diff --git a/accessible/ipc/win/moz.build b/accessible/ipc/win/moz.build
index e6478444ca..c8b5253589 100644
--- a/accessible/ipc/win/moz.build
+++ b/accessible/ipc/win/moz.build
@@ -4,7 +4,8 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 if CONFIG['COMPILE_ENVIRONMENT']:
-    DIRS += ['typelib']
+    if CONFIG['CC_TYPE'] == 'msvc':
+        DIRS += ['typelib']
 
 # With --disable-accessibility, we need to compile PDocAccessible.ipdl (which
 # also depends on COMPtrTypes.h), but not the C++.
diff --git a/accessible/ipc/win/typelib/moz.build b/accessible/ipc/win/typelib/moz.build
index 1246e80e19..e580370fd2 100644
--- a/accessible/ipc/win/typelib/moz.build
+++ b/accessible/ipc/win/typelib/moz.build
@@ -3,10 +3,11 @@
 # 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/.
 
-FINAL_TARGET_FILES += [
-    '!Accessible.tlb',
-]
+if CONFIG['CC_TYPE'] == 'msvc':
+    FINAL_TARGET_FILES += [
+        '!Accessible.tlb',
+    ]
 
-GENERATED_FILES += [
-    'Accessible.tlb',
-]
+    GENERATED_FILES += [
+        'Accessible.tlb',
+    ]
diff --git a/application/basilisk/app/nsBrowserApp.cpp b/application/basilisk/app/nsBrowserApp.cpp
index c8b6293dbb..d79c302769 100644
--- a/application/basilisk/app/nsBrowserApp.cpp
+++ b/application/basilisk/app/nsBrowserApp.cpp
@@ -7,9 +7,9 @@
 #include "mozilla/AppData.h"
 #include "application.ini.h"
 #include "nsXPCOMGlue.h"
+#include <stdlib.h>
 #if defined(XP_WIN)
 #include <windows.h>
-#include <stdlib.h>
 #elif defined(XP_UNIX)
 #include <sys/resource.h>
 #include <unistd.h>
diff --git a/application/basilisk/components/shell/nsWindowsShellService.cpp b/application/basilisk/components/shell/nsWindowsShellService.cpp
index a45f539321..413d8bada2 100644
--- a/application/basilisk/components/shell/nsWindowsShellService.cpp
+++ b/application/basilisk/components/shell/nsWindowsShellService.cpp
@@ -5,6 +5,8 @@
 
 #include "nsWindowsShellService.h"
 
+#include <stdlib.h>
+
 #include "imgIContainer.h"
 #include "imgIRequest.h"
 #include "mozilla/gfx/2D.h"
diff --git a/build/win32/moz.build b/build/win32/moz.build
index 8b0f8195e5..6ca07c1baa 100644
--- a/build/win32/moz.build
+++ b/build/win32/moz.build
@@ -14,14 +14,15 @@ if CONFIG['ENABLE_TESTS']:
 
 NO_PGO = True
 
-if CONFIG['WIN32_REDIST_DIR'] and CONFIG['COMPILE_ENVIRONMENT']:
-    for f in ['MSVC_C_RUNTIME_DLL', 'MSVC_CMP_RUNTIME_DLL', 'MSVC_CXX_RUNTIME_DLL']:
-        FINAL_TARGET_FILES += [
-            '%%%s/%s' % (CONFIG['WIN32_REDIST_DIR'], CONFIG[f])
-        ]
+if CONFIG['CC_TYPE'] == 'msvc':
+    if CONFIG['WIN32_REDIST_DIR'] and CONFIG['COMPILE_ENVIRONMENT']:
+        for f in ['MSVC_C_RUNTIME_DLL', 'MSVC_CMP_RUNTIME_DLL', 'MSVC_CXX_RUNTIME_DLL']:
+            FINAL_TARGET_FILES += [
+                '%%%s/%s' % (CONFIG['WIN32_REDIST_DIR'], CONFIG[f])
+            ]
 
-if CONFIG['WIN_UCRT_REDIST_DIR'] and CONFIG['COMPILE_ENVIRONMENT']:
-    for f in ['api-ms-win-*.dll', 'ucrtbase.dll']:
-        FINAL_TARGET_FILES += [
-            '%%%s/%s' % (CONFIG['WIN_UCRT_REDIST_DIR'], f)
-        ]
+    if CONFIG['WIN_UCRT_REDIST_DIR'] and CONFIG['COMPILE_ENVIRONMENT']:
+        for f in ['api-ms-win-*.dll', 'ucrtbase.dll']:
+            FINAL_TARGET_FILES += [
+                '%%%s/%s' % (CONFIG['WIN_UCRT_REDIST_DIR'], f)
+            ]
diff --git a/dom/media/platforms/wmf/DXVA2Manager.cpp b/dom/media/platforms/wmf/DXVA2Manager.cpp
index fbb659fac7..304b91ed36 100644
--- a/dom/media/platforms/wmf/DXVA2Manager.cpp
+++ b/dom/media/platforms/wmf/DXVA2Manager.cpp
@@ -20,7 +20,7 @@
 #include "nsPrintfCString.h"
 #include "VideoUtils.h"
 
-const CLSID CLSID_VideoProcessorMFT =
+const CLSID sCLSID_VideoProcessorMFT =
 {
   0x88753b26,
   0x5b24,
@@ -666,7 +666,7 @@ D3D11DXVA2Manager::Init(layers::KnowsCompositor* aKnowsCompositor,
   }
 
   mTransform = new MFTDecoder();
-  hr = mTransform->Create(CLSID_VideoProcessorMFT);
+  hr = mTransform->Create(sCLSID_VideoProcessorMFT);
   if (!SUCCEEDED(hr)) {
     aFailureReason = nsPrintfCString("MFTDecoder::Create(CLSID_VideoProcessorMFT) failed with code %X", hr);
     return hr;
diff --git a/dom/media/platforms/wmf/WMF.h b/dom/media/platforms/wmf/WMF.h
index 394fb455ad..aa54f8e32f 100644
--- a/dom/media/platforms/wmf/WMF.h
+++ b/dom/media/platforms/wmf/WMF.h
@@ -18,6 +18,7 @@ which makes Windows Media Foundation unavailable.
 #undef WINVER
 #define WINVER _WIN32_WINNT_WIN7
 
