check-cast-semantics.sh

#!/usr/bin/env bash
#
# Fails when our own code relies on a failing cast throwing ClassCastException.
# ParparVM's CHECKCAST is unchecked, so such a handler never runs on iOS and the
# wrong object is used instead (issue #5531). See CastSemanticsVerifier.
#
#   scripts/check-cast-semantics.sh [--write-baseline] [--require-all] [class-dir-or-jar ...]
#
# With no paths, checks every module that is already built. A module that has not
# been compiled is skipped with a note, so a partial local tree still gives a
# useful answer -- but CI passes --require-all, because there a missing module
# means the gate silently stopped covering it.
#
# NOTE: regenerate the baseline only against a FRESH build of every module. A
# stale target/classes produces a baseline that is missing methods, and the gate
# then fails on CI for code that was never new.
set -euo pipefail

SCRIPT_DIR="$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)"
REPO_ROOT="$(CDPATH= cd -- "$SCRIPT_DIR/.." && pwd)"
BASELINE="$SCRIPT_DIR/cast-semantics-baseline.txt"
TRANSLATOR="$REPO_ROOT/vm/ByteCodeTranslator/target/classes"

# The modules whose bytecode ParparVM translates and that we own. A translation
# sees maven/core, maven/ios and vm/JavaAPI, and -- in an application with
# Android sources -- maven/android-compat, whose runtime the build relocates into
# the application's own classes. Nothing else of ours.
# Deliberately NOT covered, for the one reason: the code runs on a VM whose
# CHECKCAST does throw, so its catch(ClassCastException) handlers are live and
# correct and demanding an instanceof there buys nothing.
#   - maven/android (Ports/Android) runs on ART. It is not translated -- an iOS
#     build never loads a line of it -- and ART implements CHECKCAST to spec.
#   - maven/java-runtime (Ports/CLDC11) runs on a real JVM -- the simulator and
#     desktop. ParparVM's runtime is vm/JavaAPI.
DEFAULT_ROOTS=(
  "vm/JavaAPI/target/classes"
  "maven/core/target/classes"
  "maven/ios/target/classes"
  "maven/android-compat/target/classes"
)

write_baseline=0
require_all=0
roots=()
for arg in "$@"; do
  case "$arg" in
    --write-baseline) write_baseline=1 ;;
    --require-all) require_all=1 ;;
    *) roots+=("$arg") ;;
  esac
done

if [[ ! -f "$TRANSLATOR/com/codename1/tools/translator/CastSemanticsVerifier.class" ]]; then
  echo "check-cast-semantics: building the translator" >&2
  (cd "$REPO_ROOT/vm" && mvn -q -B -pl ByteCodeTranslator -am package -DskipTests)
fi

if [[ ${#roots[@]} -eq 0 ]]; then
  missing=0
  for candidate in "${DEFAULT_ROOTS[@]}"; do
    if [[ -d "$REPO_ROOT/$candidate" ]]; then
      roots+=("$REPO_ROOT/$candidate")
    else
      echo "check-cast-semantics: skipping $candidate (not built)" >&2
      missing=1
    fi
  done
  if [[ "$require_all" -eq 1 && "$missing" -eq 1 ]]; then
    echo "check-cast-semantics: --require-all was passed but a module is not built;" >&2
    echo "  the gate would have covered less than it claims. Build it and re-run." >&2
    exit 2
  fi
fi

if [[ ${#roots[@]} -eq 0 ]]; then
  echo "check-cast-semantics: nothing to check -- no module is built" >&2
  exit 2
fi

args=()
if [[ "$write_baseline" -eq 1 ]]; then
  args+=(--write-baseline "$BASELINE")
fi
args+=(--baseline "$BASELINE")

exec java -cp "$TRANSLATOR" \
  com.codename1.tools.translator.CastSemanticsVerifier "${args[@]}" "${roots[@]}"