From 493e8a3a52bcdc1f7ccd2d4edf9cc221856373c4 Mon Sep 17 00:00:00 2001
From: Michael Ernst <mernst@cs.washington.edu>
Date: Sat, 10 Oct 2026 11:01:15 -0700
Subject: [PATCH 1/6] Use shell command substitution correctly in Makefiles

In a make recipe, $(cmd) is a make variable reference, not shell command
substitution; it must be written $$(cmd).  Outside a recipe, use $(shell cmd).
---
 tests/Makefile                          | 2 +-
 tests/Makefile.common                   | 2 +-
 tests/daikon-tests/junit/Makefile.user  | 2 +-
 tests/daikon-tests/junit5/Makefile.user | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/tests/Makefile b/tests/Makefile
index e238ef2bd2..f10e7c3beb 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -52,7 +52,7 @@ txt-chicory-diff everything-txt-diff stats dyncomp-diff txt-jaif-diff txt-jaif:
 	${MAKE} pat-daikon-tests-$@
 pat-daikon-tests-%:
 # Under CI, there are two CPUs, but limit to 1 to avoid out-of-memory error.
-	if [ -n "$("${PLUME_SCRIPTS}"/is-ci.sh)" ]; then \
+	if [ -n "$$("${PLUME_SCRIPTS}"/is-ci.sh)" ]; then \
 	  ${MAKE} -C daikon-tests --jobs=1 ${MPARG} $*; \
 	else \
 	  ${MAKE} -C daikon-tests --jobs=4 ${MPARG} $*; \
diff --git a/tests/Makefile.common b/tests/Makefile.common
index 38dde8e8cb..c151d000b3 100644
--- a/tests/Makefile.common
+++ b/tests/Makefile.common
@@ -187,7 +187,7 @@ ECLAT_SCRATCH = $(SCRATCH_FOR_DAIKON_BASE)/$(PROJECT)_eclat
 CP_PARENTS := rsync -aR
 
 ifeq ($(shell uname), Darwin)
-  JAVA_HOME ?= $(/usr/libexec/java_home)
+  JAVA_HOME ?= $(shell /usr/libexec/java_home)
 else
 ifeq ($(shell which javac > /dev/null 2>&1 && echo found || echo nonexistent), found)
   JAVA_HOME ?= $(shell readlink -f $(shell which javac) | sed "s:/bin/javac::")
diff --git a/tests/daikon-tests/junit/Makefile.user b/tests/daikon-tests/junit/Makefile.user
index 9c2889b925..20a6da71d7 100644
--- a/tests/daikon-tests/junit/Makefile.user
+++ b/tests/daikon-tests/junit/Makefile.user
@@ -1,7 +1,7 @@
 ###########################################################################
 
 ifeq ($(shell uname), Darwin)
-  JAVA_HOME ?= $(/usr/libexec/java_home)
+  JAVA_HOME ?= $(shell /usr/libexec/java_home)
 else
 ifeq ($(shell which javac > /dev/null 2>&1 && echo found || echo nonexistent), found)
   JAVA_HOME ?= $(shell readlink -f $(shell which javac) | sed "s:/bin/javac::")
diff --git a/tests/daikon-tests/junit5/Makefile.user b/tests/daikon-tests/junit5/Makefile.user
index d10d1f57d7..b820d37665 100644
--- a/tests/daikon-tests/junit5/Makefile.user
+++ b/tests/daikon-tests/junit5/Makefile.user
@@ -1,7 +1,7 @@
 ###########################################################################
 
 ifeq ($(shell uname), Darwin)
-  JAVA_HOME ?= $(/usr/libexec/java_home)
+  JAVA_HOME ?= $(shell /usr/libexec/java_home)
 else
 ifeq ($(shell which javac > /dev/null 2>&1 && echo found || echo nonexistent), found)
   JAVA_HOME ?= $(shell readlink -f $(shell which javac) | sed "s:/bin/javac::")

From 2164fed85c91c2fa9a45875549cc6cef0331ff51 Mon Sep 17 00:00:00 2001
From: Michael Ernst <mernst@cs.washington.edu>
Date: Sat, 10 Oct 2026 12:01:48 -0700
Subject: [PATCH 2/6] Fix remaining is-ci.sh substitutions; fail clearly if
 is-ci.sh is missing

---
 tests/Makefile               | 4 ++++
 tests/dyncomp-tests/Makefile | 6 +++++-
 tests/kvasir-tests/Makefile  | 9 +++++++--
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/tests/Makefile b/tests/Makefile
index f10e7c3beb..b8450521fc 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -34,6 +34,9 @@ else
   MPARG ?=
 endif
 
+ifeq ($(origin DAIKONDIR), undefined)
+  DAIKONDIR := $(realpath $(dir $(lastword $(MAKEFILE_LIST)))..)
+endif
 PLUME_SCRIPTS ?= ${DAIKONDIR}/.utils/plume-scripts
 
 all diffs: txt-diff non-txt-diff dyncomp-tests results
@@ -52,6 +55,7 @@ txt-chicory-diff everything-txt-diff stats dyncomp-diff txt-jaif-diff txt-jaif:
 	${MAKE} pat-daikon-tests-$@
 pat-daikon-tests-%:
 # Under CI, there are two CPUs, but limit to 1 to avoid out-of-memory error.
+	@test -x "${PLUME_SCRIPTS}"/is-ci.sh || { echo "Not found: ${PLUME_SCRIPTS}/is-ci.sh ; running 'make' in ${DAIKONDIR} clones it" >&2; exit 1; }
 	if [ -n "$$("${PLUME_SCRIPTS}"/is-ci.sh)" ]; then \
 	  ${MAKE} -C daikon-tests --jobs=1 ${MPARG} $*; \
 	else \
diff --git a/tests/dyncomp-tests/Makefile b/tests/dyncomp-tests/Makefile
index f3452923af..b2eaa8e885 100644
--- a/tests/dyncomp-tests/Makefile
+++ b/tests/dyncomp-tests/Makefile
@@ -18,6 +18,9 @@
 
 # Forked from $DAIKONDIR/tests/kvasir-tests/Makefile
 
+ifeq ($(origin DAIKONDIR), undefined)
+  DAIKONDIR := $(realpath $(dir $(lastword $(MAKEFILE_LIST)))../..)
+endif
 PLUME_SCRIPTS ?= ${DAIKONDIR}/.utils/plume-scripts
 
 default: summary
@@ -64,7 +67,8 @@ update-all:
 
 .PHONY: clean-all
 clean-all:
-	if [ -n "$("${PLUME_SCRIPTS}"/is-ci.sh)" ]; then \
+	@test -x "${PLUME_SCRIPTS}"/is-ci.sh || { echo "Not found: ${PLUME_SCRIPTS}/is-ci.sh ; running 'make' in ${DAIKONDIR} clones it" >&2; exit 1; }
+	if [ -n "$$("${PLUME_SCRIPTS}"/is-ci.sh)" ]; then \
 	  ${MAKE} --jobs=1 ${MPARG} nightly-tests__clean; \
 	else \
 	  ${MAKE} --jobs=4 ${MPARG} nightly-tests__clean; \
diff --git a/tests/kvasir-tests/Makefile b/tests/kvasir-tests/Makefile
index bff779dccc..7067317980 100644
--- a/tests/kvasir-tests/Makefile
+++ b/tests/kvasir-tests/Makefile
@@ -20,13 +20,17 @@ else
   MPARG ?=
 endif
 
+ifeq ($(origin DAIKONDIR), undefined)
+  DAIKONDIR := $(realpath $(dir $(lastword $(MAKEFILE_LIST)))../..)
+endif
 PLUME_SCRIPTS ?= ${DAIKONDIR}/.utils/plume-scripts
 
 default: summary-w-daikon
 
 .PHONY: regression-tests
 regression-tests:
-	if [ -n "$("${PLUME_SCRIPTS}"/is-ci.sh)" ]; then \
+	@test -x "${PLUME_SCRIPTS}"/is-ci.sh || { echo "Not found: ${PLUME_SCRIPTS}/is-ci.sh ; running 'make' in ${DAIKONDIR} clones it" >&2; exit 1; }
+	if [ -n "$$("${PLUME_SCRIPTS}"/is-ci.sh)" ]; then \
 	  ${MAKE} --jobs=1 ${MPARG} nightly-tests__diffs-w-daikon-if-working; \
 	else \
 	  ${MAKE} --jobs=4 ${MPARG} nightly-tests__diffs-w-daikon-if-working; \
@@ -80,7 +84,8 @@ update-all:
 
