Modernize build for Android API 36 + NDK 27, fix JNI class loader SIGABRT

build.gradle

@@ -1,23 +1,17 @@
-apply plugin: 'java'
-
 buildscript {
     repositories {
         google()
-        jcenter()
+        mavenCentral()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.6.0-alpha06'
-        classpath 'com.github.dcendents:android-maven-gradle-plugin:1.5'
+        classpath 'com.android.tools.build:gradle:8.7.3'
+        classpath 'de.undercouch:gradle-download-task:5.6.0'
     }
 }
 
 allprojects {
     repositories {
         google()
-        jcenter()
+        mavenCentral()
     }
 }
-
-/*task clean(type: Delete) {
-    delete rootProject.buildDir
-}*/

gradle/wrapper/gradle-wrapper.properties

@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.6-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.11.1-bin.zip

lib/build.gradle

@@ -1,75 +1,59 @@
 plugins {
-    id 'de.undercouch.download' version '3.3.0'
+    id 'com.android.library'
+    id 'de.undercouch.download'
 }
 
-apply plugin: 'com.android.library'
-apply plugin: 'de.undercouch.download'
-apply plugin: 'com.github.dcendents.android-maven'
-
-group = 'com.github.sevar83'
-
 import de.undercouch.gradle.tasks.download.Download
-import org.gradle.internal.os.OperatingSystem;
-
-gradle.projectsEvaluated {
-    preBuild.dependsOn(buildSqlite)
-}
+import org.gradle.internal.os.OperatingSystem
 
 android {
-    compileSdkVersion 29
+    compileSdk 36
+    namespace 'org.spatialite'
 
     defaultConfig {
-        minSdkVersion 16
-        targetSdkVersion 29
+        minSdk 21
+        targetSdk 36
+        ndkVersion "27.2.12479018"
         versionCode 1
         versionName project.version
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
         consumerProguardFiles 'proguard-rules.pro'
     }
+
     buildTypes {
         release {
             minifyEnabled false
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
+
     lintOptions {
         abortOnError false
     }
+
     compileOptions {
-        sourceCompatibility JavaVersion.VERSION_1_7
-        targetCompatibility JavaVersion.VERSION_1_7
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
     }
-    // ndk gradle support is still very bad so it's built with the regular ndk-build
+
+    // ndk-build is invoked manually; disable AGP's built-in JNI source scanning
     sourceSets.main.jni.srcDirs = ['src/main/none']
 }
 
 dependencies {
-    implementation 'androidx.core:core:1.0.2'
-    implementation 'androidx.annotation:annotation:1.1.0'
-    androidTestImplementation 'androidx.test:runner:1.2.0'
-    androidTestImplementation 'androidx.test:rules:1.2.0'
-    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
+    implementation 'androidx.core:core:1.13.1'
+    implementation 'androidx.annotation:annotation:1.8.2'
+    androidTestImplementation 'androidx.test:runner:1.6.2'
+    androidTestImplementation 'androidx.test:rules:1.6.1'
+    androidTestImplementation 'androidx.test.ext:junit:1.2.1'
 }
 
 ext {
-    sqliteDistributionUrl = 'http://sqlite.org/2016/sqlite-amalgamation-3150100.zip'
-}
-
-task sourcesJar(type: Jar) {
-    classifier = 'sources'
-    from android.sourceSets.main.java.srcDirs
-}
-
-task javadoc(type: Javadoc) {
-    source = android.sourceSets.main.java.srcDirs
-    classpath += project.files(android.getBootClasspath().join(File.pathSeparator))
-    classpath += configurations.compile
-    failOnError false
+    sqliteDistributionUrl = 'https://sqlite.org/2025/sqlite-amalgamation-3490100.zip'
 }
 
