1 ; Options for the C, ObjC, C++ and ObjC++ front ends.
2 ; Copyright (C) 2003-2023 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++ 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.
260 C ObjC C++ ObjC++ NoDriverArg Joined MissingArgError(missing format after %qs)
261 Structured format for output dependency information. Supported (\"p1689r5\").
264 C ObjC C++ ObjC++ NoDriverArg Joined MissingArgError(missing output path after %qs)
265 File for output dependency information.
268 C ObjC C++ ObjC++ NoDriverArg Joined MissingArgError(missing path after %qs)
269 -fdeps-target=obj.o Output file for the compile step.
273 Do not generate #line directives.
276 C ObjC C++ ObjC++ Joined Separate MissingArgError(macro name missing after %qs)
277 -U<macro> Undefine <macro>.
280 C ObjC C++ ObjC++ LTO Var(warn_nsobject_attribute) Warning Init(1)
281 Warn if the NSObject attribute is applied to a non-typedef.
284 C ObjC C++ ObjC++ LTO Var(warn_abi) Warning
285 Warn about things that will change when compiling with an ABI-compliant compiler.
288 C ObjC C++ ObjC++ LTO Joined RejectNegative UInteger Warning
289 Warn about things that change between the current -fabi-version and the specified version.
292 C++ ObjC++ Var(warn_abi_tag) Warning
293 Warn if a subobject has an abi_tag attribute that the complete object type does not have.
296 C ObjC C++ ObjC++ LTO Var(warn_psabi) Init(1) Warning Undocumented LangEnabledBy(C ObjC C++ ObjC++,Wabi)
299 C ObjC Var(warn_absolute_value) Warning EnabledBy(Wextra)
300 Warn on suspicious calls of standard functions computing absolute values.
303 C ObjC C++ ObjC++ Var(warn_address) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
304 Warn about suspicious uses of memory addresses.
307 Name(warn_aligned_new_level) Type(int) UnknownError(argument %qs to %<-Waligned-new%> not recognized)
310 Enum(warn_aligned_new_level) String(none) Value(0)
313 Enum(warn_aligned_new_level) String(global) Value(1)
316 Enum(warn_aligned_new_level) String(all) Value(2)
319 C++ ObjC++ Alias(Waligned-new=,global,none)
320 Warn about 'new' of type with extended alignment without -faligned-new.
323 C++ ObjC++ Var(warn_aligned_new) Enum(warn_aligned_new_level) Joined RejectNegative Warning LangEnabledBy(C++ ObjC++,Wall,1,0)
324 -Waligned-new=[none|global|all] Warn even if 'new' uses a class member allocation function.
327 C ObjC C++ ObjC++ Warning
328 Enable most warning messages.
331 C ObjC C++ ObjC++ Var(warn_alloca) Warning
332 Warn on any use of alloca.
334 Walloc-size-larger-than=
335 C ObjC C++ LTO ObjC++ Var(warn_alloc_size_limit) Joined Host_Wide_Int ByteSize Warning Init(HOST_WIDE_INT_MAX)
336 -Walloc-size-larger-than=<bytes> Warn for calls to allocation functions that
337 attempt to allocate objects larger than the specified number of bytes.
339 Wno-alloc-size-larger-than
340 C ObjC C++ LTO ObjC++ Alias(Walloc-size-larger-than=,18446744073709551615EiB,none) Warning
341 Disable Walloc-size-larger-than= warning. Equivalent to Walloc-size-larger-than=<SIZE_MAX> or larger.
344 C ObjC C++ ObjC++ Var(warn_alloc_zero) Warning
345 Warn for calls to allocation functions that specify zero bytes.
348 C ObjC C++ LTO ObjC++ Var(warn_alloca_limit) Warning Joined Host_Wide_Int ByteSize Init(HOST_WIDE_INT_MAX)
349 -Walloca-larger-than=<number> Warn on unbounded uses of
350 alloca, and on bounded uses of alloca whose bound can be larger than
353 Wno-alloca-larger-than
354 C ObjC C++ LTO ObjC++ Alias(Walloca-larger-than=,18446744073709551615EiB,none) Warning
355 Disable Walloca-larger-than= warning. Equivalent to Walloca-larger-than=<SIZE_MAX> or larger.
358 LangEnabledBy(C ObjC C++ LTO ObjC++,Wall,1,0)
362 C ObjC C++ ObjC++ Var(warn_array_compare) Warning LangEnabledBy(C ObjC C++ ObjC++, Wall)
363 Warn about comparisons between two operands of array type.
366 C ObjC C++ ObjC++ Warning Alias(Warray-parameter=, 2, 0)
367 Warn about mismatched declarations of array parameters and unsafe accesses to them.
370 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_array_parameter) IntegerRange(0, 2) LangEnabledBy(C ObjC C++ ObjC++,Wall, 2, 0) Warning
371 Warn about mismatched declarations of array parameters and unsafe accesses to them.
374 C ObjC C++ ObjC++ Var(warn_zero_length_bounds) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
375 Warn about accesses to interior zero-length array members.
378 ObjC ObjC++ Var(warn_assign_intercept) Warning
379 Warn whenever an Objective-C assignment is being intercepted by the garbage collector.
382 C ObjC Var(warn_bad_function_cast) Warning
383 Warn about casting functions to incompatible types.
386 C ObjC C++ ObjC++ Warning Alias(Wbidi-chars=,any,none)
390 C ObjC C++ ObjC++ RejectNegative Joined Warning CPP(cpp_warn_bidirectional) CppReason(CPP_W_BIDIRECTIONAL) Var(warn_bidirectional) Init(bidirectional_unpaired) Enum(cpp_bidirectional_level) EnumSet
391 -Wbidi-chars=[none|unpaired|any|ucn] Warn about UTF-8 bidirectional control characters.
393 ; Required for these enum values.
398 Name(cpp_bidirectional_level) Type(int) UnknownError(argument %qs to %<-Wbidi-chars%> not recognized)
401 Enum(cpp_bidirectional_level) String(none) Value(bidirectional_none) Set(1)
404 Enum(cpp_bidirectional_level) String(unpaired) Value(bidirectional_unpaired) Set(1)
407 Enum(cpp_bidirectional_level) String(any) Value(bidirectional_any) Set(1)
410 Enum(cpp_bidirectional_level) String(ucn) Value(bidirectional_ucn) Set(2)
413 C ObjC C++ ObjC++ Var(warn_bool_compare) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
414 Warn about boolean expression compared with an integer value different from true/false.
417 C ObjC C++ ObjC++ Var(warn_bool_op) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
418 Warn about certain operations on boolean expressions.
421 C ObjC C++ ObjC++ Var(warn_frame_address) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
422 Warn when __builtin_frame_address or __builtin_return_address is used unsafely.
424 Wbuiltin-declaration-mismatch
425 C ObjC C++ ObjC++ Var(warn_builtin_declaration_mismatch) Init(1) Warning
426 Warn when a built-in function is declared with the wrong signature.
428 Wbuiltin-macro-redefined
429 C ObjC C++ ObjC++ CPP(warn_builtin_macro_redefined) CppReason(CPP_W_BUILTIN_MACRO_REDEFINED) Var(cpp_warn_builtin_macro_redefined) Init(1) Warning
430 Warn when a built-in preprocessor macro is undefined or redefined.
433 C ObjC CPP(cpp_warn_c11_c2x_compat) CppReason(CPP_W_C11_C2X_COMPAT) Var(warn_c11_c2x_compat) Init(-1) Warning
434 Warn about features not present in ISO C11, but present in ISO C2X.
437 C ObjC CPP(cpp_warn_c90_c99_compat) CppReason(CPP_W_C90_C99_COMPAT) Var(warn_c90_c99_compat) Init(-1) Warning
438 Warn about features not present in ISO C90, but present in ISO C99.
441 C ObjC Var(warn_c99_c11_compat) Init(-1) Warning
442 Warn about features not present in ISO C99, but present in ISO C11.
445 C ObjC Var(warn_cxx_compat) CPP(warn_cxx_operator_names) CppReason(CPP_W_CXX_OPERATOR_NAMES) Init(0) Warning
446 Warn about C constructs that are not in the common subset of C and C++.
449 C++ ObjC++ Warning Alias(Wc++11-compat) Undocumented
452 C++ ObjC++ Var(warn_cxx11_compat) Warning LangEnabledBy(C++ ObjC++,Wall) Init(0) CPP(cpp_warn_cxx11_compat) CppReason(CPP_W_CXX11_COMPAT)
453 Warn about C++ constructs whose meaning differs between ISO C++ 1998 and ISO C++ 2011.
456 C++ ObjC++ Var(warn_cxx14_compat) Warning LangEnabledBy(C++ ObjC++,Wall)
457 Warn about C++ constructs whose meaning differs between ISO C++ 2011 and ISO C++ 2014.
460 C++ ObjC++ Warning Alias(Wc++17-compat) Undocumented
463 C++ ObjC++ Var(warn_cxx17_compat) Warning LangEnabledBy(C++ ObjC++,Wall)
464 Warn about C++ constructs whose meaning differs between ISO C++ 2014 and ISO C++ 2017.
467 C++ ObjC++ Warning Alias(Wc++20-compat) Undocumented
470 C++ ObjC++ Var(warn_cxx20_compat) Warning LangEnabledBy(C++ ObjC++,Wall) Init(0) CPP(cpp_warn_cxx20_compat) CppReason(CPP_W_CXX20_COMPAT)
