Delphi code smells — make the machine find them first

A review pass that starts with an opinion is worth little. A review pass that starts with the compiler and a leak report is worth a lot, because it is objective and free. Do that half first, every time.

Every warning code, directive and API below was produced by dcc32.exe 37.0 on this machine or copied from the shipped RTL/DUnitX source, not recalled. Where something could not be verified it says so.

What this skill owns, and what it does not

This skill is diagnosis. When a smell needs semantics to explain, it links; it does not re-teach.

Order of attack — an unfamiliar unit

Work down this list. Stop reporting when you run out of items that cost the user something.

1. Compile it with warnings and hints on and read every line of output. Free, objective, and the single highest-yield step. reference/static-analysis.md.
2. Run it with ReportMemoryLeaksOnShutdown := True. If there is a test suite, run that. reference/leaks.md.
3. Ownership by hand — every Create in the unit: who frees it, on which paths, including the raising one. This is where the compiler cannot help you.
4. Exception handling — every except without an on, every empty handler, every try/except that should have been try/finally.
5. Concurrency — anything reachable from a TThread.Execute or a TTask.Run body.
6. Everything else. Naming, with, long methods, magic numbers.

A leak the compiler cannot see outranks a naming convention, always. If the review output is a wall of style nits and no lifetime finding, the review was not done. Report defects in the order above, and say for each one what it costs at runtime — a leak, an AV, a silently wrong result. "This is ugly" is not a finding.

The five-minute pass

# 1. what the compiler already knows (see reference/static-analysis.md for the codes)
dcc32.exe -H -W MyProject.dpr

# 2. the greps that pay for themselves, in rough order of yield
rg -n -U 'try\b[^;]*?\n\s*\w+\s*:=\s*T\w+\.Create'   # constructor INSIDE the try  -> AV in the finally
rg -n -P '(?s)except\s*(//[^\n]*\n\s*)*end'          # swallowed exception
rg -n '\bwith\b\s+\w+.*\bdo\b'                       # with
rg -n 'FreeAndNil\s*\(\s*[lL]'                       # FreeAndNil on a local
rg -n 'FreeOnTerminate'                              # thread lifetime
rg -n '\w+\s*:=\s*\w+\s*\+\s*'                       # candidate string concat in a loop

Then read reference/smells.md for what each hit means and how to fix it.

Reference files

The defects worth finding, ranked

Detail and detection for each in reference/smells.md.

Reporting a review

• One line per finding: location, what goes wrong at runtime, the fix. Not an essay.
• Lead with anything that leaks, dangles or returns a wrong value. Style last, or not at all.
• If a compiler warning already covers a finding, cite the code (W1035) — it turns your opinion into something the user can put in their build and never hear from you again about.
• Never report a smell you cannot say how to detect. If you cannot name a warning, a tool or a grep for it, it is a preference, and the user did not ask for your preferences.