Make the lib/ subdirectory build more like other directories

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5025 42af7a65-404d-4744-a932-0658087f49c3

arch/Kconfig

@@ -20,7 +20,7 @@ config ARCH_ARM
 config ARCH_AVR
 	bool "AVR"
 	---help---
-		Atmel 9-bit bit AVR and 32-bit AVR32 architectures
+		Atmel 8-bit bit AVR and 32-bit AVR32 architectures
 
 config ARCH_HC
 	bool "Freescale HC"

drivers/serial/serial.c

@@ -241,7 +241,7 @@ static int uart_putxmitchar(FAR uart_dev_t *dev, int ch)
  * Name: uart_irqwrite
  ************************************************************************************/
 
-static ssize_t uart_irqwrite(FAR uart_dev_t *dev, FAR const char *buffer, size_t buflen)
+static inline ssize_t uart_irqwrite(FAR uart_dev_t *dev, FAR const char *buffer, size_t buflen)
 {
   ssize_t ret = buflen;
 
@@ -250,14 +250,17 @@ static ssize_t uart_irqwrite(FAR uart_dev_t *dev, FAR const char *buffer, size_t
   for (; buflen; buflen--)
     {
       int ch = *buffer++;
-      uart_putc(ch);
 
-     /* If this is the console, then we should replace LF with LF-CR */
+     /* If this is the console, then we should replace LF with CR-LF */
 
       if (ch == '\n')
         {
           uart_putc('\r');
         }
+
+      /* Output the character, using the low-level direct UART interfaces */
+
+      uart_putc(ch);
     }
 
   return ret;
@@ -274,14 +277,17 @@ static ssize_t uart_write(FAR struct file *filep, FAR const char *buffer, size_t
   ssize_t           nread  = buflen;
   int               ret;
 
-  /* We may receive console writes through this path from
+  /* We may receive console writes through this path from interrupt handlers and
-   * interrupt handlers and from debug output in the IDLE task!
+   * from debug output in the IDLE task!  In these cases, we will need to do things
-   * In these cases, we will need to do things a little
+   * a little differently.
-   * differently.
    */
 
   if (up_interrupt_context() || getpid() == 0)
     {
+      /* up_putc() will be used to generate the output in a busy-wait loop.
+       * up_putc() is only available for the console device.
+       */
+
       if (dev->isconsole)
         {
           irqstate_t flags = irqsave();
@@ -291,7 +297,7 @@ static ssize_t uart_write(FAR struct file *filep, FAR const char *buffer, size_t
         }
       else
         {
-          return ERROR;
+          return -EPERM;
         }
     }
 

lib/Makefile

@@ -34,6 +34,13 @@
 ###########################################################################
 
 -include $(TOPDIR)/Make.defs
+
+ASRCS =
+CSRCS =
+
+DEPPATH := --dep-path .
+VPATH := .
+
 include stdio/Make.defs
 include stdlib/Make.defs
 include unistd/Make.defs
@@ -52,41 +59,12 @@ include termios/Make.defs
 include queue/Make.defs
 include misc/Make.defs
 
-ASRCS = 
 AOBJS = $(ASRCS:.S=$(OBJEXT))
-
-CSRCS = $(STDIO_SRCS) $(STDLIB_SRCS) $(UNISTD_SRCS)  $(SCHED_SRCS) \
-		  $(STRING_SRCS) $(PTHREAD_SRCS) $(SEM_SRCS) $(SIG_SRCS) $(MQUEUE_SRCS) \
-		  $(MATH_SRCS) $(NET_SRCS) $(TIME_SRCS) $(LIBGEN_SRCS) \
-		  $(DIRENT_SRCS) $(TERMIOS_SRCS) \
-		  $(QUEUE_SRCS) $(MISC_SRCS) $(REGEX_SRCS) $(CRC_SRCS) $(DBG_SRCS) 
 COBJS = $(CSRCS:.c=$(OBJEXT))
 
 SRCS = $(ASRCS) $(CSRCS)
 OBJS = $(AOBJS) $(COBJS)
 
