ARM Compiler toolchain Using the Linker - ARM Information Center

8.34 Using preprocessing commands in a scatter file
8.34.1 See also
Using scatter files
You can pass a scatter file through a C preprocessor. This permits access to all the features of
the C preprocessor.
Use the first line in the scatter file to specify a preprocessor command that the linker invokes to
process the file. The command is of the form:
#! preprocessor [pre_processor_flags]
Most typically the command is #! armcc -E. This passes the scatter file through the armcc
preprocessor.
You can:
• add preprocessing directives to the top of the scatter file
• use simple expression evaluation in the scatter file.
For example, a scatter file, file.scat, might contain:
#! armcc -E
#define ADDRESS 0x20000000
#include "include_file_1.h"
lr1 ADDRESS
{
...
}
The linker parses the preprocessed scatter file and treats the directives as comments.
You can also use preprocessing of a scatter file in conjunction with the --predefine
command-line option. For this example:
1. Modify file.scat to delete the directive #define ADDRESS 0x20000000.
2. Specify the command:
armlink --predefine="-DADDRESS=0x20000000" --scatter=file.scat
Concepts
• Expression evaluation in scatter files on page 8-58.
Reference
Linker Reference:
• --predefine="string" on page 2-123.
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