[dbg_unix] Make sure to use execinfo.h only when available, fixes #1

lonetix/include/df/bgp/bgp.h

@@ -321,6 +321,7 @@ typedef Uint8 BgpCapCode;
 #define BGP_ATTR_LARGE_COMMUNITY                          U8_C(32)
 #define BGP_ATTR_BGPSEC_PATH                              U8_C(33)
 #define BGP_ATTR_COMMUNITY_CONTAINER                      U8_C(34)
+#define BGP_ATTR_OTC                                      U8_C(35)
 #define BGP_ATTR_PREFIX_SID                               U8_C(40)
 #define BGP_ATTR_SET                                      U8_C(128)
 #define BGP_ATTR_RESERVED                                 U8_C(255)

lonetix/sys/dbg_unix.c

@@ -18,8 +18,12 @@
 #include <string.h>
 #include <unistd.h>
 
-#ifdef __GNUC__
+#ifdef __has_include
+#if __has_include(<execinfo.h>)
 #include <execinfo.h>
+
+#define EXECINFO_AVAILABLE 1
+#endif
 #endif
 
 Boolean Sys_IsDebuggerPresent(void)
@@ -63,7 +67,7 @@ size_t Sys_GetBacktrace(void **dest, size_t n)
 	USED(dest);
 	USED(n);
 
-#ifdef __GNUC__
+#ifdef EXECINFO_AVAILABLE
 	if (n > (size_t) (INT_MAX - 1))
 		n = INT_MAX - 1;
 
@@ -84,7 +88,7 @@ size_t Sys_GetBacktrace(void **dest, size_t n)
 
 void *Sys_GetCaller(void)
 {
-#ifdef __GNUC__
+#ifdef EXECINFO_AVAILABLE
 	void *trace[3];  // ourselves, caller, caller's caller
 
 	int n = backtrace(trace, ARRAY_SIZE(trace));
@@ -100,7 +104,7 @@ char *Sys_GetSymbolName(void *sym)
 {
 	USED(sym);
 
-#ifdef __GNUC__
+#ifdef EXECINFO_AVAILABLE
 	static THREAD_LOCAL char buf[128];
 
 	char **names = backtrace_symbols(&sym, 1);
@@ -132,7 +136,7 @@ void Sys_DumpBacktrace(ConHn hn, void **trace, size_t n)
 	USED(trace);
 	USED(n);
 
-#ifdef __GNUC__
+#ifdef EXECINFO_AVAILABLE
 	backtrace_symbols_fd(trace, MIN(n, (size_t) INT_MAX), hn);
 #endif
 }

tools/bgpgrep/bgpgrep_compile.c

@@ -211,6 +211,7 @@ static BgpAttrCode ParseBgpAttr(void)
 	if (Df_stricmp(tok, "LARGE_COMMUNITY") == 0) return BGP_ATTR_LARGE_COMMUNITY;
 	if (Df_stricmp(tok, "BGPSEC_PATH") == 0) return BGP_ATTR_BGPSEC_PATH;
 	if (Df_stricmp(tok, "COMMUNITY_CONTAINER") == 0) return BGP_ATTR_COMMUNITY_CONTAINER;
+	if (Df_stricmp(tok, "OTC") == 0) return BGP_ATTR_OTC;
 	if (Df_stricmp(tok, "PREFIX_SID") == 0) return BGP_ATTR_PREFIX_SID;
 	if (Df_stricmp(tok, "SET") == 0) return BGP_ATTR_SET;