTest.java b/test/com/sun/jna/VarArgsTest.java
@@ -41,6 +41,7 @@ protected List<String> getFieldOrder() {
             }
         }
         public int addVarArgs(String fmt, Number... args);
+        public int addSeveralFixedArgsAndVarArgs(int a, int b, int c, int d, int nArgs, Integer... args);
         public String returnStringVarArgs(String fmt, Object... args);
         public void modifyStructureVarArgs(String fmt, Object... args);
         public String returnStringVarArgs2(String fmt, String... args);
@@ -102,6 +103,22 @@ public void testStringVarArgsFull() {
                      lib.returnStringVarArgs2("", "Test"));
     }
 
+    public void testSeveralFixedAndVarArgs() {
+      int fixedarg1 = 1;
+      int fixedarg2 = 2;
+      int fixedarg3 = 3;
+      int fixedarg4 = 4;
+      int vararg1 = 100;
+      int vararg2 = 200;
+
+      int expected = fixedarg1 + fixedarg2 + fixedarg3 + fixedarg4 + vararg1 + vararg2;
+      int result = lib.addSeveralFixedArgsAndVarArgs(fixedarg1, fixedarg2, fixedarg3, fixedarg4,
+                                                     2, vararg1, vararg2);
+
+      assertEquals("varargs not passed correctly with multiple fixed args",
+                   expected, result);
+    }
+
     public void testAppendNullToVarargs() {
         Number[] args = new Number[] { Integer.valueOf(1) };
         assertEquals("No trailing NULL was appended to varargs list",