Support for "virtual operands" of subroutines like this:

jsr	SomeProc
.byte	$00, $01 ; argument to SomeProc
; return here from SomeProc
bit	$3F

doc/da65.sgml

@@ -542,6 +542,18 @@ code. The following attributes are recognized:
   range, where <tt/label/ is the label name given with the <tt/NAME/
   attribute, and <tt/offs/ is the offset within the data.
 
+  <tag><tt>VOPERAND</tt></tag>
+  This optional attribute is followed by a numerical value. It tells the
+  assembler that subroutine calls to this label follow "virtual operands"
+  of the given bytes like this:
+
+<tscreen><verb>
+       	JSR	LabelWith2BytesOfVoperand
+	.byte	$00, $10    ; virtual operands
+	; return here
+	BIT	$0F
+</verb></tscreen>
+
 </descrip>
 
 

src/da65/handler.c

@@ -51,6 +51,8 @@
 
 
 
+static unsigned short SubroutineVOperandSize[0x10000];
+
 /*****************************************************************************/
 /*                             Helper functions                              */
 /*****************************************************************************/
@@ -741,3 +743,31 @@ void OH_JmpAbsoluteXIndirect (const OpcDesc* D)
     }
     SeparatorLine ();
 }
+
+
+
+void OH_JsrAbsolute (const OpcDesc* D)
+{
+    unsigned VOperandSize = SubroutineVOperandSize[GetCodeWord(PC+1)];
+    OH_Absolute (D);
+    if (VOperandSize > 0) {
+        unsigned RemainingBytes;
+        PC += D->Size;
+        RemainingBytes = GetRemainingBytes();
+        if (RemainingBytes < VOperandSize) {
+            VOperandSize = RemainingBytes;
+        }
+        if (VOperandSize > 0) {
+            DataByteLine (VOperandSize); /* FIXME: follow BytesPerLine */
+            PC += VOperandSize;
+        }
+        PC -= D->Size;
+    }
+}
+
+
+
+void SetSubroutineVOperand (unsigned Addr, unsigned Size)
+{
+    SubroutineVOperandSize[Addr] = Size;
+}

src/da65/handler.h

@@ -104,7 +104,9 @@ void OH_Rts (const OpcDesc*);
 void OH_JmpAbsolute (const OpcDesc*);
 void OH_JmpAbsoluteIndirect (const OpcDesc* D);
 void OH_JmpAbsoluteXIndirect (const OpcDesc* D);
+void OH_JsrAbsolute (const OpcDesc*);
 
+void SetSubroutineVOperand (unsigned Addr, unsigned Size);
 
 
 /* End of handler.h */

src/da65/infofile.c

@@ -59,6 +59,7 @@
 #include "opctable.h"
 #include "scanner.h"
 #include "segment.h"
+#include "handler.h"
 
 
 
@@ -380,6 +381,7 @@ static void LabelSection (void)
         {   "ADDR",     INFOTOK_ADDR    },
         {   "NAME",     INFOTOK_NAME    },
         {   "SIZE",     INFOTOK_SIZE    },
+        {   "VOPERAND", INFOTOK_VOPERAND },
     };
 
     /* Locals - initialize to avoid gcc warnings */
@@ -387,6 +389,7 @@ static void LabelSection (void)
     char* Comment = 0;
     long Value    = -1;
     long Size     = -1;
+    long VOperand = -1;
 
     /* Skip the token */
     InfoNextTok ();
@@ -448,6 +451,17 @@ static void LabelSection (void)
                 InfoNextTok ();
                 break;
 
+            case INFOTOK_VOPERAND:
+                InfoNextTok ();
+                if (VOperand >= 0) {
+                    InfoError ("VOperand already given");
+                }
+                InfoAssureInt ();
+                InfoRangeCheck (1, 0x10000);
+                VOperand = InfoIVal;
+                InfoNextTok ();
+                break;
+
             default:
                 Internal ("Unexpected token: %u", InfoTok);
         }
@@ -484,6 +498,9 @@ static void LabelSection (void)
     } else {
         AddExtLabelRange ((unsigned) Value, Name, Size);
     }
+    if (VOperand >= 0) {
+        SetSubroutineVOperand ((unsigned) Value, (unsigned) VOperand);
+    }
 
