1 ; Options for the C, ObjC, C++ and ObjC++ front ends.
2 ; Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009
3 ; Free Software Foundation, Inc.
5 ; This file is part of GCC.
7 ; GCC is free software; you can redistribute it and/or modify it under
8 ; the terms of the GNU General Public License as published by the Free
9 ; Software Foundation; either version 3, or (at your option) any later
12 ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 ; WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 ; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 ; You should have received a copy of the GNU General Public License
18 ; along with GCC; see the file COPYING3. If not see
19 ; <http://www.gnu.org/licenses/>.
21 ; See the GCC internals manual for a description of this file's format.
23 ; Please try to keep this file in ASCII collating order.
38 C ObjC C++ ObjC++ Joined Separate
41 C ObjC C++ ObjC++ Joined Separate
42 -A<question>=<answer> Assert the <answer> to <question>. Putting '-' before <question> disables the <answer> to <question>
46 Do not discard comments
50 Do not discard comments in macro expansions
53 C ObjC C++ ObjC++ Joined Separate
54 -D<macro>[=<val>] Define a <macro> with <val> as its value. If just <macro> is given, <val> is taken to be 1
57 C ObjC C++ ObjC++ Undocumented
60 C ObjC C++ ObjC++ Joined Separate
61 -F <dir> Add <dir> to the end of the main framework include path
65 Print the name of header files as they are used
68 C ObjC C++ ObjC++ Joined Separate
69 -I <dir> Add <dir> to the end of the main include path
73 Generate make dependencies
76 C ObjC C++ ObjC++ Separate
77 Generate make dependencies and compile
80 C ObjC C++ ObjC++ Joined Separate
81 -MF <file> Write dependency output to the given file
85 Treat missing header files as generated files
89 Like -M but ignore system header files
92 C ObjC C++ ObjC++ Separate
93 Like -MD but ignore system header files
97 Generate phony targets for all headers
100 C ObjC C++ ObjC++ Joined Separate
101 -MQ <target> Add a MAKE-quoted target
104 C ObjC C++ ObjC++ Joined Separate
105 -MT <target> Add an unquoted target
109 Do not generate #line directives
112 C ObjC C++ ObjC++ Joined Separate
113 -U<macro> Undefine <macro>
116 C ObjC C++ ObjC++ LTO Var(warn_abi) Warning
117 Warn about things that will change when compiling with an ABI-compliant compiler
120 C ObjC C++ ObjC++ LTO Var(warn_psabi) Init(1) Undocumented
123 C ObjC C++ ObjC++ Var(warn_address) Warning
124 Warn about suspicious uses of memory addresses
127 C ObjC C++ ObjC++ Warning
128 Enable most warning messages
131 ObjC ObjC++ Var(warn_assign_intercept) Warning
132 Warn whenever an Objective-C assignment is being intercepted by the garbage collector
135 C ObjC Var(warn_bad_function_cast) Warning
136 Warn about casting functions to incompatible types
138 Wbuiltin-macro-redefined
139 C ObjC C++ ObjC++ Warning
140 Warn when a built-in preprocessor macro is undefined or redefined
143 C ObjC Var(warn_cxx_compat) Warning
144 Warn about C constructs that are not in the common subset of C and C++
147 C++ ObjC++ Var(warn_cxx0x_compat) Warning
148 Warn about C++ constructs whose meaning differs between ISO C++ 1998 and ISO C++ 200x
151 C ObjC C++ ObjC++ Var(warn_cast_qual) Warning
152 Warn about casts which discard qualifiers
155 C ObjC C++ ObjC++ Var(warn_char_subscripts) Warning
156 Warn about subscripts whose type is \"char\"
159 C ObjC C++ ObjC++ Var(warn_clobbered) Init(-1) Warning
160 Warn about variables that might be changed by \"longjmp\" or \"vfork\"
163 C ObjC C++ ObjC++ Warning
