“Simplify” the restart mechanism using $?

Instead of having two GNUmakefile rules which are present under
different conditions (and which could hypothetically both apply), just
have one and check to see which prerequisites are out·of·date in order
to adjust the behaviour.

In order to prevent unnecessary builds of metadata and parsed files
prior to a type update, wrap the recipes in a check to see if
`$(BUILDDIR)/.update-types` was created over the course of the build.
This needs to happen in the shell, not in Make, because older versions
of Make cache the `$(wildcard)` function. The implementation of
`$(unlesstypeswillupdate)` uses an `if` function instead of a `and`
because the latter seems to trim white·space.

It is no longer an error if the type of a file cannot be determined;
this is required to enable recipe expansion when types are not yet
generated now that the test is happening in the shell. Instead, files
are given a default type of `application/octet-stream`.

diff --git a/GNUmakefile b/GNUmakefile
index a41fb96cbd042c98a9c4de3db24f25d2b604277f..78f9a41d4d1cd69fd09eef546ed32b3814453576 100644 (file)
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -269,6 +269,9 @@ override space := $(empty) $(empty)
 # A variable which contains a single comma.
 override comma := ,
 
+# (callable) Make empty strings non·empty, and non·empty strings empty.
+override not = $(if $1,,1)
+
 # (callable) Quote the given string for use within shell calls.
 override quote = '$(subst ','"'"',$1)'
 
@@ -379,7 +382,7 @@ override plaintextfiles := $(filter-out $(xmlfiles),$(call filesoftype,$(plainte
 override assetfiles := $(filter-out $(xmlfiles) $(plaintextfiles),$(sourcefiles) $(sourceincludes))
 
 # (callable) Get the types of the given files.
-override typeoffile = $(foreach file,$1,$(or $(patsubst $(file)|%,%,$(filter $(file)|%,$(types))),$(error Unable to get type of file `$(file)´)))
+override typeoffile = $(foreach file,$1,$(or $(patsubst $(file)|%,%,$(filter $(file)|%,$(types))),application/octet-stream))
 
 # Pair each source magic file with its location in the build directory.
 override magicpair := $(foreach magicfile,$(MAGIC),$(magicfile)|$(BUILDDIR)/magic/$(call namehash,$(magicfile)))
@@ -414,7 +417,7 @@ override sourcefile = $(foreach local,$1,$(patsubst %|$(local),%,$(filter %|$(lo
 #
 # This file is created before a reload due to type changes, and is removed after.
 # This ensures that file classifications are up·to·date immediately after the reload.
-override typeupdates := $(if $(wildcard $(BUILDDIR)/.update-types),FORCE,)
+override typeupdates := $(and $(wildcard $(BUILDDIR)/.update-types),FORCE)
 
 # Pair each source file and include with its metadata location.
 override sourcemetadatapair := $(foreach file,$(sourcefiles) $(sourceincludes),$(file)|$(BUILDDIR)/$(if $(filter $(file),$(sourceincludes)),includes.metadata/$(call includepath,$(file)),sources.metadata/$(call sourcepath,$(file))))
@@ -519,6 +522,9 @@ override wrapplaintext = { $(PRINTF) '%s\n%s' '<?xml version="1.0"?>' '<script x
 # This isn’t a perfect substitution (it makes some assumptions about the format of the underlying X·M·L), but it should be workable for most sensible, welformed files.
 override serializexml = $(SED) "$$($(PRINTF) '%b' '/<?xml[ \t]\\{1,\\}version=[\0042\0047]1.1/,$${ s/<?xml[^>]*?>/<!--<?xml version=\00421.1\0042?>-->/\n s/&\0043x0*[12345678BCEFbcef];/\0302\0221/g\n s/&\0043x0*1[0123456789ABCDEFabcdef];/\0302\0221/g\n s/&\00430*[12345678];/\0302\0221/g\n s/&\00430*1[12456789];/\0302\0221/g\n s/&\00430*2[0123456789];/\0302\0221/g\n s/&\00430*3[01];/\0302\0221/g\n}')" <$(call quote,$1) | $(SED) "$$($(PRINTF) '%b' ':a\n/^\\n*$$/{ $$d\n N\n ba\n}')"
 
