Remove empty dummy functions

These functions seem to have been added to avoid MSVC compiler warnigns.
However nowadays, they trigger compiler warnings from Clang (e.g. when
using --disable-lzo and --disable-lz4):

src/openvpn/fdmisc.c
/Users/arne/oss/openvpn-git/src/openvpn/comp-lz4.c:315:1: error: unused
function 'dummy' [-Werror,-Wunused-function]
dummy(void)
^
1 error generated.

Testing with MSVC shows that removing these functions does not trigger
warnings with MSVC either.

Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20210322102119.14322-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg21787.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>

src/openvpn/comp-lz4.c

@@ -309,10 +309,4 @@ const struct compress_alg lz4v2_alg = {
     lz4v2_compress,
     lz4v2_decompress
 };
-
-#else  /* if defined(ENABLE_LZ4) */
-static void
-dummy(void)
-{
-}
 #endif /* ENABLE_LZ4 */

src/openvpn/compstub.c

@@ -175,10 +175,4 @@ const struct compress_alg comp_stub_alg = {
     stub_compress,
     stub_decompress
 };
-
-#else  /* if defined(USE_COMP) */
-static void
-dummy(void)
-{
-}
 #endif /* USE_STUB */

src/openvpn/cryptoapi.c

@@ -1253,12 +1253,4 @@ err:
     CAPI_DATA_free(cd);
     return 0;
 }
-
-#else  /* ifdef ENABLE_CRYPTOAPI */
-#ifdef _MSC_VER  /* Dummy function needed to avoid empty file compiler warning in Microsoft VC */
-static void
-dummy(void)
-{
-}
-#endif
 #endif                          /* _WIN32 */

src/openvpn/fragment.c

@@ -436,10 +436,4 @@ fragment_wakeup(struct fragment_master *f, struct frame *frame)
     /* delete fragments with expired TTLs */
     fragment_ttl_reap(f);
 }
-
-#else  /* ifdef ENABLE_FRAGMENT */
-static void
-dummy(void)
-{
-}
 #endif /* ifdef ENABLE_FRAGMENT */

src/openvpn/gremlin.c

@@ -233,10 +233,4 @@ corrupt_gremlin(struct buffer *buf, int flags)
         }
     }
 }
-
-#else  /* ifdef ENABLE_DEBUG */
-static void
-dummy(void)
-{
-}
 #endif /* ifdef ENABLE_DEBUG */

src/openvpn/lzo.c

@@ -265,10 +265,4 @@ const struct compress_alg lzo_alg = {
     lzo_compress,
     lzo_decompress
 };
-
-#else  /* if defined(ENABLE_LZO) */
-static void
-dummy(void)
-{
-}
 #endif /* ENABLE_LZO */

src/openvpn/mbuf.c

@@ -171,10 +171,4 @@ mbuf_dereference_instance(struct mbuf_set *ms, struct multi_instance *mi)
         }
     }
 }
-
-#else  /* if P2MP */
-static void
-dummy(void)
-{
-}
 #endif /* P2MP */

src/openvpn/ntlm.c

@@ -412,10 +412,4 @@ ntlm_phase_3(const struct http_proxy_info *p, const char *phase_2,
     return ((const char *)make_base64_string2((unsigned char *)phase3,
                                               phase3_bufpos, gc));
 }
-
-#else  /* if NTLM */
-static void
-dummy(void)
-{
-}
 #endif /* if NTLM */

src/openvpn/perf.c

@@ -318,12 +318,4 @@ perf_print_state(int lev)
     }
     gc_free(&gc);
 }
-
-#else  /* ifdef ENABLE_PERFORMANCE_METRICS */
-#ifdef _MSC_VER  /* Dummy function needed to avoid empty file compiler warning in Microsoft VC */
-static void
-dummy(void)
-{
-}
-#endif
 #endif /* ifdef ENABLE_PERFORMANCE_METRICS */

src/openvpn/pkcs11.c

@@ -1001,12 +1001,4 @@ cleanup:
     pkcs11h_terminate();
     gc_free(&gc);
 }
-
-#else  /* if defined(ENABLE_PKCS11) */
-#ifdef _MSC_VER  /* Dummy function needed to avoid empty file compiler warning in Microsoft VC */
-static void
-dummy(void)
-{
-}
-#endif
 #endif /* ENABLE_PKCS11 */

src/openvpn/plugin.c

@@ -1014,10 +1014,4 @@ plugin_return_print(const int msglevel, const char *prefix, const struct plugin_
     }
 }
 #endif /* ifdef ENABLE_DEBUG */
-
-#else  /* ifdef ENABLE_PLUGIN */
-static void
-dummy(void)
-{
-}
 #endif /* ENABLE_PLUGIN */

src/openvpn/shaper.c

@@ -94,10 +94,4 @@ shaper_msg(struct shaper *s)
     msg(M_INFO, "Output Traffic Shaping initialized at %d bytes per second",
         s->bytes_per_second);
 }
-
-#else  /* ifdef ENABLE_FEATURE_SHAPER */
-static void
-dummy(void)
-{
-}
 #endif /* ENABLE_FEATURE_SHAPER */