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) Warning Joined LangEnabledBy(C ObjC C++ LTO ObjC++,Wall)
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 RejectNegative UInteger
321 -Walloca-larger-than=<number> Warn on unbounded uses of
322 alloca, and on bounded uses of alloca whose bound can be larger than
326 LangEnabledBy(C ObjC C++ LTO ObjC++,Wall)
330 LangEnabledBy(C ObjC C++ LTO ObjC++,Wall,1,0)
334 ObjC ObjC++ Var(warn_assign_intercept) Warning
335 Warn whenever an Objective-C assignment is being intercepted by the garbage collector.
338 C ObjC Var(warn_bad_function_cast) Warning
339 Warn about casting functions to incompatible types.
342 C ObjC C++ ObjC++ Var(warn_bool_compare) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
343 Warn about boolean expression compared with an integer value different from true/false.
346 C ObjC C++ ObjC++ Var(warn_bool_op) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
347 Warn about certain operations on boolean expressions.
350 C ObjC C++ ObjC++ Var(warn_frame_address) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
351 Warn when __builtin_frame_address or __builtin_return_address is used unsafely.
353 Wbuiltin-declaration-mismatch
354 C ObjC C++ ObjC++ Var(warn_builtin_declaraion_mismatch) Init(1) Warning
355 Warn when a built-in function is declared with the wrong signature.
357 Wbuiltin-macro-redefined
358 C ObjC C++ ObjC++ CPP(warn_builtin_macro_redefined) CppReason(CPP_W_BUILTIN_MACRO_REDEFINED) Var(cpp_warn_builtin_macro_redefined) Init(1) Warning
359 Warn when a built-in preprocessor macro is undefined or redefined.
362 C ObjC CPP(cpp_warn_c90_c99_compat) CppReason(CPP_W_C90_C99_COMPAT) Var(warn_c90_c99_compat) Init(-1) Warning
363 Warn about features not present in ISO C90, but present in ISO C99.
366 C ObjC Var(warn_c99_c11_compat) Init(-1) Warning
367 Warn about features not present in ISO C99, but present in ISO C11.
370 C ObjC Var(warn_cxx_compat) CPP(warn_cxx_operator_names) CppReason(CPP_W_CXX_OPERATOR_NAMES) Init(0) Warning
371 Warn about C constructs that are not in the common subset of C and C++.
374 C++ ObjC++ Warning Alias(Wc++11-compat) Undocumented
377 C++ ObjC++ Var(warn_cxx11_compat) Warning LangEnabledBy(C++ ObjC++,Wall) Init(0) CPP(cpp_warn_cxx11_compat) CppReason(CPP_W_CXX11_COMPAT)
378 Warn about C++ constructs whose meaning differs between ISO C++ 1998 and ISO C++ 2011.
381 C++ ObjC++ Var(warn_cxx14_compat) Warning LangEnabledBy(C++ ObjC++,Wall)
382 Warn about C++ constructs whose meaning differs between ISO C++ 2011 and ISO C++ 2014.
385 C++ ObjC++ Warning Alias(Wc++17-compat) Undocumented
388 C++ ObjC++ Var(warn_cxx17_compat) Warning LangEnabledBy(C++ ObjC++,Wall)
389 Warn about C++ constructs whose meaning differs between ISO C++ 2014 and ISO C++ 2017.
392 C ObjC C++ ObjC++ Var(warn_cast_function_type) Warning EnabledBy(Wextra)
393 Warn about casts between incompatible function types.
396 C ObjC C++ ObjC++ Var(warn_cast_qual) Warning
397 Warn about casts which discard qualifiers.
400 C++ ObjC++ Warning Alias(Wcatch-value=, 1, 0)
401 Warn about catch handlers of non-reference type.
404 C++ ObjC++ Var(warn_catch_value) Warning Joined RejectNegative UInteger LangEnabledBy(C++ ObjC++,Wall, 1, 0) IntegerRange(0, 3)
405 Warn about catch handlers of non-reference type.
408 C ObjC C++ ObjC++ Var(warn_char_subscripts) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
409 Warn about subscripts whose type is \"char\".
412 C ObjC C++ ObjC++ Var(warn_chkp) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Deprecated
413 Deprecated in GCC 9. This switch has no effect.
416 C ObjC C++ ObjC++ Var(warn_clobbered) Warning EnabledBy(Wextra)
417 Warn about variables that might be changed by \"longjmp\" or \"vfork\".
420 C ObjC C++ ObjC++ CPP(warn_comments) CppReason(CPP_W_COMMENTS) Var(cpp_warn_comment) Init(0) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
421 Warn about possibly nested block comments, and C++ comments spanning more than one physical line.
424 C ObjC C++ ObjC++ Warning Alias(Wcomment)
425 Synonym for -Wcomment.
427 Wconditionally-supported
428 C++ ObjC++ Var(warn_conditionally_supported) Warning
429 Warn for conditionally-supported constructs.
432 C ObjC C++ ObjC++ Var(warn_conversion) Warning
433 Warn for implicit type conversions that may change a value.
436 C++ ObjC++ Var(warn_conversion_null) Init(1) Warning
437 Warn for converting NULL from/to a non-pointer type.
440 C ObjC C++ ObjC++ CppReason(CPP_W_WARNING_DIRECTIVE)
441 ; Documented in common.opt
444 C++ ObjC++ Var(warn_ctor_dtor_privacy) Warning
445 Warn when all constructors and destructors are private.
448 C ObjC C++ ObjC++ Var(warn_dangling_else) Warning LangEnabledBy(C ObjC C++ ObjC++,Wparentheses)
449 Warn about dangling else.
452 C ObjC C++ ObjC++ CPP(warn_date_time) CppReason(CPP_W_DATE_TIME) Var(cpp_warn_date_time) Init(0) Warning
453 Warn about __TIME__, __DATE__ and __TIMESTAMP__ usage.
455 Wdeclaration-after-statement
456 C ObjC Var(warn_declaration_after_statement) Init(-1) Warning
457 Warn when a declaration is found after a statement.
460 C++ ObjC++ Var(warn_delete_incomplete) Init(1) Warning
461 Warn when deleting a pointer to incomplete type.
463 Wdelete-non-virtual-dtor
464 C++ ObjC++ Var(warn_delnonvdtor) Warning LangEnabledBy(C++ ObjC++,Wall || Weffc++)
465 Warn about deleting polymorphic objects with non-virtual destructors.
468 C C++ ObjC ObjC++ CPP(cpp_warn_deprecated) CppReason(CPP_W_DEPRECATED) Var(warn_deprecated) Init(1) Warning
469 Warn if a deprecated compiler feature, class, method, or field is used.
472 C++ ObjC++ Var(warn_deprecated_copy) Warning LangEnabledBy(C++ ObjC++, Wall)
473 Mark implicitly-declared copy operations as deprecated if the class has a
474 user-provided copy operation or destructor.
