mpy-cross/mpy_cross: Add a way to query the mpy version.

jimmo · jimmo · commit 12b5435ade23 · 2022-09-28T01:05:09.000+10:00
This returns the:
 - mpy_version
 - mpy_sub_version
 - native_arch
for files compiled with this mpy-cross binary.

Signed-off-by: Jim Mussared &lt;jim.mussared@gmail.com&gt;
diff --git a/mpy-cross/mpy_cross/__init__.py b/mpy-cross/mpy_cross/__init__.py
@@ -29,6 +29,7 @@
 import os
 import stat
 import subprocess
+import tempfile
 
 NATIVE_ARCH_X86 = "x86"
 NATIVE_ARCH_X64 = "x64"
@@ -54,14 +55,35 @@
     NATIVE_ARCH_XTENSAWIN,
 ]
 
-__all__ = ["compile", "run", "CrossCompileError"]
+__all__ = ["version", "compile", "run", "CrossCompileError"]
 
 
 class CrossCompileError(Exception):
     pass
 
 
-def find_mpy_cross_binary(mpy_cross):
+def version(march=None, mpy_cross=None):
+    # Compiles an empty .py file and returns the version info from the .mpy.
+    src_fd, src_path = tempfile.mkstemp(suffix=".py", text=True)
+    try:
+        dest_path = src_path[:-3] + ".mpy"
+        extra_args = ["-X", "emit=native"] if march else None
+        compile(src_path, march=march, mpy_cross=mpy_cross, extra_args=extra_args)
+        with open(dest_path, "rb") as f:
+            header = f.read(3)
+            mpy_version = header[1]
+            mpy_sub_version = 0
+            feature_byte = header[2]
+            arch = feature_byte >> 2
+            if arch != 0:
+                mpy_sub_version = feature_byte & 3
+            return mpy_version, mpy_sub_version, arch
+    finally:
+        os.unlink(src_path)
+        if os.path.exists(dest_path):
+            os.unlink(dest_path)
+
+
 
 def _find_mpy_cross_binary(mpy_cross):
     if mpy_cross:
