Andreas Sæbjørnsen wrote:

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The first '#elif' directive is registered as an 'evaluated_conditional_expression(...)', but the second '#elif' is never evaluated since the previous '#if' directive is true, and it is therefore not registered as either a 'skipped_token(...)' or an 'evaluated_conditional_expression(...)'. The way I expected it to work was to register it as a 'skipped_token(...)'. Do you have a suggestion to how I should otherwise be handling this? If not, could it be possible to add the non-evaluated '#elif' to the skipped token stream?

This is fixed now (Boost CVS::HEAD and Boost CVS::BOOST_RC_1_34). Thanks for reporting.

Thank you very much! I appreciate the fast fix.

The suggestion is for preprocessor generated tokens where the

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'macro.get_position().get_file().size() == 0'. An example of this is in the following code

#ifdef SOME_MACRO //DO SOMETHING #endif

Since 'SOME_MACRO' is not defined the 'expanding_object_like_macro(TokenT const ¯o,....)' will be passed a TokentT& const& macro with no position object, so asking for the line or column number will give a hard to debug segmentation fault.

This one is really strange, because if SOME_MACRO is not defined then the expanding_object_like_macro() pp hook shouldn't be called for this macro. For this reason I'm not able to reproduce this issue here.

Nevertheless, I think it's a bug if 'macro.get_position ().get_file().size() == 0' in any case (any token should have some associated file/position it was encountered at). Could you please try to isolate this problem and send me a sample?

No problem. I will send it to you as soon as I have it. :) A change I have done to Wave which I have not told you about earlier is to change the behaviour of on_warning(...) in 'tboost/wave/util/cpp_iterator.hpp' to continue if a #warning directive is found, and not treat it like an error. I do not know if the CVS-version still behaves in this way. I also added a preprocessing hook on_warning(..) for the warning directive as I need to extract it. What do you think of this change? (Code Below for on_warning. Changed 'preprocessing_hooks.hpp' attached). Thanks Andreas #if BOOST_WAVE_SUPPORT_WARNING_DIRECTIVE != 0 /////////////////////////////////////////////////////////////////////////////// // // on_warning(): handle #warning directives // /////////////////////////////////////////////////////////////////////////////// template <typename ContextT> inline void pp_iterator_functor<ContextT>::on_warning( typename parse_tree_type::const_iterator const &begin, typename parse_tree_type::const_iterator const &end) { BOOST_ASSERT(ctx.get_if_block_status()); // preprocess the given sequence into the provided list token_sequence_type expanded; get_token_value get_value; typename ref_transform_iterator_generator< get_token_value, typename parse_tree_type::const_iterator >::type first = make_ref_transform_iterator(begin, get_value); #if BOOST_WAVE_PREPROCESS_ERROR_MESSAGE_BODY != 0 // preprocess the body of this #warning message token_sequence_type toexpand; std::copy(first, make_ref_transform_iterator(end, get_value), std::inserter(toexpand, toexpand.end())); typename token_sequence_type::iterator begin2 = toexpand.begin(); ctx.expand_whole_tokensequence(begin2, toexpand.end(), expanded, false); #else // simply copy the body of this #warning message to the issued diagnostic // message std::copy(first, make_ref_transform_iterator(end, get_value), std::inserter(expanded, expanded.end())); #endif //AS(051706) Added an extra hook to send the warning directive std::cout << "The warning is: " << boost::wave::util::impl::as_string(expanded).c_str() << std::endl; ctx.get_hooks().on_warning(toexpand); //AS(051606) Do not treat warning directives as errors #if 0 // report the corresponding error BOOST_WAVE_THROW(preprocess_exception, warning_directive, boost::wave::util::impl::as_string(expanded).c_str(), act_pos); #endif } #endif // BOOST_WAVE_SUPPORT_WARNING_DIRECTIVE != 0 Regards Hartmut

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Hmmm. The 'warning_directive' preprocess_exception is recoverable. That means you may simply continue to iterate after catching this type of exception (see the wave driver how this may be achieved). That's the reason why I made the warning to throw an exception (same as #error). I'm not sure if we really should change this behaviour (even more as the driver currently depends on that).

OTOH I like your idea to add a on_warning() pp hook function (same should be added for #error as well). What do you think, what if we use the return value of the on_warning() pp hook to decide, whether to throw the exception? This way we could keep the default behaviour (throwing) but you could enforce the non-throwing behaviour simply by returning false.

I think using the return value form on_warning() or on_hook() to decide if an exception should be thrown is an excellent idea. That would fit very well with my needs. Regards Andreas

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Thanks Andreas

#if BOOST_WAVE_SUPPORT_WARNING_DIRECTIVE != 0 ////////////////////////////////////////////////////////////// ///////////////// // // on_warning(): handle #warning directives // ////////////////////////////////////////////////////////////// ///////////////// template <typename ContextT> inline void pp_iterator_functor<ContextT>::on_warning( typename parse_tree_type::const_iterator const &begin, typename parse_tree_type::const_iterator const &end) { BOOST_ASSERT(ctx.get_if_block_status());

// preprocess the given sequence into the provided list token_sequence_type expanded; get_token_value get_value;

typename ref_transform_iterator_generator< get_token_value, typename parse_tree_type::const_iterator >::type first = make_ref_transform_iterator(begin, get_value);

#if BOOST_WAVE_PREPROCESS_ERROR_MESSAGE_BODY != 0 // preprocess the body of this #warning message token_sequence_type toexpand;

std::copy(first, make_ref_transform_iterator(end, get_value), std::inserter(toexpand, toexpand.end()));

typename token_sequence_type::iterator begin2 = toexpand.begin(); ctx.expand_whole_tokensequence(begin2, toexpand.end(), expanded, false); #else // simply copy the body of this #warning message to the issued diagnostic // message std::copy(first, make_ref_transform_iterator(end, get_value), std::inserter(expanded, expanded.end())); #endif //AS(051706) Added an extra hook to send the warning directive std::cout << "The warning is: " << boost::wave::util::impl::as_string(expanded).c_str() << std::endl; ctx.get_hooks().on_warning(toexpand);

//AS(051606) Do not treat warning directives as errors #if 0 // report the corresponding error BOOST_WAVE_THROW(preprocess_exception, warning_directive, boost::wave::util::impl::as_string(expanded).c_str(), act_pos); #endif

} #endif // BOOST_WAVE_SUPPORT_WARNING_DIRECTIVE != 0

Regards Hartmut

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