Setting Visual C++ Studio/Express to strict ANSI mode

Question

I generally program & compile under Linux with gcc and -ansi flag; but I've been forced with doing a job in Visual C++ and whenever I compile my C code I get all the Microsoft warnings like

'fscanf': This function or variable may be unsafe. Consider using fscanf_s instead.

I get these despite following some steps on MSDN Developer's site for setting up an ANSI C project, but all the _s ("secure") calls are not ANSI C!

Any suggestions on putting Visual C++ Studio in a strict ANSI-only mode?

Thanks.

score 6 · Answer 1 · answered Mar 18 '11 at 15:39

As mentioned in another answer, #define'ing _CRT_SECURE_NO_WARNING will address the specific warnings you mentioned in your question.

If you're really looking for an ANSI-only mode, the closest thing is the /Za compiler switch. Inside the Visual Studio IDE, you can find it in the project's Properties dialog (under Configuration Properties | C/C++ | Language | Disable Language Extensions).

Note that virtually all Windows apps build with Microsoft's compiler extensions enabled; e.g., I don't think you'd even be able to consume Windows SDK headers with /Za set. If your code truly is strict ANSI, you should be OK. If you have a few Windows-specific pieces in a project that is mostly strict ANSI, you could probably isolate those sources and only build those indivudal source files with /Za unset.

You are correct: `` and the `/Za` compiler switch hate each other. [Link to Microsoft Connect - Bug is *Closed*](http://connect.microsoft.com/VisualStudio/feedback/details/780509/including-windows-h-and-compiling-with-za-disable-language-extensions). — IInspectable, Nov 12 '13 at 15:19

score 4 · Answer 2 · edited Mar 18 '11 at 15:13

4

These warnings can be suppressed by defining _CRT_SECURE_NO_WARNING

Go to Procect Settings -> Preprocessor and add _CRT_SECURE_NO_WARNING

This isn't forcing compiler to comply with ANSI. Just suppresses use ..._s warnings

edited Mar 18 '11 at 15:13

Matthieu M.

268,556
42
412
681

answered Mar 18 '11 at 15:08

Armen Tsirunyan

125,569
56
315
427

score 2 · Accepted Answer · answered Mar 18 '11 at 15:22

2

One way to suppress specific warnings is to add something like the following to the source.

#if defined( _WIN32 )
#pragma warning(disable:4996)
#endif

answered Mar 18 '11 at 15:22

Mark Wilkins

40,032
5
54
108

Setting Visual C++ Studio/Express to strict ANSI mode

3 Answers3

Linked