1 ; Options for the C, ObjC, C++ and ObjC++ front ends.
2 ; Copyright (C) 2003-2017 Free Software Foundation, Inc.
4 ; This file is part of GCC.
6 ; GCC is free software; you can redistribute it and/or modify it under
7 ; the terms of the GNU General Public License as published by the Free
8 ; Software Foundation; either version 3, or (at your option) any later
11 ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 ; WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 ; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 ; You should have received a copy of the GNU General Public License
17 ; along with GCC; see the file COPYING3. If not see
18 ; <http://www.gnu.org/licenses/>.
20 ; See the GCC internals manual for a description of this file's format.
22 ; Please try to keep this file in ASCII collating order.
37 C ObjC C++ ObjC++ Warning Alias(Wall)
40 C ObjC C++ ObjC++ Alias(ansi)
43 C ObjC C++ ObjC++ Separate Alias(A) MissingArgError(assertion missing after %qs)
46 C ObjC C++ ObjC++ Joined Alias(A) MissingArgError(assertion missing after %qs)
49 C ObjC C++ ObjC++ Alias(C)
52 C ObjC C++ ObjC++ Alias(CC)
55 C ObjC C++ ObjC++ Separate Alias(D) MissingArgError(macro name missing after %qs)
58 C ObjC C++ ObjC++ Joined Alias(D) MissingArgError(macro name missing after %qs)
61 C ObjC C++ ObjC++ Alias(M)
64 C ObjC C++ ObjC++ Separate Alias(d)
67 C ObjC C++ ObjC++ Joined Alias(d)
70 C ObjC C++ ObjC++ Separate Alias(imacros) MissingArgError(missing filename after %qs)
73 C ObjC C++ ObjC++ Joined Alias(imacros) MissingArgError(missing filename after %qs)
76 C ObjC C++ ObjC++ Separate Alias(include) MissingArgError(missing filename after %qs)
79 C ObjC C++ ObjC++ Joined Alias(include) MissingArgError(missing filename after %qs)
82 C ObjC C++ ObjC++ Alias(I, -)
85 C ObjC C++ ObjC++ Separate Alias(I) MissingArgError(missing path after %qs)
88 C ObjC C++ ObjC++ Joined Alias(I) MissingArgError(missing path after %qs)
90 -include-directory-after
91 C ObjC C++ ObjC++ Separate Alias(idirafter) MissingArgError(missing path after %qs)
93 -include-directory-after=
94 C ObjC C++ ObjC++ Joined Alias(idirafter) MissingArgError(missing path after %qs)
97 C ObjC C++ ObjC++ Separate Alias(iprefix)
100 C ObjC C++ ObjC++ JoinedOrMissing Alias(iprefix)
103 C ObjC C++ ObjC++ Separate Alias(iwithprefix)
105 -include-with-prefix=
106 C ObjC C++ ObjC++ JoinedOrMissing Alias(iwithprefix)
108 -include-with-prefix-after
109 C ObjC C++ ObjC++ Separate Alias(iwithprefix)
111 -include-with-prefix-after=
112 C ObjC C++ ObjC++ JoinedOrMissing Alias(iwithprefix)
114 -include-with-prefix-before
115 C ObjC C++ ObjC++ Separate Alias(iwithprefixbefore)
117 -include-with-prefix-before=
118 C ObjC C++ ObjC++ JoinedOrMissing Alias(iwithprefixbefore)
121 Driver Alias(no-integrated-cpp)
124 C ObjC C++ ObjC++ Alias(P)
126 -no-standard-includes
127 C ObjC C++ ObjC++ Alias(nostdinc)
130 C ObjC C++ ObjC++ Alias(w)
133 C ObjC C++ ObjC++ Separate Alias(o)
136 C ObjC C++ ObjC++ Joined Alias(o)
139 C ObjC C++ ObjC++ Joined Separate
142 C ObjC C++ ObjC++ Alias(pedantic)
145 C ObjC C++ ObjC++ Undocumented Alias(E)
147 -print-missing-file-dependencies
148 C ObjC C++ ObjC++ Alias(MG)
151 C ObjC C++ ObjC++ Alias(H)
154 Driver Alias(traditional)
157 C ObjC C++ ObjC++ Alias(traditional-cpp)
160 C ObjC C++ ObjC++ Alias(trigraphs)
163 C ObjC C++ ObjC++ Separate Alias(U) MissingArgError(macro name missing after %qs)
166 C ObjC C++ ObjC++ Joined Alias(U) MissingArgError(macro name missing after %qs)
169 C ObjC C++ ObjC++ Alias(MM)
172 Common C ObjC C++ ObjC++ Alias(v)
175 C ObjC C++ ObjC++ NoDriverArg Separate Alias(MD) MissingArgError(missing filename after %qs)
177 -write-user-dependencies
178 C ObjC C++ ObjC++ NoDriverArg Separate Alias(MMD) MissingArgError(missing filename after %qs)
181 C ObjC C++ ObjC++ Joined Separate MissingArgError(assertion missing after %qs)
182 -A<question>=<answer> Assert the <answer> to <question>. Putting '-' before <question> disables the <answer> to <question>.
186 Do not discard comments.
190 Do not discard comments in macro expansions.
193 C ObjC C++ ObjC++ Joined Separate MissingArgError(macro name missing after %qs)
194 -D<macro>[=<val>] Define a <macro> with <val> as its value. If just <macro> is given, <val> is taken to be 1.
197 C ObjC C++ ObjC++ Undocumented Var(flag_preprocess_only)
200 Driver C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
201 -F <dir> Add <dir> to the end of the main framework include path.
204 C Var(flag_gimple) Init(0)
205 Enable parsing GIMPLE.
209 Print the name of header files as they are used.
212 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
213 -I <dir> Add <dir> to the end of the main include path.
217 Generate make dependencies.
220 C ObjC C++ ObjC++ NoDriverArg Separate MissingArgError(missing filename after %qs)
221 Generate make dependencies and compile.
224 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
225 -MF <file> Write dependency output to the given file.
229 Treat missing header files as generated files.
233 Like -M but ignore system header files.
236 C ObjC C++ ObjC++ NoDriverArg Separate MissingArgError(missing filename after %qs)
237 Like -MD but ignore system header files.
241 Generate phony targets for all headers.
244 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing makefile target after %qs)
245 -MQ <target> Add a MAKE-quoted target.
248 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing makefile target after %qs)
249 -MT <target> Add an unquoted target.
253 Do not generate #line directives.
256 C ObjC C++ ObjC++ Joined Separate MissingArgError(macro name missing after %qs)
257 -U<macro> Undefine <macro>.
260 C ObjC C++ ObjC++ LTO Var(warn_abi) Warning
261 Warn about things that will change when compiling with an ABI-compliant compiler.
264 C ObjC C++ ObjC++ LTO Joined RejectNegative UInteger Warning
265 Warn about things that change between the current -fabi-version and the specified version.
268 C++ ObjC++ Var(warn_abi_tag) Warning
269 Warn if a subobject has an abi_tag attribute that the complete object type does not have.
272 C ObjC C++ ObjC++ LTO Var(warn_psabi) Init(1) Warning Undocumented LangEnabledBy(C ObjC C++ ObjC++,Wabi)
275 C ObjC C++ ObjC++ Var(warn_address) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
276 Warn about suspicious uses of memory addresses.
279 Name(warn_aligned_new_level) Type(int) UnknownError(argument %qs to %<-Waligned-new%> not recognized)
282 Enum(warn_aligned_new_level) String(none) Value(0)
285 Enum(warn_aligned_new_level) String(global) Value(1)
288 Enum(warn_aligned_new_level) String(all) Value(2)
291 C++ ObjC++ Alias(Waligned-new=,global,none)
292 Warn about 'new' of type with extended alignment without -faligned-new.
295 C++ ObjC++ Var(warn_aligned_new) Enum(warn_aligned_new_level) Joined RejectNegative Warning LangEnabledBy(C++ ObjC++,Wall,1,0)
296 -Waligned-new=[none|global|all] Warn even if 'new' uses a class member allocation function.