+# (callable) Wraps the provided shell script in a conditional which checks whether a make restart caused by `$(BUILDDIR)/.update-types´ is imminent (i·e, it was created during the course of this run) and only executes the script if it is not.
+override unlesstypeswillupdate = $(if $(call not,$(typeupdates)),if $(TEST) ! -e $(call quote,$(BUILDDIR)/.update-types); then ,)$1$(and $(call not,$(typeupdates)),; fi)
+
 # ─ ¶ Phony Targets ───────────────────────────────────────────────────
 
 # Compile all files, or error if any are recursive.
@@ -571,37 +577,12 @@ FORCE : ;
 # Phony rules; always consider these out·of·date.
 .PHONY : FORCE all default clean gone info install list listout uninstall $(call built,$(recursivefiles)) ;
 
-ifneq ($(typeupdates)$(wildcard $(BUILDDIR)/metadata),)
-# Reload this make·file if the dependency graph or output destinations have changed.
-#
-# The dependency graph and output destinations are used to set the values of variables in this make·file, so it’s important to ensure that they are actually up·to·date prior to executing any later rules.
-#
-# This recipe only exists after types have been updated or when the metadata file exists, to avoid unnecessarily executing it when parsers need updating.
-#
-# ※ There is a chance that generating the dependencies will also update the parsers.
-$(THISDIR)/GNUmakefile :: $(BUILDDIR)/dependencies $(BUILDDIR)/destinations
-       $(silent)$(TOUCH) $(THISDIR)/GNUmakefile
-ifeq ($(typeupdates),)
-       $(call inform,if $(TEST) ! -f $(call quote,$(BUILDDIR)/.update-types); then $(PRINTF) '%b\n' '\0033[1mDependency graph and output destinations updated. Restarting…\0033[22m' >&2; fi)
-else
-       $(silent)$(RM) $(call quote,$(BUILDDIR)/.update-types)
-       $(call inform,$(PRINTF) '%b\n' '\0033[1mDependency graph and output destinations updated. Restarting…\0033[22m' >&2)
-endif
-endif
-
-ifeq ($(typeupdates),)
-# Reload this make·file if any of the magic files or parsers have changed.
+# Reload this make·file if the magic file, parser, dependencies, or destinations have changed.
 #
-# These are used to classify source files, so if they have changed then the make·file must be reloaded.
-#
-# This recipe sleeps for one second to ensure that files built after the restart have a more current time·stamp.
-$(THISDIR)/GNUmakefile :: $(BUILDDIR)/magic.mgc $(BUILDDIR)/parser.xslt
+# If the magic file or parser changed, then another restart will be required, as the dependencies and destinations will need to be regenerated.
+$(THISDIR)/GNUmakefile : $(BUILDDIR)/magic.mgc $(BUILDDIR)/parser.xslt $(BUILDDIR)/dependencies $(BUILDDIR)/destinations
        $(silent)$(TOUCH) $(THISDIR)/GNUmakefile
-       $(silent)$(RM) -f $(call quote,$(BUILDDIR)/dependencies) $(call quote,$(BUILDDIR)/destinations)
-       $(call inform,$(PRINTF) '%b\n' '\0033[1mMagic file or parsers have updated. Restarting…\0033[22m' >&2)
-       $(silent)$(SLEEP) 1
-       $(silent)$(TOUCH) $(call quote,$(BUILDDIR)/.update-types)
-endif
+       $(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))
 
