-U<macro> Undefine <macro>
Wabi
-C++ ObjC++
+C++ ObjC++ Var(warn_abi)
+Warn about things that will change when compiling with an ABI-compliant compiler
Wall
C ObjC C++ ObjC++
Enable most warning messages
Wbad-function-cast
-C ObjC
+C ObjC Var(warn_bad_function_cast)
Warn about casting functions to incompatible types
Wcast-qual
-C ObjC C++ ObjC++
+C ObjC C++ ObjC++ Var(warn_cast_qual)
Warn about casts which discard qualifiers
Wchar-subscripts
-C ObjC C++ ObjC++
+C ObjC C++ ObjC++ Var(warn_char_subscripts)
Warn about subscripts whose type is \"char\"
Wcomment
Synonym for -Wcomment
Wconversion
-C ObjC C++ ObjC++
+C ObjC C++ ObjC++ Var(warn_conversion)
Warn about possibly confusing type conversions
Wctor-dtor-privacy
-C++ ObjC++
+C++ ObjC++ Var(warn_ctor_dtor_privacy)
Warn when all constructors and destructors are private
Wdeclaration-after-statement
-C ObjC
+C ObjC Var(warn_declaration_after_statement)
Warn when a declaration is found after a statement
Wdeprecated
-C++ ObjC++
+C++ ObjC++ Var(warn_deprecated) Init(1)
Warn about deprecated compiler features
Wdiv-by-zero
-C ObjC
+C ObjC Var(warn_div_by_zero) Init(1)
Warn about compile-time integer division by zero
Weffc++
-C++ ObjC++
+C++ ObjC++ Var(warn_ecpp)
Warn about violations of Effective C++ style rules
Wendif-labels
Make implicit function declarations an error
Wfloat-equal
-C ObjC C++ ObjC++
+C ObjC C++ ObjC++ Var(warn_float_equal)
Warn if testing floating point numbers for equality
Wformat
Warn about printf/scanf/strftime/strfmon format string anomalies
Wformat-extra-args
-C ObjC C++ ObjC++
+C ObjC C++ ObjC++ Var(warn_format_extra_args)
Warn if passing too many arguments to a function for its format string
Wformat-nonliteral
-C ObjC C++ ObjC++
+C ObjC C++ ObjC++ Var(warn_format_nonliteral)
Warn about format strings that are not literals
Wformat-security
-C ObjC C++ ObjC++
+C ObjC C++ ObjC++ Var(warn_format_security)
Warn about possible security problems with format functions
Wformat-y2k
-C ObjC C++ ObjC++
+C ObjC C++ ObjC++ Var(warn_format_y2k)
Warn about strftime formats yielding 2-digit years
Wformat-zero-length
-C ObjC
+C ObjC Var(warn_format_zero_length)
+Warn about zero-length formats
Wformat=
C ObjC C++ ObjC++ Joined
Winit-self
-C ObjC C++ ObjC++
+C ObjC C++ ObjC++ Var(warn_init_self)
Warn about variables which are initialized to themselves.
Wimplicit
C ObjC C++ ObjC++
Wimplicit-function-declaration
-C ObjC
+C ObjC Var(mesg_implicit_function_declaration) Init(-1)
Warn about implicit function declarations
Wimplicit-int
-C ObjC
+C ObjC Var(warn_implicit_int)
Warn when a declaration does not specify a type
Wimport
Deprecated. This switch has no effect.
