User manual

How To’s
 2012 Microchip Technology Inc. DS52053B-page 43
3.3 INVOKING THE COMPILER
This section discusses how the compiler is run, both on the command-line and from the
MPLAB IDE. It includes information about how to get the compiler to do what you want
in terms of options and the build process itself.
• How Do I Compile from Within MPLAB X IDE?
• How Do I Compile on the Command-line?
• How Do I Compile Using a Make Utility?
• How Can I Select Which Compiler I Want to Build With?
• How Can I Change the Compiler's Operating Mode?
• What Do I Need to Do When Compiling to Use a Debugger?
• How Do I Build Libraries?
• How Do I Use Library Files In My Project?
• How Do I Know What Compiler Options Are Available and What They Do?
• How Do I Know What the Build Options in MPLAB IDE do?
• What is Different About an MPLAB IDE Debug Build?
• How Do I Stop the Compiler Using Certain Memory Locations?
• What Optimizations Are Employed By The Compiler?
3.3.1 How Do I Compile from Within MPLAB X IDE?
See the documentation that comes with MPLAB X IDE for information on how to set up
a project.
If you have one or more XC8 compilers installed, you select the compiler you wish to
use in the Configuration category in the Project Properties dialog. The options for that
compiler are then shown in the XC8 Compiler and XC8 Linker categories. Note that
each of these compiler categories have several Option categories.
3.3.2 How Do I Compile on the Command-line?
The compiler driver is called xc8 for all 8-bit PIC devices; e.g., in Windows, it is named
xc8.exe. This application should be invoked for all aspects of compilation. It is located
in the bin directory of the compiler distribution. Avoid running the individual compiler
applications (such as the assembler or linker) explicitly. You can compile and link in the
one command, even if your project is spread among multiple source files.
The driver is introduced in Section 4.2 “Invoking the Compiler”. See 3.3.4 How Can
I Select Which Compiler I Want to Build With? to ensure you are running the correct
driver if you have more than one installed. The command-line options to the driver are
detailed in Section 4.7 “XC8 Driver Options”. The files that can be passed to the
driver are listed and described in Section 4.2.3 “Input File Types”.
3.3.3 How Do I Compile Using a Make Utility?
When compiling using a make utility (such as make), the compilation is usually per-
formed as a two-step process: first generating the intermediate files, then the final com-
pilation and link step to produce one binary output. This is described in Section 4.3.3
“Multi-Step Compilation”.
The XC8 compiler uses a unique technology called OCG which uses a different inter-
mediate file format to traditional compilers (including XC16 and XC32)The intermediate
file format used by XC8 is a p-code file (.p1 extension), not an object file. Generating
object files as an intermediate file for multi-step compilation will defeat many of the
advantages of this technology.