1 // stacktrace.cc - Functions for unwinding & inspecting the call stack.
3 /* Copyright (C) 2005, 2006 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
16 #include <java-interp.h>
17 #include <java-stack.h>
21 #include <java/lang/Class.h>
22 #include <java/lang/Long.h>
23 #include <java/security/AccessController.h>
24 #include <java/util/ArrayList.h>
25 #include <java/util/IdentityHashMap.h>
26 #include <gnu/java/lang/MainThread.h>
27 #include <gnu/gcj/runtime/NameFinder.h>
28 #include <gnu/gcj/runtime/StringBuffer.h>
30 #include <sysdep/backtrace.h>
31 #include <sysdep/descriptor.h>
33 using namespace java::lang;
34 using namespace java::lang::reflect;
35 using namespace java::util;
36 using namespace gnu::gcj::runtime;
38 // Maps ncode values to their containing native class.
39 // NOTE: Currently this Map contradicts class GC for native classes. This map
40 // (and the "new class stack") will need to use WeakReferences in order to
41 // enable native class GC.
42 static java::util::IdentityHashMap *ncodeMap;
44 // Check the "class stack" for any classes initialized since we were last
45 // called, and add them to ncodeMap.
47 _Jv_StackTrace::UpdateNCodeMap ()
49 // The Map should be large enough so that a typical Java app doesn't cause
50 // it to rehash, without using too much memory. ~5000 entries should be
53 ncodeMap = new java::util::IdentityHashMap (5087);
56 while ((klass = _Jv_PopClass ()))
57 if (!_Jv_IsInterpretedClass (klass))
59 //printf ("got %s\n", klass->name->data);
60 for (int i = 0; i < klass->method_count; i++)
62 _Jv_Method *method = &klass->methods[i];
63 void *ncode = method->ncode;
64 // Add non-abstract methods to ncodeMap.
67 ncode = UNWRAP_FUNCTION_DESCRIPTOR (ncode);
68 ncodeMap->put ((java::lang::Object *) ncode, klass);
74 // Given a native frame, return the class which this code belongs
75 // to. Returns NULL if this IP is not associated with a native Java class.
76 // If NCODE is supplied, it will be set with the ip for the entry point of the
79 _Jv_StackTrace::ClassForFrame (_Jv_StackFrame *frame)
81 JvAssert (frame->type == frame_native);
84 // look it up in ncodeMap
86 klass = (jclass) ncodeMap->get ((jobject) frame->start_ip);
92 _Jv_StackTrace::UnwindTraceFn (struct _Unwind_Context *context, void *state_ptr)
94 _Jv_UnwindState *state = (_Jv_UnwindState *) state_ptr;
95 jint pos = state->pos;
97 // Check if the trace buffer needs to be extended.
98 if (pos == state->length)
100 int newLength = state->length * 2;
101 void *newFrames = _Jv_AllocBytes (newLength * sizeof(_Jv_StackFrame));
102 memcpy (newFrames, state->frames, state->length * sizeof(_Jv_StackFrame));
103 state->frames = (_Jv_StackFrame *) newFrames;
104 state->length = newLength;
107 void *func_addr = (void *) _Unwind_GetRegionStart (context);
109 // If we see the interpreter's main function, "pop" an entry off the
110 // interpreter stack and use that instead, so that the trace goes through
111 // the java code and not the interpreter itself. This assumes a 1:1
112 // correspondance between call frames in the interpreted stack and occurances
113 // of _Jv_InterpMethod::run() on the native stack.
115 void *interp_run = (void *) &_Jv_InterpMethod::run;
116 if (func_addr == UNWRAP_FUNCTION_DESCRIPTOR (interp_run))
118 state->frames[pos].type = frame_interpreter;
119 state->frames[pos].interp.meth = state->interp_frame->self;
120 state->frames[pos].interp.pc = state->interp_frame->pc;
121 state->interp_frame = state->interp_frame->next;
127 int ip_before_insn = 0;
128 ip = _Unwind_GetIPInfo (context, &ip_before_insn);
130 // If the unwinder gave us a 'return' address, roll it back a little
131 // to ensure we get the correct line number for the call itself.
132 if (! ip_before_insn)
135 state->frames[pos].type = frame_native;
136 state->frames[pos].ip = (void *) ip;
137 state->frames[pos].start_ip = func_addr;
140 _Unwind_Reason_Code result = _URC_NO_REASON;
141 if (state->trace_function != NULL)
142 result = (state->trace_function) (state);
147 // Return a raw stack trace from the current point of execution. The raw
148 // trace will include all functions that have unwind info.
