why mingw32 and tdm-gcc64 behave differently using external gcc - haskell

Question

I am trying to cabal install a component of wxHaskell (Haskell platform 2013.2 against wxWidgets 3.0).
I was able to compile the git version with 32 bit mingw from mingw.org. But in the end, the installed wx cannot function correct, and running a minimal example gives runtime exceptions in wxc.dll. So I try to compile the same thing under TDM-GCC 4.8.1 64bit, since the wxWidgets people provide their binary in the form of TDM-GCC compiled binaries.
But I immediately run into compilation errors with TDM-GCC, telling me
error: 'strnlen' was not declared in this scope
What surprises me is that even though both mingw32 and TDM-gcc uses the same external gcc from Haskell Platform c:\HaskellPlatform\2013.2.0.0\mingw\bin\gcc.exe, one would give an error while the other compiles fine.
The first file causing problem is src\cpp\eljaccelerator.cpp. It compiles OK under mingw32:
...
c:\HaskellPlatform\2013.2.0.0\mingw\bin\gcc.exe -Wl,--hash-size=31 -Wl,--reduce-
memory-overheads -Isrc/include -IC:/MinGW/msys/1.0/local/include/wx-3.0 -IC:/Min
GW/msys/1.0/local/lib/wx/include/msw-unicode-3.0 -D__WXMSW__ -DWXUSINGDLL -D_LAR
GEFILE_SOURCE=unknown -DwxcREFUSE_MEDIACTRL -DBUILD_DLL -c src\cpp\eljaccelerato
r.cpp -o dist\build\src/cpp/eljaccelerator.o
but gives an error under TDM-gcc:
Building wxc
c:\HaskellPlatform\2013.2.0.0\mingw\bin\gcc.exe -Wl,--hash-size=31 -Wl,--reduce-
memory-overheads -Isrc/include -IC:/mingw/msys/1.0/local/include/wx-3.0 -IC:/min
gw/msys/1.0/local/lib/wx/include/msw-unicode-3.0 -D__WXMSW__ -DWXUSINGDLL -D_FIL
E_OFFSET_BITS=64 -DwxcREFUSE_MEDIACTRL -DBUILD_DLL -c src\cpp\eljaccelerator.cpp
-o dist\build\src/cpp/eljaccelerator.o
In file included from C:/mingw/msys/1.0/local/include/wx-3.0/wx/crt.h:19:0,
from C:/mingw/msys/1.0/local/include/wx-3.0/wx/string.h:4305,
from C:/mingw/msys/1.0/local/include/wx-3.0/wx/memory.h:15,
from C:/mingw/msys/1.0/local/include/wx-3.0/wx/object.h:19,
from C:/mingw/msys/1.0/local/include/wx-3.0/wx/wx.h:15,
from src/include/wrapper.h:20,
from src\cpp\eljaccelerator.cpp:1:
C:/mingw/msys/1.0/local/include/wx-3.0/wx/wxcrt.h: In function 'size_t wxStrnlen
(const char*, size_t)':
C:/mingw/msys/1.0/local/include/wx-3.0/wx/wxcrt.h:173:92: error: 'strnlen' was n
ot declared in this scope
C:/mingw/msys/1.0/local/include/wx-3.0/wx/wxcrt.h: In function 'size_t wxStrnlen
(const wchar_t*, size_t)':
C:/mingw/msys/1.0/local/include/wx-3.0/wx/wxcrt.h:187:95: error: 'wcsnlen' was n
ot declared in this scope
Failed to install wxc-0.90.1.1
I was wondering if anyone has any similar experience. Any idea what went wrong and how to fix compilation for TDM-GCC? I tried adding #include <cstring> to wxcrt.h but it doesn't change anything.
FYI, I have compiled wxWidgets 3.0.0 from source in mingw and tdm-gcc versions respectively, using
./configure --enable-stl && make && make install
I can provide more details if needed.

Answer 1

First of all, wxWidgets certainly does work with MinGW, the fact that only TDM binaries are provided simply means that someone volunteered to provide the latter but not the former. But all three popular versions of MinGW (the two already mentioned and MinGW-w64) do work, so there must be something wrong with the build...
However while they all work, they are certainly different compilers, so what do you mean that they both use the same gcc binary? It must be either a MinGW one or a TDM one, but it can't be both at once.
It's also very suspicious that the configure detects different flags to use for the large file support. Look at config.log, something must have gone wrong and there must be some errors in the initial stage in it.