[Bug fortran/57957] [F03] Double free with allocatable components
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57957 Dominique d'Humieres changed: What|Removed |Added Status|NEW |RESOLVED Resolution|--- |FIXED --- Comment #6 from Dominique d'Humieres --- > Confirmed for gcc 5 and trunk (6.0). The test in comment 0 succeeds with > 4.9.2, > but not the one in comment 2 (!?). Both tests fail with 4.8.5. The first test has been fixed between revisions r199435 (2013-05-30) and r199960 (2013-06-11) and the second test between r219797 (2015-01-17) and r219823 (2015-01-18). Closing as FIXED.
[Bug fortran/57957] [F03] Double free with allocatable components
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57957 Mikael Morin mikael at gcc dot gnu.org changed: What|Removed |Added CC||mikael at gcc dot gnu.org --- Comment #4 from Mikael Morin mikael at gcc dot gnu.org --- (In reply to janus from comment #2) Updated test case: That one seems to be memory-clean with current trunk. FIXED?
[Bug fortran/57957] [F03] Double free with allocatable components
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57957 --- Comment #5 from Dominique d'Humieres dominiq at lps dot ens.fr --- That one seems to be memory-clean with current trunk. FIXED? Confirmed for gcc 5 and trunk (6.0). The test in comment 0 succeeds with 4.9.2, but not the one in comment 2 (!?). Both tests fail with 4.8.5.
[Bug fortran/57957] [F03] Double free with allocatable components
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57957 --- Comment #3 from Tao Song songtao.thu at gmail dot com --- (In reply to janus from comment #2) (In reply to Tobias Burnus from comment #1) For GCC 4.9, one needs to wrap the code in the main program in BLOCK/END BLOCK as otherwise the end-of-scope deallocation does not trigger, which causes the failure. Updated test case: program main implicit none type :: type1 real, allocatable :: anum(:) end type type :: type2 type(type1) :: temp end type block type(type1) :: t1 type(type2) :: t2 t1 = type1([0.,1.]) t2 = type2(t1) end block end Note: The double free goes away when changing the line t2 = type2(t1) to t2%temp = t1 That means the actual problem is not the auto-dealloc itself (which is done properly), but the construction of t2: With the second variant, a deep copy is done (allocating a separate chunk of memory for t2%temp), while in the first one t2%temp only gets a reference to the memory allocated for t1 (which is of course wrong). Since both t1 and t2 are auto-deallocated, we try to free that memory twice. Do you mean in fortran the default structure constructor would yield a shadow copying? Is this in the standard? Thank you. Tao Song
[Bug fortran/57957] [F03] Double free with allocatable components
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57957 janus at gcc dot gnu.org changed: What|Removed |Added CC||janus at gcc dot gnu.org Summary|Double free with|[F03] Double free with |allocatable components |allocatable components --- Comment #2 from janus at gcc dot gnu.org --- (In reply to Tobias Burnus from comment #1) For GCC 4.9, one needs to wrap the code in the main program in BLOCK/END BLOCK as otherwise the end-of-scope deallocation does not trigger, which causes the failure. Updated test case: program main implicit none type :: type1 real, allocatable :: anum(:) end type type :: type2 type(type1) :: temp end type block type(type1) :: t1 type(type2) :: t2 t1 = type1([0.,1.]) t2 = type2(t1) end block end Note: The double free goes away when changing the line t2 = type2(t1) to t2%temp = t1 That means the actual problem is not the auto-dealloc itself (which is done properly), but the construction of t2: With the second variant, a deep copy is done (allocating a separate chunk of memory for t2%temp), while in the first one t2%temp only gets a reference to the memory allocated for t1 (which is of course wrong). Since both t1 and t2 are auto-deallocated, we try to free that memory twice.
