1 ; Options for the C, ObjC, C++ and ObjC++ front ends.
2 ; Copyright (C) 2003-2021 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 C++ Module dependency information.
249 Generate phony targets for all headers.
252 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing makefile target after %qs)
253 -MQ <target> Add a target that may require quoting.
256 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing makefile target after %qs)
257 -MT <target> Add a target that does not require quoting.
261 Do not generate #line directives.
264 C ObjC C++ ObjC++ Joined Separate MissingArgError(macro name missing after %qs)
265 -U<macro> Undefine <macro>.
268 C ObjC C++ ObjC++ LTO Var(warn_nsobject_attribute) Warning Init(1)
269 Warn if the NSObject attribute is applied to a non-typedef.
272 C ObjC C++ ObjC++ LTO Var(warn_abi) Warning
273 Warn about things that will change when compiling with an ABI-compliant compiler.
276 C ObjC C++ ObjC++ LTO Joined RejectNegative UInteger Warning
277 Warn about things that change between the current -fabi-version and the specified version.
280 C++ ObjC++ Var(warn_abi_tag) Warning
281 Warn if a subobject has an abi_tag attribute that the complete object type does not have.
284 C ObjC C++ ObjC++ LTO Var(warn_psabi) Init(1) Warning Undocumented LangEnabledBy(C ObjC C++ ObjC++,Wabi)
287 C ObjC Var(warn_absolute_value) Warning EnabledBy(Wextra)
288 Warn on suspicious calls of standard functions computing absolute values.
291 C ObjC C++ ObjC++ Var(warn_address) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
292 Warn about suspicious uses of memory addresses.
295 Name(warn_aligned_new_level) Type(int) UnknownError(argument %qs to %<-Waligned-new%> not recognized)
298 Enum(warn_aligned_new_level) String(none) Value(0)
301 Enum(warn_aligned_new_level) String(global) Value(1)
304 Enum(warn_aligned_new_level) String(all) Value(2)
307 C++ ObjC++ Alias(Waligned-new=,global,none)
308 Warn about 'new' of type with extended alignment without -faligned-new.
311 C++ ObjC++ Var(warn_aligned_new) Enum(warn_aligned_new_level) Joined RejectNegative Warning LangEnabledBy(C++ ObjC++,Wall,1,0)
312 -Waligned-new=[none|global|all] Warn even if 'new' uses a class member allocation function.
315 C ObjC C++ ObjC++ Warning
316 Enable most warning messages.
319 C ObjC C++ ObjC++ Var(warn_alloca) Warning
320 Warn on any use of alloca.
322 Walloc-size-larger-than=
323 C ObjC C++ LTO ObjC++ Var(warn_alloc_size_limit) Joined Host_Wide_Int ByteSize Warning Init(HOST_WIDE_INT_MAX)
324 -Walloc-size-larger-than=<bytes> Warn for calls to allocation functions that
325 attempt to allocate objects larger than the specified number of bytes.
327 Wno-alloc-size-larger-than
328 C ObjC C++ LTO ObjC++ Alias(Walloc-size-larger-than=,18446744073709551615EiB,none) Warning
329 Disable Walloc-size-larger-than= warning. Equivalent to Walloc-size-larger-than=<SIZE_MAX> or larger.
332 C ObjC C++ ObjC++ Var(warn_alloc_zero) Warning
333 Warn for calls to allocation functions that specify zero bytes.
336 C ObjC C++ LTO ObjC++ Var(warn_alloca_limit) Warning Joined Host_Wide_Int ByteSize Init(HOST_WIDE_INT_MAX)
337 -Walloca-larger-than=<number> Warn on unbounded uses of
338 alloca, and on bounded uses of alloca whose bound can be larger than
341 Wno-alloca-larger-than
342 C ObjC C++ LTO ObjC++ Alias(Walloca-larger-than=,18446744073709551615EiB,none) Warning
343 Disable Walloca-larger-than= warning. Equivalent to Walloca-larger-than=<SIZE_MAX> or larger.
346 LangEnabledBy(C ObjC C++ LTO ObjC++)
350 LangEnabledBy(C ObjC C++ LTO ObjC++,Wall,1,0)
354 C ObjC C++ ObjC++ Var(warn_array_compare) Warning LangEnabledBy(C ObjC C++ ObjC++, Wall)
355 Warn about comparisons between two operands of array type.
358 C ObjC C++ ObjC++ Warning Alias(Warray-parameter=, 2, 0)
359 Warn about mismatched declarations of array parameters and unsafe accesses to them.
362 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_array_parameter) IntegerRange(0, 2) LangEnabledBy(C ObjC C++ ObjC++,Wall, 2, 0) Warning
363 Warn about mismatched declarations of array parameters and unsafe accesses to them.
366 C ObjC C++ ObjC++ Var(warn_zero_length_bounds) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
367 Warn about accesses to interior zero-length array members.
370 ObjC ObjC++ Var(warn_assign_intercept) Warning
371 Warn whenever an Objective-C assignment is being intercepted by the garbage collector.
374 C ObjC Var(warn_bad_function_cast) Warning
375 Warn about casting functions to incompatible types.
378 C ObjC C++ ObjC++ Var(warn_bool_compare) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
379 Warn about boolean expression compared with an integer value different from true/false.
382 C ObjC C++ ObjC++ Var(warn_bool_op) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
383 Warn about certain operations on boolean expressions.
386 C ObjC C++ ObjC++ Var(warn_frame_address) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
387 Warn when __builtin_frame_address or __builtin_return_address is used unsafely.
389 Wbuiltin-declaration-mismatch
390 C ObjC C++ ObjC++ Var(warn_builtin_declaration_mismatch) Init(1) Warning
391 Warn when a built-in function is declared with the wrong signature.
393 Wbuiltin-macro-redefined
394 C ObjC C++ ObjC++ CPP(warn_builtin_macro_redefined) CppReason(CPP_W_BUILTIN_MACRO_REDEFINED) Var(cpp_warn_builtin_macro_redefined) Init(1) Warning
395 Warn when a built-in preprocessor macro is undefined or redefined.
398 C ObjC CPP(cpp_warn_c11_c2x_compat) CppReason(CPP_W_C11_C2X_COMPAT) Var(warn_c11_c2x_compat) Init(-1) Warning
399 Warn about features not present in ISO C11, but present in ISO C2X.
402 C ObjC CPP(cpp_warn_c90_c99_compat) CppReason(CPP_W_C90_C99_COMPAT) Var(warn_c90_c99_compat) Init(-1) Warning
403 Warn about features not present in ISO C90, but present in ISO C99.
406 C ObjC Var(warn_c99_c11_compat) Init(-1) Warning
407 Warn about features not present in ISO C99, but present in ISO C11.
410 C ObjC Var(warn_cxx_compat) CPP(warn_cxx_operator_names) CppReason(CPP_W_CXX_OPERATOR_NAMES) Init(0) Warning
411 Warn about C constructs that are not in the common subset of C and C++.
414 C++ ObjC++ Warning Alias(Wc++11-compat) Undocumented
417 C++ ObjC++ Var(warn_cxx11_compat) Warning LangEnabledBy(C++ ObjC++,Wall) Init(0) CPP(cpp_warn_cxx11_compat) CppReason(CPP_W_CXX11_COMPAT)
418 Warn about C++ constructs whose meaning differs between ISO C++ 1998 and ISO C++ 2011.
421 C++ ObjC++ Var(warn_cxx14_compat) Warning LangEnabledBy(C++ ObjC++,Wall)
422 Warn about C++ constructs whose meaning differs between ISO C++ 2011 and ISO C++ 2014.
425 C++ ObjC++ Warning Alias(Wc++17-compat) Undocumented
428 C++ ObjC++ Var(warn_cxx17_compat) Warning LangEnabledBy(C++ ObjC++,Wall)
429 Warn about C++ constructs whose meaning differs between ISO C++ 2014 and ISO C++ 2017.
432 C++ ObjC++ Warning Alias(Wc++20-compat) Undocumented
435 C++ ObjC++ Var(warn_cxx20_compat) Warning LangEnabledBy(C++ ObjC++,Wall)
436 Warn about C++ constructs whose meaning differs between ISO C++ 2017 and ISO C++ 2020.
439 C++ ObjC++ Var(warn_cxx11_extensions) Warning LangEnabledBy(C++ ObjC++) Init(1)
440 Warn about C++11 constructs in code compiled with an older standard.
443 C++ ObjC++ Var(warn_cxx14_extensions) Warning LangEnabledBy(C++ ObjC++) Init(1)
444 Warn about C++14 constructs in code compiled with an older standard.
447 C++ ObjC++ Var(warn_cxx17_extensions) Warning LangEnabledBy(C++ ObjC++) Init(1)
448 Warn about C++17 constructs in code compiled with an older standard.
451 C++ ObjC++ Var(warn_cxx20_extensions) Warning LangEnabledBy(C++ ObjC++) Init(1)
452 Warn about C++20 constructs in code compiled with an older standard.
455 C++ ObjC++ Var(warn_cxx23_extensions) Warning LangEnabledBy(C++ ObjC++) Init(1)
456 Warn about C++23 constructs in code compiled with an older standard.
459 C ObjC C++ ObjC++ Var(warn_cast_function_type) Warning EnabledBy(Wextra)
460 Warn about casts between incompatible function types.
463 C ObjC C++ ObjC++ Var(warn_cast_qual) Warning
464 Warn about casts which discard qualifiers.
467 C++ ObjC++ Warning Alias(Wcatch-value=, 1, 0)
468 Warn about catch handlers of non-reference type.
471 C++ ObjC++ Var(warn_catch_value) Warning Joined RejectNegative UInteger LangEnabledBy(C++ ObjC++,Wall, 1, 0) IntegerRange(0, 3)
472 Warn about catch handlers of non-reference type.
475 C ObjC C++ ObjC++ Var(warn_char_subscripts) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
476 Warn about subscripts whose type is \"char\".
479 C ObjC C++ ObjC++ Warning WarnRemoved
480 Removed in GCC 9. This switch has no effect.
483 C ObjC C++ ObjC++ Var(warn_clobbered) Warning EnabledBy(Wextra)
484 Warn about variables that might be changed by \"longjmp\" or \"vfork\".
487 C++ ObjC++ Var(warn_comma_subscript) Warning
488 Warn about uses of a comma operator within a subscripting expression.
491 C ObjC C++ ObjC++ CPP(warn_comments) CppReason(CPP_W_COMMENTS) Var(cpp_warn_comment) Init(0) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
492 Warn about possibly nested block comments, and C++ comments spanning more than one physical line.
495 C ObjC C++ ObjC++ Warning Alias(Wcomment)
496 Synonym for -Wcomment.
498 Wconditionally-supported
499 C++ ObjC++ Var(warn_conditionally_supported) Warning
500 Warn for conditionally-supported constructs.
503 C ObjC C++ ObjC++ Var(warn_conversion) Warning
504 Warn for implicit type conversions that may change a value.
507 C++ ObjC++ Var(warn_conversion_null) Init(1) Warning
508 Warn for converting NULL from/to a non-pointer type.
511 C ObjC C++ ObjC++ CppReason(CPP_W_WARNING_DIRECTIVE)
512 ; Documented in common.opt
514 Wctad-maybe-unsupported
515 C++ ObjC++ Var(warn_ctad_maybe_unsupported) Warning
516 Warn when performing class template argument deduction on a type with no
520 C++ ObjC++ Var(warn_ctor_dtor_privacy) Warning
521 Warn when all constructors and destructors are private.
524 C ObjC C++ ObjC++ Var(warn_dangling_else) Warning LangEnabledBy(C ObjC C++ ObjC++,Wparentheses)
525 Warn about dangling else.
528 C ObjC C++ ObjC++ CPP(warn_date_time) CppReason(CPP_W_DATE_TIME) Var(cpp_warn_date_time) Init(0) Warning
529 Warn about __TIME__, __DATE__ and __TIMESTAMP__ usage.
531 Wdeclaration-after-statement
532 C ObjC Var(warn_declaration_after_statement) Init(-1) Warning
533 Warn when a declaration is found after a statement.
536 C++ ObjC++ Var(warn_delete_incomplete) Init(1) Warning
537 Warn when deleting a pointer to incomplete type.
539 Wdelete-non-virtual-dtor
540 C++ ObjC++ Var(warn_delnonvdtor) Warning LangEnabledBy(C++ ObjC++,Wall || Weffc++)
541 Warn about deleting polymorphic objects with non-virtual destructors.
544 C C++ ObjC ObjC++ CPP(cpp_warn_deprecated) CppReason(CPP_W_DEPRECATED)
545 ; Documented in common.opt
548 C++ ObjC++ Var(warn_deprecated_copy) Warning LangEnabledBy(C++ ObjC++, Wextra)
549 Mark implicitly-declared copy operations as deprecated if the class has a
550 user-provided copy operation.
552 Wdeprecated-copy-dtor
553 C++ ObjC++ Var(warn_deprecated_copy, 2) Warning
554 Mark implicitly-declared copy operations as deprecated if the class has a
555 user-provided copy operation or destructor.
557 Wdeprecated-enum-enum-conversion
558 C++ ObjC++ Var(warn_deprecated_enum_enum_conv) Warning
559 Warn about deprecated arithmetic conversions on operands of enumeration types.
561 Wdeprecated-enum-float-conversion
562 C++ ObjC++ Var(warn_deprecated_enum_float_conv) Warning
563 Warn about deprecated arithmetic conversions on operands where one is of enumeration
564 type and the other is of a floating-point type.
567 C ObjC Var(warn_designated_init) Init(1) Warning
568 Warn about positional initialization of structs requiring designated initializers.
570 Wdiscarded-array-qualifiers
571 C ObjC Var(warn_discarded_array_qualifiers) Init(1) Warning
572 Warn if qualifiers on arrays which are pointer targets are discarded.
574 Wdiscarded-qualifiers
575 C ObjC Var(warn_discarded_qualifiers) Init(1) Warning
576 Warn if type qualifiers on pointers are discarded.
579 C ObjC C++ ObjC++ Var(warn_div_by_zero) Init(1) Warning
580 Warn about compile-time integer division by zero.
583 C ObjC C++ ObjC++ Var(warn_duplicated_branches) Init(0) Warning
584 Warn about duplicated branches in if-else statements.
587 C ObjC C++ ObjC++ Var(warn_duplicated_cond) Init(0) Warning
588 Warn about duplicated conditions in an if-else-if chain.
591 C++ ObjC++ Var(warn_ecpp) Warning
592 Warn about violations of Effective C++ style rules.
595 C ObjC C++ ObjC++ Var(warn_empty_body) Warning EnabledBy(Wextra)
596 Warn about an empty body in an if or else statement.
599 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)
600 Warn about stray tokens after #else and #endif.
603 C ObjC C++ ObjC++ Var(warn_enum_compare) Init(-1) Warning LangEnabledBy(C ObjC,Wall || Wc++-compat)
604 Warn about comparison of different enum types.
607 C ObjC C++ ObjC++ Var(warn_enum_conversion) Init(0) Warning LangEnabledBy(C ObjC,Wextra)
608 Warn about implicit conversion of enum types.
612 ; Documented in common.opt
614 Werror-implicit-function-declaration
615 C ObjC RejectNegative Warning Alias(Werror=, implicit-function-declaration)
616 This switch is deprecated; use -Werror=implicit-function-declaration instead.
619 C++ ObjC++ Var(warn_exceptions) Init(1) Warning
620 Warn when an exception handler is shadowed by another handler.
623 C ObjC C++ ObjC++ Warning
627 C++ ObjC++ Var(warn_extra_semi) Warning
628 Warn about semicolon after in-class function definition.
631 C ObjC C++ ObjC++ Var(warn_float_conversion) Warning LangEnabledBy(C ObjC C++ ObjC++,Wconversion)
632 Warn for implicit type conversions that cause loss of floating point precision.
635 C ObjC C++ ObjC++ Var(warn_float_equal) Warning
636 Warn if testing floating point numbers for equality.
639 C ObjC C++ ObjC++ Warning Alias(Wformat=, 1, 0)
640 Warn about printf/scanf/strftime/strfmon format string anomalies.
643 C ObjC C++ ObjC++ Var(warn_format_contains_nul) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
644 Warn about format strings that contain NUL bytes.
647 C ObjC C++ ObjC++ Var(warn_format_diag) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
648 Warn about GCC format strings with strings unsuitable for diagnostics.
651 C ObjC C++ ObjC++ Var(warn_format_extra_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
652 Warn if passing too many arguments to a function for its format string.
655 C ObjC C++ ObjC++ Var(warn_format_nonliteral) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 2, 0)
656 Warn about format strings that are not literals.
659 C ObjC C++ LTO ObjC++ Warning Alias(Wformat-overflow=, 1, 0) IntegerRange(0, 2)
660 Warn about function calls with format strings that write past the end
661 of the destination region. Same as -Wformat-overflow=1.
664 C ObjC C++ ObjC++ Var(warn_format_security) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 2, 0)
665 Warn about possible security problems with format functions.
668 C ObjC C++ ObjC++ Var(warn_format_signedness) Warning
669 Warn about sign differences with format functions.
672 C ObjC C++ LTO ObjC++ Warning Alias(Wformat-truncation=, 1, 0)
673 Warn about calls to snprintf and similar functions that truncate output.
674 Same as -Wformat-truncation=1.
677 C ObjC C++ ObjC++ Var(warn_format_y2k) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 2, 0)
678 Warn about strftime formats yielding 2-digit years.
681 C ObjC C++ ObjC++ Var(warn_format_zero_length) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 1, 0)
682 Warn about zero-length formats.
685 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_format) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0) IntegerRange(0, 2)
686 Warn about printf/scanf/strftime/strfmon format string anomalies.
689 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)
690 Warn about function calls with format strings that write past the end
691 of the destination region.
694 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)
695 Warn about calls to snprintf and similar functions that truncate output.
698 C ObjC C++ ObjC++ Var(warn_if_not_aligned) Init(1) Warning
699 Warn when the field in a struct is not aligned.
702 C C++ Var(warn_ignored_qualifiers) Warning EnabledBy(Wextra)
703 Warn whenever type qualifiers are ignored.
706 C C++ Var(warn_ignored_attributes) Init(1) Warning
707 Warn whenever attributes are ignored.
710 C++ ObjC++ Var(warn_inaccessible_base) Init(1) Warning
711 Warn when a base is inaccessible in derived due to ambiguity.
713 Wincompatible-pointer-types
714 C ObjC Var(warn_incompatible_pointer_types) Init(1) Warning
715 Warn when there is a conversion between pointers that have incompatible types.
717 Waddress-of-packed-member
718 C ObjC C++ ObjC++ Var(warn_address_of_packed_member) Init(1) Warning
719 Warn when the address of packed member of struct or union is taken.
722 C ObjC C++ ObjC++ Var(warn_init_self) Warning LangEnabledBy(C++ ObjC++,Wall)
723 Warn about variables which are initialized to themselves.
726 C++ ObjC++ Var(warn_init_list) Warning Init(1)
727 Warn about uses of std::initializer_list that can result in dangling pointers.
730 C++ ObjC++ Var(warn_interference_size) Warning Init(1)
731 Warn about nonsensical values of --param destructive-interference-size or
732 constructive-interference-size.