+#include <stdlib.h>
 #include <windows.h>
 #include <mfapi.h>
 #include <mfidl.h>
diff --git a/embedding/components/printingui/win/nsPrintDialogUtil.cpp b/embedding/components/printingui/win/nsPrintDialogUtil.cpp
index 896c58e856..5439c512b1 100644
--- a/embedding/components/printingui/win/nsPrintDialogUtil.cpp
+++ b/embedding/components/printingui/win/nsPrintDialogUtil.cpp
@@ -21,12 +21,6 @@ WIN_LIBS=                                       \
 ---------------------------------------------------------------------- */
 
 #include "plstr.h"
-#include <windows.h>
-#include <tchar.h>
-
-#include <unknwn.h>
-#include <commdlg.h>
-
 #include "nsIWebBrowserPrint.h"
 #include "nsString.h"
 #include "nsIServiceManager.h"
@@ -43,7 +37,13 @@ WIN_LIBS=                                       \
 #include "nsCRT.h"
 #include "prenv.h" /* for PR_GetEnv */
 
+#include <stdlib.h>
 #include <windows.h>
+#include <tchar.h>
+
+#include <unknwn.h>
+#include <commdlg.h>
+
 #include <winspool.h> 
 
 // For Localization
diff --git a/gfx/layers/d3d11/ReadbackManagerD3D11.h b/gfx/layers/d3d11/ReadbackManagerD3D11.h
index d15346fd86..1a22680010 100644
--- a/gfx/layers/d3d11/ReadbackManagerD3D11.h
+++ b/gfx/layers/d3d11/ReadbackManagerD3D11.h
@@ -6,6 +6,7 @@
 #ifndef GFX_READBACKMANAGERD3D11_H
 #define GFX_READBACKMANAGERD3D11_H
 
+#include <stdlib.h>
 #include <windows.h>
 #include <d3d10_1.h>
 
diff --git a/gfx/layers/d3d11/TextureD3D11.h b/gfx/layers/d3d11/TextureD3D11.h
index 86db51df13..7681b91486 100644
--- a/gfx/layers/d3d11/TextureD3D11.h
+++ b/gfx/layers/d3d11/TextureD3D11.h
@@ -238,7 +238,7 @@ public:
   virtual ID3D11ShaderResourceView* GetShaderResourceView() override;
 
   // Returns nullptr if this texture was created by a DXGI TextureHost.
-  virtual DataTextureSource* AsDataTextureSource() override { return mAllowTextureUploads ? this : false; }
+  virtual DataTextureSource* AsDataTextureSource() override { return mAllowTextureUploads ? this : nullptr; }
 
   virtual void DeallocateDeviceData() override { mTexture = nullptr; }
 
diff --git a/js/src/jsmath.cpp b/js/src/jsmath.cpp
index 92536c36e6..ef42864edc 100644
--- a/js/src/jsmath.cpp
+++ b/js/src/jsmath.cpp
@@ -709,7 +709,11 @@ GenerateRandomSeed()
 {
     uint64_t seed = 0;
 
-#if defined(__linux__)
+#if defined(XP_WIN)
+    if (SystemFunction036(&seed, sizeof(seed)))
+        return seed;
+
+#elif defined(__linux__)
     // Linux does not provide arc4random(), so use /dev/urandom.
     int fd = open("/dev/urandom", O_RDONLY);
     if (fd >= 0) {
@@ -732,8 +736,10 @@ GenerateRandomSeed()
 
 #else
     // Generic fallback
-    uint32_t lo = random();
-    uint32_t hi = random();
+    uint32_t lo = 0;
+    uint32_t hi = 0;
+    lo = static_cast<uint32_t>(rand());
+    hi = static_cast<uint32_t>(rand());
     return (static_cast<uint64_t>(hi) << 32) | lo;
 #endif
 }
diff --git a/layout/base/nsRefreshDriver.cpp b/layout/base/nsRefreshDriver.cpp
index b35316a9f5..58157d8883 100644
--- a/layout/base/nsRefreshDriver.cpp
+++ b/layout/base/nsRefreshDriver.cpp
@@ -17,6 +17,7 @@
  */
 
 #ifdef XP_WIN
+#include <stdlib.h>
 #include <windows.h>
 // mmsystem isn't part of WIN32_LEAN_AND_MEAN, so we have
 // to manually include it
diff --git a/media/libstagefright/ports/win32/include/pthread.h b/media/libstagefright/ports/win32/include/pthread.h
index 1aa4e70323..c31d9a7e54 100644
--- a/media/libstagefright/ports/win32/include/pthread.h
+++ b/media/libstagefright/ports/win32/include/pthread.h
@@ -1 +1,13 @@
-// Intentionally left blank
+/*
+ * Stagefright's win32 include path shadows the toolchain <pthread.h>.
+ * On MinGW we need the real pthread declarations for libstdc++ gthr.
+ */
+
+#ifndef stagefright_win32_pthread_h
+#define stagefright_win32_pthread_h
+
+#if defined(__MINGW32__)
+#  include_next <pthread.h>
+#endif
+
+#endif
diff --git a/media/mtransport/nrinterfaceprioritizer.cpp b/media/mtransport/nrinterfaceprioritizer.cpp
index 90ab1bc60e..47760a3997 100644
--- a/media/mtransport/nrinterfaceprioritizer.cpp
+++ b/media/mtransport/nrinterfaceprioritizer.cpp
@@ -43,9 +43,9 @@ public:
     }
     addr_ = buf;
 
