//
// Copyright (c) Microsoft Corporation.  All rights reserved.
//
//
// This source code is licensed under Microsoft Shared Source License
// Version 1.0 for Windows CE.
// For a copy of the license visit http://go.microsoft.com/fwlink/?LinkId=3223.
//
//+---------------------------------------------------------------------------------
//
//
// File:
//      stackwalk.cpp
//
// Contents:
//
//      StackWalker class implementation
//
//----------------------------------------------------------------------------------
#include "headers.h"
#include "StackWalk.h"
#include <malloc.h>

#ifndef UNDER_CE

#ifdef _DEBUG

char * mystrdup(const char * sz)
{
    int nLen = lstrlenA(sz) + 1;
    char * tmp = (char *)malloc(nLen);
    if (tmp)
        lstrcpyA(tmp, sz);
    return tmp;
}

StackWalker::SymGetModuleInfoFunc      StackWalker::_SymGetModuleInfo;
StackWalker::SymGetSymFromAddrFunc     StackWalker::_SymGetSymFromAddr;
StackWalker::SymLoadModuleFunc         StackWalker::_SymLoadModule;
StackWalker::StackWalkFunc             StackWalker::_StackWalk;
StackWalker::UndecorateSymbolNameFunc  StackWalker::_UndecorateSymbolName;
PFUNCTION_TABLE_ACCESS_ROUTINE         StackWalker::_SymFunctionTableAccess;

StackWalker::StackWalker(HANDLE hProcess)
    : _imageHlpDLL(NULL),
      _hProcess(hProcess)
{
    _imageHlpDLL = LoadLibrary(L"imagehlp.dll");
    if (_imageHlpDLL != NULL) 
    {
        // Get commonly used Sym* functions.
        if (_StackWalk == NULL) 
        {
            // If one of them are null, assume
            // they all are.  Benign race here.

            _StackWalk = (StackWalkFunc)GetProcAddress(_imageHlpDLL, "StackWalk");
            if (_StackWalk == NULL)
                return;
            _SymGetModuleInfo = (SymGetModuleInfoFunc)GetProcAddress(_imageHlpDLL,
                                                                     "SymGetModuleInfo");
            if (_SymGetModuleInfo == NULL)
                return;
            _SymGetSymFromAddr = (SymGetSymFromAddrFunc)GetProcAddress(_imageHlpDLL,
                                                                       "SymGetSymFromAddr");
            if (_SymGetSymFromAddr == NULL)
                return;
            _SymLoadModule = (SymLoadModuleFunc)GetProcAddress(_imageHlpDLL,
                                                               "SymLoadModule");
            if (_SymLoadModule == NULL)
                return;
            _UndecorateSymbolName = (UndecorateSymbolNameFunc)GetProcAddress(_imageHlpDLL,
                                                                             "UnDecorateSymbolName");
            if (_UndecorateSymbolName == NULL)
                return;
            _SymFunctionTableAccess = (PFUNCTION_TABLE_ACCESS_ROUTINE)GetProcAddress(_imageHlpDLL,
                                                                                         "SymFunctionTableAccess");
            if (_SymFunctionTableAccess == NULL)
                return;
        }

        // Sym* functions that we're only going to use locally.
        typedef BOOL (__stdcall *SymInitializeFunc)(HANDLE hProcess,
                                                    LPSTR path,
                                                    BOOL invadeProcess);
        typedef DWORD (__stdcall *SymSetOptionsFunc)(DWORD);

        SymInitializeFunc SymInitialize = (SymInitializeFunc)GetProcAddress(_imageHlpDLL,
                                                                            "SymInitialize");
        if (SymInitialize == NULL)
            return;
        SymSetOptionsFunc SymSetOptions = (SymSetOptionsFunc)GetProcAddress(_imageHlpDLL,
                                                                            "SymSetOptions");
        if (SymSetOptions == NULL)
            return;

        if (SymInitialize(hProcess, NULL, FALSE))
            SymSetOptions(0);
    }
}


StackWalker::~StackWalker() 
{
    if (_imageHlpDLL != NULL) 
    {
        typedef BOOL (__stdcall *SymCleanupFunc)(HANDLE hProcess);

        SymCleanupFunc SymCleanup = (SymCleanupFunc)GetProcAddress(_imageHlpDLL,
                                                                   "SymCleanup");
        if (SymCleanup != NULL)
            SymCleanup(_hProcess);