164 Warn about possibly nested block comments, and C++ comments spanning more than one physical line
167 C ObjC C++ ObjC++ Warning
168 Synonym for -Wcomment
171 C ObjC C++ ObjC++ Var(warn_conversion) Warning
172 Warn for implicit type conversions that may change a value
175 C++ ObjC++ Var(warn_conversion_null) Init(1) Warning
176 Warn for converting NULL from/to a non-pointer type
179 C ObjC C++ ObjC++ Var(warn_sign_conversion) Init(-1)
180 Warn for implicit type conversions between signed and unsigned integers
183 C++ ObjC++ Var(warn_ctor_dtor_privacy) Warning
184 Warn when all constructors and destructors are private
186 Wdeclaration-after-statement
187 C ObjC Var(warn_declaration_after_statement) Warning
188 Warn when a declaration is found after a statement
191 C C++ ObjC ObjC++ Var(warn_deprecated) Init(1) Warning
192 Warn if a deprecated compiler feature, class, method, or field is used
195 C ObjC C++ ObjC++ Var(warn_div_by_zero) Init(1) Warning
196 Warn about compile-time integer division by zero
199 C++ ObjC++ Var(warn_ecpp) Warning
200 Warn about violations of Effective C++ style rules
203 C ObjC C++ ObjC++ Var(warn_empty_body) Init(-1) Warning
204 Warn about an empty body in an if or else statement
207 C ObjC C++ ObjC++ Warning
208 Warn about stray tokens after #elif and #endif
211 C ObjC C++ ObjC++ Var(warn_enum_compare) Init(-1) Warning
212 Warn about comparison of different enum types
216 ; Documented in common.opt
218 Werror-implicit-function-declaration
219 C ObjC RejectNegative Warning
220 This switch is deprecated; use -Werror=implicit-function-declaration instead
223 C ObjC C++ ObjC++ Var(warn_float_equal) Warning
224 Warn if testing floating point numbers for equality
227 C ObjC C++ ObjC++ Warning
228 Warn about printf/scanf/strftime/strfmon format string anomalies
231 C ObjC C++ ObjC++ Var(warn_format_extra_args) Warning
232 Warn if passing too many arguments to a function for its format string
235 C ObjC C++ ObjC++ Var(warn_format_nonliteral) Warning
236 Warn about format strings that are not literals
239 C ObjC C++ ObjC++ Var(warn_format_contains_nul) Warning
240 Warn about format strings that contain NUL bytes
243 C ObjC C++ ObjC++ Var(warn_format_security) Warning
244 Warn about possible security problems with format functions
247 C ObjC C++ ObjC++ Var(warn_format_y2k) Warning
248 Warn about strftime formats yielding 2-digit years
251 C ObjC Var(warn_format_zero_length) Warning
252 Warn about zero-length formats
255 C ObjC C++ ObjC++ Joined Warning
258 C C++ Var(warn_ignored_qualifiers) Init(-1) Warning
259 Warn whenever type qualifiers are ignored.
262 C ObjC C++ ObjC++ Var(warn_init_self) Warning
263 Warn about variables which are initialized to themselves
266 C ObjC C++ ObjC++ Warning
268 Wimplicit-function-declaration
269 C ObjC Var(warn_implicit_function_declaration) Init(-1) Warning
270 Warn about implicit function declarations
273 C ObjC Var(warn_implicit_int) Warning
274 Warn when a declaration does not specify a type
277 C ObjC C++ ObjC++ Undocumented
280 C ObjC Var(warn_int_to_pointer_cast) Init(1) Warning
281 Warn when there is a cast to a pointer from an integer of a different size
284 C++ ObjC++ Var(warn_invalid_offsetof) Init(1) Warning
285 Warn about invalid uses of the \"offsetof\" macro
288 C ObjC C++ ObjC++ Warning
289 Warn about PCH files that are found but not used
292 C ObjC Var(warn_jump_misses_init) Init(-1) Warning
293 Warn when a jump misses a variable initialization
296 C ObjC C++ ObjC++ Var(warn_logical_op) Init(0) Warning
297 Warn when a logical operator is suspiciously always evaluating to true or false
