Bug 144580 – [CMake] Build C code with -std=c89

• Component: New Bugs
• Status: NEW

[Zan Dobersek]

[CMake] Build C code with -std=c11

[Zan Dobersek]

Created attachment 252315 [details]
Patch

[Csaba Osztrogonác]

Let me check the EFL failure.

[Csaba Osztrogonác]

The problem is that strdup in string.h is ifdef-ed 
out if we build it with -std=c11. 

Defining GNU_SOURCE solves the build error in Minibrowser/main.c,
but I'm not sure what is the proper fix for it, or if EFL wants
to build with c11 or not.

[Michael Catanzaro]

Comment on attachment 252315 [details]
Patch

I'm not at all sure this is a good idea. Microsoft has no intention of supporting C11 (or even C99) in MSVCC, so we would have to be careful to only use C11 in code that will never be used by Windows. Since we probably want to support Windows eventually, allowing C11 to creep into our codebase anywhere will make that harder. It also makes it easier to accidentally break Windows when making changes locally, and not find out until the EWS catches it.

Now, with GCC 5 the default is currently -std=gnu11, so switching to -std=c11 is more restrictive as it disables GNU extensions, which is good for us. But with Clang the default is -std=gnu99, and with GCC 4.x the default is -std=gnu89. You might call Microsoft's version ms89. So we're compiling with four different standards right now, and there is certainly good benefit to explicitly specifying a standard. But I would suggest we explicitly compile with -std=c89, rather than c11.

[Zan Dobersek]

OK, agreed. Let's settle on c89 (in 2016 :|)

[Zan Dobersek]

Created attachment 268274 [details]
Patch

[Michael Catanzaro]

Comment on attachment 268274 [details]
Patch

Patch LGTM, except for the roughly bajillion EFL and GTK build failures. :/

[Zan Dobersek]

The errors are in the Udis86 code. I'm not fixing that since the code is coming from an external project, which I hope doesn't care about C89 compliance.

MSVC has some basic support for C99, and no compiler supports it completely anyway.

C11 doesn't work with EFL headers.

So either C99 should be default, or we should make the -std= C flag port-specific.

[Zan Dobersek]

I'm not bothering with this anymore. The amount of C code that's built is minimal, and every compiler and port have their own quirks around this.

[Ahmad Saleem]

Is this required anymore? Thanks1