299 C ObjC C++ ObjC++ Warning
300 Enable most warning messages.
303 C ObjC C++ ObjC++ Var(warn_alloca) Warning
304 Warn on any use of alloca.
306 Walloc-size-larger-than=
307 C ObjC C++ ObjC++ Var(warn_alloc_size_limit) Warning Joined LangEnabledBy(C ObjC C++ ObjC++,Wall)
308 -Walloc-size-larger-than=<bytes> Warn for calls to allocation functions that
309 attempt to allocate objects larger than the specified number of bytes.
312 C ObjC C++ ObjC++ Var(warn_alloc_zero) Warning
313 -Walloc-zero Warn for calls to allocation functions that specify zero bytes.
316 C ObjC C++ LTO ObjC++ Var(warn_alloca_limit) Warning Joined RejectNegative UInteger
317 -Walloca-larger-than=<number> Warn on unbounded uses of
318 alloca, and on bounded uses of alloca whose bound can be larger than
322 LangEnabledBy(C ObjC C++ ObjC++,Wall)
326 LangEnabledBy(C ObjC C++ ObjC++,Wall,1,0)
330 ObjC ObjC++ Var(warn_assign_intercept) Warning
331 Warn whenever an Objective-C assignment is being intercepted by the garbage collector.
334 C ObjC Var(warn_bad_function_cast) Warning
335 Warn about casting functions to incompatible types.
338 C ObjC C++ ObjC++ Var(warn_bool_compare) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
339 Warn about boolean expression compared with an integer value different from true/false.
342 C ObjC C++ ObjC++ Var(warn_bool_op) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
343 Warn about certain operations on boolean expressions.
346 C ObjC C++ ObjC++ Var(warn_frame_address) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
347 Warn when __builtin_frame_address or __builtin_return_address is used unsafely.
349 Wbuiltin-declaration-mismatch
350 C ObjC C++ ObjC++ Var(warn_builtin_declaraion_mismatch) Init(1) Warning
351 Warn when a built-in function is declared with the wrong signature.
353 Wbuiltin-macro-redefined
354 C ObjC C++ ObjC++ CPP(warn_builtin_macro_redefined) CppReason(CPP_W_BUILTIN_MACRO_REDEFINED) Var(cpp_warn_builtin_macro_redefined) Init(1) Warning
355 Warn when a built-in preprocessor macro is undefined or redefined.
358 C ObjC CPP(cpp_warn_c90_c99_compat) CppReason(CPP_W_C90_C99_COMPAT) Var(warn_c90_c99_compat) Init(-1) Warning
359 Warn about features not present in ISO C90, but present in ISO C99.
362 C ObjC Var(warn_c99_c11_compat) Init(-1) Warning
363 Warn about features not present in ISO C99, but present in ISO C11.
366 C ObjC Var(warn_cxx_compat) CPP(warn_cxx_operator_names) CppReason(CPP_W_CXX_OPERATOR_NAMES) Init(0) Warning
367 Warn about C constructs that are not in the common subset of C and C++.
370 C++ ObjC++ Warning Alias(Wc++11-compat) Undocumented
373 C++ ObjC++ Var(warn_cxx11_compat) Warning LangEnabledBy(C++ ObjC++,Wall) Init(0) CPP(cpp_warn_cxx11_compat) CppReason(CPP_W_CXX11_COMPAT)
374 Warn about C++ constructs whose meaning differs between ISO C++ 1998 and ISO C++ 2011.
377 C++ ObjC++ Var(warn_cxx14_compat) Warning LangEnabledBy(C++ ObjC++,Wall)
378 Warn about C++ constructs whose meaning differs between ISO C++ 2011 and ISO C++ 2014.
381 C++ ObjC++ Var(warn_cxx1z_compat) Warning LangEnabledBy(C++ ObjC++,Wall)
382 Warn about C++ constructs whose meaning differs between ISO C++ 2014 and (forthcoming) ISO C++ 201z(7?).
385 C++ ObjC++ Warning Alias(Wc++1z-compat) Undocumented
388 C ObjC C++ ObjC++ Var(warn_cast_qual) Warning
389 Warn about casts which discard qualifiers.
392 C ObjC C++ ObjC++ Var(warn_char_subscripts) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
393 Warn about subscripts whose type is \"char\".
396 C ObjC C++ ObjC++ Var(warn_chkp) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
397 Warn about memory access errors found by Pointer Bounds Checker.
400 C ObjC C++ ObjC++ Var(warn_clobbered) Warning EnabledBy(Wextra)
401 Warn about variables that might be changed by \"longjmp\" or \"vfork\".
404 C ObjC C++ ObjC++ CPP(warn_comments) CppReason(CPP_W_COMMENTS) Var(cpp_warn_comment) Init(0) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
405 Warn about possibly nested block comments, and C++ comments spanning more than one physical line.
408 C ObjC C++ ObjC++ Warning Alias(Wcomment)
409 Synonym for -Wcomment.
411 Wconditionally-supported
412 C++ ObjC++ Var(warn_conditionally_supported) Warning
413 Warn for conditionally-supported constructs.
416 C ObjC C++ ObjC++ Var(warn_conversion) Warning
417 Warn for implicit type conversions that may change a value.
420 C++ ObjC++ Var(warn_conversion_null) Init(1) Warning
421 Warn for converting NULL from/to a non-pointer type.
424 C ObjC C++ ObjC++ CppReason(CPP_W_WARNING_DIRECTIVE)
425 ; Documented in common.opt
428 C++ ObjC++ Var(warn_ctor_dtor_privacy) Warning
429 Warn when all constructors and destructors are private.
432 C ObjC C++ ObjC++ Var(warn_dangling_else) Warning LangEnabledBy(C ObjC C++ ObjC++,Wparentheses)
433 Warn about dangling else.
436 C ObjC C++ ObjC++ CPP(warn_date_time) CppReason(CPP_W_DATE_TIME) Var(cpp_warn_date_time) Init(0) Warning
437 Warn about __TIME__, __DATE__ and __TIMESTAMP__ usage.
439 Wdeclaration-after-statement
440 C ObjC Var(warn_declaration_after_statement) Init(-1) Warning
441 Warn when a declaration is found after a statement.
444 C++ ObjC++ Var(warn_delete_incomplete) Init(1) Warning
445 Warn when deleting a pointer to incomplete type.
447 Wdelete-non-virtual-dtor
448 C++ ObjC++ Var(warn_delnonvdtor) Warning LangEnabledBy(C++ ObjC++,Wall || Weffc++)
449 Warn about deleting polymorphic objects with non-virtual destructors.
452 C C++ ObjC ObjC++ CPP(cpp_warn_deprecated) CppReason(CPP_W_DEPRECATED) Var(warn_deprecated) Init(1) Warning
453 Warn if a deprecated compiler feature, class, method, or field is used.
456 C ObjC Var(warn_designated_init) Init(1) Warning
457 Warn about positional initialization of structs requiring designated initializers.
459 Wdiscarded-array-qualifiers
460 C ObjC Var(warn_discarded_array_qualifiers) Init(1) Warning
461 Warn if qualifiers on arrays which are pointer targets are discarded.
463 Wdiscarded-qualifiers
464 C ObjC Var(warn_discarded_qualifiers) Init(1) Warning
465 Warn if type qualifiers on pointers are discarded.
468 C ObjC C++ ObjC++ Var(warn_div_by_zero) Init(1) Warning
469 Warn about compile-time integer division by zero.
472 C ObjC C++ ObjC++ Var(warn_duplicated_branches) Init(0) Warning
473 Warn about duplicated branches in if-else statements.
476 C ObjC C++ ObjC++ Var(warn_duplicated_cond) Init(0) Warning
477 Warn about duplicated conditions in an if-else-if chain.
480 C++ ObjC++ Var(warn_ecpp) Warning
481 Warn about violations of Effective C++ style rules.
484 C ObjC C++ ObjC++ Var(warn_empty_body) Warning EnabledBy(Wextra)
485 Warn about an empty body in an if or else statement.
488 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)
