cgen: make multi return decl order consistant & use typedefs. closes #7728

vlib/v/gen/cgen.v

@@ -362,6 +362,7 @@ pub fn (mut g Gen) init() {
 		g.cheaders.writeln('#include <spawn.h>')
 	}
 	g.write_builtin_types()
+	g.write_multi_return_typedefs()
 	g.write_typedef_types()
 	g.write_typeof_functions()
 	if g.pref.build_mode != .build_module {
@@ -369,7 +370,7 @@ pub fn (mut g Gen) init() {
 		g.write_str_fn_definitions()
 	}
 	g.write_sorted_types()
-	g.write_multi_return_types()
+	g.write_multi_return_structs()
 	g.definitions.writeln('// end of definitions #endif')
 	//
 	g.stringliterals.writeln('')
@@ -654,13 +655,8 @@ static inline void __${typ.cname}_pushval($typ.cname ch, $el_stype val) {
 pub fn (mut g Gen) write_fn_typesymbol_declaration(sym table.TypeSymbol) {
 	info := sym.info as table.FnType
 	func := info.func
-	mut retsym := g.table.get_type_symbol(func.return_type)
-	is_multi := retsym.kind == .multi_return
 	is_fn_sig := func.name == ''
 	not_anon := !info.is_anon
-	if is_multi {
-		g.write_multi_return_type_declaration(mut retsym)
-	}
 	if !info.has_decl && (not_anon || is_fn_sig) {
 		fn_name := sym.cname
 		g.type_definitions.write('typedef ${g.typ(func.return_type)} (*$fn_name)(')
@@ -674,30 +670,30 @@ pub fn (mut g Gen) write_fn_typesymbol_declaration(sym table.TypeSymbol) {
 	}
 }
 
-pub fn (mut g Gen) write_multi_return_type_declaration(mut sym table.TypeSymbol) {
-	if sym.is_written {
-		return
-	}
-	info := sym.info as table.MultiReturn
-	g.type_definitions.writeln('typedef struct {')
-	// TODO copy pasta StructDecl
-	// for field in struct_info.fields {
-	for i, mr_typ in info.types {
-		type_name := g.typ(mr_typ)
-		g.type_definitions.writeln('\t$type_name arg$i;')
-	}
-	g.type_definitions.writeln('} $sym.cname;\n')
-	// g.typedefs.writeln('typedef struct $name $name;')
-	sym.is_written = true
-}
-
-pub fn (mut g Gen) write_multi_return_types() {
-	g.type_definitions.writeln('\n// BEGIN_multi_return_structs')
-	for idx in 0 .. g.table.types.len {
-		if g.table.types[idx].kind != .multi_return {
+pub fn (mut g Gen) write_multi_return_typedefs() {
+	g.type_definitions.writeln('\n// BEGIN_multi_return_typedefs')
+	for sym in g.table.types {
+		if sym.kind != .multi_return {
 			continue
 		}
-		g.write_multi_return_type_declaration(mut g.table.types[idx])
+		g.type_definitions.writeln('typedef struct $sym.cname $sym.cname;')
+	}
+	g.type_definitions.writeln('// END_multi_return_typedefs\n')
+}
+
+pub fn (mut g Gen) write_multi_return_structs() {
+	g.type_definitions.writeln('\n// BEGIN_multi_return_structs')
+	for sym in g.table.types {
+		if sym.kind != .multi_return {
+			continue
+		}
+		info := sym.info as table.MultiReturn
+		g.type_definitions.writeln('struct $sym.cname {')
+		for i, mr_typ in info.types {
+			type_name := g.typ(mr_typ)
+			g.type_definitions.writeln('\t$type_name arg$i;')
+		}
+		g.type_definitions.writeln('};\n')
 	}
 	g.type_definitions.writeln('// END_multi_return_structs\n')
 }

vlib/v/table/types.v

@@ -42,7 +42,6 @@ pub mut:
 	methods    []Fn
 	mod        string
 	is_public  bool
-	is_written bool // set to true, when the backend definition for a symbol had been written, to avoid duplicates
 	language   Language
 }
 
@@ -183,7 +182,6 @@ pub fn (ts TypeSymbol) debug() []string {
 	res << 'info: $ts.info'
 	res << 'kind: $ts.kind'
 	res << 'is_public: $ts.is_public'
-	res << 'is_written: $ts.is_written'
 	res << 'language: $ts.language'
 	res << 'methods ($ts.methods.len): ' + ts.methods.map(it.str()).join(', ')
 	return res

vlib/v/tests/str_gen_test.v

@@ -390,5 +390,15 @@ fn test_multi_return() {
     value: 'one'
 }, Two{
     value: 'two'
+})"
+	anon_a := fn() (One, Two) {
+		one := One{}
+		two := Two{}
+		return one, two
+	}
+	assert '$anon_a()' == "(One{
+    value: 'one'
+}, Two{
+    value: 'two'
 })"
 }