builder: declare Darwin socket and process symbols - #5636

Scope

Add the libSystem declarations needed for Darwin sockets and posix_spawn. The minimal SDK does not provide these symbols. The builder assembles a second stub object and links it with the SDK object.

This branch now contains only the builder change and a direct socket test. The copied fcntl, process, weak-pointer and TLS commits have been removed. The shared builder support moved here from #5634 so that it has one owner. #5634 will depend on this PR instead of carrying a second copy.

This change does not need a net submodule update. A program can call the standard syscall socket API directly. Full netdev support is a separate dependency of tinygo-org/net#74.

The posix_spawn_file_actions_addchdir_np symbol requires macOS 10.15 or later when used by the process implementation.

Verification

The new host-only test testdata/darwinsockets.go creates a loopback listener with the syscall package, obtains its assigned port, connects, accepts, checks the peer address and shuts down the connection. It does not use the TinyGo netdev or require an external service.

The test passed with ordinary Go on native Darwin arm64. Fork CI at 6fded0c passed all 24 checks. See Linux, macOS, and Windows. These results are for the independent branch, not the old combined branch.

The released fork already uses the same extra-stub mechanism for its socket and process probes. That is integration evidence, not a substitute for the new independent branch test.

Downstream context

The dispat acceptance record covers files, environment variables, pipes, child processes, goroutines, network clients, real TLS, certificate rejection and self-update rollback. See the recorded acceptance. Those results are for the combined fork and the revisions named in that document. They do not prove that this one PR supplies all those features.

Related pull requests

The target partition below keeps each change in one PR. The process branch no longer contains copied builder or fcntl commits.

• sync: hand the RWMutex over instead of a re-test of the reader count #5630 fixes RWMutex handover.
• runtime: deliver os/signal notifications under the threads scheduler #5631 is closed in favor of runtime: deliver signals under the threads scheduler when blocked on I/O #5530, owned by @0pcom. The fork still uses the tested runtime: deliver os/signal notifications under the threads scheduler #5631 implementation until a replacement is checked.
• compiler,runtime: call fcntl through a C wrapper on darwin #5632 is closed in favor of compiler: implement go:cgo_import_dynamic and lower Darwin cgo import trampolines (#5604) #5612, owned by @neomantra. compiler: implement go:cgo_import_dynamic and lower Darwin cgo import trampolines (#5604) #5612 covers both stdlib and x/sys Darwin trampolines.
• runtime: implement weak.runtime_makeStrongFromWeak #5633 provides the weak-pointer runtime hook.
• os: start processes with posix_spawn #5634 provides process spawning and process state. Darwin also needs compiler: implement go:cgo_import_dynamic and lower Darwin cgo import trampolines (#5604) #5612 and builder: declare Darwin socket and process symbols #5636. Concurrent use needs sync: hand the RWMutex over instead of a re-test of the reader count #5630.
• loader: use the real crypto/tls on hosted linux and darwin #5635 selects software TLS on hosted Linux and Darwin. It needs runtime: implement weak.runtime_makeStrongFromWeak #5633. The owner closed crypto/tls: use Go's software TLS on the host target #5645 in favor of runtime: implement weak.runtime_makeStrongFromWeak #5633 and loader: use the real crypto/tls on hosted linux and darwin #5635. The explicit Linux/Darwin guard stays.
• builder: declare Darwin socket and process symbols #5636 provides the Darwin socket and process link symbols. It does not include process or TLS implementation changes.

In tinygo-org/net

• net/http: follow redirects in the client again net#72 restores HTTP redirects. It shares http/client.go with the timeout work in http: port Go net/http timeout handling net#67, so the two changes need integration review.
• net: report a name that does not exist as a not-found lookup error net#73 preserves DNS not-found errors.
• net: extend the host netdev to darwin net#74 adds Darwin host netdev support. It shares the host netdev with net: non-blocking host netdev I/O with an epoll poller net#77. Linux epoll and Darwin support must remain separate.
• net/http: give the HTTPS client trust roots on darwin net#75 supplies Darwin trust roots to the HTTP client.
• net: non-blocking host netdev I/O with an epoll poller net#77 owns Linux cancellation and deadline work, net: report the kernel-assigned port after listening on port 0 net#80 owns port-zero reporting, and net/http: add ListenAndServeTLS / ServeTLS (software TLS) net#79 owns HTTP server TLS. These are separate contributors' changes, not completed parts of this series.
• net: API-compat fills for grpc and wazero (SyscallConn, Dialer.Control, IPConn.Read) net#78 adds client API fields and related compatibility methods.