735 C ObjC Var(warn_implicit) Warning LangEnabledBy(C ObjC,Wall)
736 Warn about implicit declarations.
738 Wimplicit-fallthrough=
739 LangEnabledBy(C ObjC C++ ObjC++,Wextra,3,0)
743 C ObjC C++ ObjC++ Var(warn_double_promotion) Warning
744 Warn about implicit conversions from \"float\" to \"double\".
746 Wexpansion-to-defined
747 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)
748 Warn if \"defined\" is used outside #if.
750 Wimplicit-function-declaration
751 C ObjC Var(warn_implicit_function_declaration) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit)
752 Warn about implicit function declarations.
755 C ObjC Var(warn_implicit_int) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit)
756 Warn when a declaration does not specify a type.
759 C ObjC C++ ObjC++ Undocumented Ignore
761 Winherited-variadic-ctor
762 C++ ObjC++ Var(warn_inh_var_ctor) Init(1) Warning
763 Warn about C++11 inheriting constructors when the base has a variadic constructor.
766 C ObjC Var(warn_int_conversion) Init(1) Warning
767 Warn about incompatible integer to pointer and pointer to integer conversions.
770 C ObjC C++ ObjC++ Var(warn_int_in_bool_context) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
771 Warn for suspicious integer expressions in boolean context.
774 C ObjC C++ ObjC++ Var(warn_int_to_pointer_cast) Init(1) Warning
775 Warn when there is a cast to a pointer from an integer of a different size.
778 C++ ObjC++ Var(warn_invalid_offsetof) Init(1) Warning
779 Warn about invalid uses of the \"offsetof\" macro.
782 C ObjC C++ ObjC++ CPP(warn_invalid_pch) CppReason(CPP_W_INVALID_PCH) Var(cpp_warn_invalid_pch) Init(0) Warning
783 Warn about PCH files that are found but not used.
786 C ObjC Var(warn_jump_misses_init) Warning LangEnabledby(C ObjC,Wc++-compat)
787 Warn when a jump misses a variable initialization.
790 C++ ObjC++ CPP(warn_literal_suffix) CppReason(CPP_W_LITERAL_SUFFIX) Var(cpp_warn_literal_suffix) Init(1) Warning
791 Warn when a string or character literal is followed by a ud-suffix which does not begin with an underscore.
794 C ObjC C++ ObjC++ Var(warn_logical_op) Init(0) Warning
795 Warn when a logical operator is suspiciously always evaluating to true or false.
797 Wlogical-not-parentheses
798 C ObjC C++ ObjC++ Var(warn_logical_not_paren) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
799 Warn when logical not is used on the left hand side operand of a comparison.
802 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)
803 Do not warn about using \"long long\" when -pedantic.
806 C ObjC C++ ObjC++ Var(warn_main) Init(-1) Warning LangEnabledBy(C ObjC,Wall, 2, 0)
807 Warn about suspicious declarations of \"main\".
810 LangEnabledBy(C ObjC C++ ObjC++,Wpedantic, 2, 0)
813 Wmemset-transposed-args
814 C ObjC C++ ObjC++ Var(warn_memset_transposed_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
815 Warn about suspicious calls to memset where the third argument is constant literal zero and the second is not.
818 C ObjC C++ ObjC++ Var(warn_memset_elt_size) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
819 Warn about suspicious calls to memset where the third argument contains the number of elements not multiplied by the element size.
821 Wmisleading-indentation
822 C C++ Common Var(warn_misleading_indentation) Warning LangEnabledBy(C C++,Wall)
823 Warn when the indentation of the code does not reflect the block structure.
826 C ObjC C++ ObjC++ Var(warn_mismatched_alloc) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
827 Warn for deallocation calls with arguments returned from mismatched allocation
830 Wmismatched-new-delete
831 C++ ObjC++ Var(warn_mismatched_new_delete) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
832 Warn for mismatches between calls to operator new or delete and the corresponding
833 call to the allocation or deallocation function.
836 C++ ObjC++ Var(warn_mismatched_tags) Warning
837 Warn when a class is redeclared or referenced using a mismatched class-key.
840 C ObjC C++ ObjC++ Var(warn_missing_braces) Warning LangEnabledBy(C ObjC,Wall)
841 Warn about possibly missing braces around initializers.
843 Wmissing-declarations
844 C ObjC C++ ObjC++ Var(warn_missing_declarations) Warning
845 Warn about global functions without previous declarations.
847 Wmissing-field-initializers
848 C ObjC C++ ObjC++ Var(warn_missing_field_initializers) Warning EnabledBy(Wextra)
849 Warn about missing fields in struct initializers.
852 C++ ObjC++ Var(warn_missing_requires) Init(1) Warning
853 Warn about likely missing requires keyword.
855 Wmultistatement-macros
856 C ObjC C++ ObjC++ Var(warn_multistatement_macros) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
857 Warn about unsafe macros expanding to multiple statements used as a body of a clause such as if, else, while, switch, or for.
859 Wmultiple-inheritance
860 C++ ObjC++ Var(warn_multiple_inheritance) Warning
861 Warn on direct multiple inheritance.
864 C++ ObjC++ Var(warn_namespaces) Warning
865 Warn on namespace definition.
868 C ObjC C++ ObjC++ Var(warn_packed_not_aligned) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
869 Warn when fields in a struct with the packed attribute are misaligned.
871 Wrange-loop-construct
872 C++ ObjC++ Var(warn_range_loop_construct) Warning LangEnabledBy(C++ ObjC++,Wall)
873 Warn when a range-based for-loop is creating unnecessary copies.
876 C++ ObjC++ Var(warn_redundant_tags) Warning
877 Warn when a class or enumerated type is referenced using a redundant class-key.
880 C++ ObjC++ Var(warn_sized_deallocation) Warning EnabledBy(Wextra)
881 Warn about missing sized deallocation functions.
884 C ObjC C++ ObjC++ Var(warn_sizeof_pointer_div) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
885 Warn about suspicious divisions of two sizeof expressions that don't work correctly with pointers.
888 C ObjC C++ ObjC++ Var(warn_sizeof_array_div) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
889 Warn about divisions of two sizeof operators when the first one is applied
890 to an array and the divisor does not equal the size of the array element.
892 Wsizeof-pointer-memaccess
893 C ObjC C++ ObjC++ Var(warn_sizeof_pointer_memaccess) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
894 Warn about suspicious length parameters to certain string functions if the argument uses sizeof.
896 Wsizeof-array-argument
897 C ObjC C++ ObjC++ Var(warn_sizeof_array_argument) Warning Init(1)
898 Warn when sizeof is applied on a parameter declared as an array.
901 C ObjC C++ LTO ObjC++ Warning Var(warn_string_compare) Warning LangEnabledBy(C ObjC C++ ObjC++, Wextra)
902 Warn about calls to strcmp and strncmp used in equality expressions that
903 are necessarily true or false due to the length of one and size of the other
907 C ObjC C++ LTO ObjC++ Warning Alias(Wstringop-overflow=, 2, 0)
908 Warn about buffer overflow in string manipulation functions like memcpy
912 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)
913 Under the control of Object Size type, warn about buffer overflow in string
914 manipulation functions like memcpy and strcpy.
917 C ObjC C++ LTO ObjC++ Var(warn_stringop_overread) Init(1) Warning LangEnabledBy(C ObjC C++ LTO ObjC++, Wall)
918 Warn about reading past the end of a source array in string manipulation functions like memchr and memcpy.
921 C ObjC C++ LTO ObjC++ Var(warn_stringop_truncation) Warning Init (1) LangEnabledBy(C ObjC C++ LTO ObjC++, Wall)
922 Warn about truncation in string manipulation functions like strncat and strncpy.
924 Wsuggest-attribute=format
925 C ObjC C++ ObjC++ Var(warn_suggest_attribute_format) Warning
926 Warn about functions which might be candidates for format attributes.
929 C++ ObjC++ Var(warn_override) Warning
930 Suggest that the override keyword be used when the declaration of a virtual
931 function overrides another.
934 C ObjC C++ ObjC++ Var(warn_switch) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
935 Warn about enumerated switches, with no default, missing a case.
938 C ObjC C++ ObjC++ Var(warn_switch_default) Warning
939 Warn about enumerated switches missing a \"default:\" statement.
942 C ObjC C++ ObjC++ Var(warn_switch_enum) Warning
943 Warn about all enumerated switches missing a specific case.
946 C ObjC C++ ObjC++ Var(warn_switch_bool) Warning Init(1)
947 Warn about switches with boolean controlling expression.
949 Wswitch-outside-range
950 C ObjC C++ ObjC++ Var(warn_switch_outside_range) Warning Init(1)
951 Warn about switch values that are outside of the switch's type range.
954 C++ ObjC++ Var(warn_templates) Warning
955 Warn on primary template declaration.
958 C ObjC C++ ObjC++ Var(warn_missing_attributes) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
959 Warn about declarations of entities that may be missing attributes
960 that related entities have been declared with.
