more docs, support finding class instances

Lua_Java.org

@@ -0,0 +1,41 @@
+#+TITLE: Lua/Java
+
+* Description
+
+  Lua/Java is the low-level library that interacts with the JVM and
+  exposes a Lua API.
+
+* Notes
+  + =GlobalRef(jobject)= indicates that we return a global reference
+  + Most functions may return =nil=
+  + All functions return "raw" (pointer) jobjects. They must be
+    wrapped by Lua OO wrappers
+
+* Internal Utilities
+
+** Environment References
+   + =current_jni()= provides access to the appropriate JNI
+     environment via =AttachCurrentThread()=
+   + =current_jvmti()= provides access to the JVM TI environment for
+     the agent.
+   + =get_current_java_thread()= provides access to the =jthread=
+
+** Others
+   + =lj_check_jvmti_error()= provides an assertion-like interface to
+     check JVM TI return values.
+   + =lj_print_message()= provides a printf-style interface to stdout.
+
+* External API by Module
+
+** LJ Class
+
+   | Function                                                | Notes                                           |
+   |---------------------------------------------------------+-------------------------------------------------|
+   | *=jobject lj_find_class(string class_name)=*            | Uses =FindClass()= which is quite basi          |
+   | *=[jfield_id] lj_get_class_fields(jobject class)=*      |                                                 |
+   | *=[jmethod_id] lj_get_class_methods(jobject class)=*    |                                                 |
+   | *=string lj_get_source_filename(jobject class)=*        |                                                 |
+   | *=[sig => GlobalRef(jobject)] lj_get_loaded_classes()=* | sig is internal name, e.g. =Ljava/lang/String;= |
+
+** LJ Field
+

changes_before_failed_hd.diff

@@ -213,28 +213,6 @@ diff --git a/lua_java.c b/lua_java.c
 index 549b516..4ebabd9 100644
 --- a/lua_java.c
 +++ b/lua_java.c
-@@ -60,6 +60,21 @@ void lj_check_jvmti_error(lua_State *L)
-   (void)lua_interface_error(L, "Error %d from JVMTI: %s", lj_err, errmsg);
- }
-
-+void lj_check_jvmti_error2(lua_State *L, jvmtiEnv *jvmti)
-+{
-+  char *errmsg = "<Unknown Error>";
-+  if(lj_err == JVMTI_ERROR_NONE)
-+    return;
-+
-+  (*jvmti)->GetErrorName(jvmti, lj_err, &errmsg);
-+  /* we never Deallocate() the errmsg returned from JVMTI */
-+
-+  if (IsDebuggerPresent())
-+    DebugBreak();
-+
-+  (void)lua_interface_error(L, "Error %d from JVMTI: %s", lj_err, errmsg);
-+}
-+
- jobject get_current_java_thread()
- {
-   JNIEnv *jni = current_jni();
 @@ -751,7 +766,6 @@ static int lj_set_array_element(lua_State *L)
  	(*jni)->SetObjectArrayElement(jni, array, index, val.l);
  	EXCEPTION_CHECK(jni);
@@ -243,45 +221,6 @@ index 549b516..4ebabd9 100644
    case 'Z':
  	luaL_checktype(L, val_num, LUA_TBOOLEAN);
  	val.z = lua_toboolean(L, val_num);
-diff --git a/lua_java/lj_class.c b/lua_java/lj_class.c
-index ab2ab86..c1254f2 100644
---- a/lua_java/lj_class.c
-+++ b/lua_java/lj_class.c
-@@ -111,10 +111,34 @@ static int lj_get_source_filename(lua_State *L)
-   return 1;
- }
-
-+static int lj_get_loaded_classes(lua_State *L)
-+{
-+  JNIEnv *jni = current_jni();
-+  int i;
-+  jint class_count;
-+  jclass *classes;
-+
-+  lj_err = (*current_jvmti())->GetLoadedClasses(current_jvmti(), &class_count, &classes);
-+  lj_check_jvmti_error(L);
-+
-+  lua_newtable(L);
-+
-+  for (i = 0; i < class_count; ++i)
-+  {
-+	new_jobject(L, (*jni)->NewGlobalRef(jni, classes[i]));
-+	lua_rawseti(L, -2, i+1);
-+  }
-+
-+  free_jvmti_refs(current_jvmti(), classes, (void *)-1);
-+
-+  return 1;
-+}
-+
- void lj_class_register(lua_State *L)
- {
-   lua_register(L, "lj_find_class",                 lj_find_class);
-   lua_register(L, "lj_get_class_fields",           lj_get_class_fields);
-   lua_register(L, "lj_get_class_methods",          lj_get_class_methods);
-   lua_register(L, "lj_get_source_filename",        lj_get_source_filename);
-+  lua_register(L, "lj_get_loaded_classes",         lj_get_loaded_classes);
- }
 diff --git a/lua_java/lj_method.c b/lua_java/lj_method.c
 index 6e505ec..6399434 100644
 --- a/lua_java/lj_method.c
@@ -363,15 +302,6 @@ diff --git a/lua_jvmti_event.c b/lua_jvmti_event.c
 index 89715f9..a5e3c2f 100644
 --- a/lua_jvmti_event.c
 +++ b/lua_jvmti_event.c
-@@ -18,6 +18,8 @@ extern lua_State *lj_L;
-
- void lj_check_jvmti_error(lua_State *L);
-
-+void lj_check_jvmti_error2(lua_State *L, jvmtiEnv *jvmti);
-+
- extern jthread lj_current_thread;
-
- /* function references for callback functions */
 @@ -28,6 +30,7 @@ static struct {
    int cb_single_step_ref;
    int cb_exception_throw_ref;
@@ -405,7 +335,7 @@ index 89715f9..a5e3c2f 100644
 +  //
 +  lj_err = (*jvmti)->GetMethodName(jvmti, method_id, &method_name, &sig, NULL);
 +  siglen = strlen(sig);
-+  lj_check_jvmti_error2(L, jvmti);
++  lj_check_jvmti_error(L);
 +  printf("Returning an object: %s %s\n", method_name, sig);
 +  //new_string(L, jni, "abc");
 +  //lua_pushstring(L, "abc");

