3.2.7.3 Compiler and Toolchain Options

-mcall-prologues

Use subroutines for functions prologues and epilogues

-mno-interrupts

Change stack pointer without disabling interrupts

-funsigned-char

The default char type is unsigned

-funsigned-bitfield

The default bit field is unsigned

-nostdinc

Do not search the system directories

-E

Preprocess only

Symbols in the source can be defined (-D) or undefined (-U). New symbol declarations can be added, modified, or reordered, using the interface buttons below:

• 
  Add a new symbol. This symbol and all the following icons are reused with the same meaning in other parts of the Microchip Studio interface.

• 
  Remove the symbol.

• 
  Edit the symbol.

• 
  Move the symbol up in the parsing order.

• 
  Move the symbol down in the parsing order.

Contains all the included header and definition directories, can be modified using the same interface as symbols

Optimization level (drop-down menu): -O0, -O1, -O2, -O3, -Os

No optimization, optimize for speed (level 1 - 3), optimize for size

Other optimization flags (manual input form)

Here you should write optimization flags specific to the platform and your requirements

-ffunction-sections

Prepare functions for garbage collection. If a function is never used, its memory will be scrapped.

-fpack-struct

Pack structure members together

-fshort-enums

Allocate only as many bytes as needed by the enumerated types

-mshort-calls

Use rjmp/rcall limited range instructions on the >8K devices

Debug level (drop-down menu): none, -g1, -g2, -g3

Specifies the level of tracing and debugging code and headers left or inserted in the source code

Other debug options (form field)

Architecture specific debug options

-Wall

All warnings

-Werror

Escalate warnings to errors

-fsyntax-only

Check syntax only

-pedantic

Check conformity to GNU, raise warnings on non-standard programming practice

-pedantic-errors

Same as above, plus escalate warnings to errors

Other flags (form field)

Input other project-specific flags

-v

Verbose

-ansi

Support ANSI programs

-save-temps

Do not delete temporary files