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
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 C++ ObjC++ Var(warn_float_conversion) Warning LangEnabledBy(C ObjC C++ ObjC++,Wconversion)
509 Warn for implicit type conversions that cause loss of floating point precision.
512 C ObjC C++ ObjC++ Var(warn_float_equal) Warning
513 Warn if testing floating point numbers for equality.
516 C ObjC C++ ObjC++ Warning Alias(Wformat=, 1, 0)
517 Warn about printf/scanf/strftime/strfmon format string anomalies.
520 C ObjC C++ ObjC++ Var(warn_format_contains_nul) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
521 Warn about format strings that contain NUL bytes.
524 C ObjC C++ ObjC++ Var(warn_format_extra_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
525 Warn if passing too many arguments to a function for its format string.
528 C ObjC C++ ObjC++ Var(warn_format_nonliteral) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 2, 0)
529 Warn about format strings that are not literals.
532 C ObjC C++ LTO ObjC++ Warning Alias(Wformat-overflow=, 1, 0)
533 Warn about function calls with format strings that write past the end
534 of the destination region. Same as -Wformat-overflow=1.
537 C ObjC C++ ObjC++ Var(warn_format_security) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 2, 0)
538 Warn about possible security problems with format functions.
541 C ObjC C++ ObjC++ Var(warn_format_signedness) Warning
542 Warn about sign differences with format functions.
545 C ObjC C++ LTO ObjC++ Warning Alias(Wformat-truncation=, 1, 0)
546 Warn about calls to snprintf and similar functions that truncate output.
547 Same as -Wformat-truncation=1.
550 C ObjC C++ ObjC++ Var(warn_format_y2k) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 2, 0)
551 Warn about strftime formats yielding 2-digit years.
554 C ObjC C++ ObjC++ Var(warn_format_zero_length) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 1, 0)
555 Warn about zero-length formats.
558 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_format) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0)
559 Warn about printf/scanf/strftime/strfmon format string anomalies.
562 C ObjC C++ LTO ObjC++ Joined RejectNegative UInteger Var(warn_format_overflow) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
563 Warn about function calls with format strings that write past the end
564 of the destination region.
567 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_format_trunc) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
568 Warn about calls to snprintf and similar functions that truncate output.
571 C C++ Var(warn_ignored_qualifiers) Warning EnabledBy(Wextra)
572 Warn whenever type qualifiers are ignored.
575 C C++ Var(warn_ignored_attributes) Init(1) Warning
576 Warn whenever attributes are ignored.
578 Wincompatible-pointer-types
579 C ObjC Var(warn_incompatible_pointer_types) Init(1) Warning
580 Warn when there is a conversion between pointers that have incompatible types.
583 C ObjC C++ ObjC++ Var(warn_init_self) Warning LangEnabledBy(C++ ObjC++,Wall)
584 Warn about variables which are initialized to themselves.
587 C ObjC Var(warn_implicit) Warning LangEnabledBy(C ObjC,Wall)
588 Warn about implicit declarations.
590 Wimplicit-fallthrough=
591 LangEnabledBy(C ObjC C++ ObjC++,Wextra,3,0)
595 C ObjC C++ ObjC++ Var(warn_double_promotion) Warning
596 Warn about implicit conversions from \"float\" to \"double\".
598 Wexpansion-to-defined
599 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)
600 Warn if \"defined\" is used outside #if.
602 Wimplicit-function-declaration
603 C ObjC Var(warn_implicit_function_declaration) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit)
604 Warn about implicit function declarations.
607 C ObjC Var(warn_implicit_int) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit)
608 Warn when a declaration does not specify a type.
611 C ObjC C++ ObjC++ Undocumented Ignore
613 Winherited-variadic-ctor
614 C++ ObjC++ Var(warn_inh_var_ctor) Init(1) Warning
615 Warn about C++11 inheriting constructors when the base has a variadic constructor.
618 C ObjC Var(warn_int_conversion) Init(1) Warning
619 Warn about incompatible integer to pointer and pointer to integer conversions.
622 C ObjC C++ ObjC++ Var(warn_int_in_bool_context) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
623 Warn for suspicious integer expressions in boolean context.
626 C ObjC C++ ObjC++ Var(warn_int_to_pointer_cast) Init(1) Warning
627 Warn when there is a cast to a pointer from an integer of a different size.
630 C++ ObjC++ Var(warn_invalid_offsetof) Init(1) Warning
631 Warn about invalid uses of the \"offsetof\" macro.
634 C ObjC C++ ObjC++ CPP(warn_invalid_pch) CppReason(CPP_W_INVALID_PCH) Var(cpp_warn_invalid_pch) Init(0) Warning
635 Warn about PCH files that are found but not used.
638 C ObjC Var(warn_jump_misses_init) Warning LangEnabledby(C ObjC,Wc++-compat)
639 Warn when a jump misses a variable initialization.
642 C++ ObjC++ CPP(warn_literal_suffix) CppReason(CPP_W_LITERAL_SUFFIX) Var(cpp_warn_literal_suffix) Init(1) Warning
643 Warn when a string or character literal is followed by a ud-suffix which does not begin with an underscore.
646 C ObjC C++ ObjC++ Var(warn_logical_op) Init(0) Warning
647 Warn when a logical operator is suspiciously always evaluating to true or false.
649 Wlogical-not-parentheses
650 C ObjC C++ ObjC++ Var(warn_logical_not_paren) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
651 Warn when logical not is used on the left hand side operand of a comparison.
654 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)
655 Do not warn about using \"long long\" when -pedantic.
658 C ObjC C++ ObjC++ Var(warn_main) Init(-1) Warning LangEnabledBy(C ObjC,Wall, 2, 0)
659 Warn about suspicious declarations of \"main\".
662 LangEnabledBy(C ObjC C++ ObjC++,Wpedantic, 2, 0)
665 Wmemset-transposed-args
666 C ObjC C++ ObjC++ Var(warn_memset_transposed_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
667 Warn about suspicious calls to memset where the third argument is constant literal zero and the second is not.
670 C ObjC C++ ObjC++ Var(warn_memset_elt_size) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
671 Warn about suspicious calls to memset where the third argument contains the number of elements not multiplied by the element size.
