From 9cfe6e97a0688bd6321e4a42603e0a6ed0cb3815 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C3=ABl=20Van=20Canneyt?= <michael@freepascal.org>
Date: Thu, 5 Jan 2023 10:10:10 +0100
Subject: [PATCH] * add uachar loading for unicode rtl

---
 compiler/pmodules.pas | 26 ++++++++++++++++++++++----
 rtl/inc/uachar.pp     | 28 ++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+), 4 deletions(-)
 create mode 100644 rtl/inc/uachar.pp

diff --git a/compiler/pmodules.pas b/compiler/pmodules.pas
index bbd394de32..e5f58a82dc 100644
--- a/compiler/pmodules.pas
+++ b/compiler/pmodules.pas
@@ -36,7 +36,7 @@ implementation
        globtype,systems,tokens,
        cutils,cfileutl,cclasses,comphook,
        globals,verbose,fmodule,finput,fppu,globstat,fpcp,fpkg,
-       symconst,symbase,symtype,symdef,symsym,symtable,symcreat,
+       symconst,symbase,symtype,symdef,symsym,symtable,defutil,symcreat,
        wpoinfo,
        aasmtai,aasmdata,aasmbase,aasmcpu,
        cgbase,ngenutil,
@@ -316,6 +316,12 @@ implementation
           prevent crashes when accessing .owner }
         generrorsym.owner:=systemunit;
         generrordef.owner:=systemunit;
+        // Implicitly enable unicode strings in unicode RTL in modes objfpc/delphi.
+        { TODO: Check if we should also do this for mode macpas }
+        if not (cs_compilesystem in current_settings.moduleswitches) then
+          if ([m_objfpc,m_delphi] * current_settings.modeswitches)<>[] then
+            if is_systemunit_unicode then
+              Include(current_settings.modeswitches,m_default_unicodestring)
       end;
 
 
@@ -382,9 +388,21 @@ implementation
         if m_blocks in current_settings.modeswitches then
           AddUnit('blockrtl');
 
-        { default char=widechar? }
-        if m_default_unicodestring in current_settings.modeswitches then
-          AddUnit('uuchar');
+        { Determine char size. }
+
+        // Ansi RTL ?
+        if not is_systemunit_unicode then
+          begin
+          if m_default_unicodestring in current_settings.modeswitches then
+            AddUnit('uuchar'); // redefines char as widechar
+          end
+        else
+          begin
+          // Unicode RTL
+          if not (m_default_ansistring in current_settings.modeswitches) then
+            if not (current_module.modulename^<>'UACHAR') then
+              AddUnit('uachar'); // redefines char as ansichar
+          end;
 
         { Objective-C support unit? }
         if (m_objectivec1 in current_settings.modeswitches) then
diff --git a/rtl/inc/uachar.pp b/rtl/inc/uachar.pp
new file mode 100644
index 0000000000..8446dfe551
--- /dev/null
+++ b/rtl/inc/uachar.pp
@@ -0,0 +1,28 @@
+{
+    This file is part of the Free Pascal Run time library.
+    Copyright (c) 2011 by the Free Pascal development team
+
+    This unit redefines the Char type from widechar into ansichar
+
+    See the file COPYING.FPC, included in this distribution,
+    For details about the copyright.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+
+ **********************************************************************}
+
+unit uachar;
+
+{$h-} 
+
+interface
+
+  type
+    Char = AnsiChar;
+    PChar = PAnsiChar;
+
+implementation
+
+end.