471 Warn about C++ constructs whose meaning differs between ISO C++ 2017 and ISO C++ 2020.
474 C++ ObjC++ Var(warn_cxx11_extensions) Warning Init(1)
475 Warn about C++11 constructs in code compiled with an older standard.
478 C++ ObjC++ Var(warn_cxx14_extensions) Warning Init(1)
479 Warn about C++14 constructs in code compiled with an older standard.
482 C++ ObjC++ Var(warn_cxx17_extensions) Warning Init(1)
483 Warn about C++17 constructs in code compiled with an older standard.
486 C++ ObjC++ Var(warn_cxx20_extensions) Warning Init(1)
487 Warn about C++20 constructs in code compiled with an older standard.
490 C++ ObjC++ Var(warn_cxx23_extensions) Warning Init(1)
491 Warn about C++23 constructs in code compiled with an older standard.
494 C ObjC C++ ObjC++ Var(warn_cast_function_type) Warning EnabledBy(Wextra)
495 Warn about casts between incompatible function types.
498 C ObjC C++ ObjC++ Var(warn_cast_qual) Warning
499 Warn about casts which discard qualifiers.
502 C++ ObjC++ Warning Alias(Wcatch-value=, 1, 0)
503 Warn about catch handlers of non-reference type.
506 C++ ObjC++ Var(warn_catch_value) Warning Joined RejectNegative UInteger LangEnabledBy(C++ ObjC++,Wall, 1, 0) IntegerRange(0, 3)
507 Warn about catch handlers of non-reference type.
510 C++ ObjC++ Var(warn_changes_meaning) Warning Init(1)
511 Complain about a name being declared as a class member after a previous use of the same name.
514 C ObjC C++ ObjC++ Var(warn_char_subscripts) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
515 Warn about subscripts whose type is \"char\".
518 C ObjC C++ ObjC++ Warning WarnRemoved
519 Removed in GCC 9. This switch has no effect.
522 C ObjC C++ ObjC++ Var(warn_clobbered) Warning EnabledBy(Wextra)
523 Warn about variables that might be changed by \"longjmp\" or \"vfork\".
526 C++ ObjC++ Var(warn_comma_subscript) Warning
527 Warn about uses of a comma operator within a subscripting expression.
530 C ObjC C++ ObjC++ CPP(warn_comments) CppReason(CPP_W_COMMENTS) Var(cpp_warn_comment) Init(0) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
531 Warn about possibly nested block comments, and C++ comments spanning more than one physical line.
534 C ObjC C++ ObjC++ Warning Alias(Wcomment)
535 Synonym for -Wcomment.
537 Wconditionally-supported
538 C++ ObjC++ Var(warn_conditionally_supported) Warning
539 Warn for conditionally-supported constructs.
542 C ObjC C++ ObjC++ Var(warn_conversion) Warning
543 Warn for implicit type conversions that may change a value.
546 C++ ObjC++ Var(warn_conversion_null) Init(1) Warning
547 Warn for converting NULL from/to a non-pointer type.
550 C ObjC C++ ObjC++ CppReason(CPP_W_WARNING_DIRECTIVE)
551 ; Documented in common.opt
553 Wctad-maybe-unsupported
554 C++ ObjC++ Var(warn_ctad_maybe_unsupported) Warning
555 Warn when performing class template argument deduction on a type with no
559 C++ ObjC++ Var(warn_ctor_dtor_privacy) Warning
560 Warn when all constructors and destructors are private.
563 C ObjC C++ ObjC++ Var(warn_dangling_else) Warning LangEnabledBy(C ObjC C++ ObjC++,Wparentheses)
564 Warn about dangling else.
567 C ObjC C++ LTO ObjC++ Alias(Wdangling-pointer=, 2, 0) Warning
568 Warn for uses of pointers to auto variables whose lifetime has ended.
571 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_dangling_pointer) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall, 2, 0) IntegerRange(0, 2)
572 Warn for uses of pointers to auto variables whose lifetime has ended.
575 C++ ObjC++ Var(warn_dangling_reference) Warning LangEnabledBy(C++ ObjC++, Wall)
576 Warn when a reference is bound to a temporary whose lifetime has ended.
579 C ObjC C++ ObjC++ CPP(warn_date_time) CppReason(CPP_W_DATE_TIME) Var(cpp_warn_date_time) Init(0) Warning
580 Warn about __TIME__, __DATE__ and __TIMESTAMP__ usage.
582 Wdeclaration-after-statement
583 C ObjC Var(warn_declaration_after_statement) Init(-1) Warning
584 Warn when a declaration is found after a statement.
587 C++ ObjC++ Var(warn_delete_incomplete) Init(1) Warning
588 Warn when deleting a pointer to incomplete type.
590 Wdelete-non-virtual-dtor
591 C++ ObjC++ Var(warn_delnonvdtor) Warning LangEnabledBy(C++ ObjC++,Wall || Weffc++)
592 Warn about deleting polymorphic objects with non-virtual destructors.
595 C C++ ObjC ObjC++ CPP(cpp_warn_deprecated) CppReason(CPP_W_DEPRECATED)
596 ; Documented in common.opt
599 C++ ObjC++ Var(warn_deprecated_copy) Warning LangEnabledBy(C++ ObjC++, Wextra)
600 Mark implicitly-declared copy operations as deprecated if the class has a
601 user-provided copy operation.
603 Wdeprecated-copy-dtor
604 C++ ObjC++ Var(warn_deprecated_copy, 2) Warning
605 Mark implicitly-declared copy operations as deprecated if the class has a
606 user-provided copy operation or destructor.
608 Wdeprecated-enum-enum-conversion
609 C++ ObjC++ Var(warn_deprecated_enum_enum_conv) Warning
610 Warn about deprecated arithmetic conversions on operands of enumeration types.
612 Wdeprecated-enum-float-conversion
613 C++ ObjC++ Var(warn_deprecated_enum_float_conv) Warning
614 Warn about deprecated arithmetic conversions on operands where one is of enumeration
615 type and the other is of a floating-point type.
618 C ObjC Var(warn_designated_init) Init(1) Warning
619 Warn about positional initialization of structs requiring designated initializers.
621 Wdiscarded-array-qualifiers
622 C ObjC Var(warn_discarded_array_qualifiers) Init(1) Warning
623 Warn if qualifiers on arrays which are pointer targets are discarded.
625 Wdiscarded-qualifiers
626 C ObjC Var(warn_discarded_qualifiers) Init(1) Warning
627 Warn if type qualifiers on pointers are discarded.
630 C ObjC C++ ObjC++ Var(warn_div_by_zero) Init(1) Warning
631 Warn about compile-time integer division by zero.
634 C ObjC C++ ObjC++ Var(warn_duplicated_branches) Init(0) Warning
635 Warn about duplicated branches in if-else statements.
638 C ObjC C++ ObjC++ Var(warn_duplicated_cond) Init(0) Warning
639 Warn about duplicated conditions in an if-else-if chain.
642 C++ ObjC++ Var(warn_ecpp) Warning
643 Warn about violations of Effective C++ style rules.
646 C ObjC C++ ObjC++ Var(warn_empty_body) Warning EnabledBy(Wextra)
647 Warn about an empty body in an if or else statement.
650 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)
651 Warn about stray tokens after #else and #endif.
654 C ObjC C++ ObjC++ Var(warn_enum_compare) Init(-1) Warning LangEnabledBy(C ObjC,Wall || Wc++-compat)
655 Warn about comparison of different enum types.
658 C ObjC C++ ObjC++ Var(warn_enum_conversion) Init(0) Warning LangEnabledBy(C ObjC,Wextra)
659 Warn about implicit conversion of enum types.
662 C ObjC Var(warn_enum_int_mismatch) Warning LangEnabledBy(C ObjC,Wall || Wc++-compat)
663 Warn about enum/integer type mismatches.
667 ; Documented in common.opt
669 Werror-implicit-function-declaration
670 C ObjC RejectNegative Warning Alias(Werror=, implicit-function-declaration)
671 This switch is deprecated; use -Werror=implicit-function-declaration instead.
674 C++ ObjC++ Var(warn_exceptions) Init(1) Warning
675 Warn when an exception handler is shadowed by another handler.
678 C ObjC C++ ObjC++ Warning
682 C++ ObjC++ Var(warn_extra_semi) Warning
683 Warn about semicolon after in-class function definition.
686 C ObjC C++ ObjC++ Var(warn_float_conversion) Warning LangEnabledBy(C ObjC C++ ObjC++,Wconversion)
687 Warn for implicit type conversions that cause loss of floating point precision.
690 C ObjC C++ ObjC++ Var(warn_float_equal) Warning
691 Warn if testing floating point numbers for equality.
694 C ObjC C++ ObjC++ Warning Alias(Wformat=, 1, 0)
695 Warn about printf/scanf/strftime/strfmon format string anomalies.
698 C ObjC C++ ObjC++ Var(warn_format_contains_nul) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
699 Warn about format strings that contain NUL bytes.
702 C ObjC C++ ObjC++ Var(warn_format_diag) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
703 Warn about GCC format strings with strings unsuitable for diagnostics.
706 C ObjC C++ ObjC++ Var(warn_format_extra_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
707 Warn if passing too many arguments to a function for its format string.
710 C ObjC C++ ObjC++ Var(warn_format_nonliteral) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 2, 0)
711 Warn about format strings that are not literals.
714 C ObjC C++ LTO ObjC++ Warning Alias(Wformat-overflow=, 1, 0) IntegerRange(0, 2)
715 Warn about function calls with format strings that write past the end
716 of the destination region. Same as -Wformat-overflow=1.
719 C ObjC C++ ObjC++ Var(warn_format_security) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 2, 0)
720 Warn about possible security problems with format functions.
723 C ObjC C++ ObjC++ Var(warn_format_signedness) Warning
724 Warn about sign differences with format functions.
727 C ObjC C++ LTO ObjC++ Warning Alias(Wformat-truncation=, 1, 0)
728 Warn about calls to snprintf and similar functions that truncate output.
729 Same as -Wformat-truncation=1.
732 C ObjC C++ ObjC++ Var(warn_format_y2k) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 2, 0)
733 Warn about strftime formats yielding 2-digit years.
736 C ObjC C++ ObjC++ Var(warn_format_zero_length) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 1, 0)
737 Warn about zero-length formats.
740 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_format) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0) IntegerRange(0, 2)
741 Warn about printf/scanf/strftime/strfmon format string anomalies.
744 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)
745 Warn about function calls with format strings that write past the end
746 of the destination region.
749 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)
750 Warn about calls to snprintf and similar functions that truncate output.
752 Wflex-array-member-not-at-end
753 C C++ Var(warn_flex_array_member_not_at_end) Warning
754 Warn when a structure containing a C99 flexible array member as the last
755 field is not at the end of another structure.
758 C ObjC C++ ObjC++ Var(warn_if_not_aligned) Init(1) Warning
759 Warn when the field in a struct is not aligned.
762 C C++ Var(warn_ignored_qualifiers) Warning EnabledBy(Wextra)
763 Warn whenever type qualifiers are ignored.
766 C C++ Var(warn_ignored_attributes) Init(1) Warning
767 Warn whenever attributes are ignored.
770 C++ ObjC++ Var(warn_inaccessible_base) Init(1) Warning
771 Warn when a base is inaccessible in derived due to ambiguity.
773 Wincompatible-pointer-types
774 C ObjC Var(warn_incompatible_pointer_types) Init(1) Warning
775 Warn when there is a conversion between pointers that have incompatible types.
778 C ObjC C++ LTO ObjC++ Var(warn_infinite_recursion) Warning LangEnabledBy(C ObjC C++ LTO ObjC++, Wall)
779 Warn for infinitely recursive calls.
781 Waddress-of-packed-member
782 C ObjC C++ ObjC++ Var(warn_address_of_packed_member) Init(1) Warning
783 Warn when the address of packed member of struct or union is taken.
786 C ObjC C++ ObjC++ Var(warn_init_self) Warning LangEnabledBy(C++ ObjC++,Wall)
787 Warn about variables which are initialized to themselves.
790 C++ ObjC++ Var(warn_init_list) Warning Init(1)
791 Warn about uses of std::initializer_list that can result in dangling pointers.
794 C++ ObjC++ Var(warn_interference_size) Warning Init(1)
795 Warn about nonsensical values of --param destructive-interference-size or
796 constructive-interference-size.