 .PHONY: clean-all
 clean-all:
-	if [ -n "$("${PLUME_SCRIPTS}"/is-ci.sh)" ]; then \
+	@test -x "${PLUME_SCRIPTS}"/is-ci.sh || { echo "Not found: ${PLUME_SCRIPTS}/is-ci.sh ; running 'make' in ${DAIKONDIR} clones it" >&2; exit 1; }
+	if [ -n "$$("${PLUME_SCRIPTS}"/is-ci.sh)" ]; then \
 	  ${MAKE} --jobs=1 ${MPARG} nightly-tests__clean; \
 	else \
 	  ${MAKE} --jobs=4 ${MPARG} nightly-tests__clean; \

From c86dd6e4cd7306f1c945ff4613618cecdd9e4af7 Mon Sep 17 00:00:00 2001
From: Michael Ernst <mernst@cs.washington.edu>
Date: Sat, 10 Oct 2026 12:41:49 -0700
Subject: [PATCH 3/6] Compute test job count once; robust JAVA_HOME; consistent
 DAIKONDIR; define MPARG

- Choose --jobs once at parse time (TEST_JOBS); a missing is-ci.sh means not under CI.
- Evaluate JAVA_HOME once, and fail clearly on macOS if no JDK is found.
- Use the same DAIKONDIR idiom in the kvasir-tests and dyncomp-tests Makefile.common.
- Define MPARG in tests/dyncomp-tests/Makefile.
---
 tests/Makefile                          | 11 ++++-------
 tests/Makefile.common                   | 10 ++++++++--
 tests/daikon-tests/junit/Makefile.user  | 10 ++++++++--
 tests/daikon-tests/junit5/Makefile.user | 10 ++++++++--
 tests/dyncomp-tests/Makefile            | 17 +++++++++++------
 tests/dyncomp-tests/Makefile.common     |  4 +++-
 tests/kvasir-tests/Makefile             | 17 +++++------------
 tests/kvasir-tests/Makefile.common      |  4 +++-
 8 files changed, 50 insertions(+), 33 deletions(-)

diff --git a/tests/Makefile b/tests/Makefile
index b8450521fc..cd00967c70 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -38,6 +38,9 @@ ifeq ($(origin DAIKONDIR), undefined)
   DAIKONDIR := $(realpath $(dir $(lastword $(MAKEFILE_LIST)))..)
 endif
 PLUME_SCRIPTS ?= ${DAIKONDIR}/.utils/plume-scripts
+# Under CI, there are two CPUs, but limit to 1 to avoid out-of-memory error.
+# If is-ci.sh is absent, assume the run is not under CI.
+TEST_JOBS := $(if $(shell "${PLUME_SCRIPTS}/is-ci.sh" 2>/dev/null),1,4)
 
 all diffs: txt-diff non-txt-diff dyncomp-tests results
 
@@ -54,13 +57,7 @@ esc jml inv txt-daikon-diff txt-esc-diff txt-jml-diff txt-csharpcontract-diff tx
 txt-chicory-diff everything-txt-diff stats dyncomp-diff txt-jaif-diff txt-jaif:
 	${MAKE} pat-daikon-tests-$@
 pat-daikon-tests-%:
-# Under CI, there are two CPUs, but limit to 1 to avoid out-of-memory error.
-	@test -x "${PLUME_SCRIPTS}"/is-ci.sh || { echo "Not found: ${PLUME_SCRIPTS}/is-ci.sh ; running 'make' in ${DAIKONDIR} clones it" >&2; exit 1; }
-	if [ -n "$$("${PLUME_SCRIPTS}"/is-ci.sh)" ]; then \
-	  ${MAKE} -C daikon-tests --jobs=1 ${MPARG} $*; \
-	else \
-	  ${MAKE} -C daikon-tests --jobs=4 ${MPARG} $*; \
-	fi
+	${MAKE} -C daikon-tests --jobs=${TEST_JOBS} ${MPARG} $*
 
 list-targets:
 	${MAKE} -C daikon-tests list-targets
diff --git a/tests/Makefile.common b/tests/Makefile.common
index c151d000b3..95e6c75d96 100644
--- a/tests/Makefile.common
+++ b/tests/Makefile.common
@@ -186,17 +186,23 @@ ECLAT_SCRATCH = $(SCRATCH_FOR_DAIKON_BASE)/$(PROJECT)_eclat
 # CP_PARENTS := cp -pf --parents
 CP_PARENTS := rsync -aR
 
+# Use ":=" so that the shell commands run only once.
+ifeq ($(origin JAVA_HOME), undefined)
 ifeq ($(shell uname), Darwin)
-  JAVA_HOME ?= $(shell /usr/libexec/java_home)
+  JAVA_HOME := $(shell /usr/libexec/java_home)
+  ifeq (${JAVA_HOME},)
+    $(error /usr/libexec/java_home did not find a JDK; set JAVA_HOME)
+  endif
 else
 ifeq ($(shell which javac > /dev/null 2>&1 && echo found || echo nonexistent), found)
-  JAVA_HOME ?= $(shell readlink -f $(shell which javac) | sed "s:/bin/javac::")
+  JAVA_HOME := $(shell readlink -f $(shell which javac) | sed "s:/bin/javac::")
 else
   $(info Failure: Here is the output of: which javac)
   $(info $(shell which javac))
   $(error 'which javac' had exit status 1)
 endif
 endif
+endif
 JAVA  := ${JAVA_HOME}/bin/java
 JAVAC ?= ${JAVA_HOME}/bin/javac
 
diff --git a/tests/daikon-tests/junit/Makefile.user b/tests/daikon-tests/junit/Makefile.user
index 20a6da71d7..032cf37886 100644
--- a/tests/daikon-tests/junit/Makefile.user
+++ b/tests/daikon-tests/junit/Makefile.user
@@ -1,16 +1,22 @@
 ###########################################################################
 
+# Use ":=" so that the shell commands run only once.
+ifeq ($(origin JAVA_HOME), undefined)
 ifeq ($(shell uname), Darwin)
-  JAVA_HOME ?= $(shell /usr/libexec/java_home)
+  JAVA_HOME := $(shell /usr/libexec/java_home)
+  ifeq (${JAVA_HOME},)
+    $(error /usr/libexec/java_home did not find a JDK; set JAVA_HOME)
+  endif
 else
 ifeq ($(shell which javac > /dev/null 2>&1 && echo found || echo nonexistent), found)
-  JAVA_HOME ?= $(shell readlink -f $(shell which javac) | sed "s:/bin/javac::")
+  JAVA_HOME := $(shell readlink -f $(shell which javac) | sed "s:/bin/javac::")
 else
   $(info Failure: Here is the output of: which javac)
   $(info $(shell which javac))
   $(error 'which javac' had exit status 1)
 endif
 endif
+endif
 
 # need junit.jar on classpath to compile all junit references
 JUNIT_CLASSPATH := ${DAIKONDIR}/java/lib/*
diff --git a/tests/daikon-tests/junit5/Makefile.user b/tests/daikon-tests/junit5/Makefile.user
index b820d37665..5a03c11f02 100644
--- a/tests/daikon-tests/junit5/Makefile.user
+++ b/tests/daikon-tests/junit5/Makefile.user
@@ -1,16 +1,22 @@
 ###########################################################################
 
