build system: avoid full rebuild when EXTRAVERSION changes

The last two commits allow EXTRAVERSION to track the current state
of a git repository.  The build system was unable to determine
which files were affected by changes to EXTRAVERSION and caused
a full rebuild when it changed.

Alter how the version information is passed to the code so only
a handful of files need to be rebuilt when it changes.

7 files changed, 25 insertions, 2 deletions

diff --git a/Makefile b/Makefile
index c12b7791f..30a24f68e 100644
--- a/Makefile
+++ b/Makefile
@@ -892,7 +892,7 @@ endif
 # prepare2 creates a makefile if using a separate output directory
 prepare2: prepare3 outputmakefile
 
-prepare1: prepare2 include/config/MARKER
+prepare1: prepare2 include/config/MARKER include/BB_VER.h
 ifneq ($(KBUILD_MODULES),)
         $(Q)mkdir -p $(MODVERDIR)
         $(Q)rm -f $(MODVERDIR)/*
@@ -956,6 +956,13 @@ define filechk_version.h
         )
 endef
 
+define filechk_BB_VER.h
+        (echo \#define BB_VER \"$(KERNELRELEASE)\";)
+endef
+
+include/BB_VER.h: $(srctree)/Makefile .config .kernelrelease FORCE
+        $(call filechk,BB_VER.h)
+
 # ---------------------------------------------------------------------------
 
 PHONY += depend dep
@@ -1051,6 +1058,7 @@ CLEAN_FILES +=	busybox$(EXEEXT) busybox_unstripped* busybox.links \
 MRPROPER_DIRS  += include/config include2
 MRPROPER_FILES += .config .config.old include/asm .version .old_version \
                   include/NUM_APPLETS.h \
+                  include/BB_VER.h \
                   include/common_bufsiz.h \
                   include/autoconf.h \
                   include/bbconfigopts.h \
diff --git a/Makefile.flags b/Makefile.flags
index 8be999cb2..f24fd9475 100644
--- a/Makefile.flags
+++ b/Makefile.flags
@@ -17,7 +17,7 @@ CPPFLAGS += \
         $(if $(CONFIG_LFS),-D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64) \
         $(if $(CONFIG_TIME64),-D_TIME_BITS=64) \
         -DMINGW_VER=$(squote)$(quote)$(MINGW_VER)$(quote)$(squote) \
-        -DBB_VER=$(squote)$(quote)$(BB_VER)$(quote)$(squote)
+        $(if $(CONFIG_PLATFORM_MINGW32),,-DBB_VER=$(squote)$(quote)$(BB_VER)$(quote)$(squote))
 
 CFLAGS += $(call cc-option,-Wall,)
 CFLAGS += $(call cc-option,-Wshadow,)
diff --git a/archival/tar.c b/archival/tar.c
index bb82560b8..23ea02b5d 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -119,6 +119,9 @@
 #include "libbb.h"
 #include "common_bufsiz.h"
 #include "bb_archive.h"
+#if ENABLE_PLATFORM_MINGW32
+# include "BB_VER.h"
+#endif
 /* FIXME: Stop using this non-standard feature */
 #ifndef FNM_LEADING_DIR
 # define FNM_LEADING_DIR 0
diff --git a/editors/vi.c b/editors/vi.c
index b49d5454d..7ad8412a2 100644
--- a/editors/vi.c
+++ b/editors/vi.c
@@ -214,6 +214,9 @@
 #if ENABLE_FEATURE_VI_REGEX_SEARCH
 # include <regex.h>
 #endif
+#if ENABLE_PLATFORM_MINGW32
+# include "BB_VER.h"
+#endif
 
 // the CRASHME code is unmaintained, and doesn't currently build
 #define ENABLE_FEATURE_VI_CRASHME 0
diff --git a/libbb/messages.c b/libbb/messages.c
index 3c9d8683a..12079a2e0 100644
--- a/libbb/messages.c
+++ b/libbb/messages.c
@@ -5,6 +5,9 @@
  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 #include "libbb.h"
+#if ENABLE_PLATFORM_MINGW32
+# include "BB_VER.h"
+#endif
 
 /* allow version to be extended, via CFLAGS */
 #ifndef BB_EXTRA_VERSION
diff --git a/miscutils/bc.c b/miscutils/bc.c
index a82646674..31485ae9c 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -203,6 +203,9 @@
 
 #include "libbb.h"
 #include "common_bufsiz.h"
+#if ENABLE_PLATFORM_MINGW32
+# include "BB_VER.h"
+#endif
 
 #if !ENABLE_BC && !ENABLE_FEATURE_DC_BIG
 # include "dc.c"
diff --git a/networking/httpd.c b/networking/httpd.c
index c76ce3658..bd3a5a097 100644
--- a/networking/httpd.c
+++ b/networking/httpd.c
@@ -299,6 +299,9 @@
 
 #include "libbb.h"
 #include "common_bufsiz.h"
+#if ENABLE_PLATFORM_MINGW32
+# include "BB_VER.h"
+#endif
 #if ENABLE_PAM
 /* PAM may include <locale.h>. We may need to undefine bbox's stub define: */
 # undef setlocale