-    is_vpn_ = (local_addr.interface.type & NR_INTERFACE_TYPE_VPN) != 0 ? 1 : 0;
-    estimated_speed_ = local_addr.interface.estimated_speed;
-    type_preference_ = GetNetworkTypePreference(local_addr.interface.type);
+    is_vpn_ = (local_addr.if_info.type & NR_INTERFACE_TYPE_VPN) != 0 ? 1 : 0;
+    estimated_speed_ = local_addr.if_info.estimated_speed;
+    type_preference_ = GetNetworkTypePreference(local_addr.if_info.type);
     ip_version_ = local_addr.addr.ip_version;
     return true;
   }
diff --git a/media/mtransport/test/ice_unittest.cpp b/media/mtransport/test/ice_unittest.cpp
index c20cfd271c..0a75bd0834 100644
--- a/media/mtransport/test/ice_unittest.cpp
+++ b/media/mtransport/test/ice_unittest.cpp
@@ -1996,8 +1996,8 @@ class WebRtcIcePrioritizerTest : public StunTest {
     std::string str_addr = "10.0.0." + num;
     std::string ifname = "eth" + num;
     nr_local_addr local_addr;
-    local_addr.interface.type = type;
-    local_addr.interface.estimated_speed = estimated_speed;
+    local_addr.if_info.type = type;
+    local_addr.if_info.estimated_speed = estimated_speed;
 
     int r = nr_str_port_to_transport_addr(str_addr.c_str(), 0,
                                           IPPROTO_UDP, &(local_addr.addr));
diff --git a/media/mtransport/third_party/nICEr/src/net/local_addr.c b/media/mtransport/third_party/nICEr/src/net/local_addr.c
index c251f2215d..23777e1480 100644
--- a/media/mtransport/third_party/nICEr/src/net/local_addr.c
+++ b/media/mtransport/third_party/nICEr/src/net/local_addr.c
@@ -40,13 +40,13 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 int nr_local_addr_copy(nr_local_addr *to, nr_local_addr *from)
   {
     nr_transport_addr_copy(&(to->addr), &(from->addr));
-    to->interface = from->interface;
+    to->if_info = from->if_info;
     return(0);
   }
 
 int nr_local_addr_fmt_info_string(nr_local_addr *addr, char *buf, int len)
   {
-    int addr_type = addr->interface.type;
+    int addr_type = addr->if_info.type;
     const char *vpn = (addr_type & NR_INTERFACE_TYPE_VPN) ? "VPN on " : "";
 
     const char *type = (addr_type & NR_INTERFACE_TYPE_WIRED) ? "wired" :
@@ -55,7 +55,7 @@ int nr_local_addr_fmt_info_string(nr_local_addr *addr, char *buf, int len)
                        "unknown";
 
     snprintf(buf, len, "%s%s, estimated speed: %d kbps",
-             vpn, type, addr->interface.estimated_speed);
+             vpn, type, addr->if_info.estimated_speed);
     buf[len - 1] = '\0';
     return (0);
   }
diff --git a/media/mtransport/third_party/nICEr/src/net/local_addr.h b/media/mtransport/third_party/nICEr/src/net/local_addr.h
index 90e538856e..18d80a4551 100644
--- a/media/mtransport/third_party/nICEr/src/net/local_addr.h
+++ b/media/mtransport/third_party/nICEr/src/net/local_addr.h
@@ -50,7 +50,7 @@ typedef struct nr_interface_ {
 
 typedef struct nr_local_addr_ {
   nr_transport_addr addr;
-  nr_interface interface;
+  nr_interface if_info;
 } nr_local_addr;
 
 int nr_local_addr_copy(nr_local_addr *to, nr_local_addr *from);
diff --git a/media/mtransport/third_party/nICEr/src/stun/addrs.c b/media/mtransport/third_party/nICEr/src/stun/addrs.c
index c90191f73d..3d6a16eb34 100644
--- a/media/mtransport/third_party/nICEr/src/stun/addrs.c
+++ b/media/mtransport/third_party/nICEr/src/stun/addrs.c
@@ -220,18 +220,18 @@ stun_get_win32_addrs(nr_local_addr addrs[], int maxaddrs, int *count)
 
           strlcpy(addrs[n].addr.ifname, hex_hashed_ifname, sizeof(addrs[n].addr.ifname));
           if (tmpAddress->IfType == IF_TYPE_ETHERNET_CSMACD) {
-            addrs[n].interface.type = NR_INTERFACE_TYPE_WIRED;
+            addrs[n].if_info.type = NR_INTERFACE_TYPE_WIRED;
           } else if (tmpAddress->IfType == IF_TYPE_IEEE80211) {
             /* Note: this only works for >= Win Vista */
-            addrs[n].interface.type = NR_INTERFACE_TYPE_WIFI;
+            addrs[n].if_info.type = NR_INTERFACE_TYPE_WIFI;
           } else {
-            addrs[n].interface.type = NR_INTERFACE_TYPE_UNKNOWN;
+            addrs[n].if_info.type = NR_INTERFACE_TYPE_UNKNOWN;
           }
 #if (_WIN32_WINNT >= 0x0600)
           /* Note: only >= Vista provide link speed information */
-          addrs[n].interface.estimated_speed = tmpAddress->TransmitLinkSpeed / 1000;
+          addrs[n].if_info.estimated_speed = tmpAddress->TransmitLinkSpeed / 1000;
 #else
-          addrs[n].interface.estimated_speed = 0;
+          addrs[n].if_info.estimated_speed = 0;
 #endif
           if (++n >= maxaddrs)
             goto done;
@@ -300,11 +300,11 @@ stun_getifaddrs(nr_local_addr addrs[], int maxaddrs, int *count)
             {
                /* For wireless network, we won't get ethtool, it's a wired
                 * connection */
-               addrs[*count].interface.type = NR_INTERFACE_TYPE_WIRED;
+               addrs[*count].if_info.type = NR_INTERFACE_TYPE_WIRED;
 #ifdef DONT_HAVE_ETHTOOL_SPEED_HI
-               addrs[*count].interface.estimated_speed = ecmd.speed;
+               addrs[*count].if_info.estimated_speed = ecmd.speed;
 #else
-               addrs[*count].interface.estimated_speed = ((ecmd.speed_hi << 16) | ecmd.speed) * 1000;
+               addrs[*count].if_info.estimated_speed = ((ecmd.speed_hi << 16) | ecmd.speed) * 1000;
 #endif
             }
 
