; Options for the C, ObjC, C++ and ObjC++ front ends. ; Copyright (C) 2003-2020 Free Software Foundation, Inc. ; ; This file is part of GCC. ; ; GCC is free software; you can redistribute it and/or modify it under ; the terms of the GNU General Public License as published by the Free ; Software Foundation; either version 3, or (at your option) any later ; version. ; ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY ; WARRANTY; without even the implied warranty of MERCHANTABILITY or ; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License ; for more details. ; ; You should have received a copy of the GNU General Public License ; along with GCC; see the file COPYING3. If not see ; . ; See the GCC internals manual for a description of this file's format. ; Please try to keep this file in ASCII collating order. Language C Language ObjC Language C++ Language ObjC++ -all-warnings C ObjC C++ ObjC++ Warning Alias(Wall) -ansi C ObjC C++ ObjC++ Alias(ansi) -assert C ObjC C++ ObjC++ Separate Alias(A) MissingArgError(assertion missing after %qs) -assert= C ObjC C++ ObjC++ Joined Alias(A) MissingArgError(assertion missing after %qs) -comments C ObjC C++ ObjC++ Alias(C) -comments-in-macros C ObjC C++ ObjC++ Alias(CC) -define-macro C ObjC C++ ObjC++ Separate Alias(D) MissingArgError(macro name missing after %qs) -define-macro= C ObjC C++ ObjC++ Joined Alias(D) MissingArgError(macro name missing after %qs) -dependencies C ObjC C++ ObjC++ Alias(M) -dump C ObjC C++ ObjC++ Separate Alias(d) -dump= C ObjC C++ ObjC++ Joined Alias(d) -imacros C ObjC C++ ObjC++ Separate Alias(imacros) MissingArgError(missing filename after %qs) -imacros= C ObjC C++ ObjC++ Joined Alias(imacros) MissingArgError(missing filename after %qs) -include C ObjC C++ ObjC++ Separate Alias(include) MissingArgError(missing filename after %qs) -include= C ObjC C++ ObjC++ Joined Alias(include) MissingArgError(missing filename after %qs) -include-barrier C ObjC C++ ObjC++ Alias(I, -) -include-directory C ObjC C++ ObjC++ Separate Alias(I) MissingArgError(missing path after %qs) -include-directory= C ObjC C++ ObjC++ Joined Alias(I) MissingArgError(missing path after %qs) -include-directory-after C ObjC C++ ObjC++ Separate Alias(idirafter) MissingArgError(missing path after %qs) -include-directory-after= C ObjC C++ ObjC++ Joined Alias(idirafter) MissingArgError(missing path after %qs) -include-prefix C ObjC C++ ObjC++ Separate Alias(iprefix) -include-prefix= C ObjC C++ ObjC++ JoinedOrMissing Alias(iprefix) -include-with-prefix C ObjC C++ ObjC++ Separate Alias(iwithprefix) -include-with-prefix= C ObjC C++ ObjC++ JoinedOrMissing Alias(iwithprefix) -include-with-prefix-after C ObjC C++ ObjC++ Separate Alias(iwithprefix) -include-with-prefix-after= C ObjC C++ ObjC++ JoinedOrMissing Alias(iwithprefix) -include-with-prefix-before C ObjC C++ ObjC++ Separate Alias(iwithprefixbefore) -include-with-prefix-before= C ObjC C++ ObjC++ JoinedOrMissing Alias(iwithprefixbefore) -no-integrated-cpp Driver Alias(no-integrated-cpp) -no-line-commands C ObjC C++ ObjC++ Alias(P) -no-standard-includes C ObjC C++ ObjC++ Alias(nostdinc) -no-warnings C ObjC C++ ObjC++ Alias(w) -output C ObjC C++ ObjC++ Separate Alias(o) -output= C ObjC C++ ObjC++ Joined Alias(o) -output-pch= C ObjC C++ ObjC++ Joined Separate -pedantic C ObjC C++ ObjC++ Alias(pedantic) -preprocess C ObjC C++ ObjC++ Undocumented Alias(E) -print-missing-file-dependencies C ObjC C++ ObjC++ Alias(MG) -trace-includes C ObjC C++ ObjC++ Alias(H) -traditional Driver Alias(traditional) -traditional-cpp C ObjC C++ ObjC++ Alias(traditional-cpp) -trigraphs C ObjC C++ ObjC++ Alias(trigraphs) -undefine-macro C ObjC C++ ObjC++ Separate Alias(U) MissingArgError(macro name missing after %qs) -undefine-macro= C ObjC C++ ObjC++ Joined Alias(U) MissingArgError(macro name missing after %qs) -user-dependencies C ObjC C++ ObjC++ Alias(MM) -verbose Common C ObjC C++ ObjC++ Alias(v) -write-dependencies C ObjC C++ ObjC++ NoDriverArg Separate Alias(MD) MissingArgError(missing filename after %qs) -write-user-dependencies C ObjC C++ ObjC++ NoDriverArg Separate Alias(MMD) MissingArgError(missing filename after %qs) A C ObjC C++ ObjC++ Joined Separate MissingArgError(assertion missing after %qs) -A= Assert the to . Putting '-' before disables the to . C C ObjC C++ ObjC++ Do not discard comments. CC C ObjC C++ ObjC++ Do not discard comments in macro expansions. D C ObjC C++ ObjC++ Joined Separate MissingArgError(macro name missing after %qs) -D[=] Define a with as its value. If just is given, is taken to be 1. E C ObjC C++ ObjC++ Undocumented Var(flag_preprocess_only) F Driver C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs) -F Add to the end of the main framework include path. fgimple C Var(flag_gimple) Init(0) Enable parsing GIMPLE. H C ObjC C++ ObjC++ Print the name of header files as they are used. I C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs) -I Add to the end of the main include path. M C ObjC C++ ObjC++ Generate make dependencies. MD C ObjC C++ ObjC++ NoDriverArg Separate MissingArgError(missing filename after %qs) Generate make dependencies and compile. MF C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs) -MF Write dependency output to the given file. MG C ObjC C++ ObjC++ Treat missing header files as generated files. MM C ObjC C++ ObjC++ Like -M but ignore system header files. MMD C ObjC C++ ObjC++ NoDriverArg Separate MissingArgError(missing filename after %qs) Like -MD but ignore system header files. MP C ObjC C++ ObjC++ Generate phony targets for all headers. MQ C ObjC C++ ObjC++ Joined Separate MissingArgError(missing makefile target after %qs) -MQ Add a MAKE-quoted target. MT C ObjC C++ ObjC++ Joined Separate MissingArgError(missing makefile target after %qs) -MT Add an unquoted target. P C ObjC C++ ObjC++ Do not generate #line directives. U C ObjC C++ ObjC++ Joined Separate MissingArgError(macro name missing after %qs) -U Undefine . Wabi C ObjC C++ ObjC++ LTO Var(warn_abi) Warning Warn about things that will change when compiling with an ABI-compliant compiler. Wabi= C ObjC C++ ObjC++ LTO Joined RejectNegative UInteger Warning Warn about things that change between the current -fabi-version and the specified version. Wabi-tag C++ ObjC++ Var(warn_abi_tag) Warning Warn if a subobject has an abi_tag attribute that the complete object type does not have. Wpsabi C ObjC C++ ObjC++ LTO Var(warn_psabi) Init(1) Warning Undocumented LangEnabledBy(C ObjC C++ ObjC++,Wabi) Wabsolute-value C ObjC Var(warn_absolute_value) Warning EnabledBy(Wextra) Warn on suspicious calls of standard functions computing absolute values. Waddress C ObjC C++ ObjC++ Var(warn_address) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn about suspicious uses of memory addresses. Enum Name(warn_aligned_new_level) Type(int) UnknownError(argument %qs to %<-Waligned-new%> not recognized) EnumValue Enum(warn_aligned_new_level) String(none) Value(0) EnumValue Enum(warn_aligned_new_level) String(global) Value(1) EnumValue Enum(warn_aligned_new_level) String(all) Value(2) Waligned-new C++ ObjC++ Alias(Waligned-new=,global,none) Warn about 'new' of type with extended alignment without -faligned-new. Waligned-new= C++ ObjC++ Var(warn_aligned_new) Enum(warn_aligned_new_level) Joined RejectNegative Warning LangEnabledBy(C++ ObjC++,Wall,1,0) -Waligned-new=[none|global|all] Warn even if 'new' uses a class member allocation function. Wall C ObjC C++ ObjC++ Warning Enable most warning messages. Walloca C ObjC C++ ObjC++ Var(warn_alloca) Warning Warn on any use of alloca. Walloc-size-larger-than= C ObjC C++ LTO ObjC++ Var(warn_alloc_size_limit) Joined Host_Wide_Int ByteSize Warning Init(HOST_WIDE_INT_MAX) -Walloc-size-larger-than= Warn for calls to allocation functions that attempt to allocate objects larger than the specified number of bytes. Wno-alloc-size-larger-than C ObjC C++ LTO ObjC++ Alias(Walloc-size-larger-than=,18446744073709551615EiB,none) Warning Disable Walloc-size-larger-than= warning. Equivalent to Walloc-size-larger-than= or larger. Walloc-zero C ObjC C++ ObjC++ Var(warn_alloc_zero) Warning Warn for calls to allocation functions that specify zero bytes. Walloca-larger-than= C ObjC C++ LTO ObjC++ Var(warn_alloca_limit) Warning Joined Host_Wide_Int ByteSize Init(HOST_WIDE_INT_MAX) -Walloca-larger-than= Warn on unbounded uses of alloca, and on bounded uses of alloca whose bound can be larger than bytes. Wno-alloca-larger-than C ObjC C++ LTO ObjC++ Alias(Walloca-larger-than=,18446744073709551615EiB,none) Warning Disable Walloca-larger-than= warning. Equivalent