Build system fixes related to INSTALL_LOCATION

* The build can't descend into external submodules when there is no
configure/RULES_TOP file present in $(INSTALL_LOCATION).
* Recreate modules/RELEASE.<host>.local if configure/CONFIG_SITE or
configure/CONFIG_SITE.local have changed.
* Move the distclean of modules/RELEASE.<host>.local to RULES_TOP
* Several comment and white-space changes

configure/RULES_MODULES

@@ -22,9 +22,11 @@
 #    7. Submodules must have a configure/CONFIG_SITE file that contains
 #           -include $(TOP)/../CONFIG_SITE.local
 
-# Add checked-out submodules to DIRS
-LIVE_SUBMODULES = $(subst /Makefile,,$(wildcard $(addsuffix /Makefile, $(SUBMODULES))))
-DIRS += $(LIVE_SUBMODULES)
+# Add checked-out submodules to DIRS, unless INSTALL_LOCATION is empty
+LIVE_SUBMODULES = $(subst /Makefile,, \
+    $(wildcard $(addsuffix /Makefile, $(SUBMODULES))))
+live = $(if $(wildcard $(INSTALL_CONFIG)/RULES_TOP),LIVE,DEAD)
+DIRS += $($(live)_SUBMODULES)
 
 include $(CONFIG)/RULES_DIRS
 
@@ -37,14 +39,12 @@ all host $(DIRS) $(ARCHS) $(ACTIONS) $(dirActionTargets) $(dirArchTargets) \
 # Convenience target
 RELEASE.host: $(RELEASE_LOCAL)
 
-$(RELEASE_LOCAL): Makefile CONFIG_SITE.local
+$(RELEASE_LOCAL): Makefile $(CONFIG)/CONFIG_SITE $(CONFIG)/CONFIG_SITE.local
 	$(ECHO) Creating $@ with
 	$(ECHO) "    $(PARENT_MODULE) = $(INSTALL_ABSOLUTE)"
 	@echo $(PARENT_MODULE) = $(INSTALL_ABSOLUTE)> $@
-realclean:
-	$(RM) $(wildcard RELEASE.*.local)
 
-.PHONY: RELEASE.host realclean
+.PHONY: RELEASE.host
 
 # Testing: Combine test failure logs from the live submodules
 TESTS_FAILED_LOGS = $(wildcard $(addsuffix /$(TESTS_FAILED_LOG), \

configure/RULES_TOP

@@ -23,17 +23,24 @@ ifndef DISABLE_TOP_RULES
   # Rules for a regular application top directory
   #
 
+  # When run by 'make distclean' the realuninstall target also
+  # removes any modules/RELEASE.<host>.local files
   distclean: realclean cvsclean realuninstall
 
   realuninstall: uninstallDirs
 	$(RMDIR) $(INSTALL_LOCATION_BIN) $(INSTALL_LOCATION_LIB)
+  ifeq (modules,$(filter modules,$(DIRS)))
+    ifeq (distclean,$(filter distclean,$(MAKECMDGOALS)))
+	$(RM) $(wildcard modules/RELEASE.*.local)
+    endif
+  endif
 
   UNINSTALL_DIRS += $(INSTALL_DB) $(INSTALL_DBD) $(INSTALL_DOC) $(INSTALL_HTML)
   UNINSTALL_DIRS += $(INSTALL_INCLUDE) $(INSTALL_TEMPLATES) $(DIRECTORY_TARGETS)
   ifneq ($(INSTALL_LOCATION),$(TOP))
     UNINSTALL_DIRS += $(INSTALL_CONFIG)
   endif
-uninstallDirs: | clean
+  uninstallDirs:
 	$(RMDIR) $(UNINSTALL_DIRS)
 