-ROOTDEPPATH	= --dep-path .
-STDIODEPPATH = --dep-path stdio
-STDLIBDEPPATH = --dep-path stdlib
-UNISTDDEPPATH = --dep-path unistd
-SCHEDDEPPATH = --dep-path sched
-STRINGDEPPATH = --dep-path string
-PTHREADDEPPATH = --dep-path pthread
-SEMDEPPATH = --dep-path semaphore
-SIGDEPPATH = --dep-path signal
-MQDEPPATH = --dep-path mqueue
-MATHDEPPATH = --dep-path math
-NETDEPPATH = --dep-path net
-TIMEDEPPATH = --dep-path time
-LIBGENDEPPATH = --dep-path libgen
-DIRENTDEPPATH = --dep-path dirent
-TERMIOSDEPPATH = --dep-path termios
-QUEUEDEPPATH = --dep-path queue
-MISCDEPPATH = --dep-path misc
-
-VPATH  = stdio:stdlib:unistd:sched:string:pthread:semaphore:signal:mqueue
-VPATH += :math:net:time:libgen:dirent:termios:queue:misc
-
 UBIN = libulib$(LIBEXT)
 KBIN = libklib$(LIBEXT)
 BIN  = liblib$(LIBEXT)
@@ -121,12 +99,7 @@ $(KBIN): uclean .kernlib
 endif
 
 .depend: Makefile $(SRCS)
-	@$(MKDEP) $(ROOTDEPPATH) $(STDIODEPPATH) $(STDLIBDEPPATH) \
+	@$(MKDEP) $(DEPPATH) $(CC) -- $(CFLAGS) -- $(SRCS) >Make.dep
-	  $(UNISTDDEPPATH) $(SCHEDDEPPATH) $(STRINGDEPPATH) $(PTHREADDEPPATH) \
-	  $(SEMDEPPATH) $(SIGDEPPATH) $(MQDEPPATH) $(MATHDEPPATH) $(NETDEPPATH)  \
-	  $(TIMEDEPPATH) $(LIBGENDEPPATH) $(DIRENTDEPPATH) $(TERMIOSDEPPATH) \
-	  $(QUEUEDEPPATH) $(MISCDEPPATH) \
-	  $(CC) -- $(CFLAGS) -- $(SRCS) >Make.dep
 	@touch $@
 
 depend: .depend

lib/dirent/Make.defs

@@ -33,8 +33,16 @@
 #
 ############################################################################
 
-DIRENT_SRCS = 
 ifneq ($(CONFIG_NFILE_DESCRIPTORS),0)
-DIRENT_SRCS += lib_readdirr.c lib_telldir.c
+
+# Add the dirent C files to the build
+
+CSRCS += lib_readdirr.c lib_telldir.c
+
+# Add the dirent directory to the build
+
+DEPPATH += --dep-path dirent
+VPATH += :dirent
+
 endif
 

lib/libgen/Make.defs

@@ -1,8 +1,8 @@
 ############################################################################
 # lib/libgen/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -33,5 +33,11 @@
 #
 ############################################################################
 
-LIBGEN_SRCS = lib_basename.c lib_dirname.c
+# Add the libgen C files to the build
 
+CSRCS += lib_basename.c lib_dirname.c
+
+# Add the libgen directory to the build
+
+DEPPATH += --dep-path libgen
+VPATH += :libgen

lib/math/Make.defs

@@ -1,8 +1,8 @@
 ############################################################################
 # lib/math/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -33,5 +33,11 @@
 #
 ############################################################################
 
-MATH_SRCS = lib_rint.c lib_fixedmath.c lib_b16sin.c lib_b16cos.c lib_b16atan2.c
+# Add the math C files to the build
 
+CSRCS += lib_rint.c lib_fixedmath.c lib_b16sin.c lib_b16cos.c lib_b16atan2.c
+
+# Add the math directory to the build
+
+DEPPATH += --dep-path math
+VPATH += :math

lib/misc/Make.defs

@@ -33,18 +33,23 @@
 #
 ############################################################################
 
-MISC_SRCS = lib_init.c lib_filesem.c
+# Add the internal C files to the build
+
+CSRCS += lib_init.c lib_filesem.c
 
 ifneq ($(CONFIG_NFILE_DESCRIPTORS),0)
 ifneq ($(CONFIG_NFILE_STREAMS),0)
-MISC_SRCS += lib_streamsem.c
+CSRCS += lib_streamsem.c
 endif
 endif
 
