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[PING] [PATCH] Create internally nul terminated string literals in fortan FE
- From: Bernd Edlinger <bernd dot edlinger at hotmail dot de>
- To: "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>, "fortran at gcc dot gnu dot org" <fortran at gcc dot gnu dot org>, Richard Biener <rguenther at suse dot de>, Tobias Burnus <burnus at net-b dot de>
- Date: Wed, 8 Aug 2018 16:24:14 +0000
- Subject: [PING] [PATCH] Create internally nul terminated string literals in fortan FE
- References: <AM5PR0701MB2657951582B419E5B2AFB48CE42D0@AM5PR0701MB2657.eurprd07.prod.outlook.com>
Hi,
I'd like to ping this patch: https://gcc.gnu.org/ml/fortran/2018-08/msg00000.html
I attach a new version, which contains only a minor white-space change from
the previous version, in the function header of gfc_build_hollerith_string_const
to contain "static tree" on one line instead of two.
Thanks
Bernd.
On 08/01/18 13:32, Bernd Edlinger wrote:
> Hi,
>
> this patch changes the Fortan FE to create NUL terminated STRING_CST
> objects. This is a cleanup in preparation of a more thorough check
> on the STRING_CST objects in the middle-end.
>
>
> Bootstrapped and reg-tested on x86_64-pc-linux-gnu.
> Is it OK for trunk?
>
>
> Thanks
> Bernd.
2018-08-01 Bernd Edlinger <bernd.edlinger@hotmail.de>
* trans-array.c (gfc_conv_array_initializer): Remove excess precision
from overlength string initializers.
* trans-const.c (gfc_build_wide_string_const): Make the internal
representation of STRING_CST properly NUL terminated.
(gfc_build_hollerith_string_const): New helper function.
(gfc_conv_constant_to_tree): Use it.
diff -pur gcc/fortran/trans-array.c gcc/fortran/trans-array.c
--- gcc/fortran/trans-array.c 2018-07-02 09:24:43.000000000 +0200
+++ gcc/fortran/trans-array.c 2018-08-01 06:45:20.529923246 +0200
@@ -5964,6 +5964,32 @@ gfc_conv_array_initializer (tree type, g
{
case EXPR_CONSTANT:
gfc_conv_constant (&se, c->expr);
+
+ /* See gfortran.dg/charlen_15.f90 for instance. */
+ if (TREE_CODE (se.expr) == STRING_CST
+ && TREE_CODE (type) == ARRAY_TYPE)
+ {
+ tree atype = type;
+ while (TREE_CODE (TREE_TYPE (atype)) == ARRAY_TYPE)
+ atype = TREE_TYPE (atype);
+ if (TREE_CODE (TREE_TYPE (atype)) == INTEGER_TYPE
+ && tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (se.expr)))
+ > tree_to_uhwi (TYPE_SIZE_UNIT (atype)))
+ {
+ unsigned HOST_WIDE_INT size
+ = tree_to_uhwi (TYPE_SIZE_UNIT (atype));
+ unsigned unit
+ = TYPE_PRECISION (TREE_TYPE (atype)) / BITS_PER_UNIT;
+ const char *p = TREE_STRING_POINTER (se.expr);
+ char *q = (char *)xmalloc (size + unit);
+
+ memcpy (q, p, size);
+ memset (q + size, 0, unit);
+ se.expr = build_string (size + unit, q);
+ TREE_TYPE (se.expr) = atype;
+ free (q);
+ }
+ }
break;
case EXPR_STRUCTURE:
diff -pur gcc/fortran/trans-const.c gcc/fortran/trans-const.c
--- gcc/fortran/trans-const.c 2018-06-10 14:50:03.000000000 +0200
+++ gcc/fortran/trans-const.c 2018-07-31 20:15:21.721153877 +0200
@@ -93,13 +93,16 @@ gfc_build_wide_string_const (int kind, s
int i;
tree str, len;
size_t size;
+ size_t elem;
char *s;
i = gfc_validate_kind (BT_CHARACTER, kind, false);
- size = length * gfc_character_kinds[i].bit_size / 8;
+ elem = gfc_character_kinds[i].bit_size / 8;
+ size = (length + 1) * elem;
s = XCNEWVAR (char, size);
gfc_encode_character (kind, length, string, (unsigned char *) s, size);
+ memset (s + size - elem, 0, elem);
str = build_string (size, s);
free (s);
@@ -131,6 +134,30 @@ gfc_build_localized_cstring_const (const char *msg
}
+/* Build a hollerith string constant. */
+
+static tree
+gfc_build_hollerith_string_const (size_t length, const char *s)
+{
+ tree str;
+ tree len;
+ char *p;
+
+ p = XCNEWVAR (char, length + 1);
+ memcpy (p, s, length);
+ p[length] = '\0';
+ str = build_string (length + 1, p);
+ free (p);
+ len = size_int (length);
+ TREE_TYPE (str) =
+ build_array_type (gfc_character1_type_node,
+ build_range_type (gfc_charlen_type_node,
+ size_one_node, len));
+ TYPE_STRING_FLAG (TREE_TYPE (str)) = 1;
+ return str;
+}
+
+
/* Return a string constant with the given length. Used for static
initializers. The constant will be padded or truncated to match
length. */
@@ -363,8 +390,8 @@ gfc_conv_constant_to_tree (gfc_expr * expr)
return res;
case BT_HOLLERITH:
- return gfc_build_string_const (expr->representation.length,
- expr->representation.string);
+ return gfc_build_hollerith_string_const (expr->representation.length,
+ expr->representation.string);
default:
gcc_unreachable ();