Bug: Generated CMakeLists.txt uses non-canonical relative paths (dir/.. instead of ../dir)

[sfourdrinier]

Bug Report

Description

The generated android/CMakeLists.txt uses non-canonical relative paths like cpp/../file.cpp instead of the canonical form ../cpp/file.cpp. While both are technically valid, the non-canonical form can cause issues with some CMake versions and build tools.

Problem

When relative_to() calculates paths from android/CMakeLists.txt to files in cpp/, the pathdiff crate generates paths like:

cpp/../generated/file.cpp
cpp/../module.cpp

Impact

• Some CMake configurations may fail to find source files with non-canonical paths
• Build errors in certain environments
• Less readable generated CMakeLists.txt files

Expected Behavior

Paths should be in canonical form:

../cpp/generated/file.cpp
../cpp/module.cpp

Root Cause

The relative_to() function in crates/ubrn_cli/src/codegen/mod.rs uses pathdiff::diff_utf8_paths() directly without normalizing the result. The pathdiff crate can produce non-canonical paths when calculating relative paths.

Reproduction

1. Generate Android bindings for any project
2. Check android/CMakeLists.txt
3. Observe cpp/../ patterns in source file paths

References

• CMake best practices prefer canonical relative paths
• Issue discovered while testing 32-bit ARM fix (see PR fix: Use uint64_t for RustBuffer fields to fix 32-bit ARM crash #313)

Fix

PR #313 now includes a fix that lexically normalizes paths by processing components and eliminating dir/.. patterns.

[jhugman]

Fixed in #313