From 153b4495c1bdf38e84f75986563dbae336000fad Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso@mit.edu>
Date: Fri, 6 May 2005 09:42:34 -0400
Subject: [PATCH] If the .c and .h file already exist, and they have not
 changed, use the original versions of the files, so as to avoid rebuilding
 files when not necessary.  Also fixes a potential SMP/Parallel build problem
 when one make process runs compile_et to generate the .h file, and a
 partially generated .c file is compiled by another make process.  (Addresses
 Sourceforge Bug: #1157933)

---
 lib/et/compile_et.sh.in | 14 ++++++++++++--
 lib/et/et_c.awk         |  5 ++++-
 lib/et/et_h.awk         |  5 ++++-
 3 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/lib/et/compile_et.sh.in b/lib/et/compile_et.sh.in
index e41b51b..27bb3cd 100644
--- a/lib/et/compile_et.sh.in
+++ b/lib/et/compile_et.sh.in
@@ -32,5 +32,15 @@ if test ! -f "$ROOT.et" ; then
     exit 1;
 fi
 
-$AWK -f "${DIR}/et_h.awk" "outfile=${BASE}.h" "$ROOT.et"
-$AWK -f "${DIR}/et_c.awk" "outfile=${BASE}.c" "$ROOT.et"
+$AWK -f "${DIR}/et_h.awk" "outfile=${BASE}.h.$$" "outfn=${BASE}.h" "$ROOT.et"
+if test -f ${BASE}.h && cmp -s ${BASE}.h.$$ ${BASE}.h ; then
+    rm ${BASE}.h.$$
+else
+    mv ${BASE}.h.$$ ${BASE}.h
+fi
+$AWK -f "${DIR}/et_c.awk" "outfile=${BASE}.c.$$" "outfn=${BASE}.c" "$ROOT.et"
+if test -f ${BASE}.c && cmp -s ${BASE}.c.$$ ${BASE}.c ; then
+    rm ${BASE}.c.$$
+else
+    mv ${BASE}.c.$$ ${BASE}.c
+fi
diff --git a/lib/et/et_c.awk b/lib/et/et_c.awk
index ab0079f..1769b79 100644
--- a/lib/et/et_c.awk
+++ b/lib/et/et_c.awk
@@ -1,4 +1,7 @@
 BEGIN { 
+if ( length(outfn) == 0) {
+	outfn = outfile
+}
 char_shift=64
 ## "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_";
 c2n["A"]=1
@@ -119,7 +122,7 @@ c2n["_"]=63
 		}
 	}
 	print "/*" > outfile
-	print " * " outfile ":" > outfile
+	print " * " outfn ":" > outfile
 	print " * This file is automatically generated; please do not edit it." > outfile
 	print " */" > outfile
 
diff --git a/lib/et/et_h.awk b/lib/et/et_h.awk
index 73caffc..8337121 100644
--- a/lib/et/et_h.awk
+++ b/lib/et/et_h.awk
@@ -1,4 +1,7 @@
 BEGIN { 
+if ( length(outfn) == 0) {
+	outfn = outfile
+}
 char_shift=64
 ## "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_";
 c2n["A"]=1
@@ -123,7 +126,7 @@ c2n["_"]=63
 	curr_high = tab_base_high
 	curr_sign = tab_base_sign
 	print "/*" > outfile
-	print " * " outfile ":" > outfile
+	print " * " outfn ":" > outfile
 	print " * This file is automatically generated; please do not edit it." > outfile
 	print " */" > outfile
 	print "" > outfile
-- 
1.8.3.1