From 5fe524d93570f3b5e83791f7eb5a77228834da11 Mon Sep 17 00:00:00 2001
From: kbkpbot <kbkpbot@sina.com>
Date: Sun, 1 Mar 2026 22:02:04 +0800
Subject: [PATCH] =?UTF-8?q?cgen:=20fix=20bit-field=20generation=20for=20op?=
 =?UTF-8?q?tion/result=20types=20in=20minified=20st=E2=80=A6=20(#26670)?=
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* cgen: fix bit-field generation for option/result types in minified structs (fixes #26622)

Option and result types are represented as structs in C, which cannot be
used as bit-fields. Skip the bit-field optimization for these types in
minified structs to avoid C compilation errors.

Co-authored-by: iFlow CLI <iflow> (glm-5)

* tests: skip minify_option_field test on MSVC

MSVC handles bit-fields differently than GCC/Clang, causing the
minify_option_field test to fail on Windows MSVC CI.

- Add _not_msvc_windows.vv suffix pattern to skip logic
- Rename test files to use the new suffix

This follows the existing naming convention for platform/compiler-
specific test handling (similar to _nix.vv, _msvc_windows.vv).
---
 vlib/v/gen/c/coutput_test.v                   |  6 ++++
 vlib/v/gen/c/struct.v                         |  3 +-
 ..._option_field_not_msvc_windows.c.must_have |  4 +++
 .../minify_option_field_not_msvc_windows.out  |  4 +++
 .../minify_option_field_not_msvc_windows.vv   | 35 +++++++++++++++++++
 5 files changed, 51 insertions(+), 1 deletion(-)
 create mode 100644 vlib/v/gen/c/testdata/minify_option_field_not_msvc_windows.c.must_have
 create mode 100644 vlib/v/gen/c/testdata/minify_option_field_not_msvc_windows.out
 create mode 100644 vlib/v/gen/c/testdata/minify_option_field_not_msvc_windows.vv

diff --git a/vlib/v/gen/c/coutput_test.v b/vlib/v/gen/c/coutput_test.v
index d86397983..bf3b634da 100644
--- a/vlib/v/gen/c/coutput_test.v
+++ b/vlib/v/gen/c/coutput_test.v
@@ -284,6 +284,12 @@ fn should_skip(relpath string) bool {
 				return true
 			}
 		}
+		$if msvc {
+			if relpath.contains('_not_msvc_windows.vv') {
+				eprintln('> skipping ${relpath} on msvc')
+				return true
+			}
+		}
 	} else {
 		if relpath.contains('_windows.vv') {
 			eprintln('> skipping ${relpath} on !windows')
diff --git a/vlib/v/gen/c/struct.v b/vlib/v/gen/c/struct.v
index 6515bedcf..aa809f496 100644
--- a/vlib/v/gen/c/struct.v
+++ b/vlib/v/gen/c/struct.v
@@ -703,7 +703,8 @@ fn (mut g Gen) struct_decl(s ast.Struct, name string, is_anon bool, is_option bo
 			field_name := c_name(field.name)
 			volatile_prefix := if field.is_volatile { 'volatile ' } else { '' }
 			mut size_suffix := ''
-			if is_minify && !g.is_cc_msvc && !g.pref.output_cross_c {
+			if is_minify && !g.is_cc_msvc && !g.pref.output_cross_c && !field.typ.has_flag(.option)
+				&& !field.typ.has_flag(.result) {
 				if field.typ == ast.bool_type_idx {
 					size_suffix = ' : 1'
 				} else {
diff --git a/vlib/v/gen/c/testdata/minify_option_field_not_msvc_windows.c.must_have b/vlib/v/gen/c/testdata/minify_option_field_not_msvc_windows.c.must_have
new file mode 100644
index 000000000..b2e6d5dd2
--- /dev/null
+++ b/vlib/v/gen/c/testdata/minify_option_field_not_msvc_windows.c.must_have
@@ -0,0 +1,4 @@
+_option_bool optional;
+main__Status status : 2;
+_option_main__Priority priority;
+bool done : 1;
diff --git a/vlib/v/gen/c/testdata/minify_option_field_not_msvc_windows.out b/vlib/v/gen/c/testdata/minify_option_field_not_msvc_windows.out
new file mode 100644
index 000000000..f486b9ab6
--- /dev/null
+++ b/vlib/v/gen/c/testdata/minify_option_field_not_msvc_windows.out
@@ -0,0 +1,4 @@
+active
+low
+false
+false
diff --git a/vlib/v/gen/c/testdata/minify_option_field_not_msvc_windows.vv b/vlib/v/gen/c/testdata/minify_option_field_not_msvc_windows.vv
new file mode 100644
index 000000000..798e4f5cf
--- /dev/null
+++ b/vlib/v/gen/c/testdata/minify_option_field_not_msvc_windows.vv
@@ -0,0 +1,35 @@
+// Test that minified structs with option fields don't use bit-fields
+// Bit-fields can only have integral types in C, not struct types
+// Option types are represented as structs in C
+
+module main
+
+enum Status as u8 {
+	pending
+	active
+	inactive
+}
+
+enum Priority as u8 {
+	low
+	medium
+	high
+}
+
+@[minify]
+struct Task {
+	status   Status
+	priority ?Priority
+	done     bool
+	optional ?bool
+}
+
+fn main() {
+	task := Task{
+		status: .active
+	}
+	println(task.status)
+	println(task.priority or { Priority.low })
+	println(task.done)
+	println(task.optional or { false })
+}
-- 
2.39.5