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 Var(warn_absolute_value) Warning EnabledBy(Wextra)
276 Warn on suspicious calls of standard functions computing absolute values.
279 C ObjC C++ ObjC++ Var(warn_address) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
280 Warn about suspicious uses of memory addresses.
283 Name(warn_aligned_new_level) Type(int) UnknownError(argument %qs to %<-Waligned-new%> not recognized)
286 Enum(warn_aligned_new_level) String(none) Value(0)
289 Enum(warn_aligned_new_level) String(global) Value(1)
292 Enum(warn_aligned_new_level) String(all) Value(2)
295 C++ ObjC++ Alias(Waligned-new=,global,none)
296 Warn about 'new' of type with extended alignment without -faligned-new.
299 C++ ObjC++ Var(warn_aligned_new) Enum(warn_aligned_new_level) Joined RejectNegative Warning LangEnabledBy(C++ ObjC++,Wall,1,0)
300 -Waligned-new=[none|global|all] Warn even if 'new' uses a class member allocation function.
303 C ObjC C++ ObjC++ Warning
304 Enable most warning messages.
307 C ObjC C++ ObjC++ Var(warn_alloca) Warning
308 Warn on any use of alloca.
310 Walloc-size-larger-than=
311 C ObjC C++ LTO ObjC++ Var(warn_alloc_size_limit) Joined Host_Wide_Int ByteSize Warning Init(HOST_WIDE_INT_MAX)
312 -Walloc-size-larger-than=<bytes> Warn for calls to allocation functions that
313 attempt to allocate objects larger than the specified number of bytes.
315 Wno-alloc-size-larger-than
316 C ObjC C++ LTO ObjC++ Alias(Walloc-size-larger-than=,18446744073709551615EiB,none) Warning
317 -Wno-alloc-size-larger-than Disable Walloc-size-larger-than= warning. Equivalent to Walloc-size-larger-than=<SIZE_MAX> or larger.
320 C ObjC C++ ObjC++ Var(warn_alloc_zero) Warning
321 -Walloc-zero Warn for calls to allocation functions that specify zero bytes.
324 C ObjC C++ LTO ObjC++ Var(warn_alloca_limit) Warning Joined Host_Wide_Int ByteSize Init(HOST_WIDE_INT_MAX)
325 -Walloca-larger-than=<number> Warn on unbounded uses of
326 alloca, and on bounded uses of alloca whose bound can be larger than
329 Wno-alloca-larger-than
330 C ObjC C++ LTO ObjC++ Alias(Walloca-larger-than=,18446744073709551615EiB,none) Warning
331 -Wno-alloca-larger-than Disable Walloca-larger-than= warning. Equivalent to Walloca-larger-than=<SIZE_MAX> or larger.
334 LangEnabledBy(C ObjC C++ LTO ObjC++)
338 LangEnabledBy(C ObjC C++ LTO ObjC++,Wall,1,0)
342 ObjC ObjC++ Var(warn_assign_intercept) Warning
343 Warn whenever an Objective-C assignment is being intercepted by the garbage collector.
346 C ObjC Var(warn_bad_function_cast) Warning
347 Warn about casting functions to incompatible types.
350 C ObjC C++ ObjC++ Var(warn_bool_compare) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
351 Warn about boolean expression compared with an integer value different from true/false.
354 C ObjC C++ ObjC++ Var(warn_bool_op) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
355 Warn about certain operations on boolean expressions.
358 C ObjC C++ ObjC++ Var(warn_frame_address) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
359 Warn when __builtin_frame_address or __builtin_return_address is used unsafely.
361 Wbuiltin-declaration-mismatch
362 C ObjC C++ ObjC++ Var(warn_builtin_declaraion_mismatch) Init(1) Warning
363 Warn when a built-in function is declared with the wrong signature.
365 Wbuiltin-macro-redefined
366 C ObjC C++ ObjC++ CPP(warn_builtin_macro_redefined) CppReason(CPP_W_BUILTIN_MACRO_REDEFINED) Var(cpp_warn_builtin_macro_redefined) Init(1) Warning
367 Warn when a built-in preprocessor macro is undefined or redefined.
370 C ObjC Var(warn_c11_c2x_compat) Init(-1) Warning
371 Warn about features not present in ISO C11, but present in ISO C2X.
374 C ObjC CPP(cpp_warn_c90_c99_compat) CppReason(CPP_W_C90_C99_COMPAT) Var(warn_c90_c99_compat) Init(-1) Warning
375 Warn about features not present in ISO C90, but present in ISO C99.
378 C ObjC Var(warn_c99_c11_compat) Init(-1) Warning
379 Warn about features not present in ISO C99, but present in ISO C11.
382 C ObjC Var(warn_cxx_compat) CPP(warn_cxx_operator_names) CppReason(CPP_W_CXX_OPERATOR_NAMES) Init(0) Warning
383 Warn about C constructs that are not in the common subset of C and C++.
386 C++ ObjC++ Warning Alias(Wc++11-compat) Undocumented
389 C++ ObjC++ Var(warn_cxx11_compat) Warning LangEnabledBy(C++ ObjC++,Wall) Init(0) CPP(cpp_warn_cxx11_compat) CppReason(CPP_W_CXX11_COMPAT)
390 Warn about C++ constructs whose meaning differs between ISO C++ 1998 and ISO C++ 2011.
393 C++ ObjC++ Var(warn_cxx14_compat) Warning LangEnabledBy(C++ ObjC++,Wall)
394 Warn about C++ constructs whose meaning differs between ISO C++ 2011 and ISO C++ 2014.
397 C++ ObjC++ Warning Alias(Wc++17-compat) Undocumented
400 C++ ObjC++ Var(warn_cxx17_compat) Warning LangEnabledBy(C++ ObjC++,Wall)
401 Warn about C++ constructs whose meaning differs between ISO C++ 2014 and ISO C++ 2017.
404 C ObjC C++ ObjC++ Var(warn_cast_function_type) Warning EnabledBy(Wextra)
405 Warn about casts between incompatible function types.
408 C ObjC C++ ObjC++ Var(warn_cast_qual) Warning
409 Warn about casts which discard qualifiers.
412 C++ ObjC++ Warning Alias(Wcatch-value=, 1, 0)
413 Warn about catch handlers of non-reference type.
416 C++ ObjC++ Var(warn_catch_value) Warning Joined RejectNegative UInteger LangEnabledBy(C++ ObjC++,Wall, 1, 0) IntegerRange(0, 3)
417 Warn about catch handlers of non-reference type.
420 C ObjC C++ ObjC++ Var(warn_char_subscripts) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
421 Warn about subscripts whose type is \"char\".
424 C ObjC C++ ObjC++ Warning Deprecated
425 Deprecated in GCC 9. This switch has no effect.
428 C ObjC C++ ObjC++ Var(warn_clobbered) Warning EnabledBy(Wextra)
429 Warn about variables that might be changed by \"longjmp\" or \"vfork\".
432 C ObjC C++ ObjC++ CPP(warn_comments) CppReason(CPP_W_COMMENTS) Var(cpp_warn_comment) Init(0) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
433 Warn about possibly nested block comments, and C++ comments spanning more than one physical line.
436 C ObjC C++ ObjC++ Warning Alias(Wcomment)
437 Synonym for -Wcomment.
439 Wconditionally-supported
440 C++ ObjC++ Var(warn_conditionally_supported) Warning
441 Warn for conditionally-supported constructs.
444 C ObjC C++ ObjC++ Var(warn_conversion) Warning
445 Warn for implicit type conversions that may change a value.
448 C++ ObjC++ Var(warn_conversion_null) Init(1) Warning
449 Warn for converting NULL from/to a non-pointer type.
452 C ObjC C++ ObjC++ CppReason(CPP_W_WARNING_DIRECTIVE)
453 ; Documented in common.opt
456 C++ ObjC++ Var(warn_ctor_dtor_privacy) Warning
457 Warn when all constructors and destructors are private.
460 C ObjC C++ ObjC++ Var(warn_dangling_else) Warning LangEnabledBy(C ObjC C++ ObjC++,Wparentheses)
461 Warn about dangling else.
464 C ObjC C++ ObjC++ CPP(warn_date_time) CppReason(CPP_W_DATE_TIME) Var(cpp_warn_date_time) Init(0) Warning
465 Warn about __TIME__, __DATE__ and __TIMESTAMP__ usage.
467 Wdeclaration-after-statement
468 C ObjC Var(warn_declaration_after_statement) Init(-1) Warning
469 Warn when a declaration is found after a statement.
472 C++ ObjC++ Var(warn_delete_incomplete) Init(1) Warning
473 Warn when deleting a pointer to incomplete type.
475 Wdelete-non-virtual-dtor
476 C++ ObjC++ Var(warn_delnonvdtor) Warning LangEnabledBy(C++ ObjC++,Wall || Weffc++)
477 Warn about deleting polymorphic objects with non-virtual destructors.
480 C C++ ObjC ObjC++ CPP(cpp_warn_deprecated) CppReason(CPP_W_DEPRECATED) Var(warn_deprecated) Init(1) Warning
481 Warn if a deprecated compiler feature, class, method, or field is used.
484 C++ ObjC++ Var(warn_deprecated_copy) Warning LangEnabledBy(C++ ObjC++, Wextra)
485 Mark implicitly-declared copy operations as deprecated if the class has a
486 user-provided copy operation.
