1 ; Options for the C, ObjC, C++ and ObjC++ front ends.
2 ; Copyright (C) 2003-2018 Free Software Foundation, Inc.
4 ; This file is part of GCC.
6 ; GCC is free software; you can redistribute it and/or modify it under
7 ; the terms of the GNU General Public License as published by the Free
8 ; Software Foundation; either version 3, or (at your option) any later
11 ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 ; WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 ; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 ; You should have received a copy of the GNU General Public License
17 ; along with GCC; see the file COPYING3. If not see
18 ; <http://www.gnu.org/licenses/>.
20 ; See the GCC internals manual for a description of this file's format.
22 ; Please try to keep this file in ASCII collating order.
37 C ObjC C++ ObjC++ Warning Alias(Wall)
40 C ObjC C++ ObjC++ Alias(ansi)
43 C ObjC C++ ObjC++ Separate Alias(A) MissingArgError(assertion missing after %qs)
46 C ObjC C++ ObjC++ Joined Alias(A) MissingArgError(assertion missing after %qs)
49 C ObjC C++ ObjC++ Alias(C)
52 C ObjC C++ ObjC++ Alias(CC)
55 C ObjC C++ ObjC++ Separate Alias(D) MissingArgError(macro name missing after %qs)
58 C ObjC C++ ObjC++ Joined Alias(D) MissingArgError(macro name missing after %qs)
61 C ObjC C++ ObjC++ Alias(M)
64 C ObjC C++ ObjC++ Separate Alias(d)
67 C ObjC C++ ObjC++ Joined Alias(d)
70 C ObjC C++ ObjC++ Separate Alias(imacros) MissingArgError(missing filename after %qs)
73 C ObjC C++ ObjC++ Joined Alias(imacros) MissingArgError(missing filename after %qs)
76 C ObjC C++ ObjC++ Separate Alias(include) MissingArgError(missing filename after %qs)
79 C ObjC C++ ObjC++ Joined Alias(include) MissingArgError(missing filename after %qs)
82 C ObjC C++ ObjC++ Alias(I, -)
85 C ObjC C++ ObjC++ Separate Alias(I) MissingArgError(missing path after %qs)
88 C ObjC C++ ObjC++ Joined Alias(I) MissingArgError(missing path after %qs)
90 -include-directory-after
91 C ObjC C++ ObjC++ Separate Alias(idirafter) MissingArgError(missing path after %qs)
93 -include-directory-after=
94 C ObjC C++ ObjC++ Joined Alias(idirafter) MissingArgError(missing path after %qs)
97 C ObjC C++ ObjC++ Separate Alias(iprefix)
100 C ObjC C++ ObjC++ JoinedOrMissing Alias(iprefix)
103 C ObjC C++ ObjC++ Separate Alias(iwithprefix)
105 -include-with-prefix=
106 C ObjC C++ ObjC++ JoinedOrMissing Alias(iwithprefix)
108 -include-with-prefix-after
109 C ObjC C++ ObjC++ Separate Alias(iwithprefix)
111 -include-with-prefix-after=
112 C ObjC C++ ObjC++ JoinedOrMissing Alias(iwithprefix)
114 -include-with-prefix-before
115 C ObjC C++ ObjC++ Separate Alias(iwithprefixbefore)
117 -include-with-prefix-before=
118 C ObjC C++ ObjC++ JoinedOrMissing Alias(iwithprefixbefore)
121 Driver Alias(no-integrated-cpp)
124 C ObjC C++ ObjC++ Alias(P)
126 -no-standard-includes
127 C ObjC C++ ObjC++ Alias(nostdinc)
130 C ObjC C++ ObjC++ Alias(w)
133 C ObjC C++ ObjC++ Separate Alias(o)
136 C ObjC C++ ObjC++ Joined Alias(o)
139 C ObjC C++ ObjC++ Joined Separate
142 C ObjC C++ ObjC++ Alias(pedantic)
145 C ObjC C++ ObjC++ Undocumented Alias(E)
147 -print-missing-file-dependencies
148 C ObjC C++ ObjC++ Alias(MG)
151 C ObjC C++ ObjC++ Alias(H)
154 Driver Alias(traditional)
157 C ObjC C++ ObjC++ Alias(traditional-cpp)
160 C ObjC C++ ObjC++ Alias(trigraphs)
163 C ObjC C++ ObjC++ Separate Alias(U) MissingArgError(macro name missing after %qs)
166 C ObjC C++ ObjC++ Joined Alias(U) MissingArgError(macro name missing after %qs)
169 C ObjC C++ ObjC++ Alias(MM)
172 Common C ObjC C++ ObjC++ Alias(v)
175 C ObjC C++ ObjC++ NoDriverArg Separate Alias(MD) MissingArgError(missing filename after %qs)
177 -write-user-dependencies
178 C ObjC C++ ObjC++ NoDriverArg Separate Alias(MMD) MissingArgError(missing filename after %qs)
181 C ObjC C++ ObjC++ Joined Separate MissingArgError(assertion missing after %qs)
182 -A<question>=<answer> Assert the <answer> to <question>. Putting '-' before <question> disables the <answer> to <question>.
186 Do not discard comments.
190 Do not discard comments in macro expansions.
193 C ObjC C++ ObjC++ Joined Separate MissingArgError(macro name missing after %qs)
194 -D<macro>[=<val>] Define a <macro> with <val> as its value. If just <macro> is given, <val> is taken to be 1.
197 C ObjC C++ ObjC++ Undocumented Var(flag_preprocess_only)
200 Driver C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
201 -F <dir> Add <dir> to the end of the main framework include path.
204 C Var(flag_gimple) Init(0)
205 Enable parsing GIMPLE.
209 Print the name of header files as they are used.
212 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
213 -I <dir> Add <dir> to the end of the main include path.
217 Generate make dependencies.
220 C ObjC C++ ObjC++ NoDriverArg Separate MissingArgError(missing filename after %qs)
221 Generate make dependencies and compile.
224 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
225 -MF <file> Write dependency output to the given file.
229 Treat missing header files as generated files.
233 Like -M but ignore system header files.
236 C ObjC C++ ObjC++ NoDriverArg Separate MissingArgError(missing filename after %qs)
237 Like -MD but ignore system header files.
241 Generate phony targets for all headers.
244 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing makefile target after %qs)
245 -MQ <target> Add a MAKE-quoted target.
248 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing makefile target after %qs)
249 -MT <target> Add an unquoted target.
253 Do not generate #line directives.
256 C ObjC C++ ObjC++ Joined Separate MissingArgError(macro name missing after %qs)
257 -U<macro> Undefine <macro>.
260 C ObjC C++ ObjC++ LTO Var(warn_abi) Warning
261 Warn about things that will change when compiling with an ABI-compliant compiler.
264 C ObjC C++ ObjC++ LTO Joined RejectNegative UInteger Warning
265 Warn about things that change between the current -fabi-version and the specified version.
268 C++ ObjC++ Var(warn_abi_tag) Warning
269 Warn if a subobject has an abi_tag attribute that the complete object type does not have.
272 C ObjC C++ ObjC++ LTO Var(warn_psabi) Init(1) Warning Undocumented LangEnabledBy(C ObjC C++ ObjC++,Wabi)
275 C ObjC C++ ObjC++ Var(warn_address) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
276 Warn about suspicious uses of memory addresses.
279 Name(warn_aligned_new_level) Type(int) UnknownError(argument %qs to %<-Waligned-new%> not recognized)
282 Enum(warn_aligned_new_level) String(none) Value(0)
285 Enum(warn_aligned_new_level) String(global) Value(1)
288 Enum(warn_aligned_new_level) String(all) Value(2)
291 C++ ObjC++ Alias(Waligned-new=,global,none)
292 Warn about 'new' of type with extended alignment without -faligned-new.
295 C++ ObjC++ Var(warn_aligned_new) Enum(warn_aligned_new_level) Joined RejectNegative Warning LangEnabledBy(C++ ObjC++,Wall,1,0)
296 -Waligned-new=[none|global|all] Warn even if 'new' uses a class member allocation function.
299 C ObjC C++ ObjC++ Warning
300 Enable most warning messages.
303 C ObjC C++ ObjC++ Var(warn_alloca) Warning
304 Warn on any use of alloca.
306 Walloc-size-larger-than=
307 C ObjC C++ LTO ObjC++ Var(warn_alloc_size_limit) Joined Host_Wide_Int ByteSize Warning Init(HOST_WIDE_INT_MAX)
308 -Walloc-size-larger-than=<bytes> Warn for calls to allocation functions that
309 attempt to allocate objects larger than the specified number of bytes.
311 Wno-alloc-size-larger-than
312 C ObjC C++ LTO ObjC++ Alias(Walloc-size-larger-than=,18446744073709551615EiB,none) Warning
313 -Wno-alloc-size-larger-than Disable Walloc-size-larger-than= warning. Equivalent to Walloc-size-larger-than=<SIZE_MAX> or larger.
316 C ObjC C++ ObjC++ Var(warn_alloc_zero) Warning
317 -Walloc-zero Warn for calls to allocation functions that specify zero bytes.
