Zilog Z8F0130 - Manual (Page 282)

Using the ANSI C-Compiler UM013037-1212
258
Zilog Developer Studio II – Z8 Encore!
User Manual
Const Correctness in the Standard Header Files
In general, Zilog header files are not const correct due to the issue raised in the const
Keyword and ROM section on page 257. In the Zilog library, for example, strcpy is
(effectively) declared as:
char* strcpy( char* dst, char* src);
but the ANSI standard requires
char* strcpy( char* dst, const char* src);
As noted, this is done to avoid compile-time errors if the deprecated const variables in
ROM compilation option were selected and then strcpy() was called with an argument
for src that had not been declared const .
ANSI Promotions Disabled
The ANSI standard requires that integer variables smaller than int (such as char ) always
be promoted to int before any computation.
The Z8 Encore! C-Compiler is ANSI compliant in this regard when ANSI promotions are
enabled. The C-Compiler analyzes and promotes variables smaller than
int to int , only
where necessary to mimic the ANSI behavior.
As an example, for the following statement:
char ch1, ch2, ch3;
ch1 = ch2 * ch3;
The compiler does not promote ch2 and ch3 to int before the multiplication operation,
so the char result is not affected.
For the following statement:
char ch2, ch3;

int ii;


ii = ch2 * ch3;
The compiler promotes ch2 and ch3 to int before the multiplication operation, so the
result is of type int .
The Z8 Encore! C-Compiler also provides a deprecated option to disable ANSI promo-
tions. The ANSI behavior is not guaranteed when this option is selected, and Zilog does
not recommend using this option.
Library Files Not Required for Freestanding Implementation
As noted in the Freestanding Implementation section on page 255, only four of the stan-
dard library header files are required by the standard to be supported in a freestanding