configure: use "-Og" for non-developer builds, add COPTFLAGS variable.

Unfortuntely we get spurious uninitialized variable warnings with
anything but -O3 or no optimization, so set default CWARNFLAGS
appropriately.

MCP bench results without optimization:
   store_load_msec:28509-31001(29206.6+/-9.4e+02)
   vsz_kb:580004-580016(580006+/-4.8)
   store_rewrite_sec:11.640000-12.730000(11.908+/-0.41)
   listnodes_sec:1.790000-1.880000(1.83+/-0.032)
   listchannels_sec:21.180000-21.950000(21.476+/-0.27)
   routing_sec:2.210000-11.160000(7.126+/-3.1)
   peer_write_all_sec:36.270000-41.200000(38.168+/-1.9)

MCP bench with -Og: 22% speedup vs no optimization
   store_load_msec:21963-23645(22841+/-6.6e+02)
   vsz_kb:579916
   store_rewrite_sec:10.080000-10.960000(10.456+/-0.3)
   listnodes_sec:1.280000-1.390000(1.338+/-0.047)
   listchannels_sec:14.770000-16.080000(15.518+/-0.46)
   routing_sec:0.990000-6.660000(3.958+/-2.2)
   peer_write_all_sec:29.950000-32.950000(31.138+/-1)

MCP bench with -O2: 31% speedup vs no optimization
   store_load_msec:20713-22088(21505.6+/-4.8e+02)
   vsz_kb:579928
   store_rewrite_sec:9.570000-11.200000(10.192+/-0.54)
   listnodes_sec:0.960000-1.090000(1.028+/-0.045)
   listchannels_sec:10.400000-11.770000(11.012+/-0.48)
   routing_sec:0.300000-3.140000(1.978+/-1.1)
   peer_write_all_sec:28.980000-30.310000(29.572+/-0.44)

MCP bench with -O3 -flto: 36% speedup vs no optimization
   store_load_msec:19616-20191(19862.6+/-1.9e+02)
   vsz_kb:578452
   store_rewrite_sec:8.980000-9.960000(9.55+/-0.32)
   listnodes_sec:0.920000-1.910000(1.18+/-0.38)
   listchannels_sec:8.960000-9.450000(9.206+/-0.16)
   routing_sec:0.730000-1.850000(1.438+/-0.42)
   peer_write_all_sec:28.090000-29.410000(28.772+/-0.42)

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

.travis.yml

@@ -17,7 +17,7 @@ addons:
       - gcc-4.8
 
 env:
-  - ARCH=64 SOURCE_CHECK_ONLY=true CDEBUGFLAGS="-std=gnu11 -g -fstack-protector -O3 -flto" LDFLAGS="-O3 -flto"
+  - ARCH=64 SOURCE_CHECK_ONLY=true COPTFLAGS="-O3 -flto"
 #  - VALGRIND=0 ARCH=32 DEVELOPER=1 COMPILER=gcc TEST_GROUP=1 TEST_GROUP_COUNT=2 SOURCE_CHECK_ONLY=false
 #  - VALGRIND=0 ARCH=32 DEVELOPER=1 COMPILER=gcc TEST_GROUP=2 TEST_GROUP_COUNT=2 SOURCE_CHECK_ONLY=false
   - VALGRIND=0 ARCH=64 DEVELOPER=1 COMPILER=gcc SOURCE_CHECK_ONLY=false

CHANGELOG.md

@@ -22,6 +22,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - JSON API: `invoice` expiry defaults to 7 days, and can have s/m/h/d/w suffixes.
 - Config: Increased default amount for minimal channel capacity from 1k sat to 10k sat.
+- Build: Non-developer builds are now done with "-Og" optimization.
 
 ### Deprecated
 

Makefile

@@ -185,14 +185,12 @@ WIRE_GEN := tools/generate-wire.py
 ALL_PROGRAMS =
 
 CPPFLAGS = -DBINTOPKGLIBEXECDIR='"'$(shell sh tools/rel.sh $(bindir) $(pkglibexecdir))'"'
-CWARNFLAGS := -Werror -Wall -Wundef -Wmissing-prototypes -Wmissing-declarations -Wstrict-prototypes -Wold-style-definition
+CFLAGS = $(CPPFLAGS) $(CWARNFLAGS) $(CDEBUGFLAGS) $(COPTFLAGS) -I $(CCANDIR) $(EXTERNAL_INCLUDE_FLAGS) -I . -I/usr/local/include $(FEATURES) $(COVFLAGS) $(DEV_CFLAGS) -DSHACHAIN_BITS=48 -DJSMN_PARENT_LINKS $(PIE_CFLAGS) $(COMPAT_CFLAGS)
-CDEBUGFLAGS := -std=gnu11 -g -fstack-protector $(SANITIZER_FLAGS)
-CFLAGS = $(CPPFLAGS) $(CWARNFLAGS) $(CDEBUGFLAGS) -I $(CCANDIR) $(EXTERNAL_INCLUDE_FLAGS) -I . -I/usr/local/include $(FEATURES) $(COVFLAGS) $(DEV_CFLAGS) -DSHACHAIN_BITS=48 -DJSMN_PARENT_LINKS $(PIE_CFLAGS) $(COMPAT_CFLAGS)
 
