testing, system, netutils: do not depend on fork() where it is absent or unneeded

netutils/dropbear/port/nuttx_config.h

@@ -48,6 +48,7 @@
 #define HAVE_CLOCK_GETTIME 1
 #define HAVE_CONST_GAI_STRERROR_PROTO 1
 #define HAVE_CRYPT 1
+#define HAVE_DAEMON 1
 #define HAVE_DECL_HTOLE64 1
 #define HAVE_ENDIAN_H 1
 #define HAVE_EXPLICIT_BZERO 1

system/libuv/CMakeLists.txt

@@ -171,6 +171,13 @@ if(CONFIG_LIBUV)
         ${LIBUV_TEST_DIR}/run-tests.c ${LIBUV_TEST_DIR}/runner.c
         ${LIBUV_TEST_DIR}/runner-unix.c ${LIBUV_TEST_DIR}/echo-server.c)
     file(GLOB TEST_CSRCS ${LIBUV_TEST_DIR}/test-*.c)
+
+    # See system/libuv/Makefile.
+
+    if(NOT CONFIG_ARCH_HAVE_FORK)
+      list(REMOVE_ITEM TEST_CSRCS ${LIBUV_TEST_DIR}/test-fork.c
+           ${LIBUV_TEST_DIR}/test-pipe-close-stdout-read-stdin.c)
+    endif()
     list(APPEND LIBUV_UTILS_TEST_SRCS ${TEST_CSRCS})
     nuttx_add_application(
       NAME

system/libuv/Makefile

@@ -144,7 +144,19 @@ CSRCS += runner.c
 CSRCS += runner-unix.c
 CSRCS += echo-server.c
 
-CSRCS += $(wildcard libuv/test/test-*.c)
+LIBUV_TEST_CSRCS  = $(wildcard libuv/test/test-*.c)
+
+# test-fork.c and test-pipe-close-stdout-read-stdin.c call fork(), so they
+# cannot be built where NuttX does not provide it.  Nothing is lost either
+# way: every test they define is already excluded from the task list on
+# NuttX by 0001-libuv-port-for-nuttx.patch.
+
+ifeq ($(CONFIG_ARCH_HAVE_FORK),)
+LIBUV_TEST_CSRCS := $(filter-out libuv/test/test-fork.c,$(LIBUV_TEST_CSRCS))
+LIBUV_TEST_CSRCS := $(filter-out libuv/test/test-pipe-close-stdout-read-stdin.c,$(LIBUV_TEST_CSRCS))
+endif
+
+CSRCS += $(LIBUV_TEST_CSRCS)
 endif
 
 ifneq ($(CONFIG_LIBUV_UTILS_BENCHMARK),)

testing/drivers/nand_sim/nand_sim_main.c

@@ -25,6 +25,7 @@
  ****************************************************************************/
 
 #include <nuttx/debug.h>
+#include <sched.h>
 #include <stdio.h>
 
 #include <nuttx/drivers/drivers.h>
@@ -128,26 +129,17 @@ void terminate(int sig)
 }
 
 /****************************************************************************
- * Name: nand_sim_main
+ * Name: nand_sim_daemon
  *
  * Description:
- *   Entry point of the device emulator.
+ *   Body of the device emulator.  Registers the simulated MTD device and
+ *   then sleeps forever; all events are handled by signals.
  *
  ****************************************************************************/
 
-int main(int argc, FAR char *argv[])
+static int nand_sim_daemon(int argc, FAR char *argv[])
 {
-  int   ret;
-  pid_t pid;
-
-  /* Daemon */
-
-  pid = fork();
-
-  if (pid > 0)
-    {
-      return OK;
-    }
+  int ret;
 
   if (daemon(0, 1) == -1)
     {
@@ -223,3 +215,26 @@ int main(int argc, FAR char *argv[])
 errout:
   return ret;
 }
+
+/****************************************************************************
+ * Name: nand_sim_main
+ *
+ * Description:
+ *   Entry point of the device emulator.  Starts the emulator as an
+ *   independent task so that the caller gets its shell back.
+ *
+ ****************************************************************************/
+
+int main(int argc, FAR char *argv[])
+{
+  int ret;
+
+  ret = task_create(NAND_SIM_NAME, SCHED_PRIORITY_DEFAULT,
+                    CONFIG_TESTING_NAND_SIM_STACK, nand_sim_daemon, NULL);
+  if (ret < 0)
+    {
+      return EXIT_FAILURE;
+    }
+
+  return OK;
+}

testing/ltp/CMakeLists.txt

@@ -86,6 +86,12 @@ if(CONFIG_TESTING_LTP)
       list(APPEND BLACKWORDS "pthread_spin_init" "pthread_spin_destroy"
            "pthread_spin_trylock")
     endif()
+
+    # See testing/ltp/Makefile.
+
+    if(NOT CONFIG_ARCH_HAVE_FORK)
+      list(APPEND BLACKWORDS "[^v_]fork(")
+    endif()
     list(
       APPEND
       BLACKWORDS

testing/ltp/Makefile

@@ -44,6 +44,13 @@ BLACKWORDS  += "pthread_spin_destroy"
 BLACKWORDS  += "pthread_spin_trylock"
 endif
 
+# Where NuttX does not declare fork(), a test that calls it cannot be built.
+# The pattern spares vfork() and task_fork(), which remain available.
+
+ifeq ($(CONFIG_ARCH_HAVE_FORK),)
+BLACKWORDS  += "[^v_]fork("
+endif
+
 BLACKWORDS  += "CHILD_MAX"
 BLACKWORDS  += "setpgid("
 BLACKWORDS  += "PTHREAD_SCOPE_PROCESS"