On Fri, 25 Sept 2026 at 12:54, Bruce Richardson <[email protected]> wrote: > > On Fri, Sep 25, 2026 at 12:13:41PM +0200, David Marchand wrote: > > On Thu, 24 Sept 2026 at 16:13, Bruce Richardson > > <[email protected]> wrote: > > > > > > When the DPDK build is configured to use stdatomics rather than compiler > > > builtin atomics, the C++ chkincs builds were failing > > > > > > In file included from buildtools/chkincs/staging/generic/rte_atomic.h:18, > > > from > > > /home/morten/upstreaming/dpdk-stack-std/lib/eal/x86/include/rte_atomic.h:12, > > > from buildtools/chkincs/chkincs-cpp.p/rte_atomic.cpp:1: > > > buildtools/chkincs/staging/rte_stdatomic.h:30:9: error: ‘memory_order’ > > > does not name a type > > > 30 | typedef memory_order rte_memory_order; > > > | ^~~~~~~~~~~~ > > > > > > The cause is differences in atomics in C (C11) and C++ (e.g. C++17 as > > > supported by current GCC). As explained by AI analysis: > > > > > > " _Atomic(T) is a C11 feature. In C++ mode, GCC 15 does not support it as > > > a type specifier, and <stdatomic.h> in C++17 doesn't expose > > > memory_order in the global namespace (that's only in C++23). DPDK > > > headers also use _Atomic in anonymous unions and under extern "C", > > > which are incompatible with C++'s std::atomic<T> mapping." > > > > > > To fix this in a resilient manner we need to go from two blocks in > > > rte_atomic.h to three. We have the existing non-standard/builtin > > > atomics path, but the standard atomic path now needs to be split into C > > > compatible and C++ compatible blocks. This fixes the build issues with > > > C++ while keeping existing C builds unchanged. > > > > > > Bugzilla ID: 1985 > > > Fixes: 5c381a3587d1 ("eal: provide stdatomic API") > > > Cc: [email protected] > > > > > > Signed-off-by: Bruce Richardson <[email protected]> > > > > Probably worth squashing this in (I tested in GHA): > > > > $ git diff > > diff --git a/.ci/linux-build.sh b/.ci/linux-build.sh > > index e0b914a142..b09d72dd87 100755 > > --- a/.ci/linux-build.sh > > +++ b/.ci/linux-build.sh > > @@ -111,13 +111,12 @@ OPTS="$OPTS -Dplatform=generic" > > OPTS="$OPTS -Ddefault_library=$DEF_LIB" > > if [ "$STDATOMIC" = "true" ]; then > > OPTS="$OPTS -Denable_stdatomic=true" > > +fi > > +OPTS="$OPTS -Dcheck_includes=true" > > +if [ "${CC%%clang}" != "$CC" ]; then > > + export CXX=clang++ > > else > > - OPTS="$OPTS -Dcheck_includes=true" > > - if [ "${CC%%clang}" != "$CC" ]; then > > - export CXX=clang++ > > - else > > - export CXX=g++ > > - fi > > + export CXX=g++ > > fi > > if [ "$MINI" = "true" ]; then > > OPTS="$OPTS -Denable_drivers=net/null" > > > > > > Compilation passes fine in my env and GHA. > > > Sure. Shall I do a respin to include that?
Yes please, not worth a separate commit. -- David Marchand
