Makefile: Move conditionals into separate script

There is no portable syntax for conditionals and other more complex constructs, including shell scripts. This patch moves non-portable conditionals and other such parts into a separate script written in OCaml. The script itself is fully portable, it does not require GNU tools or even a POSIX shell. With this patch the main makefile becomes fully portable and currently works with GNU Make, BSD make, Solaris make and NMAKE.
tleedjarv · Dec 17, 2024 · af361f8 · af361f8
1 parent 035b8f3
commit af361f8
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Showing 7 changed files with 745 additions and 385 deletions.
diff --git a/Makefile b/Makefile
@@ -1,6 +1,15 @@
 # Unison file synchronizer: Makefile
 # See LICENSE for terms.
 
+# IMPORTANT!
+#
+# This file is portable and compatible with GNU Make, BSD make, Solaris
+# (d)make and NMAKE. Do not make any changes in this file unless you are
+# certain that the changes do not break this portability.
+
+default: all
+.PHONY: default
+
 # Sub-makefiles are perfectly fine for parallel builds.
 # This makefile is not, due to recursive invocations of make.
 .NOTPARALLEL:
@@ -9,85 +18,49 @@
 all: src manpage
 
 .PHONY: src
-src:
-	$(MAKE) -C src
+src: FRC
+	cd src && $(MAKE)
+FRC: ;
+# Not all make seem to work without FRC, even with .PHONY
+
+.PHONY: tui gui macui fsmonitor depend
+tui gui macui fsmonitor depend:
+	cd src && $(MAKE) $@
 
 # It's a wart that docs need "unison" built (vs some docs utility).
 .PHONY: docs
 docs: src manpage
-	$(MAKE) -C doc
+	cd doc && $(MAKE)
 
 # "src" is a prerequisite to prevent parallel build errors.
 # manpage builds currently require a pre-built "unison" binary.
 .PHONY: manpage
 manpage: src
-	$(MAKE) -C man
+	cd man && $(MAKE)
 
 .PHONY: test
-test: ./src/unison
-	./src/unison -ui text -selftest
-
-.PHONY: depend
-depend:
-	$(MAKE) -C src depend
+test:
+	ocaml src/make_tools.ml run ./src/unison -ui text -selftest
+# Note: unison binary is not built automatically for the test target,
+# so as to avoid building it with unwanted configuration.
 
+# This construct is here to remain compatible with make implementations
+# that do not have the -C option, work with different (also non-POSIX)
+# shells, and not rely on single shell per line execution.
 .PHONY: clean
-clean:
-	$(MAKE) -C doc clean
-	$(MAKE) -C man clean
-	$(MAKE) -C src clean
-
-INSTALL ?= install
-INSTALL_PROGRAM ?= $(INSTALL)
-INSTALL_DATA ?= $(INSTALL) -m 644
+clean: clean_doc clean_man clean_src
+.PHONY: clean_doc
+clean_doc:
+	cd doc && $(MAKE) clean
+.PHONY: clean_man
+clean_man:
+	cd man && $(MAKE) clean
+.PHONY: clean_src
+clean_src:
+	cd src && $(MAKE) clean
 
 prefix = /usr/local
-PREFIX ?= $(prefix)
-exec_prefix = $(PREFIX)
-EXEC_PREFIX ?= $(exec_prefix)
-bindir = $(EXEC_PREFIX)/bin
-BINDIR ?= $(bindir)
-datarootdir = $(PREFIX)/share
-DATAROOTDIR ?= $(datarootdir)
-mandir = $(DATAROOTDIR)/man
-MANDIR ?= $(mandir)
-man1dir = $(MANDIR)/man1
-MAN1DIR ?= $(man1dir)
-manext = .1
-MANEXT ?= $(manext)
 