320 C ObjC C++ LTO ObjC++ Var(warn_alloca_limit) Warning Joined Host_Wide_Int ByteSize Init(HOST_WIDE_INT_MAX)
321 -Walloca-larger-than=<number> Warn on unbounded uses of
322 alloca, and on bounded uses of alloca whose bound can be larger than
325 Wno-alloca-larger-than
326 C ObjC C++ LTO ObjC++ Alias(Walloca-larger-than=,18446744073709551615EiB,none) Warning
327 -Wno-alloca-larger-than Disable Walloca-larger-than= warning. Equivalent to Walloca-larger-than=<SIZE_MAX> or larger.
330 LangEnabledBy(C ObjC C++ LTO ObjC++)
334 LangEnabledBy(C ObjC C++ LTO ObjC++,Wall,1,0)
338 ObjC ObjC++ Var(warn_assign_intercept) Warning
339 Warn whenever an Objective-C assignment is being intercepted by the garbage collector.
342 C ObjC Var(warn_bad_function_cast) Warning
343 Warn about casting functions to incompatible types.
346 C ObjC C++ ObjC++ Var(warn_bool_compare) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
347 Warn about boolean expression compared with an integer value different from true/false.
350 C ObjC C++ ObjC++ Var(warn_bool_op) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
351 Warn about certain operations on boolean expressions.
354 C ObjC C++ ObjC++ Var(warn_frame_address) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
355 Warn when __builtin_frame_address or __builtin_return_address is used unsafely.
357 Wbuiltin-declaration-mismatch
358 C ObjC C++ ObjC++ Var(warn_builtin_declaraion_mismatch) Init(1) Warning
359 Warn when a built-in function is declared with the wrong signature.
361 Wbuiltin-macro-redefined
362 C ObjC C++ ObjC++ CPP(warn_builtin_macro_redefined) CppReason(CPP_W_BUILTIN_MACRO_REDEFINED) Var(cpp_warn_builtin_macro_redefined) Init(1) Warning
363 Warn when a built-in preprocessor macro is undefined or redefined.
366 C ObjC CPP(cpp_warn_c90_c99_compat) CppReason(CPP_W_C90_C99_COMPAT) Var(warn_c90_c99_compat) Init(-1) Warning
367 Warn about features not present in ISO C90, but present in ISO C99.
370 C ObjC Var(warn_c99_c11_compat) Init(-1) Warning
371 Warn about features not present in ISO C99, but present in ISO C11.
374 C ObjC Var(warn_cxx_compat) CPP(warn_cxx_operator_names) CppReason(CPP_W_CXX_OPERATOR_NAMES) Init(0) Warning
375 Warn about C constructs that are not in the common subset of C and C++.
378 C++ ObjC++ Warning Alias(Wc++11-compat) Undocumented
381 C++ ObjC++ Var(warn_cxx11_compat) Warning LangEnabledBy(C++ ObjC++,Wall) Init(0) CPP(cpp_warn_cxx11_compat) CppReason(CPP_W_CXX11_COMPAT)
382 Warn about C++ constructs whose meaning differs between ISO C++ 1998 and ISO C++ 2011.
385 C++ ObjC++ Var(warn_cxx14_compat) Warning LangEnabledBy(C++ ObjC++,Wall)
386 Warn about C++ constructs whose meaning differs between ISO C++ 2011 and ISO C++ 2014.
389 C++ ObjC++ Warning Alias(Wc++17-compat) Undocumented
392 C++ ObjC++ Var(warn_cxx17_compat) Warning LangEnabledBy(C++ ObjC++,Wall)
393 Warn about C++ constructs whose meaning differs between ISO C++ 2014 and ISO C++ 2017.
396 C ObjC C++ ObjC++ Var(warn_cast_function_type) Warning EnabledBy(Wextra)
397 Warn about casts between incompatible function types.
400 C ObjC C++ ObjC++ Var(warn_cast_qual) Warning
401 Warn about casts which discard qualifiers.
404 C++ ObjC++ Warning Alias(Wcatch-value=, 1, 0)
405 Warn about catch handlers of non-reference type.
408 C++ ObjC++ Var(warn_catch_value) Warning Joined RejectNegative UInteger LangEnabledBy(C++ ObjC++,Wall, 1, 0) IntegerRange(0, 3)
409 Warn about catch handlers of non-reference type.
412 C ObjC C++ ObjC++ Var(warn_char_subscripts) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
413 Warn about subscripts whose type is \"char\".
416 C ObjC C++ ObjC++ Warning Deprecated
417 Deprecated in GCC 9. This switch has no effect.
420 C ObjC C++ ObjC++ Var(warn_clobbered) Warning EnabledBy(Wextra)
421 Warn about variables that might be changed by \"longjmp\" or \"vfork\".
424 C ObjC C++ ObjC++ CPP(warn_comments) CppReason(CPP_W_COMMENTS) Var(cpp_warn_comment) Init(0) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
425 Warn about possibly nested block comments, and C++ comments spanning more than one physical line.
428 C ObjC C++ ObjC++ Warning Alias(Wcomment)
429 Synonym for -Wcomment.
431 Wconditionally-supported
432 C++ ObjC++ Var(warn_conditionally_supported) Warning
433 Warn for conditionally-supported constructs.
436 C ObjC C++ ObjC++ Var(warn_conversion) Warning
437 Warn for implicit type conversions that may change a value.
440 C++ ObjC++ Var(warn_conversion_null) Init(1) Warning
441 Warn for converting NULL from/to a non-pointer type.
444 C ObjC C++ ObjC++ CppReason(CPP_W_WARNING_DIRECTIVE)
445 ; Documented in common.opt
448 C++ ObjC++ Var(warn_ctor_dtor_privacy) Warning
449 Warn when all constructors and destructors are private.
452 C ObjC C++ ObjC++ Var(warn_dangling_else) Warning LangEnabledBy(C ObjC C++ ObjC++,Wparentheses)
453 Warn about dangling else.
456 C ObjC C++ ObjC++ CPP(warn_date_time) CppReason(CPP_W_DATE_TIME) Var(cpp_warn_date_time) Init(0) Warning
457 Warn about __TIME__, __DATE__ and __TIMESTAMP__ usage.
459 Wdeclaration-after-statement
460 C ObjC Var(warn_declaration_after_statement) Init(-1) Warning
461 Warn when a declaration is found after a statement.
464 C++ ObjC++ Var(warn_delete_incomplete) Init(1) Warning
465 Warn when deleting a pointer to incomplete type.
467 Wdelete-non-virtual-dtor
468 C++ ObjC++ Var(warn_delnonvdtor) Warning LangEnabledBy(C++ ObjC++,Wall || Weffc++)
469 Warn about deleting polymorphic objects with non-virtual destructors.
472 C C++ ObjC ObjC++ CPP(cpp_warn_deprecated) CppReason(CPP_W_DEPRECATED) Var(warn_deprecated) Init(1) Warning
473 Warn if a deprecated compiler feature, class, method, or field is used.
476 C++ ObjC++ Var(warn_deprecated_copy) Warning LangEnabledBy(C++ ObjC++, Wall)
477 Mark implicitly-declared copy operations as deprecated if the class has a
478 user-provided copy operation or destructor.
481 C ObjC Var(warn_designated_init) Init(1) Warning
482 Warn about positional initialization of structs requiring designated initializers.
484 Wdiscarded-array-qualifiers
485 C ObjC Var(warn_discarded_array_qualifiers) Init(1) Warning
486 Warn if qualifiers on arrays which are pointer targets are discarded.
488 Wdiscarded-qualifiers
489 C ObjC Var(warn_discarded_qualifiers) Init(1) Warning
490 Warn if type qualifiers on pointers are discarded.
493 C ObjC C++ ObjC++ Var(warn_div_by_zero) Init(1) Warning
494 Warn about compile-time integer division by zero.
497 C ObjC C++ ObjC++ Var(warn_duplicated_branches) Init(0) Warning
498 Warn about duplicated branches in if-else statements.
501 C ObjC C++ ObjC++ Var(warn_duplicated_cond) Init(0) Warning
502 Warn about duplicated conditions in an if-else-if chain.
505 C++ ObjC++ Var(warn_ecpp) Warning
506 Warn about violations of Effective C++ style rules.
509 C ObjC C++ ObjC++ Var(warn_empty_body) Warning EnabledBy(Wextra)
510 Warn about an empty body in an if or else statement.
513 C ObjC C++ ObjC++ CPP(warn_endif_labels) CppReason(CPP_W_ENDIF_LABELS) Var(cpp_warn_endif_labels) Init(1) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic)
514 Warn about stray tokens after #else and #endif.
517 C ObjC C++ ObjC++ Var(warn_enum_compare) Init(-1) Warning LangEnabledBy(C ObjC,Wall || Wc++-compat)
518 Warn about comparison of different enum types.
522 ; Documented in common.opt
524 Werror-implicit-function-declaration
525 C ObjC RejectNegative Warning Alias(Werror=, implicit-function-declaration)
526 This switch is deprecated; use -Werror=implicit-function-declaration instead.
529 C ObjC C++ ObjC++ Warning
533 C++ ObjC++ Var(warn_extra_semi) Warning
534 Warn about semicolon after in-class function definition.
537 C ObjC C++ ObjC++ Var(warn_float_conversion) Warning LangEnabledBy(C ObjC C++ ObjC++,Wconversion)
538 Warn for implicit type conversions that cause loss of floating point precision.
541 C ObjC C++ ObjC++ Var(warn_float_equal) Warning
542 Warn if testing floating point numbers for equality.
545 C ObjC C++ ObjC++ Warning Alias(Wformat=, 1, 0)
546 Warn about printf/scanf/strftime/strfmon format string anomalies.
549 C ObjC C++ ObjC++ Var(warn_format_contains_nul) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
550 Warn about format strings that contain NUL bytes.
553 C ObjC C++ ObjC++ Var(warn_format_extra_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
554 Warn if passing too many arguments to a function for its format string.
557 C ObjC C++ ObjC++ Var(warn_format_nonliteral) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 2, 0)
558 Warn about format strings that are not literals.
561 C ObjC C++ LTO ObjC++ Warning Alias(Wformat-overflow=, 1, 0) IntegerRange(0, 2)
562 Warn about function calls with format strings that write past the end
563 of the destination region. Same as -Wformat-overflow=1.