        FreeLibrary(_imageHlpDLL);
    }
}

DWORD_PTR StackWalker::LoadModule(HANDLE hProcess, DWORD_PTR address) 
{
    MEMORY_BASIC_INFORMATION mbi;

    if (VirtualQueryEx(hProcess, (void*)address, &mbi, sizeof mbi)) 
    {
        if (mbi.Type & MEM_IMAGE) 
        {
            char module[MAX_PATH];
            DWORD cch = GetModuleFileNameA((HINSTANCE)mbi.AllocationBase,
                                           module,
                                           MAX_PATH);

            // Ignore the return code since we can't do anything with it.
            (void)_SymLoadModule(hProcess,
                                 NULL,
                                 ((cch) ? module : NULL),
                                 NULL,
                                 (DWORD_PTR) mbi.AllocationBase,
                                 0);
            return (DWORD_PTR) mbi.AllocationBase;
        }
    }

    return 0;
}

Symbol* StackWalker::ResolveAddress(DWORD_PTR addr) 
{
    if (_imageHlpDLL == NULL)
        return NULL;

    // Find out what module the address lies in.
    char* module = NULL;
    IMAGEHLP_MODULE moduleInfo;
    moduleInfo.SizeOfStruct = sizeof moduleInfo;

    if (_SymGetModuleInfo(_hProcess, addr, &moduleInfo)) 
    {
        module = moduleInfo.ModuleName;
    }
    else 
    {
        // First attempt failed, load the module info.
        LoadModule(_hProcess, addr);
        if (_SymGetModuleInfo(_hProcess, addr, &moduleInfo))
            module = moduleInfo.ModuleName;
    }

    char* symbolName = NULL;
    char undecoratedName[512];
    IMAGEHLP_SYMBOL* symbolInfo = (IMAGEHLP_SYMBOL*)_alloca(sizeof(IMAGEHLP_SYMBOL) + 512);
    symbolInfo->SizeOfStruct = sizeof(IMAGEHLP_SYMBOL) + 512;
    symbolInfo->MaxNameLength = 512;
    DWORD_PTR displacement = 0;
    if (_SymGetSymFromAddr(_hProcess, addr, &displacement, symbolInfo)) 
    {
        DWORD flags = UNDNAME_NO_MS_KEYWORDS 
            | UNDNAME_NO_ACCESS_SPECIFIERS
            | UNDNAME_NO_FUNCTION_RETURNS
            | UNDNAME_NO_MEMBER_TYPE;
        if (_UndecorateSymbolName(symbolInfo->Name, undecoratedName, 512, flags))
            symbolName = undecoratedName;
        else
            symbolName = symbolInfo->Name;
    }
    else 
    {
        displacement = addr - moduleInfo.BaseOfImage;
    }

    return new Symbol(module, symbolName, displacement);
}



DWORD_PTR __stdcall StackWalker::GetModuleBase(HANDLE hProcess, DWORD_PTR address) 
{
    IMAGEHLP_MODULE moduleInfo;
    moduleInfo.SizeOfStruct = sizeof moduleInfo;
    
    if (_SymGetModuleInfo(hProcess, address, &moduleInfo))
        return moduleInfo.BaseOfImage;
    else
        return LoadModule(hProcess, address);

}

Symbol* StackWalker::CreateStackTrace(CONTEXT* context) 
{
    if (_imageHlpDLL == NULL)
        return NULL;

    HANDLE hThread = GetCurrentThread();

    DWORD dwMachineType;
    STACKFRAME frame = {0};
    frame.AddrPC.Mode = AddrModeFlat;
#if defined(_M_IX86)
    dwMachineType          = IMAGE_FILE_MACHINE_I386;
    frame.AddrPC.Offset    = context->Eip;  // Program Counter
    
    frame.AddrStack.Offset = context->Esp;  // Stack Pointer
    frame.AddrStack.Mode   = AddrModeFlat;
    frame.AddrFrame.Offset = context->Ebp;  // Frame Pointer
#elif defined(_M_MRX000)
    dwMachineType          = IMAGE_FILE_MACHINE_R4000;
    frame.AddrPC.Offset    = context->Fir;  // Program Counter
#elif defined(_M_ALPHA)
    dwMachineType          = IMAGE_FILE_MACHINE_ALPHA;
    frame.AddrPC.Offset    = (DWORD_PTR) context->Fir;            // Program Counter
    frame.AddrStack.Offset = (DWORD_PTR) context->IntSp;        // Stack Pointer
    frame.AddrFrame.Offset = (DWORD_PTR) context->IntFp;        // Frame Pointer