-REGEX_SRCS = lib_match.c
+# Add the miscellaneous C files to the build
 
-CRC_SRCS = lib_crc32.c
+CSRCS += lib_match.c
-
+CSRCS += lib_crc32.c
-DBG_SRCS = lib_dbg.c lib_dumpbuffer.c
+CSRCS += lib_dbg.c lib_dumpbuffer.c
 
+# Add the misc directory to the build
 
+DEPPATH += --dep-path misc
+VPATH += :misc

lib/mqueue/Make.defs

@@ -1,8 +1,8 @@
 ############################################################################
 # lib/mqueue/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -34,6 +34,15 @@
 ############################################################################
 
 ifneq ($(CONFIG_DISABLE_MQUEUE),y)
-MQUEUE_SRCS	= mq_setattr.c mq_getattr.c
+
+# Add the mqueue C files to the build
+
+CSRCS += mq_setattr.c mq_getattr.c
+
+# Add the mqueue directory to the build
+
+DEPPATH += --dep-path mqueue
+VPATH += :mqueue
+
 endif
 

lib/net/Make.defs

@@ -1,8 +1,8 @@
 ############################################################################
 # lib/net/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -33,5 +33,12 @@
 #
 ############################################################################
 
-NET_SRCS  = lib_etherntoa.c lib_htons.c lib_htonl.c lib_inetaddr.c
+# Add the networking C files to the build
-NET_SRCS += lib_inetntoa.c lib_inetntop.c lib_inetpton.c
+
+CSRCS += lib_etherntoa.c lib_htons.c lib_htonl.c lib_inetaddr.c
+CSRCS += lib_inetntoa.c lib_inetntop.c lib_inetpton.c
+
+# Add the net directory to the build
+
+DEPPATH += --dep-path net
+VPATH += :net

lib/pthread/Make.defs

@@ -1,8 +1,8 @@
 ############################################################################
 # lib/pthread/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -33,7 +33,9 @@
 #
 ############################################################################
 
-PTHREAD_SRCS = pthread_attrinit.c pthread_attrdestroy.c \
+# Add the pthread C files to the build
+
+CSRCS += pthread_attrinit.c pthread_attrdestroy.c \
 		  pthread_attrsetschedpolicy.c pthread_attrgetschedpolicy.c \
 		  pthread_attrsetinheritsched.c pthread_attrgetinheritsched.c \
 		  pthread_attrsetstacksize.c pthread_attrgetstacksize.c \
@@ -45,5 +47,10 @@ PTHREAD_SRCS = pthread_attrinit.c pthread_attrdestroy.c \
 		  pthread_mutexattrgetpshared.c pthread_mutexattrsetpshared.c
 
 ifeq ($(CONFIG_MUTEX_TYPES),y)
-PTHREAD_SRCS += pthread_mutexattrsettype.c pthread_mutexattrgettype.c
+CSRCS += pthread_mutexattrsettype.c pthread_mutexattrgettype.c
 endif
+
+# Add the pthread directory to the build
+
+DEPPATH += --dep-path pthread
+VPATH += :pthread

lib/queue/Make.defs

@@ -1,8 +1,8 @@
 ############################################################################
 # lib/queue/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -33,8 +33,15 @@
 #
 ############################################################################
 
-QUEUE_SRCS = sq_addlast.c sq_addfirst.c sq_addafter.c \
+# Add the queue C files to the build
+
+CSRCS += sq_addlast.c sq_addfirst.c sq_addafter.c \
 		  sq_rem.c sq_remlast.c sq_remfirst.c sq_remafter.c
 
-QUEUE_SRCS += dq_addlast.c dq_addfirst.c dq_addafter.c dq_addbefore.c \
+CSRCS += dq_addlast.c dq_addfirst.c dq_addafter.c dq_addbefore.c \
 		  dq_rem.c dq_remlast.c dq_remfirst.c
+
+# Add the queue directory to the build
+
+DEPPATH += --dep-path queue
+VPATH += :queue

lib/sched/Make.defs

@@ -1,8 +1,8 @@
 ############################################################################
 # lib/sched/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -33,6 +33,11 @@
 #
 ############################################################################
 
-SCHED_SRCS = sched_getprioritymax.c sched_getprioritymin.c
+# Add the sched C files to the build
 
