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shell: reflection_metaprogramming matches plain ${var} expansion (indirection marker is optional) and every $(...) -- 1,019 hits in 2,823 LOC on configure-helper.sh #2722
Description
Found while attributing #2719's golden-master diff: with per-file dynamism (reflection_metaprogramming) feeding documentation risk, 15 of the crucible's 46 shell files jump ≥ 25 points, to ~99% -- configure-helper.sh reads 1,019 reflection hits in 2,823 coding lines, ansible-galaxy__runme.sh 149 in 333, xcrun_cache.sh 122 in 225.
The shell rule (gitgalaxy/standards/language_standards/languages/shell.py):
\$\((?:[^()]|\([^()]*\))+\)|`[^`]+`|\b(?:awk|sed|perl|python[23]?|ruby)\s+['"][^'"]{0,500}|\beval\s+\$|\$\{!?[a-zA-Z0-9_]+\}
Two of its alternatives count ordinary shell as metaprogramming:
\$\{!?[a-zA-Z0-9_]+\}-- the!?makes the indirection marker optional, so plain${var}matches.${!var}(indirect expansion) is reflection;${var}is a variable. This looks like a typo for\$\{![a-zA-Z0-9_]+\}.\$\((?:...)\)and backticks -- every command substitution.test_shell_strict.pyL105 pinsoutput=$(date)as a positive, so this one is a deliberate decision by the rule's author; whether "runs a command" is the same thing as "dynamic dispatch a reader can't follow" is the question. On real shell it is one hit per ~3 lines, which is the language's vocabulary, not its dynamism -- the same shape as thecontrol_flow_ratiovocabulary leak in length leaks: func_internal_density, avg_func_loc and control_flow_ratio read file length with content and tier held equal (rosetta F.1 design pass) #2705.
Suggested fix: (1) is a one-character change (!? → !) and should be uncontroversial; for (2), keep eval, ${!var}, declare -n, source/. of a computed path, and the inline awk|sed|perl|python programs, and drop bare $(...)/backticks -- or move them to a signal that means "runs a command". reflection_metaprogramming is unplanted in keyword-rosetta, so the change is not gate-visible there; it is golden-master-visible (documentation and cognitive load on shell).
Related: #2716 (three-input model), #2719 (per-file dynamism), #2705 (vocabulary leaks).
Activity
feat(core-engine): per-file dynamism replaces the flat language irc i…
squid-protocol commentedon Sep 4, 2026
Fixed in #2725 (branch
fix/2722-shell-reflection, off4c283edf).Measured before touching anything, over the crucible's 255 shell files / 26,274 coding LOC, each alternative counted independently:
${var}$(...)`...`awk|sed|perl|python|ruby '...'eval $${!var}So (1) is even more lopsided than it looked:
${!var}, the construct the alternative exists for, does not occur in the corpus at all -- every one of those 4,117 hits was a plain variable.On (2) the registry settles it rather than the test pin. Every other language's rule counts name-based dynamic dispatch and introspection -- python
getattr/setattr/inspect., goreflect./unsafe./cgo, rubymethod_missing/define_method, jsReflect/Proxy/__proto__. None counts invoking another program; python's does not fire onsubprocess.run.$(date)is that same call and its result is data, not code.test_shell_strict.pyL105 now pins it as the NEGATIVE half of the pair, witheval "\$cmd"as the positive.Took the suggested fix in full: dropped
$(...)/backticks and the!?, kept the inline sub-language programs and${!var}, addedevalunanchored (the old\\beval\\s+\$missedeval "\$cmd"), namerefsdeclare/typeset/local -n, andsource/.of a computed path. 4,863 -> 227 hits, 73 of 255 files still carrying one;configure-helper.sh1,019 -> 15.Golden master re-blessed both venvs: 508 diffs, 0 topological, all shell files (the
shell/tree plus wrf's.csh/.kshscripts andtigerbeetle/download.sh), every other language zero, and 20 files' Documentation Exposure falls by >=25 -- the reversal of the jumps #2719 flagged. Exactly one value in the corpus rises:sqlite/tclConfigShToMake.shgains a hit for. "\$1", in a file whose header comment calls itself "a level of indirection".Considered and left out:
trap '...' SIG(code in a string, but owned bycleanup) and a "runs a command" home for$(...), which would be a new signal rather than this fix.fix(core-engine): shell reflection counts dispatch, not command subst…