488 Wdeprecated-copy-dtor
489 C++ ObjC++ Var(warn_deprecated_copy, 2) Warning
490 Mark implicitly-declared copy operations as deprecated if the class has a
491 user-provided copy operation or destructor.
494 C ObjC Var(warn_designated_init) Init(1) Warning
495 Warn about positional initialization of structs requiring designated initializers.
497 Wdiscarded-array-qualifiers
498 C ObjC Var(warn_discarded_array_qualifiers) Init(1) Warning
499 Warn if qualifiers on arrays which are pointer targets are discarded.
501 Wdiscarded-qualifiers
502 C ObjC Var(warn_discarded_qualifiers) Init(1) Warning
503 Warn if type qualifiers on pointers are discarded.
506 C ObjC C++ ObjC++ Var(warn_div_by_zero) Init(1) Warning
507 Warn about compile-time integer division by zero.
510 C ObjC C++ ObjC++ Var(warn_duplicated_branches) Init(0) Warning
511 Warn about duplicated branches in if-else statements.
514 C ObjC C++ ObjC++ Var(warn_duplicated_cond) Init(0) Warning
515 Warn about duplicated conditions in an if-else-if chain.
518 C++ ObjC++ Var(warn_ecpp) Warning
519 Warn about violations of Effective C++ style rules.
522 C ObjC C++ ObjC++ Var(warn_empty_body) Warning EnabledBy(Wextra)
523 Warn about an empty body in an if or else statement.
526 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)
527 Warn about stray tokens after #else and #endif.
530 C ObjC C++ ObjC++ Var(warn_enum_compare) Init(-1) Warning LangEnabledBy(C ObjC,Wall || Wc++-compat)
531 Warn about comparison of different enum types.
535 ; Documented in common.opt
537 Werror-implicit-function-declaration
538 C ObjC RejectNegative Warning Alias(Werror=, implicit-function-declaration)
539 This switch is deprecated; use -Werror=implicit-function-declaration instead.
542 C ObjC C++ ObjC++ Warning
546 C++ ObjC++ Var(warn_extra_semi) Warning
547 Warn about semicolon after in-class function definition.
550 C ObjC C++ ObjC++ Var(warn_float_conversion) Warning LangEnabledBy(C ObjC C++ ObjC++,Wconversion)
551 Warn for implicit type conversions that cause loss of floating point precision.
554 C ObjC C++ ObjC++ Var(warn_float_equal) Warning
555 Warn if testing floating point numbers for equality.
558 C ObjC C++ ObjC++ Warning Alias(Wformat=, 1, 0)
559 Warn about printf/scanf/strftime/strfmon format string anomalies.
562 C ObjC C++ ObjC++ Var(warn_format_contains_nul) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
563 Warn about format strings that contain NUL bytes.
566 C ObjC C++ ObjC++ Var(warn_format_extra_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
567 Warn if passing too many arguments to a function for its format string.
570 C ObjC C++ ObjC++ Var(warn_format_nonliteral) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 2, 0)
571 Warn about format strings that are not literals.
574 C ObjC C++ LTO ObjC++ Warning Alias(Wformat-overflow=, 1, 0) IntegerRange(0, 2)
575 Warn about function calls with format strings that write past the end
576 of the destination region. Same as -Wformat-overflow=1.
579 C ObjC C++ ObjC++ Var(warn_format_security) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 2, 0)
580 Warn about possible security problems with format functions.
583 C ObjC C++ ObjC++ Var(warn_format_signedness) Warning
584 Warn about sign differences with format functions.
587 C ObjC C++ LTO ObjC++ Warning Alias(Wformat-truncation=, 1, 0)
588 Warn about calls to snprintf and similar functions that truncate output.
589 Same as -Wformat-truncation=1.
592 C ObjC C++ ObjC++ Var(warn_format_y2k) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 2, 0)
593 Warn about strftime formats yielding 2-digit years.
596 C ObjC C++ ObjC++ Var(warn_format_zero_length) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 1, 0)
597 Warn about zero-length formats.
600 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_format) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0) IntegerRange(0, 2)
601 Warn about printf/scanf/strftime/strfmon format string anomalies.
604 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)
605 Warn about function calls with format strings that write past the end
606 of the destination region.
609 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)
610 Warn about calls to snprintf and similar functions that truncate output.
613 C ObjC C++ ObjC++ Var(warn_if_not_aligned) Init(1) Warning
614 Warn when the field in a struct is not aligned.
617 C C++ Var(warn_ignored_qualifiers) Warning EnabledBy(Wextra)
618 Warn whenever type qualifiers are ignored.
621 C C++ Var(warn_ignored_attributes) Init(1) Warning
622 Warn whenever attributes are ignored.
624 Wincompatible-pointer-types
625 C ObjC Var(warn_incompatible_pointer_types) Init(1) Warning
626 Warn when there is a conversion between pointers that have incompatible types.
628 Waddress-of-packed-member
629 C ObjC C++ ObjC++ Var(warn_address_of_packed_member) Init(1) Warning
630 Warn when the address of packed member of struct or union is taken.
633 C ObjC C++ ObjC++ Var(warn_init_self) Warning LangEnabledBy(C++ ObjC++,Wall)
634 Warn about variables which are initialized to themselves.
637 C++ ObjC++ Var(warn_init_list) Warning Init(1)
638 Warn about uses of std::initializer_list that can result in dangling pointers.
641 C ObjC Var(warn_implicit) Warning LangEnabledBy(C ObjC,Wall)
642 Warn about implicit declarations.
644 Wimplicit-fallthrough=
645 LangEnabledBy(C ObjC C++ ObjC++,Wextra,3,0)
649 C ObjC C++ ObjC++ Var(warn_double_promotion) Warning
650 Warn about implicit conversions from \"float\" to \"double\".
652 Wexpansion-to-defined
653 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)