+# Use ":=" so that the shell commands run only once.
+ifeq ($(origin JAVA_HOME), undefined)
 ifeq ($(shell uname), Darwin)
-  JAVA_HOME ?= $(shell /usr/libexec/java_home)
+  JAVA_HOME := $(shell /usr/libexec/java_home)
+  ifeq (${JAVA_HOME},)
+    $(error /usr/libexec/java_home did not find a JDK; set JAVA_HOME)
+  endif
 else
 ifeq ($(shell which javac > /dev/null 2>&1 && echo found || echo nonexistent), found)
-  JAVA_HOME ?= $(shell readlink -f $(shell which javac) | sed "s:/bin/javac::")
+  JAVA_HOME := $(shell readlink -f $(shell which javac) | sed "s:/bin/javac::")
 else
   $(info Failure: Here is the output of: which javac)
   $(info $(shell which javac))
   $(error 'which javac' had exit status 1)
 endif
 endif
+endif
 
 # need junit.jar on classpath to compile all junit references
 # explicit order is necessary to get versions built with JDK 8 not 5
diff --git a/tests/dyncomp-tests/Makefile b/tests/dyncomp-tests/Makefile
index b2eaa8e885..a4915c56fb 100644
--- a/tests/dyncomp-tests/Makefile
+++ b/tests/dyncomp-tests/Makefile
@@ -18,10 +18,20 @@
 
 # Forked from $DAIKONDIR/tests/kvasir-tests/Makefile
 
+ifeq (4.0,$(firstword $(sort ${MAKE_VERSION} 4.0)))
+  # Version 4.0 or higher
+  MPARG ?= -Orecurse
+else
+  MPARG ?=
+endif
+
 ifeq ($(origin DAIKONDIR), undefined)
   DAIKONDIR := $(realpath $(dir $(lastword $(MAKEFILE_LIST)))../..)
 endif
 PLUME_SCRIPTS ?= ${DAIKONDIR}/.utils/plume-scripts
+# Under CI, there are two CPUs, but limit to 1 to avoid out-of-memory error.
+# If is-ci.sh is absent, assume the run is not under CI.
+TEST_JOBS := $(if $(shell "${PLUME_SCRIPTS}/is-ci.sh" 2>/dev/null),1,4)
 
 default: summary
 
@@ -67,12 +77,7 @@ update-all:
 
 .PHONY: clean-all
 clean-all:
-	@test -x "${PLUME_SCRIPTS}"/is-ci.sh || { echo "Not found: ${PLUME_SCRIPTS}/is-ci.sh ; running 'make' in ${DAIKONDIR} clones it" >&2; exit 1; }
-	if [ -n "$$("${PLUME_SCRIPTS}"/is-ci.sh)" ]; then \
-	  ${MAKE} --jobs=1 ${MPARG} nightly-tests__clean; \
-	else \
-	  ${MAKE} --jobs=4 ${MPARG} nightly-tests__clean; \
-	fi
+	${MAKE} --jobs=${TEST_JOBS} ${MPARG} nightly-tests__clean
 
 
 default-projects__%: pgbovine-tests__%
diff --git a/tests/dyncomp-tests/Makefile.common b/tests/dyncomp-tests/Makefile.common
index 173bce853b..261b7946d0 100644
--- a/tests/dyncomp-tests/Makefile.common
+++ b/tests/dyncomp-tests/Makefile.common
@@ -3,7 +3,9 @@
 # Forked from $DAIKONDIR/tests/kvasir-tests/Makefile.common
 
 # DAIKONDIR is the clone of the 'daikon' project.
-DAIKONDIR ?= $(realpath $(dir $(lastword $(MAKEFILE_LIST)))../..)
+ifeq ($(origin DAIKONDIR), undefined)
+  DAIKONDIR := $(realpath $(dir $(lastword $(MAKEFILE_LIST)))../..)
+endif
 
 ifeq ($(shell uname -m),x86_64)
 VALGRIND_ARCH := amd64
diff --git a/tests/kvasir-tests/Makefile b/tests/kvasir-tests/Makefile
index 7067317980..7e89a2de9b 100644
--- a/tests/kvasir-tests/Makefile
+++ b/tests/kvasir-tests/Makefile
@@ -24,17 +24,15 @@ ifeq ($(origin DAIKONDIR), undefined)
   DAIKONDIR := $(realpath $(dir $(lastword $(MAKEFILE_LIST)))../..)
 endif
 PLUME_SCRIPTS ?= ${DAIKONDIR}/.utils/plume-scripts
+# Under CI, there are two CPUs, but limit to 1 to avoid out-of-memory error.
+# If is-ci.sh is absent, assume the run is not under CI.
+TEST_JOBS := $(if $(shell "${PLUME_SCRIPTS}/is-ci.sh" 2>/dev/null),1,4)
 
 default: summary-w-daikon
 
 .PHONY: regression-tests
 regression-tests:
-	@test -x "${PLUME_SCRIPTS}"/is-ci.sh || { echo "Not found: ${PLUME_SCRIPTS}/is-ci.sh ; running 'make' in ${DAIKONDIR} clones it" >&2; exit 1; }
-	if [ -n "$$("${PLUME_SCRIPTS}"/is-ci.sh)" ]; then \
-	  ${MAKE} --jobs=1 ${MPARG} nightly-tests__diffs-w-daikon-if-working; \
-	else \
-	  ${MAKE} --jobs=4 ${MPARG} nightly-tests__diffs-w-daikon-if-working; \
-	fi
+	${MAKE} --jobs=${TEST_JOBS} ${MPARG} nightly-tests__diffs-w-daikon-if-working
 	${MAKE} nightly-summary-only-w-daikon
 	@${MAKE} --no-print-directory results
 
@@ -84,12 +82,7 @@ update-all:
 
 .PHONY: clean-all
 clean-all:
-	@test -x "${PLUME_SCRIPTS}"/is-ci.sh || { echo "Not found: ${PLUME_SCRIPTS}/is-ci.sh ; running 'make' in ${DAIKONDIR} clones it" >&2; exit 1; }
-	if [ -n "$$("${PLUME_SCRIPTS}"/is-ci.sh)" ]; then \
-	  ${MAKE} --jobs=1 ${MPARG} nightly-tests__clean; \
-	else \
-	  ${MAKE} --jobs=4 ${MPARG} nightly-tests__clean; \
-	fi
+	${MAKE} --jobs=${TEST_JOBS} ${MPARG} nightly-tests__clean
 
 default-projects__%: pgbovine-tests__% smcc-tests__% tiny-real-tests__% tws-tests__%
 	@
diff --git a/tests/kvasir-tests/Makefile.common b/tests/kvasir-tests/Makefile.common
index c1fc9bd33b..aeab77975a 100644
--- a/tests/kvasir-tests/Makefile.common
+++ b/tests/kvasir-tests/Makefile.common
@@ -1,7 +1,9 @@
 # This is a -*- makefile -*-, Emacs
 
 # DAIKONDIR is the clone of the 'daikon' project.
-DAIKONDIR ?= $(realpath $(dir $(lastword $(MAKEFILE_LIST)))../..)
+ifeq ($(origin DAIKONDIR), undefined)
+  DAIKONDIR := $(realpath $(dir $(lastword $(MAKEFILE_LIST)))../..)
+endif
 DAIKON_JAR := ${DAIKONDIR}/daikon.jar
 # Fails when running "clean".
 # $(if $(wildcard ${DAIKON_JAR}),,$(error daikon.jar not found at ${DAIKON_JAR}))

From 9c658a1a2d89d26e400edee1f9a32a05b899b6c7 Mon Sep 17 00:00:00 2001
From: Michael Ernst <mernst@cs.washington.edu>
Date: Sat, 10 Oct 2026 12:58:37 -0700
Subject: [PATCH 4/6] Address code review: shared Makefile.jobs, deferred JDK
 check, consistent DAIKONDIR

