From 8f212e047de9c18e67fab7e1ab2ccfdc7c5cb5db Mon Sep 17 00:00:00 2001 From: "Wladimir J. van der Laan" Date: Tue, 23 Feb 2021 18:51:13 +0100 Subject: [PATCH] Merge #21250: build: make HAVE_O_CLOEXEC available outside LevelDB (bugfix) 9bac71350d98580cc7441957fc7c3fa2f4158553 build: make HAVE_O_CLOEXEC available outside LevelDB (bugfix) (Sebastian Falbesoner) 584fd91d2d294883e6896dbd64a2176528e94581 init: only use pipe2 if availabile, check in configure (Sebastian Falbesoner) Pull request description: The result of the O_CLOEXEC availability check is currently only set in the Makefile and passed to LevelDB (see `LEVELDB_CPPFLAGS_INT` in `src/Makefile.leveldb.include`), but not defined to be used in our codebase. This means that code within the preprocessor conditional `#if HAVE_O_CLOEXEC` was actually never compiled. On the master branch this is currently used for pipe creation in `src/shutdown.cpp`, PR #21007 moves this part to a new module (I found the issue while testing that PR). The fix is similar to the one in #19803, which solved the same problem for HAVE_FDATASYNC. In the course of working on the PR it turned out that pipe2 is not available an all platforms, hence a configure check and a corresponding define HAVE_PIPE2 is introduced and used. The PR can be tested by anyone with a system that has pipe2 and O_CLOEXEC available by putting gibberish into the HAVE_O_CLOEXEC block: on master, everything should compile fine, on PR, the compiler should abort with an error. At least that's my naive way of testing preprocessor logic, happy to hear more sophisticated ways :-) ACKs for top commit: laanwj: Code review ACK 9bac71350d98580cc7441957fc7c3fa2f4158553 Tree-SHA512: aec89faf6ba52b6f014c610ebef7b725d9e967207d58b42a4a71afc9f1268fcb673ecc85b33a2a3debba8105a304dd7edaba4208c5373fcef2ab83e48a170051 --- configure.ac | 3 +++ src/shutdown.cpp | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/configure.ac b/configure.ac index a440c33732..20344c2ed5 100644 --- a/configure.ac +++ b/configure.ac @@ -981,6 +981,8 @@ AC_CHECK_DECLS([strnlen]) dnl Check for daemon(3), unrelated to --with-daemon (although used by it) AC_CHECK_DECLS([daemon]) +AC_CHECK_DECLS([pipe2]) + AC_CHECK_DECLS([le16toh, le32toh, le64toh, htole16, htole32, htole64, be16toh, be32toh, be64toh, htobe16, htobe32, htobe64],,, [#if HAVE_ENDIAN_H #include @@ -1185,6 +1187,7 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include ]], [ AC_MSG_RESULT(yes); HAVE_O_CLOEXEC=1 ], [ AC_MSG_RESULT(no); HAVE_O_CLOEXEC=0 ] ) +AC_DEFINE_UNQUOTED([HAVE_O_CLOEXEC], [$HAVE_O_CLOEXEC], [Define to 1 if O_CLOEXEC flag is available.]) dnl crc32c platform checks AC_MSG_CHECKING(for __builtin_prefetch) diff --git a/src/shutdown.cpp b/src/shutdown.cpp index f835833f38..ea6bf9119f 100644 --- a/src/shutdown.cpp +++ b/src/shutdown.cpp @@ -50,7 +50,7 @@ static int g_shutdown_pipe[2] = {-1, -1}; bool InitShutdownState() { #ifndef WIN32 -#if HAVE_O_CLOEXEC +#if HAVE_O_CLOEXEC && HAVE_DECL_PIPE2 // If we can, make sure that the file descriptors are closed on exec() // to prevent interference. if (pipe2(g_shutdown_pipe, O_CLOEXEC) != 0) {