[dpdk-dev] [PATCH v3] mk: allow updates to build config on make install

[Thomas Monjalon <thomas.monjalon@6wind.com>]

From: Bruce Richardson <bruce.richardson@intel.com>

When running "make config", an additional config.orig file is also
generated, which is intended to hold the original, clean configuration
from the template.
When running make install, we first check if there is no existing
.config file, and run make config if not. If there is a file, we then
check if it's unmodified, in which case we regenerate a new .config to
take account of any possible updates to the template. Finally, in the
case where there is an existing .config file, and it HAS been modified,
we then do a check to see if the template has had further updates, and
throw an error if so. If no updates, we continue with the build using
the existing, user-modified config.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Signed-off-by: Thomas Monjalon <thomas.monjalon@6wind.com>
---
 mk/rte.sdkconfig.mk  |  1 +
 mk/rte.sdkinstall.mk | 13 +++++++++++++
 2 files changed, 14 insertions(+)

changes in v3:
- typos commented by Olivier
- compatibility with old builds without .orig
- prefix and suffix in tmp path
- remove tmp directory if no conflict

diff --git a/mk/rte.sdkconfig.mk b/mk/rte.sdkconfig.mk
index d0692e7..3124dce 100644
--- a/mk/rte.sdkconfig.mk
+++ b/mk/rte.sdkconfig.mk
@@ -74,6 +74,7 @@ $(RTE_OUTPUT)/.config: $(RTE_CONFIG_TEMPLATE) FORCE
 		-o $(RTE_OUTPUT)/.config_tmp $(RTE_CONFIG_TEMPLATE) ; \
 		if ! cmp -s $(RTE_OUTPUT)/.config_tmp $(RTE_OUTPUT)/.config; then \
 			cp $(RTE_OUTPUT)/.config_tmp $(RTE_OUTPUT)/.config ; \
+			cp $(RTE_OUTPUT)/.config_tmp $(RTE_OUTPUT)/.config.orig ; \
 		fi ; \
 		rm -f $(RTE_OUTPUT)/.config_tmp ; \
 	else \
diff --git a/mk/rte.sdkinstall.mk b/mk/rte.sdkinstall.mk
index 24b60cf..28eb662 100644
--- a/mk/rte.sdkinstall.mk
+++ b/mk/rte.sdkinstall.mk
@@ -58,6 +58,19 @@ install: $(INSTALL_TARGETS)
 	@echo ================== Installing $*
 	$(Q)if [ ! -f $(BUILD_DIR)/$*/.config ]; then \
 		$(MAKE) config T=$* O=$(BUILD_DIR)/$*; \
+	elif cmp -s $(BUILD_DIR)/$*/.config.orig $(BUILD_DIR)/$*/.config; then \
+		$(MAKE) config T=$* O=$(BUILD_DIR)/$*; \
+	else \
+		if [ -f $(BUILD_DIR)/$*/.config.orig ] ; then \
+			tmp_build=/tmp/dpdk-$*-$$$$; \
+			$(MAKE) config T=$* O=$$(tmp_build); \
+			if ! cmp -s $(BUILD_DIR)/$*/.config.orig $$(tmp_build)/.config ; then \
+				echo "Conflict: local config and template config have both changed"; \
+				exit 1; \
+			fi; \
+			rm -rf $$(tmp_build); \
+		fi; \
+		echo "Using local configuration"; \
 	fi
 	$(Q)$(MAKE) all O=$(BUILD_DIR)/$*
 
-- 
2.0.0