1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003-2022 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 (options.texi) for a description of this file's format.
23 ; Please try to keep this file in ASCII collating order.
37 ; Not used directly to control optimizations, only to save -Ofast
38 ; setting for "optimize" attributes.
42 ; True if this is the lto front end. This is used to disable gimple
43 ; generation and lowering passes that are normally run on the output
44 ; of a front end. These passes must be bypassed for lto since they
45 ; have already been done before the gimple was written.
49 ; This variable is set to non-0 only by LTO front-end. 1 indicates that
50 ; the output produced will be used for incremental linking (thus weak symbols
51 ; can still be bound) and 2 indicates that the IL is going to be linked and
52 ; and output to LTO object file.
54 enum incremental_link flag_incremental_link = INCREMENTAL_LINK_NONE
56 ; 0 means straightforward implementation of complex divide acceptable.
57 ; 1 means wide ranges of inputs must work for complex divide.
58 ; 2 means C99-like requirements for complex multiply and divide.
60 int flag_complex_method = 1
63 int flag_default_complex_method = 1
65 ; Language specific warning pass for unused results.
67 bool flag_warn_unused_result = false
69 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
73 ; Nonzero if we should write GIMPLE bytecode for offload compilation.
75 int flag_generate_offload = 0
77 ; Nonzero means we should be saving declaration info into a .X file.
79 int flag_gen_aux_info = 0
81 ; Nonzero if we are compiling code for a shared library, zero for
86 ; These three are really VEC(char_p,heap) *.
89 void *flag_instrument_functions_exclude_functions
92 void *flag_instrument_functions_exclude_files
95 void *flag_ignored_attributes
97 ; Generic structs (e.g. templates not explicitly specialized)
98 ; may not have a compilation unit associated with them, and so
99 ; may need to be treated differently from ordinary structs.
101 ; Structs only handled by reference (indirectly), will also usually
102 ; not need as much debugging information.
105 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
108 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
110 ; True if we should exit after parsing options.
112 bool exit_after_options
114 ; Type(s) of debugging information we are producing (if any). See
115 ; flag-types.h for the definitions of the different possible types of
116 ; debugging information.
118 uint32_t write_symbols = NO_DEBUG
120 ; Level of debugging information we are producing. See flag-types.h
121 ; for the definitions of the different possible levels.
123 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
125 ; Level of CTF debugging information we are producing. See flag-types.h
126 ; for the definitions of the different possible levels.
128 enum ctf_debug_info_levels ctf_debug_info_level = CTFINFO_LEVEL_NONE
130 ; Original value of maximum field alignment in bytes, specified via
131 ; -fpack-struct=<value>.
133 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
135 ; Type of stack check.
137 enum stack_check_type flag_stack_check = NO_STACK_CHECK
139 ; True if stack usage information needs to be computed.
141 bool flag_stack_usage_info = false
143 ; -dA causes debug commentary information to be produced in
144 ; the generated assembly code (to make it more readable). This option
145 ; is generally only of use to those who actually need to read the
146 ; generated assembly code (perhaps while debugging the compiler itself).
147 ; Currently, this switch is only used by dwarf2out.cc; however, it is intended
148 ; to be a catchall for printing debug information in the assembler file.
152 ; Balance between GNAT encodings and standard DWARF to emit.
154 enum dwarf_gnat_encodings gnat_encodings = DWARF_GNAT_ENCODINGS_DEFAULT
156 ; -dP causes the rtl to be emitted as a comment in assembly.
158 int flag_dump_rtl_in_asm
160 ; Whether -da was passed (used only in handle_common_deferred_options).
162 bool flag_dump_all_passed
164 ; Other flags saying which kinds of debugging dump have been requested.
167 int rtl_dump_and_exit
170 int flag_print_asm_name
172 ; Name of top-level original source file (what was input to cpp).
173 ; This comes from the #-command at the beginning of the actual input.
174 ; If there isn't any there, then this is the cc1 input file name.
176 const char *main_input_filename
178 ; Pointer to base name in main_input_filename, with directories and a
179 ; single final extension removed, and the length of this base
183 const char *main_input_basename
186 int main_input_baselength
188 ; The base name used for auxiliary output files.
189 ; dump_base_name minus dump_base_ext.
192 const char *aux_base_name
194 ; Which options have been printed by --help.
198 ; Which enums have been printed by --help. 0 = not printed, no
199 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
202 char *help_enum_printed
204 ; The number of columns for --help output.
206 unsigned int help_columns
208 ; Whether this options structure has been through finish_options
210 bool flag_opts_finished
212 ; What the sanitizer should instrument
214 unsigned int flag_sanitize
216 ; What sanitizers should recover from errors
218 unsigned int flag_sanitize_recover = (SANITIZE_UNDEFINED | SANITIZE_UNDEFINED_NONDEFAULT | SANITIZE_KERNEL_ADDRESS | SANITIZE_KERNEL_HWADDRESS) & ~(SANITIZE_UNREACHABLE | SANITIZE_RETURN)
220 ; What sanitizers should use __builtin_trap () instead of runtime diagnostics
222 unsigned int flag_sanitize_trap
224 ; Flag whether a prefix has been added to dump_base_name
226 bool dump_base_name_prefixed = false
228 ; What subset of registers should be zeroed on function return
230 unsigned int flag_zero_call_used_regs
242 Common Driver Joined Undocumented
243 Provide bash completion for options starting with provided string.
246 Driver Alias(coverage)
252 Common Separate Alias(d)
255 Common Joined Alias(d)
258 Driver Common Separate Alias(dumpbase)
261 Driver Common Separate Alias(dumpbase-ext)
264 Driver Common Separate Alias(dumpdir)
267 Driver Separate Alias(e)
270 Driver Joined Alias(e)
273 Common Warning Alias(Wextra)
276 Driver Separate Alias(Xassembler)
279 Driver JoinedOrMissing Alias(Xassembler)
282 Driver Separate Alias(Xlinker)
285 Driver JoinedOrMissing Alias(Xlinker)
288 Driver Separate Alias(u)
291 Driver Joined Alias(u)
294 Common Driver Var(help_flag)
295 Display this information.
299 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params.
302 Driver Separate Alias(x)
305 Driver Joined Alias(x)
308 Driver Separate Alias(L)
311 Driver Joined Alias(L)
313 -no-canonical-prefixes
314 Driver Alias(no-canonical-prefixes)
316 -no-standard-libraries
317 Driver Alias(nostdlib)
320 Driver Var(no_sysroot_suffix)
329 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
332 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
335 Driver Alias(pass-exit-codes)
338 Common Alias(Wpedantic)
341 Common Alias(pedantic-errors)
347 Driver Alias(static-pie)
353 Driver Separate Alias(B)
356 Driver JoinedOrMissing Alias(B)
362 Driver Separate Alias(print-file-name=)
365 Driver JoinedOrMissing Alias(print-file-name=)
367 -print-libgcc-file-name
368 Driver Alias(print-libgcc-file-name)
370 -print-multi-directory
371 Driver Alias(print-multi-directory)
374 Driver Alias(print-multi-lib)
376 -print-multi-os-directory
377 Driver Alias(print-multi-os-directory)
380 Driver Alias(print-multiarch)
383 Driver Separate Alias(print-prog-name=)
386 Driver JoinedOrMissing Alias(print-prog-name=)
389 Driver Alias(print-search-dirs)
392 Driver Alias(print-sysroot)
394 -print-sysroot-headers-suffix
395 Driver Alias(print-sysroot-headers-suffix)
401 Driver Alias(save-temps)
407 Driver Separate Alias(specs=)
410 Driver Joined Alias(specs=)
416 Driver Alias(symbolic)
420 Display target specific command line options (including assembler and linker options).
428 ;; The driver used to convert options such as --help into forms such
429 ;; as -fhelp; the following four entries are for compatibility with
430 ;; any direct uses of those (undocumented) -f forms
432 Common Driver Alias(-help)
435 Common Driver Joined Alias(-help=)
438 Common Driver Alias(-target-help)
441 Common Driver Alias(-version)
444 Driver Separate Alias(-sysroot=)
447 Driver JoinedOrMissing
453 Driver Joined Separate
459 Driver Joined Separate
465 Common JoinedOrMissing Optimization
466 -O<number> Set optimization level to <number>.
470 Optimize for space rather than speed.
474 Optimize for speed disregarding exact standards compliance.
478 Optimize for debugging experience rather than speed or size.
482 Optimize for space aggressively rather than speed.
494 Driver Joined Separate
500 Driver Joined Separate
521 Common RejectNegative Warning Alias(Wextra)
522 This switch is deprecated; use -Wextra instead.
525 Driver JoinedOrMissing RejectNegative
528 Driver JoinedOrMissing RejectNegative
531 Driver JoinedOrMissing RejectNegative
534 Common Var(warn_aggregate_return) Warning
535 Warn about returning structures, unions or arrays.
537 Waggressive-loop-optimizations
538 Common Var(warn_aggressive_loop_optimizations) Init(1) Warning
539 Warn if a loop with constant number of iterations triggers undefined behavior.
542 Common Alias(Warray-bounds=, 1, 0) Warning
545 Common Joined RejectNegative UInteger Var(warn_array_bounds) Warning IntegerRange(0, 2)
546 Warn if an array is accessed out of bounds.
549 Common Var(warn_use_after_free) Warning
550 Warn for uses of pointers to deallocated storage.
553 Common Joined RejectNegative UInteger Var(warn_use_after_free) Warning IntegerRange(0, 3)
554 Warn for uses of pointers to deallocated storage.
557 Common Var(warn_attributes) Init(1) Warning
558 Warn about inappropriate attribute usage.
562 Do not warn about specified attributes.
565 Common Alias(Wattribute_alias=, 1, 0) Warning
566 Warn about type safety and similar errors and mismatches in declarations with alias attributes.
569 Common Joined RejectNegative UInteger Var(warn_attribute_alias) Init(1) Warning IntegerRange(0, 2)
570 Warn about type safety and similar errors and mismatches in declarations with alias attributes.
573 Common Var(warn_cannot_profile) Init(1) Warning
574 Warn when profiling instrumentation was requested, but could not be applied to
578 Common Var(warn_cast_align) Warning
579 Warn about pointer casts which increase alignment.
582 Common Var(warn_cast_align,2) Warning
583 Warn about pointer casts which increase alignment.
586 Common Var(warn_cpp) Init(1) Warning
587 Warn when a #warning directive is encountered.
590 Common Var(warn_attribute_warning) Init(1) Warning
591 Warn about uses of __attribute__((warning)) declarations.
594 Common Var(warn_deprecated) Init(1) Warning
595 Warn if a deprecated compiler feature, class, method, or field is used.
597 Wdeprecated-declarations
598 Common Var(warn_deprecated_decl) Init(1) Warning
599 Warn about uses of __attribute__((deprecated)) declarations.
601 Wdisabled-optimization
602 Common Var(warn_disabled_optimization) Warning
603 Warn when an optimization pass is disabled.
606 Common Var(warnings_are_errors)
607 Treat all warnings as errors.
611 Treat specified warning as error.
614 Common Var(extra_warnings) Warning
615 Print extra (possibly unwanted) warnings.
618 Common Var(flag_fatal_errors)
619 Exit on the first error occurred.
622 Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_frame_larger_than_size) Init(HOST_WIDE_INT_MAX)
623 -Wframe-larger-than=<byte-size> Warn if a function's stack frame requires in excess of <byte-size>.
