Generate event-config.h with a single sed script

This approach should make the creation of the file more atomic, to
fix a bug reported by Dinh.

This patch has one change from Zack's original version: it avoids
$<, since Dave Hart tells me he thinks that's not so portable.

(commit message by nickm)

diff --git a/Makefile.am b/Makefile.am
index 09505bd76688e62c073a84b4357b01d0af730fbe..d3fb97f85e704ce21b8aed342dc7ae9f8e55e46b 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -100,6 +100,7 @@ EXTRA_DIST = \
        autogen.sh \
        event_rpcgen.py \
        libevent.pc.in \
+       make-event-config.sed \
        Doxyfile \
        whatsnew-2.0.txt \
        Makefile.nmake test/Makefile.nmake \
@@ -161,26 +162,12 @@ if SIGNAL_SUPPORT
 SYS_SRC += signal.c
 endif
 
-BUILT_SOURCES = ./include/event2/event-config.h
-
-./include/event2/event-config.h: config.h
-       @MKDIR_P@ ./include/event2
-       echo '/* event2/event-config.h' > $@
-       echo ' *' >> $@
-       echo ' * This file was generated by autoconf when libevent was built, and post-' >> $@
-       echo ' * processed by Libevent so that its macros would have a uniform prefix.' >> $@
-       echo ' *' >> $@
-       echo ' * DO NOT EDIT THIS FILE.' >> $@
-       echo ' *' >> $@
-       echo ' * Do not rely on macros in this file existing in later versions.'>> $@
-       echo ' */' >> $@
-       echo '#ifndef _EVENT2_EVENT_CONFIG_H_' >> $@
-       echo '#define _EVENT2_EVENT_CONFIG_H_' >> $@
-
-       sed -e 's/#define /#define _EVENT_/' \
-           -e 's/#undef /#undef _EVENT_/' \
-           -e 's/#ifndef /#ifndef _EVENT_/' < config.h >> $@
-       echo "#endif" >> $@
+BUILT_SOURCES = include/event2/event-config.h
+
+include/event2/event-config.h: config.h make-event-config.sed
+       test -d include/event2 || $(MKDIR_P) include/event2
+       $(SED) -f $(srcdir)/make-event-config.sed < config.h > $@T
+       mv -f $@T $@
 
 CORE_SRC = event.c evthread.c buffer.c \
        bufferevent.c bufferevent_sock.c bufferevent_filter.c \

diff --git a/make-event-config.sed b/make-event-config.sed
new file mode 100644 (file)
index 0000000..b343e3b
--- /dev/null
+++ b/make-event-config.sed
@@ -0,0 +1,23 @@
+# Sed script to postprocess config.h into event-config.h.
+
+1i\
+/* event2/event-config.h\
+ *\
+ * This file was generated by autoconf when libevent was built, and post-\
+ * processed by Libevent so that its macros would have a uniform prefix.\
+ *\
+ * DO NOT EDIT THIS FILE.\
+ *\
+ * Do not rely on macros in this file existing in later versions.\
+ */\
+\
+#ifndef _EVENT2_EVENT_CONFIG_H_\
+#define _EVENT2_EVENT_CONFIG_H_\
+
+$a\
+\
+#endif /* event2/event-config.h */
+
+s/#define /#define _EVENT_/
+s/#undef /#undef _EVENT_/
+s/#ifndef /#ifndef _EVENT_/