c++/2810: Problems with enums (gcc 2.95 regression) boost
Peter Schmid
schmid@snake.iap.physik.tu-darmstadt.de
Sat May 12 18:16:00 GMT 2001
>Number: 2810
>Category: c++
>Synopsis: Problems with enums (gcc 2.95 regression) boost
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: unassigned
>State: open
>Class: rejects-legal
>Submitter-Id: net
>Arrival-Date: Sat May 12 18:16:02 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator: Peter Schmid
>Release: 3.0 20010503 (prerelease)
>Organization:
TU Darmstadt
>Environment:
System: Linux kiste 2.4.4 #38 Tue May 8 00:13:02 CEST 2001 i686 unknown
Architecture: i686
SuSE 7.1
glibc 2.2
GNU ld version 2.11.90.0.4 (with BFD 2.11.90.0.4)
host: i686-pc-linux-gnu
build: i686-pc-linux-gnu
target: i686-pc-linux-gnu
configured with: ../gcc/configure --enable-shared --disable-nls --enable-threads=posix --enable-long-long --enable-languages=c,c++,f77,objc : (reconfigured) ../gcc/configure --enable-shared --disable-nls --enable-threads=posix --enable-long-long --enable-languages=c,c++,f77,objc : (reconfigured)
>Description:
The following source code tf.C, extracted from the file
libs/type_traits/tests/is_function_test.cpp from the boost repository
version 1.21.2, is rejected by gcc 3.0. gcc 2.95 accepts this code.
>How-To-Repeat:
Source code tf.C
# define BOOST_STATIC_CONSTANT(type, assignment) static const type assignment
namespace boost{
namespace type_traits{
typedef char yes_type;
typedef double no_type;
} // namespace type_traits
// special version for gcc compiler
//
namespace detail{
struct any_conversion
{
template <class T>
any_conversion(const T&);
};
template <class T>
struct checker
{
static boost::type_traits::no_type check(any_conversion ...);
static boost::type_traits::yes_type check(T, int);
};
} // namespace detail
template <class From, class To>
struct is_convertible
{
private:
static From from;
public:
static const bool value = sizeof( detail::checker<To>::check(from, 0) ) == sizeof(type_traits::yes_type);
void foo(); // avoid warning about all members being private
};
template <typename T>
struct add_reference
{ typedef T& type; };
template <typename T>
struct add_reference<T&>
{ typedef T& type; };
namespace detail{
struct int_convertible
{
int_convertible(int);
};
} // namespace detail
template <typename T> struct is_enum
{
private:
typedef typename ::boost::add_reference<T>::type r_type;
public:
BOOST_STATIC_CONSTANT(bool, value =
(::boost::is_convertible<r_type, detail::int_convertible>::value));
};
} // namespace boost
unsigned failures = 0;
unsigned test_count = 0;
unsigned int expected_failures = 0;
int check_result()
{
return (failures == expected_failures) ? 0 : failures;
}
template <bool>
struct checker
{
static void check(bool, bool){ ++test_count; }
};
template <>
struct checker<false>
{
static void check(bool, bool)
{
++test_count;
++failures;
}
};
#define value_test(v, x) checker<(v == x)>::check(v, x);
template <class T>
void is_function_test(T& foo)
{
value_test(false, ::boost::is_enum<T>::value);
}
void foo0(){}
void foo1(int){}
int main()
{
is_function_test(foo0);
is_function_test(foo1);
return check_result();
}
Compiling tf.C by gcc 3.0
g++ -v tf.C -W -Wall -save-temps
Reading specs from /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.0/specs
Configured with: ../gcc/configure --enable-shared --disable-nls --enable-threads=posix --enable-long-long --enable-languages=c,c++,f77,objc
Thread model: posix
gcc version 3.0 20010503 (prerelease)
/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.0/cpp0 -lang-c++ -D_GNU_SOURCE -D__GNUG__=3 -D__EXCEPTIONS -D__GXX_ABI_VERSION=100 -v -D__GNUC__=3 -D__GNUC_MINOR__=0 -D__GNUC_PATCHLEVEL__=0 -D__ELF__ -Dunix -Dlinux -D__ELF__ -D__unix__ -D__linux__ -D__unix -D__linux -Asystem=posix -D__STDC_HOSTED__=1 -W -Wall -Acpu=i386 -Amachine=i386 -Di386 -D__i386 -D__i386__ -D__tune_i686__ -D__tune_pentiumpro__ tf.C tf.ii
GNU CPP version 3.0 20010503 (prerelease) (cpplib) (i386 Linux/ELF)
#include "..." search starts here:
#include <...> search starts here:
/usr/local/include/g++-v3
/usr/local/include/g++-v3/i686-pc-linux-gnu
/usr/local/include
/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.0/include
/usr/local/i686-pc-linux-gnu/include
/usr/include
End of search list.
