Fix unsafe cast in translate_c

Fixes #4250

Author: LemonBoy

src-self-hosted/clang.zig

@@ -809,6 +809,7 @@ pub extern fn ZigClangQualType_isRestrictQualified(self: struct_ZigClangQualType
 pub extern fn ZigClangType_getTypeClass(self: ?*const struct_ZigClangType) ZigClangTypeClass;
 pub extern fn ZigClangType_getPointeeType(self: ?*const struct_ZigClangType) struct_ZigClangQualType;
 pub extern fn ZigClangType_isVoidType(self: ?*const struct_ZigClangType) bool;
+pub extern fn ZigClangType_isConstantArrayType(self: ?*const struct_ZigClangType) bool;
 pub extern fn ZigClangType_isRecordType(self: ?*const struct_ZigClangType) bool;
 pub extern fn ZigClangType_isArrayType(self: ?*const struct_ZigClangType) bool;
 pub extern fn ZigClangType_isBooleanType(self: ?*const struct_ZigClangType) bool;

src-self-hosted/translate_c.zig

@@ -1982,7 +1982,8 @@ fn transInitListExprArray(
     const arr_type = ZigClangType_getAsArrayTypeUnsafe(ty);
     const child_qt = ZigClangArrayType_getElementType(arr_type);
     const init_count = ZigClangInitListExpr_getNumInits(expr);
-    const const_arr_ty = @ptrCast(*const ZigClangConstantArrayType, ty);
+    assert(ZigClangType_isConstantArrayType(arr_type));
+    const const_arr_ty = @ptrCast(*const ZigClangConstantArrayType, arr_type);
     const size_ap_int = ZigClangConstantArrayType_getSize(const_arr_ty);
     const all_count = ZigClangAPInt_getLimitedValue(size_ap_int, math.maxInt(usize));
     const leftover_count = all_count - init_count;

src/zig_clang.cpp

@@ -1877,6 +1877,11 @@ bool ZigClangType_isRecordType(const ZigClangType *self) {
     return casted->isRecordType();
 }
 
+bool ZigClangType_isConstantArrayType(const ZigClangType *self) {
+    auto casted = reinterpret_cast<const clang::Type *>(self);
+    return casted->isConstantArrayType();
+}
+
 const char *ZigClangType_getTypeClassName(const ZigClangType *self) {
     auto casted = reinterpret_cast<const clang::Type *>(self);
     return casted->getTypeClassName();

src/zig_clang.h

@@ -945,6 +945,7 @@ ZIG_EXTERN_C bool ZigClangType_isBooleanType(const struct ZigClangType *self);
 ZIG_EXTERN_C bool ZigClangType_isVoidType(const struct ZigClangType *self);
 ZIG_EXTERN_C bool ZigClangType_isArrayType(const struct ZigClangType *self);
 ZIG_EXTERN_C bool ZigClangType_isRecordType(const struct ZigClangType *self);
+ZIG_EXTERN_C bool ZigClangType_isConstantArrayType(const ZigClangType *self);
 ZIG_EXTERN_C const char *ZigClangType_getTypeClassName(const struct ZigClangType *self);
 ZIG_EXTERN_C const struct ZigClangArrayType *ZigClangType_getAsArrayTypeUnsafe(const struct ZigClangType *self);
 ZIG_EXTERN_C const ZigClangRecordType *ZigClangType_getAsRecordType(const ZigClangType *self);

test/translate_c.zig

@@ -2,6 +2,31 @@ const tests = @import("tests.zig");
 const builtin = @import("builtin");
 
 pub fn addCases(cases: *tests.TranslateCContext) 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};
+    , &[_][]const u8{
+        \\pub const uuid_t = [16]u8;
+        \\pub const UUID_NULL: uuid_t = .{
+        \\    @bitCast(u8, @truncate(i8, @as(c_int, 0))),
+        \\    @bitCast(u8, @truncate(i8, @as(c_int, 0))),
+        \\    @bitCast(u8, @truncate(i8, @as(c_int, 0))),
+        \\    @bitCast(u8, @truncate(i8, @as(c_int, 0))),
+        \\    @bitCast(u8, @truncate(i8, @as(c_int, 0))),
+        \\    @bitCast(u8, @truncate(i8, @as(c_int, 0))),
+        \\    @bitCast(u8, @truncate(i8, @as(c_int, 0))),
+        \\    @bitCast(u8, @truncate(i8, @as(c_int, 0))),
+        \\    @bitCast(u8, @truncate(i8, @as(c_int, 0))),
+        \\    @bitCast(u8, @truncate(i8, @as(c_int, 0))),
+        \\    @bitCast(u8, @truncate(i8, @as(c_int, 0))),
+        \\    @bitCast(u8, @truncate(i8, @as(c_int, 0))),
+        \\    @bitCast(u8, @truncate(i8, @as(c_int, 0))),
+        \\    @bitCast(u8, @truncate(i8, @as(c_int, 0))),
+        \\    @bitCast(u8, @truncate(i8, @as(c_int, 0))),
+        \\    @bitCast(u8, @truncate(i8, @as(c_int, 0))),
+        \\};
+    });
+
     cases.add("empty declaration",
         \\;
     , &[_][]const u8{""});