# HG changeset patch
# Parent  1d72402c1c91f4d7f95e142562aee17aac13eca6
Issue #22359: Decouple regeneration of checked-in files from main build

Four files are now only regenerated by special “phony” Make targets:

make graminit → Include/graminit.h and Python/graminit.c
make importlib → Python/importlib.h
make importlib_external → Python/importlib_external.h

This avoids shared Make prerequisites from being built multiple times, and
also avoids concerns with regenerating files unnecessarily and running cross-
compiled programs on the native build host.

Also remove makefile variables no longer in use.

diff -r 1d72402c1c91 Grammar/Grammar
--- a/Grammar/Grammar	Tue Mar 15 13:33:28 2016 +1300
+++ b/Grammar/Grammar	Wed Mar 16 04:23:08 2016 +0000
@@ -9,6 +9,7 @@
 
 # NOTE WELL: You should also follow all the steps listed at
 # https://docs.python.org/devguide/grammar.html
+# Use "make graminit" to regenerate Include/graminit.h and Python/graminit.c.
 
 # Start symbols for the grammar:
 #       single_input is a single interactive statement;
diff -r 1d72402c1c91 Lib/importlib/_bootstrap.py
--- a/Lib/importlib/_bootstrap.py	Tue Mar 15 13:33:28 2016 +1300
+++ b/Lib/importlib/_bootstrap.py	Wed Mar 16 04:23:08 2016 +0000
@@ -8,10 +8,8 @@
 """
 #
 # IMPORTANT: Whenever making changes to this module, be sure to run
-# a top-level make in order to get the frozen version of the module
-# updated. Not doing so will result in the Makefile to fail for
-# all others who don't have a ./python around to freeze the module
-# in the early stages of compilation.
+# "make importlib" in order to get the frozen version of the module
+# updated. Not doing so will result in the frozen version being out of date.
 #
 
 # See importlib._setup() for what is injected into the global namespace.
diff -r 1d72402c1c91 Lib/importlib/_bootstrap_external.py
--- a/Lib/importlib/_bootstrap_external.py	Tue Mar 15 13:33:28 2016 +1300
+++ b/Lib/importlib/_bootstrap_external.py	Wed Mar 16 04:23:08 2016 +0000
@@ -8,10 +8,8 @@
 """
 #
 # IMPORTANT: Whenever making changes to this module, be sure to run
-# a top-level make in order to get the frozen version of the module
-# updated. Not doing so will result in the Makefile to fail for
-# all others who don't have a ./python around to freeze the module
-# in the early stages of compilation.
+# "make importlib_external" in order to get the frozen version of the module
+# updated. Not doing so will result in the frozen version being out of date.
 #
 
 # See importlib._setup() for what is injected into the global namespace.
diff -r 1d72402c1c91 Makefile.pre.in
--- a/Makefile.pre.in	Tue Mar 15 13:33:28 2016 +1300
+++ b/Makefile.pre.in	Wed Mar 16 04:23:08 2016 +0000
@@ -277,18 +277,6 @@
 # Parser
 PGEN=		Parser/pgen$(EXE)
 
-PSRCS=		\
-		Parser/acceler.c \
-		Parser/grammar1.c \
-		Parser/listnode.c \
-		Parser/node.c \
-		Parser/parser.c \
-		Parser/bitset.c \
-		Parser/metagrammar.c \
-		Parser/firstsets.c \
-		Parser/grammar.c \
-		Parser/pgen.c
-
 POBJS=		\
 		Parser/acceler.o \
 		Parser/grammar1.o \
@@ -303,16 +291,6 @@
 
 PARSER_OBJS=	$(POBJS) Parser/myreadline.o Parser/parsetok.o Parser/tokenizer.o
 
-PGSRCS=		\
-		Objects/obmalloc.c \
-		Python/dynamic_annotations.c \
-		Python/mysnprintf.c \
-		Python/pyctype.c \
-		Parser/tokenizer_pgen.c \
-		Parser/printgrammar.c \
-		Parser/parsetok_pgen.c \
-		Parser/pgenmain.c
-
 PGOBJS=		\
 		Objects/obmalloc.o \
 		Python/dynamic_annotations.o \
@@ -328,7 +306,6 @@
 		$(srcdir)/Include/parsetok.h \
 		$(srcdir)/Parser/tokenizer.h
 
-PGENSRCS=	$(PSRCS) $(PGSRCS)
 PGENOBJS=	$(POBJS) $(PGOBJS)
 
 ##########################################################################
@@ -546,7 +523,7 @@
 	@echo
 
 coverage-report:
-	: # force rebuilding of parser and importlib
+	: # force rebuilding of parser and importlib (broken!?)
 	@touch $(GRAMMAR_INPUT)
 	@touch $(srcdir)/Lib/importlib/_bootstrap.py
 	@touch $(srcdir)/Lib/importlib/_bootstrap_external.py
@@ -715,11 +692,15 @@
 Programs/_freeze_importlib: Programs/_freeze_importlib.o $(LIBRARY_OBJS_OMIT_FROZEN)
 	$(LINKCC) $(PY_LDFLAGS) -o $@ Programs/_freeze_importlib.o $(LIBRARY_OBJS_OMIT_FROZEN) $(LIBS) $(MODLIBS) $(SYSLIBS) $(LDLAST)
 
-Python/importlib_external.h: $(srcdir)/Lib/importlib/_bootstrap_external.py Programs/_freeze_importlib
+# Regenerate Python/importlib_external.h and Python/importlib.h
+# See comment for the "graminit" target about generated files.
+.PHONY: importlib_external importlib
+
+importlib_external: $(srcdir)/Lib/importlib/_bootstrap_external.py Programs/_freeze_importlib
 	./Programs/_freeze_importlib \
 		$(srcdir)/Lib/importlib/_bootstrap_external.py Python/importlib_external.h
 
-Python/importlib.h: $(srcdir)/Lib/importlib/_bootstrap.py Programs/_freeze_importlib
+importlib: $(srcdir)/Lib/importlib/_bootstrap.py Programs/_freeze_importlib
 	./Programs/_freeze_importlib \
 		$(srcdir)/Lib/importlib/_bootstrap.py Python/importlib.h
 
@@ -781,11 +762,18 @@
 
 $(IO_OBJS): $(IO_H)
 
-$(GRAMMAR_H): $(GRAMMAR_INPUT) $(PGEN)
+# Regenerate Include/graminit.h and Python/graminit.c
+# This target (and the "importlib" targets) regenerate files that are
+# checked into the repository and distributed with the Python source code.
+# These files are not automatically generated during the normal build process
+# for various reasons:
+# * To avoid building shared prerequisites multiple times
+# * To avoid running cross-compiled programs on the native build host
+# * To minimize the steps involved in a basic build of Python
+.PHONY: graminit
+graminit: $(GRAMMAR_INPUT) $(PGEN)
 		@$(MKDIR_P) Include
 		$(PGEN) $(GRAMMAR_INPUT) $(GRAMMAR_H) $(GRAMMAR_C)
-$(GRAMMAR_C): $(GRAMMAR_H)
-		touch $(GRAMMAR_C)
 
 $(PGEN): $(PGENOBJS)
 		$(CC) $(OPT) $(PY_LDFLAGS) $(PGENOBJS) $(LIBS) -o $(PGEN)