1 // jvm.h - Header file for private implementation information. -*- c++ -*-
3 /* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation
5 This file is part of libgcj.
7 This software is copyrighted work licensed under the terms of the
8 Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
11 #ifndef __JAVA_JVM_H__
12 #define __JAVA_JVM_H__
14 // Define this before including jni.h.
15 // jni.h is included by jvmpi.h, which might be included. We define
16 // this unconditionally because it is convenient and it lets other
17 // files include jni.h without difficulty.
18 #define __GCJ_JNI_IMPL__
20 #include <gcj/javaprims.h>
22 #include <java-assert.h>
23 #include <java-threads.h>
24 // Must include java-gc.h before Object.h for the implementation.
27 #include <java/lang/Object.h>
29 // Include cni.h before field.h to enable all definitions. FIXME.
31 #include <gcj/field.h>
33 /* Macro for possible unused arguments. */
34 #define MAYBE_UNUSED __attribute__((__unused__))
36 /* Structure of the virtual table. */
40 typedef struct { void *pc, *gp; } vtable_elt;
42 typedef void *vtable_elt;
47 // This must be last, as derived classes "extend" this by
48 // adding new data members.
52 void *get_method(int i) { return &method[i]; }
53 void set_method(int i, void *fptr) { method[i] = *(vtable_elt *)fptr; }
56 // We know that get_finalizer is only used for checking whether
57 // this object needs to have a finalizer registered. So it is
58 // safe to simply return just the PC component of the vtable
60 return ((vtable_elt *)(get_method(0)))->pc;
63 void *get_method(int i) { return method[i]; }
64 void set_method(int i, void *fptr) { method[i] = fptr; }
65 void *get_finalizer() { return get_method(0); }
68 static size_t vtable_elt_size() { return sizeof(vtable_elt); }
70 // Given a method index, return byte offset from the vtable pointer.
71 static jint idx_to_offset (int index)
73 return (2 * sizeof (void *)) + (index * vtable_elt_size ());
75 static _Jv_VTable *new_vtable (int count);
78 // Number of virtual methods on object. FIXME: it sucks that we have
79 // to keep this up to date by hand.
80 #define NUM_OBJECT_METHODS 5
85 jint i; // Also stores smaller integral types.
87 jint ia[1]; // Half of _Jv_word2.
90 #if SIZEOF_VOID_P == 8
91 // We can safely put a long or a double in here without increasing
92 // the size of _Jv_Word; we take advantage of this in the interpreter.
99 struct _Jv_Field *field;
100 struct _Jv_Utf8Const *utf8;
101 struct _Jv_ResolvedMethod *rmethod;
119 jdouble double_value;
120 jobject object_value;
123 /* Extract a character from a Java-style Utf8 string.
124 * PTR points to the current character.
125 * LIMIT points to the end of the Utf8 string.
126 * PTR is incremented to point after the character thta gets returns.
127 * On an error, -1 is returned. */
128 #define UTF8_GET(PTR, LIMIT) \
129 ((PTR) >= (LIMIT) ? -1 \
130 : *(PTR) < 128 ? *(PTR)++ \
131 : (*(PTR)&0xE0) == 0xC0 && ((PTR)+=2)<=(LIMIT) && ((PTR)[-1]&0xC0) == 0x80 \
132 ? (((PTR)[-2] & 0x1F) << 6) + ((PTR)[-1] & 0x3F) \
133 : (*(PTR) & 0xF0) == 0xE0 && ((PTR) += 3) <= (LIMIT) \
134 && ((PTR)[-2] & 0xC0) == 0x80 && ((PTR)[-1] & 0xC0) == 0x80 \
135 ? (((PTR)[-3]&0x0F) << 12) + (((PTR)[-2]&0x3F) << 6) + ((PTR)[-1]&0x3F) \
138 extern int _Jv_strLengthUtf8(char* str, int len);
140 typedef struct _Jv_Utf8Const Utf8Const;
141 _Jv_Utf8Const *_Jv_makeUtf8Const (char *s, int len);
142 _Jv_Utf8Const *_Jv_makeUtf8Const (jstring string);
143 extern jboolean _Jv_equalUtf8Consts (const _Jv_Utf8Const *, const _Jv_Utf8Const *);
144 extern jboolean _Jv_equal (_Jv_Utf8Const *, jstring, jint);
145 extern jboolean _Jv_equaln (_Jv_Utf8Const *, jstring, jint);
147 /* Helper class which converts a jstring to a temporary char*.
