Dear all, when simplifying SHAPE(), we rely on spec_dimen_size returning non-negative dimensions. That actually did not happen in all cases, as the testcase by Gerhard shows. (The testcase is rather fallout from the wrong simplification).
The solution is trivial: simply check the dimensions against 0 and fix if needed. Regtested on x86_64-pc-linux-gnu. OK for mainline. As it turns out that we generated "wrong code" by the simplification, I'd backport at least to 11-branch after some waiting time if no issues show up elsewhere. Thanks, Harald
From f8d6aae66b1cb3f75b47d50695ef1be7770abc30 Mon Sep 17 00:00:00 2001 From: Harald Anlauf <anl...@gmx.de> Date: Tue, 7 Dec 2021 23:06:41 +0100 Subject: [PATCH] Fortran: dimensions of an array have to be non-negative gcc/fortran/ChangeLog: PR fortran/103610 * array.c (spec_dimen_size): Fix simplification of SHAPE: dimensions must be non-negative. gcc/testsuite/ChangeLog: PR fortran/103610 * gfortran.dg/shape_11.f90: New test. --- gcc/fortran/array.c | 6 ++++-- gcc/testsuite/gfortran.dg/shape_11.f90 | 16 ++++++++++++++++ 2 files changed, 20 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/gfortran.dg/shape_11.f90 diff --git a/gcc/fortran/array.c b/gcc/fortran/array.c index e5e22099405..e4891dfef77 100644 --- a/gcc/fortran/array.c +++ b/gcc/fortran/array.c @@ -2296,8 +2296,7 @@ gfc_copy_iterator (gfc_iterator *src) /********* Subroutines for determining the size of an array *********/ /* These are needed just to accommodate RESHAPE(). There are no - diagnostics here, we just return a negative number if something - goes wrong. */ + diagnostics here, we just return false if something goes wrong. */ /* Get the size of single dimension of an array specification. The @@ -2330,6 +2329,9 @@ spec_dimen_size (gfc_array_spec *as, int dimen, mpz_t *result) mpz_add_ui (*result, *result, 1); + if (mpz_cmp_si (*result, 0) < 0) + mpz_set_si (*result, 0); + return true; } diff --git a/gcc/testsuite/gfortran.dg/shape_11.f90 b/gcc/testsuite/gfortran.dg/shape_11.f90 new file mode 100644 index 00000000000..127d221e710 --- /dev/null +++ b/gcc/testsuite/gfortran.dg/shape_11.f90 @@ -0,0 +1,16 @@ +! { dg-do compile } +! { dg-options "-fdump-tree-original" } +! PR fortran/103610 - ICE while simplifying SHAPE +! Contributed by G.Steinmetz + +program p + integer, parameter :: a(-1) = 1 + integer, parameter :: b(1) = maskl(shape(a)) + integer, parameter :: c(1) = shape(a) + integer, parameter :: d(1) = maskr(shape(a)) + if (b(1) /= 0) stop 1 + if (c(1) /= 0) stop 2 + if (d(1) /= 0) stop 3 +end + +! { dg-final { scan-tree-dump-not "_gfortran_stop_numeric" "original" } } -- 2.26.2