check that wxString is valid before dumping it
[wxWidgets.git] / src / msw / debughlp.cpp
1 /////////////////////////////////////////////////////////////////////////////
2 // Name: msw/debughlp.cpp
3 // Purpose: various Win32 debug helpers
4 // Author: Vadim Zeitlin
5 // Modified by:
6 // Created: 2005-01-08 (extracted from crashrpt.cpp)
7 // RCS-ID: $Id$
8 // Copyright: (c) 2003-2005 Vadim Zeitlin <vadim@wxwindows.org>
9 // Licence: wxWindows licence
10 /////////////////////////////////////////////////////////////////////////////
11
12 // ============================================================================
13 // declarations
14 // ============================================================================
15
16 // ----------------------------------------------------------------------------
17 // headers
18 // ----------------------------------------------------------------------------
19
20 #include "wx/wxprec.h"
21
22 #ifdef __BORLANDC__
23 #pragma hdrstop
24 #endif
25
26 #include "wx/msw/debughlp.h"
27
28 #if wxUSE_DBGHELP
29
30 // ----------------------------------------------------------------------------
31 // constants
32 // ----------------------------------------------------------------------------
33
34 // to prevent recursion which could result from corrupted data we limit
35 // ourselves to that many levels of embedded fields inside structs
36 static const unsigned MAX_DUMP_DEPTH = 20;
37
38 // ----------------------------------------------------------------------------
39 // globals
40 // ----------------------------------------------------------------------------
41
42 // error message from Init()
43 static wxString gs_errMsg;
44
45 // ============================================================================
46 // wxDbgHelpDLL implementation
47 // ============================================================================
48
49 // ----------------------------------------------------------------------------
50 // static members
51 // ----------------------------------------------------------------------------
52
53 #define DEFINE_SYM_FUNCTION(func) wxDbgHelpDLL::func ## _t wxDbgHelpDLL::func = 0
54
55 wxDO_FOR_ALL_SYM_FUNCS(DEFINE_SYM_FUNCTION);
56
57 #undef DEFINE_SYM_FUNCTION
58
59 // ----------------------------------------------------------------------------
60 // initialization methods
61 // ----------------------------------------------------------------------------
62
63 // load all function we need from the DLL
64
65 static bool BindDbgHelpFunctions(const wxDynamicLibrary& dllDbgHelp)
66 {
67 #define LOAD_SYM_FUNCTION(name) \
68 wxDbgHelpDLL::name = (wxDbgHelpDLL::name ## _t) \
69 dllDbgHelp.GetSymbol(_T(#name)); \
70 if ( !wxDbgHelpDLL::name ) \
71 { \
72 gs_errMsg += _T("Function ") _T(#name) _T("() not found.\n"); \
73 return false; \
74 }
75
76 wxDO_FOR_ALL_SYM_FUNCS(LOAD_SYM_FUNCTION);
77
78 #undef LOAD_SYM_FUNCTION
79
80 return true;
81 }
82
83 // called by Init() if we hadn't done this before
84 static bool DoInit()
85 {
86 wxDynamicLibrary dllDbgHelp(_T("dbghelp.dll"), wxDL_VERBATIM);
87 if ( dllDbgHelp.IsLoaded() )
88 {
89 if ( BindDbgHelpFunctions(dllDbgHelp) )
90 {
91 // turn on default options
92 DWORD options = wxDbgHelpDLL::SymGetOptions();
93
94 options |= SYMOPT_DEFERRED_LOADS | SYMOPT_UNDNAME | SYMOPT_DEBUG;
95
96 wxDbgHelpDLL::SymSetOptions(options);
97
98 dllDbgHelp.Detach();
99 return true;
100 }
101
102 gs_errMsg += _T("\nPlease update your dbghelp.dll version, ")
103 _T("at least version 5.1 is needed!\n")
104 _T("(if you already have a new version, please ")
105 _T("put it in the same directory where the program is.)\n");
106 }
