check ocaml version in configure script

Summary:
public
Infer depends on OCaml >= 4.02.3 now.

Reviewed By: jberdine

Differential Revision: D2865159

fb-gh-sync-id: 5ec45e5

build-infer.sh

@@ -37,6 +37,7 @@ function usage() {
 BUILD_CLANG=no
 BUILD_JAVA=no
 INTERACTIVE=yes
+ORIG_ARGS="$*"
 
 while [[ $# > 0 ]]; do
   opt_key="$1"
@@ -166,4 +167,11 @@ echo "  *************************"
 echo
 
 ./configure $CONFIGURE_ARGS
-make -j $TARGETS || (echo 'compilation failure; try running "make clean"'; exit 1)
+make -j $TARGETS || (
+  echo
+  echo '  compilation failure; you can try running'
+  echo
+  echo '    make clean'
+  echo "    $0 $ORIG_ARGS"
+  echo
+  exit 1)

configure.ac

@@ -151,6 +151,8 @@ fi
 # OCaml dependencies
 AC_PROG_OCAML
 AC_ASSERT_PROG([ocamlc], [$OCAMLC])
+# check the version of OCaml
+AC_ASSERT_OCAML_MIN_VERSION([4.02.0])
 AC_ASSERT_PROG([ocamlopt], [$OCAMLOPT])
 AC_ASSERT_PROG([ocamlbuild], [$OCAMLBUILD])
 AC_PROG_FINDLIB

m4/ac_assert_ocaml_min_version.m4

@@ -0,0 +1,22 @@
+dnl Copyright (c) 2016 - present Facebook, Inc.
+dnl All rights reserved.
+dnl
+dnl This source code is licensed under the BSD style license found in the
+dnl LICENSE file in the root directory of this source tree. An additional grant
+dnl of patent rights can be found in the PATENTS file in the same directory.
+
+AC_DEFUN([AC_ASSERT_OCAML_MIN_VERSION],
+[dnl
+  AC_REQUIRE([AC_PROG_OCAML])
+
+  AC_MSG_CHECKING([if OCaml version is >= $1])
+
+  AC_COMPARE_VERSION_STRINGS([$1], [$OCAMLVERSION],
+    [AC_MSG_RESULT([yes])],
+    [AC_MSG_ERROR([m4_join([],[found version $OCAMLVERSION.
+      m4_newline([  Please upgrade to OCaml >= $1. If you are using opam, you can run])
+      m4_newline([dnl
+    opam switch $1
+    eval \$(opam config env)])
+])])])
+])

m4/ac_check_ocaml_pkg_path.m4

@@ -28,28 +28,10 @@ AC_DEFUN([AC_CHECK_OCAML_PKG_PATH],
     path=`$OCAMLFIND query $pkg 2>/dev/null`
     if test "x$3" != "x"; then
       version=`$OCAMLFIND query -format '%v' $pkg 2>/dev/null`
-      unset major_req
-      unset minor_req
-      unset patch_req
-      unset major_inst
-      unset minor_inst
-      unset patch_inst
-
-      major_req=$(printf "$3" | cut -d . -f 1)
-      minor_req=$(printf "$3" | cut -d . -f 2)
-      patch_req=$(printf "$3" | cut -d . -f 3)
-
-      major_inst=$(printf "$version" | cut -d . -f 1)
-      minor_inst=$(printf "$version" | cut -d . -f 2)
-      # discard trailing characters after patch number, eg 1.2.3+4~5 -> 3
-      patch_inst=$(printf "$version" | cut -d . -f 3 | grep -o -e '^[[[:digit:]]]*')
-      if test $major_inst -gt $major_req || \
-         (test $major_inst -eq $major_req && \
-          (test $minor_inst -gt $minor_req || \
-           (test $minor_inst -eq $minor_req && \
-            test $path_inst -ge $path_req))); then
-        found=yes
-      fi
+      AC_COMPARE_VERSION_STRINGS([$3], [$version],
+        [found=yes],
+        [],
+      )
     else
       found=yes
     fi

m4/compare_version_strings.m4

@@ -0,0 +1,32 @@
+dnl Copyright (c) 2016 - present Facebook, Inc.
+dnl All rights reserved.
+dnl
+dnl This source code is licensed under the BSD style license found in the
+dnl LICENSE file in the root directory of this source tree. An additional grant
+dnl of patent rights can be found in the PATENTS file in the same directory.
+
+AC_DEFUN([AC_COMPARE_VERSION_STRINGS],
+[dnl
+  unset major_req
+  unset minor_req
+  unset patch_req
+  unset major_inst
+  unset minor_inst
+  unset patch_inst
+
+  major_req=$(printf "$1" | cut -d . -f 1)
+  minor_req=$(printf "$1" | cut -d . -f 2)
+  patch_req=$(printf "$1" | cut -d . -f 3)
+
+  major_inst=$(printf "$2" | cut -d . -f 1)
+  minor_inst=$(printf "$2" | cut -d . -f 2)
+  # discard trailing characters after patch number, eg 1.2.3+4~5 -> 3
+  patch_inst=$(printf "$2" | cut -d . -f 3 | grep -o -e '^[[[:digit:]]]*')
+  AS_IF([test $major_inst -gt $major_req || \
+         (test $major_inst -eq $major_req && \
+          (test $minor_inst -gt $minor_req || \
+           (test $minor_inst -eq $minor_req && \
+            test $patch_inst -ge $patch_req)))],
+        $3,
+        $4)
+])