150 _Jv_StackTrace::GetStackTrace(void)
152 int trace_size = 100;
153 _Jv_StackFrame frames[trace_size];
154 _Jv_UnwindState state (trace_size);
155 state.frames = (_Jv_StackFrame *) &frames;
157 _Unwind_Backtrace (UnwindTraceFn, &state);
159 // Copy the trace and return it.
160 int traceSize = sizeof (_Jv_StackTrace) +
161 (sizeof (_Jv_StackFrame) * state.pos);
162 _Jv_StackTrace *trace = (_Jv_StackTrace *) _Jv_AllocBytes (traceSize);
163 trace->length = state.pos;
164 memcpy (trace->frames, state.frames, sizeof (_Jv_StackFrame) * state.pos);
169 _Jv_StackTrace::getLineNumberForFrame(_Jv_StackFrame *frame, NameFinder *finder,
170 jstring *sourceFileName, jint *lineNum,
174 if (frame->type == frame_interpreter)
176 _Jv_InterpMethod *interp_meth = frame->interp.meth;
177 _Jv_InterpClass *interp_class =
178 (_Jv_InterpClass *) interp_meth->defining_class->aux_info;
179 *sourceFileName = interp_class->source_file_name;
180 // The interpreter advances the PC before executing an instruction,
181 // so roll-back 1 byte to ensure the line number is accurate.
182 *lineNum = interp_meth->get_source_line(frame->interp.pc - 1);
187 // Use _Jv_platform_dladdr() to determine in which binary the address IP
190 jstring binaryName = NULL;
191 const char *argv0 = _Jv_GetSafeArg(0);
193 void *ip = frame->ip;
194 _Unwind_Ptr offset = 0;
196 if (_Jv_platform_dladdr (ip, &info))
199 binaryName = JvNewStringUTF (info.file_name);
203 if (*methodName == NULL && info.sym_name)
204 *methodName = JvNewStringUTF (info.sym_name);
206 // addr2line expects relative addresses for shared libraries.
207 if (strcmp (info.file_name, argv0) == 0)
208 offset = (_Unwind_Ptr) ip;
210 offset = (_Unwind_Ptr) ip - (_Unwind_Ptr) info.base;
212 finder->lookup (binaryName, (jlong) offset);
213 *sourceFileName = finder->getSourceFile();
214 *lineNum = finder->getLineNum();
215 if (*lineNum == -1 && NameFinder::showRaw())
217 gnu::gcj::runtime::StringBuffer *t =
218 new gnu::gcj::runtime::StringBuffer(binaryName);
219 t->append ((jchar)' ');
220 t->append ((jchar)'[');
221 // + 1 to compensate for the - 1 adjustment above;
222 t->append (Long::toHexString (offset + 1));
223 t->append ((jchar)']');
224 *sourceFileName = t->toString();
229 // Look up class and method info for the given stack frame, setting
230 // frame->klass and frame->meth if they are known.
232 _Jv_StackTrace::FillInFrameInfo (_Jv_StackFrame *frame)
235 _Jv_Method *meth = NULL;
237 if (frame->type == frame_native)
239 klass = _Jv_StackTrace::ClassForFrame (frame);
242 // Find method in class
243 for (int j = 0; j < klass->method_count; j++)
245 void *wncode = UNWRAP_FUNCTION_DESCRIPTOR (klass->methods[j].ncode);
246 if (wncode == frame->start_ip)
248 meth = &klass->methods[j];
254 else if (frame->type == frame_interpreter)
256 _Jv_InterpMethod *interp_meth = frame->interp.meth;
257 klass = interp_meth->defining_class;
258 meth = interp_meth->self;
262 JvFail ("Unknown frame type");
264 frame->klass = klass;
268 // Convert raw stack frames to a Java array of StackTraceElement objects.
269 JArray< ::java::lang::StackTraceElement *>*
270 _Jv_StackTrace::GetStackTraceElements (_Jv_StackTrace *trace,
271 Throwable *throwable __attribute__((unused)))
273 ArrayList *list = new ArrayList ();
275 #if defined (SJLJ_EXCEPTIONS) && ! defined (WIN32)
276 // We can't use the nCodeMap without unwinder support. Instead,
277 // fake the method name by giving the IP in hex - better than nothing.
