MPLAB C Compiler for PIC24 MCUs and dsPIC DSCs ... - Microchip

3.6 ENVIRONMENT VARIABLES
Using the Compiler on the Command Line
The variables in this section are optional, but, if defined, they will be used by the
compiler. The compiler driver, or other subprogram, may choose to determine an
appropriate value for some of the following environment variables if they are unset. The
driver, or other subprogram, takes advantage of internal knowledge about the
installation of the compiler. As long as the installation structure remains intact, with all
subdirectories and executables remaining in the same relative position, the driver or
subprogram will be able to determine a usable value.
TABLE 3-16: COMPILER-RELATED ENVIRONMENTAL VARIABLES
Option Definition
PIC30_C_INCLUDE_
PATH
PIC30_COMPILER_
PATH
PIC30_EXEC_
PREFIX
PIC30_LIBRARY_
PATH
This variable’s value is a semicolon-separated list of directories, much
like PATH. When the compiler searches for header files, it tries the
directories listed in the variable, after the directories specified with -I
but before the standard header file directories.
If the environment variable is undefined, the preprocessor chooses an
appropriate value based on the standard installation. By default, the
following directories are searched for include files:
\include and
\support\h
The value of PIC30_COMPILER_PATH is a semicolon-separated list of
directories, much like PATH. The compiler tries the directories thus
specified when searching for subprograms, if it can’t find the
subprograms using PIC30_EXEC_PREFIX.
If PIC30_EXEC_PREFIX is set, it specifies a prefix to use in the
names of subprograms executed by the compiler. No directory
delimiter is added when this prefix is combined with the name of a
subprogram, but you can specify a prefix that ends with a slash if you
wish. If the compiler cannot find the subprogram using the specified
prefix, it tries looking in your PATH environment variable.
If the PIC30_EXEC_PREFIX environment variable is unset or set to
an empty value, the compiler driver chooses an appropriate value
based on the standard installation. If the installation has not been
modified, this will result in the driver being able to locate the required
subprograms.
Other prefixes specified with the -B command line option take
precedence over the user- or driver-defined value of
PIC30_EXEC_PREFIX.
Under normal circumstances it is best to leave this value undefined
and let the driver locate subprograms itself.
This variable’s value is a semicolon-separated list of directories, much
like PATH. This variable specifies a list of directories to be passed to
the linker. The driver’s default evaluation of this variable is:
\lib; \support\gld.
PIC30_OMF Specifies the OMF (Object Module Format) to be used by the compiler.
By default, the tools create COFF object files. If the environment
variable PIC30_OMF has the value elf, the tools will create ELF
object files.
TMPDIR If TMPDIR is set, it specifies the directory to use for temporary files.
The compiler uses temporary files to hold the output of one stage of
compilation that is to be used as input to the next stage: for example,
the output of the preprocessor, which is the input to the compiler
proper.
© 2008 Microchip Technology Inc. DS51284H-page 59