[Bug c++/25992] conditional expression and strings literal

[paolo.carlini at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25992

Paolo Carlini paolo.carlini at oracle dot com changed:

   What|Removed |Added

 Status|NEW |ASSIGNED
 CC|anton.kirillov@rd-software. |
   |com, gcc-bugs at gcc dot gnu.org   |
   Assignee|unassigned at gcc dot gnu.org  |paolo.carlini at oracle 
dot com

--- Comment #6 from Paolo Carlini paolo.carlini at oracle dot com ---
Mine.

[Bug c++/25992] conditional expression and strings literal

[paolo.carlini at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25992

Paolo Carlini paolo.carlini at oracle dot com changed:

   What|Removed |Added

 Status|ASSIGNED|NEW
   Assignee|paolo.carlini at oracle dot com|unassigned at gcc dot 
gnu.org

[Bug c++/25992] conditional expression and strings literal

[bangerth at dealii dot org]

--- Comment #5 from bangerth at dealii dot org  2006-03-08 05:02 ---
Confirmed. These two lines should behave the same, but don't:
--
extern bool flag;
int main()
{
  char* p;
  p = (true ? a : lalala );
  p = (flag ? a : lalala ); 
}
--

g/x /home/bangerth/bin/gcc-4.2*/bin/c++ -c x.cc -Wwrite-strings
x.cc: In function #8216;int main()#8217;:
x.cc:5: warning: deprecated conversion from string constant to
#8216;char*#8217;'
x.cc:6: error: invalid conversion from #8216;const char*#8217; to
#8216;char*#8217;

W.


-- 

bangerth at dealii dot org changed:

   What|Removed |Added

 Status|UNCONFIRMED |NEW
 Ever Confirmed|0   |1
   Keywords||diagnostic
   Last reconfirmed|-00-00 00:00:00 |2006-03-08 05:02:36
   date||


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25992

[Bug c++/25992] conditional expression and strings literal

[pinskia at gcc dot gnu dot org]

--- Comment #1 from pinskia at gcc dot gnu dot org  2006-01-27 12:39 ---
earth:~g++ t.cc -pedantic -Wwrite-strings
t.cc: In function ‘int main()’:
t.cc:5: warning: deprecated conversion from string constant to ‘char*’'


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25992

[Bug c++/25992] conditional expression and strings literal

[anton dot kirillov at rd-software dot com]

--- Comment #2 from anton dot kirillov at rd-software dot com  2006-01-27 
13:12 ---
(In reply to comment #1)
 earth:~g++ t.cc -pedantic -Wwrite-strings
 t.cc: In function ‘int main()’:
 t.cc:5: warning: deprecated conversion from string constant to ‘char*’'
 

Conversion from string constant to ‘char*’' it's legacy from C, but GCC should
not perceive it as const char*, because the type of expression is const char[]!

I think GCC have defined it as a compile-time constant, but it's infeasible
solution. 

In other situation it behaves correctly:

void foo( char* );

int main()
{
bool flag = false;
foo( flag ? a : b ); // error ( cannot convert from const char* to
char* )
}


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25992

[Bug c++/25992] conditional expression and strings literal

[anton dot kirillov at rd-software dot com]

--- Comment #4 from anton dot kirillov at rd-software dot com  2006-01-27 
14:20 ---
(In reply to comment #3)
 I have not looked into the standard yet but if GCC's warning message is 
 correct
 this is valid but deprecated code which allows for a compiler to accept it or
 not.
 

deprecated this converiont:

void foo( char* )
{
}

int main()
{
foo( lalala ); 
}

i.e. convresion from strings literal to char*, but the result of expression (0
? a : b) IS NOT STRING LITERAL!!! IT'S CONST CHAR[2]!!! ( See 5.16 )


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25992

[Bug c++/25992] conditional expression and strings literal

[pinskia at gcc dot gnu dot org]

--- Comment #3 from pinskia at gcc dot gnu dot org  2006-01-27 13:59 ---
I have not looked into the standard yet but if GCC's warning message is correct
this is valid but deprecated code which allows for a compiler to accept it or
not.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25992