public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug c++/14802] New: [3.3/3.4/3.5 Regression] Conditional expression with throw and void fails to compile
@ 2004-03-31 22:13 alexis at ortsa dot com
2004-03-31 22:53 ` [Bug c++/14802] " bangerth at dealii dot org
` (5 more replies)
0 siblings, 6 replies; 7+ messages in thread
From: alexis at ortsa dot com @ 2004-03-31 22:13 UTC (permalink / raw)
To: gcc-bugs
This code does not compile with recent versions of g++-3.3:
int main() { 0 ? (void) 0: throw 0; }
It produces the following error:
error: void value not ignored as it ought to be
The standard, as included in the comments of gcc/gcc/cp/call.c states:
[expr.cond]
If either the second or the third operand has type (possibly
cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
array-to-pointer (_conv.array_), and function-to-pointer
(_conv.func_) standard conversions are performed on the second
and third operands.
One of the following shall hold:
--The second or the third operand (but not both) is a
throw-expression (_except.throw_); the result is of the
type of the other and is an rvalue.
--Both the second and the third operands have type void; the
result is of type void and is an rvalue.
As I understand it, both cases hold in this example, and so the result is of
type void and is an rvalue. The resulting value is not used, so I think that the
code is valid.
I believe that the behavior changed because of this patch:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/call.c.diff?cvsroot=gcc&r1=1.461&r2=1.462
that fixed bug 14083. The example compiles correctly on a version of g++-3.3.3
dating around February (I don't have the exact version, sorry), as it does with
g++-3.2.3.
The following patch should eliminate the compilation error without breaking the fix:
--- call.c.orig 2004-03-31 22:23:57.000000000 +0200
+++ call.c.new 2004-03-31 22:28:40.000000000 +0200
@@ -3182,14 +3182,16 @@
if (TREE_CODE (arg2) == THROW_EXPR
&& TREE_CODE (arg3) != THROW_EXPR)
{
- arg3 = force_rvalue (arg3);
+ if (!VOID_TYPE_P (arg3_type))
+ arg3 = force_rvalue (arg3);
arg3_type = TREE_TYPE (arg3);
result_type = arg3_type;
}
else if (TREE_CODE (arg2) != THROW_EXPR
&& TREE_CODE (arg3) == THROW_EXPR)
{
- arg2 = force_rvalue (arg2);
+ if (!VOID_TYPE_P (arg2_type))
+ arg2 = force_rvalue (arg2);
arg2_type = TREE_TYPE (arg2);
result_type = arg2_type;
}
It seems that force_rvalue returns an error when given an argument of type void.
I don't know if this behavior is correct, but it's easy to contourn in this case.
Sorry for my english, I hope everything is understandable.
--
Summary: [3.3/3.4/3.5 Regression] Conditional expression with
throw and void fails to compile
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: alexis at ortsa dot com
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14802
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/14802] [3.3/3.4/3.5 Regression] Conditional expression with throw and void fails to compile
2004-03-31 22:13 [Bug c++/14802] New: [3.3/3.4/3.5 Regression] Conditional expression with throw and void fails to compile alexis at ortsa dot com
@ 2004-03-31 22:53 ` bangerth at dealii dot org
2004-03-31 23:16 ` alexis at ortsa dot com
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: bangerth at dealii dot org @ 2004-03-31 22:53 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From bangerth at dealii dot org 2004-03-31 22:53 -------
That seems about right. I can reproduce this with a 3.3.4 snapshot of
20030223 and a mainline snapshot of 20040307, but not with a 3.4 snapshot
of 20030319, so it may already be fixed. Which gcc versino did you use?
W.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |WAITING
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14802
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/14802] [3.3/3.4/3.5 Regression] Conditional expression with throw and void fails to compile
2004-03-31 22:13 [Bug c++/14802] New: [3.3/3.4/3.5 Regression] Conditional expression with throw and void fails to compile alexis at ortsa dot com
2004-03-31 22:53 ` [Bug c++/14802] " bangerth at dealii dot org
@ 2004-03-31 23:16 ` alexis at ortsa dot com
2004-03-31 23:27 ` [Bug c++/14802] [3.3/3.4 " pinskia at gcc dot gnu dot org
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: alexis at ortsa dot com @ 2004-03-31 23:16 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From alexis at ortsa dot com 2004-03-31 23:16 -------
I produced the error with gcc version 3.3.3 (Debian 20040321) and gcc version
3.4.0 20040314 (prerelease).
