From df86eca3c386ad2afaeb277f43f84fea6cecd2c0 Mon Sep 17 00:00:00 2001
From: James Roseborough <james.roseborough@luaj.org>
Date: Fri, 6 Aug 2010 14:47:00 +0000
Subject: [PATCH] Improve luajc bytecode generation.

---
 src/jse/org/luaj/vm2/luajc/BasicBlock.java |  3 +++
 src/jse/org/luaj/vm2/luajc/LuaJC.java      |  2 +-
 src/jse/org/luaj/vm2/luajc/ProtoInfo.java  | 21 +++++++++++++--------
 src/jse/org/luaj/vm2/luajc/UpvalInfo.java  | 11 +++++++----
 4 files changed, 24 insertions(+), 13 deletions(-)

diff --git a/src/jse/org/luaj/vm2/luajc/BasicBlock.java b/src/jse/org/luaj/vm2/luajc/BasicBlock.java
index ab2cbe05..2aec9efa 100644
--- a/src/jse/org/luaj/vm2/luajc/BasicBlock.java
+++ b/src/jse/org/luaj/vm2/luajc/BasicBlock.java
@@ -128,6 +128,9 @@ public class BasicBlock {
 			case Lua.OP_LOADBOOL:
 				if ( Lua.GETARG_C(ins) == 0 )
 					break;
+				if ( Lua.GET_OPCODE(code[i+1]) == Lua.OP_JMP  )
+					throw new IllegalArgumentException("OP_LOADBOOL followed by jump at "+i); 
+				break;
 			case Lua.OP_EQ:
 			case Lua.OP_LT:
 			case Lua.OP_LE:
diff --git a/src/jse/org/luaj/vm2/luajc/LuaJC.java b/src/jse/org/luaj/vm2/luajc/LuaJC.java
index 205ae5dd..0a9a49ee 100644
--- a/src/jse/org/luaj/vm2/luajc/LuaJC.java
+++ b/src/jse/org/luaj/vm2/luajc/LuaJC.java
@@ -65,7 +65,7 @@ public class LuaJC implements LuaCompiler {
 	
 	private void insert(Hashtable h, JavaGen gen) {
 		h.put(gen.classname, gen.bytecode);
-		for ( int i=0; i<gen.inners.length; i++ )
+		for ( int i=0, n=gen.inners!=null? gen.inners.length: 0; i<n; i++ )
 			insert(h, gen.inners[i]);
 	}
 
diff --git a/src/jse/org/luaj/vm2/luajc/ProtoInfo.java b/src/jse/org/luaj/vm2/luajc/ProtoInfo.java
index 2fe072f5..df0ca683 100644
--- a/src/jse/org/luaj/vm2/luajc/ProtoInfo.java
+++ b/src/jse/org/luaj/vm2/luajc/ProtoInfo.java
@@ -161,19 +161,19 @@ public class ProtoInfo {
 				for ( ; a<=b; a++ )
 					v[a][pc] = new VarInfo(a,pc);
 				break;
-			case Lua.OP_TAILCALL: /*	A B C	return R(A)(R(A+1), ... ,R(A+B-1))		*/
 			case Lua.OP_VARARG: /*	A B	R(A), R(A+1), ..., R(A+B-1) = vararg		*/			
 				a = Lua.GETARG_A( ins );
 				b = Lua.GETARG_B( ins );
-				for ( int j=0; j<b; j++, a++ )
+				for ( int j=1; j<b; j++, a++ )
 					v[a][pc] = new VarInfo(a,pc);
-				for ( ; a<m; a++ )
-					v[a][pc] = VarInfo.INVALID;
+				if ( b == 0 ) 
+					for ( ; a<m; a++ )
+						v[a][pc] = VarInfo.INVALID;
 				break;
 			case Lua.OP_CALL: /*	A B C	R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */
 				a = Lua.GETARG_A( ins );
 				c = Lua.GETARG_C( ins );
-				for ( int j=0; j<c; j++, a++ )
+				for ( int j=0; j<=c-2; j++, a++ )
 					v[a][pc] = new VarInfo(a,pc);
 				for ( ; a<m; a++ )
 					v[a][pc] = VarInfo.INVALID;
@@ -297,18 +297,23 @@ public class ProtoInfo {
 	public boolean isUpvalueAssign(int pc, int slot) {
 		if ( pc < 0 ) pc = 0;
 		VarInfo v = vars[slot][pc];
-		return v.upvalue != null && v.upvalue.rw;
+//		return v.upvalue != null && v.upvalue.rw;
+		return v != null && v.upvalue != null;
 	}
 
 	public boolean isUpvalueCreate(int pc, int slot) {
+		if ( pc < 0 ) pc = 0;
 		VarInfo v = vars[slot][pc];
-		return v.upvalue != null && v.upvalue.rw && v.allocupvalue && pc == v.pc;
+//		return v.upvalue != null && v.upvalue.rw && v.allocupvalue && pc == v.pc;
+		return v != null && v.upvalue != null && v.allocupvalue && pc == v.pc;
 	}
 
 	public boolean isUpvalueRefer(int pc, int slot) {
 		// TODO: when it is a CALL
+		if ( pc < 0 ) pc = 0;
 		VarInfo v = vars[slot][pc];
-		return v.upvalue != null && v.upvalue.rw;
+//		return v.upvalue != null && v.upvalue.rw;
+		return v != null && v.upvalue != null;
 	}
 
 	public boolean isInitialValueUsed(int slot) {
diff --git a/src/jse/org/luaj/vm2/luajc/UpvalInfo.java b/src/jse/org/luaj/vm2/luajc/UpvalInfo.java
index ebbfd25a..12ab3567 100644
--- a/src/jse/org/luaj/vm2/luajc/UpvalInfo.java
+++ b/src/jse/org/luaj/vm2/luajc/UpvalInfo.java
@@ -60,6 +60,13 @@ public class UpvalInfo {
 		
 		// check for previous assignment
 		loop: while ( true ) {
+			// invalid values terminate search
+			if ( v == VarInfo.INVALID )
+				return;
+			// nil values also terminate (TODO: mark as unintialized upvalue)
+			if ( v.pc == -1 )
+				return;
+			
 			BasicBlock b = pi.blocks[v.pc];
 			if ( v.upvalue == this ) {
 				// loop detected, include previous values
@@ -75,10 +82,6 @@ public class UpvalInfo {
 			if ( v.upvalue != null ) 
 				throw new IllegalArgumentException("upvalue collision detected between "+v.upvalue+" and "+this);
 
-			// invalid values terminate search
-			if ( v == VarInfo.INVALID )
-				return;
-			
 			// assign the variable
 			v.upvalue = this;
 			this.includeVar(v);