673 Wmisleading-indentation
674 C C++ Common Var(warn_misleading_indentation) Warning LangEnabledBy(C C++,Wall)
675 Warn when the indentation of the code does not reflect the block structure.
678 C ObjC C++ ObjC++ Var(warn_missing_braces) Warning LangEnabledBy(C ObjC,Wall)
679 Warn about possibly missing braces around initializers.
681 Wmissing-declarations
682 C ObjC C++ ObjC++ Var(warn_missing_declarations) Warning
683 Warn about global functions without previous declarations.
685 Wmissing-field-initializers
686 C ObjC C++ ObjC++ Var(warn_missing_field_initializers) Warning EnabledBy(Wextra)
687 Warn about missing fields in struct initializers.
689 Wmultiple-inheritance
690 C++ ObjC++ Var(warn_multiple_inheritance) Warning
691 Warn on direct multiple inheritance.
694 C++ ObjC++ Var(warn_namespaces) Warning
695 Warn on namespace definition.
698 C++ ObjC++ Var(warn_sized_deallocation) Warning EnabledBy(Wextra)
699 Warn about missing sized deallocation functions.
701 Wsizeof-pointer-memaccess
702 C ObjC C++ ObjC++ Var(warn_sizeof_pointer_memaccess) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
703 Warn about suspicious length parameters to certain string functions if the argument uses sizeof.
705 Wsizeof-array-argument
706 C ObjC C++ ObjC++ Var(warn_sizeof_array_argument) Warning Init(1)
707 Warn when sizeof is applied on a parameter declared as an array.
710 C ObjC C++ ObjC++ Warning Alias(Wstringop-overflow=, 2, 0)
711 Warn about buffer overflow in string manipulation functions like memcpy
715 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_stringop_overflow) Init(2) Warning
716 Under the control of Object Size type, warn about buffer overflow in string
717 manipulation functions like memcpy and strcpy.
719 Wsuggest-attribute=format
720 C ObjC C++ ObjC++ Var(warn_suggest_attribute_format) Warning
721 Warn about functions which might be candidates for format attributes.
724 C++ ObjC++ Var(warn_override) Warning
725 Suggest that the override keyword be used when the declaration of a virtual
726 function overrides another.
729 C ObjC C++ ObjC++ Var(warn_switch) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
730 Warn about enumerated switches, with no default, missing a case.
733 C ObjC C++ ObjC++ Var(warn_switch_default) Warning
734 Warn about enumerated switches missing a \"default:\" statement.
737 C ObjC C++ ObjC++ Var(warn_switch_enum) Warning
738 Warn about all enumerated switches missing a specific case.
741 C ObjC C++ ObjC++ Var(warn_switch_bool) Warning Init(1)
742 Warn about switches with boolean controlling expression.
745 C++ ObjC++ Var(warn_templates) Warning
746 Warn on primary template declaration.
748 Wmissing-format-attribute
749 C ObjC C++ ObjC++ Warning Alias(Wsuggest-attribute=format)
752 Wmissing-include-dirs
753 C ObjC C++ ObjC++ CPP(warn_missing_include_dirs) CppReason(CPP_W_MISSING_INCLUDE_DIRS) Var(cpp_warn_missing_include_dirs) Init(0) Warning
754 Warn about user-specified include directories that do not exist.
756 Wmissing-parameter-type
757 C ObjC Var(warn_missing_parameter_type) Warning EnabledBy(Wextra)
758 Warn about function parameters declared without a type specifier in K&R-style functions.
761 C ObjC Var(warn_missing_prototypes) Warning
762 Warn about global functions without prototypes.
765 C ObjC C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
768 C ObjC C++ ObjC++ CPP(warn_multichar) CppReason(CPP_W_MULTICHAR) Var(cpp_warn_multichar) Init(0) Warning
769 Warn about use of multi-character character constants.
772 C ObjC C++ ObjC++ Warning Var(warn_narrowing) Init(-1) LangEnabledBy(C++ ObjC++,Wall || Wc++11-compat)
773 Warn about narrowing conversions within { } that are ill-formed in C++11.
776 C ObjC Var(warn_nested_externs) Warning
777 Warn about \"extern\" declarations not at file scope.
780 C++ ObjC++ Var(warn_noexcept) Warning
781 Warn when a noexcept expression evaluates to false even though the expression can't actually throw.
784 C++ ObjC++ Warning Var(warn_noexcept_type) LangEnabledBy(C++ ObjC++,Wabi || Wc++1z-compat)
785 Warn if C++1z noexcept function type will change the mangled name of a symbol.
788 C++ ObjC++ Var(warn_nontemplate_friend) Init(1) Warning
789 Warn when non-templatized friend functions are declared within a template.
792 C++ ObjC++ Var(warn_nonvdtor) Warning LangEnabledBy(C++ ObjC++,Weffc++)
793 Warn about non-virtual destructors.
796 C ObjC C++ ObjC++ Var(warn_nonnull) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 1,0)
797 Warn about NULL being passed to argument slots marked as requiring non-NULL.
800 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
804 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
808 C ObjC C++ ObjC++ Warning Alias(Wnormalized=,nfc,none)
812 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)
813 -Wnormalized=[none|id|nfc|nfkc] Warn about non-normalized Unicode strings.
815 ; Required for these enum values.
