[Bug c++/63550] New: Multiple definition errors occur only with -fgnu-tm

[Bug c++/63550] New: Multiple definition errors occur only with -fgnu-tm

[spear at cse dot lehigh.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63550

            Bug ID: 63550
           Summary: Multiple definition errors occur only with -fgnu-tm
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: spear at cse dot lehigh.edu

Templates instantiated within transactions from multiple files result in
multiple-definition errors at link time.  Errors do not occur when compiling
without TM, or when all source files are concatenated.  Should these symbols be
emitted as weak?

The smallest testcase entails two files, each of which instantiates
std::vector<int> and uses the initializer list constructor.  #define is used to
show behavior with and without instantiation from within a transaction.

f1.cc:
#include <vector>

#ifdef USE_TM
#define TX __transaction_atomic
#else
#define TX
#endif

std::vector<int>* v1;

void test1() {
    TX {
        // make a vector with some elements in it
        v1 = new std::vector<int>({1, 2, 3, 4, 5});
    }
}

int main(int argc, char** argv) { }

f2.cc:
#include <vector>

#ifdef USE_TM
#define TX __transaction_atomic
#else
#define TX
#endif

std::vector<int>* v2;

void test2() {
    TX {
        v2 = new std::vector<int>({11, 13, 15, 17});
    }
}

The following script builds the two files four ways: with and without
instantation of std::vector<int>({...}) within a transaction; and with and
without multiple .cc files.

build.sh:
echo "Building from 2 files, no TM"
g++ f1.cc f2.cc -std=c++11 -fgnu-tm -o no_tm_2_file.exe

echo "Building from 2 files, TM"
g++ -DUSE_TM f1.cc f2.cc -std=c++11 -fgnu-tm -o yes_tm_2_file.exe

echo "Building from 1 file, no TM"
cat f1.cc f2.cc > f.cc; g++ f.cc -std=c++11 -fgnu-tm -o no_tm_1_file.exe; rm
f.cc

echo "Building from 1 file, TM"
cat f1.cc f2.cc > f.cc; g++ -DUSE_TM f.cc -std=c++11 -fgnu-tm -o
yes_tm_1_file.exe; rm f.cc




Link errors occur only in one case.  Other three cases produce executables:

Output:
sh build.sh
Building from 2 files, no TM
Building from 2 files, TM
/tmp/cchUc9zn.o: In function `transaction clone for std::vector<int,
std::allocator<int> >::vector(std::initializer_list<int>, std::allocator<int>
const&)':
f2.cc:(.text+0x1b4): multiple definition of `transaction clone for
std::vector<int, std::allocator<int> >::vector(std::initializer_list<int>,
std::allocator<int> const&)'
/tmp/ccvjPFgv.o:f1.cc:(.text+0x1c6): first defined here
/tmp/cchUc9zn.o: In function `transaction clone for
std::allocator<int>::allocator() [clone .localalias.31]':
f2.cc:(.text+0x180): multiple definition of `transaction clone for
std::allocator<int>::allocator()'
/tmp/ccvjPFgv.o:f1.cc:(.text+0x192): first defined here
/tmp/cchUc9zn.o: In function `transaction clone for
std::allocator<int>::~allocator() [clone .localalias.30]':
f2.cc:(.text+0x19a): multiple definition of `transaction clone for
std::allocator<int>::~allocator()'
/tmp/ccvjPFgv.o:f1.cc:(.text+0x1ac): first defined here
/tmp/cchUc9zn.o: In function `transaction clone for
__gnu_cxx::new_allocator<int>::new_allocator() [clone .localalias.29]':
f2.cc:(.text+0x24a): multiple definition of `transaction clone for
__gnu_cxx::new_allocator<int>::new_allocator()'
/tmp/ccvjPFgv.o:f1.cc:(.text+0x25c): first defined here
/tmp/cchUc9zn.o: In function `transaction clone for
__gnu_cxx::new_allocator<int>::~new_allocator() [clone .localalias.28]':
f2.cc:(.text+0x254): multiple definition of `transaction clone for
__gnu_cxx::new_allocator<int>::~new_allocator()'
/tmp/ccvjPFgv.o:f1.cc:(.text+0x266): first defined here
/tmp/cchUc9zn.o: In function `transaction clone for std::_Vector_base<int,
std::allocator<int> >::_Vector_base(std::allocator<int> const&) [clone
.localalias.27]':
f2.cc:(.text+0x25e): multiple definition of `transaction clone for
std::_Vector_base<int, std::allocator<int> >::_Vector_base(std::allocator<int>
const&)'
/tmp/ccvjPFgv.o:f1.cc:(.text+0x270): first defined here
/tmp/cchUc9zn.o: In function `transaction clone for std::_Vector_base<int,
std::allocator<int> >::~_Vector_base() [clone .localalias.23]':
f2.cc:(.text+0x3a4): multiple definition of `transaction clone for
std::_Vector_base<int, std::allocator<int> >::~_Vector_base()'
/tmp/ccvjPFgv.o:f1.cc:(.text+0x3b6): first defined here
/tmp/cchUc9zn.o: In function `transaction clone for std::_Vector_base<int,
std::allocator<int> >::_Vector_impl::_Vector_impl(std::allocator<int> const&)
[clone .localalias.22]':
f2.cc:(.text+0x412): multiple definition of `transaction clone for
std::_Vector_base<int, std::allocator<int>
>::_Vector_impl::_Vector_impl(std::allocator<int> const&)'
/tmp/ccvjPFgv.o:f1.cc:(.text+0x424): first defined here
/tmp/cchUc9zn.o: In function `transaction clone for std::_Vector_base<int,
std::allocator<int> >::_Vector_impl::~_Vector_impl() [clone .localalias.15]':
f2.cc:(.text+0x58c): multiple definition of `transaction clone for
std::_Vector_base<int, std::allocator<int> >::_Vector_impl::~_Vector_impl()'
/tmp/ccvjPFgv.o:f1.cc:(.text+0x59e): first defined here
/tmp/cchUc9zn.o: In function `transaction clone for
std::allocator<int>::allocator(std::allocator<int> const&) [clone
.localalias.14]':
f2.cc:(.text+0x5a6): multiple definition of `transaction clone for
std::allocator<int>::allocator(std::allocator<int> const&)'
/tmp/ccvjPFgv.o:f1.cc:(.text+0x5b8): first defined here
/tmp/cchUc9zn.o: In function `transaction clone for
__gnu_cxx::new_allocator<int>::new_allocator(__gnu_cxx::new_allocator<int>
const&) [clone .localalias.8]':
f2.cc:(.text+0x67e): multiple definition of `transaction clone for
__gnu_cxx::new_allocator<int>::new_allocator(__gnu_cxx::new_allocator<int>
const&)'
/tmp/ccvjPFgv.o:f1.cc:(.text+0x690): first defined here
/tmp/cchUc9zn.o: In function `transaction clone for void std::_Construct<int,
int const&>(int*, int const&) [clone .localalias.2]':
f2.cc:(.text+0x772): multiple definition of `transaction clone for void
std::_Construct<int, int const&>(int*, int const&)'
/tmp/ccvjPFgv.o:f1.cc:(.text+0x784): first defined here
collect2: error: ld returned 1 exit status
Building from 1 file, no TM
Building from 1 file, TM