654 Warn if \"defined\" is used outside #if.
656 Wimplicit-function-declaration
657 C ObjC Var(warn_implicit_function_declaration) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit)
658 Warn about implicit function declarations.
661 C ObjC Var(warn_implicit_int) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit)
662 Warn when a declaration does not specify a type.
665 C ObjC C++ ObjC++ Undocumented Ignore
667 Winherited-variadic-ctor
668 C++ ObjC++ Var(warn_inh_var_ctor) Init(1) Warning
669 Warn about C++11 inheriting constructors when the base has a variadic constructor.
672 C ObjC Var(warn_int_conversion) Init(1) Warning
673 Warn about incompatible integer to pointer and pointer to integer conversions.
676 C ObjC C++ ObjC++ Var(warn_int_in_bool_context) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
677 Warn for suspicious integer expressions in boolean context.
680 C ObjC C++ ObjC++ Var(warn_int_to_pointer_cast) Init(1) Warning
681 Warn when there is a cast to a pointer from an integer of a different size.
684 C++ ObjC++ Var(warn_invalid_offsetof) Init(1) Warning
685 Warn about invalid uses of the \"offsetof\" macro.
688 C ObjC C++ ObjC++ CPP(warn_invalid_pch) CppReason(CPP_W_INVALID_PCH) Var(cpp_warn_invalid_pch) Init(0) Warning
689 Warn about PCH files that are found but not used.
692 C ObjC Var(warn_jump_misses_init) Warning LangEnabledby(C ObjC,Wc++-compat)
693 Warn when a jump misses a variable initialization.
696 C++ ObjC++ CPP(warn_literal_suffix) CppReason(CPP_W_LITERAL_SUFFIX) Var(cpp_warn_literal_suffix) Init(1) Warning
697 Warn when a string or character literal is followed by a ud-suffix which does not begin with an underscore.
700 C ObjC C++ ObjC++ Var(warn_logical_op) Init(0) Warning
701 Warn when a logical operator is suspiciously always evaluating to true or false.
703 Wlogical-not-parentheses
704 C ObjC C++ ObjC++ Var(warn_logical_not_paren) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
705 Warn when logical not is used on the left hand side operand of a comparison.
708 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)
709 Do not warn about using \"long long\" when -pedantic.
712 C ObjC C++ ObjC++ Var(warn_main) Init(-1) Warning LangEnabledBy(C ObjC,Wall, 2, 0)
713 Warn about suspicious declarations of \"main\".
716 LangEnabledBy(C ObjC C++ ObjC++,Wpedantic, 2, 0)
719 Wmemset-transposed-args
720 C ObjC C++ ObjC++ Var(warn_memset_transposed_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
721 Warn about suspicious calls to memset where the third argument is constant literal zero and the second is not.
724 C ObjC C++ ObjC++ Var(warn_memset_elt_size) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
725 Warn about suspicious calls to memset where the third argument contains the number of elements not multiplied by the element size.
727 Wmisleading-indentation
728 C C++ Common Var(warn_misleading_indentation) Warning LangEnabledBy(C C++,Wall)
729 Warn when the indentation of the code does not reflect the block structure.
732 C ObjC C++ ObjC++ Var(warn_missing_braces) Warning LangEnabledBy(C ObjC,Wall)
733 Warn about possibly missing braces around initializers.
735 Wmissing-declarations
736 C ObjC C++ ObjC++ Var(warn_missing_declarations) Warning
737 Warn about global functions without previous declarations.
739 Wmissing-field-initializers
740 C ObjC C++ ObjC++ Var(warn_missing_field_initializers) Warning EnabledBy(Wextra)
741 Warn about missing fields in struct initializers.
743 Wmultistatement-macros
744 C ObjC C++ ObjC++ Var(warn_multistatement_macros) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
745 Warn about unsafe macros expanding to multiple statements used as a body of a clause such as if, else, while, switch, or for.
747 Wmultiple-inheritance
748 C++ ObjC++ Var(warn_multiple_inheritance) Warning
749 Warn on direct multiple inheritance.
752 C++ ObjC++ Var(warn_namespaces) Warning
753 Warn on namespace definition.
756 C ObjC C++ ObjC++ Var(warn_packed_not_aligned) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
757 Warn when fields in a struct with the packed attribute are misaligned.
760 C++ ObjC++ Var(warn_sized_deallocation) Warning EnabledBy(Wextra)
761 Warn about missing sized deallocation functions.
764 C ObjC C++ ObjC++ Var(warn_sizeof_pointer_div) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
765 Warn about suspicious divisions of two sizeof expressions that don't work correctly with pointers.
767 Wsizeof-pointer-memaccess
768 C ObjC C++ ObjC++ Var(warn_sizeof_pointer_memaccess) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
769 Warn about suspicious length parameters to certain string functions if the argument uses sizeof.
771 Wsizeof-array-argument
772 C ObjC C++ ObjC++ Var(warn_sizeof_array_argument) Warning Init(1)
773 Warn when sizeof is applied on a parameter declared as an array.
776 C ObjC C++ LTO ObjC++ Warning Alias(Wstringop-overflow=, 2, 0)
777 Warn about buffer overflow in string manipulation functions like memcpy
781 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)
782 Under the control of Object Size type, warn about buffer overflow in string
783 manipulation functions like memcpy and strcpy.
786 C ObjC C++ LTO ObjC++ Var(warn_stringop_truncation) Warning Init (1) LangEnabledBy(C ObjC C++ LTO ObjC++, Wall)
787 Warn about truncation in string manipulation functions like strncat and strncpy.
789 Wsuggest-attribute=format
790 C ObjC C++ ObjC++ Var(warn_suggest_attribute_format) Warning
791 Warn about functions which might be candidates for format attributes.
794 C++ ObjC++ Var(warn_override) Warning
795 Suggest that the override keyword be used when the declaration of a virtual
796 function overrides another.
799 C ObjC C++ ObjC++ Var(warn_switch) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
800 Warn about enumerated switches, with no default, missing a case.
803 C ObjC C++ ObjC++ Var(warn_switch_default) Warning
804 Warn about enumerated switches missing a \"default:\" statement.
807 C ObjC C++ ObjC++ Var(warn_switch_enum) Warning
808 Warn about all enumerated switches missing a specific case.
811 C ObjC C++ ObjC++ Var(warn_switch_bool) Warning Init(1)
812 Warn about switches with boolean controlling expression.
815 C++ ObjC++ Var(warn_templates) Warning
816 Warn on primary template declaration.
819 C ObjC C++ ObjC++ Var(warn_missing_attributes) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
820 Warn about declarations of entities that may be missing attributes
821 that related entities have been declared with it.
823 Wmissing-format-attribute
824 C ObjC C++ ObjC++ Warning Alias(Wsuggest-attribute=format)
827 Wmissing-include-dirs
828 C ObjC C++ ObjC++ CPP(warn_missing_include_dirs) CppReason(CPP_W_MISSING_INCLUDE_DIRS) Var(cpp_warn_missing_include_dirs) Init(0) Warning
829 Warn about user-specified include directories that do not exist.
831 Wmissing-parameter-type
832 C ObjC Var(warn_missing_parameter_type) Warning EnabledBy(Wextra)
833 Warn about function parameters declared without a type specifier in K&R-style functions.
836 C ObjC Var(warn_missing_prototypes) Warning
837 Warn about global functions without prototypes.
840 C ObjC C++ ObjC++ Deprecated
843 C ObjC C++ ObjC++ CPP(warn_multichar) CppReason(CPP_W_MULTICHAR) Var(cpp_warn_multichar) Init(0) Warning
844 Warn about use of multi-character character constants.
847 C ObjC C++ ObjC++ Warning Var(warn_narrowing) Init(-1) LangEnabledBy(C++ ObjC++,Wall || Wc++11-compat)
848 Warn about narrowing conversions within { } that are ill-formed in C++11.
851 C ObjC Var(warn_nested_externs) Warning
852 Warn about \"extern\" declarations not at file scope.
855 C++ ObjC++ Var(warn_noexcept) Warning
856 Warn when a noexcept expression evaluates to false even though the expression can't actually throw.
859 C++ ObjC++ Warning Var(warn_noexcept_type) LangEnabledBy(C++ ObjC++,Wabi || Wc++17-compat)
860 Warn if C++17 noexcept function type will change the mangled name of a symbol.
863 C++ ObjC++ Var(warn_nontemplate_friend) Init(1) Warning
864 Warn when non-templatized friend functions are declared within a template.
867 C++ ObjC++ Var(warn_class_conversion) Init(1) Warning
868 Warn when a conversion function will never be called due to the type it converts to.
871 C++ ObjC++ Var(warn_class_memaccess) Warning LangEnabledBy(C++ ObjC++, Wall)
872 Warn for unsafe raw memory writes to objects of class types.
875 C++ ObjC++ Var(warn_nonvdtor) Warning LangEnabledBy(C++ ObjC++,Weffc++)
876 Warn about non-virtual destructors.
879 C ObjC C++ LTO ObjC++ Var(warn_nonnull) Warning LangEnabledBy(C ObjC C++ LTO ObjC++,Wformat=,warn_format >= 1,0)
880 Warn about NULL being passed to argument slots marked as requiring non-NULL.
883 C ObjC C++ LTO ObjC++ LangEnabledBy(C ObjC C++ LTO ObjC++,Wall)
887 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
891 C ObjC C++ ObjC++ Warning Alias(Wnormalized=,nfc,none)
895 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)
896 -Wnormalized=[none|id|nfc|nfkc] Warn about non-normalized Unicode strings.
