Re: [C++17] Implement N3928 - Extending static_assert
Hi,
On 06/24/2015 05:32 PM, Ed Smith-Rowland wrote:
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 } }
As far as I can see, we can't really use this syntax in the cpp1z
directory: the testcase is effectively skipped. Indeed, we don't use it
anywhere else. I'm going to replace it with the straightforward:
// { dg-options -std=c++1z }
Thanks,
Paolo.
Re: [C++17] Implement N3928 - Extending static_assert
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:
Re: [C++17] Implement N3928 - Extending static_assert
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
Re: [C++17] Implement N3928 - Extending static_assert
On 06/17/2015 10:23 AM, Jason Merrill wrote: On 06/15/2015 07:14 PM, Ed Smith-Rowland wrote: I wanted to fix it up as per your suggestion. If someone wants it now I can retest and commit. Otherwise give me a bit more time. Someone in LWG was asking about it, and I figured it wouldn't hurt to have this version in now. Glad to hear you're working on the improvement as well, thanks! Jason 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? Ed
Re: [C++17] Implement N3928 - Extending static_assert
On 06/15/2015 07:14 PM, Ed Smith-Rowland wrote: I wanted to fix it up as per your suggestion. If someone wants it now I can retest and commit. Otherwise give me a bit more time. Someone in LWG was asking about it, and I figured it wouldn't hurt to have this version in now. Glad to hear you're working on the improvement as well, thanks! Jason
Re: [C++17] Implement N3928 - Extending static_assert
On 05/20/2015 11:28 AM, Jason Merrill wrote: On 05/02/2015 04:16 PM, Ed Smith-Rowland wrote: This extends' static assert to not require a message string. I elected to make this work also for C++11 and C++14 and warn only with -pedantic. I think many people just write static_assert(thing, ); . I took the path of building an empty string in the parser in this case. I wasn't sure if setting message to NULL_TREE would cause sadness later on or not. Hmm. Yes, this technically implements the feature, but my impression of the (non-normative) intent was that they wanted leaving out the string to print the argument expression, in about the same way as #define BOOST_STATIC_ASSERT( B ) static_assert(B, #B) So the patch is OK as is, but you might also look into some libcpp magic to insert a second argument that stringizes the first. Are you planning to check this in? Jason
Re: [C++17] Implement N3928 - Extending static_assert
On 06/15/2015 12:05 PM, Jason Merrill wrote: On 05/20/2015 11:28 AM, Jason Merrill wrote: On 05/02/2015 04:16 PM, Ed Smith-Rowland wrote: This extends' static assert to not require a message string. I elected to make this work also for C++11 and C++14 and warn only with -pedantic. I think many people just write static_assert(thing, ); . I took the path of building an empty string in the parser in this case. I wasn't sure if setting message to NULL_TREE would cause sadness later on or not. Hmm. Yes, this technically implements the feature, but my impression of the (non-normative) intent was that they wanted leaving out the string to print the argument expression, in about the same way as #define BOOST_STATIC_ASSERT( B ) static_assert(B, #B) So the patch is OK as is, but you might also look into some libcpp magic to insert a second argument that stringizes the first. Are you planning to check this in? Jason Jason, I wanted to fix it up as per your suggestion. If someone wants it now I can retest and commit. Otherwise give me a bit more time. Also, if you or someone else really has the whole enchilada then by all means just commit that. Ed
Re: [C++17] Implement N3928 - Extending static_assert
On 05/02/2015 04:16 PM, Ed Smith-Rowland wrote: This extends' static assert to not require a message string. I elected to make this work also for C++11 and C++14 and warn only with -pedantic. I think many people just write static_assert(thing, ); . I took the path of building an empty string in the parser in this case. I wasn't sure if setting message to NULL_TREE would cause sadness later on or not. Hmm. Yes, this technically implements the feature, but my impression of the (non-normative) intent was that they wanted leaving out the string to print the argument expression, in about the same way as #define BOOST_STATIC_ASSERT( B ) static_assert(B, #B) So the patch is OK as is, but you might also look into some libcpp magic to insert a second argument that stringizes the first. Jason
[PING] [C++17] Implement N3928 - Extending static_assert
On 05/02/2015 04:16 PM, Ed Smith-Rowland wrote: This extends' static assert to not require a message string. I elected to make this work also for C++11 and C++14 and warn only with -pedantic. I think many people just write static_assert(thing, ); . I took the path of building an empty string in the parser in this case. I wasn't sure if setting message to NULL_TREE would cause sadness later on or not. I also, perhaps in a fit of overzealousness made finish_static_assert not print the extra : and an empty message in this case. I didn't modify _Static_assert for C. Built and tested on x86_64-linux. OK Ping? Comments?
Re: [C++17] Implement N3928 - Extending static_assert
On Sat, May 02, 2015 at 04:16:18PM -0400, Ed Smith-Rowland wrote: This extends' static assert to not require a message string. I elected to make this work also for C++11 and C++14 and warn only with -pedantic. I think many people just write static_assert(thing, ); . I took the path of building an empty string in the parser in this case. I wasn't sure if setting message to NULL_TREE would cause sadness later on or not. I also, perhaps in a fit of overzealousness made finish_static_assert not print the extra : and an empty message in this case. I didn't modify _Static_assert for C. I'm not aware of any C DR that is asking for _Static_assert (cst-expr), so I suppose there's no need to change C at this point. Marek
[C++17] Implement N3928 - Extending static_assert
This extends' static assert to not require a message string.
I elected to make this work also for C++11 and C++14 and warn only with
-pedantic.
I think many people just write
static_assert(thing, );
.
I took the path of building an empty string in the parser in this case.
I wasn't sure if setting message to NULL_TREE would cause sadness later
on or not.
I also, perhaps in a fit of overzealousness made finish_static_assert
not print the extra : and an empty message in this case.
I didn't modify _Static_assert for C.
Built and tested on x86_64-linux.
OK
cp/
2015-05-02 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/
2015-05-02 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 222723)
+++ cp/parser.c (working copy)
@@ -12153,6 +12153,7 @@
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. */
@@ -12190,20 +12191,35 @@
/*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 222723)
+++ cp/semantics.c (working copy)
@@ -7184,8 +7184,17 @@
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
===
---