107 else // failed to load dbghelp.dll
108 {
109 gs_errMsg += _T("Please install dbghelp.dll available free of charge ")
110 _T("from Microsoft to get more detailed crash information!");
111 }
112
113 gs_errMsg += _T("\nLatest dbghelp.dll is available at ")
114 _T("http://www.microsoft.com/whdc/ddk/debugging/\n");
115
116 return false;
117 }
118
119 /* static */
120 bool wxDbgHelpDLL::Init()
121 {
122 // this flag is -1 until Init() is called for the first time, then it's set
123 // to either false or true depending on whether we could load the functions
124 static int s_loaded = -1;
125
126 if ( s_loaded == -1 )
127 {
128 s_loaded = DoInit();
129 }
130
131 return s_loaded != 0;
132 }
133
134 // ----------------------------------------------------------------------------
135 // error handling
136 // ----------------------------------------------------------------------------
137
138 /* static */
139 const wxString& wxDbgHelpDLL::GetErrorMessage()
140 {
141 return gs_errMsg;
142 }
143
144 /* static */
145 void wxDbgHelpDLL::LogError(const wxChar *func)
146 {
147 ::OutputDebugString(wxString::Format(_T("dbghelp: %s() failed: %s\r\n"),
148 func, wxSysErrorMsg(::GetLastError())));
149 }
150
151 // ----------------------------------------------------------------------------
152 // data dumping
153 // ----------------------------------------------------------------------------
154
155 static inline
156 bool
157 DoGetTypeInfo(DWORD64 base, ULONG ti, IMAGEHLP_SYMBOL_TYPE_INFO type, void *rc)
158 {
159 static HANDLE s_hProcess = ::GetCurrentProcess();
160
161 return wxDbgHelpDLL::SymGetTypeInfo
162 (
163 s_hProcess,
164 base,
165 ti,
166 type,
167 rc
168 ) != 0;
169 }
170
171 static inline
172 bool
173 DoGetTypeInfo(PSYMBOL_INFO pSym, IMAGEHLP_SYMBOL_TYPE_INFO type, void *rc)
174 {
175 return DoGetTypeInfo(pSym->ModBase, pSym->TypeIndex, type, rc);
176 }
177
178 static inline
179 wxDbgHelpDLL::BasicType GetBasicType(PSYMBOL_INFO pSym)
180 {
181 wxDbgHelpDLL::BasicType bt;
182 return DoGetTypeInfo(pSym, TI_GET_BASETYPE, &bt)
183 ? bt
184 : wxDbgHelpDLL::BASICTYPE_NOTYPE;
185 }
186
187 /* static */
188 wxString wxDbgHelpDLL::GetSymbolName(PSYMBOL_INFO pSym)
189 {
190 wxString s;
191
192 WCHAR *pwszTypeName;
193 if ( SymGetTypeInfo
194 (
195 GetCurrentProcess(),
196 pSym->ModBase,
197 pSym->TypeIndex,
198 TI_GET_SYMNAME,
199 &pwszTypeName
200 ) )
201 {
202 s = wxConvCurrent->cWC2WX(pwszTypeName);
203
204 ::LocalFree(pwszTypeName);
205 }
206
207 return s;
208 }
209
210 /* static */ wxString
211 wxDbgHelpDLL::DumpBaseType(BasicType bt, DWORD64 length, PVOID pAddress)
212 {
213 if ( !pAddress )
214 {
215 return _T("null");
216 }
217
218 if ( ::IsBadReadPtr(pAddress, length) != 0 )
219 {
220 return _T("BAD");
221 }
222
223
224 wxString s;
225 s.reserve(256);
226
227 if ( length == 1 )
228 {
229 const BYTE b = *(PBYTE)pAddress;
230
231 if ( bt == BASICTYPE_BOOL )
232 s = b ? _T("true") : _T("false");
233 else
234 s.Printf(_T("%#04x"), b);
235 }
236 else if ( length == 2 )
237 {
238 s.Printf(bt == BASICTYPE_UINT ? _T("%#06x") : _T("%d"),
239 *(PWORD)pAddress);
240 }
241 else if ( length == 4 )
242 {
243 bool handled = false;
244
245 if ( bt == BASICTYPE_FLOAT )
246 {
247 s.Printf(_T("%f"), *(PFLOAT)pAddress);
248
249 handled = true;
250 }
251 else if ( bt == BASICTYPE_CHAR )
252 {
253 // don't take more than 32 characters of a string
254 static const size_t NUM_CHARS = 64;
255
256 const char *pc = *(PSTR *)pAddress;
257 if ( ::IsBadStringPtrA(pc, NUM_CHARS) == 0 )
258 {
259 s += _T('"');
260 for ( size_t n = 0; n < NUM_CHARS && *pc; n++, pc++ )
261 {
262 s += *pc;
263 }
264 s += _T('"');
265
266 handled = true;
267 }
