print caught signal desc in verbose

src/host.cpp

@@ -1048,18 +1048,10 @@ void crash_signal_handler(int sig)
         array<void *, 256> addresses{};
         int num_symbols = backtrace(addresses.data(), addresses.size());
         backtrace_symbols_fd(addresses.data(), num_symbols, 2);
+#endif // defined WIN32
+
+        append_sig_desc(&ptr, ptr_end, sig);
 
-#if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 32)
-        const char *sig_desc = sigdescr_np(sig);
-#else
-        const char *sig_desc = sys_siglist[sig];
-#endif
-        if (sig_desc != NULL) {
-                strappend(&ptr, ptr_end, " (");
-                strappend(&ptr, ptr_end, sig_desc);
-                strappend(&ptr, ptr_end, ")");
-        }
-#endif
         strappend(&ptr, ptr_end, ".\n\nPlease send a bug report to address " PACKAGE_BUGREPORT ".\n");
         strappend(&ptr, ptr_end, "You may find some tips how to report bugs in file doc/REPORTING_BUGS.md distributed with " PACKAGE_NAME "\n");
         strappend(&ptr, ptr_end, "(or available online at https://github.com/CESNET/UltraGrid/blob/master/doc/REPORTING-BUGS.md).\n");

src/main.cpp

@@ -190,6 +190,7 @@ static void signal_handler(int signum)
                         *ptr++ = (char) ('0' + signum / 10);
                 }
                 *ptr++ = (char) ('0' + signum % 10);
+                append_sig_desc(&ptr, ptr_end - 1, signum);
                 *ptr++ = '\n';
                 write_all(ptr - buf, buf);
         }

src/utils/string.c

@@ -41,6 +41,9 @@
 #include "config_win32.h"
 #endif
 
+#ifndef __APPLE__
+#include <signal.h>
+#endif
 #include <string.h>
 
 #include "debug.h"
@@ -137,3 +140,26 @@ void write_all(size_t len, const char *msg) {
         } while (len > 0);
 }
 
+/**
+ * Appends signal number description to ptr and moves ptr to end of the
+ * appended string. The string is not NULL-terminated.
+ *
+ * This function is async-signal-safe.
+ */
+void
+append_sig_desc(char **ptr, const char *ptr_end, int signum)
+{
+#ifdef _WIN32
+        (void) ptr, (void) ptr_end, (void) signum;
+#else
+        strappend(ptr, ptr_end, " (");
+#if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 32)
+        strappend(ptr, ptr_end, sigabbrev_np(signum));
+        strappend(ptr, ptr_end, " - ");
+        strappend(ptr, ptr_end, sigdescr_np(signum));
+#else
+        strappend(ptr, ptr_end, sys_siglist[signum]);
+#endif
+        strappend(ptr, ptr_end, ")");
+#endif // !defined _WIN32
+}

src/utils/string.h

@@ -55,6 +55,7 @@ bool is_prefix_of(const char *haystack, const char *needle);
 /// same as strpbrk but finds in a reverse order (last occurence returned)
 char *strrpbrk(char *s, const char *accept);
 void strappend(char **ptr, const char *ptr_end, const char *src);
+void append_sig_desc(char **ptr, const char *ptr_end, int signum);
 void write_all(size_t len, const char *msg);
 
 #ifdef __cplusplus