v2: parse and build builtin/string.v; remove ssa.register_string_type()

Author: medvednikov

cmd/v2/builtin/string.v

@@ -0,0 +1,12 @@
+// Copyright (c) 2026 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+// Builtin string struct for v2 SSA backend testing.
+// This must match the definition in vlib/v2/types/universe.v
+
+pub struct string {
+	str    &u8
+	len    int
+	is_lit int
+}

cmd/v2/test_ssa_backends.v

@@ -26,6 +26,27 @@ fn main() {
 	prefs := &pref.Preferences{}
 	mut file_set := token.FileSet.new()
 	mut p := parser.Parser.new(prefs)
+	mut transformer := transform.Transformer.new()
+
+	// Get the directory where this script is located
+	exe_dir := os.dir(os.executable())
+
+	// Initialize SSA Module
+	mut mod := ssa.Module.new('main')
+	mut builder := ssa.Builder.new(mod)
+
+	// Parse and build builtin string.v first
+	builtin_file := os.join_path(exe_dir, 'builtin', 'string.v')
+	if os.exists(builtin_file) {
+		println('[*] Parsing builtin/string.v...')
+		parsed_builtin := p.parse_file(builtin_file, mut file_set)
+		if parsed_builtin.stmts.len > 0 {
+			println('    Found ${parsed_builtin.stmts.len} statements in builtin')
+			builtin_transformed := transformer.transform(parsed_builtin)
+			builder.build(builtin_transformed)
+		}
+	}
+
 	//  Parse File
 	input_file := 'test.v'
 	if !os.exists(input_file) {
@@ -39,13 +60,9 @@ fn main() {
 	}
 	// Transform AST (lower complex constructs like ArrayInitExpr)
 	println('[*] Transforming AST...')
-	mut transformer := transform.Transformer.new()
 	file := transformer.transform(parsed_file)
-	// Initialize SSA Module
-	mut mod := ssa.Module.new('main')
 	//  Build SSA from AST
 	println('[*] Building SSA...')
-	mut builder := ssa.Builder.new(mod)
 	builder.build(file)
 	// Optimize
 	println('[*] Optimizing SSA...')

vlib/v2/ssa/builder.v

@@ -45,7 +45,7 @@ struct LoopInfo {
 }
 
 pub fn Builder.new(mod &Module) &Builder {
-	mut b := &Builder{
+	return &Builder{
 		mod:              mod
 		vars:             map[string]ValueID{}
 		var_struct_types: map[string]string{}
@@ -54,30 +54,6 @@ pub fn Builder.new(mod &Module) &Builder {
 		enum_values:      map[string]int{}
 		var_array_sizes:  map[string]int{}
 	}
-	// Register builtin string struct type: { str &u8, len int, is_lit int }
-	b.register_string_type()
-	return b
-}
-
-fn (mut b Builder) register_string_type() {
-	// Get string struct definition from v2.types (defined in universe.v)
-	string_struct := types.get_string_struct()
-
-	// Convert types.Struct to SSA type
-	mut ssa_fields := []TypeID{}
-	mut ssa_field_names := []string{}
-
-	for field in string_struct.fields {
-		ssa_fields << b.type_to_ssa(field.typ)
-		ssa_field_names << field.name
-	}
-
-	string_type_id := b.mod.type_store.register(Type{
-		kind:        .struct_t
-		fields:      ssa_fields
-		field_names: ssa_field_names
-	})
-	b.struct_types['string'] = string_type_id
 }
 
 // Convert v2.types.Type to SSA TypeID

vlib/v2/types/universe.v

@@ -63,27 +63,8 @@ const f64_ = Primitive{
 	size:  64
 }
 // complex / non primitives
-// String struct as defined in builtin/string.v:
+// String struct is defined in cmd/v2/builtin/string.v:
 // pub struct string { str &u8, len int, is_lit int }
-const string_struct_ = Struct{
-	name:   'string'
-	fields: [
-		Field{
-			name: 'str'
-			typ:  Pointer{
-				base_type: u8_
-			}
-		},
-		Field{
-			name: 'len'
-			typ:  int_
-		},
-		Field{
-			name: 'is_lit'
-			typ:  int_
-		},
-	]
-}
 const string_ = String(0)
 const chan_ = Channel{}
 const char_ = Char(0)
@@ -122,11 +103,6 @@ const float_literal_ = Primitive{
 // TODO: is this what thread should be?
 const thread_ = Thread{}
 
-// Returns the string struct type definition (for SSA builder)
-pub fn get_string_struct() Struct {
-	return string_struct_
-}
-
 pub fn init_universe() &Scope {
 	// universe scope
 	mut universe_ := new_scope(unsafe { nil })