799 C ObjC Var(warn_implicit) Warning LangEnabledBy(C ObjC,Wall)
800 Warn about implicit declarations.
802 Wimplicit-fallthrough=
803 LangEnabledBy(C ObjC C++ ObjC++,Wextra,3,0)
807 C ObjC C++ ObjC++ Var(warn_double_promotion) Warning
808 Warn about implicit conversions from \"float\" to \"double\".
810 Wexpansion-to-defined
811 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)
812 Warn if \"defined\" is used outside #if.
814 Wimplicit-function-declaration
815 C ObjC Var(warn_implicit_function_declaration) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit)
816 Warn about implicit function declarations.
819 C ObjC Var(warn_implicit_int) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit)
820 Warn when a declaration does not specify a type.
823 C ObjC C++ ObjC++ Undocumented Ignore
825 Winherited-variadic-ctor
826 C++ ObjC++ Var(warn_inh_var_ctor) Init(1) Warning
827 Warn about C++11 inheriting constructors when the base has a variadic constructor.
830 C ObjC Var(warn_int_conversion) Init(1) Warning
831 Warn about incompatible integer to pointer and pointer to integer conversions.
834 C ObjC C++ ObjC++ Var(warn_int_in_bool_context) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
835 Warn for suspicious integer expressions in boolean context.
838 C ObjC C++ ObjC++ Var(warn_int_to_pointer_cast) Init(1) Warning
839 Warn when there is a cast to a pointer from an integer of a different size.
842 C++ ObjC++ Var(warn_invalid_constexpr) Init(-1) Warning
843 Warn when a function never produces a constant expression.
846 C++ ObjC++ Var(warn_invalid_offsetof) Init(1) Warning
847 Warn about invalid uses of the \"offsetof\" macro.
850 C ObjC C++ ObjC++ CPP(warn_invalid_pch) CppReason(CPP_W_INVALID_PCH) Var(cpp_warn_invalid_pch) Init(0) Warning
851 Warn about PCH files that are found but not used.
854 C ObjC C++ ObjC++ CPP(cpp_warn_invalid_utf8) CppReason(CPP_W_INVALID_UTF8) Var(warn_invalid_utf8) Init(0) Warning
855 Warn about invalid UTF-8 characters.
858 C ObjC Var(warn_jump_misses_init) Warning LangEnabledby(C ObjC,Wc++-compat)
859 Warn when a jump misses a variable initialization.
862 C++ ObjC++ CPP(warn_literal_suffix) CppReason(CPP_W_LITERAL_SUFFIX) Var(cpp_warn_literal_suffix) Init(1) Warning
863 Warn when a string or character literal is followed by a ud-suffix which does not begin with an underscore.
866 C ObjC C++ ObjC++ Var(warn_logical_op) Init(0) Warning
867 Warn when a logical operator is suspiciously always evaluating to true or false.
869 Wlogical-not-parentheses
870 C ObjC C++ ObjC++ Var(warn_logical_not_paren) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
871 Warn when logical not is used on the left hand side operand of a comparison.
874 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)
875 Do not warn about using \"long long\" when -pedantic.
878 C ObjC C++ ObjC++ Var(warn_main) Init(-1) Warning LangEnabledBy(C ObjC,Wall, 2, 0)
879 Warn about suspicious declarations of \"main\".
882 LangEnabledBy(C ObjC C++ ObjC++,Wpedantic, 2, 0)
885 Wmemset-transposed-args
886 C ObjC C++ ObjC++ Var(warn_memset_transposed_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
887 Warn about suspicious calls to memset where the third argument is constant literal zero and the second is not.
890 C ObjC C++ ObjC++ Var(warn_memset_elt_size) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
891 Warn about suspicious calls to memset where the third argument contains the number of elements not multiplied by the element size.
893 Wmisleading-indentation
894 C C++ Common Var(warn_misleading_indentation) Warning LangEnabledBy(C C++,Wall)
895 Warn when the indentation of the code does not reflect the block structure.
898 C ObjC C++ ObjC++ Var(warn_mismatched_alloc) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
899 Warn for deallocation calls with arguments returned from mismatched allocation
902 Wmismatched-new-delete
903 C++ ObjC++ Var(warn_mismatched_new_delete) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
904 Warn for mismatches between calls to operator new or delete and the corresponding
905 call to the allocation or deallocation function.
908 C++ ObjC++ Var(warn_mismatched_tags) Warning
909 Warn when a class is redeclared or referenced using a mismatched class-key.
912 C ObjC C++ ObjC++ Var(warn_missing_braces) Warning LangEnabledBy(C ObjC,Wall)
913 Warn about possibly missing braces around initializers.
915 Wmissing-declarations
916 C ObjC C++ ObjC++ Var(warn_missing_declarations) Warning
917 Warn about global functions without previous declarations.
919 Wmissing-field-initializers
920 C ObjC C++ ObjC++ Var(warn_missing_field_initializers) Warning EnabledBy(Wextra)
921 Warn about missing fields in struct initializers.
924 C++ ObjC++ Var(warn_missing_requires) Init(1) Warning
925 Warn about likely missing requires keyword.
927 Wmissing-template-keyword
928 C++ ObjC++ Var(warn_missing_template_keyword) Init(1) Warning
929 Warn when the template keyword is missing after a member access token in a dependent member access expression if that member is a template.
931 Wmultistatement-macros
932 C ObjC C++ ObjC++ Var(warn_multistatement_macros) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
933 Warn about unsafe macros expanding to multiple statements used as a body of a clause such as if, else, while, switch, or for.
935 Wmultiple-inheritance
936 C++ ObjC++ Var(warn_multiple_inheritance) Warning
937 Warn on direct multiple inheritance.
940 C++ ObjC++ Var(warn_namespaces) Warning
941 Warn on namespace definition.
944 C++ ObjC++ Var(warn_nrvo)
945 Warn if the named return value optimization is not performed although it is allowed.
948 C ObjC C++ ObjC++ Var(warn_packed_not_aligned) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
949 Warn when fields in a struct with the packed attribute are misaligned.
951 Wrange-loop-construct
952 C++ ObjC++ Var(warn_range_loop_construct) Warning LangEnabledBy(C++ ObjC++,Wall)
953 Warn when a range-based for-loop is creating unnecessary copies.
956 C++ ObjC++ Var(warn_redundant_tags) Warning
957 Warn when a class or enumerated type is referenced using a redundant class-key.
960 C++ ObjC++ Var(warn_sized_deallocation) Warning EnabledBy(Wextra)
961 Warn about missing sized deallocation functions.
964 C ObjC C++ ObjC++ Var(warn_sizeof_pointer_div) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
965 Warn about suspicious divisions of two sizeof expressions that don't work correctly with pointers.
968 C ObjC C++ ObjC++ Var(warn_sizeof_array_div) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
969 Warn about divisions of two sizeof operators when the first one is applied
970 to an array and the divisor does not equal the size of the array element.
972 Wsizeof-pointer-memaccess
973 C ObjC C++ ObjC++ Var(warn_sizeof_pointer_memaccess) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
974 Warn about suspicious length parameters to certain string functions if the argument uses sizeof.
976 Wsizeof-array-argument
977 C ObjC C++ ObjC++ Var(warn_sizeof_array_argument) Warning Init(1)
978 Warn when sizeof is applied on a parameter declared as an array.
981 C ObjC C++ LTO ObjC++ Warning Var(warn_string_compare) Warning LangEnabledBy(C ObjC C++ ObjC++, Wextra)
982 Warn about calls to strcmp and strncmp used in equality expressions that
983 are necessarily true or false due to the length of one and size of the other
987 C ObjC C++ LTO ObjC++ Warning Alias(Wstringop-overflow=, 2, 0)
988 Warn about buffer overflow in string manipulation functions like memcpy
992 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)
993 Under the control of Object Size type, warn about buffer overflow in string
994 manipulation functions like memcpy and strcpy.
997 C ObjC C++ LTO ObjC++ Var(warn_stringop_overread) Init(1) Warning LangEnabledBy(C ObjC C++ LTO ObjC++, Wall)
998 Warn about reading past the end of a source array in string manipulation functions like memchr and memcpy.
1000 Wstringop-truncation
1001 C ObjC C++ LTO ObjC++ Var(warn_stringop_truncation) Warning Init (1) LangEnabledBy(C ObjC C++ LTO ObjC++, Wall)
1002 Warn about truncation in string manipulation functions like strncat and strncpy.
1005 C C++ Var(warn_strict_flex_arrays) Warning
1006 Warn about inproper usages of flexible array members
1007 according to the level of -fstrict-flex-arrays.
1009 Wsuggest-attribute=format
1010 C ObjC C++ ObjC++ Var(warn_suggest_attribute_format) Warning
1011 Warn about functions which might be candidates for format attributes.
1014 C++ ObjC++ Var(warn_override) Warning
1015 Suggest that the override keyword be used when the declaration of a virtual
1016 function overrides another.
1019 C ObjC C++ ObjC++ Var(warn_switch) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1020 Warn about enumerated switches, with no default, missing a case.
1023 C ObjC C++ ObjC++ Var(warn_switch_default) Warning
1024 Warn about enumerated switches missing a \"default:\" statement.
1027 C ObjC C++ ObjC++ Var(warn_switch_enum) Warning
1028 Warn about all enumerated switches missing a specific case.
1031 C ObjC C++ ObjC++ Var(warn_switch_bool) Warning Init(1)
1032 Warn about switches with boolean controlling expression.
1034 Wswitch-outside-range
1035 C ObjC C++ ObjC++ Var(warn_switch_outside_range) Warning Init(1)
1036 Warn about switch values that are outside of the switch's type range.
1039 C++ ObjC++ Var(warn_templates) Warning
1040 Warn on primary template declaration.
1043 C ObjC C++ ObjC++ Var(warn_missing_attributes) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1044 Warn about declarations of entities that may be missing attributes
1045 that related entities have been declared with.
