From 8f69bd131105adf30fdad3cd5c33cc5a29563ce8 Mon Sep 17 00:00:00 2001
From: Swastik Baranwal <swstkbaranwal@gmail.com>
Date: Wed, 27 Sep 2023 23:47:17 +0530
Subject: [PATCH] cgen: fix `type VType = &C.CType` (#19452)

---
 vlib/v/gen/c/cgen.v                                    | 10 ++--------
 .../c/testdata/alias_c_parent_type_decl.c.must_have    |  1 +
 vlib/v/gen/c/testdata/alias_c_parent_type_decl.out     |  0
 vlib/v/gen/c/testdata/alias_c_parent_type_decl.vv      |  2 ++
 4 files changed, 5 insertions(+), 8 deletions(-)
 create mode 100644 vlib/v/gen/c/testdata/alias_c_parent_type_decl.c.must_have
 create mode 100644 vlib/v/gen/c/testdata/alias_c_parent_type_decl.out
 create mode 100644 vlib/v/gen/c/testdata/alias_c_parent_type_decl.vv

diff --git a/vlib/v/gen/c/cgen.v b/vlib/v/gen/c/cgen.v
index ce829ef87c2d1f..13229b09668285 100644
--- a/vlib/v/gen/c/cgen.v
+++ b/vlib/v/gen/c/cgen.v
@@ -1518,17 +1518,11 @@ static inline void __${sym.cname}_pushval(${sym.cname} ch, ${push_arg} val) {
 pub fn (mut g Gen) write_alias_typesymbol_declaration(sym ast.TypeSymbol) {
 	parent := g.table.type_symbols[sym.parent_idx]
 	is_c_parent := parent.name.len > 2 && parent.name[0] == `C` && parent.name[1] == `.`
-	mut is_typedef := false
 	mut is_fixed_array_of_non_builtin := false
-	if parent.info is ast.Struct {
-		is_typedef = parent.info.is_typedef
-	}
 	mut parent_styp := parent.cname
 	if is_c_parent {
-		if !is_typedef {
-			parent_styp = 'struct ' + parent.cname[3..]
-		} else {
-			parent_styp = parent.cname[3..]
+		if sym.info is ast.Alias {
+			parent_styp = g.typ(sym.info.parent_type)
 		}
 	} else {
 		if sym.info is ast.Alias {
diff --git a/vlib/v/gen/c/testdata/alias_c_parent_type_decl.c.must_have b/vlib/v/gen/c/testdata/alias_c_parent_type_decl.c.must_have
new file mode 100644
index 00000000000000..1fa0852bbb1b6a
--- /dev/null
+++ b/vlib/v/gen/c/testdata/alias_c_parent_type_decl.c.must_have
@@ -0,0 +1 @@
+typedef struct atype* main__BType;
diff --git a/vlib/v/gen/c/testdata/alias_c_parent_type_decl.out b/vlib/v/gen/c/testdata/alias_c_parent_type_decl.out
new file mode 100644
index 00000000000000..e69de29bb2d1d6
diff --git a/vlib/v/gen/c/testdata/alias_c_parent_type_decl.vv b/vlib/v/gen/c/testdata/alias_c_parent_type_decl.vv
new file mode 100644
index 00000000000000..0623498bd29d63
--- /dev/null
+++ b/vlib/v/gen/c/testdata/alias_c_parent_type_decl.vv
@@ -0,0 +1,2 @@
+struct C.atype{}
+type BType = &C.atype