; Options for the C, ObjC, C++ and ObjC++ front ends.
-; Copyright (C) 2003-2017 Free Software Foundation, Inc.
+; Copyright (C) 2003-2019 Free Software Foundation, Inc.
;
; This file is part of GCC.
;
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.
Waligned-new=
C++ ObjC++ Var(warn_aligned_new) Enum(warn_aligned_new_level) Joined RejectNegative Warning LangEnabledBy(C++ ObjC++,Wall,1,0)
--Waligned-new=all Warn even if 'new' uses a class member allocation function.
+-Waligned-new=[none|global|all] Warn even if 'new' uses a class member allocation function.
Wall
C ObjC C++ ObjC++ Warning
Warn on any use of alloca.
Walloc-size-larger-than=
-C ObjC C++ ObjC++ Var(warn_alloc_size_limit) Warning Joined
+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=<bytes> 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
+-Wno-alloc-size-larger-than Disable Walloc-size-larger-than= warning. Equivalent to Walloc-size-larger-than=<SIZE_MAX> or larger.
+
Walloc-zero
C ObjC C++ ObjC++ Var(warn_alloc_zero) Warning
-Walloc-zero Warn for calls to allocation functions that specify zero bytes.
Walloca-larger-than=
-C ObjC C++ ObjC++ Var(warn_alloca_limit) Warning Joined RejectNegative UInteger
--Walloca-larger-than=<number> Warn on unbounded uses of
+C ObjC C++ LTO ObjC++ Var(warn_alloca_limit) Warning Joined Host_Wide_Int ByteSize Init(HOST_WIDE_INT_MAX)
+-Walloca-larger-than=<number> Warn on unbounded uses of
alloca, and on bounded uses of alloca whose bound can be larger than
<number> bytes.
+Wno-alloca-larger-than
+C ObjC C++ LTO ObjC++ Alias(Walloca-larger-than=,18446744073709551615EiB,none) Warning
+-Wno-alloca-larger-than Disable Walloca-larger-than= warning. Equivalent to Walloca-larger-than=<SIZE_MAX> or larger.
+
Warray-bounds
-LangEnabledBy(C ObjC C++ ObjC++,Wall)
+LangEnabledBy(C ObjC C++ LTO ObjC++)
; in common.opt
Warray-bounds=
-LangEnabledBy(C ObjC C++ ObjC++,Wall,1,0)
+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.
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.
Warn about C++ constructs whose meaning differs between ISO C++ 2011 and ISO C++ 2014.
Wc++1z-compat
-C++ ObjC++ Var(warn_cxx1z_compat) Warning LangEnabledBy(C++ ObjC++,Wall)
-Warn about C++ constructs whose meaning differs between ISO C++ 2014 and (forthcoming) ISO C++ 201z(7?).
+C++ ObjC++ Warning Alias(Wc++17-compat) Undocumented
Wc++17-compat
-C++ ObjC++ Warning Alias(Wc++1z-compat) Undocumented
+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++ Var(warn_chkp) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
-Warn about memory access errors found by Pointer Bounds Checker.
+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.
Warn about deleting polymorphic objects with non-virtual destructors.
Wdeprecated
-C C++ ObjC ObjC++ CPP(cpp_warn_deprecated) CppReason(CPP_W_DEPRECATED) Var(warn_deprecated) Init(1) Warning
-Warn if a deprecated compiler feature, class, method, or field is used.
+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
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.
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 #elif and #endif.
+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
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.
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-length
-C ObjC C++ ObjC++ Warning Alias(Wformat-length=, 1, 0)
-Warn about function calls with format strings that write past the end
-of the destination region. Same as -Wformat-length=1.
-
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.
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.
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)
+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-length=
-C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_format_length) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=, warn_format >= 1, 0)
+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.
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.
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.
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.
+
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.
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++ ObjC++ Warning Alias(Wstringop-overflow=, 2, 0)
+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++ ObjC++ Joined RejectNegative UInteger Var(warn_stringop_overflow) Init(2) Warning
+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.
