From: mike stump <mrs@windriver.com>
To: dewar@gnat.com, jbuck@synopsys.COM
Cc: gcc@gcc.gnu.org, moshier@moshier.ne.mediaone.net
Subject: Re: What is acceptable for -ffast-math? (Was: associative law in combine)
Date: Tue, 31 Jul 2001 08:36:00 -0000 [thread overview]
Message-ID: <200107311535.IAA19969@kankakee.wrs.com> (raw)
> From: dewar@gnat.com
> To: dewar@gnat.com, jbuck@synopsys.COM
> Cc: gcc@gcc.gnu.org, moshier@moshier.ne.mediaone.net, mrs@windriver.com
> Date: Mon, 30 Jul 2001 21:38:24 -0400 (EDT)
> But it is interesting that many of the GNU extensions do not
> conflict with the standard (e.g. nested procedures, dynamic arrays),
> so these are not examples of GNU-C not meeting the criterion of
> being standard by default.
?
When there is wording that states that the value inside the [] shall
be a constant greater than 0 and non-negative, there is absolutely no
room for gcc to extend the sematics to include dynamicly sized arrays,
sorry.
If the constant-expression (5.19) is present, it shall be an
integral constant expression and its value shall be greater than
zero.
From:
1 In a declaration T D where D has the form
D1 [constant-expressionopt]
and the type of the identifier in the declaration T D1 is derived-
declarator-type-list T, then the type of the identifier of D is an
array type. T is called the array element type; this type shall
not be a reference type, the type void, a function type or an
abstract class type. If the constant-expression (5.19) is present,
it shall be an integral constant expression and its value shall be
greater than zero. The constant expression specifies the bound of
(number of elements in) the array. If the value of the constant
expression is N, the array has N elements numbered 0 to N-1, and
the type of the identifier of D is derived-declarator-type-list array
of N T. An object of array type contains a contiguously allocated
8.3.4 Arrays DRAFT: 2 December 1996 Declarators 8-11
non-empty set of N sub-objects of type T. If the constant
expression is omitted, the type of the identifier of D is derived-
declarator-type-list array of unknown bound of T, an incomplete
object type. The type derived-declarator-type-list array of N T is
a different type from the type derived-declarator-type-list array of
unknown bound of T, see 3.9. Any type of the form cv-qualifier-seq
array of N T is adjusted to array of N cv-qualifier-seq T, and
similarly for array of unknown bound of T. [Example:
typedef int A[5], AA[2][3];
typedef const A CA; // type is ``array of 5 const int''
typedef const AA CAA; // type is ``array of 2 array of 3 const int'\
'
-end example] [Note: an array of N cv-qualifier-seq T has cv-
qualified type; such an array has internal linkage unless explicitly
declared extern (7.1.5.1) and must be initialized as specified in
8.5. ]
I don't have any clue how you were so misled on this. Similar I
suspect for nested procedures. When the standard says that violation
of a mandate of the standard must result in a diagnostic:
2 Every conforming C++ implementation shall, within its resource limits,
accept and correctly execute well-formed C++ programs, and shall issue
at least one diagnostic message when presented with any ill-formed
program that contains a violation of any diagnosable semantic rule or
of any syntax rule.
this _does_ result in failure to comply with the standard and gcc does
fail to meet a criterion of the standard, as you put it. These are
reasonably safe extensions, as no conforming program can use the
standard to complain about the semantics then, but that is all.
#include <alloca.h> is an example of an allowed extension. It isn't
defined in the standard, and the standard doesn't mandate a
diagnostic.
next reply other threads:[~2001-07-31 8:36 UTC|newest]
Thread overview: 114+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-07-31 8:36 mike stump [this message]
-- strict thread matches above, loose matches on Subject: below --
2001-08-03 14:48 dewar
2001-08-02 3:37 Vincent Penquerc'h
2001-08-01 19:04 Carlo Wood
2001-08-01 12:06 Phil Edwards
2001-08-01 10:39 dewar
2001-08-01 10:38 dewar
2001-08-01 10:13 dewar
2001-08-01 10:05 dewar
2001-08-01 10:04 dewar
2001-08-01 10:28 ` Gabriel Dos_Reis
2001-08-01 9:59 dewar
2001-08-01 9:58 What is acceptable for -ffast-math? (Was: associative law incombine) Gabriel Dos_Reis
2001-08-01 10:08 ` Wolfgang Bangerth
2001-08-01 11:12 ` Gabriel Dos_Reis