* New tests/Makefile.jobs holds MPARG, DAIKONDIR, PLUME_SCRIPTS and TEST_JOBS
  for the three test-driver Makefiles.  It fails clearly if is-ci.sh is
  missing, computes TEST_JOBS once and exports it, and honors a TEST_JOBS
  value from the command line or environment.
* tests/Makefile.common sets JAVA_HOME before including Makefile.user, so the
  junit and junit5 Makefile.user files no longer duplicate the detection.
  Locate javac with a single shell command.  Check for a missing JDK only when
  JAVA or JAVAC is expanded, so targets such as "clean" work without a JDK.
* java/Makefile: compute JAVA_HOME once and fail clearly if no JDK is found.
* Define DAIKONDIR with ":=" in the remaining test Makefiles; fix its depth in
  tests/daikon-tests/Makefile.
---
 java/Makefile                                 | 20 ++++-----
 tests/Makefile                                | 17 +-------
 tests/Makefile.common                         | 41 +++++++++----------
 tests/Makefile.jobs                           | 32 +++++++++++++++
 tests/daikon-tests/Makefile                   |  4 +-
 tests/daikon-tests/junit/Makefile.user        | 20 +--------
 tests/daikon-tests/junit5/Makefile.user       | 20 +--------
 tests/diff-tests/Makefile.common              |  4 +-
 tests/dyncomp-tests/Makefile                  | 15 +------
 tests/kvasir-tests/Makefile                   | 15 +------
 tests/merge-invariants-tests/drawlet/Makefile |  4 +-
 tests/parser-tests/Makefile                   |  4 +-
 12 files changed, 78 insertions(+), 118 deletions(-)
 create mode 100644 tests/Makefile.jobs

diff --git a/java/Makefile b/java/Makefile
index ce436e5d69..65dab35496 100644
--- a/java/Makefile
+++ b/java/Makefile
@@ -25,16 +25,16 @@ JAR ?= jar
 
 BuildJDKTool = BuildJDK
 
-ifeq ($(shell uname), Darwin)
-  JAVA_HOME ?= $(shell /usr/libexec/java_home)
-else
-ifeq ($(shell which javac > /dev/null 2>&1 && echo found || echo nonexistent), found)
-  JAVA_HOME ?= $(shell readlink -f $(shell which javac) | sed "s:/bin/javac::")
-else
-  $(info Failure: Here is the output of: which javac)
-  $(info $(shell which javac))
-  $(error 'which javac' had exit status 1)
-endif
+# Use ":=" so that the shell commands run only once.
+ifeq ($(origin JAVA_HOME), undefined)
+  ifeq ($(shell uname), Darwin)
+    JAVA_HOME := $(shell /usr/libexec/java_home)
+  else
+    JAVA_HOME := $(shell javac=$$(command -v javac) && readlink -f "$$javac" | sed 's:/bin/javac$$::')
+  endif
+  ifeq (${JAVA_HOME},)
+    $(error No JDK found; set JAVA_HOME or put javac on the PATH)
+  endif
 endif
 
 # The "JAVANN" variables mean "at least version NN", except JAVA8.
diff --git a/tests/Makefile b/tests/Makefile
index cd00967c70..7ae1ffebe6 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -25,22 +25,7 @@ help-recurse-list:
 	@echo " which are ones that have been selected as useful tests.)"
 	@echo ""
 
-# To produce incremental output, invoke make as: make MPARG=-Otarget ...
-# To not run in parallel, invoke make as: make MPARG=-j1 ...
-ifeq (4.0,$(firstword $(sort ${MAKE_VERSION} 4.0)))
-  # Version 4.0 or higher
-  MPARG ?= -Orecurse
-else
-  MPARG ?=
-endif
-
-ifeq ($(origin DAIKONDIR), undefined)
-  DAIKONDIR := $(realpath $(dir $(lastword $(MAKEFILE_LIST)))..)
-endif
-PLUME_SCRIPTS ?= ${DAIKONDIR}/.utils/plume-scripts
-# Under CI, there are two CPUs, but limit to 1 to avoid out-of-memory error.
-# If is-ci.sh is absent, assume the run is not under CI.
-TEST_JOBS := $(if $(shell "${PLUME_SCRIPTS}/is-ci.sh" 2>/dev/null),1,4)
+include $(dir $(lastword $(MAKEFILE_LIST)))Makefile.jobs
 
 all diffs: txt-diff non-txt-diff dyncomp-tests results
 
diff --git a/tests/Makefile.common b/tests/Makefile.common
index 95e6c75d96..7013f200a2 100644
--- a/tests/Makefile.common
+++ b/tests/Makefile.common
@@ -149,6 +149,20 @@ ifndef COMMON_HERE
   $(error Test directory ${DAIKONDIR}/tests does not exist)
 endif
 
+# JAVA_HOME is set before Makefile.user is included, so that Makefile.user can use or override it.
+# Use ":=" so that the shell commands run only once.
+ifeq ($(origin JAVA_HOME), undefined)
+  ifeq ($(shell uname), Darwin)
+    JAVA_HOME := $(shell /usr/libexec/java_home)
+  else
+    JAVA_HOME := $(shell javac=$$(command -v javac) && readlink -f "$$javac" | sed 's:/bin/javac$$::')
+  endif
+endif
+# CHECKED_JAVA_HOME is JAVA_HOME, but expanding it fails if no JDK was found.
+# The check happens only when a variable that uses it is expanded, so targets
+# that do not run Java (such as "clean") work without a JDK.
+CHECKED_JAVA_HOME = $(or ${JAVA_HOME},$(error No JDK found; set JAVA_HOME))
+
 # Put user-specific changes in your own Makefile.user
 #  (such as changes to PLUME_DIR or JAVAC or PATH).
 # Make will silently continue if the file does not exist.
@@ -186,25 +200,8 @@ ECLAT_SCRATCH = $(SCRATCH_FOR_DAIKON_BASE)/$(PROJECT)_eclat
 # CP_PARENTS := cp -pf --parents
 CP_PARENTS := rsync -aR
 
-# Use ":=" so that the shell commands run only once.
-ifeq ($(origin JAVA_HOME), undefined)
-ifeq ($(shell uname), Darwin)
-  JAVA_HOME := $(shell /usr/libexec/java_home)
-  ifeq (${JAVA_HOME},)
-    $(error /usr/libexec/java_home did not find a JDK; set JAVA_HOME)
-  endif
-else
-ifeq ($(shell which javac > /dev/null 2>&1 && echo found || echo nonexistent), found)
-  JAVA_HOME := $(shell readlink -f $(shell which javac) | sed "s:/bin/javac::")
-else
-  $(info Failure: Here is the output of: which javac)
-  $(info $(shell which javac))
-  $(error 'which javac' had exit status 1)
-endif
-endif
-endif
-JAVA  := ${JAVA_HOME}/bin/java
-JAVAC ?= ${JAVA_HOME}/bin/javac
+JAVA  = ${CHECKED_JAVA_HOME}/bin/java
+JAVAC ?= ${CHECKED_JAVA_HOME}/bin/javac
 
 JUNIT_CLASSPATH ?=
 
@@ -215,7 +212,7 @@ DAIKON_CLASSPATH := ${DAIKONDIR}/java:${DAIKONDIR}/java/lib/*:${DAIKONDIR}/daiko
 export DAIKON_TESTS_CLASSPATH := .:$(JAVALIB_CLASSPATH):$(SCRATCH_FOR_DAIKON):$(JUNIT_CLASSPATH):$(DAIKON_CLASSPATH)
 
 # Dynamic instrumentation based java front end command.
-CHICORY := $(JAVA) -ea -cp "$(DAIKON_TESTS_CLASSPATH)" daikon.Chicory
+CHICORY = $(JAVA) -ea -cp "$(DAIKON_TESTS_CLASSPATH)" daikon.Chicory
 CHICORY_EXEC := ${DAIKONDIR}/java/daikon/Chicory.class
 
 # As of JDK 1.3 (and 1.4, I think), don't use "-server" here.
@@ -308,12 +305,12 @@ endif
 
 # If specified, setup for the old declaration format
 ifeq (old,${DECL_FORMAT})
-  CHICORY := $(CHICORY) --new_decl_format=false
+  CHICORY += --new_decl_format=false
 endif
 
 # "make PROFILE_JAVA=1 <target>" to get profile information
 ifdef PROFILE_JAVA
-RUN_JAVA:=$(RUN_JAVA) -Xrunhprof:cpu=samples,file=${PROJECT_FILE}.profile.txt,depth=3
+RUN_JAVA += -Xrunhprof:cpu=samples,file=${PROJECT_FILE}.profile.txt,depth=3
 endif
 
