1 ; Options for the C, ObjC, C++ and ObjC++ front ends.
2 ; Copyright (C) 2003-2019 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++ Warning Alias(Wc++20-compat) Undocumented
407 C++ ObjC++ Var(warn_cxx20_compat) Warning LangEnabledBy(C++ ObjC++,Wall)
408 Warn about C++ constructs whose meaning differs between ISO C++ 2017 and ISO C++ 2020.
411 C ObjC C++ ObjC++ Var(warn_cast_function_type) Warning EnabledBy(Wextra)
412 Warn about casts between incompatible function types.
415 C ObjC C++ ObjC++ Var(warn_cast_qual) Warning
416 Warn about casts which discard qualifiers.
419 C++ ObjC++ Warning Alias(Wcatch-value=, 1, 0)
420 Warn about catch handlers of non-reference type.
423 C++ ObjC++ Var(warn_catch_value) Warning Joined RejectNegative UInteger LangEnabledBy(C++ ObjC++,Wall, 1, 0) IntegerRange(0, 3)
424 Warn about catch handlers of non-reference type.
427 C ObjC C++ ObjC++ Var(warn_char_subscripts) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
428 Warn about subscripts whose type is \"char\".
431 C ObjC C++ ObjC++ Warning Deprecated
432 Deprecated in GCC 9. This switch has no effect.
435 C ObjC C++ ObjC++ Var(warn_clobbered) Warning EnabledBy(Wextra)
436 Warn about variables that might be changed by \"longjmp\" or \"vfork\".
439 C++ ObjC++ Var(warn_comma_subscript) Warning
440 Warn about uses of a comma operator within a subscripting expression.
443 C ObjC C++ ObjC++ CPP(warn_comments) CppReason(CPP_W_COMMENTS) Var(cpp_warn_comment) Init(0) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
444 Warn about possibly nested block comments, and C++ comments spanning more than one physical line.
447 C ObjC C++ ObjC++ Warning Alias(Wcomment)
448 Synonym for -Wcomment.
450 Wconditionally-supported
451 C++ ObjC++ Var(warn_conditionally_supported) Warning
452 Warn for conditionally-supported constructs.
455 C ObjC C++ ObjC++ Var(warn_conversion) Warning
456 Warn for implicit type conversions that may change a value.
459 C++ ObjC++ Var(warn_conversion_null) Init(1) Warning
460 Warn for converting NULL from/to a non-pointer type.
463 C ObjC C++ ObjC++ CppReason(CPP_W_WARNING_DIRECTIVE)
464 ; Documented in common.opt
467 C++ ObjC++ Var(warn_ctor_dtor_privacy) Warning
468 Warn when all constructors and destructors are private.
471 C ObjC C++ ObjC++ Var(warn_dangling_else) Warning LangEnabledBy(C ObjC C++ ObjC++,Wparentheses)
472 Warn about dangling else.
475 C ObjC C++ ObjC++ CPP(warn_date_time) CppReason(CPP_W_DATE_TIME) Var(cpp_warn_date_time) Init(0) Warning
476 Warn about __TIME__, __DATE__ and __TIMESTAMP__ usage.
478 Wdeclaration-after-statement
479 C ObjC Var(warn_declaration_after_statement) Init(-1) Warning
480 Warn when a declaration is found after a statement.
483 C++ ObjC++ Var(warn_delete_incomplete) Init(1) Warning
484 Warn when deleting a pointer to incomplete type.
486 Wdelete-non-virtual-dtor
487 C++ ObjC++ Var(warn_delnonvdtor) Warning LangEnabledBy(C++ ObjC++,Wall || Weffc++)
488 Warn about deleting polymorphic objects with non-virtual destructors.
491 C C++ ObjC ObjC++ CPP(cpp_warn_deprecated) CppReason(CPP_W_DEPRECATED)
492 ; Documented in common.opt
495 C++ ObjC++ Var(warn_deprecated_copy) Warning LangEnabledBy(C++ ObjC++, Wextra)
496 Mark implicitly-declared copy operations as deprecated if the class has a
497 user-provided copy operation.
499 Wdeprecated-copy-dtor
500 C++ ObjC++ Var(warn_deprecated_copy, 2) Warning
501 Mark implicitly-declared copy operations as deprecated if the class has a
502 user-provided copy operation or destructor.
505 C ObjC Var(warn_designated_init) Init(1) Warning
506 Warn about positional initialization of structs requiring designated initializers.
508 Wdiscarded-array-qualifiers
509 C ObjC Var(warn_discarded_array_qualifiers) Init(1) Warning
510 Warn if qualifiers on arrays which are pointer targets are discarded.
512 Wdiscarded-qualifiers
513 C ObjC Var(warn_discarded_qualifiers) Init(1) Warning
514 Warn if type qualifiers on pointers are discarded.
517 C ObjC C++ ObjC++ Var(warn_div_by_zero) Init(1) Warning
518 Warn about compile-time integer division by zero.
521 C ObjC C++ ObjC++ Var(warn_duplicated_branches) Init(0) Warning
522 Warn about duplicated branches in if-else statements.
525 C ObjC C++ ObjC++ Var(warn_duplicated_cond) Init(0) Warning
526 Warn about duplicated conditions in an if-else-if chain.
529 C++ ObjC++ Var(warn_ecpp) Warning
530 Warn about violations of Effective C++ style rules.
533 C ObjC C++ ObjC++ Var(warn_empty_body) Warning EnabledBy(Wextra)
534 Warn about an empty body in an if or else statement.
537 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)
538 Warn about stray tokens after #else and #endif.
541 C ObjC C++ ObjC++ Var(warn_enum_compare) Init(-1) Warning LangEnabledBy(C ObjC,Wall || Wc++-compat)
542 Warn about comparison of different enum types.
545 C ObjC Var(warn_enum_conversion) Init(0) Warning LangEnabledBy(C ObjC,Wextra)
546 Warn about implicit conversion of enum types.
550 ; Documented in common.opt
552 Werror-implicit-function-declaration
553 C ObjC RejectNegative Warning Alias(Werror=, implicit-function-declaration)
554 This switch is deprecated; use -Werror=implicit-function-declaration instead.
557 C ObjC C++ ObjC++ Warning
561 C++ ObjC++ Var(warn_extra_semi) Warning
562 Warn about semicolon after in-class function definition.
565 C ObjC C++ ObjC++ Var(warn_float_conversion) Warning LangEnabledBy(C ObjC C++ ObjC++,Wconversion)
566 Warn for implicit type conversions that cause loss of floating point precision.
569 C ObjC C++ ObjC++ Var(warn_float_equal) Warning
570 Warn if testing floating point numbers for equality.
573 C ObjC C++ ObjC++ Warning Alias(Wformat=, 1, 0)
574 Warn about printf/scanf/strftime/strfmon format string anomalies.
577 C ObjC C++ ObjC++ Var(warn_format_contains_nul) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
578 Warn about format strings that contain NUL bytes.
581 C ObjC C++ ObjC++ Var(warn_format_diag) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
582 Warn about GCC format strings with strings unsuitable for diagnostics.
585 C ObjC C++ ObjC++ Var(warn_format_extra_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
586 Warn if passing too many arguments to a function for its format string.
589 C ObjC C++ ObjC++ Var(warn_format_nonliteral) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 2, 0)
590 Warn about format strings that are not literals.
593 C ObjC C++ LTO ObjC++ Warning Alias(Wformat-overflow=, 1, 0) IntegerRange(0, 2)
594 Warn about function calls with format strings that write past the end
595 of the destination region. Same as -Wformat-overflow=1.