But I made the diff using call.c from the CVS, so if something got fixed it must
be in force_rvalue, and the change occured between the 14th and the 19th of March.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14802
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/14802] [3.3/3.4 Regression] Conditional expression with throw and void fails to compile
2004-03-31 22:13 [Bug c++/14802] New: [3.3/3.4/3.5 Regression] Conditional expression with throw and void fails to compile alexis at ortsa dot com
2004-03-31 22:53 ` [Bug c++/14802] " bangerth at dealii dot org
2004-03-31 23:16 ` alexis at ortsa dot com
@ 2004-03-31 23:27 ` pinskia at gcc dot gnu dot org
2004-03-31 23:35 ` [Bug c++/14802] [3.3 " pinskia at gcc dot gnu dot org
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-03-31 23:27 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-03-31 23:27 -------
I also cannot reproduce it on the mainline built last night.
--
What |Removed |Added
----------------------------------------------------------------------------
Known to work| |3.5.0 3.4.0
Summary|[3.3/3.4/3.5 Regression] |[3.3/3.4 Regression]
|Conditional expression with |Conditional expression with
|throw and void fails to |throw and void fails to
|compile |compile
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14802
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/14802] [3.3 Regression] Conditional expression with throw and void fails to compile
2004-03-31 22:13 [Bug c++/14802] New: [3.3/3.4/3.5 Regression] Conditional expression with throw and void fails to compile alexis at ortsa dot com
` (2 preceding siblings ...)
2004-03-31 23:27 ` [Bug c++/14802] [3.3/3.4 " pinskia at gcc dot gnu dot org
@ 2004-03-31 23:35 ` pinskia at gcc dot gnu dot org
2004-04-01 0:29 ` alexis at ortsa dot com
2004-05-17 13:18 ` gdr at gcc dot gnu dot org
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-03-31 23:35 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-03-31 23:35 -------
Fixed in 3.4 and 3.5.0 by: <http://gcc.gnu.org/ml/gcc-patches/2004-03/msg01568.html>.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|WAITING |NEW
Ever Confirmed| |1
Keywords| |rejects-valid
Last reconfirmed|0000-00-00 00:00:00 |2004-03-31 23:35:21
date| |
Summary|[3.3/3.4 Regression] |[3.3 Regression] Conditional
|Conditional expression with |expression with throw and
|throw and void fails to |void fails to compile
|compile |
Target Milestone|--- |3.3.4
Version|unknown |3.3.4
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14802
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/14802] [3.3 Regression] Conditional expression with throw and void fails to compile
2004-03-31 22:13 [Bug c++/14802] New: [3.3/3.4/3.5 Regression] Conditional expression with throw and void fails to compile alexis at ortsa dot com
` (3 preceding siblings ...)
2004-03-31 23:35 ` [Bug c++/14802] [3.3 " pinskia at gcc dot gnu dot org
@ 2004-04-01 0:29 ` alexis at ortsa dot com
2004-05-17 13:18 ` gdr at gcc dot gnu dot org
5 siblings, 0 replies; 7+ messages in thread
From: alexis at ortsa dot com @ 2004-04-01 0:29 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From alexis at ortsa dot com 2004-04-01 00:29 -------
It seems that I got the wrong version of call.c from the CVS, sorry.
So I guess you should just apply the same patch on 3.3?
Anyway, it seems that I was correct and 2 weeks late, I promiss do be more
careful next time.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14802
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/14802] [3.3 Regression] Conditional expression with throw and void fails to compile
2004-03-31 22:13 [Bug c++/14802] New: [3.3/3.4/3.5 Regression] Conditional expression with throw and void fails to compile alexis at ortsa dot com
` (4 preceding siblings ...)
2004-04-01 0:29 ` alexis at ortsa dot com
@ 2004-05-17 13:18 ` gdr at gcc dot gnu dot org
5 siblings, 0 replies; 7+ messages in thread
From: gdr at gcc dot gnu dot org @ 2004-05-17 13:18 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From gdr at gcc dot gnu dot org 2004-05-16 22:59 -------
Patch applied.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution| |FIXED
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14802
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2004-05-16 23:00 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-03-31 22:13 [Bug c++/14802] New: [3.3/3.4/3.5 Regression] Conditional expression with throw and void fails to compile alexis at ortsa dot com
2004-03-31 22:53 ` [Bug c++/14802] " bangerth at dealii dot org
2004-03-31 23:16 ` alexis at ortsa dot com
2004-03-31 23:27 ` [Bug c++/14802] [3.3/3.4 " pinskia at gcc dot gnu dot org
2004-03-31 23:35 ` [Bug c++/14802] [3.3 " pinskia at gcc dot gnu dot org
2004-04-01 0:29 ` alexis at ortsa dot com
2004-05-17 13:18 ` gdr at gcc dot gnu dot org
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).