962 Wmissing-format-attribute
963 C ObjC C++ ObjC++ Warning Alias(Wsuggest-attribute=format)
966 Wmissing-include-dirs
967 C ObjC C++ ObjC++ CPP(warn_missing_include_dirs) CppReason(CPP_W_MISSING_INCLUDE_DIRS) Var(cpp_warn_missing_include_dirs) Init(0) Warning
968 Warn about user-specified include directories that do not exist.
970 Wmissing-parameter-type
971 C ObjC Var(warn_missing_parameter_type) Warning EnabledBy(Wextra)
972 Warn about function parameters declared without a type specifier in K&R-style functions.
975 C ObjC Var(warn_missing_prototypes) Warning
976 Warn about global functions without prototypes.
979 C ObjC C++ ObjC++ WarnRemoved
982 C ObjC C++ ObjC++ CPP(warn_multichar) CppReason(CPP_W_MULTICHAR) Var(cpp_warn_multichar) Init(0) Warning
983 Warn about use of multi-character character constants.
986 C ObjC C++ ObjC++ Warning Var(warn_narrowing) Init(-1) LangEnabledBy(C++ ObjC++,Wall || Wc++11-compat)
987 Warn about narrowing conversions within { } that are ill-formed in C++11.
990 C ObjC Var(warn_nested_externs) Warning
991 Warn about \"extern\" declarations not at file scope.
994 C++ ObjC++ Var(warn_noexcept) Warning
995 Warn when a noexcept expression evaluates to false even though the expression can't actually throw.
998 C++ ObjC++ Warning Var(warn_noexcept_type) LangEnabledBy(C++ ObjC++,Wabi || Wc++17-compat)
999 Warn if C++17 noexcept function type will change the mangled name of a symbol.
1001 Wnon-template-friend
1002 C++ ObjC++ Var(warn_nontemplate_friend) Init(1) Warning
1003 Warn when non-templatized friend functions are declared within a template.
1006 C++ ObjC++ Var(warn_class_conversion) Init(1) Warning
1007 Warn when a conversion function will never be called due to the type it converts to.
1010 C++ ObjC++ Var(warn_class_memaccess) Warning LangEnabledBy(C++ ObjC++, Wall)
1011 Warn for unsafe raw memory writes to objects of class types.
1014 C++ ObjC++ Var(warn_nonvdtor) Warning LangEnabledBy(C++ ObjC++,Weffc++)
1015 Warn about non-virtual destructors.
1018 C ObjC C++ LTO ObjC++ Var(warn_nonnull) Warning LangEnabledBy(C ObjC C++ LTO ObjC++,Wformat=,warn_format >= 1,0)
1019 Warn about NULL being passed to argument slots marked as requiring non-NULL.
1022 C ObjC C++ LTO ObjC++ LangEnabledBy(C ObjC C++ LTO ObjC++,Wall)
1026 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
1030 C ObjC C++ ObjC++ Warning Alias(Wnormalized=,nfc,none)
1034 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)
1035 -Wnormalized=[none|id|nfc|nfkc] Warn about non-normalized Unicode strings.
1037 ; Required for these enum values.
1042 Name(cpp_normalize_level) Type(int) UnknownError(argument %qs to %<-Wnormalized%> not recognized)
1045 Enum(cpp_normalize_level) String(none) Value(normalized_none)
1048 Enum(cpp_normalize_level) String(nfkc) Value(normalized_KC)
1051 Enum(cpp_normalize_level) String(id) Value(normalized_identifier_C)
1054 Enum(cpp_normalize_level) String(nfc) Value(normalized_C)
1057 ObjC ObjC++ Var(warn_objc_root_class) Warning Init(1)
1058 Warn if a class interface has no superclass. Root classes may use an attribute
1059 to suppress this warning.
1062 C++ ObjC++ Var(warn_old_style_cast) Warning
1063 Warn if a C-style cast is used in a program.
1065 Wold-style-declaration
1066 C ObjC Var(warn_old_style_declaration) Warning EnabledBy(Wextra)
1067 Warn for obsolescent usage in a declaration.
1069 Wold-style-definition
1070 C ObjC Var(warn_old_style_definition) Init(-1) Warning
1071 Warn if an old-style parameter definition is used.
1073 Wopenacc-parallelism
1074 C C++ Var(warn_openacc_parallelism) Warning
1075 Warn about potentially suboptimal choices related to OpenACC parallelism.
1078 C C++ Var(warn_openmp_simd) Warning LangEnabledBy(C C++,Wall)
1079 Warn if a simd directive is overridden by the vectorizer cost model.
1082 C ObjC C++ ObjC++ Var(warn_overlength_strings) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic)
1083 Warn if a string is longer than the maximum portable length specified by the standard.
1086 C++ ObjC++ Var(warn_overloaded_virtual) Warning
1087 Warn about overloaded virtual function names.
1090 C ObjC Var(warn_override_init) Warning EnabledBy(Wextra)
1091 Warn about overriding initializers without side effects.
1093 Woverride-init-side-effects
1094 C ObjC Var(warn_override_init_side_effects) Init(1) Warning
1095 Warn about overriding initializers with side effects.
1097 Wpacked-bitfield-compat
1098 C ObjC C++ ObjC++ Var(warn_packed_bitfield_compat) Init(-1) Warning
1099 Warn about packed bit-fields whose offset changed in GCC 4.4.
1102 C ObjC C++ ObjC++ Var(warn_parentheses) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1103 Warn about possibly missing parentheses.
1106 C ObjC C++ ObjC++ CPP(cpp_pedantic) CppReason(CPP_W_PEDANTIC) Warning
1107 ; Documented in common.opt
1110 C++ ObjC++ Var(warn_pessimizing_move) Warning LangEnabledBy(C++ ObjC++, Wall)
1111 Warn about calling std::move on a local object in a return statement preventing copy elision.
1114 C++ ObjC++ Var(warn_pmf2ptr) Init(1) Warning
1115 Warn when converting the type of pointers to member functions.
1118 C ObjC C++ ObjC++ Var(warn_pointer_arith) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic)
1119 Warn about function pointer arithmetic.
1122 C ObjC Var(warn_pointer_sign) Warning LangEnabledBy(C ObjC,Wall || Wpedantic)
1123 Warn when a pointer differs in signedness in an assignment.
1126 C ObjC C++ ObjC++ Var(warn_pointer_compare) Init(1) Warning
1127 Warn when a pointer is compared with a zero character constant.
1129 Wpointer-to-int-cast
1130 C ObjC Var(warn_pointer_to_int_cast) Init(1) Warning
1131 Warn when a pointer is cast to an integer of a different size.
1134 C ObjC C++ ObjC++ Var(warn_pragmas) Init(1) Warning
1135 Warn about misuses of pragmas.
1138 C ObjC C++ ObjC++ Var(warn_prio_ctor_dtor) Init(1) Warning
1139 Warn if constructor or destructors with priorities from 0 to 100 are used.
1141 Wproperty-assign-default
1142 ObjC ObjC++ Var(warn_property_assign_default) Init(1) Warning
1143 Warn if a property for an Objective-C object has no assign semantics specified.
1146 ObjC ObjC++ Var(warn_protocol) Init(1) Warning
1147 Warn if inherited methods are unimplemented.
1150 C++ Warning Alias(Wplacement-new=, 1, 0)
1151 Warn for placement new expressions with undefined behavior.
1154 C++ Joined RejectNegative UInteger Var(warn_placement_new) Init(-1) Warning IntegerRange(0, 2)
1155 Warn for placement new expressions with undefined behavior.
1158 C ObjC C++ ObjC++ Var(warn_redundant_decls) Warning
1159 Warn about multiple declarations of the same object.
1162 C++ ObjC++ Var(warn_redundant_move) Warning LangEnabledBy(C++ ObjC++,Wextra)
1163 Warn about redundant calls to std::move.
1166 C++ ObjC++ Var(warn_register) Warning
1167 Warn about uses of register storage specifier.
1170 C++ ObjC++ Var(warn_reorder) Warning LangEnabledBy(C++ ObjC++,Wall)
1171 Warn when the compiler reorders code.
1174 C ObjC C++ ObjC++ Var(warn_return_type) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Init(-1)
1175 Warn whenever a function's return type defaults to \"int\" (C), or about inconsistent return types (C++).
1177 Wscalar-storage-order
1178 C ObjC C++ ObjC++ Var(warn_scalar_storage_order) Init(1) Warning
1179 Warn on suspicious constructs involving reverse scalar storage order.
1182 ObjC ObjC++ Var(warn_selector) Warning
1183 Warn if a selector has multiple methods.
1186 C ObjC C++ ObjC++ Var(warn_sequence_point) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1187 Warn about possible violations of sequence point rules.
1190 ObjC ObjC++ Var(warn_shadow_ivar) EnabledBy(Wshadow) Init(1) Warning
1191 Warn if a local declaration hides an instance variable.
1194 C ObjC C++ ObjC++ Warning Alias(Wshift-overflow=, 1, 0)
1195 Warn if left shift of a signed value overflows.
1198 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_shift_overflow) Init(-1) Warning IntegerRange(0, 2)
1199 Warn if left shift of a signed value overflows.
1201 Wshift-count-negative
1202 C ObjC C++ ObjC++ Var(warn_shift_count_negative) Init(1) Warning
1203 Warn if shift count is negative.
1205 Wshift-count-overflow
1206 C ObjC C++ ObjC++ Var(warn_shift_count_overflow) Init(1) Warning
1207 Warn if shift count >= width of type.
1209 Wshift-negative-value
1210 C ObjC C++ ObjC++ Var(warn_shift_negative_value) Init(-1) Warning
1211 Warn if left shifting a negative value.
1214 C ObjC C++ ObjC++ Var(warn_arith_conv) Warning
1215 Warn if conversion of the result of arithmetic might change the value even though converting the operands cannot.
1218 C ObjC C++ ObjC++ Var(warn_sign_compare) Warning LangEnabledBy(C++ ObjC++,Wall)
1219 Warn about signed-unsigned comparisons.
1222 C ObjC C++ ObjC++ EnabledBy(Wextra)
1226 C ObjC C++ ObjC++ Var(warn_sign_conversion) Warning LangEnabledBy(C ObjC,Wconversion)
1227 Warn for implicit type conversions between signed and unsigned integers.
1230 C++ ObjC++ Var(warn_sign_promo) Warning
1231 Warn when overload promotes from unsigned to signed.
1233 Wstrict-null-sentinel
1234 C++ ObjC++ Warning Var(warn_strict_null_sentinel)
1235 Warn about uncasted NULL used as sentinel.
1238 C ObjC Var(warn_strict_prototypes) Warning
1239 Warn about unprototyped function declarations.
1242 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 3, 0) IntegerRange(0, 3)
1246 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0) IntegerRange(0, 5)
1249 Wstrict-selector-match
1250 ObjC ObjC++ Var(warn_strict_selector_match) Warning
1251 Warn if type signatures of candidate methods do not match exactly.
1254 C C++ Var(warn_sync_nand) Init(1) Warning
1255 Warn when __sync_fetch_and_nand and __sync_nand_and_fetch built-in functions are used.
1258 C++ ObjC++ Var(warn_synth) Warning
1259 Deprecated. This switch has no effect.
1262 C ObjC C++ ObjC++ Warning
1263 ; Documented in common.opt
1265 Wtautological-compare
1266 C ObjC C++ ObjC++ Var(warn_tautological_compare) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1267 Warn if a comparison always evaluates to true or false.
