diff --git a/vlib/compiler/expression.v b/vlib/compiler/expression.v
index a6a47bbb34..5f9db45316 100644
--- a/vlib/compiler/expression.v
+++ b/vlib/compiler/expression.v
@@ -831,7 +831,7 @@ fn (p mut Parser) factor() string {
 			is_sum_type := type_of_var in p.table.sum_types
 			if is_sum_type && vname.len > 0 {
 				// TODO: make this work for arbitrary sumtype expressions, not just simple vars
-				p.gen('tos3(__SumTypeNames__${type_of_var}[${vname}.typ - 1])')
+				p.gen('${vname}.typ == 0 ? tos3("typeof(): typ == 0") : tos3(__SumTypeNames__${type_of_var}[${vname}.typ - 1])')
 			}else{
 				p.gen('tos3("$type_of_var")')
 			}
diff --git a/vlib/compiler/main.v b/vlib/compiler/main.v
index 201b44c594..c60e2238b6 100644
--- a/vlib/compiler/main.v
+++ b/vlib/compiler/main.v
@@ -340,7 +340,7 @@ pub fn (v mut V) compile2() {
 		println(v.files)
 	}
 	mut b := v.new_v2()
-	b.build_c(v.files, v.pref.out_name)
+	b.build_c(v.files, v.out_name_c)// v.pref.out_name + '.c')
 	v.cc()
 }
 
diff --git a/vlib/hash/wyhash/rand.v b/vlib/hash/wyhash/rand.v
index 3f6e9a86b6..a22edc8ef6 100644
--- a/vlib/hash/wyhash/rand.v
+++ b/vlib/hash/wyhash/rand.v
@@ -5,10 +5,12 @@ module wyhash
 
 pub fn rand_u64(seed &u64) u64 {
 	mut seed0 := seed
+	// QTODO
 	unsafe{
 		mut seed1 := *seed0
 		seed1+=wyp0
 		*seed0 = seed1
 		return wymum(seed1^wyp1, seed1)
 	}
+	//return 0
 }
diff --git a/vlib/v/ast/ast.v b/vlib/v/ast/ast.v
index de724b9b7a..67236ea3f2 100644
--- a/vlib/v/ast/ast.v
+++ b/vlib/v/ast/ast.v
@@ -18,18 +18,14 @@ pub type Stmt = VarDecl | GlobalDecl | FnDecl | Return | Module | Import | ExprS
 ForStmt | StructDecl | ForCStmt | ForInStmt | CompIf | ConstDecl | Attr | BranchStmt | 	
 HashStmt | AssignStmt | EnumDecl | TypeDecl | DeferStmt | GotoLabel | GotoStmt | 	
 LineComment | MultiLineComment | AssertStmt | UnsafeStmt
-
 // pub type Type = StructType | ArrayType
-
 // pub struct StructType {
-// 	fields []Field
+// fields []Field
 // }
-
 // pub struct ArrayType {}
-
 pub struct Type {
 pub:
-	typ  table.Type
+	typ table.Type
 }
 
 // | IncDecStmt k
@@ -333,12 +329,12 @@ mut:
 
 pub struct MatchExpr {
 pub:
-	tok_kind    token.Kind
-	cond        Expr
-	branches    []MatchBranch
-	pos         token.Position
+	tok_kind  token.Kind
+	cond      Expr
+	branches  []MatchBranch
+	pos       token.Position
 mut:
-	typ         table.Type
+	expr_type table.Type // type of `x` in `match x {`
 }
 
 pub struct MatchBranch {
@@ -348,7 +344,6 @@ pub:
 	pos   token.Position
 }
 
-
 pub struct CompIf {
 pub:
 	cond       Expr
@@ -477,11 +472,11 @@ pub:
 
 pub struct ArrayInit {
 pub:
-	pos   token.Position
-	exprs []Expr
+	pos       token.Position
+	exprs     []Expr
 mut:
 	elem_type table.Type
-	typ   table.Type
+	typ       table.Type
 }
 
 pub struct MapInit {
diff --git a/vlib/v/builder/builder.v b/vlib/v/builder/builder.v
index 5d0237c340..5029b045fc 100644
--- a/vlib/v/builder/builder.v
+++ b/vlib/v/builder/builder.v
@@ -42,10 +42,15 @@ pub fn (b mut Builder) gen_c(v_files []string) string {
 	if b.checker.nr_errors > 0 {
 		exit(1)
 	}
-	return gen.cgen(b.parsed_files, b.table)
+	// println('starting cgen...')
+	res := gen.cgen(b.parsed_files, b.table)
+	println('cgen done')
+	// println(res)
+	return res
 }
 
 pub fn (b mut Builder) build_c(v_files []string, out_file string) {
+	println('build_c($out_file)')
 	os.write_file(out_file, b.gen_c(v_files))
 }
 
