[ruby-core:26217] [Bug #2247] Fixing compiler warnings

[Sakuro OZAWA]

Bug #2247: Fixing compiler warnings
http://redmine.ruby-lang.org/issues/show/2247

Author: Міхаіл T.
Status: Open, Priority: Normal
Category: build
ruby -v: ruby 1.8.7 (2009-06-12 patchlevel 174) [x86_64-linux]

When debugging a problem, gratuitous compiler warnings often get in the way by obscuring real problems.

This is why projects should try to eliminate them -- so that when a new one pops up, such as when new code is added, or the build is performed on a new platform -- the issue can attract its due attention.

The attached patch fixes warnings, that I observed compiling with ``-Wall -Werror'' on RHEL-5.4/x86_64 system. Please, consider merging these changes in.

The addressed problems are:

 * rb_thread_join was not declared (intern.h) with the rest of the rb_thread functions. Private declarations
   existed in some C-files...
 * The PUSH_FRAME duly defined the local variable _frame as volatile. However, when the value of _frame was
   assigned to the global ruby_frame, this qualifier was lost. There were as many warnings about this, as
   there are invocations of the PUSH_FRAME macro.
 * The little thread_timer() function MUST be declared as returning void*, because it is passed to
   pthread_create(). Compiler warned, that a non-void function lacked the return-statement. I added one...
 * regex.c in its error reporting tried to print ptrdiff_t value as int. On 64-bit platforms ptrdiff_t is,
   usually, long int, but that's an impossibly large value for a regular expression's length.
   Explicit casting of the pointer-difference down to int should be fine.
 * parse.y defined an unused static function arg_prepend()

Also, when compiling with a recent gcc at optimization level -O2 (or higher), util.c throws a number of warnings about breaking strict-aliasing rules. There is no /easy/ fix for this, but the work-around is to simply compile that one file with -fno-strict-aliasing (or whatever flag is needed for this with non-gcc compilers). A /sample/ patch for this issue is attached separately.

Thanks! Yours,

        -mi


----------------------------------------
http://redmine.ruby-lang.org

[Nobuyoshi Nakada-2]

At Thu, 22 Oct 2009 00:59:42 +0900,
Mikhail T. <redmine@...> wrote in [ruby-core:26217]:
> The attached patch fixes warnings, that I observed compiling
> with ``-Wall -Werror'' on RHEL-5.4/x86_64 system. Please,
> consider merging these changes in.

Thank you.

> The addressed problems are:
>
>  * rb_thread_join was not declared (intern.h) with the rest of the rb_thread functions. Private declarations
>    existed in some C-files...

Applied in r25431.

>  * The PUSH_FRAME duly defined the local variable _frame as volatile. However, when the value of _frame was
>    assigned to the global ruby_frame, this qualifier was lost. There were as many warnings about this, as
>    there are invocations of the PUSH_FRAME macro.

Fixed in r17831.

>  * The little thread_timer() function MUST be declared as returning void*, because it is passed to
>    pthread_create(). Compiler warned, that a non-void function lacked the return-statement. I added one...

Fixed in r23201.

>  * regex.c in its error reporting tried to print ptrdiff_t value as int. On 64-bit platforms ptrdiff_t is,
>    usually, long int, but that's an impossibly large value for a regular expression's length.
>    Explicit casting of the pointer-difference down to int should be fine.

Fixed in r20465

>  * parse.y defined an unused static function arg_prepend()

Applied in r25432.

> Also, when compiling with a recent gcc at optimization level
> -O2 (or higher), util.c throws a number of warnings about
> breaking strict-aliasing rules. There is no /easy/ fix for
> this, but the work-around is to simply compile that one file
> with -fno-strict-aliasing (or whatever flag is needed for
> this with non-gcc compilers). A /sample/ patch for this issue
> is attached separately.

Fixed in r23353.

--
Nobu Nakada

[Sakuro OZAWA]

Issue #2247 has been updated by Міхаіл T..

File patch-ruby-openssl added

The attached new patch almost fixes the OpenSSL-extension. The bulk of it is casts from char* to unsigned char*
with some const-ification thrown in.

This should help concentrate on fixing /real/ problems, such as:

gcc44 -I. -I../.. -I/home/mteterin/ruby-1.8.7-p174 -I/home/mteterin/ruby-1.8.7-p174/ext/openssl -DRUBY_EXTCONF_H=\"extconf.h\"    -fPIC -O2 -Wall -Wno-unused -Werror -pipe -march=nocona   -c /home/mteterin/ruby-1.8.7-p174/ext/openssl/ossl_pkey_dh.c
cc1: warnings being treated as errors
ext/openssl/ossl_pkey_dh.c: In function 'ossl_dh_initialize':
ext/openssl/ossl_pkey_dh.c:173: error: function called through a non-compatible type
ext/openssl/ossl_pkey_dh.c:173: note: if this code is reached, the program will abort
ext/openssl/ossl_pkey_dh.c: In function 'ossl_dh_to_public_key':
ext/openssl/ossl_pkey_dh.c:333: error: function called through a non-compatible type
ext/openssl/ossl_pkey_dh.c:333: note: if this code is reached, the program will abort
make: *** [ossl_pkey_dh.o] Помилка 1

The above problems -- triggered in several files -- seem to be with OpenSSL, rather than Ruby or its openssl-extension. I'm unsure, if any work-around is possible. These are NOT fixed by the attached patch.
----------------------------------------
http://redmine.ruby-lang.org/issues/show/2247

----------------------------------------
http://redmine.ruby-lang.org

[Sakuro OZAWA]

Issue #2247 has been updated by Nobuyoshi Nakada.


backport r18168?
----------------------------------------
http://redmine.ruby-lang.org/issues/show/2247

----------------------------------------
http://redmine.ruby-lang.org

[Sakuro OZAWA]

Issue #2247 has been updated by Міхаіл T..


> backport r18168?

Sorry, I'm unsure, what you mean :( If you suggest, I build a snapshot of the repository -- sorry, I can't do that. We only deal with /released/ versions here -- patched, if need be... Maybe, it is time for another patch-release for the 1.8.7pX branch?

Thanks!
----------------------------------------
http://redmine.ruby-lang.org/issues/show/2247

----------------------------------------
http://redmine.ruby-lang.org

[Sakuro OZAWA]

Issue #2247 has been updated by Міхаіл T..


Also, each occurrence of BIO_reset() triggers a warning like:

ext/openssl/ossl_pkey_dh.c: In function 'ossl_dh_initialize':
ext/openssl/ossl_pkey_dh.c:172: error: value computed is not used

The following command (on Linux -- requires pcre in grep) silences all of them at once:

find ext/openssl -type f -name '*.c' | xargs grep -P -l '\sBIO_reset' | xargs perl -p -i.iorig -e 's/(\s)BIO_reset/\1(void)BIO_rest/'

It changes BIO_reset to (void)BIO_reset...
----------------------------------------
http://redmine.ruby-lang.org/issues/show/2247

----------------------------------------
http://redmine.ruby-lang.org