Fixed C deprecated enum support. Added C++03 support for examples (#997)

* Fixed deprecated option declarations to work in C mode
* Fixed old compiler support. Fixed no-C++11 support for examples

CMakeLists.txt

@@ -832,7 +832,7 @@ macro(srt_make_application name)
 	endif()
 
 	# We state that Darwin always uses CLANG compiler, which honors this flag the same way.
-	set_target_properties(${name} PROPERTIES COMPILE_FLAGS "${CFLAGS_CXX_STANDARD} ${EXTRA_stransmit}" ${FORCE_RPATH})
+	set_target_properties(${name} PROPERTIES COMPILE_FLAGS "${CFLAGS_CXX_STANDARD}" ${FORCE_RPATH})
 
 	target_link_libraries(${name} ${srt_link_library})
 	if (USE_GNUSTL)
@@ -878,6 +878,9 @@ if (ENABLE_APPS)
 	# Applications
 
 	srt_add_application(srt-live-transmit ${VIRTUAL_srtsupport})
+	if (DEFINED EXTRA_stransmit)
+		set_target_properties(srt-live-transmit PROPERTIES COMPILE_FLAGS "${EXTRA_stransmit}")
+	endif()
 	srt_add_application(srt-file-transmit ${VIRTUAL_srtsupport})
 
 	if (MINGW)
@@ -940,13 +943,13 @@ if (ENABLE_EXAMPLES)
 		srt_add_program(${name} examples/${mainsrc} ${ARGN})
 	endmacro()
 
-	srt_add_example(sendfile.cpp apps/logsupport.cpp)
+	srt_add_example(sendfile.cpp)
 	srt_make_application(sendfile)
 
-	srt_add_example(recvfile.cpp apps/logsupport.cpp)
+	srt_add_example(recvfile.cpp)
 	srt_make_application(recvfile)
 
-	srt_add_example(recvlive.cpp apps/logsupport.cpp)
+	srt_add_example(recvlive.cpp)
 	srt_make_application(recvlive)
 
 	srt_add_example(test-c-client.c)

examples/recvlive.cpp

@@ -26,7 +26,7 @@ int main(int argc, char* argv[])
    // use this function to initialize the UDT library
    srt_startup();
 
-   srt_setloglevel(logging::LogLevel::debug);
+   srt_setloglevel(srt_logging::LogLevel::debug);
 
    addrinfo hints;
    addrinfo* res;
@@ -110,7 +110,7 @@ int main(int argc, char* argv[])
       return 0;
    }
 
-   constexpr int srtrfdslenmax = 100;
+   const int srtrfdslenmax = 100;
    SRTSOCKET srtrfds[srtrfdslenmax];
    char data[1500];
 

srtcore/srt.h

@@ -72,13 +72,20 @@ written by
 // When compiling in C++17 mode, use the standard C++17 attributes
 // (out of these, only [[deprecated]] is supported in C++14, so
 // for all lesser standard use compiler-specific attributes).
-#if defined(__cplusplus) && __cplusplus > 201406
+#if defined(SRT_NO_DEPRECATED)
+
+#define SRT_ATR_UNUSED
+#define SRT_ATR_DEPRECATED
+#define SRT_ATR_NODISCARD
+
+#elif defined(__cplusplus) && __cplusplus > 201406
+
 #define SRT_ATR_UNUSED [[maybe_unused]]
 #define SRT_ATR_DEPRECATED [[deprecated]]
 #define SRT_ATR_NODISCARD [[nodiscard]]
 
-// GNUG is GNU C++; this syntax is also supported by Clang
-#elif defined( __GNUG__)
+// GNUG is GNU C/C++; this syntax is also supported by Clang
+#elif defined( __GNUC__)
 #define SRT_ATR_UNUSED __attribute__((unused))
 #define SRT_ATR_DEPRECATED __attribute__((deprecated))
 #define SRT_ATR_NODISCARD __attribute__((warn_unused_result))
@@ -185,6 +192,27 @@ typedef enum SRT_SOCKOPT {
    SRTO_PACKETFILTER = 60          // Add and configure a packet filter
 } SRT_SOCKOPT;
 