268 }
269
270 if ( !handled )
271 {
272 // treat just as an opaque DWORD
273 s.Printf(_T("%#x"), *(PDWORD)pAddress);
274 }
275 }
276 else if ( length == 8 )
277 {
278 if ( bt == BASICTYPE_FLOAT )
279 {
280 s.Printf(_T("%lf"), *(double *)pAddress);
281 }
282 else // opaque 64 bit value
283 {
284 s.Printf(_T("%#" wxLongLongFmtSpec _T("x")), *(PDWORD *)pAddress);
285 }
286 }
287
288 return s;
289 }
290
291 wxString
292 wxDbgHelpDLL::DumpField(PSYMBOL_INFO pSym, void *pVariable, unsigned level)
293 {
294 wxString s;
295
296 // avoid infinite recursion
297 if ( level > MAX_DUMP_DEPTH )
298 {
299 return s;
300 }
301
302 SymbolTag tag = SYMBOL_TAG_NULL;
303 if ( !DoGetTypeInfo(pSym, TI_GET_SYMTAG, &tag) )
304 {
305 return s;
306 }
307
308 switch ( tag )
309 {
310 case SYMBOL_TAG_UDT:
311 case SYMBOL_TAG_BASE_CLASS:
312 s = DumpUDT(pSym, pVariable, level);
313 break;
314
315 case SYMBOL_TAG_DATA:
316 if ( !pVariable )
317 {
318 s = _T("NULL");
319 }
320 else // valid location
321 {
322 wxDbgHelpDLL::DataKind kind;
323 if ( !DoGetTypeInfo(pSym, TI_GET_DATAKIND, &kind) ||
324 kind != DATA_MEMBER )
325 {
326 // maybe it's a static member? we're not interested in them...
327 break;
328 }
329
330 // get the offset of the child member, relative to its parent
331 DWORD ofs = 0;
332 if ( !DoGetTypeInfo(pSym, TI_GET_OFFSET, &ofs) )
333 break;
334
335 pVariable = (void *)((DWORD_PTR)pVariable + ofs);
336
337
338 // now pass to the type representing the type of this member
339 SYMBOL_INFO sym = *pSym;
340 if ( !DoGetTypeInfo(pSym, TI_GET_TYPEID, &sym.TypeIndex) )
341 break;
342
343 ULONG64 size;
344 DoGetTypeInfo(&sym, TI_GET_LENGTH, &size);
345
346 switch ( DereferenceSymbol(&sym, &pVariable) )
347 {
348 case SYMBOL_TAG_BASE_TYPE:
349 {
350 BasicType bt = GetBasicType(&sym);
351 if ( bt )
352 {
353 s = DumpBaseType(bt, size, pVariable);
354 }
355 }
356 break;
357
358 case SYMBOL_TAG_UDT:
359 case SYMBOL_TAG_BASE_CLASS:
360 s = DumpUDT(&sym, pVariable, level);
361 break;
362 }
363 }
364
365 if ( !s.empty() )
366 {
367 s = GetSymbolName(pSym) + _T(" = ") + s;
368 }
369 break;
370 }
371
372 if ( !s.empty() )
373 {
374 s = wxString(_T('\t'), level + 1) + s + _T('\n');
375 }
376
377 return s;
378 }
379
380 /* static */ wxString
381 wxDbgHelpDLL::DumpUDT(PSYMBOL_INFO pSym, void *pVariable, unsigned level)
382 {
383 wxString s;
384
385 // we have to limit the depth of UDT dumping as otherwise we get in
386 // infinite loops trying to dump linked lists... 10 levels seems quite
387 // reasonable, full information is in minidump file anyhow
388 if ( level > 10 )
389 return s;
390
391 s.reserve(512);
392 s = GetSymbolName(pSym);
393
394 #if !wxUSE_STL
395 // special handling for ubiquitous wxString: although the code below works
396 // for it as well, it shows the wxStringBase class and takes 4 lines
397 // instead of only one as this branch
398 if ( s == _T("wxString") )
399 {
400 wxString *ps = (wxString *)pVariable;
401
402 // we can't just dump wxString directly as it could be corrupted or
403 // invalid and it could also be locked for writing (i.e. if we're
404 // between GetWriteBuf() and UngetWriteBuf() calls) and assert when we
405 // try to access it contents using public methods, so instead use our
406 // knowledge of its internals
407 const wxChar *p = ps->data();
408 wxStringData *data = (wxStringData *)p - 1;
409 if ( ::IsBadReadPtr(data, sizeof(wxStringData)) ||
410 ::IsBadReadPtr(p, sizeof(wxChar *)*data->nAllocLength) )
411 {
412 p = _T("???");
413 }
414
415 s << _T("(\"") << p << _T(")\"");
416 }
417 else // any other UDT
418 #endif // !wxUSE_STL
419 {
420 // Determine how many children this type has.