to Walloca-larger-than= or larger. Warray-bounds LangEnabledBy(C ObjC C++ LTO ObjC++) ; in common.opt Warray-bounds= LangEnabledBy(C ObjC C++ LTO ObjC++,Wall,1,0) ; in common.opt Wzero-length-bounds C ObjC C++ ObjC++ Var(warn_zero_length_bounds) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn about accesses to interior zero-length array members. Wassign-intercept ObjC ObjC++ Var(warn_assign_intercept) Warning Warn whenever an Objective-C assignment is being intercepted by the garbage collector. Wbad-function-cast C ObjC Var(warn_bad_function_cast) Warning Warn about casting functions to incompatible types. Wbool-compare C ObjC C++ ObjC++ Var(warn_bool_compare) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn about boolean expression compared with an integer value different from true/false. Wbool-operation C ObjC C++ ObjC++ Var(warn_bool_op) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn about certain operations on boolean expressions. Wframe-address C ObjC C++ ObjC++ Var(warn_frame_address) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn when __builtin_frame_address or __builtin_return_address is used unsafely. Wbuiltin-declaration-mismatch C ObjC C++ ObjC++ Var(warn_builtin_declaraion_mismatch) Init(1) Warning Warn when a built-in function is declared with the wrong signature. Wbuiltin-macro-redefined C ObjC C++ ObjC++ CPP(warn_builtin_macro_redefined) CppReason(CPP_W_BUILTIN_MACRO_REDEFINED) Var(cpp_warn_builtin_macro_redefined) Init(1) Warning Warn when a built-in preprocessor macro is undefined or redefined. Wc11-c2x-compat C ObjC CPP(cpp_warn_c11_c2x_compat) CppReason(CPP_W_C11_C2X_COMPAT) Var(warn_c11_c2x_compat) Init(-1) Warning Warn about features not present in ISO C11, but present in ISO C2X. Wc90-c99-compat C ObjC CPP(cpp_warn_c90_c99_compat) CppReason(CPP_W_C90_C99_COMPAT) Var(warn_c90_c99_compat) Init(-1) Warning Warn about features not present in ISO C90, but present in ISO C99. Wc99-c11-compat C ObjC Var(warn_c99_c11_compat) Init(-1) Warning Warn about features not present in ISO C99, but present in ISO C11. Wc++-compat C ObjC Var(warn_cxx_compat) CPP(warn_cxx_operator_names) CppReason(CPP_W_CXX_OPERATOR_NAMES) Init(0) Warning Warn about C constructs that are not in the common subset of C and C++. Wc++0x-compat C++ ObjC++ Warning Alias(Wc++11-compat) Undocumented Wc++11-compat C++ ObjC++ Var(warn_cxx11_compat) Warning LangEnabledBy(C++ ObjC++,Wall) Init(0) CPP(cpp_warn_cxx11_compat) CppReason(CPP_W_CXX11_COMPAT) Warn about C++ constructs whose meaning differs between ISO C++ 1998 and ISO C++ 2011. Wc++14-compat C++ ObjC++ Var(warn_cxx14_compat) Warning LangEnabledBy(C++ ObjC++,Wall) Warn about C++ constructs whose meaning differs between ISO C++ 2011 and ISO C++ 2014. Wc++1z-compat C++ ObjC++ Warning Alias(Wc++17-compat) Undocumented Wc++17-compat C++ ObjC++ Var(warn_cxx17_compat) Warning LangEnabledBy(C++ ObjC++,Wall) Warn about C++ constructs whose meaning differs between ISO C++ 2014 and ISO C++ 2017. Wc++2a-compat C++ ObjC++ Warning Alias(Wc++20-compat) Undocumented Wc++20-compat C++ ObjC++ Var(warn_cxx20_compat) Warning LangEnabledBy(C++ ObjC++,Wall) Warn about C++ constructs whose meaning differs between ISO C++ 2017 and ISO C++ 2020. Wcast-function-type C ObjC C++ ObjC++ Var(warn_cast_function_type) Warning EnabledBy(Wextra) Warn about casts between incompatible function types. Wcast-qual C ObjC C++ ObjC++ Var(warn_cast_qual) Warning Warn about casts which discard qualifiers. Wcatch-value C++ ObjC++ Warning Alias(Wcatch-value=, 1, 0) Warn about catch handlers of non-reference type. Wcatch-value= C++ ObjC++ Var(warn_catch_value) Warning Joined RejectNegative UInteger LangEnabledBy(C++ ObjC++,Wall, 1, 0) IntegerRange(0, 3) Warn about catch handlers of non-reference type. Wchar-subscripts C ObjC C++ ObjC++ Var(warn_char_subscripts) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn about subscripts whose type is \"char\". Wchkp C ObjC C++ ObjC++ Warning WarnRemoved Removed in GCC 9. This switch has no effect. Wclobbered C ObjC C++ ObjC++ Var(warn_clobbered) Warning EnabledBy(Wextra) Warn about variables that might be changed by \"longjmp\" or \"vfork\". Wcomma-subscript C++ ObjC++ Var(warn_comma_subscript) Warning Warn about uses of a comma operator within a subscripting expression. Wcomment C ObjC C++ ObjC++ CPP(warn_comments) CppReason(CPP_W_COMMENTS) Var(cpp_warn_comment) Init(0) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn about possibly nested block comments, and C++ comments spanning more than one physical line. Wcomments C ObjC C++ ObjC++ Warning Alias(Wcomment) Synonym for -Wcomment. Wconditionally-supported C++ ObjC++ Var(warn_conditionally_supported) Warning Warn for conditionally-supported constructs. Wconversion C ObjC C++ ObjC++ Var(warn_conversion) Warning Warn for implicit type conversions that may change a value. Wconversion-null C++ ObjC++ Var(warn_conversion_null) Init(1) Warning Warn for converting NULL from/to a non-pointer type. Wcpp C ObjC C++ ObjC++ CppReason(CPP_W_WARNING_DIRECTIVE) ; Documented in common.opt Wctor-dtor-privacy C++ ObjC++ Var(warn_ctor_dtor_privacy) Warning Warn when all constructors and destructors are private. Wdangling-else C ObjC C++ ObjC++ Var(warn_dangling_else) Warning LangEnabledBy(C ObjC C++ ObjC++,Wparentheses) Warn about dangling else. Wdate-time C ObjC C++ ObjC++ CPP(warn_date_time) CppReason(CPP_W_DATE_TIME) Var(cpp_warn_date_time) Init(0) Warning Warn about __TIME__, __DATE__ and __TIMESTAMP__ usage. Wdeclaration-after-statement C ObjC Var(warn_declaration_after_statement) Init(-1) Warning Warn when a declaration is found after a statement. Wdelete-incomplete C++ ObjC++ Var(warn_delete_incomplete) Init(1) Warning Warn when deleting a pointer to incomplete type. Wdelete-non-virtual-dtor C++ ObjC++ Var(warn_delnonvdtor) Warning LangEnabledBy(C++ ObjC++,Wall || Weffc++) Warn about deleting polymorphic objects with non-virtual destructors. Wdeprecated C C++ ObjC ObjC++ CPP(cpp_warn_deprecated) CppReason(CPP_W_DEPRECATED) ; Documented in common.opt Wdeprecated-copy C++ ObjC++ Var(warn_deprecated_copy) Warning LangEnabledBy(C++ ObjC++, Wextra) Mark implicitly-declared copy operations as deprecated if the class has a user-provided copy operation. Wdeprecated-copy-dtor C++ ObjC++ Var(warn_deprecated_copy, 2) Warning Mark implicitly-declared copy operations as deprecated if the class has a user-provided copy operation or destructor. Wdesignated-init C ObjC Var(warn_designated_init) Init(1) Warning Warn about positional initialization of structs requiring designated initializers. Wdiscarded-array-qualifiers C ObjC Var(warn_discarded_array_qualifiers) Init(1) Warning Warn if qualifiers on arrays which are pointer targets are discarded. Wdiscarded-qualifiers C ObjC Var(warn_discarded_qualifiers) Init(1) Warning Warn if type qualifiers on pointers are discarded. Wdiv-by-zero C ObjC C++ ObjC++ Var(warn_div_by_zero) Init(1) Warning Warn about compile-time integer division by zero. Wduplicated-branches C ObjC C++ ObjC++ Var(warn_duplicated_branches) Init(0) Warning Warn about duplicated branches in if-else statements. Wduplicated-cond C ObjC C++ ObjC++ Var(warn_duplicated_cond) Init(0) Warning Warn about duplicated conditions in an if-else-if chain. Weffc++ C++ ObjC++ Var(warn_ecpp) Warning Warn about violations of Effective C++ style rules. Wempty-body C ObjC C++ ObjC++ Var(warn_empty_body) Warning EnabledBy(Wextra) Warn about an empty body in an if or else statement. Wendif-labels 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) Warn about stray tokens after #else and #endif. Wenum-compare C ObjC C++ ObjC++ Var(warn_enum_compare) Init(-1) Warning LangEnabledBy(C ObjC,Wall || Wc++-compat) Warn about comparison of different enum types. Wenum-conversion C ObjC Var(warn_enum_conversion) Init(0) Warning LangEnabledBy(C ObjC,Wextra) Warn about implicit conversion of enum types. Werror C ObjC C++ ObjC++ ; Documented in common.opt Werror-implicit-function-declaration C ObjC RejectNegative Warning Alias(Werror=, implicit-function-declaration) This switch is deprecated; use -Werror=implicit-function-declaration instead. Wextra C ObjC C++ ObjC++ Warning ; in common.opt Wextra-semi C++ ObjC++ Var(warn_extra_semi) Warning Warn about semicolon after in-class function definition. Wfloat-conversion C ObjC C++ ObjC++ Var(warn_float_conversion) Warning LangEnabledBy(C ObjC C++ ObjC++,Wconversion) Warn for implicit type conversions that cause loss of floating point precision. Wfloat-equal C ObjC C++ ObjC++ Var(warn_float_equal) Warning Warn if testing floating point numbers for equality. Wformat C ObjC C++ ObjC++ Warning Alias(Wformat=, 1, 0) Warn about printf/scanf/strftime/strfmon format string anomalies. Wformat-contains-nul C ObjC C++ ObjC++ Var(warn_format_contains_nul) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0) Warn about format strings that contain NUL bytes. Wformat-diag C ObjC C++ ObjC++ Var(warn_format_diag) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0) Warn about GCC format strings with strings unsuitable for diagnostics. Wformat-extra-args C ObjC C++ ObjC++ Var(warn_format_extra_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0) Warn if passing too many arguments to a function for its format string. Wformat-nonliteral C ObjC C++ ObjC++ Var(warn_format_nonliteral) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 2, 0) Warn about format strings that are not literals. Wformat-overflow C ObjC C++ LTO ObjC++ Warning Alias(Wformat-overflow=, 1, 0) IntegerRange(0, 2) Warn about function calls with format strings that write past the end of the destination region. Same as -Wformat-overflow=1. Wformat-security C ObjC C++ ObjC++ Var(warn_format_security) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 2, 0) Warn about possible security problems with format functions. Wformat-signedness C ObjC C++ ObjC++ Var(warn_format_signedness) Warning Warn about sign differences with format functions. Wformat-truncation C ObjC C++ LTO ObjC++ Warning Alias(Wformat-truncation=, 1, 0) Warn about calls to snprintf and similar functions that truncate output. Same as -Wformat-truncation=1. Wformat-y2k C ObjC C++ ObjC++ Var(warn_format_y2k) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 2, 0) Warn about strftime formats yielding 2-digit years. Wformat-zero-length C ObjC C++ ObjC++ Var(warn_format_zero_length) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 1, 0) Warn about zero-length formats. Wformat= C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_format) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0) IntegerRange(0, 2) Warn about printf/scanf/strftime/strfmon format string anomalies. Wformat-overflow= C ObjC C++ LTO ObjC++ Joined RejectNegative UInteger Var(warn_format_overflow) Warning LangEnabledBy(C ObjC C++ LTO ObjC++,Wformat=, warn_format >= 1, 0) IntegerRange(0, 2) Warn about function calls with format strings that write past the end of the destination region. Wformat-truncation= C ObjC C++ LTO ObjC++ Joined RejectNegative UInteger Var(warn_format_trunc) Warning LangEnabledBy(C ObjC C++ LTO ObjC++,Wformat=, warn_format >= 1, 0) IntegerRange(0, 2) Warn about calls to snprintf and similar functions that truncate output. Wif-not-aligned C ObjC C++ ObjC++ Var(warn_if_not_aligned) Init(1) Warning Warn when the field in a struct is not aligned. Wignored-qualifiers C C++ Var(warn_ignored_qualifiers) Warning EnabledBy(Wextra) Warn whenever type qualifiers are ignored. Wignored-attributes C C++ Var(warn_ignored_attributes) Init(1) Warning Warn whenever attributes are ignored. Winaccessible-base C++ ObjC++ Var(warn_inaccessible_base) Init(1) Warning Warn when a base is inaccessible in derived due to ambiguity. Wincompatible-pointer-types C ObjC Var(warn_incompatible_pointer_types) Init(1) Warning Warn when there is a conversion between pointers that have incompatible types. Waddress-of-packed-member C ObjC C++ ObjC++ Var(warn_address_of_packed_member) Init(1) Warning Warn when the address of packed member of struct or union is taken. Winit-self C ObjC C++ ObjC++ Var(warn_init_self) Warning LangEnabledBy(C++ ObjC++,Wall) Warn about variables which are initialized to themselves. Winit-list-lifetime C++ ObjC++ Var(warn_init_list) Warning Init(1) Warn about uses of std::initializer_list that can result in dangling pointers. Wimplicit C ObjC Var(warn_implicit) Warning LangEnabledBy(C ObjC,Wall) Warn about implicit declarations. Wimplicit-fallthrough= LangEnabledBy(C ObjC C++ ObjC++,Wextra,3,0) ; in common.opt Wdouble-promotion C ObjC C++ ObjC++ Var(warn_double_promotion) Warning Warn about implicit conversions from \"float\" to \"double\". Wexpansion-to-defined 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) Warn if \"defined\" is used outside #if. Wimplicit-function-declaration C ObjC Var(warn_implicit_function_declaration) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit) Warn about implicit function declarations. Wimplicit-int C ObjC Var(warn_implicit_int) Init(-1) Warning LangEnabledBy(C ObjC,Wimplicit) Warn when a declaration does not specify a type. Wimport C ObjC C++ ObjC++ Undocumented Ignore Winherited-variadic-ctor C++ ObjC++ Var(warn_inh_var_ctor) Init(1) Warning Warn about C++11 inheriting constructors when the base has a variadic constructor. Wint-conversion C ObjC Var(warn_int_conversion) Init(1) Warning Warn about incompatible integer to pointer and pointer to integer conversions. Wint-in-bool-context C ObjC C++ ObjC++ Var(warn_int_in_bool_context) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn for suspicious integer expressions in boolean context. Wint-to-pointer-cast C ObjC C++ ObjC++ Var(warn_int_to_pointer_cast) Init(1) Warning Warn when there is a cast to a pointer from an integer of a different size. Winvalid-offsetof C++ ObjC++ Var(warn_invalid_offsetof) Init(1) Warning Warn about invalid uses of the \"offsetof\" macro. Winvalid-pch C ObjC C++ ObjC++ CPP(warn_invalid_pch) CppReason(CPP_W_INVALID_PCH) Var(cpp_warn_invalid_pch) Init(0) Warning Warn about PCH files that are found but not used. Wjump-misses-init C ObjC Var(warn_jump_misses_init) Warning LangEnabledby(C ObjC,Wc++-compat) Warn when a jump misses a variable initialization. Wliteral-suffix C++ ObjC++ CPP(warn_literal_suffix) CppReason(CPP_W_LITERAL_SUFFIX) Var(cpp_warn_literal_suffix) Init(1) Warning Warn when a string or character literal is followed by a ud-suffix which does not begin with an underscore. Wlogical-op C ObjC C++ ObjC++ Var(warn_logical_op) Init(0) Warning Warn when a logical operator is suspiciously always evaluating to true or false. Wlogical-not-parentheses C ObjC C++ ObjC++ Var(warn_logical_not_paren) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn when logical not is used on the left hand side operand of a comparison. Wlong-long 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) Do not warn about using \"long long\" when -pedantic. Wmain C ObjC C++ ObjC++ Var(warn_main) Init(-1) Warning LangEnabledBy(C ObjC,Wall, 2, 0) Warn about suspicious declarations of \"main\". Wmain LangEnabledBy(C ObjC C++ ObjC++,Wpedantic, 2, 0) ; Wmemset-transposed-args C ObjC C++ ObjC++ Var(warn_memset_transposed_args) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn about suspicious calls to memset where the third argument is constant literal zero and the second is not. Wmemset-elt-size C ObjC C++ ObjC++ Var(warn_memset_elt_size) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn about suspicious calls to memset where the third argument contains the number of elements not multiplied by the element size. Wmisleading-indentation C C++ Common Var(warn_misleading_indentation) Warning LangEnabledBy(C C++,Wall) Warn when the indentation of the code does not reflect the block structure. Wmismatched-tags C++ ObjC++ Var(warn_mismatched_tags) Warning Warn when a class is redeclared or referenced using a mismatched class-key. Wmissing-braces C ObjC C++ ObjC++ Var(warn_missing_braces) Warning LangEnabledBy(C ObjC,Wall) Warn about possibly missing braces around initializers. Wmissing-declarations C ObjC C++ ObjC++ Var(warn_missing_declarations) Warning Warn about global functions without previous declarations. Wmissing-field-initializers C ObjC C++ ObjC++ Var(warn_missing_field_initializers) Warning EnabledBy(Wextra) Warn about missing fields in struct initializers. Wmultistatement-macros C ObjC C++ ObjC++ Var(warn_multistatement_macros) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn about unsafe macros expanding to multiple statements used as a body of a clause such as if, else, while, switch, or for. Wmultiple-inheritance C++ ObjC++ Var(warn_multiple_inheritance) Warning Warn on direct multiple inheritance. Wnamespaces C++ ObjC++ Var(warn_namespaces) Warning Warn on namespace definition. Wpacked-not-aligned C ObjC C++ ObjC++ Var(warn_packed_not_aligned) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn when fields in a struct with the packed attribute are misaligned. Wredundant-tags C++ ObjC++ Var(warn_redundant_tags) Warning Warn when a class or enumerated