From 801110b30319a8ab1f8f29eedbac3798b03afb55 Mon Sep 17 00:00:00 2001
From: Martin Panter <vadmium+py@gmail.com>
Date: Thu, 28 Jul 2016 01:28:27 +0000
Subject: [PATCH] Issue #27490: Do not build pgen when cross-compiling

The dependendency on the $(PGEN) variable must only be
set when not cross-compiling. When cross-compiling,
$(PGEN) will not be used, so no need to build it.

Patch by Thomas Perl.
---
 Makefile.pre.in | 2 +-
 Misc/ACKS       | 1 +
 Misc/NEWS       | 3 +++
 configure       | 4 ++++
 configure.ac    | 3 +++
 5 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/Makefile.pre.in b/Makefile.pre.in
index dffc0b99731..ccfdd59952e 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -680,7 +680,7 @@ Modules/grpmodule.o: $(srcdir)/Modules/grpmodule.c $(srcdir)/Modules/posixmodule
 
 Modules/pwdmodule.o: $(srcdir)/Modules/pwdmodule.c $(srcdir)/Modules/posixmodule.h
 
-$(GRAMMAR_H): $(GRAMMAR_INPUT) $(PGEN)
+$(GRAMMAR_H): $(GRAMMAR_INPUT) @PGEN_DEPENDENCY@
 	@$(MKDIR_P) Include
 	# Avoid copying the file onto itself for an in-tree build
 	if test "$(cross_compiling)" != "yes"; then \
diff --git a/Misc/ACKS b/Misc/ACKS
index 8edea85e4c4..7aa8fc8af82 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1056,6 +1056,7 @@ Steven Pemberton
 Bo Peng
 Santiago Peresón
 George Peristerakis
+Thomas Perl
 Mathieu Perreault
 Mark Perrego
 Trevor Perrin
diff --git a/Misc/NEWS b/Misc/NEWS
index 3158c33d07f..0676ff841a6 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -90,6 +90,9 @@ What's New in Python 2.7.12?
 Build
 -----
 
+- Issue #27490: Do not build pgen when cross-compiling.  Patch by Thomas
+  Perl.
+
 - Issue #26930: Update Windows builds to use OpenSSL 1.0.2h.
 
 IDLE
diff --git a/configure b/configure
index 897f0a244f2..521dd7a06ce 100755
--- a/configure
+++ b/configure
@@ -735,6 +735,7 @@ UNIVERSALSDK
 CONFIG_ARGS
 SOVERSION
 VERSION
+PGEN_DEPENDENCY
 PYTHON_FOR_BUILD
 host_os
 host_vendor
@@ -2924,14 +2925,17 @@ $as_echo_n "checking for python interpreter for cross build... " >&6; }
 $as_echo "$interp" >&6; }
 	PYTHON_FOR_BUILD='_PYTHON_PROJECT_BASE=$(abs_builddir) _PYTHON_HOST_PLATFORM=$(_PYTHON_HOST_PLATFORM) PYTHONPATH=$(shell test -f pybuilddir.txt && echo $(abs_builddir)/`cat pybuilddir.txt`:)$(srcdir)/Lib:$(srcdir)/Lib/$(PLATDIR) '$interp
     fi
+    PGEN_DEPENDENCY=''
 elif test "$cross_compiling" = maybe; then
     as_fn_error $? "Cross compiling required --host=HOST-TUPLE and --build=ARCH" "$LINENO" 5
 else
     PYTHON_FOR_BUILD='./$(BUILDPYTHON) -E'
+    PGEN_DEPENDENCY='$(PGEN)'
 fi
 
 
 
+
 if test "$prefix" != "/"; then
     prefix=`echo "$prefix" | sed -e 's/\/$//g'`
 fi
diff --git a/configure.ac b/configure.ac
index f5e741d29ba..c4dfe79053e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -36,12 +36,15 @@ if test "$cross_compiling" = yes; then
         AC_MSG_RESULT($interp)
 	PYTHON_FOR_BUILD='_PYTHON_PROJECT_BASE=$(abs_builddir) _PYTHON_HOST_PLATFORM=$(_PYTHON_HOST_PLATFORM) PYTHONPATH=$(shell test -f pybuilddir.txt && echo $(abs_builddir)/`cat pybuilddir.txt`:)$(srcdir)/Lib:$(srcdir)/Lib/$(PLATDIR) '$interp
     fi
+    PGEN_DEPENDENCY=''
 elif test "$cross_compiling" = maybe; then
     AC_MSG_ERROR([Cross compiling required --host=HOST-TUPLE and --build=ARCH])
 else
     PYTHON_FOR_BUILD='./$(BUILDPYTHON) -E'
+    PGEN_DEPENDENCY='$(PGEN)'
 fi
 AC_SUBST(PYTHON_FOR_BUILD)
+AC_SUBST(PGEN_DEPENDENCY)
 
 dnl Ensure that if prefix is specified, it does not end in a slash. If
 dnl it does, we get path names containing '//' which is both ugly and