[lmi-commits] [lmi] master 3ff6c00 16/16: Rewrite for clarity

[Greg Chicares]

branch: master
commit 3ff6c0081ebfcf5987da3e15b6dcbd558cb67fd8
Author: Gregory W. Chicares <address@hidden>
Commit: Gregory W. Chicares <address@hidden>

    Rewrite for clarity
    
    There is no need for a phony target with a static name to create a file
    with a dynamic name. It is clearer to write a non-phony target that
    generates the file directly.
---
 gwc/parent.make | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/gwc/parent.make b/gwc/parent.make
index 8186415..81fd3eb 100644
--- a/gwc/parent.make
+++ b/gwc/parent.make
@@ -2,12 +2,13 @@
 # and export environment variables set by that script to make's
 # environment:
 #  - form a unique name $LMI_ENV_FILE for a file to hold the value
-#  - add a 'source_env_vars' prerequisite for the top-level makefile,
-#    with recipe "$(eval include $LMI_ENV_FILE)"
-#  - add a phony 'source_env_vars' target that sources the script
+#  - give the top-level makefile a target to remake itself, with
+#     - $(eval include $(LMI_ENV_FILE)) in its recipe, and
+#     - $(LMI_ENV_FILE) as a prerequisite
+#  - add a phony $(LMI_ENV_FILE) target that sources the script
 #  - make the script write 'make' assignments like "export foo := bar"
-#    for each desired environment variable to $LMI_ENV_FILE iff that
-#    filename is of nonzero length
+#    for each desired environment variable to a file named
+#    $LMI_ENV_FILE, iff that filename is of nonzero length
 # To test:
 #   $export LMI_IN=Russia;   make -f parent.make all
 #   $export LMI_IN=Mongolia; make -f parent.make all
@@ -15,13 +16,12 @@
 
 export LMI_ENV_FILE := env_$(shell date -u +'%s_%N').eraseme
 
-parent.make:: source_env_vars ;
+parent.make:: $(LMI_ENV_FILE)
        $(eval include $(LMI_ENV_FILE))
        @echo "'$$LMI_IN' --> '$$LMI_OUT1', '$$LMI_OUT2' : eval in 
'parent.make'"
        rm $(LMI_ENV_FILE)
 
-.PHONY: source_env_vars
-source_env_vars:
+$(LMI_ENV_FILE):
        @echo "Sourcing 'set.sh'"; \
        . ./set.sh ; \
        echo "'$$LMI_IN' --> '$$LMI_OUT1', '$$LMI_OUT2' : sourced in 
'parent.make'"