598 C ObjC C++ ObjC++ Var(warn_format_security) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 2, 0)
599 Warn about possible security problems with format functions.
602 C ObjC C++ ObjC++ Var(warn_format_signedness) Warning
603 Warn about sign differences with format functions.
606 C ObjC C++ LTO ObjC++ Warning Alias(Wformat-truncation=, 1, 0)
607 Warn about calls to snprintf and similar functions that truncate output.
608 Same as -Wformat-truncation=1.
611 C ObjC C++ ObjC++ Var(warn_format_y2k) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 2, 0)
612 Warn about strftime formats yielding 2-digit years.
615 C ObjC C++ ObjC++ Var(warn_format_zero_length) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 1, 0)
616 Warn about zero-length formats.
619 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_format) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0) IntegerRange(0, 2)
620 Warn about printf/scanf/strftime/strfmon format string anomalies.
623 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)
624 Warn about function calls with format strings that write past the end
625 of the destination region.
628 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)
629 Warn about calls to snprintf and similar functions that truncate output.
632 C ObjC C++ ObjC++ Var(warn_if_not_aligned) Init(1) Warning
633 Warn when the field in a struct is not aligned.
636 C C++ Var(warn_ignored_qualifiers) Warning EnabledBy(Wextra)
637 Warn whenever type qualifiers are ignored.
640 C C++ Var(warn_ignored_attributes) Init(1) Warning
641 Warn whenever attributes are ignored.
644 C++ ObjC++ Var(warn_inaccessible_base) Init(1) Warning
645 Warn when a base is inaccessible in derived due to ambiguity.
647 Wincompatible-pointer-types
648 C ObjC Var(warn_incompatible_pointer_types) Init(1) Warning
649 Warn when there is a conversion between pointers that have incompatible types.
651 Waddress-of-packed-member
652 C ObjC C++ ObjC++ Var(warn_address_of_packed_member) Init(1) Warning
653 Warn when the address of packed member of struct or union is taken.
656 C ObjC C++ ObjC++ Var(warn_init_self) Warning LangEnabledBy(C++ ObjC++,Wall)
657 Warn about variables which are initialized to themselves.
660 C++ ObjC++ Var(warn_init_list) Warning Init(1)
661 Warn about uses of std::initializer_list that can result in dangling pointers.
664 C ObjC Var(warn_implicit) Warning LangEnabledBy(C ObjC,Wall)
665 Warn about implicit declarations.
667 Wimplicit-fallthrough=
668 LangEnabledBy(C ObjC C++ ObjC++,Wextra,3,0)
672 C ObjC C++ ObjC++ Var(warn_double_promotion) Warning
673 Warn about implicit conversions from \"float\" to \"double\".
675 Wexpansion-to-defined
676 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)
677 Warn if \"defined\" is used outside #if.
679 Wimplicit-function-declaration
680 C ObjC Var(warn_implicit_function_declaration) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit)
681 Warn about implicit function declarations.
684 C ObjC Var(warn_implicit_int) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit)
685 Warn when a declaration does not specify a type.
688 C ObjC C++ ObjC++ Undocumented Ignore
690 Winherited-variadic-ctor
691 C++ ObjC++ Var(warn_inh_var_ctor) Init(1) Warning
692 Warn about C++11 inheriting constructors when the base has a variadic constructor.
695 C ObjC Var(warn_int_conversion) Init(1) Warning
696 Warn about incompatible integer to pointer and pointer to integer conversions.
699 C ObjC C++ ObjC++ Var(warn_int_in_bool_context) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
700 Warn for suspicious integer expressions in boolean context.
703 C ObjC C++ ObjC++ Var(warn_int_to_pointer_cast) Init(1) Warning
704 Warn when there is a cast to a pointer from an integer of a different size.
707 C++ ObjC++ Var(warn_invalid_offsetof) Init(1) Warning
708 Warn about invalid uses of the \"offsetof\" macro.
711 C ObjC C++ ObjC++ CPP(warn_invalid_pch) CppReason(CPP_W_INVALID_PCH) Var(cpp_warn_invalid_pch) Init(0) Warning
712 Warn about PCH files that are found but not used.
715 C ObjC Var(warn_jump_misses_init) Warning LangEnabledby(C ObjC,Wc++-compat)
716 Warn when a jump misses a variable initialization.
719 C++ ObjC++ CPP(warn_literal_suffix) CppReason(CPP_W_LITERAL_SUFFIX) Var(cpp_warn_literal_suffix) Init(1) Warning
720 Warn when a string or character literal is followed by a ud-suffix which does not begin with an underscore.
723 C ObjC C++ ObjC++ Var(warn_logical_op) Init(0) Warning
724 Warn when a logical operator is suspiciously always evaluating to true or false.
726 Wlogical-not-parentheses
727 C ObjC C++ ObjC++ Var(warn_logical_not_paren) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
728 Warn when logical not is used on the left hand side operand of a comparison.
731 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)
732 Do not warn about using \"long long\" when -pedantic.
735 C ObjC C++ ObjC++ Var(warn_main) Init(-1) Warning LangEnabledBy(C ObjC,Wall, 2, 0)
736 Warn about suspicious declarations of \"main\".
739 LangEnabledBy(C ObjC C++ ObjC++,Wpedantic, 2, 0)
742 Wmemset-transposed-args
743 C ObjC C++ ObjC++ Var(warn_memset_transposed_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
744 Warn about suspicious calls to memset where the third argument is constant literal zero and the second is not.
747 C ObjC C++ ObjC++ Var(warn_memset_elt_size) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
748 Warn about suspicious calls to memset where the third argument contains the number of elements not multiplied by the element size.
750 Wmisleading-indentation
751 C C++ Common Var(warn_misleading_indentation) Warning LangEnabledBy(C C++,Wall)
752 Warn when the indentation of the code does not reflect the block structure.
755 C ObjC C++ ObjC++ Var(warn_missing_braces) Warning LangEnabledBy(C ObjC,Wall)
756 Warn about possibly missing braces around initializers.
758 Wmissing-declarations
759 C ObjC C++ ObjC++ Var(warn_missing_declarations) Warning
760 Warn about global functions without previous declarations.
762 Wmissing-field-initializers
763 C ObjC C++ ObjC++ Var(warn_missing_field_initializers) Warning EnabledBy(Wextra)
764 Warn about missing fields in struct initializers.
766 Wmultistatement-macros
767 C ObjC C++ ObjC++ Var(warn_multistatement_macros) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
768 Warn about unsafe macros expanding to multiple statements used as a body of a clause such as if, else, while, switch, or for.
770 Wmultiple-inheritance
771 C++ ObjC++ Var(warn_multiple_inheritance) Warning
772 Warn on direct multiple inheritance.
775 C++ ObjC++ Var(warn_namespaces) Warning
776 Warn on namespace definition.
779 C ObjC C++ ObjC++ Var(warn_packed_not_aligned) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
780 Warn when fields in a struct with the packed attribute are misaligned.
783 C++ ObjC++ Var(warn_sized_deallocation) Warning EnabledBy(Wextra)
784 Warn about missing sized deallocation functions.
787 C ObjC C++ ObjC++ Var(warn_sizeof_pointer_div) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
788 Warn about suspicious divisions of two sizeof expressions that don't work correctly with pointers.
790 Wsizeof-pointer-memaccess
791 C ObjC C++ ObjC++ Var(warn_sizeof_pointer_memaccess) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
792 Warn about suspicious length parameters to certain string functions if the argument uses sizeof.
794 Wsizeof-array-argument
795 C ObjC C++ ObjC++ Var(warn_sizeof_array_argument) Warning Init(1)
796 Warn when sizeof is applied on a parameter declared as an array.
799 C ObjC C++ LTO ObjC++ Warning Alias(Wstringop-overflow=, 2, 0)
800 Warn about buffer overflow in string manipulation functions like memcpy
804 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)
805 Under the control of Object Size type, warn about buffer overflow in string
806 manipulation functions like memcpy and strcpy.