-task javadocJar(type: Jar, dependsOn: javadoc) {
-    classifier = 'javadoc'
-    from javadoc.destinationDir
+gradle.projectsEvaluated {
+    preBuild.dependsOn(buildSqlite)
 }
 
 task downloadSqlite(type: Download) {
@@ -93,34 +77,32 @@ if (ndkDir == null) {
         properties.load(propertiesFile.newDataInputStream())
         ndkDir = properties.getProperty('ndk.dir')
         if (ndkDir == null) {
-            throw GradleScriptException("Either NDK_HOME or ndk.dir in local.properties should point to Android NDK!")
+            throw new GradleException("Either NDK_HOME or ndk.dir in local.properties must point to the Android NDK.")
         }
     } else {
-        throw GradleScriptException("Either NDK_HOME or ndk.dir in local.properties should point to Android NDK!")
+        throw new GradleException("Either NDK_HOME or ndk.dir in local.properties must point to the Android NDK.")
     }
 }
 
 task buildSqlite(dependsOn: installSqlite, type: Exec) {
     println("NDK directory: $ndkDir")
-
-    // Add NDK_DEBUG=1 for debug symbols or V=1 for verbose building output
     if (OperatingSystem.current().linux) {
         commandLine "$ndkDir/ndk-build", '-j8', '-C', file('src/main/jni').absolutePath
     } else if (OperatingSystem.current().windows) {
         commandLine "$ndkDir/ndk-build.cmd", '-j8', '-C', file('src/main/jni').absolutePath
     } else {
-        throw GradleScriptException("Unsupported OS")
+        throw new GradleException("Unsupported OS: ${OperatingSystem.current()}")
     }
 }
 
-task ndkClean(type: Exec, description: 'Clean NDK Binaries') {
+task ndkClean(type: Exec, description: 'Clean NDK binaries') {
     if (OperatingSystem.current().linux) {
         commandLine "$ndkDir/ndk-build", 'clean', '-C', file('src/main/jni').absolutePath
     } else if (OperatingSystem.current().windows) {
         commandLine "$ndkDir/ndk-build.cmd", 'clean', '-C', file('src/main/jni').absolutePath
     } else {
-        throw GradleScriptException("Unsupported OS")
+        throw new GradleException("Unsupported OS: ${OperatingSystem.current()}")
     }
 }
 
-clean.dependsOn 'ndkClean'
+clean.dependsOn 'ndkClean'

lib/src/main/jni/Application.mk

@@ -1,9 +1,8 @@
-APP_STL := c++_shared
-APP_OPTIM := release
-APP_ABI := armeabi-v7a,arm64-v8a,x86,x86_64
-APP_PLATFORM := android-16
+APP_STL               := c++_static
+APP_OPTIM             := release
+APP_ABI               := armeabi-v7a arm64-v8a x86_64
+APP_PLATFORM          := android-21
 NDK_TOOLCHAIN_VERSION := clang
-NDK_APP_LIBS_OUT=../jniLibs
-# Temp workaround for https://github.com/android-ndk/ndk/issues/332
-APP_DEPRECATED_HEADERS := true
-APP_SHORT_COMMANDS := true
+NDK_APP_LIBS_OUT      := ../jniLibs
+# Use response files to avoid Windows command-line length limit (Error 87 from llvm-ar)
+NDK_APP_SHORT_COMMANDS := true

lib/src/main/jni/android_database_SQLiteConnection.cpp

@@ -30,6 +30,7 @@
 #include "CursorWindow.h"
 
 #include <string>
+#include <mutex>
 
 #include <spatialite.h>
 
@@ -54,6 +55,31 @@ static const int BUSY_TIMEOUT_MS = 2500;
 
 static JavaVM *gpJavaVM = 0;
 