 # To turn off Simplify, put this in the project's own Makefile, after
diff --git a/tests/Makefile.jobs b/tests/Makefile.jobs
new file mode 100644
index 0000000000..e3736b3ca6
--- /dev/null
+++ b/tests/Makefile.jobs
@@ -0,0 +1,32 @@
+# This is a -*- makefile -*-, Emacs
+#
+# Settings shared by the Makefiles that drive a whole test suite:
+# tests/Makefile, tests/kvasir-tests/Makefile, and tests/dyncomp-tests/Makefile.
+# Include it before any other include, so that MAKEFILE_LIST ends with this file.
+
+# To produce incremental output, invoke make as: make MPARG=-Otarget ...
+# To not run in parallel, invoke make as: make MPARG=-j1 ...
+ifeq (4.0,$(firstword $(sort ${MAKE_VERSION} 4.0)))
+  # Version 4.0 or higher
+  MPARG ?= -Orecurse
+else
+  MPARG ?=
+endif
+
+# DAIKONDIR is the clone of the 'daikon' project.
+ifeq ($(origin DAIKONDIR), undefined)
+  DAIKONDIR := $(realpath $(dir $(lastword $(MAKEFILE_LIST)))..)
+endif
+PLUME_SCRIPTS ?= ${DAIKONDIR}/.utils/plume-scripts
+
+# TEST_JOBS is the number of tests to run in parallel.
+# Under CI, there are two CPUs, but limit to 1 to avoid out-of-memory error.
+# The value is exported, so recursive invocations of make do not recompute it.
+# To override it, set TEST_JOBS on the command line or in the environment.
+ifeq ($(origin TEST_JOBS), undefined)
+  ifeq ($(wildcard ${PLUME_SCRIPTS}/is-ci.sh),)
+    $(error ${PLUME_SCRIPTS}/is-ci.sh not found; run "make" in ${DAIKONDIR} to clone plume-scripts, or set TEST_JOBS)
+  endif
+  TEST_JOBS := $(if $(shell sh "${PLUME_SCRIPTS}/is-ci.sh"),1,4)
+endif
+export TEST_JOBS
diff --git a/tests/daikon-tests/Makefile b/tests/daikon-tests/Makefile
index 3342685d68..aa5b656531 100644
--- a/tests/daikon-tests/Makefile
+++ b/tests/daikon-tests/Makefile
@@ -2,7 +2,9 @@
 # Read Makefile in parent directory to see what this all means
 
 # DAIKONDIR is the clone of the 'daikon' project.
-DAIKONDIR ?= $(realpath $(dir $(lastword ${MAKEFILE_LIST}))..)
+ifeq ($(origin DAIKONDIR), undefined)
+  DAIKONDIR := $(realpath $(dir $(lastword ${MAKEFILE_LIST}))../..)
+endif
 SCRIPTS=${DAIKONDIR}/scripts
 
 # Help system
diff --git a/tests/daikon-tests/junit/Makefile.user b/tests/daikon-tests/junit/Makefile.user
index 032cf37886..169d40bfae 100644
--- a/tests/daikon-tests/junit/Makefile.user
+++ b/tests/daikon-tests/junit/Makefile.user
@@ -1,23 +1,5 @@
 ###########################################################################
 
-# Use ":=" so that the shell commands run only once.
-ifeq ($(origin JAVA_HOME), undefined)
-ifeq ($(shell uname), Darwin)
-  JAVA_HOME := $(shell /usr/libexec/java_home)
-  ifeq (${JAVA_HOME},)
-    $(error /usr/libexec/java_home did not find a JDK; set JAVA_HOME)
-  endif
-else
-ifeq ($(shell which javac > /dev/null 2>&1 && echo found || echo nonexistent), found)
-  JAVA_HOME := $(shell readlink -f $(shell which javac) | sed "s:/bin/javac::")
-else
-  $(info Failure: Here is the output of: which javac)
-  $(info $(shell which javac))
-  $(error 'which javac' had exit status 1)
-endif
-endif
-endif
-
 # need junit.jar on classpath to compile all junit references
 JUNIT_CLASSPATH := ${DAIKONDIR}/java/lib/*
-JAVAC := $(JAVA_HOME)/bin/javac -cp .:$(JUNIT_CLASSPATH)
+JAVAC = ${CHECKED_JAVA_HOME}/bin/javac -cp .:$(JUNIT_CLASSPATH)
diff --git a/tests/daikon-tests/junit5/Makefile.user b/tests/daikon-tests/junit5/Makefile.user
index 5a03c11f02..90c4b5cdad 100644
--- a/tests/daikon-tests/junit5/Makefile.user
+++ b/tests/daikon-tests/junit5/Makefile.user
@@ -1,24 +1,6 @@
 ###########################################################################
 
-# Use ":=" so that the shell commands run only once.
-ifeq ($(origin JAVA_HOME), undefined)
-ifeq ($(shell uname), Darwin)
-  JAVA_HOME := $(shell /usr/libexec/java_home)
-  ifeq (${JAVA_HOME},)
-    $(error /usr/libexec/java_home did not find a JDK; set JAVA_HOME)
-  endif
-else
-ifeq ($(shell which javac > /dev/null 2>&1 && echo found || echo nonexistent), found)
-  JAVA_HOME := $(shell readlink -f $(shell which javac) | sed "s:/bin/javac::")
-else
-  $(info Failure: Here is the output of: which javac)
-  $(info $(shell which javac))
-  $(error 'which javac' had exit status 1)
-endif
-endif
-endif
-
 # need junit.jar on classpath to compile all junit references
 # explicit order is necessary to get versions built with JDK 8 not 5
 JUNIT_CLASSPATH := ${DAIKONDIR}/java/lib/junit-4.13.2-Daikon.jar:${DAIKONDIR}/java/lib/hamcrest-core-1.3-Daikon.jar:${DAIKONDIR}/java/lib/*
-JAVAC := $(JAVA_HOME)/bin/javac -cp .:$(JUNIT_CLASSPATH)
+JAVAC = ${CHECKED_JAVA_HOME}/bin/javac -cp .:$(JUNIT_CLASSPATH)
diff --git a/tests/diff-tests/Makefile.common b/tests/diff-tests/Makefile.common
index 7a22461dfd..c0edcaf4ab 100644
--- a/tests/diff-tests/Makefile.common
+++ b/tests/diff-tests/Makefile.common
@@ -6,7 +6,9 @@
 # of Diff.
 
 # DAIKONDIR is the clone of the 'daikon' project.
-DAIKONDIR ?= $(realpath $(dir $(lastword $(MAKEFILE_LIST)))../..)
+ifeq ($(origin DAIKONDIR), undefined)
+  DAIKONDIR := $(realpath $(dir $(lastword $(MAKEFILE_LIST)))../..)
+endif
 
 DAIKON_CLASSPATH := ${DAIKONDIR}/java:${DAIKONDIR}/java/lib/*:${DAIKONDIR}/daikon.jar
 
diff --git a/tests/dyncomp-tests/Makefile b/tests/dyncomp-tests/Makefile
index a4915c56fb..e69a8eb91a 100644
--- a/tests/dyncomp-tests/Makefile
+++ b/tests/dyncomp-tests/Makefile
@@ -18,20 +18,7 @@
 
 # Forked from $DAIKONDIR/tests/kvasir-tests/Makefile
 
-ifeq (4.0,$(firstword $(sort ${MAKE_VERSION} 4.0)))
-  # Version 4.0 or higher
-  MPARG ?= -Orecurse
-else
-  MPARG ?=
-endif
-
-ifeq ($(origin DAIKONDIR), undefined)
-  DAIKONDIR := $(realpath $(dir $(lastword $(MAKEFILE_LIST)))../..)
-endif
-PLUME_SCRIPTS ?= ${DAIKONDIR}/.utils/plume-scripts
-# Under CI, there are two CPUs, but limit to 1 to avoid out-of-memory error.
-# If is-ci.sh is absent, assume the run is not under CI.
-TEST_JOBS := $(if $(shell "${PLUME_SCRIPTS}/is-ci.sh" 2>/dev/null),1,4)
+include $(dir $(lastword $(MAKEFILE_LIST)))../Makefile.jobs
 
 default: summary
 
diff --git a/tests/kvasir-tests/Makefile b/tests/kvasir-tests/Makefile
index 7e89a2de9b..9e86fee177 100644
--- a/tests/kvasir-tests/Makefile
+++ b/tests/kvasir-tests/Makefile
@@ -13,20 +13,7 @@
 #    category to contain it.
 #
 