809 C ObjC C++ LTO ObjC++ Var(warn_stringop_truncation) Warning Init (1) LangEnabledBy(C ObjC C++ LTO ObjC++, Wall)
810 Warn about truncation in string manipulation functions like strncat and strncpy.
812 Wsuggest-attribute=format
813 C ObjC C++ ObjC++ Var(warn_suggest_attribute_format) Warning
814 Warn about functions which might be candidates for format attributes.
817 C++ ObjC++ Var(warn_override) Warning
818 Suggest that the override keyword be used when the declaration of a virtual
819 function overrides another.
822 C ObjC C++ ObjC++ Var(warn_switch) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
823 Warn about enumerated switches, with no default, missing a case.
826 C ObjC C++ ObjC++ Var(warn_switch_default) Warning
827 Warn about enumerated switches missing a \"default:\" statement.
830 C ObjC C++ ObjC++ Var(warn_switch_enum) Warning
831 Warn about all enumerated switches missing a specific case.
834 C ObjC C++ ObjC++ Var(warn_switch_bool) Warning Init(1)
835 Warn about switches with boolean controlling expression.
837 Wswitch-outside-range
838 C ObjC C++ ObjC++ Var(warn_switch_outside_range) Warning Init(1)
839 Warn about switch values that are outside of the switch's type range.
842 C++ ObjC++ Var(warn_templates) Warning
843 Warn on primary template declaration.
846 C ObjC C++ ObjC++ Var(warn_missing_attributes) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
847 Warn about declarations of entities that may be missing attributes
848 that related entities have been declared with.
850 Wmissing-format-attribute
851 C ObjC C++ ObjC++ Warning Alias(Wsuggest-attribute=format)
854 Wmissing-include-dirs
855 C ObjC C++ ObjC++ CPP(warn_missing_include_dirs) CppReason(CPP_W_MISSING_INCLUDE_DIRS) Var(cpp_warn_missing_include_dirs) Init(0) Warning
856 Warn about user-specified include directories that do not exist.
858 Wmissing-parameter-type
859 C ObjC Var(warn_missing_parameter_type) Warning EnabledBy(Wextra)
860 Warn about function parameters declared without a type specifier in K&R-style functions.
863 C ObjC Var(warn_missing_prototypes) Warning
864 Warn about global functions without prototypes.
867 C ObjC C++ ObjC++ Deprecated
870 C ObjC C++ ObjC++ CPP(warn_multichar) CppReason(CPP_W_MULTICHAR) Var(cpp_warn_multichar) Init(0) Warning
871 Warn about use of multi-character character constants.
874 C ObjC C++ ObjC++ Warning Var(warn_narrowing) Init(-1) LangEnabledBy(C++ ObjC++,Wall || Wc++11-compat)
875 Warn about narrowing conversions within { } that are ill-formed in C++11.
878 C ObjC Var(warn_nested_externs) Warning
879 Warn about \"extern\" declarations not at file scope.
882 C++ ObjC++ Var(warn_noexcept) Warning
883 Warn when a noexcept expression evaluates to false even though the expression can't actually throw.
886 C++ ObjC++ Warning Var(warn_noexcept_type) LangEnabledBy(C++ ObjC++,Wabi || Wc++17-compat)
887 Warn if C++17 noexcept function type will change the mangled name of a symbol.
890 C++ ObjC++ Var(warn_nontemplate_friend) Init(1) Warning
891 Warn when non-templatized friend functions are declared within a template.
894 C++ ObjC++ Var(warn_class_conversion) Init(1) Warning
895 Warn when a conversion function will never be called due to the type it converts to.
898 C++ ObjC++ Var(warn_class_memaccess) Warning LangEnabledBy(C++ ObjC++, Wall)
899 Warn for unsafe raw memory writes to objects of class types.
902 C++ ObjC++ Var(warn_nonvdtor) Warning LangEnabledBy(C++ ObjC++,Weffc++)
903 Warn about non-virtual destructors.
906 C ObjC C++ LTO ObjC++ Var(warn_nonnull) Warning LangEnabledBy(C ObjC C++ LTO ObjC++,Wformat=,warn_format >= 1,0)
907 Warn about NULL being passed to argument slots marked as requiring non-NULL.
910 C ObjC C++ LTO ObjC++ LangEnabledBy(C ObjC C++ LTO ObjC++,Wall)
914 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
918 C ObjC C++ ObjC++ Warning Alias(Wnormalized=,nfc,none)
922 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)
923 -Wnormalized=[none|id|nfc|nfkc] Warn about non-normalized Unicode strings.
925 ; Required for these enum values.