477 C ObjC Var(warn_designated_init) Init(1) Warning
478 Warn about positional initialization of structs requiring designated initializers.
480 Wdiscarded-array-qualifiers
481 C ObjC Var(warn_discarded_array_qualifiers) Init(1) Warning
482 Warn if qualifiers on arrays which are pointer targets are discarded.
484 Wdiscarded-qualifiers
485 C ObjC Var(warn_discarded_qualifiers) Init(1) Warning
486 Warn if type qualifiers on pointers are discarded.
489 C ObjC C++ ObjC++ Var(warn_div_by_zero) Init(1) Warning
490 Warn about compile-time integer division by zero.
493 C ObjC C++ ObjC++ Var(warn_duplicated_branches) Init(0) Warning
494 Warn about duplicated branches in if-else statements.
497 C ObjC C++ ObjC++ Var(warn_duplicated_cond) Init(0) Warning
498 Warn about duplicated conditions in an if-else-if chain.
501 C++ ObjC++ Var(warn_ecpp) Warning
502 Warn about violations of Effective C++ style rules.
505 C ObjC C++ ObjC++ Var(warn_empty_body) Warning EnabledBy(Wextra)
506 Warn about an empty body in an if or else statement.
509 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)
510 Warn about stray tokens after #else and #endif.
513 C ObjC C++ ObjC++ Var(warn_enum_compare) Init(-1) Warning LangEnabledBy(C ObjC,Wall || Wc++-compat)
514 Warn about comparison of different enum types.
518 ; Documented in common.opt
520 Werror-implicit-function-declaration
521 C ObjC RejectNegative Warning Alias(Werror=, implicit-function-declaration)
522 This switch is deprecated; use -Werror=implicit-function-declaration instead.
525 C ObjC C++ ObjC++ Warning
529 C++ ObjC++ Var(warn_extra_semi) Warning
530 Warn about semicolon after in-class function definition.
533 C ObjC C++ ObjC++ Var(warn_float_conversion) Warning LangEnabledBy(C ObjC C++ ObjC++,Wconversion)
534 Warn for implicit type conversions that cause loss of floating point precision.
537 C ObjC C++ ObjC++ Var(warn_float_equal) Warning
538 Warn if testing floating point numbers for equality.
541 C ObjC C++ ObjC++ Warning Alias(Wformat=, 1, 0)
542 Warn about printf/scanf/strftime/strfmon format string anomalies.
545 C ObjC C++ ObjC++ Var(warn_format_contains_nul) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
546 Warn about format strings that contain NUL bytes.
549 C ObjC C++ ObjC++ Var(warn_format_extra_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
550 Warn if passing too many arguments to a function for its format string.
553 C ObjC C++ ObjC++ Var(warn_format_nonliteral) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 2, 0)
554 Warn about format strings that are not literals.
557 C ObjC C++ LTO ObjC++ Warning Alias(Wformat-overflow=, 1, 0) IntegerRange(0, 2)
558 Warn about function calls with format strings that write past the end
559 of the destination region. Same as -Wformat-overflow=1.
562 C ObjC C++ ObjC++ Var(warn_format_security) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 2, 0)
563 Warn about possible security problems with format functions.
566 C ObjC C++ ObjC++ Var(warn_format_signedness) Warning
567 Warn about sign differences with format functions.
570 C ObjC C++ LTO ObjC++ Warning Alias(Wformat-truncation=, 1, 0)
571 Warn about calls to snprintf and similar functions that truncate output.
572 Same as -Wformat-truncation=1.
575 C ObjC C++ ObjC++ Var(warn_format_y2k) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 2, 0)
576 Warn about strftime formats yielding 2-digit years.
579 C ObjC C++ ObjC++ Var(warn_format_zero_length) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 1, 0)
580 Warn about zero-length formats.
583 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_format) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0) IntegerRange(0, 2)
584 Warn about printf/scanf/strftime/strfmon format string anomalies.
587 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)
588 Warn about function calls with format strings that write past the end
589 of the destination region.
592 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)
593 Warn about calls to snprintf and similar functions that truncate output.
596 C ObjC C++ ObjC++ Var(warn_if_not_aligned) Init(1) Warning
597 Warn when the field in a struct is not aligned.
600 C C++ Var(warn_ignored_qualifiers) Warning EnabledBy(Wextra)
601 Warn whenever type qualifiers are ignored.
604 C C++ Var(warn_ignored_attributes) Init(1) Warning
605 Warn whenever attributes are ignored.
607 Wincompatible-pointer-types
608 C ObjC Var(warn_incompatible_pointer_types) Init(1) Warning
609 Warn when there is a conversion between pointers that have incompatible types.
612 C ObjC C++ ObjC++ Var(warn_init_self) Warning LangEnabledBy(C++ ObjC++,Wall)
613 Warn about variables which are initialized to themselves.
616 C++ ObjC++ Var(warn_init_list) Warning Init(1)
617 Warn about uses of std::initializer_list that can result in dangling pointers.
620 C ObjC Var(warn_implicit) Warning LangEnabledBy(C ObjC,Wall)
621 Warn about implicit declarations.
623 Wimplicit-fallthrough=
624 LangEnabledBy(C ObjC C++ ObjC++,Wextra,3,0)
628 C ObjC C++ ObjC++ Var(warn_double_promotion) Warning
629 Warn about implicit conversions from \"float\" to \"double\".
631 Wexpansion-to-defined
632 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)
633 Warn if \"defined\" is used outside #if.
635 Wimplicit-function-declaration
636 C ObjC Var(warn_implicit_function_declaration) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit)
637 Warn about implicit function declarations.
640 C ObjC Var(warn_implicit_int) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit)
641 Warn when a declaration does not specify a type.
644 C ObjC C++ ObjC++ Undocumented Ignore
646 Winherited-variadic-ctor
647 C++ ObjC++ Var(warn_inh_var_ctor) Init(1) Warning
648 Warn about C++11 inheriting constructors when the base has a variadic constructor.
651 C ObjC Var(warn_int_conversion) Init(1) Warning
652 Warn about incompatible integer to pointer and pointer to integer conversions.
655 C ObjC C++ ObjC++ Var(warn_int_in_bool_context) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
656 Warn for suspicious integer expressions in boolean context.
659 C ObjC C++ ObjC++ Var(warn_int_to_pointer_cast) Init(1) Warning
660 Warn when there is a cast to a pointer from an integer of a different size.
663 C++ ObjC++ Var(warn_invalid_offsetof) Init(1) Warning
664 Warn about invalid uses of the \"offsetof\" macro.
667 C ObjC C++ ObjC++ CPP(warn_invalid_pch) CppReason(CPP_W_INVALID_PCH) Var(cpp_warn_invalid_pch) Init(0) Warning
668 Warn about PCH files that are found but not used.
671 C ObjC Var(warn_jump_misses_init) Warning LangEnabledby(C ObjC,Wc++-compat)
672 Warn when a jump misses a variable initialization.
675 C++ ObjC++ CPP(warn_literal_suffix) CppReason(CPP_W_LITERAL_SUFFIX) Var(cpp_warn_literal_suffix) Init(1) Warning
676 Warn when a string or character literal is followed by a ud-suffix which does not begin with an underscore.
679 C ObjC C++ ObjC++ Var(warn_logical_op) Init(0) Warning
680 Warn when a logical operator is suspiciously always evaluating to true or false.
682 Wlogical-not-parentheses
683 C ObjC C++ ObjC++ Var(warn_logical_not_paren) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
684 Warn when logical not is used on the left hand side operand of a comparison.
687 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)
688 Do not warn about using \"long long\" when -pedantic.
691 C ObjC C++ ObjC++ Var(warn_main) Init(-1) Warning LangEnabledBy(C ObjC,Wall, 2, 0)
692 Warn about suspicious declarations of \"main\".
695 LangEnabledBy(C ObjC C++ ObjC++,Wpedantic, 2, 0)
698 Wmemset-transposed-args
699 C ObjC C++ ObjC++ Var(warn_memset_transposed_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
700 Warn about suspicious calls to memset where the third argument is constant literal zero and the second is not.
703 C ObjC C++ ObjC++ Var(warn_memset_elt_size) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
704 Warn about suspicious calls to memset where the third argument contains the number of elements not multiplied by the element size.
