Tags on pointers need to be cleared on Linux

3 files changed, 14 insertions, 18 deletions

diff --git a/src/javascript/jsc/api/transpiler.zig b/src/javascript/jsc/api/transpiler.zig
index cdc5dc39a..0390be154 100644
--- a/src/javascript/jsc/api/transpiler.zig
+++ b/src/javascript/jsc/api/transpiler.zig
@@ -203,13 +203,11 @@ pub const TransformTask = struct {
 
         if (printed > 0) {
             buffer_writer = printer.ctx;
-            buffer_writer.buffer.list.expandToCapacity();
+            buffer_writer.buffer.list.items = buffer_writer.written;
 
             // This works around a mimalloc and/or Zig allocator bug
-            buffer_writer.buffer.list.items = buffer_writer.buffer.list.items[0..printed];
-            var output_code = JSC.ZigString.init(buffer_writer.buffer.toOwnedSlice());
-            output_code.mark();
-            this.output_code = output_code;
+            this.output_code = JSC.ZigString.init(buffer_writer.written);
+            this.output_code.mark();
         } else {
             this.output_code = ZigString.init("");
         }
diff --git a/src/javascript/jsc/bindings/bindings.zig b/src/javascript/jsc/bindings/bindings.zig
index f7b270a40..6c7cbd523 100644
--- a/src/javascript/jsc/bindings/bindings.zig
+++ b/src/javascript/jsc/bindings/bindings.zig
@@ -97,7 +97,7 @@ pub const ZigString = extern struct {
     }
 
     pub inline fn utf16Slice(this: *const ZigString) []align(1) const u16 {
-        return @ptrCast([*]align(1) const u16, this.ptr)[0..this.len];
+        return @ptrCast([*]align(1) const u16, untagged(this.ptr))[0..this.len];
     }
 
     pub fn fromStringPointer(ptr: StringPointer, buf: string, to: *ZigString) void {
@@ -163,8 +163,14 @@ pub const ZigString = extern struct {
 
     pub const Empty = ZigString{ .ptr = "", .len = 0 };
 
+    inline fn untagged(ptr: [*]const u8) [*]const u8 {
+        // this can be null ptr, so long as it's also a 0 length string
+        @setRuntimeSafety(false);
+        return @intToPtr([*]const u8, @truncate(u53, @ptrToInt(ptr)));
+    }
+
     pub fn slice(this: *const ZigString) []const u8 {
-        return this.ptr[0..@minimum(this.len, std.math.maxInt(u32))];
+        return untagged(this.ptr)[0..@minimum(this.len, std.math.maxInt(u32))];
     }
 
     pub fn sliceZBuf(this: ZigString, buf: *[std.fs.MAX_PATH_BYTES]u8) ![:0]const u8 {
@@ -172,7 +178,7 @@ pub const ZigString = extern struct {
     }
 
     pub inline fn full(this: *const ZigString) []const u8 {
-        return this.ptr[0..this.len];
+        return untagged(this.ptr)[0..this.len];
     }
 
     pub fn trimmedSlice(this: *const ZigString) []const u8 {
diff --git a/src/javascript/jsc/bindings/helpers.h b/src/javascript/jsc/bindings/helpers.h
index 1c1237969..9aa1c218a 100644
--- a/src/javascript/jsc/bindings/helpers.h
+++ b/src/javascript/jsc/bindings/helpers.h
@@ -90,19 +90,11 @@ static const WTF::String toString(ZigString str) {
 }
 
 static const WTF::String toStringCopy(ZigString str) {
-  if (str.len == 0 || str.ptr == nullptr) { return WTF::String(); }
-
-  return !isTaggedUTF16Ptr(str.ptr) ? WTF::String(WTF::StringImpl::create(str.ptr, str.len))
-                                    : WTF::String(WTF::StringImpl::create(
-                                        reinterpret_cast<const UChar *>(str.ptr), str.len));
+  return toString(str).isolatedCopy();
 }
 
 static WTF::String toStringNotConst(ZigString str) {
-  if (str.len == 0 || str.ptr == nullptr) { return WTF::String(); }
-
-  return !isTaggedUTF16Ptr(str.ptr) ? WTF::String(WTF::StringImpl::create(str.ptr, str.len))
-                                    : WTF::String(WTF::StringImpl::create(
-                                        reinterpret_cast<const UChar *>(str.ptr), str.len));
+  return toString(str).isolatedCopy();
 }
 
 static const JSC::JSString *toJSString(ZigString str, JSC::JSGlobalObject *global) {