[Bug fortran/100440] allocated() gives True for unallocated variable

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100440

--- Comment #5 from kargl at gcc dot gnu.org ---
David,

On amd64-*-freebsd, I see 

% gfcx -o z -O2 -fcheck=all allocate_error.f95
% ./z

 Sample 10.  Eigenvalue from matrix powers.

 Iteration    eigenvalue approximation 

         0     1.000000000000000000000000000000000000000000000000000000000
 21 j=           1  allocated(FMMATMUL21_FM(J)%MFM%mp) =  F
  allocated(FMMATMUL21_FM(J)%MFM%mp) =  F
At line 2499 of file allocate_error.f95
Fortran runtime error: Allocatable argument 'fmmatmul21_fm' is not allocated

with a number of different options.  The runtime error is expected as
'allocated(FMMATMUL21_FM(J)%MFM%mp) = F', and the print statement checking
size() is not protected by an 'if' statement.

valgrind shows 

==8708== HEAP SUMMARY:
==8708==     in use at exit: 10,737 bytes in 68 blocks
==8708==   total heap usage: 170 allocs, 102 frees, 40,166 bytes allocated
==8708== 
==8708== LEAK SUMMARY:
==8708==    definitely lost: 0 bytes in 0 blocks
==8708==    indirectly lost: 0 bytes in 0 blocks
==8708==      possibly lost: 0 bytes in 0 blocks
==8708==    still reachable: 10,737 bytes in 68 blocks
==8708==         suppressed: 0 bytes in 0 blocks

which suggests that this might be a MacOS specific bug.

Note, if I comment out your print statement for diagnostics, I see

 % ./z                                                           

 Sample 10.  Eigenvalue from matrix powers.

 Iteration    eigenvalue approximation 

         0     1.000000000000000000000000000000000000000000000000000000000
         1    24.238372093023255813953488372093023255813953488372093023260
         2  .889072890369341844887411185964338107009906299229814263038M+20
         3  .102214801410512542129975983352534954405105702575200225476M+43
         4  .133558489514054527062720546215032551914781174136345314241M+87
         5 .321140870607048831918216893831115589158773657747578318060M+175
         6 .205341864155723417152215792855218285040195823798023639691M+352
         7 .667355770417440618516624449043958628107088436355045114363M+705