625 Wno-frame-larger-than
626 Common Alias(Wframe-larger-than=,18446744073709551615EiB,none) Warning
627 Disable -Wframe-larger-than= warning. Equivalent to -Wframe-larger-than=<SIZE_MAX> or larger.
630 Common Var(warn_free_nonheap_object) Init(1) Warning
631 Warn when attempting to free a non-heap object.
634 Common Ignore Warning
635 Does nothing. Preserved for backward compatibility.
637 Wimplicit-fallthrough
638 Common Alias(Wimplicit-fallthrough=,3,0) Warning
640 Wimplicit-fallthrough=
641 Common Var(warn_implicit_fallthrough) RejectNegative Joined UInteger Warning IntegerRange(0, 5)
642 Warn when a switch case falls through.
645 Var(warn_infinite_recursion) Warning
646 Warn for infinitely recursive calls.
649 Common Var(warn_inline) Warning Optimization
650 Warn when an inlined function cannot be inlined.
652 Winvalid-memory-model
653 Common Var(warn_invalid_memory_model) Init(1) Warning
654 Warn when an atomic memory model parameter is known to be outside the valid range.
657 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
660 Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_larger_than_size) Init(HOST_WIDE_INT_MAX)
661 -Wlarger-than=<byte-size> Warn if an object's size exceeds <byte-size>.
664 Common Alias(Wlarger-than=,18446744073709551615EiB,none) Warning
665 Disable -Wlarger-than= warning. Equivalent to -Wlarger-than=<SIZE_MAX> or larger.
668 Var(warn_nonnull_compare) Warning
669 Warn if comparing pointer parameter with nonnull attribute with NULL.
672 Common Var(warn_null_dereference) Warning
673 Warn if dereferencing a NULL pointer may lead to erroneous or undefined behavior.
675 Wunsafe-loop-optimizations
676 Common Ignore Warning
677 Does nothing. Preserved for backward compatibility.
680 Common Warning Alias(Wsuggest-attribute=noreturn)
683 Common Var(warn_odr_violations) Init(1) Warning
684 Warn about some C++ One Definition Rule violations during link time optimization.
687 Common Var(warn_overflow) Init(1) Warning
688 Warn about overflow in arithmetic expressions.
691 Common Var(warn_lto_type_mismatch) Init(1) Warning
692 During link time optimization warn about mismatched types of global declarations.
695 Common Var(warn_packed) Warning
696 Warn when the packed attribute has no effect on struct layout.
699 Common Var(warn_padded) Warning
700 Warn when padding is required to align structure members.
703 Common Var(pedantic) Init(0) Warning
704 Issue warnings needed for strict compliance to the standard.
707 Common Var(warn_return_local_addr) Init(1) Warning
708 Warn about returning a pointer/reference to a local or temporary variable.
711 Common Var(warn_shadow) Warning
712 Warn when one variable shadows another. Same as -Wshadow=global.
715 Common Warning Alias(Wshadow)
716 Warn when one variable shadows another (globally).
719 Common Var(warn_shadow_local) Warning EnabledBy(Wshadow)
720 Warn when one local variable shadows another local variable or parameter.
723 Common Warning Undocumented Alias(Wshadow=local)
725 Wshadow=compatible-local
726 Common Var(warn_shadow_compatible_local) Warning EnabledBy(Wshadow=local)
727 Warn when one local variable shadows another local variable or parameter of compatible type.
729 Wshadow-compatible-local
730 Common Warning Undocumented Alias(Wshadow=compatible-local)
733 Common Var(warn_stack_protect) Warning
734 Warn when not issuing stack smashing protection for some reason.
737 Common Joined RejectNegative Host_Wide_Int ByteSize Var(warn_stack_usage) Warning Init(HOST_WIDE_INT_MAX)
738 -Wstack-usage=<byte-size> Warn if stack usage might exceed <byte-size>.
741 Common Alias(Wstack-usage=,18446744073709551615EiB,none) Warning
742 Disable Wstack-usage= warning. Equivalent to Wstack-usage=<SIZE_MAX> or larger.
746 Warn about code which might break strict aliasing rules.
749 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
750 Warn about code which might break strict aliasing rules.
754 Warn about optimizations that assume that signed overflow is undefined.
757 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
758 Warn about optimizations that assume that signed overflow is undefined.
760 Wsuggest-attribute=cold
761 Common Var(warn_suggest_attribute_cold) Warning
762 Warn about functions which might be candidates for __attribute__((cold)).
764 Wsuggest-attribute=const
765 Common Var(warn_suggest_attribute_const) Warning
766 Warn about functions which might be candidates for __attribute__((const)).
768 Wsuggest-attribute=pure
769 Common Var(warn_suggest_attribute_pure) Warning
770 Warn about functions which might be candidates for __attribute__((pure)).
772 Wsuggest-attribute=noreturn
773 Common Var(warn_suggest_attribute_noreturn) Warning
774 Warn about functions which might be candidates for __attribute__((noreturn)).
776 Wsuggest-attribute=malloc
777 Common Var(warn_suggest_attribute_malloc) Warning
778 Warn about functions which might be candidates for __attribute__((malloc)).
781 Common Var(warn_suggest_final_types) Warning
782 Warn about C++ polymorphic types where adding final keyword would improve code quality.
784 Wsuggest-final-methods
785 Common Var(warn_suggest_final_methods) Warning
786 Warn about C++ virtual methods where adding final keyword would improve code quality.
789 Common Var(warn_switch_unreachable) Warning Init(1)
790 Warn about statements between switch's controlling expression and the first
794 Common Var(warn_system_headers) Warning
795 Do not suppress warnings from system headers.
798 Common Var(warn_trampolines) Warning
799 Warn whenever a trampoline is generated.
801 Wtrivial-auto-var-init
802 Common Var(warn_trivial_auto_var_init) Warning Init(0)
803 Warn about cases where -ftrivial-auto-var-init cannot initialize an auto variable.
806 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
807 Warn if a comparison is always true or always false due to the limited range of the data type.
810 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
811 Warn about uninitialized automatic variables.
814 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
815 Warn about maybe uninitialized automatic variables.
818 Common Ignore Warning
819 Does nothing. Preserved for backward compatibility.
822 Common Var(warn_unused) Init(0) Warning
823 Enable all -Wunused- warnings.
825 Wunused-but-set-parameter
826 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
827 Warn when a function parameter is only set, otherwise unused.
829 Wunused-but-set-variable
830 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
831 Warn when a variable is only set, otherwise unused.
834 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
835 Warn when a function is unused.
838 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
839 Warn when a label is unused.
842 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
843 Warn when a function parameter is unused.
846 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
847 Warn when an expression value is unused.
850 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
851 Warn when a variable is unused.
854 Common Var(warn_coverage_mismatch) Init(1) Warning
855 Warn in case profiles in -fprofile-use do not match.
857 Wcoverage-invalid-line-number
858 Common Var(warn_coverage_invalid_linenum) Init(1) Warning
859 Warn in case a function ends earlier than it begins due to an invalid linenum macros.
862 Common Var(warn_missing_profile) Init(1) Warning
863 Warn in case profiles in -fprofile-use do not exist.
865 Wvector-operation-performance
866 Common Var(warn_vector_operation_performance) Warning
867 Warn when a vector operation is compiled outside the SIMD.
870 Common Var(warn_tsan) Init(1) Warning
871 Warn about unsupported features in ThreadSanitizer.
886 Common Separate Var(aux_info_file_name)
887 -aux-info <file> Emit declaration information into <file>.
890 Common Joined Alias(aux-info)
900 -d<letters> Enable dumps from specific passes of the compiler.
903 Driver Common Separate Var(dump_base_name)
904 -dumpbase <file> Set the file basename to be used for dumps.
907 Driver Common Separate Var(dump_base_ext)
908 -dumpbase-ext .<ext> Drop a trailing .<ext> from the dump basename to name auxiliary output files.
911 Driver Common Separate Var(dump_dir_name)
912 -dumpdir <dir> Set the directory name to be used for dumps.
927 Driver Joined Separate
929 ; This option has historically been passed down to the linker by an
930 ; accident of a %{e*} spec, so ensure it continues to be passed down
931 ; as a single option. The supported option for this purpose is
932 ; -rdynamic. See PR 47390.
936 ; The version of the C++ ABI in use. The following values are allowed:
938 ; 0: The version of the ABI believed most conformant with the C++ ABI
939 ; specification. This ABI may change as bugs are discovered and fixed.
940 ; Therefore, 0 will not necessarily indicate the same ABI in different
943 ; 1: The version of the ABI first used in G++ 3.2. No longer selectable.
945 ; 2: The version of the ABI first used in G++ 3.4, and the default
948 ; 3: The version of the ABI that fixes the missing underscore
949 ; in template non-type arguments of pointer type.
951 ; 4: The version of the ABI that introduces unambiguous mangling of
952 ; vector types. First selectable in G++ 4.5.
954 ; 5: The version of the ABI that ignores attribute const/noreturn
955 ; in function pointer mangling, and corrects mangling of decltype and
956 ; function parameters used in other parameters and the return type.
957 ; First selectable in G++ 4.6.
959 ; 6: The version of the ABI that doesn't promote scoped enums to int and
960 ; changes the mangling of template argument packs, const/static_cast,
961 ; prefix ++ and --, and a class scope function used as a template
963 ; First selectable in G++ 4.7.
965 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
966 ; corrects the mangling of lambdas in default argument scope.
967 ; First selectable in G++ 4.8.
969 ; 8: The version of the ABI that corrects the substitution behavior of
970 ; function types with function-cv-qualifiers.
971 ; First selectable in G++ 4.9 and default in G++ 5.
973 ; 9: The version of the ABI that corrects the alignment of nullptr_t.
974 ; First selectable and default in G++ 5.2.
976 ; 10: The version of the ABI that mangles attributes that affect type
977 ; identity, such as ia32 calling convention attributes (stdcall, etc.)
978 ; Default in G++ 6 (set in c_common_post_options).
980 ; 11: The version of the ABI that corrects mangling of sizeof... expressions
981 ; and introduces new inheriting constructor handling.
984 ; 12: Corrects the calling convention for classes with only deleted copy/move
985 ; constructors and changes passing/returning of empty records.
986 ; Default in G++ 8.1.
