From 7107d58ec5a3c45967e77525809612a5f89b97f3 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sat, 1 Oct 2016 13:35:13 -0400
Subject: [PATCH] Fix misplacement of submake-generated-headers prerequisites.

The sequence "configure; cd src/pl/plpython; make -j" failed due to
trying to compile plpython's .o files before the generated headers
finished building.  (This is an important real-world case, since it's
the typical second step when building both plpython2 and plpython3.)
This happens because the submake-generated-headers target is not
placed in a way to make it a prerequisite to compiling the .o files.
Fix that.

Checking other uses of submake-generated-headers, I noted that the one
attached to pg_regress was similarly misplaced; but it's actually not
needed at all for pg_regress.o, rather regress.o, so move it to be a
prerequisite of that.

Back-patch to 9.6 where submake-generated-headers was introduced
(by commit 548af97fc).  It's not immediately clear to me why the
previous coding didn't have the same issue; but since we've not
had field reports of plpython make failing, leave it alone in the
older branches.

Pavel Raiskup and Tom Lane

Discussion: <1925924.izSMJEZO3x@unused-4-107.brq.redhat.com>
---
 src/pl/plpython/Makefile     | 4 +++-
 src/test/regress/GNUmakefile | 4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/pl/plpython/Makefile b/src/pl/plpython/Makefile
index 647b4b1b96f..7680d49cb69 100644
--- a/src/pl/plpython/Makefile
+++ b/src/pl/plpython/Makefile
@@ -95,7 +95,9 @@ REGRESS_PLPYTHON3_MANGLE := $(REGRESS)
 
 include $(top_srcdir)/src/Makefile.shlib
 
-all: submake-generated-headers all-lib
+all: all-lib
+
+$(OBJS): | submake-generated-headers
 
 
 install: all install-lib install-data
diff --git a/src/test/regress/GNUmakefile b/src/test/regress/GNUmakefile
index 6a275cb729c..469b0937a23 100644
--- a/src/test/regress/GNUmakefile
+++ b/src/test/regress/GNUmakefile
@@ -36,7 +36,7 @@ EXTRADEFS = '-DHOST_TUPLE="$(host_tuple)"' \
 
 all: pg_regress$(X)
 
-pg_regress$(X): pg_regress.o pg_regress_main.o $(WIN32RES) | submake-libpgport submake-generated-headers
+pg_regress$(X): pg_regress.o pg_regress_main.o $(WIN32RES) | submake-libpgport
 	$(CC) $(CFLAGS) $^ $(LDFLAGS) $(LDFLAGS_EX) $(LIBS) -o $@
 
 # dependencies ensure that path changes propagate
@@ -65,6 +65,8 @@ include $(top_srcdir)/src/Makefile.shlib
 
 all: all-lib
 
+$(OBJS): | submake-generated-headers
+
 # Test input and expected files.  These are created by pg_regress itself, so we
 # don't have a rule to create them.  We do need rules to clean them however.
 input_files = $(patsubst $(srcdir)/input/%.source,sql/%.sql, $(wildcard $(srcdir)/input/*.source))
-- 
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