type is referenced using a redundant class-key. Wsized-deallocation C++ ObjC++ Var(warn_sized_deallocation) Warning EnabledBy(Wextra) Warn about missing sized deallocation functions. Wsizeof-pointer-div C ObjC C++ ObjC++ Var(warn_sizeof_pointer_div) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn about suspicious divisions of two sizeof expressions that don't work correctly with pointers. Wsizeof-pointer-memaccess C ObjC C++ ObjC++ Var(warn_sizeof_pointer_memaccess) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn about suspicious length parameters to certain string functions if the argument uses sizeof. Wsizeof-array-argument C ObjC C++ ObjC++ Var(warn_sizeof_array_argument) Warning Init(1) Warn when sizeof is applied on a parameter declared as an array. Wstring-compare C ObjC C++ LTO ObjC++ Warning Var(warn_string_compare) Warning LangEnabledBy(C ObjC C++ ObjC++, Wextra) Warn about calls to strcmp and strncmp used in equality expressions that are necessarily true or false due to the length of one and size of the other argument. Wstringop-overflow C ObjC C++ LTO ObjC++ Warning Alias(Wstringop-overflow=, 2, 0) Warn about buffer overflow in string manipulation functions like memcpy and strcpy. Wstringop-overflow= C ObjC C++ LTO ObjC++ Joined RejectNegative UInteger Var(warn_stringop_overflow) Init(2) Warning LangEnabledBy(C ObjC C++ LTO ObjC++, Wall, 2, 0) IntegerRange(0, 4) Under the control of Object Size type, warn about buffer overflow in string manipulation functions like memcpy and strcpy. Wstringop-truncation C ObjC C++ LTO ObjC++ Var(warn_stringop_truncation) Warning Init (1) LangEnabledBy(C ObjC C++ LTO ObjC++, Wall) Warn about truncation in string manipulation functions like strncat and strncpy. Wsuggest-attribute=format C ObjC C++ ObjC++ Var(warn_suggest_attribute_format) Warning Warn about functions which might be candidates for format attributes. Wsuggest-override C++ ObjC++ Var(warn_override) Warning Suggest that the override keyword be used when the declaration of a virtual function overrides another. Wswitch C ObjC C++ ObjC++ Var(warn_switch) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn about enumerated switches, with no default, missing a case. Wswitch-default C ObjC C++ ObjC++ Var(warn_switch_default) Warning Warn about enumerated switches missing a \"default:\" statement. Wswitch-enum C ObjC C++ ObjC++ Var(warn_switch_enum) Warning Warn about all enumerated switches missing a specific case. Wswitch-bool C ObjC C++ ObjC++ Var(warn_switch_bool) Warning Init(1) Warn about switches with boolean controlling expression. Wswitch-outside-range C ObjC C++ ObjC++ Var(warn_switch_outside_range) Warning Init(1) Warn about switch values that are outside of the switch's type range. Wtemplates C++ ObjC++ Var(warn_templates) Warning Warn on primary template declaration. Wmissing-attributes C ObjC C++ ObjC++ Var(warn_missing_attributes) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn about declarations of entities that may be missing attributes that related entities have been declared with. Wmissing-format-attribute C ObjC C++ ObjC++ Warning Alias(Wsuggest-attribute=format) ; Wmissing-include-dirs C ObjC C++ ObjC++ CPP(warn_missing_include_dirs) CppReason(CPP_W_MISSING_INCLUDE_DIRS) Var(cpp_warn_missing_include_dirs) Init(0) Warning Warn about user-specified include directories that do not exist. Wmissing-parameter-type C ObjC Var(warn_missing_parameter_type) Warning EnabledBy(Wextra) Warn about function parameters declared without a type specifier in K&R-style functions. Wmissing-prototypes C ObjC Var(warn_missing_prototypes) Warning Warn about global functions without prototypes. Wmudflap C ObjC C++ ObjC++ WarnRemoved Wmultichar C ObjC C++ ObjC++ CPP(warn_multichar) CppReason(CPP_W_MULTICHAR) Var(cpp_warn_multichar) Init(0) Warning Warn about use of multi-character character constants. Wnarrowing C ObjC C++ ObjC++ Warning Var(warn_narrowing) Init(-1) LangEnabledBy(C++ ObjC++,Wall || Wc++11-compat) Warn about narrowing conversions within { } that are ill-formed in C++11. Wnested-externs C ObjC Var(warn_nested_externs) Warning Warn about \"extern\" declarations not at file scope. Wnoexcept C++ ObjC++ Var(warn_noexcept) Warning Warn when a noexcept expression evaluates to false even though the expression can't actually throw. Wnoexcept-type C++ ObjC++ Warning Var(warn_noexcept_type) LangEnabledBy(C++ ObjC++,Wabi || Wc++17-compat) Warn if C++17 noexcept function type will change the mangled name of a symbol. Wnon-template-friend C++ ObjC++ Var(warn_nontemplate_friend) Init(1) Warning Warn when non-templatized friend functions are declared within a template. Wclass-conversion C++ ObjC++ Var(warn_class_conversion) Init(1) Warning Warn when a conversion function will never be called due to the type it converts to. Wclass-memaccess C++ ObjC++ Var(warn_class_memaccess) Warning LangEnabledBy(C++ ObjC++, Wall) Warn for unsafe raw memory writes to objects of class types. Wnon-virtual-dtor C++ ObjC++ Var(warn_nonvdtor) Warning LangEnabledBy(C++ ObjC++,Weffc++) Warn about non-virtual destructors. Wnonnull C ObjC C++ LTO ObjC++ Var(warn_nonnull) Warning LangEnabledBy(C ObjC C++ LTO ObjC++,Wformat=,warn_format >= 1,0) Warn about NULL being passed to argument slots marked as requiring non-NULL. Wnonnull C ObjC C++ LTO ObjC++ LangEnabledBy(C ObjC C++ LTO ObjC++,Wall) ; Wnonnull-compare C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall) ; Wnormalized C ObjC C++ ObjC++ Warning Alias(Wnormalized=,nfc,none) ; Wnormalized= 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) -Wnormalized=[none|id|nfc|nfkc] Warn about non-normalized Unicode strings. ; Required for these enum values. SourceInclude cpplib.h Enum Name(cpp_normalize_level) Type(int) UnknownError(argument %qs to %<-Wnormalized%> not recognized) EnumValue Enum(cpp_normalize_level) String(none) Value(normalized_none) EnumValue Enum(cpp_normalize_level) String(nfkc) Value(normalized_KC) EnumValue Enum(cpp_normalize_level) String(id) Value(normalized_identifier_C) EnumValue Enum(cpp_normalize_level) String(nfc) Value(normalized_C) Wold-style-cast C++ ObjC++ Var(warn_old_style_cast) Warning Warn if a C-style cast is used in a program. Wold-style-declaration C ObjC Var(warn_old_style_declaration) Warning EnabledBy(Wextra) Warn for obsolescent usage in a declaration. Wold-style-definition C ObjC Var(warn_old_style_definition) Init(-1) Warning Warn if an old-style parameter definition is used. Wopenmp-simd C C++ Var(warn_openmp_simd) Warning LangEnabledBy(C C++,Wall) Warn if a simd directive is overridden by the vectorizer cost model. Woverlength-strings C ObjC C++ ObjC++ Var(warn_overlength_strings) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic) Warn if a string is longer than the maximum portable length specified by the standard. Woverloaded-virtual C++ ObjC++ Var(warn_overloaded_virtual) Warning Warn about overloaded virtual function names. Woverride-init C ObjC Var(warn_override_init) Warning EnabledBy(Wextra) Warn about overriding initializers without side effects. Woverride-init-side-effects C ObjC Var(warn_override_init_side_effects) Init(1) Warning Warn about overriding initializers with side effects. Wpacked-bitfield-compat C ObjC C++ ObjC++ Var(warn_packed_bitfield_compat) Init(-1) Warning Warn about packed bit-fields whose offset changed in GCC 4.4. Wparentheses C ObjC C++ ObjC++ Var(warn_parentheses) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn about possibly missing parentheses. Wpedantic C ObjC C++ ObjC++ CPP(cpp_pedantic) CppReason(CPP_W_PEDANTIC) Warning ; Documented in common.opt Wpessimizing-move C++ ObjC++ Var(warn_pessimizing_move) Warning LangEnabledBy(C++ ObjC++, Wall) Warn about calling std::move on a local object in a return statement preventing copy elision. Wpmf-conversions C++ ObjC++ Var(warn_pmf2ptr) Init(1) Warning Warn when converting the type of pointers to member functions. Wpointer-arith C ObjC C++ ObjC++ Var(warn_pointer_arith) Warning LangEnabledBy(C ObjC C++ ObjC++,Wpedantic) Warn about function pointer arithmetic. Wpointer-sign C ObjC Var(warn_pointer_sign) Warning LangEnabledBy(C ObjC,Wall || Wpedantic) Warn when a pointer differs in signedness in an assignment. Wpointer-compare C ObjC C++ ObjC++ Var(warn_pointer_compare) Init(1) Warning Warn when a pointer is compared with a zero character constant. Wpointer-to-int-cast C ObjC Var(warn_pointer_to_int_cast) Init(1) Warning Warn when a pointer is cast to an integer of a different size. Wpragmas C ObjC C++ ObjC++ Var(warn_pragmas) Init(1) Warning