 # We can get configurator to run a different compile cmd to cross-configure.
 CONFIGURATOR_CC := $(CC)
 
-LDFLAGS = $(PIE_LDFLAGS) $(SANITIZER_FLAGS)
+LDFLAGS = $(PIE_LDFLAGS) $(SANITIZER_FLAGS) $(COPTFLAGS)
 ifeq ($(STATIC),1)
 LDLIBS = -L/usr/local/lib -Wl,-dn -lgmp -lsqlite3 -lz -Wl,-dy -lm -lpthread -ldl $(COVFLAGS)
 else

configure

@@ -6,7 +6,6 @@ set -e
 # Default values, loaded from environment or canned.
 PREFIX=${PREFIX:-/usr/local}
 CC=${CC:-cc}
-CWARNFLAGS=${CWARNFLAGS:--Werror -Wall -Wundef -Wmissing-prototypes -Wmissing-declarations -Wstrict-prototypes -Wold-style-definition}
 CDEBUGFLAGS=${CDEBUGFLAGS:--std=gnu11 -g -fstack-protector}
 DEVELOPER=${DEVELOPER:-0}
 EXPERIMENTAL_FEATURES=${EXPERIMENTAL_FEATURES:-0}
@@ -43,6 +42,7 @@ usage()
     usage_with_default "CDEBUGFLAGS" "$CDEBUGFLAGS"
     usage_with_default "CONFIGURATOR_CC" "$CONFIGURATOR_CC"
     usage_with_default "PYTEST" "$PYTEST"
+    usage_with_default "COPTFLAGS" "$COPTFLAGS"
     echo "    To override compile line for configurator itself"
 
     echo "Options include:"
@@ -110,6 +110,7 @@ for opt in "$@"; do
 	CONFIGURATOR_CC=*) CONFIGURATOR_CC="${opt#CONFIGURATOR_CC=}";;
 	CWARNFLAGS=*) CWARNFLAGS="${opt#CWARNFLAGS=}";;
 	CDEBUGFLAGS=*) CDEBUGFLAGS="${opt#CDEBUGFLAGS=}";;
+	COPTFLAGS=*) COPTFLAGS="${opt#COPTFLAGS=}";;
 	PYTEST=*) PYTEST="${opt#PYTEST=}";;
 	--prefix=*) PREFIX="${opt#--prefix=}";;
 	--enable-developer) DEVELOPER=1;;
@@ -132,8 +133,26 @@ for opt in "$@"; do
     esac
 done
 
+# Default COPTFLAGS is only set if not developer
+if [ -z ${COPTFLAGS+x} ]; then
+   if [ "$DEVELOPER" = 0 ]; then
+       COPTFLAGS="-Og"
+   else
+       COPTFLAGS=""
+   fi
+fi
+
+# We only enable Werror if we're -O3 or no-optimization.  Otherwise gcc gives
+# false positives.
+if [ -z ${CWARNFLAGS+x} ]; then
+    CWARNFLAGS="-Wall -Wundef -Wmissing-prototypes -Wmissing-declarations -Wstrict-prototypes -Wold-style-definition"
+    if [ -x ${COPTFLAGS+x} ] || [ -z "${COPTFLAGS##*-O3*}" ]; then
+	CWARNFLAGS="$CWARNFLAGS -Werror"
+    fi
+fi
+
 echo -n "Compiling $CONFIGURATOR..."
-$CC $CWARNFLAGS $CDEBUGFLAGS -o $CONFIGURATOR $CONFIGURATOR.c
+$CC $CWARNFLAGS $CDEBUGFLAGS $COPTFLAGS -o $CONFIGURATOR $CONFIGURATOR.c
 echo "done"
 
 if [ -z "$VALGRIND" ]; then
@@ -156,7 +175,7 @@ if [ "$ASAN" = "1" ]; then
 fi
 
 rm -f $CONFIG_VAR_FILE.$$
-$CONFIGURATOR --extra-tests --autotools-style --var-file=$CONFIG_VAR_FILE.$$ --header-file=$CONFIG_HEADER --configurator-cc="$CONFIGURATOR_CC" "$CC" $CWARNFLAGS $CDEBUGFLAGS <<EOF
+$CONFIGURATOR --extra-tests --autotools-style --var-file=$CONFIG_VAR_FILE.$$ --header-file=$CONFIG_HEADER --configurator-cc="$CONFIGURATOR_CC" "$CC" $CWARNFLAGS $CDEBUGFLAGS $COPTFLAGS <<EOF
 var=HAVE_GOOD_LIBSODIUM
 desc=libsodium with IETF chacha20 variants
 style=DEFINES_EVERYTHING|EXECUTE|MAY_NOT_COMPILE
@@ -194,6 +213,7 @@ add_var CC "$CC"
 add_var CONFIGURATOR_CC "$CONFIGURATOR_CC"
 add_var CWARNFLAGS "$CWARNFLAGS"
 add_var CDEBUGFLAGS "$CDEBUGFLAGS"
+add_var COPTFLAGS "$COPTFLAGS"
 add_var VALGRIND "$VALGRIND"
 add_var DEVELOPER "$DEVELOPER" $CONFIG_HEADER
 add_var EXPERIMENTAL_FEATURES "$EXPERIMENTAL_FEATURES" $CONFIG_HEADER