820 Name(cpp_normalize_level) Type(int) UnknownError(argument %qs to %<-Wnormalized%> not recognized)
823 Enum(cpp_normalize_level) String(none) Value(normalized_none)
826 Enum(cpp_normalize_level) String(nfkc) Value(normalized_KC)
829 Enum(cpp_normalize_level) String(id) Value(normalized_identifier_C)
832 Enum(cpp_normalize_level) String(nfc) Value(normalized_C)
835 C++ ObjC++ Var(warn_old_style_cast) Warning
836 Warn if a C-style cast is used in a program.
838 Wold-style-declaration
839 C ObjC Var(warn_old_style_declaration) Warning EnabledBy(Wextra)
840 Warn for obsolescent usage in a declaration.
842 Wold-style-definition
843 C ObjC Var(warn_old_style_definition) Warning
844 Warn if an old-style parameter definition is used.
847 C C++ Var(warn_openmp_simd) Warning LangEnabledBy(C C++,Wall)
848 Warn if a simd directive is overridden by the vectorizer cost model.
851 C ObjC C++ ObjC++ Var(warn_overlength_strings) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic)
852 Warn if a string is longer than the maximum portable length specified by the standard.
855 C++ ObjC++ Var(warn_overloaded_virtual) Warning
856 Warn about overloaded virtual function names.
859 C ObjC Var(warn_override_init) Warning EnabledBy(Wextra)
860 Warn about overriding initializers without side effects.
862 Woverride-init-side-effects
863 C ObjC Var(warn_override_init_side_effects) Init(1) Warning
864 Warn about overriding initializers with side effects.
866 Wpacked-bitfield-compat
867 C ObjC C++ ObjC++ Var(warn_packed_bitfield_compat) Init(-1) Warning
868 Warn about packed bit-fields whose offset changed in GCC 4.4.
871 C ObjC C++ ObjC++ Var(warn_parentheses) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
872 Warn about possibly missing parentheses.
875 C ObjC C++ ObjC++ CPP(cpp_pedantic) CppReason(CPP_W_PEDANTIC) Warning
876 ; Documented in common.opt
879 C++ ObjC++ Var(warn_pmf2ptr) Init(1) Warning
880 Warn when converting the type of pointers to member functions.
883 C ObjC C++ ObjC++ Var(warn_pointer_arith) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic)
884 Warn about function pointer arithmetic.
887 C ObjC Var(warn_pointer_sign) Warning LangEnabledBy(C ObjC,Wall || Wpedantic)
888 Warn when a pointer differs in signedness in an assignment.
891 C ObjC C++ ObjC++ Var(warn_pointer_compare) Init(1) Warning
892 Warn when a pointer is compared with a zero character constant.
895 C ObjC Var(warn_pointer_to_int_cast) Init(1) Warning
896 Warn when a pointer is cast to an integer of a different size.
899 C ObjC C++ ObjC++ Var(warn_pragmas) Init(1) Warning
900 Warn about misuses of pragmas.
902 Wproperty-assign-default
903 ObjC ObjC++ Var(warn_property_assign_default) Init(1) Warning
904 Warn if a property for an Objective-C object has no assign semantics specified.
907 ObjC ObjC++ Var(warn_protocol) Init(1) Warning
908 Warn if inherited methods are unimplemented.
911 C++ Warning Alias(Wplacement-new=, 1, 0)
912 Warn for placement new expressions with undefined behavior.
915 C++ Joined RejectNegative UInteger Var(warn_placement_new) Init(-1) Warning
916 Warn for placement new expressions with undefined behavior.
919 C ObjC C++ ObjC++ Var(warn_redundant_decls) Warning
920 Warn about multiple declarations of the same object.
923 C++ ObjC++ Var(warn_register) Warning
924 Warn about uses of register storage specifier.
927 C++ ObjC++ Var(warn_reorder) Warning LangEnabledBy(C++ ObjC++,Wall)
928 Warn when the compiler reorders code.
931 C ObjC C++ ObjC++ Var(warn_return_type) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
932 Warn whenever a function's return type defaults to \"int\" (C), or about inconsistent return types (C++).
934 Wscalar-storage-order
935 C ObjC C++ ObjC++ Init(1) Warning
936 Warn on suspicious constructs involving reverse scalar storage order.
939 ObjC ObjC++ Var(warn_selector) Warning
940 Warn if a selector has multiple methods.
943 C ObjC C++ ObjC++ Var(warn_sequence_point) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
944 Warn about possible violations of sequence point rules.
947 ObjC ObjC++ Var(warn_shadow_ivar) EnabledBy(Wshadow) Init(1) Warning
948 Warn if a local declaration hides an instance variable.
951 C ObjC C++ ObjC++ Warning Alias(Wshift-overflow=, 1, 0)
952 Warn if left shift of a signed value overflows.
955 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_shift_overflow) Init(-1) Warning
956 Warn if left shift of a signed value overflows.
958 Wshift-count-negative
959 C ObjC C++ ObjC++ Var(warn_shift_count_negative) Init(1) Warning
960 Warn if shift count is negative.
962 Wshift-count-overflow
963 C ObjC C++ ObjC++ Var(warn_shift_count_overflow) Init(1) Warning
964 Warn if shift count >= width of type.
966 Wshift-negative-value
967 C ObjC C++ ObjC++ Var(warn_shift_negative_value) Init(-1) Warning
968 Warn if left shifting a negative value.
971 C ObjC C++ ObjC++ Var(warn_sign_compare) Warning LangEnabledBy(C++ ObjC++,Wall)
972 Warn about signed-unsigned comparisons.
975 C ObjC C++ ObjC++ EnabledBy(Wextra)
979 C ObjC C++ ObjC++ Var(warn_sign_conversion) Warning LangEnabledBy(C ObjC,Wconversion)
980 Warn for implicit type conversions between signed and unsigned integers.
983 C++ ObjC++ Var(warn_sign_promo) Warning
984 Warn when overload promotes from unsigned to signed.
986 Wstrict-null-sentinel
987 C++ ObjC++ Warning Var(warn_strict_null_sentinel)
988 Warn about uncasted NULL used as sentinel.
991 C ObjC Var(warn_strict_prototypes) Warning
992 Warn about unprototyped function declarations.
995 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 3, 0)
999 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0)
1002 Wstrict-selector-match
1003 ObjC ObjC++ Var(warn_strict_selector_match) Warning
1004 Warn if type signatures of candidate methods do not match exactly.
1007 C C++ Var(warn_sync_nand) Init(1) Warning
1008 Warn when __sync_fetch_and_nand and __sync_nand_and_fetch built-in functions are used.
1011 C++ ObjC++ Var(warn_synth) Warning
1012 Deprecated. This switch has no effect.
1015 C ObjC C++ ObjC++ Warning
1016 ; Documented in common.opt
1018 Wtautological-compare
1019 C ObjC C++ ObjC++ Var(warn_tautological_compare) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1020 Warn if a comparison always evaluates to true or false.