Warn about misuses of pragmas. Wprio-ctor-dtor C ObjC C++ ObjC++ Var(warn_prio_ctor_dtor) Init(1) Warning Warn if constructor or destructors with priorities from 0 to 100 are used. Wproperty-assign-default ObjC ObjC++ Var(warn_property_assign_default) Init(1) Warning Warn if a property for an Objective-C object has no assign semantics specified. Wprotocol ObjC ObjC++ Var(warn_protocol) Init(1) Warning Warn if inherited methods are unimplemented. Wplacement-new C++ Warning Alias(Wplacement-new=, 1, 0) Warn for placement new expressions with undefined behavior. Wplacement-new= C++ Joined RejectNegative UInteger Var(warn_placement_new) Init(-1) Warning IntegerRange(0, 2) Warn for placement new expressions with undefined behavior. Wredundant-decls C ObjC C++ ObjC++ Var(warn_redundant_decls) Warning Warn about multiple declarations of the same object. Wredundant-move C++ ObjC++ Var(warn_redundant_move) Warning LangEnabledBy(C++ ObjC++,Wextra) Warn about redundant calls to std::move. Wregister C++ ObjC++ Var(warn_register) Warning Warn about uses of register storage specifier. Wreorder C++ ObjC++ Var(warn_reorder) Warning LangEnabledBy(C++ ObjC++,Wall) Warn when the compiler reorders code. Wreturn-type C ObjC C++ ObjC++ Var(warn_return_type) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Init(-1) Warn whenever a function's return type defaults to \"int\" (C), or about inconsistent return types (C++). Wscalar-storage-order C ObjC C++ ObjC++ Init(1) Warning Warn on suspicious constructs involving reverse scalar storage order. Wselector ObjC ObjC++ Var(warn_selector) Warning Warn if a selector has multiple methods. Wsequence-point C ObjC C++ ObjC++ Var(warn_sequence_point) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn about possible violations of sequence point rules. Wshadow-ivar ObjC ObjC++ Var(warn_shadow_ivar) EnabledBy(Wshadow) Init(1) Warning Warn if a local declaration hides an instance variable. Wshift-overflow C ObjC C++ ObjC++ Warning Alias(Wshift-overflow=, 1, 0) Warn if left shift of a signed value overflows. Wshift-overflow= C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_shift_overflow) Init(-1) Warning IntegerRange(0, 2) Warn if left shift of a signed value overflows. Wshift-count-negative C ObjC C++ ObjC++ Var(warn_shift_count_negative) Init(1) Warning Warn if shift count is negative. Wshift-count-overflow C ObjC C++ ObjC++ Var(warn_shift_count_overflow) Init(1) Warning Warn if shift count >= width of type. Wshift-negative-value C ObjC C++ ObjC++ Var(warn_shift_negative_value) Init(-1) Warning Warn if left shifting a negative value. Warith-conversion C ObjC C++ ObjC++ Var(warn_arith_conv) Warning Warn if conversion of the result of arithmetic might change the value even though converting the operands cannot. Wsign-compare C ObjC C++ ObjC++ Var(warn_sign_compare) Warning LangEnabledBy(C++ ObjC++,Wall) Warn about signed-unsigned comparisons. Wsign-compare C ObjC C++ ObjC++ EnabledBy(Wextra) ; Wsign-conversion C ObjC C++ ObjC++ Var(warn_sign_conversion) Warning LangEnabledBy(C ObjC,Wconversion) Warn for implicit type conversions between signed and unsigned integers. Wsign-promo C++ ObjC++ Var(warn_sign_promo) Warning Warn when overload promotes from unsigned to signed. Wstrict-null-sentinel C++ ObjC++ Warning Var(warn_strict_null_sentinel) Warn about uncasted NULL used as sentinel. Wstrict-prototypes C ObjC Var(warn_strict_prototypes) Warning Warn about unprototyped function declarations. Wstrict-aliasing= C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 3, 0) IntegerRange(0, 3) ; Wstrict-overflow= C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0) IntegerRange(0, 5) ; Wstrict-selector-match ObjC ObjC++ Var(warn_strict_selector_match) Warning Warn if type signatures of candidate methods do not match exactly. Wsync-nand C C++ Var(warn_sync_nand) Init(1) Warning Warn when __sync_fetch_and_nand and __sync_nand_and_fetch built-in functions are used. Wsynth C++ ObjC++ Var(warn_synth) Warning Deprecated. This switch has no effect. Wsystem-headers C ObjC C++ ObjC++ Warning ; Documented in common.opt Wtautological-compare C ObjC C++ ObjC++ Var(warn_tautological_compare) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn if a comparison always evaluates to true or false. Wterminate C++ ObjC++ Warning Var(warn_terminate) Init(1) Warn if a throw expression will always result in a call to terminate(). Wtraditional C ObjC CPP(cpp_warn_traditional) CppReason(CPP_W_TRADITIONAL) Var(warn_traditional) Init(0) Warning Warn about features not present in traditional C. Wtraditional-conversion C ObjC Var(warn_traditional_conversion) Warning Warn of prototypes causing type conversions different from what would happen in the absence of prototype. Wtrigraphs C ObjC C++ ObjC++ CPP(warn_trigraphs) CppReason(CPP_W_TRIGRAPHS) Var(cpp_warn_trigraphs) Init(2) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn if trigraphs are encountered that might affect the meaning of the program. Wundeclared-selector ObjC ObjC++ Var(warn_undeclared_selector) Warning Warn about @selector()s without previously declared methods. Wundef C ObjC C++ ObjC++ CPP(warn_undef) CppReason(CPP_W_UNDEF) Var(cpp_warn_undef) Init(0) Warning Warn if an undefined macro is used in an #if directive. Wuninitialized C ObjC C++ ObjC++ LTO LangEnabledBy(C ObjC C++ ObjC++ LTO,Wall) ; Wmaybe-uninitialized C ObjC C++ ObjC++ LTO LangEnabledBy(C ObjC C++ ObjC++ LTO,Wall) ; Wunknown-pragmas C ObjC C++ ObjC++ Warning Var(warn_unknown_pragmas) LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0) Warn about unrecognized pragmas. Wunsuffixed-float-constants C ObjC Var(warn_unsuffixed_float_constants) Warning Warn about unsuffixed float constants. Wunused C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall) ; documented in common.opt Wunused-local-typedefs C ObjC C++ ObjC++ Var(warn_unused_local_typedefs) Warning EnabledBy(Wunused) Warn when typedefs locally defined in a function are not used. Wunused-macros C ObjC C++ ObjC++ CppReason(CPP_W_UNUSED_MACROS) Var(cpp_warn_unused_macros) Warning Warn about macros defined in the main file that are not used. Wunused-result C ObjC C++ ObjC++ Var(warn_unused_result) Init(1) Warning Warn if a caller of a function, marked with attribute warn_unused_result, does not use its return value. Wunused-variable C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wunused) ; documented in common.opt Wunused-const-variable C ObjC C++ ObjC++ Warning Alias(Wunused-const-variable=, 2, 0) Warn when a const variable is unused. Wunused-const-variable= C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_unused_const_variable) Warning LangEnabledBy(C ObjC,Wunused-variable, 1, 0) IntegerRange(0, 2) Warn when a const variable is unused. Wvariadic-macros 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) Warn about using variadic macros. Wvarargs C ObjC C++ ObjC++ Warning Var(warn_varargs) Init(1) Warn about questionable usage of the macros used to retrieve variable arguments. Wvla C ObjC C++ ObjC++ Var(warn_vla) Init(-1) Warning Warn if a variable length array is used. Wvla-larger-than= C ObjC C++ LTO ObjC++ Var(warn_vla_limit) Warning Joined Host_Wide_Int ByteSize Init(HOST_WIDE_INT_MAX) -Wvla-larger-than= Warn on unbounded uses of variable-length arrays, and on bounded uses of variable-length arrays whose bound can be larger than bytes. bytes. Wno-vla-larger-than C ObjC C++ LTO ObjC++ Alias(Wvla-larger-than=,18446744073709551615EiB,none) Warning Disable Wvla-larger-than= warning. Equivalent to Wvla-larger-than= or larger. Wvolatile C++ ObjC++ Var(warn_volatile) Warning Warn about deprecated uses of volatile qualifier. Wvolatile-register-var C ObjC C++ ObjC++ Var(warn_volatile_register_var) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall) Warn when a register variable is declared volatile. Wvirtual-inheritance C++ ObjC++ Var(warn_virtual_inheritance) Warning Warn on direct virtual inheritance. Wvirtual-move-assign C++ ObjC++ Var(warn_virtual_move_assign) Warning Init(1) Warn if a virtual base has a non-trivial move assignment operator. Wwrite-strings C ObjC C++ ObjC++ Var(warn_write_strings) Warning 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. Wzero-as-null-pointer-constant C++ ObjC++ Var(warn_zero_as_null_pointer_constant) Warning Warn when a literal '0' is used as null pointer. Wuseless-cast C++ ObjC++ Var(warn_useless_cast) Warning Warn about useless casts. Wsubobject-linkage C++ ObjC++ Var(warn_subobject_linkage) Warning Init(1) 