From f3d60905c4aa3b85e61a218e67903185c68f1074 Mon Sep 17 00:00:00 2001
From: Daniel Bosk <dbosk@kth.se>
Date: Thu, 11 Jan 2018 11:04:34 +0100
Subject: [PATCH 1/3] Adds SUBDIR_ALL to make it optional that all targets
 recurse

---
 subdir.mk.nw | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/subdir.mk.nw b/subdir.mk.nw
index e8b0f65..1559685 100644
--- a/subdir.mk.nw
+++ b/subdir.mk.nw
@@ -6,8 +6,15 @@ The subdirectories must be listed in the variable [[SUBDIR]], which holds
 a space-separated list of directory names.
 Then each subdirectory may in turn hold a new set of subdirectories to descend 
 into.
-We note that the subdirectories will be built in depth-first search order.
+We note that the subdirectories will be built in depth-first search order 
+(unless we allow parallel execution).
 
+By default, for any goals passed on the command line we will add the directories 
+in [[SUBDIR]] as prerequisites.
+This behaviour can be overridden by setting [[SUBDIR_ALL]] to anything different 
+from [[yes]].
+Like this we can add the subdirectories in [[SUBDIR]] as prerequisites manually 
+to only a subset of desired targets.
 
 \section{Implementation}
 
@@ -20,10 +27,15 @@ ifndef SUBDIR_MK
 SUBDIR_MK=true
 
 ifdef SUBDIR
-<<add subdirectories as prerequisites for the goals>>
 <<let the recipe for each subdirectory recurse into it>>
 endif
 
+SUBDIR_ALL?=yes
+
+ifeq (${SUBDIR_ALL},yes)
+<<add subdirectories as prerequisites for the goals>>
+endif
+
 endif
 @
 
@@ -35,7 +47,9 @@ with the goals specified on the command-line.
 <<let the recipe for each subdirectory recurse into it>>=
 ${SUBDIR}::
 	${MAKE} -C $@ ${MAKECMDGOALS}
-@ To ensure these recipes are run we need to ensure that they are prerequisites
+@
+
+To ensure these recipes are run we need to ensure that they are prerequisites
 to the goals.
 This also means that if no goals are given on the command-line, then we should 
 use the default goal.

From 64f6866ba3f12c265c27b723cb760be947cbc808 Mon Sep 17 00:00:00 2001
From: Daniel Bosk <dbosk@kth.se>
Date: Thu, 11 Jan 2018 11:05:59 +0100
Subject: [PATCH 2/3] Adds new precompiled version of subdir.mk

---
 subdir.mk | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/subdir.mk b/subdir.mk
index b689b61..2c6c54e 100644
--- a/subdir.mk
+++ b/subdir.mk
@@ -2,14 +2,19 @@ ifndef SUBDIR_MK
 SUBDIR_MK=true
 
 ifdef SUBDIR
+${SUBDIR}::
+	${MAKE} -C $@ ${MAKECMDGOALS}
+endif
+
+SUBDIR_ALL?=yes
+
+ifeq (${SUBDIR_ALL},yes)
 ifneq (${MAKECMDGOALS},)
 .PHONY: ${MAKECMDGOALS}
 ${MAKECMDGOALS}: ${SUBDIR}
 else
 ${.DEFAULT_GOAL}: ${SUBDIR}
 endif
-${SUBDIR}::
-	${MAKE} -C $@ ${MAKECMDGOALS}
 endif
 
 endif

From 87566175636a4868c280df90c94ec567488a867c Mon Sep 17 00:00:00 2001
From: Daniel Bosk <dbosk@kth.se>
Date: Thu, 11 Jan 2018 11:26:49 +0100
Subject: [PATCH 3/3] subdir.mk propagates INCLUDE_MAKEFILES as search path

We want to propagate the INCLUDE_MAKEFILES so that we only have to
modify the root Makefile in an old (MIUN) repo.
---
 subdir.mk    |  5 ++++-
 subdir.mk.nw | 11 +++++++++--
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/subdir.mk b/subdir.mk
index 2c6c54e..be687fc 100644
--- a/subdir.mk
+++ b/subdir.mk
@@ -1,9 +1,12 @@
 ifndef SUBDIR_MK
 SUBDIR_MK=true
 
+INCLUDE_MAKEFILES?=.
+
 ifdef SUBDIR
+.PHONY: ${SUBDIR}
 ${SUBDIR}::
-	${MAKE} -C $@ ${MAKECMDGOALS}
+	${MAKE} -C $@ -I ${INCLUDE_MAKEFILES} ${MAKECMDGOALS}
 endif
 
 SUBDIR_ALL?=yes
diff --git a/subdir.mk.nw b/subdir.mk.nw
index 1559685..95228ed 100644
--- a/subdir.mk.nw
+++ b/subdir.mk.nw
@@ -26,6 +26,8 @@ containing the space-separated list of subdirectories, exists.
 ifndef SUBDIR_MK
 SUBDIR_MK=true
 
+INCLUDE_MAKEFILES?=.
+
 ifdef SUBDIR
 <<let the recipe for each subdirectory recurse into it>>
 endif
@@ -45,9 +47,14 @@ the targets specified on the command-line, in all subdirectories listed in
 For each directory, we specify a recipe which runs make in the subdirectory 
 with the goals specified on the command-line.
 <<let the recipe for each subdirectory recurse into it>>=
+.PHONY: ${SUBDIR}
 ${SUBDIR}::
-	${MAKE} -C $@ ${MAKECMDGOALS}
-@
+	${MAKE} -C $@ -I ${INCLUDE_MAKEFILES} ${MAKECMDGOALS}
+@ We also want to give the sub-make access to our [[INCLUDE_MAKEFILES]], hence 
+the [[-I]] option.
+This is mostly due to (backwards) compatibility with the MIUN versions (see 
+\cref{miun.compat.mk}) of the makefiles, which pre-dates the 
+[[INCLUDE_MAKEFILES]] construction.
 
 To ensure these recipes are run we need to ensure that they are prerequisites
 to the goals.