In wxDev-C++ 188.8.131.52 (and possibly other versions as well; I haven't checked), adding C source code to a project results in the generated makefile compiling the code with the C++ compiler and not the C compiler; upon closer inspection of the .dev file for my project, I noticed that the C source code that I wrote (my entire project is in C) appeared to be indicated to be C++ source code by all of their respective "CompileCpp" attributes set to one. I quickly tried changing all of these values to zero, and noticed that the generated makefile then regarded these files as C code and switched to using the C compiler instead. A problem remained, however, that the linker remained to be g++ and not gcc; I don't know if this affects the final, linked binary, but I would assume that gcc should be used instead.
Furthermore, if I were to change "IsCpp" in the .dev file to zero (as opposed to its initial value of one), it is automatically reverted to one, and no change is made in the makefile.
On a side note, the "Compile" and "Link" attributes of all of the header files in my project were set to one and not zero; I changed these to zero thinking their compilation unnecessary, but am unsure if it made any difference (I have not compared the generated makefiles).
I am running wxWidgets 184.108.40.206 (as I noted earlier) on a licensed copy of Windows 7 with the latest patches applied, though I doubt the operating system makes a difference in this case.