2001-08-01 11:27 ` What is acceptable for -ffast-math? (Was: associative law in combine) Theodore Papadopoulo
2001-08-01 11:47 ` Gabriel Dos_Reis
2001-08-03 7:32 ` Nick Ing-Simmons
2001-08-03 6:01 ` Per Abrahamsen
2001-08-01 6:52 dewar
2001-08-01 6:04 dewar
2001-08-01 6:48 ` Vincent Penquerc'h
2001-08-03 0:46 ` Eric W. Biederman
2001-08-01 3:02 Vincent Penquerc'h
2001-07-31 19:10 dewar
2001-07-31 18:23 dewar
2001-07-31 18:20 dewar
2001-07-31 18:50 ` Joern Rennecke
2001-07-31 21:27 ` Tim Prince
2001-07-31 18:15 dewar
2001-07-31 18:12 What is acceptable for -ffast-math? (Was: associative law incombine) Linus Torvalds
2001-07-31 20:55 ` What is acceptable for -ffast-math? (Was: associative law in combine) Gabriel Dos Reis
2001-07-31 17:37 dewar
2001-07-31 16:38 dewar
2001-07-31 9:22 mike stump
2001-07-31 8:37 dewar
2001-07-31 8:36 dewar
2001-07-31 8:35 dewar
2001-07-31 8:19 mike stump
2001-07-31 7:59 mike stump
2001-07-31 7:26 dewar
2001-07-31 15:57 ` Toon Moene
2001-07-31 21:55 ` Tim Prince
2001-08-03 6:12 ` Per Abrahamsen
2001-07-30 21:13 dewar
2001-07-30 21:34 ` Gabriel Dos Reis
2001-07-30 21:43 ` Joern Rennecke
2001-07-30 21:53 ` Gabriel Dos Reis
2001-08-03 7:12 ` Nick Ing-Simmons
2001-08-01 8:55 ` Theodore Papadopoulo
2001-08-01 9:15 ` Gabriel Dos Reis
2001-08-01 11:21 ` Theodore Papadopoulo
2001-08-01 11:44 ` Gabriel Dos Reis
2001-08-01 9:24 ` Tim Hollebeek
2001-08-01 9:54 ` What is acceptable for -ffast-math? (Was: associative law incombine) Linus Torvalds
2001-08-01 10:26 ` Gabriel Dos_Reis
2001-08-01 11:13 ` What is acceptable for -ffast-math? (Was: associative law in combine) Alexandre Oliva
2001-08-01 11:36 ` Gabriel Dos Reis
2001-08-01 12:07 ` Alexandre Oliva
2001-08-01 13:21 ` Gabriel Dos_Reis
2001-08-01 14:20 ` Toon Moene
2001-07-30 20:54 dewar
2001-07-30 21:11 ` Gabriel Dos Reis
2001-07-30 21:39 ` Joern Rennecke
2001-07-30 19:46 dewar
2001-07-30 20:00 ` Gabriel Dos Reis
2001-07-30 20:20 ` Alexandre Oliva
2001-07-30 20:25 ` Gabriel Dos Reis
2001-07-30 18:39 dewar
2001-07-30 18:38 dewar
2001-07-30 18:08 dewar
2001-07-30 18:02 dewar
2001-07-30 18:00 dewar
2001-07-30 18:25 ` Joe Buck
2001-07-30 16:11 dewar
2001-07-30 16:29 ` Alexandre Oliva
2001-07-31 8:13 ` Kevin Handy
2001-07-30 15:29 dewar
2001-07-30 15:39 ` Toon Moene
2001-07-30 13:10 dewar
2001-07-30 12:26 dewar
2001-07-30 11:52 dewar
2001-07-30 11:37 What is acceptable for -ffast-math? (Was: associative law incombine) Linus Torvalds
2001-07-30 11:53 ` What is acceptable for -ffast-math? (Was: associative law in combine) Gabriel Dos Reis
2001-07-30 18:40 ` Olivier Galibert
2001-07-30 19:06 ` Gabriel Dos Reis
2001-07-31 1:35 ` Linus Torvalds
2001-07-31 2:04 ` Gabriel Dos Reis
2001-07-31 2:35 ` Olivier Galibert
2001-07-31 2:58 ` Gabriel Dos Reis
2001-07-31 18:10 ` Linus Torvalds
2001-07-30 8:59 mike stump
2001-07-30 6:14 dewar
2001-07-30 8:30 ` Kevin Handy
2001-07-30 6:01 dewar
2001-07-30 6:53 ` Tim Hollebeek
2001-07-30 6:00 dewar
2001-07-30 13:08 ` Toon Moene
2001-07-30 5:57 dewar
2001-07-29 21:33 What is acceptable for -ffast-math? (Was: associative law incombine) Linus Torvalds
2001-07-30 14:43 ` What is acceptable for -ffast-math? (Was: associative law in combine) Alexandre Oliva
2001-07-30 15:45 ` Neil Booth
2001-07-30 16:03 ` Alexandre Oliva
2001-07-30 16:11 ` Neil Booth
2001-07-30 16:28 ` Alexandre Oliva
2001-07-30 19:08 ` Joern Rennecke
2001-07-30 19:22 ` Alexandre Oliva
2001-07-30 19:29 ` Gabriel Dos Reis
2001-07-30 19:34 ` Alexandre Oliva
2001-07-30 19:54 ` Gabriel Dos Reis
2001-07-30 19:27 ` Gabriel Dos Reis
2001-07-29 14:22 dewar
2001-07-29 12:52 * Re: What is acceptable for -ffast-math? (Was: associative lawin combine) Linus Torvalds
2001-07-29 14:03 ` What is acceptable for -ffast-math? (Was: associative law incombine) Stephen L Moshier
2001-07-29 21:17 ` What is acceptable for -ffast-math? (Was: associative law in combine) Fergus Henderson
2001-07-30 0:23 ` Gabriel Dos Reis
2001-07-17 15:59 associative law in combine Joern Rennecke
2001-07-18 1:01 ` Toon Moene
2001-07-18 1:47 ` What is acceptable for -ffast-math? (Was: associative law in combine) Jan Hubicka
2001-07-28 23:04 ` Tim Prince
2001-07-29 6:33 ` Jan Hubicka
2001-07-29 10:18 ` Tim Prince
2001-07-29 10:26 ` Jan Hubicka
2001-07-29 12:11 ` Tim Prince
2001-07-29 12:17 ` Jan Hubicka
2001-07-29 10:50 ` Linus Torvalds
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