configure: support sanitizers properly.

For example, if we use -fsanitize=undefined, we can't do unaligned
integer access, but since we didn't test with the sanitizer flags, we
didn't know this, and set `HAVE_UNALIGNED_ACCESS=1`.

Also, add -fno-sanitize-recover= in developer mode, so we actually
fail binaries if something is detected.

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

Makefile

@@ -43,20 +43,6 @@ VG=VALGRIND=1 valgrind -q --error-exitcode=7
 VG_TEST_ARGS = --track-origins=yes --leak-check=full --show-reachable=yes --errors-for-leak-kinds=all
 endif
 
-SANITIZER_FLAGS :=
-
-ifneq ($(ASAN),0)
-SANITIZER_FLAGS += -fsanitize=address
-endif
-
-ifneq ($(UBSAN),0)
-SANITIZER_FLAGS += -fsanitize=undefined
-endif
-
-ifneq ($(FUZZING), 0)
-SANITIZER_FLAGS += -fsanitize=fuzzer-no-link
-endif
-
 ifeq ($(DEVELOPER),1)
 DEV_CFLAGS=-DCCAN_TAKE_DEBUG=1 -DCCAN_TAL_DEBUG=1 -DCCAN_JSON_OUT_DEBUG=1
 else
@@ -256,7 +242,7 @@ LIBRARY_PATH := /usr/local/lib
 endif
 
 CPPFLAGS += -DBINTOPKGLIBEXECDIR="\"$(shell sh tools/rel.sh $(bindir) $(pkglibexecdir))\""
-CFLAGS = $(CPPFLAGS) $(CWARNFLAGS) $(CDEBUGFLAGS) $(COPTFLAGS) -I $(CCANDIR) $(EXTERNAL_INCLUDE_FLAGS) -I . -I$(CPATH) $(SQLITE3_CFLAGS) $(POSTGRES_INCLUDE) $(FEATURES) $(COVFLAGS) $(DEV_CFLAGS) -DSHACHAIN_BITS=48 -DJSMN_PARENT_LINKS $(PIE_CFLAGS) $(COMPAT_CFLAGS) -DBUILD_ELEMENTS=1
+CFLAGS = $(CPPFLAGS) $(CWARNFLAGS) $(CDEBUGFLAGS) $(COPTFLAGS) -I $(CCANDIR) $(EXTERNAL_INCLUDE_FLAGS) -I . -I$(CPATH) $(SQLITE3_CFLAGS) $(POSTGRES_INCLUDE) $(FEATURES) $(COVFLAGS) $(DEV_CFLAGS) -DSHACHAIN_BITS=48 -DJSMN_PARENT_LINKS $(PIE_CFLAGS) $(COMPAT_CFLAGS) $(CSANFLAGS) -DBUILD_ELEMENTS=1
 
 # If CFLAGS is already set in the environment of make (to whatever value, it
 # does not matter) then it would export it to subprocesses with the above value
@@ -268,8 +254,7 @@ unexport CFLAGS
 # We can get configurator to run a different compile cmd to cross-configure.
 CONFIGURATOR_CC := $(CC)
 
-LDFLAGS += $(PIE_LDFLAGS) $(SANITIZER_FLAGS) $(COPTFLAGS)
+LDFLAGS += $(PIE_LDFLAGS) $(CSANFLAGS) $(COPTFLAGS)
-CFLAGS += $(SANITIZER_FLAGS)
 
 ifeq ($(STATIC),1)
 # For MacOS, Jacob Rapoport <jacob@rumblemonkey.com> changed this to:

