Re: [Flex-help] help needed in the transition from flex 2.59 to 2.6

[Rollastre P. <rol...@gm...>]

Thanks for the response.

I am sorry. You are right. I did read the version wrong.  When I say 
2.59 it should have been 2.5.39. But the problem is the same.

JDF@JDF /usr/bin
$ flex -V
flex 2.5.39

which is when it works fine as it assigns a reference to std::cin to the 
pointer yyin  (yyin=&std::cin).

but when using flex 2.6.1

JDF@JDF /usr/bin
$ flex --version
flex 2.6.1

is when it uses the . operator

     yyin.rdbuf(std::cin.rdbuf());

when it should be using the -> operator.

      yyin->rdbuf(std::cin.rdbuf());

In fact, if I edit it manually, the compile error goes away.

I don't know if this is a bug or that I have to specify something in the 
.ll file.


On 07-Oct-16 1:57 PM, Will Estes wrote:
> THe version numbers you are siting are a bit muddled. What does "flex --version" report in both cases?
>
> On Friday,  7 October 2016,  8:45 am +0200, Rollastre Prostit <rol...@gm...> wrote:
>
>> Hello list.
>>
>> I looks like there are some changes in the code generated by flex 2.59
>> and 2.6 (in C++) that break my build.
>>
>> in 2.59 the code in question in the XXXX.lexer.cpp is this:
>>
>> if(!yyin)
>>
>> /*%if-c-only*/
>>
>> /*%endif*/
>>
>> /*%if-c++-only*/
>>
>> yyin=&std::cin;
>>
>> /*%endif*/
>>
>> if(!yyout)
>>
>> /*%if-c-only*/
>>
>> /*%endif*/
>>
>> /*%if-c++-only*/
>>
>> yyout=&std::cout;
>>
>> /*%endif*/
>>
>>
>> and in 2.6 is like this:
>> if(!yyin)
>>
>> /*%if-c-only*/
>>
>> /*%endif*/
>>
>> /*%if-c++-only*/
>>
>> yyin.rdbuf(std::cin.rdbuf());
>>
>> /*%endif*/
>>
>> if(!yyout)
>>
>> /*%if-c-only*/
>>
>> /*%endif*/
>>
>> /*%if-c++-only*/
>>
>> yyout.rdbuf(std::cout.rdbuf());
>>
>> /*%endif*/
>>
>>
>>
>> It turns out that the 2.59 version works fine but the 2.6 doesn't
>> compile because yyin and yyout are pointers. I have searched for a
>> solution for my problem in the list but I couldn't find anything. I also
>> googled and found this
>>
>> http://stackoverflow.com/questions/34438023/openfoam-flex-yyin-rdbufstdcin-rdbuf-error
>>
>> http://htaccess9simo.blogspot.com.es/2015/12/openfoam-flex-yyinrdbufstdcinrdbuf-error.html
>>
>> Which basically workaround the problem by downgrading to 2.59 in the
>> /usr/bin. I already tested this and worked for me too. But I would
>> expect there is a better solution which doesn't require that my build
>> system ships a specific version of flex. Does somebody know what am I
>> doing (or not doing) that causes this problem?
>>
>> Thank you and sorry if the question is already posted, I just couldn't
>> find it!
>>
>>
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