Merge fixes for MinGW 4.8

Fix compilation problems in ANSI build and when using an old SDK.

Closes https://github.com/wxWidgets/wxWidgets/pull/289

include/wx/msw/private/dcdynwrap.h

@@ -0,0 +1,39 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        wx/msw/private/dcdynwrap.h
+// Purpose:     Private dynamically loaded HDC-related functions
+// Author:      Vadim Zeitlin
+// Created:     2016-05-26 (extracted from src/msw/dc.cpp)
+// Copyright:   (c) 2016 Vadim Zeitlin <vadim@wxwidgets.org>
+// Licence:     wxWindows licence
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_MSW_PRIVATE_DCDYNWRAP_H_
+#define _WX_MSW_PRIVATE_DCDYNWRAP_H_
+
+#include "wx/msw/wrapwin.h"
+
+// Namespace for the wrapper functions, hopefully one day we'll be able to get
+// rid of all of them and then it will be easy to find all occurrences of their
+// use by just searching for this namespace name.
+//
+// All of the functions in this namespace must work *exactly* like the standard
+// functions with the same name and just return an error if dynamically loading
+// them failed.
+//
+// And they're all implemented in src/msw/dc.cpp.
+namespace wxDynLoadWrappers
+{
+
+DWORD GetLayout(HDC hdc);
+DWORD SetLayout(HDC hdc, DWORD dwLayout);
+
+BOOL AlphaBlend(HDC hdcDest, int xDest, int yDest, int wDest, int hDest,
+                HDC hdcSrc, int xSrc, int ySrc, int wSrc, int hSrc,
+                BLENDFUNCTION bf);
+
+BOOL GradientFill(HDC hdc, PTRIVERTEX pVert, ULONG numVert,
+                  PVOID pMesh, ULONG numMesh, ULONG mode);
+
+} // namespace wxDynLoadWrappers
+
+#endif // _WX_MSW_PRIVATE_DCDYNWRAP_H_

src/common/time.cpp

@@ -22,23 +22,6 @@
     #pragma hdrstop
 #endif
 
-// This is a horrible hack which only works because we don't currently include
-// <time.h> from wx/wxprec.h. It is needed because we need timezone-related
-// stuff from MinGW time.h, but it is not compiled in strict ANSI mode and it
-// is too complicated to be dealt with using wxDECL_FOR_STRICT_MINGW32(). So we
-// just include the header after undefining __STRICT_ANSI__ to get all the
-// declarations we need -- and then define it back to avoid inconsistencies in
-// all our other headers.
-//
-// Note that the same hack is used for "environ" in utilscmn.cpp, so if the
-// code here is modified because this hack becomes unnecessary or a better
-// solution is found, the code there should be updated as well.
-#ifdef wxNEEDS_STRICT_ANSI_WORKAROUNDS
-    #undef __STRICT_ANSI__
-    #include <time.h>
-    #define __STRICT_ANSI__
-#endif
-
 #include "wx/time.h"
 
 #ifndef WX_PRECOMP
@@ -59,6 +42,7 @@
 
 #include <time.h>
 
+wxDECL_FOR_STRICT_MINGW32(void, tzset, (void));
 
 #if !defined(__WXMAC__)
     #include <sys/types.h>      // for time_t

src/common/utilscmn.cpp

@@ -23,12 +23,27 @@
     #pragma hdrstop
 #endif
 
-// See comment about this hack in time.cpp: here we do it for environ external
+// This is a needed to get the declaration of the global "environ" variable
-// variable which can't be easily declared when using MinGW in strict ANSI mode.
+// from MinGW headers which don't declare it there when in strict ANSI mode. We
+// can't use the usual wxDECL_FOR_STRICT_MINGW32() hack for it because it's not
+// even a variable, but a macro expanding to a function or a variable depending
+// on the build and this is horribly brittle but there just doesn't seem to be
+// any other alternative.
 #ifdef wxNEEDS_STRICT_ANSI_WORKAROUNDS
-    #undef __STRICT_ANSI__
+    // Notice that undefining __STRICT_ANSI__ and including it here doesn't
+    // work because it could have been already included, e.g. when using PCH.
     #include <stdlib.h>
-    #define __STRICT_ANSI__
+
+    #ifndef environ
+        // This just reproduces what stdlib.h does in MinGW 4.8.1.
+        #ifdef __MSVCRT__
+            wxDECL_FOR_STRICT_MINGW32(char ***, __p__environ, (void));
+            #define environ (*__p__environ())
+        #else
+            extern char *** _imp___environ_dll;
+            #define environ (*_imp___environ_dll)
+        #endif
+    #endif // defined(environ)
 #endif
 
 #ifndef WX_PRECOMP

src/msw/checklst.cpp

@@ -47,6 +47,7 @@
 #include "wx/renderer.h"
 #include "wx/msw/private.h"
 #include "wx/msw/dc.h"
+#include "wx/msw/private/dcdynwrap.h"
 
 // ----------------------------------------------------------------------------
 // private functions
@@ -159,7 +160,7 @@ bool wxCheckListBoxItem::OnDrawItem(wxDC& dc, const wxRect& rc,
     UINT uState = stat & wxOwnerDrawn::wxODSelected ? wxDSB_SELECTED : wxDSB_NORMAL;
 
     // checkmarks should not be mirrored in RTL layout
-    DWORD oldLayout = ::GetLayout(hdc);
+    DWORD oldLayout = wxDynLoadWrappers::GetLayout(hdc);
     if ( oldLayout & LAYOUT_RTL )
         ::SetLayout(hdc, oldLayout | LAYOUT_BITMAPORIENTATIONPRESERVED);
     wxDrawStateBitmap(hdc, hBmpCheck, x, y, uState);

src/msw/dc.cpp

@@ -240,13 +240,6 @@ wxIMPLEMENT_DYNAMIC_CLASS(wxGDIDLLsCleanupModule, wxModule);
 
 #endif // USE_DYNAMIC_GDI_FUNCS
 
-// Namespace for the wrapper functions, hopefully one day we'll be able to get
-// rid of all of them and then it will be easy to find all occurrences of their
-// use by just searching for this namespace name.
-//
-// All of the functions in this namespace must work *exactly* like the standard
-// functions with the same name and just return an error if dynamically loading
-// them failed.
 namespace wxDynLoadWrappers
 {
 
@@ -317,19 +310,16 @@ BOOL GradientFill(HDC hdc, PTRIVERTEX pVert, ULONG numVert,
 
 #elif defined(USE_STATIC_GDI_FUNCS)
 
-inline
 DWORD GetLayout(HDC hdc)
 {
     return ::GetLayout(hdc);
 }
 
-inline
 DWORD SetLayout(HDC hdc, DWORD dwLayout)
 {
     return ::SetLayout(hdc, dwLayout);
 }
 
-inline
 BOOL AlphaBlend(HDC hdcDest, int xDest, int yDest, int wDest, int hDest,
                 HDC hdcSrc, int xSrc, int ySrc, int wSrc, int hSrc,
                 BLENDFUNCTION bf)
@@ -339,7 +329,6 @@ BOOL AlphaBlend(HDC hdcDest, int xDest, int yDest, int wDest, int hDest,
                         bf);
 }
 
-inline
 BOOL GradientFill(HDC hdc, PTRIVERTEX pVert, ULONG numVert,
                   PVOID pMesh, ULONG numMesh, ULONG mode)
 {