 # ─ ¶ Build Targets ───────────────────────────────────────────────────
 
@@ -633,29 +614,30 @@ $(BUILDDIR)/parser.xslt : $(BUILDDIR)/parser.catalog $(THISDIR)/lib/catalog2pars
 # Generate R·D·F metadata for files.
 #
 # This “depends” on `$(THISDIR)/lib/expandmetadata.xslt´ not because it is an actual dependency, but because a change to that file strongly suggests a change to these rules has occurred as well.
+#
+# If the types have been updated but `typeupdates´ is not active, this recipe is skipped because a restart is forthcoming.
 $(call metadata,$(sourcefiles) $(sourceincludes)) : % : $$(call datadata,$$@) $(THISDIR)/lib/expandmetadata.xslt $(typeupdates)
-       $(call inform,$(PRINTF) '%s\n' $(call quote,Generating metadata for `$<´…) >&2)
-       $(silent)$(call ensuredirectory,$(dir $@))
-       $(silent){ if $(TEST) ! -f $(call quote,$(BUILDDIR)/.mtime); then $(PRINTF) '%b' '\n' >|$(call quote,$(BUILDDIR)/.mtime); fi; $(TOUCH) -r $(call quote,$<) $(call quote,$(BUILDDIR)/.mtime); $(DIFF) -u $(call quote,$(BUILDDIR)/.mtime) /dev/null | $(SED) '1!d;s/.*   \([^ ]*\) \([^ ]*\).*$$/\1T\2Z/'; $(CKSUM) $(call quote,$<) | $(SED) 's/[ ].*//'; } | $(xargsmultiquote) | $(XARGS) -E '' $(PRINTF) '<?xml version="1.0"?><书社vocab:$(if $(filter $<,$(sourceincludes)),IncludeFile,SourceFile) 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:" rdf:about="%s" 书社vocab:path="%s"><nie:interpretedAs>$(if $(filter $<,$(assetfiles)),<nfo:InformationElement nie:mimeType="%s"/>,<nfo:PlainTextDocument nie:mimeType="%s"/>)</nie:interpretedAs><nfo:fileLastModified rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">%s</nfo:fileLastModified><nfo:hasHash nfo:hashAlgorithm="CRC32" nfo:hashValue="%s"/></书社vocab:$(if $(filter $<,$(sourceincludes)),IncludeFile,SourceFile)>' $(call quote,$(call attresc,$(call localuri,$<))) $(call quote,$(call attresc,$(if $(filter $<,$(sourceincludes)),$(call includepath,$<),$(call sourcepath,$<)))) $(call quote,$(call attresc,$(call typeoffile,$<))) >|$(call quote,$@)
+       $(call inform,$(call unlesstypeswillupdate,$(PRINTF) '%s\n' $(call quote,Generating metadata for `$<´…) >&2))
+       $(silent)$(call unlesstypeswillupdate,$(call ensuredirectory,$(dir $@)); { if $(TEST) ! -f $(call quote,$(BUILDDIR)/.mtime); then $(PRINTF) '%b' '\n' >|$(call quote,$(BUILDDIR)/.mtime); fi; $(TOUCH) -r $(call quote,$<) $(call quote,$(BUILDDIR)/.mtime); $(DIFF) -u $(call quote,$(BUILDDIR)/.mtime) /dev/null | $(SED) '1!d;s/.*   \([^ ]*\) \([^ ]*\).*$$/\1T\2Z/'; $(CKSUM) $(call quote,$<) | $(SED) 's/[ ].*//'; } | $(xargsmultiquote) | $(XARGS) -E '' $(PRINTF) '<?xml version="1.0"?><书社vocab:$(if $(filter $<,$(sourceincludes)),IncludeFile,SourceFile) 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:" rdf:about="%s" 书社vocab:path="%s"><nie:interpretedAs>$(if $(filter $<,$(assetfiles)),<nfo:InformationElement nie:mimeType="%s"/>,<nfo:PlainTextDocument nie:mimeType="%s"/>)</nie:interpretedAs><nfo:fileLastModified rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">%s</nfo:fileLastModified><nfo:hasHash nfo:hashAlgorithm="CRC32" nfo:hashValue="%s"/></书社vocab:$(if $(filter $<,$(sourceincludes)),IncludeFile,SourceFile)>' $(call quote,$(call attresc,$(call localuri,$<))) $(call quote,$(call attresc,$(if $(filter $<,$(sourceincludes)),$(call includepath,$<),$(call sourcepath,$<)))) $(call quote,$(call attresc,$(call typeoffile,$<))) >|$(call quote,$@))
 