566 C ObjC C++ ObjC++ Var(warn_format_security) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 2, 0)
567 Warn about possible security problems with format functions.
570 C ObjC C++ ObjC++ Var(warn_format_signedness) Warning
571 Warn about sign differences with format functions.
574 C ObjC C++ LTO ObjC++ Warning Alias(Wformat-truncation=, 1, 0)
575 Warn about calls to snprintf and similar functions that truncate output.
576 Same as -Wformat-truncation=1.
579 C ObjC C++ ObjC++ Var(warn_format_y2k) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 2, 0)
580 Warn about strftime formats yielding 2-digit years.
583 C ObjC C++ ObjC++ Var(warn_format_zero_length) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 1, 0)
584 Warn about zero-length formats.
587 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_format) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0) IntegerRange(0, 2)
588 Warn about printf/scanf/strftime/strfmon format string anomalies.
591 C ObjC C++ LTO ObjC++ Joined RejectNegative UInteger Var(warn_format_overflow) Warning LangEnabledBy(C ObjC C++ LTO ObjC++,Wformat=, warn_format >= 1, 0) IntegerRange(0, 2)
592 Warn about function calls with format strings that write past the end
593 of the destination region.
596 C ObjC C++ LTO ObjC++ Joined RejectNegative UInteger Var(warn_format_trunc) Warning LangEnabledBy(C ObjC C++ LTO ObjC++,Wformat=, warn_format >= 1, 0) IntegerRange(0, 2)
597 Warn about calls to snprintf and similar functions that truncate output.
600 C ObjC C++ ObjC++ Var(warn_if_not_aligned) Init(1) Warning
601 Warn when the field in a struct is not aligned.
604 C C++ Var(warn_ignored_qualifiers) Warning EnabledBy(Wextra)
605 Warn whenever type qualifiers are ignored.
608 C C++ Var(warn_ignored_attributes) Init(1) Warning
609 Warn whenever attributes are ignored.
611 Wincompatible-pointer-types
612 C ObjC Var(warn_incompatible_pointer_types) Init(1) Warning
613 Warn when there is a conversion between pointers that have incompatible types.
616 C ObjC C++ ObjC++ Var(warn_init_self) Warning LangEnabledBy(C++ ObjC++,Wall)
617 Warn about variables which are initialized to themselves.
620 C++ ObjC++ Var(warn_init_list) Warning Init(1)
621 Warn about uses of std::initializer_list that can result in dangling pointers.
624 C ObjC Var(warn_implicit) Warning LangEnabledBy(C ObjC,Wall)
625 Warn about implicit declarations.
627 Wimplicit-fallthrough=
628 LangEnabledBy(C ObjC C++ ObjC++,Wextra,3,0)
632 C ObjC C++ ObjC++ Var(warn_double_promotion) Warning
633 Warn about implicit conversions from \"float\" to \"double\".
635 Wexpansion-to-defined
636 C ObjC C++ ObjC++ CPP(warn_expansion_to_defined) CppReason(CPP_W_EXPANSION_TO_DEFINED) Var(cpp_warn_expansion_to_defined) Init(0) Warning EnabledBy(Wextra || Wpedantic)
637 Warn if \"defined\" is used outside #if.
639 Wimplicit-function-declaration
640 C ObjC Var(warn_implicit_function_declaration) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit)
641 Warn about implicit function declarations.
644 C ObjC Var(warn_implicit_int) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit)
645 Warn when a declaration does not specify a type.
648 C ObjC C++ ObjC++ Undocumented Ignore
650 Winherited-variadic-ctor
651 C++ ObjC++ Var(warn_inh_var_ctor) Init(1) Warning
652 Warn about C++11 inheriting constructors when the base has a variadic constructor.
655 C ObjC Var(warn_int_conversion) Init(1) Warning
656 Warn about incompatible integer to pointer and pointer to integer conversions.
659 C ObjC C++ ObjC++ Var(warn_int_in_bool_context) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
660 Warn for suspicious integer expressions in boolean context.
663 C ObjC C++ ObjC++ Var(warn_int_to_pointer_cast) Init(1) Warning
664 Warn when there is a cast to a pointer from an integer of a different size.
667 C++ ObjC++ Var(warn_invalid_offsetof) Init(1) Warning
668 Warn about invalid uses of the \"offsetof\" macro.
671 C ObjC C++ ObjC++ CPP(warn_invalid_pch) CppReason(CPP_W_INVALID_PCH) Var(cpp_warn_invalid_pch) Init(0) Warning
672 Warn about PCH files that are found but not used.
675 C ObjC Var(warn_jump_misses_init) Warning LangEnabledby(C ObjC,Wc++-compat)
676 Warn when a jump misses a variable initialization.
679 C++ ObjC++ CPP(warn_literal_suffix) CppReason(CPP_W_LITERAL_SUFFIX) Var(cpp_warn_literal_suffix) Init(1) Warning
680 Warn when a string or character literal is followed by a ud-suffix which does not begin with an underscore.
683 C ObjC C++ ObjC++ Var(warn_logical_op) Init(0) Warning
684 Warn when a logical operator is suspiciously always evaluating to true or false.
686 Wlogical-not-parentheses
687 C ObjC C++ ObjC++ Var(warn_logical_not_paren) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
688 Warn when logical not is used on the left hand side operand of a comparison.
691 C ObjC C++ ObjC++ CPP(cpp_warn_long_long) CppReason(CPP_W_LONG_LONG) Var(warn_long_long) Init(-1) Warning LangEnabledBy(C ObjC,Wc90-c99-compat)
692 Do not warn about using \"long long\" when -pedantic.
695 C ObjC C++ ObjC++ Var(warn_main) Init(-1) Warning LangEnabledBy(C ObjC,Wall, 2, 0)
696 Warn about suspicious declarations of \"main\".
699 LangEnabledBy(C ObjC C++ ObjC++,Wpedantic, 2, 0)
702 Wmemset-transposed-args
703 C ObjC C++ ObjC++ Var(warn_memset_transposed_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
704 Warn about suspicious calls to memset where the third argument is constant literal zero and the second is not.
707 C ObjC C++ ObjC++ Var(warn_memset_elt_size) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
708 Warn about suspicious calls to memset where the third argument contains the number of elements not multiplied by the element size.
710 Wmisleading-indentation
711 C C++ Common Var(warn_misleading_indentation) Warning LangEnabledBy(C C++,Wall)
712 Warn when the indentation of the code does not reflect the block structure.
715 C ObjC C++ ObjC++ Var(warn_missing_braces) Warning LangEnabledBy(C ObjC,Wall)
716 Warn about possibly missing braces around initializers.
718 Wmissing-declarations
719 C ObjC C++ ObjC++ Var(warn_missing_declarations) Warning
720 Warn about global functions without previous declarations.
722 Wmissing-field-initializers
723 C ObjC C++ ObjC++ Var(warn_missing_field_initializers) Warning EnabledBy(Wextra)
724 Warn about missing fields in struct initializers.
726 Wmultistatement-macros
727 C ObjC C++ ObjC++ Var(warn_multistatement_macros) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
728 Warn about unsafe macros expanding to multiple statements used as a body of a clause such as if, else, while, switch, or for.