930 Name(cpp_normalize_level) Type(int) UnknownError(argument %qs to %<-Wnormalized%> not recognized)
933 Enum(cpp_normalize_level) String(none) Value(normalized_none)
936 Enum(cpp_normalize_level) String(nfkc) Value(normalized_KC)
939 Enum(cpp_normalize_level) String(id) Value(normalized_identifier_C)
942 Enum(cpp_normalize_level) String(nfc) Value(normalized_C)
945 C++ ObjC++ Var(warn_old_style_cast) Warning
946 Warn if a C-style cast is used in a program.
948 Wold-style-declaration
949 C ObjC Var(warn_old_style_declaration) Warning EnabledBy(Wextra)
950 Warn for obsolescent usage in a declaration.
952 Wold-style-definition
953 C ObjC Var(warn_old_style_definition) Warning
954 Warn if an old-style parameter definition is used.
957 C C++ Var(warn_openmp_simd) Warning LangEnabledBy(C C++,Wall)
958 Warn if a simd directive is overridden by the vectorizer cost model.
961 C ObjC C++ ObjC++ Var(warn_overlength_strings) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic)
962 Warn if a string is longer than the maximum portable length specified by the standard.
965 C++ ObjC++ Var(warn_overloaded_virtual) Warning
966 Warn about overloaded virtual function names.
969 C ObjC Var(warn_override_init) Warning EnabledBy(Wextra)
970 Warn about overriding initializers without side effects.
972 Woverride-init-side-effects
973 C ObjC Var(warn_override_init_side_effects) Init(1) Warning
974 Warn about overriding initializers with side effects.
976 Wpacked-bitfield-compat
977 C ObjC C++ ObjC++ Var(warn_packed_bitfield_compat) Init(-1) Warning
978 Warn about packed bit-fields whose offset changed in GCC 4.4.
981 C ObjC C++ ObjC++ Var(warn_parentheses) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
982 Warn about possibly missing parentheses.
985 C ObjC C++ ObjC++ CPP(cpp_pedantic) CppReason(CPP_W_PEDANTIC) Warning
986 ; Documented in common.opt
989 C++ ObjC++ Var(warn_pessimizing_move) Warning LangEnabledBy(C++ ObjC++, Wall)
990 Warn about calling std::move on a local object in a return statement preventing copy elision.
993 C++ ObjC++ Var(warn_pmf2ptr) Init(1) Warning
994 Warn when converting the type of pointers to member functions.
997 C ObjC C++ ObjC++ Var(warn_pointer_arith) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic)
998 Warn about function pointer arithmetic.
1001 C ObjC Var(warn_pointer_sign) Warning LangEnabledBy(C ObjC,Wall || Wpedantic)
1002 Warn when a pointer differs in signedness in an assignment.
1005 C ObjC C++ ObjC++ Var(warn_pointer_compare) Init(1) Warning
1006 Warn when a pointer is compared with a zero character constant.
1008 Wpointer-to-int-cast
1009 C ObjC Var(warn_pointer_to_int_cast) Init(1) Warning
1010 Warn when a pointer is cast to an integer of a different size.
1013 C ObjC C++ ObjC++ Var(warn_pragmas) Init(1) Warning
1014 Warn about misuses of pragmas.
1017 C ObjC C++ ObjC++ Var(warn_prio_ctor_dtor) Init(1) Warning
1018 Warn if constructor or destructors with priorities from 0 to 100 are used.
1020 Wproperty-assign-default
1021 ObjC ObjC++ Var(warn_property_assign_default) Init(1) Warning
1022 Warn if a property for an Objective-C object has no assign semantics specified.
1025 ObjC ObjC++ Var(warn_protocol) Init(1) Warning
1026 Warn if inherited methods are unimplemented.
1029 C++ Warning Alias(Wplacement-new=, 1, 0)
1030 Warn for placement new expressions with undefined behavior.
1033 C++ Joined RejectNegative UInteger Var(warn_placement_new) Init(-1) Warning IntegerRange(0, 2)
1034 Warn for placement new expressions with undefined behavior.
1037 C ObjC C++ ObjC++ Var(warn_redundant_decls) Warning
1038 Warn about multiple declarations of the same object.
1041 C++ ObjC++ Var(warn_redundant_move) Warning LangEnabledBy(C++ ObjC++,Wextra)
1042 Warn about redundant calls to std::move.
1045 C++ ObjC++ Var(warn_register) Warning
1046 Warn about uses of register storage specifier.
1049 C++ ObjC++ Var(warn_reorder) Warning LangEnabledBy(C++ ObjC++,Wall)
1050 Warn when the compiler reorders code.
1053 C ObjC C++ ObjC++ Var(warn_return_type) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Init(-1)
1054 Warn whenever a function's return type defaults to \"int\" (C), or about inconsistent return types (C++).
1056 Wscalar-storage-order
1057 C ObjC C++ ObjC++ Init(1) Warning
1058 Warn on suspicious constructs involving reverse scalar storage order.
1061 ObjC ObjC++ Var(warn_selector) Warning
1062 Warn if a selector has multiple methods.
1065 C ObjC C++ ObjC++ Var(warn_sequence_point) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1066 Warn about possible violations of sequence point rules.
1069 ObjC ObjC++ Var(warn_shadow_ivar) EnabledBy(Wshadow) Init(1) Warning
1070 Warn if a local declaration hides an instance variable.
1073 C ObjC C++ ObjC++ Warning Alias(Wshift-overflow=, 1, 0)
1074 Warn if left shift of a signed value overflows.
1077 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_shift_overflow) Init(-1) Warning IntegerRange(0, 2)
1078 Warn if left shift of a signed value overflows.
1080 Wshift-count-negative
1081 C ObjC C++ ObjC++ Var(warn_shift_count_negative) Init(1) Warning
1082 Warn if shift count is negative.
1084 Wshift-count-overflow
1085 C ObjC C++ ObjC++ Var(warn_shift_count_overflow) Init(1) Warning
1086 Warn if shift count >= width of type.
1088 Wshift-negative-value
1089 C ObjC C++ ObjC++ Var(warn_shift_negative_value) Init(-1) Warning
1090 Warn if left shifting a negative value.
1093 C ObjC C++ ObjC++ Var(warn_sign_compare) Warning LangEnabledBy(C++ ObjC++,Wall)
1094 Warn about signed-unsigned comparisons.
1097 C ObjC C++ ObjC++ EnabledBy(Wextra)
1101 C ObjC C++ ObjC++ Var(warn_sign_conversion) Warning LangEnabledBy(C ObjC,Wconversion)
1102 Warn for implicit type conversions between signed and unsigned integers.
1105 C++ ObjC++ Var(warn_sign_promo) Warning
1106 Warn when overload promotes from unsigned to signed.
1108 Wstrict-null-sentinel
1109 C++ ObjC++ Warning Var(warn_strict_null_sentinel)
1110 Warn about uncasted NULL used as sentinel.
1113 C ObjC Var(warn_strict_prototypes) Warning
1114 Warn about unprototyped function declarations.
1117 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 3, 0) IntegerRange(0, 3)
1121 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0) IntegerRange(0, 5)
1124 Wstrict-selector-match
1125 ObjC ObjC++ Var(warn_strict_selector_match) Warning
1126 Warn if type signatures of candidate methods do not match exactly.
1129 C C++ Var(warn_sync_nand) Init(1) Warning
1130 Warn when __sync_fetch_and_nand and __sync_nand_and_fetch built-in functions are used.
1133 C++ ObjC++ Var(warn_synth) Warning
1134 Deprecated. This switch has no effect.
1137 C ObjC C++ ObjC++ Warning
1138 ; Documented in common.opt
1140 Wtautological-compare
1141 C ObjC C++ ObjC++ Var(warn_tautological_compare) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1142 Warn if a comparison always evaluates to true or false.
1145 C++ ObjC++ Warning Var(warn_terminate) Init(1)
1146 Warn if a throw expression will always result in a call to terminate().
1149 C ObjC CPP(cpp_warn_traditional) CppReason(CPP_W_TRADITIONAL) Var(warn_traditional) Init(0) Warning
1150 Warn about features not present in traditional C.
1152 Wtraditional-conversion
1153 C ObjC Var(warn_traditional_conversion) Warning
1154 Warn of prototypes causing type conversions different from what would happen in the absence of prototype.
1157 C ObjC C++ ObjC++ CPP(warn_trigraphs) CppReason(CPP_W_TRIGRAPHS) Var(cpp_warn_trigraphs) Init(2) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1158 Warn if trigraphs are encountered that might affect the meaning of the program.
1160 Wundeclared-selector
1161 ObjC ObjC++ Var(warn_undeclared_selector) Warning
1162 Warn about @selector()s without previously declared methods.
1165 C ObjC C++ ObjC++ CPP(warn_undef) CppReason(CPP_W_UNDEF) Var(cpp_warn_undef) Init(0) Warning
1166 Warn if an undefined macro is used in an #if directive.
1169 C ObjC C++ ObjC++ LTO LangEnabledBy(C ObjC C++ ObjC++ LTO,Wall)
1172 Wmaybe-uninitialized
1173 C ObjC C++ ObjC++ LTO LangEnabledBy(C ObjC C++ ObjC++ LTO,Wall)
1177 C ObjC C++ ObjC++ Warning Var(warn_unknown_pragmas) LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0)
1178 Warn about unrecognized pragmas.
1180 Wunsuffixed-float-constants
1181 C ObjC Var(warn_unsuffixed_float_constants) Warning
1182 Warn about unsuffixed float constants.
1185 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
1186 ; documented in common.opt
1188 Wunused-local-typedefs
1189 C ObjC C++ ObjC++ Var(warn_unused_local_typedefs) Warning EnabledBy(Wunused)
1190 Warn when typedefs locally defined in a function are not used.
1193 C ObjC C++ ObjC++ CppReason(CPP_W_UNUSED_MACROS) Var(cpp_warn_unused_macros) Warning
1194 Warn about macros defined in the main file that are not used.
1197 C ObjC C++ ObjC++ Var(warn_unused_result) Init(1) Warning
1198 Warn if a caller of a function, marked with attribute warn_unused_result, does not use its return value.
1201 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wunused)
1202 ; documented in common.opt
1204 Wunused-const-variable
1205 C ObjC C++ ObjC++ Warning Alias(Wunused-const-variable=, 2, 0)
1206 Warn when a const variable is unused.
1208 Wunused-const-variable=
1209 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_unused_const_variable) Warning LangEnabledBy(C ObjC,Wunused-variable, 1, 0) IntegerRange(0, 2)
1210 Warn when a const variable is unused.
1213 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)
1214 Warn about using variadic macros.
1217 C ObjC C++ ObjC++ Warning Var(warn_varargs) Init(1)
1218 Warn about questionable usage of the macros used to retrieve variable arguments.
1221 C ObjC C++ ObjC++ Var(warn_vla) Init(-1) Warning
1222 Warn if a variable length array is used.
1225 C ObjC C++ LTO ObjC++ Var(warn_vla_limit) Warning Joined Host_Wide_Int ByteSize Init(HOST_WIDE_INT_MAX)
1226 -Wvla-larger-than=<number> Warn on unbounded uses of variable-length
1227 arrays, and on bounded uses of variable-length arrays whose bound can be
1228 larger than <number> bytes.
