From fd023fe5e2cd4f729176cb070b7972f227706195 Mon Sep 17 00:00:00 2001
From: paokito <paokito.takasu@gmail.com>
Date: Mon, 21 Jul 2025 11:08:54 +0200
Subject: [PATCH 1/3] translate-c: fix function pointers casting

---
 src/translate_c.zig | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/translate_c.zig b/src/translate_c.zig
index f1f3ad865946..0b60fb0e7d27 100644
--- a/src/translate_c.zig
+++ b/src/translate_c.zig
@@ -4030,7 +4030,10 @@ fn transCPtrCast(
     const src_child_type = src_ty.getPointeeType();
     const dst_type_node = try transType(c, scope, ty, loc);
 
-    if (!src_ty.isArrayType() and ((src_child_type.isConstQualified() and
+    if (!src_ty.isArrayType() and (((
+            src_child_type.isConstQualified() or
+            qualTypeIsFunction(src_child_type)   // C function pointers get translated to Zig const function pointers
+        ) and
         !child_type.isConstQualified()) or
         (src_child_type.isVolatileQualified() and
             !child_type.isVolatileQualified())))
@@ -4342,6 +4345,11 @@ fn qualTypeIsBoolean(qt: clang.QualType) bool {
     return qualTypeCanon(qt).isBooleanType();
 }
 
+fn qualTypeIsFunction(qt: clang.QualType) bool {
+    const type_class = qualTypeCanon(qt).getTypeClass();
+    return type_class == .FunctionProto or type_class == .FunctionNoProto;
+}
+
 fn qualTypeIntBitWidth(c: *Context, qt: clang.QualType) !u32 {
     const ty = qt.getTypePtr();
 

From c63a69a14ecb9cb14163022359ad6bb1d51089d1 Mon Sep 17 00:00:00 2001
From: paokito <paokito.takasu@gmail.com>
Date: Mon, 21 Jul 2025 11:09:55 +0200
Subject: [PATCH 2/3] translate-c: allow constCast and alignCast at the same
 time

---
 src/translate_c.zig | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/src/translate_c.zig b/src/translate_c.zig
index 0b60fb0e7d27..48996886cb8e 100644
--- a/src/translate_c.zig
+++ b/src/translate_c.zig
@@ -4030,6 +4030,18 @@ fn transCPtrCast(
     const src_child_type = src_ty.getPointeeType();
     const dst_type_node = try transType(c, scope, ty, loc);
 
+    // Implicit downcasting from higher to lower alignment values is forbidden,
+    // use @alignCast to side-step this problem
+    const rhs = if (qualTypeCanon(child_type).isVoidType())
+        // void has 1-byte alignment, so @alignCast is not needed
+        expr
+    else if (typeIsOpaque(c, qualTypeCanon(child_type), loc))
+        // For opaque types a ptrCast is enough
+        expr
+    else blk: {
+        break :blk try Tag.align_cast.create(c.arena, expr);
+    };
+
     if (!src_ty.isArrayType() and (((
             src_child_type.isConstQualified() or
             qualTypeIsFunction(src_child_type)   // C function pointers get translated to Zig const function pointers
@@ -4038,19 +4050,8 @@ fn transCPtrCast(
         (src_child_type.isVolatileQualified() and
             !child_type.isVolatileQualified())))
     {
-        return removeCVQualifiers(c, dst_type_node, expr);
+        return removeCVQualifiers(c, dst_type_node, rhs);
     } else {
-        // Implicit downcasting from higher to lower alignment values is forbidden,
-        // use @alignCast to side-step this problem
-        const rhs = if (qualTypeCanon(child_type).isVoidType())
-            // void has 1-byte alignment, so @alignCast is not needed
-            expr
-        else if (typeIsOpaque(c, qualTypeCanon(child_type), loc))
-            // For opaque types a ptrCast is enough
-            expr
-        else blk: {
-            break :blk try Tag.align_cast.create(c.arena, expr);
-        };
         return Tag.as.create(c.arena, .{
             .lhs = dst_type_node,
             .rhs = try Tag.ptr_cast.create(c.arena, rhs),

From 9737749e1c69763a84f634ad03628f5b77673b17 Mon Sep 17 00:00:00 2001
From: paokito <paokito.takasu@gmail.com>
Date: Sun, 3 Aug 2025 22:59:43 +0200
Subject: [PATCH 3/3] fix formatting

---
 src/translate_c.zig | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/src/translate_c.zig b/src/translate_c.zig
index 48996886cb8e..959855311821 100644
--- a/src/translate_c.zig
+++ b/src/translate_c.zig
@@ -4042,13 +4042,11 @@ fn transCPtrCast(
         break :blk try Tag.align_cast.create(c.arena, expr);
     };
 
-    if (!src_ty.isArrayType() and (((
-            src_child_type.isConstQualified() or
-            qualTypeIsFunction(src_child_type)   // C function pointers get translated to Zig const function pointers
-        ) and
-        !child_type.isConstQualified()) or
-        (src_child_type.isVolatileQualified() and
-            !child_type.isVolatileQualified())))
+    if (!src_ty.isArrayType() and
+        (((src_child_type.isConstQualified() or qualTypeIsFunction(src_child_type)) and
+            !child_type.isConstQualified()) or
+            (src_child_type.isVolatileQualified() and
+                !child_type.isVolatileQualified())))
     {
         return removeCVQualifiers(c, dst_type_node, rhs);
     } else {