489 Warn about stray tokens after #else and #endif.
492 C ObjC C++ ObjC++ Var(warn_enum_compare) Init(-1) Warning LangEnabledBy(C ObjC,Wall || Wc++-compat)
493 Warn about comparison of different enum types.
497 ; Documented in common.opt
499 Werror-implicit-function-declaration
500 C ObjC RejectNegative Warning Alias(Werror=, implicit-function-declaration)
501 This switch is deprecated; use -Werror=implicit-function-declaration instead.
504 C ObjC C++ ObjC++ Warning
508 C++ ObjC++ Var(warn_extra_semi) Warning
509 Warn about semicolon after in-class function definition.
512 C ObjC C++ ObjC++ Var(warn_float_conversion) Warning LangEnabledBy(C ObjC C++ ObjC++,Wconversion)
513 Warn for implicit type conversions that cause loss of floating point precision.
516 C ObjC C++ ObjC++ Var(warn_float_equal) Warning
517 Warn if testing floating point numbers for equality.
520 C ObjC C++ ObjC++ Warning Alias(Wformat=, 1, 0)
521 Warn about printf/scanf/strftime/strfmon format string anomalies.
524 C ObjC C++ ObjC++ Var(warn_format_contains_nul) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
525 Warn about format strings that contain NUL bytes.
528 C ObjC C++ ObjC++ Var(warn_format_extra_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
529 Warn if passing too many arguments to a function for its format string.
532 C ObjC C++ ObjC++ Var(warn_format_nonliteral) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 2, 0)
533 Warn about format strings that are not literals.
536 C ObjC C++ LTO ObjC++ Warning Alias(Wformat-overflow=, 1, 0)
537 Warn about function calls with format strings that write past the end
538 of the destination region. Same as -Wformat-overflow=1.
541 C ObjC C++ ObjC++ Var(warn_format_security) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 2, 0)
542 Warn about possible security problems with format functions.
545 C ObjC C++ ObjC++ Var(warn_format_signedness) Warning
546 Warn about sign differences with format functions.
549 C ObjC C++ LTO ObjC++ Warning Alias(Wformat-truncation=, 1, 0)
550 Warn about calls to snprintf and similar functions that truncate output.
551 Same as -Wformat-truncation=1.
554 C ObjC C++ ObjC++ Var(warn_format_y2k) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 2, 0)
555 Warn about strftime formats yielding 2-digit years.
558 C ObjC C++ ObjC++ Var(warn_format_zero_length) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 1, 0)
559 Warn about zero-length formats.
562 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_format) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0)
563 Warn about printf/scanf/strftime/strfmon format string anomalies.
566 C ObjC C++ LTO ObjC++ Joined RejectNegative UInteger Var(warn_format_overflow) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
567 Warn about function calls with format strings that write past the end
568 of the destination region.
571 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_format_trunc) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
572 Warn about calls to snprintf and similar functions that truncate output.
575 C C++ Var(warn_ignored_qualifiers) Warning EnabledBy(Wextra)
576 Warn whenever type qualifiers are ignored.
579 C C++ Var(warn_ignored_attributes) Init(1) Warning
580 Warn whenever attributes are ignored.
582 Wincompatible-pointer-types
583 C ObjC Var(warn_incompatible_pointer_types) Init(1) Warning
584 Warn when there is a conversion between pointers that have incompatible types.
587 C ObjC C++ ObjC++ Var(warn_init_self) Warning LangEnabledBy(C++ ObjC++,Wall)
588 Warn about variables which are initialized to themselves.
591 C ObjC Var(warn_implicit) Warning LangEnabledBy(C ObjC,Wall)
592 Warn about implicit declarations.
594 Wimplicit-fallthrough=
595 LangEnabledBy(C ObjC C++ ObjC++,Wextra,3,0)
599 C ObjC C++ ObjC++ Var(warn_double_promotion) Warning
600 Warn about implicit conversions from \"float\" to \"double\".
602 Wexpansion-to-defined
603 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)
604 Warn if \"defined\" is used outside #if.
606 Wimplicit-function-declaration
607 C ObjC Var(warn_implicit_function_declaration) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit)
608 Warn about implicit function declarations.
611 C ObjC Var(warn_implicit_int) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit)
612 Warn when a declaration does not specify a type.
615 C ObjC C++ ObjC++ Undocumented Ignore
617 Winherited-variadic-ctor
618 C++ ObjC++ Var(warn_inh_var_ctor) Init(1) Warning
619 Warn about C++11 inheriting constructors when the base has a variadic constructor.
622 C ObjC Var(warn_int_conversion) Init(1) Warning
623 Warn about incompatible integer to pointer and pointer to integer conversions.
626 C ObjC C++ ObjC++ Var(warn_int_in_bool_context) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
627 Warn for suspicious integer expressions in boolean context.
630 C ObjC C++ ObjC++ Var(warn_int_to_pointer_cast) Init(1) Warning
631 Warn when there is a cast to a pointer from an integer of a different size.
634 C++ ObjC++ Var(warn_invalid_offsetof) Init(1) Warning
635 Warn about invalid uses of the \"offsetof\" macro.
638 C ObjC C++ ObjC++ CPP(warn_invalid_pch) CppReason(CPP_W_INVALID_PCH) Var(cpp_warn_invalid_pch) Init(0) Warning
639 Warn about PCH files that are found but not used.
642 C ObjC Var(warn_jump_misses_init) Warning LangEnabledby(C ObjC,Wc++-compat)
643 Warn when a jump misses a variable initialization.
646 C++ ObjC++ CPP(warn_literal_suffix) CppReason(CPP_W_LITERAL_SUFFIX) Var(cpp_warn_literal_suffix) Init(1) Warning
647 Warn when a string or character literal is followed by a ud-suffix which does not begin with an underscore.
650 C ObjC C++ ObjC++ Var(warn_logical_op) Init(0) Warning
651 Warn when a logical operator is suspiciously always evaluating to true or false.
653 Wlogical-not-parentheses
654 C ObjC C++ ObjC++ Var(warn_logical_not_paren) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
655 Warn when logical not is used on the left hand side operand of a comparison.
658 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)
659 Do not warn about using \"long long\" when -pedantic.
662 C ObjC C++ ObjC++ Var(warn_main) Init(-1) Warning LangEnabledBy(C ObjC,Wall, 2, 0)
663 Warn about suspicious declarations of \"main\".
666 LangEnabledBy(C ObjC C++ ObjC++,Wpedantic, 2, 0)
669 Wmemset-transposed-args
670 C ObjC C++ ObjC++ Var(warn_memset_transposed_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
671 Warn about suspicious calls to memset where the third argument is constant literal zero and the second is not.
674 C ObjC C++ ObjC++ Var(warn_memset_elt_size) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
675 Warn about suspicious calls to memset where the third argument contains the number of elements not multiplied by the element size.
677 Wmisleading-indentation
678 C C++ Common Var(warn_misleading_indentation) Warning LangEnabledBy(C C++,Wall)
679 Warn when the indentation of the code does not reflect the block structure.
682 C ObjC C++ ObjC++ Var(warn_missing_braces) Warning LangEnabledBy(C ObjC,Wall)
683 Warn about possibly missing braces around initializers.
685 Wmissing-declarations
686 C ObjC C++ ObjC++ Var(warn_missing_declarations) Warning
687 Warn about global functions without previous declarations.
689 Wmissing-field-initializers
690 C ObjC C++ ObjC++ Var(warn_missing_field_initializers) Warning EnabledBy(Wextra)
691 Warn about missing fields in struct initializers.
693 Wmultiple-inheritance
694 C++ ObjC++ Var(warn_multiple_inheritance) Warning
695 Warn on direct multiple inheritance.
698 C++ ObjC++ Var(warn_namespaces) Warning
699 Warn on namespace definition.
702 C++ ObjC++ Var(warn_sized_deallocation) Warning EnabledBy(Wextra)
703 Warn about missing sized deallocation functions.
705 Wsizeof-pointer-memaccess
706 C ObjC C++ ObjC++ Var(warn_sizeof_pointer_memaccess) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
707 Warn about suspicious length parameters to certain string functions if the argument uses sizeof.
709 Wsizeof-array-argument
710 C ObjC C++ ObjC++ Var(warn_sizeof_array_argument) Warning Init(1)
711 Warn when sizeof is applied on a parameter declared as an array.
714 C ObjC C++ ObjC++ Warning Alias(Wstringop-overflow=, 2, 0)
715 Warn about buffer overflow in string manipulation functions like memcpy
719 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_stringop_overflow) Init(2) Warning LangEnabledBy(C ObjC C++ ObjC++, Wall)
720 Under the control of Object Size type, warn about buffer overflow in string
721 manipulation functions like memcpy and strcpy.