@@ -312,20 +312,20 @@ stun_getifaddrs(nr_local_addr addrs[], int maxaddrs, int *count)
             e = ioctl(s, SIOCGIWRATE, &wrq);
             if (e == 0)
             {
-               addrs[*count].interface.type = NR_INTERFACE_TYPE_WIFI;
-               addrs[*count].interface.estimated_speed = wrq.u.bitrate.value / 1000;
+              addrs[*count].if_info.type = NR_INTERFACE_TYPE_WIFI;
+              addrs[*count].if_info.estimated_speed = wrq.u.bitrate.value / 1000;
             }
 
             close(s);
 
             if (if_addr->ifa_flags & IFF_POINTOPOINT)
             {
-               addrs[*count].interface.type = NR_INTERFACE_TYPE_UNKNOWN | NR_INTERFACE_TYPE_VPN;
+              addrs[*count].if_info.type = NR_INTERFACE_TYPE_UNKNOWN | NR_INTERFACE_TYPE_VPN;
                /* TODO (Bug 896913): find backend network type of this VPN */
             }
 #else
-            addrs[*count].interface.type = NR_INTERFACE_TYPE_UNKNOWN;
-            addrs[*count].interface.estimated_speed = 0;
+            addrs[*count].if_info.type = NR_INTERFACE_TYPE_UNKNOWN;
+            addrs[*count].if_info.estimated_speed = 0;
 #endif
             strlcpy(addrs[*count].addr.ifname, if_addr->ifa_name, sizeof(addrs[*count].addr.ifname));
             ++(*count);
diff --git a/media/webrtc/trunk/webrtc/base/platform_thread.cc b/media/webrtc/trunk/webrtc/base/platform_thread.cc
index 0a394331ff..398617f66f 100644
--- a/media/webrtc/trunk/webrtc/base/platform_thread.cc
+++ b/media/webrtc/trunk/webrtc/base/platform_thread.cc
@@ -73,11 +73,17 @@ void SetCurrentThreadName(const char* name) {
     DWORD dwFlags;
   } threadname_info = {0x1000, name, static_cast<DWORD>(-1), 0};
 
+#if defined(_MSC_VER)
   __try {
     ::RaiseException(0x406D1388, 0, sizeof(threadname_info) / sizeof(DWORD),
                      reinterpret_cast<ULONG_PTR*>(&threadname_info));
   } __except (EXCEPTION_EXECUTE_HANDLER) {
   }
+#else
+  // MinGW does not support MSVC's __try/__except syntax.
+  ::RaiseException(0x406D1388, 0, sizeof(threadname_info) / sizeof(DWORD),
+                   reinterpret_cast<ULONG_PTR*>(&threadname_info));
+#endif
 #elif defined(WEBRTC_LINUX) || defined(WEBRTC_ANDROID)
   prctl(PR_SET_NAME, reinterpret_cast<unsigned long>(name));
 #elif defined(WEBRTC_MAC) || defined(WEBRTC_IOS)
diff --git a/media/webrtc/trunk/webrtc/base/proxydetect.cc b/media/webrtc/trunk/webrtc/base/proxydetect.cc
index 30959ca1d3..6e38f4a64b 100644
--- a/media/webrtc/trunk/webrtc/base/proxydetect.cc
+++ b/media/webrtc/trunk/webrtc/base/proxydetect.cc
@@ -605,7 +605,7 @@ BOOL MyWinHttpGetProxyForUrl(pfnWinHttpGetProxyForUrl pWHGPFU,
   // error.
   BOOL success = FALSE;
 
-#if (_HAS_EXCEPTIONS == 0)
+#if (_HAS_EXCEPTIONS == 0) && defined(_MSC_VER)
   __try {
     success = pWHGPFU(hWinHttp, url, options, info);
   } __except(EXCEPTION_EXECUTE_HANDLER) {
diff --git a/media/webrtc/trunk/webrtc/modules/video_capture/windows/video_capture_ds.h b/media/webrtc/trunk/webrtc/modules/video_capture/windows/video_capture_ds.h
index ab4f69157b..5fe56c9013 100644
--- a/media/webrtc/trunk/webrtc/modules/video_capture/windows/video_capture_ds.h
+++ b/media/webrtc/trunk/webrtc/modules/video_capture/windows/video_capture_ds.h
@@ -60,7 +60,7 @@ protected:
                         int32_t capabilityIndex);
 
     int32_t DisconnectGraph();
-    HRESULT VideoCaptureDS::ConnectDVCamera();
+    HRESULT ConnectDVCamera();
 
     DeviceInfoDS _dsInfo;
     VideoCaptureCapability _activeCapability;
diff --git a/media/webrtc/trunk/webrtc/test/testsupport/fileutils.cc b/media/webrtc/trunk/webrtc/test/testsupport/fileutils.cc
index 15abf5c517..af389272bd 100644
--- a/media/webrtc/trunk/webrtc/test/testsupport/fileutils.cc
+++ b/media/webrtc/trunk/webrtc/test/testsupport/fileutils.cc
@@ -12,6 +12,8 @@
 
 #include <assert.h>
 
+#include <stdlib.h>
+
 #ifdef WIN32
 #include <direct.h>
 #include <tchar.h>
@@ -33,7 +35,6 @@
 #endif
 
 #include <stdio.h>
-#include <stdlib.h>
 #include <string.h>
 
 #include "webrtc/typedefs.h"  // For architecture defines
diff --git a/memory/mozjemalloc/jemalloc.c b/memory/mozjemalloc/jemalloc.c
index f4a9fd5d75..7b42753b63 100644
--- a/memory/mozjemalloc/jemalloc.c
+++ b/memory/mozjemalloc/jemalloc.c
@@ -212,6 +212,7 @@ static unsigned long tlsIndex = 0xffffffff;
 #define	_pthread_self() __threadid()
 
 /* use MSVC intrinsics */
+#if defined(_MSC_VER)
 #pragma intrinsic(_BitScanForward)
 static __forceinline int
 ffs(int x)
@@ -223,6 +224,16 @@ ffs(int x)
 
 	return (0);
 }
+#else
+static inline int
+ffs(int x)
+{
+	if (x == 0)
+		return (0);
+
+	return (__builtin_ctz((unsigned int)x) + 1);
+}
+#endif
 
 /* Implement getenv without using malloc */
 static char mozillaMallocOptionsBuf[64];
@@ -243,11 +254,13 @@ typedef unsigned char uint8_t;
 typedef unsigned uint32_t;
 typedef unsigned long long uint64_t;
 typedef unsigned long long uintmax_t;
+#if !defined(_SSIZE_T_) && !defined(_SSIZE_T_DEFINED)
 #if defined(_WIN64)
 typedef long long ssize_t;
 #else
 typedef long ssize_t;
 #endif
+#endif
 