1232 C ObjC C++ LTO ObjC++ Alias(Wvla-larger-than=,18446744073709551615EiB,none) Warning
1233 -Wno-vla-larger-than Disable Wvla-larger-than= warning. Equivalent to Wvla-larger-than=<SIZE_MAX> or larger.
1236 C++ ObjC++ Var(warn_volatile) Warning
1237 Warn about deprecated uses of volatile qualifier.
1239 Wvolatile-register-var
1240 C ObjC C++ ObjC++ Var(warn_volatile_register_var) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1241 Warn when a register variable is declared volatile.
1243 Wvirtual-inheritance
1244 C++ ObjC++ Var(warn_virtual_inheritance) Warning
1245 Warn on direct virtual inheritance.
1247 Wvirtual-move-assign
1248 C++ ObjC++ Var(warn_virtual_move_assign) Warning Init(1)
1249 Warn if a virtual base has a non-trivial move assignment operator.
1252 C ObjC C++ ObjC++ Var(warn_write_strings) Warning
1253 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.
1255 Wzero-as-null-pointer-constant
1256 C++ ObjC++ Var(warn_zero_as_null_pointer_constant) Warning
1257 Warn when a literal '0' is used as null pointer.
1260 C++ ObjC++ Var(warn_useless_cast) Warning
1261 Warn about useless casts.
1264 C++ ObjC++ Var(warn_subobject_linkage) Warning Init(1)
1265 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.
1267 Wduplicate-decl-specifier
1268 C ObjC Var(warn_duplicate_decl_specifier) Warning LangEnabledBy(C ObjC,Wall)
1269 Warn when a declaration has duplicate const, volatile, restrict or _Atomic specifier.
1272 C ObjC C++ ObjC++ Var(warn_restrict) Warning LangEnabledBy(C ObjC C++ ObjC++, Wall)
1273 Warn when an argument passed to a restrict-qualified parameter aliases with
1278 A synonym for -std=c89 (for C) or -std=c++98 (for C++).
1281 C ObjC C++ ObjC++ Joined
1282 ; Documented in common.opt. FIXME - what about -dI, -dD, -dN and -dD?
1284 fabi-compat-version=
1285 C++ ObjC++ Joined RejectNegative UInteger Var(flag_abi_compat_version) Init(-1)
1286 The version of the C++ ABI used for -Wabi warnings and link compatibility aliases.
1289 C++ ObjC++ Var(flag_access_control) Init(1)
1290 Enforce class member access control semantics.
1293 C ObjC C++ ObjC++ RejectNegative Joined Var(ada_specs_parent)
1294 -fada-spec-parent=unit Dump Ada specs as child units of given parent.
1297 C++ ObjC++ Alias(faligned-new=,1,0)
1298 Support C++17 allocation of over-aligned types.
1301 C++ ObjC++ Joined RejectNegative Var(aligned_new_threshold) UInteger Init(-1)
1302 -faligned-new=<N> Use C++17 over-aligned type allocation for alignments greater than N.
1305 C++ ObjC++ Deprecated
1307 fallow-parameterless-variadic-functions
1308 C ObjC Var(flag_allow_parameterless_variadic_functions)
1309 Allow variadic functions without named parameter.
1311 falt-external-templates
1312 C++ ObjC++ Deprecated
1313 No longer supported.
1316 C ObjC C++ ObjC++ Var(flag_no_asm, 0)
1317 Recognize the \"asm\" keyword.
1319 ; Define extra predefined macros for use in libgcc.
1321 C ObjC C++ ObjC++ Undocumented Var(flag_building_libgcc)
1324 C ObjC C++ ObjC++ Var(flag_no_builtin, 0)
1325 Recognize built-in functions.
1328 C ObjC C++ ObjC++ Joined
1330 fcanonical-system-headers
1332 Where shorter, use canonicalized paths to systems headers.
1335 C++ ObjC++ Var(flag_char8_t) Init(-1)
1336 Enable the char8_t fundamental type and use it as the type for UTF-8 string
1337 and character literals.
1339 fcheck-pointer-bounds
1340 C ObjC C++ ObjC++ LTO Deprecated
1341 Deprecated in GCC 9. This switch has no effect.
1343 fchkp-check-incomplete-type
1344 C ObjC C++ ObjC++ LTO Deprecated
1345 Deprecated in GCC 9. This switch has no effect.
1347 fchkp-zero-input-bounds-for-main
1348 C ObjC C++ ObjC++ LTO Deprecated
1349 Deprecated in GCC 9. This switch has no effect.
1351 fchkp-first-field-has-own-bounds
1352 C ObjC C++ ObjC++ LTO Deprecated RejectNegative
1353 Deprecated in GCC 9. This switch has no effect.
1356 C ObjC C++ ObjC++ LTO Deprecated
1357 Deprecated in GCC 9. This switch has no effect.
1359 fchkp-narrow-to-innermost-array
1360 C ObjC C++ ObjC++ LTO Deprecated RejectNegative
1361 Deprecated in GCC 9. This switch has no effect.
1363 fchkp-flexible-struct-trailing-arrays
1364 C ObjC C++ ObjC++ LTO Deprecated
1365 Deprecated in GCC 9. This switch has no effect.
1368 C ObjC C++ ObjC++ LTO Deprecated
1370 fchkp-use-fast-string-functions
1371 C ObjC C++ ObjC++ LTO Deprecated
1372 Deprecated in GCC 9. This switch has no effect.
1374 fchkp-use-nochk-string-functions
1375 C ObjC C++ ObjC++ LTO Deprecated
1376 Deprecated in GCC 9. This switch has no effect.
1378 fchkp-use-static-bounds
1379 C ObjC C++ ObjC++ LTO Deprecated
1380 Deprecated in GCC 9. This switch has no effect.
1382 fchkp-use-static-const-bounds
1383 C ObjC C++ ObjC++ LTO Deprecated
1384 Deprecated in GCC 9. This switch has no effect.
1386 fchkp-treat-zero-dynamic-size-as-infinite
1387 C ObjC C++ ObjC++ LTO Deprecated
1388 Deprecated in GCC 9. This switch has no effect.
1391 C ObjC C++ ObjC++ LTO Deprecated
1392 Deprecated in GCC 9. This switch has no effect.
1395 C ObjC C++ ObjC++ LTO Deprecated
1396 Deprecated in GCC 9. This switch has no effect.
1399 C ObjC C++ ObjC++ LTO Deprecated
1400 Deprecated in GCC 9. This switch has no effect.
1402 fchkp-instrument-calls
1403 C ObjC C++ ObjC++ LTO Deprecated
1404 Deprecated in GCC 9. This switch has no effect.
1406 fchkp-instrument-marked-only
1407 C ObjC C++ ObjC++ LTO Deprecated
1408 Deprecated in GCC 9. This switch has no effect.
1411 C ObjC C++ ObjC++ LTO Deprecated
1412 Deprecated in GCC 9. This switch has no effect.
1416 Deprecated in GCC 9. This switch has no effect.
1418 static-libmpxwrappers
1420 Deprecated in GCC 9. This switch has no effect.
1423 C ObjC C++ ObjC++ LTO Undocumented Ignore
1424 Deprecated in GCC 8. This switch has no effect.
1427 C++ ObjC++ Var(flag_concepts)
1428 Enable support for C++ concepts.
1432 Allow the arguments of the '?' operator to have different types.
1436 Does nothing. Preserved for backward compatibility.
1438 fconstant-string-class=
1439 ObjC ObjC++ Joined MissingArgError(no class name specified with %qs)
1440 -fconst-string-class=<name> Use class <name> for constant strings.