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. Wduplicate-decl-specifier C ObjC Var(warn_duplicate_decl_specifier) Warning LangEnabledBy(C ObjC,Wall) Warn when a declaration has duplicate const, volatile, restrict or _Atomic specifier. Wrestrict C ObjC C++ ObjC++ Var(warn_restrict) Warning LangEnabledBy(C ObjC C++ ObjC++, Wall) Warn when an argument passed to a restrict-qualified parameter aliases with another argument. ansi C ObjC C++ ObjC++ A synonym for -std=c89 (for C) or -std=c++98 (for C++). ; This should really just be C++/ObjC++ but we (NetBSD) use it when ; calling C and ObjC compilers as well. cxx-isystem C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs) -cxx-isystem Add to the start of the C++ system include path d C ObjC C++ ObjC++ Joined ; Documented in common.opt. FIXME - what about -dI, -dD, -dN and -dD? fabi-compat-version= C++ ObjC++ Joined RejectNegative UInteger Var(flag_abi_compat_version) Init(-1) The version of the C++ ABI used for -Wabi warnings and link compatibility aliases. faccess-control C++ ObjC++ Var(flag_access_control) Init(1) Enforce class member access control semantics. fada-spec-parent= C ObjC C++ ObjC++ RejectNegative Joined Var(ada_specs_parent) -fada-spec-parent=unit Dump Ada specs as child units of given parent. faligned-new C++ ObjC++ Alias(faligned-new=,1,0) Support C++17 allocation of over-aligned types. faligned-new= C++ ObjC++ Joined RejectNegative Var(aligned_new_threshold) UInteger Init(-1) -faligned-new= Use C++17 over-aligned type allocation for alignments greater than N. fall-virtual C++ ObjC++ WarnRemoved fallow-parameterless-variadic-functions C ObjC Var(flag_allow_parameterless_variadic_functions) Allow variadic functions without named parameter. falt-external-templates C++ ObjC++ WarnRemoved No longer supported. fasm C ObjC C++ ObjC++ Var(flag_no_asm, 0) Recognize the \"asm\" keyword. ; Define extra predefined macros for use in libgcc. fbuilding-libgcc C ObjC C++ ObjC++ Undocumented Var(flag_building_libgcc) fbuiltin C ObjC C++ ObjC++ Var(flag_no_builtin, 0) Recognize built-in functions. fbuiltin- C ObjC C++ ObjC++ Joined fcanonical-system-headers C ObjC C++ ObjC++ Where shorter, use canonicalized paths to systems headers. fchar8_t C++ ObjC++ Var(flag_char8_t) Init(-1) Enable the char8_t fundamental type and use it as the type for UTF-8 string and character literals. fcheck-pointer-bounds C ObjC C++ ObjC++ LTO WarnRemoved Removed in GCC 9. This switch has no effect. fchkp-check-incomplete-type C ObjC C++ ObjC++ LTO WarnRemoved Removed in GCC 9. This switch has no effect. fchkp-zero-input-bounds-for-main C ObjC C++ ObjC++ LTO WarnRemoved Removed in GCC 9. This switch has no effect. fchkp-first-field-has-own-bounds C ObjC C++ ObjC++ LTO WarnRemoved RejectNegative Removed in GCC 9. This switch has no effect. fchkp-narrow-bounds C ObjC C++ ObjC++ LTO WarnRemoved Removed in GCC 9. This switch has no effect. fchkp-narrow-to-innermost-array C ObjC C++ ObjC++ LTO WarnRemoved RejectNegative Removed in GCC 9. This switch has no effect. fchkp-flexible-struct-trailing-arrays C ObjC C++ ObjC++ LTO WarnRemoved Removed in GCC 9. This switch has no effect. fchkp-optimize C ObjC C++ ObjC++ LTO WarnRemoved fchkp-use-fast-string-functions C ObjC C++ ObjC++ LTO WarnRemoved Removed in GCC 9. This switch has no effect. fchkp-use-nochk-string-functions C ObjC C++ ObjC++ LTO WarnRemoved Removed in GCC 9. This switch has no effect. fchkp-use-static-bounds C ObjC C++ ObjC++ LTO WarnRemoved Removed in GCC 9. This switch has no effect. fchkp-use-static-const-bounds C ObjC C++ ObjC++ LTO WarnRemoved Removed in GCC 9. This switch has no effect. fchkp-treat-zero-dynamic-size-as-infinite C ObjC C++ ObjC++ LTO WarnRemoved Removed in GCC 9. This switch has no effect. fchkp-check-read C ObjC C++ ObjC++ LTO WarnRemoved Removed in GCC 9. This switch has no effect. fchkp-check-write C ObjC C++ ObjC++ LTO WarnRemoved Removed in GCC 9. This switch has no effect. fchkp-store-bounds C ObjC C++ ObjC++ LTO WarnRemoved Removed in GCC 9. This switch has no effect. fchkp-instrument-calls C ObjC C++ ObjC++ LTO WarnRemoved Removed in GCC 9. This switch has no effect. fchkp-instrument-marked-only C ObjC C++ ObjC++ LTO WarnRemoved Removed in GCC 9. This switch has no effect. fchkp-use-wrappers C ObjC C++ ObjC++ LTO WarnRemoved Removed in GCC 9. This switch has no effect. static-libmpx Driver WarnRemoved Removed in GCC 9. This switch has no effect. static-libmpxwrappers Driver WarnRemoved Removed in GCC 9. This switch has no effect. fcilkplus C ObjC C++ ObjC++ LTO Undocumented Ignore Removed in GCC 8. This switch has no effect. fconcepts C++ ObjC++ Var(flag_concepts) Enable support for C++ concepts. fconcepts-ts C++ ObjC++ Var(flag_concepts_ts) Init(0) Enable certain features present in the Concepts TS. fconcepts-diagnostics-depth= C++ ObjC++ Joined RejectNegative UInteger Var(concepts_diagnostics_max_depth) Init(1) Specify maximum error replay depth during recursive diagnosis of a constraint satisfaction failure. fcond-mismatch C ObjC C++ ObjC++ Allow the arguments of the '?' operator to have different types. fconserve-space C++ ObjC++ Ignore Does nothing. Preserved for backward compatibility. fconstant-string-class= ObjC ObjC++ Joined MissingArgError(no class name specified with %qs) -fconst-string-class= Use class for constant strings. fconstexpr-depth= C++ ObjC++ Joined RejectNegative UInteger Var(max_constexpr_depth) Init(512) -fconstexpr-depth= Specify maximum constexpr recursion depth. fconstexpr-cache-depth= C++ ObjC++ Joined RejectNegative UInteger Var(constexpr_cache_depth) Init(8) -fconstexpr-cache-depth= Specify maximum constexpr recursion cache depth. fconstexpr-loop-limit= C++ ObjC++ Joined RejectNegative UInteger Var(constexpr_loop_limit) Init(262144) -fconstexpr-loop-limit= Specify maximum constexpr loop iteration count. fconstexpr-ops-limit= C++ ObjC++ Joined RejectNegative Host_Wide_Int Var(constexpr_ops_limit) Init(33554432) -fconstexpr-ops-limit= Specify maximum number of constexpr operations during a single constexpr evaluation. fcoroutines C++ LTO Var(flag_coroutines) Enable C++ coroutines (experimental). fdebug-cpp C ObjC C++ ObjC++ Emit debug annotations during preprocessing. fdeduce-init-list C++ ObjC++ Ignore Does nothing. Preserved for backward compatibility. fdeclone-ctor-dtor C++ ObjC++ Var(flag_declone_ctor_dtor) Init(-1) Factor complex constructors and destructors to favor space over speed. fdefault-inline C++ ObjC++ Ignore Does nothing. Preserved for backward compatibility. fdiagnostics-show-template-tree C++ ObjC++ Var(flag_diagnostics_show_template_tree) Init(0) Print hierarchical comparisons when template types are mismatched. fdirectives-only C ObjC C++ ObjC++ Preprocess directives only. fdollars-in-identifiers C ObjC C++ ObjC++ Permit '$' as an identifier character. fmacro-prefix-map= C ObjC C++ ObjC++ Joined RejectNegative -fmacro-prefix-map== Map one directory name to another in __FILE__, __BASE_FILE__, and __builtin_FILE(). fdump-ada-spec C ObjC C++ ObjC++ RejectNegative Var(flag_dump_ada_spec) Write all declarations as Ada code transitively. fdump-ada-spec-slim C ObjC C++ ObjC++ RejectNegative Var(flag_dump_ada_spec_slim) Write all declarations as Ada code for the given file only. felide-constructors C++ ObjC++ Var(flag_elide_constructors) Init(1) felide-type C++ ObjC++ Var(flag_elide_type) Init(1) Do not elide common elements in template comparisons. fenforce-eh-specs C++ ObjC++ Var(flag_enforce_eh_specs) Init(1) Generate code to check exception specifications. fenum-int-equiv C++ ObjC++ WarnRemoved fexec-charset= C ObjC C++ ObjC++ Joined RejectNegative -fexec-charset= Convert all strings and character constants to character set . fextended-identifiers C ObjC C++ ObjC++ Permit universal character names (\\u and \\U) in identifiers. finput-charset= C ObjC C++ ObjC++ Joined RejectNegative -finput-charset= Specify the default character set for source files. fextern-tls-init C++ ObjC++ Var(flag_extern_tls_init) Init(-1) Support dynamic initialization of thread-local variables in a different translation unit. fexternal-templates C++ ObjC++ WarnRemoved ffor-scope C++ ObjC++ WarnRemoved ffreestanding C ObjC C++ ObjC++ Do not assume that standard C libraries and \"main\" exist. fgnu-keywords C++ ObjC++ Var(flag_no_gnu_keywords, 0) Recognize GNU-defined keywords. fgnu-runtime ObjC ObjC++ LTO Report RejectNegative Var(flag_next_runtime,0) Init(NEXT_OBJC_RUNTIME) Generate code for GNU runtime environment. fgnu89-inline C ObjC Var(flag_gnu89_inline) Init(-1) Use traditional GNU semantics for inline