 #define	MALLOC_DECOMMIT
 #endif
diff --git a/modules/zlib/src/chunkcopy.h b/modules/zlib/src/chunkcopy.h
index 70a5686008..2c73b14e9f 100644
--- a/modules/zlib/src/chunkcopy.h
+++ b/modules/zlib/src/chunkcopy.h
@@ -36,6 +36,12 @@ typedef __m128i z_vec128i_t;
 #error chunkcopy.h inflate chunk SIMD is not defined for your build target
 #endif
 
+#if defined(_MSC_VER)
+#define Z_ALIGN16(type, name) __declspec(align(16)) type name
+#else
+#define Z_ALIGN16(type, name) type name __attribute__((aligned(16)))
+#endif
+
 #ifdef _MSC_VER
 #if _MSC_VER < 1900
 #define inline 
@@ -222,7 +228,7 @@ static inline z_vec128i_t v_load64_dup(const void* src) {
 #if 0//def _WIN64
   return _mm_set1_epi64x(i64);
 #else
-  _declspec(align(16)) uint64_t temp[2] = {i64, i64};
+  Z_ALIGN16(uint64_t, temp[2]) = {i64, i64};
   return _mm_load_si128((const __m128i*)temp);
 #endif
 }
diff --git a/modules/zlib/src/moz.build b/modules/zlib/src/moz.build
index 2634a3bd9f..324ac6cb17 100644
--- a/modules/zlib/src/moz.build
+++ b/modules/zlib/src/moz.build
@@ -88,4 +88,8 @@ else:
         'inflate.c',
     ]
 
+if CONFIG['OS_ARCH'] == 'WINNT' and CONFIG['GNU_CC']:
+    SOURCES['crc32_simd.c'].flags += ['-msse4.2', '-mpclmul']
+    SOURCES['crc_folding.c'].flags += ['-msse4.2', '-mpclmul']
+
 
diff --git a/mozconfigs/uxp-win32-mingw32 b/mozconfigs/uxp-win32-mingw32
new file mode 100644
index 0000000000..d81cb1b072
--- /dev/null
+++ b/mozconfigs/uxp-win32-mingw32
@@ -0,0 +1,85 @@
+## UXP mozconfig thing based off roytam1's config and r3dfox config
+
+##Uncomment PGO for release build
+
+# 16 jobs for 16 cores
+mk_add_options MOZ_MAKE_FLAGS="-j6"
+
+# x86 build
+ac_add_options --host=i686-pc-mingw32
+ac_add_options --target=i686-pc-mingw32
+WIN32_REDIST_DIR=$VCINSTALLDIR/Redist/MSVC/14.16.27012/x86
+WIN_UCRT_REDIST_DIR=$WINDOWSSDKDIR/Redist/10.0.19041.0/ucrt/DLLs/r86
+
+CC=gcc
+CXX=g++
+LD=g++
+AR=ar
+AS=as
+RANLIB=ranlib
+
+# Build only Hydra
+ac_add_options --enable-application=basilisk
+ac_add_options --disable-artifact-builds
+
+# Updater stuffs
+ac_add_options --disable-updater
+# Enable if update server and signatures are figured out
+#ac_add_options --enable-nss-mar
+
+# Optimization settings
+ac_add_options --disable-accessibility
+ac_add_options --disable-debug
+ac_add_options --disable-debug-js-modules
+ac_add_options --disable-debug-symbols
+ac_add_options --disable-tests
+ac_add_options --enable-devtools
+#ac_add_options --enable-install-strip
+ac_add_options --enable-jemalloc
+ac_add_options --enable-js-lto
+ac_add_options --enable-optimize="-O2"
+ac_add_options --enable-phoenix-extensions
+ac_add_options --enable-release
+ac_add_options --enable-shared-js
+ac_add_options --enable-strip
+MOZ_OPTIMIZE=1
+export MOZ_OPTIMIZE=1
+mk_add_options MOZ_OPTIMIZE=1
+export MOZILLA_OFFICIAL=1
+export STRIP_FLAGS="--strip-debug --strip-unneeded"
+
+# Media settings
+ac_add_options --enable-av1
+ac_add_options --enable-jxl
+ac_add_options --enable-raw
+ac_add_options --disable-webrtc
+
+
+# Client settings
+ac_add_options --disable-crashreporter
+ac_add_options --disable-eme
+ac_add_options --disable-maintenance-service
+ac_add_options --disable-parental-controls
+mk_add_options MOZ_SERVICES_HEALTHREPORT=0
+export CROSS_COMPILE=0
+export MOZ_CRASHREPORTER=0
+export MOZ_DATA_REPORTING=0
+export MOZ_INCLUDE_SOURCE_INFO=1
+export MOZ_REQUIRE_SIGNING=
+export MOZ_SOURCE_CHANGESET=iloveneedingtobodgechangesetfornoreason
+export MOZ_TELEMETRY_REPORTING=
+export MOZ_PACKAGE_JSSHELL=1
+
+# Set -Copt-level=3
+export OPT_LEVEL="3"
+ac_add_options OPT_LEVEL="3"
+
+# Enable LTO
+export MOZ_LTO=1
+ac_add_options MOZ_LTO=1
+
+# Stops the compiler from bitching
+export CFLAGS="-O2 -std=gnu++17"
+export CPPFLAGS="-O2 -std=gnu++17"
+export CXXFLAGS="-O2 -std=gnu++17"
+export VERBOSE=0
\ No newline at end of file
diff --git a/mozconfigs/uxp-win32 b/mozconfigs/uxp-win32-msvc
similarity index 100%
rename from mozconfigs/uxp-win32
rename to mozconfigs/uxp-win32-msvc
diff --git a/netwerk/base/NetworkInfoServiceWindows.cpp b/netwerk/base/NetworkInfoServiceWindows.cpp
index 533e1a67b2..b6f6c00364 100644
--- a/netwerk/base/NetworkInfoServiceWindows.cpp
+++ b/netwerk/base/NetworkInfoServiceWindows.cpp
@@ -3,11 +3,12 @@
  * 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 <stdlib.h>
 #include <winsock2.h>
 #include <ws2ipdef.h>
 #include <iphlpapi.h>
 
