[PHP.wasm] Export filesystem symbols for PHP side modules

[adamziel]

What

Exports filesystem/libc symbols used by PHP.wasm side modules from the Node PHP artifacts, and adds them to the canonical PHP exported-functions list for future builds.

This extends the earlier SQLite auto-extension exports with the POSIX helpers needed by side modules that read and write mounted files:

• closedir
• fseek
• ftell
• isalnum
• mkdir
• opendir
• readdir
• rename
• rmdir
• unlink

The checked-in Node PHP artifacts for PHP 5.2, 7.4, and 8.0-8.5 were updated for both asyncify and JSPI modes. The web artifacts already exported the target symbols where present.

Why

A PHP side module can load successfully but still fail lazily at runtime when it first calls a filesystem helper that the main PHP wasm module does not export. The observed failure was:

TypeError: resolved is not a function

Debugging showed the unresolved dynamic symbol was opendir, called when a SQLite virtual table extension scanned a mounted Markdown directory.

Local verification

Verified against a local Playground checkout from this branch using a PHP 8.4 JSPI side module mounted into WordPress:

PATH=/Users/cloudnik/.local/share/nvm/v24.14.0/bin:$PATH \
  npx nx dev playground-cli server \
  --php=8.4 \
  --port=9418 \
  --login \
  --php-extension=/Users/cloudnik/conductor/workspaces/wp-extensions/tunis-v1/markdown-editor/sqlite-markdown-extension/dist/manifest.json \
  --mount-dir /Users/cloudnik/conductor/workspaces/wp-extensions/tunis-v1/content /markdown-root \
  --mount-dir /Users/cloudnik/conductor/workspaces/wp-extensions/tunis-v1/markdown-editor /wordpress/wp-content/mu-plugins \
  --mount-dir /Users/cloudnik/conductor/workspaces/wp-extensions/tunis-v1/markdown-editor /internal/shared/markdown-editor

Then requested:

curl -fsSL -c /tmp/wp-md-cookies.txt -b /tmp/wp-md-cookies.txt \
  http://127.0.0.1:9418/wp-admin/edit.php?post_type=page \
  -o /tmp/markdown-editor-local-final.html

The response completed successfully and grep found no TypeError, resolved is not a function, unresolved wasm symbol, PHP warning, or WordPress database error.

Also verified all checked-in PHP wasm artifacts export each target symbol wherever the function exists.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds POSIX filesystem/libc symbols to the PHP exported-functions list so PHP.wasm side modules can resolve them at runtime, preventing lazy "resolved is not a function" failures.

Changes:

• Adds 10 filesystem/libc symbols (closedir, fseek, ftell, isalnum, mkdir, opendir, readdir, rename, rmdir, unlink) to the canonical exported-functions list.
• (Per PR description) Regenerates Node PHP artifacts for 5.2, 7.4, 8.0–8.5 in both asyncify and JSPI modes.

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