From 6d85ba384f35ff51200f27461b54457488fc27ce Mon Sep 17 00:00:00 2001
From: Nicolas Williams <nico@twosigma.com>
Date: Tue, 19 Jan 2021 14:23:58 -0600
Subject: [PATCH] clang-format generated code for easier debugging

---
 cf/Makefile.am.common | 13 +++++++++++--
 configure.ac          |  1 +
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/cf/Makefile.am.common b/cf/Makefile.am.common
index 72b22d304..e79bb62ee 100644
--- a/cf/Makefile.am.common
+++ b/cf/Makefile.am.common
@@ -143,11 +143,20 @@ check-local::
 
 SUFFIXES += .x .z .hx
 
+# It's useful for debugging to format generated sources.  The default for all
+# clang-format styles is to sort includes, but in many cases in-tree we really
+# don't want to do that.
 .x.c:
-	@cmp -s $< $@ 2> /dev/null || cp $< $@
+	@if [ -z "$(CLANG_FORMAT)" ]; then \
+	    cmp -s $< $@ 2> /dev/null || cp $< $@; \
+	else \
+	    cp $< $@.tmp.c; \
+            $(CLANG_FORMAT) -style='{BasedOnStyle: Chromium, SortIncludes: false}' -i $@.tmp.c; \
+	    cmp -s $@.tmp.c $@ 2> /dev/null || mv $@.tmp.c $@; \
+	fi
 
 .hx.h:
-	@cmp -s $< $@ 2> /dev/null || cp $< $@
+	@cmp -s $< $@ 2> /dev/null || cp $< $@;
 
 SUFFIXES += .1 .3 .5 .7 .8 .cat1 .cat3 .cat5 .cat7 .cat8
 
diff --git a/configure.ac b/configure.ac
index 396d978ee..1c4267179 100644
--- a/configure.ac
+++ b/configure.ac
@@ -18,6 +18,7 @@ dnl Checks for programs.
 AC_PROG_CC
 AM_PROG_CC_C_O
 AC_PROG_CPP
+AC_CHECK_PROG(CLANG_FORMAT, clang-format, [clang-format], [no])
 
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])