From 7a34677b2ab134fab30a19c6bb6249425e802daf Mon Sep 17 00:00:00 2001
From: Sven/Sarah Barth <pascaldragon@gmail.com>
Date: Fri, 2 Dec 2022 17:06:18 +0100
Subject: [PATCH] * as long as the type passed into a TypeInfo() is not an
 undefined or error def the resulting value will always be constant at compile
 time, so it can be compared to another then no matter if typenode or not +
 added tests

---
 compiler/nadd.pas   |  7 ++++---
 tests/tbs/tb0699.pp | 16 ++++++++++++++++
 tests/tbs/tb0700.pp | 14 ++++++++++++++
 tests/tbs/tb0701.pp | 24 ++++++++++++++++++++++++
 tests/tbs/tb0702.pp | 22 ++++++++++++++++++++++
 5 files changed, 80 insertions(+), 3 deletions(-)
 create mode 100644 tests/tbs/tb0699.pp
 create mode 100644 tests/tbs/tb0700.pp
 create mode 100644 tests/tbs/tb0701.pp
 create mode 100644 tests/tbs/tb0702.pp

diff --git a/compiler/nadd.pas b/compiler/nadd.pas
index 4b8eb188a2..aacfc28706 100644
--- a/compiler/nadd.pas
+++ b/compiler/nadd.pas
@@ -1429,13 +1429,14 @@ implementation
         righttarget:=actualtargetnode(@right)^;
         if (nodetype in [equaln,unequaln]) and (lefttarget.nodetype=inlinen) and (righttarget.nodetype=inlinen) and
           (tinlinenode(lefttarget).inlinenumber=in_typeinfo_x) and (tinlinenode(righttarget).inlinenumber=in_typeinfo_x) and
-          (tinlinenode(lefttarget).left.nodetype=typen) and (tinlinenode(righttarget).left.nodetype=typen) then
+          not (tinlinenode(lefttarget).left.resultdef.typ in [undefineddef,errordef]) and
+          not (tinlinenode(righttarget).left.resultdef.typ in [undefineddef,errordef]) then
           begin
             case nodetype of
               equaln:
-                result:=cordconstnode.create(ord(ttypenode(tinlinenode(lefttarget).left).resultdef=ttypenode(tinlinenode(righttarget).left).resultdef),bool8type,false);
+                result:=cordconstnode.create(ord(tinlinenode(lefttarget).left.resultdef=tinlinenode(righttarget).left.resultdef),bool8type,false);
               unequaln:
-                result:=cordconstnode.create(ord(ttypenode(tinlinenode(lefttarget).left).resultdef<>ttypenode(tinlinenode(righttarget).left).resultdef),bool8type,false);
+                result:=cordconstnode.create(ord(tinlinenode(lefttarget).left.resultdef<>tinlinenode(righttarget).left.resultdef),bool8type,false);
               else
                 Internalerror(2020092901);
             end;
diff --git a/tests/tbs/tb0699.pp b/tests/tbs/tb0699.pp
new file mode 100644
index 0000000000..53714fe627
--- /dev/null
+++ b/tests/tbs/tb0699.pp
@@ -0,0 +1,16 @@
+{ %FAIL }
+{ %OPT=-Sew }
+
+{ Note: we are speculating for "Unreachable code" warnings here }
+
+program tb0699;
+
+procedure Test(aArg: LongInt);
+begin
+  if TypeInfo(aArg) <> TypeInfo(LongInt) then
+    Writeln('False');
+end;
+
+begin
+
+end.
diff --git a/tests/tbs/tb0700.pp b/tests/tbs/tb0700.pp
new file mode 100644
index 0000000000..e6c0ac9a94
--- /dev/null
+++ b/tests/tbs/tb0700.pp
@@ -0,0 +1,14 @@
+{ %FAIL }
+{ %OPT=-Sew }
+
+{ Note: we are speculating for "Unreachable code" warnings here }
+
+program tb0700;
+
+var
+  arr: array of LongInt;
+begin
+  arr := Nil;
+  if TypeInfo(arr[0]) <> TypeInfo(LongInt) then
+    Writeln('False');
+end.
diff --git a/tests/tbs/tb0701.pp b/tests/tbs/tb0701.pp
new file mode 100644
index 0000000000..4f3c346407
--- /dev/null
+++ b/tests/tbs/tb0701.pp
@@ -0,0 +1,24 @@
+{ %FAIL }
+{ %OPT=-Sew }
+
+{ Note: we are speculating for "Unreachable code" warnings here }
+
+program tb0701;
+
+{$mode objfpc}
+
+type
+  TTest = class
+    f: LongInt;
+    procedure Test;
+  end;
+
+procedure TTest.Test;
+begin
+  if TypeInfo(f) <> TypeInfo(LongInt) then
+    Writeln('False');
+end;
+
+begin
+
+end.
diff --git a/tests/tbs/tb0702.pp b/tests/tbs/tb0702.pp
new file mode 100644
index 0000000000..c8392e9955
--- /dev/null
+++ b/tests/tbs/tb0702.pp
@@ -0,0 +1,22 @@
+{ %OPT=-Sew }
+
+{ don't optimize TypeInfo comparisons if undefined types are involved }
+
+program tb0702;
+
+{$mode objfpc}
+
+type
+  generic TTest<S> = class
+    procedure Test;
+  end;
+
+procedure TTest.Test;
+begin
+  if TypeInfo(S) = TypeInfo(LongInt) then
+    Writeln('Test');
+end;
+
+begin
+
+end.