From 19f8a2d37281f22d7f9829bac412a20734d7701a Mon Sep 17 00:00:00 2001
From: James Roseborough <james.roseborough@luaj.org>
Date: Tue, 20 Apr 2010 00:37:23 +0000
Subject: [PATCH] Fix to tailcall processing.

---
 src/core/org/luaj/vm2/LuaClosure.java      |  5 +++++
 src/core/org/luaj/vm2/LuaError.java        | 14 ++++++++++++++
 src/core/org/luaj/vm2/TailcallVarargs.java |  7 +++++--
 src/core/org/luaj/vm2/Varargs.java         |  6 ++++++
 src/core/org/luaj/vm2/lib/BaseLib.java     |  5 ++---
 src/core/org/luaj/vm2/lib/PackageLib.java  | 14 ++++++++------
 6 files changed, 40 insertions(+), 11 deletions(-)

diff --git a/src/core/org/luaj/vm2/LuaClosure.java b/src/core/org/luaj/vm2/LuaClosure.java
index 7e8d2692..79178dfa 100644
--- a/src/core/org/luaj/vm2/LuaClosure.java
+++ b/src/core/org/luaj/vm2/LuaClosure.java
@@ -101,6 +101,10 @@ public class LuaClosure extends LuaFunction {
 	}
 
 	public final Varargs invoke(Varargs varargs) {
+		return oninvoke( varargs ).eval();
+	}
+	
+	final Varargs oninvoke(Varargs varargs) {
 		LuaValue[] stack = new LuaValue[p.maxstacksize];
 		System.arraycopy(NILS, 0, stack, 0, p.maxstacksize);
 		for ( int i=0; i<p.numparams; i++ )
@@ -108,6 +112,7 @@ public class LuaClosure extends LuaFunction {
 		return execute(stack,p.is_vararg!=0? varargs.subargs(p.numparams+1): NONE);
 	}
 	
+	
 	protected Varargs execute( LuaValue[] stack, Varargs varargs ) {
 		// loop through instructions
 		int i,a,b,c,pc=0,top=0;
diff --git a/src/core/org/luaj/vm2/LuaError.java b/src/core/org/luaj/vm2/LuaError.java
index 049fbafc..20e7e78c 100644
--- a/src/core/org/luaj/vm2/LuaError.java
+++ b/src/core/org/luaj/vm2/LuaError.java
@@ -71,6 +71,20 @@ public class LuaError extends RuntimeException {
 	public LuaError(String message) {
 		super( errorHook( message ) );
 	}		
+
+	/**
+	 * @param message message to supply
+	 * @param level where to supply line info from in call stack
+	 */
+	public LuaError(String message, int level) {
+		super( errorHook( addFileLine( message, level ) ) );
+	}	
+
+	/** Add file and line info to a message */
+	private static String addFileLine( String message, int level ) {
+		LuaFunction f = LuaThread.getCallstackFunction(level);
+		return f!=null? f+": "+message: message;		
+	}
 	
 	/** Get the message, including source line info if there is any */
 	public String getMessage() {		
diff --git a/src/core/org/luaj/vm2/TailcallVarargs.java b/src/core/org/luaj/vm2/TailcallVarargs.java
index c6068198..0acf0664 100644
--- a/src/core/org/luaj/vm2/TailcallVarargs.java
+++ b/src/core/org/luaj/vm2/TailcallVarargs.java
@@ -32,13 +32,15 @@ public class TailcallVarargs extends Varargs {
 		this.args = args;
 	}
 	
-	private void eval() {
+	public Varargs eval() {
 		TailcallVarargs nextcall = this;
 		do {
 			LuaValue func = nextcall.func;
 			Varargs args = nextcall.args;
 			nextcall = null;
-			Varargs r = func.invoke(args);
+			Varargs r = func.isclosure()? 
+					((LuaClosure) func).oninvoke(args):
+					func.invoke(args);
 			
 			if (r instanceof TailcallVarargs)
 				nextcall = (TailcallVarargs)r;
@@ -46,6 +48,7 @@ public class TailcallVarargs extends Varargs {
 				this.result = r;
 			