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)
;
Warn about global functions without prototypes.
Wmudflap
-C ObjC C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
+C ObjC C++ ObjC++ WarnRemoved
Wmultichar
C ObjC C++ ObjC++ CPP(warn_multichar) CppReason(CPP_W_MULTICHAR) Var(cpp_warn_multichar) Init(0) Warning
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++ ObjC++ Var(warn_nonnull) Warning LangEnabledBy(C ObjC C++ ObjC++,Wformat=,warn_format >= 1,0)
+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++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
+C ObjC C++ LTO ObjC++ LangEnabledBy(C ObjC C++ LTO ObjC++,Wall)
;
Wnonnull-compare
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-normalised Unicode strings.
+-Wnormalized=[none|id|nfc|nfkc] Warn about non-normalized Unicode strings.
; Required for these enum values.
SourceInclude
Warn for obsolescent usage in a declaration.
Wold-style-definition
-C ObjC Var(warn_old_style_definition) Warning
+C ObjC Var(warn_old_style_definition) Init(-1) Warning
Warn if an old-style parameter definition is used.
Wopenmp-simd
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.
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.
Warn for placement new expressions with undefined behavior.
Wplacement-new=
-C++ Joined RejectNegative UInteger Var(warn_placement_new) Init(-1) Warning
+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.
Warn when the compiler reorders code.
Wreturn-type
-C ObjC C++ ObjC++ Var(warn_return_type) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
+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
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
+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
Warn about unprototyped function declarations.
Wstrict-aliasing=
-C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 3, 0)
+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)
+C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0) IntegerRange(0, 5)
;
Wstrict-selector-match
Warn if an undefined macro is used in an #if directive.
Wuninitialized
-C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
+C ObjC C++ ObjC++ LTO LangEnabledBy(C ObjC C++ ObjC++ LTO,Wall)
;
Wmaybe-uninitialized
-C ObjC C++ ObjC++ LangEnabledBy(C ObjC C++ ObjC++,Wall)
+C ObjC C++ ObjC++ LTO LangEnabledBy(C ObjC C++ ObjC++ LTO,Wall)
;
Wunknown-pragmas
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)
+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
Warn if a variable length array is used.
Wvla-larger-than=
-C ObjC C++ ObjC++ Var(warn_vla_limit) Warning Joined RejectNegative UInteger
--Wvla-larger-than=<number> Warn on unbounded uses of variable-length arrays, and
-on bounded uses of variable-length arrays whose bound can be
+C ObjC C++ LTO ObjC++ Var(warn_vla_limit) Warning Joined Host_Wide_Int ByteSize Init(HOST_WIDE_INT_MAX)
+-Wvla-larger-than=<number> Warn on unbounded uses of variable-length
+arrays, and on bounded uses of variable-length arrays whose bound can be
larger than <number> bytes.
+<number> bytes.
+
+Wno-vla-larger-than
+C ObjC C++ LTO ObjC++ Alias(Wvla-larger-than=,18446744073709551615EiB,none) Warning
+-Wno-vla-larger-than Disable Wvla-larger-than= warning. Equivalent to Wvla-larger-than=<SIZE_MAX> 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 declaration has duplicate const, volatile, restrict or _Atomic specifier.
Wrestrict
-C ObjC C++ ObjC++ Var(warn_restrict) Warning LangEnabledBy(C ObjC C++ ObjC++)
+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.
-faligned-new=<N> Use C++17 over-aligned type allocation for alignments greater than N.
fall-virtual
-C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
+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++ Ignore Warn(switch %qs is no longer supported)
+C++ ObjC++ WarnRemoved
No longer supported.
fasm
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 Report Var(flag_check_pointer_bounds)
-Add Pointer Bounds Checker instrumentation. fchkp-* flags are used to
-control instrumentation. Currently available for C, C++ and ObjC.
