Patch RFC: Fix broken builds with Sun CC

[Jens Erat]

Hi Ellie,

thank you for the detailed analysis.

>> This is not as simple as just removing the casts from lib/imapopts.c --
>> it's a generated file.  Note the comments at the top:
>>
>>> /* auto-generated by config2header 1.17 */
>>>
>>> /* DO NOT EDIT */
>>>
>>> /* THIS FILE AUTOMATICALLY GENERATED BY config2header 1.17 */
>>

Indeed, this is not the way to go.


> I don't know what the Sun compiler is called, though I'm assuming it
> doesn't call itself "gcc".  If it does, there is your problem.
>
> Otherwise, you should be able to do something like this to make sure it
> uses the same compiler for the whole build:
>
>> make clean
>> ./configure CC=/path/to/sun/compiler [...]
>> make

We already set `CC=cc`, which resulted in following `configure` output:

checking build system type... i386-pc-solaris2.11
checking host system type... i386-pc-solaris2.11
checking target system type... i386-pc-solaris2.11
checking for a BSD-compatible install... /usr/bin/ginstall -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... /usr/bin/gmkdir -p
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
checking whether to enable maintainer-specific portions of Makefiles... no
checking for gcc... cc
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables...
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C compiler... no
checking whether cc accepts -g... yes
checking for cc option to accept ISO C89... none needed
checking for style of include used by make... GNU
checking dependency style of cc... none
checking whether cc understands -c and -o together... yes
checking whether ln -s works... yes
checking whether make sets $(MAKE)... (cached) yes
checking how to run the C preprocessor... cc -E
checking for grep that handles long lines and -e... /usr/bin/ggrep
checking for egrep... /usr/bin/ggrep -E
checking for ANSI C header files... yes


Also if using `export CC=/opt/solarisstudio12.4/bin/cc`, union casts are
created, but one single line changes to

checking fgor gcc... /opt/solarisstudio12.4/bin/cc

`./configure CC=/opt/solarisstudio12.4/bin/cc [...]` does not change
anything, either. GCC _is_ installed as `/usr/bin/gcc`, but should not
have been used.

Interestingly, configure also recognizes `make` as GNU make (available
under `gmake`, though); resulting in a GNU-style make file (and we have
to use `gmake` for Cyrus IMAP instead of `make`, but I guess that's just
fine, at least for us, but also might hint a problem).



>> The mailing list discussions you reference talk about this being a
>> result of the Sun compiler being strict about "Ansi C", by which I'm
>> assuming they mean C89/C90.  We generally target C99 these days (it is,
>> after all, 16 years old, and has itself already been superceded by
>> C11...).
>>
>> I don't know if the Sun compiler has options to support C99, but if it
>> does, have you tried using them?

Following the man pages, Sun CC not only supports C99, but also C11, and
C11 is set as default:

     -std=value

         C language standard selection flag.

         value is defined as one of the following:


         c89          C source language accepted is that  defined
                      by the ISO C90 standard.


         c99          C source language accepted is that  defined
                      by the ISO C99 standard.


         c11          C source language accepted is that  defined
                      by the ISO C11 standard.

         The first default is c11, implying acceptance of  the  C
         source  language as defined by ANSI C11 with extensions.

Enforcing C99 by adding `-std=c99` to CFLAGS did not resolve the issue,
but c11 should be the default, anyway...


> If your $CC evaluates to 'gcc' then it will generate union casts;
> otherwise, it will generate (void *) casts.  Watch:
>
>> $rm lib/imapopts.c
>> $make CC=gcc lib/imapopts.c

If I run

    gmake CC=`which cc` lib/imapopts.c

indeed, void casts are generated. For now, the issue is resolved by
exporting the full path of the Sun C compiler.

Regards,
Jens

-- 
Jens Erat
Universität Konstanz
Kommunikations-, Infomations-, Medienzentrum (KIM)
Abteilung Basisdienste
D-78457 Konstanz
Mail: jens.erat at uni-konstanz.de


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