Fix keyword is hidden by macro definition compiler warning (#209)

* Do not redefine keyword thread_local

* Eliminate implicit type conversions

* Add news item

* Remove unused inline functions in timeconv.h

* Add note on `thread_local` to src/README.md

Author: shikokuchuo

NEWS.md

@@ -1,5 +1,7 @@
 # later (development version)
 
+* Fixed #208: Fixed `keyword is hidden by macro definition` compiler warning when using a C23 compiler. (@shikokuchuo, #209)
+
 # later 1.4.1
 
 * Fixed #203: Resolves an issue where packages that have `LinkingTo: later` (including `promises` and `httpuv`) and were built against `later` 1.4.0, would fail to load on systems that actually had older versions of `later` installed, erroring out with the message "function 'execLaterFdNative' not provided by package 'later'". With this fix, such dependent packages should gracefully deal with older versions at load time, and complain with helpful error messages if newer C interfaces (than are available on the installed `later`) are accessed. (#204)

src/README.md

@@ -10,7 +10,7 @@ The tinycthread library is from https://github.com/tinycthread/tinycthread, and
 
 To work around the problem of linking to (incorrect) system functions with the same name, our version of tinycthread has modified names for all externally-visible functions and values: they all begin with `tct_`.
 
-We also added a dummry header file called `badthreads.h`. For all of the names from C11 threads.h, it `#define`s them to a value that will cause an error at compile time. This is to make sure that we don't accidentally use anything from threads.h.
+We also added a dummy header file called `badthreads.h`. For all of the names from C11 threads.h, it `#define`s them to a value that will cause an error at compile time. This is to make sure that we don't accidentally use anything from threads.h. Note: `thread_local` is no longer redefined as it has become a keyword in C23 - it is not used in our code base and we should take care not to use it.
 
 There is another change that we have made to tinycthread is in `tinycthread.h`. It is a workaround for building on CRAN's Solaris build machine which was needed at some point in the past. Note that when we tested on a Solaris VM, it didn't seem to be necessary, but we kept it there just to be safe, because we can't actually test on the CRAN Solaris build machine.
 

src/badthreads.h

@@ -45,7 +45,7 @@
 #define cnd_wait            THREADS_H_ERROR
 #define cnd_timedwait       THREADS_H_ERROR
 #define cnd_destroy         THREADS_H_ERROR
-#define thread_local        THREADS_H_ERROR
+// #define thread_local        THREADS_H_ERROR /* Don't redefine thread_local as it is a keyword in C23 */
 #define tss_t               THREADS_H_ERROR
 #define TSS_DTOR_ITERATIONS THREADS_H_ERROR
 #define tss_dtor_t          THREADS_H_ERROR

src/fd.cpp

@@ -119,7 +119,7 @@ static int wait_thread(void *arg) {
   do {
     // Never wait for longer than ~1 second so we can check for cancellation
     waitFor = std::fmin(waitFor, 1.024);
-    ready = LATER_POLL_FUNC(args->fds.data(), args->fds.size(), static_cast<int>(waitFor * 1000));
+    ready = LATER_POLL_FUNC(args->fds.data(), static_cast<LATER_NFDS_T>(args->fds.size()), static_cast<int>(waitFor * 1000));
     if (!args->active->load()) return 1;
     if (ready) break;
   } while ((waitFor = args->timeout.diff_secs(Timestamp())) > 0);

src/fd.h

@@ -12,8 +12,10 @@
 
 #ifdef _WIN32
 #define LATER_POLL_FUNC WSAPoll
+#define LATER_NFDS_T ULONG
 #else
 #define LATER_POLL_FUNC poll
+#define LATER_NFDS_T nfds_t
 #endif
 
 #endif // _LATER_FD_H_

src/timeconv.h

@@ -8,30 +8,16 @@
 // anyone who uses these functions.
 #include "tinycthread.h"
 
-inline timespec timevalToTimespec(const timeval& tv) {
-  timespec ts;
-  ts.tv_sec = tv.tv_sec;
-  ts.tv_nsec = tv.tv_usec * 1000;
-  return ts;
-}
-
-inline timeval timespecToTimeval(const timespec& ts) {
-  timeval tv;
-  tv.tv_sec = ts.tv_sec;
-  tv.tv_usec = ts.tv_nsec / 1000;
-  return tv;
-}
-
 inline timespec addSeconds(const timespec& time, double secs) {
   timespec ts = time;
   ts.tv_sec += (time_t)secs;
-  ts.tv_nsec += (secs - (time_t)secs) * 1e9;
+  ts.tv_nsec += (secs - (time_t)secs) * 1e9L;
   if (ts.tv_nsec < 0) {
-    ts.tv_nsec += 1e9;
+    ts.tv_nsec += 1e9L;
     ts.tv_sec--;
   }
-  if (ts.tv_nsec >= 1e9) {
-    ts.tv_nsec -= 1e9;
+  if (ts.tv_nsec >= 1e9L) {
+    ts.tv_nsec -= 1e9L;
     ts.tv_sec++;
   }
   return ts;