+CSRCS += sched_getprioritymax.c sched_getprioritymin.c
 
+# Add the sched directory to the build
+
+DEPPATH += --dep-path sched
+VPATH += :sched

lib/semaphore/Make.defs

@@ -1,8 +1,8 @@
 ############################################################################
 # lib/semaphore/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -33,4 +33,11 @@
 #
 ############################################################################
 
-SEM_SRCS = sem_init.c sem_getvalue.c
+# Add the semaphore C files to the build
+
+CSRCS += sem_init.c sem_getvalue.c
+
+# Add the semaphore directory to the build
+
+DEPPATH += --dep-path semaphore
+VPATH += :semaphore

lib/signal/Make.defs

@@ -1,8 +1,8 @@
 ############################################################################
 # lib/signal/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -34,7 +34,14 @@
 ############################################################################
 
 ifneq ($(CONFIG_DISABLE_SIGNALS),y)
-SIG_SRCS = sig_emptyset.c sig_fillset.c sig_addset.c sig_delset.c sig_ismember.c
+
+# Add the signal C files to the build
+
+CSRCS += sig_emptyset.c sig_fillset.c sig_addset.c sig_delset.c sig_ismember.c
+
+# Add the signal directory to the build
+
+DEPPATH += --dep-path signal
+VPATH += :signal
+
 endif
-
-

lib/stdio/Make.defs

@@ -33,7 +33,9 @@
 #
 ############################################################################
 
-STDIO_SRCS = lib_fileno.c lib_printf.c lib_rawprintf.c lib_lowprintf.c \
+# Add the stdio C files to the build
+
+CSRCS += lib_fileno.c lib_printf.c lib_rawprintf.c lib_lowprintf.c \
 		  lib_sprintf.c lib_asprintf.c lib_snprintf.c lib_libsprintf.c \
 		  lib_vsprintf.c lib_avsprintf.c lib_vsnprintf.c lib_libvsprintf.c \
 		  lib_meminstream.c lib_memoutstream.c lib_lowinstream.c \
@@ -41,9 +43,9 @@ STDIO_SRCS = lib_fileno.c lib_printf.c lib_rawprintf.c lib_lowprintf.c \
 		  lib_nulloutstream.c lib_sscanf.c
 
 ifneq ($(CONFIG_NFILE_DESCRIPTORS),0)
-STDIO_SRCS += lib_rawinstream.c lib_rawoutstream.c
+CSRCS += lib_rawinstream.c lib_rawoutstream.c
 ifneq ($(CONFIG_NFILE_STREAMS),0)
-STDIO_SRCS += lib_fopen.c lib_fclose.c lib_fread.c lib_libfread.c lib_fseek.c \
+CSRCS += lib_fopen.c lib_fclose.c lib_fread.c lib_libfread.c lib_fseek.c \
 		   lib_ftell.c lib_fsetpos.c lib_fgetpos.c lib_fgetc.c lib_fgets.c \
 		   lib_gets.c lib_fwrite.c lib_libfwrite.c lib_fflush.c \
 		   lib_libflushall.c lib_libfflush.c lib_rdflush.c lib_wrflush.c \
@@ -53,13 +55,18 @@ endif
 endif
 
 ifeq ($(CONFIG_SYSLOG),y)
-STDIO_SRCS += lib_syslogstream.c
+CSRCS += lib_syslogstream.c
 endif
 
 ifeq ($(CONFIG_LIBC_FLOATINGPOINT),y)
-STDIO_SRCS += lib_dtoa.c
+CSRCS += lib_dtoa.c
 endif
 
 ifeq ($(CONFIG_STDIO_LINEBUFFER),y)
-STDIO_SRCS += lib_libnoflush.c
+CSRCS += lib_libnoflush.c
 endif
+
+# Add the stdio directory to the build
+
+DEPPATH += --dep-path stdio
+VPATH += :stdio

lib/stdio/lib_rawoutstream.c

@@ -72,7 +72,7 @@ static void rawoutstream_putc(FAR struct lib_outstream_s *this, int ch)
 
       /* The only expected error is EINTR, meaning that the write operation
        * was awakened by a signal.  Zero would not be a valid return value
-       * either.
+       * from write().
        */
 
       DEBUGASSERT(nwritten < 0 && get_errno() == EINTR);

lib/stdlib/Make.defs

@@ -33,6 +33,12 @@
 #
 ############################################################################
 