-ifeq (4.0,$(firstword $(sort ${MAKE_VERSION} 4.0)))
-  # Version 4.0 or higher
-  MPARG ?= -Orecurse
-else
-  MPARG ?=
-endif
-
-ifeq ($(origin DAIKONDIR), undefined)
-  DAIKONDIR := $(realpath $(dir $(lastword $(MAKEFILE_LIST)))../..)
-endif
-PLUME_SCRIPTS ?= ${DAIKONDIR}/.utils/plume-scripts
-# Under CI, there are two CPUs, but limit to 1 to avoid out-of-memory error.
-# If is-ci.sh is absent, assume the run is not under CI.
-TEST_JOBS := $(if $(shell "${PLUME_SCRIPTS}/is-ci.sh" 2>/dev/null),1,4)
+include $(dir $(lastword $(MAKEFILE_LIST)))../Makefile.jobs
 
 default: summary-w-daikon
 
diff --git a/tests/merge-invariants-tests/drawlet/Makefile b/tests/merge-invariants-tests/drawlet/Makefile
index da2a137a0f..332447d42a 100644
--- a/tests/merge-invariants-tests/drawlet/Makefile
+++ b/tests/merge-invariants-tests/drawlet/Makefile
@@ -9,7 +9,9 @@
 # files are in drawlet_src.zip in this directory
 
 # DAIKONDIR is the clone of the 'daikon' project.
-DAIKONDIR ?= $(realpath $(dir $(lastword ${MAKEFILE_LIST}))../../..)
+ifeq ($(origin DAIKONDIR), undefined)
+  DAIKONDIR := $(realpath $(dir $(lastword ${MAKEFILE_LIST}))../../..)
+endif
 
 DAIKON_ARGS = '--ppt-omit-pattern=^org\.' --no_text_output --no_show_progress --config_option daikon.Debug.show_stack_trace=true
 DAIKON = ${DAIKONDIR}/java/daikon/Daikon.class
diff --git a/tests/parser-tests/Makefile b/tests/parser-tests/Makefile
index 6a1755c3ea..4adb545dde 100644
--- a/tests/parser-tests/Makefile
+++ b/tests/parser-tests/Makefile
@@ -1,5 +1,7 @@
 # DAIKONDIR is the clone of the 'daikon' project.
-DAIKONDIR ?= $(realpath $(dir $(lastword ${MAKEFILE_LIST}))../..)
+ifeq ($(origin DAIKONDIR), undefined)
+  DAIKONDIR := $(realpath $(dir $(lastword ${MAKEFILE_LIST}))../..)
+endif
 
 DAIKON_CLASSPATH := ${DAIKONDIR}/java:${DAIKONDIR}/java/lib/*:${DAIKONDIR}/daikon.jar
 

From b31b497c9c327b9e807756c30bddce56b0980692 Mon Sep 17 00:00:00 2001
From: Michael Ernst <mernst@cs.washington.edu>
Date: Sat, 10 Oct 2026 13:04:08 -0700
Subject: [PATCH 5/6] Move the JAVA_HOME and DAIKONDIR changes to separate pull
 requests

---
 java/Makefile                                 | 20 +++++------
 tests/Makefile.common                         | 35 +++++++++----------
 tests/daikon-tests/Makefile                   |  4 +--
 tests/daikon-tests/junit/Makefile.user        | 14 +++++++-
 tests/daikon-tests/junit5/Makefile.user       | 14 +++++++-
 tests/diff-tests/Makefile.common              |  4 +--
 tests/dyncomp-tests/Makefile.common           |  4 +--
 tests/kvasir-tests/Makefile.common            |  4 +--
 tests/merge-invariants-tests/drawlet/Makefile |  4 +--
 tests/parser-tests/Makefile                   |  4 +--
 10 files changed, 58 insertions(+), 49 deletions(-)

diff --git a/java/Makefile b/java/Makefile
index 65dab35496..ce436e5d69 100644
--- a/java/Makefile
+++ b/java/Makefile
@@ -25,16 +25,16 @@ JAR ?= jar
 
 BuildJDKTool = BuildJDK
 
-# Use ":=" so that the shell commands run only once.
-ifeq ($(origin JAVA_HOME), undefined)
-  ifeq ($(shell uname), Darwin)
-    JAVA_HOME := $(shell /usr/libexec/java_home)
-  else
-    JAVA_HOME := $(shell javac=$$(command -v javac) && readlink -f "$$javac" | sed 's:/bin/javac$$::')
-  endif
-  ifeq (${JAVA_HOME},)
-    $(error No JDK found; set JAVA_HOME or put javac on the PATH)
-  endif
+ifeq ($(shell uname), Darwin)
+  JAVA_HOME ?= $(shell /usr/libexec/java_home)
+else
+ifeq ($(shell which javac > /dev/null 2>&1 && echo found || echo nonexistent), found)
+  JAVA_HOME ?= $(shell readlink -f $(shell which javac) | sed "s:/bin/javac::")
+else
+  $(info Failure: Here is the output of: which javac)
+  $(info $(shell which javac))
+  $(error 'which javac' had exit status 1)
+endif
 endif
 
 # The "JAVANN" variables mean "at least version NN", except JAVA8.
diff --git a/tests/Makefile.common b/tests/Makefile.common
index 7013f200a2..38dde8e8cb 100644
--- a/tests/Makefile.common
+++ b/tests/Makefile.common
@@ -149,20 +149,6 @@ ifndef COMMON_HERE
   $(error Test directory ${DAIKONDIR}/tests does not exist)
 endif
 
-# JAVA_HOME is set before Makefile.user is included, so that Makefile.user can use or override it.
-# Use ":=" so that the shell commands run only once.
-ifeq ($(origin JAVA_HOME), undefined)
-  ifeq ($(shell uname), Darwin)
-    JAVA_HOME := $(shell /usr/libexec/java_home)
-  else
-    JAVA_HOME := $(shell javac=$$(command -v javac) && readlink -f "$$javac" | sed 's:/bin/javac$$::')
-  endif
-endif
-# CHECKED_JAVA_HOME is JAVA_HOME, but expanding it fails if no JDK was found.
-# The check happens only when a variable that uses it is expanded, so targets
-# that do not run Java (such as "clean") work without a JDK.
-CHECKED_JAVA_HOME = $(or ${JAVA_HOME},$(error No JDK found; set JAVA_HOME))
-
 # Put user-specific changes in your own Makefile.user
 #  (such as changes to PLUME_DIR or JAVAC or PATH).
 # Make will silently continue if the file does not exist.
@@ -200,8 +186,19 @@ ECLAT_SCRATCH = $(SCRATCH_FOR_DAIKON_BASE)/$(PROJECT)_eclat
 # CP_PARENTS := cp -pf --parents
 CP_PARENTS := rsync -aR
 
-JAVA  = ${CHECKED_JAVA_HOME}/bin/java
-JAVAC ?= ${CHECKED_JAVA_HOME}/bin/javac
+ifeq ($(shell uname), Darwin)
+  JAVA_HOME ?= $(/usr/libexec/java_home)
+else
+ifeq ($(shell which javac > /dev/null 2>&1 && echo found || echo nonexistent), found)
+  JAVA_HOME ?= $(shell readlink -f $(shell which javac) | sed "s:/bin/javac::")
+else
+  $(info Failure: Here is the output of: which javac)
+  $(info $(shell which javac))
+  $(error 'which javac' had exit status 1)
+endif
+endif
+JAVA  := ${JAVA_HOME}/bin/java
+JAVAC ?= ${JAVA_HOME}/bin/javac
 