1443 C++ ObjC++ Joined RejectNegative UInteger Var(max_constexpr_depth) Init(512)
1444 -fconstexpr-depth=<number> Specify maximum constexpr recursion depth.
1446 fconstexpr-cache-depth=
1447 C++ ObjC++ Joined RejectNegative UInteger Var(constexpr_cache_depth) Init(8)
1448 -fconstexpr-cache-depth=<number> Specify maximum constexpr recursion cache depth.
1450 fconstexpr-loop-limit=
1451 C++ ObjC++ Joined RejectNegative UInteger Var(constexpr_loop_limit) Init(262144)
1452 -fconstexpr-loop-limit=<number> Specify maximum constexpr loop iteration count.
1454 fconstexpr-ops-limit=
1455 C++ ObjC++ Joined RejectNegative Host_Wide_Int Var(constexpr_ops_limit) Init(33554432)
1456 -fconstexpr-ops-limit=<number> Specify maximum number of constexpr operations during a single constexpr evaluation.
1460 Emit debug annotations during preprocessing.
1464 Does nothing. Preserved for backward compatibility.
1467 C++ ObjC++ Var(flag_declone_ctor_dtor) Init(-1)
1468 Factor complex constructors and destructors to favor space over speed.
1472 Does nothing. Preserved for backward compatibility.
1474 fdiagnostics-show-template-tree
1475 C++ ObjC++ Var(flag_diagnostics_show_template_tree) Init(0)
1476 Print hierarchical comparisons when template types are mismatched.
1480 Preprocess directives only.
1482 fdollars-in-identifiers
1484 Permit '$' as an identifier character.
1487 C ObjC C++ ObjC++ Joined RejectNegative
1488 -fmacro-prefix-map=<old>=<new> Map one directory name to another in __FILE__, __BASE_FILE__, and __builtin_FILE().
1491 C ObjC C++ ObjC++ RejectNegative Var(flag_dump_ada_spec)
1492 Write all declarations as Ada code transitively.
1495 C ObjC C++ ObjC++ RejectNegative Var(flag_dump_ada_spec_slim)
1496 Write all declarations as Ada code for the given file only.
1499 C++ ObjC++ Var(flag_elide_constructors) Init(1)
1502 C++ ObjC++ Var(flag_elide_type) Init(1)
1503 -fno-elide-type Do not elide common elements in template comparisons.
1506 C++ ObjC++ Var(flag_enforce_eh_specs) Init(1)
1507 Generate code to check exception specifications.
1510 C++ ObjC++ Deprecated
1513 C ObjC C++ ObjC++ Joined RejectNegative
1514 -fexec-charset=<cset> Convert all strings and character constants to character set <cset>.
1516 fextended-identifiers
1518 Permit universal character names (\\u and \\U) in identifiers.
1521 C ObjC C++ ObjC++ Joined RejectNegative
1522 -finput-charset=<cset> Specify the default character set for source files.
1525 C++ ObjC++ Var(flag_extern_tls_init) Init(-1)
1526 Support dynamic initialization of thread-local variables in a different translation unit.
1529 C++ ObjC++ Deprecated
1532 C++ ObjC++ Deprecated
1536 Do not assume that standard C libraries and \"main\" exist.
1539 C++ ObjC++ Var(flag_no_gnu_keywords, 0)
1540 Recognize GNU-defined keywords.
1543 ObjC ObjC++ LTO Report RejectNegative Var(flag_next_runtime,0) Init(NEXT_OBJC_RUNTIME)
1544 Generate code for GNU runtime environment.
1547 C ObjC Var(flag_gnu89_inline) Init(-1)
1548 Use traditional GNU semantics for inline functions.
1551 C++ ObjC++ Deprecated
1554 C++ ObjC++ Optimization Alias(fexceptions) Warn({%<-fhandle-exceptions%> has been renamed %<-fexceptions%> (and is now on by default)})
1557 C++ ObjC++ Deprecated
1561 Assume normal C execution environment.
1564 C++ ObjC++ Deprecated
1565 No longer supported.
1568 C++ ObjC++ Var(flag_implement_inlines) Init(1)
1569 Export functions even if they can be inlined.
1571 fimplicit-inline-templates
1572 C++ ObjC++ Var(flag_implicit_inline_templates) Init(1)
1573 Emit implicit instantiations of inline templates.
1576 C++ ObjC++ Var(flag_implicit_templates) Init(1)
1577 Emit implicit instantiations of templates.
1579 fnew-inheriting-ctors
1580 C++ ObjC++ Var(flag_new_inheriting_ctors) Init(1)
1581 Implement C++17 inheriting constructor semantics.
1584 C++ ObjC++ Deprecated
1586 fkeep-inline-dllexport
1587 C C++ ObjC ObjC++ Var(flag_keep_inline_dllexport) Init(1) Report Condition(TARGET_DLLIMPORT_DECL_ATTRIBUTES)
1588 Don't emit dllexported inline functions unless needed.
1591 C++ ObjC++ Deprecated
1593 flax-vector-conversions
1594 C ObjC C++ ObjC++ Var(flag_lax_vector_conversions)
1595 Allow implicit conversions between vectors with differing numbers of subparts and/or differing element types.
1598 C ObjC C++ ObjC++ Joined RejectNegative UInteger
1599 fmax-include-depth=<number> Set the maximum depth of the nested #include.
1602 C ObjC C++ ObjC++ Var(flag_ms_extensions)
1603 Don't warn about uses of Microsoft extensions.
1606 C ObjC C++ ObjC++ Deprecated
1609 C ObjC C++ ObjC++ Deprecated
1612 C ObjC C++ ObjC++ Deprecated
1614 fname-mangling-version-
1615 C++ ObjC++ Joined Deprecated
1618 C++ ObjC++ Deprecated
1621 C++ ObjC++ Var(flag_new_ttp)
1622 Implement resolution of DR 150 for matching of template template arguments.
1625 ObjC ObjC++ LTO Report RejectNegative Var(flag_next_runtime)
1626 Generate code for NeXT (Apple Mac OS X) runtime environment.
1629 ObjC ObjC++ Var(flag_nil_receivers) Init(1)
1630 Assume that receivers of Objective-C messages may be nil.
1633 ObjC ObjC++ Var(flag_local_ivars) Init(1)
1634 Allow access to instance variables as if they were local declarations within instance method implementations.
1637 ObjC ObjC++ Joined RejectNegative Enum(ivar_visibility) Var(default_ivar_visibility) Init(IVAR_VISIBILITY_PROTECTED)
1638 -fvisibility=[private|protected|public|package] Set the default symbol visibility.
1641 Name(ivar_visibility) Type(enum ivar_visibility) UnknownError(unrecognized ivar visibility value %qs)
1644 Enum(ivar_visibility) String(private) Value(IVAR_VISIBILITY_PRIVATE)
1647 Enum(ivar_visibility) String(protected) Value(IVAR_VISIBILITY_PROTECTED)
1650 Enum(ivar_visibility) String(public) Value(IVAR_VISIBILITY_PUBLIC)
1653 Enum(ivar_visibility) String(package) Value(IVAR_VISIBILITY_PACKAGE)
1656 C++ ObjC++ Var(flag_no_nonansi_builtin, 0)
1659 C++ ObjC++ Deprecated
1662 C++ ObjC++ Optimization Var(flag_nothrow_opt)
1663 Treat a throw() exception specification as noexcept to improve code size.
1666 ObjC ObjC++ LTO Joined Report RejectNegative UInteger Var(flag_objc_abi)
1667 Specify which ABI to use for Objective-C family code and meta-data generation.
1669 ; Generate special '- .cxx_construct' and '- .cxx_destruct' methods
1670 ; to initialize any non-POD ivars in Objective-C++ classes.
