* [C++ PATCH] Handle correctly ARRAY_REFs from STRING_CST for wchar_t/char{16,32}_t (PR c++/48570)
@ 2011-04-12 17:06 Jakub Jelinek
2011-04-12 23:14 ` Jason Merrill
0 siblings, 1 reply; 4+ messages in thread
From: Jakub Jelinek @ 2011-04-12 17:06 UTC (permalink / raw)
To: Jason Merrill; +Cc: gcc-patches
Hi!
As the testcase below shows, cxx_eval_array_reference only works
properly if ary is CONSTRUCTOR or narrow STRING_CST, if it is
wchar_t/char16_t/char32_t string literal, it still reads a single
byte from the string as if it was a char string.
The following patch fixes that, bootstrapped/regtested on x86_64-linux
and i686-linux, ok for trunk/4.6?
2011-04-12 Jakub Jelinek <jakub@redhat.com>
PR c++/48570
* semantics.c (cxx_eval_array_reference): Handle reading from
wchar_t, char16_t and char32_t STRING_CST.
* g++.dg/cpp0x/constexpr-wstring.C: New test.
--- gcc/cp/semantics.c.jj 2011-04-12 09:37:43.000000000 +0200
+++ gcc/cp/semantics.c 2011-04-12 15:46:43.000000000 +0200
@@ -6293,7 +6293,9 @@ cxx_eval_array_reference (const constexp
return build4 (ARRAY_REF, TREE_TYPE (t), ary, index, NULL, NULL);
len = (TREE_CODE (ary) == CONSTRUCTOR
? CONSTRUCTOR_NELTS (ary)
- : (unsigned)TREE_STRING_LENGTH (ary));
+ : (unsigned)TREE_STRING_LENGTH (ary)
+ * (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (ary)))
+ / TYPE_PRECISION (char_type_node)));
if (compare_tree_int (index, len) >= 0)
{
if (!allow_non_constant)
@@ -6304,9 +6306,19 @@ cxx_eval_array_reference (const constexp
i = tree_low_cst (index, 0);
if (TREE_CODE (ary) == CONSTRUCTOR)
return VEC_index (constructor_elt, CONSTRUCTOR_ELTS (ary), i)->value;
- else
+ else if (TYPE_PRECISION (TREE_TYPE (t)) == TYPE_PRECISION (char_type_node))
return build_int_cst (cv_unqualified (TREE_TYPE (TREE_TYPE (ary))),
TREE_STRING_POINTER (ary)[i]);
+ else
+ {
+ tree type = cv_unqualified (TREE_TYPE (TREE_TYPE (ary)));
+ unsigned elem_len = (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (ary)))
+ / TYPE_PRECISION (char_type_node));
+ return native_interpret_expr (type,
+ (const unsigned char *)
+ TREE_STRING_POINTER (ary) + i * elem_len,
+ elem_len);
+ }
/* Don't VERIFY_CONSTANT here. */
}
--- gcc/testsuite/g++.dg/cpp0x/constexpr-wstring.C.jj 2011-04-12 15:49:44.000000000 +0200
+++ gcc/testsuite/g++.dg/cpp0x/constexpr-wstring.C 2011-04-12 15:48:55.000000000 +0200
@@ -0,0 +1,34 @@
+// PR c++/48570
+// { dg-do run }
+// { dg-options "-std=c++0x" }
+
+extern "C" void abort ();
+constexpr wchar_t foo (int i) { return L"0123"[i]; }
+constexpr char16_t bar (int i) { return u"0123"[i]; }
+constexpr char32_t baz (int i) { return U"0123"[i]; }
+const wchar_t foo0 = foo (0);
+const wchar_t foo1 = foo (1);
+const wchar_t foo2 = foo (2);