+
+#ifdef __cplusplus
+
+typedef SRT_ATR_DEPRECATED SRT_SOCKOPT SRT_SOCKOPT_DEPRECATED;
+#define SRT_DEPRECATED_OPTION(value) ((SRT_SOCKOPT_DEPRECATED)value)
+
+#else
+
+// deprecated enum labels are supported only since gcc 6, so in C there
+// will be a whole deprecated enum type, as it's not an error in C to mix
+// enum types
+enum SRT_ATR_DEPRECATED SRT_SOCKOPT_DEPRECATED
+{
+
+    // Dummy last option, as every entry ends with a comma
+    SRTO_DEPRECATED_END = 0
+
+};
+#define SRT_DEPRECATED_OPTION(value) ((enum SRT_SOCKOPT_DEPRECATED)value)
+#endif
+
 // DEPRECATED OPTIONS:
 
 // SRTO_TWOWAYDATA: not to be used. SRT connection is always bidirectional if
@@ -194,36 +222,37 @@ typedef enum SRT_SOCKOPT {
 // differences between bidirectional support (especially concerning encryption)
 // with HSv4 and HSv5 (that is, HSv4 was decided to remain unidirectional only,
 // even though partial support is already provided in this version).
-static const SRT_SOCKOPT SRTO_TWOWAYDATA SRT_ATR_DEPRECATED = (SRT_SOCKOPT)37;
+
+#define SRTO_TWOWAYDATA SRT_DEPRECATED_OPTION(37)
 
 // This has been deprecated a long time ago, treat this as never implemented.
 // The value is also already reused for another option.
-static const SRT_SOCKOPT SRTO_TSBPDMAXLAG SRT_ATR_DEPRECATED = (SRT_SOCKOPT)32;
+#define SRTO_TSBPDMAXLAG SRT_DEPRECATED_OPTION(32)
 
 // This option is a derivative from UDT; the mechanism that uses it is now
 // settable by SRTO_CONGESTION, or more generally by SRTO_TRANSTYPE. The freed
 // number has been reused for a read-only option SRTO_ISN. This option should
 // have never been used anywhere, just for safety this is temporarily declared
 // as deprecated.
-static const SRT_SOCKOPT SRTO_CC SRT_ATR_DEPRECATED = (SRT_SOCKOPT)3;
+#define SRTO_CC SRT_DEPRECATED_OPTION(3)
 
 // These two flags were derived from UDT, but they were never used.
 // Probably it didn't make sense anyway. The maximum size of the message
 // in File/Message mode is defined by SRTO_SNDBUF, and the MSGTTL is
 // a parameter used in `srt_sendmsg` and `srt_sendmsg2`.
-static const SRT_SOCKOPT SRTO_MAXMSG SRT_ATR_DEPRECATED = (SRT_SOCKOPT)10;
-static const SRT_SOCKOPT SRTO_MSGTTL SRT_ATR_DEPRECATED = (SRT_SOCKOPT)11;
+#define SRTO_MAXMSG SRT_DEPRECATED_OPTION(10)
+#define SRTO_MSGTTL SRT_DEPRECATED_OPTION(11)
 
 // These flags come from an older experimental implementation of bidirectional
 // encryption support, which were used two different SEKs, KEKs and passphrases
 // per direction. The current implementation uses just one in both directions,
 // so SRTO_PBKEYLEN should be used for both cases.
-static const SRT_SOCKOPT SRTO_SNDPBKEYLEN SRT_ATR_DEPRECATED = (SRT_SOCKOPT)38;
-static const SRT_SOCKOPT SRTO_RCVPBKEYLEN SRT_ATR_DEPRECATED = (SRT_SOCKOPT)39;
+#define SRTO_SNDPBKEYLEN SRT_DEPRECATED_OPTION(38)
+#define SRTO_RCVPBKEYLEN SRT_DEPRECATED_OPTION(39)
 
 // Keeping old name for compatibility (deprecated)
-static const SRT_SOCKOPT SRTO_SMOOTHER SRT_ATR_DEPRECATED = SRTO_CONGESTION;
-static const SRT_SOCKOPT SRTO_STRICTENC SRT_ATR_DEPRECATED = SRTO_ENFORCEDENCRYPTION;
+#define SRTO_SMOOTHER SRT_DEPRECATED_OPTION(47)
+#define SRTO_STRICTENC SRT_DEPRECATED_OPTION(53)
 
 typedef enum SRT_TRANSTYPE
 {