988 ; 13: Fixes the accidental change in 12 to the calling convention for classes
989 ; with deleted copy constructor and trivial move constructor.
990 ; Default in G++ 8.2.
992 ; 14: Corrects the mangling of nullptr expression.
995 ; 15: Corrects G++ 10 ABI tag regression [PR98481].
996 ; Available, but not default, in G++ 10.3.
998 ; 16: Changes the mangling of __alignof__ to be distinct from that of alignof.
999 ; Adds missing 'on' in mangling of operator names in some cases.
1000 ; Default in G++ 11.
1002 ; 17: Fixes layout of classes that inherit from aggregate classes with default
1003 ; member initializers in C++14 and up.
1004 ; Default in G++ 12.
1006 ; 18: Corrects errors in mangling of lambdas with additional context.
1007 ; Default in G++ 13.
1009 ; Additional positive integers will be assigned as new versions of
1010 ; the ABI become the default version of the ABI.
1012 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
1013 The version of the C++ ABI in use.
1015 faggressive-loop-optimizations
1016 Common Var(flag_aggressive_loop_optimizations) Optimization Init(1)
1017 Aggressively optimize loops using language constraints.
1020 Common Var(flag_align_functions) Optimization
1021 Align the start of functions.
1024 Common RejectNegative Joined Var(str_align_functions) Optimization
1026 flimit-function-alignment
1027 Common Var(flag_limit_function_alignment) Optimization Init(0)
1030 Common Var(flag_align_jumps) Optimization
1031 Align labels which are only reached by jumping.
1034 Common RejectNegative Joined Var(str_align_jumps) Optimization
1037 Common Var(flag_align_labels) Optimization
1041 Common RejectNegative Joined Var(str_align_labels) Optimization
1044 Common Var(flag_align_loops) Optimization
1045 Align the start of loops.
1048 Common RejectNegative Joined Var(str_align_loops) Optimization
1050 fallow-store-data-races
1051 Common Var(flag_store_data_races) Optimization
1052 Allow the compiler to introduce new data races on stores.
1055 Common Var(flag_analyzer)
1056 Enable static analysis pass.
1060 Does nothing. Preserved for backward compatibility.
1064 Does nothing. Preserved for backward compatibility.
1066 fargument-noalias-global
1068 Does nothing. Preserved for backward compatibility.
1070 fargument-noalias-anything
1072 Does nothing. Preserved for backward compatibility.
1075 Common Driver Joined
1076 Select what to sanitize.
1079 Common Joined Enum(sanitize_coverage) Var(flag_sanitize_coverage) EnumBitSet
1080 Select type of coverage sanitization.
1083 Name(sanitize_coverage) Type(int)
1086 Enum(sanitize_coverage) String(trace-pc) Value(SANITIZE_COV_TRACE_PC)
1089 Enum(sanitize_coverage) String(trace-cmp) Value(SANITIZE_COV_TRACE_CMP)
1091 fasan-shadow-offset=
1092 Common Joined RejectNegative Var(common_deferred_options) Defer
1093 -fasan-shadow-offset=<number> Use custom shadow memory offset.
1096 Common Joined RejectNegative Var(common_deferred_options) Defer
1097 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
1098 in user-defined sections.
1102 After diagnosing undefined behavior attempt to continue execution.
1106 This switch is deprecated; use -fsanitize-recover= instead.
1109 Common Driver Joined
1110 Use traps instead of diagnostics of undefined behavior sanitizers.
1115 fsanitize-address-use-after-scope
1116 Common Driver Var(flag_sanitize_address_use_after_scope) Init(0)
1118 fsanitize-undefined-trap-on-error
1119 Common Driver Alias(fsanitize-trap)
1120 This switch is deprecated; use -fsanitize-trap= instead.
1122 fasynchronous-unwind-tables
1123 Common Var(flag_asynchronous_unwind_tables) Optimization
1124 Generate unwind tables that are exact at each instruction boundary.
1127 Common Var(flag_auto_inc_dec) Init(1) Optimization
1128 Generate auto-inc/dec instructions.
1131 Common Var(flag_auto_profile)
1132 Use sample profile information for call graph node weights. The default
1133 profile file is fbdata.afdo in 'pwd'.
1136 Common Joined RejectNegative Var(auto_profile_file)
1137 Use sample profile information for call graph node weights. The profile
1138 file is specified in the argument.
1140 ; -fcheck-bounds causes gcc to generate array bounds checks.
1141 ; For C, C++ and ObjC: defaults off.
1142 ; For Java: defaults to on.
1143 ; For Fortran: defaults to off.
1145 Common Var(flag_bounds_check)
1146 Generate code to check bounds before indexing arrays.
1149 Common Var(flag_branch_on_count_reg) Optimization
1150 Replace add, compare, branch with branch on count register.
1152 fbranch-probabilities
1153 Common Var(flag_branch_probabilities) Optimization
1154 Use profiling information for branch probabilities.
1156 fbranch-target-load-optimize
1158 Does nothing. Preserved for backward compatibility.
1160 fbranch-target-load-optimize2
1162 Does nothing. Preserved for backward compatibility.
1166 Does nothing. Preserved for backward compatibility.
1169 Common RejectNegative Var(flag_callgraph_info) Init(NO_CALLGRAPH_INFO);
1170 Output callgraph information on a per-file basis.
1173 Common RejectNegative Joined
1174 Output callgraph information on a per-file basis with decorations.
1177 Common Joined RejectNegative Var(common_deferred_options) Defer
1178 -fcall-saved-<register> Mark <register> as being preserved across functions.
1181 Common Joined RejectNegative Var(common_deferred_options) Defer
1182 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1184 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1185 ; be saved across function calls, if that produces overall better code.
1186 ; Optional now, so people can test it.
1188 Common Var(flag_caller_saves) Optimization
1189 Save registers around function calls.
1193 This switch is deprecated; do not use.
1196 Common Var(flag_check_new)
1197 Check the return value of new in C++.
1200 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1201 Perform internal consistency checkings.
1204 Common Joined RejectNegative UInteger Var(flag_checking)
1205 Perform internal consistency checkings.
1208 Common Var(flag_code_hoisting) Optimization
1209 Enable code hoisting.
1211 fcombine-stack-adjustments
1212 Common Var(flag_combine_stack_adjustments) Optimization
1213 Looks for opportunities to reduce stack adjustments and stack references.
1216 Common Var(flag_no_common,0) Init(1)
1217 Put uninitialized globals in the common section.
1221 ; Converted by the driver to -fcompare-debug= options.
1224 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1225 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1227 fcompare-debug-second
1228 Common Driver RejectNegative Var(flag_compare_debug)
1229 Run only the second compilation of -fcompare-debug.
1232 Common Var(flag_compare_elim_after_reload) Optimization
1233 Perform comparison elimination after register allocation has finished.
1236 Common Var(flag_conserve_stack) Optimization
1237 Do not perform optimizations increasing noticeably stack usage.
1240 Common Var(flag_cprop_registers) Optimization
1241 Perform a register copy-propagation optimization pass.
1244 Common Var(flag_crossjumping) Optimization
1245 Perform cross-jumping optimization.
1248 Common Var(flag_cse_follow_jumps) Optimization
1249 When running CSE, follow jumps to their targets.
1253 Does nothing. Preserved for backward compatibility.
1256 Common Var(flag_cx_limited_range) Optimization SetByCombined
1257 Omit range reduction step when performing complex division.
1260 Common Var(flag_cx_fortran_rules) Optimization
1261 Complex multiplication and division follow Fortran rules.
1264 Common Var(flag_data_sections)
1265 Place data items into their own section.
1268 Common Var(flag_dbg_cnt_list)
1269 List all available debugging counters with their limits and counts.
1272 Common RejectNegative Joined Var(common_deferred_options) Defer
1273 -fdbg-cnt=<counter>[:<lower_limit1>-]<upper_limit1>[:<lower_limit2>-<upper_limit2>:...][,<counter>:...] Set the debug counter limit.
1276 Common Joined RejectNegative Var(common_deferred_options) Defer
1277 -fdebug-prefix-map=<old>=<new> Map one directory name to another in debug information.
1280 Common Joined RejectNegative Var(common_deferred_options) Defer
1281 -ffile-prefix-map=<old>=<new> Map one directory name to another in compilation result.
1283 fdebug-types-section
1284 Common Var(flag_debug_types_section) Init(0)
1285 Output .debug_types section when using DWARF v4 debuginfo.
1287 ; Nonzero for -fdefer-pop: don't pop args after each function call
1288 ; instead save them up to pop many calls' args with one insns.
1290 Common Var(flag_defer_pop) Optimization
1291 Defer popping functions args from stack until later.
1294 Common Var(flag_delayed_branch) Optimization
1295 Attempt to fill delay slots of branch instructions.
1297 fdelete-dead-exceptions
1298 Common Var(flag_delete_dead_exceptions) Init(0) Optimization
1299 Delete dead instructions that may throw exceptions.
1301 fdelete-null-pointer-checks
1302 Common Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1303 Delete useless null pointer checks.
1305 fdevirtualize-at-ltrans
1306 Common Var(flag_ltrans_devirtualize)
1307 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1309 fdevirtualize-speculatively
1310 Common Var(flag_devirtualize_speculatively) Optimization
1311 Perform speculative devirtualization.
1314 Common Var(flag_devirtualize) Optimization
1315 Try to convert virtual calls to direct ones.
1317 fdiagnostics-show-location=
1318 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1319 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1321 ; Required for these enum values.
1326 Name(diagnostic_prefixing_rule) Type(int)
1329 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1332 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1334 fdiagnostics-show-caret
1335 Common Var(flag_diagnostics_show_caret) Init(1)
1336 Show the source line with a caret indicating the column.
1338 fdiagnostics-show-labels
1339 Common Var(flag_diagnostics_show_labels) Init(1)
1340 Show labels annotating ranges of source code when showing source.
1342 fdiagnostics-show-line-numbers
1343 Common Var(flag_diagnostics_show_line_numbers) Init(1)
1344 Show line numbers in the left margin when showing source.
1347 Common Alias(fdiagnostics-color=,always,never)
1351 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1352 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1354 ; Required for these enum values.
1359 Name(diagnostic_color_rule) Type(int)
1362 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1365 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1368 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1371 Driver Common Joined RejectNegative Var(flag_diagnostics_show_urls) Enum(diagnostic_url_rule) Init(DIAGNOSTICS_URL_AUTO)
1372 -fdiagnostics-urls=[never|always|auto] Embed URLs in diagnostics.
1374 ; Required for these enum values.
1379 Name(diagnostic_url_rule) Type(int)
1382 Enum(diagnostic_url_rule) String(never) Value(DIAGNOSTICS_URL_NO)
1385 Enum(diagnostic_url_rule) String(always) Value(DIAGNOSTICS_URL_YES)
1388 Enum(diagnostic_url_rule) String(auto) Value(DIAGNOSTICS_URL_AUTO)
1390 fdiagnostics-column-unit=
1391 Common Joined RejectNegative Enum(diagnostics_column_unit)
1392 -fdiagnostics-column-unit=[display|byte] Select whether column numbers are output as display columns (default) or raw bytes.
