Dotted / namespace unit names in uses

• Type: feature (Track A compiler / unit resolver)
• Status: done
• Owner: Track A
• Opened: 2026-06-21 (Synapse POSIX profile smoke)
• Relation: unblocks feature-networking / Synapse Delphi-Posix.* path; companion to feature-dynamic-include-paths-config

Problem

PXX currently treats a dotted uses entry as only its first identifier. Synapse's Delphi-POSIX path uses units such as:

• Posix.SysSocket
• Posix.SysSelect
• Posix.SysTime
• Posix.NetinetIn
• Posix.StrOpts
• Posix.Errno
• later: Posix.Base, Posix.Unistd, Posix.ArpaInet, Posix.NetDB
• System.Generics.Collections, System.Generics.Defaults in blcksock

With the manual Synapse POSIX profile (SYNAPSE_PROFILE=posix), the pinned stable compiler fails before any Posix.* shim can be tested:

pascal26:2316: error: uses: unit source not found: posix ()

That is a compiler resolver/parser gap, not a library workaround target.

Required behavior

• Parse the full dotted name in a uses clause as one logical unit name.
• Preserve the dotted name for qualified references such as Posix.SysSocket.Socket and System.Generics.Collections.
• Define and document the source-file lookup rule for dotted units. A practical implementation should support at least one stable mapping from search roots, for example Posix/SysSocket.pas and/or Posix.SysSocket.pas.
• Keep existing non-dotted unit lookup behavior unchanged.

Non-goals

• Do not add Synapse-specific path hacks.
• Do not require PAL/network code to flatten names into fake units such as posixsyssocket.
• Do not implement the Posix.* socket shims in this compiler ticket.

Acceptance

• A focused test with uses Posix.SysSocket; resolves a local stub unit and can reference an exported symbol through Posix.SysSocket.SymbolName.
• A focused test with uses System.Generics.Collections; resolves the full dotted unit name rather than looking for only system.
• Re-running SYNAPSE_PROFILE=posix test/manual/try_synapse_compile.sh no longer reports uses: unit source not found: posix or uses: unit source not found: system for failures caused by dotted-name truncation.

Log

• 2026-06-21 — filed from Track B Synapse smoke. The PAL/network layer already has socket primitives; Synapse's Delphi-POSIX path now needs compiler support for real Delphi namespace unit names before library shims can be useful.
• 2026-06-21 — DONE (commit 73b5b3a). Three parser changes (parser.inc):
  1. ReadDottedUsesName reads ident('.'ident)* in every uses clause (program / unit interface / unit implementation) and in the unit X.Y; header, so the full dotted name reaches the resolver. ParseUsesUnit already looks up the lowercased name in each search root, so a 2-part Posix.SysSocket maps to posix.syssocket.pas — the stable flat-filename mapping — with no resolver change.
  2. ConsumeUnitQualifier rewritten to match the LONGEST dotted compiled-unit prefix that still leaves a trailing .member, so Posix.SysSocket.Symbol resolves Posix.SysSocket as the unit (not Posix), leaving the parser on Symbol. Non-dotted Unit.Member and record.field are unchanged (it consumes nothing unless the prefix is a compiled unit).
  3. unit Posix.SysSocket; headers accepted (dotted name read; symbols still registered under CurrentUnitIdx = the interned dotted name).
  • Acceptance 1 (uses Posix.SysSocket; + Posix.SysSocket.AF_INET / .SockTag): PASS. Acceptance 2 (uses System.Generics.Collections;): PASS (3-part unit resolves; its ListTag callable). Regression test test/dotted/test_dotted_uses.pas (+ stub units posix.syssocket.pas, system.generics.collections.pas) in make test-core, prints 2/42/7.
  • Acceptance 3 (Synapse smoke): PASS — truncated unit source not found: posix / system errors gone. Synapse now advances to full-dotted misses (posix.base, system.ansistrings) = the library/shim work (out of scope per non-goals), proving dotted-name resolution works end to end.
  • File mapping is flat (Posix.SysSocket → posix.syssocket.pas, lowercased); a Posix/SysSocket.pas subdir mapping was not added (the ticket asked for "at least one stable mapping"). Gate green: self-host + threadsafe byte-identical.