   # Remove the bin and lib directories if they have no sub-directories
@@ -41,12 +48,12 @@ uninstallDirs: | clean
   EMPTY_INSTALL_DIRS = \
       $(if $(wildcard $(INSTALL_LOCATION_BIN)/*),,$(INSTALL_LOCATION_BIN)) \
       $(if $(wildcard $(INSTALL_LOCATION_LIB)/*),,$(INSTALL_LOCATION_LIB))
-uninstall: archuninstall uninstallDirs | clean
+  uninstall: archuninstall uninstallDirs
 	$(RMDIR) $(EMPTY_INSTALL_DIRS)
 
   archuninstall: $(addprefix uninstall$(DIVIDER),$(BUILD_ARCHS))
 
-uninstall$(DIVIDER)%: | clean
+  uninstall$(DIVIDER)%:
 	$(RMDIR) $(addsuffix /$(subst uninstall$(DIVIDER),,$@), \
 	    $(INSTALL_LOCATION_BIN) $(INSTALL_LOCATION_LIB))
 
@@ -76,7 +83,6 @@ help:
 	@echo "     inc            - Installs header, dbd and html files"
 	@echo "     build          - Builds and installs all targets"
 	@echo "     install        - Builds and installs all targets"
-	@echo "     buildInstall   - Same as install (deprecated)"
 	@echo "     clean          - Removes the O.<arch> dirs created by running make"
 	@echo "                      In O.<arch> dir, clean removes build created files"
 	@echo "     realclean      - Removes ALL O.<arch> dirs"
@@ -101,7 +107,8 @@ ifndef DISABLE_TOP_RULES
 	@echo "     uninstall$(DIVIDER)<arch> - Remove bin & lib directories for <arch> only."
 	@echo "     uninstall      - Remove install directories created by this hostarch."
 	@echo "     realuninstall  - Removes ALL install dirs"
-	@echo "     distclean      - Same as realclean cvsclean realuninstall."
+	@echo "     distclean      - Does realclean cvsclean realuninstall and deletes any"
+	@echo "                      generated modules/RELEASE.<host>.local files"
 endif
 	@echo "     help           - Prints this list of valid make targets "
 	@echo "Object targets are supported by the O.<arch> level Makefile .e.g"

documentation/RELEASE_NOTES.md

@@ -16,6 +16,24 @@ should also be read to understand what has changed since earlier releases.
 
 <!-- Insert new items immediately below here ... -->
 
+### Build System updates
+
+The top-level make targets `uninstall`, `archuninstall` and similar no
+longer trigger the `clean` target which empties build directories, this
+was a bug introduced in 7.0.5.
+
+The `make distclean` target now properly deletes the generated file(s)
+`modules/RELEASE.<host>.local` which are essential to build the external
+submodules under the `modules` directory, and should not crash if the
+build is configured with `INSTALL_LOCATION` pointing to an empty external directory (i.e. if you run `make distclean` twice in succession). When
+`INSTALL_LOCATION` is set in the files `configure/CONFIG_SITE` or
+`configure/CONFIG_SITE.local` the `modules/RELEASE.<host>.local` file
+will now be regenerated in case the install path has been modified.
+
+Note that passing `INSTALL_LOCATION=<path>` on the make command-line will
+only work if you have run `make distclean` immediately beforehand, as the
+`modules/RELEASE.<host>.local` file must be recreated using the new path.
+
 ### Enhancements to `capr.pl`
 
 The `capr.pl` script can now display records from older Base versions to

modules/CONFIG_SITE.local

@@ -2,6 +2,16 @@
 # EPICS BASE is distributed subject to a Software License Agreement found
 # in file LICENSE that is included with this distribution.
 #*************************************************************************
+#
+#   modules/CONFIG_SITE.local
+#
+# Despite the .local in its name, this file *is* included in EPICS Base
+# sources and should *not* be modified by sites. This trick is necessary
+# to allow external submodules to be placed inside the modules directory
+# without having to modify them, as long as their configure/CONFIG_SITE
+# file includes the standard line
+#       -include $(TOP)/../CONFIG_SITE.local
+# that causes this file to be read in during submodule builds.
 
 # The name our submodules know us by:
 PARENT_MODULE = EPICS_BASE