configure

@@ -147,12 +147,29 @@ set_defaults()
     STATIC=${STATIC:-0}
     ASAN=${ASAN:-0}
     UBSAN=${UBSAN:-0}
+    FUZZING=${FUZZING:-0}
+    CSANFLAGS=""
+    if [ "$ASAN" != 0 ]; then
+	CSANFLAGS="$CSANFLAGS -fsanitize=address"
+	if [ "$DEVELOPER" != 0 ]; then
+	    CSANFLAGS="$CSANFLAGS -fno-sanitize-recover=address"
+	fi
+    fi
+    if [ "$UBSAN" != 0 ]; then
+	CSANFLAGS="$CSANFLAGS -fsanitize=undefined"
+	if [ "$DEVELOPER" != 0 ]; then
+	    CSANFLAGS="$CSANFLAGS -fno-sanitize-recover=undefined"
+	fi
+    fi
+    if [ "$FUZZING" != 0 ]; then
+	CSANFLAGS="$CSANFLAGS -fsanitize=fuzzer-no-link"
+    fi
+    echo CSANFLAGS = $CSANFLAGS
     PYTEST=${PYTEST-$(default_pytest)}
     COPTFLAGS=${COPTFLAGS-$(default_coptflags "$DEVELOPER")}
     CONFIGURATOR_CC=${CONFIGURATOR_CC-$CC}
     VALGRIND=${VALGRIND:-$(default_valgrind_setting)}
     TEST_NETWORK=${TEST_NETWORK:-regtest}
-    FUZZING=${FUZZING:-0}
     RUST=${RUST:-$(default_rust_setting)}
 }
 
@@ -309,7 +326,7 @@ fi
 # Clean up on exit.
 trap "rm -f $CONFIG_VAR_FILE.$$" 0
 
-$CONFIGURATOR --extra-tests --autotools-style --var-file=$CONFIG_VAR_FILE.$$ --header-file=$CONFIG_HEADER.$$ --configurator-cc="$CONFIGURATOR_CC" --wrapper="$CONFIGURATOR_WRAPPER" "$CC" ${CWARNFLAGS-$BASE_WARNFLAGS} $CDEBUGFLAGS $COPTFLAGS -I$CPATH -L$LIBRARY_PATH $SQLITE3_CFLAGS $POSTGRES_INCLUDE <<EOF
+$CONFIGURATOR --extra-tests --autotools-style --var-file=$CONFIG_VAR_FILE.$$ --header-file=$CONFIG_HEADER.$$ --configurator-cc="$CONFIGURATOR_CC" --wrapper="$CONFIGURATOR_WRAPPER" "$CC" ${CWARNFLAGS-$BASE_WARNFLAGS} $CDEBUGFLAGS $COPTFLAGS $CSANFLAGS -I$CPATH -L$LIBRARY_PATH $SQLITE3_CFLAGS $POSTGRES_INCLUDE <<EOF
 
 var=HAVE_GOOD_LIBSODIUM
 desc=libsodium with IETF chacha20 variants
@@ -455,6 +472,7 @@ add_var CONFIGURATOR_CC "$CONFIGURATOR_CC"
 add_var CWARNFLAGS "$CWARNFLAGS"
 add_var CDEBUGFLAGS "$CDEBUGFLAGS"
 add_var COPTFLAGS "$COPTFLAGS"
+add_var CSANFLAGS "$CSANFLAGS"
 add_var SQLITE3_CFLAGS "$SQLITE3_CFLAGS"
 add_var SQLITE3_LDLIBS "$SQLITE3_LDLIBS"
 add_var POSTGRES_INCLUDE "$POSTGRES_INCLUDE"

doc/FUZZING.md

@@ -24,7 +24,7 @@ a few sanitizers for bug detections as well as experimental features for an exte
 coverage (not required though).
 
 ```
-DEVELOPER=1 EXPERIMENTAL_FEATURES=1 ASAN=1 UBSAN=1 VALGRIND=0 FUZZING=1 CC=clang ./configure && make
+./configure --enable-developer --enable-experimental-features --enable-address-sanitizer --enable-ub-sanitizer --enable-fuzzing --disable-valgrind CC=clang && make
 ```
 
 The targets will be built in `tests/fuzz/` as `fuzz-` binaries.