From 87f8893886570364ce18776490f470232860772e Mon Sep 17 00:00:00 2001
From: acqn <acqn163@outlook.com>
Date: Sat, 9 Dec 2023 17:33:46 +0800
Subject: [PATCH 1/2] Avoided "Variable 'XXX' is defined but never used" error
 message resulted from an earlier error.

---
 src/cc65/symtab.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/cc65/symtab.c b/src/cc65/symtab.c
index a4ca9e23d..86a92a019 100644
--- a/src/cc65/symtab.c
+++ b/src/cc65/symtab.c
@@ -178,7 +178,7 @@ static void CheckSymTable (SymTable* Tab)
                         if (IS_Get (&WarnUnusedFunc)) {
                             Warning ("Function '%s' is defined but never used", Entry->Name);
                         }
-                    } else {
+                    } else if (!IsAnonName (Entry->Name)) {
                         if (IS_Get (&WarnUnusedVar)) {
                             Warning ("Variable '%s' is defined but never used", Entry->Name);
                         }

From d8a722b63826ea4a1df2bb7a7f4e1197f7707117 Mon Sep 17 00:00:00 2001
From: acqn <acqn163@outlook.com>
Date: Sat, 9 Dec 2023 17:34:01 +0800
Subject: [PATCH 2/2] Improved diagnostics on multiple definition of
 struct/union types.

---
 src/cc65/declare.c | 10 ----------
 src/cc65/symtab.c  | 19 +++++++++++--------
 2 files changed, 11 insertions(+), 18 deletions(-)

diff --git a/src/cc65/declare.c b/src/cc65/declare.c
index b6620785f..96e1f1074 100644
--- a/src/cc65/declare.c
+++ b/src/cc65/declare.c
@@ -1220,11 +1220,6 @@ NextMember: if (CurTok.Tok != TOK_COMMA) {
         Flags |= SC_FICTITIOUS;
     }
 
-    /* Empty union is not supported now */
-    if (UnionSize == 0) {
-        Error ("Empty union type '%s' is not supported", Name);
-    }
-
     /* Make a real entry from the forward decl and return it */
     return AddStructSym (Name, SC_UNION | SC_DEF | Flags, UnionSize, FieldTab, DSFlags);
 }
@@ -1471,11 +1466,6 @@ NextMember: if (CurTok.Tok != TOK_COMMA) {
         Flags |= SC_FICTITIOUS;
     }
 
-    /* Empty struct is not supported now */
-    if (StructSize == 0) {
-        Error ("Empty struct type '%s' is not supported", Name);
-    }
-
     /* Make a real entry from the forward decl and return it */
     return AddStructSym (Name, SC_STRUCT | SC_DEF | Flags, StructSize, FieldTab, DSFlags);
 }
diff --git a/src/cc65/symtab.c b/src/cc65/symtab.c
index 86a92a019..1b5c1e0b5 100644
--- a/src/cc65/symtab.c
+++ b/src/cc65/symtab.c
@@ -919,14 +919,8 @@ SymEntry* AddStructSym (const char* Name, unsigned Flags, unsigned Size, SymTabl
     /* SCType must be struct or union */
     PRECONDITION (SCType == SC_STRUCT || SCType == SC_UNION);
 
-    if ((Flags & SC_FICTITIOUS) == 0) {
-        /* Do we have an entry with this name already? */
-        TagEntry = FindSymInTable (CurTagTab, Name, HashStr (Name));
-    } else {
-        /* Add a fictitious symbol in the fail-safe table */
-        TagEntry = 0;
-        CurTagTab = FailSafeTab;
-    }
+    /* Do we have an entry with this name already? */
+    TagEntry = FindSymInTable (CurTagTab, Name, HashStr (Name));
 
     if (TagEntry) {
 
@@ -954,6 +948,15 @@ SymEntry* AddStructSym (const char* Name, unsigned Flags, unsigned Size, SymTabl
                 if (DSFlags != 0) {
                     *DSFlags |= DS_NEW_TYPE_DEF;
                 }
+
+                if ((Flags & SC_FICTITIOUS) == SC_FICTITIOUS) {
+                    /* Add a fictitious symbol in the fail-safe table */
+                    TagEntry = 0;
+                } else if (Size == 0) {
+                    /* Empty struct is not supported now */
+                    Error ("Empty %s type '%s' is not supported", SCType == SC_STRUCT ? "struct" : "union", Name);
+                    TagEntry = 0;
+                }
             }
         }