     /* Define the comment */
     if (Comment) {

src/da65/opc6502.c

@@ -79,7 +79,7 @@ const OpcDesc OpcTable_6502[256] = {
     {   "ora",  3,  flUseLabel|flAbsOverride, OH_AbsoluteX             }, /* $1d */
     {   "asl",  3,  flUseLabel|flAbsOverride, OH_AbsoluteX             }, /* $1e */
     {   "",     1,  flIllegal,                OH_Illegal,              }, /* $1f */
-    {   "jsr",  3,  flLabel,                  OH_Absolute              }, /* $20 */
+    {   "jsr",  3,  flLabel,                  OH_JsrAbsolute           }, /* $20 */
     {   "and",  2,  flUseLabel,               OH_DirectXIndirect       }, /* $21 */
     {   "",     1,  flIllegal,                OH_Illegal,              }, /* $22 */
     {   "",     1,  flIllegal,                OH_Illegal,              }, /* $23 */

src/da65/opc65816.c

@@ -79,7 +79,7 @@ const OpcDesc OpcTable_65816[256] = {
     {   "ora",  3,  flUseLabel|flAbsOverride, OH_AbsoluteX             }, /* $1d */
     {   "asl",  3,  flUseLabel|flAbsOverride, OH_AbsoluteX             }, /* $1e */
     {   "ora",  4,  flUseLabel,               OH_AbsoluteLongX         }, /* $1f */
-    {   "jsr",  3,  flLabel,                  OH_Absolute              }, /* $20 */
+    {   "jsr",  3,  flLabel,                  OH_JsrAbsolute           }, /* $20 */
     {   "and",  2,  flUseLabel,               OH_DirectXIndirect       }, /* $21 */
     {   "jsl",  3,  flLabel,                  OH_AbsoluteLong          }, /* $22 */
     {   "and",  2,  flNone,                   OH_StackRelative         }, /* $23 */

src/da65/opc65c02.c

@@ -79,7 +79,7 @@ const OpcDesc OpcTable_65C02[256] = {
     {   "ora",  3,  flUseLabel|flAbsOverride, OH_AbsoluteX             }, /* $1d */
     {   "asl",  3,  flUseLabel|flAbsOverride, OH_AbsoluteX             }, /* $1e */
     {   "bbr1", 3,  flUseLabel,               OH_BitBranch             }, /* $1f */
-    {   "jsr",  3,  flLabel,                  OH_Absolute              }, /* $20 */
+    {   "jsr",  3,  flLabel,                  OH_JsrAbsolute           }, /* $20 */
     {   "and",  2,  flUseLabel,               OH_DirectXIndirect       }, /* $21 */
     {   "",     1,  flIllegal,                OH_Illegal,              }, /* $22 */
     {   "",     1,  flIllegal,                OH_Illegal,              }, /* $23 */

src/da65/opc65sc02.c

@@ -79,7 +79,7 @@ const OpcDesc OpcTable_65SC02[256] = {
     {   "ora",  3,  flUseLabel|flAbsOverride, OH_AbsoluteX             }, /* $1d */
     {   "asl",  3,  flUseLabel|flAbsOverride, OH_AbsoluteX             }, /* $1e */
     {   "",     1,  flIllegal,                OH_Illegal,              }, /* $1f */
-    {   "jsr",  3,  flLabel,                  OH_Absolute              }, /* $20 */
+    {   "jsr",  3,  flLabel,                  OH_JsrAbsolute           }, /* $20 */
     {   "and",  2,  flUseLabel,               OH_DirectXIndirect       }, /* $21 */
     {   "",     1,  flIllegal,                OH_Illegal,              }, /* $22 */
     {   "",     1,  flIllegal,                OH_Illegal,              }, /* $23 */

src/da65/scanner.h

@@ -105,6 +105,7 @@ typedef enum token_t {
     INFOTOK_COMMENT,
     INFOTOK_ADDR,
     INFOTOK_SIZE,
+    INFOTOK_VOPERAND,
 
     /* ASMINC section */
     INFOTOK_FILE,