1047 Wmissing-format-attribute
1048 C ObjC C++ ObjC++ Warning Alias(Wsuggest-attribute=format)
1051 Wmissing-include-dirs
1052 C ObjC C++ ObjC++ CPP(warn_missing_include_dirs) CppReason(CPP_W_MISSING_INCLUDE_DIRS) Var(cpp_warn_missing_include_dirs) Init(0) Warning
1053 Warn about user-specified include directories that do not exist.
1055 Wmissing-parameter-type
1056 C ObjC Var(warn_missing_parameter_type) Warning EnabledBy(Wextra)
1057 Warn about function parameters declared without a type specifier in K&R-style functions.
1060 C ObjC Var(warn_missing_prototypes) Warning
1061 Warn about global functions without prototypes.
1063 Wmissing-variable-declarations
1064 C ObjC Var(warn_missing_variable_declarations) Warning
1065 Warn about global variables without previous declarations.
1068 C ObjC C++ ObjC++ WarnRemoved
1071 C ObjC C++ ObjC++ CPP(warn_multichar) CppReason(CPP_W_MULTICHAR) Var(cpp_warn_multichar) Init(0) Warning
1072 Warn about use of multi-character character constants.
1075 C ObjC C++ ObjC++ Warning Var(warn_narrowing) Init(-1) LangEnabledBy(C++ ObjC++,Wall || Wc++11-compat)
1076 Warn about narrowing conversions within { } that are ill-formed in C++11.
1079 C ObjC Var(warn_nested_externs) Warning
1080 Warn about \"extern\" declarations not at file scope.
1083 C++ ObjC++ Var(warn_noexcept) Warning
1084 Warn when a noexcept expression evaluates to false even though the expression can't actually throw.
1087 C++ ObjC++ Warning Var(warn_noexcept_type) LangEnabledBy(C++ ObjC++,Wabi || Wc++17-compat)
1088 Warn if C++17 noexcept function type will change the mangled name of a symbol.
1090 Wnon-template-friend
1091 C++ ObjC++ Var(warn_nontemplate_friend) Init(1) Warning
1092 Warn when non-templatized friend functions are declared within a template.
1095 C++ ObjC++ Var(warn_class_conversion) Init(1) Warning
1096 Warn when a conversion function will never be called due to the type it converts to.
1099 C++ ObjC++ Var(warn_class_memaccess) Warning LangEnabledBy(C++ ObjC++, Wall)
1100 Warn for unsafe raw memory writes to objects of class types.
1103 C++ ObjC++ Var(warn_nonvdtor) Warning LangEnabledBy(C++ ObjC++,Weffc++)
1104 Warn about non-virtual destructors.
1107 C ObjC C++ LTO ObjC++ Var(warn_nonnull) Warning LangEnabledBy(C ObjC C++ LTO ObjC++,Wformat=,warn_format >= 1,0)
1108 Warn about NULL being passed to argument slots marked as requiring non-NULL.
1111 C ObjC C++ LTO ObjC++ LangEnabledBy(C ObjC C++ LTO ObjC++,Wall)
1115 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
1119 C ObjC C++ ObjC++ Warning Alias(Wnormalized=,nfc,none)
1123 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)
1124 -Wnormalized=[none|id|nfc|nfkc] Warn about non-normalized Unicode strings.
1126 ; Required for these enum values.
1131 Name(cpp_normalize_level) Type(int) UnknownError(argument %qs to %<-Wnormalized%> not recognized)
1134 Enum(cpp_normalize_level) String(none) Value(normalized_none)
1137 Enum(cpp_normalize_level) String(nfkc) Value(normalized_KC)
1140 Enum(cpp_normalize_level) String(id) Value(normalized_identifier_C)
1143 Enum(cpp_normalize_level) String(nfc) Value(normalized_C)
1146 ObjC ObjC++ Var(warn_objc_root_class) Warning Init(1)
1147 Warn if a class interface has no superclass. Root classes may use an attribute
1148 to suppress this warning.
1151 C++ ObjC++ Var(warn_old_style_cast) Warning
1152 Warn if a C-style cast is used in a program.
1154 Wold-style-declaration
1155 C ObjC Var(warn_old_style_declaration) Warning EnabledBy(Wextra)
1156 Warn for obsolescent usage in a declaration.
1158 Wold-style-definition
1159 C ObjC Var(warn_old_style_definition) Init(-1) Warning
1160 Warn if an old-style parameter definition is used.
1162 Wopenacc-parallelism
1163 C C++ Var(warn_openacc_parallelism) Warning
1164 Warn about potentially suboptimal choices related to OpenACC parallelism.
1167 C C++ Var(warn_openmp_simd) Warning LangEnabledBy(C C++,Wall)
1168 Warn if a simd directive is overridden by the vectorizer cost model.
1171 C ObjC C++ ObjC++ Var(warn_overlength_strings) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic)
1172 Warn if a string is longer than the maximum portable length specified by the standard.
1175 C++ ObjC++ Warning Alias(Woverloaded-virtual=,2,0)
1176 Warn about overloaded virtual function names.
1178 Woverloaded-virtual=
1179 C++ ObjC++ Joined UInteger IntegerRange(0,2) Var(warn_overloaded_virtual) Warning LangEnabledBy(C++ ObjC++,Wall,1,0)
1180 Warn about overloaded virtual function names.
1183 C ObjC Var(warn_override_init) Warning EnabledBy(Wextra)
1184 Warn about overriding initializers without side effects.
1186 Woverride-init-side-effects
1187 C ObjC Var(warn_override_init_side_effects) Init(1) Warning
1188 Warn about overriding initializers with side effects.
1190 Wpacked-bitfield-compat
1191 C ObjC C++ ObjC++ Var(warn_packed_bitfield_compat) Init(-1) Warning
1192 Warn about packed bit-fields whose offset changed in GCC 4.4.
1195 C ObjC C++ ObjC++ Var(warn_parentheses) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1196 Warn about possibly missing parentheses.
1199 C ObjC C++ ObjC++ CPP(cpp_pedantic) CppReason(CPP_W_PEDANTIC) Warning
1200 ; Documented in common.opt
1203 C++ ObjC++ Var(warn_pessimizing_move) Warning LangEnabledBy(C++ ObjC++, Wall)
1204 Warn about calling std::move on a local object in a return statement preventing copy elision.
1207 C++ ObjC++ Var(warn_pmf2ptr) Init(1) Warning
1208 Warn when converting the type of pointers to member functions.
1211 C ObjC C++ ObjC++ Var(warn_pointer_arith) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic)
1212 Warn about function pointer arithmetic.
1215 C ObjC Var(warn_pointer_sign) Warning LangEnabledBy(C ObjC,Wall || Wpedantic)
1216 Warn when a pointer differs in signedness in an assignment.
1219 C ObjC C++ ObjC++ Var(warn_pointer_compare) Init(1) Warning
1220 Warn when a pointer is compared with a zero character constant.
1222 Wpointer-to-int-cast
1223 C ObjC Var(warn_pointer_to_int_cast) Init(1) Warning
1224 Warn when a pointer is cast to an integer of a different size.
1227 C ObjC C++ ObjC++ Var(warn_pragmas) Init(1) Warning
1228 Warn about misuses of pragmas.
1231 C ObjC C++ ObjC++ Var(warn_prio_ctor_dtor) Init(1) Warning
1232 Warn if constructor or destructors with priorities from 0 to 100 are used.
1234 Wproperty-assign-default
1235 ObjC ObjC++ Var(warn_property_assign_default) Init(1) Warning
1236 Warn if a property for an Objective-C object has no assign semantics specified.
1239 ObjC ObjC++ Var(warn_protocol) Init(1) Warning
1240 Warn if inherited methods are unimplemented.
1243 C++ Warning Alias(Wplacement-new=, 1, 0)
1244 Warn for placement new expressions with undefined behavior.
1247 C++ Joined RejectNegative UInteger Var(warn_placement_new) Init(-1) Warning IntegerRange(0, 2)
1248 Warn for placement new expressions with undefined behavior.
1251 C ObjC C++ ObjC++ Var(warn_redundant_decls) Warning
1252 Warn about multiple declarations of the same object.
1255 C++ ObjC++ Var(warn_redundant_move) Warning LangEnabledBy(C++ ObjC++,Wextra)
1256 Warn about redundant calls to std::move.
1259 C++ ObjC++ Var(warn_register) Warning
1260 Warn about uses of register storage specifier.
1263 C++ ObjC++ Var(warn_reorder) Warning LangEnabledBy(C++ ObjC++,Wall)
1264 Warn when the compiler reorders code.
1267 C ObjC C++ ObjC++ Var(warn_return_type) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Init(-1)
1268 Warn whenever a function's return type defaults to \"int\" (C), or about inconsistent return types (C++).
1270 Wscalar-storage-order
1271 C ObjC C++ ObjC++ Var(warn_scalar_storage_order) Init(1) Warning
1272 Warn on suspicious constructs involving reverse scalar storage order.
1275 ObjC ObjC++ Var(warn_selector) Warning
1276 Warn if a selector has multiple methods.
1279 C++ ObjC++ Var(warn_self_move) Warning LangEnabledBy(C++ ObjC++, Wall)
1280 Warn when a value is moved to itself with std::move.
1283 C ObjC C++ ObjC++ Var(warn_sequence_point) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1284 Warn about possible violations of sequence point rules.
1287 ObjC ObjC++ Var(warn_shadow_ivar) EnabledBy(Wshadow) Init(1) Warning
1288 Warn if a local declaration hides an instance variable.
1291 C ObjC C++ ObjC++ Warning Alias(Wshift-overflow=, 1, 0)
1292 Warn if left shift of a signed value overflows.
1295 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_shift_overflow) Init(-1) Warning IntegerRange(0, 2)
1296 Warn if left shift of a signed value overflows.
1298 Wshift-count-negative
1299 C ObjC C++ ObjC++ Var(warn_shift_count_negative) Init(1) Warning
1300 Warn if shift count is negative.
1302 Wshift-count-overflow
1303 C ObjC C++ ObjC++ Var(warn_shift_count_overflow) Init(1) Warning
1304 Warn if shift count >= width of type.
1306 Wshift-negative-value
1307 C ObjC C++ ObjC++ Var(warn_shift_negative_value) Init(-1) Warning
1308 Warn if left shifting a negative value.
1311 C ObjC C++ ObjC++ Var(warn_arith_conv) Warning
1312 Warn if conversion of the result of arithmetic might change the value even though converting the operands cannot.
1315 C ObjC C++ ObjC++ Var(warn_sign_compare) Warning LangEnabledBy(C++ ObjC++,Wall)
1316 Warn about signed-unsigned comparisons.
1319 C ObjC C++ ObjC++ EnabledBy(Wextra)
1323 C ObjC C++ ObjC++ Var(warn_sign_conversion) Warning LangEnabledBy(C ObjC,Wconversion)
1324 Warn for implicit type conversions between signed and unsigned integers.
1327 C++ ObjC++ Var(warn_sign_promo) Warning
1328 Warn when overload promotes from unsigned to signed.
1330 Wstrict-null-sentinel
1331 C++ ObjC++ Warning Var(warn_strict_null_sentinel)
1332 Warn about uncasted NULL used as sentinel.
1335 C ObjC Var(warn_strict_prototypes) Warning
1336 Warn about unprototyped function declarations.
1339 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 3, 0) IntegerRange(0, 3)
1343 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0) IntegerRange(0, 5)
1346 Wstrict-selector-match
1347 ObjC ObjC++ Var(warn_strict_selector_match) Warning
1348 Warn if type signatures of candidate methods do not match exactly.
1351 C C++ Var(warn_sync_nand) Init(1) Warning
1352 Warn when __sync_fetch_and_nand and __sync_nand_and_fetch built-in functions are used.
1355 C++ ObjC++ Var(warn_synth) Warning
1356 Deprecated. This switch has no effect.
1359 C ObjC C++ ObjC++ Warning
1360 ; Documented in common.opt
1362 Wtautological-compare
1363 C ObjC C++ ObjC++ Var(warn_tautological_compare) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1364 Warn if a comparison always evaluates to true or false.
