[build] use `./config.status`

Summary: We had our own mechanism for saving `./configure` flags, which does not work if flags contain whitespace. It turns out that `./config.stats --config` is a thing though.

Reviewed By: mbouaziz

Differential Revision: D4642422

fbshipit-source-id: ae075ca

.gitignore

@@ -46,7 +46,6 @@ infer/tests/build_systems/differential_*/infer-previous
 /aclocal.m4
 /autom4te.cache
 /config.status
-/config.flags
 /configure
 /Makefile.autoconf
 /.buckversion

Makefile

@@ -88,7 +88,7 @@ configure: configure.ac $(wildcard m4/*.m4)
 
 Makefile.autoconf: configure
 #	rerun ./configure with the flags that were used last time it was run (if available)
-	./configure $(shell cat config.flags 2> /dev/null || true)
+	./configure $(shell ./config.status --config || true)
 
 .PHONY: src_build
 src_build: $(MAKEFILE_LIST)

configure.ac

@@ -18,10 +18,6 @@ AC_INIT([Infer],
         [0.10.0],
         [https://github.com/facebook/infer/issues/])
 
-# this has to happen just after AC_INIT() because later macros may mess with the arguments passed to
-# this script
-config_flags="$*"
-
 AC_CONFIG_SRCDIR([infer/src/IR/Sil.re])
 
 # WARNING: keep in sync with above
@@ -276,6 +272,8 @@ fi
 AC_ARG_VAR([MVN], [command to execute Maven when running tests])
 AS_IF([test "x$MVN" = "x"], [
   AC_CHECK_TOOL([MVN], [mvn], [no])
+], [
+  AC_MSG_RESULT([checking for mvn... $MVN])
 ])
 AC_CHECK_TOOL([NDKBUILD], [ndk-build], [no])
 if test x"$NDKBUILD" = x"no"; then
@@ -318,7 +316,4 @@ AC_CONFIG_FILES([
   Makefile.autoconf
 ])
 
-AC_MSG_NOTICE([saving configure flags to ./config.flags])
-echo $config_flags > config.flags
-
 AC_OUTPUT