1 files changed, 40 insertions, 0 deletions
diff --git a/src/javascript/jsc/headergen/sizegen.cpp b/src/javascript/jsc/headergen/sizegen.cpp
new file mode 100644
index 000000000..6999fcda0
--- /dev/null
+++ b/src/javascript/jsc/headergen/sizegen.cpp
@@ -0,0 +1,40 @@
+#include <iostream>
+#include <fstream>
+#include <ctime> 
+using namespace std;
+
+#include "headers-cpp.h"
+
+int main() {
+    time_t rawtime;
+    struct tm * timeinfo;
+    char buf [80];
+
+    time (&rawtime);
+    timeinfo = localtime (&rawtime);
+
+    strftime (buf,80,"%Y-%m-%d %H:%M:%s",timeinfo);
+
+    cout <<  "// Auto-generated by src/javascript/jsc/headergen/sizegen.cpp at " << buf << ".\n";
+    cout <<  "// These are the byte sizes for the different object types with bindings in JavaScriptCore.\n";
+    cout <<  "// This allows us to safely return stack allocated C++ types to Zig.\n";
+    cout <<  "// It is only safe to do this when these sizes are correct.\n";
+    cout <<  "// That means:\n";
+    cout <<  "// 1. We can't dynamically link JavaScriptCore\n";
+    cout <<  "// 2. It's important that this is run whenever JavaScriptCore is updated or the bindings on the Zig side change.\n";
+    cout <<  "//    Failure to do so will lead to undefined behavior and probably some frustrated people.\n";
+    cout <<  "// --- Regenerate this: --- \n";
+    cout <<  "// 1. \"make jsc-bindings-headers\"\n";
+    cout <<  "// 2. \"make sizegen\"\n";
+    cout <<  "// 3. \"make jsc-bindings-headers\"\n";
+    cout <<  "// You can verify the numbers written in this file at runtime via the `extern`d types\n";
+    cout <<  "// Run \"jsc-bindings-headers\" twice because it uses these values in the output. That's how all the bJSC__.* types are created - from these values. \n";
+    cout <<  "// The data for this file is generated in headers-cpp.h \n";
+    int i = 0;
+    int len = sizeof(sizes)/sizeof(sizes[0]);
+    for (i = 0; i <  len ; i++) {
+        cout <<  "pub const " << names[i] << " = " << sizes[i] << ";\n";
+    }
+	
+	return 0;
+}
+\ No newline at end of file