148 Uses the supplied buffer, if non-null. Otherwise, allocates
149 the buffer on the heap. Use the JV_TEMP_UTF_STRING macro,
150 which follows, to automatically allocate a stack buffer if
151 the string is small enough. */
152 class _Jv_TempUTFString
155 _Jv_TempUTFString(jstring jstr, char* buf=0);
156 ~_Jv_TempUTFString();
159 operator const char*() const
163 const char* buf() const
177 inline _Jv_TempUTFString::_Jv_TempUTFString (jstring jstr, char* buf)
178 : buf_(0), heapAllocated_(false)
181 jsize len = JvGetStringUTFLength (jstr);
186 buf_ = (char*) _Jv_Malloc (len+1);
187 heapAllocated_ = true;
190 JvGetStringUTFRegion (jstr, 0, jstr->length(), buf_);
194 inline _Jv_TempUTFString::~_Jv_TempUTFString ()
200 /* Macro which uses _Jv_TempUTFString. Allocates a stack-based
201 buffer if the string and its null terminator are <= 256
202 characters in length. Otherwise, a heap-based buffer is
203 used. The parameters to this macro are the variable name
204 which is an instance of _Jv_TempUTFString (above) and a
209 jstring jstr = getAJString();
210 JV_TEMP_UTF_STRING(utfstr, jstr);
211 printf("The string is: %s\n", utfstr.buf());
214 #define JV_TEMP_UTF_STRING(utfstr, jstr) \
215 jstring utfstr##thejstr = (jstr); \
216 jsize utfstr##_len = utfstr##thejstr ? JvGetStringUTFLength (utfstr##thejstr) + 1 : 0; \
217 char utfstr##_buf[utfstr##_len <= 256 ? utfstr##_len : 0]; \
218 _Jv_TempUTFString utfstr(utfstr##thejstr, sizeof(utfstr##_buf)==0 ? 0 : utfstr##_buf)
222 /* Some constants used during lookup of special class methods. */
223 extern _Jv_Utf8Const *void_signature; /* "()V" */
224 extern _Jv_Utf8Const *clinit_name; /* "<clinit>" */
225 extern _Jv_Utf8Const *init_name; /* "<init>" */
226 extern _Jv_Utf8Const *finit_name; /* "finit$", */
228 /* Set to true by _Jv_CreateJavaVM. */
229 extern bool runtimeInitialized;
231 /* Print out class names as they are initialized. */
232 extern bool verbose_class_flag;
235 // This class handles all aspects of class preparation and linking.
239 static _Jv_Field *find_field_helper(jclass, _Jv_Utf8Const *, _Jv_Utf8Const *,
241 static _Jv_Field *find_field(jclass, jclass, _Jv_Utf8Const *,
243 static void prepare_constant_time_tables(jclass);
244 static jshort get_interfaces(jclass, _Jv_ifaces *);
245 static void link_symbol_table(jclass);
246 static void link_exception_table(jclass);
247 static void layout_interface_methods(jclass);
248 static void layout_vtable_methods(jclass);
249 static void set_vtable_entries(jclass, _Jv_VTable *);
250 static void make_vtable(jclass);
251 static void ensure_fields_laid_out(jclass);
252 static void ensure_class_linked(jclass);
253 static void ensure_supers_installed(jclass);
254 static void add_miranda_methods(jclass, jclass);
255 static void ensure_method_table_complete(jclass);
256 static void verify_class(jclass);
257 static jshort find_iindex(jclass *, jshort *, jshort);
258 static jshort indexof(void *, void **, jshort);
259 static int get_alignment_from_class(jclass);
260 static void generate_itable(jclass, _Jv_ifaces *, jshort *);
261 static jshort append_partial_itable(jclass, jclass, void **, jshort);
262 static _Jv_Method *search_method_in_class (jclass, jclass,
268 static bool has_field_p (jclass, _Jv_Utf8Const *);
269 static void print_class_loaded (jclass);
270 static void resolve_class_ref (jclass, jclass *);
271 static void wait_for_state(jclass, int);
272 static _Jv_word resolve_pool_entry (jclass, int);
273 static void resolve_field (_Jv_Field *, java::lang::ClassLoader *);
274 static void verify_type_assertions (jclass);
277 /* Type of pointer used as finalizer. */
278 typedef void _Jv_FinalizerFunc (jobject);
280 /* Allocate space for a new Java object. */
281 void *_Jv_AllocObj (jsize size, jclass cl) __attribute__((__malloc__));
282 /* Allocate space for a potentially uninitialized pointer-free object.