grimple-mode.el

@@ -47,7 +47,8 @@
   :group 'grimple)
 
 (setq grimple-soot-jar
-	  "/home/jbalint/sw/java-sw/soot-2.5.0.jar")
+;;	  "/home/jbalint/sw/java-sw/soot-2.5.0.jar")
+"/home/jbalint/sw/java-sw/soot-trunk-2015-04-19.jar")
 
 (setq grimple-soot-classpath nil)
 	  ;;'("/home/jbalint/sw/stardog-2.1.3/expand"))

java_bridge/jclass.lua

@@ -177,6 +177,17 @@ function jclass:find_field(search_name)
    return nil
 end
 
+-- ============================================================
+-- Find all instances of the current class
+function jclass:find_instances()
+   local instances = lj_get_class_instances(self.object_raw)
+   -- transform the raw instances to jobject instances
+   for i = 1, #instances do
+	  instances[i] = jobject.create(instances[i])
+   end
+   return instances
+end
+
 -- bootstrap the lowest-level class
 jclass.java_lang_Class_instance = {}
 jclass.java_lang_Class_instance.object_raw = lj_new_global_ref(lj_find_class("java/lang/Class"))

lua_java.c

@@ -42,7 +42,8 @@ jvmtiEnv *current_jvmti()
   return lj_jvmti;
 }
 
-void lj_check_jvmti_error(lua_State *L)
+/* TODO: should wrap this in a macro to better report error location */
+void lj_check_jvmti_error_internal(lua_State *L, const char *file, int line, const char *func)
 {
   char *errmsg = "<Unknown Error>";
   if(lj_err == JVMTI_ERROR_NONE)
@@ -54,7 +55,7 @@ void lj_check_jvmti_error(lua_State *L)
   if (IsDebuggerPresent())
     DebugBreak();
 
-  (void)lua_interface_error(L, "Error %d from JVMTI: %s", lj_err, errmsg);
+  (void) lua_interface_error(L, "[%s:%d:%s] Error %d from JVMTI: %s", file, line, func, lj_err, errmsg);
 }
 
 jobject get_current_java_thread()

lua_java/lj_class.c

@@ -5,6 +5,8 @@
 #include "java_bridge.h"
 #include "lj_internal.h"
 