730 Wmultiple-inheritance
731 C++ ObjC++ Var(warn_multiple_inheritance) Warning
732 Warn on direct multiple inheritance.
735 C++ ObjC++ Var(warn_namespaces) Warning
736 Warn on namespace definition.
739 C ObjC C++ ObjC++ Var(warn_packed_not_aligned) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
740 Warn when fields in a struct with the packed attribute are misaligned.
743 C++ ObjC++ Var(warn_sized_deallocation) Warning EnabledBy(Wextra)
744 Warn about missing sized deallocation functions.
747 C ObjC C++ ObjC++ Var(warn_sizeof_pointer_div) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
748 Warn about suspicious divisions of two sizeof expressions that don't work correctly with pointers.
750 Wsizeof-pointer-memaccess
751 C ObjC C++ ObjC++ Var(warn_sizeof_pointer_memaccess) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
752 Warn about suspicious length parameters to certain string functions if the argument uses sizeof.
754 Wsizeof-array-argument
755 C ObjC C++ ObjC++ Var(warn_sizeof_array_argument) Warning Init(1)
756 Warn when sizeof is applied on a parameter declared as an array.
759 C ObjC C++ LTO ObjC++ Warning Alias(Wstringop-overflow=, 2, 0)
760 Warn about buffer overflow in string manipulation functions like memcpy
764 C ObjC C++ LTO ObjC++ Joined RejectNegative UInteger Var(warn_stringop_overflow) Init(2) Warning LangEnabledBy(C ObjC C++ LTO ObjC++, Wall, 2, 0) IntegerRange(0, 4)
765 Under the control of Object Size type, warn about buffer overflow in string
766 manipulation functions like memcpy and strcpy.
769 C ObjC C++ LTO ObjC++ Var(warn_stringop_truncation) Warning Init (1) LangEnabledBy(C ObjC C++ LTO ObjC++, Wall)
770 Warn about truncation in string manipulation functions like strncat and strncpy.
772 Wsuggest-attribute=format
773 C ObjC C++ ObjC++ Var(warn_suggest_attribute_format) Warning
774 Warn about functions which might be candidates for format attributes.
777 C++ ObjC++ Var(warn_override) Warning
778 Suggest that the override keyword be used when the declaration of a virtual
779 function overrides another.
782 C ObjC C++ ObjC++ Var(warn_switch) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
783 Warn about enumerated switches, with no default, missing a case.
786 C ObjC C++ ObjC++ Var(warn_switch_default) Warning
787 Warn about enumerated switches missing a \"default:\" statement.
790 C ObjC C++ ObjC++ Var(warn_switch_enum) Warning
791 Warn about all enumerated switches missing a specific case.
794 C ObjC C++ ObjC++ Var(warn_switch_bool) Warning Init(1)
795 Warn about switches with boolean controlling expression.
798 C++ ObjC++ Var(warn_templates) Warning
799 Warn on primary template declaration.
802 C ObjC C++ ObjC++ Var(warn_missing_attributes) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
803 Warn about declarations of entities that may be missing attributes
804 that related entities have been declared with it.
806 Wmissing-format-attribute
807 C ObjC C++ ObjC++ Warning Alias(Wsuggest-attribute=format)
810 Wmissing-include-dirs
811 C ObjC C++ ObjC++ CPP(warn_missing_include_dirs) CppReason(CPP_W_MISSING_INCLUDE_DIRS) Var(cpp_warn_missing_include_dirs) Init(0) Warning
812 Warn about user-specified include directories that do not exist.
814 Wmissing-parameter-type
815 C ObjC Var(warn_missing_parameter_type) Warning EnabledBy(Wextra)
816 Warn about function parameters declared without a type specifier in K&R-style functions.
819 C ObjC Var(warn_missing_prototypes) Warning
820 Warn about global functions without prototypes.
823 C ObjC C++ ObjC++ Deprecated
826 C ObjC C++ ObjC++ CPP(warn_multichar) CppReason(CPP_W_MULTICHAR) Var(cpp_warn_multichar) Init(0) Warning
827 Warn about use of multi-character character constants.
830 C ObjC C++ ObjC++ Warning Var(warn_narrowing) Init(-1) LangEnabledBy(C++ ObjC++,Wall || Wc++11-compat)
831 Warn about narrowing conversions within { } that are ill-formed in C++11.
834 C ObjC Var(warn_nested_externs) Warning
835 Warn about \"extern\" declarations not at file scope.
838 C++ ObjC++ Var(warn_noexcept) Warning
839 Warn when a noexcept expression evaluates to false even though the expression can't actually throw.
842 C++ ObjC++ Warning Var(warn_noexcept_type) LangEnabledBy(C++ ObjC++,Wabi || Wc++17-compat)
843 Warn if C++17 noexcept function type will change the mangled name of a symbol.
846 C++ ObjC++ Var(warn_nontemplate_friend) Init(1) Warning
847 Warn when non-templatized friend functions are declared within a template.
850 C++ ObjC++ Var(warn_class_memaccess) Warning LangEnabledBy(C++ ObjC++, Wall)
851 Warn for unsafe raw memory writes to objects of class types.
854 C++ ObjC++ Var(warn_nonvdtor) Warning LangEnabledBy(C++ ObjC++,Weffc++)
855 Warn about non-virtual destructors.
858 C ObjC C++ LTO ObjC++ Var(warn_nonnull) Warning LangEnabledBy(C ObjC C++ LTO ObjC++,Wformat=,warn_format >= 1,0)
859 Warn about NULL being passed to argument slots marked as requiring non-NULL.
862 C ObjC C++ LTO ObjC++ LangEnabledBy(C ObjC C++ LTO ObjC++,Wall)
866 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
870 C ObjC C++ ObjC++ Warning Alias(Wnormalized=,nfc,none)
874 C ObjC C++ ObjC++ RejectNegative Joined Warning CPP(warn_normalize) CppReason(CPP_W_NORMALIZE) Init(normalized_C) Var(cpp_warn_normalize) Enum(cpp_normalize_level)
875 -Wnormalized=[none|id|nfc|nfkc] Warn about non-normalized Unicode strings.
877 ; Required for these enum values.
882 Name(cpp_normalize_level) Type(int) UnknownError(argument %qs to %<-Wnormalized%> not recognized)
885 Enum(cpp_normalize_level) String(none) Value(normalized_none)
888 Enum(cpp_normalize_level) String(nfkc) Value(normalized_KC)
891 Enum(cpp_normalize_level) String(id) Value(normalized_identifier_C)
894 Enum(cpp_normalize_level) String(nfc) Value(normalized_C)
897 C++ ObjC++ Var(warn_old_style_cast) Warning
898 Warn if a C-style cast is used in a program.
900 Wold-style-declaration
901 C ObjC Var(warn_old_style_declaration) Warning EnabledBy(Wextra)
902 Warn for obsolescent usage in a declaration.
904 Wold-style-definition
905 C ObjC Var(warn_old_style_definition) Warning
906 Warn if an old-style parameter definition is used.
909 C C++ Var(warn_openmp_simd) Warning LangEnabledBy(C C++,Wall)
910 Warn if a simd directive is overridden by the vectorizer cost model.
913 C ObjC C++ ObjC++ Var(warn_overlength_strings) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic)
914 Warn if a string is longer than the maximum portable length specified by the standard.
917 C++ ObjC++ Var(warn_overloaded_virtual) Warning
918 Warn about overloaded virtual function names.
921 C ObjC Var(warn_override_init) Warning EnabledBy(Wextra)
922 Warn about overriding initializers without side effects.
924 Woverride-init-side-effects
925 C ObjC Var(warn_override_init_side_effects) Init(1) Warning
926 Warn about overriding initializers with side effects.
928 Wpacked-bitfield-compat
929 C ObjC C++ ObjC++ Var(warn_packed_bitfield_compat) Init(-1) Warning
930 Warn about packed bit-fields whose offset changed in GCC 4.4.
933 C ObjC C++ ObjC++ Var(warn_parentheses) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
934 Warn about possibly missing parentheses.
937 C ObjC C++ ObjC++ CPP(cpp_pedantic) CppReason(CPP_W_PEDANTIC) Warning
938 ; Documented in common.opt
941 C++ ObjC++ Var(warn_pmf2ptr) Init(1) Warning
942 Warn when converting the type of pointers to member functions.
945 C ObjC C++ ObjC++ Var(warn_pointer_arith) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic)
946 Warn about function pointer arithmetic.
949 C ObjC Var(warn_pointer_sign) Warning LangEnabledBy(C ObjC,Wall || Wpedantic)
950 Warn when a pointer differs in signedness in an assignment.
953 C ObjC C++ ObjC++ Var(warn_pointer_compare) Init(1) Warning
954 Warn when a pointer is compared with a zero character constant.
957 C ObjC Var(warn_pointer_to_int_cast) Init(1) Warning
958 Warn when a pointer is cast to an integer of a different size.
961 C ObjC C++ ObjC++ Var(warn_pragmas) Init(1) Warning
962 Warn about misuses of pragmas.
964 Wproperty-assign-default
965 ObjC ObjC++ Var(warn_property_assign_default) Init(1) Warning
966 Warn if a property for an Objective-C object has no assign semantics specified.
969 ObjC ObjC++ Var(warn_protocol) Init(1) Warning
970 Warn if inherited methods are unimplemented.
973 C++ Warning Alias(Wplacement-new=, 1, 0)
974 Warn for placement new expressions with undefined behavior.
977 C++ Joined RejectNegative UInteger Var(warn_placement_new) Init(-1) Warning IntegerRange(0, 2)
978 Warn for placement new expressions with undefined behavior.
981 C ObjC C++ ObjC++ Var(warn_redundant_decls) Warning
982 Warn about multiple declarations of the same object.
985 C++ ObjC++ Var(warn_register) Warning
986 Warn about uses of register storage specifier.
989 C++ ObjC++ Var(warn_reorder) Warning LangEnabledBy(C++ ObjC++,Wall)
990 Warn when the compiler reorders code.
993 C ObjC C++ ObjC++ Var(warn_return_type) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Init(-1)
994 Warn whenever a function's return type defaults to \"int\" (C), or about inconsistent return types (C++).
996 Wscalar-storage-order
997 C ObjC C++ ObjC++ Init(1) Warning
998 Warn on suspicious constructs involving reverse scalar storage order.
1001 ObjC ObjC++ Var(warn_selector) Warning
1002 Warn if a selector has multiple methods.
1005 C ObjC C++ ObjC++ Var(warn_sequence_point) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1006 Warn about possible violations of sequence point rules.