1394 fdiagnostics-column-origin=
1395 Common Joined RejectNegative UInteger
1396 -fdiagnostics-column-origin=<number> Set the number of the first column. The default is 1-based as per GNU style, but some utilities may expect 0-based, for example.
1398 fdiagnostics-format=
1399 Common Joined RejectNegative Enum(diagnostics_output_format)
1400 -fdiagnostics-format=[text|sarif-stderr|sarif-file|json|json-stderr|json-file] Select output format.
1402 fdiagnostics-escape-format=
1403 Common Joined RejectNegative Enum(diagnostics_escape_format)
1404 -fdiagnostics-escape-format=[unicode|bytes] Select how to escape non-printable-ASCII bytes in the source for diagnostics that suggest it.
1406 ; Required for these enum values.
1411 Name(diagnostics_column_unit) Type(int)
1414 Enum(diagnostics_column_unit) String(display) Value(DIAGNOSTICS_COLUMN_UNIT_DISPLAY)
1417 Enum(diagnostics_column_unit) String(byte) Value(DIAGNOSTICS_COLUMN_UNIT_BYTE)
1420 Name(diagnostics_escape_format) Type(int)
1423 Enum(diagnostics_escape_format) String(unicode) Value(DIAGNOSTICS_ESCAPE_FORMAT_UNICODE)
1426 Enum(diagnostics_escape_format) String(bytes) Value(DIAGNOSTICS_ESCAPE_FORMAT_BYTES)
1429 Name(diagnostics_output_format) Type(int)
1432 Enum(diagnostics_output_format) String(text) Value(DIAGNOSTICS_OUTPUT_FORMAT_TEXT)
1435 Enum(diagnostics_output_format) String(json) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_STDERR)
1438 Enum(diagnostics_output_format) String(json-stderr) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_STDERR)
1441 Enum(diagnostics_output_format) String(json-file) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON_FILE)
1444 Enum(diagnostics_output_format) String(sarif-stderr) Value(DIAGNOSTICS_OUTPUT_FORMAT_SARIF_STDERR)
1447 Enum(diagnostics_output_format) String(sarif-file) Value(DIAGNOSTICS_OUTPUT_FORMAT_SARIF_FILE)
1449 fdiagnostics-parseable-fixits
1450 Common Var(flag_diagnostics_parseable_fixits)
1451 Print fix-it hints in machine-readable form.
1453 fdiagnostics-generate-patch
1454 Common Var(flag_diagnostics_generate_patch)
1455 Print fix-it hints to stderr in unified diff format.
1457 fdiagnostics-show-option
1458 Common Var(flag_diagnostics_show_option) Init(1)
1459 Amend appropriate diagnostic messages with the command line option that controls them.
1461 fdiagnostics-show-cwe
1462 Common Var(flag_diagnostics_show_cwe) Init(1)
1463 Print CWE identifiers for diagnostic messages, where available.
1465 fdiagnostics-show-rules
1466 Common Var(flag_diagnostics_show_rules) Init(1)
1467 Print any rules associated with diagnostic messages.
1469 fdiagnostics-path-format=
1470 Common Joined RejectNegative Var(flag_diagnostics_path_format) Enum(diagnostic_path_format) Init(DPF_INLINE_EVENTS)
1471 Specify how to print any control-flow path associated with a diagnostic.
1473 fdiagnostics-plain-output
1474 Driver Common RejectNegative
1475 Turn off any diagnostics features that complicate the output, such as line numbers, color, and warning URLs.
1478 Common Joined RejectNegative UInteger
1479 -ftabstop=<number> Distance between tab stops for column reporting.
1482 Name(diagnostic_path_format) Type(int)
1485 Enum(diagnostic_path_format) String(none) Value(DPF_NONE)
1488 Enum(diagnostic_path_format) String(separate-events) Value(DPF_SEPARATE_EVENTS)
1491 Enum(diagnostic_path_format) String(inline-events) Value(DPF_INLINE_EVENTS)
1493 fdiagnostics-show-path-depths
1494 Common Var(flag_diagnostics_show_path_depths) Init(0)
1495 Show stack depths of events in paths.
1497 fdiagnostics-minimum-margin-width=
1498 Common Joined UInteger Var(diagnostics_minimum_margin_width) Init(6)
1499 Set minimum width of left margin of source code when showing source.
1502 Common Joined RejectNegative Var(common_deferred_options) Defer
1503 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 Disable an optimization pass.
1506 Common Joined RejectNegative Var(common_deferred_options) Defer
1507 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 Enable an optimization pass.
1510 Common Joined RejectNegative Var(common_deferred_options) Defer
1511 -fdump-<type> Dump various compiler internals to a file.
1514 Driver RejectNegative
1517 Common RejectNegative Joined Var(flag_dump_final_insns)
1518 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1521 Common RejectNegative Joined Var(flag_dump_go_spec)
1522 -fdump-go-spec=filename Write all declarations to file as Go code.
1525 Common Var(flag_dump_noaddr)
1526 Suppress output of addresses in debugging dumps.
1529 Common Driver Var(flag_report_bug)
1530 Collect and dump debug information into temporary file if ICE in C/C++
1533 fdump-internal-locations
1534 Common Var(flag_dump_locations) Init(0)
1535 Dump detailed information on GCC's internal representation of source code locations.
1538 Common Var(flag_dump_passes) Init(0)
1539 Dump optimization passes.
1542 Common Var(flag_dump_unnumbered)
1543 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1545 fdump-unnumbered-links
1546 Common Var(flag_dump_unnumbered_links)
1547 Suppress output of previous and next insn numbers in debugging dumps.
1550 Common Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1551 Enable CFI tables via GAS assembler directives.
1554 Common Var(flag_early_inlining) Init(1) Optimization
1555 Perform early inlining.
1557 feliminate-dwarf2-dups
1559 Does nothing. Preserved for backward compatibility.
1562 Common Var(flag_ipa_sra) Init(0) Optimization
1563 Perform interprocedural reduction of aggregates.
1565 feliminate-unused-debug-symbols
1566 Common Var(flag_debug_only_used_symbols) Init(1)
1567 Perform unused symbol elimination in debug info.
1569 feliminate-unused-debug-types
1570 Common Var(flag_eliminate_unused_debug_types) Init(1)
1571 Perform unused type elimination in debug info.
1573 femit-class-debug-always
1574 Common Var(flag_emit_class_debug_always) Init(0)
1575 Do not suppress C++ class debug information.
1578 Common Var(flag_exceptions) Optimization EnabledBy(fnon-call-exceptions)
1579 Enable exception handling.
1581 fexpensive-optimizations
1582 Common Var(flag_expensive_optimizations) Optimization
1583 Perform a number of minor, expensive optimizations.
1586 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision) Init(EXCESS_PRECISION_DEFAULT) Optimization SetByCombined
1587 -fexcess-precision=[fast|standard|16] Specify handling of excess floating-point precision.
1590 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1593 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1596 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1599 Enum(excess_precision) String(16) Value(EXCESS_PRECISION_FLOAT16)
1601 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1602 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1603 fpermitted-flt-eval-methods=
1604 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1605 -fpermitted-flt-eval-methods=[c11|ts-18661] Specify which values of FLT_EVAL_METHOD are permitted.
1608 Name(permitted_flt_eval_methods) Type(enum permitted_flt_eval_methods) UnknownError(unknown specification for the set of FLT_EVAL_METHOD values to permit %qs)
1611 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1614 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1620 Common Var(flag_fat_lto_objects)
1621 Output lto objects containing both the intermediate language and binary output.
1624 Common Var(flag_finite_math_only) Optimization SetByCombined
1625 Assume no NaNs or infinities are generated.
1628 Common Var(flag_finite_loops) Optimization Init(0)
1629 Assume that loops with an exit will terminate and not loop indefinitely.
1632 Common Joined RejectNegative Var(common_deferred_options) Defer
1633 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1636 Common Var(flag_float_store) Optimization
1637 Don't allocate floats and doubles in extended-precision registers.
1641 Does nothing. Preserved for backward compatibility.
1644 Common Var(flag_forward_propagate) Optimization
1645 Perform a forward propagation pass on RTL.
1648 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1649 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1652 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1655 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1657 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1659 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1662 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1664 ffp-int-builtin-inexact
1665 Common Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1666 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1668 ; Nonzero means don't put addresses of constant functions in registers.
1669 ; Used for compiling the Unix kernel, where strange substitutions are
1670 ; done on the assembly output.
1672 Common Var(flag_no_function_cse,0) Optimization
1673 Allow function addresses to be held in registers.
1676 Common Var(flag_function_sections)
1677 Place each function into its own section.
1680 Common Var(flag_gcse) Optimization
1681 Perform global common subexpression elimination.
1684 Common Var(flag_gcse_lm) Init(1) Optimization
1685 Perform enhanced load motion during global common subexpression elimination.
1688 Common Var(flag_gcse_sm) Init(0) Optimization
1689 Perform store motion after global common subexpression elimination.
1692 Common Var(flag_gcse_las) Init(0) Optimization
1693 Perform redundant load after store elimination in global common subexpression
1697 Common Var(flag_gcse_after_reload) Optimization
1698 Perform global common subexpression elimination after register allocation has
1702 Name(dwarf_gnat_encodings) Type(int)
1705 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1708 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1711 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1714 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Undocumented Var(gnat_encodings)
1715 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information.
1717 ; This option is not documented yet as its semantics will change.
1719 Common Var(flag_graphite) Optimization
1720 Enable in and out of Graphite representation.
1723 Common Var(flag_graphite_identity) Optimization
1724 Enable Graphite Identity transformation.
1726 fhoist-adjacent-loads
1727 Common Var(flag_hoist_adjacent_loads) Optimization
1728 Enable hoisting adjacent loads to encourage generating conditional move
1732 Common Undocumented Var(flag_keep_gc_roots_live) Optimization
1733 ; Always keep a pointer to a live memory block
1736 Common Var(flag_large_source_files) Init(0)
1737 Improve GCC's ability to track column numbers in large source files,
1738 at the expense of slower compilation.
