From 7502203f597bd81366d036188c6bb0cb4872feea Mon Sep 17 00:00:00 2001
From: Rainer Schuetze <r.sagitario@gmx.de>
Date: Sat, 23 Jul 2016 21:06:02 +0200
Subject: [PATCH] implement demangler for back references

---
 src/core/demangle.d | 54 +++++++++++++++++++++++++++++++++------------
 1 file changed, 40 insertions(+), 14 deletions(-)

diff --git a/src/core/demangle.d b/src/core/demangle.d
index 56b2fe3db79..510e7e306f4 100644
--- a/src/core/demangle.d
+++ b/src/core/demangle.d
@@ -470,7 +470,7 @@ private struct Demangle
     /*
     LName:
         Number Name
-
+        Number %
     Name:
         Namestart
         Namestart Namechars
@@ -493,19 +493,37 @@ private struct Demangle
         debug(trace) scope(success) printf( "parseLName-\n" );
 
         auto n = decodeNumber();
-
-        if( !n || n > buf.length || n > buf.length - pos )
-            error( "LName must be at least 1 character" );
-        if( '_' != front && !isAlpha( front ) )
-            error( "Invalid character in LName" );
-        foreach(char e; buf[pos + 1 .. pos + n] )
-        {
-            if( '_' != e && !isAlpha( e ) && !isDigit( e ) )
-                error( "Invalid character in LName" );
-        }
-
-        put( buf[pos .. pos + n] );
-        pos += n;
+        if( pos < buf.length && buf[pos] == '%' )
+	{
+	    // back reference to LName
+	    if( n >= pos )
+	        error( "invalid LName back reference" );
+	    size_t p = n;
+	    n = 0;
+	    while( isDigit( buf[p] ) )
+	    {
+	        n = n * 10 + buf[p] - '0';
+		p++;
+	    }
+	    if( n > pos - p )
+	        error( "invalid LName length" );
+	    put( buf[p .. p + n] );
+	    pos++;
+	}
+	else
+	{
+	    if( !n || n > buf.length || n > buf.length - pos )
+	        error( "LName must be at least 1 character" );
+	    if( '_' != front && !isAlpha( front ) )
+	        error( "Invalid character in LName" );
+	    foreach(char e; buf[pos + 1 .. pos + n] )
+	    {
+	        if( '_' != e && !isAlpha( e ) && !isDigit( e ) )
+		    error( "Invalid character in LName" );
+	    }
+	    put( buf[pos .. pos + n] );
+	    pos += n;
+	}
     }
 
 
@@ -715,6 +733,14 @@ private struct Demangle
 
         switch( t )
         {
+	case '$':
+            popFront();
+	    auto n = decodeNumber();
+	    auto savePos = pos;
+	    pos = n;
+	    auto ret = parseType();
+	    pos = savePos;
+	    return ret;
         case 'O': // Shared (O Type)
             popFront();
             put( "shared(" );