+const wchar_t foo3 = foo (3);
+const wchar_t foo4 = foo (4);
+const char16_t bar0 = bar (0);
+const char16_t bar1 = bar (1);
+const char16_t bar2 = bar (2);
+const char16_t bar3 = bar (3);
+const char16_t bar4 = bar (4);
+const char32_t baz0 = baz (0);
+const char32_t baz1 = baz (1);
+const char32_t baz2 = baz (2);
+const char32_t baz3 = baz (3);
+const char32_t baz4 = baz (4);
+
+int
+main ()
+{
+ if (foo0 != L'0' || foo1 != L'1' || foo2 != L'2' || foo3 != L'3' || foo4 != L'\0')
+ abort ();
+ if (bar0 != u'0' || bar1 != u'1' || bar2 != u'2' || bar3 != u'3' || bar4 != u'\0')
+ abort ();
+ if (baz0 != U'0' || baz1 != U'1' || baz2 != U'2' || baz3 != U'3' || baz4 != U'\0')
+ abort ();
+}
Jakub
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [C++ PATCH] Handle correctly ARRAY_REFs from STRING_CST for wchar_t/char{16,32}_t (PR c++/48570)
2011-04-12 17:06 [C++ PATCH] Handle correctly ARRAY_REFs from STRING_CST for wchar_t/char{16,32}_t (PR c++/48570) Jakub Jelinek
@ 2011-04-12 23:14 ` Jason Merrill
2011-04-13 8:49 ` Jakub Jelinek
0 siblings, 1 reply; 4+ messages in thread
From: Jason Merrill @ 2011-04-12 23:14 UTC (permalink / raw)
To: Jakub Jelinek; +Cc: gcc-patches
On 04/12/2011 01:06 PM, Jakub Jelinek wrote:
> + : (unsigned)TREE_STRING_LENGTH (ary)
> + * (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (ary)))
> + / TYPE_PRECISION (char_type_node)));
Don't you mean / instead of * here? Let's also calculate the size of
the element once rather than here and again later.
Jason
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [C++ PATCH] Handle correctly ARRAY_REFs from STRING_CST for wchar_t/char{16,32}_t (PR c++/48570)
2011-04-12 23:14 ` Jason Merrill
@ 2011-04-13 8:49 ` Jakub Jelinek
2011-04-13 14:14 ` Jason Merrill
0 siblings, 1 reply; 4+ messages in thread
From: Jakub Jelinek @ 2011-04-13 8:49 UTC (permalink / raw)
To: Jason Merrill; +Cc: gcc-patches
On Tue, Apr 12, 2011 at 07:13:51PM -0400, Jason Merrill wrote:
> On 04/12/2011 01:06 PM, Jakub Jelinek wrote:
> >+ : (unsigned)TREE_STRING_LENGTH (ary)
> >+ * (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (ary)))
> >+ / TYPE_PRECISION (char_type_node)));
>
> Don't you mean / instead of * here?
You're right, thanks for catching it. I've added a testcase
for the out of bounds case too.
> Let's also calculate the size
> of the element once rather than here and again later.
Like this? Bootstrapped/regtested on x86_64-linux and i686-linux:
2011-04-13 Jakub Jelinek <jakub@redhat.com>
PR c++/48570
* semantics.c (cxx_eval_array_reference): Handle reading from
wchar_t, char16_t and char32_t STRING_CST.
* g++.dg/cpp0x/constexpr-wstring1.C: New test.
* g++.dg/cpp0x/constexpr-wstring2.C: New test.
