Hi Thomas,
> Le 12 mars 2014 à 14:54, Thomas Jahns <ja...@dkrz.de> a écrit :
>
> Hello,
>
> I'm trying to build bison-3.0.2 on IBM AIX 6.1 with xlc/xlC 11.1.0.8 (I've
> also
> tried later versions) but I'm running into problems on "make check".
>
> If I understand the code generated from variant.hh correctly it assumes that
> for
>
> someClass a;
>
> typeid(a).name() == typeid(a).name()
>
> Because it stores the result of calling name() in the yytname_ member.
> Unfortunately this assumption is incorrect
Bummer... Yes, of course.
> and only
>
> typeid(a) == typeid(a)
>
> is strictly conformant. Which I wouldn't care about, but IBM xlC does generate
> different results for calling name() and therefore the calc++ test fails on
> me.
>
> Given the above I guess the cleanest solution would be to store the result of
> typeid as yytname_ and use typeid((void *)0) or similar instead of YY_NULLPTR.
> Asserting strcmp(yytname_, other.yytname_) == 0 instead of comparing the
> pointers would probably also work.
Actually I think the safest approach is to store pointers
to the type_info structure, we allows to use nullptr. And
then to dereference to compare them. That's roughly the
same as using type_index, but sticking to C++98.
I'm about to push the following commit for 3.0.3 (the "maint"
branch). WDYT?
Thanks (both late, and in advance :).
commit 7cf84b13a079740a638fed6b46634bc888bd2622
Author: Akim Demaille <a...@lrde.epita.fr>
Date: Wed Jan 7 10:24:53 2015 +0100
c++: variants: comparing addresses of typeid.name() is undefined
Instead of storing and comparing pointers to names of types, store
pointers to the typeids, and compares the typeids.
Reported by Thomas Jahns.
<http://lists.gnu.org/archive/html/bug-bison/2014-03/msg00001.html>
* data/variant.hh (yytname_): Replace with...
(yytypeid_): this.
diff --git a/THANKS b/THANKS
index 2436f00..908498c 100644
--- a/THANKS
+++ b/THANKS
@@ -132,6 +132,7 @@ Steve Murphy m...@parsetree.com
Sum Wu s...@geekhouse.org
Théophile Ranquet theophile.ranq...@gmail.com
Thiru Ramakrishnan thiru.ramakrish...@gmail.com
+Thomas Jahns ja...@dkrz.de
Tim Josling t...@melbpc.org.au
Tim Landscheidt t...@tim-landscheidt.de
Tim Van Holder tim.van.hol...@pandora.be
diff --git a/data/variant.hh b/data/variant.hh
index 78c2f94..f918e34 100644
--- a/data/variant.hh
+++ b/data/variant.hh
@@ -95,13 +95,13 @@ m4_define([b4_variant_define],
/// Empty construction.
variant ()]b4_parse_assert_if([
- : yytname_ (YY_NULLPTR)])[
+ : yytypeid_ (YY_NULLPTR)])[
{}
/// Construct and fill.
template <typename T>
variant (const T& t)]b4_parse_assert_if([
- : yytname_ (typeid (T).name ())])[
+ : yytypeid_ (&typeid (T))])[
{
YYASSERT (sizeof (T) <= S);
new (yyas_<T> ()) T (t);
@@ -110,7 +110,7 @@ m4_define([b4_variant_define],
/// Destruction, allowed only if empty.
~variant ()
{]b4_parse_assert_if([
- YYASSERT (!yytname_);
+ YYASSERT (!yytypeid_);
])[}
/// Instantiate an empty \a T in here.
@@ -118,9 +118,9 @@ m4_define([b4_variant_define],
T&
build ()
{]b4_parse_assert_if([
- YYASSERT (!yytname_);
+ YYASSERT (!yytypeid_);
YYASSERT (sizeof (T) <= S);
- yytname_ = typeid (T).name ();])[
+ yytypeid_ = & typeid (T);])[
return *new (yyas_<T> ()) T;
}
@@ -129,9 +129,9 @@ m4_define([b4_variant_define],
T&
build (const T& t)
{]b4_parse_assert_if([
- YYASSERT (!yytname_);
+ YYASSERT (!yytypeid_);
YYASSERT (sizeof (T) <= S);
- yytname_ = typeid (T).name ();])[
+ yytypeid_ = & typeid (T);])[
return *new (yyas_<T> ()) T (t);
}
@@ -140,7 +140,7 @@ m4_define([b4_variant_define],
T&
as ()
{]b4_parse_assert_if([
- YYASSERT (yytname_ == typeid (T).name ());
+ YYASSERT (*yytypeid_ == typeid (T));
YYASSERT (sizeof (T) <= S);])[
return *yyas_<T> ();
}
@@ -150,7 +150,7 @@ m4_define([b4_variant_define],
const T&
as () const
{]b4_parse_assert_if([
- YYASSERT (yytname_ == typeid (T).name ());
+ YYASSERT (*yytypeid_ == typeid (T));
YYASSERT (sizeof (T) <= S);])[
return *yyas_<T> ();
}
@@ -167,8 +167,8 @@ m4_define([b4_variant_define],
void
swap (self_type& other)
{]b4_parse_assert_if([
- YYASSERT (yytname_);
- YYASSERT (yytname_ == other.yytname_);])[
+ YYASSERT (yytypeid_);
+ YYASSERT (*yytypeid_ == *other.yytypeid_);])[
std::swap (as<T> (), other.as<T> ());
}
@@ -198,7 +198,7 @@ m4_define([b4_variant_define],
destroy ()
{
as<T> ().~T ();]b4_parse_assert_if([
- yytname_ = YY_NULLPTR;])[
+ yytypeid_ = YY_NULLPTR;])[
}
private:
@@ -233,7 +233,7 @@ m4_define([b4_variant_define],
} yybuffer_;]b4_parse_assert_if([
/// Whether the content is built: if defined, the name of the stored type.
- const char *yytname_;])[
+ const std::type_info *yytypeid_;])[
};
]])