functions. fguiding-decls C++ ObjC++ WarnRemoved fhandle-exceptions C++ ObjC++ Optimization Alias(fexceptions) Warn({%<-fhandle-exceptions%> has been renamed %<-fexceptions%> (and is now on by default)}) fhonor-std C++ ObjC++ WarnRemoved fhosted C ObjC Assume normal C execution environment. fhuge-objects C++ ObjC++ WarnRemoved No longer supported. fimplement-inlines C++ ObjC++ Var(flag_implement_inlines) Init(1) Export functions even if they can be inlined. fimplicit-inline-templates C++ ObjC++ Var(flag_implicit_inline_templates) Init(1) Emit implicit instantiations of inline templates. fimplicit-templates C++ ObjC++ Var(flag_implicit_templates) Init(1) Emit implicit instantiations of templates. fnew-inheriting-ctors C++ ObjC++ Var(flag_new_inheriting_ctors) Init(1) Implement C++17 inheriting constructor semantics. ffriend-injection C++ ObjC++ WarnRemoved fkeep-inline-dllexport C C++ ObjC ObjC++ Var(flag_keep_inline_dllexport) Init(1) Report Condition(TARGET_DLLIMPORT_DECL_ATTRIBUTES) Don't emit dllexported inline functions unless needed. flabels-ok C++ ObjC++ WarnRemoved flax-vector-conversions C ObjC C++ ObjC++ Var(flag_lax_vector_conversions) Allow implicit conversions between vectors with differing numbers of subparts and/or differing element types. fmax-include-depth= C ObjC C++ ObjC++ Joined RejectNegative UInteger fmax-include-depth= Set the maximum depth of the nested #include. fms-extensions C ObjC C++ ObjC++ Var(flag_ms_extensions) Don't warn about uses of Microsoft extensions. fmudflap C ObjC C++ ObjC++ WarnRemoved fmudflapth C ObjC C++ ObjC++ WarnRemoved fmudflapir C ObjC C++ ObjC++ WarnRemoved fname-mangling-version- C++ ObjC++ Joined WarnRemoved fnew-abi C++ ObjC++ WarnRemoved fnew-ttp-matching C++ ObjC++ Var(flag_new_ttp) Implement resolution of DR 150 for matching of template template arguments. fnext-runtime ObjC ObjC++ LTO Report RejectNegative Var(flag_next_runtime) Generate code for NeXT (Apple Mac OS X) runtime environment. fnil-receivers ObjC ObjC++ Var(flag_nil_receivers) Init(1) Assume that receivers of Objective-C messages may be nil. flocal-ivars ObjC ObjC++ Var(flag_local_ivars) Init(1) Allow access to instance variables as if they were local declarations within instance method implementations. fivar-visibility= ObjC ObjC++ Joined RejectNegative Enum(ivar_visibility) Var(default_ivar_visibility) Init(IVAR_VISIBILITY_PROTECTED) -fvisibility=[private|protected|public|package] Set the default symbol visibility. Enum Name(ivar_visibility) Type(enum ivar_visibility) UnknownError(unrecognized ivar visibility value %qs) EnumValue Enum(ivar_visibility) String(private) Value(IVAR_VISIBILITY_PRIVATE) EnumValue Enum(ivar_visibility) String(protected) Value(IVAR_VISIBILITY_PROTECTED) EnumValue Enum(ivar_visibility) String(public) Value(IVAR_VISIBILITY_PUBLIC) EnumValue Enum(ivar_visibility) String(package) Value(IVAR_VISIBILITY_PACKAGE) fnonansi-builtins C++ ObjC++ Var(flag_no_nonansi_builtin, 0) fnonnull-objects C++ ObjC++ WarnRemoved fnothrow-opt C++ ObjC++ Optimization Var(flag_nothrow_opt) Treat a throw() exception specification as noexcept to improve code size. fobjc-abi-version= ObjC ObjC++ LTO Joined Report RejectNegative UInteger Var(flag_objc_abi) Specify which ABI to use for Objective-C family code and meta-data generation. ; Generate special '- .cxx_construct' and '- .cxx_destruct' methods ; to initialize any non-POD ivars in Objective-C++ classes. fobjc-call-cxx-cdtors ObjC++ Var(flag_objc_call_cxx_cdtors) Generate special Objective-C methods to initialize/destroy non-POD C++ ivars, if needed. fobjc-direct-dispatch ObjC ObjC++ Var(flag_objc_direct_dispatch) Allow fast jumps to the message dispatcher. ; Nonzero means that we will allow new ObjC exception syntax (@throw, ; @try, etc.) in source code. fobjc-exceptions ObjC ObjC++ Var(flag_objc_exceptions) Enable Objective-C exception and synchronization syntax. fobjc-gc ObjC ObjC++ LTO Var(flag_objc_gc) Enable garbage collection (GC) in Objective-C/Objective-C++ programs. fobjc-nilcheck ObjC ObjC++ Var(flag_objc_nilcheck,1) Enable inline checks for nil receivers with the NeXT runtime and ABI version 2. ; Nonzero means that we generate NeXT setjmp based exceptions. fobjc-sjlj-exceptions ObjC ObjC++ Var(flag_objc_sjlj_exceptions) Init(-1) Enable Objective-C setjmp exception handling runtime. fobjc-std=objc1 ObjC ObjC++ Var(flag_objc1_only) Conform to the Objective-C 1.0 language as implemented in GCC 4.0. fopenacc C ObjC C++ ObjC++ LTO Var(flag_openacc) Enable OpenACC. fopenacc-dim= C ObjC C++ ObjC++ LTO Joined Var(flag_openacc_dims) Specify default OpenACC compute dimensions. fopenmp C ObjC C++ ObjC++ LTO Var(flag_openmp) Enable OpenMP (implies -frecursive in Fortran). fopenmp-simd C ObjC C++ ObjC++ Var(flag_openmp_simd) Enable OpenMP's SIMD directives. foperator-names C++ ObjC++ Recognize C++ keywords like \"compl\" and \"xor\". foptional-diags C++ ObjC++ Ignore Does nothing. Preserved for backward compatibility. fpch-deps C ObjC C++ ObjC++ fpch-preprocess C ObjC C++ ObjC++ Look for and use PCH files even when preprocessing. fpermissive C++ ObjC++ Var(flag_permissive) Downgrade conformance errors to warnings. fplan9-extensions C ObjC Var(flag_plan9_extensions) Enable Plan 9 language extensions. fpreprocessed C ObjC C++ ObjC++ Treat the input file as already preprocessed. ftrack-macro-expansion C ObjC C++ ObjC++ JoinedOrMissing RejectNegative UInteger ; converted into ftrack-macro-expansion= ftrack-macro-expansion= C ObjC C++ ObjC++ JoinedOrMissing RejectNegative UInteger -ftrack-macro-expansion=<0|1|2> Track locations of tokens coming from macro expansion and display them in error messages. fpretty-templates C++ ObjC++ Var(flag_pretty_templates) Init(1) Do not pretty-print template specializations as the template signature followed by the arguments. fprintf-return-value C ObjC C++ ObjC++ LTO Optimization Var(flag_printf_return_value) Init(1) Treat known sprintf return values as constants. freplace-objc-classes ObjC ObjC++ LTO Var(flag_replace_objc_classes) Used in Fix-and-Continue mode to indicate that object files may be swapped in at runtime. frepo C++ ObjC++ WarnRemoved Removed in GCC 10. This switch has no effect. frtti C++ ObjC++ Optimization Var(flag_rtti) Init(1) Generate run time type descriptor information. fshort-enums C ObjC C++ ObjC++ LTO Optimization Var(flag_short_enums) Use the narrowest integer type possible for enumeration types. fshort-wchar C ObjC C++ ObjC++ LTO Optimization Var(flag_short_wchar) Force the underlying type for \"wchar_t\" to be \"unsigned short\". fsigned-bitfields C ObjC C++ ObjC++ Var(flag_signed_bitfields) Init(1) When \"signed\" or \"unsigned\" is not given make the bitfield signed. fsigned-char C ObjC C++ ObjC++ LTO Var(flag_signed_char) Make \"char\" signed by default. fsized-deallocation C++ ObjC++ Var(flag_sized_deallocation) Init(-1) Enable C++14 sized deallocation support. fsquangle C++ ObjC++ WarnRemoved fsso-struct= C ObjC Joined RejectNegative Enum(sso_struct) Var(default_sso) Init(SSO_NATIVE) -fsso-struct=[big-endian|little-endian|native] Set the default scalar storage order. Enum Name(sso_struct) Type(enum scalar_storage_order_kind) UnknownError(unrecognized scalar storage order value %qs) EnumValue Enum(sso_struct) String(big-endian) Value(SSO_BIG_ENDIAN) EnumValue Enum(sso_struct) String(little-endian) Value(SSO_LITTLE_ENDIAN) EnumValue Enum(sso_struct) String(native) Value(SSO_NATIVE) fstats C++ ObjC++ Var(flag_detailed_statistics) Display statistics accumulated during compilation. fstrict-enums C++ ObjC++ Optimization Var(flag_strict_enums) Assume that values of enumeration type are always within the minimum range of that type. fstrict-prototype C++ ObjC++ WarnRemoved fstrong-eval-order C++ ObjC++ Common Alias(fstrong-eval-order=, all, none) Follow the C++17 evaluation order requirements for assignment expressions, shift, member function calls, etc. fstrong-eval-order= C++ ObjC++ Common Var(flag_strong_eval_order) Joined Enum(strong_eval_order) RejectNegative Init(-1) Follow the C++17 evaluation order requirements for assignment expressions, shift, member function calls, etc. Enum Name(strong_eval_order) Type(int) EnumValue Enum(strong_eval_order) String(none) Value(0) EnumValue Enum(strong_eval_order) String(some) Value(1) EnumValue Enum(strong_eval_order) String(all) Value(2) ftabstop= C ObjC C++ ObjC++ Joined RejectNegative UInteger -ftabstop= Distance between tab stops for column reporting. ftemplate-backtrace-limit= C++ ObjC++ Joined RejectNegative UInteger