723 Wsuggest-attribute=format
724 C ObjC C++ ObjC++ Var(warn_suggest_attribute_format) Warning
725 Warn about functions which might be candidates for format attributes.
728 C++ ObjC++ Var(warn_override) Warning
729 Suggest that the override keyword be used when the declaration of a virtual
730 function overrides another.
733 C ObjC C++ ObjC++ Var(warn_switch) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
734 Warn about enumerated switches, with no default, missing a case.
737 C ObjC C++ ObjC++ Var(warn_switch_default) Warning
738 Warn about enumerated switches missing a \"default:\" statement.
741 C ObjC C++ ObjC++ Var(warn_switch_enum) Warning
742 Warn about all enumerated switches missing a specific case.
745 C ObjC C++ ObjC++ Var(warn_switch_bool) Warning Init(1)
746 Warn about switches with boolean controlling expression.
749 C++ ObjC++ Var(warn_templates) Warning
750 Warn on primary template declaration.
752 Wmissing-format-attribute
753 C ObjC C++ ObjC++ Warning Alias(Wsuggest-attribute=format)
756 Wmissing-include-dirs
757 C ObjC C++ ObjC++ CPP(warn_missing_include_dirs) CppReason(CPP_W_MISSING_INCLUDE_DIRS) Var(cpp_warn_missing_include_dirs) Init(0) Warning
758 Warn about user-specified include directories that do not exist.
760 Wmissing-parameter-type
761 C ObjC Var(warn_missing_parameter_type) Warning EnabledBy(Wextra)
762 Warn about function parameters declared without a type specifier in K&R-style functions.
765 C ObjC Var(warn_missing_prototypes) Warning
766 Warn about global functions without prototypes.
769 C ObjC C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
772 C ObjC C++ ObjC++ CPP(warn_multichar) CppReason(CPP_W_MULTICHAR) Var(cpp_warn_multichar) Init(0) Warning
773 Warn about use of multi-character character constants.
776 C ObjC C++ ObjC++ Warning Var(warn_narrowing) Init(-1) LangEnabledBy(C++ ObjC++,Wall || Wc++11-compat)
777 Warn about narrowing conversions within { } that are ill-formed in C++11.
780 C ObjC Var(warn_nested_externs) Warning
781 Warn about \"extern\" declarations not at file scope.
784 C++ ObjC++ Var(warn_noexcept) Warning
785 Warn when a noexcept expression evaluates to false even though the expression can't actually throw.
788 C++ ObjC++ Warning Var(warn_noexcept_type) LangEnabledBy(C++ ObjC++,Wabi || Wc++1z-compat)
789 Warn if C++1z noexcept function type will change the mangled name of a symbol.
792 C++ ObjC++ Var(warn_nontemplate_friend) Init(1) Warning
793 Warn when non-templatized friend functions are declared within a template.
796 C++ ObjC++ Var(warn_nonvdtor) Warning LangEnabledBy(C++ ObjC++,Weffc++)
797 Warn about non-virtual destructors.
800 C ObjC C++ ObjC++ Var(warn_nonnull) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 1,0)
801 Warn about NULL being passed to argument slots marked as requiring non-NULL.
804 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
808 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
812 C ObjC C++ ObjC++ Warning Alias(Wnormalized=,nfc,none)
816 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)
817 -Wnormalized=[none|id|nfc|nfkc] Warn about non-normalized Unicode strings.
819 ; Required for these enum values.