 .PHONY: install
-install: all
-	$(INSTALL) -d "$(DESTDIR)$(BINDIR)"
-ifneq ($(wildcard src/unison),)
-	$(INSTALL_PROGRAM) src/unison "$(DESTDIR)$(BINDIR)/unison"
-endif
-ifneq ($(wildcard src/unison-gui),)
-	$(INSTALL_PROGRAM) src/unison-gui "$(DESTDIR)$(BINDIR)/unison-gui"
-endif
-ifneq ($(wildcard src/unison-fsmonitor),)
-	$(INSTALL_PROGRAM) src/unison-fsmonitor "$(DESTDIR)$(BINDIR)/unison-fsmonitor"
-else
-  ifneq ($(wildcard src/fsmonitor.py),)
-	$(INSTALL_PROGRAM) src/fsmonitor.py "$(DESTDIR)$(BINDIR)/fsmonitor.py"
-  endif
-endif
-ifneq ($(wildcard man/unison.1),)
-	$(INSTALL) -d "$(DESTDIR)$(MAN1DIR)"
-	$(INSTALL_DATA) man/unison.1 "$(DESTDIR)$(MAN1DIR)/unison$(MANEXT)"
-endif
-ifneq ($(wildcard src/uimac/build/Default/Unison.app),)
-	$(info !!! The GUI for macOS has been built but will NOT be installed automatically. \
-    You can find the built GUI package at $(abspath src/uimac/build/Default/Unison.app))
-endif
-
-# Delegate other targets to the sub-makefile
-.PHONY: Makefile
-
-./src/%:
-	$(MAKE) -C src $*
-
-%: FORCE
-	$(MAKE) -C src $@
-.PHONY: FORCE
-FORCE: ;
+install:
+	ocaml src/make_tools.ml install
diff --git a/src/.depend b/src/.depend
@@ -628,6 +628,8 @@ main.cmx : \
     remote.cmx \
     ubase/prefs.cmx \
     os.cmx
+make_tools.cmo :
+make_tools.cmx :
 name.cmo : \
     ubase/util.cmi \
     ubase/umarshal.cmi \

diff --git a/src/Makefile b/src/Makefile
@@ -1,39 +1,55 @@
 # Unison file synchronizer: src/Makefile
-# Copyright 1999-2023 (see ../LICENSE for terms).
+# Copyright 1999-2024 (see ../LICENSE for terms).
 
-## User Settings
-
-# Set NATIVE=false if you are not using the native code compiler (ocamlopt)
-# This is not advised, though: Unison runs much slower when byte-compiled.
-# Set NATIVE=true to force a native build, should auto-detection fail.
-NATIVE=auto
+# IMPORTANT!
+#
+# This file is portable and compatible with GNU Make, BSD make, Solaris
+# (d)make and NMAKE. Do not make any changes in this file unless you are
+# certain that the changes do not break this portability.
 
 ########################################################################
 ########################################################################
 #     (There should be no need to change anything from here on)       ##
 ########################################################################
 
-######################################################################
-# Building installation instructions
-
-.PHONY: all
-all: tui guimaybe macuimaybe fsmonitor
-
-########################################################################
-## Miscellaneous developer-only switches
-# [2023-05] This check is here only temporarily for a smooth transition
-ifeq ($(STATIC), true)
-  $(error Variable STATIC is no longer in use. Please set appropriate LDFLAGS,\
-    like -static, instead)
-endif
-
-# NAME, VERSION, and MAJORVERSION, automatically generated
--include Makefile.ProjectInfo
-
-########################################################################
-### Compilation rules
+default: all
+.PHONY: default
+
+# Executed only by BSD make
+.BEGIN:
+	@touch _mk.cfg
+	@ocaml make_tools.ml conf > Makefile.cfg
+	@ocaml make_tools.ml conf2 > Makefile2.cfg
+
+# Executed only by Solaris dmake
+.INIT:
+	@touch _mk.cfg
+	@ocaml make_tools.ml conf ASSUME_DMAKE=true > Makefile.cfg
+	@ocaml make_tools.ml conf2 ASSUME_DMAKE=true > Makefile2.cfg
+
+# Executed only by GNU Make and NMAKE
+Makefile.cfg: _mk.cfg
+	@ocaml make_tools.ml conf > Makefile.cfg
+	@ocaml make_tools.ml conf2 MAKE="$(MAKE)" > Makefile2.cfg
+_mk.cfg: ;
+
+TARGETS = all tui gui macui fsmonitor clean depend dependgraph paths
+FILES = unison unison.exe
+
+.NOTPARALLEL:
+.PHONY: $(TARGETS)
+$(TARGETS) $(FILES): Makefile.cfg
+	$(MAKE) -f Makefile.OCaml $@
+
+# Though not ideal, recursive make is needed here, in the name of portability.
+#
+# Directly including the freshly-generated Makefile.cfg could work with GNU
+# Make (when the target filename in the rule is guarded by $(MAKE_RESTARTS)
+# to prevent gmake from going into infinite loop), but fails with all other
+# make implementations. Solaris make, BSD make and NMAKE all read Makefile.cfg
+# before generating it (failing when *.cfg does not exist, reading stale
+# contents otherwise). "-include" instead of "include" is not portable.
 
-include Makefile.OCaml
 
 ######################################################################
 # For developers
@@ -55,19 +71,3 @@ tags:
 	  ; fi
 
 TAGS: tags
-
-######################################################################
-# Misc
-
-.PHONY: clean
-
-####################################################################
-# Documentation strings
-
-# Cons up a fake strings.ml if necessary (the real one is generated when
-# we build the documentation, but we need to be able to compile the
-# executable here to do that!)
-strings.ml:
-	echo "(* Dummy strings.ml *)" > strings.ml
-	echo "let docs = []" >> strings.ml
-