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/util/ArrayList.h>
24 #include <java/util/IdentityHashMap.h>
25 #include <gnu/java/lang/MainThread.h>
26 #include <gnu/gcj/runtime/NameFinder.h>
27 #include <gnu/gcj/runtime/StringBuffer.h>
29 #include <sysdep/backtrace.h>
30 #include <sysdep/descriptor.h>
32 using namespace java::lang;
33 using namespace java::lang::reflect;
34 using namespace java::util;
35 using namespace gnu::gcj::runtime;
37 // Maps ncode values to their containing native class.
38 // NOTE: Currently this Map contradicts class GC for native classes. This map
39 // (and the "new class stack") will need to use WeakReferences in order to
40 // enable native class GC.
41 static java::util::IdentityHashMap *ncodeMap;
43 // Check the "class stack" for any classes initialized since we were last
44 // called, and add them to ncodeMap.
46 _Jv_StackTrace::UpdateNCodeMap ()
48 // The Map should be large enough so that a typical Java app doesn't cause
49 // it to rehash, without using too much memory. ~5000 entries should be
52 ncodeMap = new java::util::IdentityHashMap (5087);
55 while ((klass = _Jv_PopClass ()))
56 if (!_Jv_IsInterpretedClass (klass))
58 //printf ("got %s\n", klass->name->data);
59 for (int i = 0; i < klass->method_count; i++)
61 _Jv_Method *method = &klass->methods[i];
62 void *ncode = method->ncode;
63 // Add non-abstract methods to ncodeMap.
66 ncode = UNWRAP_FUNCTION_DESCRIPTOR (ncode);
67 ncodeMap->put ((java::lang::Object *) ncode, klass);
73 // Given a native frame, return the class which this code belongs
74 // to. Returns NULL if this IP is not associated with a native Java class.
75 // If NCODE is supplied, it will be set with the ip for the entry point of the
78 _Jv_StackTrace::ClassForFrame (_Jv_StackFrame *frame)
80 JvAssert (frame->type == frame_native);
82 // use _Unwind_FindEnclosingFunction to find start of method
83 //void *entryPoint = _Unwind_FindEnclosingFunction (ip);
85 // look it up in ncodeMap
87 klass = (jclass) ncodeMap->get ((jobject) frame->start_ip);
93 _Jv_StackTrace::UnwindTraceFn (struct _Unwind_Context *context, void *state_ptr)
95 _Jv_UnwindState *state = (_Jv_UnwindState *) state_ptr;
96 jint pos = state->pos;
98 // Check if the trace buffer needs to be extended.
99 if (pos == state->length)
101 int newLength = state->length * 2;
102 void *newFrames = _Jv_AllocBytes (newLength * sizeof(_Jv_StackFrame));
103 memcpy (newFrames, state->frames, state->length * sizeof(_Jv_StackFrame));
104 state->frames = (_Jv_StackFrame *) newFrames;
105 state->length = newLength;
108 void *func_addr = (void *) _Unwind_GetRegionStart (context);
110 // If we see the interpreter's main function, "pop" an entry off the
111 // interpreter stack and use that instead, so that the trace goes through
112 // the java code and not the interpreter itself. This assumes a 1:1
113 // correspondance between call frames in the interpreted stack and occurances
114 // of _Jv_InterpMethod::run() on the native stack.
116 void *interp_run = (void *) &_Jv_InterpMethod::run;
117 if (func_addr == UNWRAP_FUNCTION_DESCRIPTOR (interp_run))
119 state->frames[pos].type = frame_interpreter;
120 state->frames[pos].interp.meth = state->interp_frame->self;
121 state->frames[pos].interp.pc = state->interp_frame->pc;
122 state->interp_frame = state->interp_frame->next;
127 state->frames[pos].type = frame_native;
128 state->frames[pos].ip = (void *) _Unwind_GetIP (context);
129 state->frames[pos].start_ip = func_addr;
132 //printf ("unwind ip: %p\n", _Unwind_GetIP (context));
134 _Unwind_Reason_Code result = _URC_NO_REASON;
135 if (state->trace_function != NULL)
136 result = (state->trace_function) (state);
141 // Return a raw stack trace from the current point of execution. The raw
142 // trace will include all functions that have unwind info.