421 DWORD dwChildrenCount = 0;
422 DoGetTypeInfo(pSym, TI_GET_CHILDRENCOUNT, &dwChildrenCount);
423
424 // Prepare to get an array of "TypeIds", representing each of the children.
425 TI_FINDCHILDREN_PARAMS *children = (TI_FINDCHILDREN_PARAMS *)
426 malloc(sizeof(TI_FINDCHILDREN_PARAMS) +
427 (dwChildrenCount - 1)*sizeof(ULONG));
428 if ( !children )
429 return s;
430
431 children->Count = dwChildrenCount;
432 children->Start = 0;
433
434 // Get the array of TypeIds, one for each child type
435 if ( !DoGetTypeInfo(pSym, TI_FINDCHILDREN, children) )
436 {
437 free(children);
438 return s;
439 }
440
441 s << _T(" {\n");
442
443 // Iterate through all children
444 SYMBOL_INFO sym;
445 wxZeroMemory(sym);
446 sym.ModBase = pSym->ModBase;
447 for ( unsigned i = 0; i < dwChildrenCount; i++ )
448 {
449 sym.TypeIndex = children->ChildId[i];
450
451 // children here are in lexicographic sense, i.e. we get all our nested
452 // classes and not only our member fields, but we can't get the values
453 // for the members of the nested classes, of course!
454 DWORD nested;
455 if ( DoGetTypeInfo(&sym, TI_GET_NESTED, &nested) && nested )
456 continue;
457
458 // avoid infinite recursion: this does seem to happen sometimes with
459 // complex typedefs...
460 if ( sym.TypeIndex == pSym->TypeIndex )
461 continue;
462
463 s += DumpField(&sym, pVariable, level + 1);
464 }
465
466 free(children);
467
468 s << wxString(_T('\t'), level + 1) << _T('}');
469 }
470
471 return s;
472 }
473
474 /* static */
475 wxDbgHelpDLL::SymbolTag
476 wxDbgHelpDLL::DereferenceSymbol(PSYMBOL_INFO pSym, void **ppData)
477 {
478 SymbolTag tag = SYMBOL_TAG_NULL;
479 for ( ;; )
480 {
481 if ( !DoGetTypeInfo(pSym, TI_GET_SYMTAG, &tag) )
482 break;
483
484 if ( tag != SYMBOL_TAG_POINTER_TYPE )
485 break;
486
487 ULONG tiNew;
488 if ( !DoGetTypeInfo(pSym, TI_GET_TYPEID, &tiNew) ||
489 tiNew == pSym->TypeIndex )
490 break;
491
492 pSym->TypeIndex = tiNew;
493
494 // remove one level of indirection except for the char strings: we want
495 // to dump "char *" and not a single "char" for them
496 if ( ppData && *ppData && GetBasicType(pSym) != BASICTYPE_CHAR )
497 {
498 DWORD_PTR *pData = (DWORD_PTR *)*ppData;
499
500 if ( ::IsBadReadPtr(pData, sizeof(DWORD_PTR *)) )
501 {
502 break;
503 }
504
505 *ppData = (void *)*pData;
506 }
507 }
508
509 return tag;
510 }
511
512 /* static */ wxString
513 wxDbgHelpDLL::DumpSymbol(PSYMBOL_INFO pSym, void *pVariable)
514 {
515 wxString s;
516 SYMBOL_INFO symDeref = *pSym;
517 switch ( DereferenceSymbol(&symDeref, &pVariable) )
518 {
519 case SYMBOL_TAG_UDT:
520 // show UDT recursively
521 s = DumpUDT(&symDeref, pVariable);
522 break;
523
524 case SYMBOL_TAG_BASE_TYPE:
525 // variable of simple type, show directly
526 BasicType bt = GetBasicType(&symDeref);
527 if ( bt )
528 {
529 s = DumpBaseType(bt, pSym->Size, pVariable);
530 }
531 break;
532 }
533
534 return s;
535 }
536
537 // ----------------------------------------------------------------------------
538 // debugging helpers
539 // ----------------------------------------------------------------------------
540
541 // this code is very useful when debugging debughlp.dll-related code but
542 // probably not worth having compiled in normally, please do not remove it!
