On 7/27/20 3:16 PM, Jakub Jelinek wrote:
On Mon, Jul 27, 2020 at 02:32:15PM +0200, Martin Liška wrote:
As mentioned in the PR, we should not create a string constant for a type
that is different from char_type_node. Looking at expr.c, I was inspired
and used 'TYPE_MAIN_VARIANT (chartype) == char_type_node' to verify that
underlying
type is a character type.
That doesn't look correct, there is char, signed char, unsigned char,
or say std::byte, and all of them are perfectly fine.
So, rather than requiring it is char and nothing else, you should instead
check that it is an INTEGRAL_TYPE_P (maybe better other than BOOLEAN_TYPE?),
which is complete and has the same TYPE_PRECISION as char_type_node.
All right, the following survives tests and bootstraps.
Ready to be installed?
Thanks,
Martin
Jakub
>From d40967eb2ef27b512ae177b1aee5e85ac2246acd Mon Sep 17 00:00:00 2001
From: Martin Liska <mli...@suse.cz>
Date: Mon, 27 Jul 2020 12:30:24 +0200
Subject: [PATCH] expr: build string_constant only for a char type
gcc/ChangeLog:
PR tree-optimization/96058
* expr.c (string_constant): Build string_constant only
for a type that has same precision as char_type_node
and is an integral type.
---
gcc/expr.c | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)
diff --git a/gcc/expr.c b/gcc/expr.c
index 5db0a7a8565..a150fa0d3b5 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -11828,17 +11828,22 @@ string_constant (tree arg, tree *ptr_offset, tree *mem_size, tree *decl)
chartype = TREE_TYPE (chartype);
while (TREE_CODE (chartype) == ARRAY_TYPE)
chartype = TREE_TYPE (chartype);
- /* Convert a char array to an empty STRING_CST having an array
- of the expected type and size. */
- if (!initsize)
- initsize = integer_zero_node;
- unsigned HOST_WIDE_INT size = tree_to_uhwi (initsize);
- init = build_string_literal (size, NULL, chartype, size);
- init = TREE_OPERAND (init, 0);
- init = TREE_OPERAND (init, 0);
+ if (INTEGRAL_TYPE_P (chartype)
+ && TYPE_PRECISION (chartype) == TYPE_PRECISION (char_type_node))
+ {
+ /* Convert a char array to an empty STRING_CST having an array
+ of the expected type and size. */
+ if (!initsize)
+ initsize = integer_zero_node;
+
+ unsigned HOST_WIDE_INT size = tree_to_uhwi (initsize);
+ init = build_string_literal (size, NULL, chartype, size);
+ init = TREE_OPERAND (init, 0);
+ init = TREE_OPERAND (init, 0);
- *ptr_offset = integer_zero_node;
+ *ptr_offset = integer_zero_node;
+ }
}
if (decl)
--
2.27.0