1023 C++ ObjC++ Warning Var(warn_terminate) Init(1)
1024 Warn if a throw expression will always result in a call to terminate().
1027 C ObjC CPP(cpp_warn_traditional) CppReason(CPP_W_TRADITIONAL) Var(warn_traditional) Init(0) Warning
1028 Warn about features not present in traditional C.
1030 Wtraditional-conversion
1031 C ObjC Var(warn_traditional_conversion) Warning
1032 Warn of prototypes causing type conversions different from what would happen in the absence of prototype.
1035 C ObjC C++ ObjC++ CPP(warn_trigraphs) CppReason(CPP_W_TRIGRAPHS) Var(cpp_warn_trigraphs) Init(2) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1036 Warn if trigraphs are encountered that might affect the meaning of the program.
1038 Wundeclared-selector
1039 ObjC ObjC++ Var(warn_undeclared_selector) Warning
1040 Warn about @selector()s without previously declared methods.
1043 C ObjC C++ ObjC++ CPP(warn_undef) CppReason(CPP_W_UNDEF) Var(cpp_warn_undef) Init(0) Warning
1044 Warn if an undefined macro is used in an #if directive.
1047 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
1050 Wmaybe-uninitialized
1051 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
1055 C ObjC C++ ObjC++ Warning Var(warn_unknown_pragmas) LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0)
1056 Warn about unrecognized pragmas.
1058 Wunsuffixed-float-constants
1059 C ObjC Var(warn_unsuffixed_float_constants) Warning
1060 Warn about unsuffixed float constants.
1063 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
1064 ; documented in common.opt
1066 Wunused-local-typedefs
1067 C ObjC C++ ObjC++ Var(warn_unused_local_typedefs) Warning EnabledBy(Wunused)
1068 Warn when typedefs locally defined in a function are not used.
1071 C ObjC C++ ObjC++ CppReason(CPP_W_UNUSED_MACROS) Var(cpp_warn_unused_macros) Warning
1072 Warn about macros defined in the main file that are not used.
1075 C ObjC C++ ObjC++ Var(warn_unused_result) Init(1) Warning
1076 Warn if a caller of a function, marked with attribute warn_unused_result, does not use its return value.
1079 C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wunused)
1080 ; documented in common.opt
1082 Wunused-const-variable
1083 C ObjC C++ ObjC++ Warning Alias(Wunused-const-variable=, 2, 0)
1084 Warn when a const variable is unused.
1086 Wunused-const-variable=
1087 C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_unused_const_variable) Warning LangEnabledBy(C ObjC,Wunused-variable, 1, 0)
1088 Warn when a const variable is unused.
1091 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)
1092 Warn about using variadic macros.
1095 C ObjC C++ ObjC++ Warning Var(warn_varargs) Init(1)
1096 Warn about questionable usage of the macros used to retrieve variable arguments.
1099 C ObjC C++ ObjC++ Var(warn_vla) Init(-1) Warning
1100 Warn if a variable length array is used.
1103 C ObjC C++ ObjC++ Var(warn_vla_limit) Warning Joined RejectNegative UInteger
1104 -Wvla-larger-than=<number> Warn on unbounded uses of variable-length arrays, and
1105 on bounded uses of variable-length arrays whose bound can be
1106 larger than <number> bytes.
1108 Wvolatile-register-var
1109 C ObjC C++ ObjC++ Var(warn_volatile_register_var) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
1110 Warn when a register variable is declared volatile.
1112 Wvirtual-inheritance
1113 C++ ObjC++ Var(warn_virtual_inheritance) Warning
1114 Warn on direct virtual inheritance.
1116 Wvirtual-move-assign
1117 C++ ObjC++ Var(warn_virtual_move_assign) Warning Init(1)
1118 Warn if a virtual base has a non-trivial move assignment operator.
1121 C ObjC C++ ObjC++ Var(warn_write_strings) Warning
1122 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.
1124 Wzero-as-null-pointer-constant
1125 C++ ObjC++ Var(warn_zero_as_null_pointer_constant) Warning
1126 Warn when a literal '0' is used as null pointer.
1129 C++ ObjC++ Var(warn_useless_cast) Warning
1130 Warn about useless casts.
1133 C++ ObjC++ Var(warn_subobject_linkage) Warning Init(1)
1134 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.
1136 Wduplicate-decl-specifier
1137 C ObjC Var(warn_duplicate_decl_specifier) Warning LangEnabledBy(C ObjC,Wall)
1138 Warn when a declaration has duplicate const, volatile, restrict or _Atomic specifier.
1141 C ObjC C++ ObjC++ Var(warn_restrict) Warning LangEnabledBy(C ObjC C++ ObjC++)
1142 Warn when an argument passed to a restrict-qualified parameter aliases with
1147 A synonym for -std=c89 (for C) or -std=c++98 (for C++).
1150 C ObjC C++ ObjC++ Joined
1151 ; Documented in common.opt. FIXME - what about -dI, -dD, -dN and -dD?
1153 fabi-compat-version=
1154 C++ ObjC++ Joined RejectNegative UInteger Var(flag_abi_compat_version) Init(-1)
1155 The version of the C++ ABI used for -Wabi warnings and link compatibility aliases.
1158 C++ ObjC++ Var(flag_access_control) Init(1)
1159 Enforce class member access control semantics.
1162 C ObjC C++ ObjC++ RejectNegative Joined Var(ada_specs_parent)
1163 -fada-spec-parent=unit Dump Ada specs as child units of given parent.
1166 C++ ObjC++ Alias(faligned-new=,1,0)
1167 Support C++17 allocation of over-aligned types.
1170 C++ ObjC++ Joined RejectNegative Var(aligned_new_threshold) UInteger Init(-1)
1171 -faligned-new=<N> Use C++17 over-aligned type allocation for alignments greater than N.
1174 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1176 fallow-parameterless-variadic-functions
1177 C ObjC Var(flag_allow_parameterless_variadic_functions)
1178 Allow variadic functions without named parameter.
1180 falt-external-templates
1181 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1182 No longer supported.
1185 C ObjC C++ ObjC++ Var(flag_no_asm, 0)
1186 Recognize the \"asm\" keyword.
1188 ; Define extra predefined macros for use in libgcc.
