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Tree-shake the clojure.core prelude too (whole-program DCE)

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--tree-shake now shakes the clojure.core/stdlib prelude in the same reachability
graph as the app + libraries — only core fns actually reached from -main ship.

dce-blob-records reads prelude.ss with Chez `read`, unwraps each
(guard ... (def-var! "ns" "name" V)) and builds the core->core call graph from the
(var-deref/jolt-var "ns" "name") refs in V — the real emitted edges, no
re-analysis. bld-shake-all merges core + app records into one BFS; roots are -main,
side-effecting forms, and the clojure.core fns the runtime .ss shims reference by
name (enumerated in dce-runtime-core-roots). The shaken core is spliced where the
prelude.ss blob was, in original (tier) order, so load-time deps are preserved.
Bail (reachable runtime resolve) keeps the prelude whole.

Soundness follows Stalin's rule (any reference, value or call, keeps a def live):
dce-collect-refs counts :var and :the-var; non-def registration forms are always
kept (covers protocol/multimethod dispatch). Validated by make shakesmoke: the four
deps.edn git-lib apps build byte-identical output shaken vs not.

Wins (binary): build-app 9.84MB -> 8.12MB (dropped 403/457 core defs); malli-app
10.0MB -> 8.1MB; markdown 9.9 -> 8.3; commonmark 9.8 -> 8.1 — all output-identical.
build-smoke asserts an unused core fn (group-by) is dropped; full make test green.
This commit is contained in:
Yogthos 2026-06-23 20:42:23 -04:00
parent f7fd73c448
commit 298ac66fb1
3 changed files with 96 additions and 38 deletions
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6
host/chez/build-smoke.sh
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@ -96,4 +96,8 @@ fi
if grep -q 'def-var! "jolt.analyzer"' "$out.build/flat.ss"; then
echo " FAIL: --tree-shake kept the compiler image in a no-eval app"; exit 1
fi
echo "build smoke: passed (release + optimized + direct-link + tree-shake + compiler-drop)"
# Core is shaken: a clojure.core overlay fn this app never uses is dropped.
if grep -q 'def-var! "clojure.core" "group-by"' "$out.build/flat.ss"; then
echo " FAIL: --tree-shake kept an unreachable clojure.core fn (group-by)"; exit 1
fi
echo "build smoke: passed (release + optimized + direct-link + tree-shake + compiler+core shake)"