3.3.6 How Do I Build Libraries?
Note that XC8 uses a different code generation framework (OCG) that uses additional
library files to those used by traditional compilers (including XC16 and XC32). See
Section 4.3.1 “The Compiler Applications”, for general information on the library types
available and how they fit into the compilation process.
When you have functions and data that are commonly used in applications, you can
either make all the C source and header files available so that other developers can
copy these into their projects. Alternatively you can bundle these source files up into a
library which, along with the accompanying header files, can be linked into a project.
Libraries are more convenient because there are fewer files to deal with. Compiling
code from a library can also be fractionally faster. However, libraries do need to be
maintained. XC8 must use LPP libraries for library routines written in C; the old-style
LIB libraries are used for library routines written in assembly source. It is recommended
that even these libraries be rebuilt if your project is moving to a new compiler version.
Using the compiler driver, libraries can be built by listing all of the files that are to be
included into the library on the command line. None of these files should contain a
main() function, nor settings for Configuration bits or any other such data. Use the
--OUTPUT=lpp option; see Section 4.8.48 “--OUTPUT= type: Specify Output File
Type”, to indicate that a library file is required. For example:
XC8 --chip=16f877a --output=lpp lcd.c utils.c io.c
creates a library file called lcd.lpp. You can specify another name using the -O
option; see Section 4.8.9 “-O: Specify Output File”, or just rename the file.
3.6.18 How Do I Use Library Files in My Project?
See Section 3.3.6 “How Do I Build Libraries?” for information on how you build your
own library files. The compiler will automatically include any applicable standard library
into the build process when you compile, so you never need to control these files.
To use one or more library files that were built by yourself or a colleague, include them
in the list of files being compiled on the command line. The library files can be specified
in any position in the file list relative to the source files, but if there is more than one
library file, they will be searched in the order specified in the command line. The LPP
libraries do not need to be specified if you are compiling to an intermediate file, i.e.,
using the --PASS1 option (see Section 4.8.50 “--PASS1: Compile to P-code”). For
xc8 --chip=16f1937 main.c int.c lcd.lpp
If you are using MPLAB X IDE to build a project, add the library file(s) to the Libraries
folder that will shown in your project, in the order in which they should be searched. The
IDE will ensure that they are passed to the compiler at the appropriate point in the build