From 995ded07a5937fd8d0579dddcdf12e493ba3db6b Mon Sep 17 00:00:00 2001
From: Stephen Heumann <stephenheumann@gmail.com>
Date: Tue, 4 Oct 2022 18:45:11 -0500
Subject: [PATCH] Always treat "struct T;" as declaring the tag within the
 current scope.

A declaration of this exact form always declares the tag T within the current scope, and as such makes this "struct T" a distinct type from any other "struct T" type in an outer scope. (Similarly for unions.)

See C17 section 6.7.2.3 p7 (and corresponding places in all other C standards).

Here is an example of a program affected by this:

struct S {char a;};
int main(void) {
        struct S;
        struct S *sp;
        struct S {long b;} s;
        sp = &s;
        sp->b = sizeof(*sp);
        return s.b;
}
---
 Parser.pas | 4 +++-
 cc.notes   | 4 ++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/Parser.pas b/Parser.pas
index 04dbd52..444557a 100644
--- a/Parser.pas
+++ b/Parser.pas
@@ -3265,7 +3265,9 @@ while token.kind in allowedTokens do begin
             NextToken;                  {skip the structure name}
             if structPtr = nil then begin {if the name hasn't been defined then...}
                if token.kind <> lbracech then
-                  structPtr := FindSymbol(ttoken, tagSpace, false, true);
+                  if (token.kind <> semicolonch) or 
+                     (myDeclarationModifiers <> []) then
+                     structPtr := FindSymbol(ttoken, tagSpace, false, true);
                if structPtr <> nil then
                   structTypePtr := structPtr^.itype
                else begin
diff --git a/cc.notes b/cc.notes
index be023c1..eded887 100644
--- a/cc.notes
+++ b/cc.notes
@@ -1899,6 +1899,10 @@ int foo(int[42]);
 
 206. If an enum type defined in an outer scope was used in an inner scope, and then a new struct, union, or enum type was declared with the same tag in the same inner scope, a spurious error was reported.
 
+(Bug fixes below here were added in ORCA/C 2.2.0 B7.)
+
+207. If a struct or union type with a tag T has been declared within an outer scope, a declaration "struct T;" or "union T;" within an inner scope should declare a separate type, distinct from the one in the outer scope.
+
 -- Bugs from C 2.1.0 that have been fixed -----------------------------------
 
 1.  In some situations, fread() reread the first 1K or so of the file.