144 _Jv_StackTrace::GetStackTrace(void)
146 int trace_size = 100;
147 _Jv_StackFrame frames[trace_size];
148 _Jv_UnwindState state (trace_size);
149 state.frames = (_Jv_StackFrame *) &frames;
151 #ifdef SJLJ_EXCEPTIONS
152 // The Unwind interface doesn't work with the SJLJ exception model.
153 // Fall back to a platform-specific unwinder.
154 fallback_backtrace (&state);
155 #else /* SJLJ_EXCEPTIONS */
156 _Unwind_Backtrace (UnwindTraceFn, &state);
157 #endif /* SJLJ_EXCEPTIONS */
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 *lineNum = interp_meth->get_source_line(frame->interp.pc);
185 // Use _Jv_platform_dladdr() to determine in which binary the address IP
188 jstring binaryName = NULL;
189 const char *argv0 = _Jv_GetSafeArg(0);
191 void *ip = frame->ip;
192 _Unwind_Ptr offset = 0;
194 if (_Jv_platform_dladdr (ip, &info))
197 binaryName = JvNewStringUTF (info.file_name);
201 if (*methodName == NULL && info.sym_name)
202 *methodName = JvNewStringUTF (info.sym_name);
204 // addr2line expects relative addresses for shared libraries.
205 if (strcmp (info.file_name, argv0) == 0)
206 offset = (_Unwind_Ptr) ip;
208 offset = (_Unwind_Ptr) ip - (_Unwind_Ptr) info.base;
210 // The unwinder gives us the return address. In order to get the right
211 // line number for the stack trace, roll it back a little.
214 finder->lookup (binaryName, (jlong) offset);
215 *sourceFileName = finder->getSourceFile();
216 *lineNum = finder->getLineNum();
217 if (*lineNum == -1 && NameFinder::showRaw())
219 gnu::gcj::runtime::StringBuffer *t =
220 new gnu::gcj::runtime::StringBuffer(binaryName);
221 t->append ((jchar)' ');
222 t->append ((jchar)'[');
223 // + 1 to compensate for the - 1 adjustment above;
224 t->append (Long::toHexString (offset + 1));
225 t->append ((jchar)']');
226 *sourceFileName = t->toString();
231 // Look up class and method info for the given stack frame, setting
232 // frame->klass and frame->meth if they are known.
234 _Jv_StackTrace::FillInFrameInfo (_Jv_StackFrame *frame)
237 _Jv_Method *meth = NULL;
239 if (frame->type == frame_native)
241 klass = _Jv_StackTrace::ClassForFrame (frame);
244 // Find method in class
245 for (int j = 0; j < klass->method_count; j++)
247 void *wncode = UNWRAP_FUNCTION_DESCRIPTOR (klass->methods[j].ncode);
248 if (wncode == frame->start_ip)
250 meth = &klass->methods[j];
256 else if (frame->type == frame_interpreter)
258 _Jv_InterpMethod *interp_meth = frame->interp.meth;
259 klass = interp_meth->defining_class;
260 meth = interp_meth->self;
264 JvFail ("Unknown frame type");
266 frame->klass = klass;
270 // Convert raw stack frames to a Java array of StackTraceElement objects.
271 JArray< ::java::lang::StackTraceElement *>*
272 _Jv_StackTrace::GetStackTraceElements (_Jv_StackTrace *trace,
273 Throwable *throwable __attribute__((unused)))
275 ArrayList *list = new ArrayList ();
277 #if defined (SJLJ_EXCEPTIONS) && ! defined (WIN32)
278 // We can't use the nCodeMap without unwinder support. Instead,
279 // fake the method name by giving the IP in hex - better than nothing.
