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The second field of an option record can specify any of the following properties. When an option takes an argument, it is enclosed in parentheses following the option property name. The parser that handles option files is quite simplistic, and will be tricked by any nested parentheses within the argument text itself; in this case, the entire option argument can be wrapped in curly braces within the parentheses to demarcate it, e.g.:
Condition({defined (USE_CYGWIN_LIBSTDCXX_WRAPPERS)})
Common
Target
Driver
It is possible to specify several different languages for the same
option. Each language must have been declared by an earlier
Language
record. See Option file format.
RejectDriver
RejectNegative
Negative(
othername)
Negative
property of the option to be
turned off. The driver will prune options, removing those that are
turned off by some later option. This pruning is not done for options
with Joined
or JoinedOrMissing
properties, unless the
options have both the RejectNegative
property and the Negative
property mentions itself.
As a consequence, if you have a group of mutually-exclusive
options, their Negative
properties should form a circular chain.
For example, if options -a, -b and
-c are mutually exclusive, their respective Negative
properties should be `Negative(b)', `Negative(c)'
and `Negative(a)'.
Joined
Separate
Joined
indicates
that the option and argument can be included in the same argv
entry (as with -mflush-func=
name, for example).
Separate
indicates that the option and argument can be
separate argv
entries (as with -o
). An option is
allowed to have both of these properties.
JoinedOrMissing
argv
entry as the option itself.
This property cannot be used alongside Joined
or Separate
.
MissingArgError(
message)
Joined
or Separate
, the message
message will be used as an error message if the mandatory
argument is missing; for options without MissingArgError
, a
generic error message is used. message should contain a single
`%qs' format, which will be used to format the name of the option
passed.
Args(
n)
Separate
, indicate that it takes n
arguments. The default is 1.
UInteger
int
. Hexadecimal
integers may optionally start with the 0x
or 0X
prefix.
The option parser validates and converts the argument before passing
it to the relevant option handler. UInteger
should also be used
with options like -falign-loops
where both -falign-loops
and -falign-loops
=n are supported to make sure the saved
options are given a full integer. Positive values of the argument in
excess of INT_MAX
wrap around zero.
Host_Wide_Int
UInteger
argument, hexadecimal integers
may optionally start with the 0x
or 0X
prefix. The option
parser validates and converts the argument before passing it to
the relevant option handler. Host_Wide_Int
should be used with
options that need to accept very large values. Positive values of
the argument in excess of HOST_WIDE_INT_M1U
are assigned
HOST_WIDE_INT_M1U
.
IntegerRange(
n,
m)
int
. The option's
parser validates that the value of an option integer argument is within
the closed range [n, m].
ByteSize
UInteger
or Host_Wide_Int
arguments. The option's integer argument is interpreted as if in infinite
precision using saturation arithmetic in the corresponding type. The argument
may be followed by a `byte-size' suffix designating a multiple of bytes
such as kB
and KiB
for kilobyte and kibibyte, respectively,
MB
and MiB
for megabyte and mebibyte, GB
and GiB
for gigabyte and gigibyte, and so on. ByteSize
should be used for
with options that take a very large argument representing a size in bytes,
such as -Wlarger-than=.
ToLower
Enum
property.
NoDriverArg
Separate
, the option only takes an
argument in the compiler proper, not in the driver. This is for
compatibility with existing options that are used both directly and
via -Wp,; new options should not have this property.
Var(
var)
global_options.x_
var).
The way that the state is stored depends on the type of option:
WarnRemoved
Var(
var,
set)
!
set
when the “no-” form is used.
var is declared in the same way as for the single-argument form described above.
Mask
or InverseMask
properties,
var is the integer variable that contains the mask.
UInteger
property,
var is an integer variable that stores the value of the argument.
Enum
property,
var is a variable (type given in the Type
property of the
`Enum' record whose Name
property has the same argument as
the Enum
property of this option) that stores the value of the
argument.
Defer
property, var is a pointer to
a VEC(cl_deferred_option,heap)
that stores the option for later
processing. (var is declared with type void *
and needs
to be cast to VEC(cl_deferred_option,heap)
before use.)
The option-processing script will usually zero-initialize var.
You can modify this behavior using Init
.
Init(
value)
Var
property should be statically
initialized to value. If more than one option using the same
variable specifies Init
, all must specify the same initializer.
Mask(
name)
target_flags
variable (see Run-time Target) and is active when that bit is set.
You may also specify Var
to select a variable other than
target_flags
.