#elif defined(_M_PPC)
    dwMachineType          = IMAGE_FILE_MACHINE_POWERPC;
    frame.AddrPC.Offset    = context->Iar;  // Program Counter
#elif defined(_M_IA64)

    dwMachineType          = IMAGE_FILE_MACHINE_IA64;
    frame.AddrPC.Offset    = context->StIIP;  // Program Counter
    
    frame.AddrStack.Offset = context->IntSp; //Stack Pointer
    frame.AddrStack.Mode   = AddrModeFlat;
    // No Frame pointer information for IA64 (per Intel folks)
    //frame.AddrFrame.Offset = context->Ebp;  // Frame Pointer
#elif defined(_M_AXP64)
    dwMachineType          = IMAGE_FILE_MACHINE_AXP64;
    frame.AddrPC.Offset    = (DWORD_PTR) context->Fir;  // Program Counter
    frame.AddrStack.Offset = (DWORD_PTR) context->IntSp;        // Stack Pointer
    frame.AddrFrame.Offset = (DWORD_PTR) context->IntFp;        // Frame Pointer
#else
#error Unknown Target Machine
#endif
    const DWORD dwMaxNumRepetitions = 40;
    DWORD dwRepetitions    = 0;
    ADDRESS addrRepeated = {0, 0, AddrModeFlat};

    // Walk the stack...
    Symbol* prev = NULL;
    Symbol* head = NULL;

    for (;;) {
        if (!_StackWalk(dwMachineType,
                        _hProcess,
                        hThread,
                        &frame,
                        &context,
                        NULL,
                        _SymFunctionTableAccess,
                        GetModuleBase,
                        NULL))
            break;
        if (frame.AddrPC.Offset == 0)
            break;

        // Check for repeated addresses;  if dwMaxNumRepetitions are found,
        // then we break out of the loop and exit the stack walk
        if (addrRepeated.Offset == frame.AddrPC.Offset &&
            addrRepeated.Mode == frame.AddrPC.Mode) {
            dwRepetitions ++;
            if (dwRepetitions == dwMaxNumRepetitions) {
                break;
            }
        } else {
            dwRepetitions = 0;
            addrRepeated.Offset = frame.AddrPC.Offset;
            addrRepeated.Mode = frame.AddrPC.Mode;
        }

        Symbol* sym = ResolveAddress(frame.AddrPC.Offset);
        if (sym == NULL)
            break;

        // Append this symbol to the previous one, if any.
        if (prev == NULL) {
            prev = sym;
            head = sym;
        }
        else {
            prev->Append(sym);
            prev = sym;
        }
    }

    return head;
}

int StackWalker::GetCallStackSize(Symbol* symbol)
{
    int nSize = 2; // Start with a "\r\n".
    const char* module = NULL;
    const char* symbolName = NULL;    
    Symbol * sym = symbol;
    while (sym != NULL)
    {
        module = sym->moduleName();
        symbolName = sym->symbolName();    
        nSize += lstrlenA(module);
        nSize += lstrlenA(symbolName);
        nSize += 32; // displacement, spaces, etc.
        sym = sym -> next();
    }

    return nSize;
}
BOOL StackWalker::GetCallStack(Symbol * symbol, int nChars, WCHAR * sz)
{
    if (!symbol || !nChars)
        return FALSE;

    Symbol* sym = symbol;
    
    const char* module = NULL;
    const char* symbolName = NULL;    
    char * szStack = (char * )CoTaskMemAlloc(nChars);
    if (!szStack)
        return FALSE;
    ZeroMemory(szStack, nChars);
    lstrcpyA(szStack, "\r\n"); // Start with a CR-LF.
    Symbol* tmp  = NULL;
    while (sym != NULL) 
    {    
        module = sym->moduleName();
        symbolName = sym->symbolName();            
        if (module != NULL) 
        {
            lstrcatA(szStack, module);
            if (symbolName != NULL)
                lstrcatA(szStack, "!");
        }

        if (symbolName != NULL)
            lstrcatA(szStack, symbolName);

        sym -> AppendDisplacement(szStack);

        lstrcatA(szStack, "\r\n");
        tmp = sym;
        sym = sym->next();
        delete tmp;
    }

    int nLen = lstrlenA(szStack);
    nLen++;        
    MultiByteToWideChar(CP_ACP, 0, szStack, nLen, sz, nLen);
    CoTaskMemFree(szStack);
    return TRUE;
    
}

Symbol::Symbol(const char* moduleName, const char* symbolName, DWORD_PTR displacement)
    : _moduleName(NULL),
      _symbolName(NULL),
      _displacement(displacement),
      _next(NULL)
{
    if (moduleName != NULL)
        _moduleName = mystrdup(moduleName);
    if (symbolName != NULL)
        _symbolName = mystrdup(symbolName);
}

Symbol::~Symbol() {
    free(_moduleName);
    free(_symbolName);
}

void Symbol::Append(Symbol* sym) {
    _next = sym;
}

#endif

#endif