300 C ObjC C++ ObjC++ Var(warn_long_long) Init(-1) Warning
301 Do not warn about using \"long long\" when -pedantic
304 C ObjC C++ ObjC++ Var(warn_main) Init(-1) Warning
305 Warn about suspicious declarations of \"main\"
308 C ObjC C++ ObjC++ Var(warn_missing_braces) Warning
309 Warn about possibly missing braces around initializers
311 Wmissing-declarations
312 C ObjC C++ ObjC++ Var(warn_missing_declarations) Warning
313 Warn about global functions without previous declarations
315 Wmissing-field-initializers
316 C ObjC C++ ObjC++ Var(warn_missing_field_initializers) Init(-1) Warning
317 Warn about missing fields in struct initializers
319 Wmissing-format-attribute
320 C ObjC C++ ObjC++ Var(warn_missing_format_attribute) Warning
321 Warn about functions which might be candidates for format attributes
323 Wmissing-include-dirs
324 C ObjC C++ ObjC++ Warning
325 Warn about user-specified include directories that do not exist
327 Wmissing-parameter-type
328 C ObjC Var(warn_missing_parameter_type) Init(-1) Warning
329 Warn about function parameters declared without a type specifier in K&R-style functions
332 C ObjC Var(warn_missing_prototypes) Warning
333 Warn about global functions without prototypes
336 C ObjC C++ ObjC++ Warning
337 Warn about use of multi-character character constants
340 C ObjC Var(warn_nested_externs) Warning
341 Warn about \"extern\" declarations not at file scope
344 C++ ObjC++ Var(warn_nontemplate_friend) Init(1) Warning
345 Warn when non-templatized friend functions are declared within a template
348 C++ ObjC++ Var(warn_nonvdtor) Warning
349 Warn about non-virtual destructors
352 C ObjC Var(warn_nonnull) Warning
353 Warn about NULL being passed to argument slots marked as requiring non-NULL
356 C ObjC C++ ObjC++ Joined Warning
357 -Wnormalized=<id|nfc|nfkc> Warn about non-normalised Unicode strings
360 C++ ObjC++ Var(warn_old_style_cast) Warning
361 Warn if a C-style cast is used in a program
363 Wold-style-declaration
364 C ObjC Var(warn_old_style_declaration) Init(-1) Warning
365 Warn for obsolescent usage in a declaration
367 Wold-style-definition
368 C ObjC Var(warn_old_style_definition) Warning
369 Warn if an old-style parameter definition is used
372 C ObjC C++ ObjC++ Var(warn_overlength_strings) Init(-1) Warning
373 Warn if a string is longer than the maximum portable length specified by the standard
376 C++ ObjC++ Var(warn_overloaded_virtual) Warning
377 Warn about overloaded virtual function names
380 C ObjC Var(warn_override_init) Init(-1) Warning
381 Warn about overriding initializers without side effects
383 Wpacked-bitfield-compat
384 C ObjC C++ ObjC++ Var(warn_packed_bitfield_compat) Init(-1) Warning
385 Warn about packed bit-fields whose offset changed in GCC 4.4
388 C ObjC C++ ObjC++ Var(warn_parentheses) Warning
389 Warn about possibly missing parentheses
392 C++ ObjC++ Var(warn_pmf2ptr) Init(1) Warning
393 Warn when converting the type of pointers to member functions
396 C ObjC C++ ObjC++ Var(warn_pointer_arith) Warning
397 Warn about function pointer arithmetic
400 C ObjC Var(warn_pointer_to_int_cast) Init(1) Warning
401 Warn when a pointer is cast to an integer of a different size
404 C ObjC C++ ObjC++ Var(warn_pragmas) Init(1) Warning
405 Warn about misuses of pragmas
408 ObjC ObjC++ Var(warn_protocol) Init(1) Warning
409 Warn if inherited methods are unimplemented
412 C ObjC C++ ObjC++ Var(warn_redundant_decls) Warning
413 Warn about multiple declarations of the same object
416 C++ ObjC++ Var(warn_reorder) Warning
417 Warn when the compiler reorders code