1367 C++ ObjC++ Warning Var(warn_terminate) Init(1)
1368 Warn if a throw expression will always result in a call to terminate().
1371 C ObjC CPP(cpp_warn_traditional) CppReason(CPP_W_TRADITIONAL) Var(warn_traditional) Init(0) Warning
1372 Warn about features not present in traditional C.
1374 Wtraditional-conversion
1375 C ObjC Var(warn_traditional_conversion) Warning
1376 Warn of prototypes causing type conversions different from what would happen in the absence of prototype.
1379 C ObjC C++ ObjC++ CPP(warn_trigraphs) CppReason(CPP_W_TRIGRAPHS) Var(cpp_warn_trigraphs) Init(2) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1380 Warn if trigraphs are encountered that might affect the meaning of the program.
1382 Wundeclared-selector
1383 ObjC ObjC++ Var(warn_undeclared_selector) Warning
1384 Warn about @selector()s without previously declared methods.
1387 C ObjC C++ ObjC++ CPP(warn_undef) CppReason(CPP_W_UNDEF) Var(cpp_warn_undef) Init(0) Warning
1388 Warn if an undefined macro is used in an #if directive.
1391 C ObjC C++ ObjC++ CPP(cpp_warn_unicode) CppReason(CPP_W_UNICODE) Var(warn_unicode) Init(1) Warning
1392 Warn about invalid forms of delimited or named escape sequences.
1395 C ObjC C++ ObjC++ LTO LangEnabledBy(C ObjC C++ ObjC++ LTO,Wall)
1398 Wmaybe-uninitialized
1399 C ObjC C++ ObjC++ LTO LangEnabledBy(C ObjC C++ ObjC++ LTO,Wall)
1403 C ObjC C++ ObjC++ Warning Var(warn_unknown_pragmas) LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0)
1404 Warn about unrecognized pragmas.
1406 Wunsuffixed-float-constants
1407 C ObjC Var(warn_unsuffixed_float_constants) Warning
1408 Warn about unsuffixed float constants.
1411 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
1412 ; documented in common.opt
1414 Wunused-local-typedefs
1415 C ObjC C++ ObjC++ Var(warn_unused_local_typedefs) Warning EnabledBy(Wunused)
1416 Warn when typedefs locally defined in a function are not used.
1419 C ObjC C++ ObjC++ CppReason(CPP_W_UNUSED_MACROS) Var(cpp_warn_unused_macros) Warning
1420 Warn about macros defined in the main file that are not used.
1423 C ObjC C++ ObjC++ Var(warn_unused_result) Init(1) Warning
1424 Warn if a caller of a function, marked with attribute warn_unused_result, does not use its return value.
1427 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wunused)
1428 ; documented in common.opt
1430 Wunused-const-variable
1431 C ObjC C++ ObjC++ Warning Alias(Wunused-const-variable=, 2, 0)
1432 Warn when a const variable is unused.
1434 Wunused-const-variable=
1435 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_unused_const_variable) Warning LangEnabledBy(C ObjC,Wunused-variable, 1, 0) IntegerRange(0, 2)
1436 Warn when a const variable is unused.
1438 ; Defining this option here in addition to common.opt is necessary
1439 ; in order for the default -Wall setting of -Wuse-after-free=2 to take
1443 LangEnabledBy(C ObjC C++ LTO ObjC++, Wall,2,0)
1447 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)
1448 Warn about using variadic macros.
1451 C ObjC C++ ObjC++ Warning Var(warn_varargs) Init(1)
1452 Warn about questionable usage of the macros used to retrieve variable arguments.
1455 C++ ObjC++ Warning Var(warn_vexing_parse) Init(1)
1456 Warn about the most vexing parse syntactic ambiguity.
1459 C ObjC C++ ObjC++ Var(warn_vla) Init(-1) Warning
1460 Warn if a variable length array is used.
1463 C ObjC C++ LTO ObjC++ Var(warn_vla_limit) Warning Joined Host_Wide_Int ByteSize Init(HOST_WIDE_INT_MAX)
1464 -Wvla-larger-than=<number> Warn on unbounded uses of variable-length
1465 arrays, and on bounded uses of variable-length arrays whose bound can be
1466 larger than <number> bytes.
1469 C ObjC C++ LTO ObjC++ Alias(Wvla-larger-than=,18446744073709551615EiB,none) Warning
1470 Disable Wvla-larger-than= warning. Equivalent to Wvla-larger-than=<SIZE_MAX> or larger.
1473 C ObjC C++ ObjC++ Var(warn_vla_parameter) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1474 Warn about mismatched declarations of VLA parameters.
1477 C++ ObjC++ Var(warn_volatile) Warning
1478 Warn about deprecated uses of volatile qualifier.
1480 Wvolatile-register-var
1481 C ObjC C++ ObjC++ Var(warn_volatile_register_var) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1482 Warn when a register variable is declared volatile.
1484 Wvirtual-inheritance
1485 C++ ObjC++ Var(warn_virtual_inheritance) Warning
1486 Warn on direct virtual inheritance.
1488 Wvirtual-move-assign
1489 C++ ObjC++ Var(warn_virtual_move_assign) Warning Init(1)
1490 Warn if a virtual base has a non-trivial move assignment operator.
1493 C ObjC C++ ObjC++ Var(warn_write_strings) Warning
1494 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.
1497 C ObjC C++ ObjC++ Var(warn_xor_used_as_pow) Warning Init(1)
1498 Warn about xor operators where it appears the user meant exponentiation.
1500 Wzero-as-null-pointer-constant
1501 C++ ObjC++ Var(warn_zero_as_null_pointer_constant) Warning
1502 Warn when a literal '0' is used as null pointer.
1505 C ObjC C++ ObjC++ Var(warn_useless_cast) Warning
1506 Warn about useless casts.
1509 C++ ObjC++ Var(warn_subobject_linkage) Warning Init(1)
1510 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.
1512 Welaborated-enum-base
1513 C++ ObjC++ Var(warn_elaborated_enum_base) Warning Init(1)
1514 Warn if an additional enum-base is used in an elaborated-type-specifier.
1516 Wduplicate-decl-specifier
1517 C ObjC Var(warn_duplicate_decl_specifier) Warning LangEnabledBy(C ObjC,Wall)
1518 Warn when a declaration has duplicate const, volatile, restrict or _Atomic specifier.
1521 C ObjC C++ ObjC++ Var(warn_restrict) Warning LangEnabledBy(C ObjC C++ ObjC++, Wall)
1522 Warn when an argument passed to a restrict-qualified parameter aliases with
1527 A synonym for -std=c89 (for C) or -std=c++98 (for C++).
1530 C ObjC C++ ObjC++ Joined
1531 ; Documented in common.opt. FIXME - what about -dI, -dD, -dN and -dD?
1533 fabi-compat-version=
1534 C++ ObjC++ Joined RejectNegative UInteger Var(flag_abi_compat_version) Init(-1)
1535 The version of the C++ ABI used for -Wabi warnings and link compatibility aliases.
1538 C++ ObjC++ Var(flag_access_control) Init(1)
1539 Enforce class member access control semantics.
1542 C ObjC C++ ObjC++ RejectNegative Joined Var(ada_specs_parent)
1543 -fada-spec-parent=unit Dump Ada specs as child units of given parent.
1546 C++ ObjC++ Alias(faligned-new=,1,0)
1547 Support C++17 allocation of over-aligned types.
1550 C++ ObjC++ Joined RejectNegative Var(aligned_new_threshold) UInteger Init(-1)
1551 -faligned-new=<N> Use C++17 over-aligned type allocation for alignments greater than N.
1554 C++ ObjC++ WarnRemoved
1556 fallow-parameterless-variadic-functions
1558 Does nothing. Preserved for backward compatibility.
1560 falt-external-templates
1561 C++ ObjC++ WarnRemoved
1562 No longer supported.
1565 C ObjC C++ ObjC++ Var(flag_no_asm, 0)
1566 Recognize the \"asm\" keyword.
1568 ; Define extra predefined macros for use in libgcc.
1570 C ObjC C++ ObjC++ Undocumented Var(flag_building_libgcc)
1573 C ObjC C++ ObjC++ Var(flag_no_builtin, 0)
1574 Recognize built-in functions.
1577 C ObjC C++ ObjC++ Joined
1579 fcanonical-system-headers
1581 Where shorter, use canonicalized paths to systems headers.
1584 C++ ObjC++ Var(flag_char8_t) Init(-1)
1585 Enable the char8_t fundamental type and use it as the type for UTF-8 string
1586 and character literals.