/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.0/cc1plus -fpreprocessed tf.ii -quiet -dumpbase tf.C -W -Wall -version -o tf.s
GNU CPP version 3.0 20010503 (prerelease) (cpplib) (i386 Linux/ELF)
GNU C++ version 3.0 20010503 (prerelease) (i686-pc-linux-gnu)
compiled by GNU C version 3.0 20010503 (prerelease).
tf.C: In instantiation of `boost::is_convertible<void (&)(), boost::detail::int_convertible>':
tf.C:53: instantiated from `boost::is_enum<void ()()>'
tf.C:88: instantiated from `void is_function_test(T&) [with T = void ()()]'
tf.C:96: instantiated from here
tf.C:29: no matching function for call to
`boost::detail::checker<boost::detail::int_convertible>::check(void (&)(),
int)'
tf.C:19: candidates are: static no_type
boost::detail::checker<T>::check(boost::detail::any_conversion, ...) [with T
= boost::detail::int_convertible]
tf.C:20: static yes_type boost::detail::checker<T>::check(T,
int) [with T = boost::detail::int_convertible]
tf.C: In function `void is_function_test(T&) [with T = void ()()]':
tf.C:96: instantiated from here
tf.C:87: warning: unused parameter `void (&foo)()'
tf.C: At global scope:
tf.C: In instantiation of `boost::is_convertible<void (&)(int), boost::detail::int_convertible>':
tf.C:53: instantiated from `boost::is_enum<void ()(int)>'
tf.C:88: instantiated from `void is_function_test(T&) [with T = void ()(int)]'
tf.C:97: instantiated from here
tf.C:29: no matching function for call to
`boost::detail::checker<boost::detail::int_convertible>::check(void
(&)(int), int)'
tf.C:19: candidates are: static no_type
boost::detail::checker<T>::check(boost::detail::any_conversion, ...) [with T
= boost::detail::int_convertible]
tf.C:20: static yes_type boost::detail::checker<T>::check(T,
int) [with T = boost::detail::int_convertible]
tf.C: In function `void is_function_test(T&) [with T = void ()(int)]':
tf.C:97: instantiated from here
tf.C:87: warning: unused parameter `void (&foo)(int)'
Compiling tf.C by gcc 2.95.2
/usr/bin/g++ -v tf.C -W -Wall
Reading specs from /usr/lib/gcc-lib/i486-suse-linux/2.95.2/specs
gcc version 2.95.2 19991024 (release)
/usr/lib/gcc-lib/i486-suse-linux/2.95.2/cpp -lang-c++ -v -D__GNUC__=2 -D__GNUG__=2 -D__GNUC_MINOR__=95 -D__cplusplus -D__ELF__ -Dunix -D__i386__ -Dlinux -D__ELF__ -D__unix__ -D__i386__ -D__linux__ -D__unix -D__linux -Asystem(posix) -D__EXCEPTIONS -W -Wall -Acpu(i386) -Amachine(i386) -Di386 -D__i386 -D__i386__ -Di486 -D__i486 -D__i486__ tf.C /tmp/ccS2brQq.ii
GNU CPP version 2.95.2 19991024 (release) (i386 Linux/ELF)
#include "..." search starts here:
#include <...> search starts here:
/usr/include/g++
/usr/local/include
/usr/lib/gcc-lib/i486-suse-linux/2.95.2/include
/usr/include
End of search list.
