-Wsign-compare -Wsign-conversion -Wstack-protector @gol
-Wstrict-aliasing -Wstrict-aliasing=n @gol
-Wstrict-overflow -Wstrict-overflow=@var{n} @gol
+-Wsuggest-attribute=@r{[}const@r{|}pure@r{]} @gol
-Wswitch -Wswitch-default -Wswitch-enum -Wsync-nand @gol
-Wsystem-headers -Wtrigraphs -Wtype-limits -Wundef -Wuninitialized @gol
-Wunknown-pragmas -Wno-pragmas @gol
-fgcse-sm -fif-conversion -fif-conversion2 -findirect-inlining @gol
-finline-functions -finline-functions-called-once -finline-limit=@var{n} @gol
-finline-small-functions -fipa-cp -fipa-cp-clone -fipa-matrix-reorg -fipa-pta @gol
--fipa-pure-const -fipa-reference -fipa-struct-reorg @gol
--fipa-type-escape -fira-algorithm=@var{algorithm} @gol
+-fipa-profile -fipa-pure-const -fipa-reference -fipa-struct-reorg @gol
+-fira-algorithm=@var{algorithm} @gol
-fira-region=@var{region} -fira-coalesce @gol
-fira-loop-pressure -fno-ira-share-save-slots @gol
-fno-ira-share-spill-slots -fira-verbose=@var{n} @gol
-mprefergot -musermode -multcost=@var{number} -mdiv=@var{strategy} @gol
-mdivsi3_libfunc=@var{name} -mfixed-range=@var{register-range} @gol
-madjust-unroll -mindexed-addressing -mgettrcost=@var{number} -mpt-fixed @gol
--minvalid-symbols}
+-maccumulate-outgoing-args -minvalid-symbols}
@emph{SPARC Options}
@gccoptlist{-mcpu=@var{cpu-type} @gol
@item -###
@opindex ###
-Like @option{-v} except the commands are not executed and all command
-arguments are quoted. This is useful for shell scripts to capture the
-driver-generated command lines.
+Like @option{-v} except the commands are not executed and arguments
+are quoted unless they contain only alphanumeric characters or @code{./-_}.
+This is useful for shell scripts to capture the driver-generated command lines.
@item -pipe
@opindex pipe
@w{@uref{http://gcc.gnu.org/c99status.html}} for more information. The
names @samp{c9x} and @samp{iso9899:199x} are deprecated.
+@item c1x
+ISO C1X, the draft of the next revision of the ISO C standard.
+Support is limited and experimental and features enabled by this
+option may be changed or removed if changed in or removed from the
+standard draft.
+
@item gnu90
@itemx gnu89
GNU dialect of ISO C90 (including some C99 features). This
GNU dialect of ISO C99. When ISO C99 is fully implemented in GCC,
this will become the default. The name @samp{gnu9x} is deprecated.
+@item gnu1x
+GNU dialect of ISO C1X. Support is limited and experimental and
+features enabled by this option may be changed or removed if changed
+in or removed from the standard draft.
+
@item c++98
The 1998 ISO C++ standard plus amendments. Same as @option{-ansi} for
C++ code.
ANSI/ISO C@. These include @code{ffs}, @code{alloca}, @code{_exit},
@code{index}, @code{bzero}, @code{conjf}, and other related functions.
+@item -fnothrow-opt
+@opindex fnothrow-opt
+Treat a @code{throw()} exception specification as though it were a
+@code{noexcept} specification to reduce or eliminate the text size
+overhead relative to a function with no exception specification. The
+semantic effect is that an exception thrown out of a function with
+such an exception specification will result in a call to
+@code{terminate} rather than @code{unexpected}.
+
@item -fno-operator-names
@opindex fno-operator-names
Do not treat the operator name keywords @code{and}, @code{bitand},
Emit statistics about front-end processing at the end of the compilation.
This information is generally only useful to the G++ development team.
+@item -fstrict-enums
+@opindex fstrict-enums
+Allow the compiler to optimize using the assumption that a value of
+enumeration type can only be one of the values of the enumeration (as
+defined in the C++ standard; basically, a value which can be
+represented in the minimum number of bits needed to represent all the
+enumerators). This assumption may not be valid if the program uses a
+cast to convert an arbitrary integer value to the enumeration type.
+
@item -ftemplate-depth=@var{n}
@opindex ftemplate-depth
Set the maximum instantiation depth for template classes to @var{n}.
If a source file was changed between @option{-fprofile-gen} and
@option{-fprofile-use}, the files with the profile feedback can fail
to match the source file and GCC can not use the profile feedback
-information. By default, GCC emits an error message in this case.
-The option @option{-Wcoverage-mismatch} emits a warning instead of an
-error. GCC does not use appropriate feedback profiles, so using this
-option can result in poorly optimized code. This option is useful
-only in the case of very minor changes such as bug fixes to an
-existing code-base.
+information. By default, this warning is enabled and is treated as an
+error. @option{-Wno-coverage-mismatch} can be used to disable the
+warning or @option{-Wno-error=coverage-mismatch} can be used to
+disable the error. Disable the error for this warning can result in
+poorly optimized code, so disabling the error is useful only in the
+case of very minor changes such as bug fixes to an existing code-base.
+Completely disabling the warning is not recommended.
@end table
language-specific options also refer to @ref{C++ Dialect Options} and
@ref{Objective-C and Objective-C++ Dialect Options}.