Var(template_backtrace_limit) Init(10) Set the maximum number of template instantiation notes for a single warning or error. ftemplate-depth- C++ ObjC++ Joined RejectNegative Undocumented Alias(ftemplate-depth=) ftemplate-depth= C++ ObjC++ Joined RejectNegative UInteger -ftemplate-depth= Specify maximum template instantiation depth. fthis-is-variable C++ ObjC++ WarnRemoved fthreadsafe-statics C++ ObjC++ Optimization Var(flag_threadsafe_statics) Init(1) -fno-threadsafe-statics Do not generate thread-safe code for initializing local statics. funsigned-bitfields C ObjC C++ ObjC++ Var(flag_signed_bitfields, 0) When \"signed\" or \"unsigned\" is not given make the bitfield unsigned. funsigned-char C ObjC C++ ObjC++ LTO Var(flag_signed_char, 0) Make \"char\" unsigned by default. fuse-cxa-atexit C++ ObjC++ Var(flag_use_cxa_atexit) Init(DEFAULT_USE_CXA_ATEXIT) Use __cxa_atexit to register destructors. fuse-cxa-get-exception-ptr C++ ObjC++ Var(flag_use_cxa_get_exception_ptr) Init(2) Use __cxa_get_exception_ptr in exception handling. fvisibility-inlines-hidden C++ ObjC++ Marks all inlined functions and methods as having hidden visibility. fvisibility-ms-compat C++ ObjC++ Var(flag_visibility_ms_compat) Changes visibility to match Microsoft Visual Studio by default. fvtable-gc C++ ObjC++ WarnRemoved No longer supported. fvtable-thunks C++ ObjC++ WarnRemoved No longer supported. fweak C++ ObjC++ Var(flag_weak) Init(1) Emit common-like symbols as weak symbols. fwide-exec-charset= C ObjC C++ ObjC++ Joined RejectNegative -fwide-exec-charset= Convert all wide strings and character constants to character set . fworking-directory C ObjC C++ ObjC++ Var(flag_working_directory) Init(-1) Generate a #line directive pointing at the current working directory. fxref C++ ObjC++ WarnRemoved No longer supported. fzero-link ObjC ObjC++ Var(flag_zero_link) Generate lazy class lookup (via objc_getClass()) for use in Zero-Link mode. gen-decls ObjC ObjC++ Driver Var(flag_gen_declaration) RejectNegative Dump declarations to a .decl file. femit-struct-debug-baseonly C ObjC C++ ObjC++ -femit-struct-debug-baseonly Aggressive reduced debug info for structs. femit-struct-debug-reduced C ObjC C++ ObjC++ -femit-struct-debug-reduced Conservative reduced debug info for structs. femit-struct-debug-detailed= C ObjC C++ ObjC++ Joined -femit-struct-debug-detailed= Detailed reduced debug info for structs. fext-numeric-literals C++ ObjC++ Var(flag_ext_numeric_literals) Init(1) Interpret imaginary, fixed-point, or other gnu number suffix as the corresponding number literal rather than a user-defined number literal. idirafter C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs) -idirafter Add to the end of the system include path. imacros C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs) -imacros Accept definition of macros in . imultilib C ObjC C++ ObjC++ Joined Separate -imultilib Set to be the multilib include subdirectory. include C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs) -include Include the contents of before other files. iprefix C ObjC C++ ObjC++ Joined Separate -iprefix Specify as a prefix for next two options. isysroot C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs) -isysroot Set to be the system root directory. isystem C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs) -isystem Add to the start of the system include path. iquote C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs) -iquote Add to the end of the quote include path. iremap C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs) -iremap Convert to if it occurs as prefix in __FILE__. iwithprefix C ObjC C++ ObjC++ Joined Separate -iwithprefix Add to the end of the system include path. iwithprefixbefore C ObjC C++ ObjC++ Joined Separate -iwithprefixbefore Add to the end of the main include path. lang-asm C Undocumented RejectDriver no-integrated-cpp Driver nostdinc C ObjC C++ ObjC++ Do not search standard system include directories (those specified with -isystem will still be used). nostdinc++ C++ ObjC++ Do not search standard system include directories for C++. o C ObjC C++ ObjC++ Joined Separate ; Documented in common.opt pedantic C ObjC C++ ObjC++ Alias(Wpedantic) ; Documented in common.opt print-objc-runtime-info ObjC ObjC++ Generate C header of platform-specific features. remap C ObjC C++ ObjC++ Remap file names when including files. std=c++98 C++ ObjC++ Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum. std=c++03 C++ ObjC++ Alias(std=c++98) Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum. std=c++11 C++ ObjC++ Conform to the ISO 2011 C++ standard. std=c++0x C++ ObjC++ Alias(std=c++11) Undocumented Deprecated in favor of -std=c++11. std=c++1y C++ ObjC++ Alias(std=c++14) Undocumented Deprecated in favor of -std=c++14. std=c++14 C++ ObjC++ Conform to the ISO 2014 C++ standard. std=c++1z C++ ObjC++ Alias(std=c++17) Undocumented Deprecated in favor of -std=c++17. std=c++17 C++ ObjC++ Conform to the ISO 2017 C++ standard. std=c++2a C++ ObjC++ Conform to the ISO 2020 C++ draft standard (experimental and incomplete support). std=c++20 C++ ObjC++ Alias(std=c++2a) Conform to the ISO 2020 C++ draft standard (experimental and incomplete support). std=c11 C ObjC Conform to the ISO 2011 C standard. std=c1x C ObjC Alias(std=c11) Deprecated in favor of -std=c11. std=c17 C ObjC Conform to the ISO 2017 C standard (published in 2018). std=c18 C ObjC Alias(std=c17) Conform to the ISO 2017 C standard (published in 2018). std=c2x C ObjC Conform to the ISO 202X C standard draft (experimental and incomplete support). std=c89 C ObjC Alias(std=c90) Conform to the ISO 1990 C standard. std=c90 C ObjC Conform to the ISO 1990 C standard. std=c99 C ObjC Conform to the ISO 1999 C standard. std=c9x C ObjC Alias(std=c99) Deprecated in favor of -std=c99. std=gnu++98 C++ ObjC++ Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum with GNU extensions. std=gnu++03 C++ ObjC++ Alias(std=gnu++98) Conform to the ISO 1998 C++ standard revised by the 2003 technical corrigendum with GNU extensions. std=gnu++11 C++ ObjC++ Conform to the ISO 2011 C++ standard with GNU extensions. std=gnu++0x C++ ObjC++ Alias(std=gnu++11) Undocumented Deprecated in favor of -std=gnu++11. std=gnu++1y C++ ObjC++ Alias(std=gnu++14) Undocumented Deprecated in favor of -std=gnu++14. std=gnu++14 C++ ObjC++ Conform to the ISO 2014 C++ standard with GNU extensions. std=gnu++1z C++ ObjC++ Alias(std=gnu++17) Undocumented Deprecated in favor of -std=gnu++17. std=gnu++17 C++ ObjC++ Conform to the ISO 2017 C++ standard with GNU extensions. std=gnu++2a C++ ObjC++ Conform to the ISO 2020 C++ draft standard with GNU extensions (experimental and incomplete support). std=gnu++20 C++ ObjC++ Alias(std=gnu++2a) Conform to the ISO 2020 C++ draft standard with GNU extensions (experimental and incomplete support). std=gnu11 C ObjC Conform to the ISO 2011 C standard with GNU extensions. std=gnu1x C ObjC Alias(std=gnu11) Deprecated in favor of -std=gnu11. std=gnu17 C ObjC Conform to the ISO 2017 C standard (published in 2018) with GNU extensions. std=gnu18 C ObjC Alias(std=gnu17) Conform to the ISO 2017 C standard (published in 2018) with GNU extensions. std=gnu2x C ObjC Conform to the ISO 202X C standard draft with GNU extensions (experimental and incomplete support). std=gnu89 C ObjC Alias(std=gnu90) Conform to the ISO 1990 C standard with GNU extensions. std=gnu90 C ObjC Conform to the ISO 1990 C standard with GNU extensions. std=gnu99 C ObjC Conform to the ISO 1999 C standard with GNU extensions. std=gnu9x C ObjC Alias(std=gnu99) Deprecated in favor of -std=gnu99. std=iso9899:1990 C ObjC Alias(std=c90) Conform to the ISO 1990 C standard. std=iso9899:199409 C ObjC Conform to the ISO 1990 C standard as amended in 1994. std=iso9899:1999 C ObjC Alias(std=c99) Conform to the ISO 1999 C standard. std=iso9899:199x C ObjC Alias(std=c99) Deprecated in favor of -std=iso9899:1999. std=iso9899:2011 C ObjC Alias(std=c11) Conform to the ISO 2011 C standard. std=iso9899:2017 C ObjC Alias(std=c17) Conform to the ISO 2017 C standard (published in 2018). std=iso9899:2018 C ObjC Alias(std=c17) Conform to the ISO 2017 C standard (published in 2018). traditional Driver traditional-cpp C ObjC C++ ObjC++ Enable traditional preprocessing. trigraphs C ObjC C++ ObjC++ -trigraphs Support ISO C trigraphs. undef C ObjC C++ ObjC++ Var(flag_undef) Do not predefine system-specific and GCC-specific macros. v C ObjC C++ ObjC++ ; Documented in common.opt w C ObjC C++ ObjC++ ; Documented in common.opt ; This comment is to ensure we retain the blank line above.