1740 floop-parallelize-all
1741 Common Var(flag_loop_parallelize_all) Optimization
1742 Mark all loops as parallel.
1745 Common Alias(floop-nest-optimize)
1746 Enable loop nest transforms. Same as -floop-nest-optimize.
1749 Common Var(flag_loop_interchange) Optimization
1750 Enable loop interchange on trees.
1753 Common Alias(floop-nest-optimize)
1754 Enable loop nest transforms. Same as -floop-nest-optimize.
1756 floop-unroll-and-jam
1757 Common Var(flag_unroll_jam) Optimization
1758 Perform unroll-and-jam on loops.
1762 Enable support for GNU transactional memory.
1765 Common Var(flag_gnu_unique) Init(1)
1766 Use STB_GNU_UNIQUE if supported by the assembler.
1770 Does nothing. Preserved for backward compatibility.
1773 Common Var(flag_loop_nest_optimize) Optimization
1774 Enable the loop nest optimizer.
1776 fstrict-volatile-bitfields
1777 Common Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1778 Force bitfield accesses to match their type width.
1781 Common Var(flag_store_merging) Optimization
1782 Merge adjacent stores.
1784 fguess-branch-probability
1785 Common Var(flag_guess_branch_prob) Optimization
1786 Enable guessing of branch probabilities.
1789 Common Var(flag_harden_compares) Optimization
1790 Harden conditionals not used in branches, checking reversed conditions.
1792 fharden-conditional-branches
1793 Common Var(flag_harden_conditional_branches) Optimization
1794 Harden conditional branches by checking reversed conditions.
1796 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1797 ; Generate position-independent code for executables if possible
1798 ; On SVR4 targets, it also controls whether or not to emit a
1799 ; string identifying the compiler.
1801 Common Var(flag_no_ident,0)
1802 Process #ident directives.
1805 Common Var(flag_if_conversion) Optimization
1806 Perform conversion of conditional jumps to branchless equivalents.
1809 Common Var(flag_if_conversion2) Optimization
1810 Perform conversion of conditional jumps to conditional execution.
1813 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1814 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1817 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1820 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1823 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1826 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1828 ftree-loop-if-convert
1829 Common Var(flag_tree_loop_if_convert) Init(-1) Optimization
1830 Convert conditional jumps in innermost loops to branchless equivalents.
1832 ftree-loop-if-convert-stores
1834 Does nothing. Preserved for backward compatibility.
1836 ; -finhibit-size-directive inhibits output of .size for ELF.
1837 ; This is used only for compiling crtstuff.c,
1838 ; and it may be extended to other effects
1839 ; needed for crtstuff.c on other systems.
1840 finhibit-size-directive
1841 Common Var(flag_inhibit_size_directive)
1842 Do not generate .size directives.
1845 Common Var(flag_indirect_inlining) Optimization
1846 Perform indirect inlining.
1848 ; General flag to enable inlining. Specifying -fno-inline will disable
1849 ; all inlining apart from always-inline functions.
1851 Common Var(flag_no_inline,0) Init(0) Optimization
1852 Enable inlining of function declared \"inline\", disabling disables all inlining.
1854 finline-small-functions
1855 Common Var(flag_inline_small_functions) Optimization
1856 Integrate functions into their callers when code size is known not to grow.
1859 Common Var(flag_inline_functions) Optimization
1860 Integrate functions not declared \"inline\" into their callers when profitable.
1862 finline-functions-called-once
1863 Common Var(flag_inline_functions_called_once) Optimization
1864 Integrate functions only required by their single caller.
1867 Common RejectNegative Joined Alias(finline-limit=)
1870 Common RejectNegative Joined UInteger
1871 -finline-limit=<number> Limit the size of inlined functions to <number>.
1874 Common Var(flag_inline_atomics) Init(1) Optimization
1875 Inline __atomic operations when a lock free instruction sequence is available.
1878 Common RejectNegative Alias(fcf-protection=,full)
1881 Common Joined RejectNegative Enum(cf_protection_level) Var(flag_cf_protection) Init(CF_NONE)
1882 -fcf-protection=[full|branch|return|none|check] Instrument functions with checks to verify jump/call/return control-flow transfer
1883 instructions have valid targets.
1886 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Control-Flow Protection Level %qs)
1889 Enum(cf_protection_level) String(full) Value(CF_FULL)
1892 Enum(cf_protection_level) String(branch) Value(CF_BRANCH)
1895 Enum(cf_protection_level) String(return) Value(CF_RETURN)
1898 Enum(cf_protection_level) String(check) Value(CF_CHECK)
1901 Enum(cf_protection_level) String(none) Value(CF_NONE)
1903 finstrument-functions
1904 Common Var(flag_instrument_function_entry_exit,1)
1905 Instrument function entry and exit with profiling calls.
1907 finstrument-functions-once
1908 Common Var(flag_instrument_function_entry_exit,2)
1909 Instrument function entry and exit with profiling calls invoked once.
1911 finstrument-functions-exclude-function-list=
1912 Common RejectNegative Joined
1913 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
1915 finstrument-functions-exclude-file-list=
1916 Common RejectNegative Joined
1917 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
1920 Common Var(flag_ipa_cp) Optimization
1921 Perform interprocedural constant propagation.
1924 Common Var(flag_ipa_cp_clone) Optimization
1925 Perform cloning to make Interprocedural constant propagation stronger.
1929 Does nothing. Preserved for backward compatibility.
1932 Common Var(flag_ipa_bit_cp) Optimization
1933 Perform interprocedural bitwise constant propagation.
1936 Common Var(flag_ipa_modref) Optimization
1937 Perform interprocedural modref analysis.
1940 Common Var(flag_ipa_profile) Init(0) Optimization
1941 Perform interprocedural profile propagation.
1944 Common Var(flag_ipa_pta) Init(0) Optimization
1945 Perform interprocedural points-to analysis.
1948 Common Var(flag_ipa_pure_const) Init(0) Optimization
1949 Discover pure and const functions.
1952 Common Var(flag_ipa_icf) Optimization
1953 Perform Identical Code Folding for functions and read-only variables.
1956 Common Var(flag_ipa_icf_functions) Optimization
1957 Perform Identical Code Folding for functions.
1960 Common Var(flag_ipa_icf_variables) Optimization
1961 Perform Identical Code Folding for variables.
1964 Common Var(flag_ipa_reference) Init(0) Optimization
1965 Discover read-only and non addressable static variables.
1967 fipa-reference-addressable
1968 Common Var(flag_ipa_reference_addressable) Init(0) Optimization
1969 Discover read-only, write-only and non-addressable static variables.
1971 fipa-stack-alignment
1972 Common Var(flag_ipa_stack_alignment) Init(1) Optimization
1973 Reduce stack alignment on call sites if possible.
1977 Does nothing. Preserved for backward compatibility.
1981 Does nothing. Preserved for backward compatibility.
1984 Common Var(flag_ipa_vrp) Optimization
1985 Perform IPA Value Range Propagation.
1988 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
1989 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
1991 fipa-strict-aliasing
1992 Common Var(flag_ipa_strict_aliasing) Init(1) Optimization
1993 Assume strict aliasing rules apply across (uninlined) function boundaries.
1996 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1999 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
2002 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
2005 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_ONE) Optimization
2006 -fira-region=[one|all|mixed] Set regions for IRA.
2009 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
2012 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
2015 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
2018 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
2021 Common Var(flag_ira_hoist_pressure) Init(1) Optimization
2022 Use IRA based register pressure calculation
2023 in RTL hoist optimizations.
2026 Common Var(flag_ira_loop_pressure) Optimization
2027 Use IRA based register pressure calculation
2028 in RTL loop optimizations.
2030 fira-share-save-slots
2031 Common Var(flag_ira_share_save_slots) Init(1) Optimization
2032 Share slots for saving different hard registers.
2034 fira-share-spill-slots
2035 Common Var(flag_ira_share_spill_slots) Init(1) Optimization
2036 Share stack slots for spilled pseudo-registers.
2039 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
2040 -fira-verbose=<number> Control IRA's level of diagnostic messages.
2043 Common Var(flag_ivopts) Init(1) Optimization
2044 Optimize induction variables on trees.
2047 Common Var(flag_jump_tables) Init(1) Optimization
2048 Use jump tables for sufficiently large switch statements.
2051 Common Var(flag_bit_tests) Init(1) Optimization
2052 Use bit tests for sufficiently large switch statements.
2054 fkeep-inline-functions
2055 Common Var(flag_keep_inline_functions)
2056 Generate code for functions even if they are fully inlined.
2058 fkeep-static-functions
2059 Common Var(flag_keep_static_functions)
2060 Generate code for static functions even if they are never called.
2063 Common Var(flag_keep_static_consts) Init(1)
2064 Emit static const variables even if they are not used.
2067 Common Var(flag_leading_underscore) Init(-1)
2068 Give external symbols a leading underscore.
2072 Does nothing. Preserved for backward compatibility.
2075 Common Var(flag_lra_remat) Optimization
2076 Do CFG-sensitive rematerialization in LRA.
2080 Enable link-time optimization.
2083 Common RejectNegative Joined Var(flag_lto)
2084 Link-time optimization with number of parallel jobs or jobserver.
2087 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
2090 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
2093 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
2096 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
2099 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
2102 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
2105 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
2106 Specify the algorithm to partition symbols and vars at linktime.
2108 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
2109 flto-compression-level=
2110 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 19)
2111 Use zlib/zstd compression level <number> for IL.
2113 flto-odr-type-merging
2115 Does nothing. Preserved for backward compatibility.
2118 Common Var(flag_lto_report) Init(0)
2119 Report various link-time optimization statistics.
2122 Common Var(flag_lto_report_wpa) Init(0)
2123 Report various link-time optimization statistics for WPA only.
2126 Common Var(flag_errno_math) Init(1) Optimization SetByCombined
2127 Set errno after built-in math functions.
2130 Common Joined RejectNegative UInteger Var(flag_max_errors)
2131 -fmax-errors=<number> Maximum number of errors to report.
2134 Common Var(mem_report)
2135 Report on permanent memory allocation.
2138 Common Var(mem_report_wpa)
2139 Report on permanent memory allocation in WPA only.
2141 ; This will attempt to merge constant section constants, if 1 only
2142 ; string constants and constants from constant pool, if 2 also constant
2144 fmerge-all-constants
2145 Common Var(flag_merge_constants,2) Init(1)
2146 Attempt to merge identical constants and constant variables.
2149 Common Var(flag_merge_constants,1)
2150 Attempt to merge identical constants across compilation units.
2152 fmerge-debug-strings
2153 Common Var(flag_merge_debug_strings) Init(1)
2154 Attempt to merge identical debug strings across compilation units.
2157 Common RejectNegative Joined UInteger
2158 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
2161 Common Var(flag_modulo_sched) Optimization
2162 Perform SMS based modulo scheduling before the first scheduling pass.
2164 fmodulo-sched-allow-regmoves
2165 Common Var(flag_modulo_sched_allow_regmoves) Optimization
2166 Perform SMS based modulo scheduling with register moves allowed.
2168 fmove-loop-invariants
2169 Common Var(flag_move_loop_invariants) Optimization
2170 Move loop invariant computations out of loops.
2173 Common Var(flag_move_loop_stores) Optimization
2174 Move stores out of loops.
2178 Building block for specs-based multilib-aware TFLAGS.
2181 Common Var(flag_dce) Init(1) Optimization
2182 Use the RTL dead code elimination pass.
2185 Common Var(flag_dse) Init(0) Optimization
2186 Use the RTL dead store elimination pass.
2188 freschedule-modulo-scheduled-loops
2189 Common Var(flag_resched_modulo_sched) Optimization
2190 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
2192 fnon-call-exceptions
2193 Common Var(flag_non_call_exceptions) Optimization
2194 Support synchronous non-call exceptions.
2197 Driver Joined MissingArgError(targets missing after %qs)
2200 Common Driver Joined MissingArgError(options or targets=options missing after %qs)
2201 -foffload-options=<targets>=<options> Specify options for the offloading targets.