+// ---------------------------------------------------------------------------
+// Lazy JNI registration
+//
+// JNI_OnLoad fires on the Mono bootstrap thread, which holds the *system*
+// class loader.  FindClass("org/spatialite/...") therefore returns null and
+// the subsequent LOG_FATAL_IF aborts the process (SIGABRT).
+//
+// Fix: skip all RegisterNatives in JNI_OnLoad; call them once from nativeOpen()
+// which always runs on a Java application thread that owns the app class loader.
+// ---------------------------------------------------------------------------
+static std::once_flag g_jni_register_once;
+// Forward declarations (definitions are near the bottom of this file / other TUs)
+static int register_android_database_SQLiteConnection(JNIEnv *env);
+extern int register_android_database_SQLiteGlobal(JNIEnv *env);
+extern int register_android_database_SQLiteDebug(JNIEnv *env);
+extern int register_android_database_CursorWindow(JNIEnv *env);
+
+static void doLazyRegisterAll(JNIEnv* env) {
+    register_android_database_SQLiteConnection(env);
+    register_android_database_SQLiteDebug(env);
+    register_android_database_SQLiteGlobal(env);
+    register_android_database_CursorWindow(env);
+}
+// ---------------------------------------------------------------------------
+
 static struct {
     jfieldID name;
     jfieldID numArgs;
@@ -134,6 +160,10 @@ static int coll_localized(
 
 static jlong nativeOpen(JNIEnv* env, jclass clazz, jstring pathStr, jint openFlags,
         jstring labelStr, jboolean enableTrace, jboolean enableProfile) {
+    // Ensure all four JNI native-method tables are registered exactly once, on
+    // an app thread so FindClass resolves against the app class loader.
+    std::call_once(g_jni_register_once, doLazyRegisterAll, env);
+
     int sqliteFlags;
     if (openFlags & SQLiteConnection::CREATE_IF_NECESSARY) {
         sqliteFlags = SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE;
@@ -930,7 +960,8 @@ static JNINativeMethod sMethods[] =
 int register_android_database_SQLiteConnection(JNIEnv *env)
 {
     jclass clazz;
-    FIND_CLASS(clazz, "org/spatialite/database/SQLiteCustomFunction");
+    clazz = env->FindClass("org/spatialite/database/SQLiteCustomFunction");
+    LOG_FATAL_IF(!clazz, "Unable to find class org/spatialite/database/SQLiteCustomFunction");
 
     GET_FIELD_ID(gSQLiteCustomFunctionClassInfo.name, clazz,
             "name", "Ljava/lang/String;");
@@ -939,7 +970,8 @@ int register_android_database_SQLiteConnection(JNIEnv *env)
     GET_METHOD_ID(gSQLiteCustomFunctionClassInfo.dispatchCallback,
             clazz, "dispatchCallback", "([Ljava/lang/String;)Ljava/lang/String;");
 
-    FIND_CLASS(clazz, "java/lang/String");
+    clazz = env->FindClass("java/lang/String");
+    LOG_FATAL_IF(!clazz, "Unable to find class java/lang/String");
     gStringClassInfo.clazz = jclass(env->NewGlobalRef(clazz));
 
     return jniRegisterNativeMethods(env, 
@@ -948,23 +980,13 @@ int register_android_database_SQLiteConnection(JNIEnv *env)
     );
 }
 
-extern int register_android_database_SQLiteGlobal(JNIEnv *env);
-extern int register_android_database_SQLiteDebug(JNIEnv *env);
-extern int register_android_database_CursorWindow(JNIEnv *env);
-
 } // namespace android
 
 extern "C" JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM* vm, void* reserved) {
-  JNIEnv *env = 0;
-
+  // Only save the VM pointer here. All RegisterNatives calls happen lazily
+  // from nativeOpen() (the first native call on an app thread) so that
+  // FindClass resolves against the app class loader, not the bootstrap loader.
   android::gpJavaVM = vm;
-  vm->GetEnv((void**)&env, JNI_VERSION_1_4);
-
-  android::register_android_database_SQLiteConnection(env);
-  android::register_android_database_SQLiteDebug(env);
-  android::register_android_database_SQLiteGlobal(env);
-  android::register_android_database_CursorWindow(env);
-
   return JNI_VERSION_1_4;
 }
 

lib/src/main/jni/ndk-modules/freexl/freexl-1.0.2.mk

@@ -8,7 +8,7 @@ LOCAL_MODULE := freexl
 FREEXL_FILES :=  \
 	${FREEXL_PATH}/src/freexl.c
 