1190 C ObjC C++ ObjC++ Undocumented Var(flag_building_libgcc)
1193 C ObjC C++ ObjC++ Var(flag_no_builtin, 0)
1194 Recognize built-in functions.
1197 C ObjC C++ ObjC++ Joined
1199 fcanonical-system-headers
1201 Where shorter, use canonicalized paths to systems headers.
1203 fcheck-pointer-bounds
1204 C ObjC C++ ObjC++ LTO Report Var(flag_check_pointer_bounds)
1205 Add Pointer Bounds Checker instrumentation. fchkp-* flags are used to
1206 control instrumentation. Currently available for C, C++ and ObjC.
1208 fchkp-check-incomplete-type
1209 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_incomplete_type) Init(1)
1210 Generate pointer bounds checks for variables with incomplete type.
1212 fchkp-zero-input-bounds-for-main
1213 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_zero_input_bounds_for_main) Init(0)
1214 Use zero bounds for all incoming arguments in 'main' function. It helps when
1215 instrumented binaries are used with legacy libs.
1217 fchkp-first-field-has-own-bounds
1218 C ObjC C++ ObjC++ LTO RejectNegative Report Var(flag_chkp_first_field_has_own_bounds)
1219 Forces Pointer Bounds Checker to use narrowed bounds for address of the first
1220 field in the structure. By default pointer to the first field has the same
1221 bounds as pointer to the whole structure.
1224 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_narrow_bounds) Init(1)
1225 Control how Pointer Bounds Checker handle pointers to object fields. When
1226 narrowing is on, field bounds are used. Otherwise full object bounds are used.
1228 fchkp-narrow-to-innermost-array
1229 C ObjC C++ ObjC++ LTO RejectNegative Report Var(flag_chkp_narrow_to_innermost_arrray)
1230 Forces Pointer Bounds Checker to use bounds of the innermost arrays in case of
1231 nested static arrays access. By default outermost array is used.
1233 fchkp-flexible-struct-trailing-arrays
1234 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_flexible_struct_trailing_arrays)
1235 Forces Pointer Bounds Checker to treat all trailing arrays in structures as
1236 possibly flexible. By default only arrays fields with zero length or that are
1237 marked with attribute bnd_variable_size are treated as flexible.
1240 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_optimize) Init(-1)
1241 Allow Pointer Bounds Checker optimizations. By default allowed
1242 on optimization levels >0.
1244 fchkp-use-fast-string-functions
1245 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_fast_string_functions) Init(0)
1246 Allow to use *_nobnd versions of string functions by Pointer Bounds Checker.
1248 fchkp-use-nochk-string-functions
1249 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_nochk_string_functions) Init(0)
1250 Allow to use *_nochk versions of string functions by Pointer Bounds Checker.
1252 fchkp-use-static-bounds
1253 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_static_bounds) Init(1)
1254 Use statically initialized variable for vars bounds instead of
1255 generating them each time it is required.
1257 fchkp-use-static-const-bounds
1258 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_static_const_bounds) Init(-1)
1259 Use statically initialized variable for constant bounds instead of
1260 generating them each time it is required.
1262 fchkp-treat-zero-dynamic-size-as-infinite
1263 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_zero_dynamic_size_as_infinite) Init(0)
1264 With this option zero size obtained dynamically for objects with
1265 incomplete type will be treated as infinite.
1268 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_check_read) Init(1)
1269 Generate checks for all read accesses to memory.
1272 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_check_write) Init(1)
1273 Generate checks for all write accesses to memory.
1276 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_store_bounds) Init(1)
1277 Generate bounds stores for pointer writes.
1279 fchkp-instrument-calls
1280 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_instrument_calls) Init(1)
1281 Generate bounds passing for calls.
1283 fchkp-instrument-marked-only
1284 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_instrument_marked_only) Init(0)
1285 Instrument only functions marked with bnd_instrument attribute.
1288 C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_wrappers) Init(1)
1289 Transform instrumented builtin calls into calls to wrappers.
1294 static-libmpxwrappers
1298 C ObjC C++ ObjC++ LTO Report Var(flag_cilkplus) Init(0)
1302 C++ ObjC++ Var(flag_concepts)
1303 Enable support for C++ concepts.
1307 Allow the arguments of the '?' operator to have different types.
1310 C++ ObjC++ Var(flag_conserve_space)
1311 Does nothing. Preserved for backward compatibility.
1313 fconstant-string-class=
1314 ObjC ObjC++ Joined MissingArgError(no class name specified with %qs)
1315 -fconst-string-class=<name> Use class <name> for constant strings.
1318 C++ ObjC++ Joined RejectNegative UInteger Var(max_constexpr_depth) Init(512)
1319 -fconstexpr-depth=<number> Specify maximum constexpr recursion depth.
1321 fconstexpr-loop-limit=
1322 C++ ObjC++ Joined RejectNegative UInteger Var(constexpr_loop_limit) Init(262144)
1323 -fconstexpr-loop-limit=<number> Specify maximum constexpr loop iteration count.
1327 Emit debug annotations during preprocessing.
1330 C++ ObjC++ Var(flag_deduce_init_list) Init(0)
1331 -fdeduce-init-list enable deduction of std::initializer_list for a template type parameter from a brace-enclosed initializer-list.
1334 C++ ObjC++ Var(flag_declone_ctor_dtor) Init(-1)
1335 Factor complex constructors and destructors to favor space over speed.
1339 Does nothing. Preserved for backward compatibility.
1343 Preprocess directives only.
1345 fdollars-in-identifiers
1347 Permit '$' as an identifier character.
1350 C ObjC C++ ObjC++ RejectNegative Var(flag_dump_ada_spec)
1351 Write all declarations as Ada code transitively.
1354 C ObjC C++ ObjC++ RejectNegative Var(flag_dump_ada_spec_slim)
1355 Write all declarations as Ada code for the given file only.
1358 C++ ObjC++ Var(flag_elide_constructors) Init(1)
1361 C++ ObjC++ Var(flag_enforce_eh_specs) Init(1)
1362 Generate code to check exception specifications.
1365 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1368 C ObjC C++ ObjC++ Joined RejectNegative
1369 -fexec-charset=<cset> Convert all strings and character constants to character set <cset>.