 		} while (nextcall != null);
+		return result;
 	}
 	
 	public LuaValue arg( int i ) {
diff --git a/src/core/org/luaj/vm2/Varargs.java b/src/core/org/luaj/vm2/Varargs.java
index a2ab56b5..4fb7b0dc 100644
--- a/src/core/org/luaj/vm2/Varargs.java
+++ b/src/core/org/luaj/vm2/Varargs.java
@@ -45,6 +45,12 @@ public abstract class Varargs {
 	 * @return Value
 	 */
 	abstract public LuaValue arg1();
+
+	/** 
+	 * Evaluate any pending tail call and return result
+	 * @return the evaluated tail call result 
+	 */
+	public Varargs eval() { return this; }
 	
 	// -----------------------------------------------------------------------
 	// utilities to get specific arguments and type-check them.
diff --git a/src/core/org/luaj/vm2/lib/BaseLib.java b/src/core/org/luaj/vm2/lib/BaseLib.java
index 3982ddcb..fe092859 100644
--- a/src/core/org/luaj/vm2/lib/BaseLib.java
+++ b/src/core/org/luaj/vm2/lib/BaseLib.java
@@ -26,7 +26,6 @@ import java.io.PrintStream;
 
 import org.luaj.vm2.LoadState;
 import org.luaj.vm2.LuaError;
-import org.luaj.vm2.LuaFunction;
 import org.luaj.vm2.LuaString;
 import org.luaj.vm2.LuaTable;
 import org.luaj.vm2.LuaThread;
@@ -162,7 +161,7 @@ public class BaseLib extends OneArgFunction implements ResourceFinder {
 			}
 			return NIL;
 		case 1: // "error", // ( message [,level] ) -> ERR
-			throw new LuaError( arg1.isnil()? null: arg1.toString() );
+			throw new LuaError( arg1.isnil()? null: arg1.toString(), arg2.optint(1) );
 		case 2: // "rawequal", // (v1, v2) -> boolean
 			return valueOf(arg1 == arg2);
 		case 3: { // "setfenv", // (f, table) -> void
@@ -347,7 +346,7 @@ public class BaseLib extends OneArgFunction implements ResourceFinder {
 		return NONE;
 	}
 
-	private Varargs loadFile(String filename) throws IOException {
+	public static Varargs loadFile(String filename) throws IOException {
 		InputStream is = FINDER.findResource(filename);
 		if ( is == null )
 			return varargsOf(NIL, valueOf("not found: "+filename));
diff --git a/src/core/org/luaj/vm2/lib/PackageLib.java b/src/core/org/luaj/vm2/lib/PackageLib.java
index c06389e7..5cfe9d11 100644
--- a/src/core/org/luaj/vm2/lib/PackageLib.java
+++ b/src/core/org/luaj/vm2/lib/PackageLib.java
@@ -21,6 +21,7 @@
 ******************************************************************************/
 package org.luaj.vm2.lib;
 
+import java.io.IOException;
 import java.io.InputStream;
 import java.io.PrintStream;
 
@@ -306,11 +307,6 @@ public class PackageLib extends OneArgFunction {
 		String name = args.checkString(1);
 		InputStream is = null;
 		
-		// try to use loadfile for the file
-		LuaValue loadfile = env.get(_LOADFILE);
-		if ( ! loadfile.isfunction() ) 
-			return valueOf("loadfile is not a function" );
-		
 		
 		// get package path
 		LuaValue pp = PACKAGE.get(_PATH);
@@ -340,7 +336,13 @@ public class PackageLib extends OneArgFunction {
 			}
 			
 			// try loading the file
-			Varargs v = loadfile.invoke(valueOf(filename));
+			Varargs v; 
+			try {
+				v = BaseLib.loadFile(filename);
+			} catch ( IOException ioe ) {
+				v = varargsOf(NIL, valueOf(ioe.getMessage()));
+				
+			}
 			if ( v.arg1().isfunction() )
 				return v.arg1();