1671 fobjc-call-cxx-cdtors
1672 ObjC++ Var(flag_objc_call_cxx_cdtors)
1673 Generate special Objective-C methods to initialize/destroy non-POD C++ ivars, if needed.
1675 fobjc-direct-dispatch
1676 ObjC ObjC++ Var(flag_objc_direct_dispatch)
1677 Allow fast jumps to the message dispatcher.
1679 ; Nonzero means that we will allow new ObjC exception syntax (@throw,
1680 ; @try, etc.) in source code.
1682 ObjC ObjC++ Var(flag_objc_exceptions)
1683 Enable Objective-C exception and synchronization syntax.
1686 ObjC ObjC++ LTO Var(flag_objc_gc)
1687 Enable garbage collection (GC) in Objective-C/Objective-C++ programs.
1690 ObjC ObjC++ Var(flag_objc_nilcheck,1)
1691 Enable inline checks for nil receivers with the NeXT runtime and ABI version 2.
1693 ; Nonzero means that we generate NeXT setjmp based exceptions.
1694 fobjc-sjlj-exceptions
1695 ObjC ObjC++ Var(flag_objc_sjlj_exceptions) Init(-1)
1696 Enable Objective-C setjmp exception handling runtime.
1699 ObjC ObjC++ Var(flag_objc1_only)
1700 Conform to the Objective-C 1.0 language as implemented in GCC 4.0.
1703 C ObjC C++ ObjC++ LTO Var(flag_openacc)
1707 C ObjC C++ ObjC++ LTO Joined Var(flag_openacc_dims)
1708 Specify default OpenACC compute dimensions.
1711 C ObjC C++ ObjC++ LTO Var(flag_openmp)
1712 Enable OpenMP (implies -frecursive in Fortran).
1715 C ObjC C++ ObjC++ Var(flag_openmp_simd)
1716 Enable OpenMP's SIMD directives.
1720 Recognize C++ keywords like \"compl\" and \"xor\".
1724 Does nothing. Preserved for backward compatibility.
1731 Look for and use PCH files even when preprocessing.
1734 C++ ObjC++ Var(flag_permissive)
1735 Downgrade conformance errors to warnings.
1738 C ObjC Var(flag_plan9_extensions)
1739 Enable Plan 9 language extensions.
1743 Treat the input file as already preprocessed.
1745 ftrack-macro-expansion
1746 C ObjC C++ ObjC++ JoinedOrMissing RejectNegative UInteger
1747 ; converted into ftrack-macro-expansion=
1749 ftrack-macro-expansion=
1750 C ObjC C++ ObjC++ JoinedOrMissing RejectNegative UInteger
1751 -ftrack-macro-expansion=<0|1|2> Track locations of tokens coming from macro expansion and display them in error messages.
1754 C++ ObjC++ Var(flag_pretty_templates) Init(1)
1755 -fno-pretty-templates Do not pretty-print template specializations as the template signature followed by the arguments.
1757 fprintf-return-value
1758 C ObjC C++ ObjC++ LTO Optimization Var(flag_printf_return_value) Init(1)
1759 Treat known sprintf return values as constants.
1761 freplace-objc-classes
1762 ObjC ObjC++ LTO Var(flag_replace_objc_classes)
1763 Used in Fix-and-Continue mode to indicate that object files may be swapped in at runtime.
1766 C++ ObjC++ Deprecated
1767 Deprecated in GCC 10. This switch has no effect.
1770 C++ ObjC++ Optimization Var(flag_rtti) Init(1)
1771 Generate run time type descriptor information.
1774 C ObjC C++ ObjC++ LTO Optimization Var(flag_short_enums)
1775 Use the narrowest integer type possible for enumeration types.
1778 C ObjC C++ ObjC++ LTO Optimization Var(flag_short_wchar)
1779 Force the underlying type for \"wchar_t\" to be \"unsigned short\".
1782 C ObjC C++ ObjC++ Var(flag_signed_bitfields) Init(1)
1783 When \"signed\" or \"unsigned\" is not given make the bitfield signed.
1786 C ObjC C++ ObjC++ LTO Var(flag_signed_char)
1787 Make \"char\" signed by default.
1790 C++ ObjC++ Var(flag_sized_deallocation) Init(-1)
1791 Enable C++14 sized deallocation support.
1794 C++ ObjC++ Deprecated
1797 C ObjC Joined RejectNegative Enum(sso_struct) Var(default_sso) Init(SSO_NATIVE)
1798 -fsso-struct=[big-endian|little-endian|native] Set the default scalar storage order.
1801 Name(sso_struct) Type(enum scalar_storage_order_kind) UnknownError(unrecognized scalar storage order value %qs)
1804 Enum(sso_struct) String(big-endian) Value(SSO_BIG_ENDIAN)
1807 Enum(sso_struct) String(little-endian) Value(SSO_LITTLE_ENDIAN)
1810 Enum(sso_struct) String(native) Value(SSO_NATIVE)
1813 C++ ObjC++ Var(flag_detailed_statistics)
1814 Display statistics accumulated during compilation.
1817 C++ ObjC++ Optimization Var(flag_strict_enums)
1818 Assume that values of enumeration type are always within the minimum range of that type.
1821 C++ ObjC++ Deprecated
1824 C++ ObjC++ Common Alias(fstrong-eval-order=, all, none)
1825 Follow the C++17 evaluation order requirements for assignment expressions,
1826 shift, member function calls, etc.
1829 C++ ObjC++ Common Var(flag_strong_eval_order) Joined Enum(strong_eval_order) RejectNegative Init(-1)
1830 Follow the C++17 evaluation order requirements for assignment expressions,
1831 shift, member function calls, etc.
1834 Name(strong_eval_order) Type(int)
1837 Enum(strong_eval_order) String(none) Value(0)
1840 Enum(strong_eval_order) String(some) Value(1)
1843 Enum(strong_eval_order) String(all) Value(2)
1846 C ObjC C++ ObjC++ Joined RejectNegative UInteger
1847 -ftabstop=<number> Distance between tab stops for column reporting.
1849 ftemplate-backtrace-limit=
1850 C++ ObjC++ Joined RejectNegative UInteger Var(template_backtrace_limit) Init(10)
1851 Set the maximum number of template instantiation notes for a single warning or error.
1854 C++ ObjC++ Joined RejectNegative Undocumented Alias(ftemplate-depth=)
1857 C++ ObjC++ Joined RejectNegative UInteger
1858 -ftemplate-depth=<number> Specify maximum template instantiation depth.
1861 C++ ObjC++ Deprecated
1864 C++ ObjC++ Optimization Var(flag_threadsafe_statics) Init(1)
1865 -fno-threadsafe-statics Do not generate thread-safe code for initializing local statics.
