commit r16-8479-g7660e3067481159acc3ad76cfae22f71606670c7
Author: Christopher Albert <[email protected]>
Date: Fri Apr 3 12:45:57 2026 +0200
fortran: Clean up charlens after rejected parameter arrays [PR79524]
I will backport after some time.
Jerry
On 4/4/26 10:32 AM, Jerry D wrote:
Hi all,
As stated in the PR, I was able to verify the valgrind error and after applying
the patch, confirmed the errors go away.
Regression tested on X86_64.
I plan to commit this in the next day or so unless additional comments.
Regards,
Jerry
---
fortran: Clean up charlens after rejected parameter arrays
[PR79524]
When a parameter array declaration such as
character(*), parameter :: z(2) = [character(n) :: 'x', 'y']
is rejected, declaration-local charlen nodes from that statement can remain on
cl_list and later be resolved again. The charlen's length expression still
references the symbol 'n' whose symtree was already freed by gfc_undo_symbols,
causing a heap-use-after-free in resolve_charlen.
Clean up those statement-local charlens at the rejection point in decl.cc,
after clearing the surviving owners in that path.
PR fortran/79524
gcc/fortran/ChangeLog:
PR fortran/79524
* decl.cc (discard_pending_charlens): New helper.
(add_init_expr_to_sym): Drop statement-local charlens when
rejecting variable-length parameter arrays.
(variable_decl, do_parm, enumerator_decl): Save the current
namespace charlen list before parsing declarations with
initializers.
(match_procedure_decl): Adjust call to add_init_expr_to_sym.
gcc/testsuite/ChangeLog:
PR fortran/79524
* gfortran.dg/pr79524.f90: New test.
Signed-off-by: Christopher Albert <[email protected]>
