testing/ostest: split the fork test into task_fork, vfork and fork

interpreters/python/Makefile

@@ -114,6 +114,11 @@ ifeq ($(CONFIG_ARCH_HAVE_FORK),y)
 else
 	@echo "export ac_cv_func_fork=\"no\"" >> $@
 endif
+ifneq ($(CONFIG_ARCH_HAVE_VFORK)$(CONFIG_ARCH_HAVE_FORK),)
+	@echo "export ac_cv_func_vfork=\"yes\"" >> $@
+else
+	@echo "export ac_cv_func_vfork=\"no\"" >> $@
+endif
 ifeq ($(CONFIG_SYSTEM_SYSTEM),y)
 	@echo "export ac_cv_func_system=\"yes\"" >> $@
 else
@@ -135,7 +140,10 @@ endif
 
 $(SETUP_LOCAL):
 	$(Q) ( cp $(SETUP_LOCAL).in $(SETUP_LOCAL))
-ifneq ($(CONFIG_ARCH_HAVE_FORK),y)
+# _posixsubprocess is the fork-then-exec path, so vfork() is enough for it;
+# os.fork() itself needs a real fork() and is governed by ac_cv_func_fork
+# above.
+ifeq ($(CONFIG_ARCH_HAVE_FORK)$(CONFIG_ARCH_HAVE_VFORK),)
 	@echo "_posixsubprocess" >> $@
 endif
 ifneq ($(CONFIG_LIBC_DLFCN),y)

netutils/libwebsockets/lws_config_private.h

@@ -43,7 +43,10 @@
 /* #undef USE_CYASSL */
 
 /* Define to 1 if you have the `fork' function. */
+
+#ifdef CONFIG_ARCH_HAVE_FORK
 #define LWS_HAVE_FORK
+#endif
 
 #ifndef CONFIG_DISABLE_ENVIRON
 /* Define to 1 if you have the `getenv' function. */
@@ -111,10 +114,14 @@
 /* #undef LWS_HAVE_VFORK_H */
 
 /* Define to 1 if `fork' works. */
+#ifdef CONFIG_ARCH_HAVE_FORK
 #define LWS_HAVE_WORKING_FORK
+#endif
 
 /* Define to 1 if `vfork' works. */
+#if defined(CONFIG_ARCH_HAVE_VFORK) || defined(CONFIG_ARCH_HAVE_FORK)
 #define LWS_HAVE_WORKING_VFORK
+#endif
 
 /* Define to 1 if execvpe() exists */
 #define LWS_HAVE_EXECVPE

system/libuv/CMakeLists.txt

@@ -171,6 +171,11 @@ 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.
+
+    list(REMOVE_ITEM TEST_CSRCS ${LIBUV_TEST_DIR}/test-fork.c
+         ${LIBUV_TEST_DIR}/test-pipe-close-stdout-read-stdin.c)
     list(APPEND LIBUV_UTILS_TEST_SRCS ${TEST_CSRCS})
     nuttx_add_application(
       NAME

system/libuv/Makefile

@@ -144,7 +144,15 @@ CSRCS += runner.c
 CSRCS += runner-unix.c
 CSRCS += echo-server.c
 
-CSRCS += $(wildcard libuv/test/test-*.c)
+# test-fork.c and test-pipe-close-stdout-read-stdin.c call fork().  Every
+# test they define is already excluded from the task list on NuttX by
+# 0001-libuv-port-for-nuttx.patch, so they are dead code here.
+
+LIBUV_TEST_CSRCS  = $(wildcard libuv/test/test-*.c)
+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))
+
+CSRCS += $(LIBUV_TEST_CSRCS)
 endif
 
 ifneq ($(CONFIG_LIBUV_UTILS_BENCHMARK),)

testing/drivers/nand_sim/Kconfig

@@ -6,6 +6,7 @@
 config TESTING_NAND_SIM
 	boolean "NAND Flash Simulator"
 	depends on MTD_NAND_RAM && ENABLE_ALL_SIGNALS
+	depends on ARCH_HAVE_TASK_FORK || ARCH_HAVE_FORK
 	default n
 	---help---
 		Enable the NAND Flash Simulator device.

testing/drivers/nand_sim/nand_sim_main.c

@@ -25,7 +25,9 @@
  ****************************************************************************/
 
 #include <nuttx/debug.h>
+#include <sched.h>
 #include <stdio.h>
+#include <unistd.h>
 