1270 C++ ObjC++ Warning Var(warn_terminate) Init(1)
1271 Warn if a throw expression will always result in a call to terminate().
1274 C ObjC CPP(cpp_warn_traditional) CppReason(CPP_W_TRADITIONAL) Var(warn_traditional) Init(0) Warning
1275 Warn about features not present in traditional C.
1277 Wtraditional-conversion
1278 C ObjC Var(warn_traditional_conversion) Warning
1279 Warn of prototypes causing type conversions different from what would happen in the absence of prototype.
1282 C ObjC C++ ObjC++ CPP(warn_trigraphs) CppReason(CPP_W_TRIGRAPHS) Var(cpp_warn_trigraphs) Init(2) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1283 Warn if trigraphs are encountered that might affect the meaning of the program.
1285 Wundeclared-selector
1286 ObjC ObjC++ Var(warn_undeclared_selector) Warning
1287 Warn about @selector()s without previously declared methods.
1290 C ObjC C++ ObjC++ CPP(warn_undef) CppReason(CPP_W_UNDEF) Var(cpp_warn_undef) Init(0) Warning
1291 Warn if an undefined macro is used in an #if directive.
1294 C ObjC C++ ObjC++ LTO LangEnabledBy(C ObjC C++ ObjC++ LTO,Wall)
1297 Wmaybe-uninitialized
1298 C ObjC C++ ObjC++ LTO LangEnabledBy(C ObjC C++ ObjC++ LTO,Wall)
1302 C ObjC C++ ObjC++ Warning Var(warn_unknown_pragmas) LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0)
1303 Warn about unrecognized pragmas.
1305 Wunsuffixed-float-constants
1306 C ObjC Var(warn_unsuffixed_float_constants) Warning
1307 Warn about unsuffixed float constants.
1310 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
1311 ; documented in common.opt
1313 Wunused-local-typedefs
1314 C ObjC C++ ObjC++ Var(warn_unused_local_typedefs) Warning EnabledBy(Wunused)
1315 Warn when typedefs locally defined in a function are not used.
1318 C ObjC C++ ObjC++ CppReason(CPP_W_UNUSED_MACROS) Var(cpp_warn_unused_macros) Warning
1319 Warn about macros defined in the main file that are not used.
1322 C ObjC C++ ObjC++ Var(warn_unused_result) Init(1) Warning
1323 Warn if a caller of a function, marked with attribute warn_unused_result, does not use its return value.
1326 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wunused)
1327 ; documented in common.opt
1329 Wunused-const-variable
1330 C ObjC C++ ObjC++ Warning Alias(Wunused-const-variable=, 2, 0)
1331 Warn when a const variable is unused.
1333 Wunused-const-variable=
1334 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_unused_const_variable) Warning LangEnabledBy(C ObjC,Wunused-variable, 1, 0) IntegerRange(0, 2)
1335 Warn when a const variable is unused.
1338 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)
1339 Warn about using variadic macros.
1342 C ObjC C++ ObjC++ Warning Var(warn_varargs) Init(1)
1343 Warn about questionable usage of the macros used to retrieve variable arguments.
1346 C++ ObjC++ Warning Var(warn_vexing_parse) Init(1)
1347 Warn about the most vexing parse syntactic ambiguity.
1350 C ObjC C++ ObjC++ Var(warn_vla) Init(-1) Warning
1351 Warn if a variable length array is used.
1354 C ObjC C++ LTO ObjC++ Var(warn_vla_limit) Warning Joined Host_Wide_Int ByteSize Init(HOST_WIDE_INT_MAX)
1355 -Wvla-larger-than=<number> Warn on unbounded uses of variable-length
1356 arrays, and on bounded uses of variable-length arrays whose bound can be
1357 larger than <number> bytes.
1360 C ObjC C++ LTO ObjC++ Alias(Wvla-larger-than=,18446744073709551615EiB,none) Warning
1361 Disable Wvla-larger-than= warning. Equivalent to Wvla-larger-than=<SIZE_MAX> or larger.
1364 C ObjC C++ ObjC++ Var(warn_vla_parameter) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1365 Warn about mismatched declarations of VLA parameters.
1368 C++ ObjC++ Var(warn_volatile) Warning
1369 Warn about deprecated uses of volatile qualifier.
1371 Wvolatile-register-var
1372 C ObjC C++ ObjC++ Var(warn_volatile_register_var) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1373 Warn when a register variable is declared volatile.
1375 Wvirtual-inheritance
1376 C++ ObjC++ Var(warn_virtual_inheritance) Warning
1377 Warn on direct virtual inheritance.
1379 Wvirtual-move-assign
1380 C++ ObjC++ Var(warn_virtual_move_assign) Warning Init(1)
1381 Warn if a virtual base has a non-trivial move assignment operator.
1384 C ObjC C++ ObjC++ Var(warn_write_strings) Warning
1385 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.
1387 Wzero-as-null-pointer-constant
1388 C++ ObjC++ Var(warn_zero_as_null_pointer_constant) Warning
1389 Warn when a literal '0' is used as null pointer.
1392 C++ ObjC++ Var(warn_useless_cast) Warning
1393 Warn about useless casts.
1396 C++ ObjC++ Var(warn_subobject_linkage) Warning Init(1)
1397 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.
1399 Wduplicate-decl-specifier
1400 C ObjC Var(warn_duplicate_decl_specifier) Warning LangEnabledBy(C ObjC,Wall)
1401 Warn when a declaration has duplicate const, volatile, restrict or _Atomic specifier.
1404 C ObjC C++ ObjC++ Var(warn_restrict) Warning LangEnabledBy(C ObjC C++ ObjC++, Wall)
1405 Warn when an argument passed to a restrict-qualified parameter aliases with
1410 A synonym for -std=c89 (for C) or -std=c++98 (for C++).
1413 C ObjC C++ ObjC++ Joined
1414 ; Documented in common.opt. FIXME - what about -dI, -dD, -dN and -dD?
1416 fabi-compat-version=
1417 C++ ObjC++ Joined RejectNegative UInteger Var(flag_abi_compat_version) Init(-1)
1418 The version of the C++ ABI used for -Wabi warnings and link compatibility aliases.
1421 C++ ObjC++ Var(flag_access_control) Init(1)
1422 Enforce class member access control semantics.
1425 C ObjC C++ ObjC++ RejectNegative Joined Var(ada_specs_parent)
1426 -fada-spec-parent=unit Dump Ada specs as child units of given parent.
1429 C++ ObjC++ Alias(faligned-new=,1,0)
1430 Support C++17 allocation of over-aligned types.
1433 C++ ObjC++ Joined RejectNegative Var(aligned_new_threshold) UInteger Init(-1)
1434 -faligned-new=<N> Use C++17 over-aligned type allocation for alignments greater than N.
1437 C++ ObjC++ WarnRemoved
1439 fallow-parameterless-variadic-functions
1440 C ObjC Var(flag_allow_parameterless_variadic_functions)
1441 Allow variadic functions without named parameter.
1443 falt-external-templates
1444 C++ ObjC++ WarnRemoved
1445 No longer supported.
1448 C ObjC C++ ObjC++ Var(flag_no_asm, 0)
1449 Recognize the \"asm\" keyword.
1451 ; Define extra predefined macros for use in libgcc.
1453 C ObjC C++ ObjC++ Undocumented Var(flag_building_libgcc)
1456 C ObjC C++ ObjC++ Var(flag_no_builtin, 0)
1457 Recognize built-in functions.
1460 C ObjC C++ ObjC++ Joined
1462 fcanonical-system-headers
1464 Where shorter, use canonicalized paths to systems headers.
1467 C++ ObjC++ Var(flag_char8_t) Init(-1)
1468 Enable the char8_t fundamental type and use it as the type for UTF-8 string
1469 and character literals.