898 ; Required for these enum values.
903 Name(cpp_normalize_level) Type(int) UnknownError(argument %qs to %<-Wnormalized%> not recognized)
906 Enum(cpp_normalize_level) String(none) Value(normalized_none)
909 Enum(cpp_normalize_level) String(nfkc) Value(normalized_KC)
912 Enum(cpp_normalize_level) String(id) Value(normalized_identifier_C)
915 Enum(cpp_normalize_level) String(nfc) Value(normalized_C)
918 C++ ObjC++ Var(warn_old_style_cast) Warning
919 Warn if a C-style cast is used in a program.
921 Wold-style-declaration
922 C ObjC Var(warn_old_style_declaration) Warning EnabledBy(Wextra)
923 Warn for obsolescent usage in a declaration.
925 Wold-style-definition
926 C ObjC Var(warn_old_style_definition) Warning
927 Warn if an old-style parameter definition is used.
930 C C++ Var(warn_openmp_simd) Warning LangEnabledBy(C C++,Wall)
931 Warn if a simd directive is overridden by the vectorizer cost model.
934 C ObjC C++ ObjC++ Var(warn_overlength_strings) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic)
935 Warn if a string is longer than the maximum portable length specified by the standard.
938 C++ ObjC++ Var(warn_overloaded_virtual) Warning
939 Warn about overloaded virtual function names.
942 C ObjC Var(warn_override_init) Warning EnabledBy(Wextra)
943 Warn about overriding initializers without side effects.
945 Woverride-init-side-effects
946 C ObjC Var(warn_override_init_side_effects) Init(1) Warning
947 Warn about overriding initializers with side effects.
949 Wpacked-bitfield-compat
950 C ObjC C++ ObjC++ Var(warn_packed_bitfield_compat) Init(-1) Warning
951 Warn about packed bit-fields whose offset changed in GCC 4.4.
954 C ObjC C++ ObjC++ Var(warn_parentheses) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
955 Warn about possibly missing parentheses.
958 C ObjC C++ ObjC++ CPP(cpp_pedantic) CppReason(CPP_W_PEDANTIC) Warning
959 ; Documented in common.opt
962 C++ ObjC++ Var(warn_pessimizing_move) Warning LangEnabledBy(C++ ObjC++, Wall)
963 Warn about calling std::move on a local object in a return statement preventing copy elision.
966 C++ ObjC++ Var(warn_pmf2ptr) Init(1) Warning
967 Warn when converting the type of pointers to member functions.
970 C ObjC C++ ObjC++ Var(warn_pointer_arith) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic)
971 Warn about function pointer arithmetic.
974 C ObjC Var(warn_pointer_sign) Warning LangEnabledBy(C ObjC,Wall || Wpedantic)
975 Warn when a pointer differs in signedness in an assignment.
978 C ObjC C++ ObjC++ Var(warn_pointer_compare) Init(1) Warning
979 Warn when a pointer is compared with a zero character constant.
982 C ObjC Var(warn_pointer_to_int_cast) Init(1) Warning
983 Warn when a pointer is cast to an integer of a different size.
986 C ObjC C++ ObjC++ Var(warn_pragmas) Init(1) Warning
987 Warn about misuses of pragmas.
990 C ObjC C++ ObjC++ Var(warn_prio_ctor_dtor) Init(1) Warning
991 Warn if constructor or destructors with priorities from 0 to 100 are used.
993 Wproperty-assign-default
994 ObjC ObjC++ Var(warn_property_assign_default) Init(1) Warning
995 Warn if a property for an Objective-C object has no assign semantics specified.
998 ObjC ObjC++ Var(warn_protocol) Init(1) Warning
999 Warn if inherited methods are unimplemented.
1002 C++ Warning Alias(Wplacement-new=, 1, 0)
1003 Warn for placement new expressions with undefined behavior.
1006 C++ Joined RejectNegative UInteger Var(warn_placement_new) Init(-1) Warning IntegerRange(0, 2)
1007 Warn for placement new expressions with undefined behavior.
1010 C ObjC C++ ObjC++ Var(warn_redundant_decls) Warning
1011 Warn about multiple declarations of the same object.
1014 C++ ObjC++ Var(warn_redundant_move) Warning LangEnabledBy(C++ ObjC++,Wextra)
1015 Warn about redundant calls to std::move.
1018 C++ ObjC++ Var(warn_register) Warning
1019 Warn about uses of register storage specifier.
1022 C++ ObjC++ Var(warn_reorder) Warning LangEnabledBy(C++ ObjC++,Wall)
1023 Warn when the compiler reorders code.
1026 C ObjC C++ ObjC++ Var(warn_return_type) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Init(-1)
1027 Warn whenever a function's return type defaults to \"int\" (C), or about inconsistent return types (C++).
1029 Wscalar-storage-order
1030 C ObjC C++ ObjC++ Init(1) Warning
1031 Warn on suspicious constructs involving reverse scalar storage order.
1034 ObjC ObjC++ Var(warn_selector) Warning
1035 Warn if a selector has multiple methods.
1038 C ObjC C++ ObjC++ Var(warn_sequence_point) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1039 Warn about possible violations of sequence point rules.
1042 ObjC ObjC++ Var(warn_shadow_ivar) EnabledBy(Wshadow) Init(1) Warning
1043 Warn if a local declaration hides an instance variable.
1046 C ObjC C++ ObjC++ Warning Alias(Wshift-overflow=, 1, 0)
1047 Warn if left shift of a signed value overflows.
1050 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_shift_overflow) Init(-1) Warning IntegerRange(0, 2)
1051 Warn if left shift of a signed value overflows.
1053 Wshift-count-negative
1054 C ObjC C++ ObjC++ Var(warn_shift_count_negative) Init(1) Warning
1055 Warn if shift count is negative.
1057 Wshift-count-overflow
1058 C ObjC C++ ObjC++ Var(warn_shift_count_overflow) Init(1) Warning
1059 Warn if shift count >= width of type.
1061 Wshift-negative-value
1062 C ObjC C++ ObjC++ Var(warn_shift_negative_value) Init(-1) Warning
1063 Warn if left shifting a negative value.
1066 C ObjC C++ ObjC++ Var(warn_sign_compare) Warning LangEnabledBy(C++ ObjC++,Wall)
1067 Warn about signed-unsigned comparisons.
1070 C ObjC C++ ObjC++ EnabledBy(Wextra)
1074 C ObjC C++ ObjC++ Var(warn_sign_conversion) Warning LangEnabledBy(C ObjC,Wconversion)
1075 Warn for implicit type conversions between signed and unsigned integers.
1078 C++ ObjC++ Var(warn_sign_promo) Warning
1079 Warn when overload promotes from unsigned to signed.
1081 Wstrict-null-sentinel
1082 C++ ObjC++ Warning Var(warn_strict_null_sentinel)
1083 Warn about uncasted NULL used as sentinel.
1086 C ObjC Var(warn_strict_prototypes) Warning
1087 Warn about unprototyped function declarations.
1090 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 3, 0) IntegerRange(0, 3)
1094 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0) IntegerRange(0, 5)
1097 Wstrict-selector-match
1098 ObjC ObjC++ Var(warn_strict_selector_match) Warning
1099 Warn if type signatures of candidate methods do not match exactly.
1102 C C++ Var(warn_sync_nand) Init(1) Warning
1103 Warn when __sync_fetch_and_nand and __sync_nand_and_fetch built-in functions are used.
1106 C++ ObjC++ Var(warn_synth) Warning
1107 Deprecated. This switch has no effect.
1110 C ObjC C++ ObjC++ Warning
1111 ; Documented in common.opt
1113 Wtautological-compare
1114 C ObjC C++ ObjC++ Var(warn_tautological_compare) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1115 Warn if a comparison always evaluates to true or false.