1009 ObjC ObjC++ Var(warn_shadow_ivar) EnabledBy(Wshadow) Init(1) Warning
1010 Warn if a local declaration hides an instance variable.
1013 C ObjC C++ ObjC++ Warning Alias(Wshift-overflow=, 1, 0)
1014 Warn if left shift of a signed value overflows.
1017 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_shift_overflow) Init(-1) Warning IntegerRange(0, 2)
1018 Warn if left shift of a signed value overflows.
1020 Wshift-count-negative
1021 C ObjC C++ ObjC++ Var(warn_shift_count_negative) Init(1) Warning
1022 Warn if shift count is negative.
1024 Wshift-count-overflow
1025 C ObjC C++ ObjC++ Var(warn_shift_count_overflow) Init(1) Warning
1026 Warn if shift count >= width of type.
1028 Wshift-negative-value
1029 C ObjC C++ ObjC++ Var(warn_shift_negative_value) Init(-1) Warning
1030 Warn if left shifting a negative value.
1033 C ObjC C++ ObjC++ Var(warn_sign_compare) Warning LangEnabledBy(C++ ObjC++,Wall)
1034 Warn about signed-unsigned comparisons.
1037 C ObjC C++ ObjC++ EnabledBy(Wextra)
1041 C ObjC C++ ObjC++ Var(warn_sign_conversion) Warning LangEnabledBy(C ObjC,Wconversion)
1042 Warn for implicit type conversions between signed and unsigned integers.
1045 C++ ObjC++ Var(warn_sign_promo) Warning
1046 Warn when overload promotes from unsigned to signed.
1048 Wstrict-null-sentinel
1049 C++ ObjC++ Warning Var(warn_strict_null_sentinel)
1050 Warn about uncasted NULL used as sentinel.
1053 C ObjC Var(warn_strict_prototypes) Warning
1054 Warn about unprototyped function declarations.
1057 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 3, 0) IntegerRange(0, 3)
1061 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0) IntegerRange(0, 5)
1064 Wstrict-selector-match
1065 ObjC ObjC++ Var(warn_strict_selector_match) Warning
1066 Warn if type signatures of candidate methods do not match exactly.
1069 C C++ Var(warn_sync_nand) Init(1) Warning
1070 Warn when __sync_fetch_and_nand and __sync_nand_and_fetch built-in functions are used.
1073 C++ ObjC++ Var(warn_synth) Warning
1074 Deprecated. This switch has no effect.
1077 C ObjC C++ ObjC++ Warning
1078 ; Documented in common.opt
1080 Wtautological-compare
1081 C ObjC C++ ObjC++ Var(warn_tautological_compare) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1082 Warn if a comparison always evaluates to true or false.
1085 C++ ObjC++ Warning Var(warn_terminate) Init(1)
1086 Warn if a throw expression will always result in a call to terminate().
1089 C ObjC CPP(cpp_warn_traditional) CppReason(CPP_W_TRADITIONAL) Var(warn_traditional) Init(0) Warning
1090 Warn about features not present in traditional C.
1092 Wtraditional-conversion
1093 C ObjC Var(warn_traditional_conversion) Warning
1094 Warn of prototypes causing type conversions different from what would happen in the absence of prototype.
1097 C ObjC C++ ObjC++ CPP(warn_trigraphs) CppReason(CPP_W_TRIGRAPHS) Var(cpp_warn_trigraphs) Init(2) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1098 Warn if trigraphs are encountered that might affect the meaning of the program.
1100 Wundeclared-selector
1101 ObjC ObjC++ Var(warn_undeclared_selector) Warning
1102 Warn about @selector()s without previously declared methods.
1105 C ObjC C++ ObjC++ CPP(warn_undef) CppReason(CPP_W_UNDEF) Var(cpp_warn_undef) Init(0) Warning
1106 Warn if an undefined macro is used in an #if directive.
1109 C ObjC C++ ObjC++ LTO LangEnabledBy(C ObjC C++ ObjC++ LTO,Wall)
1112 Wmaybe-uninitialized
1113 C ObjC C++ ObjC++ LTO LangEnabledBy(C ObjC C++ ObjC++ LTO,Wall)
1117 C ObjC C++ ObjC++ Warning Var(warn_unknown_pragmas) LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0)
1118 Warn about unrecognized pragmas.
1120 Wunsuffixed-float-constants
1121 C ObjC Var(warn_unsuffixed_float_constants) Warning
1122 Warn about unsuffixed float constants.
1125 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
1126 ; documented in common.opt
1128 Wunused-local-typedefs
1129 C ObjC C++ ObjC++ Var(warn_unused_local_typedefs) Warning EnabledBy(Wunused)
1130 Warn when typedefs locally defined in a function are not used.
1133 C ObjC C++ ObjC++ CppReason(CPP_W_UNUSED_MACROS) Var(cpp_warn_unused_macros) Warning
1134 Warn about macros defined in the main file that are not used.
1137 C ObjC C++ ObjC++ Var(warn_unused_result) Init(1) Warning
1138 Warn if a caller of a function, marked with attribute warn_unused_result, does not use its return value.
1141 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wunused)
1142 ; documented in common.opt
1144 Wunused-const-variable
1145 C ObjC C++ ObjC++ Warning Alias(Wunused-const-variable=, 2, 0)
1146 Warn when a const variable is unused.
1148 Wunused-const-variable=
1149 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_unused_const_variable) Warning LangEnabledBy(C ObjC,Wunused-variable, 1, 0) IntegerRange(0, 2)
1150 Warn when a const variable is unused.
1153 C ObjC C++ ObjC++ CPP(warn_variadic_macros) CppReason(CPP_W_VARIADIC_MACROS) Var(cpp_warn_variadic_macros) Init(0) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic || Wtraditional)
1154 Warn about using variadic macros.
1157 C ObjC C++ ObjC++ Warning Var(warn_varargs) Init(1)
1158 Warn about questionable usage of the macros used to retrieve variable arguments.
1161 C ObjC C++ ObjC++ Var(warn_vla) Init(-1) Warning
1162 Warn if a variable length array is used.
1165 C ObjC C++ LTO ObjC++ Var(warn_vla_limit) Warning Joined Host_Wide_Int ByteSize Init(HOST_WIDE_INT_MAX)
1166 -Wvla-larger-than=<number> Warn on unbounded uses of variable-length
1167 arrays, and on bounded uses of variable-length arrays whose bound can be
1168 larger than <number> bytes.
1172 C ObjC C++ LTO ObjC++ Alias(Wvla-larger-than=,18446744073709551615EiB,none) Warning
1173 -Wno-vla-larger-than Disable Wvla-larger-than= warning. Equivalent to Wvla-larger-than=<SIZE_MAX> or larger.
1175 Wvolatile-register-var
1176 C ObjC C++ ObjC++ Var(warn_volatile_register_var) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1177 Warn when a register variable is declared volatile.
1179 Wvirtual-inheritance
1180 C++ ObjC++ Var(warn_virtual_inheritance) Warning
1181 Warn on direct virtual inheritance.
1183 Wvirtual-move-assign
1184 C++ ObjC++ Var(warn_virtual_move_assign) Warning Init(1)
1185 Warn if a virtual base has a non-trivial move assignment operator.
1188 C ObjC C++ ObjC++ Var(warn_write_strings) Warning
1189 In C++, nonzero means warn about deprecated conversion from string literals to 'char *'. In C, similar warning, except that the conversion is of course not deprecated by the ISO C standard.
1191 Wzero-as-null-pointer-constant
1192 C++ ObjC++ Var(warn_zero_as_null_pointer_constant) Warning
1193 Warn when a literal '0' is used as null pointer.
1196 C++ ObjC++ Var(warn_useless_cast) Warning
1197 Warn about useless casts.
1200 C++ ObjC++ Var(warn_subobject_linkage) Warning Init(1)
1201 Warn if a class type has a base or a field whose type uses the anonymous namespace or depends on a type with no linkage.
1203 Wduplicate-decl-specifier
1204 C ObjC Var(warn_duplicate_decl_specifier) Warning LangEnabledBy(C ObjC,Wall)
1205 Warn when a declaration has duplicate const, volatile, restrict or _Atomic specifier.
1208 C ObjC C++ ObjC++ Var(warn_restrict) Warning LangEnabledBy(C ObjC C++ ObjC++, Wall)
1209 Warn when an argument passed to a restrict-qualified parameter aliases with
1214 A synonym for -std=c89 (for C) or -std=c++98 (for C++).
1217 C ObjC C++ ObjC++ Joined
1218 ; Documented in common.opt. FIXME - what about -dI, -dD, -dN and -dD?