1471 fcheck-pointer-bounds
1472 C ObjC C++ ObjC++ LTO WarnRemoved
1473 Removed in GCC 9. This switch has no effect.
1475 fchkp-check-incomplete-type
1476 C ObjC C++ ObjC++ LTO WarnRemoved
1477 Removed in GCC 9. This switch has no effect.
1479 fchkp-zero-input-bounds-for-main
1480 C ObjC C++ ObjC++ LTO WarnRemoved
1481 Removed in GCC 9. This switch has no effect.
1483 fchkp-first-field-has-own-bounds
1484 C ObjC C++ ObjC++ LTO WarnRemoved RejectNegative
1485 Removed in GCC 9. This switch has no effect.
1488 C ObjC C++ ObjC++ LTO WarnRemoved
1489 Removed in GCC 9. This switch has no effect.
1491 fchkp-narrow-to-innermost-array
1492 C ObjC C++ ObjC++ LTO WarnRemoved RejectNegative
1493 Removed in GCC 9. This switch has no effect.
1495 fchkp-flexible-struct-trailing-arrays
1496 C ObjC C++ ObjC++ LTO WarnRemoved
1497 Removed in GCC 9. This switch has no effect.
1500 C ObjC C++ ObjC++ LTO WarnRemoved
1502 fchkp-use-fast-string-functions
1503 C ObjC C++ ObjC++ LTO WarnRemoved
1504 Removed in GCC 9. This switch has no effect.
1506 fchkp-use-nochk-string-functions
1507 C ObjC C++ ObjC++ LTO WarnRemoved
1508 Removed in GCC 9. This switch has no effect.
1510 fchkp-use-static-bounds
1511 C ObjC C++ ObjC++ LTO WarnRemoved
1512 Removed in GCC 9. This switch has no effect.
1514 fchkp-use-static-const-bounds
1515 C ObjC C++ ObjC++ LTO WarnRemoved
1516 Removed in GCC 9. This switch has no effect.
1518 fchkp-treat-zero-dynamic-size-as-infinite
1519 C ObjC C++ ObjC++ LTO WarnRemoved
1520 Removed in GCC 9. This switch has no effect.
1523 C ObjC C++ ObjC++ LTO WarnRemoved
1524 Removed in GCC 9. This switch has no effect.
1527 C ObjC C++ ObjC++ LTO WarnRemoved
1528 Removed in GCC 9. This switch has no effect.
1531 C ObjC C++ ObjC++ LTO WarnRemoved
1532 Removed in GCC 9. This switch has no effect.
1534 fchkp-instrument-calls
1535 C ObjC C++ ObjC++ LTO WarnRemoved
1536 Removed in GCC 9. This switch has no effect.
1538 fchkp-instrument-marked-only
1539 C ObjC C++ ObjC++ LTO WarnRemoved
1540 Removed in GCC 9. This switch has no effect.
1543 C ObjC C++ ObjC++ LTO WarnRemoved
1544 Removed in GCC 9. This switch has no effect.
1548 Removed in GCC 9. This switch has no effect.
1550 static-libmpxwrappers
1552 Removed in GCC 9. This switch has no effect.
1555 C ObjC C++ ObjC++ LTO Undocumented Ignore
1556 Removed in GCC 8. This switch has no effect.
1559 C++ ObjC++ Var(flag_concepts)
1560 Enable support for C++ concepts.
1563 C++ ObjC++ Var(flag_concepts_ts) Init(0)
1564 Enable certain features present in the Concepts TS.
1566 fconcepts-diagnostics-depth=
1567 C++ ObjC++ Joined RejectNegative UInteger Var(concepts_diagnostics_max_depth) Init(1)
1568 Specify maximum error replay depth during recursive diagnosis of a constraint satisfaction failure.
1572 Allow the arguments of the '?' operator to have different types.
1576 Does nothing. Preserved for backward compatibility.
1578 fconstant-string-class=
1579 ObjC ObjC++ Joined MissingArgError(no class name specified with %qs)
1580 -fconst-string-class=<name> Use class <name> for constant strings.
1583 C++ ObjC++ Joined RejectNegative UInteger Var(max_constexpr_depth) Init(512)
1584 -fconstexpr-depth=<number> Specify maximum constexpr recursion depth.
1586 fconstexpr-cache-depth=
1587 C++ ObjC++ Joined RejectNegative UInteger Var(constexpr_cache_depth) Init(8)
1588 -fconstexpr-cache-depth=<number> Specify maximum constexpr recursion cache depth.
1590 fconstexpr-loop-limit=
1591 C++ ObjC++ Joined RejectNegative UInteger Var(constexpr_loop_limit) Init(262144)
1592 -fconstexpr-loop-limit=<number> Specify maximum constexpr loop iteration count.
1594 fconstexpr-ops-limit=
1595 C++ ObjC++ Joined RejectNegative Host_Wide_Int Var(constexpr_ops_limit) Init(33554432)
1596 -fconstexpr-ops-limit=<number> Specify maximum number of constexpr operations during a single constexpr evaluation.
1599 C++ LTO Var(flag_coroutines)
1600 Enable C++ coroutines (experimental).
1604 Emit debug annotations during preprocessing.
1608 Does nothing. Preserved for backward compatibility.
1611 C++ ObjC++ Var(flag_declone_ctor_dtor) Init(-1)
1612 Factor complex constructors and destructors to favor space over speed.
1616 Does nothing. Preserved for backward compatibility.
1618 fdiagnostics-show-template-tree
1619 C++ ObjC++ Var(flag_diagnostics_show_template_tree) Init(0)
1620 Print hierarchical comparisons when template types are mismatched.
1624 Preprocess directives only.
1626 fdollars-in-identifiers
1628 Permit '$' as an identifier character.
1631 C ObjC C++ ObjC++ Joined RejectNegative
1632 -fmacro-prefix-map=<old>=<new> Map one directory name to another in __FILE__, __BASE_FILE__, and __builtin_FILE().
1635 C ObjC C++ ObjC++ RejectNegative Var(flag_dump_ada_spec)
1636 Write all declarations as Ada code transitively.
1639 C ObjC C++ ObjC++ RejectNegative Var(flag_dump_ada_spec_slim)
1640 Write all declarations as Ada code for the given file only.
1643 C++ ObjC++ Var(flag_elide_constructors) Init(1)
1646 C++ ObjC++ Var(flag_elide_type) Init(1)
1647 Do not elide common elements in template comparisons.
1650 C++ ObjC++ Var(flag_enforce_eh_specs) Init(1)
1651 Generate code to check exception specifications.
1654 C++ ObjC++ WarnRemoved
1657 C ObjC C++ ObjC++ Joined RejectNegative
1658 -fexec-charset=<cset> Convert all strings and character constants to character set <cset>.
1660 fextended-identifiers
1662 Permit universal character names (\\u and \\U) in identifiers.
1665 C ObjC C++ ObjC++ Joined RejectNegative
1666 -finput-charset=<cset> Specify the default character set for source files.
1669 C++ ObjC++ Var(flag_extern_tls_init) Init(-1)
1670 Support dynamic initialization of thread-local variables in a different translation unit.
1673 C++ ObjC++ WarnRemoved
1676 C++ ObjC++ WarnRemoved
1680 Do not assume that standard C libraries and \"main\" exist.
1683 C++ ObjC++ Var(flag_no_gnu_keywords, 0)
1684 Recognize GNU-defined keywords.
1687 ObjC ObjC++ LTO RejectNegative Var(flag_next_runtime,0) Init(NEXT_OBJC_RUNTIME)
1688 Generate code for GNU runtime environment.
1691 C ObjC Var(flag_gnu89_inline) Init(-1)
1692 Use traditional GNU semantics for inline functions.
1695 C++ ObjC++ WarnRemoved
1698 C++ ObjC++ Optimization Alias(fexceptions) Warn({%<-fhandle-exceptions%> has been renamed %<-fexceptions%> (and is now on by default)})
1701 C++ ObjC++ WarnRemoved
1705 Assume normal C execution environment.
1708 C++ ObjC++ WarnRemoved
1709 No longer supported.
1712 C++ ObjC++ Var(flag_implement_inlines) Init(1)
1713 Export functions even if they can be inlined.
1715 fimplicit-inline-templates
1716 C++ ObjC++ Var(flag_implicit_inline_templates) Init(1)
1717 Emit implicit instantiations of inline templates.
1720 C++ ObjC++ Var(flag_implicit_templates) Init(1)
1721 Emit implicit instantiations of templates.
1723 fnew-inheriting-ctors
1724 C++ ObjC++ Var(flag_new_inheriting_ctors) Init(1)
1725 Implement C++17 inheriting constructor semantics.
1728 C++ ObjC++ WarnRemoved
1730 fkeep-inline-dllexport
1731 C C++ ObjC ObjC++ Var(flag_keep_inline_dllexport) Init(1) Condition(TARGET_DLLIMPORT_DECL_ATTRIBUTES)
1732 Don't emit dllexported inline functions unless needed.
1735 C++ ObjC++ WarnRemoved
1737 flax-vector-conversions
1738 C ObjC C++ ObjC++ Var(flag_lax_vector_conversions)
1739 Allow implicit conversions between vectors with differing numbers of subparts and/or differing element types.
1742 C++ ObjC++ Var(flag_modules) Integer Init(0)
1743 Enable C++ modules-ts (experimental).
1746 C++ ObjC++ Undocumented RejectNegative Var(flag_modules,0) Integer
1750 C++ ObjC RejectNegative Var(flag_header_unit,0) Integer
1751 Enable C++ header module (experimental).
1754 C++ ObjC++ Joined RejectNegative Undocumented
1756 fmodule-implicit-inline
1757 C++ ObjC++ Var(flag_module_implicit_inline,0) Integer
1758 Member functions defined within their class are inline in module purview.
1761 C++ ObjC RejectNegative Var(flag_module_only) Integer
1762 Only emit Compiled Module Interface.
1765 C++ ObjC++ Joined RejectNegative MissingArgError(missing mapper)
1766 Mapper for module to CMI files.
1769 C++ ObjC++ Var(flag_module_lazy) Init(1)
1770 Enable lazy module importing.
1772 fmodule-version-ignore
1773 C++ ObjC Var(flag_module_version_ignore) Integer
1774 ; undocumented, Very dangerous, but occasionally useful
1776 Winvalid-imported-macros
1777 C++ ObjC++ Var(warn_imported_macros) Warning
1778 Warn about macros that have conflicting header units definitions.
1780 flang-info-include-translate
1781 C++ Var(note_include_translate_yes)
1782 Note #include directives translated to import declarations.
1784 flang-info-include-translate-not
1785 C++ Var(note_include_translate_no)
1786 Note #include directives not translated to import declarations, and not known to be textual.
1788 flang-info-include-translate=
1789 C++ Joined RejectNegative MissingArgError(missing header name)
1790 Note a #include translation of a specific header.
1792 flang-info-module-cmi
1793 C++ Var(note_module_cmi_yes)
1794 Note Compiled Module Interface pathnames.
1796 flang-info-module-cmi=
1797 C++ Joined RejectNegative MissingArgError(missing module name)
1798 Note Compiled Module Interface pathname of a specific module or header-unit.
1801 C ObjC C++ ObjC++ Joined RejectNegative UInteger
1802 fmax-include-depth=<number> Set the maximum depth of the nested #include.