1118 C++ ObjC++ Warning Var(warn_terminate) Init(1)
1119 Warn if a throw expression will always result in a call to terminate().
1122 C ObjC CPP(cpp_warn_traditional) CppReason(CPP_W_TRADITIONAL) Var(warn_traditional) Init(0) Warning
1123 Warn about features not present in traditional C.
1125 Wtraditional-conversion
1126 C ObjC Var(warn_traditional_conversion) Warning
1127 Warn of prototypes causing type conversions different from what would happen in the absence of prototype.
1130 C ObjC C++ ObjC++ CPP(warn_trigraphs) CppReason(CPP_W_TRIGRAPHS) Var(cpp_warn_trigraphs) Init(2) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1131 Warn if trigraphs are encountered that might affect the meaning of the program.
1133 Wundeclared-selector
1134 ObjC ObjC++ Var(warn_undeclared_selector) Warning
1135 Warn about @selector()s without previously declared methods.
1138 C ObjC C++ ObjC++ CPP(warn_undef) CppReason(CPP_W_UNDEF) Var(cpp_warn_undef) Init(0) Warning
1139 Warn if an undefined macro is used in an #if directive.
1142 C ObjC C++ ObjC++ LTO LangEnabledBy(C ObjC C++ ObjC++ LTO,Wall)
1145 Wmaybe-uninitialized
1146 C ObjC C++ ObjC++ LTO LangEnabledBy(C ObjC C++ ObjC++ LTO,Wall)
1150 C ObjC C++ ObjC++ Warning Var(warn_unknown_pragmas) LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0)
1151 Warn about unrecognized pragmas.
1153 Wunsuffixed-float-constants
1154 C ObjC Var(warn_unsuffixed_float_constants) Warning
1155 Warn about unsuffixed float constants.
1158 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
1159 ; documented in common.opt
1161 Wunused-local-typedefs
1162 C ObjC C++ ObjC++ Var(warn_unused_local_typedefs) Warning EnabledBy(Wunused)
1163 Warn when typedefs locally defined in a function are not used.
1166 C ObjC C++ ObjC++ CppReason(CPP_W_UNUSED_MACROS) Var(cpp_warn_unused_macros) Warning
1167 Warn about macros defined in the main file that are not used.
1170 C ObjC C++ ObjC++ Var(warn_unused_result) Init(1) Warning
1171 Warn if a caller of a function, marked with attribute warn_unused_result, does not use its return value.
1174 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wunused)
1175 ; documented in common.opt
1177 Wunused-const-variable
1178 C ObjC C++ ObjC++ Warning Alias(Wunused-const-variable=, 2, 0)
1179 Warn when a const variable is unused.
1181 Wunused-const-variable=
1182 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_unused_const_variable) Warning LangEnabledBy(C ObjC,Wunused-variable, 1, 0) IntegerRange(0, 2)
1183 Warn when a const variable is unused.
1186 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)
1187 Warn about using variadic macros.
1190 C ObjC C++ ObjC++ Warning Var(warn_varargs) Init(1)
1191 Warn about questionable usage of the macros used to retrieve variable arguments.
1194 C ObjC C++ ObjC++ Var(warn_vla) Init(-1) Warning
1195 Warn if a variable length array is used.
1198 C ObjC C++ LTO ObjC++ Var(warn_vla_limit) Warning Joined Host_Wide_Int ByteSize Init(HOST_WIDE_INT_MAX)
1199 -Wvla-larger-than=<number> Warn on unbounded uses of variable-length
1200 arrays, and on bounded uses of variable-length arrays whose bound can be
1201 larger than <number> bytes.
1205 C ObjC C++ LTO ObjC++ Alias(Wvla-larger-than=,18446744073709551615EiB,none) Warning
1206 -Wno-vla-larger-than Disable Wvla-larger-than= warning. Equivalent to Wvla-larger-than=<SIZE_MAX> or larger.
1208 Wvolatile-register-var
1209 C ObjC C++ ObjC++ Var(warn_volatile_register_var) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1210 Warn when a register variable is declared volatile.
1212 Wvirtual-inheritance
1213 C++ ObjC++ Var(warn_virtual_inheritance) Warning
1214 Warn on direct virtual inheritance.
1216 Wvirtual-move-assign
1217 C++ ObjC++ Var(warn_virtual_move_assign) Warning Init(1)
1218 Warn if a virtual base has a non-trivial move assignment operator.
1221 C ObjC C++ ObjC++ Var(warn_write_strings) Warning
1222 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.
1224 Wzero-as-null-pointer-constant
1225 C++ ObjC++ Var(warn_zero_as_null_pointer_constant) Warning
1226 Warn when a literal '0' is used as null pointer.
1229 C++ ObjC++ Var(warn_useless_cast) Warning
1230 Warn about useless casts.
1233 C++ ObjC++ Var(warn_subobject_linkage) Warning Init(1)
1234 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.
1236 Wduplicate-decl-specifier
1237 C ObjC Var(warn_duplicate_decl_specifier) Warning LangEnabledBy(C ObjC,Wall)
1238 Warn when a declaration has duplicate const, volatile, restrict or _Atomic specifier.
1241 C ObjC C++ ObjC++ Var(warn_restrict) Warning LangEnabledBy(C ObjC C++ ObjC++, Wall)
1242 Warn when an argument passed to a restrict-qualified parameter aliases with
1247 A synonym for -std=c89 (for C) or -std=c++98 (for C++).
1250 C ObjC C++ ObjC++ Joined
1251 ; Documented in common.opt. FIXME - what about -dI, -dD, -dN and -dD?
1253 fabi-compat-version=
1254 C++ ObjC++ Joined RejectNegative UInteger Var(flag_abi_compat_version) Init(-1)
1255 The version of the C++ ABI used for -Wabi warnings and link compatibility aliases.
1258 C++ ObjC++ Var(flag_access_control) Init(1)
1259 Enforce class member access control semantics.
1262 C ObjC C++ ObjC++ RejectNegative Joined Var(ada_specs_parent)
1263 -fada-spec-parent=unit Dump Ada specs as child units of given parent.
1266 C++ ObjC++ Alias(faligned-new=,1,0)
1267 Support C++17 allocation of over-aligned types.
1270 C++ ObjC++ Joined RejectNegative Var(aligned_new_threshold) UInteger Init(-1)
1271 -faligned-new=<N> Use C++17 over-aligned type allocation for alignments greater than N.
1274 C++ ObjC++ Deprecated
1276 fallow-parameterless-variadic-functions
1277 C ObjC Var(flag_allow_parameterless_variadic_functions)
1278 Allow variadic functions without named parameter.
1280 falt-external-templates
1281 C++ ObjC++ Deprecated
1282 No longer supported.
1285 C ObjC C++ ObjC++ Var(flag_no_asm, 0)
1286 Recognize the \"asm\" keyword.
1288 ; Define extra predefined macros for use in libgcc.