+#include <string.h>
+
 /* Lua wrappers for class operations */
 
 static int lj_find_class(lua_State *L)
@@ -133,6 +135,7 @@ static int lj_get_loaded_classes(lua_State *L)
 	lj_check_jvmti_error(L);
 	lua_pushstring(L, class_sig);
     new_jobject(L, (*jni)->NewGlobalRef(jni, classes[i]));
+	EXCEPTION_CHECK(jni);
 	/* newtable[class_sig] = classes[i] */
     lua_rawset(L, -3);
 	free_jvmti_refs(current_jvmti(), class_sig, (void *) -1);
@@ -144,11 +147,67 @@ static int lj_get_loaded_classes(lua_State *L)
   return 1;
 }
 
+/* This value is used to tag all objects visited. It is then
+   incremented for the next iteration. We need to tag all items and
+   then retrieve them. There is no reason/method to clear all tags so
+   we increment the number so it's different next time. It's
+   *possible* that if you used this method a (max jlong) times that
+   there may be objects leftover with an old tag.
+ */
+static jlong class_instances_search_tag = 1000;
+
+static jint heap_iter_tag_item(jlong class_tag, jlong size, jlong* tag_ptr, jint length, void* user_data) {
+  *tag_ptr = class_instances_search_tag;
+  return 0;
+}
+
+static int lj_get_class_instances(lua_State *L) {
+  jclass class;
+  jvmtiHeapCallbacks callbacks;
+  JNIEnv *jni = current_jni();
+  jobject *obj_output;
+  jlong *tag_output;
+  jint output_count;
+  int i;
+
+  class = *(jclass *)luaL_checkudata(L, 1, "jobject");
+  lua_pop(L, 1);
+
+  /* get a new tag for this search */
+  class_instances_search_tag++;
+
+  memset(&callbacks, 0, sizeof(jvmtiHeapCallbacks));
+  callbacks.heap_iteration_callback = &heap_iter_tag_item;
+
+  lj_err = (*current_jvmti())->IterateThroughHeap(current_jvmti(), 0, class, &callbacks, L);
+  lj_check_jvmti_error(L);
+
+  /* get all tagged objects */
+  lj_err = (*current_jvmti())->GetObjectsWithTags(current_jvmti(), 1, &class_instances_search_tag, &output_count, &obj_output, &tag_output);
+  lj_check_jvmti_error(L);
+
+  fprintf(stderr, "output_count=%d\n", output_count);
+
+  /* add it to the result */
+  lua_createtable(L, output_count, 0);
+  for (i = 0; i < output_count; ++i) {
+	new_jobject(L, (*jni)->NewGlobalRef(jni, obj_output[i]));
+	EXCEPTION_CHECK(jni);
+	lua_rawseti(L, -2, i + 1);
+  }
+
+  if (obj_output)
+	free_jvmti_refs(current_jvmti(), obj_output, tag_output, (void *)-1);
+
+  return 1;
+}
+
 void lj_class_register(lua_State *L)
 {
   lua_register(L, "lj_find_class",                 lj_find_class);
   lua_register(L, "lj_get_class_fields",           lj_get_class_fields);
   lua_register(L, "lj_get_class_methods",          lj_get_class_methods);
   lua_register(L, "lj_get_source_filename",        lj_get_source_filename);
   lua_register(L, "lj_get_loaded_classes",         lj_get_loaded_classes);
+  lua_register(L, "lj_get_class_instances",        lj_get_class_instances);
 }

lua_java/lj_internal.h

@@ -7,7 +7,8 @@ jobject get_current_java_thread();
 jvmtiEnv *current_jvmti();
 JNIEnv *current_jni();
 
-void lj_check_jvmti_error(lua_State *L);
+void lj_check_jvmti_error_internal(lua_State *, const char *, int, const char *);
+#define lj_check_jvmti_error(L) lj_check_jvmti_error_internal(L, __FILE__, __LINE__, __FUNCTION__)
 
 extern jvmtiError lj_err;
 

lua_jvmti_event.c

@@ -16,8 +16,6 @@
 /* from lua_java.c */
 extern lua_State *lj_L;
 
-void lj_check_jvmti_error(lua_State *L);
-
 extern jthread lj_current_thread;
 
 /* function references for callback functions */

yt.c

@@ -125,7 +125,7 @@ Agent_OnLoad(JavaVM *jvm, char *options, void *reserved)
   caps.can_generate_method_entry_events = 1;
   caps.can_generate_method_exit_events = 1;
   caps.can_generate_exception_events = 1;
-/*   caps.can_tag_objects = 1; */
+  caps.can_tag_objects = 1;
   caps.can_get_source_file_name = 1;
   caps.can_get_line_numbers = 1;
   caps.can_access_local_variables = 1;