On 06/17/2015 03:22 PM, Jason Merrill wrote:
On 06/17/2015 01:53 PM, Ed Smith-Rowland wrote:
I tried the obvious: an error message with %qE and got 'false'.
constexpr values are evaluated early on.
Is there a possibility that late folding could help or is that
completely different?
Late folding could help, but I think handling it in libcpp (by
actually stringizing the argument) would work better.
Jason
OK, Doing the bit with libcpp and getting a better message is taking
longer than I thought it would.
I'm going ahead with what I had back in May.
I'm still working on better - it'll just take a hot minute.
Meanwhile, this takes care of an annoyance for many.
Committed 224903.
Ed
cp/
2015-06-24 Edward Smith-Rowland <3dw...@verizon.net>
Implement N3928 - Extending static_assert
* parser.c (cp_parser_static_assert): Support static_assert with
no message string. Supply an empty string in this case.
* semantics.c (finish_static_assert): Don't try to print a message if
the message strnig is empty.
testsuite/
2015-06-24 Edward Smith-Rowland <3dw...@verizon.net>
Implement N3928 - Extending static_assert
* g++.dg/cpp0x/static_assert8.C: Adjust.
* g++.dg/cpp0x/static_assert12.C: New.
* g++.dg/cpp0x/static_assert13.C: New.
* g++.dg/cpp1y/static_assert1.C: New.
* g++.dg/cpp1y/static_assert2.C: New.
* g++.dg/cpp1z/static_assert-nomsg.C: New.
Index: cp/parser.c
===================================================================
--- cp/parser.c (revision 224897)
+++ cp/parser.c (working copy)
@@ -12173,6 +12173,7 @@
static_assert-declaration:
static_assert ( constant-expression , string-literal ) ;
+ static_assert ( constant-expression ) ; (C++1Z)
If MEMBER_P, this static_assert is a class member. */
@@ -12210,20 +12211,35 @@
/*allow_non_constant_p=*/true,
/*non_constant_p=*/&dummy);
- /* Parse the separating `,'. */
- cp_parser_require (parser, CPP_COMMA, RT_COMMA);
+ if (cp_lexer_peek_token (parser->lexer)->type == CPP_CLOSE_PAREN)
+ {
+ if (cxx_dialect < cxx1z)
+ pedwarn (input_location, OPT_Wpedantic,
+ "static_assert without a message "
+ "only available with -std=c++1z or -std=gnu++1z");
+ /* Eat the ')' */
+ cp_lexer_consume_token (parser->lexer);
+ message = build_string (1, "");
+ TREE_TYPE (message) = char_array_type_node;
+ fix_string_type (message);
+ }
+ else
+ {
+ /* Parse the separating `,'. */
+ cp_parser_require (parser, CPP_COMMA, RT_COMMA);
- /* Parse the string-literal message. */
- message = cp_parser_string_literal (parser,
- /*translate=*/false,
- /*wide_ok=*/true);
+ /* Parse the string-literal message. */
+ message = cp_parser_string_literal (parser,
+ /*translate=*/false,
+ /*wide_ok=*/true);
- /* A `)' completes the static assertion. */
- if (!cp_parser_require (parser, CPP_CLOSE_PAREN, RT_CLOSE_PAREN))
- cp_parser_skip_to_closing_parenthesis (parser,
- /*recovering=*/true,
- /*or_comma=*/false,
- /*consume_paren=*/true);
+ /* A `)' completes the static assertion. */
+ if (!cp_parser_require (parser, CPP_CLOSE_PAREN, RT_CLOSE_PAREN))
+ cp_parser_skip_to_closing_parenthesis (parser,
+ /*recovering=*/true,
+ /*or_comma=*/false,
+ /*consume_paren=*/true);
+ }
/* A semicolon terminates the declaration. */
cp_parser_require (parser, CPP_SEMICOLON, RT_SEMICOLON);
Index: cp/semantics.c
===================================================================
--- cp/semantics.c (revision 224897)
+++ cp/semantics.c (working copy)
@@ -7174,8 +7174,17 @@
input_location = location;
if (TREE_CODE (condition) == INTEGER_CST
&& integer_zerop (condition))
- /* Report the error. */
- error ("static assertion failed: %s", TREE_STRING_POINTER (message));
+ {
+ int sz = TREE_INT_CST_LOW (TYPE_SIZE_UNIT
+ (TREE_TYPE (TREE_TYPE (message))));
+ int len = TREE_STRING_LENGTH (message) / sz - 1;
+ /* Report the error. */
+ if (len == 0)
+ error ("static assertion failed");
+ else
+ error ("static assertion failed: %s",
+ TREE_STRING_POINTER (message));
+ }
else if (condition && condition != error_mark_node)
{
error ("non-constant condition for static assertion");
Index: testsuite/g++.dg/cpp0x/static_assert12.C
===================================================================
--- testsuite/g++.dg/cpp0x/static_assert12.C (revision 0)
+++ testsuite/g++.dg/cpp0x/static_assert12.C (working copy)
@@ -0,0 +1,30 @@
+// { dg-do compile }