1290 C ObjC C++ ObjC++ Undocumented Var(flag_building_libgcc)
1293 C ObjC C++ ObjC++ Var(flag_no_builtin, 0)
1294 Recognize built-in functions.
1297 C ObjC C++ ObjC++ Joined
1299 fcanonical-system-headers
1301 Where shorter, use canonicalized paths to systems headers.
1303 fcheck-pointer-bounds
1304 C ObjC C++ ObjC++ LTO Deprecated
1305 Deprecated in GCC 9. This switch has no effect.
1307 fchkp-check-incomplete-type
1308 C ObjC C++ ObjC++ LTO Deprecated
1309 Deprecated in GCC 9. This switch has no effect.
1311 fchkp-zero-input-bounds-for-main
1312 C ObjC C++ ObjC++ LTO Deprecated
1313 Deprecated in GCC 9. This switch has no effect.
1315 fchkp-first-field-has-own-bounds
1316 C ObjC C++ ObjC++ LTO Deprecated RejectNegative
1317 Deprecated in GCC 9. This switch has no effect.
1320 C ObjC C++ ObjC++ LTO Deprecated
1321 Deprecated in GCC 9. This switch has no effect.
1323 fchkp-narrow-to-innermost-array
1324 C ObjC C++ ObjC++ LTO Deprecated RejectNegative
1325 Deprecated in GCC 9. This switch has no effect.
1327 fchkp-flexible-struct-trailing-arrays
1328 C ObjC C++ ObjC++ LTO Deprecated
1329 Deprecated in GCC 9. This switch has no effect.
1332 C ObjC C++ ObjC++ LTO Deprecated
1334 fchkp-use-fast-string-functions
1335 C ObjC C++ ObjC++ LTO Deprecated
1336 Deprecated in GCC 9. This switch has no effect.
1338 fchkp-use-nochk-string-functions
1339 C ObjC C++ ObjC++ LTO Deprecated
1340 Deprecated in GCC 9. This switch has no effect.
1342 fchkp-use-static-bounds
1343 C ObjC C++ ObjC++ LTO Deprecated
1344 Deprecated in GCC 9. This switch has no effect.
1346 fchkp-use-static-const-bounds
1347 C ObjC C++ ObjC++ LTO Deprecated
1348 Deprecated in GCC 9. This switch has no effect.
1350 fchkp-treat-zero-dynamic-size-as-infinite
1351 C ObjC C++ ObjC++ LTO Deprecated
1352 Deprecated in GCC 9. This switch has no effect.
1355 C ObjC C++ ObjC++ LTO Deprecated
1356 Deprecated in GCC 9. This switch has no effect.
1359 C ObjC C++ ObjC++ LTO Deprecated
1360 Deprecated in GCC 9. This switch has no effect.
1363 C ObjC C++ ObjC++ LTO Deprecated
1364 Deprecated in GCC 9. This switch has no effect.
1366 fchkp-instrument-calls
1367 C ObjC C++ ObjC++ LTO Deprecated
1368 Deprecated in GCC 9. This switch has no effect.
1370 fchkp-instrument-marked-only
1371 C ObjC C++ ObjC++ LTO Deprecated
1372 Deprecated in GCC 9. This switch has no effect.
1375 C ObjC C++ ObjC++ LTO Deprecated
1376 Deprecated in GCC 9. This switch has no effect.
1380 Deprecated in GCC 9. This switch has no effect.
1382 static-libmpxwrappers
1384 Deprecated in GCC 9. This switch has no effect.
1387 C ObjC C++ ObjC++ LTO Undocumented Ignore
1388 Deprecated in GCC 8. This switch has no effect.
1391 C++ ObjC++ Var(flag_concepts)
1392 Enable support for C++ concepts.
1396 Allow the arguments of the '?' operator to have different types.
1400 Does nothing. Preserved for backward compatibility.
1402 fconstant-string-class=
1403 ObjC ObjC++ Joined MissingArgError(no class name specified with %qs)
1404 -fconst-string-class=<name> Use class <name> for constant strings.
1407 C++ ObjC++ Joined RejectNegative UInteger Var(max_constexpr_depth) Init(512)
1408 -fconstexpr-depth=<number> Specify maximum constexpr recursion depth.
1410 fconstexpr-loop-limit=
1411 C++ ObjC++ Joined RejectNegative UInteger Var(constexpr_loop_limit) Init(262144)
1412 -fconstexpr-loop-limit=<number> Specify maximum constexpr loop iteration count.
1416 Emit debug annotations during preprocessing.
1419 C++ ObjC++ Var(flag_deduce_init_list) Init(0)
1420 -fdeduce-init-list enable deduction of std::initializer_list for a template type parameter from a brace-enclosed initializer-list.
1423 C++ ObjC++ Var(flag_declone_ctor_dtor) Init(-1)
1424 Factor complex constructors and destructors to favor space over speed.
1428 Does nothing. Preserved for backward compatibility.
1430 fdiagnostics-show-template-tree
1431 C++ ObjC++ Var(flag_diagnostics_show_template_tree) Init(0)
1432 Print hierarchical comparisons when template types are mismatched.
1436 Preprocess directives only.
1438 fdollars-in-identifiers
1440 Permit '$' as an identifier character.
1443 C ObjC C++ ObjC++ Joined RejectNegative
1444 -fmacro-prefix-map=<old>=<new> Map one directory name to another in __FILE__, __BASE_FILE__, and __builtin_FILE().
1447 C ObjC C++ ObjC++ RejectNegative Var(flag_dump_ada_spec)
1448 Write all declarations as Ada code transitively.
1451 C ObjC C++ ObjC++ RejectNegative Var(flag_dump_ada_spec_slim)
1452 Write all declarations as Ada code for the given file only.
1455 C++ ObjC++ Var(flag_elide_constructors) Init(1)
1458 C++ ObjC++ Var(flag_elide_type) Init(1)
1459 -fno-elide-type Do not elide common elements in template comparisons.
1462 C++ ObjC++ Var(flag_enforce_eh_specs) Init(1)
1463 Generate code to check exception specifications.
1466 C++ ObjC++ Deprecated
1469 C ObjC C++ ObjC++ Joined RejectNegative
1470 -fexec-charset=<cset> Convert all strings and character constants to character set <cset>.
1472 fextended-identifiers
1474 Permit universal character names (\\u and \\U) in identifiers.
1477 C ObjC C++ ObjC++ Joined RejectNegative
1478 -finput-charset=<cset> Specify the default character set for source files.
1481 C++ ObjC++ Var(flag_extern_tls_init) Init(-1)
1482 Support dynamic initialization of thread-local variables in a different translation unit.
1485 C++ ObjC++ Deprecated
1488 C++ ObjC++ Deprecated
1492 Do not assume that standard C libraries and \"main\" exist.
1495 C++ ObjC++ Var(flag_no_gnu_keywords, 0)
1496 Recognize GNU-defined keywords.
1499 ObjC ObjC++ LTO Report RejectNegative Var(flag_next_runtime,0) Init(NEXT_OBJC_RUNTIME)
1500 Generate code for GNU runtime environment.
1503 C ObjC Var(flag_gnu89_inline) Init(-1)
1504 Use traditional GNU semantics for inline functions.
1507 C++ ObjC++ Deprecated
1510 C++ ObjC++ Optimization Alias(fexceptions) Warn({-fhandle-exceptions has been renamed -fexceptions (and is now on by default)})
1513 C++ ObjC++ Deprecated
1517 Assume normal C execution environment.
1520 C++ ObjC++ Deprecated
1521 No longer supported.
1524 C++ ObjC++ Var(flag_implement_inlines) Init(1)
1525 Export functions even if they can be inlined.
1527 fimplicit-inline-templates
1528 C++ ObjC++ Var(flag_implicit_inline_templates) Init(1)
1529 Emit implicit instantiations of inline templates.
1532 C++ ObjC++ Var(flag_implicit_templates) Init(1)
1533 Emit implicit instantiations of templates.
1535 fnew-inheriting-ctors
1536 C++ ObjC++ Var(flag_new_inheriting_ctors) Init(1)
1537 Implement C++17 inheriting constructor semantics.
1540 C++ ObjC++ Deprecated
1542 fkeep-inline-dllexport
1543 C C++ ObjC ObjC++ Var(flag_keep_inline_dllexport) Init(1) Report Condition(TARGET_DLLIMPORT_DECL_ATTRIBUTES)
1544 Don't emit dllexported inline functions unless needed.
1547 C++ ObjC++ Deprecated
1549 flax-vector-conversions
1550 C ObjC C++ ObjC++ Var(flag_lax_vector_conversions)
1551 Allow implicit conversions between vectors with differing numbers of subparts and/or differing element types.
1554 C ObjC C++ ObjC++ Var(flag_ms_extensions)
1555 Don't warn about uses of Microsoft extensions.
1558 C ObjC C++ ObjC++ Deprecated
1561 C ObjC C++ ObjC++ Deprecated
1564 C ObjC C++ ObjC++ Deprecated
1566 fname-mangling-version-
1567 C++ ObjC++ Joined Deprecated
1570 C++ ObjC++ Deprecated
1573 C++ ObjC++ Var(flag_new_ttp)
1574 Implement resolution of DR 150 for matching of template template arguments.
1577 ObjC ObjC++ LTO Report RejectNegative Var(flag_next_runtime)
1578 Generate code for NeXT (Apple Mac OS X) runtime environment.
1581 ObjC ObjC++ Var(flag_nil_receivers) Init(1)
1582 Assume that receivers of Objective-C messages may be nil.
1585 ObjC ObjC++ Var(flag_local_ivars) Init(1)
1586 Allow access to instance variables as if they were local declarations within instance method implementations.
1589 ObjC ObjC++ Joined RejectNegative Enum(ivar_visibility) Var(default_ivar_visibility) Init(IVAR_VISIBILITY_PROTECTED)
1590 -fvisibility=[private|protected|public|package] Set the default symbol visibility.