+C ObjC C++ ObjC++ LTO WarnRemoved
+Removed in GCC 9. This switch has no effect.
fchkp-check-incomplete-type
-C ObjC C++ ObjC++ LTO Report Var(flag_chkp_incomplete_type) Init(1)
-Generate pointer bounds checks for variables with 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 Report Var(flag_chkp_zero_input_bounds_for_main) Init(0)
-Use zero bounds for all incoming arguments in 'main' function. It helps when
-instrumented binaries are used with legacy libs.
+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 RejectNegative Report Var(flag_chkp_first_field_has_own_bounds)
-Forces Pointer Bounds Checker to use narrowed bounds for address of the first
-field in the structure. By default pointer to the first field has the same
-bounds as pointer to the whole structure.
+C ObjC C++ ObjC++ LTO WarnRemoved RejectNegative
+Removed in GCC 9. This switch has no effect.
fchkp-narrow-bounds
-C ObjC C++ ObjC++ LTO Report Var(flag_chkp_narrow_bounds) Init(1)
-Control how Pointer Bounds Checker handle pointers to object fields. When
-narrowing is on, field bounds are used. Otherwise full object bounds are used.
+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 RejectNegative Report Var(flag_chkp_narrow_to_innermost_arrray)
-Forces Pointer Bounds Checker to use bounds of the innermost arrays in case of
-nested static arrays access. By default outermost array is used.
+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 Report Var(flag_chkp_flexible_struct_trailing_arrays)
-Forces Pointer Bounds Checker to treat all trailing arrays in structures as
-possibly flexible. By default only arrays fields with zero length or that are
-marked with attribute bnd_variable_size are treated as flexible.
+C ObjC C++ ObjC++ LTO WarnRemoved
+Removed in GCC 9. This switch has no effect.
fchkp-optimize
-C ObjC C++ ObjC++ LTO Report Var(flag_chkp_optimize) Init(-1)
-Allow Pointer Bounds Checker optimizations. By default allowed
-on optimization levels >0.
+C ObjC C++ ObjC++ LTO WarnRemoved
fchkp-use-fast-string-functions
-C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_fast_string_functions) Init(0)
-Allow to use *_nobnd versions of string functions by Pointer Bounds Checker.
+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 Report Var(flag_chkp_use_nochk_string_functions) Init(0)
-Allow to use *_nochk versions of string functions by Pointer Bounds Checker.
+C ObjC C++ ObjC++ LTO WarnRemoved
+Removed in GCC 9. This switch has no effect.
fchkp-use-static-bounds
-C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_static_bounds) Init(1)
-Use statically initialized variable for vars bounds instead of
-generating them each time it is required.
+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 Report Var(flag_chkp_use_static_const_bounds) Init(-1)
-Use statically initialized variable for constant bounds instead of
-generating them each time it is required.
+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 Report Var(flag_chkp_zero_dynamic_size_as_infinite) Init(0)
-With this option zero size obtained dynamically for objects with
-incomplete type will be treated 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 Report Var(flag_chkp_check_read) Init(1)
-Generate checks for all read accesses to memory.
+C ObjC C++ ObjC++ LTO WarnRemoved
+Removed in GCC 9. This switch has no effect.
fchkp-check-write
-C ObjC C++ ObjC++ LTO Report Var(flag_chkp_check_write) Init(1)
-Generate checks for all write accesses to memory.
+C ObjC C++ ObjC++ LTO WarnRemoved
+Removed in GCC 9. This switch has no effect.
fchkp-store-bounds
-C ObjC C++ ObjC++ LTO Report Var(flag_chkp_store_bounds) Init(1)
-Generate bounds stores for pointer writes.
+C ObjC C++ ObjC++ LTO WarnRemoved
+Removed in GCC 9. This switch has no effect.
fchkp-instrument-calls
-C ObjC C++ ObjC++ LTO Report Var(flag_chkp_instrument_calls) Init(1)
-Generate bounds passing for 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 Report Var(flag_chkp_instrument_marked_only) Init(0)
-Instrument only functions marked with bnd_instrument attribute.
