From f4b3f1d6022265992f87cea1d9591ffa8ec226d6 Mon Sep 17 00:00:00 2001
From: Evan Haas <evan@lagerdata.com>
Date: Mon, 10 Jan 2022 11:54:11 -0800
Subject: [PATCH] translate-c: Handle typedef'ed void return type for
 functions.

Fixes #10356
---
 src/translate_c.zig       | 15 +++++++++++----
 test/run_translated_c.zig | 10 ++++++++++
 test/translate_c.zig      |  2 +-
 3 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/src/translate_c.zig b/src/translate_c.zig
index 4d993e62ea..971551fb69 100644
--- a/src/translate_c.zig
+++ b/src/translate_c.zig
@@ -4824,11 +4824,18 @@ fn qualTypeWasDemotedToOpaque(c: *Context, qt: clang.QualType) bool {
 
 fn isAnyopaque(qt: clang.QualType) bool {
     const ty = qt.getTypePtr();
-    if (ty.getTypeClass() == .Builtin) {
-        const builtin_ty = @ptrCast(*const clang.BuiltinType, ty);
-        return builtin_ty.getKind() == .Void;
+    switch (ty.getTypeClass()) {
+        .Builtin => {
+            const builtin_ty = @ptrCast(*const clang.BuiltinType, ty);
+            return builtin_ty.getKind() == .Void;
+        },
+        .Typedef => {
+            const typedef_ty = @ptrCast(*const clang.TypedefType, ty);
+            const typedef_decl = typedef_ty.getDecl();
+            return isAnyopaque(typedef_decl.getUnderlyingType());
+        },
+        else => return false,
     }
-    return false;
 }
 
 const FnDeclContext = struct {
diff --git a/test/run_translated_c.zig b/test/run_translated_c.zig
index 99ff869b11..80e889b44c 100644
--- a/test/run_translated_c.zig
+++ b/test/run_translated_c.zig
@@ -1809,4 +1809,14 @@ pub fn addCases(cases: *tests.RunTranslatedCContext) void {
         \\    return 0;
         \\}
     , "");
+
+    cases.add("Typedef'ed void used as return type. Issue #10356",
+        \\typedef void V;
+        \\V foo(V *f) {}
+        \\int main(void) {
+        \\    int x = 0;
+        \\    foo(&x);
+        \\    return 0;
+        \\}
+    , "");
 }
diff --git a/test/translate_c.zig b/test/translate_c.zig
index 50072d8085..d1e071deb7 100644
--- a/test/translate_c.zig
+++ b/test/translate_c.zig
@@ -814,7 +814,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
     , &[_][]const u8{
         \\pub const Foo = anyopaque;
         ,
-        \\pub extern fn fun(a: ?*Foo) Foo;
+        \\pub extern fn fun(a: ?*Foo) void;
     });
 
     cases.add("duplicate typedef",