[Info-vax] Color me confused (VMS C issues, this time with %zu)

[John Reagan]

On Wednesday, October 26, 2016 at 3:41:13 AM UTC-4, Richard Levitte wrote:
> I'm a little confused...  The VMS C manual [1] states that:
> 
> -----8<-----
> It also provides complete language support for ISO/IEC 9899:1999, informally called C99, although not all run-time library routines are currently implemented, floating-point environment access controls are not effective, and Annex F (the optional __STDC_IEC_559__ extension) is not supported.
> -----8<-----
> 
> And sure enough, __STDC_VERSION__ is 199901L.
> 
> And yet, this fails to run properly:
> 
> -----8<-----
> #include <stdio.h>
> 
> #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
> # define zu "zu"
> #else
> # define zu "llu"
> #endif
> 
> int main()
> {
>     size_t foo = 1;
> 
>     printf("__STDC_VERSION__ is %lu\n", __STDC_VERSION__);
>     printf("zu is '%s'\n", zu);
>     printf("foo is %" zu "\n", foo);
> }
> -----8<-----
> 
> See this session:
> 
> -----8<-----
> $ cc/version
> HP C V7.3-018 on OpenVMS IA64 V8.4    
> $ cc foo.c
> 
>     printf("foo is %" zu "\n", foo);
> ...............................^
> %CC-W-UNSUPCONVSPEC, In this statement, this argument to printf has a conversion
>  specification "%zu" that is not supported or not fully supported on this platfo
> rm.
> at line number 15 in file PROGRAM:[LEVITTE-BUILDS.OPENSSL-EXPERIMENTAL.IA64]FOO.
> C;4
> $ link foo
> %ILINK-W-COMPWARN, compilation warnings
> 	module: FOO 
> 	file: PROGRAM:[LEVITTE-BUILDS.OPENSSL-EXPERIMENTAL.IA64]FOO.OBJ;4 
> $ run foo
> __STDC_VERSION__ is 199901
> zu is 'zu'
> foo is zu
> -----8<-----
> 
> As far as I know, %zu isa C99 feature and not part of Annex F, so for a compiler that "provides complete language support for ISO/IEC 9899:1999", this leads to fairly ackward preprocessor conditions specially for VMS.
> 
> Or really, the the compiler doesn't provide complete language support for C99, should it pretend it does?
> 
> Cheers,
> Richard

You are correct.  Looking back, it should not have set that symbol.

We just added the support to the CRTL to bring it to C99 (the "z" and a few others; stdint.h; moving stuff around in inttypes.h, fp.h, float.h, and math.h) and it will soon be going to some form of field test.  Interested?  This is for VSI systems.