1593 Name(ivar_visibility) Type(enum ivar_visibility) UnknownError(unrecognized ivar visibility value %qs)
1596 Enum(ivar_visibility) String(private) Value(IVAR_VISIBILITY_PRIVATE)
1599 Enum(ivar_visibility) String(protected) Value(IVAR_VISIBILITY_PROTECTED)
1602 Enum(ivar_visibility) String(public) Value(IVAR_VISIBILITY_PUBLIC)
1605 Enum(ivar_visibility) String(package) Value(IVAR_VISIBILITY_PACKAGE)
1608 C++ ObjC++ Var(flag_no_nonansi_builtin, 0)
1611 C++ ObjC++ Deprecated
1614 C++ ObjC++ Optimization Var(flag_nothrow_opt)
1615 Treat a throw() exception specification as noexcept to improve code size.
1618 ObjC ObjC++ LTO Joined Report RejectNegative UInteger Var(flag_objc_abi)
1619 Specify which ABI to use for Objective-C family code and meta-data generation.
1621 ; Generate special '- .cxx_construct' and '- .cxx_destruct' methods
1622 ; to initialize any non-POD ivars in Objective-C++ classes.
1623 fobjc-call-cxx-cdtors
1624 ObjC++ Var(flag_objc_call_cxx_cdtors)
1625 Generate special Objective-C methods to initialize/destroy non-POD C++ ivars, if needed.
1627 fobjc-direct-dispatch
1628 ObjC ObjC++ Var(flag_objc_direct_dispatch)
1629 Allow fast jumps to the message dispatcher.
1631 ; Nonzero means that we will allow new ObjC exception syntax (@throw,
1632 ; @try, etc.) in source code.
1634 ObjC ObjC++ Var(flag_objc_exceptions)
1635 Enable Objective-C exception and synchronization syntax.
1638 ObjC ObjC++ LTO Var(flag_objc_gc)
1639 Enable garbage collection (GC) in Objective-C/Objective-C++ programs.
1642 ObjC ObjC++ Var(flag_objc_nilcheck,1)
1643 Enable inline checks for nil receivers with the NeXT runtime and ABI version 2.
1645 ; Nonzero means that we generate NeXT setjmp based exceptions.
1646 fobjc-sjlj-exceptions
1647 ObjC ObjC++ Var(flag_objc_sjlj_exceptions) Init(-1)
1648 Enable Objective-C setjmp exception handling runtime.
1651 ObjC ObjC++ Var(flag_objc1_only)
1652 Conform to the Objective-C 1.0 language as implemented in GCC 4.0.
1655 C ObjC C++ ObjC++ LTO Var(flag_openacc)
1659 C ObjC C++ ObjC++ LTO Joined Var(flag_openacc_dims)
1660 Specify default OpenACC compute dimensions.
1663 C ObjC C++ ObjC++ LTO Var(flag_openmp)
1664 Enable OpenMP (implies -frecursive in Fortran).
1667 C ObjC C++ ObjC++ Var(flag_openmp_simd)
1668 Enable OpenMP's SIMD directives.
1672 Recognize C++ keywords like \"compl\" and \"xor\".
1676 Does nothing. Preserved for backward compatibility.
1683 Look for and use PCH files even when preprocessing.
1686 C++ ObjC++ Var(flag_permissive)
1687 Downgrade conformance errors to warnings.
1690 C ObjC Var(flag_plan9_extensions)
1691 Enable Plan 9 language extensions.
1695 Treat the input file as already preprocessed.
1697 ftrack-macro-expansion
1698 C ObjC C++ ObjC++ JoinedOrMissing RejectNegative UInteger
1699 ; converted into ftrack-macro-expansion=
1701 ftrack-macro-expansion=
1702 C ObjC C++ ObjC++ JoinedOrMissing RejectNegative UInteger
1703 -ftrack-macro-expansion=<0|1|2> Track locations of tokens coming from macro expansion and display them in error messages.
1706 C++ ObjC++ Var(flag_pretty_templates) Init(1)
1707 -fno-pretty-templates Do not pretty-print template specializations as the template signature followed by the arguments.
1709 fprintf-return-value
1710 C ObjC C++ ObjC++ LTO Optimization Var(flag_printf_return_value) Init(1)
1711 Treat known sprintf return values as constants.
1713 freplace-objc-classes
1714 ObjC ObjC++ LTO Var(flag_replace_objc_classes)
1715 Used in Fix-and-Continue mode to indicate that object files may be swapped in at runtime.
1719 Enable automatic template instantiation.
1722 C++ ObjC++ Optimization Var(flag_rtti) Init(1)
1723 Generate run time type descriptor information.
1726 C ObjC C++ ObjC++ LTO Optimization Var(flag_short_enums)
1727 Use the narrowest integer type possible for enumeration types.
1730 C ObjC C++ ObjC++ LTO Optimization Var(flag_short_wchar)
1731 Force the underlying type for \"wchar_t\" to be \"unsigned short\".
1734 C ObjC C++ ObjC++ Var(flag_signed_bitfields) Init(1)
1735 When \"signed\" or \"unsigned\" is not given make the bitfield signed.
1738 C ObjC C++ ObjC++ LTO Var(flag_signed_char)
1739 Make \"char\" signed by default.
1742 C++ ObjC++ Var(flag_sized_deallocation) Init(-1)
1743 Enable C++14 sized deallocation support.
1746 C++ ObjC++ Deprecated
1749 C ObjC Joined RejectNegative Enum(sso_struct) Var(default_sso) Init(SSO_NATIVE)
1750 -fsso-struct=[big-endian|little-endian|native] Set the default scalar storage order.
1753 Name(sso_struct) Type(enum scalar_storage_order_kind) UnknownError(unrecognized scalar storage order value %qs)
1756 Enum(sso_struct) String(big-endian) Value(SSO_BIG_ENDIAN)
1759 Enum(sso_struct) String(little-endian) Value(SSO_LITTLE_ENDIAN)
1762 Enum(sso_struct) String(native) Value(SSO_NATIVE)
1765 C++ ObjC++ Var(flag_detailed_statistics)
1766 Display statistics accumulated during compilation.
1769 C++ ObjC++ Optimization Var(flag_strict_enums)
1770 Assume that values of enumeration type are always within the minimum range of that type.
1773 C++ ObjC++ Deprecated
1776 C++ ObjC++ Common Alias(fstrong-eval-order=, all, none)
1777 Follow the C++17 evaluation order requirements for assignment expressions,
1778 shift, member function calls, etc.
1781 C++ ObjC++ Common Var(flag_strong_eval_order) Joined Enum(strong_eval_order) RejectNegative Init(-1)
1782 Follow the C++17 evaluation order requirements for assignment expressions,
1783 shift, member function calls, etc.
1786 Name(strong_eval_order) Type(int)
1789 Enum(strong_eval_order) String(none) Value(0)
1792 Enum(strong_eval_order) String(some) Value(1)
1795 Enum(strong_eval_order) String(all) Value(2)
1798 C ObjC C++ ObjC++ Joined RejectNegative UInteger
1799 -ftabstop=<number> Distance between tab stops for column reporting.
1801 ftemplate-backtrace-limit=
1802 C++ ObjC++ Joined RejectNegative UInteger Var(template_backtrace_limit) Init(10)
1803 Set the maximum number of template instantiation notes for a single warning or error.
1806 C++ ObjC++ Joined RejectNegative Undocumented Alias(ftemplate-depth=)
1809 C++ ObjC++ Joined RejectNegative UInteger
1810 -ftemplate-depth=<number> Specify maximum template instantiation depth.
1813 C++ ObjC++ Deprecated
1816 C++ ObjC++ Optimization Var(flag_threadsafe_statics) Init(1)
1817 -fno-threadsafe-statics Do not generate thread-safe code for initializing local statics.