-LOCAL_CFLAGS += -fvisibility=hidden
+LOCAL_CFLAGS += -fvisibility=hidden -Wno-int-conversion -Wno-implicit-function-declaration
 
 LOCAL_C_INCLUDES := \
     $(LOCAL_PATH)/$(FREEXL_PATH) \

lib/src/main/jni/ndk-modules/geos/geos-3.4.2.mk

@@ -306,6 +306,12 @@ LOCAL_SRC_FILES := \
     $(GEOS_FILES) \
     src-io-CLocalizer.cpp
 
+# GEOS 3.4.2 uses std::auto_ptr which was removed in C++17.
+# Force C++14 for this module so it compiles with NDK r21+.
+LOCAL_CPPFLAGS += -std=c++14
+# Use response files to avoid Windows command-line length limit (Error 87 from llvm-ar).
+LOCAL_SHORT_COMMANDS := true
+
 TARGET-process-src-files-tags += $(call add-src-files-target-cflags, \
    geos/src/io/WKTReader.cpp, -include cctype)
 

lib/src/main/jni/ndk-modules/libiconv/libiconv-1.13.mk

@@ -5,6 +5,8 @@ LOCAL_MODULE := iconv
 
 LOCAL_CFLAGS    := \
     -Wno-multichar \
+    -Wno-int-conversion \
+    -Wno-implicit-function-declaration \
     -D_ANDROID \
     -DLIBDIR "$(LOCAL_PATH)/$(ICONV_PATH)/libcharset/lib" \
     -DBUILDING_LIBICONV \

lib/src/main/jni/ndk-modules/liblzma/xz-5.2.1.mk

@@ -10,7 +10,9 @@ LOCAL_MODULE    := liblzma
 lzma_flags := \
  -DHAVE_CONFIG_H \
  -g -O2 \
- -std=gnu99
+ -std=gnu99 \
+ -Wno-int-conversion \
+ -Wno-implicit-function-declaration
 
 LOCAL_CFLAGS    := \
  $(lzma_flags)

lib/src/main/jni/ndk-modules/libspatialite/libspatialite-4.3.0a.mk

@@ -173,7 +173,9 @@ spatialite_flags := \
 
 LOCAL_CFLAGS    := \
    $(common_sqlite_flags) \
-   $(spatialite_flags)
+   $(spatialite_flags) \
+   -Wno-int-conversion \
+   -Wno-implicit-function-declaration
 
 LOCAL_STATIC_LIBRARIES := proj4 geos libsqlite3x iconv libxml2 freexl
 

lib/src/main/jni/ndk-modules/libxml2/libxml2-2.9.2.mk

@@ -14,7 +14,9 @@ xml2_flags := \
  -DLIBXML_THREAD_ENABLED=1
 
 LOCAL_CFLAGS    := \
- $(xml2_flags)
+ $(xml2_flags) \
+ -Wno-int-conversion \
+ -Wno-implicit-function-declaration
 
 LOCAL_C_INCLUDES := \
  $(LOCAL_PATH)/$(XML2_PATH)/include \

lib/src/main/jni/ndk-modules/proj.4/proj-4.8.0.mk

@@ -5,7 +5,7 @@ LOCAL_MODULE := proj4
 
 PROJ4_CONFIG := $(LOCAL_PATH)/config
 
-LOCAL_CFLAGS += -fvisibility=hidden
+LOCAL_CFLAGS += -fvisibility=hidden -Wno-int-conversion -Wno-implicit-function-declaration
 LOCAL_C_INCLUDES := $(LOCAL_PATH)/$(PROJ4_PATH)/proj/src $(PROJ4_CONFIG)
 LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/$(PROJ4_PATH)/proj/src $(PROJ4_CONFIG)
 LOCAL_SRC_FILES := \