1371 fextended-identifiers
1373 Permit universal character names (\\u and \\U) in identifiers.
1376 C ObjC C++ ObjC++ Joined RejectNegative
1377 -finput-charset=<cset> Specify the default character set for source files.
1380 C++ ObjC++ Var(flag_extern_tls_init) Init(-1)
1381 Support dynamic initialization of thread-local variables in a different translation unit.
1384 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1387 C++ ObjC++ Var(flag_new_for_scope) Init(1)
1388 Scope of for-init-statement variables is local to the loop.
1392 Do not assume that standard C libraries and \"main\" exist.
1395 C++ ObjC++ Var(flag_no_gnu_keywords, 0)
1396 Recognize GNU-defined keywords.
1399 ObjC ObjC++ LTO Report RejectNegative Var(flag_next_runtime,0) Init(NEXT_OBJC_RUNTIME)
1400 Generate code for GNU runtime environment.
1403 C ObjC Var(flag_gnu89_inline) Init(-1)
1404 Use traditional GNU semantics for inline functions.
1407 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1410 C++ ObjC++ Optimization Alias(fexceptions) Warn({-fhandle-exceptions has been renamed -fexceptions (and is now on by default)})
1413 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1417 Assume normal C execution environment.
1420 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1421 No longer supported.
1424 C++ ObjC++ Var(flag_implement_inlines) Init(1)
1425 Export functions even if they can be inlined.
1427 fimplicit-inline-templates
1428 C++ ObjC++ Var(flag_implicit_inline_templates) Init(1)
1429 Emit implicit instantiations of inline templates.
1432 C++ ObjC++ Var(flag_implicit_templates) Init(1)
1433 Emit implicit instantiations of templates.
1435 fnew-inheriting-ctors
1436 C++ ObjC++ Var(flag_new_inheriting_ctors) Init(1)
1437 Implement C++17 inheriting constructor semantics.
1440 C++ ObjC++ Var(flag_friend_injection)
1441 Inject friend functions into enclosing namespace.
1443 fkeep-inline-dllexport
1444 C C++ ObjC ObjC++ Var(flag_keep_inline_dllexport) Init(1) Report Condition(TARGET_DLLIMPORT_DECL_ATTRIBUTES)
1445 Don't emit dllexported inline functions unless needed.
1448 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1450 flax-vector-conversions
1451 C ObjC C++ ObjC++ Var(flag_lax_vector_conversions)
1452 Allow implicit conversions between vectors with differing numbers of subparts and/or differing element types.
1455 C ObjC C++ ObjC++ Var(flag_ms_extensions)
1456 Don't warn about uses of Microsoft extensions.
1459 C ObjC C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1462 C ObjC C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1465 C ObjC C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1467 fname-mangling-version-
1468 C++ ObjC++ Joined Ignore Warn(switch %qs is no longer supported)
1471 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1474 C++ ObjC++ Var(flag_new_ttp)
1475 Implement resolution of DR 150 for matching of template template arguments.
1478 ObjC ObjC++ LTO Report RejectNegative Var(flag_next_runtime)
1479 Generate code for NeXT (Apple Mac OS X) runtime environment.
1482 ObjC ObjC++ Var(flag_nil_receivers) Init(1)
1483 Assume that receivers of Objective-C messages may be nil.
1486 ObjC ObjC++ Var(flag_local_ivars) Init(1)
1487 Allow access to instance variables as if they were local declarations within instance method implementations.
1490 ObjC ObjC++ Joined RejectNegative Enum(ivar_visibility) Var(default_ivar_visibility) Init(IVAR_VISIBILITY_PROTECTED)
1491 -fvisibility=[private|protected|public|package] Set the default symbol visibility.
1494 Name(ivar_visibility) Type(enum ivar_visibility) UnknownError(unrecognized ivar visibility value %qs)
1497 Enum(ivar_visibility) String(private) Value(IVAR_VISIBILITY_PRIVATE)
1500 Enum(ivar_visibility) String(protected) Value(IVAR_VISIBILITY_PROTECTED)
1503 Enum(ivar_visibility) String(public) Value(IVAR_VISIBILITY_PUBLIC)
1506 Enum(ivar_visibility) String(package) Value(IVAR_VISIBILITY_PACKAGE)
1509 C++ ObjC++ Var(flag_no_nonansi_builtin, 0)
1512 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1515 C++ ObjC++ Optimization Var(flag_nothrow_opt)
1516 Treat a throw() exception specification as noexcept to improve code size.
1519 ObjC ObjC++ LTO Joined Report RejectNegative UInteger Var(flag_objc_abi)
1520 Specify which ABI to use for Objective-C family code and meta-data generation.
1522 ; Generate special '- .cxx_construct' and '- .cxx_destruct' methods
1523 ; to initialize any non-POD ivars in Objective-C++ classes.
1524 fobjc-call-cxx-cdtors
1525 ObjC++ Var(flag_objc_call_cxx_cdtors)
1526 Generate special Objective-C methods to initialize/destroy non-POD C++ ivars, if needed.
1528 fobjc-direct-dispatch
1529 ObjC ObjC++ Var(flag_objc_direct_dispatch)
1530 Allow fast jumps to the message dispatcher.
1532 ; Nonzero means that we will allow new ObjC exception syntax (@throw,
1533 ; @try, etc.) in source code.
1535 ObjC ObjC++ Var(flag_objc_exceptions)
1536 Enable Objective-C exception and synchronization syntax.
1539 ObjC ObjC++ LTO Var(flag_objc_gc)
1540 Enable garbage collection (GC) in Objective-C/Objective-C++ programs.
1543 ObjC ObjC++ Var(flag_objc_nilcheck,1)
1544 Enable inline checks for nil receivers with the NeXT runtime and ABI version 2.
1546 ; Nonzero means that we generate NeXT setjmp based exceptions.
