Microchip Technology XC8 Standard Compiler (Workstation) SW006021-1 SW006021-1 User Manual

®

DS52053A-page 20

 2012 Microchip Technology Inc.

char

The type of a plain char is unsigned char. It is generally recommended that all def-
initions for the char type explicitly state the signedness of the object.

2.4.7.1

EXAMPLE

The following example

char foobar;

defines an unsigned char object called foobar.

2.4.7.2

DIFFERENCES

The 8-bit compilers have always treated plain char as an unsigned type.

The 16- and 32-bit compilers used signed char as the default plain char type. The 
-funsigned-char

 option on those compilers changed the default type to be 

unsigned char

.

2.4.7.3

MIGRATION TO THE CCI

Any definition of an object defined as a plain char and using the 16- or 32-bit compilers 
needs review. Any plain char that was intended to be a signed quantity should be 
replaced with an explicit definition, for example.

signed char foobar;

You may use the -funsigned-char option on XC16/32 to change the type of plain 
char

, but since this option is not supported on XC8, the code is not strictly conforming.

The value of a signed integer is determined by taking the two’s complement of the inte-
ger.

2.4.8.1

EXAMPLE

The following shows a variable, test, that is assigned the value -28 decimal.

signed char test = 0xE4;

2.4.8.2

DIFFERENCES

All compilers have represented signed integers in the way described in this section.

2.4.8.3

MIGRATION TO THE CCI

No action required.