From dd27ec8696224a782154f2cd3a77a3b0428c2fcd Mon Sep 17 00:00:00 2001
From: Kugel Fuhr <98353208+kugelfuhr@users.noreply.github.com>
Date: Thu, 3 Jul 2025 08:54:10 +0200
Subject: [PATCH] When creating a VICE label file, replace characters in labels
 that VICE doesn't understand with '_'. Fixes #836.

---
 src/ld65/dbgsyms.c |  2 +-
 src/ld65/exports.c | 34 +++++++++++++++++++++++++++++++++-
 src/ld65/exports.h |  3 +++
 3 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/src/ld65/dbgsyms.c b/src/ld65/dbgsyms.c
index 955f0f76d..082954b07 100644
--- a/src/ld65/dbgsyms.c
+++ b/src/ld65/dbgsyms.c
@@ -532,7 +532,7 @@ void PrintDbgSymLabels (FILE* F)
             if (GetDbgSym (D, Val) == 0) {
 
                 /* Emit the VICE label line */
-                fprintf (F, "al %06lX .%s\n", Val, GetString (D->Name));
+                PrintLabelLine (F, D->Name, Val);
 
                 /* Insert the symbol into the table */
                 InsertDbgSym (D, Val);
diff --git a/src/ld65/exports.c b/src/ld65/exports.c
index 9fa0e4019..f457b5490 100644
--- a/src/ld65/exports.c
+++ b/src/ld65/exports.c
@@ -39,6 +39,7 @@
 
 /* common */
 #include "addrsize.h"
+#include "chartype.h"
 #include "check.h"
 #include "hashfunc.h"
 #include "lidefs.h"
@@ -1006,6 +1007,36 @@ void PrintImportMap (FILE* F)
 
 
 
+void PrintLabelLine (FILE* F, unsigned NameId, long Val)
+/* Output one label into a vice label file doing some cleanup on the name. */
+{
+    /* Get the name */
+    const char* N = GetString (NameId);
+
+    /* Cleanup the name. It might be generated by the assembler when creating
+    ** internally used labels. Such names contain invalid characters to avoid
+    ** clashes with user input and cannot be read by VICE.
+    */
+    fprintf (F, "al %06lX .", Val);
+    if (IsAlpha (*N) || *N == '@' || *N == '?' || *N == '_') {
+        putc (*N, F);
+    } else {
+        putc ('_', F);
+    }
+    ++N;
+    while (*N) {
+        if (IsAlpha (*N) || IsDigit (*N) || *N == '_') {
+            putc (*N, F);
+        } else {
+            putc ('_', F);
+        }
+        ++N;
+    }
+    putc ('\n', F);
+}
+
+
+
 void PrintExportLabels (FILE* F)
 /* Print the exports in a VICE label file */
 {
@@ -1014,7 +1045,8 @@ void PrintExportLabels (FILE* F)
     /* Print all exports */
     for (I = 0; I < ExpCount; ++I) {
         const Export* E = ExpPool [I];
-        fprintf (F, "al %06lX .%s\n", GetExportVal (E), GetString (E->Name));
+        PrintLabelLine (F, E->Name, GetExportVal (E));
+
     }
 }
 
diff --git a/src/ld65/exports.h b/src/ld65/exports.h
index d69e6d7ad..cc7870bc5 100644
--- a/src/ld65/exports.h
+++ b/src/ld65/exports.h
@@ -195,6 +195,9 @@ void PrintExportMapByValue (FILE* F);
 void PrintImportMap (FILE* F);
 /* Print an import map to the given file */
 
+void PrintLabelLine (FILE* F, unsigned NameId, long Val);
+/* Output one label into a vice label file doing some cleanup on the name. */
+
 void PrintExportLabels (FILE* F);
 /* Print the exports in a VICE label file */