1220 fabi-compat-version=
1221 C++ ObjC++ Joined RejectNegative UInteger Var(flag_abi_compat_version) Init(-1)
1222 The version of the C++ ABI used for -Wabi warnings and link compatibility aliases.
1225 C++ ObjC++ Var(flag_access_control) Init(1)
1226 Enforce class member access control semantics.
1229 C ObjC C++ ObjC++ RejectNegative Joined Var(ada_specs_parent)
1230 -fada-spec-parent=unit Dump Ada specs as child units of given parent.
1233 C++ ObjC++ Alias(faligned-new=,1,0)
1234 Support C++17 allocation of over-aligned types.
1237 C++ ObjC++ Joined RejectNegative Var(aligned_new_threshold) UInteger Init(-1)
1238 -faligned-new=<N> Use C++17 over-aligned type allocation for alignments greater than N.
1241 C++ ObjC++ Deprecated
1243 fallow-parameterless-variadic-functions
1244 C ObjC Var(flag_allow_parameterless_variadic_functions)
1245 Allow variadic functions without named parameter.
1247 falt-external-templates
1248 C++ ObjC++ Deprecated
1249 No longer supported.
1252 C ObjC C++ ObjC++ Var(flag_no_asm, 0)
1253 Recognize the \"asm\" keyword.
1255 ; Define extra predefined macros for use in libgcc.
1257 C ObjC C++ ObjC++ Undocumented Var(flag_building_libgcc)
1260 C ObjC C++ ObjC++ Var(flag_no_builtin, 0)
1261 Recognize built-in functions.
1264 C ObjC C++ ObjC++ Joined
1266 fcanonical-system-headers
1268 Where shorter, use canonicalized paths to systems headers.
1270 fcheck-pointer-bounds
1271 C ObjC C++ ObjC++ LTO Deprecated
1272 Deprecated in GCC 9. This switch has no effect.
1274 fchkp-check-incomplete-type
1275 C ObjC C++ ObjC++ LTO Deprecated
1276 Deprecated in GCC 9. This switch has no effect.
1278 fchkp-zero-input-bounds-for-main
1279 C ObjC C++ ObjC++ LTO Deprecated
1280 Deprecated in GCC 9. This switch has no effect.
1282 fchkp-first-field-has-own-bounds
1283 C ObjC C++ ObjC++ LTO Deprecated RejectNegative
1284 Deprecated in GCC 9. This switch has no effect.
1287 C ObjC C++ ObjC++ LTO Deprecated
1288 Deprecated in GCC 9. This switch has no effect.
1290 fchkp-narrow-to-innermost-array
1291 C ObjC C++ ObjC++ LTO Deprecated RejectNegative
1292 Deprecated in GCC 9. This switch has no effect.
1294 fchkp-flexible-struct-trailing-arrays
1295 C ObjC C++ ObjC++ LTO Deprecated
1296 Deprecated in GCC 9. This switch has no effect.
1299 C ObjC C++ ObjC++ LTO Deprecated
1301 fchkp-use-fast-string-functions
1302 C ObjC C++ ObjC++ LTO Deprecated
1303 Deprecated in GCC 9. This switch has no effect.
1305 fchkp-use-nochk-string-functions
1306 C ObjC C++ ObjC++ LTO Deprecated
1307 Deprecated in GCC 9. This switch has no effect.
1309 fchkp-use-static-bounds
1310 C ObjC C++ ObjC++ LTO Deprecated
1311 Deprecated in GCC 9. This switch has no effect.
1313 fchkp-use-static-const-bounds
1314 C ObjC C++ ObjC++ LTO Deprecated
1315 Deprecated in GCC 9. This switch has no effect.
1317 fchkp-treat-zero-dynamic-size-as-infinite
1318 C ObjC C++ ObjC++ LTO Deprecated
1319 Deprecated in GCC 9. This switch has no effect.
1322 C ObjC C++ ObjC++ LTO Deprecated
1323 Deprecated in GCC 9. This switch has no effect.
1326 C ObjC C++ ObjC++ LTO Deprecated
1327 Deprecated in GCC 9. This switch has no effect.
1330 C ObjC C++ ObjC++ LTO Deprecated
1331 Deprecated in GCC 9. This switch has no effect.
1333 fchkp-instrument-calls
1334 C ObjC C++ ObjC++ LTO Deprecated
1335 Deprecated in GCC 9. This switch has no effect.
1337 fchkp-instrument-marked-only
1338 C ObjC C++ ObjC++ LTO Deprecated
1339 Deprecated in GCC 9. This switch has no effect.
1342 C ObjC C++ ObjC++ LTO Deprecated
1343 Deprecated in GCC 9. This switch has no effect.
1347 Deprecated in GCC 9. This switch has no effect.
1349 static-libmpxwrappers
1351 Deprecated in GCC 9. This switch has no effect.
1354 C ObjC C++ ObjC++ LTO Undocumented Ignore
1355 Deprecated in GCC 8. This switch has no effect.
1358 C++ ObjC++ Var(flag_concepts)
1359 Enable support for C++ concepts.
1363 Allow the arguments of the '?' operator to have different types.
1367 Does nothing. Preserved for backward compatibility.
1369 fconstant-string-class=
1370 ObjC ObjC++ Joined MissingArgError(no class name specified with %qs)
1371 -fconst-string-class=<name> Use class <name> for constant strings.
1374 C++ ObjC++ Joined RejectNegative UInteger Var(max_constexpr_depth) Init(512)
1375 -fconstexpr-depth=<number> Specify maximum constexpr recursion depth.
1377 fconstexpr-loop-limit=
1378 C++ ObjC++ Joined RejectNegative UInteger Var(constexpr_loop_limit) Init(262144)
1379 -fconstexpr-loop-limit=<number> Specify maximum constexpr loop iteration count.
1383 Emit debug annotations during preprocessing.
1386 C++ ObjC++ Var(flag_deduce_init_list) Init(0)
1387 -fdeduce-init-list enable deduction of std::initializer_list for a template type parameter from a brace-enclosed initializer-list.
1390 C++ ObjC++ Var(flag_declone_ctor_dtor) Init(-1)
1391 Factor complex constructors and destructors to favor space over speed.
1395 Does nothing. Preserved for backward compatibility.
1397 fdiagnostics-show-template-tree
1398 C++ ObjC++ Var(flag_diagnostics_show_template_tree) Init(0)
1399 Print hierarchical comparisons when template types are mismatched.
1403 Preprocess directives only.
1405 fdollars-in-identifiers
1407 Permit '$' as an identifier character.
1410 C ObjC C++ ObjC++ Joined RejectNegative
1411 -fmacro-prefix-map=<old>=<new> Map one directory name to another in __FILE__, __BASE_FILE__, and __builtin_FILE().
1414 C ObjC C++ ObjC++ RejectNegative Var(flag_dump_ada_spec)
1415 Write all declarations as Ada code transitively.
1418 C ObjC C++ ObjC++ RejectNegative Var(flag_dump_ada_spec_slim)
1419 Write all declarations as Ada code for the given file only.
1422 C++ ObjC++ Var(flag_elide_constructors) Init(1)
1425 C++ ObjC++ Var(flag_elide_type) Init(1)
1426 -fno-elide-type Do not elide common elements in template comparisons.
1429 C++ ObjC++ Var(flag_enforce_eh_specs) Init(1)
1430 Generate code to check exception specifications.
1433 C++ ObjC++ Deprecated
1436 C ObjC C++ ObjC++ Joined RejectNegative
1437 -fexec-charset=<cset> Convert all strings and character constants to character set <cset>.
1439 fextended-identifiers
1441 Permit universal character names (\\u and \\U) in identifiers.
1444 C ObjC C++ ObjC++ Joined RejectNegative
1445 -finput-charset=<cset> Specify the default character set for source files.