283 Interesting only with JV_HASH_SYNCHRONIZATION. */
284 void *_Jv_AllocPtrFreeObj (jsize size, jclass cl) __attribute__((__malloc__));
285 /* Allocate space for an array of Java objects. */
286 void *_Jv_AllocArray (jsize size, jclass cl) __attribute__((__malloc__));
287 /* Allocate space that is known to be pointer-free. */
288 void *_Jv_AllocBytes (jsize size) __attribute__((__malloc__));
289 /* Allocate space for a new non-Java object, which does not have the usual
290 Java object header but may contain pointers to other GC'ed objects. */
291 void *_Jv_AllocRawObj (jsize size) __attribute__((__malloc__));
292 /* Explicitly throw an out-of-memory exception. */
293 void _Jv_ThrowNoMemory() __attribute__((__noreturn__));
294 /* Allocate an object with a single pointer. The first word is reserved
295 for the GC, and the second word is the traced pointer. */
296 void *_Jv_AllocTraceOne (jsize size /* incl. reserved slot */);
297 /* Ditto, but for two traced pointers. */
298 void *_Jv_AllocTraceTwo (jsize size /* incl. reserved slot */);
299 /* Initialize the GC. */
300 void _Jv_InitGC (void);
301 /* Register a finalizer. */
302 void _Jv_RegisterFinalizer (void *object, _Jv_FinalizerFunc *method);
303 /* Compute the GC descriptor for a class */
304 void * _Jv_BuildGCDescr(jclass);
306 /* Allocate some unscanned, unmoveable memory. Return NULL if out of
308 void *_Jv_MallocUnchecked (jsize size) __attribute__((__malloc__));
310 /* Initialize finalizers. The argument is a function to be called
311 when a finalizer is ready to be run. */
312 void _Jv_GCInitializeFinalizers (void (*notifier) (void));
313 /* Run finalizers for objects ready to be finalized.. */
314 void _Jv_RunFinalizers (void);
315 /* Run all finalizers. Should be called only before exit. */
316 void _Jv_RunAllFinalizers (void);
318 void _Jv_RunGC (void);
319 /* Disable and enable GC. */
320 void _Jv_DisableGC (void);
321 void _Jv_EnableGC (void);
322 /* Register a disappearing link. This is a field F which should be
323 cleared when *F is found to be inaccessible. This is used in the
324 implementation of java.lang.ref.Reference. */
325 void _Jv_GCRegisterDisappearingLink (jobject *objp);
326 /* Return true if OBJECT should be reclaimed. This is used to
327 implement soft references. */
328 jboolean _Jv_GCCanReclaimSoftReference (jobject obj);
330 /* Register a finalizer for a String object. This is only used by
331 the intern() implementation. */
332 void _Jv_RegisterStringFinalizer (jobject str);
333 /* This is called to actually finalize a possibly-intern()d String. */
334 void _Jv_FinalizeString (jobject str);
336 /* Return approximation of total size of heap. */
337 long _Jv_GCTotalMemory (void);
338 /* Return approximation of total free memory. */
339 long _Jv_GCFreeMemory (void);
341 /* Set initial heap size. If SIZE==0, ignore. Should be run before
342 _Jv_InitGC. Not required to have any actual effect. */
343 void _Jv_GCSetInitialHeapSize (size_t size);
345 /* Set maximum heap size. If SIZE==0, unbounded. Should be run
346 before _Jv_InitGC. Not required to have any actual effect. */
347 void _Jv_GCSetMaximumHeapSize (size_t size);
349 /* External interface to setting the heap size. Parses ARG (a number
350 which can optionally have "k" or "m" appended and calls
351 _Jv_GCSetInitialHeapSize. */
352 void _Jv_SetInitialHeapSize (const char *arg);
354 /* External interface to setting the maximum heap size. Parses ARG (a
355 number which can optionally have "k" or "m" appended and calls
356 _Jv_GCSetMaximumHeapSize. */
357 void _Jv_SetMaximumHeapSize (const char *arg);
359 extern "C" void JvRunMain (jclass klass, int argc, const char **argv);
360 void _Jv_RunMain (jclass klass, const char *name, int argc, const char **argv,
363 void _Jv_RunMain (struct _Jv_VMInitArgs *vm_args, jclass klass,
364 const char *name, int argc, const char **argv, bool is_jar);
366 // Delayed until after _Jv_AllocBytes is declared.
