From 5d894620b437a28a3742df35cbdd2b7d2f2cdea7 Mon Sep 17 00:00:00 2001
From: Simon Kelley <simon@thekelleys.org.uk>
Date: Fri, 17 Jan 2025 16:48:08 +0000
Subject: [PATCH] Extend build fingerprinting to include CFLAGS.

If the value of CFLAGS is changed between builds, the makefile
will rebuid, in the same way as for COPTS.
---
 Makefile     | 4 ++--
 src/config.h | 5 +++++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 5a9025b..9158050 100644
--- a/Makefile
+++ b/Makefile
@@ -71,8 +71,8 @@ nft_cflags =    `echo $(COPTS) | $(top)/bld/pkg-wrapper HAVE_NFTSET $(PKG_CONFIG
 nft_libs =      `echo $(COPTS) | $(top)/bld/pkg-wrapper HAVE_NFTSET $(PKG_CONFIG) --libs libnftables`
 version =       -DVERSION='\"`$(top)/bld/get-version $(top)`\"'
 
-sum?=$(shell $(CC) -DDNSMASQ_COMPILE_OPTS $(COPTS) -E $(top)/$(SRC)/dnsmasq.h | ( md5sum 2>/dev/null || md5 ) | cut -f 1 -d ' ')
-sum!=$(CC) -DDNSMASQ_COMPILE_OPTS $(COPTS) -E $(top)/$(SRC)/dnsmasq.h | ( md5sum 2>/dev/null || md5 ) | cut -f 1 -d ' '
+sum?=$(shell echo $(CC) -DDNSMASQ_COMPILE_FLAGS="$(CFLAGS)" -DDNSMASQ_COMPILE_OPTS $(COPTS) -E $(top)/$(SRC)/dnsmasq.h | ( md5sum 2>/dev/null || md5 ) | cut -f 1 -d ' ')
+sum!=echo $(CC) -DDNSMASQ_COMPILE_FLAGS="$(CFLAGS)" -DDNSMASQ_COMPILE_OPTS $(COPTS) -E $(top)/$(SRC)/dnsmasq.h | ( md5sum 2>/dev/null || md5 ) | cut -f 1 -d ' '
 copts_conf = .copts_$(sum)
 
 objs = cache.o rfc1035.o util.o option.o forward.o network.o \
diff --git a/src/config.h b/src/config.h
index 5e65df6..6f89b71 100644
--- a/src/config.h
+++ b/src/config.h
@@ -362,6 +362,11 @@ HAVE_SOCKADDR_SA_LEN
 #define HAVE_INOTIFY
 #endif
 
+/* This never compiles code, it's only used by the makefile to fingerprint builds. */
+#ifdef DNSMASQ_COMPILE_FLAGS
+static char *compile_flags = DNSMASQ_COMPILE_FLAGS;
+#endif
+
 /* Define a string indicating which options are in use.
    DNSMASQ_COMPILE_OPTS is only defined in dnsmasq.c */