2204 Common Joined RejectNegative Enum(offload_abi)
2205 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
2208 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
2211 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
2214 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
2217 Common Var(flag_omit_frame_pointer) Optimization
2218 When possible do not generate stack frames.
2220 fopenmp-target-simd-clone
2221 Common Alias(fopenmp-target-simd-clone=,any,none)
2223 fopenmp-target-simd-clone=
2224 Common Joined RejectNegative Enum(target_simd_clone_device) Var(flag_openmp_target_simd_clone) Init(OMP_TARGET_SIMD_CLONE_NONE) Optimization
2225 Generate SIMD clones for functions with the OpenMP declare target directive.
2228 Name(target_simd_clone_device) Type(int)
2231 Enum(target_simd_clone_device) String(none) Value(OMP_TARGET_SIMD_CLONE_NONE)
2234 Enum(target_simd_clone_device) String(host) Value(OMP_TARGET_SIMD_CLONE_HOST)
2237 Enum(target_simd_clone_device) String(nohost) Value(OMP_TARGET_SIMD_CLONE_NOHOST)
2240 Enum(target_simd_clone_device) String(any) Value(OMP_TARGET_SIMD_CLONE_ANY)
2243 Common Var(flag_opt_info) Optimization
2244 Enable all optimization info dumps on stderr.
2247 Common Joined RejectNegative Var(common_deferred_options) Defer
2248 -fopt-info[-<type>=filename] Dump compiler optimization details.
2250 fsave-optimization-record
2251 Common Var(flag_save_optimization_record) Optimization
2252 Write a SRCFILE.opt-record.json file detailing what optimizations were performed.
2254 foptimize-register-move
2256 Does nothing. Preserved for backward compatibility.
2258 foptimize-sibling-calls
2259 Common Var(flag_optimize_sibling_calls) Optimization
2260 Optimize sibling and tail recursive calls.
2263 Common Var(flag_partial_inlining) Optimization
2264 Perform partial inlining.
2267 Common Var(pre_ipa_mem_report)
2268 Report on memory allocation before interprocedural optimization.
2270 fpost-ipa-mem-report
2271 Common Var(post_ipa_mem_report)
2272 Report on memory allocation before interprocedural optimization.
2275 Common Var(flag_pack_struct) Optimization
2276 Pack structure members together without holes.
2279 Common RejectNegative Joined UInteger Optimization
2280 -fpack-struct=<number> Set initial maximum structure member alignment.
2283 Common Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
2284 Return small aggregates in memory, not registers.
2287 Common Var(flag_peel_loops) Optimization
2288 Perform loop peeling.
2291 Common Var(flag_no_peephole,0) Optimization
2292 Enable machine specific peephole optimizations.
2295 Common Var(flag_peephole2) Optimization
2296 Enable an RTL peephole pass before sched2.
2299 Common Var(flag_pic,2) Negative(fPIE) Init(-1)
2300 Generate position-independent code if possible (large mode).
2303 Common Var(flag_pie,2) Negative(fpic) Init(-1)
2304 Generate position-independent code for executables if possible (large mode).
2307 Common Var(flag_pic,1) Negative(fpie) Init(-1)
2308 Generate position-independent code if possible (small mode).
2311 Common Var(flag_pie,1) Negative(fPIC) Init(-1)
2312 Generate position-independent code for executables if possible (small mode).
2315 Common Var(flag_plt) Init(1) Optimization
2316 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2319 Common Joined RejectNegative Var(common_deferred_options) Defer
2320 Specify a plugin to load.
2323 Common Joined RejectNegative Var(common_deferred_options) Defer
2324 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
2326 fpredictive-commoning
2327 Common Var(flag_predictive_commoning) Optimization
2328 Run predictive commoning optimization.
2330 fprefetch-loop-arrays
2331 Common Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2332 Generate prefetch instructions, if available, for arrays in loops.
2335 Common Var(profile_flag)
2336 Enable basic program profiling code.
2339 Common Var(profile_abs_path_flag)
2340 Generate absolute source path names for gcov.
2343 Common Var(profile_arc_flag)
2344 Insert arc-based program profiling code.
2347 Common Joined RejectNegative Var(profile_data_prefix)
2348 Set the top-level directory for storing the profile data.
2349 The default is 'pwd'.
2352 Common Joined RejectNegative Var(profile_note_location)
2353 Select the name for storing the profile note file.
2356 Common Var(flag_profile_correction)
2357 Enable correction of flow inconsistent profile data input.
2360 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2361 -fprofile-update=[single|atomic|prefer-atomic] Set the profile update method.
2363 fprofile-filter-files=
2364 Common Joined RejectNegative Var(flag_profile_filter_files)
2365 Instrument only functions from files whose name matches any of the regular expressions (separated by semi-colons).
2367 fprofile-exclude-files=
2368 Common Joined RejectNegative Var(flag_profile_exclude_files)
2369 Instrument only functions from files whose name does not match any of the regular expressions (separated by semi-colons).
2372 Name(profile_reproducibility) Type(enum profile_reproducibility) UnknownError(unknown profile reproducibility method %qs)
2375 Enum(profile_reproducibility) String(serial) Value(PROFILE_REPRODUCIBILITY_SERIAL)
2378 Enum(profile_reproducibility) String(parallel-runs) Value(PROFILE_REPRODUCIBILITY_PARALLEL_RUNS)
2381 Enum(profile_reproducibility) String(multithreaded) Value(PROFILE_REPRODUCIBILITY_MULTITHREADED)
2383 fprofile-reproducible=
2384 Common Joined RejectNegative Var(flag_profile_reproducible) Enum(profile_reproducibility) Init(PROFILE_REPRODUCIBILITY_SERIAL)
2385 -fprofile-reproducible=[serial|parallel-runs|multithreaded] Control level of reproducibility of profile gathered by -fprofile-generate.
2388 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2391 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2394 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2397 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2399 fprofile-prefix-path=
2400 Common Joined RejectNegative Var(profile_prefix_path)
2401 Remove prefix from absolute path before mangling name for -fprofile-generate= and -fprofile-use=.
2403 fprofile-prefix-map=
2404 Common Joined RejectNegative Var(common_deferred_options) Defer
2405 -fprofile-prefix-map=<old>=<new> Map one directory name to another in GCOV coverage result.
2409 Enable common options for generating profile info for profile feedback directed optimizations.
2412 Common Joined RejectNegative
2413 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2415 fprofile-info-section
2416 Common RejectNegative
2417 Register the profile information in the .gcov_info section instead of using a constructor/destructor.
2419 fprofile-info-section=
2420 Common Joined RejectNegative Var(profile_info_section)
2421 Register the profile information in the specified section instead of using a constructor/destructor.
2423 fprofile-partial-training
2424 Common Var(flag_profile_partial_training) Optimization
2425 Do not assume that functions never executed during the train run are cold.
2428 Common Var(flag_profile_use)
2429 Enable common options for performing profile feedback directed optimizations.
2432 Common Joined RejectNegative
2433 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2436 Common Var(flag_profile_values)
2437 Insert code to profile values of expressions.
2440 Common Var(profile_report)
2441 Report on consistency of profile.
2443 fprofile-reorder-functions
2444 Common Var(flag_profile_reorder_functions) Optimization
2445 Enable function reordering that improves code placement.
2447 fpatchable-function-entry=
2448 Common Var(flag_patchable_function_entry) Joined Optimization
2449 Insert NOP instructions at each function entry.
2452 Common Var(common_deferred_options) Defer
2455 Common Joined RejectNegative Var(common_deferred_options) Defer
2456 -frandom-seed=<string> Make compile reproducible using <string>.
2458 ; This switch causes the command line that was used to create an
2459 ; object file to be recorded into the object file. The exact format
2460 ; of this recording is target and binary file format dependent.
2461 ; It is related to the -fverbose-asm switch, but that switch only
2462 ; records information in the assembler output file as comments, so
2463 ; they never reach the object file.
2464 frecord-gcc-switches
2465 Common Var(flag_record_gcc_switches)
2466 Record gcc command line switches in the object file.
2469 Common Var(flag_pcc_struct_return,0) Optimization
2470 Return small aggregates in registers.
2474 Does nothing. Preserved for backward compatibility.
2477 Common Var(flag_lifetime_dse,2) Init(2) Optimization
2478 Tell DSE that the storage for a C++ object is dead when the constructor
2479 starts and when the destructor finishes.
2482 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2485 Common RejectNegative Alias(flive-patching=,inline-clone) Optimization
2488 Common Joined RejectNegative Enum(live_patching_level) Var(flag_live_patching) Init(LIVE_PATCHING_NONE) Optimization
2489 -flive-patching=[inline-only-static|inline-clone] Control IPA
2490 optimizations to provide a safe compilation for live-patching. At the same
2491 time, provides multiple-level control on the enabled IPA optimizations.
2494 Name(live_patching_level) Type(enum live_patching_level) UnknownError(unknown Live-Patching Level %qs)
2497 Enum(live_patching_level) String(inline-only-static) Value(LIVE_PATCHING_INLINE_ONLY_STATIC)
2500 Enum(live_patching_level) String(inline-clone) Value(LIVE_PATCHING_INLINE_CLONE)
2503 Common Var(flag_allocation_dce) Init(1) Optimization
2504 Tell DCE to remove unused C++ allocations.
2506 flive-range-shrinkage
2507 Common Var(flag_live_range_shrinkage) Init(0) Optimization
2508 Relief of register pressure through live range shrinkage.
2511 Common Var(flag_rename_registers) Optimization EnabledBy(funroll-loops)
2512 Perform a register renaming optimization pass.
2515 Common Var(flag_schedule_fusion) Init(2) Optimization
2516 Perform a target dependent instruction fusion optimization pass.
2519 Common Var(flag_reorder_blocks) Optimization
2520 Reorder basic blocks to improve code placement.
2522 freorder-blocks-algorithm=
2523 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2524 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2527 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2530 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2533 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2535 freorder-blocks-and-partition
2536 Common Var(flag_reorder_blocks_and_partition) Optimization
2537 Reorder basic blocks and partition into hot and cold sections.
2540 Common Var(flag_reorder_functions) Optimization
2541 Reorder functions to improve code placement.
2543 frerun-cse-after-loop
2544 Common Var(flag_rerun_cse_after_loop) Optimization
2545 Add a common subexpression elimination pass after loop optimizations.
2549 Does nothing. Preserved for backward compatibility.
2552 Common Var(flag_rounding_math) Optimization SetByCombined
2553 Disable optimizations that assume default FP rounding behavior.
2556 Common Var(flag_schedule_interblock) Init(1) Optimization
2557 Enable scheduling across basic blocks.
2560 Common Var(flag_sched_pressure) Init(0) Optimization
2561 Enable register pressure sensitive insn scheduling.
2564 Common Var(flag_schedule_speculative) Init(1) Optimization
2565 Allow speculative motion of non-loads.
2568 Common Var(flag_schedule_speculative_load) Optimization
2569 Allow speculative motion of some loads.
2571 fsched-spec-load-dangerous
2572 Common Var(flag_schedule_speculative_load_dangerous) Optimization
2573 Allow speculative motion of more loads.
2576 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2577 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2579 fsched2-use-superblocks
2580 Common Var(flag_sched2_use_superblocks) Optimization
2581 If scheduling post reload, do superblock scheduling.
2585 Does nothing. Preserved for backward compatibility.
2588 Common Var(flag_schedule_insns) Optimization
2589 Reschedule instructions before register allocation.
2592 Common Var(flag_schedule_insns_after_reload) Optimization
2593 Reschedule instructions after register allocation.
2595 ; This flag should be on when a target implements non-trivial
2596 ; scheduling hooks, maybe saving some information for its own sake.
