From f7db9305aa8642cb5145bba6f8948400c52396af Mon Sep 17 00:00:00 2001
From: Willy Tarreau <w@1wt.eu>
Date: Thu, 20 Sep 2018 10:38:08 +0200
Subject: [PATCH] BUILD: build with -Wextra and sort out certain warnings

We're not far from being able to build with -Wextra -Werror. The
following warnings had to be disabled to enable a clean build at
-Wextra on x86_64 using gcc 4.7, 5.5, 6.4 and 7.3 :

   sign-compare, unused-parameter, old-style-declaration,
   ignored-qualifiers, clobbered, missing-field-initializers,
   implicit-fallthrough

The following extra warnings could be added without side effects :

   type-limits, shift-negative-value, shift-overflow=2 duplicated-cond,
   null-dereference

As a result, -Wextra was enabled by default, hoping it will help catch
issues over the long term. If new undesired warnings pop up, it's easy
to disable them using the nowarn call.
---
 Makefile | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 4b5cc4072..382f944f3 100644
--- a/Makefile
+++ b/Makefile
@@ -153,8 +153,19 @@ SPEC_CFLAGS += $(call cc-opt,-fwrapv)
 SPEC_CFLAGS += $(call cc-opt,-fno-strict-overflow)
 SPEC_CFLAGS += $(call cc-nowarn,format-truncation)
 SPEC_CFLAGS += $(call cc-nowarn,address-of-packed-member)
-SPEC_CFLAGS += $(call cc-nowarn,null-dereference)
 SPEC_CFLAGS += $(call cc-nowarn,unused-label)
+SPEC_CFLAGS += $(call cc-nowarn,sign-compare)
+SPEC_CFLAGS += $(call cc-nowarn,unused-parameter)
+SPEC_CFLAGS += $(call cc-nowarn,old-style-declaration)
+SPEC_CFLAGS += $(call cc-nowarn,ignored-qualifiers)
+SPEC_CFLAGS += $(call cc-nowarn,clobbered)
+SPEC_CFLAGS += $(call cc-nowarn,missing-field-initializers)
+SPEC_CFLAGS += $(call cc-nowarn,implicit-fallthrough)
+SPEC_CFLAGS += $(call cc-opt,-Wtype-limits)
+SPEC_CFLAGS += $(call cc-opt,-Wshift-negative-value)
+SPEC_CFLAGS += $(call cc-opt,-Wshift-overflow=2)
+SPEC_CFLAGS += $(call cc-opt,-Wduplicated-cond)
+SPEC_CFLAGS += $(call cc-opt,-Wnull-dereference)
 
 #### Memory usage tuning
 # If small memory footprint is required, you can reduce the buffer size. There
@@ -806,7 +817,7 @@ EBTREE_DIR := ebtree
 
 #### Global compile options
 VERBOSE_CFLAGS = $(CFLAGS) $(TARGET_CFLAGS) $(SMALL_OPTS) $(DEFINE)
-COPTS  = -Iinclude -I$(EBTREE_DIR) -Wall
+COPTS  = -Iinclude -I$(EBTREE_DIR) -Wall -Wextra
 COPTS += $(CFLAGS) $(TARGET_CFLAGS) $(SMALL_OPTS) $(DEFINE) $(SILENT_DEFINE)
 COPTS += $(DEBUG) $(OPTIONS_CFLAGS) $(ADDINC)