706 Wmisleading-indentation
707 C C++ Common Var(warn_misleading_indentation) Warning LangEnabledBy(C C++,Wall)
708 Warn when the indentation of the code does not reflect the block structure.
711 C ObjC C++ ObjC++ Var(warn_missing_braces) Warning LangEnabledBy(C ObjC,Wall)
712 Warn about possibly missing braces around initializers.
714 Wmissing-declarations
715 C ObjC C++ ObjC++ Var(warn_missing_declarations) Warning
716 Warn about global functions without previous declarations.
718 Wmissing-field-initializers
719 C ObjC C++ ObjC++ Var(warn_missing_field_initializers) Warning EnabledBy(Wextra)
720 Warn about missing fields in struct initializers.
722 Wmultistatement-macros
723 C ObjC C++ ObjC++ Var(warn_multistatement_macros) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
724 Warn about unsafe macros expanding to multiple statements used as a body of a clause such as if, else, while, switch, or for.
726 Wmultiple-inheritance
727 C++ ObjC++ Var(warn_multiple_inheritance) Warning
728 Warn on direct multiple inheritance.
731 C++ ObjC++ Var(warn_namespaces) Warning
732 Warn on namespace definition.
735 C ObjC C++ ObjC++ Var(warn_packed_not_aligned) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
736 Warn when fields in a struct with the packed attribute are misaligned.
739 C++ ObjC++ Var(warn_sized_deallocation) Warning EnabledBy(Wextra)
740 Warn about missing sized deallocation functions.
743 C ObjC C++ ObjC++ Var(warn_sizeof_pointer_div) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
744 Warn about suspicious divisions of two sizeof expressions that don't work correctly with pointers.
746 Wsizeof-pointer-memaccess
747 C ObjC C++ ObjC++ Var(warn_sizeof_pointer_memaccess) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
748 Warn about suspicious length parameters to certain string functions if the argument uses sizeof.
750 Wsizeof-array-argument
751 C ObjC C++ ObjC++ Var(warn_sizeof_array_argument) Warning Init(1)
752 Warn when sizeof is applied on a parameter declared as an array.
755 C ObjC C++ LTO ObjC++ Warning Alias(Wstringop-overflow=, 2, 0)
756 Warn about buffer overflow in string manipulation functions like memcpy
760 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)
761 Under the control of Object Size type, warn about buffer overflow in string
762 manipulation functions like memcpy and strcpy.
765 C ObjC C++ LTO ObjC++ Var(warn_stringop_truncation) Warning Init (1) LangEnabledBy(C ObjC C++ LTO ObjC++, Wall)
766 Warn about truncation in string manipulation functions like strncat and strncpy.
768 Wsuggest-attribute=format
769 C ObjC C++ ObjC++ Var(warn_suggest_attribute_format) Warning
770 Warn about functions which might be candidates for format attributes.
773 C++ ObjC++ Var(warn_override) Warning
774 Suggest that the override keyword be used when the declaration of a virtual
775 function overrides another.
778 C ObjC C++ ObjC++ Var(warn_switch) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
779 Warn about enumerated switches, with no default, missing a case.
782 C ObjC C++ ObjC++ Var(warn_switch_default) Warning
783 Warn about enumerated switches missing a \"default:\" statement.
786 C ObjC C++ ObjC++ Var(warn_switch_enum) Warning
787 Warn about all enumerated switches missing a specific case.
790 C ObjC C++ ObjC++ Var(warn_switch_bool) Warning Init(1)
791 Warn about switches with boolean controlling expression.
794 C++ ObjC++ Var(warn_templates) Warning
795 Warn on primary template declaration.
798 C ObjC C++ ObjC++ Var(warn_missing_attributes) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
799 Warn about declarations of entities that may be missing attributes
800 that related entities have been declared with it.
802 Wmissing-format-attribute
803 C ObjC C++ ObjC++ Warning Alias(Wsuggest-attribute=format)
806 Wmissing-include-dirs
807 C ObjC C++ ObjC++ CPP(warn_missing_include_dirs) CppReason(CPP_W_MISSING_INCLUDE_DIRS) Var(cpp_warn_missing_include_dirs) Init(0) Warning
808 Warn about user-specified include directories that do not exist.
810 Wmissing-parameter-type
811 C ObjC Var(warn_missing_parameter_type) Warning EnabledBy(Wextra)
812 Warn about function parameters declared without a type specifier in K&R-style functions.
815 C ObjC Var(warn_missing_prototypes) Warning
816 Warn about global functions without prototypes.
819 C ObjC C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
822 C ObjC C++ ObjC++ CPP(warn_multichar) CppReason(CPP_W_MULTICHAR) Var(cpp_warn_multichar) Init(0) Warning
823 Warn about use of multi-character character constants.
826 C ObjC C++ ObjC++ Warning Var(warn_narrowing) Init(-1) LangEnabledBy(C++ ObjC++,Wall || Wc++11-compat)
827 Warn about narrowing conversions within { } that are ill-formed in C++11.
830 C ObjC Var(warn_nested_externs) Warning
831 Warn about \"extern\" declarations not at file scope.
834 C++ ObjC++ Var(warn_noexcept) Warning
835 Warn when a noexcept expression evaluates to false even though the expression can't actually throw.
838 C++ ObjC++ Warning Var(warn_noexcept_type) LangEnabledBy(C++ ObjC++,Wabi || Wc++17-compat)
839 Warn if C++17 noexcept function type will change the mangled name of a symbol.
842 C++ ObjC++ Var(warn_nontemplate_friend) Init(1) Warning
843 Warn when non-templatized friend functions are declared within a template.
846 C++ ObjC++ Var(warn_class_memaccess) Warning LangEnabledBy(C++ ObjC++, Wall)
847 Warn for unsafe raw memory writes to objects of class types.
850 C++ ObjC++ Var(warn_nonvdtor) Warning LangEnabledBy(C++ ObjC++,Weffc++)
851 Warn about non-virtual destructors.
854 C ObjC C++ LTO ObjC++ Var(warn_nonnull) Warning LangEnabledBy(C ObjC C++ LTO ObjC++,Wformat=,warn_format >= 1,0)
855 Warn about NULL being passed to argument slots marked as requiring non-NULL.
858 C ObjC C++ LTO ObjC++ LangEnabledBy(C ObjC C++ LTO ObjC++,Wall)
862 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
866 C ObjC C++ ObjC++ Warning Alias(Wnormalized=,nfc,none)
870 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)
871 -Wnormalized=[none|id|nfc|nfkc] Warn about non-normalized Unicode strings.
873 ; Required for these enum values.
