From b266466e0a05b30615ec43d72782c345470455b9 Mon Sep 17 00:00:00 2001
From: Pierre-Marie de Rodat <derodat@adacore.com>
Date: Thu, 17 Jul 2025 07:38:41 +0000
Subject: [PATCH] Opt_Parse: refactor to avoid a new accessibility check
 failure

Use cursor types rather than reference types for return types when the
referenced vector element come from a function formal. This is necessary
to avoid the failure of a new accessibility check that was just
implemented in GNAT. It will also be necessary once reference types are
made limited (as per AI22-0082).
---
 core/src/gnatcoll-opt_parse.adb | 39 ++++++++++++++++-----------------
 1 file changed, 19 insertions(+), 20 deletions(-)

diff --git a/core/src/gnatcoll-opt_parse.adb b/core/src/gnatcoll-opt_parse.adb
index 5e52684c..09ae755b 100644
--- a/core/src/gnatcoll-opt_parse.adb
+++ b/core/src/gnatcoll-opt_parse.adb
@@ -77,11 +77,10 @@ package body GNATCOLL.Opt_Parse is
    --  to Col, and set the next start column to `Col`, so that text on
    --  subsequent lines starts at `Col`.
 
-   subtype XString_Ref is XString_Vectors.Reference_Type;
-   --  Shortcut for a reference to a XString
+   subtype XString_Cur is XString_Vectors.Cursor;
+   --  Shortcut for a XString vector cursor
 
-   function Append_Line
-     (Self : aliased in out Text_Wrapper) return XString_Ref;
+   function Append_Line (Self : in out Text_Wrapper) return XString_Cur;
    --  Append a new line to Self
 
    procedure Append_Line
@@ -92,11 +91,10 @@ package body GNATCOLL.Opt_Parse is
    --  `Col_After` is not `No_Col`, then set the next start column to
    --  `Col_After`.
 
-   function Current_Line
-     (Self : aliased in out Text_Wrapper) return XString_Ref
+   function Current_Line (Self : in out Text_Wrapper) return XString_Cur
    is
      (if Self.Lines.Is_Empty
-      then Self.Append_Line else Self.Lines.Reference (Self.Lines.Last_Index));
+      then Self.Append_Line else Self.Lines.Last);
    --  Return a reference to the current line.
 
    function Render (Self : Text_Wrapper) return String;
@@ -191,7 +189,7 @@ package body GNATCOLL.Opt_Parse is
       end if;
 
       declare
-         Dummy : XString_Ref := Self.Append_Line;
+         Dummy : XString_Cur := Self.Append_Line;
       begin
          null;
       end;
@@ -204,14 +202,15 @@ package body GNATCOLL.Opt_Parse is
    procedure Set_Column
      (Self : in out Text_Wrapper; Col : Col_Type)
    is
+      Current_Line_Length : constant Natural :=
+        Self.Lines.Reference (Self.Current_Line).Length;
    begin
       Self.Set_Next_Start_Column (Col);
 
-      if Self.Current_Line.Length > Col then
+      if Current_Line_Length > Col then
          Self.Append_Line;
       else
-         Self.Append_Text
-           ((1 .. Col - Self.Current_Line.Length => ' '), False);
+         Self.Append_Text ((1 .. Col - Current_Line_Length => ' '), False);
       end if;
    end Set_Column;
 
@@ -233,19 +232,16 @@ package body GNATCOLL.Opt_Parse is
    -- Append_Line --
    -----------------
 
-   function Append_Line
-     (Self : aliased in out Text_Wrapper) return XString_Vectors.Reference_Type
-   is
+   function Append_Line (Self : in out Text_Wrapper) return XString_Cur is
       Ret : XString;
    begin
       Self.Lines.Append (Ret);
 
       declare
-         L : constant XString_Ref := Self.Current_Line;
+         L : constant XString_Cur := Self.Current_Line;
       begin
          if Self.Start_Col > 0 then
-
-            L.Append ((1 .. Self.Start_Col => ' '));
+            Self.Lines.Reference (L).Append ((1 .. Self.Start_Col => ' '));
          end if;
 
          return L;
@@ -276,7 +272,8 @@ package body GNATCOLL.Opt_Parse is
          end;
       else
          declare
-            Cur_Line : constant XString_Ref := Self.Current_Line;
+            Cur_Line : XString renames
+              Self.Lines.Reference (Self.Current_Line);
          begin
             if Cur_Line.Length + Text'Length <= Self.Wrap_Col then
                Cur_Line.Append (Text);
@@ -285,7 +282,8 @@ package body GNATCOLL.Opt_Parse is
          end;
 
          declare
-            Cur_Line : constant XString_Ref := Append_Line (Self);
+            Cur_Line : XString renames
+              Self.Lines.Reference (Append_Line (Self));
          begin
             Cur_Line.Append (Text);
          end;
@@ -301,7 +299,8 @@ package body GNATCOLL.Opt_Parse is
      (Self : in out Text_Wrapper; Col : Col_Type := 0) is
    begin
       if Col = Current_Col then
-         Self.Start_Col := Col_Type (Self.Current_Line.Length);
+         Self.Start_Col :=
+           Col_Type (Self.Lines.Reference (Self.Current_Line).Length);
       else
          Self.Start_Col := Col;
       end if;