420 C ObjC C++ ObjC++ Var(warn_return_type) Warning
421 Warn whenever a function's return type defaults to \"int\" (C), or about inconsistent return types (C++)
424 ObjC ObjC++ Var(warn_selector) Warning
425 Warn if a selector has multiple methods
428 C ObjC C++ ObjC++ Var(warn_sequence_point) Warning
429 Warn about possible violations of sequence point rules
432 C ObjC C++ ObjC++ Var(warn_sign_compare) Init(-1) Warning
433 Warn about signed-unsigned comparisons
436 C++ ObjC++ Var(warn_sign_promo) Warning
437 Warn when overload promotes from unsigned to signed
439 Wstrict-null-sentinel
441 Warn about uncasted NULL used as sentinel
444 C ObjC Var(warn_strict_prototypes) Warning
445 Warn about unprototyped function declarations
447 Wstrict-selector-match
448 ObjC ObjC++ Var(warn_strict_selector_match) Warning
449 Warn if type signatures of candidate methods do not match exactly
452 C C++ Var(warn_sync_nand) Init(1) Warning
453 Warn when __sync_fetch_and_nand and __sync_nand_and_fetch built-in functions are used
456 C++ ObjC++ Var(warn_synth) Warning
457 Deprecated. This switch has no effect
460 C ObjC C++ ObjC++ Warning
461 ; Documented in common.opt
464 C ObjC Var(warn_traditional) Warning
465 Warn about features not present in traditional C
467 Wtraditional-conversion
468 C ObjC Var(warn_traditional_conversion) Warning
469 Warn of prototypes causing type conversions different from what would happen in the absence of prototype
472 C ObjC C++ ObjC++ Warning
473 Warn if trigraphs are encountered that might affect the meaning of the program
476 ObjC ObjC++ Var(warn_undeclared_selector) Warning
477 Warn about @selector()s without previously declared methods
480 C ObjC C++ ObjC++ Warning
481 Warn if an undefined macro is used in an #if directive
484 C ObjC C++ ObjC++ Warning
485 Warn about unrecognized pragmas
487 Wunsuffixed-float-constants
488 C ObjC Var(warn_unsuffixed_float_constants) Warning
489 Warn about unsuffixed float constants
492 C ObjC C++ ObjC++ Warning
493 Warn about macros defined in the main file that are not used
496 C ObjC C++ ObjC++ Var(warn_unused_result) Init(1) Warning
497 Warn if a caller of a function, marked with attribute warn_unused_result, does not use its return value
500 C ObjC C++ ObjC++ Warning
501 Do not warn about using variadic macros when -pedantic
504 C ObjC C++ ObjC++ Var(warn_vla) Init(-1) Warning
505 Warn if a variable length array is used
507 Wvolatile-register-var
508 C ObjC C++ ObjC++ Var(warn_volatile_register_var) Warning
509 Warn when a register variable is declared volatile
512 C ObjC C++ ObjC++ Var(warn_write_strings) Warning
513 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.
516 C ObjC Var(warn_pointer_sign) Init(-1) Warning
517 Warn when a pointer differs in signedness in an assignment
521 A synonym for -std=c89 (for C) or -std=c++98 (for C++)
524 C ObjC C++ ObjC++ Joined
525 ; Documented in common.opt. FIXME - what about -dI, -dD, -dN and -dD?
529 Enforce class member access control semantics
534 falt-external-templates
536 Change when template instances are emitted
540 Recognize the \"asm\" keyword
544 Recognize built-in functions
547 C ObjC C++ ObjC++ Joined
551 Check the return value of new
555 Allow the arguments of the '?' operator to have different types
559 Reduce the size of object files
561 fconstant-string-class=
563 -fconst-string-class=<name> Use class <name> for constant strings
566 C++ ObjC++ Var(flag_deduce_init_list) Init(1)
567 -fno-deduce-init-list disable deduction of std::initializer_list for a template type parameter from a brace-enclosed initializer-list