878 Name(cpp_normalize_level) Type(int) UnknownError(argument %qs to %<-Wnormalized%> not recognized)
881 Enum(cpp_normalize_level) String(none) Value(normalized_none)
884 Enum(cpp_normalize_level) String(nfkc) Value(normalized_KC)
887 Enum(cpp_normalize_level) String(id) Value(normalized_identifier_C)
890 Enum(cpp_normalize_level) String(nfc) Value(normalized_C)
893 C++ ObjC++ Var(warn_old_style_cast) Warning
894 Warn if a C-style cast is used in a program.
896 Wold-style-declaration
897 C ObjC Var(warn_old_style_declaration) Warning EnabledBy(Wextra)
898 Warn for obsolescent usage in a declaration.
900 Wold-style-definition
901 C ObjC Var(warn_old_style_definition) Warning
902 Warn if an old-style parameter definition is used.
905 C C++ Var(warn_openmp_simd) Warning LangEnabledBy(C C++,Wall)
906 Warn if a simd directive is overridden by the vectorizer cost model.
909 C ObjC C++ ObjC++ Var(warn_overlength_strings) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic)
910 Warn if a string is longer than the maximum portable length specified by the standard.
913 C++ ObjC++ Var(warn_overloaded_virtual) Warning
914 Warn about overloaded virtual function names.
917 C ObjC Var(warn_override_init) Warning EnabledBy(Wextra)
918 Warn about overriding initializers without side effects.
920 Woverride-init-side-effects
921 C ObjC Var(warn_override_init_side_effects) Init(1) Warning
922 Warn about overriding initializers with side effects.
924 Wpacked-bitfield-compat
925 C ObjC C++ ObjC++ Var(warn_packed_bitfield_compat) Init(-1) Warning
926 Warn about packed bit-fields whose offset changed in GCC 4.4.
929 C ObjC C++ ObjC++ Var(warn_parentheses) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
930 Warn about possibly missing parentheses.
933 C ObjC C++ ObjC++ CPP(cpp_pedantic) CppReason(CPP_W_PEDANTIC) Warning
934 ; Documented in common.opt
937 C++ ObjC++ Var(warn_pmf2ptr) Init(1) Warning
938 Warn when converting the type of pointers to member functions.
941 C ObjC C++ ObjC++ Var(warn_pointer_arith) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic)
942 Warn about function pointer arithmetic.
945 C ObjC Var(warn_pointer_sign) Warning LangEnabledBy(C ObjC,Wall || Wpedantic)
946 Warn when a pointer differs in signedness in an assignment.
949 C ObjC C++ ObjC++ Var(warn_pointer_compare) Init(1) Warning
950 Warn when a pointer is compared with a zero character constant.
953 C ObjC Var(warn_pointer_to_int_cast) Init(1) Warning
954 Warn when a pointer is cast to an integer of a different size.
957 C ObjC C++ ObjC++ Var(warn_pragmas) Init(1) Warning
958 Warn about misuses of pragmas.
960 Wproperty-assign-default
961 ObjC ObjC++ Var(warn_property_assign_default) Init(1) Warning
962 Warn if a property for an Objective-C object has no assign semantics specified.
965 ObjC ObjC++ Var(warn_protocol) Init(1) Warning
966 Warn if inherited methods are unimplemented.
969 C++ Warning Alias(Wplacement-new=, 1, 0)
970 Warn for placement new expressions with undefined behavior.
973 C++ Joined RejectNegative UInteger Var(warn_placement_new) Init(-1) Warning IntegerRange(0, 2)
974 Warn for placement new expressions with undefined behavior.
977 C ObjC C++ ObjC++ Var(warn_redundant_decls) Warning
978 Warn about multiple declarations of the same object.
981 C++ ObjC++ Var(warn_register) Warning
982 Warn about uses of register storage specifier.
985 C++ ObjC++ Var(warn_reorder) Warning LangEnabledBy(C++ ObjC++,Wall)
986 Warn when the compiler reorders code.
989 C ObjC C++ ObjC++ Var(warn_return_type) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Init(-1)
990 Warn whenever a function's return type defaults to \"int\" (C), or about inconsistent return types (C++).
992 Wscalar-storage-order
993 C ObjC C++ ObjC++ Init(1) Warning
994 Warn on suspicious constructs involving reverse scalar storage order.
997 ObjC ObjC++ Var(warn_selector) Warning
998 Warn if a selector has multiple methods.
1001 C ObjC C++ ObjC++ Var(warn_sequence_point) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1002 Warn about possible violations of sequence point rules.
1005 ObjC ObjC++ Var(warn_shadow_ivar) EnabledBy(Wshadow) Init(1) Warning
1006 Warn if a local declaration hides an instance variable.
1009 C ObjC C++ ObjC++ Warning Alias(Wshift-overflow=, 1, 0)
1010 Warn if left shift of a signed value overflows.
1013 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_shift_overflow) Init(-1) Warning IntegerRange(0, 2)
1014 Warn if left shift of a signed value overflows.
1016 Wshift-count-negative
1017 C ObjC C++ ObjC++ Var(warn_shift_count_negative) Init(1) Warning
1018 Warn if shift count is negative.
1020 Wshift-count-overflow
1021 C ObjC C++ ObjC++ Var(warn_shift_count_overflow) Init(1) Warning
1022 Warn if shift count >= width of type.
1024 Wshift-negative-value
1025 C ObjC C++ ObjC++ Var(warn_shift_negative_value) Init(-1) Warning
1026 Warn if left shifting a negative value.
1029 C ObjC C++ ObjC++ Var(warn_sign_compare) Warning LangEnabledBy(C++ ObjC++,Wall)
1030 Warn about signed-unsigned comparisons.
1033 C ObjC C++ ObjC++ EnabledBy(Wextra)
1037 C ObjC C++ ObjC++ Var(warn_sign_conversion) Warning LangEnabledBy(C ObjC,Wconversion)
1038 Warn for implicit type conversions between signed and unsigned integers.
1041 C++ ObjC++ Var(warn_sign_promo) Warning
1042 Warn when overload promotes from unsigned to signed.
1044 Wstrict-null-sentinel
1045 C++ ObjC++ Warning Var(warn_strict_null_sentinel)
1046 Warn about uncasted NULL used as sentinel.
1049 C ObjC Var(warn_strict_prototypes) Warning
1050 Warn about unprototyped function declarations.
1053 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 3, 0) IntegerRange(0, 3)
1057 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0) IntegerRange(0, 5)
1060 Wstrict-selector-match
1061 ObjC ObjC++ Var(warn_strict_selector_match) Warning
1062 Warn if type signatures of candidate methods do not match exactly.
1065 C C++ Var(warn_sync_nand) Init(1) Warning
1066 Warn when __sync_fetch_and_nand and __sync_nand_and_fetch built-in functions are used.
1069 C++ ObjC++ Var(warn_synth) Warning
1070 Deprecated. This switch has no effect.
1073 C ObjC C++ ObjC++ Warning
1074 ; Documented in common.opt
1076 Wtautological-compare
1077 C ObjC C++ ObjC++ Var(warn_tautological_compare) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1078 Warn if a comparison always evaluates to true or false.
1081 C++ ObjC++ Warning Var(warn_terminate) Init(1)
1082 Warn if a throw expression will always result in a call to terminate().
1085 C ObjC CPP(cpp_warn_traditional) CppReason(CPP_W_TRADITIONAL) Var(warn_traditional) Init(0) Warning
1086 Warn about features not present in traditional C.
1088 Wtraditional-conversion
1089 C ObjC Var(warn_traditional_conversion) Warning
1090 Warn of prototypes causing type conversions different from what would happen in the absence of prototype.
1093 C ObjC C++ ObjC++ CPP(warn_trigraphs) CppReason(CPP_W_TRIGRAPHS) Var(cpp_warn_trigraphs) Init(2) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1094 Warn if trigraphs are encountered that might affect the meaning of the program.