280 jstring hex = JvNewStringUTF ("0x");
282 for (int i = 0; i < trace->length; i++)
284 jstring sourceFileName = NULL;
286 _Jv_StackFrame *frame = &trace->frames[i];
288 jstring className = NULL;
289 jstring methodName = hex->concat (Long::toHexString ((jlong) frame->ip));
291 StackTraceElement *element = new StackTraceElement (sourceFileName,
292 lineNum, className, methodName, 0);
296 #else /* SJLJ_EXCEPTIONS && !WIN32 */
298 //JvSynchronized (ncodeMap);
301 NameFinder *finder = new NameFinder();
303 int end_idx = trace->length - 1;
305 // First pass: strip superfluous frames from beginning and end of the trace.
306 for (int i = 0; i < trace->length; i++)
308 _Jv_StackFrame *frame = &trace->frames[i];
309 FillInFrameInfo (frame);
311 if (!frame->klass || !frame->meth)
315 // Throw away the top of the stack till we see:
316 // - the constructor(s) of this Throwable, or
317 // - the Throwable.fillInStackTrace call.
318 if (frame->klass == throwable->getClass()
319 && strcmp (frame->meth->name->chars(), "<init>") == 0)
322 if (frame->klass == &Throwable::class$
323 && strcmp (frame->meth->name->chars(), "fillInStackTrace") == 0)
326 // End the trace at the application's main() method if we see call_main.
327 if (frame->klass == &gnu::java::lang::MainThread::class$
328 && strcmp (frame->meth->name->chars(), "call_main") == 0)
332 const jboolean remove_unknown
333 = gnu::gcj::runtime::NameFinder::removeUnknown();
335 // Second pass: Look up line-number info for remaining frames.
336 for (int i = start_idx; i <= end_idx; i++)
338 _Jv_StackFrame *frame = &trace->frames[i];
340 if (frame->klass == NULL && remove_unknown)
344 jstring className = NULL;
345 if (frame->klass != NULL)
346 className = frame->klass->getName ();
348 jstring methodName = NULL;
350 methodName = JvNewStringUTF (frame->meth->name->chars());
352 jstring sourceFileName = NULL;
355 getLineNumberForFrame(frame, finder, &sourceFileName, &lineNum,
358 StackTraceElement *element = new StackTraceElement (sourceFileName, lineNum,
359 className, methodName, 0);
364 #endif /* SJLJ_EXCEPTIONS && !WIN32 */
366 JArray<Object *> *array = JvNewObjectArray (list->size (),
367 &StackTraceElement::class$, NULL);
369 return (JArray<StackTraceElement *>*) list->toArray (array);
372 struct CallingClassTraceData
376 _Jv_Method *foundMeth;
377 bool seen_checkClass;
381 _Jv_StackTrace::calling_class_trace_fn (_Jv_UnwindState *state)
383 CallingClassTraceData *trace_data = (CallingClassTraceData *)
385 _Jv_StackFrame *frame = &state->frames[state->pos];
386 FillInFrameInfo (frame);
388 if (trace_data->seen_checkClass
390 && frame->klass != trace_data->checkClass)
392 trace_data->foundClass = frame->klass;
393 trace_data->foundMeth = frame->meth;
394 return _URC_NORMAL_STOP;
397 if (frame->klass == trace_data->checkClass)
398 trace_data->seen_checkClass = true;
400 return _URC_NO_REASON;
403 // Find the class immediately above the given class on the call stack. Any
404 // intermediate non-Java
405 // frames are ignored. If the calling class could not be determined (eg because
406 // the unwinder is not supported on this platform), NULL is returned.
407 // This function is used to implement calling-classloader checks and reflection
408 // accessibility checks.
409 // CHECKCLASS is typically the class calling GetCallingClass. The first class
410 // above CHECKCLASS on the call stack will be returned.
