Boost C++ Libraries: Ticket #3603: Fix warnings when compiling test cases

attachment set

s.ochsenknecht@… — Tue, 10 Nov 2009 06:54:07 GMT

attachment → fix_warnings.patch

patch

Vladimir Prus — Tue, 10 Nov 2009 06:59:59 GMT

(In [57535]) Fix warnings.

Addresses #3603. Patch from Sascha Ochsenknecht.

Vladimir Prus — Tue, 10 Nov 2009 07:03:12 GMT

Sascha, I have checked in this patch. I'll leave the issue open until the warnings from integer is resolved somehow -- and I'm posting an email about that.

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Tue, 10 Nov 2009 10:13:59 GMT

cc mateusz@… added

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s.ochsenknecht@… — Tue, 10 Nov 2009 13:46:16 GMT

attachment → any_cast_warning.patch

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type changed

anonymous — Tue, 10 Nov 2009 13:56:29 GMT

type Patches → Bugs

I got some other warnings when compiling options_description_test.cpp:

../../../boost/any.hpp: In member function ‘void boost::program_options::typed_value<T, charT>::notify(const boost::any&) const [with T = double, charT = char]’:
options_description_test.cpp:182:   instantiated from here
../../../boost/any.hpp:216: warning: type qualifiers ignored on function return type
../../../boost/any.hpp: In member function ‘void boost::program_options::typed_value<T, charT>::notify(const boost::any&) const [with T = int, charT = char]’:
options_description_test.cpp:182:   instantiated from here
../../../boost/any.hpp:216: warning: type qualifiers ignored on function return type

Probably these warnings point to a real bug (changed type to "bug" until it is clear).

I compiled "by-hand" with:

g++ options_description_test.cpp \
   -g -Wall -Wextra -pedantic -I../../.. -L/my/private/libdir -lboost_program_options -o a.out

I'm not quite sure, but I think any_cast is used in a wrong way. I added any_cast_warning.patch which should solve this problem ... but please review!

Thanks

Vladimir Prus — Wed, 18 Nov 2009 16:43:20 GMT

options_description_test.cpp does not even have line 182 in my copy. And I don't get the warning either. So, how do I reproduce this?

Vladimir Prus — Wed, 18 Nov 2009 16:49:24 GMT

Hmm, the any_cast that reports the error is the one taking reference to any, while The code in typed_value::notify is supposed to call the one taking pointer. I am completely confused.

anonymous — Wed, 18 Nov 2009 18:59:14 GMT

Looking deeper to it, confuses me also :-(. Will comment on that asap.

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Sascha Ochsenknecht — Thu, 19 Nov 2009 07:25:23 GMT

attachment → any_cast_warning.2.patch

patch

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Sascha Ochsenknecht — Thu, 19 Nov 2009 07:26:25 GMT

attachment → any_warning.cpp

test case

Sascha Ochsenknecht — Thu, 19 Nov 2009 07:28:12 GMT

I guess I found the problem, my first approach was due to misunderstanding. Sorry for confusion.

Here is what the gcc manual says about this warning:

Warn if the return type of a function has a type qualifier such as const. For ISO C such a type qualifier has no effect, since the value returned by a function is not an lvalue.

So, the any cast is supposed to return "const T* const" due to the template parameter <const T>. Here is declaration of the any_cast:

template<typename ValueType> const ValueType * any_cast(const any * operand);

So, the line in detail/value_semantic.hpp has to be changed from:

const T* value = boost::any_cast<const T>(&value_store);

const T* value = boost::any_cast<T>(&value_store);

I attached a new any_cast_warning.2.patch and a test case any_warning.cpp

Cheers, Sascha

Sascha Ochsenknecht — Fri, 20 Nov 2009 16:00:35 GMT

The any_cast issue is resolved, see #2562

This ticket is still open due to the integer issue which is still not resolved.

status, milestone changed; resolution set

Sascha Ochsenknecht — Thu, 03 Dec 2009 17:58:22 GMT

status new → closed
resolution → fixed
milestone Boost 1.41.0 → Boost 1.42.0

The integer issue seems to be resolved on trunk, so I close the ticket. I could not see any warning currently (using bjam gcc warnings=all cxxflags=-Wextra)