571 Inline member functions by default
575 Preprocess directives only.
577 fdollars-in-identifiers
579 Permit '$' as an identifier character
586 Generate code to check exception specifications
592 C ObjC C++ ObjC++ Joined RejectNegative
593 -fexec-charset=<cset> Convert all strings and character constants to character set <cset>
595 fextended-identifiers
597 Permit universal character names (\\u and \\U) in identifiers
600 C ObjC C++ ObjC++ Joined RejectNegative
601 -finput-charset=<cset> Specify the default character set for source files
609 Scope of for-init-statement variables is local to the loop
613 Do not assume that standard C libraries and \"main\" exist
617 Recognize GNU-defined keywords
621 Generate code for GNU runtime environment
624 C ObjC Var(flag_gnu89_inline) Init(-1)
625 Use traditional GNU semantics for inline functions
631 C++ ObjC++ Optimization
638 Assume normal C execution environment
642 Enable support for huge objects
646 Export functions even if they can be inlined
648 fimplicit-inline-templates
650 Emit implicit instantiations of inline templates
654 Emit implicit instantiations of templates
657 C++ ObjC++ Var(flag_friend_injection)
658 Inject friend functions into enclosing namespace
663 flax-vector-conversions
665 Allow implicit conversions between vectors with differing numbers of subparts and/or differing element types.
669 Don't warn about uses of Microsoft extensions
671 fname-mangling-version-
679 Generate code for NeXT (Apple Mac OS X) runtime environment
683 Assume that receivers of Objective-C messages may be nil
691 ; Generate special '- .cxx_construct' and '- .cxx_destruct' methods
692 ; to initialize any non-POD ivars in Objective-C++ classes.
693 fobjc-call-cxx-cdtors
694 ObjC++ Var(flag_objc_call_cxx_cdtors)
695 Generate special Objective-C methods to initialize/destroy non-POD C++ ivars, if needed
697 fobjc-direct-dispatch
698 ObjC ObjC++ Var(flag_objc_direct_dispatch)
699 Allow fast jumps to the message dispatcher
701 ; Nonzero means that we will allow new ObjC exception syntax (@throw,
702 ; @try, etc.) in source code.
704 ObjC ObjC++ Var(flag_objc_exceptions)
705 Enable Objective-C exception and synchronization syntax
708 ObjC ObjC++ Var(flag_objc_gc)
709 Enable garbage collection (GC) in Objective-C/Objective-C++ programs
711 ; Nonzero means that we generate NeXT setjmp based exceptions.
712 fobjc-sjlj-exceptions
713 ObjC ObjC++ Var(flag_objc_sjlj_exceptions) Init(-1)
714 Enable Objective-C setjmp exception handling runtime
717 C ObjC C++ ObjC++ Var(flag_openmp)
718 Enable OpenMP (implies -frecursive in Fortran)
722 Recognize C++ keywords like \"compl\" and \"xor\"
726 Enable optional diagnostics
733 Look for and use PCH files even when preprocessing
737 Downgrade conformance errors to warnings
741 Treat the input file as already preprocessed
745 -fno-pretty-templates Do not pretty-print template specializations as the template signature followed by the arguments
747 freplace-objc-classes
749 Used in Fix-and-Continue mode to indicate that object files may be swapped in at runtime
753 Enable automatic template instantiation
756 C++ ObjC++ Optimization
757 Generate run time type descriptor information
760 C ObjC C++ ObjC++ Optimization
761 Use the same size for double as for float
764 C ObjC C++ ObjC++ Optimization
765 Use the narrowest integer type possible for enumeration types
768 C ObjC C++ ObjC++ Optimization
769 Force the underlying type for \"wchar_t\" to be \"unsigned short\"
773 When \"signed\" or \"unsigned\" is not given make the bitfield signed
776 C ObjC C++ ObjC++ LTO
777 Make \"char\" signed by default
784 Display statistics accumulated during compilation
790 C ObjC C++ ObjC++ Joined RejectNegative UInteger
791 -ftabstop=<number> Distance between tab stops for column reporting
794 C++ ObjC++ Joined RejectNegative UInteger
795 -ftemplate-depth-<number> Specify maximum template instantiation depth
801 C++ ObjC++ Optimization
802 -fno-threadsafe-statics Do not generate thread-safe code for initializing local statics
806 When \"signed\" or \"unsigned\" is not given make the bitfield unsigned
809 C ObjC C++ ObjC++ LTO
810 Make \"char\" unsigned by default
