From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Wed, 13 Nov 2019 22:12:10 +0000 (+0000)
Subject: Documentation for clean.sd.mk and cdeps.sd.mk
X-Git-Tag: subdirmk/0.1~43
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ian/git?p=subdirmk.git;a=commitdiff_plain;h=5c99a7202fe6895190cbc7e3fdc0948e04ab73d1;hp=a2d0da0b0b2f40319d8787b98f5198f78303f85d

Documentation for clean.sd.mk and cdeps.sd.mk

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---

diff --git a/subdirmk/cdeps.sd.mk b/subdirmk/cdeps.sd.mk
index 5d58b6b..402e687 100644
--- a/subdirmk/cdeps.sd.mk
+++ b/subdirmk/cdeps.sd.mk
@@ -3,6 +3,18 @@
 #  Copyright 2019 Ian Jackson
 # SPDX-License-Identifier: LGPL-2.0-or-later
 
+&# Usage:
+&#   &:include subdirmk/cdeps.sd.mk
+&# (probably in Perdir.sd.mk)
+&#
+&# Arranges for automatic #include dependency tracking for
+&# C compilation.  The compiler is asked to write the dependencies to
+&#  .*.d and these are automatically included.
+&#
+&# There is a bug: if a #included file is deleted and all references
+&# in .c files to it removed, `make' will complain that it is needed
+&# and can't be built.  `make clean' will fix this.
+
 CDEPS_CFLAGS ?= -MD -MF $(*D)/.$(*F).d
 
 &DEPFILES += $(foreach b,$(patsubst %.o,%,$(&OBJECTS)), \
diff --git a/subdirmk/clean.sd.mk b/subdirmk/clean.sd.mk
index e235fcd..08f8dcc 100644
--- a/subdirmk/clean.sd.mk
+++ b/subdirmk/clean.sd.mk
@@ -3,6 +3,18 @@
 #  Copyright 2019 Ian Jackson
 # SPDX-License-Identifier: LGPL-2.0-or-later
 
+&# Usage:
+&#   &:include subdirmk/clean.sd.mk
+&# (probably in Perdir.sd.mk)
+&#
+&# Provides a per-directory `clean' target, which deletes all the files
+&# in &CLEAN.  &OBJECTS, &DEPFILES and &TARGETS are automatically deleted.
+&#
+&# If you want to delete a directory, extend the target with
+&#   &/clean::
+&#	$(RM) -r somethingn
+&# ($(RM) conventionally contains `-f'.)
+
 &CLEAN += & *~ *.tmp
 &CLEAN += $(&OBJECTS)
 &CLEAN += $(&TARGETS)