1448 C++ ObjC++ Var(flag_extern_tls_init) Init(-1)
1449 Support dynamic initialization of thread-local variables in a different translation unit.
1452 C++ ObjC++ Deprecated
1455 C++ ObjC++ Deprecated
1459 Do not assume that standard C libraries and \"main\" exist.
1462 C++ ObjC++ Var(flag_no_gnu_keywords, 0)
1463 Recognize GNU-defined keywords.
1466 ObjC ObjC++ LTO Report RejectNegative Var(flag_next_runtime,0) Init(NEXT_OBJC_RUNTIME)
1467 Generate code for GNU runtime environment.
1470 C ObjC Var(flag_gnu89_inline) Init(-1)
1471 Use traditional GNU semantics for inline functions.
1474 C++ ObjC++ Deprecated
1477 C++ ObjC++ Optimization Alias(fexceptions) Warn({-fhandle-exceptions has been renamed -fexceptions (and is now on by default)})
1480 C++ ObjC++ Deprecated
1484 Assume normal C execution environment.
1487 C++ ObjC++ Deprecated
1488 No longer supported.
1491 C++ ObjC++ Var(flag_implement_inlines) Init(1)
1492 Export functions even if they can be inlined.
1494 fimplicit-inline-templates
1495 C++ ObjC++ Var(flag_implicit_inline_templates) Init(1)
1496 Emit implicit instantiations of inline templates.
1499 C++ ObjC++ Var(flag_implicit_templates) Init(1)
1500 Emit implicit instantiations of templates.
1502 fnew-inheriting-ctors
1503 C++ ObjC++ Var(flag_new_inheriting_ctors) Init(1)
1504 Implement C++17 inheriting constructor semantics.
1507 C++ ObjC++ Deprecated
1509 fkeep-inline-dllexport
1510 C C++ ObjC ObjC++ Var(flag_keep_inline_dllexport) Init(1) Report Condition(TARGET_DLLIMPORT_DECL_ATTRIBUTES)
1511 Don't emit dllexported inline functions unless needed.
1514 C++ ObjC++ Deprecated
1516 flax-vector-conversions
1517 C ObjC C++ ObjC++ Var(flag_lax_vector_conversions)
1518 Allow implicit conversions between vectors with differing numbers of subparts and/or differing element types.
1521 C ObjC C++ ObjC++ Var(flag_ms_extensions)
1522 Don't warn about uses of Microsoft extensions.
1525 C ObjC C++ ObjC++ Deprecated
1528 C ObjC C++ ObjC++ Deprecated
1531 C ObjC C++ ObjC++ Deprecated
1533 fname-mangling-version-
1534 C++ ObjC++ Joined Deprecated
1537 C++ ObjC++ Deprecated
1540 C++ ObjC++ Var(flag_new_ttp)
1541 Implement resolution of DR 150 for matching of template template arguments.
1544 ObjC ObjC++ LTO Report RejectNegative Var(flag_next_runtime)
1545 Generate code for NeXT (Apple Mac OS X) runtime environment.
1548 ObjC ObjC++ Var(flag_nil_receivers) Init(1)
1549 Assume that receivers of Objective-C messages may be nil.
1552 ObjC ObjC++ Var(flag_local_ivars) Init(1)
1553 Allow access to instance variables as if they were local declarations within instance method implementations.
1556 ObjC ObjC++ Joined RejectNegative Enum(ivar_visibility) Var(default_ivar_visibility) Init(IVAR_VISIBILITY_PROTECTED)
1557 -fvisibility=[private|protected|public|package] Set the default symbol visibility.
1560 Name(ivar_visibility) Type(enum ivar_visibility) UnknownError(unrecognized ivar visibility value %qs)
1563 Enum(ivar_visibility) String(private) Value(IVAR_VISIBILITY_PRIVATE)
1566 Enum(ivar_visibility) String(protected) Value(IVAR_VISIBILITY_PROTECTED)
1569 Enum(ivar_visibility) String(public) Value(IVAR_VISIBILITY_PUBLIC)
1572 Enum(ivar_visibility) String(package) Value(IVAR_VISIBILITY_PACKAGE)
1575 C++ ObjC++ Var(flag_no_nonansi_builtin, 0)
1578 C++ ObjC++ Deprecated
1581 C++ ObjC++ Optimization Var(flag_nothrow_opt)
1582 Treat a throw() exception specification as noexcept to improve code size.
1585 ObjC ObjC++ LTO Joined Report RejectNegative UInteger Var(flag_objc_abi)
1586 Specify which ABI to use for Objective-C family code and meta-data generation.
1588 ; Generate special '- .cxx_construct' and '- .cxx_destruct' methods
1589 ; to initialize any non-POD ivars in Objective-C++ classes.
1590 fobjc-call-cxx-cdtors
1591 ObjC++ Var(flag_objc_call_cxx_cdtors)
1592 Generate special Objective-C methods to initialize/destroy non-POD C++ ivars, if needed.
1594 fobjc-direct-dispatch
1595 ObjC ObjC++ Var(flag_objc_direct_dispatch)
1596 Allow fast jumps to the message dispatcher.
1598 ; Nonzero means that we will allow new ObjC exception syntax (@throw,
1599 ; @try, etc.) in source code.
1601 ObjC ObjC++ Var(flag_objc_exceptions)
1602 Enable Objective-C exception and synchronization syntax.
1605 ObjC ObjC++ LTO Var(flag_objc_gc)
1606 Enable garbage collection (GC) in Objective-C/Objective-C++ programs.
1609 ObjC ObjC++ Var(flag_objc_nilcheck,1)
1610 Enable inline checks for nil receivers with the NeXT runtime and ABI version 2.
1612 ; Nonzero means that we generate NeXT setjmp based exceptions.
1613 fobjc-sjlj-exceptions
1614 ObjC ObjC++ Var(flag_objc_sjlj_exceptions) Init(-1)
1615 Enable Objective-C setjmp exception handling runtime.
1618 ObjC ObjC++ Var(flag_objc1_only)
1619 Conform to the Objective-C 1.0 language as implemented in GCC 4.0.
1622 C ObjC C++ ObjC++ LTO Var(flag_openacc)
1626 C ObjC C++ ObjC++ LTO Joined Var(flag_openacc_dims)
1627 Specify default OpenACC compute dimensions.
1630 C ObjC C++ ObjC++ LTO Var(flag_openmp)
1631 Enable OpenMP (implies -frecursive in Fortran).
1634 C ObjC C++ ObjC++ Var(flag_openmp_simd)
1635 Enable OpenMP's SIMD directives.
1639 Recognize C++ keywords like \"compl\" and \"xor\".
1643 Does nothing. Preserved for backward compatibility.
1650 Look for and use PCH files even when preprocessing.
1653 C++ ObjC++ Var(flag_permissive)
1654 Downgrade conformance errors to warnings.
1657 C ObjC Var(flag_plan9_extensions)
1658 Enable Plan 9 language extensions.
1662 Treat the input file as already preprocessed.
1664 ftrack-macro-expansion
1665 C ObjC C++ ObjC++ JoinedOrMissing RejectNegative UInteger
1666 ; converted into ftrack-macro-expansion=
1668 ftrack-macro-expansion=
1669 C ObjC C++ ObjC++ JoinedOrMissing RejectNegative UInteger
1670 -ftrack-macro-expansion=<0|1|2> Track locations of tokens coming from macro expansion and display them in error messages.
1673 C++ ObjC++ Var(flag_pretty_templates) Init(1)
1674 -fno-pretty-templates Do not pretty-print template specializations as the template signature followed by the arguments.
1676 fprintf-return-value
1677 C ObjC C++ ObjC++ LTO Optimization Var(flag_printf_return_value) Init(1)
1678 Treat known sprintf return values as constants.
1680 freplace-objc-classes
1681 ObjC ObjC++ LTO Var(flag_replace_objc_classes)
1682 Used in Fix-and-Continue mode to indicate that object files may be swapped in at runtime.
1686 Enable automatic template instantiation.
1689 C++ ObjC++ Optimization Var(flag_rtti) Init(1)
1690 Generate run time type descriptor information.
1693 C ObjC C++ ObjC++ LTO Optimization Var(flag_short_enums)
1694 Use the narrowest integer type possible for enumeration types.
1697 C ObjC C++ ObjC++ LTO Optimization Var(flag_short_wchar)
1698 Force the underlying type for \"wchar_t\" to be \"unsigned short\".
1701 C ObjC C++ ObjC++ Var(flag_signed_bitfields) Init(1)
1702 When \"signed\" or \"unsigned\" is not given make the bitfield signed.
1705 C ObjC C++ ObjC++ LTO Var(flag_signed_char)
1706 Make \"char\" signed by default.
1709 C++ ObjC++ Var(flag_sized_deallocation) Init(-1)
1710 Enable C++14 sized deallocation support.
1713 C++ ObjC++ Deprecated
1716 C ObjC Joined RejectNegative Enum(sso_struct) Var(default_sso) Init(SSO_NATIVE)
1717 -fsso-struct=[big-endian|little-endian|native] Set the default scalar storage order.
1720 Name(sso_struct) Type(enum scalar_storage_order_kind) UnknownError(unrecognized scalar storage order value %qs)
1723 Enum(sso_struct) String(big-endian) Value(SSO_BIG_ENDIAN)
1726 Enum(sso_struct) String(little-endian) Value(SSO_LITTLE_ENDIAN)
1729 Enum(sso_struct) String(native) Value(SSO_NATIVE)
1732 C++ ObjC++ Var(flag_detailed_statistics)
1733 Display statistics accumulated during compilation.
1736 C++ ObjC++ Optimization Var(flag_strict_enums)
1737 Assume that values of enumeration type are always within the minimum range of that type.
1740 C++ ObjC++ Deprecated
1743 C++ ObjC++ Common Alias(fstrong-eval-order=, all, none)
1744 Follow the C++17 evaluation order requirements for assignment expressions,
1745 shift, member function calls, etc.
1748 C++ ObjC++ Common Var(flag_strong_eval_order) Joined Enum(strong_eval_order) RejectNegative Init(-1)
1749 Follow the C++17 evaluation order requirements for assignment expressions,
1750 shift, member function calls, etc.