1547 fobjc-sjlj-exceptions
1548 ObjC ObjC++ Var(flag_objc_sjlj_exceptions) Init(-1)
1549 Enable Objective-C setjmp exception handling runtime.
1552 ObjC ObjC++ Var(flag_objc1_only)
1553 Conform to the Objective-C 1.0 language as implemented in GCC 4.0.
1556 C ObjC C++ ObjC++ LTO Var(flag_openacc)
1560 C ObjC C++ ObjC++ LTO Joined Var(flag_openacc_dims)
1561 Specify default OpenACC compute dimensions.
1564 C ObjC C++ ObjC++ LTO Var(flag_openmp)
1565 Enable OpenMP (implies -frecursive in Fortran).
1568 C ObjC C++ ObjC++ Var(flag_openmp_simd)
1569 Enable OpenMP's SIMD directives.
1573 Recognize C++ keywords like \"compl\" and \"xor\".
1577 Does nothing. Preserved for backward compatibility.
1584 Look for and use PCH files even when preprocessing.
1587 C++ ObjC++ Var(flag_permissive)
1588 Downgrade conformance errors to warnings.
1591 C ObjC Var(flag_plan9_extensions)
1592 Enable Plan 9 language extensions.
1596 Treat the input file as already preprocessed.
1598 ftrack-macro-expansion
1599 C ObjC C++ ObjC++ JoinedOrMissing RejectNegative UInteger
1600 ; converted into ftrack-macro-expansion=
1602 ftrack-macro-expansion=
1603 C ObjC C++ ObjC++ JoinedOrMissing RejectNegative UInteger
1604 -ftrack-macro-expansion=<0|1|2> Track locations of tokens coming from macro expansion and display them in error messages.
1607 C++ ObjC++ Var(flag_pretty_templates) Init(1)
1608 -fno-pretty-templates Do not pretty-print template specializations as the template signature followed by the arguments.
1610 fprintf-return-value
1611 C ObjC C++ ObjC++ LTO Optimization Var(flag_printf_return_value) Init(1)
1612 Treat known sprintf return values as constants.
1614 freplace-objc-classes
1615 ObjC ObjC++ LTO Var(flag_replace_objc_classes)
1616 Used in Fix-and-Continue mode to indicate that object files may be swapped in at runtime.
1620 Enable automatic template instantiation.
1623 C++ ObjC++ Optimization Var(flag_rtti) Init(1)
1624 Generate run time type descriptor information.
1627 C ObjC C++ ObjC++ LTO Optimization Var(flag_short_enums)
1628 Use the narrowest integer type possible for enumeration types.
1631 C ObjC C++ ObjC++ LTO Optimization Var(flag_short_wchar)
1632 Force the underlying type for \"wchar_t\" to be \"unsigned short\".
1635 C ObjC C++ ObjC++ Var(flag_signed_bitfields) Init(1)
1636 When \"signed\" or \"unsigned\" is not given make the bitfield signed.
1639 C ObjC C++ ObjC++ LTO Var(flag_signed_char)
1640 Make \"char\" signed by default.
1643 C++ ObjC++ Var(flag_sized_deallocation) Init(-1)
1644 Enable C++14 sized deallocation support.
1647 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1650 C ObjC Joined RejectNegative Enum(sso_struct) Var(default_sso) Init(SSO_NATIVE)
1651 -fsso-struct=[big-endian|little-endian|native] Set the default scalar storage order.
1654 Name(sso_struct) Type(enum scalar_storage_order_kind) UnknownError(unrecognized scalar storage order value %qs)
1657 Enum(sso_struct) String(big-endian) Value(SSO_BIG_ENDIAN)
1660 Enum(sso_struct) String(little-endian) Value(SSO_LITTLE_ENDIAN)
1663 Enum(sso_struct) String(native) Value(SSO_NATIVE)
1666 C++ ObjC++ Var(flag_detailed_statistics)
1667 Display statistics accumulated during compilation.
1670 C++ ObjC++ Optimization Var(flag_strict_enums)
1671 Assume that values of enumeration type are always within the minimum range of that type.
1674 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1677 C++ ObjC++ Common Alias(fstrong-eval-order=, all, none)
1678 Follow the C++17 evaluation order requirements for assignment expressions,
1679 shift, member function calls, etc.
1682 C++ ObjC++ Common Var(flag_strong_eval_order) Joined Enum(strong_eval_order) RejectNegative Init(-1)
1683 Follow the C++17 evaluation order requirements for assignment expressions,
1684 shift, member function calls, etc.
1687 Name(strong_eval_order) Type(int)
1690 Enum(strong_eval_order) String(none) Value(0)
1693 Enum(strong_eval_order) String(some) Value(1)
1696 Enum(strong_eval_order) String(all) Value(2)
1699 C ObjC C++ ObjC++ Joined RejectNegative UInteger
1700 -ftabstop=<number> Distance between tab stops for column reporting.
1702 ftemplate-backtrace-limit=
1703 C++ ObjC++ Joined RejectNegative UInteger Var(template_backtrace_limit) Init(10)
1704 Set the maximum number of template instantiation notes for a single warning or error.
1707 C++ ObjC++ Joined RejectNegative Undocumented Alias(ftemplate-depth=)
1710 C++ ObjC++ Joined RejectNegative UInteger
1711 -ftemplate-depth=<number> Specify maximum template instantiation depth.
1714 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1717 C++ ObjC++ Optimization Var(flag_threadsafe_statics) Init(1)
1718 -fno-threadsafe-statics Do not generate thread-safe code for initializing local statics.
1721 C ObjC C++ ObjC++ Var(flag_signed_bitfields, 0)
1722 When \"signed\" or \"unsigned\" is not given make the bitfield unsigned.
1725 C ObjC C++ ObjC++ LTO Var(flag_signed_char, 0)
1726 Make \"char\" unsigned by default.
1729 C++ ObjC++ Var(flag_use_cxa_atexit) Init(DEFAULT_USE_CXA_ATEXIT)
1730 Use __cxa_atexit to register destructors.
1732 fuse-cxa-get-exception-ptr
1733 C++ ObjC++ Var(flag_use_cxa_get_exception_ptr) Init(2)
1734 Use __cxa_get_exception_ptr in exception handling.
1736 fvisibility-inlines-hidden
1738 Marks all inlined functions and methods as having hidden visibility.
1740 fvisibility-ms-compat
1741 C++ ObjC++ Var(flag_visibility_ms_compat)
1742 Changes visibility to match Microsoft Visual Studio by default.
1745 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1746 No longer supported.
