Re: [Chicken-users] Compiling Chicken with Watcom .. type errors

[Bob McIsaac]

Sergey Khorev wrote: Finally I've figured out the main showstopper to get Chicken compiled by Watcom (at least at the moment). To be precise, chicken.exe and chicken-static.exe can be compiled but they don't work :) The problem is in the default Watcom calling convention (it's similar to MSVC's __fastcall): it uses registers to pass few first arguments. This doesn't work for functions with a variable number of arguments. E.g., the following program will not work properly without the -ecc switch (== use __cdecl calling convention) ----- #include <stdio.h> typedef void (*proc3)(int a1, int a2, int a3); void proc(int a1, int a2, int a3, ...) { printf("%d %d %d\n", a1, a2, a3); } int main() { proc3 p = (proc3)proc; p(1, 2, 3); return 1; } ----- But, the -ecc switch causes internal compiler error. I've created a bug report (http://bugzilla.openwatcom.org/show_bug.cgi?id=505) for it. Workaround "#pragma inline-depth(0);" doesn't help. If I correctly undertsand, Chicken-generated C can cast to C_procXX both "normal" and vararg functions. Should we wait for feedback or does anyone know any workarounds? Felix, can we add __cdecl for each C_procXX typedef and every function, which can be called by casting to C_procXX? Theoretically speaking, this might help to avoid internal compiler error because not all functions will be __cdecl'ed, but I hardly believe in that. PS Please keep both my emails in cc field, it's intended. _______________________________________________ Chicken-users mailing list Chicken-users@nongnu.org http://lists.nongnu.org/mailman/listinfo/chicken-users Hi: I moved my computer away from the internet, fired up ol win98 and tried your program.  As expected, it compiled ok and printed garbage. Next I removed the cast from the function pointer proc3 p = (proc3)proc; // (proc3) cast hides error Now the problem is exposed:- cd C:\bins\wtest wmake -f C:\bins\wtest\v1.mk -h -e wcc386 var.c -i=C:\watcom\h;C:\watcom\h\nt -w4 -e25 -zq -od -d2 -6r -bt=nt -mf var.c(14): Warning! W102: Type mismatch (warning) var.c(14): Note! N2003: source conversion type is 'void (*)(int __p1,int __p2,int __p3,... )' var.c(14): Note! N2004: target conversion type is 'void (*)(int __p1,int __p2,int __p3)' wlink name v1 d all SYS nt op m op maxe=25 op q op symf @v1.lk1 Execution complete The solution is the to have the function pointer typedef match the declaration of the pointed to function which has ellipses.    typedef void (*proc3)(int a1, int a2, int a3, ...); // added 'dots' to match function Depending upon design of the source, it might be better to include <stdarg.h>  which has _va_list and so on. Note that watcom provides examples of a function that iterates through variable parameters. It is at least instructive if not useful here. Hope this helps, -BobMc-

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