1588 fcheck-pointer-bounds
1589 C ObjC C++ ObjC++ LTO WarnRemoved
1590 Removed in GCC 9. This switch has no effect.
1592 fchkp-check-incomplete-type
1593 C ObjC C++ ObjC++ LTO WarnRemoved
1594 Removed in GCC 9. This switch has no effect.
1596 fchkp-zero-input-bounds-for-main
1597 C ObjC C++ ObjC++ LTO WarnRemoved
1598 Removed in GCC 9. This switch has no effect.
1600 fchkp-first-field-has-own-bounds
1601 C ObjC C++ ObjC++ LTO WarnRemoved RejectNegative
1602 Removed in GCC 9. This switch has no effect.
1605 C ObjC C++ ObjC++ LTO WarnRemoved
1606 Removed in GCC 9. This switch has no effect.
1608 fchkp-narrow-to-innermost-array
1609 C ObjC C++ ObjC++ LTO WarnRemoved RejectNegative
1610 Removed in GCC 9. This switch has no effect.
1612 fchkp-flexible-struct-trailing-arrays
1613 C ObjC C++ ObjC++ LTO WarnRemoved
1614 Removed in GCC 9. This switch has no effect.
1617 C ObjC C++ ObjC++ LTO WarnRemoved
1619 fchkp-use-fast-string-functions
1620 C ObjC C++ ObjC++ LTO WarnRemoved
1621 Removed in GCC 9. This switch has no effect.
1623 fchkp-use-nochk-string-functions
1624 C ObjC C++ ObjC++ LTO WarnRemoved
1625 Removed in GCC 9. This switch has no effect.
1627 fchkp-use-static-bounds
1628 C ObjC C++ ObjC++ LTO WarnRemoved
1629 Removed in GCC 9. This switch has no effect.
1631 fchkp-use-static-const-bounds
1632 C ObjC C++ ObjC++ LTO WarnRemoved
1633 Removed in GCC 9. This switch has no effect.
1635 fchkp-treat-zero-dynamic-size-as-infinite
1636 C ObjC C++ ObjC++ LTO WarnRemoved
1637 Removed in GCC 9. This switch has no effect.
1640 C ObjC C++ ObjC++ LTO WarnRemoved
1641 Removed in GCC 9. This switch has no effect.
1644 C ObjC C++ ObjC++ LTO WarnRemoved
1645 Removed in GCC 9. This switch has no effect.
1648 C ObjC C++ ObjC++ LTO WarnRemoved
1649 Removed in GCC 9. This switch has no effect.
1651 fchkp-instrument-calls
1652 C ObjC C++ ObjC++ LTO WarnRemoved
1653 Removed in GCC 9. This switch has no effect.
1655 fchkp-instrument-marked-only
1656 C ObjC C++ ObjC++ LTO WarnRemoved
1657 Removed in GCC 9. This switch has no effect.
1660 C ObjC C++ ObjC++ LTO WarnRemoved
1661 Removed in GCC 9. This switch has no effect.
1665 Removed in GCC 9. This switch has no effect.
1667 static-libmpxwrappers
1669 Removed in GCC 9. This switch has no effect.
1672 C ObjC C++ ObjC++ LTO Undocumented Ignore
1673 Removed in GCC 8. This switch has no effect.
1676 C++ ObjC++ Var(flag_concepts)
1677 Enable support for C++ concepts.
1680 C++ ObjC++ Var(flag_concepts_ts) Init(0)
1681 Enable certain features present in the Concepts TS.
1683 fconcepts-diagnostics-depth=
1684 C++ ObjC++ Joined RejectNegative UInteger Var(concepts_diagnostics_max_depth) Init(1)
1685 Specify maximum error replay depth during recursive diagnosis of a constraint satisfaction failure.
1689 Allow the arguments of the '?' operator to have different types.
1693 Does nothing. Preserved for backward compatibility.
1695 fconstant-string-class=
1696 ObjC ObjC++ Joined MissingArgError(no class name specified with %qs)
1697 -fconst-string-class=<name> Use class <name> for constant strings.
1700 C++ ObjC++ Joined RejectNegative UInteger Var(max_constexpr_depth) Init(512)
1701 -fconstexpr-depth=<number> Specify maximum constexpr recursion depth.
1703 fconstexpr-cache-depth=
1704 C++ ObjC++ Joined RejectNegative UInteger Var(constexpr_cache_depth) Init(8)
1705 -fconstexpr-cache-depth=<number> Specify maximum constexpr recursion cache depth.
1707 fconstexpr-fp-except
1708 C++ ObjC++ Var(flag_constexpr_fp_except) Init(0)
1709 Allow IEC559 floating point exceptions in constant expressions.
1711 fconstexpr-loop-limit=
1712 C++ ObjC++ Joined RejectNegative UInteger Var(constexpr_loop_limit) Init(262144)
1713 -fconstexpr-loop-limit=<number> Specify maximum constexpr loop iteration count.
1715 fconstexpr-ops-limit=
1716 C++ ObjC++ Joined RejectNegative Host_Wide_Int Var(constexpr_ops_limit) Init(33554432)
1717 -fconstexpr-ops-limit=<number> Specify maximum number of constexpr operations during a single constexpr evaluation.
1720 C++ ObjC++ Var(flag_contracts) Init(0)
1721 Enable certain features present in drafts of C++ Contracts.
1724 Name(on_off) Type(int) UnknownError(argument %qs must be either %<on%> or %<off%>)
1727 Enum(on_off) String(off) Value(0)
1730 Enum(on_off) String(on) Value(1)
1732 fcontract-assumption-mode=
1733 C++ Joined RejectNegative
1734 -fcontract-assumption-mode=[on|off] Enable or disable treating axiom level contracts as assumptions (default on).
1736 fcontract-build-level=
1737 C++ Joined RejectNegative
1738 -fcontract-build-level=[off|default|audit] Specify max contract level to generate runtime checks for.
1740 fcontract-strict-declarations=
1741 C++ Var(flag_contract_strict_declarations) Enum(on_off) Joined Init(0) RejectNegative
1742 -fcontract-strict-declarations=[on|off] Enable or disable warnings on generalized redeclaration of functions with contracts (default off).
1745 C++ Var(flag_contract_mode) Enum(on_off) Joined Init(1) RejectNegative
1746 -fcontract-mode=[on|off] Enable or disable all contract facilities (default on).
1748 fcontract-continuation-mode=
1749 C++ Joined RejectNegative
1750 -fcontract-continuation-mode=[on|off] Enable or disable contract continuation mode (default off).
1753 C++ Joined RejectNegative
1754 -fcontract-role=<name>:<semantics> Specify the semantics for all levels in a role (default, review), or a custom contract role with given semantics (ex: opt:assume,assume,assume).
1757 C++ Joined RejectNegative
1758 -fcontract-semantic=<level>:<semantic> Specify the concrete semantics for level.
1761 C++ LTO Var(flag_coroutines)
1762 Enable C++ coroutines (experimental).
1766 Emit debug annotations during preprocessing.
1770 Does nothing. Preserved for backward compatibility.
1773 C++ ObjC++ Var(flag_declone_ctor_dtor) Init(-1)
1774 Factor complex constructors and destructors to favor space over speed.
1778 Does nothing. Preserved for backward compatibility.
1780 fdiagnostics-show-template-tree
1781 C++ ObjC++ Var(flag_diagnostics_show_template_tree) Init(0)
1782 Print hierarchical comparisons when template types are mismatched.
1786 Preprocess directives only.
1788 fdollars-in-identifiers
1790 Permit '$' as an identifier character.
1793 C ObjC C++ ObjC++ Joined RejectNegative
1794 -fmacro-prefix-map=<old>=<new> Map one directory name to another in __FILE__, __BASE_FILE__, and __builtin_FILE().
1797 C ObjC C++ ObjC++ RejectNegative Var(flag_dump_ada_spec)
1798 Write all declarations as Ada code transitively.
1801 C ObjC C++ ObjC++ RejectNegative Var(flag_dump_ada_spec_slim)
1802 Write all declarations as Ada code for the given file only.
1805 C++ ObjC++ Var(flag_elide_constructors) Init(1)
1808 C++ ObjC++ Var(flag_elide_type) Init(1)
1809 Do not elide common elements in template comparisons.
1812 C++ ObjC++ Var(flag_enforce_eh_specs) Init(1)
1813 Generate code to check exception specifications.
1816 C++ ObjC++ WarnRemoved
1819 C ObjC C++ ObjC++ Joined RejectNegative
1820 -fexec-charset=<cset> Convert all strings and character constants to character set <cset>.
1822 fextended-identifiers
1824 Permit universal character names (\\u and \\U) in identifiers.
1827 C ObjC C++ ObjC++ Joined RejectNegative
1828 -finput-charset=<cset> Specify the default character set for source files.
1831 C++ ObjC++ Var(flag_extern_tls_init) Init(-1)
1832 Support dynamic initialization of thread-local variables in a different translation unit.
1835 C++ ObjC++ WarnRemoved
1837 ffold-simple-inlines
1838 C++ ObjC++ Optimization Var(flag_fold_simple_inlines)
1839 Fold calls to simple inline functions.
1842 C++ ObjC++ WarnRemoved
1846 Do not assume that standard C libraries and \"main\" exist.
1849 C++ ObjC++ Var(flag_no_gnu_keywords, 0)
1850 Recognize GNU-defined keywords.
1853 ObjC ObjC++ LTO RejectNegative Var(flag_next_runtime,0) Init(NEXT_OBJC_RUNTIME)
1854 Generate code for GNU runtime environment.
1857 C ObjC Var(flag_gnu89_inline) Init(-1)
1858 Use traditional GNU semantics for inline functions.
1861 C++ ObjC++ WarnRemoved
1864 C++ ObjC++ Optimization Alias(fexceptions) Warn({%<-fhandle-exceptions%> has been renamed %<-fexceptions%> (and is now on by default)})