2597 ; On IA64, for example, this is used for correct bundling.
2598 fselective-scheduling
2599 Common Var(flag_selective_scheduling) Optimization
2600 Schedule instructions using selective scheduling algorithm.
2602 fselective-scheduling2
2603 Common Var(flag_selective_scheduling2) Optimization
2604 Run selective scheduling after reload.
2607 Common Undocumented Joined Var(flag_self_test)
2608 Run self-tests, using the given path to locate test files.
2610 fsel-sched-pipelining
2611 Common Var(flag_sel_sched_pipelining) Init(0) Optimization
2612 Perform software pipelining of inner loops during selective scheduling.
2614 fsel-sched-pipelining-outer-loops
2615 Common Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2616 Perform software pipelining of outer loops during selective scheduling.
2618 fsel-sched-reschedule-pipelined
2619 Common Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2620 Reschedule pipelined regions without pipelining.
2622 fsemantic-interposition
2623 Common Var(flag_semantic_interposition) Init(1) Optimization
2624 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2626 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2627 ; of stalled insns into the ready list.
2628 fsched-stalled-insns
2629 Common Var(flag_sched_stalled_insns) Optimization UInteger
2630 Allow premature scheduling of queued insns.
2632 fsched-stalled-insns=
2633 Common RejectNegative Joined UInteger Optimization
2634 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2636 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2637 ; be examined for a dependency on a stalled insn that is candidate for
2638 ; premature removal from the queue of stalled insns into the ready list (has
2639 ; an effect only if the flag 'sched_stalled_insns' is set).
2640 fsched-stalled-insns-dep
2641 Common Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2642 Set dependence distance checking in premature scheduling of queued insns.
2644 fsched-stalled-insns-dep=
2645 Common RejectNegative Joined UInteger Optimization
2646 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2648 fsched-group-heuristic
2649 Common Var(flag_sched_group_heuristic) Init(1) Optimization
2650 Enable the group heuristic in the scheduler.
2652 fsched-critical-path-heuristic
2653 Common Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2654 Enable the critical path heuristic in the scheduler.
2656 fsched-spec-insn-heuristic
2657 Common Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2658 Enable the speculative instruction heuristic in the scheduler.
2660 fsched-rank-heuristic
2661 Common Var(flag_sched_rank_heuristic) Init(1) Optimization
2662 Enable the rank heuristic in the scheduler.
2664 fsched-last-insn-heuristic
2665 Common Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2666 Enable the last instruction heuristic in the scheduler.
2668 fsched-dep-count-heuristic
2669 Common Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2670 Enable the dependent count heuristic in the scheduler.
2673 Common Var(flag_section_anchors) Optimization
2674 Access data in the same section from shared anchor points.
2678 Does nothing. Preserved for backward compatibility.
2682 Does nothing. Preserved for backward compatibility.
2685 Common Var(flag_ree) Init(0) Optimization
2686 Turn on Redundant Extensions Elimination pass.
2689 Common Var(flag_show_column) Init(1)
2690 Show column numbers in diagnostics, when available. Default on.
2693 Common Var(flag_shrink_wrap) Optimization
2694 Emit function prologues only before parts of the function that need it,
2695 rather than at the top of the function.
2697 fshrink-wrap-separate
2698 Common Var(flag_shrink_wrap_separate) Init(1) Optimization
2699 Shrink-wrap parts of the prologue and epilogue separately.
2702 Common Var(flag_signaling_nans) Optimization SetByCombined
2703 Disable optimizations observable by IEEE signaling NaNs.
2706 Common Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2707 Disable floating point optimizations that ignore the IEEE signedness of zero.
2709 fsingle-precision-constant
2710 Common Var(flag_single_precision_constant) Optimization
2711 Convert floating point constants to single precision constants.
2713 fsplit-ivs-in-unroller
2714 Common Var(flag_split_ivs_in_unroller) Init(1) Optimization
2715 Split lifetimes of induction variables when loops are unrolled.
2718 Common Var(flag_split_stack) Init(-1)
2719 Generate discontiguous stack frames.
2722 Common Var(flag_split_wide_types) Optimization
2723 Split wide types into independent registers.
2725 fsplit-wide-types-early
2726 Common Var(flag_split_wide_types_early) Optimization
2727 Split wide types into independent registers earlier.
2730 Common Var(flag_ssa_backprop) Init(1) Optimization
2731 Enable backward propagation of use properties at the SSA level.
2734 Common Var(flag_ssa_phiopt) Optimization
2735 Optimize conditional patterns using SSA PHI nodes.
2738 Common Var(flag_stdarg_opt) Init(1) Optimization
2739 Optimize amount of stdarg registers saved to stack at start of function.
2741 fvariable-expansion-in-unroller
2742 Common Var(flag_variable_expansion_in_unroller) Optimization
2743 Apply variable expansion when loops are unrolled.
2746 Common RejectNegative Joined Optimization
2747 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2750 Common Alias(fstack-check=, specific, no)
2751 Insert stack checking code into the program. Same as -fstack-check=specific.
2753 fstack-clash-protection
2754 Common Var(flag_stack_clash_protection) Optimization
2755 Insert code to probe each page of stack space as it is allocated to protect
2756 from stack-clash style attacks.
2759 Common Var(common_deferred_options) Defer
2761 fstack-limit-register=
2762 Common RejectNegative Joined Var(common_deferred_options) Defer
2763 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2765 fstack-limit-symbol=
2766 Common RejectNegative Joined Var(common_deferred_options) Defer
2767 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2770 Common Var(flag_stack_protect, 1) Init(-1) Optimization
2771 Use propolice as a stack protection method.
2773 fstack-protector-all
2774 Common RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2775 Use a stack protection method for every function.
2777 fstack-protector-strong
2778 Common RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2779 Use a smart stack protection method for certain functions.
2781 fstack-protector-explicit
2782 Common RejectNegative Var(flag_stack_protect, 4) Optimization
2783 Use stack protection method only for functions with the stack_protect attribute.
2786 Common RejectNegative Var(flag_stack_usage)
2787 Output stack usage information on a per-function basis.
2791 Does nothing. Preserved for backward compatibility.
2793 ; Nonzero if we should do (language-dependent) alias analysis.
2794 ; Typically, this analysis will assume that expressions of certain
2795 ; types do not alias expressions of certain other types. Only used
2796 ; if alias analysis (in general) is enabled.
2798 Common Var(flag_strict_aliasing) Optimization
2799 Assume strict aliasing rules apply.
2803 Treat signed overflow as undefined. Negated as -fwrapv -fwrapv-pointer.
2806 Common Var(flag_sync_libcalls) Init(1)
2807 Implement __atomic operations via libcalls to legacy __sync functions.
2810 Common Var(flag_syntax_only)
2811 Check for syntax errors, then stop.
2814 Common Var(flag_test_coverage)
2815 Create data files needed by \"gcov\".
2818 Common Var(flag_thread_jumps) Optimization
2819 Perform jump threading optimizations.
2822 Common Var(time_report)
2823 Report the time taken by each compiler pass.
2825 ftime-report-details
2826 Common Var(time_report_details)
2827 Record times taken by sub-phases separately.
2830 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2831 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2834 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2837 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2840 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2843 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2846 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2849 Common Var(flag_toplevel_reorder) Init(2) Optimization
2850 Reorder top level functions, variables, and asms.
2853 Common Var(flag_tracer) Optimization
2854 Perform superblock formation via tail duplication.
2857 Common Var(flag_trampolines) Init(0)
2858 For targets that normally need trampolines for nested functions, always
2859 generate them instead of using descriptors.
2861 ; Zero means that floating-point math operations cannot generate a
2862 ; (user-visible) trap. This is the case, for example, in nonstop
2863 ; IEEE 754 arithmetic.
2865 Common Var(flag_trapping_math) Init(1) Optimization SetByCombined
2866 Assume floating-point operations can trap.
2869 Common Var(flag_trapv) Optimization
2870 Trap for signed overflow in addition, subtraction and multiplication.
2873 Common Var(flag_tree_ccp) Optimization
2874 Enable SSA-CCP optimization on trees.
2877 Common Var(flag_tree_bit_ccp) Optimization
2878 Enable SSA-BIT-CCP optimization on trees.
2882 Does nothing. Preserved for backward compatibility.
2885 Common Var(flag_tree_ch) Optimization
2886 Enable loop header copying on trees.
2888 ftree-coalesce-inlined-vars
2889 Common Ignore RejectNegative
2890 Does nothing. Preserved for backward compatibility.
2893 Common Var(flag_tree_coalesce_vars) Optimization
2894 Enable SSA coalescing of user variables.
2898 Does nothing. Preserved for backward compatibility.
2901 Common Var(flag_tree_copy_prop) Optimization
2902 Enable copy propagation on trees.
2904 ftree-store-copy-prop
2906 Does nothing. Preserved for backward compatibility.
2909 Common Var(flag_tree_cselim) Optimization
2910 Transform condition stores into unconditional ones.
2912 ftree-switch-conversion
2913 Common Var(flag_tree_switch_conversion) Optimization
2914 Perform conversions of switch initializations.
2917 Common Var(flag_tree_dce) Optimization
2918 Enable SSA dead code elimination optimization on trees.
2920 ftree-dominator-opts
2921 Common Var(flag_tree_dom) Optimization
2922 Enable dominator optimizations.
2925 Common Var(flag_tree_tail_merge) Optimization
2926 Enable tail merging on trees.
2929 Common Var(flag_tree_dse) Optimization
2930 Enable dead store elimination.
2933 Common Var(flag_tree_forwprop) Init(1) Optimization
2934 Enable forward propagation on trees.
2937 Common Var(flag_tree_fre) Optimization
2938 Enable Full Redundancy Elimination (FRE) on trees.
2941 Common Var(flag_optimize_strlen) Optimization
2942 Enable string length optimizations on trees.
2944 fisolate-erroneous-paths-dereference
2945 Common Var(flag_isolate_erroneous_paths_dereference) Optimization
2946 Detect paths that trigger erroneous or undefined behavior due to
2947 dereferencing a null pointer. Isolate those paths from the main control
2948 flow and turn the statement with erroneous or undefined behavior into a trap.
