| Summary: | out of bounds error array I/O not picked up with -fbounds-check | ||
|---|---|---|---|
| Product: | gcc | Reporter: | Gareth Vaughan <glv> |
| Component: | fortran | Assignee: | anlauf |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | anlauf, anthony.debeus, Edouard.Canot, gcc-bugs, jvdelisle2, P.Schaffnit, tkoenig, vivekrao4 |
| Priority: | P3 | Keywords: | diagnostic |
| Version: | 4.1.1 | ||
| Target Milestone: | 14.0 | ||
| See Also: | https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97039 | ||
| Host: | Target: | ||
| Build: | Known to work: | ||
| Known to fail: | 4.1.2, 4.2.0, 4.3.0 | Last reconfirmed: | 2007-05-09 08:09:27 |
| Bug Depends on: | |||
| Bug Blocks: | 27766, 37802 | ||
|
Description
Gareth Vaughan
2007-02-15 00:28:39 UTC
*** Bug 31059 has been marked as a duplicate of this bug. *** It's not about being allocatable, it's the I/O operation that doesn't perform the necessary check: $ cat a.f90 real :: x(2,2) x = 0. print *, x(5,:) x(5,:) = 1. end $ gfortran -fbounds-check a.f90 && ./a.out 0.000000 5.8787666E-39 At line 4 of file a.f90 Fortran runtime error: Array reference out of bounds for array 'x', upper bound of dimension 1 exceeded I think the problem is that we don't insert bounds checking in gfc_conv_expr_descriptor. Another test case: $ cat index.f90 module bar contains subroutine foo(a) real, dimension(:) :: a a = 3. end subroutine foo end module bar program main use bar real, dimension(2,2) :: a n = 3 call foo(a(n,:)) end program main $ gfortran index.f90 $ gfortran -fbounds-check index.f90 $ ./a.out Re-confirmed. We have no bounds checking code in fortran/io.c nor in the I/O library. Intentionally not in the library for efficiency. However we can build in some runtime checks with -fcheck=. This one is on my radar and I was just looking at it a few days ago. Not taking assignment yet. *** Bug 52788 has been marked as a duplicate of this bug. *** trunk (10.0 svn revision 280100) Current state of play: For arrays allocated at compile time bounds checking works at compile time: program test integer, dimension(10,10) :: x print *, x(0,:) end program test $ gfortran -fbounds-check pr30802.f90 7 | print *, x(0,:) | 1 Warning: Array reference at (1) is out of bounds (0 < 1) in dimension 1 Changing to allocated arrays and bounds checking does not work at compile time but does at runtime: program test real, allocatable :: x(:) allocate(x(10)) x = 0.0 print *, x(0) deallocate(x) end program test $ gfortran -fbounds-check pr30802.f90 $ ./a.out At line 5 of file pr30802.f90 Fortran runtime error: Index '0' of dimension 1 of array 'x' below lower bound of 1 Error termination. Backtrace: #0 0x400ea1 in ??? #1 0x400f6d in ??? #2 0x4380b2 in ??? #3 0x438471 in ??? #4 0x400c69 in ??? (In reply to markeggleston from comment #8) > Changing to allocated arrays and bounds checking does not work at compile > time but does at runtime: > > program test > real, allocatable :: x(:) > allocate(x(10)) > x = 0.0 > print *, x(0) > deallocate(x) > end program test > > $ gfortran -fbounds-check pr30802.f90 > $ ./a.out > > At line 5 of file pr30802.f90 > Fortran runtime error: Index '0' of dimension 1 of array 'x' below lower > bound of 1 > > Error termination. Backtrace: > #0 0x400ea1 in ??? > #1 0x400f6d in ??? > #2 0x4380b2 in ??? > #3 0x438471 in ??? > #4 0x400c69 in ??? I think the point is that bounds-checking does not work for sections of rank-2 arrays. See also PR97039. This is not I/O specific, but what Thomas said in comment#3. I am working on a patch. The master branch has been updated by Harald Anlauf <anlauf@gcc.gnu.org>: https://gcc.gnu.org/g:1cbf18978aa384bd0ed2dc29b107fc3423cf8e62 commit r14-4039-g1cbf18978aa384bd0ed2dc29b107fc3423cf8e62 Author: Harald Anlauf <anlauf@gmx.de> Date: Fri Sep 15 19:13:38 2023 +0200 Fortran: improve bounds-checking for array sections [PR30802] gcc/fortran/ChangeLog: PR fortran/30802 * trans-array.cc (trans_array_bound_check): Add optional argument COMPNAME for explicit specification of array component name. (array_bound_check_elemental): Helper function for generating bounds-checking code for elemental dimensions. (gfc_conv_expr_descriptor): Use bounds-checking also for elemental dimensions, i.e. those not handled by the scalarizer. gcc/testsuite/ChangeLog: PR fortran/30802 * gfortran.dg/bounds_check_fail_6.f90: New test. *** Bug 97039 has been marked as a duplicate of this bug. *** Fixed on mainline for gcc-14. The master branch has been updated by Harald Anlauf <anlauf@gcc.gnu.org>: https://gcc.gnu.org/g:509352069d6f166d396f4b4a86e71ea521f2ca78 commit r14-9597-g509352069d6f166d396f4b4a86e71ea521f2ca78 Author: Harald Anlauf <anlauf@gmx.de> Date: Wed Mar 20 20:59:24 2024 +0100 Fortran: improve array component description in runtime error message [PR30802] Runtime error messages for array bounds violation shall use the following scheme for a coherent, abridged description of arrays or array components of derived types: (1) If x is an ordinary array variable, use "x" (2) if z is a DT scalar and x an array component at level 1, use "z%x" (3) if z is a DT scalar and x an array component at level > 1, or if z is a DT array and x an array (at any level), use "z...%x" Use a new helper function abridged_ref_name for construction of that name. gcc/fortran/ChangeLog: PR fortran/30802 * trans-array.cc (abridged_ref_name): New helper function. (trans_array_bound_check): Use it. (array_bound_check_elemental): Likewise. (gfc_conv_array_ref): Likewise. gcc/testsuite/ChangeLog: PR fortran/30802 * gfortran.dg/bounds_check_17.f90: Adjust pattern. * gfortran.dg/bounds_check_fail_8.f90: New test. |