https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127892
Bug ID: 127892
Summary: valgrind error in gfc_simplify_expr(gfc_expr*, int)
(expr.cc:2531)
Product: gcc
Version: 17.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: dcb314 at hotmail dot com
Target Milestone: ---
Created attachment 65840
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=65840&action=edit
f90 source code
For the attached F90 code with a recent gfortran, compiled
with valgrind, does this:
$ ~/gcc/results.20261009.valgrind/bin/gfortran -c -w
/home/dcb42/llvm/trunk/flang/test/Evaluate/fold-transfer-partial.f90
==10592== Invalid read of size 2
==10592== at 0x48501B0: memmove (vg_replace_strmem.c:1429)
==10592== by 0x4D478B: gfc_simplify_expr(gfc_expr*, int) (expr.cc:2531)
==10592== by 0x4D40EB: gfc_simplify_expr(gfc_expr*, int) (expr.cc:2488)
==10592== by 0x4F573C: gfc_intrinsic_func_interface(gfc_expr*, int)
(intrinsic.cc:5483)
The code is from the flang testsuite, part of llvm on github.
The bug seems to first occur sometime before 20261003.
The relevant lines of code are
s = gfc_get_wide_string (end - start + 2);
memcpy (s, p->value.character.string + start,
(end - start) * sizeof (gfc_char_t));
s[end - start + 1] = '\0'; /* TODO: C-style string. */