543 #if 0 // ndef NDEBUG
544
545 static wxString TagString(wxDbgHelpDLL::SymbolTag tag)
546 {
547 static const wxChar *tags[] =
548 {
549 _T("null"),
550 _T("exe"),
551 _T("compiland"),
552 _T("compiland details"),
553 _T("compiland env"),
554 _T("function"),
555 _T("block"),
556 _T("data"),
557 _T("annotation"),
558 _T("label"),
559 _T("public symbol"),
560 _T("udt"),
561 _T("enum"),
562 _T("function type"),
563 _T("pointer type"),
564 _T("array type"),
565 _T("base type"),
566 _T("typedef"),
567 _T("base class"),
568 _T("friend"),
569 _T("function arg type"),
570 _T("func debug start"),
571 _T("func debug end"),
572 _T("using namespace"),
573 _T("vtable shape"),
574 _T("vtable"),
575 _T("custom"),
576 _T("thunk"),
577 _T("custom type"),
578 _T("managed type"),
579 _T("dimension"),
580 };
581
582 wxCOMPILE_TIME_ASSERT( WXSIZEOF(tags) == wxDbgHelpDLL::SYMBOL_TAG_MAX,
583 SymbolTagStringMismatch );
584
585 wxString s;
586 if ( tag < WXSIZEOF(tags) )
587 s = tags[tag];
588 else
589 s.Printf(_T("unrecognized tag (%d)"), tag);
590
591 return s;
592 }
593
594 static wxString KindString(wxDbgHelpDLL::DataKind kind)
595 {
596 static const wxChar *kinds[] =
597 {
598 _T("unknown"),
599 _T("local"),
600 _T("static local"),
601 _T("param"),
602 _T("object ptr"),
603 _T("file static"),
604 _T("global"),
605 _T("member"),
606 _T("static member"),
607 _T("constant"),
608 };
609
610 wxCOMPILE_TIME_ASSERT( WXSIZEOF(kinds) == wxDbgHelpDLL::DATA_MAX,
611 DataKindStringMismatch );
612
613 wxString s;
614 if ( kind < WXSIZEOF(kinds) )
615 s = kinds[kind];
616 else
617 s.Printf(_T("unrecognized kind (%d)"), kind);
618
619 return s;
620 }
621
622 static wxString UdtKindString(wxDbgHelpDLL::UdtKind kind)
623 {
624 static const wxChar *kinds[] =
625 {
626 _T("struct"),
627 _T("class"),
628 _T("union"),
629 };
630
631 wxCOMPILE_TIME_ASSERT( WXSIZEOF(kinds) == wxDbgHelpDLL::UDT_MAX,
632 UDTKindStringMismatch );
633
634 wxString s;
635 if ( kind < WXSIZEOF(kinds) )
636 s = kinds[kind];
637 else
638 s.Printf(_T("unrecognized UDT (%d)"), kind);
639
640 return s;
641 }
642
643 static wxString TypeString(wxDbgHelpDLL::BasicType bt)
644 {
645 static const wxChar *types[] =
646 {
647 _T("no type"),
648 _T("void"),
649 _T("char"),
650 _T("wchar"),
651 _T(""),
652 _T(""),
653 _T("int"),
654 _T("uint"),
655 _T("float"),
656 _T("bcd"),
657 _T("bool"),
658 _T(""),
659 _T(""),
660 _T("long"),
661 _T("ulong"),
662 _T(""),
663 _T(""),
664 _T(""),
665 _T(""),
