Microchip Technology SW006023-1N Data Sheet

®

DS51686E-page 64

 2012 Microchip Technology Inc.

The following options define the kind of C++ dialect used by the compiler.

-fsigned-char

Let the type 

char

 be signed, like 

signed char

. 

-fsigned-bitfields

-funsigned-bitfields

-fno-signed-bitfields

-fno-unsigned-bitfields

These options control whether a bit field is signed or 
unsigned, when the declaration does not use either signed 
or unsigned. By default, such a bit field is signed, unless 
-traditional

 is used, in which case bit fields are always 

unsigned.

-funsigned-char

Let the type char be unsigned, like unsigned char.

-fwritable-strings

Store strings in the writable data segment and do not make 
them unique.

-ansi

Support all (and only) ANSI-standard C++ programs.

-aux-info filename

Output to the given filename prototyped declarations for all 
functions declared and/or defined in a translation unit, 
including those in header files. This option is silently ignored 
in any language other than C++. Besides declarations, the 
file indicates, in comments, the origin of each declaration 
(source file and line), whether the declaration was implicit, 
prototyped or unprototyped (I, N for new or O for old, 
respectively, in the first character after the line number and 
the colon), and whether it came from a declaration or a 
definition (C or F, respectively, in the following character). In 
the case of function definitions, a K&R-style list of arguments 
followed by their declarations is also provided, inside 
comments, after the declaration.

-ffreestanding

Assert that compilation takes place in a freestanding 
environment. This implies -fno-builtin. A freestanding 
environment is one in which the standard library may not 
exist, and program start-up may not necessarily be at main. 
The most obvious example is an OS kernel. This is 
equivalent to -fno-hosted.

-fno-asm

Do not recognize asm, inline or

 

typeof

 as a keyword, so 

that code can use these words as identifiers. You can use 
the keywords __asm__, __inline_ _ and __typeof__ 
instead.
-ansi

 implies -fno-asm.

-fno-builtin

-fno-builtin-function

Don’t recognize built-in functions that do not begin with 
_ _builtin_

 as prefix.

-fsigned-char

Let the type char be signed, like signed char. 
(This is the default.)

-fsigned-bitfields

-funsigned-bitfields

-fno-signed-bitfields

-fno-unsigned-bitfields

These options control whether a bit field is signed or 
unsigned, when the declaration does not use either signed 
or unsigned. By default, such a bit field is signed, unless 
-traditional

 is used, in which case bit fields are always 

unsigned.

-funsigned-char

Let the type char be unsigned, like unsigned char.

-fwritable-strings

Store strings in the writable data segment and do not make 
them unique.