internal: silence compiler warnings about unused return values (#13997)

* misc: silence warnings about ignoring return value on reads

silence warnings on ignored return values on read() and print an error
if it occurs.

* misc: silence warnings about ignoring return value on writes

silence warnings on ignored return values on write() and print an error
where we can, or pass them the maybe_unused attribute.

* misc: silence warnings about ignoring return value on pipe

silence warnings on ignored return value on pipe(), print an error and
exit on failure.

1 files changed, 8 insertions, 6 deletions

diff --git a/src/Compositor.cpp b/src/Compositor.cpp
index 18d158ae..2a9b0947 100644
--- a/src/Compositor.cpp
+++ b/src/Compositor.cpp
@@ -117,8 +117,8 @@ static void handleUnrecoverableSignal(int sig) {
 
     // Kill the program if the crash-reporter is caught in a deadlock.
     signal(SIGALRM, [](int _) {
-        char const* msg = "\nCrashReporter exceeded timeout, forcefully exiting\n";
-        write(2, msg, strlen(msg));
+        char const*           msg = "\nCrashReporter exceeded timeout, forcefully exiting\n";
+        [[maybe_unused]] auto w   = write(2, msg, strlen(msg));
         abort();
     });
     alarm(15);
@@ -550,8 +550,8 @@ void CCompositor::cleanup() {
     if (!m_wlDisplay)
         return;
 
-    if (m_watchdogWriteFd.isValid())
-        write(m_watchdogWriteFd.get(), "end", 3);
+    if (m_watchdogWriteFd.isValid()) [[maybe_unused]]
+        auto w = write(m_watchdogWriteFd.get(), "end", 3);
 
     signal(SIGABRT, SIG_DFL);
     signal(SIGSEGV, SIG_DFL);
@@ -803,8 +803,10 @@ void CCompositor::startCompositor() {
 
     Event::bus()->m_events.ready.emit();
 
-    if (m_watchdogWriteFd.isValid())
-        write(m_watchdogWriteFd.get(), "vax", 3);
+    if (m_watchdogWriteFd.isValid()) {
+        if (write(m_watchdogWriteFd.get(), "vax", 3) < 0)
+            Log::logger->log(Log::ERR, "startCompositor: failed to write to watchdogWriteFd {}: {}", m_watchdogWriteFd.get(), strerror(errno));
+    }
 
     // This blocks until we are done.
     Log::logger->log(Log::DEBUG, "Hyprland is ready, running the event loop!");