1805 C ObjC C++ ObjC++ Var(flag_ms_extensions)
1806 Don't warn about uses of Microsoft extensions.
1809 C ObjC C++ ObjC++ WarnRemoved
1812 C ObjC C++ ObjC++ WarnRemoved
1815 C ObjC C++ ObjC++ WarnRemoved
1817 fname-mangling-version-
1818 C++ ObjC++ Joined WarnRemoved
1821 C++ ObjC++ WarnRemoved
1824 C++ ObjC++ Var(flag_new_ttp)
1825 Implement resolution of DR 150 for matching of template template arguments.
1828 ObjC ObjC++ LTO RejectNegative Var(flag_next_runtime)
1829 Generate code for NeXT (Apple Mac OS X) runtime environment.
1832 ObjC ObjC++ Var(flag_nil_receivers) Init(1)
1833 Assume that receivers of Objective-C messages may be nil.
1836 ObjC ObjC++ Var(flag_local_ivars) Init(1)
1837 Allow access to instance variables as if they were local declarations within instance method implementations.
1840 ObjC ObjC++ Joined RejectNegative Enum(ivar_visibility) Var(default_ivar_visibility) Init(IVAR_VISIBILITY_PROTECTED)
1841 -fvisibility=[private|protected|public|package] Set the default symbol visibility.
1844 Name(ivar_visibility) Type(enum ivar_visibility) UnknownError(unrecognized ivar visibility value %qs)
1847 Enum(ivar_visibility) String(private) Value(IVAR_VISIBILITY_PRIVATE)
1850 Enum(ivar_visibility) String(protected) Value(IVAR_VISIBILITY_PROTECTED)
1853 Enum(ivar_visibility) String(public) Value(IVAR_VISIBILITY_PUBLIC)
1856 Enum(ivar_visibility) String(package) Value(IVAR_VISIBILITY_PACKAGE)
1859 C++ ObjC++ Var(flag_no_nonansi_builtin, 0)
1862 C++ ObjC++ WarnRemoved
1865 C++ ObjC++ Optimization Var(flag_nothrow_opt)
1866 Treat a throw() exception specification as noexcept to improve code size.
1869 ObjC ObjC++ LTO Joined RejectNegative UInteger Var(flag_objc_abi)
1870 Specify which ABI to use for Objective-C family code and meta-data generation.
1872 ; Generate special '- .cxx_construct' and '- .cxx_destruct' methods
1873 ; to initialize any non-POD ivars in Objective-C++ classes.
1874 fobjc-call-cxx-cdtors
1875 ObjC++ Var(flag_objc_call_cxx_cdtors)
1876 Generate special Objective-C methods to initialize/destroy non-POD C++ ivars, if needed.
1878 fobjc-direct-dispatch
1879 ObjC ObjC++ Var(flag_objc_direct_dispatch)
1880 Allow fast jumps to the message dispatcher.
1882 ; Nonzero means that we will allow new ObjC exception syntax (@throw,
1883 ; @try, etc.) in source code.
1885 ObjC ObjC++ Var(flag_objc_exceptions)
1886 Enable Objective-C exception and synchronization syntax.
1889 ObjC ObjC++ LTO Var(flag_objc_gc)
1890 Enable garbage collection (GC) in Objective-C/Objective-C++ programs.
1893 ObjC ObjC++ Var(flag_objc_nilcheck,1)
1894 Enable inline checks for nil receivers with the NeXT runtime and ABI version 2.
1896 ; Nonzero means that we generate NeXT setjmp based exceptions.
1897 fobjc-sjlj-exceptions
1898 ObjC ObjC++ Var(flag_objc_sjlj_exceptions) Init(-1)
1899 Enable Objective-C setjmp exception handling runtime.
1902 ObjC ObjC++ Var(flag_objc1_only)
1903 Conform to the Objective-C 1.0 language as implemented in GCC 4.0.
1906 C ObjC C++ ObjC++ LTO Var(flag_openacc)
1910 C ObjC C++ ObjC++ LTO Joined Var(flag_openacc_dims)
1911 Specify default OpenACC compute dimensions.
1914 C ObjC C++ ObjC++ LTO Var(flag_openmp)
1915 Enable OpenMP (implies -frecursive in Fortran).
1918 C ObjC C++ ObjC++ Var(flag_openmp_simd)
1919 Enable OpenMP's SIMD directives.
1923 Recognize C++ keywords like \"compl\" and \"xor\".
1927 Does nothing. Preserved for backward compatibility.
1934 Look for and use PCH files even when preprocessing.
1937 C++ ObjC++ Var(flag_permissive)
1938 Downgrade conformance errors to warnings.
1941 C ObjC Var(flag_plan9_extensions)
1942 Enable Plan 9 language extensions.
1946 Treat the input file as already preprocessed.
1948 ftrack-macro-expansion
1949 C ObjC C++ ObjC++ JoinedOrMissing RejectNegative UInteger
1950 ; converted into ftrack-macro-expansion=
1952 ftrack-macro-expansion=
1953 C ObjC C++ ObjC++ JoinedOrMissing RejectNegative UInteger
1954 -ftrack-macro-expansion=<0|1|2> Track locations of tokens coming from macro expansion and display them in error messages.
1957 C++ ObjC++ Var(flag_pretty_templates) Init(1)
1958 Do not pretty-print template specializations as the template signature followed by the arguments.
1960 fprintf-return-value
1961 C ObjC C++ ObjC++ LTO Optimization Var(flag_printf_return_value) Init(1)
1962 Treat known sprintf return values as constants.
1964 freplace-objc-classes
1965 ObjC ObjC++ LTO Var(flag_replace_objc_classes)
1966 Used in Fix-and-Continue mode to indicate that object files may be swapped in at runtime.
1969 C++ ObjC++ WarnRemoved
1970 Removed in GCC 10. This switch has no effect.
1973 C++ ObjC++ Optimization Var(flag_rtti) Init(1)
1974 Generate run time type descriptor information.
1977 C ObjC C++ ObjC++ LTO Optimization Var(flag_short_enums)
1978 Use the narrowest integer type possible for enumeration types.
1981 C ObjC C++ ObjC++ LTO Optimization Var(flag_short_wchar)
1982 Force the underlying type for \"wchar_t\" to be \"unsigned short\".
1985 C ObjC C++ ObjC++ Var(flag_signed_bitfields) Init(1)
1986 When \"signed\" or \"unsigned\" is not given make the bitfield signed.
1989 C ObjC C++ ObjC++ LTO Var(flag_signed_char)
1990 Make \"char\" signed by default.
1993 C++ ObjC++ Var(flag_sized_deallocation) Init(-1)
1994 Enable C++14 sized deallocation support.
1997 C++ ObjC++ WarnRemoved
2000 C ObjC Joined RejectNegative Enum(sso_struct) Var(default_sso) Init(SSO_NATIVE)
2001 -fsso-struct=[big-endian|little-endian|native] Set the default scalar storage order.
2004 Name(sso_struct) Type(enum scalar_storage_order_kind) UnknownError(unrecognized scalar storage order value %qs)
2007 Enum(sso_struct) String(big-endian) Value(SSO_BIG_ENDIAN)
2010 Enum(sso_struct) String(little-endian) Value(SSO_LITTLE_ENDIAN)
2013 Enum(sso_struct) String(native) Value(SSO_NATIVE)
2016 C++ ObjC++ Var(flag_detailed_statistics)
2017 Display statistics accumulated during compilation.
2020 C++ ObjC++ Optimization Var(flag_strict_enums)
2021 Assume that values of enumeration type are always within the minimum range of that type.
2024 C++ ObjC++ WarnRemoved
2027 C++ ObjC++ Common Alias(fstrong-eval-order=, all, none)
2028 Follow the C++17 evaluation order requirements for assignment expressions,
2029 shift, member function calls, etc.
2032 C++ ObjC++ Common Var(flag_strong_eval_order) Joined Enum(strong_eval_order) RejectNegative Init(-1)
2033 Follow the C++17 evaluation order requirements for assignment expressions,
2034 shift, member function calls, etc.
2037 Name(strong_eval_order) Type(int)
2040 Enum(strong_eval_order) String(none) Value(0)
2043 Enum(strong_eval_order) String(some) Value(1)
2046 Enum(strong_eval_order) String(all) Value(2)
2048 ftemplate-backtrace-limit=
2049 C++ ObjC++ Joined RejectNegative UInteger Var(template_backtrace_limit) Init(10)
2050 Set the maximum number of template instantiation notes for a single warning or error.
2053 C++ ObjC++ Joined RejectNegative Undocumented Alias(ftemplate-depth=)
2056 C++ ObjC++ Joined RejectNegative UInteger
2057 -ftemplate-depth=<number> Specify maximum template instantiation depth.
2060 C++ ObjC++ WarnRemoved
2063 C++ ObjC++ Optimization Var(flag_threadsafe_statics) Init(1)
2064 -fno-threadsafe-statics Do not generate thread-safe code for initializing local statics.
