jw-pkg/make/cache.mk
Jan Lindemann f05e1ee0e3 make/[Makefile|*.mk): Improve variable caching
This commit aims at improving speed by using better caching.

  - Makefile, cache.mk: Split .cache.mk up

    To allow caching of runtime path variables which are
    project-specific, split .cache.mk up in .cache-project.mk and
    .cache-projects.mk

  - ldlibpath.mk: Cache ldlibpath, exepath and pythonpath

    Place the output of $(call proj_query ldlibpath), $(call
    proj_query, exepath) and $(call proj_query pythonpath) in
    JW_PKG_LD_LIBRARY_PATH, JW_PKG_EXE_PATH, and JW_PKG_PYTHON_PATH
    respectively, and cache the variables in make/.project-cache.mk.

  - cache.mk: Use = instead of :=

    Recursively expanded variables are nearly as fast as := variables
    if the assigned value is a fixed string. And sometimes it's not,
    rightly so, because variables get assigned below, as with
    JW_PKG_XXX for instance.

  - cache.mk: Use $(TOPDIR) as variable values

    Replace absolute references to project's topdir by $(TOPDIR) with
    sed. As soon as the project queries produce absolute paths, they
    will be transformed into relative paths which allow the code base
    to be moved to a different location and still remain functional
    without a rebuild.

Signed-off-by: Jan Lindemann <jan@janware.com>
2026-01-26 17:17:23 +01:00

39 lines
1.1 KiB
Makefile

# ----- define these variables
# CACHED_FILES = $(TOPDIR)/VERSION
# CACHED_VARS = VERSION
.PHONY: cache clean-cache clean-cache-projects
CACHE_PROJECT_MK ?= .cache-project.mk
CACHE_PROJECTS_MK ?= .cache-projects.mk
CACHE_FILES_MK = $(CACHE_PROJECT_MK) $(CACHE_PROJECTS_MK)
CACHED_VARS_ONLY_PROJECT ?= \
PROJECT \
PREREQ \
VERSION \
HEX_VERSION \
FULL_NAME \
JW_PKG_LD_LIBRARY_PATH \
JW_PKG_EXE_PATH \
JW_PKG_PYTHON_PATH
all: cache
clean: clean-cache
clean-cache:
rm -f $(CACHE_PROJECT_MK)
cache: $(CACHE_PROJECT_MK)
$(CACHE_PROJECT_MK): $(CACHED_FILES) $(JWBDIR)/make/cache.mk
@echo $(foreach v,$(CACHED_VARS),$v = $(value $(v))EOL) | \
$(SED) 's/EOL */\n/g;' | \
$(SED) 's|$(realpath $(TOPDIR))|$$(TOPDIR)|g' | \
$(SED) 's|$(realpath $(PROJECTS_DIR))|$$(PROJECTS_DIR)|g' | \
$(GREP) . | \
tee $@.tmp
mv $@.tmp $@
# -- Only used in jw-pkg
cache-projects: $(CACHE_PROJECTS_MK)
clean-cache-projects:
rm -f $(CACHE_PROJECTS_MK)
$(CACHE_PROJECTS_MK): $(CACHE_PROJECT_MK)
sed '/\($(subst $(space),\|,$(CACHED_VARS_ONLY_PROJECT))\)\s*[:?]\?=/ d' $< > $@.tmp
mv $@.tmp $@