-#include "mozilla/UniquePtr.h"
+#include "mozilla/UniquePtrExtensions.h"
 
 #include "NetworkInfoServiceImpl.h"
 
@@ -17,7 +18,7 @@ namespace net {
 nsresult
 DoListAddresses(AddrMapType& aAddrMap)
 {
-  UniquePtr<MIB_IPADDRTABLE> ipAddrTable;
+  UniqueFreePtr<MIB_IPADDRTABLE> ipAddrTable;
   DWORD size = sizeof(MIB_IPADDRTABLE);
 
   ipAddrTable.reset((MIB_IPADDRTABLE*) malloc(size));
diff --git a/netwerk/base/nsNetworkInfoService.cpp b/netwerk/base/nsNetworkInfoService.cpp
index 2d63ae94e6..21963cf5ec 100644
--- a/netwerk/base/nsNetworkInfoService.cpp
+++ b/netwerk/base/nsNetworkInfoService.cpp
@@ -6,6 +6,7 @@
 #if defined(XP_MACOSX) || defined(XP_LINUX)
 #include <unistd.h>
 #elif defined(XP_WIN)
+#include <stdlib.h>
 #include <winsock2.h>
 #endif
 
diff --git a/netwerk/system/win32/nsNotifyAddrListener.cpp b/netwerk/system/win32/nsNotifyAddrListener.cpp
index 58f4345ef8..0832fff860 100644
--- a/netwerk/system/win32/nsNotifyAddrListener.cpp
+++ b/netwerk/system/win32/nsNotifyAddrListener.cpp
@@ -8,6 +8,7 @@
 // inet_ntop() doesn't exist on Windows XP.
 #define _WINSOCK_DEPRECATED_NO_WARNINGS
 
+#include <stdlib.h>
 #include <stdarg.h>
 #include <windef.h>
 #include <winbase.h>
diff --git a/python/mozbuild/mozbuild/backend/visualstudio.py b/python/mozbuild/mozbuild/backend/visualstudio.py
index 86e97d13d3..1cb01c5f89 100644
--- a/python/mozbuild/mozbuild/backend/visualstudio.py
+++ b/python/mozbuild/mozbuild/backend/visualstudio.py
@@ -66,7 +66,7 @@ class VisualStudioBackend(CommonBackend):
         self._out_dir = os.path.join(self.environment.topobjdir, 'msvc')
         self._projsubdir = 'projects'
 
-        self._version = self.environment.substs.get('MSVS_VERSION', '2015')
+        self._version = self.environment.substs.get('MSVS_VERSION')
 
         self._paths_to_sources = {}
         self._paths_to_includes = {}
@@ -132,6 +132,12 @@ class VisualStudioBackend(CommonBackend):
         out_dir = self._out_dir
         out_proj_dir = os.path.join(self._out_dir, self._projsubdir)
 
+        # If we do not have an MSVC version, we should not generate Visual
+        # Studio projects.
+        version = self._version
+        if not version:
+            return
+
         projects = self._write_projects_for_sources(self._libs_to_paths,
             "library", out_proj_dir)
         projects.update(self._write_projects_for_sources(self._progs_to_paths,
diff --git a/toolkit/mozapps/update/common/updatecommon.cpp b/toolkit/mozapps/update/common/updatecommon.cpp
index aff7d72602..6d86022d26 100644
--- a/toolkit/mozapps/update/common/updatecommon.cpp
+++ b/toolkit/mozapps/update/common/updatecommon.cpp
@@ -3,13 +3,13 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #if defined(XP_WIN)
+#include <stdlib.h>
 #include <windows.h>
 #endif
 
 
 #include <stdio.h>
 #include <string.h>
-#include <stdlib.h>
 #include <stdarg.h>
 
 #include "updatecommon.h"
diff --git a/toolkit/system/windowsproxy/nsWindowsSystemProxySettings.cpp b/toolkit/system/windowsproxy/nsWindowsSystemProxySettings.cpp
index bb5f72b691..26b724d3eb 100644
--- a/toolkit/system/windowsproxy/nsWindowsSystemProxySettings.cpp
+++ b/toolkit/system/windowsproxy/nsWindowsSystemProxySettings.cpp
@@ -3,6 +3,7 @@
  * 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 <stdlib.h>
 #include <windows.h>
 #include <ras.h>
 #include <wininet.h>
diff --git a/toolkit/xre/nsAppRunner.cpp b/toolkit/xre/nsAppRunner.cpp
index c11ca26c40..673f663b7b 100644
--- a/toolkit/xre/nsAppRunner.cpp
+++ b/toolkit/xre/nsAppRunner.cpp
@@ -93,6 +93,7 @@
 
 #ifdef XP_WIN
 #include "nsIWinAppHelper.h"
+#include <stdlib.h>
 #include <windows.h>
 #include <intrin.h>
 #include <math.h>
@@ -136,7 +137,6 @@
 #include "mozilla/StartupTimeline.h"
 #include "mozilla/LateWriteChecks.h"
 
-#include <stdlib.h>
 #include <locale.h>
 
 #ifdef XP_UNIX
diff --git a/toolkit/xre/nsNativeAppSupportWin.cpp b/toolkit/xre/nsNativeAppSupportWin.cpp
index 0605ccb5af..7d046f977e 100644
--- a/toolkit/xre/nsNativeAppSupportWin.cpp
+++ b/toolkit/xre/nsNativeAppSupportWin.cpp
@@ -41,11 +41,11 @@
 #include "nsNativeCharsetUtils.h"
 #include "nsIAppStartup.h"
 
+#include <stdlib.h>
+#include <stdio.h>
 #include <windows.h>
 #include <shellapi.h>
 #include <ddeml.h>
-#include <stdlib.h>
-#include <stdio.h>
 #include <io.h>
 #include <direct.h>
 #include <fcntl.h>
diff --git a/widget/windows/AudioSession.cpp b/widget/windows/AudioSession.cpp
index 11e5ba50cd..084fd3d7dd 100644
--- a/widget/windows/AudioSession.cpp
+++ b/widget/windows/AudioSession.cpp
@@ -4,6 +4,7 @@
  * 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 <stdlib.h>
 #include <windows.h>
 #include <audiopolicy.h>
 #include <mmdeviceapi.h>
diff --git a/widget/windows/JumpListBuilder.h b/widget/windows/JumpListBuilder.h
index 553ff765d0..4e64d1cb2f 100644
--- a/widget/windows/JumpListBuilder.h
+++ b/widget/windows/JumpListBuilder.h
@@ -6,6 +6,8 @@
 #ifndef __JumpListBuilder_h__
 #define __JumpListBuilder_h__
 
