[Bug fortran/34956] -fbounds-check: bounds_check_9.f90: Use of uninitialized memory

[fxcoudert at gcc dot gnu dot org]

------- Comment #2 from fxcoudert at gcc dot gnu dot org  2008-02-29 18:27 
-------
The following patch fixes it, but I don't know yet if it regtests...

Index: trans-array.c
===================================================================
--- trans-array.c       (revision 132578)
+++ trans-array.c       (working copy)
@@ -2912,9 +2912,13 @@

       for (ss = loop->ss; ss != gfc_ss_terminator; ss = ss->loop_chain)
        {
+         stmtblock_t inner;
+
          if (ss->type != GFC_SS_SECTION)
            continue;

+         gfc_start_block (&inner);
+
          /* TODO: range checking for mapped dimensions.  */
          info = &ss->data.info;

@@ -2941,7 +2945,7 @@
              asprintf (&msg, "Zero stride is not allowed, for dimension %d "
                        "of array '%s'", info->dim[n]+1,
                        ss->expr->symtree->name);
-             gfc_trans_runtime_check (tmp, &block, &ss->expr->where, msg);
+             gfc_trans_runtime_check (tmp, &inner, &ss->expr->where, msg);
              gfc_free (msg);

              desc = ss->data.info.descriptor;
@@ -2983,7 +2987,7 @@
              asprintf (&msg, "%s, lower bound of dimension %d of array '%s'"
                        " exceeded (%%ld < %%ld)", gfc_msg_fault,
                        info->dim[n]+1, ss->expr->symtree->name);
-             gfc_trans_runtime_check (tmp, &block, &ss->expr->where, msg,
+             gfc_trans_runtime_check (tmp, &inner, &ss->expr->where, msg,
                                       fold_convert (long_integer_type_node,
                                                     info->start[n]),
                                       fold_convert (long_integer_type_node,
@@ -2999,7 +3003,7 @@
                  asprintf (&msg, "%s, upper bound of dimension %d of array "
                            "'%s' exceeded (%%ld > %%ld)", gfc_msg_fault,
                            info->dim[n]+1, ss->expr->symtree->name);
-                 gfc_trans_runtime_check (tmp, &block, &ss->expr->where, msg,
+                 gfc_trans_runtime_check (tmp, &inner, &ss->expr->where, msg,
                        fold_convert (long_integer_type_node, info->start[n]),
                        fold_convert (long_integer_type_node, ubound));
                  gfc_free (msg);
@@ -3021,7 +3025,7 @@
              asprintf (&msg, "%s, lower bound of dimension %d of array '%s'"
                        " exceeded (%%ld < %%ld)", gfc_msg_fault,
                        info->dim[n]+1, ss->expr->symtree->name);
-             gfc_trans_runtime_check (tmp, &block, &ss->expr->where, msg,
+             gfc_trans_runtime_check (tmp, &inner, &ss->expr->where, msg,
                                       fold_convert (long_integer_type_node,
                                                     tmp2),
                                       fold_convert (long_integer_type_node,
@@ -3036,7 +3040,7 @@
                  asprintf (&msg, "%s, upper bound of dimension %d of array "
                            "'%s' exceeded (%%ld > %%ld)", gfc_msg_fault,
                            info->dim[n]+1, ss->expr->symtree->name);
-                 gfc_trans_runtime_check (tmp, &block, &ss->expr->where, msg,
+                 gfc_trans_runtime_check (tmp, &inner, &ss->expr->where, msg,
                        fold_convert (long_integer_type_node, tmp2),
                        fold_convert (long_integer_type_node, ubound));
                  gfc_free (msg);
@@ -3054,30 +3058,30 @@
                  tree tmp3;

                  tmp3 = fold_build2 (NE_EXPR, boolean_type_node, tmp,
size[n]);
-
-                 /* For optional arguments, only check bounds if the
-                    argument is present.  */
-                 if (ss->expr->symtree->n.sym->attr.optional
-                     || ss->expr->symtree->n.sym->attr.not_always_present)
-                   {
-                     tree cond;
-
-                     cond = gfc_conv_expr_present (ss->expr->symtree->n.sym);
-                     tmp3 = fold_build2 (TRUTH_AND_EXPR, boolean_type_node,
-                                         cond, tmp3);
-                   }
-
                  asprintf (&msg, "%s, size mismatch for dimension %d "
                            "of array '%s' (%%ld/%%ld)", gfc_msg_bounds,
                            info->dim[n]+1, ss->expr->symtree->name);
-                 gfc_trans_runtime_check (tmp3, &block, &ss->expr->where, msg,
+                 gfc_trans_runtime_check (tmp3, &inner, &ss->expr->where, msg,
                        fold_convert (long_integer_type_node, tmp),
                        fold_convert (long_integer_type_node, size[n]));
                  gfc_free (msg);
                }
              else
-               size[n] = gfc_evaluate_now (tmp, &block);
+               size[n] = gfc_evaluate_now (tmp, &inner);
            }
+
+         tmp = gfc_finish_block (&inner);
+
+         /* For optional arguments, only check bounds if the argument is
+            present.  */
+         if (ss->expr->symtree->n.sym->attr.optional
+             || ss->expr->symtree->n.sym->attr.not_always_present)
+           tmp = build3_v (COND_EXPR,
+                           gfc_conv_expr_present (ss->expr->symtree->n.sym),
+                           tmp, build_empty_stmt ());
+
+         gfc_add_expr_to_block (&block, tmp);
+
        }

       tmp = gfc_finish_block (&block);


-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |fxcoudert at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
           Keywords|                            |patch
   Last reconfirmed|2008-02-28 12:51:22         |2008-02-29 18:27:35
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34956