 #include <nuttx/drivers/drivers.h>
 #include <nuttx/mtd/nand.h>
@@ -140,9 +142,16 @@ int main(int argc, FAR char *argv[])
   int   ret;
   pid_t pid;
 
-  /* Daemon */
+  /* task_fork() rather than fork():  this wants a clone that outlives the
+   * caller and shares its memory.  The fallback below covers a nuttx that
+   * does not have task_fork() yet.
+   */
 
-  pid = fork();
+#ifndef CONFIG_ARCH_HAVE_TASK_FORK
+#  define task_fork() fork()
+#endif
+
+  pid = task_fork();
 
   if (pid > 0)
     {

testing/fs/fdsantest/fdsantest_simple.c

@@ -96,6 +96,7 @@ static void test_case_overflow(void **state)
   assert_int_equal(open_count, close_count);
 }
 
+#if defined(CONFIG_ARCH_HAVE_VFORK) || defined(CONFIG_ARCH_HAVE_FORK)
 static void test_case_vfork(void **state)
 {
   int fd = open("/dev/null", O_RDONLY);
@@ -112,6 +113,7 @@ static void test_case_vfork(void **state)
 
   android_fdsan_close_with_tag(fd, 0xbadc0de);
 }
+#endif
 
 /****************************************************************************
  * Public Functions
@@ -129,7 +131,9 @@ int main(int argc, FAR char *argv[])
     cmocka_unit_test(test_case_unowned_tagged_close),
     cmocka_unit_test(test_case_owned_tagged_close),
     cmocka_unit_test(test_case_overflow),
+#if defined(CONFIG_ARCH_HAVE_VFORK) || defined(CONFIG_ARCH_HAVE_FORK)
     cmocka_unit_test(test_case_vfork),
+#endif
   };
 
   return cmocka_run_group_tests(tests, NULL, NULL);

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 AND NOT CONFIG_FORK_IS_TASK_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 ($(CONFIG_ARCH_HAVE_FORK)$(CONFIG_FORK_IS_TASK_FORK),)
+BLACKWORDS  += "[^v_]fork("
+endif
+
 BLACKWORDS  += "CHILD_MAX"
 BLACKWORDS  += "setpgid("
 BLACKWORDS  += "PTHREAD_SCOPE_PROCESS"

testing/ostest/CMakeLists.txt

@@ -143,10 +143,19 @@ if(CONFIG_TESTING_OSTEST)
     endif()
   endif()
 
-  if(CONFIG_ARCH_HAVE_FORK)
-    if(CONFIG_SCHED_WAITPID)
-      list(APPEND SRCS vfork.c)
-    endif()
+  # See testing/ostest/Makefile for why each test also accepts the symbol that
+  # stands in for it on a nuttx without the fork()/vfork() split.
+
+  if(CONFIG_ARCH_HAVE_TASK_FORK OR CONFIG_ARCH_HAVE_FORK)
+    list(APPEND SRCS task_fork.c)
+  endif()
+
+  if(CONFIG_ARCH_HAVE_VFORK OR (CONFIG_ARCH_HAVE_FORK AND CONFIG_SCHED_WAITPID))
+    list(APPEND SRCS vfork.c)
+  endif()
+
+  if(CONFIG_ARCH_HAVE_FORK AND CONFIG_ARCH_HAVE_VFORK)
+    list(APPEND SRCS fork.c)
   endif()
 
   if(CONFIG_ARCH_SETJMP_H)

testing/ostest/Makefile

@@ -144,10 +144,21 @@ CSRCS += sigev_thread.c
 endif
 endif
 
-ifeq ($(CONFIG_ARCH_HAVE_FORK),y)
-ifeq ($(CONFIG_SCHED_WAITPID),y)
+# Each test is built where the primitive it tests exists.  See ostest.h for
+# why each also accepts ARCH_HAVE_FORK, and why fork.c does not.
+
+ifneq ($(CONFIG_ARCH_HAVE_TASK_FORK)$(CONFIG_ARCH_HAVE_FORK),)
+CSRCS += task_fork.c
+endif
+
+ifeq ($(CONFIG_ARCH_HAVE_VFORK),y)
+CSRCS += vfork.c
+else ifeq ($(CONFIG_ARCH_HAVE_FORK)$(CONFIG_SCHED_WAITPID),yy)
 CSRCS += vfork.c
 endif
+
+ifeq ($(CONFIG_ARCH_HAVE_FORK)$(CONFIG_ARCH_HAVE_VFORK),yy)
+CSRCS += fork.c
 endif
 
 ifeq ($(CONFIG_ARCH_SETJMP_H),y)