666 _T(""),
667 _T(""),
668 _T(""),
669 _T(""),
670 _T(""),
671 _T(""),
672 _T("CURRENCY"),
673 _T("DATE"),
674 _T("VARIANT"),
675 _T("complex"),
676 _T("bit"),
677 _T("BSTR"),
678 _T("HRESULT"),
679 };
680
681 wxCOMPILE_TIME_ASSERT( WXSIZEOF(types) == wxDbgHelpDLL::BASICTYPE_MAX,
682 BasicTypeStringMismatch );
683
684 wxString s;
685 if ( bt < WXSIZEOF(types) )
686 s = types[bt];
687
688 if ( s.empty() )
689 s.Printf(_T("unrecognized type (%d)"), bt);
690
691 return s;
692 }
693
694 // this function is meant to be called from under debugger to see the
695 // proprieties of the given type id
696 extern "C" void DumpTI(ULONG ti)
697 {
698 SYMBOL_INFO sym = { sizeof(SYMBOL_INFO) };
699 sym.ModBase = 0x400000; // it's a constant under Win32
700 sym.TypeIndex = ti;
701
702 wxDbgHelpDLL::SymbolTag tag = wxDbgHelpDLL::SYMBOL_TAG_NULL;
703 DoGetTypeInfo(&sym, TI_GET_SYMTAG, &tag);
704 DoGetTypeInfo(&sym, TI_GET_TYPEID, &ti);
705
706 OutputDebugString(wxString::Format(_T("Type 0x%x: "), sym.TypeIndex));
707 wxString name = wxDbgHelpDLL::GetSymbolName(&sym);
708 if ( !name.empty() )
709 {
710 OutputDebugString(wxString::Format(_T("name=\"%s\", "), name.c_str()));
711 }
712
713 DWORD nested;
714 if ( !DoGetTypeInfo(&sym, TI_GET_NESTED, &nested) )
715 {
716 nested = FALSE;
717 }
718
719 OutputDebugString(wxString::Format(_T("tag=%s%s"),
720 nested ? _T("nested ") : wxEmptyString,
721 TagString(tag).c_str()));
722 if ( tag == wxDbgHelpDLL::SYMBOL_TAG_UDT )
723 {
724 wxDbgHelpDLL::UdtKind udtKind;
725 if ( DoGetTypeInfo(&sym, TI_GET_UDTKIND, &udtKind) )
726 {
727 OutputDebugString(_T(" (") + UdtKindString(udtKind) + _T(')'));
728 }
729 }
730
731 wxDbgHelpDLL::DataKind kind = wxDbgHelpDLL::DATA_UNKNOWN;
732 if ( DoGetTypeInfo(&sym, TI_GET_DATAKIND, &kind) )
733 {
734 OutputDebugString(wxString::Format(
735 _T(", kind=%s"), KindString(kind).c_str()));
736 if ( kind == wxDbgHelpDLL::DATA_MEMBER )
737 {
738 DWORD ofs = 0;
739 if ( DoGetTypeInfo(&sym, TI_GET_OFFSET, &ofs) )
740 {
741 OutputDebugString(wxString::Format(_T(" (ofs=0x%x)"), ofs));
742 }
743 }
744 }
745
746 wxDbgHelpDLL::BasicType bt = GetBasicType(&sym);
747 if ( bt )
748 {
749 OutputDebugString(wxString::Format(_T(", type=%s"),
750 TypeString(bt).c_str()));
751 }
752
753 if ( ti != sym.TypeIndex )
754 {
755 OutputDebugString(wxString::Format(_T(", next ti=0x%x"), ti));
756 }
757
758 OutputDebugString(_T("\r\n"));
759 }
760
761 #endif // NDEBUG
762
763 #endif // wxUSE_DBGHELP