--- gcc/cp/semantics.c.jj 2011-04-12 19:43:49.433483082 +0200
+++ gcc/cp/semantics.c 2011-04-13 08:25:07.904796653 +0200
@@ -6279,7 +6279,7 @@ cxx_eval_array_reference (const constexp
non_constant_p);
tree index, oldidx;
HOST_WIDE_INT i;
- unsigned len;
+ unsigned len, elem_nchars = 1;
if (*non_constant_p)
return t;
oldidx = TREE_OPERAND (t, 1);
@@ -6291,9 +6291,14 @@ cxx_eval_array_reference (const constexp
return t;
else if (addr)
return build4 (ARRAY_REF, TREE_TYPE (t), ary, index, NULL, NULL);
- len = (TREE_CODE (ary) == CONSTRUCTOR
- ? CONSTRUCTOR_NELTS (ary)
- : (unsigned)TREE_STRING_LENGTH (ary));
+ if (TREE_CODE (ary) == CONSTRUCTOR)
+ len = CONSTRUCTOR_NELTS (ary);
+ else
+ {
+ elem_nchars = (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (ary)))
+ / TYPE_PRECISION (char_type_node));
+ len = (unsigned) TREE_STRING_LENGTH (ary) / elem_nchars;
+ }
if (compare_tree_int (index, len) >= 0)
{
if (!allow_non_constant)
@@ -6304,9 +6309,16 @@ cxx_eval_array_reference (const constexp
i = tree_low_cst (index, 0);
if (TREE_CODE (ary) == CONSTRUCTOR)
return VEC_index (constructor_elt, CONSTRUCTOR_ELTS (ary), i)->value;
- else
+ else if (elem_nchars == 1)
return build_int_cst (cv_unqualified (TREE_TYPE (TREE_TYPE (ary))),
TREE_STRING_POINTER (ary)[i]);
+ else
+ {
+ tree type = cv_unqualified (TREE_TYPE (TREE_TYPE (ary)));
+ return native_interpret_expr (type, (const unsigned char *)
+ TREE_STRING_POINTER (ary)
+ + i * elem_nchars, elem_nchars);
+ }
/* Don't VERIFY_CONSTANT here. */
}
--- gcc/testsuite/g++.dg/cpp0x/constexpr-wstring1.C.jj 2011-04-13 08:21:23.079513403 +0200
+++ gcc/testsuite/g++.dg/cpp0x/constexpr-wstring1.C 2011-04-13 08:21:23.079513403 +0200
@@ -0,0 +1,34 @@
+// PR c++/48570
+// { dg-do run }
+// { dg-options "-std=c++0x" }
+
+extern "C" void abort ();
+constexpr wchar_t foo (int i) { return L"0123"[i]; }
+constexpr char16_t bar (int i) { return u"0123"[i]; }
+constexpr char32_t baz (int i) { return U"0123"[i]; }
+const wchar_t foo0 = foo (0);
+const wchar_t foo1 = foo (1);
+const wchar_t foo2 = foo (2);
+const wchar_t foo3 = foo (3);
+const wchar_t foo4 = foo (4);
+const char16_t bar0 = bar (0);
+const char16_t bar1 = bar (1);
+const char16_t bar2 = bar (2);
+const char16_t bar3 = bar (3);
+const char16_t bar4 = bar (4);
+const char32_t baz0 = baz (0);
+const char32_t baz1 = baz (1);
+const char32_t baz2 = baz (2);
+const char32_t baz3 = baz (3);
+const char32_t baz4 = baz (4);
+
+int
+main ()
+{
+ if (foo0 != L'0' || foo1 != L'1' || foo2 != L'2' || foo3 != L'3' || foo4 != L'\0')
+ abort ();
+ if (bar0 != u'0' || bar1 != u'1' || bar2 != u'2' || bar3 != u'3' || bar4 != u'\0')
+ abort ();
+ if (baz0 != U'0' || baz1 != U'1' || baz2 != U'2' || baz3 != U'3' || baz4 != U'\0')
+ abort ();
+}
--- gcc/testsuite/g++.dg/cpp0x/constexpr-wstring2.C.jj 2011-04-13 08:26:01.158764728 +0200
+++ gcc/testsuite/g++.dg/cpp0x/constexpr-wstring2.C 2011-04-13 08:29:31.321808236 +0200
@@ -0,0 +1,7 @@
+// PR c++/48570
+// { dg-do compile }
+// { dg-options -std=c++0x }
+
+constexpr wchar_t c1 = L"hi"[3]; // { dg-error "out of bound" }
+constexpr char16_t c2 = u"hi"[3]; // { dg-error "out of bound" }
+constexpr char32_t c3 = U"hi"[3]; // { dg-error "out of bound" }
Jakub
^ permalink raw reply [flat|nested] 4+ messages in thread
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2011-04-12 17:06 [C++ PATCH] Handle correctly ARRAY_REFs from STRING_CST for wchar_t/char{16,32}_t (PR c++/48570) Jakub Jelinek
2011-04-12 23:14 ` Jason Merrill
2011-04-13 8:49 ` Jakub Jelinek
2011-04-13 14:14 ` Jason Merrill
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