From b092055ca87a9e6f9d489d967d2ff27870687ce4 Mon Sep 17 00:00:00 2001
From: William S Fulton <wsf@fultondesigns.co.uk>
Date: Tue, 26 Mar 2019 07:48:33 +0000
Subject: [PATCH] Fix parallel 'make check-ocaml-examples'

Some versions of ocamlc create a file of the same name in the tmp directory when invoking
using ocalmc on swigp4.ml. The name is the same even from different example directories.
TMPDIR is a workaround to make ocamlc use a different directory for this temp file.
Parallel make (-j) broke because different instances of ocamlc tried to
create the same temp file.
Issue #1503
---
 Examples/Makefile.in | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/Examples/Makefile.in b/Examples/Makefile.in
index 7022166a0..2688b16f3 100644
--- a/Examples/Makefile.in
+++ b/Examples/Makefile.in
@@ -865,12 +865,15 @@ NOLINK ?= false
 OCAMLPP= -pp "camlp4o ./swigp4.cmo"
 OCAMLP4WHERE=`$(COMPILETOOL) @CAMLP4@ -where`
 OCAMLCORE=\
-	(test -f swig.mli   || $(SWIG) -ocaml -co swig.mli 2>/dev/null) &&  \
-	(test -f swig.ml    || $(SWIG) -ocaml -co swig.ml 2>/dev/null) &&  \
-	(test -f swigp4.ml  || $(SWIG) -ocaml -co swigp4.ml 2>/dev/null) &&  \
-	(test -f swig.cmi   || $(OCC) -c swig.mli) &&  \
-	(test -f swig.cmo   || $(OCC) -c swig.ml) &&  \
-	(test -f swigp4.cmi || $(OCC) -I $(OCAMLP4WHERE) -pp "camlp4o pa_extend.cmo q_MLast.cmo" -c swigp4.ml)
+	$(SWIG) -ocaml -co swig.mli 2>/dev/null &&  \
+	$(SWIG) -ocaml -co swig.ml 2>/dev/null &&  \
+	$(SWIG) -ocaml -co swigp4.ml 2>/dev/null &&  \
+	$(OCC) -c swig.mli &&  \
+	$(OCC) -c swig.ml &&  \
+	mkdir -p ./localtmp &&  \
+	env TMPDIR=./localtmp $(OCC) -I $(OCAMLP4WHERE) -pp "camlp4o pa_extend.cmo q_MLast.cmo" -c swigp4.ml && \
+	rm -rf ./localtmp
+# TMPDIR above is a workaround for some ocamlc versions, such as 4.05.0, which always create a temp file of the same name breaking parallel make
 
 ocaml_static: $(SRCDIR_SRCS)
 	$(OCAMLCORE)
@@ -957,6 +960,7 @@ ocaml_clean:
 	rm -f *_wrap* *~ .~* *.cmo *.cmi *.mli $(TARGET).ml $(RUNME) $(RUNME)_top swig.ml swigp4.ml
 	rm -f core @EXTRA_CLEAN@
 	rm -f *.@OBJEXT@ *@SO@
+	rm -rf ./localtmp
 
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