[checkmk-commits] Some localtime_s/localtime_r Kung Fu, level: Black belt :-P

Module: check_mk Branch: master Commit: f2e47d7b9369aec61969a77d45c16fb0bc644ea7 URL: http://git.mathias-kettner.de/git/?p=check_mk.git;a=commit;h=f2e47d7b9369ae… Author: Sven Panne &lt;sp(a)mathias-kettner.de&gt; Date: Fri Sep 8 15:23:34 2017 +0200 Some localtime_s/localtime_r Kung Fu, level: Black belt :-P Change-Id: Ib9735c0b466baa384e8f06285748d3cff4a2560e --- configure.ac | 8 ++++++++ livestatus/src/ChronoUtils.h | 25 ++++++++++++++++++++++++- 2 files changed, 32 insertions(+), 1 deletion(-) diff --git a/configure.ac b/configure.ac index d00f144..44ef454 100644 --- a/configure.ac +++ b/configure.ac @@ -164,6 +164,14 @@ AC_DEFINE([_GLIBCXX_REGEX_STATE_LIMIT], [2500], AC_DEFINE([BOOST_SYSTEM_NO_DEPRECATED], [1], [we do not want any old stuff]) +# GCC is a bit picky about redefinitions of built-in macros. Alas, "built-in" +# simply means "starts with double underscore", so we have to hack around that +# below. Note that clang is happy, even without the guard. +AH_VERBATIM([__STDC_WANT_LIB_EXT1__], [/* we want C11 library extensions */ +#ifndef __STDC_WANT_LIB_EXT1__ +# define __STDC_WANT_LIB_EXT1__ 1 +#endif]) + # HACKING ALERT: automake can't really handle optional subdirectories, so we # have to do this in a slightly hacky way by using M4's silent includes. m4_sinclude([livestatus/config_files.m4]) diff --git a/livestatus/src/ChronoUtils.h b/livestatus/src/ChronoUtils.h index 5399b37..a55d22d 100644 --- a/livestatus/src/ChronoUtils.h +++ b/livestatus/src/ChronoUtils.h @@ -26,7 +26,7 @@ #define ChronoUtils_h #include "config.h" // IWYU pragma: keep -#include <sys/time.h> +#include <time.h> #include <chrono> #include <cstdlib> #include <ctime> @@ -46,7 +46,30 @@ inline double elapsed_ms_since(std::chrono::steady_clock::time_point then) { inline tm to_tm(std::chrono::system_clock::time_point tp) { time_t t = std::chrono::system_clock::to_time_t(tp); struct tm ret; + // NOTE: A brilliant example of how to make a simple API function a total + // chaos follows... +#if defined(__STDC_LIB_EXT1__) + // C11 function, only guaranteed to be available when a + // #define __STDC_WANT_LIB_EXT1_ 1 + // is done before including <time.h>. Signature: + // struct tm *localtime_s(const time_t *restrict timer, + // struct tm *restrict result) + localtime_s(&t, &ret); +#elif defined(__WIN32) + // Win32 variant, it keeps us entertained with swapped parameters and a + // different return value, yay! Signature: + // errno_t localtime_s(struct tm* _tm, const time_t *time) + // We have to de-confuse cppcheck: + // cppcheck-suppress uninitvar + localtime_s(&ret, &t); +#else + // POSIX.1-2008 variant, available under MinGW64 only under obscure + // circumstances, so better avoid it there. Signature: + // struct tm *localtime(const time_t *timer) localtime_r(&t, &ret); +#endif + // Reason: see Win32 section above + // cppcheck-suppress uninitvar return ret; }