[gcc r12-5829] Fortran: perform array subscript checks only for valid INTEGER bounds

[Harald Anlauf]

https://gcc.gnu.org/g:9eec77c0df9e5c67454a2e8f83246104458ba4f0

commit r12-5829-g9eec77c0df9e5c67454a2e8f83246104458ba4f0
Author: Harald Anlauf <anlauf@gmx.de>
Date:   Tue Dec 7 21:34:31 2021 +0100

    Fortran: perform array subscript checks only for valid INTEGER bounds
    
    gcc/fortran/ChangeLog:
    
            PR fortran/103607
            * frontend-passes.c (do_subscript): Ensure that array bounds are
            of type INTEGER before performing checks on array subscripts.
    
    gcc/testsuite/ChangeLog:
    
            PR fortran/103607
            * gfortran.dg/pr103607.f90: New test.

Diff:
---
 gcc/fortran/frontend-passes.c          |  4 ++++
 gcc/testsuite/gfortran.dg/pr103607.f90 | 12 ++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/gcc/fortran/frontend-passes.c b/gcc/fortran/frontend-passes.c
index 4764c834f4f..57b24a11cbe 100644
--- a/gcc/fortran/frontend-passes.c
+++ b/gcc/fortran/frontend-passes.c
@@ -2914,6 +2914,7 @@ do_subscript (gfc_expr **e)
 		    {
 		      if (ar->as->lower[i]
 			  && ar->as->lower[i]->expr_type == EXPR_CONSTANT
+			  && ar->as->lower[i]->ts.type == BT_INTEGER
 			  && mpz_cmp (val, ar->as->lower[i]->value.integer) < 0)
 			gfc_warning (warn, "Array reference at %L out of bounds "
 				     "(%ld < %ld) in loop beginning at %L",
@@ -2923,6 +2924,7 @@ do_subscript (gfc_expr **e)
 
 		      if (ar->as->upper[i]
 			  && ar->as->upper[i]->expr_type == EXPR_CONSTANT
+			  && ar->as->upper[i]->ts.type == BT_INTEGER
 			  && mpz_cmp (val, ar->as->upper[i]->value.integer) > 0)
 			    gfc_warning (warn, "Array reference at %L out of bounds "
 					 "(%ld > %ld) in loop beginning at %L",
@@ -2938,6 +2940,7 @@ do_subscript (gfc_expr **e)
 		    {
 		      if (ar->as->lower[i]
 			  && ar->as->lower[i]->expr_type == EXPR_CONSTANT
+			  && ar->as->lower[i]->ts.type == BT_INTEGER
 			  && mpz_cmp (val, ar->as->lower[i]->value.integer) < 0)
 			gfc_warning (warn, "Array reference at %L out of bounds "
 				     "(%ld < %ld) in loop beginning at %L",
@@ -2947,6 +2950,7 @@ do_subscript (gfc_expr **e)
 
 		      if (ar->as->upper[i]
 			  && ar->as->upper[i]->expr_type == EXPR_CONSTANT
+			  && ar->as->upper[i]->ts.type == BT_INTEGER
 			  && mpz_cmp (val, ar->as->upper[i]->value.integer) > 0)
 			gfc_warning (warn, "Array reference at %L out of bounds "
 				     "(%ld > %ld) in loop beginning at %L",
diff --git a/gcc/testsuite/gfortran.dg/pr103607.f90 b/gcc/testsuite/gfortran.dg/pr103607.f90
new file mode 100644
index 00000000000..a6a2c4fdfd0
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr103607.f90
@@ -0,0 +1,12 @@
+! { dg-do compile }
+! PR fortran/103607 - ICE in do_subscript, at fortran/frontend-passes.c:2927
+! Contributed by G.Steinmetz
+
+program p
+  integer :: i, x(abs(2.)) ! { dg-error "must be of INTEGER type" }
+  do i = 1, 2
+     x(i) = 0
+  end do
+end
+
+! { dg-prune-output "must have constant shape" }