The following default directories have been omitted from the search path:
/usr/lib/gcc-lib/i486-suse-linux/2.95.2/../../../../i486-suse-linux/include
End of omitted list.
/usr/lib/gcc-lib/i486-suse-linux/2.95.2/cc1plus /tmp/ccS2brQq.ii -quiet -dumpbase tf.cc -W -Wall -version -o /tmp/ccOisxRL.s
GNU C++ version 2.95.2 19991024 (release) (i486-suse-linux) compiled by GNU C version 2.95.2 19991024 (release).
tf.C: In function `void is_function_test<void ()()>(void (&)())':
tf.C:96: instantiated from here
tf.C:87: warning: unused parameter `void (& foo)()'
tf.C: In function `void is_function_test<void ()(int)>(void (&)(int))':
tf.C:97: instantiated from here
tf.C:87: warning: unused parameter `void (& foo)(int)'
/usr/i486-suse-linux/bin/as -V -Qy -o /tmp/ccHStcFV.o /tmp/ccOisxRL.s
GNU assembler version 2.10.91 (i486-suse-linux) using BFD version 2.10.0.33
/usr/lib/gcc-lib/i486-suse-linux/2.95.2/collect2 -m elf_i386 -dynamic-linker /lib/ld-linux.so.2 /usr/lib/crt1.o /usr/lib/crti.o /usr/lib/gcc-lib/i486-suse-linux/2.95.2/crtbegin.o -L/usr/lib/gcc-lib/i486-suse-linux/2.95.2 -L/usr/i486-suse-linux/lib /tmp/ccHStcFV.o -lstdc++ -lm -lgcc -lc -lgcc /usr/lib/gcc-lib/i486-suse-linux/2.95.2/crtend.o /usr/lib/crtn.o
./a.out
echo $?
0
Preprocessed source code tf.ii from gcc 3.0
# 2 "tf.C"
namespace boost{
namespace type_traits{
typedef char yes_type;
typedef double no_type;
}
namespace detail{
struct any_conversion
{
template <class T>
any_conversion(const T&);
};
template <class T>
struct checker
{
static boost::type_traits::no_type check(any_conversion ...);
static boost::type_traits::yes_type check(T, int);
};
}
template <class From, class To>
struct is_convertible
{
private:
static From from;
public:
static const bool value = sizeof( detail::checker<To>::check(from, 0) ) == sizeof(type_traits::yes_type);
void foo();
};
template <typename T>
struct add_reference
{ typedef T& type; };
template <typename T>
struct add_reference<T&>
{ typedef T& type; };
namespace detail{
struct int_convertible
{
int_convertible(int);
};
}
template <typename T> struct is_enum
{
private:
typedef typename ::boost::add_reference<T>::type r_type;
public:
static const bool value = (::boost::is_convertible<r_type, detail::int_convertible>::value);
};
}
unsigned failures = 0;
unsigned test_count = 0;
unsigned int expected_failures = 0;
int check_result()
{
return (failures == expected_failures) ? 0 : failures;
}
template <bool>
struct checker
{
static void check(bool, bool){ ++test_count; }
};
template <>
struct checker<false>
{
static void check(bool, bool)
{
++test_count;
++failures;
}
};
template <class T>
void is_function_test(T& foo)
{
checker<(false == ::boost::is_enum<T>::value)>::check(false, ::boost::is_enum<T>::value);;
}
void foo0(){}
void foo1(int){}
int main()
{
is_function_test(foo0);
is_function_test(foo1);
return check_result();
}
>Fix:
>Release-Note:
>Audit-Trail:
>Unformatted:
More information about the Gcc-bugs
mailing list