From 7eb0406db88e876cb1f70ea5ddbf7af0a99b5cb3 Mon Sep 17 00:00:00 2001
From: Volker Berlin <volker.berlin@googlemail.com>
Date: Sun, 26 Apr 2020 19:47:51 +0200
Subject: [PATCH] Only ASCII strings as comment

---
 .../jwebassembly/module/WasmCodeBuilder.java  | 25 ++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/de/inetsoftware/jwebassembly/module/WasmCodeBuilder.java b/src/de/inetsoftware/jwebassembly/module/WasmCodeBuilder.java
index 49e791e..3689f25 100644
--- a/src/de/inetsoftware/jwebassembly/module/WasmCodeBuilder.java
+++ b/src/de/inetsoftware/jwebassembly/module/WasmCodeBuilder.java
@@ -458,7 +458,11 @@ public abstract class WasmCodeBuilder {
             Integer id = strings.get( value );
             FunctionName name = strings.getStringConstantFunction();
             instructions.add( new WasmConstInstruction( id, ValueType.i32, javaCodePos, lineNumber ) );
-            instructions.add( new WasmCallInstruction( name, javaCodePos, lineNumber, types, false, (String)value ) );
+            String comment = (String)value;
+            if( !isAscii( comment ) ) {
+                comment = null;
+            }
+            instructions.add( new WasmCallInstruction( name, javaCodePos, lineNumber, types, false, comment ) );
         } else if( value instanceof Number ) {
             instructions.add( new WasmConstInstruction( (Number)value, javaCodePos, lineNumber ) );
         } else if( value instanceof ConstantClass ) {
@@ -473,6 +477,25 @@ public abstract class WasmCodeBuilder {
         }
     }
 
+    /**
+     * if the string contains only ASCCI characters
+     * 
+     * @param str
+     *            the staring
+     * @return true, if only ASCII
+     */
+    private static boolean isAscii( String str ) {
+        int length = str.length();
+        for( int i = 0; i < length; i++ ) {
+            int c = str.charAt( i );
+            if( c >= 0x20 && c < 0x7F ) {
+                continue;
+            }
+            return false;
+        }
+        return true;
+    }
+
     /**
      * Add a numeric operation instruction
      *