824 Name(cpp_normalize_level) Type(int) UnknownError(argument %qs to %<-Wnormalized%> not recognized)
827 Enum(cpp_normalize_level) String(none) Value(normalized_none)
830 Enum(cpp_normalize_level) String(nfkc) Value(normalized_KC)
833 Enum(cpp_normalize_level) String(id) Value(normalized_identifier_C)
836 Enum(cpp_normalize_level) String(nfc) Value(normalized_C)
839 C++ ObjC++ Var(warn_old_style_cast) Warning
840 Warn if a C-style cast is used in a program.
842 Wold-style-declaration
843 C ObjC Var(warn_old_style_declaration) Warning EnabledBy(Wextra)
844 Warn for obsolescent usage in a declaration.
846 Wold-style-definition
847 C ObjC Var(warn_old_style_definition) Warning
848 Warn if an old-style parameter definition is used.
851 C C++ Var(warn_openmp_simd) Warning LangEnabledBy(C C++,Wall)
852 Warn if a simd directive is overridden by the vectorizer cost model.
855 C ObjC C++ ObjC++ Var(warn_overlength_strings) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic)
856 Warn if a string is longer than the maximum portable length specified by the standard.
859 C++ ObjC++ Var(warn_overloaded_virtual) Warning
860 Warn about overloaded virtual function names.
863 C ObjC Var(warn_override_init) Warning EnabledBy(Wextra)
864 Warn about overriding initializers without side effects.
866 Woverride-init-side-effects
867 C ObjC Var(warn_override_init_side_effects) Init(1) Warning
868 Warn about overriding initializers with side effects.
870 Wpacked-bitfield-compat
871 C ObjC C++ ObjC++ Var(warn_packed_bitfield_compat) Init(-1) Warning
872 Warn about packed bit-fields whose offset changed in GCC 4.4.
875 C ObjC C++ ObjC++ Var(warn_parentheses) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
876 Warn about possibly missing parentheses.
879 C ObjC C++ ObjC++ CPP(cpp_pedantic) CppReason(CPP_W_PEDANTIC) Warning
880 ; Documented in common.opt
883 C++ ObjC++ Var(warn_pmf2ptr) Init(1) Warning
884 Warn when converting the type of pointers to member functions.
887 C ObjC C++ ObjC++ Var(warn_pointer_arith) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic)
888 Warn about function pointer arithmetic.
891 C ObjC Var(warn_pointer_sign) Warning LangEnabledBy(C ObjC,Wall || Wpedantic)
892 Warn when a pointer differs in signedness in an assignment.
895 C ObjC C++ ObjC++ Var(warn_pointer_compare) Init(1) Warning
896 Warn when a pointer is compared with a zero character constant.
899 C ObjC Var(warn_pointer_to_int_cast) Init(1) Warning
900 Warn when a pointer is cast to an integer of a different size.
903 C ObjC C++ ObjC++ Var(warn_pragmas) Init(1) Warning
904 Warn about misuses of pragmas.
906 Wproperty-assign-default
907 ObjC ObjC++ Var(warn_property_assign_default) Init(1) Warning
908 Warn if a property for an Objective-C object has no assign semantics specified.
911 ObjC ObjC++ Var(warn_protocol) Init(1) Warning
912 Warn if inherited methods are unimplemented.
915 C++ Warning Alias(Wplacement-new=, 1, 0)
916 Warn for placement new expressions with undefined behavior.
919 C++ Joined RejectNegative UInteger Var(warn_placement_new) Init(-1) Warning
920 Warn for placement new expressions with undefined behavior.
923 C ObjC C++ ObjC++ Var(warn_redundant_decls) Warning
924 Warn about multiple declarations of the same object.
927 C++ ObjC++ Var(warn_register) Warning
928 Warn about uses of register storage specifier.
931 C++ ObjC++ Var(warn_reorder) Warning LangEnabledBy(C++ ObjC++,Wall)
932 Warn when the compiler reorders code.
935 C ObjC C++ ObjC++ Var(warn_return_type) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
936 Warn whenever a function's return type defaults to \"int\" (C), or about inconsistent return types (C++).
938 Wscalar-storage-order
939 C ObjC C++ ObjC++ Init(1) Warning
940 Warn on suspicious constructs involving reverse scalar storage order.
943 ObjC ObjC++ Var(warn_selector) Warning
944 Warn if a selector has multiple methods.
947 C ObjC C++ ObjC++ Var(warn_sequence_point) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
948 Warn about possible violations of sequence point rules.
951 ObjC ObjC++ Var(warn_shadow_ivar) EnabledBy(Wshadow) Init(1) Warning
952 Warn if a local declaration hides an instance variable.
955 C ObjC C++ ObjC++ Warning Alias(Wshift-overflow=, 1, 0)
956 Warn if left shift of a signed value overflows.
959 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_shift_overflow) Init(-1) Warning
960 Warn if left shift of a signed value overflows.
962 Wshift-count-negative
963 C ObjC C++ ObjC++ Var(warn_shift_count_negative) Init(1) Warning
964 Warn if shift count is negative.
966 Wshift-count-overflow
967 C ObjC C++ ObjC++ Var(warn_shift_count_overflow) Init(1) Warning
968 Warn if shift count >= width of type.
970 Wshift-negative-value
971 C ObjC C++ ObjC++ Var(warn_shift_negative_value) Init(-1) Warning
972 Warn if left shifting a negative value.
975 C ObjC C++ ObjC++ Var(warn_sign_compare) Warning LangEnabledBy(C++ ObjC++,Wall)
976 Warn about signed-unsigned comparisons.
979 C ObjC C++ ObjC++ EnabledBy(Wextra)
983 C ObjC C++ ObjC++ Var(warn_sign_conversion) Warning LangEnabledBy(C ObjC,Wconversion)
984 Warn for implicit type conversions between signed and unsigned integers.
987 C++ ObjC++ Var(warn_sign_promo) Warning
988 Warn when overload promotes from unsigned to signed.
990 Wstrict-null-sentinel
991 C++ ObjC++ Warning Var(warn_strict_null_sentinel)
992 Warn about uncasted NULL used as sentinel.
995 C ObjC Var(warn_strict_prototypes) Warning
996 Warn about unprototyped function declarations.
999 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 3, 0)
1003 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0)
1006 Wstrict-selector-match
1007 ObjC ObjC++ Var(warn_strict_selector_match) Warning
1008 Warn if type signatures of candidate methods do not match exactly.
1011 C C++ Var(warn_sync_nand) Init(1) Warning
1012 Warn when __sync_fetch_and_nand and __sync_nand_and_fetch built-in functions are used.
1015 C++ ObjC++ Var(warn_synth) Warning
1016 Deprecated. This switch has no effect.
1019 C ObjC C++ ObjC++ Warning
1020 ; Documented in common.opt
1022 Wtautological-compare
1023 C ObjC C++ ObjC++ Var(warn_tautological_compare) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1024 Warn if a comparison always evaluates to true or false.
1027 C++ ObjC++ Warning Var(warn_terminate) Init(1)
1028 Warn if a throw expression will always result in a call to terminate().
1031 C ObjC CPP(cpp_warn_traditional) CppReason(CPP_W_TRADITIONAL) Var(warn_traditional) Init(0) Warning
1032 Warn about features not present in traditional C.
1034 Wtraditional-conversion
1035 C ObjC Var(warn_traditional_conversion) Warning
1036 Warn of prototypes causing type conversions different from what would happen in the absence of prototype.
1039 C ObjC C++ ObjC++ CPP(warn_trigraphs) CppReason(CPP_W_TRIGRAPHS) Var(cpp_warn_trigraphs) Init(2) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1040 Warn if trigraphs are encountered that might affect the meaning of the program.
1042 Wundeclared-selector
1043 ObjC ObjC++ Var(warn_undeclared_selector) Warning
1044 Warn about @selector()s without previously declared methods.
1047 C ObjC C++ ObjC++ CPP(warn_undef) CppReason(CPP_W_UNDEF) Var(cpp_warn_undef) Init(0) Warning
1048 Warn if an undefined macro is used in an #if directive.
1051 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
1054 Wmaybe-uninitialized
1055 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
1059 C ObjC C++ ObjC++ Warning Var(warn_unknown_pragmas) LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0)
1060 Warn about unrecognized pragmas.
1062 Wunsuffixed-float-constants
1063 C ObjC Var(warn_unsuffixed_float_constants) Warning
1064 Warn about unsuffixed float constants.
1067 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
1068 ; documented in common.opt
1070 Wunused-local-typedefs
1071 C ObjC C++ ObjC++ Var(warn_unused_local_typedefs) Warning EnabledBy(Wunused)
1072 Warn when typedefs locally defined in a function are not used.
1075 C ObjC C++ ObjC++ CppReason(CPP_W_UNUSED_MACROS) Var(cpp_warn_unused_macros) Warning
1076 Warn about macros defined in the main file that are not used.
1079 C ObjC C++ ObjC++ Var(warn_unused_result) Init(1) Warning
1080 Warn if a caller of a function, marked with attribute warn_unused_result, does not use its return value.
1083 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wunused)
1084 ; documented in common.opt
1086 Wunused-const-variable
1087 C ObjC C++ ObjC++ Warning Alias(Wunused-const-variable=, 2, 0)
1088 Warn when a const variable is unused.
1090 Wunused-const-variable=
1091 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_unused_const_variable) Warning LangEnabledBy(C ObjC,Wunused-variable, 1, 0)
1092 Warn when a const variable is unused.
1095 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)
1096 Warn about using variadic macros.
1099 C ObjC C++ ObjC++ Warning Var(warn_varargs) Init(1)
1100 Warn about questionable usage of the macros used to retrieve variable arguments.
1103 C ObjC C++ ObjC++ Var(warn_vla) Init(-1) Warning
1104 Warn if a variable length array is used.
1107 C ObjC C++ ObjC++ Var(warn_vla_limit) Warning Joined RejectNegative UInteger
1108 -Wvla-larger-than=<number> Warn on unbounded uses of variable-length arrays, and
1109 on bounded uses of variable-length arrays whose bound can be
1110 larger than <number> bytes.
1112 Wvolatile-register-var
1113 C ObjC C++ ObjC++ Var(warn_volatile_register_var) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1114 Warn when a register variable is declared volatile.
1116 Wvirtual-inheritance
1117 C++ ObjC++ Var(warn_virtual_inheritance) Warning
1118 Warn on direct virtual inheritance.
1120 Wvirtual-move-assign
1121 C++ ObjC++ Var(warn_virtual_move_assign) Warning Init(1)
1122 Warn if a virtual base has a non-trivial move assignment operator.
1125 C ObjC C++ ObjC++ Var(warn_write_strings) Warning
1126 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.
1128 Wzero-as-null-pointer-constant
1129 C++ ObjC++ Var(warn_zero_as_null_pointer_constant) Warning
1130 Warn when a literal '0' is used as null pointer.
1133 C++ ObjC++ Var(warn_useless_cast) Warning
1134 Warn about useless casts.
1137 C++ ObjC++ Var(warn_subobject_linkage) Warning Init(1)
1138 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.
1140 Wduplicate-decl-specifier
1141 C ObjC Var(warn_duplicate_decl_specifier) Warning LangEnabledBy(C ObjC,Wall)
1142 Warn when a declaration has duplicate const, volatile, restrict or _Atomic specifier.
1145 C ObjC C++ ObjC++ Var(warn_restrict) Warning LangEnabledBy(C ObjC C++ ObjC++)
1146 Warn when an argument passed to a restrict-qualified parameter aliases with
1151 A synonym for -std=c89 (for C) or -std=c++98 (for C++).
1154 C ObjC C++ ObjC++ Joined
1155 ; Documented in common.opt. FIXME - what about -dI, -dD, -dN and -dD?
1157 fabi-compat-version=
1158 C++ ObjC++ Joined RejectNegative UInteger Var(flag_abi_compat_version) Init(-1)
1159 The version of the C++ ABI used for -Wabi warnings and link compatibility aliases.
1162 C++ ObjC++ Var(flag_access_control) Init(1)
1163 Enforce class member access control semantics.
1166 C ObjC C++ ObjC++ RejectNegative Joined Var(ada_specs_parent)
1167 -fada-spec-parent=unit Dump Ada specs as child units of given parent.
1170 C++ ObjC++ Alias(faligned-new=,1,0)
1171 Support C++17 allocation of over-aligned types.
1174 C++ ObjC++ Joined RejectNegative Var(aligned_new_threshold) UInteger Init(-1)
1175 -faligned-new=<N> Use C++17 over-aligned type allocation for alignments greater than N.
1178 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1180 fallow-parameterless-variadic-functions
1181 C ObjC Var(flag_allow_parameterless_variadic_functions)
1182 Allow variadic functions without named parameter.
1184 falt-external-templates
1185 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1186 No longer supported.