1820 C ObjC C++ ObjC++ Var(flag_signed_bitfields, 0)
1821 When \"signed\" or \"unsigned\" is not given make the bitfield unsigned.
1824 C ObjC C++ ObjC++ LTO Var(flag_signed_char, 0)
1825 Make \"char\" unsigned by default.
1828 C++ ObjC++ Var(flag_use_cxa_atexit) Init(DEFAULT_USE_CXA_ATEXIT)
1829 Use __cxa_atexit to register destructors.
1831 fuse-cxa-get-exception-ptr
1832 C++ ObjC++ Var(flag_use_cxa_get_exception_ptr) Init(2)
1833 Use __cxa_get_exception_ptr in exception handling.
1835 fvisibility-inlines-hidden
1837 Marks all inlined functions and methods as having hidden visibility.
1839 fvisibility-ms-compat
1840 C++ ObjC++ Var(flag_visibility_ms_compat)
1841 Changes visibility to match Microsoft Visual Studio by default.
1844 C++ ObjC++ Deprecated
1845 No longer supported.
1848 C++ ObjC++ Deprecated
1849 No longer supported.
1852 C++ ObjC++ Var(flag_weak) Init(1)
1853 Emit common-like symbols as weak symbols.
1856 C ObjC C++ ObjC++ Joined RejectNegative
1857 -fwide-exec-charset=<cset> Convert all wide strings and character constants to character set <cset>.
1860 C ObjC C++ ObjC++ Var(flag_working_directory) Init(-1)
1861 Generate a #line directive pointing at the current working directory.
1864 C++ ObjC++ Deprecated
1865 No longer supported.
1868 ObjC ObjC++ Var(flag_zero_link)
1869 Generate lazy class lookup (via objc_getClass()) for use in Zero-Link mode.
1872 ObjC ObjC++ Driver Var(flag_gen_declaration) RejectNegative
1873 Dump declarations to a .decl file.
1875 femit-struct-debug-baseonly
1877 -femit-struct-debug-baseonly Aggressive reduced debug info for structs.
1879 femit-struct-debug-reduced
1881 -femit-struct-debug-reduced Conservative reduced debug info for structs.
1883 femit-struct-debug-detailed=
1884 C ObjC C++ ObjC++ Joined
1885 -femit-struct-debug-detailed=<spec-list> Detailed reduced debug info for structs.
1887 fext-numeric-literals
1888 C++ ObjC++ Var(flag_ext_numeric_literals) Init(1)
1889 Interpret imaginary, fixed-point, or other gnu number suffix as the corresponding
1890 number literal rather than a user-defined number literal.
1893 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1894 -idirafter <dir> Add <dir> to the end of the system include path.
1897 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
1898 -imacros <file> Accept definition of macros in <file>.
1901 C ObjC C++ ObjC++ Joined Separate
1902 -imultilib <dir> Set <dir> to be the multilib include subdirectory.
1905 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
1906 -include <file> Include the contents of <file> before other files.
1909 C ObjC C++ ObjC++ Joined Separate
1910 -iprefix <path> Specify <path> as a prefix for next two options.
1913 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1914 -isysroot <dir> Set <dir> to be the system root directory.
1917 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1918 -isystem <dir> Add <dir> to the start of the system include path.
1921 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1922 -iquote <dir> Add <dir> to the end of the quote include path.
1925 C ObjC C++ ObjC++ Joined Separate
1926 -iwithprefix <dir> Add <dir> to the end of the system include path.
1929 C ObjC C++ ObjC++ Joined Separate
1930 -iwithprefixbefore <dir> Add <dir> to the end of the main include path.
1933 C Undocumented RejectDriver
1940 Do not search standard system include directories (those specified with -isystem will still be used).
1944 Do not search standard system include directories for C++.
1947 C ObjC C++ ObjC++ Joined Separate
1948 ; Documented in common.opt
1951 C ObjC C++ ObjC++ Alias(Wpedantic)
1952 ; Documented in common.opt
1954 print-objc-runtime-info
1956 Generate C header of platform-specific features.
1960 Remap file names when including files.
1964 Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum.
1967 C++ ObjC++ Alias(std=c++98)
1968 Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum.
1972 Conform to the ISO 2011 C++ standard.
1975 C++ ObjC++ Alias(std=c++11) Undocumented
1976 Deprecated in favor of -std=c++11.
1979 C++ ObjC++ Alias(std=c++14) Undocumented
1980 Deprecated in favor of -std=c++14.
1984 Conform to the ISO 2014 C++ standard.
1987 C++ ObjC++ Alias(std=c++17) Undocumented
1988 Deprecated in favor of -std=c++17.
1992 Conform to the ISO 2017 C++ standard.
1996 Conform to the ISO 2020(?) C++ draft standard (experimental and incomplete support).
2000 Conform to the ISO 2011 C standard.
2003 C ObjC Alias(std=c11)
2004 Deprecated in favor of -std=c11.
2008 Conform to the ISO 2017 C standard (published in 2018).
2011 C ObjC Alias(std=c17)
2012 Conform to the ISO 2017 C standard (published in 2018).
2016 Conform to the ISO 202X C standard draft (experimental and incomplete support).
2019 C ObjC Alias(std=c90)
2020 Conform to the ISO 1990 C standard.
2024 Conform to the ISO 1990 C standard.
2028 Conform to the ISO 1999 C standard.
2031 C ObjC Alias(std=c99)
2032 Deprecated in favor of -std=c99.
2036 Conform to the ISO 1998 C++ standard revised by the 2003 technical
2037 corrigendum with GNU extensions.
2040 C++ ObjC++ Alias(std=gnu++98)
2041 Conform to the ISO 1998 C++ standard revised by the 2003 technical
2042 corrigendum with GNU extensions.
2046 Conform to the ISO 2011 C++ standard with GNU extensions.
2049 C++ ObjC++ Alias(std=gnu++11) Undocumented
2050 Deprecated in favor of -std=gnu++11.
2053 C++ ObjC++ Alias(std=gnu++14) Undocumented
2054 Deprecated in favor of -std=gnu++14.
2058 Conform to the ISO 2014 C++ standard with GNU extensions.
2061 C++ ObjC++ Alias(std=gnu++17) Undocumented
2062 Deprecated in favor of -std=gnu++17.
2066 Conform to the ISO 2017 C++ standard with GNU extensions.
2070 Conform to the ISO 2020(?) C++ draft standard with GNU extensions (experimental and incomplete support).
2074 Conform to the ISO 2011 C standard with GNU extensions.
2077 C ObjC Alias(std=gnu11)
2078 Deprecated in favor of -std=gnu11.
2082 Conform to the ISO 2017 C standard (published in 2018) with GNU extensions.
2085 C ObjC Alias(std=gnu17)
2086 Conform to the ISO 2017 C standard (published in 2018) with GNU extensions.
2090 Conform to the ISO 202X C standard draft with GNU extensions (experimental and incomplete support).
2093 C ObjC Alias(std=gnu90)
2094 Conform to the ISO 1990 C standard with GNU extensions.
2098 Conform to the ISO 1990 C standard with GNU extensions.
2102 Conform to the ISO 1999 C standard with GNU extensions.
2105 C ObjC Alias(std=gnu99)
2106 Deprecated in favor of -std=gnu99.
2109 C ObjC Alias(std=c90)
2110 Conform to the ISO 1990 C standard.
2114 Conform to the ISO 1990 C standard as amended in 1994.
2117 C ObjC Alias(std=c99)
2118 Conform to the ISO 1999 C standard.
2121 C ObjC Alias(std=c99)
2122 Deprecated in favor of -std=iso9899:1999.
2125 C ObjC Alias(std=c11)
2126 Conform to the ISO 2011 C standard.
2129 C ObjC Alias(std=c17)
2130 Conform to the ISO 2017 C standard (published in 2018).
2133 C ObjC Alias(std=c17)
2134 Conform to the ISO 2017 C standard (published in 2018).
2141 Enable traditional preprocessing.
2145 -trigraphs Support ISO C trigraphs.
2148 C ObjC C++ ObjC++ Var(flag_undef)
2149 Do not predefine system-specific and GCC-specific macros.
2153 ; Documented in common.opt
2157 ; Documented in common.opt
2159 ; This comment is to ensure we retain the blank line above.