1096 Wundeclared-selector
1097 ObjC ObjC++ Var(warn_undeclared_selector) Warning
1098 Warn about @selector()s without previously declared methods.
1101 C ObjC C++ ObjC++ CPP(warn_undef) CppReason(CPP_W_UNDEF) Var(cpp_warn_undef) Init(0) Warning
1102 Warn if an undefined macro is used in an #if directive.
1105 C ObjC C++ ObjC++ LTO LangEnabledBy(C ObjC C++ ObjC++ LTO,Wall)
1108 Wmaybe-uninitialized
1109 C ObjC C++ ObjC++ LTO LangEnabledBy(C ObjC C++ ObjC++ LTO,Wall)
1113 C ObjC C++ ObjC++ Warning Var(warn_unknown_pragmas) LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0)
1114 Warn about unrecognized pragmas.
1116 Wunsuffixed-float-constants
1117 C ObjC Var(warn_unsuffixed_float_constants) Warning
1118 Warn about unsuffixed float constants.
1121 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
1122 ; documented in common.opt
1124 Wunused-local-typedefs
1125 C ObjC C++ ObjC++ Var(warn_unused_local_typedefs) Warning EnabledBy(Wunused)
1126 Warn when typedefs locally defined in a function are not used.
1129 C ObjC C++ ObjC++ CppReason(CPP_W_UNUSED_MACROS) Var(cpp_warn_unused_macros) Warning
1130 Warn about macros defined in the main file that are not used.
1133 C ObjC C++ ObjC++ Var(warn_unused_result) Init(1) Warning
1134 Warn if a caller of a function, marked with attribute warn_unused_result, does not use its return value.
1137 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wunused)
1138 ; documented in common.opt
1140 Wunused-const-variable
1141 C ObjC C++ ObjC++ Warning Alias(Wunused-const-variable=, 2, 0)
1142 Warn when a const variable is unused.
1144 Wunused-const-variable=
1145 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_unused_const_variable) Warning LangEnabledBy(C ObjC,Wunused-variable, 1, 0) IntegerRange(0, 2)
1146 Warn when a const variable is unused.
1149 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)
1150 Warn about using variadic macros.
1153 C ObjC C++ ObjC++ Warning Var(warn_varargs) Init(1)
1154 Warn about questionable usage of the macros used to retrieve variable arguments.
1157 C ObjC C++ ObjC++ Var(warn_vla) Init(-1) Warning
1158 Warn if a variable length array is used.
1161 C ObjC C++ ObjC++ Var(warn_vla_limit) Warning Joined RejectNegative UInteger
1162 -Wvla-larger-than=<number> Warn on unbounded uses of variable-length arrays, and
1163 on bounded uses of variable-length arrays whose bound can be
1164 larger than <number> bytes.
1166 Wvolatile-register-var
1167 C ObjC C++ ObjC++ Var(warn_volatile_register_var) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1168 Warn when a register variable is declared volatile.
1170 Wvirtual-inheritance
1171 C++ ObjC++ Var(warn_virtual_inheritance) Warning
1172 Warn on direct virtual inheritance.
1174 Wvirtual-move-assign
1175 C++ ObjC++ Var(warn_virtual_move_assign) Warning Init(1)
1176 Warn if a virtual base has a non-trivial move assignment operator.
1179 C ObjC C++ ObjC++ Var(warn_write_strings) Warning
1180 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.
1182 Wzero-as-null-pointer-constant
1183 C++ ObjC++ Var(warn_zero_as_null_pointer_constant) Warning
1184 Warn when a literal '0' is used as null pointer.
1187 C++ ObjC++ Var(warn_useless_cast) Warning
1188 Warn about useless casts.
1191 C++ ObjC++ Var(warn_subobject_linkage) Warning Init(1)
1192 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.
1194 Wduplicate-decl-specifier
1195 C ObjC Var(warn_duplicate_decl_specifier) Warning LangEnabledBy(C ObjC,Wall)
1196 Warn when a declaration has duplicate const, volatile, restrict or _Atomic specifier.
1199 C ObjC C++ ObjC++ Var(warn_restrict) Warning LangEnabledBy(C ObjC C++ ObjC++, Wall)
1200 Warn when an argument passed to a restrict-qualified parameter aliases with
1205 A synonym for -std=c89 (for C) or -std=c++98 (for C++).
1208 C ObjC C++ ObjC++ Joined
1209 ; Documented in common.opt. FIXME - what about -dI, -dD, -dN and -dD?
1211 fabi-compat-version=
1212 C++ ObjC++ Joined RejectNegative UInteger Var(flag_abi_compat_version) Init(-1)
1213 The version of the C++ ABI used for -Wabi warnings and link compatibility aliases.
1216 C++ ObjC++ Var(flag_access_control) Init(1)
1217 Enforce class member access control semantics.
1220 C ObjC C++ ObjC++ RejectNegative Joined Var(ada_specs_parent)
1221 -fada-spec-parent=unit Dump Ada specs as child units of given parent.
1224 C++ ObjC++ Alias(faligned-new=,1,0)
1225 Support C++17 allocation of over-aligned types.
1228 C++ ObjC++ Joined RejectNegative Var(aligned_new_threshold) UInteger Init(-1)
1229 -faligned-new=<N> Use C++17 over-aligned type allocation for alignments greater than N.
1232 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1234 fallow-parameterless-variadic-functions
1235 C ObjC Var(flag_allow_parameterless_variadic_functions)
1236 Allow variadic functions without named parameter.
1238 falt-external-templates
1239 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1240 No longer supported.
1243 C ObjC C++ ObjC++ Var(flag_no_asm, 0)
1244 Recognize the \"asm\" keyword.
1246 ; Define extra predefined macros for use in libgcc.
1248 C ObjC C++ ObjC++ Undocumented Var(flag_building_libgcc)
1251 C ObjC C++ ObjC++ Var(flag_no_builtin, 0)
1252 Recognize built-in functions.
1255 C ObjC C++ ObjC++ Joined
1257 fcanonical-system-headers
1259 Where shorter, use canonicalized paths to systems headers.
1261 fcheck-pointer-bounds
1262 C ObjC C++ ObjC++ LTO Report Var(flag_check_pointer_bounds) Deprecated
1263 Deprecated in GCC 9. This switch has no effect.
1265 fchkp-check-incomplete-type
1266 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_incomplete_type) Init(1) Deprecated
1267 Deprecated in GCC 9. This switch has no effect.
1269 fchkp-zero-input-bounds-for-main
1270 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_zero_input_bounds_for_main) Init(0) Deprecated
1271 Deprecated in GCC 9. This switch has no effect.
1273 fchkp-first-field-has-own-bounds
1274 C ObjC C++ ObjC++ LTO RejectNegative Report Var(flag_chkp_first_field_has_own_bounds) Deprecated
1275 Deprecated in GCC 9. This switch has no effect.
1278 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_narrow_bounds) Init(1) Deprecated
1279 Deprecated in GCC 9. This switch has no effect.
1281 fchkp-narrow-to-innermost-array
1282 C ObjC C++ ObjC++ LTO RejectNegative Report Var(flag_chkp_narrow_to_innermost_arrray) Deprecated
1283 Deprecated in GCC 9. This switch has no effect.
1285 fchkp-flexible-struct-trailing-arrays
1286 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_flexible_struct_trailing_arrays) Deprecated
1287 Deprecated in GCC 9. This switch has no effect.
1290 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_optimize) Init(-1)
1292 fchkp-use-fast-string-functions
1293 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_fast_string_functions) Init(0) Deprecated
1294 Deprecated in GCC 9. This switch has no effect.
1296 fchkp-use-nochk-string-functions
1297 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_nochk_string_functions) Init(0) Deprecated
1298 Deprecated in GCC 9. This switch has no effect.
1300 fchkp-use-static-bounds
1301 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_static_bounds) Init(1) Deprecated
1302 Deprecated in GCC 9. This switch has no effect.
1304 fchkp-use-static-const-bounds
1305 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_static_const_bounds) Init(-1) Deprecated
1306 Deprecated in GCC 9. This switch has no effect.
1308 fchkp-treat-zero-dynamic-size-as-infinite
1309 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_zero_dynamic_size_as_infinite) Init(0) Deprecated
1310 Deprecated in GCC 9. This switch has no effect.
1313 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_check_read) Init(1) Deprecated