368 // Note that we allocate this as unscanned memory -- the vtables
369 // are handled specially by the GC.
372 _Jv_VTable::new_vtable (int count)
374 size_t size = sizeof(_Jv_VTable) + (count - 1) * vtable_elt_size ();
375 return (_Jv_VTable *) _Jv_AllocBytes (size);
378 // Determine if METH gets an entry in a VTable.
379 static inline jboolean _Jv_isVirtualMethod (_Jv_Method *meth)
381 using namespace java::lang::reflect;
382 return (((meth->accflags & (Modifier::STATIC | Modifier::PRIVATE)) == 0)
383 && meth->name->first() != '<');
386 // This function is used to determine the hash code of an object.
388 _Jv_HashCode (jobject obj)
390 // This was chosen to yield relatively well distributed results on
391 // both 32- and 64-bit architectures. Note 0x7fffffff is prime.
392 // FIXME: we assume sizeof(long) == sizeof(void *).
393 return (jint) ((unsigned long) obj % 0x7fffffff);
396 // Return a raw pointer to the elements of an array given the array
397 // and its element type. You might think we could just pick a single
398 // array type and use elements() on it, but we can't because we must
399 // account for alignment of the element type. When ARRAY is null, we
400 // obtain the number of bytes taken by the base part of the array.
402 _Jv_GetArrayElementFromElementType (jobject array,
406 if (element_type == JvPrimClass (byte))
407 elts = (char *) elements ((jbyteArray) array);
408 else if (element_type == JvPrimClass (short))
409 elts = (char *) elements ((jshortArray) array);
410 else if (element_type == JvPrimClass (int))
411 elts = (char *) elements ((jintArray) array);
412 else if (element_type == JvPrimClass (long))
413 elts = (char *) elements ((jlongArray) array);
414 else if (element_type == JvPrimClass (boolean))
415 elts = (char *) elements ((jbooleanArray) array);
416 else if (element_type == JvPrimClass (char))
417 elts = (char *) elements ((jcharArray) array);
418 else if (element_type == JvPrimClass (float))
419 elts = (char *) elements ((jfloatArray) array);
420 else if (element_type == JvPrimClass (double))
421 elts = (char *) elements ((jdoubleArray) array);
423 elts = (char *) elements ((jobjectArray) array);
427 extern "C" void _Jv_ThrowBadArrayIndex (jint bad_index)
428 __attribute__((noreturn));
429 extern "C" void _Jv_ThrowNullPointerException (void)
430 __attribute__((noreturn));
431 extern "C" jobject _Jv_NewArray (jint type, jint size)
432 __attribute__((__malloc__));
433 extern "C" jobject _Jv_NewMultiArray (jclass klass, jint dims, ...)
434 __attribute__((__malloc__));
435 extern "C" void *_Jv_CheckCast (jclass klass, jobject obj);
436 extern "C" void *_Jv_LookupInterfaceMethod (jclass klass, Utf8Const *name,
437 Utf8Const *signature);
438 extern "C" void *_Jv_LookupInterfaceMethodIdx (jclass klass, jclass iface,
440 extern "C" void _Jv_CheckArrayStore (jobject array, jobject obj);
441 extern "C" void _Jv_RegisterClass (jclass klass);
442 extern "C" void _Jv_RegisterClasses (const jclass *classes);
443 extern "C" void _Jv_RegisterClasses_Counted (const jclass *classes,
445 extern "C" void _Jv_RegisterResource (void *vptr);
446 extern void _Jv_UnregisterClass (_Jv_Utf8Const*, java::lang::ClassLoader*);
448 extern jclass _Jv_FindClass (_Jv_Utf8Const *name,
449 java::lang::ClassLoader *loader);
450 extern jclass _Jv_FindClassFromSignature (char *,
451 java::lang::ClassLoader *loader);
452 extern void _Jv_GetTypesFromSignature (jmethodID method,
453 jclass declaringClass,
454 JArray<jclass> **arg_types_out,
455 jclass *return_type_out);
457 extern jboolean _Jv_CheckAccess (jclass self_klass, jclass other_klass,