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index da6c708c8f..62fd439a26 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -16,13 +16,13 @@ const (
 )
 
 pub struct Checker {
-	table           &table.Table
+	table          &table.Table
 mut:
-	file            ast.File
-	nr_errors       int
-	errors          []string
-	expected_type   table.Type
-	fn_return_type  table.Type // current function's return type
+	file           ast.File
+	nr_errors      int
+	errors         []string
+	expected_type  table.Type
+	fn_return_type table.Type // current function's return type
 }
 
 pub fn new_checker(table &table.Table) Checker {
@@ -466,10 +466,10 @@ fn (c mut Checker) stmt(node ast.Stmt) {
 			typ := c.expr(it.expr)
 			it.typ = typ
 		}
-		else {
-			// println('checker.stmt(): unhandled node')
-			// println('checker.stmt(): unhandled node (${typeof(node)})')
-		}
+		else {}
+		// println('checker.stmt(): unhandled node')
+		// println('checker.stmt(): unhandled node (${typeof(node)})')
+		// }
 	}
 }
 
@@ -577,11 +577,10 @@ pub fn (c mut Checker) expr(node ast.Expr) table.Type {
 		}
 		*/
 
-		else {
-			// println('checker.expr(): unhandled node')
-			// TODO: find nil string bug triggered with typeof
-			// println('checker.expr(): unhandled node (${typeof(node)})')
-		}
+		else {}
+		// println('checker.expr(): unhandled node')
+		// TODO: find nil string bug triggered with typeof
+		// println('checker.expr(): unhandled node (${typeof(node)})')
 	}
 	return table.void_type
 }
@@ -670,12 +669,15 @@ pub fn (c mut Checker) ident(ident mut ast.Ident) table.Type {
 }
 
 pub fn (c mut Checker) match_expr(node mut ast.MatchExpr) table.Type {
-	t := c.expr(node.cond)
-	c.expected_type = t
+	expr_type := c.expr(node.cond)
+	if expr_type == 0 {
+		c.error('match 0 expr type', node.pos)
+	}
+	c.expected_type = expr_type
 	mut ret_type := table.void_type
 	for branch in node.branches {
 		for expr in branch.exprs {
-			c.expected_type = t
+			c.expected_type = expr_type
 			typ := c.expr(expr)
 			typ_sym := c.table.get_type_symbol(typ)
 			// TODO:
@@ -695,10 +697,11 @@ pub fn (c mut Checker) match_expr(node mut ast.MatchExpr) table.Type {
 				// node.typ = typ
 				// return typ
 				else {}
-			}
+	}
 		}
 	}
-	node.typ = t
+	node.expr_type = expr_type
+	// println('!m $expr_type')
 	return ret_type
 }
 
diff --git a/vlib/v/gen/cgen.v b/vlib/v/gen/cgen.v
index b8030734d8..c107389690 100644
--- a/vlib/v/gen/cgen.v
+++ b/vlib/v/gen/cgen.v
@@ -76,10 +76,10 @@ fn (g mut Gen) stmt(node ast.Stmt) {
 			// }
 			// g.writeln(';')
 			// }
-			println('assign')
+			g.write('') // /*assign*/')
 		}
 		ast.AssertStmt {
-			println('// assert')
+			g.write('// assert')
 			// TODO
 		}
 		ast.Attr {
@@ -105,6 +105,9 @@ fn (g mut Gen) stmt(node ast.Stmt) {
 			g.stmts(it.stmts)
 			g.writeln('#endif')
 		}
+		ast.DeferStmt {
+			g.writeln('// defer')
+		}
 		ast.EnumDecl {
 			g.writeln('typedef enum {')
 			for i, val in it.vals {
@@ -193,6 +196,9 @@ fn (g mut Gen) stmt(node ast.Stmt) {
 			// TODO
 			g.writeln('__global')
 		}
+		ast.GotoLabel {
+			g.writeln('$it.name:')
+		}
 		ast.HashStmt {
 			g.writeln('#$it.name')
 		}
@@ -227,6 +233,9 @@ fn (g mut Gen) stmt(node ast.Stmt) {
 			}
 			g.writeln('} $it.name;')
 		}
+		ast.TypeDecl {
+			g.writeln('// type')
+		}
 		ast.UnsafeStmt {
 			g.stmts(it.stmts)
 		}
@@ -243,7 +252,7 @@ fn (g mut Gen) stmt(node ast.Stmt) {
 }
 