1314 Deprecated in GCC 9. This switch has no effect.
1317 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_check_write) Init(1) Deprecated
1318 Deprecated in GCC 9. This switch has no effect.
1321 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_store_bounds) Init(1) Deprecated
1322 Deprecated in GCC 9. This switch has no effect.
1324 fchkp-instrument-calls
1325 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_instrument_calls) Init(1) Deprecated
1326 Deprecated in GCC 9. This switch has no effect.
1328 fchkp-instrument-marked-only
1329 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_instrument_marked_only) Init(0) Deprecated
1330 Deprecated in GCC 9. This switch has no effect.
1333 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_wrappers) Init(1) Deprecated
1334 Deprecated in GCC 9. This switch has no effect.
1338 Deprecated in GCC 9. This switch has no effect.
1340 static-libmpxwrappers
1342 Deprecated in GCC 9. This switch has no effect.
1344 fcilkplus Undocumented
1345 C ObjC C++ ObjC++ LTO Report Var(flag_cilkplus) Init(0)
1346 Deprecated in GCC 8. This switch has no effect.
1349 C++ ObjC++ Var(flag_concepts)
1350 Enable support for C++ concepts.
1354 Allow the arguments of the '?' operator to have different types.
1357 C++ ObjC++ Var(flag_conserve_space)
1358 Does nothing. Preserved for backward compatibility.
1360 fconstant-string-class=
1361 ObjC ObjC++ Joined MissingArgError(no class name specified with %qs)
1362 -fconst-string-class=<name> Use class <name> for constant strings.
1365 C++ ObjC++ Joined RejectNegative UInteger Var(max_constexpr_depth) Init(512)
1366 -fconstexpr-depth=<number> Specify maximum constexpr recursion depth.
1368 fconstexpr-loop-limit=
1369 C++ ObjC++ Joined RejectNegative UInteger Var(constexpr_loop_limit) Init(262144)
1370 -fconstexpr-loop-limit=<number> Specify maximum constexpr loop iteration count.
1374 Emit debug annotations during preprocessing.
1377 C++ ObjC++ Var(flag_deduce_init_list) Init(0)
1378 -fdeduce-init-list enable deduction of std::initializer_list for a template type parameter from a brace-enclosed initializer-list.
1381 C++ ObjC++ Var(flag_declone_ctor_dtor) Init(-1)
1382 Factor complex constructors and destructors to favor space over speed.
1386 Does nothing. Preserved for backward compatibility.
1388 fdiagnostics-show-template-tree
1389 C++ ObjC++ Var(flag_diagnostics_show_template_tree) Init(0)
1390 Print hierarchical comparisons when template types are mismatched.
1394 Preprocess directives only.
1396 fdollars-in-identifiers
1398 Permit '$' as an identifier character.
1401 C ObjC C++ ObjC++ Joined RejectNegative
1402 -fmacro-prefix-map=<old>=<new> Map one directory name to another in __FILE__, __BASE_FILE__, and __builtin_FILE().
1405 C ObjC C++ ObjC++ RejectNegative Var(flag_dump_ada_spec)
1406 Write all declarations as Ada code transitively.
1409 C ObjC C++ ObjC++ RejectNegative Var(flag_dump_ada_spec_slim)
1410 Write all declarations as Ada code for the given file only.
1413 C++ ObjC++ Var(flag_elide_constructors) Init(1)
1416 C++ ObjC++ Var(flag_elide_type) Init(1)
1417 -fno-elide-type Do not elide common elements in template comparisons.
1420 C++ ObjC++ Var(flag_enforce_eh_specs) Init(1)
1421 Generate code to check exception specifications.
1424 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1427 C ObjC C++ ObjC++ Joined RejectNegative
1428 -fexec-charset=<cset> Convert all strings and character constants to character set <cset>.
1430 fextended-identifiers
1432 Permit universal character names (\\u and \\U) in identifiers.
1435 C ObjC C++ ObjC++ Joined RejectNegative
1436 -finput-charset=<cset> Specify the default character set for source files.
1439 C++ ObjC++ Var(flag_extern_tls_init) Init(-1)
1440 Support dynamic initialization of thread-local variables in a different translation unit.
1443 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1446 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1450 Do not assume that standard C libraries and \"main\" exist.
1453 C++ ObjC++ Var(flag_no_gnu_keywords, 0)
1454 Recognize GNU-defined keywords.
1457 ObjC ObjC++ LTO Report RejectNegative Var(flag_next_runtime,0) Init(NEXT_OBJC_RUNTIME)
1458 Generate code for GNU runtime environment.
1461 C ObjC Var(flag_gnu89_inline) Init(-1)
1462 Use traditional GNU semantics for inline functions.
1465 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1468 C++ ObjC++ Optimization Alias(fexceptions) Warn({-fhandle-exceptions has been renamed -fexceptions (and is now on by default)})
1471 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1475 Assume normal C execution environment.
1478 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1479 No longer supported.
1482 C++ ObjC++ Var(flag_implement_inlines) Init(1)
1483 Export functions even if they can be inlined.
1485 fimplicit-inline-templates
1486 C++ ObjC++ Var(flag_implicit_inline_templates) Init(1)
1487 Emit implicit instantiations of inline templates.
1490 C++ ObjC++ Var(flag_implicit_templates) Init(1)
1491 Emit implicit instantiations of templates.
1493 fnew-inheriting-ctors
1494 C++ ObjC++ Var(flag_new_inheriting_ctors) Init(1)
1495 Implement C++17 inheriting constructor semantics.
1498 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1500 fkeep-inline-dllexport
1501 C C++ ObjC ObjC++ Var(flag_keep_inline_dllexport) Init(1) Report Condition(TARGET_DLLIMPORT_DECL_ATTRIBUTES)
1502 Don't emit dllexported inline functions unless needed.
1505 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1507 flax-vector-conversions
1508 C ObjC C++ ObjC++ Var(flag_lax_vector_conversions)
1509 Allow implicit conversions between vectors with differing numbers of subparts and/or differing element types.
1512 C ObjC C++ ObjC++ Var(flag_ms_extensions)
1513 Don't warn about uses of Microsoft extensions.
1516 C ObjC C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1519 C ObjC C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1522 C ObjC C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1524 fname-mangling-version-
1525 C++ ObjC++ Joined Ignore Warn(switch %qs is no longer supported)
1528 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1531 C++ ObjC++ Var(flag_new_ttp)
1532 Implement resolution of DR 150 for matching of template template arguments.
1535 ObjC ObjC++ LTO Report RejectNegative Var(flag_next_runtime)
1536 Generate code for NeXT (Apple Mac OS X) runtime environment.
1539 ObjC ObjC++ Var(flag_nil_receivers) Init(1)
1540 Assume that receivers of Objective-C messages may be nil.
1543 ObjC ObjC++ Var(flag_local_ivars) Init(1)
1544 Allow access to instance variables as if they were local declarations within instance method implementations.
1547 ObjC ObjC++ Joined RejectNegative Enum(ivar_visibility) Var(default_ivar_visibility) Init(IVAR_VISIBILITY_PROTECTED)
1548 -fvisibility=[private|protected|public|package] Set the default symbol visibility.
