ERROR: more than one instance of overloaded function "vprintf" has "C" linkage

[Chanquete]

Hi people!
I've got this own library:
--------------------------------------------
Personal.h
--------------------------------------------
#ifdef __cplusplus
extern "C" {
#endif
#include
#include
#include
#include
....
MY_STREAM *wprintf(MY_STREAM *_this, const char *format, ...);
....
#ifdef __cplusplus
}
#endif
--------------------------------------------

Well, this function 'wprintf()' already exists in /usr/include/wchar.h. I can't change Personal.h, because is a customer's library.

I have problems when i try to compile a C++ program -my_program.C- (each one that includes Personal.h).

More, compiling it in a HP-UX B.11.11 PA_RISC (with CC compiler) it was OK. But now, compiling it in a HP-UX B.11.23 ITANIUM (with aCC) I obtain this error:
--------------------------------------------
"/usr/include/wchar.h", line 134: error #2338: more than one instance of overloaded function "wprintf" has "C" linkage
extern int wprintf __((const wchar_t *, ...));
^
--------------------------------------------
It could be a problem in the order of include files passing to the compiler, but i think it's fine.

I put down the logs of compiler (using option -v). I hope someone can help me.
Best regards!


--------------------------------------------
HP-UX B.11.11 PA-RISC (CC)
--------------------------------------------
/opt/CC/bin/CC -v
-D_HPUX_SOURCE -DHPUX -DHP9800 -DVERMAJOR=10 -DVERMINOR=0 -DSYSV -DMOTIF -DY2000 -DSPANIEN
+a1 -Aa +DAportable +DS1.1 +z -c /..../my_program.C
-I
/opt/langtools/lbin/cpp.ansi
-D_HPUX_SOURCE -DHPUX -DHP9800 -DVERMAJOR=10 -DVERMINOR=0 -DSYSV -DMOTIF -DY2000 -DSPANIEN
-I
-D__hp9000s700 -D_PA_RISC1_1 -$ -Z -Dc_plusplus -D__cplusplus -D__hp9000s800 -D__hppa -D__hpux -D__unix -Dhp9000s800
-Dhppa -Dhpux -Dunix -I/opt/CC/include/CC -I/usr/include /..../my_program.C /var/tmp/AAAa05164.i
/opt/CC/lbin/cfront +DAportable +DS1.1 +z +a1 +b1 +T/var/tmp/BAAa05164 +s +t/var/tmp/CAAa05164
+f/..../my_program.C +XCddp_data.o
--------------------------------------------
HP-UX B.11.23 ITANIUM (aCC)
--------------------------------------------
/opt/aCC/lbin/ecom -architecture 32 -ia64abi all -inst compiletime
-sysdir /usr/include -test namespaces -koenig_lookup on -ansi_for_scope on -inline_power 1 -link_type dynamic
-fpeval float -fpevaldec _Decimal32 -tls_dyn on -target_os 11.23

--sys_include /opt/aCC/include_std
--sys_include /opt/aCC/include_std/iostream_compat
--sys_include /usr/include --sys_include /usr -D_HP_IA64ABI -D_BIND_LIBCALLS -D_Math_errhandling=MATH_ERREXCEPT
-D__hpux -D__unix -D__ia64=1 -D__ia64__=1 -D_BIG_ENDIAN=1 -D__STDCPP__ -D_HP_NAMESPACE_STD -D_ILP32
-D__cplusplus=199711L -D_INCLUDE__STDC_A1_SOURCE -D__HP_aCC=62000 -D_HP_INSTANTIATE_T_IN_LIB -D_INLINE_ASM
-D_FLT_EVAL_METHOD=0 -D_DEC_EVAL_METHOD=0 -D_HPUX_SOURCE -DHPUX -DHP9800 -DVERMAJOR=10 -DVERMINOR=0 -DSYSV
-DMOTIF -DY2000 -DSPANIEN -ucode hdriver=optlevel%1% -plusolistoption -Ol06all! -plusolistoption -Ol13moderate!
-plusooption -Oq01,al,ag,cn,sz,ic,vo,Mf,Po,es,rs,Rf,Pr,sp,in,cl,om,vc,pi,fa,pe,rr,pa,pv,nf,cp,lx,Pg,ug,lu,lb,uj,
dn,sg,pt,kt,em,np,ar,rp,dl,fs,bp,wp,pc,mp,lr,cx,cr,pi,so,Rc,fa,ft,fe,ap,st,lc,Bl,sr,Qs,do,ib,pl,sd,ll,rl,dl,
Lt,ol,fl,lm,ts,rd,dp,If!
/..../my_program.C

[Chanquete]

Hi again, people.

If i comile my C++ program (in 11.23 ITANIUM machine) with 'aCC -Ae' i don't obtain the error.

Now i have an important existential doubt. In the previous machine (11.11 PA-RISC) i was compiling with 'cc -Aa' whit no errors. 'cc -Aa' is 'strict ANSI', and it seems to be a more securely option, is it? And i want to do this way in ITANIUM.
But, by the other side, the libraries and programs i was compiling are between 10 and 20 years ago, i can't change it (i do not want to change it). Furthermore, are in a 95% ANSI C source code, while other source code are C++.

With this info, what do you recommend to do?
'aCC -Aa' or 'aCC -Ae'?

Thanks so much in advance!

[Dennis Handly · Accepted solution]

#ifdef __cplusplus
extern "C" {
#endif
#include
#include

You must never ever put system include files in an extern "C" block! They are already C++ified.

>/opt/CC/bin/CC

This is the unsupported cfront compiler!

>it seems to be a more securely option, is it?

It might be better to use -AC99.

>With this info, what do you recommend to do?
'aCC -Aa' or 'aCC -Ae'?

You compile C with cc and C++ with aCC.

Note: If you want strict C89, you use "aCC -AC89", not -Aa. -Aa means something special in C++ mode.

[Chanquete]

OK Dennis!

I'll try to fix programs to use only aCC, i'm working with very old source code and it will be very 'ugly' to do.

Best regards!

[Dennis Handly]

>I'll try to fix programs to use only aCC

What are you trying to do? Compile old C++ source?

Ok, I read a little more closely.
It seems you have your own version of wprintf. This is illegal since wprintf is reserved in C99 and C++, 17.4.3.1.3(4).

You could put your wprintf in another namespace and then modify all of the callers.

You could use a macro to rename all of your uses to wprintf.

Or if you compile with -U_INCLUDE__STDC_A1_SOURCE it may make it go away.

[Chanquete]

Hi again!

If i compile my C++ sources with '-U_INCLUDE__STDC_A1_SOURCE' option, everything is OK!!!

Can you give me a little explanation of this option? I guess it takes old std libraries, at least it takes the right libraries for my source code compatibility!

Thanks so much Dennis, although i gave you disorganized information, you could find the right solution!

Best wishes!

[Dennis Handly]

>Can you give me a little explanation of this option?

The definition of wprintf in is under #ifdef _INCLUDE__STDC_A1_SOURCE.
Using -U undefines the driver default.

[Chanquete]

You're great, man!

Thanks a lot!