[posix] enhance reset implementation to support code coverage (#3071)

examples/apps/cli/Makefile.am

@@ -129,6 +129,10 @@ ot_cli_mtd_LDFLAGS                                                    += -Wl,-Ma
 endif
 
 if OPENTHREAD_BUILD_COVERAGE
+CPPFLAGS_COMMON                                                       += \
+    -DOPENTHREAD_ENABLE_COVERAGE                                         \
+    $(NULL)
+
 CLEANFILES                                                             = $(wildcard *.gcda *.gcno)
 endif # OPENTHREAD_BUILD_COVERAGE
 

examples/apps/cli/main.c

@@ -37,6 +37,15 @@
 
 #include "openthread-system.h"
 
+#if OPENTHREAD_EXAMPLES_POSIX
+#include <setjmp.h>
+#include <unistd.h>
+
+jmp_buf gResetJump;
+
+void __gcov_flush();
+#endif
+
 #if OPENTHREAD_ENABLE_MULTIPLE_INSTANCES
 void *otPlatCAlloc(size_t aNum, size_t aSize)
 {
@@ -58,6 +67,17 @@ int main(int argc, char *argv[])
 {
     otInstance *sInstance;
 
+#if OPENTHREAD_EXAMPLES_POSIX
+    if (setjmp(gResetJump))
+    {
+        alarm(0);
+#if OPENTHREAD_ENABLE_COVERAGE
+        __gcov_flush();
+#endif
+        execvp(argv[0], argv);
+    }
+#endif
+
 #if OPENTHREAD_ENABLE_MULTIPLE_INSTANCES
     size_t   otInstanceBufferLength = 0;
     uint8_t *otInstanceBuffer       = NULL;