460 extern jobject _Jv_CallAnyMethodA (jobject obj, jclass return_type,
461 jmethodID meth, jboolean is_constructor,
462 JArray<jclass> *parameter_types,
464 jclass iface = NULL);
467 extern void _Jv_CallAnyMethodA (jobject obj,
470 jboolean is_constructor,
471 jboolean is_virtual_call,
472 JArray<jclass> *parameter_types,
475 jboolean is_jni_call = true,
476 jclass iface = NULL);
478 extern jobject _Jv_NewMultiArray (jclass, jint ndims, jint* dims)
479 __attribute__((__malloc__));
481 /* Checked divide subroutines. */
484 jint _Jv_divI (jint, jint);
485 jint _Jv_remI (jint, jint);
486 jlong _Jv_divJ (jlong, jlong);
487 jlong _Jv_remJ (jlong, jlong);
490 /* Get the number of arguments (cf. argc) or 0 if our argument
491 list was never initialized. */
492 extern int _Jv_GetNbArgs (void);
494 /* Get the specified argument (cf. argv[index]) or "" if either
495 our argument list was never initialized or the specified index
497 extern const char * _Jv_GetSafeArg (int index);
499 /* Sets our argument list. Can be used by programs with non-standard
501 extern void _Jv_SetArgs (int argc, const char **argv);
503 /* Get the name of the running executable. */
504 extern const char *_Jv_ThisExecutable (void);
506 /* Return a pointer to a symbol in executable or loaded library. */
507 void *_Jv_FindSymbolInExecutable (const char *);
509 /* Initialize JNI. */
510 extern void _Jv_JNI_Init (void);
512 /* Get or set the per-thread JNIEnv used by the invocation API. */
513 _Jv_JNIEnv *_Jv_GetCurrentJNIEnv ();
514 void _Jv_SetCurrentJNIEnv (_Jv_JNIEnv *);
517 void _Jv_FreeJNIEnv (_Jv_JNIEnv *);
520 void _Jv_FreeJNIEnv (_Jv_JNIEnv *);
523 _Jv_JavaVM *_Jv_GetJavaVM ();
525 // Some verification functions from defineclass.cc.
526 bool _Jv_VerifyFieldSignature (_Jv_Utf8Const*sig);
527 bool _Jv_VerifyMethodSignature (_Jv_Utf8Const*sig);
528 bool _Jv_VerifyClassName (unsigned char* ptr, _Jv_ushort length);
529 bool _Jv_VerifyClassName (_Jv_Utf8Const *name);
530 bool _Jv_VerifyIdentifier (_Jv_Utf8Const *);
531 bool _Jv_ClassNameSamePackage (_Jv_Utf8Const *name1, _Jv_Utf8Const *name2);
533 struct _Jv_core_chain
540 struct _Jv_core_chain *next;
543 // This is called when new core data is loaded.
544 extern void (*_Jv_RegisterCoreHook) (_Jv_core_chain *);
546 _Jv_core_chain *_Jv_FindCore (_Jv_core_chain *node, jstring name);
547 void _Jv_FreeCoreChain (_Jv_core_chain *chain);
553 extern void (*_Jv_JVMPI_Notify_OBJECT_ALLOC) (JVMPI_Event *event);
554 extern void (*_Jv_JVMPI_Notify_THREAD_START) (JVMPI_Event *event);
555 extern void (*_Jv_JVMPI_Notify_THREAD_END) (JVMPI_Event *event);
558 /* FIXME: this should really be defined in some more generic place */
559 #define ROUND(V, A) (((((unsigned) (V))-1) | ((A)-1))+1)
561 extern void _Jv_RegisterBootstrapPackages ();
564 // This is used to find ABI versions we recognize.
565 #define GCJ_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 10)
566 #define GCJ_BINARYCOMPAT_ADDITION 5
568 // At present we know we are compatible with the BC ABI as used in GCC
570 #define GCJ_40_BC_ABI_VERSION (4 * 10000 + 0 * 10 + GCJ_BINARYCOMPAT_ADDITION)
573 _Jv_CheckABIVersion (unsigned long value)
575 // Recognize our defined C++ ABI.
576 return (value == GCJ_VERSION
577 // At the moment this is the only BC ABI we recognize.
578 || value == GCJ_40_BC_ABI_VERSION);
581 // It makes the source cleaner if we simply always define this
582 // function. If the interpreter is not built, it will never return
584 extern inline jboolean
585 _Jv_IsInterpretedClass (jclass c)
587 return (c->accflags & java::lang::reflect::Modifier::INTERPRETED) != 0;
590 #endif /* __JAVA_JVM_H__ */