From 534014f84e2e9605022ba6d6c2d2b7be1e575468 Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Wed, 29 Jan 2020 09:55:40 +0100
Subject: [PATCH] translate-c: Handle fn protos wrapped in parenthesis

Closes #4289
---
 src-self-hosted/translate_c.zig | 24 +++++++++++++++++-------
 test/translate_c.zig            | 11 ++++++++++-
 2 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/src-self-hosted/translate_c.zig b/src-self-hosted/translate_c.zig
index 18c4cafbe3..d4df998774 100644
--- a/src-self-hosted/translate_c.zig
+++ b/src-self-hosted/translate_c.zig
@@ -443,12 +443,22 @@ fn visitFnDecl(c: *Context, fn_decl: *const ZigClangFunctionDecl) Error!void {
     };
 
     var fn_qt = ZigClangFunctionDecl_getType(fn_decl);
-    var fn_type = ZigClangQualType_getTypePtr(fn_qt);
-    if (ZigClangType_getTypeClass(fn_type) == .Attributed) {
-        const attr_type = @ptrCast(*const ZigClangAttributedType, fn_type);
-        fn_qt = ZigClangAttributedType_getEquivalentType(attr_type);
-        fn_type = ZigClangQualType_getTypePtr(fn_qt);
-    }
+
+    const fn_type = while (true) {
+        const fn_type = ZigClangQualType_getTypePtr(fn_qt);
+
+        switch (ZigClangType_getTypeClass(fn_type)) {
+            .Attributed => {
+                const attr_type = @ptrCast(*const ZigClangAttributedType, fn_type);
+                fn_qt = ZigClangAttributedType_getEquivalentType(attr_type);
+            },
+            .Paren => {
+                const paren_type = @ptrCast(*const ZigClangParenType, fn_type);
+                fn_qt = ZigClangParenType_getInnerType(paren_type);
+            },
+            else => break fn_type,
+        }
+    } else unreachable;
 
     const proto_node = switch (ZigClangType_getTypeClass(fn_type)) {
         .FunctionProto => blk: {
@@ -505,7 +515,7 @@ fn visitFnDecl(c: *Context, fn_decl: *const ZigClangFunctionDecl) Error!void {
 
         const arg_name = blk: {
             const param_prefix = if (is_const) "" else "arg_";
-            const bare_arg_name = try std.fmt.allocPrint(c.a(), "{}{}", .{param_prefix, mangled_param_name});
+            const bare_arg_name = try std.fmt.allocPrint(c.a(), "{}{}", .{ param_prefix, mangled_param_name });
             break :blk try block_scope.makeMangledName(c, bare_arg_name);
         };
 
diff --git a/test/translate_c.zig b/test/translate_c.zig
index 1bc54badf3..af79fe2ff5 100644
--- a/test/translate_c.zig
+++ b/test/translate_c.zig
@@ -3,6 +3,16 @@ const builtin = @import("builtin");
 const Target = @import("std").Target;
 
 pub fn addCases(cases: *tests.TranslateCContext) void {
+    cases.add("function prototype with parenthesis",
+        \\void (f0) (void *L);
+        \\void ((f1)) (void *L);
+        \\void (((f2))) (void *L);
+    , &[_][]const u8{
+        \\pub extern fn f0(L: ?*c_void) void;
+        \\pub extern fn f1(L: ?*c_void) void;
+        \\pub extern fn f2(L: ?*c_void) void;
+    });
+
     cases.add("array initializer w/ typedef",
         \\typedef unsigned char uuid_t[16];
         \\static const uuid_t UUID_NULL __attribute__ ((unused)) = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
@@ -2642,5 +2652,4 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\    return if (x > y) x else y;
         \\}
     });
-            
 }