2067 C ObjC C++ ObjC++ Var(flag_signed_bitfields, 0)
2068 When \"signed\" or \"unsigned\" is not given make the bitfield unsigned.
2071 C ObjC C++ ObjC++ LTO Var(flag_signed_char, 0)
2072 Make \"char\" unsigned by default.
2075 C++ ObjC++ Var(flag_use_cxa_atexit) Init(DEFAULT_USE_CXA_ATEXIT)
2076 Use __cxa_atexit to register destructors.
2078 fuse-cxa-get-exception-ptr
2079 C++ ObjC++ Var(flag_use_cxa_get_exception_ptr) Init(2)
2080 Use __cxa_get_exception_ptr in exception handling.
2082 fvisibility-inlines-hidden
2084 Marks all inlined functions and methods as having hidden visibility.
2086 fvisibility-ms-compat
2087 C++ ObjC++ Var(flag_visibility_ms_compat)
2088 Changes visibility to match Microsoft Visual Studio by default.
2091 C++ ObjC++ WarnRemoved
2092 No longer supported.
2095 C++ ObjC++ WarnRemoved
2096 No longer supported.
2099 C++ ObjC++ Var(flag_weak) Init(1)
2100 Emit common-like symbols as weak symbols.
2103 C ObjC C++ ObjC++ Joined RejectNegative
2104 -fwide-exec-charset=<cset> Convert all wide strings and character constants to character set <cset>.
2107 C ObjC C++ ObjC++ Var(flag_working_directory) Init(-1)
2108 Generate a #line directive pointing at the current working directory.
2111 C++ ObjC++ WarnRemoved
2112 No longer supported.
2115 ObjC ObjC++ Var(flag_zero_link)
2116 Generate lazy class lookup (via objc_getClass()) for use in Zero-Link mode.
2119 ObjC ObjC++ Driver Var(flag_gen_declaration) RejectNegative
2120 Dump declarations to a .decl file.
2122 femit-struct-debug-baseonly
2124 -femit-struct-debug-baseonly Aggressive reduced debug info for structs.
2126 femit-struct-debug-reduced
2128 -femit-struct-debug-reduced Conservative reduced debug info for structs.
2130 femit-struct-debug-detailed=
2131 C ObjC C++ ObjC++ Joined
2132 -femit-struct-debug-detailed=<spec-list> Detailed reduced debug info for structs.
2134 fext-numeric-literals
2135 C++ ObjC++ Var(flag_ext_numeric_literals) Init(1)
2136 Interpret imaginary, fixed-point, or other gnu number suffix as the corresponding
2137 number literal rather than a user-defined number literal.
2140 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
2141 -idirafter <dir> Add <dir> to the end of the system include path.
2144 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
2145 -imacros <file> Accept definition of macros in <file>.
2148 C ObjC C++ ObjC++ Joined Separate
2149 -imultilib <dir> Set <dir> to be the multilib include subdirectory.
2152 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
2153 -include <file> Include the contents of <file> before other files.
2156 C ObjC C++ ObjC++ Joined Separate
2157 -iprefix <path> Specify <path> as a prefix for next two options.
2160 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
2161 -isysroot <dir> Set <dir> to be the system root directory.
2164 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
2165 -isystem <dir> Add <dir> to the start of the system include path.
2168 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
2169 -iquote <dir> Add <dir> to the end of the quote include path.
2172 C ObjC C++ ObjC++ Joined Separate
2173 -iwithprefix <dir> Add <dir> to the end of the system include path.
2176 C ObjC C++ ObjC++ Joined Separate
2177 -iwithprefixbefore <dir> Add <dir> to the end of the main include path.
2180 C Undocumented RejectDriver
2187 Do not search standard system include directories (those specified with -isystem will still be used).
2191 Do not search standard system include directories for C++.
2194 C ObjC C++ ObjC++ Joined Separate
2195 ; Documented in common.opt
2198 C ObjC C++ ObjC++ Alias(Wpedantic)
2199 ; Documented in common.opt
2201 print-objc-runtime-info
2203 Generate C header of platform-specific features.
2207 Remap file names when including files.
2211 Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum.
2214 C++ ObjC++ Alias(std=c++98)
2215 Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum.
2219 Conform to the ISO 2011 C++ standard.
2222 C++ ObjC++ Alias(std=c++11) Undocumented
2223 Deprecated in favor of -std=c++11.
2226 C++ ObjC++ Alias(std=c++14) Undocumented
2227 Deprecated in favor of -std=c++14.
2231 Conform to the ISO 2014 C++ standard.
2234 C++ ObjC++ Alias(std=c++17) Undocumented
2235 Deprecated in favor of -std=c++17.
2239 Conform to the ISO 2017 C++ standard.
2242 C++ ObjC++ Alias(std=c++20) Undocumented
2243 Conform to the ISO 2020 C++ standard (experimental and incomplete support).
2247 Conform to the ISO 2020 C++ standard (experimental and incomplete support).
2250 C++ ObjC++ Alias(std=c++23)
2251 Conform to the ISO 2023 C++ draft standard (experimental and incomplete support).
2254 C++ ObjC++ Undocumented
2255 Conform to the ISO 2023 C++ draft standard (experimental and incomplete support).
2259 Conform to the ISO 2011 C standard.
2262 C ObjC Alias(std=c11)
2263 Deprecated in favor of -std=c11.
2267 Conform to the ISO 2017 C standard (published in 2018).
2270 C ObjC Alias(std=c17)
2271 Conform to the ISO 2017 C standard (published in 2018).
2275 Conform to the ISO 202X C standard draft (experimental and incomplete support).
2278 C ObjC Alias(std=c90)
2279 Conform to the ISO 1990 C standard.
2283 Conform to the ISO 1990 C standard.
2287 Conform to the ISO 1999 C standard.
2290 C ObjC Alias(std=c99)
2291 Deprecated in favor of -std=c99.
2295 Conform to the ISO 1998 C++ standard revised by the 2003 technical
2296 corrigendum with GNU extensions.
2299 C++ ObjC++ Alias(std=gnu++98)
2300 Conform to the ISO 1998 C++ standard revised by the 2003 technical
2301 corrigendum with GNU extensions.
2305 Conform to the ISO 2011 C++ standard with GNU extensions.
2308 C++ ObjC++ Alias(std=gnu++11) Undocumented
2309 Deprecated in favor of -std=gnu++11.
2312 C++ ObjC++ Alias(std=gnu++14) Undocumented
2313 Deprecated in favor of -std=gnu++14.
2317 Conform to the ISO 2014 C++ standard with GNU extensions.
2320 C++ ObjC++ Alias(std=gnu++17) Undocumented
2321 Deprecated in favor of -std=gnu++17.
2325 Conform to the ISO 2017 C++ standard with GNU extensions.
2328 C++ ObjC++ Alias(std=gnu++20) Undocumented
2329 Conform to the ISO 2020 C++ standard with GNU extensions (experimental and incomplete support).
2333 Conform to the ISO 2020 C++ standard with GNU extensions (experimental and incomplete support).
2336 C++ ObjC++ Alias(std=gnu++23)
2337 Conform to the ISO 2023 C++ draft standard with GNU extensions (experimental and incomplete support).
2340 C++ ObjC++ Undocumented
2341 Conform to the ISO 2023 C++ draft standard with GNU extensions (experimental and incomplete support).
2345 Conform to the ISO 2011 C standard with GNU extensions.
2348 C ObjC Alias(std=gnu11)
2349 Deprecated in favor of -std=gnu11.
2353 Conform to the ISO 2017 C standard (published in 2018) with GNU extensions.
2356 C ObjC Alias(std=gnu17)
2357 Conform to the ISO 2017 C standard (published in 2018) with GNU extensions.
2361 Conform to the ISO 202X C standard draft with GNU extensions (experimental and incomplete support).
2364 C ObjC Alias(std=gnu90)
2365 Conform to the ISO 1990 C standard with GNU extensions.
2369 Conform to the ISO 1990 C standard with GNU extensions.
2373 Conform to the ISO 1999 C standard with GNU extensions.
2376 C ObjC Alias(std=gnu99)
2377 Deprecated in favor of -std=gnu99.
2380 C ObjC Alias(std=c90)
2381 Conform to the ISO 1990 C standard.
2385 Conform to the ISO 1990 C standard as amended in 1994.
2388 C ObjC Alias(std=c99)
2389 Conform to the ISO 1999 C standard.
2392 C ObjC Alias(std=c99)
2393 Deprecated in favor of -std=iso9899:1999.
2396 C ObjC Alias(std=c11)
2397 Conform to the ISO 2011 C standard.
2400 C ObjC Alias(std=c17)
2401 Conform to the ISO 2017 C standard (published in 2018).
2404 C ObjC Alias(std=c17)
2405 Conform to the ISO 2017 C standard (published in 2018).
2408 Driver C++ ObjC++ Common Condition(ENABLE_STDLIB_OPTION) Var(flag_stdlib_kind) Joined Enum(stdlib_kind) RejectNegative Init(1)
2409 -stdlib=[libstdc++|libc++] The standard library to be used for C++ headers
2413 Name(stdlib_kind) Type(int)
2416 Enum(stdlib_kind) String(libstdc++) Value(1)
2419 Enum(stdlib_kind) String(libc++) Value(2)
2426 Enable traditional preprocessing.
2430 -trigraphs Support ISO C trigraphs.
2433 C ObjC C++ ObjC++ Var(flag_undef)
2434 Do not predefine system-specific and GCC-specific macros.
2438 ; Documented in common.opt
2442 ; Documented in common.opt
2444 ; This comment is to ensure we retain the blank line above.