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-rw-r--r--python/Python-parallel-make.patch36
1 files changed, 36 insertions, 0 deletions
diff --git a/python/Python-parallel-make.patch b/python/Python-parallel-make.patch
new file mode 100644
index 000000000000..81ce8dabe35b
--- /dev/null
+++ b/python/Python-parallel-make.patch
@@ -0,0 +1,36 @@
+--- misc/Python-2.6.1/Makefile.pre.in.fix-parallel-make 2010-07-22 15:01:39.567996932 -0400
++++ misc/build/Python-2.6.1/Makefile.pre.in 2010-07-22 15:47:02.437998509 -0400
+@@ -207,6 +207,7 @@ SIGNAL_OBJS= @SIGNAL_OBJS@
+
+ ##########################################################################
+ # Grammar
++GRAMMAR_STAMP= $(srcdir)/grammar-stamp
+ GRAMMAR_H= $(srcdir)/Include/graminit.h
+ GRAMMAR_C= $(srcdir)/Python/graminit.c
+ GRAMMAR_INPUT= $(srcdir)/Grammar/Grammar
+@@ -530,10 +531,24 @@ Modules/getpath.o: $(srcdir)/Modules/get
+ Modules/python.o: $(srcdir)/Modules/python.c
+ $(MAINCC) -c $(PY_CFLAGS) -o $@ $(srcdir)/Modules/python.c
+
++# GNU "make" interprets rules with two dependents as two copies of the rule.
++#
++# In a parallel build this can lead to pgen being run twice, once for each of
++# GRAMMAR_H and GRAMMAR_C, leading to race conditions in which the compiler
++# reads a partially-overwritten copy of one of these files, leading to syntax
++# errors (or linker errors if the fragment happens to be syntactically valid C)
++#
++# See http://www.gnu.org/software/hello/manual/automake/Multiple-Outputs.html
++# for more information
++#
++# Introduce ".grammar-stamp" as a contrived single output from PGEN to avoid
++# this:
++$(GRAMMAR_H) $(GRAMMAR_C): $(GRAMMAR_STAMP)
+
+-$(GRAMMAR_H) $(GRAMMAR_C): $(PGEN) $(GRAMMAR_INPUT)
++$(GRAMMAR_STAMP): $(PGEN) $(GRAMMAR_INPUT)
+ -@$(INSTALL) -d Include
+ -$(PGEN) $(GRAMMAR_INPUT) $(GRAMMAR_H) $(GRAMMAR_C)
++ touch $(GRAMMAR_STAMP)
+
+ $(PGEN): $(PGENOBJS)
+ $(CC) $(OPT) $(LDFLAGS) $(PGENOBJS) $(LIBS) -o $(PGEN)