 JUNIT_CLASSPATH ?=
 
@@ -212,7 +209,7 @@ DAIKON_CLASSPATH := ${DAIKONDIR}/java:${DAIKONDIR}/java/lib/*:${DAIKONDIR}/daiko
 export DAIKON_TESTS_CLASSPATH := .:$(JAVALIB_CLASSPATH):$(SCRATCH_FOR_DAIKON):$(JUNIT_CLASSPATH):$(DAIKON_CLASSPATH)
 
 # Dynamic instrumentation based java front end command.
-CHICORY = $(JAVA) -ea -cp "$(DAIKON_TESTS_CLASSPATH)" daikon.Chicory
+CHICORY := $(JAVA) -ea -cp "$(DAIKON_TESTS_CLASSPATH)" daikon.Chicory
 CHICORY_EXEC := ${DAIKONDIR}/java/daikon/Chicory.class
 
 # As of JDK 1.3 (and 1.4, I think), don't use "-server" here.
@@ -305,12 +302,12 @@ endif
 
 # If specified, setup for the old declaration format
 ifeq (old,${DECL_FORMAT})
-  CHICORY += --new_decl_format=false
+  CHICORY := $(CHICORY) --new_decl_format=false
 endif
 
 # "make PROFILE_JAVA=1 <target>" to get profile information
 ifdef PROFILE_JAVA
-RUN_JAVA += -Xrunhprof:cpu=samples,file=${PROJECT_FILE}.profile.txt,depth=3
+RUN_JAVA:=$(RUN_JAVA) -Xrunhprof:cpu=samples,file=${PROJECT_FILE}.profile.txt,depth=3
 endif
 
 # To turn off Simplify, put this in the project's own Makefile, after
diff --git a/tests/daikon-tests/Makefile b/tests/daikon-tests/Makefile
index aa5b656531..3342685d68 100644
--- a/tests/daikon-tests/Makefile
+++ b/tests/daikon-tests/Makefile
@@ -2,9 +2,7 @@
 # Read Makefile in parent directory to see what this all means
 
 # DAIKONDIR is the clone of the 'daikon' project.
-ifeq ($(origin DAIKONDIR), undefined)
-  DAIKONDIR := $(realpath $(dir $(lastword ${MAKEFILE_LIST}))../..)
-endif
+DAIKONDIR ?= $(realpath $(dir $(lastword ${MAKEFILE_LIST}))..)
 SCRIPTS=${DAIKONDIR}/scripts
 
 # Help system
diff --git a/tests/daikon-tests/junit/Makefile.user b/tests/daikon-tests/junit/Makefile.user
index 169d40bfae..9c2889b925 100644
--- a/tests/daikon-tests/junit/Makefile.user
+++ b/tests/daikon-tests/junit/Makefile.user
@@ -1,5 +1,17 @@
 ###########################################################################
 
+ifeq ($(shell uname), Darwin)
+  JAVA_HOME ?= $(/usr/libexec/java_home)
+else
+ifeq ($(shell which javac > /dev/null 2>&1 && echo found || echo nonexistent), found)
+  JAVA_HOME ?= $(shell readlink -f $(shell which javac) | sed "s:/bin/javac::")
+else
+  $(info Failure: Here is the output of: which javac)
+  $(info $(shell which javac))
+  $(error 'which javac' had exit status 1)
+endif
+endif
+
 # need junit.jar on classpath to compile all junit references
 JUNIT_CLASSPATH := ${DAIKONDIR}/java/lib/*
-JAVAC = ${CHECKED_JAVA_HOME}/bin/javac -cp .:$(JUNIT_CLASSPATH)
+JAVAC := $(JAVA_HOME)/bin/javac -cp .:$(JUNIT_CLASSPATH)
diff --git a/tests/daikon-tests/junit5/Makefile.user b/tests/daikon-tests/junit5/Makefile.user
index 90c4b5cdad..d10d1f57d7 100644
--- a/tests/daikon-tests/junit5/Makefile.user
+++ b/tests/daikon-tests/junit5/Makefile.user
@@ -1,6 +1,18 @@
 ###########################################################################
 
+ifeq ($(shell uname), Darwin)
+  JAVA_HOME ?= $(/usr/libexec/java_home)
+else
+ifeq ($(shell which javac > /dev/null 2>&1 && echo found || echo nonexistent), found)
+  JAVA_HOME ?= $(shell readlink -f $(shell which javac) | sed "s:/bin/javac::")
+else
+  $(info Failure: Here is the output of: which javac)
+  $(info $(shell which javac))
+  $(error 'which javac' had exit status 1)
+endif
+endif
+
 # need junit.jar on classpath to compile all junit references
 # explicit order is necessary to get versions built with JDK 8 not 5
 JUNIT_CLASSPATH := ${DAIKONDIR}/java/lib/junit-4.13.2-Daikon.jar:${DAIKONDIR}/java/lib/hamcrest-core-1.3-Daikon.jar:${DAIKONDIR}/java/lib/*
-JAVAC = ${CHECKED_JAVA_HOME}/bin/javac -cp .:$(JUNIT_CLASSPATH)
+JAVAC := $(JAVA_HOME)/bin/javac -cp .:$(JUNIT_CLASSPATH)
diff --git a/tests/diff-tests/Makefile.common b/tests/diff-tests/Makefile.common
index c0edcaf4ab..7a22461dfd 100644
--- a/tests/diff-tests/Makefile.common
+++ b/tests/diff-tests/Makefile.common
@@ -6,9 +6,7 @@
 # of Diff.
 
 # DAIKONDIR is the clone of the 'daikon' project.
-ifeq ($(origin DAIKONDIR), undefined)
-  DAIKONDIR := $(realpath $(dir $(lastword $(MAKEFILE_LIST)))../..)
-endif
+DAIKONDIR ?= $(realpath $(dir $(lastword $(MAKEFILE_LIST)))../..)
 
 DAIKON_CLASSPATH := ${DAIKONDIR}/java:${DAIKONDIR}/java/lib/*:${DAIKONDIR}/daikon.jar
 
diff --git a/tests/dyncomp-tests/Makefile.common b/tests/dyncomp-tests/Makefile.common
index 261b7946d0..173bce853b 100644
--- a/tests/dyncomp-tests/Makefile.common
+++ b/tests/dyncomp-tests/Makefile.common
@@ -3,9 +3,7 @@
 # Forked from $DAIKONDIR/tests/kvasir-tests/Makefile.common
 
 # DAIKONDIR is the clone of the 'daikon' project.
-ifeq ($(origin DAIKONDIR), undefined)
-  DAIKONDIR := $(realpath $(dir $(lastword $(MAKEFILE_LIST)))../..)
-endif
+DAIKONDIR ?= $(realpath $(dir $(lastword $(MAKEFILE_LIST)))../..)
 
 ifeq ($(shell uname -m),x86_64)
 VALGRIND_ARCH := amd64
diff --git a/tests/kvasir-tests/Makefile.common b/tests/kvasir-tests/Makefile.common
index aeab77975a..c1fc9bd33b 100644
--- a/tests/kvasir-tests/Makefile.common
+++ b/tests/kvasir-tests/Makefile.common
@@ -1,9 +1,7 @@
 # This is a -*- makefile -*-, Emacs
 
 # DAIKONDIR is the clone of the 'daikon' project.
-ifeq ($(origin DAIKONDIR), undefined)
-  DAIKONDIR := $(realpath $(dir $(lastword $(MAKEFILE_LIST)))../..)
-endif
+DAIKONDIR ?= $(realpath $(dir $(lastword $(MAKEFILE_LIST)))../..)
 DAIKON_JAR := ${DAIKONDIR}/daikon.jar
 # Fails when running "clean".
 # $(if $(wildcard ${DAIKON_JAR}),,$(error daikon.jar not found at ${DAIKON_JAR}))
diff --git a/tests/merge-invariants-tests/drawlet/Makefile b/tests/merge-invariants-tests/drawlet/Makefile
index 332447d42a..da2a137a0f 100644
--- a/tests/merge-invariants-tests/drawlet/Makefile
+++ b/tests/merge-invariants-tests/drawlet/Makefile
@@ -9,9 +9,7 @@
 # files are in drawlet_src.zip in this directory
 
 # DAIKONDIR is the clone of the 'daikon' project.
-ifeq ($(origin DAIKONDIR), undefined)
-  DAIKONDIR := $(realpath $(dir $(lastword ${MAKEFILE_LIST}))../../..)
-endif
+DAIKONDIR ?= $(realpath $(dir $(lastword ${MAKEFILE_LIST}))../../..)
 
