[Bug fortran/52843] New: Unexpected rejection of pure recursive function

[fmartinez at gmv dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52843

             Bug #: 52843
           Summary: Unexpected rejection of pure recursive function
    Classification: Unclassified
           Product: gcc
           Version: 4.7.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: fmarti...@gmv.com


Created attachment 27074
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27074
Sample code for bug

When a functions returns a string declared as character(len=:), allocatable the
compiler complains about the function not allowed to be pure or recursive.

The attached file produces the following diagnostics (note that messages appear
twice):


fmmf@porfmmf:~/gfortran_bugs/pure_returns_character_allocatable$
/opt/gcc-4.7/bin/gfortran -c m_module.f90 
m_module.f90:31:

pure function f_p( x ) result(res)
1
Error: CHARACTER(*) function 'f_p' at (1) cannot be pure
m_module.f90:20:

recursive function f_r( x ) result(res)
1
Error: CHARACTER(*) function 'f_r' at (1) cannot be recursive
m_module.f90:8:

recursive pure function f_r_p( x ) result(res)
1
Error: CHARACTER(*) function 'f_r_p' at (1) cannot be pure
m_module.f90:8:

recursive pure function f_r_p( x ) result(res)
1
Error: CHARACTER(*) function 'f_r_p' at (1) cannot be recursive
m_module.f90:31:

pure function f_p( x ) result(res)
1
Error: CHARACTER(*) function 'f_p' at (1) cannot be pure
m_module.f90:20:

recursive function f_r( x ) result(res)
1
Error: CHARACTER(*) function 'f_r' at (1) cannot be recursive
m_module.f90:8:

recursive pure function f_r_p( x ) result(res)
1
Error: CHARACTER(*) function 'f_r_p' at (1) cannot be pure
m_module.f90:8:

recursive pure function f_r_p( x ) result(res)
1
Error: CHARACTER(*) function 'f_r_p' at (1) cannot be recursive