* Further improvement for r40180:

    An uninitialized function Result of a managed type needs special handling.
    When passing it as a var parameter a warning need to be emitted, since a user
    may expect Result to be empty (nil) by default as it happens with local vars
    of a managed type. But this is not true for Result and may lead to serious issues.

    The only exception is SetLength(Result, ?) for a string Result. A user always
    expects undefined contents of the string after calling SetLength(). In such
    case a hint need to be emitted.
+ Tests for this.

git-svn-id: https://svn.freepascal.org/svn/fpc/trunk@40216 3ad0048d-3df7-0310-abae-a5850022a9f2

3 files changed, 75 insertions, 5 deletions

diff --git a/tests/tbf/tb0258.pp b/tests/tbf/tb0258.pp
index b4eda048ca..17857b534e 100644
--- a/tests/tbf/tb0258.pp
+++ b/tests/tbf/tb0258.pp
@@ -1,13 +1,26 @@
 { %fail% }
 { %opt=-Sew -vw -O- }
 
-procedure p;
-var
-  a : array of longint;
+{
+  Test for correct emitting of warnings/hints for uninitialized variables of management types
+  See also tbs/tb0653.pp, tbf/tb0259.pp, tbf/tb0260.pp
+}
+
+// This code must issue warnings "Function result variable of a managed type does not seem to be initialized".
+
+{$mode objfpc}
+
+type
+  TLongArray = array of longint;
+
+function f: TLongArray;
 begin
-  setlength(a,100);
+  // Warning for the dyn array Result, since contents of the Result after calling SetLength()
+  // is expected to be zeroed, but instead it is undefined.
+  setlength(Result,100);
+  Result[2]:=1;
 end;
 
 begin
+  f;
 end.
-
diff --git a/tests/tbf/tb0259.pp b/tests/tbf/tb0259.pp
new file mode 100644
index 0000000000..5e3d7c31e3
--- /dev/null
+++ b/tests/tbf/tb0259.pp
@@ -0,0 +1,30 @@
+{ %fail% }
+{ %opt=-Sew -vw -O- }
+
+{
+  Test for correct emitting of warnings/hints for uninitialized variables of management types
+  See also tbf/tb0258.pp
+}
+
+// This code must issue warnings "Function result variable of a managed type does not seem to be initialized".
+
+{$mode objfpc}
+
+type
+  TLongArray = array of longint;
+
+procedure fvar(var a: TLongArray);
+begin
+  setlength(a,100);
+  a[2]:=1;
+end;
+
+function f: TLongArray;
+begin
+  // Warning for the dyn array Result, since initial contents of the Result is undefined.
+  fvar(Result);
+end;
+
+begin
+  f;
+end.
diff --git a/tests/tbf/tb0260.pp b/tests/tbf/tb0260.pp
new file mode 100644
index 0000000000..6379aa0e39
--- /dev/null
+++ b/tests/tbf/tb0260.pp
@@ -0,0 +1,27 @@
+{ %fail% }
+{ %opt=-Sew -vw -O- }
+
+{
+  Test for correct emitting of warnings/hints for uninitialized variables of management types
+  See also tbf/tb0258.pp
+}
+
+// This code must issue warnings "Function result variable of a managed type does not seem to be initialized".
+
+{$mode objfpc}
+
+procedure fvar(var a: ansistring);
+begin
+  setlength(a,100);
+  a[2]:='a';
+end;
+
+function f: ansistring;
+begin
+  // Warning for the ansistring Result, since initial contents of the Result is undefined.
+  fvar(Result);
+end;
+
+begin
+  f;
+end.