From 533e2e1b465ae009797d8d1ce44a9777da831cca Mon Sep 17 00:00:00 2001
From: Ulya Trofimovich <skvadrik@gmail.com>
Date: Tue, 10 Nov 2015 22:17:36 +0000
Subject: [PATCH] Added [-Wswapped-range] description.

---
 .../warnings/swapped_range/wswapped_range.rst | 57 +++++++++++++++++++
 src/manual/warnings/warnings.rst              |  2 +-
 src/manual/warnings/wswapped_range.rst        |  5 --
 3 files changed, 58 insertions(+), 6 deletions(-)
 create mode 100644 src/manual/warnings/swapped_range/wswapped_range.rst
 delete mode 100644 src/manual/warnings/wswapped_range.rst

diff --git a/src/manual/warnings/swapped_range/wswapped_range.rst b/src/manual/warnings/swapped_range/wswapped_range.rst
new file mode 100644
index 00000000..2efefd62
--- /dev/null
+++ b/src/manual/warnings/swapped_range/wswapped_range.rst
@@ -0,0 +1,57 @@
+[-Wswapped-range]
+--------------------------
+
+.. include:: ../home.rst
+
+This warning is very simple.
+It warns you in cases when character class contains a range which lower bound is greater than upper bound.
+For some strange reason re2c never considered it an error:
+it simply swaps range bounds and goes on.
+
+.. code-block:: cpp
+    :number-lines:
+
+    /*!re2c
+        *     { return "*"; }
+        [a-Z] { return "is it what you want?"; }
+    */
+
+Given this code, ```re2c -i -Wswapped-range``` generates the following:
+
+.. code-block:: cpp
+    :number-lines:
+
+    /* Generated by re2c 0.14.1.dev on Tue Nov 10 22:07:31 2015*/
+    
+    {
+            YYCTYPE yych;
+            if (YYLIMIT <= YYCURSOR) YYFILL(1);
+            yych = *YYCURSOR;
+            switch (yych) {
+            case 'Z':
+            case '[':
+            case '\\':
+            case ']':
+            case '^':
+            case '_':
+            case '`':
+            case 'a':       goto yy4;
+            default:        goto yy2;
+            }
+    yy2:
+            ++YYCURSOR;
+            { return "*"; }
+    yy4:
+            ++YYCURSOR;
+            { return "is it what you want?"; }
+    }
+
+And reports a warning:
+
+.. code-block::
+
+    re2c: warning: line 3: range lower bound (0x61) is greater than upper bound (0x5A), swapping [-Wswapped-range]
+
+Use ``[-Werror-swapped-range]`` to make it an error.
+
+
diff --git a/src/manual/warnings/warnings.rst b/src/manual/warnings/warnings.rst
index e8886170..70a21cab 100644
--- a/src/manual/warnings/warnings.rst
+++ b/src/manual/warnings/warnings.rst
@@ -10,7 +10,7 @@ Warnings
 * `[-Wunreachable-rules]      <unreachable_rules/wunreachable_rules.html>`_
 * `[-Wcondition-order]        <condition_order/wcondition_order.html>`_
 * `[-Wuseless-escape]         <useless_escape/wuseless_escape.html>`_
-* `[-Wswapped-range]          <wswapped_range.html>`_
+* `[-Wswapped-range]          <swapped_range/wswapped_range.html>`_
 * `[-Wempty-character-class]  <wempty_character_class.html>`_
 * `[-Wmatch-empty-string]     <wmatch_empty_string.html>`_
 
diff --git a/src/manual/warnings/wswapped_range.rst b/src/manual/warnings/wswapped_range.rst
deleted file mode 100644
index 6158501c..00000000
--- a/src/manual/warnings/wswapped_range.rst
+++ /dev/null
@@ -1,5 +0,0 @@
-[-Wswapped-range]
---------------------------
-
-.. include:: home.rst
-
-- 
2.40.0