gnu /
gcc /
fc5c603da3c9b186308fb3afef7bcf3f3bf695e8 fortran: Ignore use statements on error [PR107426]
This fixes an access to freed memory on the testcase from the PR.
The problem comes from an invalid subroutine statement in an interface,
which is ignored and causes the following statements forming the procedure
body to be rejected. One of them use-associates the intrinsic ISO_C_BINDING
module, which imports new symbols in a namespace that is freed at the time
the statement is rejected. However, this creates dangling pointers as
ISO_C_BINDING is special and its import creates a reference to the imported
C_PTR symbol in the return type of the global intrinsic symbol for C_LOC
(see the function create_intrinsic_function).
This change saves and restores the list of use statements, so that rejected
use statements are removed before they have a chance to be applied to the
current namespace and create dangling pointers.
PR fortran/107426
gcc/fortran/ChangeLog:
* gfortran.h (gfc_save_module_list, gfc_restore_old_module_list):
New declarations.
* module.cc (old_module_list_tail): New global variable.
(gfc_save_module_list, gfc_restore_old_module_list): New functions.
(gfc_use_modules): Set module_list and old_module_list_tail.
* parse.cc (next_statement): Save module_list before doing any work.
(reject_statement): Restore module_list to its saved value.
gcc/testsuite/ChangeLog:
* gfortran.dg/pr89943_3.f90: Update error pattern.
* gfortran.dg/pr89943_4.f90: Likewise.
* gfortran.dg/use_31.f90: New test.
(cherry picked from commit a44d7e8a52007c2d45217709ca02947c6600de87)
6 files changed
