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 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 #include <windows.h>

 #include <tlhelp32.h>

 #include <dbghelp.h>

 #include <sstream>

 #include "shared-libraries.h"

 #include "nsWindowsHelpers.h"

 #define CV_SIGNATURE 0x53445352 // 'SDSR'

 struct CodeViewRecord70

 {

   uint32_t signature;

   GUID pdbSignature;

   uint32_t pdbAge;

   char pdbFileName[1];

 };

 static bool GetPdbInfo(uintptr_t aStart, nsID& aSignature, uint32_t& aAge, char** aPdbName)

 {

   if (!aStart) {

     return false;

   }

   PIMAGE_DOS_HEADER dosHeader = reinterpret_cast<PIMAGE_DOS_HEADER>(aStart);

   if (dosHeader->e_magic != IMAGE_DOS_SIGNATURE) {

     return false;

   }

   PIMAGE_NT_HEADERS ntHeaders = reinterpret_cast<PIMAGE_NT_HEADERS>(

       aStart + dosHeader->e_lfanew);

   if (ntHeaders->Signature != IMAGE_NT_SIGNATURE) {

     return false;

   }

   uint32_t relativeVirtualAddress =

     ntHeaders->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_DEBUG].VirtualAddress;

   if (!relativeVirtualAddress) {

     return false;

   }

   PIMAGE_DEBUG_DIRECTORY debugDirectory =

     reinterpret_cast<PIMAGE_DEBUG_DIRECTORY>(aStart + relativeVirtualAddress);

   if (!debugDirectory || debugDirectory->Type != IMAGE_DEBUG_TYPE_CODEVIEW) {

     return false;

   }

   CodeViewRecord70 *debugInfo = reinterpret_cast<CodeViewRecord70 *>(

       aStart + debugDirectory->AddressOfRawData);

   if (!debugInfo || debugInfo->signature != CV_SIGNATURE) {

     return false;

   }

   aAge = debugInfo->pdbAge;

   GUID& pdbSignature = debugInfo->pdbSignature;

   aSignature.m0 = pdbSignature.Data1;

   aSignature.m1 = pdbSignature.Data2;

   aSignature.m2 = pdbSignature.Data3;

   memcpy(aSignature.m3, pdbSignature.Data4, sizeof(pdbSignature.Data4));

   // The PDB file name could be different from module filename, so report both

   // e.g. The PDB for C:\Windows\SysWOW64\ntdll.dll is wntdll.pdb

   char * leafName = strrchr(debugInfo->pdbFileName, '\\');

   if (leafName) {

     // Only report the file portion of the path

     *aPdbName = leafName + 1;

   } else {

     *aPdbName = debugInfo->pdbFileName;

   }

   return true;

 }

 static bool IsDashOrBraces(char c)

 {

   return c == '-' || c == '{' || c == '}';

 }

 SharedLibraryInfo SharedLibraryInfo::GetInfoForSelf()

 {

   SharedLibraryInfo sharedLibraryInfo;

   nsAutoHandle snap(CreateToolhelp32Snapshot(TH32CS_SNAPMODULE, GetCurrentProcessId()));

   MODULEENTRY32 module = {0};

   module.dwSize = sizeof(MODULEENTRY32);

   if (Module32First(snap, &module)) {

     do {

       nsID pdbSig;

       uint32_t pdbAge;

       char *pdbName = NULL;

       // Load the module again to make sure that its handle will remain remain

       // valid as we attempt to read the PDB information from it.  We load the

       // DLL as a datafile so that if the module actually gets unloaded between

       // the call to Module32Next and the following LoadLibraryEx, we don't end

       // up running the now newly loaded module's DllMain function.  If the

       // module is already loaded, LoadLibraryEx just increments its refcount.

       //

       // Note that because of the race condition above, merely loading the DLL

       // again is not safe enough, therefore we also need to make sure that we

       // can read the memory mapped at the base address before we can safely

       // proceed to actually access those pages.

       HMODULE handleLock = LoadLibraryEx(module.szExePath, NULL, LOAD_LIBRARY_AS_DATAFILE);

       MEMORY_BASIC_INFORMATION vmemInfo = {0};

       if (handleLock &&

           sizeof(vmemInfo) == VirtualQuery(module.modBaseAddr, &vmemInfo, sizeof(vmemInfo)) &&

           vmemInfo.State == MEM_COMMIT &&

           GetPdbInfo((uintptr_t)module.modBaseAddr, pdbSig, pdbAge, &pdbName)) {

         std::ostringstream stream;

         stream << pdbSig.ToString() << std::hex << pdbAge;

         std::string breakpadId = stream.str();

         std::string::iterator end =

           std::remove_if(breakpadId.begin(), breakpadId.end(), IsDashOrBraces);

         breakpadId.erase(end, breakpadId.end());

         std::transform(breakpadId.begin(), breakpadId.end(),

                        breakpadId.begin(), toupper);

         SharedLibrary shlib((uintptr_t)module.modBaseAddr,

                             (uintptr_t)module.modBaseAddr+module.modBaseSize,

                             0, // DLLs are always mapped at offset 0 on Windows

                             breakpadId,

                             pdbName);

         sharedLibraryInfo.AddSharedLibrary(shlib);

       }

       FreeLibrary(handleLock); // ok to free null handles

     } while (Module32Next(snap, &module));

   }

   return sharedLibraryInfo;

 }