[PATCH] build: drop variable HAVE_EMACS. use WITH_EMACS instead

[David Bremner]

The extra flexibility of having both HAVE_EMACS (for yes, there is an
emacs we can use) and WITH_EMACS (the user wants emacs support) lead
to confusion and bugs. We now just force WITH_EMACS to 0 if no
suitable emacs is detected.
---
 configure            | 18 ++++++++----------
 doc/Makefile.local   |  6 +++---
 doc/conf.py          |  2 +-
 emacs/Makefile.local | 10 ++++------
 4 files changed, 16 insertions(+), 20 deletions(-)

diff --git a/configure b/configure
index 8b80f0e0..554e10c9 100755
--- a/configure
+++ b/configure
@@ -677,13 +677,14 @@ if [ -z "${EMACSETCDIR-}" ]; then
     EMACSETCDIR="\$(prefix)/share/emacs/site-lisp"
 fi
 
-printf "Checking if emacs (>= 24) is available... "
-if emacs --quick --batch --eval '(if (< emacs-major-version 24) (kill-emacs 1))' > /dev/null 2>&1; then
-    printf "Yes.\n"
-    have_emacs=1
-else
-    printf "No (so will not byte-compile emacs code)\n"
-    have_emacs=0
+if [ $WITH_EMACS = "1" ]; then
+    printf "Checking if emacs (>= 24) is available... "
+    if emacs --quick --batch --eval '(if (< emacs-major-version 24) (kill-emacs 1))' > /dev/null 2>&1; then
+        printf "Yes.\n"
+    else
+        printf "No (disabling emacs related parts of build)\n"
+        WITH_EMACS=0
+    fi
 fi
 
 have_doxygen=0
@@ -1165,9 +1166,6 @@ BASH_ABSOLUTE = ${bash_absolute}
 HAVE_PERL = ${have_perl}
 PERL_ABSOLUTE = ${perl_absolute}
 
-# Whether there's an emacs binary available for byte-compiling
-HAVE_EMACS = ${have_emacs}
-
 # Whether there's a sphinx-build binary available for building documentation
 HAVE_SPHINX=${have_sphinx}
 
diff --git a/doc/Makefile.local b/doc/Makefile.local
index d733b51e..b4e0c955 100644
--- a/doc/Makefile.local
+++ b/doc/Makefile.local
@@ -4,7 +4,7 @@ dir := doc
 
 # You can set these variables from the command line.
 SPHINXOPTS    := -q
-SPHINXBUILD   = HAVE_EMACS=${HAVE_EMACS} WITH_EMACS=${WITH_EMACS} sphinx-build
+SPHINXBUILD   = WITH_EMACS=${WITH_EMACS} sphinx-build
 DOCBUILDDIR      := $(dir)/_build
 
 # Internal variables.
@@ -29,8 +29,8 @@ MAN1_TEXI := $(patsubst $(srcdir)/doc/man1/%.rst,$(DOCBUILDDIR)/texinfo/%.texi,$
 MAN5_TEXI := $(patsubst $(srcdir)/doc/man5/%.rst,$(DOCBUILDDIR)/texinfo/%.texi,$(MAN5_RST))
 MAN7_TEXI := $(patsubst $(srcdir)/doc/man7/%.rst,$(DOCBUILDDIR)/texinfo/%.texi,$(MAN7_RST))
 INFO_TEXI_FILES := $(MAN1_TEXI) $(MAN5_TEXI) $(MAN7_TEXI)
-ifeq ($(HAVE_EMACS)$(WITH_EMACS),11)
-	INFO_TEXI_FILES := $(INFO_TEXI_FILES) $(DOCBUILDDIR)/texinfo/notmuch-emacs.texi
+ifeq ($(WITH_EMACS),1)
+	INFO_TEXI_FILES += $(DOCBUILDDIR)/texinfo/notmuch-emacs.texi
 endif
 
 INFO_INFO_FILES := $(INFO_TEXI_FILES:.texi=.info)
diff --git a/doc/conf.py b/doc/conf.py
index 8afff929..fc9738ff 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -32,7 +32,7 @@ exclude_patterns = ['_build']
 # If we don't have emacs (or the user configured --without-emacs),
 # don't build the notmuch-emacs docs, as they need emacs to generate
 # the docstring include files
-if os.environ.get('HAVE_EMACS') != '1' or os.environ.get('WITH_EMACS') != '1':
+if os.environ.get('WITH_EMACS') != '1':
     exclude_patterns.append('notmuch-emacs.rst')
 
 # The name of the Pygments (syntax highlighting) style to use.
diff --git a/emacs/Makefile.local b/emacs/Makefile.local
index 40b7c14f..141f5868 100644
--- a/emacs/Makefile.local
+++ b/emacs/Makefile.local
@@ -47,7 +47,7 @@ emacs_images := \
 emacs_bytecode = $(emacs_sources:.el=.elc)
 emacs_docstrings = $(emacs_sources:.el=.rsti)
 
-ifneq ($(HAVE_SPHINX)$(HAVE_EMACS),11)
+ifneq ($(HAVE_SPHINX)$(WITH_EMACS),11)
 docstring.stamp:
 	@echo "Missing prerequisites, not collecting docstrings"
 else
@@ -60,7 +60,7 @@ endif
 # the byte compiler may load an old .elc file when processing a
 # "require" or we may fail to rebuild a .elc that depended on a macro
 # from an updated file.
-ifeq ($(HAVE_EMACS),1)
+ifeq ($(WITH_EMACS),1)
 $(dir)/.eldeps: $(dir)/Makefile.local $(dir)/make-deps.el $(emacs_sources)
 	$(call quiet,EMACS) --directory emacs -batch -l make-deps.el \
 		-f batch-make-deps $(emacs_sources) > $@.tmp && \
@@ -82,7 +82,7 @@ $(dir)/notmuch-lib.elc: $(dir)/notmuch-version.elc
 endif
 CLEAN+=$(dir)/.eldeps $(dir)/.eldeps.tmp $(dir)/.eldeps.x
 
-ifeq ($(HAVE_EMACS),1)
+ifeq ($(WITH_EMACS),1)
 %.elc: %.el $(global_deps)
 	$(call quiet,EMACS) --directory emacs -batch -f batch-byte-compile $<
 %.rsti: %.el
@@ -103,10 +103,8 @@ endif
 	rm -r .elpa-build
 
 ifeq ($(WITH_EMACS),1)
-ifeq ($(HAVE_EMACS),1)
 all: $(emacs_bytecode) $(emacs_docstrings)
 install-emacs: $(emacs_bytecode)
-endif
 
 install: install-emacs
 endif
@@ -115,7 +113,7 @@ endif
 install-emacs: $(emacs_sources) $(emacs_images)
 	mkdir -p "$(DESTDIR)$(emacslispdir)"
 	install -m0644 $(emacs_sources) "$(DESTDIR)$(emacslispdir)"
-ifeq ($(HAVE_EMACS),1)
+ifeq ($(WITH_EMACS),1)
 	install -m0644 $(emacs_bytecode) "$(DESTDIR)$(emacslispdir)"
 endif
 	mkdir -p "$(DESTDIR)$(emacsetcdir)"
-- 
2.20.1