Re: ARM Build

[Guy Harris <guy () alum mit edu>]

On Oct 16, 2014, at 4:50 AM, Graham Bloice <graham.bloice () trihedral com> wrote:

> Visual Studio (VS2013 at least) as 32 & 64 bit ARM compilers.

        http://msdn.microsoft.com/en-us/library/0w6ke344.aspx

"Type char

Visual Studio 2013      Other Versions          1 out of 1 rated this helpful - Rate this topic

The char type is used to store the integer value of a member of the representable character set. That integer value is 
the ASCII code corresponding to the specified character.

Microsoft Specific

Character values of type unsigned char have a range from 0 to 0xFF hexadecimal. A signed char has range 0x80 to 0x7F. 
These ranges translate to 0 to 255 decimal, and –128 to +127 decimal, respectively. *The /J compiler option changes the 
default from signed to unsigned.*

END Microsoft Specific"

(emphasis mine, as that seems to implicitly indicate that an unqualified "char" is signed by default).

So, unless that page discusses *only* the x86-32/x86-64/Itanium-if-they-still-support-it compilers, it appears that 
char is signed by default on all platforms, presumably including ARM.

What we *could* do is, on some platform or platforms, do both default compiles and char-is-unsigned compiles, using /J 
for MSVC and -funsigned-char with GCC (and Clang?).

(I couldn't find any -W option for GCC that warns about code that would behave differently with char-is-signed and 
char-is-unsigned. There should be, but, then, there should also be an option to warn about *all* implicit shortenings - 
or, at least, all implicit shortenings that aren't known to be safe, such as converting "sizeof (int)" to a type 
shorter than size_t - even though there should be.)
___________________________________________________________________________
Sent via:    Wireshark-dev mailing list <wireshark-dev () wireshark org>
Archives:    http://www.wireshark.org/lists/wireshark-dev
Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev
             mailto:wireshark-dev-request () wireshark org?subject=unsubscribe