[Buildroot] [PATCH 3 of 3 v2] uclibc: update-config: preserve freshly configured settings

[Thomas De Schampheleire <patrickdepinguin@gmail.com>]

In the sequence:

make uclibc-menuconfig
make uclibc-update-config

the freshly configured settings from the menuconfig are lost during the
update-config step. This is because update-config depends on the configure
step, which starts by copying the config file to the build directory.

Instead, stop depending on the configure step from update-config, and
introduce a new stamp file .stamp_config_fixup_done, which applies any
fixups on the .config file.
An alternative solution would be to add a call to UCLIBC_FIXUP_DOT_CONFIG to
the relevant targets instead of depending on a new stamp file, but this
would unnecessarily repeat the fixups on subsequent invocations of
update-config, for example.

No longer depending on the configure step has the added bonus that
'uclibc-update-config' no longer needs the toolchain to be available, which
makes:
    make clean uclibc-menuconfig uclibc-update-config
much faster and user-friendly.

Additionally, make sure that 'make clean uclibc-update-config' works
properly, by depending on .stamp_config_fixup_done so that the config file
is present and fixed.

Fixes bug #7154 https://bugs.busybox.net/show_bug.cgi?id=7154

Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>

---
v2:
- use $(Q)touch iso touch (Arnout)
- update commit message to clarify stamp file choice (Arnout)

rfc->patch:
- rebase
- rename .stamp_config_file_fixed into .stamp_config_fixup_done
- add dependency on .config from .stamp_config_file_fixed (Arnout)
- remove explicit call to UCLIBC_FIXUP_DOT_CONFIG from configure commands,
  and instead depend on .stamp_config_fixup_done.

 package/uclibc/uclibc.mk |  12 ++++++++----
 1 files changed, 8 insertions(+), 4 deletions(-)

diff -r a22b18c9a90d -r f2da132c93ad package/uclibc/uclibc.mk
--- a/package/uclibc/uclibc.mk	Sun Jun 22 10:37:22 2014 +0200
+++ b/package/uclibc/uclibc.mk	Mon Jun 16 20:18:23 2014 +0200
@@ -432,7 +432,6 @@
 endef
 
 define UCLIBC_CONFIGURE_CMDS
-	$(UCLIBC_FIXUP_DOT_CONFIG)
 	$(MAKE1) -C $(UCLIBC_DIR) \
 		$(UCLIBC_MAKE_FLAGS) \
 		PREFIX=$(STAGING_DIR) \
@@ -537,7 +536,11 @@
 $(UCLIBC_DIR)/.config: $(UCLIBC_CONFIG_FILE) | uclibc-patch
 	$(INSTALL) -m 0644 $(UCLIBC_CONFIG_FILE) $(UCLIBC_DIR)/.config
 
-$(UCLIBC_TARGET_CONFIGURE): $(UCLIBC_DIR)/.config
+$(UCLIBC_DIR)/.stamp_config_fixup_done: $(UCLIBC_DIR)/.config
+	$(UCLIBC_FIXUP_DOT_CONFIG)
+	$(Q)touch $@
+
+$(UCLIBC_TARGET_CONFIGURE): $(UCLIBC_DIR)/.stamp_config_fixup_done
 
 uclibc-menuconfig: $(UCLIBC_DIR)/.config
 	$(MAKE1) -C $(UCLIBC_DIR) \
@@ -546,9 +549,10 @@
 		DEVEL_PREFIX=/usr/ \
 		RUNTIME_PREFIX=$(STAGING_DIR)/ \
 		menuconfig
-	rm -f $(UCLIBC_DIR)/.stamp_{configured,built,target_installed,staging_installed}
+	rm -f $(UCLIBC_DIR)/.stamp_{config_fixup_done,configured,built}
+	rm -f $(UCLIBC_DIR)/.stamp_{target,staging}_installed
 
-uclibc-update-config: $(UCLIBC_DIR)/.stamp_configured
+uclibc-update-config: $(UCLIBC_DIR)/.stamp_config_fixup_done
 	cp -f $(UCLIBC_DIR)/.config $(UCLIBC_CONFIG_FILE)
 
 # Before uClibc is built, we must have the second stage cross-compiler