build: add Darwin/macOS support

Adds platform handling for macOS:
 - Guard GCC-only -Wno-stringop-truncation behind a compiler check and
   silence Clang warnings promoted to errors by -Werror.
 - Wire up empty RT/SOCKET libraries and test libraries for Darwin.
 - Use the macOS pthread_setname_np signature (current thread only) and
   skip pthread_condattr_setclock(CLOCK_MONOTONIC), which is unavailable.

Author: felipek

CMakeLists.txt

@@ -261,9 +261,23 @@ add_compile_options(
     -Wcast-qual
     -Wno-system-headers
     -Wno-unused-function
-    -Wno-stringop-truncation
+    $<$<C_COMPILER_ID:GNU>:-Wno-stringop-truncation>
 )
 
+if(APPLE)
+    # Clang on macOS is stricter than GCC on some warnings that are promoted to
+    # errors by -Werror above.  Suppress the ones triggered by current code until
+    # the upstream sources are fixed.
+    add_compile_options(
+        -Wno-sign-conversion
+        -Wno-implicit-int-conversion
+        -Wno-shorten-64-to-32
+        -Wno-strict-prototypes
+        -Wno-static-in-inline
+        -Wno-gnu-folding-constant
+    )
+endif()
+
 if(WITH_DOC STREQUAL "OFF")
     set(PACKAGE_DOC "#")
 else()

src/lib/CMakeLists.txt

@@ -34,6 +34,9 @@ add_library(dlt ${dlt_LIB_SRCS})
 if("${CMAKE_SYSTEM_NAME}" MATCHES "Linux|CYGWIN|MSYS")
     set(RT_LIBRARY rt)
     set(SOCKET_LIBRARY "")
+elseif("${CMAKE_SYSTEM_NAME}" MATCHES "Darwin")
+    set(RT_LIBRARY "")
+    set(SOCKET_LIBRARY "")
 else()
     set(RT_LIBRARY "")
     set(SOCKET_LIBRARY socket)

src/lib/dlt_user.c

@@ -3949,7 +3949,11 @@ void *dlt_user_trace_network_segmented_thread(void *unused)
     /* Unused on purpose. */
     (void)unused;
 #ifdef DLT_USE_PTHREAD_SETNAME_NP
+#ifdef __APPLE__
+    if (pthread_setname_np("dlt_segmented"))
+#else
     if (pthread_setname_np(dlt_user.dlt_segmented_nwt_handle, "dlt_segmented"))
+#endif
         dlt_log(LOG_WARNING, "Failed to rename segmented thread!\n");
 #elif linux
     if (prctl(PR_SET_NAME, "dlt_segmented", 0, 0, 0) < 0)
@@ -4835,7 +4839,11 @@ void *dlt_user_housekeeperthread_function(void *ptr)
 #endif
 
 #ifdef DLT_USE_PTHREAD_SETNAME_NP
+#ifdef __APPLE__
+    if (pthread_setname_np("dlt_housekeeper"))
+#else
     if (pthread_setname_np(dlt_housekeeperthread_handle, "dlt_housekeeper"))
+#endif
         dlt_log(LOG_WARNING, "Failed to rename housekeeper thread!\n");
 #elif linux
     if (prctl(PR_SET_NAME, "dlt_housekeeper", 0, 0, 0) < 0)
@@ -7362,7 +7370,9 @@ int dlt_start_threads()
      */
     pthread_condattr_t attr;
     pthread_condattr_init(&attr);
+#ifndef __APPLE__
     pthread_condattr_setclock(&attr, CLOCK_MONOTONIC);
+#endif
     pthread_cond_init(&dlt_housekeeper_running_cond, &attr);
 
     if (pthread_create(&(dlt_housekeeperthread_handle),

tests/CMakeLists.txt

@@ -27,6 +27,8 @@ if("${CMAKE_SYSTEM_NAME}" MATCHES "Linux|CYGWIN")
     set(LIBRARIES "")
 elseif("${CMAKE_SYSTEM_NAME}" MATCHES "QNX")
     set(LIBRARIES regex)
+elseif("${CMAKE_SYSTEM_NAME}" MATCHES "Darwin")
+    set(LIBRARIES "")
 else()
     set(LIBRARIES socket)
 endif()