From 1fd40e59d84ad6cad8d33cb0cbe7f8b890f2e465 Mon Sep 17 00:00:00 2001
From: vkalintiris <vasilis@netdata.cloud>
Date: Tue, 7 Dec 2021 15:13:21 +0200
Subject: [PATCH] Detect whether libatomic should be linked in when using CXX
linker. (#11818)
* Detect whether libatomic should be linked in when using CXX linker.
There was already a check for this when building with the bundled
protobuf. Considering that we needed the same check when building for
ML, I moved the check so that it can happen in either case when a
C++ linker is required for the build to succeed.
* Try to unconditionally link with -latomic, if the library is available.
---
Makefile.am | 2 +-
configure.ac | 64 +++++++++++++++++++++++++++++++---------------------
2 files changed, 39 insertions(+), 27 deletions(-)
diff --git a/Makefile.am b/Makefile.am
index 61213ca8d9..5b1c7a31af 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -969,6 +969,7 @@ NETDATA_COMMON_LIBS = \
$(OPTIONAL_JUDY_LIBS) \
$(OPTIONAL_SSL_LIBS) \
$(OPTIONAL_JSONC_LIBS) \
+ $(OPTIONAL_ATOMIC_LIBS) \
$(NULL)
if LINK_STATIC_JSONC
@@ -995,7 +996,6 @@ netdata_LDADD = \
if ACLK_NG
netdata_LDADD += $(OPTIONAL_PROTOBUF_LIBS) \
- $(OPTIONAL_ATOMIC_LIBS) \
$(NULL)
endif
diff --git a/configure.ac b/configure.ac
index b5b6893e57..b9b49d276e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -799,27 +799,6 @@ if test "$enable_cloud" != "no" -a "$aclk_ng" != "no"; then
AC_MSG_RESULT([yes])
fi
- if test "${with_bundled_protobuf}" = "yes"; then
- AC_LANG_PUSH([C++])
- CXXFLAGS="${CXXFLAGS} -std=c++11"
-
- # On some platforms, std::atomic needs a helper library
- AC_MSG_CHECKING(whether -latomic is needed for static protobuf)
- AC_LINK_IFELSE([AC_LANG_SOURCE([[
- #include <atomic>
- #include <cstdint>
- std::atomic<std::int64_t> v;
- int main() {
- return v;
- }
- ]])], STD_ATOMIC_NEED_LIBATOMIC=no, STD_ATOMIC_NEED_LIBATOMIC=yes)
- AC_MSG_RESULT($STD_ATOMIC_NEED_LIBATOMIC)
- if test "x$STD_ATOMIC_NEED_LIBATOMIC" = xyes; then
- OPTIONAL_ATOMIC_LIBS="-latomic"
- fi
- AC_SUBST([OPTIONAL_ATOMIC_LIBS])
- AC_LANG_POP([C++])
- fi
AC_MSG_CHECKING([ACLK Next Generation can support New Cloud protocol])
AC_MSG_RESULT([${can_build_new_cloud_protocol}])
if test "$new_cloud_protocol" = "yes" -a "$can_build_new_cloud_protocol" != "yes"; then
@@ -1655,11 +1634,44 @@ AC_MSG_RESULT([${enable_lto}])
# -----------------------------------------------------------------------------
-AM_CONDITIONAL([ENABLE_CXX_LINKER], [test "${enable_backend_kinesis}" = "yes" \
- -o "${enable_exporting_pubsub}" = "yes" \
- -o "${enable_backend_prometheus_remote_write}" = "yes" \
- -o "${new_cloud_protocol}" = "yes" \
- -o "${build_ml}" = "yes"])
+if test "${enable_backend_kinesis}" = "yes" -o \
+ "${enable_exporting_pubsub}" = "yes" -o \
+ "${enable_backend_prometheus_remote_write}" = "yes" -o \
+ "${new_cloud_protocol}" = "yes" -o \
+ "${build_ml}" = "yes"; then
+ enable_cxx_linker="yes"
+
+ # Try to unconditionally link with -latomic. If the compiler can satisfy
+ # all the atomic ops with builtins then, the library will be left unused.
+ # Otherwise, some ops will be covered by the compiler's intrinsics and some
+ # will be picked up by the linker from -latomic. In the later case, if
+ # -latomic is not available there will be a build failure, which would
+ # have happened either way before this change.
+ AC_LANG_PUSH([C++])
+
+ AC_MSG_CHECKING(whether we can use -latomic)
+ OLD_LIBS="${LIBS}"
+ LIBS="-latomic"
+ AC_LINK_IFELSE([AC_LANG_SOURCE([[
+ #include <atomic>
+ #include <cstdint>
+ std::atomic<std::int64_t> v;
+ int main() {
+ return v;
+ }
+ ]])], CAN_USE_LIBATOMIC=yes, CAN_USE_LIBATOMIC=no)
+ LIBS="${OLD_LIBS}"
+ AC_MSG_RESULT($CAN_USE_LIBATOMIC)
+
+ if test "x$CAN_USE_LIBATOMIC" = xyes; then
+ OPTIONAL_ATOMIC_LIBS="-latomic"
+ fi
+ AC_SUBST([OPTIONAL_ATOMIC_LIBS])
+
+ AC_LANG_POP([C++])
+fi
+
+AM_CONDITIONAL([ENABLE_CXX_LINKER], [test "${enable_cxx_linker}" = "yes"])
AC_DEFINE_UNQUOTED([NETDATA_USER], ["${with_user}"], [use this user to drop privileged])