Don’t recompile without transform/dependency change

Because any change to a file updates its metadata, and metadata is
a dependency of the main transform, changing any file used to require
recompiling all of them. This is needlessly expensive: Files should
only be recompiled for changes to files they actually depend on. (Of
course, files might have an undeclared dependency, but relying on this
is at user’s own risk.)

This commit changes compiled files to depend only on the transform
catalog, not the transform itself, and only the metadata of files they
depend on (which presumably will always be updated alongside the
files). The main transform itself is now a make·file prerequisite,
mirroring the main parser, to ensure it is always current even tho no
compilation properly depends on it anymore.

diff --git a/GNUmakefile b/GNUmakefile
index d0e4346fc6fb7a16212a372ab021f8739a253e29..c601097ab563bfa17a69c97bbfb5d495d985a65a 100644 (file)
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -619,12 +619,12 @@ FORCE : ;
 .PHONY : FORCE all clean gone help install list listout uninstall $(call built,$(recursivefiles)) ;
 
 ifeq ($(notbuilding),)
-# Reload this make·file if the magic file, parser, dependencies, or destinations have changed.
+# Reload this make·file if the magic file, parser, or transform have changed.
 #
 # If the magic file or parser changed, then another restart will be required, as the dependencies and destinations will need to be regenerated.
-$(THISDIR)/GNUmakefile : $(BUILDDIR)/magic.mgc $(BUILDDIR)/parser.xslt $(BUILDDIR)/dependencies $(BUILDDIR)/destinations
+$(THISDIR)/GNUmakefile : $(BUILDDIR)/magic.mgc $(BUILDDIR)/parser.xslt $(BUILDDIR)/transform.xslt
        $(silent)$(TOUCH) $(THISDIR)/GNUmakefile
-       $(if $(filter $(BUILDDIR)/magic.mgc $(BUILDDIR)/parser.xslt,$?),$(call inform,$(PRINTF) '%b\n' '\0033[1mMagic file or parsers have updated. Restarting…\0033[22m' >&2)$(newline)$(silent)$(SLEEP) 1,$(if $(typeupdates),$(silent)$(RM) $(call quote,$(BUILDDIR)/.update-types)$(newline),)$(call inform,$(PRINTF) '%b\n' '\0033[1mDependency graph and output destinations updated. Restarting…\0033[22m' >&2))
+       $(if $(filter $(BUILDDIR)/magic.mgc $(BUILDDIR)/parser.xslt,$?),$(call inform,$(PRINTF) '%b\n' '\0033[1mMagic file or parsers have updated. Restarting…\0033[22m' >&2)$(newline)$(silent)$(SLEEP) 1,$(if $(typeupdates),$(silent)$(RM) $(call quote,$(BUILDDIR)/.update-types)$(newline),)$(call inform,$(PRINTF) '%b\n' '\0033[1mDependency graph$(comma) output destinations$(comma) or transforms updated. Restarting…\0033[22m' >&2))
 endif
 
 # ─ ¶ Build Targets ───────────────────────────────────────────────────
@@ -681,6 +681,8 @@ $(BUILDDIR)/dependencies $(BUILDDIR)/destinations $(BUILDDIR)/metadata : $(call
        $(silent)$(call unlesstypeswillupdate,{ $(PRINTF) '<?xml version="1.0"?><rdf:RDF xmlns:nie="http://www.semanticdesktop.org/ontologies/2007/01/19/nie#" xmlns:nfo="http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:书社vocab="urn:fdc:ladys.computer:20231231:Shu1She4:vocab:"><书社vocab:BuildDirectory nfo:fileUrl="%s"/>' $(call quote,$(call attresc,$(call fileuri,$(BUILDDIR)))); {$(foreach meta,$(call metadata,$(sort $(sourcefiles) $(sourceincludes))), $(CAT) $(call quote,$(meta));) } | $(SED) 's/<?xml version="1.0"?>//g'; $(PRINTF) '%s\n' '</rdf:RDF>'; } | ( $(CD) $(call quote,$(BUILDDIR)); $(XSLTPROC) --nonet --novalid --nomkdir $(call quote,$(abspath $(THISDIR)/lib/expandmetadata.xslt)) - ) | $(XMLLINT) --nonet --nsclean - >|$(call quote,$(BUILDDIR)/metadata))
 
 # Generate the main transform.
+#
+# Because this depends on the metadata, it will also update the dependencies and destinations.
 $(BUILDDIR)/transform.catalog : $(call diffprereqs,transforms,$(sort $(TRANSFORMS)))
        $(call inform,$(PRINTF) '%s\n' 'Generating catalog of transforms…' >&2)
        $(silent)$(XMLCATALOG) --create --noout $(call quote,$@)
@@ -690,7 +692,14 @@ $(BUILDDIR)/transform.xslt : $(BUILDDIR)/transform.catalog $(BUILDDIR)/metadata
        $(silent)$(XSLTPROC) --nonet --novalid --nomkdir --nowrite --stringparam METADATA $(call quote,$(call fileuri,$(BUILDDIR))/metadata) $(call quote,$(THISDIR)/lib/catalog2transform.xslt) $(call quote,$<) >|$(call quote,$@)
 
 # Compile the result files using the dependencies as necessary.
-$(call compiled,$(compilablefiles)) : $(BUILDDIR)/results/% : $$(call parsed,$$(call uncompiled,$$@)) $$(call parsed,$$(call dependencies,$$(call uncompiled,$$@))) $(BUILDDIR)/transform.xslt $(TRANSFORMLIBS) $(BUILDDIR)/metadata
+#
+# Altho this (obviously) depends on the main transform, it is not listed as a prerequisite (rather, the main transform is listed as a prerequisite for the make·file writ large). This is because the transform will update after every metadata change (i·e, basically constantly), but compiled files should only actually be updated in two cases :⁠—
+#
+# • When one of the actual transforms are updated (tracked by `transform.catalog´), and
+# • When the metadata of ⹐source files they depend on⹑ change.
+#
+# This is to reduce the number of needless regenerations of files with no substantial change.
+$(call compiled,$(compilablefiles)) : $(BUILDDIR)/results/% : $$(call parsed,$$(call uncompiled,$$@)) $$(call parsed,$$(call dependencies,$$(call uncompiled,$$@))) $(BUILDDIR)/transform.catalog $(TRANSFORMLIBS) $$(call metadata,$$(call dependencies,$$(call uncompiled,$$@)))
        $(call inform,$(PRINTF) '%s\n' $(call quote,Compiling </$*>…) >&2)
        $(silent)$(call ensuredirectory,$(dir $@))
        $(silent)$(XSLTPROC) --nonet --novalid --nomkdir --nowrite --stringparam METADATA 'metadata' --stringparam BUILDTIME $$($(DATE) -u '+%Y-%m-%dT%H:%M:%SZ') --stringparam IDENTIFIER $(call quote,$(call localuri,$(call uncompiled,$@)))$(if $(THISREV), --stringparam THISREV $(call quote,$(THISREV)),)$(if $(SRCREV), --stringparam SRCREV $(call quote,$(SRCREV)),) $(call quote,$(BUILDDIR)/transform.xslt) $(call quote,$<) >|$(call quote,$@)