1189 C ObjC C++ ObjC++ Var(flag_no_asm, 0)
1190 Recognize the \"asm\" keyword.
1192 ; Define extra predefined macros for use in libgcc.
1194 C ObjC C++ ObjC++ Undocumented Var(flag_building_libgcc)
1197 C ObjC C++ ObjC++ Var(flag_no_builtin, 0)
1198 Recognize built-in functions.
1201 C ObjC C++ ObjC++ Joined
1203 fcanonical-system-headers
1205 Where shorter, use canonicalized paths to systems headers.
1207 fcheck-pointer-bounds
1208 C ObjC C++ ObjC++ LTO Report Var(flag_check_pointer_bounds)
1209 Add Pointer Bounds Checker instrumentation. fchkp-* flags are used to
1210 control instrumentation. Currently available for C, C++ and ObjC.
1212 fchkp-check-incomplete-type
1213 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_incomplete_type) Init(1)
1214 Generate pointer bounds checks for variables with incomplete type.
1216 fchkp-zero-input-bounds-for-main
1217 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_zero_input_bounds_for_main) Init(0)
1218 Use zero bounds for all incoming arguments in 'main' function. It helps when
1219 instrumented binaries are used with legacy libs.
1221 fchkp-first-field-has-own-bounds
1222 C ObjC C++ ObjC++ LTO RejectNegative Report Var(flag_chkp_first_field_has_own_bounds)
1223 Forces Pointer Bounds Checker to use narrowed bounds for address of the first
1224 field in the structure. By default pointer to the first field has the same
1225 bounds as pointer to the whole structure.
1228 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_narrow_bounds) Init(1)
1229 Control how Pointer Bounds Checker handle pointers to object fields. When
1230 narrowing is on, field bounds are used. Otherwise full object bounds are used.
1232 fchkp-narrow-to-innermost-array
1233 C ObjC C++ ObjC++ LTO RejectNegative Report Var(flag_chkp_narrow_to_innermost_arrray)
1234 Forces Pointer Bounds Checker to use bounds of the innermost arrays in case of
1235 nested static arrays access. By default outermost array is used.
1237 fchkp-flexible-struct-trailing-arrays
1238 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_flexible_struct_trailing_arrays)
1239 Forces Pointer Bounds Checker to treat all trailing arrays in structures as
1240 possibly flexible. By default only arrays fields with zero length or that are
1241 marked with attribute bnd_variable_size are treated as flexible.
1244 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_optimize) Init(-1)
1245 Allow Pointer Bounds Checker optimizations. By default allowed
1246 on optimization levels >0.
1248 fchkp-use-fast-string-functions
1249 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_fast_string_functions) Init(0)
1250 Allow to use *_nobnd versions of string functions by Pointer Bounds Checker.
1252 fchkp-use-nochk-string-functions
1253 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_nochk_string_functions) Init(0)
1254 Allow to use *_nochk versions of string functions by Pointer Bounds Checker.
1256 fchkp-use-static-bounds
1257 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_static_bounds) Init(1)
1258 Use statically initialized variable for vars bounds instead of
1259 generating them each time it is required.
1261 fchkp-use-static-const-bounds
1262 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_static_const_bounds) Init(-1)
1263 Use statically initialized variable for constant bounds instead of
1264 generating them each time it is required.
1266 fchkp-treat-zero-dynamic-size-as-infinite
1267 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_zero_dynamic_size_as_infinite) Init(0)
1268 With this option zero size obtained dynamically for objects with
1269 incomplete type will be treated as infinite.
1272 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_check_read) Init(1)
1273 Generate checks for all read accesses to memory.
1276 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_check_write) Init(1)
1277 Generate checks for all write accesses to memory.
1280 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_store_bounds) Init(1)
1281 Generate bounds stores for pointer writes.
1283 fchkp-instrument-calls
1284 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_instrument_calls) Init(1)
1285 Generate bounds passing for calls.
1287 fchkp-instrument-marked-only
1288 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_instrument_marked_only) Init(0)
1289 Instrument only functions marked with bnd_instrument attribute.
1292 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_wrappers) Init(1)
1293 Transform instrumented builtin calls into calls to wrappers.
1298 static-libmpxwrappers
1302 C ObjC C++ ObjC++ LTO Report Var(flag_cilkplus) Init(0)
1306 C++ ObjC++ Var(flag_concepts)
1307 Enable support for C++ concepts.
1311 Allow the arguments of the '?' operator to have different types.
1314 C++ ObjC++ Var(flag_conserve_space)
1315 Does nothing. Preserved for backward compatibility.
1317 fconstant-string-class=
1318 ObjC ObjC++ Joined MissingArgError(no class name specified with %qs)
1319 -fconst-string-class=<name> Use class <name> for constant strings.
1322 C++ ObjC++ Joined RejectNegative UInteger Var(max_constexpr_depth) Init(512)
1323 -fconstexpr-depth=<number> Specify maximum constexpr recursion depth.
1325 fconstexpr-loop-limit=
1326 C++ ObjC++ Joined RejectNegative UInteger Var(constexpr_loop_limit) Init(262144)
1327 -fconstexpr-loop-limit=<number> Specify maximum constexpr loop iteration count.
1331 Emit debug annotations during preprocessing.
1334 C++ ObjC++ Var(flag_deduce_init_list) Init(0)
1335 -fdeduce-init-list enable deduction of std::initializer_list for a template type parameter from a brace-enclosed initializer-list.
1338 C++ ObjC++ Var(flag_declone_ctor_dtor) Init(-1)
1339 Factor complex constructors and destructors to favor space over speed.
1343 Does nothing. Preserved for backward compatibility.
1347 Preprocess directives only.
1349 fdollars-in-identifiers
1351 Permit '$' as an identifier character.
1354 C ObjC C++ ObjC++ RejectNegative Var(flag_dump_ada_spec)
1355 Write all declarations as Ada code transitively.
1358 C ObjC C++ ObjC++ RejectNegative Var(flag_dump_ada_spec_slim)
1359 Write all declarations as Ada code for the given file only.
1362 C++ ObjC++ Var(flag_elide_constructors) Init(1)
1365 C++ ObjC++ Var(flag_enforce_eh_specs) Init(1)
1366 Generate code to check exception specifications.
1369 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1372 C ObjC C++ ObjC++ Joined RejectNegative
1373 -fexec-charset=<cset> Convert all strings and character constants to character set <cset>.
1375 fextended-identifiers
1377 Permit universal character names (\\u and \\U) in identifiers.
1380 C ObjC C++ ObjC++ Joined RejectNegative
1381 -finput-charset=<cset> Specify the default character set for source files.
1384 C++ ObjC++ Var(flag_extern_tls_init) Init(-1)
1385 Support dynamic initialization of thread-local variables in a different translation unit.
1388 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1391 C++ ObjC++ Var(flag_new_for_scope) Init(1)
1392 Scope of for-init-statement variables is local to the loop.
1396 Do not assume that standard C libraries and \"main\" exist.
1399 C++ ObjC++ Var(flag_no_gnu_keywords, 0)
1400 Recognize GNU-defined keywords.
1403 ObjC ObjC++ LTO Report RejectNegative Var(flag_next_runtime,0) Init(NEXT_OBJC_RUNTIME)
1404 Generate code for GNU runtime environment.
1407 C ObjC Var(flag_gnu89_inline) Init(-1)
1408 Use traditional GNU semantics for inline functions.
1411 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1414 C++ ObjC++ Optimization Alias(fexceptions) Warn({-fhandle-exceptions has been renamed -fexceptions (and is now on by default)})
1417 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1421 Assume normal C execution environment.
1424 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1425 No longer supported.