412 _Jv_StackTrace::GetCallingClass (jclass checkClass)
414 jclass result = NULL;
415 GetCallerInfo (checkClass, &result, NULL);
420 _Jv_StackTrace::GetCallerInfo (jclass checkClass, jclass *caller_class,
421 _Jv_Method **caller_meth)
423 #ifndef SJLJ_EXCEPTIONS
425 _Jv_StackFrame frames[trace_size];
426 _Jv_UnwindState state (trace_size);
427 state.frames = (_Jv_StackFrame *) &frames;
429 CallingClassTraceData trace_data;
430 trace_data.checkClass = checkClass;
431 trace_data.seen_checkClass = false;
432 trace_data.foundClass = NULL;
433 trace_data.foundMeth = NULL;
435 state.trace_function = calling_class_trace_fn;
436 state.trace_data = (void *) &trace_data;
438 //JvSynchronized (ncodeMap);
441 _Unwind_Backtrace (UnwindTraceFn, &state);
444 *caller_class = trace_data.foundClass;
446 *caller_meth = trace_data.foundMeth;
452 // Return a java array containing the Java classes on the stack above CHECKCLASS.
454 _Jv_StackTrace::GetClassContext (jclass checkClass)
456 JArray<jclass> *result = NULL;
458 int trace_size = 100;
459 _Jv_StackFrame frames[trace_size];
460 _Jv_UnwindState state (trace_size);
461 state.frames = (_Jv_StackFrame *) &frames;
463 //JvSynchronized (ncodeMap);
466 #ifdef SJLJ_EXCEPTIONS
467 // The Unwind interface doesn't work with the SJLJ exception model.
468 // Fall back to a platform-specific unwinder.
469 fallback_backtrace (&state);
470 #else /* SJLJ_EXCEPTIONS */
471 _Unwind_Backtrace (UnwindTraceFn, &state);
472 #endif /* SJLJ_EXCEPTIONS */
474 // Count the number of Java frames on the stack.
475 int jframe_count = 0;
476 bool seen_checkClass = false;
478 for (int i = 0; i < state.pos; i++)
480 _Jv_StackFrame *frame = &state.frames[i];
481 FillInFrameInfo (frame);
493 seen_checkClass = frame->klass == checkClass;
495 result = (JArray<jclass> *) _Jv_NewObjectArray (jframe_count, &Class::class$, NULL);
498 for (int i = start_pos; i < state.pos; i++)
500 _Jv_StackFrame *frame = &state.frames[i];
502 elements(result)[pos++] = frame->klass;
508 _Jv_StackTrace::non_system_trace_fn (_Jv_UnwindState *state)
510 _Jv_StackFrame *frame = &state->frames[state->pos];
511 FillInFrameInfo (frame);
513 ClassLoader *classLoader = NULL;
517 classLoader = frame->klass->getClassLoaderInternal();
519 if (classLoader != NULL)
521 state->trace_data = (void *) classLoader;
522 return _URC_NORMAL_STOP;
527 return _URC_NO_REASON;
531 _Jv_StackTrace::GetFirstNonSystemClassLoader ()
534 _Jv_StackFrame frames[trace_size];
535 _Jv_UnwindState state (trace_size);
536 state.frames = (_Jv_StackFrame *) &frames;
537 state.trace_function = non_system_trace_fn;
538 state.trace_data = NULL;
540 //JvSynchronized (ncodeMap);
543 #ifdef SJLJ_EXCEPTIONS
544 // The Unwind interface doesn't work with the SJLJ exception model.
545 // Fall back to a platform-specific unwinder.
546 fallback_backtrace (&state);
547 #else /* SJLJ_EXCEPTIONS */
548 _Unwind_Backtrace (UnwindTraceFn, &state);
549 #endif /* SJLJ_EXCEPTIONS */
551 if (state.trace_data)
552 return (ClassLoader *) state.trace_data;