Build fails with gcc 4 due to missing forward class declarartions

[psorensen]

When I try to compile base-3.14.7 with a gcc-4 compiler, I get error messages such as the following in the src/cas/generic directory:

../../../../src/cas/generic/casdef.h:513: error: ISO C++ forbids declaration of 'casPVI' with no type
../../../../src/cas/generic/casdef.h:513: error: expected ';' before '*' token

By adding a forward declaration such as "class casPVI;" before the structure definition a am able to compile.

Additional information:
I am now using the following patch to build base.

--- START PATCH ---

diff -uNr base-3.14.7-orig/src/cas/generic/casdef.h base-3.14.7/src/cas/generic/casdef.h
--- base-3.14.7-orig/src/cas/generic/casdef.h 2004-10-08 10:54:45.000000000 -0400
+++ base-3.14.7/src/cas/generic/casdef.h 2005-09-15 13:23:45.000000000 -0400
@@ -108,6 +108,7 @@
     pverAsyncCompletion };

 class casPV;
+class casPVI;
 class casCtx;
 class casChannel;

diff -uNr base-3.14.7-orig/src/cas/generic/inBuf.h base-3.14.7/src/cas/generic/inBuf.h
--- base-3.14.7-orig/src/cas/generic/inBuf.h 2003-04-16 16:57:56.000000000 -0400
+++ base-3.14.7/src/cas/generic/inBuf.h 2005-09-15 15:25:18.000000000 -0400
@@ -27,6 +27,8 @@

 #include "clientBufMemoryManager.h"

+class inBuf;
+
 class inBufCtx {
     friend class inBuf;
 public:
diff -uNr base-3.14.7-orig/src/cas/generic/ioBlocked.h base-3.14.7/src/cas/generic/ioBlocked.h
--- base-3.14.7-orig/src/cas/generic/ioBlocked.h 2003-02-12 14:06:09.000000000 -0500
+++ base-3.14.7/src/cas/generic/ioBlocked.h 2005-09-15 13:26:03.000000000 -0400
@@ -31,6 +31,8 @@
 # include "shareLib.h"
 #endif

+class ioBlockedList;
+
 class ioBlocked : public tsDLNode < ioBlocked > {
 friend class ioBlockedList;
 public:
diff -uNr base-3.14.7-orig/src/cas/generic/outBuf.h base-3.14.7/src/cas/generic/outBuf.h
--- base-3.14.7-orig/src/cas/generic/outBuf.h 2003-02-12 14:06:10.000000000 -0500
+++ base-3.14.7/src/cas/generic/outBuf.h 2005-09-15 15:24:42.000000000 -0400
@@ -26,6 +26,8 @@
 #include "casdef.h"
 #include "clientBufMemoryManager.h"

+class outBuf;
+
 //
 // outBufCtx
 //
diff -uNr base-3.14.7-orig/src/cas/generic/st/casDGIntfOS.h base-3.14.7/src/cas/generic/st/casDGIntfOS.h
--- base-3.14.7-orig/src/cas/generic/st/casDGIntfOS.h 2003-03-10 17:26:32.000000000 -0500
+++ base-3.14.7/src/cas/generic/st/casDGIntfOS.h 2005-09-15 15:29:59.000000000 -0400
@@ -19,6 +19,10 @@
 #include "casDGIOWakeup.h"
 #include "casDGEvWakeup.h"

+class casDGReadReg;
+class casDGBCastReadReg;
+class casDGWriteReg;
+
 class casDGIntfOS : public casDGIntfIO {
     friend class casDGReadReg;
     friend class casDGBCastReadReg;
diff -uNr base-3.14.7-orig/src/cas/generic/st/casIntfOS.h base-3.14.7/src/cas/generic/st/casIntfOS.h
--- base-3.14.7-orig/src/cas/generic/st/casIntfOS.h 2003-03-10 17:26:32.000000000 -0500
+++ base-3.14.7/src/cas/generic/st/casIntfOS.h 2005-09-15 15:30:52.000000000 -0400
@@ -22,6 +22,8 @@
 #include "casIntfIO.h"
 #include "casDGIntfOS.h"

+class casServerReg;
+
 //
 // casIntfOS
 //

--- END PATCH ---

Original Mantis Bug: mantis-216
    http://www.aps.anl.gov/epics/mantis/view_bug_page.php?f_id=216

[markwag (markwag)]

I can confirm that this patch fixes the missing-forward-class-definitions problem.

host: x86-linux
gcc (GCC) 4.0.1 (Debian 4.0.1-2)

target: vxWorks-68040
gcc-2.96

[Jeff Hill (johill-lanl)]

I committed a fix, but can't test it because I don’t have gcc 4.0 installed here (it's not yet available from cygwin and my linux system isn’t that new).

cvs diff -- casdef.h (in directory D:\users\hill\epicsDvl\epics\base\src\cas\generic\)
Index: casdef.h
===================================================================
RCS file: /net/phoebus/epicsmgr/cvsroot/epics/base/src/cas/generic/casdef.h,v
retrieving revision 1.60
diff -c -r1.60 casdef.h
*** casdef.h 5 Aug 2005 20:54:36 -0000 1.60
--- casdef.h 26 Oct 2005 18:46:30 -0000
***************
*** 108,113 ****
--- 108,114 ----
      pverAsyncCompletion };

  class casPV;
+ class casPVI;
  class casCtx;
  class casChannel;

***** CVS exited normally with code 1 *****

[Jeff Hill (johill-lanl)]

from ernest

Works fine also on:
Fedora Core release 4
Linux matrix 2.6.13-1.1526_FC4
gcc version 4.0.1 20050919 (Red Hat 4.0.1-14)

from eric

Works fine on OS X with
powerpc-apple-darwin8-gcc-4.0.0 (GCC) 4.0.0 (Apple Computer, Inc. build 5026)

[Jeff Hill (johill-lanl)]

fixed in R3.14.8

[Andrew Johnson (anj)]

R3.14.8 Release.