+C ObjC C++ ObjC++ LTO WarnRemoved
+Removed in GCC 9. This switch has no effect.
fchkp-use-wrappers
-C ObjC C++ ObjC++ LTO Report Var(flag_chkp_use_wrappers) Init(1)
-Transform instrumented builtin calls into calls to wrappers.
+C ObjC C++ ObjC++ LTO WarnRemoved
+Removed in GCC 9. This switch has no effect.
static-libmpx
-Driver
+Driver WarnRemoved
+Removed in GCC 9. This switch has no effect.
static-libmpxwrappers
-Driver
+Driver WarnRemoved
+Removed in GCC 9. This switch has no effect.
fcilkplus
-C ObjC C++ ObjC++ LTO Report Var(flag_cilkplus) Init(0)
-Enable Cilk Plus.
+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.
+
fcond-mismatch
C ObjC C++ ObjC++
Allow the arguments of the '?' operator to have different types.
fconserve-space
-C++ ObjC++ Var(flag_conserve_space)
+C++ ObjC++ Ignore
Does nothing. Preserved for backward compatibility.
fconstant-string-class=
C++ ObjC++ Joined RejectNegative UInteger Var(max_constexpr_depth) Init(512)
-fconstexpr-depth=<number> Specify maximum constexpr recursion depth.
+fconstexpr-cache-depth=
+C++ ObjC++ Joined RejectNegative UInteger Var(constexpr_cache_depth) Init(8)
+-fconstexpr-cache-depth=<number> Specify maximum constexpr recursion cache depth.
+
fconstexpr-loop-limit=
C++ ObjC++ Joined RejectNegative UInteger Var(constexpr_loop_limit) Init(262144)
-fconstexpr-loop-limit=<number> 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=<number> Specify maximum number of constexpr operations during a single constexpr evaluation.
+
fdebug-cpp
C ObjC C++ ObjC++
Emit debug annotations during preprocessing.
fdeduce-init-list
-C++ ObjC++ Var(flag_deduce_init_list) Init(0)
--fdeduce-init-list enable deduction of std::initializer_list for a template type parameter from a brace-enclosed initializer-list.
+C++ ObjC++ Ignore
+Does nothing. Preserved for backward compatibility.
fdeclone-ctor-dtor
C++ ObjC++ Var(flag_declone_ctor_dtor) Init(-1)
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.
C ObjC C++ ObjC++
Permit '$' as an identifier character.
+fmacro-prefix-map=
+C ObjC C++ ObjC++ Joined RejectNegative
+-fmacro-prefix-map=<old>=<new> 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.
felide-constructors
C++ ObjC++ Var(flag_elide_constructors) Init(1)
+felide-type
+C++ ObjC++ Var(flag_elide_type) Init(1)
+-fno-elide-type 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++ Ignore Warn(switch %qs is no longer supported)
+C++ ObjC++ WarnRemoved
fexec-charset=
C ObjC C++ ObjC++ Joined RejectNegative
Support dynamic initialization of thread-local variables in a different translation unit.
fexternal-templates
-C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
+C++ ObjC++ WarnRemoved
ffor-scope
-C++ ObjC++ Var(flag_new_for_scope) Init(1)
-Scope of for-init-statement variables is local to the loop.
+C++ ObjC++ WarnRemoved
ffreestanding
C ObjC C++ ObjC++
Use traditional GNU semantics for inline functions.
fguiding-decls
-C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
+C++ ObjC++ WarnRemoved
fhandle-exceptions
-C++ ObjC++ Optimization Alias(fexceptions) Warn({-fhandle-exceptions has been renamed -fexceptions (and is now on by default)})
+C++ ObjC++ Optimization Alias(fexceptions) Warn({%<-fhandle-exceptions%> has been renamed %<-fexceptions%> (and is now on by default)})
fhonor-std
-C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
+C++ ObjC++ WarnRemoved
fhosted
C ObjC
Assume normal C execution environment.
fhuge-objects
-C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
+C++ ObjC++ WarnRemoved
No longer supported.
fimplement-inlines
Implement C++17 inheriting constructor semantics.
ffriend-injection
-C++ ObjC++ Var(flag_friend_injection)
-Inject friend functions into enclosing namespace.
