3.6.4.1 Input Section Basics

An input section description consists of a file name optionally followed by a list of section names in parentheses.

The file name and the section name may be wildcard patterns, which we describe further below (see Input Section Wildcards).

The most common input section description is to include all input sections with a particular name in the output section. For example, to include all input `.text' sections, you would write:

     *(.text)

Here the `*' is a wildcard which matches any file name. To exclude a list of files from matching the file name wildcard, EXCLUDE_FILE may be used to match all files except the ones specified in the EXCLUDE_FILE list. For example:

     (*(EXCLUDE_FILE (*crtend.o *otherfile.o) .ctors))

will cause all .ctors sections from all files except crtend.o and otherfile.o to be included.

There are two ways to include more than one section:

     *(.text .rdata)
     *(.text) *(.rdata)

The difference between these is the order in which the `.text' and `.rdata' input sections will appear in the output section. In the first example, they will be intermingled, appearing in the same order as they are found in the linker input. In the second example, all `.text' input sections will appear first, followed by all `.rdata' input sections.

You can specify a file name to include sections from a particular file. You would do this if one or more of your files contain special data that needs to be at a particular location in memory. For example:

     data.o(.data)

If you use a file name without a list of sections, then all sections in the input file will be included in the output section. This is not commonly done, but it may by useful on occasion. For example:

     data.o

When you use a file name which does not contain any wild card characters, the linker will first see if you also specified the file name on the linker command line or in an INPUT command. If you did not, the linker will attempt to open the file as an input file, as though it appeared on the command line. Note that this differs from an INPUT command, because the linker will not search for the file in the archive search path.