pyrox.dev
1diff -up Python-2.7/Makefile.pre.in.fix-parallel-make Python-2.7/Makefile.pre.in
2--- Python-2.7/Makefile.pre.in.fix-parallel-make 2010-07-22 15:01:39.567996932 -0400
3+++ Python-2.7/Makefile.pre.in 2010-07-22 15:47:02.437998509 -0400
4@@ -207,6 +207,7 @@ SIGNAL_OBJS= @SIGNAL_OBJS@
5
6 ##########################################################################
7 # Grammar
8+GRAMMAR_STAMP= $(srcdir)/grammar-stamp
9 GRAMMAR_H= $(srcdir)/Include/graminit.h
10 GRAMMAR_C= $(srcdir)/Python/graminit.c
11 GRAMMAR_INPUT= $(srcdir)/Grammar/Grammar
12@@ -530,10 +531,24 @@ Modules/getpath.o: $(srcdir)/Modules/get
13 Modules/python.o: $(srcdir)/Modules/python.c
14 $(MAINCC) -c $(PY_CFLAGS) -o $@ $(srcdir)/Modules/python.c
15
16+# GNU "make" interprets rules with two dependents as two copies of the rule.
17+#
18+# In a parallel build this can lead to pgen being run twice, once for each of
19+# GRAMMAR_H and GRAMMAR_C, leading to race conditions in which the compiler
20+# reads a partially-overwritten copy of one of these files, leading to syntax
21+# errors (or linker errors if the fragment happens to be syntactically valid C)
22+#
23+# See http://www.gnu.org/software/hello/manual/automake/Multiple-Outputs.html
24+# for more information
25+#
26+# Introduce ".grammar-stamp" as a contrived single output from PGEN to avoid
27+# this:
28+$(GRAMMAR_H) $(GRAMMAR_C): $(GRAMMAR_STAMP)
29
30-$(GRAMMAR_H) $(GRAMMAR_C): $(PGEN) $(GRAMMAR_INPUT)
31+$(GRAMMAR_STAMP): $(PGEN) $(GRAMMAR_INPUT)
32 -@$(INSTALL) -d Include
33 -$(PGEN) $(GRAMMAR_INPUT) $(GRAMMAR_H) $(GRAMMAR_C)
34+ touch $(GRAMMAR_STAMP)
35
36 $(PGEN): $(PGENOBJS)
37 $(CC) $(OPT) $(LDFLAGS) $(PGENOBJS) $(LIBS) -o $(PGEN)