fortran: fix checking of CHARACTER lengths in array constructors [PR70231]

gcc/fortran/ChangeLog:

	PR fortran/70231
	* trans-array.cc (trans_array_constructor): In absence of a typespec,
	use string length determined by get_array_ctor_strlen() to reasonably
	initialize auxiliary variable for bounds-checking.

gcc/testsuite/ChangeLog:

	PR fortran/70231
	* gfortran.dg/bounds_check_fail_7.f90: New test.

diff --git a/gcc/fortran/trans-array.cc b/gcc/fortran/trans-array.cc
index 1640587cd7146dcfed882f80ca27bf4e6fc567b6..e0fc8ebc46bff70503c805ecb100a4f71f560966 100644 (file)
--- a/gcc/fortran/trans-array.cc
+++ b/gcc/fortran/trans-array.cc
@@ -2852,6 +2852,23 @@ trans_array_constructor (gfc_ss * ss, locus * where)
          const_string = get_array_ctor_strlen (&outer_loop->pre, c,
                                                &ss_info->string_length);
          force_new_cl = true;
+
+         /* Initialize "len" with string length for bounds checking.  */
+         if ((gfc_option.rtcheck & GFC_RTCHECK_BOUNDS)
+             && !typespec_chararray_ctor
+             && ss_info->string_length)
+           {
+             gfc_se length_se;
+
+             gfc_init_se (&length_se, NULL);
+             gfc_add_modify (&length_se.pre, first_len_val,
+                             fold_convert (TREE_TYPE (first_len_val),
+                                           ss_info->string_length));
+             ss_info->string_length = gfc_evaluate_now (ss_info->string_length,
+                                                        &length_se.pre);
+             gfc_add_block_to_block (&outer_loop->pre, &length_se.pre);
+             gfc_add_block_to_block (&outer_loop->post, &length_se.post);
+           }
        }
 
       /* Complex character array constructors should have been taken care of

diff --git a/gcc/testsuite/gfortran.dg/bounds_check_fail_7.f90 b/gcc/testsuite/gfortran.dg/bounds_check_fail_7.f90
new file mode 100644 (file)
index 0000000..6a8dafc
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/bounds_check_fail_7.f90
@@ -0,0 +1,20 @@
+! { dg-do run }
+! { dg-additional-options "-fcheck=bounds -g" }
+! { dg-output "At line 18 .*" }
+! { dg-shouldfail "Different CHARACTER lengths (32/0) in array constructor" }
+!
+! PR fortran/70231 - CHARACTER lengths in array constructors
+
+program p
+  implicit none
+  integer, parameter  :: char_len = 32
+  integer             :: l = 0
+  character(char_len) :: ch = "a"
+  character(char_len), allocatable :: ch_array(:), res1(:), res2(:)
+
+  allocate(ch_array(0))
+  res1 = [ ch_array, ch ]               ! was false positive
+  print *, res1
+  res2 = [[ch_array, ch(1:l)], ch(1:l)] ! was false negative on x86
+  print *, res2
+end