QUERY · ISSUE

mpy_ld.py: "AttributeError: 'Symbol' object has no attribute 'section'" when relocating data section

openby phlashopened 2022-06-19updated 2022-06-19

bug

While linking a larg(ish) project, with the latest micropython and ESP-IDF compiler, I had a failure in mpy_ld.py due to a relocation in a .data.rel.ro section that went via an unresolved (UND) symbol. The symbol was correctly resolved later on, however the logic in do_relocation_data does not take account of this fact, and fails when trying to de-reference the non-existant section attribute. Applying similar logic to that in do_relocation_text (see diff below) appears to fix this issue:

@@ -638,6 +639,9 @@ def do_relocation_data(env, text_addr, r):
         or env.arch.name == "EM_XTENSA"
         and r_info_type == R_XTENSA_32
     ):
+        # Bug fix: use resolved symbol if available (as per text relocs)
+        if hasattr(s, "resolved"):
+            s = s.resolved
         # Relocation in data.rel.ro to internal/external symbol
         if env.arch.word_size == 4:

CANDIDATE · PULL REQUEST

tools/mpy_ld.py: support absolute relocations in text section on Thumb targets

mergedby dpgeorgeopened 2025-05-28updated 2025-06-10

tools

Summary

Add support for R_ARM_ABS32 relocations in native .mpy files.

Also, enable float by default on armv6m and armv7m native mpy targets, since soft-float now works correctly.

Should fix issue #14430.

Testing

Tested with ARCH=armv6m on RPI_PICO_W, and ARCH=armv7emdp on PYBD_SF6. The update features2 -- calling sin() and cos() -- works on both these targets.

Trade-offs and Alternatives

This is a relatively minimal change, but nonetheless tools/mpy_ld.py is getting quite unwieldy now and pretty hard to follow what relocations are/aren't allowed. Maybe in the future it can be cleaned up, but we'd need more tests before doing that to ensure something doesn't break.