1867 C++ ObjC++ WarnRemoved
1871 Assume normal C execution environment.
1874 C++ ObjC++ WarnRemoved
1875 No longer supported.
1878 C++ ObjC++ Var(flag_implement_inlines) Init(1)
1879 Export functions even if they can be inlined.
1882 C++ ObjC++ Var(flag_implicit_constexpr)
1883 Make inline functions constexpr by default.
1885 fimplicit-inline-templates
1886 C++ ObjC++ Var(flag_implicit_inline_templates) Init(1)
1887 Emit implicit instantiations of inline templates.
1890 C++ ObjC++ Var(flag_implicit_templates) Init(1)
1891 Emit implicit instantiations of templates.
1893 fnew-inheriting-ctors
1894 C++ ObjC++ Var(flag_new_inheriting_ctors) Init(1)
1895 Implement C++17 inheriting constructor semantics.
1898 C++ ObjC++ WarnRemoved
1900 fkeep-inline-dllexport
1901 C C++ ObjC ObjC++ Var(flag_keep_inline_dllexport) Init(1) Condition(TARGET_DLLIMPORT_DECL_ATTRIBUTES)
1902 Don't emit dllexported inline functions unless needed.
1905 C++ ObjC++ WarnRemoved
1907 flax-vector-conversions
1908 C ObjC C++ ObjC++ Var(flag_lax_vector_conversions)
1909 Allow implicit conversions between vectors with differing numbers of subparts and/or differing element types.
1912 C++ ObjC++ Var(flag_modules) Integer Init(0)
1913 Enable C++ modules-ts (experimental).
1916 C++ ObjC++ Undocumented RejectNegative Var(flag_modules,0) Integer
1920 C++ ObjC RejectNegative Var(flag_header_unit,0) Integer
1921 Enable C++ header module (experimental).
1924 C++ ObjC++ Joined RejectNegative Undocumented
1926 fmodule-implicit-inline
1927 C++ ObjC++ Var(flag_module_implicit_inline,0) Integer
1928 Member functions defined within their class are inline in module purview.
1931 C++ ObjC RejectNegative Var(flag_module_only) Integer
1932 Only emit Compiled Module Interface.
1935 C++ ObjC++ Joined RejectNegative MissingArgError(missing mapper)
1936 Mapper for module to CMI files.
1939 C++ ObjC++ Var(flag_module_lazy) Init(1)
1940 Enable lazy module importing.
1942 fmodule-version-ignore
1943 C++ ObjC Var(flag_module_version_ignore) Integer
1944 ; undocumented, Very dangerous, but occasionally useful
1946 Winvalid-imported-macros
1947 C++ ObjC++ Var(warn_imported_macros) Warning
1948 Warn about macros that have conflicting header units definitions.
1950 Wcompare-distinct-pointer-types
1951 C ObjC Var(warn_compare_distinct_pointer_types) Warning Init(1)
1952 Warn if pointers of distinct types are compared without a cast.
1954 flang-info-include-translate
1955 C++ Var(note_include_translate_yes)
1956 Note #include directives translated to import declarations.
1958 flang-info-include-translate-not
1959 C++ Var(note_include_translate_no)
1960 Note #include directives not translated to import declarations, and not known to be textual.
1962 flang-info-include-translate=
1963 C++ Joined RejectNegative MissingArgError(missing header name)
1964 Note a #include translation of a specific header.
1966 flang-info-module-cmi
1967 C++ Var(note_module_cmi_yes)
1968 Note Compiled Module Interface pathnames.
1970 flang-info-module-cmi=
1971 C++ Joined RejectNegative MissingArgError(missing module name)
1972 Note Compiled Module Interface pathname of a specific module or header-unit.
1975 C ObjC C++ ObjC++ Joined RejectNegative UInteger
1976 fmax-include-depth=<number> Set the maximum depth of the nested #include.
1979 C ObjC C++ ObjC++ Var(flag_ms_extensions)
1980 Don't warn about uses of Microsoft extensions.
1983 C ObjC C++ ObjC++ WarnRemoved
1986 C ObjC C++ ObjC++ WarnRemoved
1989 C ObjC C++ ObjC++ WarnRemoved
1991 fname-mangling-version-
1992 C++ ObjC++ Joined WarnRemoved
1995 C++ ObjC++ WarnRemoved
1998 C++ ObjC++ Var(flag_new_ttp)
1999 Implement resolution of DR 150 for matching of template template arguments.
2002 ObjC ObjC++ LTO RejectNegative Var(flag_next_runtime)
2003 Generate code for NeXT (Apple macOS) runtime environment.
2006 ObjC ObjC++ Var(flag_nil_receivers) Init(1)
2007 Assume that receivers of Objective-C messages may be nil.
2010 ObjC ObjC++ Var(flag_local_ivars) Init(1)
2011 Allow access to instance variables as if they were local declarations within instance method implementations.
2014 ObjC ObjC++ Joined RejectNegative Enum(ivar_visibility) Var(default_ivar_visibility) Init(IVAR_VISIBILITY_PROTECTED)
2015 -fvisibility=[private|protected|public|package] Set the default symbol visibility.
2018 Name(ivar_visibility) Type(enum ivar_visibility) UnknownError(unrecognized ivar visibility value %qs)
2021 Enum(ivar_visibility) String(private) Value(IVAR_VISIBILITY_PRIVATE)
2024 Enum(ivar_visibility) String(protected) Value(IVAR_VISIBILITY_PROTECTED)
2027 Enum(ivar_visibility) String(public) Value(IVAR_VISIBILITY_PUBLIC)
2030 Enum(ivar_visibility) String(package) Value(IVAR_VISIBILITY_PACKAGE)
2033 C++ ObjC++ Var(flag_no_nonansi_builtin, 0)
2036 C++ ObjC++ WarnRemoved
2039 C++ ObjC++ Optimization Var(flag_nothrow_opt)
2040 Treat a throw() exception specification as noexcept to improve code size.
2043 ObjC ObjC++ LTO Joined RejectNegative UInteger Var(flag_objc_abi)
2044 Specify which ABI to use for Objective-C family code and meta-data generation.
2046 ; Generate special '- .cxx_construct' and '- .cxx_destruct' methods
2047 ; to initialize any non-POD ivars in Objective-C++ classes.
2048 fobjc-call-cxx-cdtors
2049 ObjC++ Var(flag_objc_call_cxx_cdtors)
2050 Generate special Objective-C methods to initialize/destroy non-POD C++ ivars, if needed.
2052 fobjc-direct-dispatch
2053 ObjC ObjC++ Var(flag_objc_direct_dispatch)
2054 Allow fast jumps to the message dispatcher.
2056 ; Nonzero means that we will allow new ObjC exception syntax (@throw,
2057 ; @try, etc.) in source code.
2059 ObjC ObjC++ Var(flag_objc_exceptions)
2060 Enable Objective-C exception and synchronization syntax.
2063 ObjC ObjC++ LTO Var(flag_objc_gc)
2064 Enable garbage collection (GC) in Objective-C/Objective-C++ programs.
2067 ObjC ObjC++ Var(flag_objc_nilcheck,1)
2068 Enable inline checks for nil receivers with the NeXT runtime and ABI version 2.
2070 ; Nonzero means that we generate NeXT setjmp based exceptions.
2071 fobjc-sjlj-exceptions
2072 ObjC ObjC++ Var(flag_objc_sjlj_exceptions) Init(-1)
2073 Enable Objective-C setjmp exception handling runtime.
2076 ObjC ObjC++ Var(flag_objc1_only)
2077 Conform to the Objective-C 1.0 language as implemented in GCC 4.0.
2080 C ObjC C++ ObjC++ LTO Var(flag_openacc)
2084 C ObjC C++ ObjC++ LTO Joined Var(flag_openacc_dims)
2085 Specify default OpenACC compute dimensions.
2088 C ObjC C++ ObjC++ LTO Var(flag_openmp)
2089 Enable OpenMP (implies -frecursive in Fortran).
2092 C ObjC C++ ObjC++ Var(flag_openmp_simd)
2093 Enable OpenMP's SIMD directives.
2097 Recognize C++ keywords like \"compl\" and \"xor\".
2101 Does nothing. Preserved for backward compatibility.
2108 Look for and use PCH files even when preprocessing.
2111 C++ ObjC++ Var(flag_permissive)
2112 Downgrade conformance errors to warnings.
2115 C ObjC Var(flag_plan9_extensions)
2116 Enable Plan 9 language extensions.
2120 Treat the input file as already preprocessed.
2122 ftrack-macro-expansion
2123 C ObjC C++ ObjC++ JoinedOrMissing RejectNegative UInteger
2124 ; converted into ftrack-macro-expansion=
2126 ftrack-macro-expansion=
2127 C ObjC C++ ObjC++ JoinedOrMissing RejectNegative UInteger
2128 -ftrack-macro-expansion=<0|1|2> Track locations of tokens coming from macro expansion and display them in error messages.
2131 C++ ObjC++ Var(flag_pretty_templates) Init(1)
2132 Do not pretty-print template specializations as the template signature followed by the arguments.
2134 fprintf-return-value
2135 C ObjC C++ ObjC++ LTO Optimization Var(flag_printf_return_value) Init(1)
2136 Treat known sprintf return values as constants.
2138 freplace-objc-classes
2139 ObjC ObjC++ LTO Var(flag_replace_objc_classes)
2140 Used in Fix-and-Continue mode to indicate that object files may be swapped in at runtime.
2143 C++ ObjC++ WarnRemoved
2144 Removed in GCC 10. This switch has no effect.
2147 C++ ObjC++ Optimization Var(flag_rtti) Init(1)
2148 Generate run time type descriptor information.
2151 C ObjC C++ ObjC++ LTO Optimization Var(flag_short_enums)
2152 Use the narrowest integer type possible for enumeration types.
2155 C ObjC C++ ObjC++ LTO Optimization Var(flag_short_wchar)
2156 Force the underlying type for \"wchar_t\" to be \"unsigned short\".
2159 C ObjC C++ ObjC++ Var(flag_signed_bitfields) Init(1)
2160 When \"signed\" or \"unsigned\" is not given make the bitfield signed.
2163 C ObjC C++ ObjC++ LTO Var(flag_signed_char)
2164 Make \"char\" signed by default.
2167 C++ ObjC++ Var(flag_sized_deallocation) Init(-1)
2168 Enable C++14 sized deallocation support.
2171 C C++ Common Alias(fstrict-flex-arrays=,3,0)
2173 fstrict-flex-arrays=
2174 C C++ Common Joined RejectNegative UInteger Var(flag_strict_flex_arrays) Init(0) IntegerRange(0,3)
2175 -fstrict-flex-arrays=<level> Control when to treat the trailing array of a structure as a flexible array member for the purposes of accessing the elements of such an array. The default is treating all trailing arrays of structures as flexible array members.
2178 C++ ObjC++ WarnRemoved
2181 C ObjC Joined RejectNegative Enum(sso_struct) Var(default_sso) Init(SSO_NATIVE)
2182 -fsso-struct=[big-endian|little-endian|native] Set the default scalar storage order.
2185 Name(sso_struct) Type(enum scalar_storage_order_kind) UnknownError(unrecognized scalar storage order value %qs)
2188 Enum(sso_struct) String(big-endian) Value(SSO_BIG_ENDIAN)
2191 Enum(sso_struct) String(little-endian) Value(SSO_LITTLE_ENDIAN)
2194 Enum(sso_struct) String(native) Value(SSO_NATIVE)
2197 C++ ObjC++ Var(flag_detailed_statistics)
2198 Display statistics accumulated during compilation.
2201 C++ ObjC++ Optimization Var(flag_strict_enums)
2202 Assume that values of enumeration type are always within the minimum range of that type.
2205 C++ ObjC++ WarnRemoved
2208 C++ ObjC++ Common Alias(fstrong-eval-order=, all, none)
2209 Follow the C++17 evaluation order requirements for assignment expressions,
2210 shift, member function calls, etc.
2213 C++ ObjC++ Common Var(flag_strong_eval_order) Joined Enum(strong_eval_order) RejectNegative Init(-1)
2214 Follow the C++17 evaluation order requirements for assignment expressions,
2215 shift, member function calls, etc.