 DAIKON_ARGS = '--ppt-omit-pattern=^org\.' --no_text_output --no_show_progress --config_option daikon.Debug.show_stack_trace=true
 DAIKON = ${DAIKONDIR}/java/daikon/Daikon.class
diff --git a/tests/parser-tests/Makefile b/tests/parser-tests/Makefile
index 4adb545dde..6a1755c3ea 100644
--- a/tests/parser-tests/Makefile
+++ b/tests/parser-tests/Makefile
@@ -1,7 +1,5 @@
 # DAIKONDIR is the clone of the 'daikon' project.
-ifeq ($(origin DAIKONDIR), undefined)
-  DAIKONDIR := $(realpath $(dir $(lastword ${MAKEFILE_LIST}))../..)
-endif
+DAIKONDIR ?= $(realpath $(dir $(lastword ${MAKEFILE_LIST}))../..)
 
 DAIKON_CLASSPATH := ${DAIKONDIR}/java:${DAIKONDIR}/java/lib/*:${DAIKONDIR}/daikon.jar
 

From 562057df71bc5bb9176811b0501c8f30af321d5a Mon Sep 17 00:00:00 2001
From: Michael Ernst <mernst@cs.washington.edu>
Date: Sat, 10 Oct 2026 13:28:10 -0700
Subject: [PATCH 6/6] Address code review: compute DAIKON_TEST_JOBS lazily,
 rename it, and do not set DAIKONDIR

Computing the job count only when a recipe uses it lets targets such as
clean and help work when plume-scripts is absent.  An empty value is
treated as unset.  The variable is no longer exported.
---
 tests/Makefile               |  2 +-
 tests/Makefile.jobs          | 26 +++++++++++---------------
 tests/dyncomp-tests/Makefile |  2 +-
 tests/kvasir-tests/Makefile  |  4 ++--
 4 files changed, 15 insertions(+), 19 deletions(-)

diff --git a/tests/Makefile b/tests/Makefile
index 7ae1ffebe6..aa5b7c2fdd 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -42,7 +42,7 @@ esc jml inv txt-daikon-diff txt-esc-diff txt-jml-diff txt-csharpcontract-diff tx
 txt-chicory-diff everything-txt-diff stats dyncomp-diff txt-jaif-diff txt-jaif:
 	${MAKE} pat-daikon-tests-$@
 pat-daikon-tests-%:
-	${MAKE} -C daikon-tests --jobs=${TEST_JOBS} ${MPARG} $*
+	${MAKE} -C daikon-tests --jobs=${DAIKON_TEST_JOBS} ${MPARG} $*
 
 list-targets:
 	${MAKE} -C daikon-tests list-targets
diff --git a/tests/Makefile.jobs b/tests/Makefile.jobs
index e3736b3ca6..16e741d962 100644
--- a/tests/Makefile.jobs
+++ b/tests/Makefile.jobs
@@ -2,7 +2,8 @@
 #
 # Settings shared by the Makefiles that drive a whole test suite:
 # tests/Makefile, tests/kvasir-tests/Makefile, and tests/dyncomp-tests/Makefile.
-# Include it before any other include, so that MAKEFILE_LIST ends with this file.
+# The including Makefile locates this file via $(lastword $(MAKEFILE_LIST)),
+# so its include line must precede any other include in that Makefile.
 
 # To produce incremental output, invoke make as: make MPARG=-Otarget ...
 # To not run in parallel, invoke make as: make MPARG=-j1 ...
@@ -13,20 +14,15 @@ else
   MPARG ?=
 endif
 
-# DAIKONDIR is the clone of the 'daikon' project.
-ifeq ($(origin DAIKONDIR), undefined)
-  DAIKONDIR := $(realpath $(dir $(lastword $(MAKEFILE_LIST)))..)
+ifndef PLUME_SCRIPTS
+  PLUME_SCRIPTS := $(or ${DAIKONDIR},$(realpath $(dir $(lastword $(MAKEFILE_LIST)))..))/.utils/plume-scripts
 endif
-PLUME_SCRIPTS ?= ${DAIKONDIR}/.utils/plume-scripts
 
-# TEST_JOBS is the number of tests to run in parallel.
-# Under CI, there are two CPUs, but limit to 1 to avoid out-of-memory error.
-# The value is exported, so recursive invocations of make do not recompute it.
-# To override it, set TEST_JOBS on the command line or in the environment.
-ifeq ($(origin TEST_JOBS), undefined)
-  ifeq ($(wildcard ${PLUME_SCRIPTS}/is-ci.sh),)
-    $(error ${PLUME_SCRIPTS}/is-ci.sh not found; run "make" in ${DAIKONDIR} to clone plume-scripts, or set TEST_JOBS)
-  endif
-  TEST_JOBS := $(if $(shell sh "${PLUME_SCRIPTS}/is-ci.sh"),1,4)
+# DAIKON_TEST_JOBS is the number of tests to run in parallel.
+# Under CI, limit to 1 to avoid out-of-memory errors.
+# To override it, set DAIKON_TEST_JOBS on the command line or in the environment.
+# The default is computed only when a recipe uses it, so targets such as
+# "clean" and "help" work even if plume-scripts has not been cloned.
+ifeq ($(strip ${DAIKON_TEST_JOBS}),)
+  override DAIKON_TEST_JOBS = $(if $(wildcard ${PLUME_SCRIPTS}/is-ci.sh),$(if $(shell sh "${PLUME_SCRIPTS}/is-ci.sh"),1,4),$(error ${PLUME_SCRIPTS}/is-ci.sh not found; clone plume-scripts there, or set DAIKON_TEST_JOBS))
 endif
-export TEST_JOBS
diff --git a/tests/dyncomp-tests/Makefile b/tests/dyncomp-tests/Makefile
index e69a8eb91a..3838027735 100644
--- a/tests/dyncomp-tests/Makefile
+++ b/tests/dyncomp-tests/Makefile
@@ -64,7 +64,7 @@ update-all:
 
 .PHONY: clean-all
 clean-all:
-	${MAKE} --jobs=${TEST_JOBS} ${MPARG} nightly-tests__clean
+	${MAKE} --jobs=${DAIKON_TEST_JOBS} ${MPARG} nightly-tests__clean
 
 
 default-projects__%: pgbovine-tests__%
diff --git a/tests/kvasir-tests/Makefile b/tests/kvasir-tests/Makefile
index 9e86fee177..6774e5bb39 100644
--- a/tests/kvasir-tests/Makefile
+++ b/tests/kvasir-tests/Makefile
@@ -19,7 +19,7 @@ default: summary-w-daikon
 
 .PHONY: regression-tests
 regression-tests:
-	${MAKE} --jobs=${TEST_JOBS} ${MPARG} nightly-tests__diffs-w-daikon-if-working
+	${MAKE} --jobs=${DAIKON_TEST_JOBS} ${MPARG} nightly-tests__diffs-w-daikon-if-working
 	${MAKE} nightly-summary-only-w-daikon
 	@${MAKE} --no-print-directory results
 
@@ -69,7 +69,7 @@ update-all:
 
 .PHONY: clean-all
 clean-all:
-	${MAKE} --jobs=${TEST_JOBS} ${MPARG} nightly-tests__clean
+	${MAKE} --jobs=${DAIKON_TEST_JOBS} ${MPARG} nightly-tests__clean
 
 default-projects__%: pgbovine-tests__% smcc-tests__% tiny-real-tests__% tws-tests__%
 	@