1749 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1750 No longer supported.
1753 C++ ObjC++ Var(flag_weak) Init(1)
1754 Emit common-like symbols as weak symbols.
1757 C ObjC C++ ObjC++ Joined RejectNegative
1758 -fwide-exec-charset=<cset> Convert all wide strings and character constants to character set <cset>.
1761 C ObjC C++ ObjC++ Var(flag_working_directory) Init(-1)
1762 Generate a #line directive pointing at the current working directory.
1765 C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
1766 No longer supported.
1769 ObjC ObjC++ Var(flag_zero_link)
1770 Generate lazy class lookup (via objc_getClass()) for use in Zero-Link mode.
1773 ObjC ObjC++ Driver Var(flag_gen_declaration)
1774 Dump declarations to a .decl file.
1776 femit-struct-debug-baseonly
1778 -femit-struct-debug-baseonly Aggressive reduced debug info for structs.
1780 femit-struct-debug-reduced
1782 -femit-struct-debug-reduced Conservative reduced debug info for structs.
1784 femit-struct-debug-detailed=
1785 C ObjC C++ ObjC++ Joined
1786 -femit-struct-debug-detailed=<spec-list> Detailed reduced debug info for structs.
1788 fext-numeric-literals
1789 C++ ObjC++ Var(flag_ext_numeric_literals) Init(1)
1790 Interpret imaginary, fixed-point, or other gnu number suffix as the corresponding
1791 number literal rather than a user-defined number literal.
1794 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1795 -idirafter <dir> Add <dir> to the end of the system include path.
1798 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
1799 -imacros <file> Accept definition of macros in <file>.
1802 C ObjC C++ ObjC++ Joined Separate
1803 -imultilib <dir> Set <dir> to be the multilib include subdirectory.
1806 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
1807 -include <file> Include the contents of <file> before other files.
1810 C ObjC C++ ObjC++ Joined Separate
1811 -iprefix <path> Specify <path> as a prefix for next two options.
1814 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1815 -isysroot <dir> Set <dir> to be the system root directory.
1818 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1819 -isystem <dir> Add <dir> to the start of the system include path.
1822 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
1823 -iquote <dir> Add <dir> to the end of the quote include path.
1826 C ObjC C++ ObjC++ Joined Separate
1827 -iwithprefix <dir> Add <dir> to the end of the system include path.
1830 C ObjC C++ ObjC++ Joined Separate
1831 -iwithprefixbefore <dir> Add <dir> to the end of the main include path.
1834 C Undocumented RejectDriver
1841 Do not search standard system include directories (those specified with -isystem will still be used).
1845 Do not search standard system include directories for C++.
1848 C ObjC C++ ObjC++ Joined Separate
1849 ; Documented in common.opt
1852 C ObjC C++ ObjC++ Alias(Wpedantic)
1853 ; Documented in common.opt
1855 print-objc-runtime-info
1857 Generate C header of platform-specific features.
1861 Remap file names when including files.
1865 Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum.
1868 C++ ObjC++ Alias(std=c++98)
1869 Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum.
1873 Conform to the ISO 2011 C++ standard.
1876 C++ ObjC++ Alias(std=c++11) Undocumented
1877 Deprecated in favor of -std=c++11.
1880 C++ ObjC++ Alias(std=c++14) Undocumented
1881 Deprecated in favor of -std=c++14.
1885 Conform to the ISO 2014 C++ standard.
1889 Conform to the ISO 2017(?) C++ draft standard (experimental and incomplete support).
1892 C++ ObjC++ Alias(std=c++1z) Undocumented
1896 Conform to the ISO 2011 C standard.
1899 C ObjC Alias(std=c11)
1900 Deprecated in favor of -std=c11.
1903 C ObjC Alias(std=c90)
1904 Conform to the ISO 1990 C standard.
1908 Conform to the ISO 1990 C standard.
1912 Conform to the ISO 1999 C standard.
1915 C ObjC Alias(std=c99)
1916 Deprecated in favor of -std=c99.
1920 Conform to the ISO 1998 C++ standard revised by the 2003 technical
1921 corrigendum with GNU extensions.
1924 C++ ObjC++ Alias(std=gnu++98)
1925 Conform to the ISO 1998 C++ standard revised by the 2003 technical
1926 corrigendum with GNU extensions.
1930 Conform to the ISO 2011 C++ standard with GNU extensions.
1933 C++ ObjC++ Alias(std=gnu++11) Undocumented
1934 Deprecated in favor of -std=gnu++11.
1937 C++ ObjC++ Alias(std=gnu++14) Undocumented
1938 Deprecated in favor of -std=gnu++14.
1942 Conform to the ISO 2014 C++ standard with GNU extensions.
1946 Conform to the ISO 201z(7?) C++ draft standard with GNU extensions (experimental and incomplete support).
1949 C++ ObjC++ Alias(std=gnu++1z) Undocumented
1953 Conform to the ISO 2011 C standard with GNU extensions.
1956 C ObjC Alias(std=gnu11)
1957 Deprecated in favor of -std=gnu11.
1960 C ObjC Alias(std=gnu90)
1961 Conform to the ISO 1990 C standard with GNU extensions.
1965 Conform to the ISO 1990 C standard with GNU extensions.
1969 Conform to the ISO 1999 C standard with GNU extensions.
1972 C ObjC Alias(std=gnu99)
1973 Deprecated in favor of -std=gnu99.
1976 C ObjC Alias(std=c90)
1977 Conform to the ISO 1990 C standard.
1981 Conform to the ISO 1990 C standard as amended in 1994.
1984 C ObjC Alias(std=c99)
1985 Conform to the ISO 1999 C standard.
1988 C ObjC Alias(std=c99)
1989 Deprecated in favor of -std=iso9899:1999.
1992 C ObjC Alias(std=c11)
1993 Conform to the ISO 2011 C standard.
2000 Enable traditional preprocessing.
2004 -trigraphs Support ISO C trigraphs.
2007 C ObjC C++ ObjC++ Var(flag_undef)
2008 Do not predefine system-specific and GCC-specific macros.
2012 ; Documented in common.opt
2016 ; Documented in common.opt
2018 ; This comment is to ensure we retain the blank line above.