GNU Info

(ld.info)Environment

---

Prev: Options Up: Invocation

---

Enter node , (file) or (file)node

Environment Variables
=====================

   You can change the behavior of `ld' with the environment variables
`GNUTARGET', `LDEMULATION', and `COLLECT_NO_DEMANGLE'.

   `GNUTARGET' determines the input-file object format if you don't use
`-b' (or its synonym `--format').  Its value should be one of the BFD
names for an input format (Note: BFD).  If there is no `GNUTARGET' in
the environment, `ld' uses the natural format of the target. If
`GNUTARGET' is set to `default' then BFD attempts to discover the input
format by examining binary input files; this method often succeeds, but
there are potential ambiguities, since there is no method of ensuring
that the magic number used to specify object-file formats is unique.
However, the configuration procedure for BFD on each system places the
conventional format for that system first in the search-list, so
ambiguities are resolved in favor of convention.

   `LDEMULATION' determines the default emulation if you don't use the
`-m' option.  The emulation can affect various aspects of linker
behaviour, particularly the default linker script.  You can list the
available emulations with the `--verbose' or `-V' options.  If the `-m'
option is not used, and the `LDEMULATION' environment variable is not
defined, the default emulation depends upon how the linker was
configured.

   Normally, the linker will default to demangling symbols.  However, if
`COLLECT_NO_DEMANGLE' is set in the environment, then it will default
to not demangling symbols.  This environment variable is used in a
similar fashion by the `gcc' linker wrapper program.  The default may
be overridden by the `--demangle' and `--no-demangle' options.