Full Darwin networking also needs the merged net changes and a later src/net pin update. No upstream merge or current full-suite pass is implied by this list.

Additional independent gaps found in Crier are covered by #5655 (cookie-jar loader merge) and tinygo-org/net#82 (ListenConfig). They do not duplicate the process, TLS, deadline or server-TLS changes above. Current Crier comparison work is separate from its standard-Go release.

Published fork and downstream evidence

The net.2 fork release combines the coordinated changes at 95fba82a, with net 0f460803. It differs from accepted candidate e7d34c8c only in the version constant. Linux, macOS and Windows branch CI and tag CI passed on their first attempts.

Dispat source 909dc401, with harness 0990c6db, passed 796 test events with no failures or skips on each native Darwin ARM64 and Linux ARM64 candidate run. Crier source 7d687fc8 passed raw and stripped E2E on native Linux ARM64 and emulated Linux AMD64, each with 144 top-level tests and 156 passing events, no failures or skips. Both applications use TinyGo-built update fixtures and test trusted TLS, certificate refusal, original backup hashes and byte-identical offline rollback. Their workflows also exercise files, environment variables, concurrency and child processes. Crier includes real FFmpeg and webrender/canvas rendering.

Crier's unchanged 13-image pixel gate passed. It uses an approved two-line explicit-rounding webrender build patch for both compilers. The earlier gradient mismatch was permitted fused arithmetic, not a TinyGo compiler error. Candidate stripped sizes are 13,835,824 versus 30,277,794 Go bytes on ARM64 (54.30% smaller), and 16,446,968 versus 32,518,306 on AMD64 (49.42% smaller).

These are combined-candidate application results, not proof that this PR alone supplies the features. They supersede the earlier Crier comparison. Published-toolchain probes and application acceptance have since completed. The final Crier v1.1.1 release evidence is below. Dispat controls its own publication. WaitDelay, in-flight deadlines and full descriptor lifetime remain open. This enables tested CLI client workflows, not general Go or server compatibility.

Published Crier v1.1.1 evidence

Crier v1.1.1 is public at source acac2f0e and uses published TinyGo 0.43.0-net.2. Its final acceptance report and SHA-256 manifest identify the exact release bytes. The public tag, asset sizes and report digest were checked. These final sizes supersede the candidate sizes above.

The report records 144 top-level tests and 156 passing events for each raw and stripped run on native ARM64 and emulated AMD64, with no failures or skips. It covers real CLI files, environment and concurrent work, child processes, TLS, update/rollback fixtures, uploads, real FFmpeg, and webrender/canvas rendering. The unchanged 13-image gate passes on both targets. AMD64 is exact; ARM64 has 12 exact images and four event-card pixels with channel difference 1. Both compilers use the same explicit-rounding webrender build patch. Standard Go tests, 90.6% coverage, lint and docs also pass.

This is combined-fork application evidence, not isolated proof for this PR or general server support. The generic emulated AMD64 os closure assertions still fail and also fail with ordinary Go under that emulation; they are not counted as passing. Native AMD64 CI and the final published AMD64 net package pass. The report retains other platform and deadline/descriptor limits. Tiny binaries are opt-in; normal install/self-update selects standard Go assets.

Published Dispat v1.8.1 CLI evidence

Dispat v1.8.1 CLI is public. Its size and SHA-256 manifest records build source 40c58236, Go 1.26.8 and TinyGo 0.43.0-net.2. The public asset metadata and manifest digest were checked.

These are final published CLI asset sizes, not the earlier candidate measurements. They do not replace the separately identified test evidence or remove known runtime limits. The full release workflow has now completed successfully at the recorded build source, including its Windows, macOS and Ubuntu checks. This does not change the test and platform limits stated above.