From caa0e25939493aaae571772dc24072f4726bd716 Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Sun, 20 Mar 2022 20:23:48 +0200
Subject: [PATCH] cgen: fix struct type dependency sorting, when struct field
 types, are aliases to struct types from other modules (#13779)

---
 vlib/v/gen/c/cgen.v                           | 25 +++++++++++++------
 .../modules/alias_to_another_module/alias.v   |  9 +++++++
 vlib/v/tests/modules/another_module/module.v  | 12 +++++++++
 ...from_another_module_in_struct_field_test.v | 14 +++++++++++
 4 files changed, 53 insertions(+), 7 deletions(-)
 create mode 100644 vlib/v/tests/modules/alias_to_another_module/alias.v
 create mode 100644 vlib/v/tests/modules/another_module/module.v
 create mode 100644 vlib/v/tests/use_alias_from_another_module_in_struct_field_test.v

diff --git a/vlib/v/gen/c/cgen.v b/vlib/v/gen/c/cgen.v
index f40d88bc92..b3db40405a 100644
--- a/vlib/v/gen/c/cgen.v
+++ b/vlib/v/gen/c/cgen.v
@@ -4524,17 +4524,17 @@ fn (mut g Gen) write_builtin_types() {
 // Sort the types, make sure types that are referenced by other types
 // are added before them.
 fn (mut g Gen) write_sorted_types() {
+	g.type_definitions.writeln('// #start sorted_symbols')
+	defer {
+		g.type_definitions.writeln('// #end sorted_symbols')
+	}
 	mut symbols := []&ast.TypeSymbol{cap: g.table.type_symbols.len} // structs that need to be sorted
 	for sym in g.table.type_symbols {
 		if sym.name !in c.builtins {
 			symbols << sym
 		}
 	}
-	// sort structs
 	sorted_symbols := g.sort_structs(symbols)
-	// Generate C code
-	g.type_definitions.writeln('// builtin types:')
-	g.type_definitions.writeln('//------------------ #endbuiltin')
 	g.write_types(sorted_symbols)
 }
 
@@ -4706,7 +4706,7 @@ fn (mut g Gen) write_types(symbols []&ast.TypeSymbol) {
 }
 
 // sort structs by dependant fields
-fn (g &Gen) sort_structs(typesa []&ast.TypeSymbol) []&ast.TypeSymbol {
+fn (mut g Gen) sort_structs(typesa []&ast.TypeSymbol) []&ast.TypeSymbol {
 	util.timing_start(@METHOD)
 	defer {
 		util.timing_measure(@METHOD)
@@ -4742,12 +4742,23 @@ fn (g &Gen) sort_structs(typesa []&ast.TypeSymbol) []&ast.TypeSymbol {
 					field_deps << dep
 				}
 				for field in sym.info.fields {
-					dep := g.table.sym(field.typ).name
+					if field.typ.is_ptr() {
+						continue
+					}
+					fsym := g.table.sym(field.typ)
+					dep := fsym.name
 					// skip if not in types list or already in deps
-					if dep !in type_names || dep in field_deps || field.typ.is_ptr() {
+					if dep !in type_names || dep in field_deps {
 						continue
 					}
 					field_deps << dep
+					if fsym.info is ast.Alias {
+						xdep := g.table.sym(fsym.info.parent_type).name
+						if xdep !in type_names || xdep in field_deps {
+							continue
+						}
+						field_deps << xdep
+					}
 				}
 			}
 			// ast.Interface {}
diff --git a/vlib/v/tests/modules/alias_to_another_module/alias.v b/vlib/v/tests/modules/alias_to_another_module/alias.v
new file mode 100644
index 0000000000..d92a17ea62
--- /dev/null
+++ b/vlib/v/tests/modules/alias_to_another_module/alias.v
@@ -0,0 +1,9 @@
+module alias_to_another_module
+
+import another_module
+
+pub type MyAlias = another_module.SomeStruct
+
+pub fn (m MyAlias) alias_method() int {
+	return 42
+}
diff --git a/vlib/v/tests/modules/another_module/module.v b/vlib/v/tests/modules/another_module/module.v
new file mode 100644
index 0000000000..a21270ea7c
--- /dev/null
+++ b/vlib/v/tests/modules/another_module/module.v
@@ -0,0 +1,12 @@
+module another_module
+
+pub struct SomeStruct {
+pub mut:
+	x int
+	y int
+	z int
+}
+
+pub fn (s SomeStruct) some_method() int {
+	return 999 + s.x + s.y + s.z
+}
diff --git a/vlib/v/tests/use_alias_from_another_module_in_struct_field_test.v b/vlib/v/tests/use_alias_from_another_module_in_struct_field_test.v
new file mode 100644
index 0000000000..ed4d194279
--- /dev/null
+++ b/vlib/v/tests/use_alias_from_another_module_in_struct_field_test.v
@@ -0,0 +1,14 @@
+import alias_to_another_module
+
+struct MyStruct {
+	myfield alias_to_another_module.MyAlias
+}
+
+fn test_using_struct_with_alias() {
+	m := MyStruct{
+		myfield: alias_to_another_module.MyAlias{1, 2, 3}
+	}
+	dump(m)
+	assert m.myfield.alias_method() == 42
+	assert m.myfield.some_method() == 1005
+}