278 jstring hex = JvNewStringUTF ("0x");
280 for (int i = 0; i < trace->length; i++)
282 jstring sourceFileName = NULL;
284 _Jv_StackFrame *frame = &trace->frames[i];
286 jstring className = NULL;
287 jstring methodName = hex->concat (Long::toHexString ((jlong) frame->ip));
289 StackTraceElement *element = new StackTraceElement (sourceFileName,
290 lineNum, className, methodName, 0);
294 #else /* SJLJ_EXCEPTIONS && !WIN32 */
296 //JvSynchronized (ncodeMap);
299 NameFinder *finder = new NameFinder();
301 int end_idx = trace->length - 1;
303 // First pass: strip superfluous frames from beginning and end of the trace.
304 for (int i = 0; i < trace->length; i++)
306 _Jv_StackFrame *frame = &trace->frames[i];
307 FillInFrameInfo (frame);
309 if (!frame->klass || !frame->meth)
313 // Throw away the top of the stack till we see:
314 // - the constructor(s) of this Throwable, or
315 // - the Throwable.fillInStackTrace call.
316 if (frame->klass == throwable->getClass()
317 && strcmp (frame->meth->name->chars(), "<init>") == 0)
320 if (frame->klass == &Throwable::class$
321 && strcmp (frame->meth->name->chars(), "fillInStackTrace") == 0)
324 // End the trace at the application's main() method if we see call_main.
325 if (frame->klass == &gnu::java::lang::MainThread::class$
326 && strcmp (frame->meth->name->chars(), "call_main") == 0)
330 const jboolean remove_unknown
331 = gnu::gcj::runtime::NameFinder::removeUnknown();
333 // Second pass: Look up line-number info for remaining frames.
334 for (int i = start_idx; i <= end_idx; i++)
336 _Jv_StackFrame *frame = &trace->frames[i];
338 if (frame->klass == NULL && remove_unknown)
342 jstring className = NULL;
343 if (frame->klass != NULL)
344 className = frame->klass->getName ();
346 jstring methodName = NULL;
348 methodName = JvNewStringUTF (frame->meth->name->chars());
350 jstring sourceFileName = NULL;
353 getLineNumberForFrame(frame, finder, &sourceFileName, &lineNum,
356 StackTraceElement *element = new StackTraceElement (sourceFileName, lineNum,
357 className, methodName, 0);
362 #endif /* SJLJ_EXCEPTIONS && !WIN32 */
364 JArray<Object *> *array = JvNewObjectArray (list->size (),
365 &StackTraceElement::class$, NULL);
367 return (JArray<StackTraceElement *>*) list->toArray (array);
370 struct CallingClassTraceData
374 _Jv_Method *foundMeth;
375 bool seen_checkClass;
379 _Jv_StackTrace::calling_class_trace_fn (_Jv_UnwindState *state)
381 CallingClassTraceData *trace_data = (CallingClassTraceData *)
383 _Jv_StackFrame *frame = &state->frames[state->pos];
384 FillInFrameInfo (frame);
386 if (trace_data->seen_checkClass
388 && frame->klass != trace_data->checkClass)
390 trace_data->foundClass = frame->klass;
391 trace_data->foundMeth = frame->meth;
392 return _URC_NORMAL_STOP;
395 if (frame->klass == trace_data->checkClass)
396 trace_data->seen_checkClass = true;
398 return _URC_NO_REASON;
401 // Find the class immediately above the given class on the call stack. Any
402 // intermediate non-Java
403 // frames are ignored. If the calling class could not be determined (eg because
404 // the unwinder is not supported on this platform), NULL is returned.
405 // This function is used to implement calling-classloader checks and reflection
406 // accessibility checks.
407 // CHECKCLASS is typically the class calling GetCallingClass. The first class
408 // above CHECKCLASS on the call stack will be returned.
410 _Jv_StackTrace::GetCallingClass (jclass checkClass)
412 jclass result = NULL;
413 GetCallerInfo (checkClass, &result, NULL);
418 _Jv_StackTrace::GetCallerInfo (jclass checkClass, jclass *caller_class,
419 _Jv_Method **caller_meth)
422 _Jv_StackFrame frames[trace_size];
423 _Jv_UnwindState state (trace_size);
424 state.frames = (_Jv_StackFrame *) &frames;
426 CallingClassTraceData trace_data;
427 trace_data.checkClass = checkClass;
428 trace_data.seen_checkClass = false;
429 trace_data.foundClass = NULL;
430 trace_data.foundMeth = NULL;
432 state.trace_function = calling_class_trace_fn;
433 state.trace_data = (void *) &trace_data;
435 //JvSynchronized (ncodeMap);
438 _Unwind_Backtrace (UnwindTraceFn, &state);
441 *caller_class = trace_data.foundClass;
443 *caller_meth = trace_data.foundMeth;
446 // Return a java array containing the Java classes on the stack above CHECKCLASS.