2218 Name(strong_eval_order) Type(int)
2221 Enum(strong_eval_order) String(none) Value(0)
2224 Enum(strong_eval_order) String(some) Value(1)
2227 Enum(strong_eval_order) String(all) Value(2)
2229 ftemplate-backtrace-limit=
2230 C++ ObjC++ Joined RejectNegative UInteger Var(template_backtrace_limit) Init(10)
2231 Set the maximum number of template instantiation notes for a single warning or error.
2234 C++ ObjC++ Joined RejectNegative Undocumented Alias(ftemplate-depth=)
2237 C++ ObjC++ Joined RejectNegative UInteger
2238 -ftemplate-depth=<number> Specify maximum template instantiation depth.
2241 C++ ObjC++ WarnRemoved
2244 C++ ObjC++ Optimization Var(flag_threadsafe_statics) Init(1)
2245 -fno-threadsafe-statics Do not generate thread-safe code for initializing local statics.
2248 C ObjC C++ ObjC++ Var(flag_signed_bitfields, 0)
2249 When \"signed\" or \"unsigned\" is not given make the bitfield unsigned.
2252 C ObjC C++ ObjC++ LTO Var(flag_signed_char, 0)
2253 Make \"char\" unsigned by default.
2256 C++ ObjC++ Var(flag_use_cxa_atexit) Init(DEFAULT_USE_CXA_ATEXIT)
2257 Use __cxa_atexit to register destructors.
2259 fuse-cxa-get-exception-ptr
2260 C++ ObjC++ Var(flag_use_cxa_get_exception_ptr) Init(2)
2261 Use __cxa_get_exception_ptr in exception handling.
2263 fvisibility-inlines-hidden
2265 Marks all inlined functions and methods as having hidden visibility.
2267 fvisibility-ms-compat
2268 C++ ObjC++ Var(flag_visibility_ms_compat)
2269 Changes visibility to match Microsoft Visual Studio by default.
2272 C++ ObjC++ WarnRemoved
2273 No longer supported.
2276 C++ ObjC++ WarnRemoved
2277 No longer supported.
2280 C++ ObjC++ Var(flag_weak) Init(1)
2281 Emit common-like symbols as weak symbols.
2284 C ObjC C++ ObjC++ Joined RejectNegative
2285 -fwide-exec-charset=<cset> Convert all wide strings and character constants to character set <cset>.
2288 C ObjC C++ ObjC++ Var(flag_working_directory) Init(-1)
2289 Generate a #line directive pointing at the current working directory.
2292 C++ ObjC++ WarnRemoved
2293 No longer supported.
2296 ObjC ObjC++ Var(flag_zero_link)
2297 Generate lazy class lookup (via objc_getClass()) for use in Zero-Link mode.
2300 ObjC ObjC++ Driver Var(flag_gen_declaration) RejectNegative
2301 Dump declarations to a .decl file.
2303 femit-struct-debug-baseonly
2305 -femit-struct-debug-baseonly Aggressive reduced debug info for structs.
2307 femit-struct-debug-reduced
2309 -femit-struct-debug-reduced Conservative reduced debug info for structs.
2311 femit-struct-debug-detailed=
2312 C ObjC C++ ObjC++ Joined
2313 -femit-struct-debug-detailed=<spec-list> Detailed reduced debug info for structs.
2315 fext-numeric-literals
2316 C++ ObjC++ Var(flag_ext_numeric_literals) Init(1)
2317 Interpret imaginary, fixed-point, or other gnu number suffix as the corresponding
2318 number literal rather than a user-defined number literal.
2321 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
2322 -idirafter <dir> Add <dir> to the end of the system include path.
2325 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
2326 -imacros <file> Accept definition of macros in <file>.
2329 C ObjC C++ ObjC++ Joined Separate
2330 -imultilib <dir> Set <dir> to be the multilib include subdirectory.
2333 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
2334 -include <file> Include the contents of <file> before other files.
2337 C ObjC C++ ObjC++ Joined Separate
2338 -iprefix <path> Specify <path> as a prefix for next two options.
2341 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
2342 -isysroot <dir> Set <dir> to be the system root directory.
2345 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
2346 -isystem <dir> Add <dir> to the start of the system include path.
2349 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
2350 -iquote <dir> Add <dir> to the end of the quote include path.
2353 C ObjC C++ ObjC++ Joined Separate
2354 -iwithprefix <dir> Add <dir> to the end of the system include path.
2357 C ObjC C++ ObjC++ Joined Separate
2358 -iwithprefixbefore <dir> Add <dir> to the end of the main include path.
2361 C Undocumented RejectDriver
2368 Do not search standard system include directories (those specified with -isystem will still be used).
2372 Do not search standard system include directories for C++.
2375 C ObjC C++ ObjC++ Joined Separate
2376 ; Documented in common.opt
2379 C ObjC C++ ObjC++ Alias(Wpedantic)
2380 ; Documented in common.opt
2382 print-objc-runtime-info
2384 Generate C header of platform-specific features.
2388 Remap file names when including files.
2392 Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum.
2395 C++ ObjC++ Alias(std=c++98)
2396 Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum.
2400 Conform to the ISO 2011 C++ standard.
2403 C++ ObjC++ Alias(std=c++11) Undocumented
2404 Deprecated in favor of -std=c++11.
2407 C++ ObjC++ Alias(std=c++14) Undocumented
2408 Deprecated in favor of -std=c++14.
2412 Conform to the ISO 2014 C++ standard.
2415 C++ ObjC++ Alias(std=c++17) Undocumented
2416 Deprecated in favor of -std=c++17.
2420 Conform to the ISO 2017 C++ standard.
2423 C++ ObjC++ Alias(std=c++20) Undocumented
2424 Conform to the ISO 2020 C++ standard (experimental and incomplete support).
2428 Conform to the ISO 2020 C++ standard (experimental and incomplete support).
2431 C++ ObjC++ Alias(std=c++23) Undocumented
2432 Conform to the ISO 2023 C++ draft standard (experimental and incomplete support).
2436 Conform to the ISO 2023 C++ draft standard (experimental and incomplete support).
2439 C++ ObjC++ Alias(std=c++26)
2440 Conform to the ISO 2026 C++ draft standard (experimental and incomplete support).
2443 C++ ObjC++ Undocumented
2444 Conform to the ISO 2026 C++ draft standard (experimental and incomplete support).
2448 Conform to the ISO 2011 C standard.
2451 C ObjC Alias(std=c11)
2452 Deprecated in favor of -std=c11.
2456 Conform to the ISO 2017 C standard (published in 2018).
2459 C ObjC Alias(std=c17)
2460 Conform to the ISO 2017 C standard (published in 2018).
2464 Conform to the ISO 202X C standard draft (experimental and incomplete support).
2467 C ObjC Alias(std=c90)
2468 Conform to the ISO 1990 C standard.
2472 Conform to the ISO 1990 C standard.
2476 Conform to the ISO 1999 C standard.
2479 C ObjC Alias(std=c99)
2480 Deprecated in favor of -std=c99.
2484 Conform to the ISO 1998 C++ standard revised by the 2003 technical
2485 corrigendum with GNU extensions.
2488 C++ ObjC++ Alias(std=gnu++98)
2489 Conform to the ISO 1998 C++ standard revised by the 2003 technical
2490 corrigendum with GNU extensions.
2494 Conform to the ISO 2011 C++ standard with GNU extensions.
2497 C++ ObjC++ Alias(std=gnu++11) Undocumented
2498 Deprecated in favor of -std=gnu++11.
2501 C++ ObjC++ Alias(std=gnu++14) Undocumented
2502 Deprecated in favor of -std=gnu++14.
2506 Conform to the ISO 2014 C++ standard with GNU extensions.
2509 C++ ObjC++ Alias(std=gnu++17) Undocumented
2510 Deprecated in favor of -std=gnu++17.
2514 Conform to the ISO 2017 C++ standard with GNU extensions.
2517 C++ ObjC++ Alias(std=gnu++20) Undocumented
2518 Conform to the ISO 2020 C++ standard with GNU extensions (experimental and incomplete support).
2522 Conform to the ISO 2020 C++ standard with GNU extensions (experimental and incomplete support).
2525 C++ ObjC++ Alias(std=gnu++23) Undocumented
2526 Conform to the ISO 2023 C++ draft standard with GNU extensions (experimental and incomplete support).
2530 Conform to the ISO 2023 C++ draft standard with GNU extensions (experimental and incomplete support).
2533 C++ ObjC++ Alias(std=gnu++26)
2534 Conform to the ISO 2026 C++ draft standard with GNU extensions (experimental and incomplete support).
2537 C++ ObjC++ Undocumented
2538 Conform to the ISO 2026 C++ draft standard with GNU extensions (experimental and incomplete support).
2542 Conform to the ISO 2011 C standard with GNU extensions.
2545 C ObjC Alias(std=gnu11)
2546 Deprecated in favor of -std=gnu11.
2550 Conform to the ISO 2017 C standard (published in 2018) with GNU extensions.
2553 C ObjC Alias(std=gnu17)
2554 Conform to the ISO 2017 C standard (published in 2018) with GNU extensions.
2558 Conform to the ISO 202X C standard draft with GNU extensions (experimental and incomplete support).
2561 C ObjC Alias(std=gnu90)
2562 Conform to the ISO 1990 C standard with GNU extensions.
2566 Conform to the ISO 1990 C standard with GNU extensions.
2570 Conform to the ISO 1999 C standard with GNU extensions.
2573 C ObjC Alias(std=gnu99)
2574 Deprecated in favor of -std=gnu99.
2577 C ObjC Alias(std=c90)
2578 Conform to the ISO 1990 C standard.
2582 Conform to the ISO 1990 C standard as amended in 1994.
2585 C ObjC Alias(std=c99)
2586 Conform to the ISO 1999 C standard.
2589 C ObjC Alias(std=c99)
2590 Deprecated in favor of -std=iso9899:1999.
2593 C ObjC Alias(std=c11)
2594 Conform to the ISO 2011 C standard.
2597 C ObjC Alias(std=c17)
2598 Conform to the ISO 2017 C standard (published in 2018).
2601 C ObjC Alias(std=c17)
2602 Conform to the ISO 2017 C standard (published in 2018).
2605 Driver C++ ObjC++ Common Condition(ENABLE_STDLIB_OPTION) Var(flag_stdlib_kind) Joined Enum(stdlib_kind) RejectNegative Init(1)
2606 -stdlib=[libstdc++|libc++] The standard library to be used for C++ headers
2610 Name(stdlib_kind) Type(int)
2613 Enum(stdlib_kind) String(libstdc++) Value(1)
2616 Enum(stdlib_kind) String(libc++) Value(2)
2623 Enable traditional preprocessing.
2627 -trigraphs Support ISO C trigraphs.
2630 C ObjC C++ ObjC++ Var(flag_undef)
2631 Do not predefine system-specific and GCC-specific macros.
2635 ; Documented in common.opt
2639 ; Documented in common.opt
2641 ; This comment is to ensure we retain the blank line above.