+When an unrecognized warning label is requested (e.g.,
+@option{-Wunknown-warning}), GCC will emit a diagnostic stating
+that the option is not recognized. However, if the @samp{-Wno-} form
+is used, the behavior is slightly different: No diagnostic will be
+produced for @option{-Wno-unknown-warning} unless other diagnostics
+are being produced. This allows the use of new @option{-Wno-} options
+with old compilers, but if something goes wrong, the compiler will
+warn that an unrecognized option was used.
+
@table @gcctabopt
@item -pedantic
@opindex pedantic
-Wc++0x-compat @gol
-Wchar-subscripts @gol
-Wenum-compare @r{(in C/Objc; this is on by default in C++)} @gol
--Wimplicit-int @gol
--Wimplicit-function-declaration @gol
+-Wimplicit-int @r{(C and Objective-C only)} @gol
+-Wimplicit-function-declaration @r{(C and Objective-C only)} @gol
-Wcomment @gol
-Wformat @gol
-Wmain @r{(only for C/ObjC and unless} @option{-ffreestanding}@r{)} @gol
@option{-pedantic-errors}. This warning is also enabled by
@option{-Wall}.
-@item -Wimplicit
+@item -Wimplicit @r{(C and Objective-C only)}
@opindex Wimplicit
@opindex Wno-implicit
Same as @option{-Wimplicit-int} and @option{-Wimplicit-function-declaration}.
false positives.
@end table
+@item -Wsuggest-attribute=@r{[}const@r{|}pure@r{]}
+@opindex Wsuggest-attribute=
+@opindex Wno-suggest-attribute=
+Warn for cases where adding an attribute may be beneficial. The
+attributes currently supported are listed below.
+
+@table @gcctabopt
+@item -Wsuggest-attribute=pure
+@itemx -Wsuggest-attribute=const
+@opindex Wsuggest-attribute=pure
+@opindex Wno-suggest-attribute=pure
+@opindex Wsuggest-attribute=const
+@opindex Wno-suggest-attribute=const
+
+Warn about functions which might be candidates for attributes
+@code{pure} or @code{const}. The compiler only warns for functions
+visible in other compilation units or if it cannot prove that the
+function returns normally. A function returns normally if it doesn't
+contain an infinite loop nor returns abnormally by throwing, calling
+@code{abort()} or trapping. This analysis requires option
+@option{-fipa-pure-const}, which is enabled by default at @option{-O}
+and higher. Higher optimization levels improve the accuracy of the
+analysis.
+@end table
+
@item -Warray-bounds
@opindex Wno-array-bounds
@opindex Warray-bounds
This option is only active when @option{-ftree-vrp} is active
-(default for -O2 and above). It warns about subscripts to arrays
+(default for @option{-O2} and above). It warns about subscripts to arrays
that are always out of bounds. This warning is enabled by @option{-Wall}.
@item -Wno-div-by-zero
-fif-conversion2 @gol
-fif-conversion @gol
-fipa-pure-const @gol
+-fipa-profile @gol
-fipa-reference @gol
-fmerge-constants
-fsplit-wide-types @gol
layout in order to better utilize spatial locality. This transformation is
affective for programs containing arrays of structures. Available in two
compilation modes: profile-based (enabled with @option{-fprofile-generate})
-or static (which uses built-in heuristics). Require @option{-fipa-type-escape}
-to provide the safety of this transformation. It works only in whole program
+or static (which uses built-in heuristics). It works only in whole program
mode, so it requires @option{-fwhole-program} and @option{-combine} to be
enabled. Structures considered @samp{cold} by this transformation are not
affected (see @option{--param struct-reorg-cold-struct-ratio=@var{value}}).
Disabled by default.
-This option is experimental.
-
@item -fwpa
@opindex fwpa
This is an internal option used by GCC when compiling with
@item min-insn-to-prefetch-ratio
The minimum ratio between the number of instructions and the
-number of prefetches to enable prefetching in a loop with an
-unknown trip count.
+number of prefetches to enable prefetching in a loop.
@item prefetch-min-insn-to-mem-ratio
The minimum ratio between the number of instructions and the
by default. This can be overridden with the @code{section} attribute.
@xref{Variable Attributes}.
-@item -mfix-cortex-m3-ldrd
-@opindex mfix-cortex-m3-ldrd
-Some Cortex-M3 cores can cause data corruption when @code{ldrd} instructions
-with overlapping destination and base registers are used. This option avoids
-generating these instructions. This option is enabled by default when
-@option{-mcpu=cortex-m3} is specified.
-
@end table
@node ARM Options
loader imposes this restriction, and when @option{-fpic} or @option{-fPIC}
is specified.
+@item -mfix-cortex-m3-ldrd
+@opindex mfix-cortex-m3-ldrd
+Some Cortex-M3 cores can cause data corruption when @code{ldrd} instructions
+with overlapping destination and base registers are used. This option avoids
+generating these instructions. This option is enabled by default when
+@option{-mcpu=cortex-m3} is specified.
+
@end table
@node AVR Options
slows down the case of larger dividends. inv20u assumes the case of a such
a small dividend to be unlikely, and inv20l assumes it to be likely.
+@item -maccumulate-outgoing-args
+@opindex maccumulate-outgoing-args
+Reserve space once for outgoing arguments in the function prologue rather
+than around each call. Generally beneficial for performance and size. Also
+needed for unwinding to avoid changing the stack frame around conditional code.
+
@item -mdivsi3_libfunc=@var{name}
@opindex mdivsi3_libfunc=@var{name}
Set the name of the library function used for 32 bit signed division to