python3/python-3.1-fix-parallel-make.patch
Toshio Kuratomi 4c1f6daa7c * Fri Aug 6 2010 Toshio Kuratomi <toshio@fedoraproject.org> - 3.1.2-13
- Turn on computed-gotos.
- Fix for parallel make and graminit.c
2010-08-19 14:12:57 -04:00

39 lines
1.4 KiB
Diff

Index: Python-3.1.2/Makefile.pre.in
===================================================================
--- Python-3.1.2.orig/Makefile.pre.in
+++ Python-3.1.2/Makefile.pre.in
@@ -215,6 +215,7 @@ IO_OBJS= \
##########################################################################
# Grammar
+GRAMMAR_STAMP= $(srcdir)/grammar-stamp
GRAMMAR_H= $(srcdir)/Include/graminit.h
GRAMMAR_C= $(srcdir)/Python/graminit.c
GRAMMAR_INPUT= $(srcdir)/Grammar/Grammar
@@ -535,9 +536,24 @@ Modules/python.o: $(srcdir)/Modules/pyth
$(IO_OBJS): $(IO_H)
-$(GRAMMAR_H) $(GRAMMAR_C): $(PGEN) $(GRAMMAR_INPUT)
+# GNU "make" interprets rules with two dependents as two copies of the rule.
+#
+# In a parallel build this can lead to pgen being run twice, once for each of
+# GRAMMAR_H and GRAMMAR_C, leading to race conditions in which the compiler
+# reads a partially-overwritten copy of one of these files, leading to syntax
+# errors (or linker errors if the fragment happens to be syntactically valid C)
+#
+# See http://www.gnu.org/software/hello/manual/automake/Multiple-Outputs.html
+# for more information
+#
+# Introduce ".grammar-stamp" as a contrived single output from PGEN to avoid
+# this:
+$(GRAMMAR_H) $(GRAMMAR_C): $(GRAMMAR_STAMP)
+
+$(GRAMMAR_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)