-STDLIB_SRCS = lib_abs.c lib_abort.c lib_imaxabs.c lib_labs.c lib_llabs.c \
+# Add the stdlib C files to the build
+
+CSRCS += lib_abs.c lib_abort.c lib_imaxabs.c lib_labs.c lib_llabs.c \
 		  lib_rand.c lib_qsort.c
 
+# Add the stdlib directory to the build
+
+DEPPATH += --dep-path stdlib
+VPATH += :stdlib

lib/string/Make.defs

@@ -33,7 +33,9 @@
 #
 ############################################################################
 
-STRING_SRCS	= lib_checkbase.c lib_isbasedigit.c lib_memset.c lib_memchr.c \
+# Add the string C files to the build
+
+CSRCS += lib_checkbase.c lib_isbasedigit.c lib_memset.c lib_memchr.c \
 		  lib_memccpy.c lib_memcpy.c lib_memcmp.c lib_memmove.c lib_skipspace.c \
 		  lib_strcasecmp.c lib_strcat.c lib_strchr.c lib_strcpy.c lib_strcmp.c \
 		  lib_strcspn.c lib_strdup.c lib_strerror.c lib_strlen.c lib_strnlen.c \
@@ -41,3 +43,8 @@ STRING_SRCS	= lib_checkbase.c lib_isbasedigit.c lib_memset.c lib_memchr.c \
 		  lib_strndup.c lib_strcasestr.c lib_strpbrk.c lib_strrchr.c\
 		  lib_strspn.c lib_strstr.c lib_strtok.c lib_strtokr.c lib_strtol.c \
 		  lib_strtoll.c lib_strtoul.c lib_strtoull.c lib_strtod.c
+
+# Add the string directory to the build
+
+DEPPATH += --dep-path string
+VPATH += :string

lib/termios/Make.defs

@@ -33,11 +33,22 @@
 #
 ############################################################################
 
-TERMIOS_SRCS =
+# termios.h support requires file descriptors and that CONFIG_SERIAL_TERMIOS
+# is defined
 
 ifneq ($(CONFIG_NFILE_DESCRIPTORS),0)
+ifeq ($(CONFIG_SERIAL_TERMIOS),y)
 
-TERMIOS_SRCS += lib_cfgetspeed.c lib_cfsetspeed.c lib_tcflush.c
+# Add the termios C files to the build
-TERMIOS_SRCS += lib_tcgetattr.c lib_tcsetattr.c
+
+CSRCS += lib_cfgetspeed.c lib_cfsetspeed.c lib_tcflush.c
+CSRCS += lib_tcgetattr.c lib_tcsetattr.c
+
+# Add the termios directory to the build
+
+DEPPATH += --dep-path termios
+VPATH += termios
 
 endif
+endif
+

lib/time/Make.defs

@@ -1,8 +1,8 @@
 ############################################################################
 # lib/time/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -33,5 +33,12 @@
 #
 ############################################################################
 
-TIME_SRCS = lib_mktime.c lib_gmtime.c lib_gmtimer.c lib_strftime.c \
+# Add the time C files to the build
+
+CSRCS += lib_mktime.c lib_gmtime.c lib_gmtimer.c lib_strftime.c \
 		  lib_calendar2utc.c lib_daysbeforemonth.c lib_isleapyear.c lib_time.c
+
+# Add the time directory to the build
+
+DEPPATH += --dep-path time
+VPATH += :time

lib/unistd/Make.defs

@@ -1,8 +1,8 @@
 ############################################################################
 # lib/unistd/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -33,10 +33,17 @@
 #
 ############################################################################
 
-UNISTD_SRCS = lib_getopt.c lib_getoptargp.c lib_getoptindp.c lib_getoptoptp.c
+# Add the unistd C files to the build
+
+CSRCS += lib_getopt.c lib_getoptargp.c lib_getoptindp.c lib_getoptoptp.c
+
 ifneq ($(CONFIG_NFILE_DESCRIPTORS),0)
 ifneq ($(CONFIG_DISABLE_ENVIRON),y)
-UNISTD_SRCS +=  lib_chdir.c lib_getcwd.c
+CSRCS +=  lib_chdir.c lib_getcwd.c
 endif
 endif
 
+# Add the unistd directory to the build
+
+DEPPATH += --dep-path unistd
+VPATH += :unistd