id summary reporter owner description type status priority milestone component version resolution keywords cc difficulty 850 dbus: Scheme closure passed where function pointer is expected and triple compilation sjamaan Shawn Rutledge "Recently we ran Salmonella with the option {{{-specialize}}}, to find problems with the scrutinizer (flow analysis) and bugs in eggs, and it found a problem with dbus: http://parenteses.org/mario/misc/specialize-report/install/dbus.html Due to the fact that dbus builds with -O3 you can also see this in action in the latest salmonella run based on the git master branch of Chicken: http://tests.call-cc.org/master/linux/x86/2012/05/17/salmonella-report/install/dbus.html The warning is due to the fact that the {{{vtable-message_function}}} is declared as type {{{c-pointer}}}, but a plain Scheme closure object is set to that pointer. This is not correct, and should usually cause a segfault since Scheme objects are not generally usable as pointers. In this case it happens to extract a pointer to the procedure correctly because closures are represented similarly to pointer objects, but Scheme closures expect an argument count and a continuation as the first two parameters. If you want to pass a C function pointer correctly, I think you'll need to declare a function in C (or use {{{define-external}}} or something similar) and use {{{foreign-value}}} with type {{{c-pointer}}} to reify it as a pointer. Finally, it looks like the egg's Make recipe in the .setup-file is all wrong; the same file gets compiled up to three times! This is due to the fact that the rule for {{{dbus.so}}} doesn't use {{{dbus.c}}} but {{{dbus.scm}}}, making the step to generate the {{{.c}}}-file unneccessary. Actually, this file even gets '''deleted''' after this is compiled. That causes the {{{dbus.import.scm}}} line to trigger compilation of {{{dbus.c}}} via that line yet again, even though the import file already exists. Here's a patch to do it more or less correctly, if you really need to split up compilation into two stages (which is completely unneccessary): {{{ Index: dbus.setup =================================================================== --- dbus.setup (revision 26708) +++ dbus.setup (working copy) @@ -1,14 +1,14 @@ ;;;; dbus.setup -*- Scheme -*- -(use files utils) - (make ( - (""dbus.import.so"" (""dbus.c"") + (""dbus.import.so"" (""dbus.import.scm"") (compile -s -O3 -d0 dbus.import.scm)) (""dbus.so"" (""dbus.c"") - (compile -s -O3 -d1 dbus.scm -C ""`pkg-config --cflags dbus-1`"" -L ""`pkg-config --libs dbus-1`"")) + (compile -s -O3 -d1 dbus.c -C ""`pkg-config --cflags dbus-1`"" -L ""`pkg-config --libs dbus-1`"")) + (""dbus.import.scm"" (""dbus.scm"") + (compile -A dbus.scm -X easyffi -j dbus)) (""dbus.c"" (""dbus.scm"") - (compile -t dbus.scm -O3 -d1 -X easyffi -C -g -j dbus))) + (compile -t dbus.scm -O3 -d1 -X easyffi))) '(""dbus.so"" ""dbus.import.so"")) (install-extension 'dbus }}} I've removed the ""(use files utils)"" line since it isn't using anything from there. Notice the fact that to do this, we still need to run the csc command twice on dbus.scm, because when you want the output {{{dbus.c}}} normally a side-effect of running the command is that {{{dbus.import.scm}}} is emitted (via the {{{-j}}} switch). If you want to split it up like this, you need to run the compilation twice. This means the compiler gets invoked twice and has to do all that work again. Normally you use ""make"" to avoid building things more than once or over and over again, but the irony is that this setup-file is actually causing it to do exactly that! You don't need the ""make"" form at all (which, by the way, is deprecated and [http://wiki.call-cc.org/eggref/4/make moved into an egg] now). You can simplify {{{dbus.setup}}} into this (that's the entire file): {{{ ;;;; dbus.setup -*- Scheme -*- (compile -s -O3 -d1 dbus.scm -C ""`pkg-config --cflags dbus-1`"" -L ""`pkg-config --libs dbus-1`"" -j dbus)) (compile -s -O3 -d1 dbus.import.scm)) (install-extension 'dbus `(""dbus.so"" ""dbus.import.so"") `((version ""0.91""))) }}}" defect closed major extensions 4.7.x fixed