+// { dg-options "-std=gnu++11 -pedantic" }
+
+template<typename T>
+ struct is_float
+ {
+ static constexpr bool value = false;
+ };
+
+template<>
+ struct is_float<float>
+ {
+ static constexpr bool value = true;
+ };
+
+template<typename T>
+ T
+ float_thing(T __x)
+ {
+ static_assert(is_float<T>::value, ""); // { dg-error "static assertion
failed" }
+ static_assert(is_float<T>::value); // { dg-error "static assertion failed"
}
+ }
+
+int
+main()
+{
+ float_thing(1);
+}
+
+// { dg-warning "static_assert without a message only available with " "" {
target *-*-* } 21 }
Index: testsuite/g++.dg/cpp0x/static_assert13.C
===================================================================
--- testsuite/g++.dg/cpp0x/static_assert13.C (revision 0)
+++ testsuite/g++.dg/cpp0x/static_assert13.C (working copy)
@@ -0,0 +1,28 @@
+// { dg-do compile }
+// { dg-options "-std=gnu++11" }
+
+template<typename T>
+ struct is_float
+ {
+ static constexpr bool value = false;
+ };
+
+template<>
+ struct is_float<float>
+ {
+ static constexpr bool value = true;
+ };
+
+template<typename T>
+ T
+ float_thing(T __x)
+ {
+ static_assert(is_float<T>::value, ""); // { dg-error "static assertion
failed" }
+ static_assert(is_float<T>::value); // { dg-error "static assertion failed"
}
+ }
+
+int
+main()
+{
+ float_thing(1);
+}
Index: testsuite/g++.dg/cpp0x/static_assert8.C
===================================================================
--- testsuite/g++.dg/cpp0x/static_assert8.C (revision 224897)
+++ testsuite/g++.dg/cpp0x/static_assert8.C (working copy)
@@ -1,7 +1,9 @@
// { dg-do compile { target c++11 } }
-static_assert (1 == 0); // { dg-error "expected (string-literal|',') before" }
+static_assert (1 == 0); // { dg-error "static assertion failed" }
static_assert (1 == 0,); // { dg-error "expected string-literal before '\\)'" }
static_assert (1 == 0, "oops"); // { dg-error "static assertion failed" }
+
+// { dg-error "static_assert without a message only available with " "" {
target *-*-* } 3 }
Index: testsuite/g++.dg/cpp1y/static_assert1.C
===================================================================
--- testsuite/g++.dg/cpp1y/static_assert1.C (revision 0)
+++ testsuite/g++.dg/cpp1y/static_assert1.C (working copy)
@@ -0,0 +1,30 @@
+// { dg-do compile }
+// { dg-options "-std=gnu++14 -pedantic" }
+
+template<typename T>
+ struct is_float
+ {
+ static constexpr bool value = false;
+ };
+
+template<>
+ struct is_float<float>
+ {
+ static constexpr bool value = true;
+ };
+
+template<typename T>
+ T
+ float_thing(T __x)
+ {
+ static_assert(is_float<T>::value, ""); // { dg-error "static assertion
failed" }
+ static_assert(is_float<T>::value); // { dg-error "static assertion failed"
}
+ }
+
+int
+main()
+{
+ float_thing(1);
+}
+
+// { dg-warning "static_assert without a message only available with " "" {
target *-*-* } 21 }
Index: testsuite/g++.dg/cpp1y/static_assert2.C
===================================================================
--- testsuite/g++.dg/cpp1y/static_assert2.C (revision 0)
+++ testsuite/g++.dg/cpp1y/static_assert2.C (working copy)
@@ -0,0 +1,28 @@
+// { dg-do compile }
+// { dg-options "-std=gnu++14" }
+
+template<typename T>
+ struct is_float
+ {
+ static constexpr bool value = false;
+ };
+
+template<>
+ struct is_float<float>
+ {
+ static constexpr bool value = true;
+ };
+
+template<typename T>
+ T
+ float_thing(T __x)
+ {
+ static_assert(is_float<T>::value, ""); // { dg-error "static assertion
failed" }
+ static_assert(is_float<T>::value); // { dg-error "static assertion failed"
}
+ }
+
+int
+main()
+{
+ float_thing(1);
+}
Index: testsuite/g++.dg/cpp1z/static_assert-nomsg.C
===================================================================
--- testsuite/g++.dg/cpp1z/static_assert-nomsg.C (revision 0)
+++ testsuite/g++.dg/cpp1z/static_assert-nomsg.C (working copy)
@@ -0,0 +1,27 @@
+// { dg-do compile { target c++1z } }
+
+template<typename T>
+ struct is_float
+ {
+ static constexpr bool value = false;
+ };
+
+template<>
+ struct is_float<float>
+ {
+ static constexpr bool value = true;
+ };
+
+template<typename T>
+ T
+ float_thing(T __x)
+ {
+ static_assert(is_float<T>::value, ""); // { dg-error "static assertion
failed" }
+ static_assert(is_float<T>::value); // { dg-error "static assertion failed"
}
+ }
+
+int
+main()
+{
+ float_thing(1);
+}
