From 43ec8b856a67a1b70744e5c0d50ea7fa2dd9a8ee Mon Sep 17 00:00:00 2001 From: Harald Anlauf Date: Mon, 16 Oct 2023 21:02:20 +0200 Subject: [PATCH] Fortran: out of bounds access with nested implied-do IO [PR111837] gcc/fortran/ChangeLog: PR fortran/111837 * frontend-passes.cc (traverse_io_block): Dependency check of loop nest shall be triangular, not banded. gcc/testsuite/ChangeLog: PR fortran/111837 * gfortran.dg/implied_do_io_8.f90: New test. --- gcc/fortran/frontend-passes.cc | 2 +- gcc/testsuite/gfortran.dg/implied_do_io_8.f90 | 18 ++++++++++++++++++ 2 files changed, 19 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gfortran.dg/implied_do_io_8.f90 diff --git a/gcc/fortran/frontend-passes.cc b/gcc/fortran/frontend-passes.cc index 136a292807d..536884b13f0 100644 --- a/gcc/fortran/frontend-passes.cc +++ b/gcc/fortran/frontend-passes.cc @@ -1326,7 +1326,7 @@ traverse_io_block (gfc_code *code, bool *has_reached, gfc_code *prev) if (iters[i]) { gfc_expr *var = iters[i]->var; - for (int j = i - 1; j < i; j++) + for (int j = 0; j < i; j++) { if (iters[j] && (var_in_expr (var, iters[j]->start) diff --git a/gcc/testsuite/gfortran.dg/implied_do_io_8.f90 b/gcc/testsuite/gfortran.dg/implied_do_io_8.f90 new file mode 100644 index 00000000000..c66a0f6fde6 --- /dev/null +++ b/gcc/testsuite/gfortran.dg/implied_do_io_8.f90 @@ -0,0 +1,18 @@ +! { dg-do run } +! { dg-additional-options "-fcheck=bounds" } +! PR fortran/111837 - out of bounds access with front-end optimization + +program implied_do_bug + implicit none + integer :: i,j,k + real :: arr(1,1,1) + integer :: ni(1) + ni(1) = 1 + arr = 1 + write(*,*) (((arr(i,j,k), i=1,ni(k)), k=1,1), j=1,1) + write(*,*) (((arr(i,j,k), i=1,ni(k)), j=1,1), k=1,1) + write(*,*) (((arr(k,i,j), i=1,ni(k)), k=1,1), j=1,1) + write(*,*) (((arr(k,i,j), i=1,ni(k)), j=1,1), k=1,1) + write(*,*) (((arr(j,k,i), i=1,ni(k)), k=1,1), j=1,1) + write(*,*) (((arr(j,k,i), i=1,ni(k)), j=1,1), k=1,1) +end -- 2.35.3