+#include <stdlib.h>
+
 #include <windows.h>
 
 #undef NTDDI_VERSION
diff --git a/widget/windows/TaskbarPreview.cpp b/widget/windows/TaskbarPreview.cpp
index ec182d8ae0..0a54d7ade2 100644
--- a/widget/windows/TaskbarPreview.cpp
+++ b/widget/windows/TaskbarPreview.cpp
@@ -4,6 +4,7 @@
  * 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 <stdlib.h>
 #include "TaskbarPreview.h"
 #include <nsITaskbarPreviewController.h>
 #include <windows.h>
diff --git a/widget/windows/WinTaskbar.cpp b/widget/windows/WinTaskbar.cpp
index 03a525d538..02cb74eaf9 100644
--- a/widget/windows/WinTaskbar.cpp
+++ b/widget/windows/WinTaskbar.cpp
@@ -4,6 +4,7 @@
  * 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 <stdlib.h>
 #include "WinTaskbar.h"
 #include "TaskbarPreview.h"
 #include <nsITaskbarPreviewController.h>
diff --git a/widget/windows/WinUtils.h b/widget/windows/WinUtils.h
index 5fa2dbd9f7..3dda5e4088 100644
--- a/widget/windows/WinUtils.h
+++ b/widget/windows/WinUtils.h
@@ -39,7 +39,7 @@
 
 // Starting with version 10.0.22621.0 of the Windows SDK the AR_STATE enum and
 // types are only defined when building for Windows 8 instead of Windows 7.
-#if (WDK_NTDDI_VERSION >= 0x0A00000C) && (WINVER < 0x0602)
+#if (WDK_NTDDI_VERSION >= 0x0A00000C) && (WINVER < 0x0602) && !defined(MOZ_AR_STATE_DEFINED)
 
 enum tagAR_STATE {
   AR_ENABLED = 0x0,
@@ -57,6 +57,8 @@ typedef enum tagAR_STATE AR_STATE;
 
 using PAR_STATE = enum tagAR_STATE*;
 
+#define MOZ_AR_STATE_DEFINED 1
+
 #endif  // (WDK_NTDDI_VERSION >= 0x0A00000C) && (WINVER < 0x0602)
 
 /**
diff --git a/widget/windows/WindowsUIUtils.cpp b/widget/windows/WindowsUIUtils.cpp
index 78ac39b93c..0f95c33e8b 100644
--- a/widget/windows/WindowsUIUtils.cpp
+++ b/widget/windows/WindowsUIUtils.cpp
@@ -3,6 +3,7 @@
  * 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 <stdlib.h>
 #include <windows.h>
 #include <winsdkver.h>
 #include "mozwrlbase.h"
diff --git a/widget/windows/nsFilePicker.h b/widget/windows/nsFilePicker.h
index 0a2e01b90b..737cfcce8f 100644
--- a/widget/windows/nsFilePicker.h
+++ b/widget/windows/nsFilePicker.h
@@ -7,6 +7,7 @@
 #ifndef nsFilePicker_h__
 #define nsFilePicker_h__
 
+#include <stdlib.h>
 #include <windows.h>
 
 // For Vista IFileDialog interfaces which aren't exposed
diff --git a/widget/windows/nsLookAndFeel.h b/widget/windows/nsLookAndFeel.h
index ecc1e83045..6fb489ac8e 100644
--- a/widget/windows/nsLookAndFeel.h
+++ b/widget/windows/nsLookAndFeel.h
@@ -42,6 +42,7 @@ typedef enum _AR_STATE
   AR_DOCKED         = 0x40,
   AR_LAPTOP         = 0x80
 } AR_STATE, *PAR_STATE;
+#define MOZ_AR_STATE_DEFINED 1
 #endif
 
 class nsLookAndFeel: public nsXPLookAndFeel {
diff --git a/xpcom/base/nsSetDllDirectory.h b/xpcom/base/nsSetDllDirectory.h
index 5fae3a895e..2748a6786d 100644
--- a/xpcom/base/nsSetDllDirectory.h
+++ b/xpcom/base/nsSetDllDirectory.h
@@ -10,9 +10,9 @@
 #error This file only makes sense on Windows.
 #endif
 
+#include <stdlib.h>
 #include <windows.h>
 #include <nscore.h>
-#include <stdlib.h>
 
 namespace mozilla {
 
diff --git a/xpcom/base/nsUUIDGenerator.cpp b/xpcom/base/nsUUIDGenerator.cpp
index 2f9fd257e2..55a8715b19 100644
--- a/xpcom/base/nsUUIDGenerator.cpp
+++ b/xpcom/base/nsUUIDGenerator.cpp
@@ -4,6 +4,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #if defined(XP_WIN)
+#include <stdlib.h>
 #include <windows.h>
 #include <objbase.h>
 #elif defined(XP_MACOSX)
diff --git a/xpcom/build/perfprobe.cpp b/xpcom/build/perfprobe.cpp
index 5a52e3be24..f38a624dea 100644
--- a/xpcom/build/perfprobe.cpp
+++ b/xpcom/build/perfprobe.cpp
@@ -6,6 +6,7 @@
 /*****************************
  Windows implementation of probes, using xperf
  *****************************/
+#include <stdlib.h>
 #include <windows.h>
 #include <wmistr.h>
 #include <evntrace.h>
diff --git a/xpcom/ds/nsWindowsRegKey.cpp b/xpcom/ds/nsWindowsRegKey.cpp
index 9e1b5a96ac..ac276dba63 100644
--- a/xpcom/ds/nsWindowsRegKey.cpp
+++ b/xpcom/ds/nsWindowsRegKey.cpp
@@ -3,9 +3,9 @@
  * 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 <stdlib.h>
 #include <windows.h>
 #include <shlwapi.h>
-#include <stdlib.h>
 #include "nsWindowsRegKey.h"
 #include "nsString.h"
 #include "nsCOMPtr.h"
diff --git a/xpcom/io/FileUtilsWin.cpp b/xpcom/io/FileUtilsWin.cpp
index 98173b6bad..b2e083e47a 100644
--- a/xpcom/io/FileUtilsWin.cpp
+++ b/xpcom/io/FileUtilsWin.cpp
@@ -4,7 +4,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "FileUtilsWin.h"
-
+#include <stdlib.h>
 #include <windows.h>
 #include <psapi.h>
 