1551 Name(ivar_visibility) Type(enum ivar_visibility) UnknownError(unrecognized ivar visibility value %qs)
1554 Enum(ivar_visibility) String(private) Value(IVAR_VISIBILITY_PRIVATE)
1557 Enum(ivar_visibility) String(protected) Value(IVAR_VISIBILITY_PROTECTED)
1560 Enum(ivar_visibility) String(public) Value(IVAR_VISIBILITY_PUBLIC)
1563 Enum(ivar_visibility) String(package) Value(IVAR_VISIBILITY_PACKAGE)
1566 C++ ObjC++ Var(flag_no_nonansi_builtin, 0)
1569 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1572 C++ ObjC++ Optimization Var(flag_nothrow_opt)
1573 Treat a throw() exception specification as noexcept to improve code size.
1576 ObjC ObjC++ LTO Joined Report RejectNegative UInteger Var(flag_objc_abi)
1577 Specify which ABI to use for Objective-C family code and meta-data generation.
1579 ; Generate special '- .cxx_construct' and '- .cxx_destruct' methods
1580 ; to initialize any non-POD ivars in Objective-C++ classes.
1581 fobjc-call-cxx-cdtors
1582 ObjC++ Var(flag_objc_call_cxx_cdtors)
1583 Generate special Objective-C methods to initialize/destroy non-POD C++ ivars, if needed.
1585 fobjc-direct-dispatch
1586 ObjC ObjC++ Var(flag_objc_direct_dispatch)
1587 Allow fast jumps to the message dispatcher.
1589 ; Nonzero means that we will allow new ObjC exception syntax (@throw,
1590 ; @try, etc.) in source code.
1592 ObjC ObjC++ Var(flag_objc_exceptions)
1593 Enable Objective-C exception and synchronization syntax.
1596 ObjC ObjC++ LTO Var(flag_objc_gc)
1597 Enable garbage collection (GC) in Objective-C/Objective-C++ programs.
1600 ObjC ObjC++ Var(flag_objc_nilcheck,1)
1601 Enable inline checks for nil receivers with the NeXT runtime and ABI version 2.
1603 ; Nonzero means that we generate NeXT setjmp based exceptions.
1604 fobjc-sjlj-exceptions
1605 ObjC ObjC++ Var(flag_objc_sjlj_exceptions) Init(-1)
1606 Enable Objective-C setjmp exception handling runtime.
1609 ObjC ObjC++ Var(flag_objc1_only)
1610 Conform to the Objective-C 1.0 language as implemented in GCC 4.0.
1613 C ObjC C++ ObjC++ LTO Var(flag_openacc)
1617 C ObjC C++ ObjC++ LTO Joined Var(flag_openacc_dims)
1618 Specify default OpenACC compute dimensions.
1621 C ObjC C++ ObjC++ LTO Var(flag_openmp)
1622 Enable OpenMP (implies -frecursive in Fortran).
1625 C ObjC C++ ObjC++ Var(flag_openmp_simd)
1626 Enable OpenMP's SIMD directives.
1630 Recognize C++ keywords like \"compl\" and \"xor\".
1634 Does nothing. Preserved for backward compatibility.
1641 Look for and use PCH files even when preprocessing.
1644 C++ ObjC++ Var(flag_permissive)
1645 Downgrade conformance errors to warnings.
1648 C ObjC Var(flag_plan9_extensions)
1649 Enable Plan 9 language extensions.
1653 Treat the input file as already preprocessed.
1655 ftrack-macro-expansion
1656 C ObjC C++ ObjC++ JoinedOrMissing RejectNegative UInteger
1657 ; converted into ftrack-macro-expansion=
1659 ftrack-macro-expansion=
1660 C ObjC C++ ObjC++ JoinedOrMissing RejectNegative UInteger
1661 -ftrack-macro-expansion=<0|1|2> Track locations of tokens coming from macro expansion and display them in error messages.
1664 C++ ObjC++ Var(flag_pretty_templates) Init(1)
1665 -fno-pretty-templates Do not pretty-print template specializations as the template signature followed by the arguments.
1667 fprintf-return-value
1668 C ObjC C++ ObjC++ LTO Optimization Var(flag_printf_return_value) Init(1)
1669 Treat known sprintf return values as constants.
1671 freplace-objc-classes
1672 ObjC ObjC++ LTO Var(flag_replace_objc_classes)
1673 Used in Fix-and-Continue mode to indicate that object files may be swapped in at runtime.
1677 Enable automatic template instantiation.
1680 C++ ObjC++ Optimization Var(flag_rtti) Init(1)
1681 Generate run time type descriptor information.
1684 C ObjC C++ ObjC++ LTO Optimization Var(flag_short_enums)
1685 Use the narrowest integer type possible for enumeration types.
1688 C ObjC C++ ObjC++ LTO Optimization Var(flag_short_wchar)
1689 Force the underlying type for \"wchar_t\" to be \"unsigned short\".
1692 C ObjC C++ ObjC++ Var(flag_signed_bitfields) Init(1)
1693 When \"signed\" or \"unsigned\" is not given make the bitfield signed.
1696 C ObjC C++ ObjC++ LTO Var(flag_signed_char)
1697 Make \"char\" signed by default.
1700 C++ ObjC++ Var(flag_sized_deallocation) Init(-1)
1701 Enable C++14 sized deallocation support.
1704 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1707 C ObjC Joined RejectNegative Enum(sso_struct) Var(default_sso) Init(SSO_NATIVE)
1708 -fsso-struct=[big-endian|little-endian|native] Set the default scalar storage order.
1711 Name(sso_struct) Type(enum scalar_storage_order_kind) UnknownError(unrecognized scalar storage order value %qs)
1714 Enum(sso_struct) String(big-endian) Value(SSO_BIG_ENDIAN)
1717 Enum(sso_struct) String(little-endian) Value(SSO_LITTLE_ENDIAN)
1720 Enum(sso_struct) String(native) Value(SSO_NATIVE)
1723 C++ ObjC++ Var(flag_detailed_statistics)
1724 Display statistics accumulated during compilation.
1727 C++ ObjC++ Optimization Var(flag_strict_enums)
1728 Assume that values of enumeration type are always within the minimum range of that type.
1731 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1734 C++ ObjC++ Common Alias(fstrong-eval-order=, all, none)
1735 Follow the C++17 evaluation order requirements for assignment expressions,
1736 shift, member function calls, etc.
1739 C++ ObjC++ Common Var(flag_strong_eval_order) Joined Enum(strong_eval_order) RejectNegative Init(-1)
1740 Follow the C++17 evaluation order requirements for assignment expressions,
1741 shift, member function calls, etc.
1744 Name(strong_eval_order) Type(int)
1747 Enum(strong_eval_order) String(none) Value(0)
1750 Enum(strong_eval_order) String(some) Value(1)
1753 Enum(strong_eval_order) String(all) Value(2)
1756 C ObjC C++ ObjC++ Joined RejectNegative UInteger
1757 -ftabstop=<number> Distance between tab stops for column reporting.
1759 ftemplate-backtrace-limit=
1760 C++ ObjC++ Joined RejectNegative UInteger Var(template_backtrace_limit) Init(10)
1761 Set the maximum number of template instantiation notes for a single warning or error.
1764 C++ ObjC++ Joined RejectNegative Undocumented Alias(ftemplate-depth=)
1767 C++ ObjC++ Joined RejectNegative UInteger
1768 -ftemplate-depth=<number> Specify maximum template instantiation depth.
1771 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1774 C++ ObjC++ Optimization Var(flag_threadsafe_statics) Init(1)
1775 -fno-threadsafe-statics Do not generate thread-safe code for initializing local statics.
