Bug 1242343 - p1. ConstructSystem32Path from LoadLibrarySystem32 - r=jimm

Part 1: Refactored LoadLibrarySystem32 to expose the system32-path
construction code, so it can be re-used in the following patch.

MozReview-Commit-ID: J5BcI34VPnN
This commit is contained in:
Gerald Squelart 2016-03-03 08:40:23 +11:00
parent eb4b12ce18
commit 18397e72f3

View File

@ -10,6 +10,7 @@
#include <windows.h>
#include "nsAutoRef.h"
#include "nscore.h"
#include "mozilla/Assertions.h"
// ----------------------------------------------------------------------------
// Critical Section helper class
@ -223,30 +224,57 @@ typedef nsAutoRef<DEVMODEW*> nsAutoDevMode;
namespace {
// Construct a path "<system32>\<aModule>". return false if the output buffer
// is too small.
// Note: If the system path cannot be found, or doesn't fit in the output buffer
// with the module name, we will just ignore the system path and output the
// module name alone;
// this may mean using a normal search path wherever the output is used.
bool inline
ConstructSystem32Path(LPCWSTR aModule, WCHAR* aSystemPath, UINT aSize)
{
MOZ_ASSERT(aSystemPath);
size_t fileLen = wcslen(aModule);
if (fileLen >= aSize) {
// The module name alone cannot even fit!
return false;
}
size_t systemDirLen = GetSystemDirectoryW(aSystemPath, aSize);
if (systemDirLen) {
if (systemDirLen < aSize - fileLen) {
// Make the system directory path terminate with a slash.
if (aSystemPath[systemDirLen - 1] != L'\\') {
if (systemDirLen + 1 < aSize - fileLen) {
aSystemPath[systemDirLen] = L'\\';
++systemDirLen;
// No need to re-nullptr terminate.
} else {
// Couldn't fit the system path with added slash.
systemDirLen = 0;
}
}
} else {
// Couldn't fit the system path.
systemDirLen = 0;
}
}
MOZ_ASSERT(systemDirLen + fileLen < aSize);
wcsncpy(aSystemPath + systemDirLen, aModule, fileLen);
aSystemPath[systemDirLen + fileLen] = L'\0';
return true;
}
HMODULE inline
LoadLibrarySystem32(LPCWSTR aModule)
{
WCHAR systemPath[MAX_PATH + 1] = { L'\0' };
// If GetSystemPath fails we accept that we'll load the DLLs from the
// normal search path.
GetSystemDirectoryW(systemPath, MAX_PATH + 1);
size_t systemDirLen = wcslen(systemPath);
// Make the system directory path terminate with a slash
if (systemDirLen && systemPath[systemDirLen - 1] != L'\\') {
systemPath[systemDirLen] = L'\\';
++systemDirLen;
// No need to re-nullptr terminate
}
size_t fileLen = wcslen(aModule);
wcsncpy(systemPath + systemDirLen, aModule,
MAX_PATH - systemDirLen);
if (systemDirLen + fileLen <= MAX_PATH) {
systemPath[systemDirLen + fileLen] = L'\0';
} else {
systemPath[MAX_PATH] = L'\0';
WCHAR systemPath[MAX_PATH + 1];
if (!ConstructSystem32Path(aModule, systemPath, MAX_PATH + 1)) {
return NULL;
}
return LoadLibraryW(systemPath);
}