The options-processing script will automatically allocate a unique bit
for the option. If the option is attached to `target_flags',
the script will set the macro MASK_
name to the appropriate
bitmask. It will also declare a TARGET_
name macro that has
the value 1 when the option is active and 0 otherwise. If you use Var
to attach the option to a different variable, the bitmask macro with be
called OPTION_MASK_
name.
InverseMask(
othername)
InverseMask(
othername,
thisname)
Mask(
othername)
property. If thisname is given,
the options-processing script will declare a TARGET_
thisname
macro that is 1 when the option is active and 0 otherwise.
Enum(
name)
EnumSet
Enum(
name)
property.
Corresponding `Enum' record must use Set
properties.
The option's argument is either a string from the set like for
Enum(
name)
, but with a slightly different behavior that
the whole Var
isn't overwritten, but only the bits in all the
enumeration values with the same set bitwise ored together.
Or option's argument can be a comma separated list of strings where
each string is from a different Set(
number)
.
EnumBitSet
Enum(
name)
property.
Similar to `EnumSet', but corresponding `Enum' record must
not use Set
properties, each EnumValue
should have
Value
that is a power of 2, each value is treated as its own
set and its value as the set's mask, so there are no mutually
exclusive arguments.
Defer
Var
,
for later processing.
Alias(
opt)
Alias(
opt,
arg)
Alias(
opt,
posarg,
negarg)
NegativeAlias
). In the first form,
any argument passed to the alias is considered to be passed to
-opt, and -opt is considered to be
negated if the alias is used in negated form. In the second form, the
alias may not be negated or have an argument, and posarg is
considered to be passed as an argument to -opt. In the
third form, the alias may not have an argument, if the alias is used
in the positive form then posarg is considered to be passed to
-opt, and if the alias is used in the negative form
then negarg is considered to be passed to -opt.
Aliases should not specify Var
or Mask
or
UInteger
. Aliases should normally specify the same languages
as the target of the alias; the flags on the target will be used to
determine any diagnostic for use of an option for the wrong language,
while those on the alias will be used to identify what command-line
text is the option and what text is any argument to that option.
When an Alias
definition is used for an option, driver specs do
not need to handle it and no `OPT_' enumeration value is defined
for it; only the canonical form of the option will be seen in those
places.
NegativeAlias
Alias(
opt)
, the option is
considered to be an alias for the positive form of -opt
if negated and for the negative form of -opt if not
negated. NegativeAlias
may not be used with the forms of
Alias
taking more than one argument.
Ignore
Warn
. The option will not be seen by specs and no `OPT_'
enumeration value is defined for it.
SeparateAlias
Joined
, Separate
and
Alias
, the option only acts as an alias when passed a separate
argument; with a joined argument it acts as a normal option, with an
`OPT_' enumeration value. This is for compatibility with the
Java -d option and should not be used for new options.
Warn(
message)
Warn
, the target of the alias must not also be marked
Warn
.
Warning
Optimization
Var
should be saved and restored when the optimization level is
changed with optimize
attributes.
PerFunction
Optimization
implies PerFunction
, but options that do not
affect executable code generation may use this flag instead, so that the
option is not taken into account in ways that might affect executable
code generation.
Param
Undocumented
Condition(
cond)
Save
cl_target_option
structure to hold a copy of the
option, add the functions cl_target_option_save
and
cl_target_option_restore
to save and restore the options.
SetByCombined
gcc_options
struct to
have a field frontend_set_
name, where name
is the name of the field holding the value of this option (without the
leading x_
). This gives the front end a way to indicate that
the value has been set explicitly and should not be changed by the
combined option. For example, some front ends use this to prevent
-ffast-math and -fno-fast-math from changing the
value of -fmath-errno for languages that do not use
errno
.
EnabledBy(
opt)
EnabledBy(
opt ||
opt2)
EnabledBy(
opt &&
opt2)
||
. The third form using &&
specifies that the option is
only set if both opt and opt2 are set. The options opt
and opt2 must have the Common
property; otherwise, use
LangEnabledBy
.
LangEnabledBy(
language,
opt)
LangEnabledBy(
language,
opt,
posarg,
negarg)
||
separated options. In the second form, if
opt is used in the positive form then posarg is considered
to be passed to the option, and if opt is used in the negative
form then negarg is considered to be passed to the option. It
is possible to specify several different languages. Each
language must have been declared by an earlier Language
record. See Option file format.
NoDWARFRecord
PchIgnore
CPP(
var)
Var
and Init
must be set as well.
CppReason(
CPP_W_Enum)
cpplib.h
warning reason code
CPP_W_Enum. This should only be used for warning options of the
C-family front-ends.