1428 C++ ObjC++ Var(flag_implement_inlines) Init(1)
1429 Export functions even if they can be inlined.
1431 fimplicit-inline-templates
1432 C++ ObjC++ Var(flag_implicit_inline_templates) Init(1)
1433 Emit implicit instantiations of inline templates.
1436 C++ ObjC++ Var(flag_implicit_templates) Init(1)
1437 Emit implicit instantiations of templates.
1439 fnew-inheriting-ctors
1440 C++ ObjC++ Var(flag_new_inheriting_ctors) Init(1)
1441 Implement C++17 inheriting constructor semantics.
1444 C++ ObjC++ Var(flag_friend_injection)
1445 Inject friend functions into enclosing namespace.
1447 fkeep-inline-dllexport
1448 C C++ ObjC ObjC++ Var(flag_keep_inline_dllexport) Init(1) Report Condition(TARGET_DLLIMPORT_DECL_ATTRIBUTES)
1449 Don't emit dllexported inline functions unless needed.
1452 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1454 flax-vector-conversions
1455 C ObjC C++ ObjC++ Var(flag_lax_vector_conversions)
1456 Allow implicit conversions between vectors with differing numbers of subparts and/or differing element types.
1459 C ObjC C++ ObjC++ Var(flag_ms_extensions)
1460 Don't warn about uses of Microsoft extensions.
1463 C ObjC C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1466 C ObjC C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1469 C ObjC C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1471 fname-mangling-version-
1472 C++ ObjC++ Joined Ignore Warn(switch %qs is no longer supported)
1475 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1478 C++ ObjC++ Var(flag_new_ttp)
1479 Implement resolution of DR 150 for matching of template template arguments.
1482 ObjC ObjC++ LTO Report RejectNegative Var(flag_next_runtime)
1483 Generate code for NeXT (Apple Mac OS X) runtime environment.
1486 ObjC ObjC++ Var(flag_nil_receivers) Init(1)
1487 Assume that receivers of Objective-C messages may be nil.
1490 ObjC ObjC++ Var(flag_local_ivars) Init(1)
1491 Allow access to instance variables as if they were local declarations within instance method implementations.
1494 ObjC ObjC++ Joined RejectNegative Enum(ivar_visibility) Var(default_ivar_visibility) Init(IVAR_VISIBILITY_PROTECTED)
1495 -fvisibility=[private|protected|public|package] Set the default symbol visibility.
1498 Name(ivar_visibility) Type(enum ivar_visibility) UnknownError(unrecognized ivar visibility value %qs)
1501 Enum(ivar_visibility) String(private) Value(IVAR_VISIBILITY_PRIVATE)
1504 Enum(ivar_visibility) String(protected) Value(IVAR_VISIBILITY_PROTECTED)
1507 Enum(ivar_visibility) String(public) Value(IVAR_VISIBILITY_PUBLIC)
1510 Enum(ivar_visibility) String(package) Value(IVAR_VISIBILITY_PACKAGE)
1513 C++ ObjC++ Var(flag_no_nonansi_builtin, 0)
1516 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1519 C++ ObjC++ Optimization Var(flag_nothrow_opt)
1520 Treat a throw() exception specification as noexcept to improve code size.
1523 ObjC ObjC++ LTO Joined Report RejectNegative UInteger Var(flag_objc_abi)
1524 Specify which ABI to use for Objective-C family code and meta-data generation.
1526 ; Generate special '- .cxx_construct' and '- .cxx_destruct' methods
1527 ; to initialize any non-POD ivars in Objective-C++ classes.
1528 fobjc-call-cxx-cdtors
1529 ObjC++ Var(flag_objc_call_cxx_cdtors)
1530 Generate special Objective-C methods to initialize/destroy non-POD C++ ivars, if needed.
1532 fobjc-direct-dispatch
1533 ObjC ObjC++ Var(flag_objc_direct_dispatch)
1534 Allow fast jumps to the message dispatcher.
1536 ; Nonzero means that we will allow new ObjC exception syntax (@throw,
1537 ; @try, etc.) in source code.
1539 ObjC ObjC++ Var(flag_objc_exceptions)
1540 Enable Objective-C exception and synchronization syntax.
1543 ObjC ObjC++ LTO Var(flag_objc_gc)
1544 Enable garbage collection (GC) in Objective-C/Objective-C++ programs.
1547 ObjC ObjC++ Var(flag_objc_nilcheck,1)
1548 Enable inline checks for nil receivers with the NeXT runtime and ABI version 2.
1550 ; Nonzero means that we generate NeXT setjmp based exceptions.
1551 fobjc-sjlj-exceptions
1552 ObjC ObjC++ Var(flag_objc_sjlj_exceptions) Init(-1)
1553 Enable Objective-C setjmp exception handling runtime.
1556 ObjC ObjC++ Var(flag_objc1_only)
1557 Conform to the Objective-C 1.0 language as implemented in GCC 4.0.
1560 C ObjC C++ ObjC++ LTO Var(flag_openacc)
1564 C ObjC C++ ObjC++ LTO Joined Var(flag_openacc_dims)
1565 Specify default OpenACC compute dimensions.
1568 C ObjC C++ ObjC++ LTO Var(flag_openmp)
1569 Enable OpenMP (implies -frecursive in Fortran).
1572 C ObjC C++ ObjC++ Var(flag_openmp_simd)
1573 Enable OpenMP's SIMD directives.
1577 Recognize C++ keywords like \"compl\" and \"xor\".
1581 Does nothing. Preserved for backward compatibility.
1588 Look for and use PCH files even when preprocessing.
1591 C++ ObjC++ Var(flag_permissive)
1592 Downgrade conformance errors to warnings.
1595 C ObjC Var(flag_plan9_extensions)
1596 Enable Plan 9 language extensions.
1600 Treat the input file as already preprocessed.
1602 ftrack-macro-expansion
1603 C ObjC C++ ObjC++ JoinedOrMissing RejectNegative UInteger
1604 ; converted into ftrack-macro-expansion=
1606 ftrack-macro-expansion=
1607 C ObjC C++ ObjC++ JoinedOrMissing RejectNegative UInteger
1608 -ftrack-macro-expansion=<0|1|2> Track locations of tokens coming from macro expansion and display them in error messages.
1611 C++ ObjC++ Var(flag_pretty_templates) Init(1)
1612 -fno-pretty-templates Do not pretty-print template specializations as the template signature followed by the arguments.
1614 fprintf-return-value
1615 C ObjC C++ ObjC++ LTO Optimization Var(flag_printf_return_value) Init(1)
1616 Treat known sprintf return values as constants.
1618 freplace-objc-classes
1619 ObjC ObjC++ LTO Var(flag_replace_objc_classes)
1620 Used in Fix-and-Continue mode to indicate that object files may be swapped in at runtime.
1624 Enable automatic template instantiation.
1627 C++ ObjC++ Optimization Var(flag_rtti) Init(1)
1628 Generate run time type descriptor information.
1631 C ObjC C++ ObjC++ LTO Optimization Var(flag_short_enums)
1632 Use the narrowest integer type possible for enumeration types.
1635 C ObjC C++ ObjC++ LTO Optimization Var(flag_short_wchar)
1636 Force the underlying type for \"wchar_t\" to be \"unsigned short\".
1639 C ObjC C++ ObjC++ Var(flag_signed_bitfields) Init(1)
1640 When \"signed\" or \"unsigned\" is not given make the bitfield signed.
1643 C ObjC C++ ObjC++ LTO Var(flag_signed_char)
1644 Make \"char\" signed by default.
1647 C++ ObjC++ Var(flag_sized_deallocation) Init(-1)
1648 Enable C++14 sized deallocation support.
1651 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1654 C ObjC Joined RejectNegative Enum(sso_struct) Var(default_sso) Init(SSO_NATIVE)
1655 -fsso-struct=[big-endian|little-endian|native] Set the default scalar storage order.
1658 Name(sso_struct) Type(enum scalar_storage_order_kind) UnknownError(unrecognized scalar storage order value %qs)
1661 Enum(sso_struct) String(big-endian) Value(SSO_BIG_ENDIAN)
1664 Enum(sso_struct) String(little-endian) Value(SSO_LITTLE_ENDIAN)
1667 Enum(sso_struct) String(native) Value(SSO_NATIVE)
1670 C++ ObjC++ Var(flag_detailed_statistics)
1671 Display statistics accumulated during compilation.
1674 C++ ObjC++ Optimization Var(flag_strict_enums)
1675 Assume that values of enumeration type are always within the minimum range of that type.
1678 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1681 C++ ObjC++ Common Alias(fstrong-eval-order=, all, none)
1682 Follow the C++17 evaluation order requirements for assignment expressions,
1683 shift, member function calls, etc.
1686 C++ ObjC++ Common Var(flag_strong_eval_order) Joined Enum(strong_eval_order) RejectNegative Init(-1)
1687 Follow the C++17 evaluation order requirements for assignment expressions,
1688 shift, member function calls, etc.
