Red Hat ENTERPRISE LINUX 4 Manual page 99

Chapter 4. GCC Command Options
*startfile:
crt0%O%s %:if-exists(crti%O%s) \
%:if-exists-else(crtbeginT%O%s crtbegin%O%s)
%{ }
S
Substitutes the
-S
substitutes nothing. Note that the leading dash is omitted when specifying this option, and it is
automatically inserted if the substitution is performed. Thus the spec string
the command-line option
%W{ }
S
Like %{ } but mark last argument supplied within as a file to be deleted on failure.
S
%{ *}
S
Substitutes all the switches specified to GCC whose names start with
argument. This is used for switches like
switch whose names starts with
two arguments would be generated.
%{ *& *}
S T
Like %{ *}, but preserve order of
S
significant). There can be any number of ampersand-separated variables; for each the wild card
is optional. Useful for CPP as
%{ : }
S X
Substitutes , if the
X
%{! : }
S X
Substitutes , if the
X
%{ *: }
S X
Substitutes if one or more switches whose names start with
X
is substituted only once, no matter how many such switches appeared. However, if
X
somewhere in
X
by the part of that switch that matched the
%{. : }
S X
Substitutes , if processing a file with suffix
X
%{!. : }
S X
Substitutes , if not processing a file with suffix
X
%{ | : }
S P X
Substitutes if either
X
sequences as well, although they have a stronger binding than the
alternatives must be starred, and only the first matching alternative is substituted.
For example, a spec string like this:
%{.c:-foo} %{!.c:-bar} %{.c|d:-baz} %{!.c|d:-boggle}
will output the following command-line options from the following input command-line options:
switch, if that switch was given to GCC. If that switch was not specified, this
and would output the command line option
-foo
. %{o*} would substitute this text, including the space. Thus
o
%{D*&U*&A*}
switch was given to GCC.
-S
switch was not given to GCC.
-S
, then will be substituted once for each matching switch, with the
X
or was given to GCC. This may be combined with
-S -P
, , , etc. GCC considers
-o -D -I
and options (the order of
S T
.
.
*
.
S
.
S
%{foo}
.
-foo
, but which also take an
-S
-o foo
and in the spec is not
S T
are specified to GCC. Normally
-S
. If appears in
| %*
91
would match
as being one
appears
%*
replaced
%*
, , and
! . *
, all of the
X