Check for dead code in CI

.github/workflows/ci.yml

@@ -275,6 +275,13 @@ jobs:
         if: matrix.build_playground
         run: opam exec -- make playground
 
+      # Runs after the playground build, whose browser-profile tree it
+      # analyzes together with the native one. reanalyze is a test
+      # dependency, installed with the switch.
+      - name: Check for dead code
+        if: matrix.build_playground
+        run: opam exec -- make dead-code
+
       - name: Test playground compiler
         if: matrix.build_playground
         run: yarn workspace playground test

changes/dead-code-ci.internal.md

@@ -0,0 +1 @@
+- Check in CI that reanalyze reports no dead code in the OCaml sources.

dune-project

@@ -61,7 +61,13 @@
    (and
     (<> :os "win32")
     :with-test
-    (= 6.5.0)))))
+    (= 6.5.0)))
+  ; make dead-code
+  (reanalyze
+   (and
+    (<> :os "win32")
+    :with-test
+    (= 2.27.0)))))
 
 (package
  (name analysis)

rescript.opam

@@ -27,6 +27,7 @@ depends: [
   "ocaml-lsp-server" {with-dev-setup & >= "1.23.0"}
   "js_of_ocaml" {os != "win32" & with-test & = "6.5.0"}
   "wasm_of_ocaml-compiler" {os != "win32" & with-test & = "6.5.0"}
+  "reanalyze" {os != "win32" & with-test & = "2.27.0"}
 ]
 build: [
   ["dune" "subst"] {dev}

scripts/dead_code.sh

@@ -4,8 +4,8 @@
 # anything.
 #
 # Usage: REANALYZE=/path/to/reanalyze.exe ./scripts/dead_code.sh
-# (defaults to reanalyze.exe on PATH; needs a reanalyze that analyzes several
-# build trees together, rescript-lang/reanalyze#224)
+# (defaults to reanalyze.exe on PATH. reanalyze is a test dependency in
+# rescript.opam, installed by opam install . --deps-only --with-test.)
 
 set -euo pipefail
 cd "$(dirname "$0")/.."