otherwise clang build fails with
../cryptonote_core/libcryptonote_core.a(miner.cpp.o): In function
`std::__atomic_base<unsigned long long>::load(std::memory_order) const':
/usr/bin/../lib/gcc/i686-pc-linux-gnu/6.1.1/../../../../include/c++/6.1.1/bits/atomic_base.h:396:
undefined reference to `__atomic_load_8'
This has no effect on the gcc build.
The one strange thing is that test code like
std::atomic<int> x;
int main() { return x; }
compiles and links without errors with clang, without -latomic. This
alone would suggest that this patch is unnecessary, but that is not the
case. It's not clear exactly why, though. The bitmonero code is
including the same header, but it must be doing something more complex
than in this test code snippet that causes the failure at link time
pasted above. In any case, passing -latomic fixes the problem and
seems safe.
.
This does two things:
1. fixes clang build, which otherwise errors with undefined symbol
'dlsym'.
2. simplifies the cmake script, delegating to cmake to figure
out platform-specific flags for linking against the dl library.
Tested that it builds with:
gcc 6.1.1, STATIC=OFF,i686
gcc 6.1.1, STATIC=OFF,armv7h
clang 3.8, STATIC=OFF,i686
clang 3.8, STATIC=OFF,armv7h
gcc 6.1.1, STATIC=ON,i686
clang 3.8, STATIC=ON,i686
Also tested that stack trace is generated fine on exception on:
i686, gcc 6.1.1, STATIC=OFF
(didn't bother testing all the other platforms/configs)
This should fix the build problem on OSX (#871, #901), but
I don't have OSX, so I could only test Clang on Linux.
Tested on Linux (Arch) with clang 3.7 and 3.8 i686 and ARM:
if -stdlib=c++ is passed to clang, then the build errors
out with <string>,<iostrea>,etc. headers not found. Simply
not passing the arg fixes the problem.
**NOTE**: not tested on OSX.
The noexcept specs were added to make GCC 6.1.1 happy (#846), but this
one was missing (because GCC did not complain about it on Linux, but
does complain on OSX).
We need ARCH, because it needs to be set for ARM7, ARM6 to be
initialized.
Strangely, on different machines (both ARMv7, Arch), ${ARCH}
var is either empty or 'native'. Handle both cases.
The destructors get a noexcept(true) spec by default, but these
destructors in fact throw exceptions. An alternative fix might be to not
throw (most if not all of these throws are non-essential
error-reporting/logging).
The destructors get a noexcept(true) spec by default, but these
destructors in fact throw exceptions. An alternative fix might be to not
throw (most if not all of these throws are non-essential
error-reporting/logging).
redfish