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Alexander Liberov edited this page Nov 8, 2026 · 2 revisions

Missing unit in uses (rule unit-missing-from-uses)

You typed CodeSite.Send('Loaded'); but CodeSiteLogging is not in the unit's uses clause yet. The IDE only says Undeclared identifier: 'CodeSite'. drag-lint says which unit declares it and where to add it:

uMain.pas:120:3  [warning] unit-missing-from-uses: 'CodeSite' is declared in unit CodeSiteLogging -- add it to the implementation uses clause

Where the unit goes

  • interface uses clause -- when the name is used anywhere in the interface section (a field type, a parameter type, a constant of the class...);
  • implementation uses clause -- otherwise.

The clause is created when the section has none, and an existing clause keeps its own layout (one-line, one unit per line, or comma-first).

Cycle check before the edit

Before offering the edit, drag-lint walks the project's uses graph for the new edge:

  • If adding the unit to the interface would close a circular unit reference (the compiler's E2047), the message recommends the implementation clause instead and names the cycle: ... -- add it to the implementation uses clause and move its interface use there (the interface uses clause would create a circular unit reference: uA -> uB -> uA). The interface edit is still offered as a second quick-fix, marked with the warning.
  • If the recommended edit would still close a uses cycle (the kind circular-uses reports), the message ends with (warning: this creates a uses cycle: ...).

Fixing it

Where How
IDE Put the caret on the flagged line and press Ctrl+Alt+U, or choose drag-lint > Uses & Dependencies > Quick-Fix: Add Unit for Undeclared at Cursor (Ctrl+Alt+U). The unit goes to the clause the message names; one undo reverts it.
VS Code / any LSP client The light bulb on the diagnostic: Add CodeSiteLogging to the implementation uses clause.
Command line drag-lint lint <file> --db <db> --rule unit-missing-from-uses --fix previews; add --apply to write. Every missing unit of the file is added in one edit per clause.

When it says nothing (on purpose)

The rule is built to be quiet rather than wrong. It reports nothing when:

  • the unit is already in either uses clause (also as SysUtils for System.SysUtils);
  • the file declares the name itself (a local, a field, a parameter, a generic parameter, an anonymous-method parameter);
  • the name follows a dot (Obj.CodeSite is a member, not a unit-level name);
  • inside a method, the name is also a member of some class (it may be inherited); inside a routine with with, a member of any type;
  • the file uses a unit the index does not know, or no platform library is available -- either could declare the name;
  • the code sits in an inactive {$IFDEF} branch;
  • the index is older than the text at that position (save, let the IDE reindex, and it comes back). A unit taken out of uses is still reported before the reindex wherever the names below it kept their lines (it was on a shared uses line, or the line was blanked): the rule trusts the text you have, not the uses list the index remembers.

When several units declare the name, they are listed and no fix is offered: 'TBitmap' is declared in units Vcl.Graphics, FMX.Graphics -- add one of them to the uses clause. A VCL unit filters out FMX candidates and vice versa.

Needs

A project index that contains the file, and the platform library index (both resolve automatically from the manifest). Turn the rule off with "disabled": ["unit-missing-from-uses"] in drag-lint-lint.json, or review a single site with // dl:ok unit-missing-from-uses -- why.

Related: find-unit (ask for one symbol), Add Missing Units (whole unit), circular-uses.

In VS Code the single-resolution fix also runs on save: see Auto uses on save.

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