 # Parse the files.
 #
 # Even plain X·M·L files are parsed, because they may contain X·H·T·M·L `<script>´ elements which contain other kinds of data.
 # Asset files are turned into H·T·M·L embeds pointing to `data:´ U·R·I’s.
+#
+# If the types have been updated but `typeupdates´ is not active, this recipe is skipped because a restart is forthcoming.
 $(call parsed,$(sourcefiles) $(sourceincludes)) : % : $$(call unparsed,$$@) $(BUILDDIR)/parser.xslt $(typeupdates)
-       $(call inform,$(PRINTF) '%s\n' $(call quote,Processing `$<´…) >&2)
-       $(silent)$(call ensuredirectory,$(dir $@))
-       $(silent)$(if $(filter $<,$(assetfiles)),$(PRINTF) '%s\n' $(call quote,<?xml version="1.0"?><object xmlns="http://www.w3.org/1999/xhtml" type="$(call typeoffile,$<)" data="$(call datauri,$<)"/>) >|$(call quote,$@),$(if $(filter $<,$(plaintextfiles)),$(call wrapplaintext,$<),$(call serializexml,$<)) | $(XSLTPROC) --nonet --novalid --nomkdir --nowrite --stringparam BUILDTIME $$($(DATE) -u '+%Y-%m-%dT%H:%M:%SZ') --stringparam IDENTIFIER $(call quote,$(call localuri,$<))$(if $(THISREV), --stringparam THISREV $(call quote,$(THISREV)),)$(if $(SRCREV), --stringparam SRCREV $(call quote,$(SRCREV)),) $(call quote,$(BUILDDIR)/parser.xslt) - >|$(call quote,$@))
+       $(call inform,$(call unlesstypeswillupdate,$(PRINTF) '%s\n' $(call quote,Processing `$<´…) >&2))
+       $(silent)$(call unlesstypeswillupdate,$(call ensuredirectory,$(dir $@)); $(if $(filter $<,$(assetfiles)),$(PRINTF) '%s\n' $(call quote,<?xml version="1.0"?><object xmlns="http://www.w3.org/1999/xhtml" type="$(call typeoffile,$<)" data="$(call datauri,$<)"/>) >|$(call quote,$@),$(if $(filter $<,$(plaintextfiles)),$(call wrapplaintext,$<),$(call serializexml,$<)) | $(XSLTPROC) --nonet --novalid --nomkdir --nowrite --stringparam BUILDTIME $$($(DATE) -u '+%Y-%m-%dT%H:%M:%SZ') --stringparam IDENTIFIER $(call quote,$(call localuri,$<))$(if $(THISREV), --stringparam THISREV $(call quote,$(THISREV)),)$(if $(SRCREV), --stringparam SRCREV $(call quote,$(SRCREV)),) $(call quote,$(BUILDDIR)/parser.xslt) - >|$(call quote,$@)))
 
 # Collect the metadata into a single file, and generate the dependencies and destinations files as side·effects.
 #
 # Doing this all in one step reduces the number of calls to `xsltproc´ required, but requires that it be called from the build directory (necessitating a subshell).
-$(BUILDDIR)/metadata : $(call diffprereqs,metadatas,$(call metadata,$(sort $(sourcefiles) $(sourceincludes)))) $(call parsed,$(filter-out $(assetfiles),$(sourcefiles) $(sourceincludes))) $(THISDIR)/lib/expandmetadata.xslt
-       $(call inform,$(PRINTF) '%s\n' 'Compiling metadata…' >&2)
-       $(silent){ $(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,$(BUILDDIR)/metadata)
-
-# The dependencies and destinations files are side·effects of building the metadata file.
-$(BUILDDIR)/dependencies $(BUILDDIR)/destinations : $(BUILDDIR)/metadata ;
+#
+# If the types have been updated but `typeupdates´ is not active, this recipe is skipped because a restart is forthcoming.
+$(BUILDDIR)/dependencies $(BUILDDIR)/destinations $(BUILDDIR)/metadata : $(call diffprereqs,metadatas,$(call metadata,$(sort $(sourcefiles) $(sourceincludes)))) $(call parsed,$(filter-out $(assetfiles),$(sourcefiles) $(sourceincludes))) $(THISDIR)/lib/expandmetadata.xslt
+       $(call inform,$(call unlesstypeswillupdate,$(PRINTF) '%s\n' 'Compiling metadata…' >&2))
+       $(silent)$(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.
 $(BUILDDIR)/transform.catalog : $(call diffprereqs,transforms,$(sort $(TRANSFORMS)))