diff --git a/xpcom/io/FileUtilsWin.h b/xpcom/io/FileUtilsWin.h
index 8056f5a942..f9b1c4e329 100644
--- a/xpcom/io/FileUtilsWin.h
+++ b/xpcom/io/FileUtilsWin.h
@@ -6,6 +6,7 @@
 #ifndef mozilla_FileUtilsWin_h
 #define mozilla_FileUtilsWin_h
 
+#include <stdlib.h>
 #include <windows.h>
 
 #include "mozilla/Scoped.h"
diff --git a/xpcom/io/SpecialSystemDirectory.cpp b/xpcom/io/SpecialSystemDirectory.cpp
index 67e7f0059d..8f7564dfed 100644
--- a/xpcom/io/SpecialSystemDirectory.cpp
+++ b/xpcom/io/SpecialSystemDirectory.cpp
@@ -3,6 +3,7 @@
  * 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 <stdlib.h>
 #include "SpecialSystemDirectory.h"
 #include "nsString.h"
 #include "nsDependentString.h"
@@ -10,9 +11,9 @@
 
 #if defined(XP_WIN)
 
+#include <stdlib.h>
 #include <windows.h>
 #include <shlobj.h>
-#include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
 #include <direct.h>
diff --git a/xpcom/io/nsAppFileLocationProvider.cpp b/xpcom/io/nsAppFileLocationProvider.cpp
index d5569985cf..d723bb55eb 100644
--- a/xpcom/io/nsAppFileLocationProvider.cpp
+++ b/xpcom/io/nsAppFileLocationProvider.cpp
@@ -19,11 +19,11 @@
 #include <Carbon/Carbon.h>
 #include "nsILocalFileMac.h"
 #elif defined(XP_WIN)
+#include <stdlib.h>
 #include <windows.h>
 #include <shlobj.h>
 #elif defined(XP_UNIX)
 #include <unistd.h>
-#include <stdlib.h>
 #include <sys/param.h>
 #endif
 
diff --git a/xpcom/io/nsDirectoryService.cpp b/xpcom/io/nsDirectoryService.cpp
index dae8521485..8a2135bfdb 100644
--- a/xpcom/io/nsDirectoryService.cpp
+++ b/xpcom/io/nsDirectoryService.cpp
@@ -19,9 +19,9 @@
 #include "nsIStringEnumerator.h"
 
 #if defined(XP_WIN)
+#include <stdlib.h>
 #include <windows.h>
 #include <shlobj.h>
-#include <stdlib.h>
 #include <stdio.h>
 #elif defined(XP_UNIX)
 #include <unistd.h>
diff --git a/xpcom/io/nsLocalFileWin.cpp b/xpcom/io/nsLocalFileWin.cpp
index 0aa430d9dd..8fb6f49fd3 100644
--- a/xpcom/io/nsLocalFileWin.cpp
+++ b/xpcom/io/nsLocalFileWin.cpp
@@ -29,16 +29,16 @@
 #include "nsReadableUtils.h"
 
 #include <direct.h>
-#include <windows.h>
+#include <stdlib.h>
 #include <shlwapi.h>
 #include <aclapi.h>
+#include <windows.h>
 
 #include "shellapi.h"
 #include "shlguid.h"
 
 #include  <io.h>
 #include  <stdio.h>
-#include  <stdlib.h>
 #include  <mbstring.h>
 
 #include "nsXPIDLString.h"
diff --git a/xpcom/io/nsNativeCharsetUtils.cpp b/xpcom/io/nsNativeCharsetUtils.cpp
index 3ed20d7f04..7bc97a9154 100644
--- a/xpcom/io/nsNativeCharsetUtils.cpp
+++ b/xpcom/io/nsNativeCharsetUtils.cpp
@@ -9,7 +9,7 @@
 // Windows
 //-----------------------------------------------------------------------------
 #if defined(XP_WIN)
-
+#include <stdlib.h>
 #include <windows.h>
 #include "nsString.h"
 #include "nsAString.h"
diff --git a/xpcom/threads/nsTimerImpl.cpp b/xpcom/threads/nsTimerImpl.cpp
index 2a3531a858..a8c2a19db7 100644
--- a/xpcom/threads/nsTimerImpl.cpp
+++ b/xpcom/threads/nsTimerImpl.cpp
@@ -519,14 +519,16 @@ nsTimerImpl::Fire(int32_t aGeneration)
           this, (TimeStamp::Now() - now).ToMilliseconds()));
 }
 
-#if defined(HAVE_DLADDR) && defined(HAVE___CXA_DEMANGLE)
+#if defined(HAVE_DLADDR) && defined(HAVE___CXA_DEMANGLE) && !defined(XP_WIN)
 #define USE_DLADDR 1
 #endif
 
 #ifdef USE_DLADDR
+#if !defined(XP_WIN)
 #include <cxxabi.h>
 #include <dlfcn.h>
 #endif
+#endif
 
 // See the big comment above GetTimerFiringsLog() to understand this code.
 void
diff --git a/xpcom/windbgdlg/windbgdlg.cpp b/xpcom/windbgdlg/windbgdlg.cpp
index 9153dc006f..843864901d 100644
--- a/xpcom/windbgdlg/windbgdlg.cpp
+++ b/xpcom/windbgdlg/windbgdlg.cpp
@@ -4,8 +4,8 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /* Windows only app to show a modal debug dialog - launched by nsDebug.cpp */
-#include <windows.h>
 #include <stdlib.h>
+#include <windows.h>
 #ifdef _MSC_VER
 #include <strsafe.h>
 #endif