Merge bitcoin/bitcoin#25599: build: Check for std::atomic::exchange rather than std::atomic_exchange

4de4221ab4b645ff77503c777c9b195a962e9fa1 build: Check for std::atomic::exchange rather than std::atomic_exchange (Andrew Chow)

Pull request description:

  Our usage of std::atomic is with it's own exchange function, not std::atomic_exchange. So we should be looking specifically for that function.

  This removes the need for -latomic for riscv builds, which resolves a guix cross architecture reproducibility issue.

ACKs for top commit:
  hebasto:
    ACK 4de4221ab4b645ff77503c777c9b195a962e9fa1
  fanquake:
    ACK 4de4221ab4b645ff77503c777c9b195a962e9fa1

Tree-SHA512: dd8225fc9c6a335601f611700003d0249b9ef941efa502db39306129677929d013048e9221be1d6d7f0ea2d90313d4b87de239f441be21b25bea40a6c19a031e
This commit is contained in:
fanquake 2022-07-18 16:31:44 +01:00 committed by pasta
parent 1204dc0f83
commit b66eebe64d
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GPG Key ID: E2F3D7916E722D38
2 changed files with 7 additions and 4 deletions

View File

@ -18,7 +18,7 @@ m4_define([_CHECK_ATOMIC_testbody], [[
int main() {
std::atomic<bool> lock{true};
std::atomic_exchange(&lock, false);
lock.exchange(false);
std::atomic<std::chrono::seconds> t{0s};
t.store(2s);
@ -34,6 +34,8 @@ m4_define([_CHECK_ATOMIC_testbody], [[
AC_DEFUN([CHECK_ATOMIC], [
AC_LANG_PUSH(C++)
TEMP_CXXFLAGS="$CXXFLAGS"
CXXFLAGS="$CXXFLAGS $PTHREAD_CFLAGS"
AC_MSG_CHECKING([whether std::atomic can be used without link library])
@ -51,5 +53,6 @@ AC_DEFUN([CHECK_ATOMIC], [
])
])
CXXFLAGS="$TEMP_CXXFLAGS"
AC_LANG_POP
])

View File

@ -79,9 +79,6 @@ else
AX_CXX_COMPILE_STDCXX([20], [noext], [mandatory])
fi
dnl Check if -latomic is required for <std::atomic>
CHECK_ATOMIC
dnl check if additional link flags are required for std::filesystem
CHECK_FILESYSTEM
@ -896,6 +893,9 @@ AC_C_BIGENDIAN
dnl Check for pthread compile/link requirements
AX_PTHREAD
dnl Check if -latomic is required for <std::atomic>
CHECK_ATOMIC
dnl The following macro will add the necessary defines to bitcoin-config.h, but
dnl they also need to be passed down to any subprojects. Pull the results out of
dnl the cache and add them to CPPFLAGS.