 fn (g mut Gen) expr(node ast.Expr) {
-	// println('cgen expr()')
+	// println('cgen expr() line_nr=$node.pos.line_nr')
 	match node {
 		ast.ArrayInit {
 			type_sym := g.table.get_type_symbol(it.typ)
@@ -254,11 +263,17 @@ fn (g mut Gen) expr(node ast.Expr) {
 			}
 			g.write('\n})')
 		}
+		ast.AsCast {
+			g.write('/* as */')
+		}
 		ast.AssignExpr {
 			g.expr(it.left)
 			g.write(' $it.op.str() ')
 			g.expr(it.val)
 		}
+		ast.Assoc {
+			g.write('/* assoc */')
+		}
 		ast.BoolLiteral {
 			g.write(it.val.str())
 		}
@@ -310,10 +325,8 @@ fn (g mut Gen) expr(node ast.Expr) {
 			g.writeln(') {')
 			for i, stmt in it.stmts {
 				// Assign ret value
-				if i == it.stmts.len - 1 && type_sym.kind != .void {
-					// g.writeln('$tmp =')
-					println(1)
-				}
+				if i == it.stmts.len - 1 && type_sym.kind != .void {}
+				// g.writeln('$tmp =')
 				g.stmt(stmt)
 			}
 			g.writeln('}')
@@ -325,6 +338,9 @@ fn (g mut Gen) expr(node ast.Expr) {
 				g.writeln('}')
 			}
 		}
+		ast.IfGuardExpr {
+			g.write('/* guard */')
+		}
 		ast.IndexExpr {
 			g.index_expr(it)
 		}
@@ -343,7 +359,13 @@ fn (g mut Gen) expr(node ast.Expr) {
 			g.write(it.val.str())
 		}
 		ast.MatchExpr {
-			type_sym := g.table.get_type_symbol(it.typ)
+			// println('match expr typ=$it.expr_type')
+			// TODO
+			if it.expr_type == 0 {
+				g.writeln('// match 0')
+				return
+			}
+			type_sym := g.table.get_type_symbol(it.expr_type)
 			mut tmp := ''
 			if type_sym.kind != .void {
 				tmp = g.new_tmp_var()
@@ -356,7 +378,7 @@ fn (g mut Gen) expr(node ast.Expr) {
 				for i, expr in branch.exprs {
 					g.write('$tmp == ')
 					g.expr(expr)
-					if i < branch.exprs.len-1 {
+					if i < branch.exprs.len - 1 {
 						g.write(' || ')
 					}
 				}
@@ -376,6 +398,9 @@ fn (g mut Gen) expr(node ast.Expr) {
 			g.call_args(it.args)
 			g.write(')')
 		}
+		ast.None {
+			g.write('0')
+		}
 		ast.ParExpr {
 			g.write('(')
 			g.expr(it.expr)
@@ -425,6 +450,9 @@ fn (g mut Gen) expr(node ast.Expr) {
 			g.write('.')
 			g.write(it.field)
 		}
+		ast.Type {
+			g.write('/* Type */')
+		}
 		else {
 			// #printf("node=%d\n", node.typ);
 			println(term.red('cgen.expr(): bad node ' + typeof(node)))
@@ -467,6 +495,6 @@ fn (g mut Gen) call_args(args []ast.Expr) {
 }
 
 fn verror(s string) {
-	println(s)
-	exit(1)
+	println('cgen error: $s')
+	// exit(1)
 }
diff --git a/vlib/v/table/table.v b/vlib/v/table/table.v
index 565587ff95..f7cf5de05f 100644
--- a/vlib/v/table/table.v
+++ b/vlib/v/table/table.v
@@ -182,6 +182,7 @@ pub fn (t &Table) find_type(name string) ?TypeSymbol {
 
 [inline]
 pub fn (t &Table) get_type_symbol(typ Type) &TypeSymbol {
+	// println('get_type_symbol $typ')
 	idx := type_idx(typ)
 	if idx > 0 {
 		return &t.types[idx]
@@ -400,8 +401,7 @@ pub fn (t &Table) check(got, expected Type) bool {
 	}
 	// TODO: actually check for & handle pointers with name_expr
 	// see hack in checker IndexExpr line #691
-	if (got_type_sym.kind == .byte && exp_type_sym.kind == .byteptr) ||
-	(exp_type_sym.kind == .byte && got_type_sym.kind == .byteptr) {
+	if (got_type_sym.kind == .byte && exp_type_sym.kind == .byteptr) || (exp_type_sym.kind == .byte && got_type_sym.kind == .byteptr) {
 		return true
 	}
 	// TODO
@@ -424,8 +424,7 @@ pub fn (t &Table) check(got, expected Type) bool {
 		return true
 	}
 	// type alias
-	if (got_type_sym.kind == .alias && got_type_sym.parent_idx == exp_idx) ||
-	(exp_type_sym.kind == .alias && exp_type_sym.parent_idx == got_idx) {
+	if (got_type_sym.kind == .alias && got_type_sym.parent_idx == exp_idx) || (exp_type_sym.kind == .alias && exp_type_sym.parent_idx == got_idx) {
 		return true
 	}
 	// sum type