1691 Name(strong_eval_order) Type(int)
1694 Enum(strong_eval_order) String(none) Value(0)
1697 Enum(strong_eval_order) String(some) Value(1)
1700 Enum(strong_eval_order) String(all) Value(2)
1703 C ObjC C++ ObjC++ Joined RejectNegative UInteger
1704 -ftabstop=<number> Distance between tab stops for column reporting.
1706 ftemplate-backtrace-limit=
1707 C++ ObjC++ Joined RejectNegative UInteger Var(template_backtrace_limit) Init(10)
1708 Set the maximum number of template instantiation notes for a single warning or error.
1711 C++ ObjC++ Joined RejectNegative Undocumented Alias(ftemplate-depth=)
1714 C++ ObjC++ Joined RejectNegative UInteger
1715 -ftemplate-depth=<number> Specify maximum template instantiation depth.
1718 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1721 C++ ObjC++ Optimization Var(flag_threadsafe_statics) Init(1)
1722 -fno-threadsafe-statics Do not generate thread-safe code for initializing local statics.
1725 C ObjC C++ ObjC++ Var(flag_signed_bitfields, 0)
1726 When \"signed\" or \"unsigned\" is not given make the bitfield unsigned.
1729 C ObjC C++ ObjC++ LTO Var(flag_signed_char, 0)
1730 Make \"char\" unsigned by default.
1733 C++ ObjC++ Var(flag_use_cxa_atexit) Init(DEFAULT_USE_CXA_ATEXIT)
1734 Use __cxa_atexit to register destructors.
1736 fuse-cxa-get-exception-ptr
1737 C++ ObjC++ Var(flag_use_cxa_get_exception_ptr) Init(2)
1738 Use __cxa_get_exception_ptr in exception handling.
1740 fvisibility-inlines-hidden
1742 Marks all inlined functions and methods as having hidden visibility.
1744 fvisibility-ms-compat
1745 C++ ObjC++ Var(flag_visibility_ms_compat)
1746 Changes visibility to match Microsoft Visual Studio by default.
1749 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1750 No longer supported.
1753 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1754 No longer supported.
1757 C++ ObjC++ Var(flag_weak) Init(1)
1758 Emit common-like symbols as weak symbols.
1761 C ObjC C++ ObjC++ Joined RejectNegative
1762 -fwide-exec-charset=<cset> Convert all wide strings and character constants to character set <cset>.
1765 C ObjC C++ ObjC++ Var(flag_working_directory) Init(-1)
1766 Generate a #line directive pointing at the current working directory.
1769 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1770 No longer supported.
1773 ObjC ObjC++ Var(flag_zero_link)
1774 Generate lazy class lookup (via objc_getClass()) for use in Zero-Link mode.
1777 ObjC ObjC++ Driver Var(flag_gen_declaration)
1778 Dump declarations to a .decl file.
1780 femit-struct-debug-baseonly
1782 -femit-struct-debug-baseonly Aggressive reduced debug info for structs.
1784 femit-struct-debug-reduced
1786 -femit-struct-debug-reduced Conservative reduced debug info for structs.
1788 femit-struct-debug-detailed=
1789 C ObjC C++ ObjC++ Joined
1790 -femit-struct-debug-detailed=<spec-list> Detailed reduced debug info for structs.
1792 fext-numeric-literals
1793 C++ ObjC++ Var(flag_ext_numeric_literals) Init(1)
1794 Interpret imaginary, fixed-point, or other gnu number suffix as the corresponding
1795 number literal rather than a user-defined number literal.
1798 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1799 -idirafter <dir> Add <dir> to the end of the system include path.
1802 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
1803 -imacros <file> Accept definition of macros in <file>.
1806 C ObjC C++ ObjC++ Joined Separate
1807 -imultilib <dir> Set <dir> to be the multilib include subdirectory.
1810 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
1811 -include <file> Include the contents of <file> before other files.
1814 C ObjC C++ ObjC++ Joined Separate
1815 -iprefix <path> Specify <path> as a prefix for next two options.
1818 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1819 -isysroot <dir> Set <dir> to be the system root directory.
1822 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1823 -isystem <dir> Add <dir> to the start of the system include path.
1826 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1827 -iquote <dir> Add <dir> to the end of the quote include path.
1830 C ObjC C++ ObjC++ Joined Separate
1831 -iwithprefix <dir> Add <dir> to the end of the system include path.
1834 C ObjC C++ ObjC++ Joined Separate
1835 -iwithprefixbefore <dir> Add <dir> to the end of the main include path.
1838 C Undocumented RejectDriver
1845 Do not search standard system include directories (those specified with -isystem will still be used).
1849 Do not search standard system include directories for C++.
1852 C ObjC C++ ObjC++ Joined Separate
1853 ; Documented in common.opt
1856 C ObjC C++ ObjC++ Alias(Wpedantic)
1857 ; Documented in common.opt
1859 print-objc-runtime-info
1861 Generate C header of platform-specific features.
1865 Remap file names when including files.
1869 Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum.
1872 C++ ObjC++ Alias(std=c++98)
1873 Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum.
1877 Conform to the ISO 2011 C++ standard.
1880 C++ ObjC++ Alias(std=c++11) Undocumented
1881 Deprecated in favor of -std=c++11.
1884 C++ ObjC++ Alias(std=c++14) Undocumented
1885 Deprecated in favor of -std=c++14.
1889 Conform to the ISO 2014 C++ standard.
1893 Conform to the ISO 2017(?) C++ draft standard (experimental and incomplete support).
1896 C++ ObjC++ Alias(std=c++1z) Undocumented
1900 Conform to the ISO 2011 C standard.
1903 C ObjC Alias(std=c11)
1904 Deprecated in favor of -std=c11.
1907 C ObjC Alias(std=c90)
1908 Conform to the ISO 1990 C standard.
1912 Conform to the ISO 1990 C standard.
1916 Conform to the ISO 1999 C standard.
1919 C ObjC Alias(std=c99)
1920 Deprecated in favor of -std=c99.
1924 Conform to the ISO 1998 C++ standard revised by the 2003 technical
1925 corrigendum with GNU extensions.
1928 C++ ObjC++ Alias(std=gnu++98)
1929 Conform to the ISO 1998 C++ standard revised by the 2003 technical
1930 corrigendum with GNU extensions.
1934 Conform to the ISO 2011 C++ standard with GNU extensions.
1937 C++ ObjC++ Alias(std=gnu++11) Undocumented
1938 Deprecated in favor of -std=gnu++11.
1941 C++ ObjC++ Alias(std=gnu++14) Undocumented
1942 Deprecated in favor of -std=gnu++14.
1946 Conform to the ISO 2014 C++ standard with GNU extensions.
1950 Conform to the ISO 201z(7?) C++ draft standard with GNU extensions (experimental and incomplete support).
1953 C++ ObjC++ Alias(std=gnu++1z) Undocumented
1957 Conform to the ISO 2011 C standard with GNU extensions.
1960 C ObjC Alias(std=gnu11)
1961 Deprecated in favor of -std=gnu11.
1964 C ObjC Alias(std=gnu90)
1965 Conform to the ISO 1990 C standard with GNU extensions.
1969 Conform to the ISO 1990 C standard with GNU extensions.
1973 Conform to the ISO 1999 C standard with GNU extensions.
1976 C ObjC Alias(std=gnu99)
1977 Deprecated in favor of -std=gnu99.
1980 C ObjC Alias(std=c90)
1981 Conform to the ISO 1990 C standard.
1985 Conform to the ISO 1990 C standard as amended in 1994.
1988 C ObjC Alias(std=c99)
1989 Conform to the ISO 1999 C standard.
1992 C ObjC Alias(std=c99)
1993 Deprecated in favor of -std=iso9899:1999.
1996 C ObjC Alias(std=c11)
1997 Conform to the ISO 2011 C standard.
2004 Enable traditional preprocessing.
2008 -trigraphs Support ISO C trigraphs.
2011 C ObjC C++ ObjC++ Var(flag_undef)
2012 Do not predefine system-specific and GCC-specific macros.
2016 ; Documented in common.opt
2020 ; Documented in common.opt
2022 ; This comment is to ensure we retain the blank line above.