From edb55a94fc5c0473e57f5a61c0c723194c2ff414 Mon Sep 17 00:00:00 2001
From: Pierre-Marie Pédrot
Date: Tue, 27 Sep 2016 17:15:10 +0200
Subject: Fix bug #4798: compat notations should not modify the parser.

This is a quick fix. The Metasyntax module should be thoroughly revised
in trunk, because it starts featuring a lot of spaghetti code and redundant
data.
---
 lib/flags.ml  | 27 ++++++++++++++++-----------
 lib/flags.mli |  1 +
 2 files changed, 17 insertions(+), 11 deletions(-)

(limited to 'lib')

diff --git a/lib/flags.ml b/lib/flags.ml
index d29064c97f..af55e9e2bb 100644
--- a/lib/flags.ml
+++ b/lib/flags.ml
@@ -112,17 +112,22 @@ type compat_version = V8_2 | V8_3 | V8_4 | V8_5 | Current
 
 let compat_version = ref Current
 
-let version_strictly_greater v = match !compat_version, v with
-| V8_2, (V8_2 | V8_3 | V8_4 | V8_5 | Current) -> false
-| V8_3, (V8_3 | V8_4 | V8_5 | Current) -> false
-| V8_4, (V8_4 | V8_5 | Current) -> false
-| V8_5, (V8_5 | Current) -> false
-| Current, Current -> false
-| V8_3, V8_2 -> true
-| V8_4, (V8_2 | V8_3) -> true
-| V8_5, (V8_2 | V8_3 | V8_4) -> true
-| Current, (V8_2 | V8_3 | V8_4 | V8_5) -> true
-
+let version_compare v1 v2 = match v1, v2 with
+| V8_2, V8_2 -> 0
+| V8_2, (V8_3 | V8_4 | V8_5 | Current) -> -1
+| V8_3, V8_2 -> 1
+| V8_3, V8_3 -> 0
+| V8_3, (V8_4 | V8_5 | Current) -> -1
+| V8_4, (V8_2 | V8_3) -> 1
+| V8_4, V8_4 -> 0
+| V8_4, (V8_5 | Current) -> -1
+| V8_5, (V8_2 | V8_3 | V8_4) -> 1
+| V8_5, V8_5 -> 0
+| V8_5, Current -> -1
+| Current, Current -> 0
+| Current, (V8_2 | V8_3 | V8_4 | V8_5) -> 1
+
+let version_strictly_greater v = version_compare !compat_version v > 0
 let version_less_or_equal v = not (version_strictly_greater v)
 
 let pr_version = function
diff --git a/lib/flags.mli b/lib/flags.mli
index 839c252cbb..9dc0c9c048 100644
--- a/lib/flags.mli
+++ b/lib/flags.mli
@@ -64,6 +64,7 @@ val univ_print : bool ref
 
 type compat_version = V8_2 | V8_3 | V8_4 | V8_5 | Current
 val compat_version : compat_version ref
+val version_compare : compat_version -> compat_version -> int
 val version_strictly_greater : compat_version -> bool
 val version_less_or_equal : compat_version -> bool
 val pr_version : compat_version -> string
-- 
cgit v1.2.3