448 _Jv_StackTrace::GetClassContext (jclass checkClass)
450 JArray<jclass> *result = NULL;
452 int trace_size = 100;
453 _Jv_StackFrame frames[trace_size];
454 _Jv_UnwindState state (trace_size);
455 state.frames = (_Jv_StackFrame *) &frames;
457 //JvSynchronized (ncodeMap);
460 _Unwind_Backtrace (UnwindTraceFn, &state);
462 // Count the number of Java frames on the stack.
463 int jframe_count = 0;
464 bool seen_checkClass = false;
466 for (int i = 0; i < state.pos; i++)
468 _Jv_StackFrame *frame = &state.frames[i];
469 FillInFrameInfo (frame);
481 seen_checkClass = frame->klass == checkClass;
483 result = (JArray<jclass> *) _Jv_NewObjectArray (jframe_count, &Class::class$, NULL);
486 for (int i = start_pos; i < state.pos; i++)
488 _Jv_StackFrame *frame = &state.frames[i];
490 elements(result)[pos++] = frame->klass;
496 _Jv_StackTrace::non_system_trace_fn (_Jv_UnwindState *state)
498 _Jv_StackFrame *frame = &state->frames[state->pos];
499 FillInFrameInfo (frame);
501 ClassLoader *classLoader = NULL;
505 classLoader = frame->klass->getClassLoaderInternal();
507 if (classLoader != NULL)
509 state->trace_data = (void *) classLoader;
510 return _URC_NORMAL_STOP;
515 return _URC_NO_REASON;
519 _Jv_StackTrace::GetFirstNonSystemClassLoader ()
522 _Jv_StackFrame frames[trace_size];
523 _Jv_UnwindState state (trace_size);
524 state.frames = (_Jv_StackFrame *) &frames;
525 state.trace_function = non_system_trace_fn;
526 state.trace_data = NULL;
528 //JvSynchronized (ncodeMap);
531 _Unwind_Backtrace (UnwindTraceFn, &state);
533 if (state.trace_data)
534 return (ClassLoader *) state.trace_data;
540 _Jv_StackTrace::accesscontrol_trace_fn (_Jv_UnwindState *state)
542 _Jv_StackFrame *frame = &state->frames[state->pos];
543 FillInFrameInfo (frame);
545 bool *stopping = (bool *) state->trace_data;
547 return _URC_NORMAL_STOP;
549 if (frame->klass == &::java::security::AccessController::class$
551 && strcmp (frame->meth->name->chars(), "doPrivileged") == 0)
554 return _URC_NO_REASON;
557 JArray<jobjectArray> *
558 _Jv_StackTrace::GetAccessControlStack (void)
560 int trace_size = 100;
561 _Jv_StackFrame frames[trace_size];
562 _Jv_UnwindState state (trace_size);
563 state.frames = (_Jv_StackFrame *) &frames;
564 state.trace_function = accesscontrol_trace_fn;
565 bool stopping = false;
566 state.trace_data = (void *) &stopping;
569 _Unwind_Backtrace (UnwindTraceFn, &state);
573 for (int i = 0; i < state.pos; i++)
575 _Jv_StackFrame *frame = &state.frames[i];
577 if (frame->klass && frame->meth)
581 jclass array_class = _Jv_GetArrayClass (&::java::lang::Object::class$, NULL);
582 JArray<jobjectArray> *result =
583 (JArray<jobjectArray> *) _Jv_NewObjectArray (2, array_class, NULL);
584 JArray<jclass> *classes = (JArray<jclass> *)
585 _Jv_NewObjectArray (length, &::java::lang::Class::class$, NULL);
586 JArray<jstring> *methods = (JArray<jstring> *)
587 _Jv_NewObjectArray (length, &::java::lang::String::class$, NULL);
588 jclass *c = elements (classes);
589 jstring *m = elements (methods);
591 for (int i = 0, j = 0; i < state.pos; i++)
593 _Jv_StackFrame *frame = &state.frames[i];
594 if (!frame->klass || !frame->meth)
597 m[j] = JvNewStringUTF (frame->meth->name->chars());
601 jobjectArray *elems = elements (result);
602 elems[0] = (jobjectArray) classes;
603 elems[1] = (jobjectArray) methods;