Updates public build to work with JDK implementations that do not include jmod files...

make/common.mk

@@ -198,8 +198,7 @@ endif
 
 # Used to build JRE module.
 ifndef JAVA_PLATFORM
-JAVA_PLATFORM = \
-  $(shell $(JAVA_HOME)/bin/jmod describe $(JAVA_HOME)/jmods/java.base.jmod |grep -i '^platform'|cut -d' ' -f2)
+  JAVA_PLATFORM := $(shell $(J2OBJC_ROOT)/scripts/detect-java-platform.sh)
 endif
 
 ifndef MEMORY_MODEL_FLAG

scripts/detect-java-platform.sh

@@ -0,0 +1,64 @@
+#!/bin/sh
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# POSIX-compatible script to print the JDK platform tag, e.g. "macos-aarch64".
+# Prefers $JAVA_HOME/release (OS_NAME + OS_ARCH). Falls back to jmod describe
+# if jmods are available (not true for all JDK distributions).
+set -eu
+
+# Find JAVA_HOME if not set
+if [ -z "${JAVA_HOME:-}" ]; then
+  JAVA_HOME=$(/usr/libexec/java_home)
+fi
+
+release="$JAVA_HOME/release"
+platform=""
+
+# Parse release file if present
+if [ -f "$release" ]; then
+  os_raw=$(awk -F= '/^OS_NAME=/{sub(/^"/,"",$2); sub(/"$/,"",$2); print $2; exit}' "$release" || true)
+  arch_raw=$(awk -F= '/^OS_ARCH=/{sub(/^"/,"",$2); sub(/"$/,"",$2); print $2; exit}' "$release" || true)
+
+  os=$(echo "${os_raw:-}" | tr '[:upper:]' '[:lower:]')
+  arch=$(echo "${arch_raw:-}" | tr '[:upper:]' '[:lower:]')
+
+  case "$os" in
+    *mac*|*darwin*) os=macos ;;
+    *linux*)        os=linux ;;
+  esac
+
+  case "$arch" in
+    amd64|x86_64|x86-64) arch=x86_64 ;;
+    aarch64|arm64)      arch=aarch64 ;;
+    armv7l|armv7*)      arch=armv7l ;;
+  esac
+
+  if [ -n "$os" ] && [ -n "$arch" ]; then
+    platform="$os-$arch"
+  fi
+fi
+
+# Fallback: use jmod describe if release not available or parsing failed
+if [ -z "$platform" ]; then
+  jmod_cmd="$JAVA_HOME/bin/jmod"
+  if [ -f "$JAVA_HOME/jmods/java.base.jmod" ]; then
+    platform=$($jmod_cmd describe "$JAVA_HOME/jmods/java.base.jmod" 2>/dev/null | awk '/^platform /{print $2; exit}' || true)
+  fi
+fi
+
+if [ -z "$platform" ]; then
+  echo "ERROR: failed to determine Java platform target" >&2
+  exit 3
+fi
+
+printf '%s\n' "$platform"