814 Use __cxa_atexit to register destructors
816 fuse-cxa-get-exception-ptr
818 Use __cxa_get_exception_ptr in exception handling
820 fvisibility-inlines-hidden
822 Marks all inlined methods as having hidden visibility
824 fvisibility-ms-compat
825 C++ ObjC++ Var(flag_visibility_ms_compat)
826 Changes visibility to match Microsoft Visual Studio by default
830 Discard unused virtual functions
834 Implement vtables using thunks
838 Emit common-like symbols as weak symbols
841 C ObjC C++ ObjC++ Joined RejectNegative
842 -fwide-exec-charset=<cset> Convert all wide strings and character constants to character set <cset>
846 Generate a #line directive pointing at the current working directory
850 Emit cross referencing information
854 Generate lazy class lookup (via objc_getClass()) for use in Zero-Link mode
858 Dump declarations to a .decl file
860 femit-struct-debug-baseonly
862 -femit-struct-debug-baseonly Aggressive reduced debug info for structs
864 femit-struct-debug-reduced
866 -femit-struct-debug-reduced Conservative reduced debug info for structs
868 femit-struct-debug-detailed=
869 C ObjC C++ ObjC++ Joined
870 -femit-struct-debug-detailed=<spec-list> Detailed reduced debug info for structs
873 C ObjC C++ ObjC++ Joined Separate
874 -idirafter <dir> Add <dir> to the end of the system include path
877 C ObjC C++ ObjC++ Joined Separate
878 -imacros <file> Accept definition of macros in <file>
881 C ObjC C++ ObjC++ Joined Separate
882 -imultilib <dir> Set <dir> to be the multilib include subdirectory
885 C ObjC C++ ObjC++ Joined Separate
886 -include <file> Include the contents of <file> before other files
889 C ObjC C++ ObjC++ Joined Separate
890 -iprefix <path> Specify <path> as a prefix for next two options
893 C ObjC C++ ObjC++ Joined Separate
894 -isysroot <dir> Set <dir> to be the system root directory
897 C ObjC C++ ObjC++ Joined Separate
898 -isystem <dir> Add <dir> to the start of the system include path
901 C ObjC C++ ObjC++ Joined Separate
902 -iquote <dir> Add <dir> to the end of the quote include path
905 C ObjC C++ ObjC++ Joined Separate
906 -iwithprefix <dir> Add <dir> to the end of the system include path
909 C ObjC C++ ObjC++ Joined Separate
910 -iwithprefixbefore <dir> Add <dir> to the end of the main include path
916 C ObjC C++ ObjC++ Undocumented
920 Do not search standard system include directories (those specified with -isystem will still be used)
924 Do not search standard system include directories for C++
927 C ObjC C++ ObjC++ Joined Separate
928 ; Documented in common.opt
932 ; Documented in common.opt
936 ; Documented in common.opt
938 print-objc-runtime-info
940 Generate C header of platform-specific features
944 Print a checksum of the executable for PCH validity checking, and stop
948 Remap file names when including files
952 Conform to the ISO 1998 C++ standard
956 Conform to the ISO 1998 C++ standard, with extensions that are likely to
957 become a part of the upcoming ISO C++ standard, dubbed C++0x. Note that the
958 extensions enabled by this mode are experimental and may be removed in
959 future releases of GCC.
963 Conform to the ISO 1990 C standard
967 Conform to the ISO 1999 C standard
971 Deprecated in favor of -std=c99
975 Conform to the ISO 1998 C++ standard with GNU extensions
979 Conform to the ISO 1998 C++ standard, with GNU extensions and
980 extensions that are likely to become a part of the upcoming ISO C++
981 standard, dubbed C++0x. Note that the extensions enabled by this mode
982 are experimental and may be removed in future releases of GCC.
986 Conform to the ISO 1990 C standard with GNU extensions
990 Conform to the ISO 1999 C standard with GNU extensions
994 Deprecated in favor of -std=gnu99
998 Conform to the ISO 1990 C standard
1002 Conform to the ISO 1990 C standard as amended in 1994
1006 Conform to the ISO 1999 C standard
1010 Deprecated in favor of -std=iso9899:1999
1014 Enable traditional preprocessing
1018 -trigraphs Support ISO C trigraphs
1022 Do not predefine system-specific and GCC-specific macros
1025 Common C ObjC C++ ObjC++
1026 Enable verbose output
1030 ; Documented in common.opt
1032 ; This comment is to ensure we retain the blank line above.