[junyeong-Cho]

Summary

net/src/net_posix.c uses eNet types at file scope without an #if EOS_ENABLE_NET guard, while net/include/eos/net.h declares those types only when EOS_ENABLE_NET is enabled.

Because EOS_ENABLE_NET defaults to 0 and CMake still adds net_posix.c to eos_net for non-cross builds, the default host build documented in the README fails to compile when networking is disabled.

This includes the standard README build:

cmake -B build/host -DCMAKE_BUILD_TYPE=Release
cmake --build build/host --parallel

This PR wraps the implementation in net_posix.c with #if EOS_ENABLE_NET / #endif, following the existing pattern used by net/src/net.c, and adds CI coverage for configurations that leave eNet disabled.

Type of Change

• feat — New feature
• fix — Bug fix
• docs — Documentation only
• style — Formatting, no code change
• refactor — Code restructuring without behavior change
• test — Add or fix tests
• build — Build system or dependency changes
• ci — CI/CD pipeline changes
• perf — Performance improvement

Changes

• Updated net/src/net_posix.c to compile its implementation only when EOS_ENABLE_NET is enabled, leaving an empty translation unit when networking is disabled.
• Added a default-config CI job in .github/workflows/ci.yml to build the default README configuration and selected product profiles where eNet is disabled.

Testing

• Unit tests pass (ctest --test-dir build/test --output-on-failure)
• Integration tests pass
• Manual testing performed
• New tests added for new functionality

Local test environment:

• WSL Ubuntu
• GCC 11.4.0

Default host build

The README build was configured and built successfully:

cmake -B build/host -DCMAKE_BUILD_TYPE=Release
cmake --build build/host --parallel

The build completed successfully through 100%.

Before the fix, the same configuration failed in net/src/net_posix.c with errors such as:

error: unknown type name 'eos_net_addr_t'
error: unknown type name 'eos_socket_t'
error: unknown type name 'eos_net_proto_t'

The root cause is that these types are unavailable when EOS_ENABLE_NET=0, while net_posix.c was still being compiled.

Test suite

Configured and built the test profile with:

cmake -B build/test -DEOS_BUILD_TESTS=ON -DEOS_PRODUCT=vbox_test
cmake --build build/test --parallel
ctest --test-dir build/test --output-on-failure

Result:

28/28 tests passed

100% tests passed, 0 tests failed out of 28

Total Test time (real) = 0.65 sec

Regression coverage

The bug is configuration-dependent rather than a runtime behavior that can be meaningfully exercised by a ctest case.

The new CI job therefore builds:

• the default configuration shown in the README;
• the medical product profile;
• the aerospace product profile.

This ensures that configurations with EOS_ENABLE_NET disabled remain buildable.

Pre-Submission Checklist

• Code compiles without warnings (-Wall -Wextra -Werror for C)
• All existing tests pass
• New tests added for new functionality — CI build coverage added for the affected configurations
• Documentation updated if API changed — no API change required
• Commit messages follow <type>(<scope>): <description> convention
• Branch is rebased on latest master

Related Issues

Related to #102, which applies a similar empty-translation-unit guard to hal_linux.c under a different feature/platform condition.

This PR addresses the equivalent missing guard in net_posix.c; it is a separate issue and does not close #102.

Screenshots / Logs

Before the fix, the default configuration fails while compiling net/src/net_posix.c:

net/src/net_posix.c:43:30: error: unknown type name 'eos_net_addr_t'
net/src/net_posix.c:73:1: error: unknown type name 'eos_socket_t'
net/src/net_posix.c:73:29: error: unknown type name 'eos_net_proto_t'

After the fix, the default README build completes successfully:

[100%] Linking C static library libeos_compat.a
[100%] Built target eos_compat

The test suite also completes successfully:

28/28 Test #28: test_devicetree ............ Passed

100% tests passed, 0 tests failed out of 28
Total Test time (real) = 0.65 sec

Additional Notes

The change does not alter networking behavior when EOS_ENABLE_NET=1. It only prevents the POSIX networking implementation from referencing unavailable eNet types when the feature is disabled.

The in-file guard follows the convention already used by net/src/net.c. I intentionally did not change the target_sources() condition in CMake because EOS_ENABLE_NET is handled as a compile definition elsewhere, and keeping the guard at the source level is consistent with the existing implementation pattern.

The local build produced several pre-existing compiler warnings in unrelated files, including warnings involving strncpy, snprintf, ignored return values, and similar code. The build nevertheless completed successfully, and this PR does not modify those warning-producing code paths.