1 files changed, 78 insertions, 0 deletions
diff --git a/util/wasm/preload/wasm_binary_tools.py b/util/wasm/preload/wasm_binary_tools.py
new file mode 100644
index 0000000000..9a2150b964
--- /dev/null
+++ b/util/wasm/preload/wasm_binary_tools.py
@@ -0,0 +1,78 @@
+
+#!/usr/bin/env python3
+# Copyright (C) 2024 The Qt Company Ltd.
+# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+import sys
+import struct
+
+
+class WasmBinary:
+    """For reference of binary format see Emscripten source code, especially library_dylink.js."""
+
+    def __init__(self, filepath):
+        self._offset = 0
+        self._end = 0
+        self._dependencies = []
+        with open(filepath, 'rb') as file:
+            self._binary = file.read()
+            self._check_preamble()
+            self._parse_subsections()
+
+    def get_dependencies(self):
+        return self._dependencies
+
+    def _get_leb(self):
+        ret = 0
+        mul = 1
+        while True:
+            byte = self._binary[self._offset]
+            self._offset += 1
+            ret += (byte & 0x7f) * mul
+            mul *= 0x80
+            if not (byte & 0x80):
+                break
+        return ret
+
+    def _get_string(self):
+        length = self._get_leb()
+        self._offset += length
+        return self._binary[self._offset - length:self._offset].decode('utf-8')
+
+    def _check_preamble(self):
+        preamble = memoryview(self._binary)[:24]
+        int32View = struct.unpack('<6I', preamble)
+        assert int32View[0] == 0x6d736100, "magic number not found"
+        assert self._binary[8] == 0, "dynlink section needs to be first"
+        self._offset = 9
+        section_size = self._get_leb()
+        self._end = self._offset + section_size
+        name = self._get_string()
+        assert name == "dylink.0", "section dylink.0 not found"
+
+    def _parse_subsections(self):
+        WASM_DYLINK_NEEDED = 0x2
+
+        while self._offset < self._end:
+            subsection_type = self._binary[self._offset]
+            self._offset += 1
+            subsection_size = self._get_leb()
+
+            if subsection_type == WASM_DYLINK_NEEDED:
+                needed_dynlibs_count = self._get_leb()
+                for _ in range(needed_dynlibs_count):
+                    self._dependencies.append(self._get_string())
+            else:
+                self._offset += subsection_size  # we don't care about other sections for now
+
+
+if __name__ == "__main__":
+    if len(sys.argv) != 2:
+        print("Usage: python wasm_binary_tools.py <shared_object>")
+        sys.exit(1)
+
+    file_path = sys.argv[1]
+    binary = WasmBinary(file_path)
+    dependencies = binary.get_dependencies()
+    for d in dependencies:
+        print(d)