From 753615e856d28aa22517ce33b4896a17f48b009b Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Thu, 26 Feb 2026 08:38:34 +0300
Subject: [PATCH] cgen: fix enum explicit size for tcc and gcc (fixes #25041)

---
 vlib/v/gen/c/cgen.v                                  |  6 ++++--
 .../enums/enum_explicit_size_big_and_small_test.v    | 12 ++++++------
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/vlib/v/gen/c/cgen.v b/vlib/v/gen/c/cgen.v
index 64b5ce20f..b10d06d75 100644
--- a/vlib/v/gen/c/cgen.v
+++ b/vlib/v/gen/c/cgen.v
@@ -5148,10 +5148,12 @@ fn (mut g Gen) debugger_stmt(node ast.DebuggerStmt) {
 fn (mut g Gen) enum_decl(node ast.EnumDecl) {
 	enum_name := util.no_dots(node.name)
 	is_flag := node.is_flag
-	if g.is_cc_msvc {
+	// Explicit-size enums are emitted as typedef + defines, so all C compilers
+	// (including tinyc) respect the selected storage size.
+	if g.is_cc_msvc || node.typ != ast.int_type {
 		mut last_value := '0'
 		enum_typ_name := g.table.get_type_name(node.typ)
-		if g.pref.skip_unused && node.typ.idx() !in g.table.used_features.used_syms {
+		if g.pref.skip_unused && node.enum_typ !in g.table.used_features.used_syms {
 			return
 		}
 		g.enum_typedefs.writeln('')
diff --git a/vlib/v/tests/enums/enum_explicit_size_big_and_small_test.v b/vlib/v/tests/enums/enum_explicit_size_big_and_small_test.v
index e4ba5ded6..d8ac11f18 100644
--- a/vlib/v/tests/enums/enum_explicit_size_big_and_small_test.v
+++ b/vlib/v/tests/enums/enum_explicit_size_big_and_small_test.v
@@ -6,6 +6,10 @@ enum SmallEnum as i8 {
 	e
 }
 
+struct SmallEnumWrap {
+	value SmallEnum
+}
+
 enum BigEnum as u64 {
 	a = 0xABCD_EF09_1234_5678
 	b = 0xFFFF_FFFF_FFFF_FFF0
@@ -24,12 +28,8 @@ enum BigIEnum as i64 {
 
 fn test_small_enum() {
 	dump(sizeof(SmallEnum))
-	$if tinyc {
-		// TODO: TCC currently ignores `__attribute__((packed))` for enums, and uses an int instead, even with -fshort-enums :-|
-		assert sizeof(SmallEnum) == 4
-	} $else {
-		assert sizeof(SmallEnum) == 1
-	}
+	assert sizeof(SmallEnum) == 1
+	assert sizeof(SmallEnumWrap) == 1
 	dump(i8(SmallEnum.a))
 	dump(i8(SmallEnum.b))
 	dump(i8(SmallEnum.c))
-- 
2.39.5