1868 C ObjC C++ ObjC++ Var(flag_signed_bitfields, 0)
1869 When \"signed\" or \"unsigned\" is not given make the bitfield unsigned.
1872 C ObjC C++ ObjC++ LTO Var(flag_signed_char, 0)
1873 Make \"char\" unsigned by default.
1876 C++ ObjC++ Var(flag_use_cxa_atexit) Init(DEFAULT_USE_CXA_ATEXIT)
1877 Use __cxa_atexit to register destructors.
1879 fuse-cxa-get-exception-ptr
1880 C++ ObjC++ Var(flag_use_cxa_get_exception_ptr) Init(2)
1881 Use __cxa_get_exception_ptr in exception handling.
1883 fvisibility-inlines-hidden
1885 Marks all inlined functions and methods as having hidden visibility.
1887 fvisibility-ms-compat
1888 C++ ObjC++ Var(flag_visibility_ms_compat)
1889 Changes visibility to match Microsoft Visual Studio by default.
1892 C++ ObjC++ Deprecated
1893 No longer supported.
1896 C++ ObjC++ Deprecated
1897 No longer supported.
1900 C++ ObjC++ Var(flag_weak) Init(1)
1901 Emit common-like symbols as weak symbols.
1904 C ObjC C++ ObjC++ Joined RejectNegative
1905 -fwide-exec-charset=<cset> Convert all wide strings and character constants to character set <cset>.
1908 C ObjC C++ ObjC++ Var(flag_working_directory) Init(-1)
1909 Generate a #line directive pointing at the current working directory.
1912 C++ ObjC++ Deprecated
1913 No longer supported.
1916 ObjC ObjC++ Var(flag_zero_link)
1917 Generate lazy class lookup (via objc_getClass()) for use in Zero-Link mode.
1920 ObjC ObjC++ Driver Var(flag_gen_declaration) RejectNegative
1921 Dump declarations to a .decl file.
1923 femit-struct-debug-baseonly
1925 -femit-struct-debug-baseonly Aggressive reduced debug info for structs.
1927 femit-struct-debug-reduced
1929 -femit-struct-debug-reduced Conservative reduced debug info for structs.
1931 femit-struct-debug-detailed=
1932 C ObjC C++ ObjC++ Joined
1933 -femit-struct-debug-detailed=<spec-list> Detailed reduced debug info for structs.
1935 fext-numeric-literals
1936 C++ ObjC++ Var(flag_ext_numeric_literals) Init(1)
1937 Interpret imaginary, fixed-point, or other gnu number suffix as the corresponding
1938 number literal rather than a user-defined number literal.
1941 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1942 -idirafter <dir> Add <dir> to the end of the system include path.
1945 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
1946 -imacros <file> Accept definition of macros in <file>.
1949 C ObjC C++ ObjC++ Joined Separate
1950 -imultilib <dir> Set <dir> to be the multilib include subdirectory.
1953 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
1954 -include <file> Include the contents of <file> before other files.
1957 C ObjC C++ ObjC++ Joined Separate
1958 -iprefix <path> Specify <path> as a prefix for next two options.
1961 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1962 -isysroot <dir> Set <dir> to be the system root directory.
1965 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1966 -isystem <dir> Add <dir> to the start of the system include path.
1969 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1970 -iquote <dir> Add <dir> to the end of the quote include path.
1973 C ObjC C++ ObjC++ Joined Separate
1974 -iwithprefix <dir> Add <dir> to the end of the system include path.
1977 C ObjC C++ ObjC++ Joined Separate
1978 -iwithprefixbefore <dir> Add <dir> to the end of the main include path.
1981 C Undocumented RejectDriver
1988 Do not search standard system include directories (those specified with -isystem will still be used).
1992 Do not search standard system include directories for C++.
1995 C ObjC C++ ObjC++ Joined Separate
1996 ; Documented in common.opt
1999 C ObjC C++ ObjC++ Alias(Wpedantic)
2000 ; Documented in common.opt
2002 print-objc-runtime-info
2004 Generate C header of platform-specific features.
2008 Remap file names when including files.
2012 Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum.
2015 C++ ObjC++ Alias(std=c++98)
2016 Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum.
2020 Conform to the ISO 2011 C++ standard.
2023 C++ ObjC++ Alias(std=c++11) Undocumented
2024 Deprecated in favor of -std=c++11.
2027 C++ ObjC++ Alias(std=c++14) Undocumented
2028 Deprecated in favor of -std=c++14.
2032 Conform to the ISO 2014 C++ standard.
2035 C++ ObjC++ Alias(std=c++17) Undocumented
2036 Deprecated in favor of -std=c++17.
2040 Conform to the ISO 2017 C++ standard.
2044 Conform to the ISO 2020(?) C++ draft standard (experimental and incomplete support).
2048 Conform to the ISO 2011 C standard.
2051 C ObjC Alias(std=c11)
2052 Deprecated in favor of -std=c11.
2056 Conform to the ISO 2017 C standard (published in 2018).
2059 C ObjC Alias(std=c17)
2060 Conform to the ISO 2017 C standard (published in 2018).
2064 Conform to the ISO 202X C standard draft (experimental and incomplete support).
2067 C ObjC Alias(std=c90)
2068 Conform to the ISO 1990 C standard.
2072 Conform to the ISO 1990 C standard.
2076 Conform to the ISO 1999 C standard.
2079 C ObjC Alias(std=c99)
2080 Deprecated in favor of -std=c99.
2084 Conform to the ISO 1998 C++ standard revised by the 2003 technical
2085 corrigendum with GNU extensions.
2088 C++ ObjC++ Alias(std=gnu++98)
2089 Conform to the ISO 1998 C++ standard revised by the 2003 technical
2090 corrigendum with GNU extensions.
2094 Conform to the ISO 2011 C++ standard with GNU extensions.
2097 C++ ObjC++ Alias(std=gnu++11) Undocumented
2098 Deprecated in favor of -std=gnu++11.
2101 C++ ObjC++ Alias(std=gnu++14) Undocumented
2102 Deprecated in favor of -std=gnu++14.
2106 Conform to the ISO 2014 C++ standard with GNU extensions.
2109 C++ ObjC++ Alias(std=gnu++17) Undocumented
2110 Deprecated in favor of -std=gnu++17.
2114 Conform to the ISO 2017 C++ standard with GNU extensions.
2118 Conform to the ISO 2020(?) C++ draft standard with GNU extensions (experimental and incomplete support).
2122 Conform to the ISO 2011 C standard with GNU extensions.
2125 C ObjC Alias(std=gnu11)
2126 Deprecated in favor of -std=gnu11.
2130 Conform to the ISO 2017 C standard (published in 2018) with GNU extensions.
2133 C ObjC Alias(std=gnu17)
2134 Conform to the ISO 2017 C standard (published in 2018) with GNU extensions.
2138 Conform to the ISO 202X C standard draft with GNU extensions (experimental and incomplete support).
2141 C ObjC Alias(std=gnu90)
2142 Conform to the ISO 1990 C standard with GNU extensions.
2146 Conform to the ISO 1990 C standard with GNU extensions.
2150 Conform to the ISO 1999 C standard with GNU extensions.
2153 C ObjC Alias(std=gnu99)
2154 Deprecated in favor of -std=gnu99.
2157 C ObjC Alias(std=c90)
2158 Conform to the ISO 1990 C standard.
2162 Conform to the ISO 1990 C standard as amended in 1994.
2165 C ObjC Alias(std=c99)
2166 Conform to the ISO 1999 C standard.
2169 C ObjC Alias(std=c99)
2170 Deprecated in favor of -std=iso9899:1999.
2173 C ObjC Alias(std=c11)
2174 Conform to the ISO 2011 C standard.
2177 C ObjC Alias(std=c17)
2178 Conform to the ISO 2017 C standard (published in 2018).
2181 C ObjC Alias(std=c17)
2182 Conform to the ISO 2017 C standard (published in 2018).
2189 Enable traditional preprocessing.
2193 -trigraphs Support ISO C trigraphs.
2196 C ObjC C++ ObjC++ Var(flag_undef)
2197 Do not predefine system-specific and GCC-specific macros.
2201 ; Documented in common.opt
2205 ; Documented in common.opt
2207 ; This comment is to ensure we retain the blank line above.