Winvalid-offsetof
-C++ ObjC++
+C++ ObjC++ Var(warn_invalid_offsetof) Init(1)
Warn about invalid uses of the \"offsetof\" macro
Winvalid-pch
Warn about PCH files that are found but not used
Wlong-long
-C ObjC C++ ObjC++
+C ObjC C++ ObjC++ Var(warn_long_long) Init(1)
Do not warn about using \"long long\" when -pedantic
Wmain
Warn about suspicious declarations of \"main\"
Wmissing-braces
-C ObjC C++ ObjC++
+C ObjC C++ ObjC++ Var(warn_missing_braces)
Warn about possibly missing braces around initializers
Wmissing-declarations
-C ObjC
+C ObjC Var(warn_missing_declarations)
Warn about global functions without previous declarations
Wmissing-format-attribute
-C ObjC C++ ObjC++
+C ObjC C++ ObjC++ Var(warn_missing_format_attribute)
Warn about functions which might be candidates for format attributes
Wmissing-include-dirs
Warn about user-specified include directories that do not exist
Wmissing-prototypes
-C ObjC
+C ObjC Var(warn_missing_prototypes)
Warn about global functions without prototypes
Wmultichar
Warn about use of multi-character character constants
Wnested-externs
-C ObjC
+C ObjC Var(warn_nested_externs)
Warn about \"extern\" declarations not at file scope
Wnon-template-friend
-C++ ObjC++
+C++ ObjC++ Var(warn_nontemplate_friend) Init(1)
Warn when non-templatized friend functions are declared within a template
Wnon-virtual-dtor
-C++ ObjC++
+C++ ObjC++ Var(warn_nonvdtor)
Warn about non-virtual destructors
Wnonnull
-C ObjC
+C ObjC Var(warn_nonnull)
+Warn about NULL being passed to argument slots marked as requiring non-NULL
Wold-style-cast
-C++ ObjC++
+C++ ObjC++ Var(warn_old_style_cast)
Warn if a C-style cast is used in a program
Wold-style-definition
-C ObjC
+C ObjC Var(warn_old_style_definition)
Warn if an old-style parameter definition is used
Woverloaded-virtual
-C++ ObjC++
+C++ ObjC++ Var(warn_overloaded_virtual)
Warn about overloaded virtual function names
Wparentheses
-C ObjC C++ ObjC++
+C ObjC C++ ObjC++ Var(warn_parentheses)
Warn about possibly missing parentheses
Wpmf-conversions
-C++ ObjC++
+C++ ObjC++ Var(warn_pmf2ptr) Init(1)
Warn when converting the type of pointers to member functions
Wpointer-arith
-C ObjC C++ ObjC++
+C ObjC C++ ObjC++ Var(warn_pointer_arith)
Warn about function pointer arithmetic
Wprotocol
-ObjC ObjC++
+ObjC ObjC++ Var(warn_protocol) Init(1)
Warn if inherited methods are unimplemented
Wredundant-decls
-C ObjC C++ ObjC++
+C ObjC C++ ObjC++ Var(warn_redundant_decls)
Warn about multiple declarations of the same object
Wreorder
-C++ ObjC++
+C++ ObjC++ Var(warn_reorder)
Warn when the compiler reorders code
Wreturn-type
Warn whenever a function's return type defaults to \"int\" (C), or about inconsistent return types (C++)
Wselector
-ObjC ObjC++
+ObjC ObjC++ Var(warn_selector)
Warn if a selector has multiple methods
Wsequence-point
-C ObjC
+C ObjC Var(warn_sequence_point)
Warn about possible violations of sequence point rules
Wsign-compare
-C ObjC C++ ObjC++
+C ObjC C++ ObjC++ Var(warn_sign_compare) Init(-1)
Warn about signed-unsigned comparisons
Wsign-promo
-C++ ObjC++
+C++ ObjC++ Var(warn_sign_promo)
Warn when overload promotes from unsigned to signed
Wstrict-prototypes
-C ObjC
+C ObjC Var(warn_strict_prototypes)
Warn about unprototyped function declarations
Wsynth
-C++ ObjC++
+C++ ObjC++ Var(warn_synth)
Warn when synthesis behavior differs from Cfront
Wsystem-headers
Do not suppress warnings from system headers
Wtraditional
-C ObjC
+C ObjC Var(warn_traditional)
Warn about features not present in traditional C
Wtrigraphs
Warn if trigraphs are encountered that might affect the meaning of the program
Wundeclared-selector
-ObjC ObjC++
+ObjC ObjC++ Var(warn_undeclared_selector)
+Warn about @selector()s without previously declared methods
Wundef
C ObjC C++ ObjC++