+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++ Ignore Warn(switch %qs is no longer supported)
+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=<number> 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++ Ignore Warn(switch %qs is no longer supported)
+C ObjC C++ ObjC++ WarnRemoved
fmudflapth
-C ObjC C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
+C ObjC C++ ObjC++ WarnRemoved
fmudflapir
-C ObjC C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
+C ObjC C++ ObjC++ WarnRemoved
fname-mangling-version-
-C++ ObjC++ Joined Ignore Warn(switch %qs is no longer supported)
+C++ ObjC++ Joined WarnRemoved
fnew-abi
-C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
+C++ ObjC++ WarnRemoved
fnew-ttp-matching
C++ ObjC++ Var(flag_new_ttp)
C++ ObjC++ Var(flag_no_nonansi_builtin, 0)
fnonnull-objects
-C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
+C++ ObjC++ WarnRemoved
fnothrow-opt
C++ ObjC++ Optimization Var(flag_nothrow_opt)
Used in Fix-and-Continue mode to indicate that object files may be swapped in at runtime.
frepo
-C++ ObjC++
-Enable automatic template instantiation.
+C++ ObjC++ WarnRemoved
+Removed in GCC 10. This switch has no effect.
frtti
C++ ObjC++ Optimization Var(flag_rtti) Init(1)
Enable C++14 sized deallocation support.
fsquangle
-C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
+C++ ObjC++ WarnRemoved
fsso-struct=
C ObjC Joined RejectNegative Enum(sso_struct) Var(default_sso) Init(SSO_NATIVE)
Assume that values of enumeration type are always within the minimum range of that type.
fstrict-prototype
-C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
+C++ ObjC++ WarnRemoved
fstrong-eval-order
C++ ObjC++ Common Alias(fstrong-eval-order=, all, none)
-ftemplate-depth=<number> Specify maximum template instantiation depth.
fthis-is-variable
-C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
+C++ ObjC++ WarnRemoved
fthreadsafe-statics
C++ ObjC++ Optimization Var(flag_threadsafe_statics) Init(1)
Changes visibility to match Microsoft Visual Studio by default.
fvtable-gc
-C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
+C++ ObjC++ WarnRemoved
No longer supported.
fvtable-thunks
-C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
+C++ ObjC++ WarnRemoved
No longer supported.
fweak
Generate a #line directive pointing at the current working directory.
fxref
-C++ ObjC++ Ignore Warn(switch %qs is no longer supported)
+C++ ObjC++ WarnRemoved
No longer supported.
fzero-link
Generate lazy class lookup (via objc_getClass()) for use in Zero-Link mode.
gen-decls
-ObjC ObjC++ Var(flag_gen_declaration)
+ObjC ObjC++ Driver Var(flag_gen_declaration) RejectNegative
Dump declarations to a .decl file.
femit-struct-debug-baseonly
Conform to the ISO 2014 C++ standard.
std=c++1z
-C++ ObjC++
-Conform to the ISO 2017(?) C++ draft standard (experimental and incomplete support).
+C++ ObjC++ Alias(std=c++17) Undocumented
+Deprecated in favor of -std=c++17.
std=c++17
-C++ ObjC++ Alias(std=c++1z) Undocumented
+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=c11
C ObjC
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.
Conform to the ISO 2014 C++ standard with GNU extensions.
std=gnu++1z
-C++ ObjC++
-Conform to the ISO 201z(7?) C++ draft standard with GNU extensions (experimental and incomplete support).
+C++ ObjC++ Alias(std=gnu++17) Undocumented
+Deprecated in favor of -std=gnu++17.
std=gnu++17
-C++ ObjC++ Alias(std=gnu++1z) Undocumented
+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=gnu11
C ObjC
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.
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
projects / platform / upstream / gcc.git / blobdiff