On Tue, Jan 10 2023, Christian Weisgerber <na...@mips.inka.de> wrote:
> Jeremie Courreges-Anglas:
>
>> > https://wxcvbn.org/~jca/build-failures/amd64-clang/2023-01-03/x11/xpostit.txt
>> menu.c:123:58: error: incompatible integer to pointer conversion passing
>> 'int' to parameter of type 'XtPointer' (aka 'void *') [-Wint-conversion]
>> XtAddCallback(entry, XtNcallback, HandleMenuSelection, i);
>> ^
>
> That's a pattern found in old X11 code. Callbacks take a pointer
> to be able to pass arbitrary data, but instead of allocating an int
> and passing a pointer to it, people just jam the int directly into
> the pointer for an int -> pointer -> int conversion.
>
> I guess an explicit cast will fix it?
clang would compile the code, albeit with a warning:
y.c:11:4: warning: cast to 'void *' from smaller integer type 'int'
[-Wint-to-void-pointer-cast]
I think the appropriate idiom to do this would be to include stdint.h
and use a double cast, diff below tested with clang 15. But please go
ahead with a shorter (void *) cast if you prefer, there's a lot of
warnings in the logs anyway...
Index: Makefile
===================================================================
RCS file: /home/cvs/ports/x11/xpostit/Makefile,v
retrieving revision 1.30
diff -u -p -r1.30 Makefile
--- Makefile 11 Mar 2022 20:18:07 -0000 1.30
+++ Makefile 10 Jan 2023 15:35:30 -0000
@@ -2,7 +2,7 @@ COMMENT= PostIt (R) messages onto your X
DISTNAME= xpostit3.3.1
PKGNAME= xpostit-3.3.1
-REVISION= 2
+REVISION= 3
CATEGORIES= x11
MASTER_SITES= ${MASTER_SITE_R5CONTRIB}
Index: patches/patch-menu_c
===================================================================
RCS file: patches/patch-menu_c
diff -N patches/patch-menu_c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ patches/patch-menu_c 10 Jan 2023 15:35:05 -0000
@@ -0,0 +1,22 @@
+Use casts to appease clang 15 -Wint-conversion.
+
+Index: menu.c
+--- menu.c.orig
++++ menu.c
+@@ -49,6 +49,7 @@ static char *RCSid = "$Header: /home/harbor/davy/stuff
+ #include <X11/Xaw/SmeBSB.h>
+ #include <X11/Shell.h>
+ #include <stdio.h>
++#include <stdint.h>
+
+ #include "xpostit.h"
+
+@@ -120,7 +121,7 @@ CreateMenuWidget()
+ smeBSBObjectClass, menuwidget,
+ NULL, 0);
+
+- XtAddCallback(entry, XtNcallback, HandleMenuSelection, i);
++ XtAddCallback(entry, XtNcallback, HandleMenuSelection, (void
*)(uintptr_t)i);
+ }
+
+ XawSimpleMenuAddGlobalActions(appcontext);
--
jca | PGP : 0x1524E7EE / 5135 92C1 AD36 5293 2BDF DDCC 0DFA 74AE 1524 E7EE