1753 Name(strong_eval_order) Type(int)
1756 Enum(strong_eval_order) String(none) Value(0)
1759 Enum(strong_eval_order) String(some) Value(1)
1762 Enum(strong_eval_order) String(all) Value(2)
1765 C ObjC C++ ObjC++ Joined RejectNegative UInteger
1766 -ftabstop=<number> Distance between tab stops for column reporting.
1768 ftemplate-backtrace-limit=
1769 C++ ObjC++ Joined RejectNegative UInteger Var(template_backtrace_limit) Init(10)
1770 Set the maximum number of template instantiation notes for a single warning or error.
1773 C++ ObjC++ Joined RejectNegative Undocumented Alias(ftemplate-depth=)
1776 C++ ObjC++ Joined RejectNegative UInteger
1777 -ftemplate-depth=<number> Specify maximum template instantiation depth.
1780 C++ ObjC++ Deprecated
1783 C++ ObjC++ Optimization Var(flag_threadsafe_statics) Init(1)
1784 -fno-threadsafe-statics Do not generate thread-safe code for initializing local statics.
1787 C ObjC C++ ObjC++ Var(flag_signed_bitfields, 0)
1788 When \"signed\" or \"unsigned\" is not given make the bitfield unsigned.
1791 C ObjC C++ ObjC++ LTO Var(flag_signed_char, 0)
1792 Make \"char\" unsigned by default.
1795 C++ ObjC++ Var(flag_use_cxa_atexit) Init(DEFAULT_USE_CXA_ATEXIT)
1796 Use __cxa_atexit to register destructors.
1798 fuse-cxa-get-exception-ptr
1799 C++ ObjC++ Var(flag_use_cxa_get_exception_ptr) Init(2)
1800 Use __cxa_get_exception_ptr in exception handling.
1802 fvisibility-inlines-hidden
1804 Marks all inlined functions and methods as having hidden visibility.
1806 fvisibility-ms-compat
1807 C++ ObjC++ Var(flag_visibility_ms_compat)
1808 Changes visibility to match Microsoft Visual Studio by default.
1811 C++ ObjC++ Deprecated
1812 No longer supported.
1815 C++ ObjC++ Deprecated
1816 No longer supported.
1819 C++ ObjC++ Var(flag_weak) Init(1)
1820 Emit common-like symbols as weak symbols.
1823 C ObjC C++ ObjC++ Joined RejectNegative
1824 -fwide-exec-charset=<cset> Convert all wide strings and character constants to character set <cset>.
1827 C ObjC C++ ObjC++ Var(flag_working_directory) Init(-1)
1828 Generate a #line directive pointing at the current working directory.
1831 C++ ObjC++ Deprecated
1832 No longer supported.
1835 ObjC ObjC++ Var(flag_zero_link)
1836 Generate lazy class lookup (via objc_getClass()) for use in Zero-Link mode.
1839 ObjC ObjC++ Driver Var(flag_gen_declaration) RejectNegative
1840 Dump declarations to a .decl file.
1842 femit-struct-debug-baseonly
1844 -femit-struct-debug-baseonly Aggressive reduced debug info for structs.
1846 femit-struct-debug-reduced
1848 -femit-struct-debug-reduced Conservative reduced debug info for structs.
1850 femit-struct-debug-detailed=
1851 C ObjC C++ ObjC++ Joined
1852 -femit-struct-debug-detailed=<spec-list> Detailed reduced debug info for structs.
1854 fext-numeric-literals
1855 C++ ObjC++ Var(flag_ext_numeric_literals) Init(1)
1856 Interpret imaginary, fixed-point, or other gnu number suffix as the corresponding
1857 number literal rather than a user-defined number literal.
1860 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1861 -idirafter <dir> Add <dir> to the end of the system include path.
1864 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
1865 -imacros <file> Accept definition of macros in <file>.
1868 C ObjC C++ ObjC++ Joined Separate
1869 -imultilib <dir> Set <dir> to be the multilib include subdirectory.
1872 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
1873 -include <file> Include the contents of <file> before other files.
1876 C ObjC C++ ObjC++ Joined Separate
1877 -iprefix <path> Specify <path> as a prefix for next two options.
1880 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1881 -isysroot <dir> Set <dir> to be the system root directory.
1884 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1885 -isystem <dir> Add <dir> to the start of the system include path.
1888 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1889 -iquote <dir> Add <dir> to the end of the quote include path.
1892 C ObjC C++ ObjC++ Joined Separate
1893 -iwithprefix <dir> Add <dir> to the end of the system include path.
1896 C ObjC C++ ObjC++ Joined Separate
1897 -iwithprefixbefore <dir> Add <dir> to the end of the main include path.
1900 C Undocumented RejectDriver
1907 Do not search standard system include directories (those specified with -isystem will still be used).
1911 Do not search standard system include directories for C++.
1914 C ObjC C++ ObjC++ Joined Separate
1915 ; Documented in common.opt
1918 C ObjC C++ ObjC++ Alias(Wpedantic)
1919 ; Documented in common.opt
1921 print-objc-runtime-info
1923 Generate C header of platform-specific features.
1927 Remap file names when including files.
1931 Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum.
1934 C++ ObjC++ Alias(std=c++98)
1935 Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum.
1939 Conform to the ISO 2011 C++ standard.
1942 C++ ObjC++ Alias(std=c++11) Undocumented
1943 Deprecated in favor of -std=c++11.
1946 C++ ObjC++ Alias(std=c++14) Undocumented
1947 Deprecated in favor of -std=c++14.
1951 Conform to the ISO 2014 C++ standard.
1954 C++ ObjC++ Alias(std=c++17) Undocumented
1955 Deprecated in favor of -std=c++17.
1959 Conform to the ISO 2017 C++ standard.
1963 Conform to the ISO 2020(?) C++ draft standard (experimental and incomplete support).
1967 Conform to the ISO 2011 C standard.
1970 C ObjC Alias(std=c11)
1971 Deprecated in favor of -std=c11.
1975 Conform to the ISO 2017 C standard (expected to be published in 2018).
1978 C ObjC Alias(std=c17)
1979 Conform to the ISO 2017 C standard (expected to be published in 2018).
1982 C ObjC Alias(std=c90)
1983 Conform to the ISO 1990 C standard.
1987 Conform to the ISO 1990 C standard.
1991 Conform to the ISO 1999 C standard.
1994 C ObjC Alias(std=c99)
1995 Deprecated in favor of -std=c99.
1999 Conform to the ISO 1998 C++ standard revised by the 2003 technical
2000 corrigendum with GNU extensions.
2003 C++ ObjC++ Alias(std=gnu++98)
2004 Conform to the ISO 1998 C++ standard revised by the 2003 technical
2005 corrigendum with GNU extensions.
2009 Conform to the ISO 2011 C++ standard with GNU extensions.
2012 C++ ObjC++ Alias(std=gnu++11) Undocumented
2013 Deprecated in favor of -std=gnu++11.
2016 C++ ObjC++ Alias(std=gnu++14) Undocumented
2017 Deprecated in favor of -std=gnu++14.
2021 Conform to the ISO 2014 C++ standard with GNU extensions.
2024 C++ ObjC++ Alias(std=gnu++17) Undocumented
2025 Deprecated in favor of -std=gnu++17.
2029 Conform to the ISO 2017 C++ standard with GNU extensions.
2033 Conform to the ISO 2020(?) C++ draft standard with GNU extensions (experimental and incomplete support).
2037 Conform to the ISO 2011 C standard with GNU extensions.
2040 C ObjC Alias(std=gnu11)
2041 Deprecated in favor of -std=gnu11.
2045 Conform to the ISO 2017 C standard (expected to be published in 2018) with GNU extensions.
2048 C ObjC Alias(std=gnu17)
2049 Conform to the ISO 2017 C standard (expected to be published in 2018) with GNU extensions.
2052 C ObjC Alias(std=gnu90)
2053 Conform to the ISO 1990 C standard with GNU extensions.
2057 Conform to the ISO 1990 C standard with GNU extensions.
2061 Conform to the ISO 1999 C standard with GNU extensions.
2064 C ObjC Alias(std=gnu99)
2065 Deprecated in favor of -std=gnu99.
2068 C ObjC Alias(std=c90)
2069 Conform to the ISO 1990 C standard.
2073 Conform to the ISO 1990 C standard as amended in 1994.
2076 C ObjC Alias(std=c99)
2077 Conform to the ISO 1999 C standard.
2080 C ObjC Alias(std=c99)
2081 Deprecated in favor of -std=iso9899:1999.
2084 C ObjC Alias(std=c11)
2085 Conform to the ISO 2011 C standard.
2088 C ObjC Alias(std=c17)
2089 Conform to the ISO 2017 C standard (expected to be published in 2018).
2092 C ObjC Alias(std=c17)
2093 Conform to the ISO 2017 C standard (expected to be published in 2018).
2100 Enable traditional preprocessing.
2104 -trigraphs Support ISO C trigraphs.
2107 C ObjC C++ ObjC++ Var(flag_undef)
2108 Do not predefine system-specific and GCC-specific macros.
2112 ; Documented in common.opt
2116 ; Documented in common.opt
2118 ; This comment is to ensure we retain the blank line above.