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?
/Bruce