1778 C ObjC C++ ObjC++ Var(flag_signed_bitfields, 0)
1779 When \"signed\" or \"unsigned\" is not given make the bitfield unsigned.
1782 C ObjC C++ ObjC++ LTO Var(flag_signed_char, 0)
1783 Make \"char\" unsigned by default.
1786 C++ ObjC++ Var(flag_use_cxa_atexit) Init(DEFAULT_USE_CXA_ATEXIT)
1787 Use __cxa_atexit to register destructors.
1789 fuse-cxa-get-exception-ptr
1790 C++ ObjC++ Var(flag_use_cxa_get_exception_ptr) Init(2)
1791 Use __cxa_get_exception_ptr in exception handling.
1793 fvisibility-inlines-hidden
1795 Marks all inlined functions and methods as having hidden visibility.
1797 fvisibility-ms-compat
1798 C++ ObjC++ Var(flag_visibility_ms_compat)
1799 Changes visibility to match Microsoft Visual Studio by default.
1802 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1803 No longer supported.
1806 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1807 No longer supported.
1810 C++ ObjC++ Var(flag_weak) Init(1)
1811 Emit common-like symbols as weak symbols.
1814 C ObjC C++ ObjC++ Joined RejectNegative
1815 -fwide-exec-charset=<cset> Convert all wide strings and character constants to character set <cset>.
1818 C ObjC C++ ObjC++ Var(flag_working_directory) Init(-1)
1819 Generate a #line directive pointing at the current working directory.
1822 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1823 No longer supported.
1826 ObjC ObjC++ Var(flag_zero_link)
1827 Generate lazy class lookup (via objc_getClass()) for use in Zero-Link mode.
1830 ObjC ObjC++ Driver Var(flag_gen_declaration) RejectNegative
1831 Dump declarations to a .decl file.
1833 femit-struct-debug-baseonly
1835 -femit-struct-debug-baseonly Aggressive reduced debug info for structs.
1837 femit-struct-debug-reduced
1839 -femit-struct-debug-reduced Conservative reduced debug info for structs.
1841 femit-struct-debug-detailed=
1842 C ObjC C++ ObjC++ Joined
1843 -femit-struct-debug-detailed=<spec-list> Detailed reduced debug info for structs.
1845 fext-numeric-literals
1846 C++ ObjC++ Var(flag_ext_numeric_literals) Init(1)
1847 Interpret imaginary, fixed-point, or other gnu number suffix as the corresponding
1848 number literal rather than a user-defined number literal.
1851 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1852 -idirafter <dir> Add <dir> to the end of the system include path.
1855 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
1856 -imacros <file> Accept definition of macros in <file>.
1859 C ObjC C++ ObjC++ Joined Separate
1860 -imultilib <dir> Set <dir> to be the multilib include subdirectory.
1863 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
1864 -include <file> Include the contents of <file> before other files.
1867 C ObjC C++ ObjC++ Joined Separate
1868 -iprefix <path> Specify <path> as a prefix for next two options.
1871 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1872 -isysroot <dir> Set <dir> to be the system root directory.
1875 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1876 -isystem <dir> Add <dir> to the start of the system include path.
1879 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1880 -iquote <dir> Add <dir> to the end of the quote include path.
1883 C ObjC C++ ObjC++ Joined Separate
1884 -iwithprefix <dir> Add <dir> to the end of the system include path.
1887 C ObjC C++ ObjC++ Joined Separate
1888 -iwithprefixbefore <dir> Add <dir> to the end of the main include path.
1891 C Undocumented RejectDriver
1898 Do not search standard system include directories (those specified with -isystem will still be used).
1902 Do not search standard system include directories for C++.
1905 C ObjC C++ ObjC++ Joined Separate
1906 ; Documented in common.opt
1909 C ObjC C++ ObjC++ Alias(Wpedantic)
1910 ; Documented in common.opt
1912 print-objc-runtime-info
1914 Generate C header of platform-specific features.
1918 Remap file names when including files.
1922 Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum.
1925 C++ ObjC++ Alias(std=c++98)
1926 Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum.
1930 Conform to the ISO 2011 C++ standard.
1933 C++ ObjC++ Alias(std=c++11) Undocumented
1934 Deprecated in favor of -std=c++11.
1937 C++ ObjC++ Alias(std=c++14) Undocumented
1938 Deprecated in favor of -std=c++14.
1942 Conform to the ISO 2014 C++ standard.
1945 C++ ObjC++ Alias(std=c++17) Undocumented
1946 Deprecated in favor of -std=c++17.
1950 Conform to the ISO 2017 C++ standard.
1954 Conform to the ISO 2020(?) C++ draft standard (experimental and incomplete support).
1958 Conform to the ISO 2011 C standard.
1961 C ObjC Alias(std=c11)
1962 Deprecated in favor of -std=c11.
1966 Conform to the ISO 2017 C standard (expected to be published in 2018).
1969 C ObjC Alias(std=c17)
1970 Conform to the ISO 2017 C standard (expected to be published in 2018).
1973 C ObjC Alias(std=c90)
1974 Conform to the ISO 1990 C standard.
1978 Conform to the ISO 1990 C standard.
1982 Conform to the ISO 1999 C standard.
1985 C ObjC Alias(std=c99)
1986 Deprecated in favor of -std=c99.
1990 Conform to the ISO 1998 C++ standard revised by the 2003 technical
1991 corrigendum with GNU extensions.
1994 C++ ObjC++ Alias(std=gnu++98)
1995 Conform to the ISO 1998 C++ standard revised by the 2003 technical
1996 corrigendum with GNU extensions.
2000 Conform to the ISO 2011 C++ standard with GNU extensions.
2003 C++ ObjC++ Alias(std=gnu++11) Undocumented
2004 Deprecated in favor of -std=gnu++11.
2007 C++ ObjC++ Alias(std=gnu++14) Undocumented
2008 Deprecated in favor of -std=gnu++14.
2012 Conform to the ISO 2014 C++ standard with GNU extensions.
2015 C++ ObjC++ Alias(std=gnu++17) Undocumented
2016 Deprecated in favor of -std=gnu++17.
2020 Conform to the ISO 2017 C++ standard with GNU extensions.
2024 Conform to the ISO 2020(?) C++ draft standard with GNU extensions (experimental and incomplete support).
2028 Conform to the ISO 2011 C standard with GNU extensions.
2031 C ObjC Alias(std=gnu11)
2032 Deprecated in favor of -std=gnu11.
2036 Conform to the ISO 2017 C standard (expected to be published in 2018) with GNU extensions.
2039 C ObjC Alias(std=gnu17)
2040 Conform to the ISO 2017 C standard (expected to be published in 2018) with GNU extensions.
2043 C ObjC Alias(std=gnu90)
2044 Conform to the ISO 1990 C standard with GNU extensions.
2048 Conform to the ISO 1990 C standard with GNU extensions.
2052 Conform to the ISO 1999 C standard with GNU extensions.
2055 C ObjC Alias(std=gnu99)
2056 Deprecated in favor of -std=gnu99.
2059 C ObjC Alias(std=c90)
2060 Conform to the ISO 1990 C standard.
2064 Conform to the ISO 1990 C standard as amended in 1994.
2067 C ObjC Alias(std=c99)
2068 Conform to the ISO 1999 C standard.
2071 C ObjC Alias(std=c99)
2072 Deprecated in favor of -std=iso9899:1999.
2075 C ObjC Alias(std=c11)
2076 Conform to the ISO 2011 C standard.
2079 C ObjC Alias(std=c17)
2080 Conform to the ISO 2017 C standard (expected to be published in 2018).
2083 C ObjC Alias(std=c17)
2084 Conform to the ISO 2017 C standard (expected to be published in 2018).
2091 Enable traditional preprocessing.
2095 -trigraphs Support ISO C trigraphs.
2098 C ObjC C++ ObjC++ Var(flag_undef)
2099 Do not predefine system-specific and GCC-specific macros.
2103 ; Documented in common.opt
2107 ; Documented in common.opt
2109 ; This comment is to ensure we retain the blank line above.