2950 fisolate-erroneous-paths-attribute
2951 Common Var(flag_isolate_erroneous_paths_attribute) Optimization
2952 Detect paths that trigger erroneous or undefined behavior due to a null value
2953 being used in a way forbidden by a returns_nonnull or nonnull
2954 attribute. Isolate those paths from the main control flow and turn the
2955 statement with erroneous or undefined behavior into a trap.
2957 ftree-loop-distribution
2958 Common Var(flag_tree_loop_distribution) Optimization
2959 Enable loop distribution on trees.
2961 ftree-loop-distribute-patterns
2962 Common Var(flag_tree_loop_distribute_patterns) Optimization
2963 Enable loop distribution for patterns transformed into a library call.
2966 Common Var(flag_tree_loop_im) Init(1) Optimization
2967 Enable loop invariant motion on trees.
2970 Common Alias(floop-nest-optimize)
2971 Enable loop nest transforms. Same as -floop-nest-optimize.
2974 Common Var(flag_tree_loop_ivcanon) Init(1) Optimization
2975 Create canonical induction variables in loops.
2978 Common Var(flag_tree_loop_optimize) Init(1) Optimization
2979 Enable loop optimizations on tree level.
2981 ftree-parallelize-loops=
2982 Common Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
2983 -ftree-parallelize-loops=<number> Enable automatic parallelization of loops.
2986 Common Var(flag_tree_phiprop) Init(1) Optimization
2987 Enable hoisting loads from conditional pointers.
2990 Common Var(flag_tree_pre) Optimization
2991 Enable SSA-PRE optimization on trees.
2994 Common Var(flag_tree_partial_pre) Optimization
2995 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
2998 Common Var(flag_tree_pta) Optimization
2999 Perform function-local points-to analysis on trees.
3002 Common Var(flag_tree_reassoc) Init(1) Optimization
3003 Enable reassociation on tree level.
3007 Does nothing. Preserved for backward compatibility.
3010 Common Var(flag_tree_sink) Optimization
3011 Enable SSA code sinking on trees.
3014 Common Var(flag_tree_slsr) Optimization
3015 Perform straight-line strength reduction.
3018 Common Var(flag_tree_sra) Optimization
3019 Perform scalar replacement of aggregates.
3022 Common Var(flag_tree_ter) Optimization
3023 Replace temporary expressions in the SSA->normal pass.
3026 Common Var(flag_tree_live_range_split) Optimization
3027 Perform live range splitting during the SSA->normal pass.
3030 Common Var(flag_tree_vrp) Init(0) Optimization
3031 Perform Value Range Propagation on trees.
3034 Common Var(flag_split_paths) Init(0) Optimization
3035 Split paths leading to loop backedges.
3037 funconstrained-commons
3038 Common Var(flag_unconstrained_commons) Optimization
3039 Assume common declarations may be overridden with ones with a larger
3043 Common Var(flag_unit_at_a_time) Init(1)
3044 Compile whole compilation unit at a time.
3047 Common Var(flag_unreachable_traps) Optimization
3048 Trap on __builtin_unreachable instead of using it for optimization.
3051 Common Var(flag_unroll_loops) Optimization EnabledBy(funroll-all-loops)
3052 Perform loop unrolling when iteration count is known.
3055 Common Var(flag_unroll_all_loops) Optimization
3056 Perform loop unrolling for all loops.
3058 funroll-completely-grow-size
3059 Undocumented Var(flag_cunroll_grow_size) Optimization
3060 ; Internal undocumented flag, allow size growth during complete unrolling
3062 ; Nonzero means that loop optimizer may assume that the induction variables
3063 ; that control loops do not overflow and that the loops with nontrivial
3064 ; exit condition are not infinite
3065 funsafe-loop-optimizations
3067 Does nothing. Preserved for backward compatibility.
3070 Common Var(flag_associative_math) SetByCombined Optimization
3071 Allow optimization for floating-point arithmetic which may change the
3072 result of the operation due to rounding.
3075 Common Var(flag_reciprocal_math) SetByCombined Optimization
3076 Same as -fassociative-math for expressions which include division.
3078 ; Nonzero means that unsafe floating-point math optimizations are allowed
3079 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
3080 ; are allowed to assume that their arguments and results are "normal"
3081 ; (e.g., nonnegative for SQRT).
3082 funsafe-math-optimizations
3083 Common Var(flag_unsafe_math_optimizations) Optimization SetByCombined
3084 Allow math optimizations that may violate IEEE or ISO standards.
3087 Common Var(flag_unswitch_loops) Optimization
3088 Perform loop unswitching.
3091 Common Var(flag_split_loops) Optimization
3092 Perform loop splitting.
3094 fversion-loops-for-strides
3095 Common Var(flag_version_loops_for_strides) Optimization
3096 Version loops based on whether indices have a stride of one.
3099 Common Var(flag_unwind_tables) Optimization
3100 Just generate unwind tables for exception handling.
3103 Common Driver Negative(fuse-ld=gold)
3104 Use the bfd linker instead of the default linker.
3107 Common Driver Negative(fuse-ld=bfd)
3108 Use the gold linker instead of the default linker.
3111 Common Driver Negative(fuse-ld=lld)
3112 Use the lld LLVM linker instead of the default linker.
3115 Common Driver Negative(fuse-ld=mold)
3116 Use the Modern linker (MOLD) linker instead of the default linker.
3119 Common Undocumented Var(flag_use_linker_plugin)
3121 ; Positive if we should track variables, negative if we should run
3122 ; the var-tracking pass only to discard debug annotations, zero if
3123 ; we're not to run it.
3125 Common Var(flag_var_tracking) PerFunction EnabledBy(fvar-tracking-uninit)
3126 Perform variable tracking.
3128 ; Positive if we should track variables at assignments, negative if
3129 ; we should run the var-tracking pass only to discard debug
3131 fvar-tracking-assignments
3132 Common Var(flag_var_tracking_assignments) PerFunction
3133 Perform variable tracking by annotating assignments.
3135 ; Nonzero if we should toggle flag_var_tracking_assignments after
3136 ; processing options and computing its default. */
3137 fvar-tracking-assignments-toggle
3138 Common Var(flag_var_tracking_assignments_toggle) PerFunction
3139 Toggle -fvar-tracking-assignments.
3141 ; Positive if we should track uninitialized variables, negative if
3142 ; we should run the var-tracking pass only to discard debug
3144 fvar-tracking-uninit
3145 Common Var(flag_var_tracking_uninit) PerFunction
3146 Perform variable tracking and also tag variables that are uninitialized.
3148 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
3150 Common Var(flag_tree_vectorize) Optimization
3151 Enable vectorization on trees.
3153 ftree-vectorizer-verbose=
3154 Common Joined RejectNegative Ignore
3155 Does nothing. Preserved for backward compatibility.
3157 ftree-loop-vectorize
3158 Common Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
3159 Enable loop vectorization on trees.
3162 Common Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
3163 Enable basic block vectorization (SLP) on trees.
3166 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
3167 -fvect-cost-model=[unlimited|dynamic|cheap|very-cheap] Specifies the cost model for vectorization.
3170 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
3171 -fsimd-cost-model=[unlimited|dynamic|cheap|very-cheap] Specifies the vectorization cost model for code marked with a simd directive.
3174 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
3177 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
3180 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
3183 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
3186 Enum(vect_cost_model) String(very-cheap) Value(VECT_COST_MODEL_VERY_CHEAP)
3189 Common Alias(fvect-cost-model=,dynamic,unlimited)
3190 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
3192 ftree-vect-loop-version
3194 Does nothing. Preserved for backward compatibility.
3197 Common Var(flag_tree_scev_cprop) Init(1) Optimization
3198 Enable copy propagation of scalar-evolution information.
3200 ftrivial-auto-var-init=
3201 Common Joined RejectNegative Enum(auto_init_type) Var(flag_auto_var_init) Init(AUTO_INIT_UNINITIALIZED) Optimization
3202 -ftrivial-auto-var-init=[uninitialized|pattern|zero] Add initializations to automatic variables.
3205 Name(auto_init_type) Type(enum auto_init_type) UnknownError(unrecognized automatic variable initialization type %qs)
3208 Enum(auto_init_type) String(uninitialized) Value(AUTO_INIT_UNINITIALIZED)
3211 Enum(auto_init_type) String(pattern) Value(AUTO_INIT_PATTERN)
3214 Enum(auto_init_type) String(zero) Value(AUTO_INIT_ZERO)
3216 ; -fverbose-asm causes extra commentary information to be produced in
3217 ; the generated assembly code (to make it more readable). This option
3218 ; is generally only of use to those who actually need to read the
3219 ; generated assembly code (perhaps while debugging the compiler itself).
3220 ; -fno-verbose-asm, the default, causes the extra information
3221 ; to not be added and is useful when comparing two assembler files.
3223 Common Var(flag_verbose_asm)
3224 Add extra commentary to assembler output.
3227 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
3228 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
3231 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
3234 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
3237 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
3240 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
3243 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
3246 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
3247 Validate vtable pointers before using them.
3250 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
3253 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
3256 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
3259 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
3262 Common Var(flag_vtv_counts)
3263 Output vtable verification counters.
3266 Common Var(flag_vtv_debug)
3267 Output vtable verification pointer sets information.
3270 Common Var(flag_value_profile_transformations) Optimization
3271 Use expression value profiles in optimizations.
3274 Common Var(flag_web) Optimization EnabledBy(funroll-loops)
3275 Construct webs and split unrelated uses of single variable.
3277 ftree-builtin-call-dce
3278 Common Var(flag_tree_builtin_call_dce) Init(0) Optimization
3279 Enable conditional dead code elimination for builtin calls.
3282 Common Var(flag_whole_program) Init(0)
3283 Perform whole program optimizations.
3286 Common Var(flag_wrapv_pointer) Optimization
3287 Assume pointer overflow wraps around.
3290 Common Var(flag_wrapv) Optimization
3291 Assume signed arithmetic overflow wraps around.
3293 fzero-initialized-in-bss
3294 Common Var(flag_zero_initialized_in_bss) Init(1)
3295 Put zero initialized data in the bss section.
3297 fzero-call-used-regs=
3298 Common RejectNegative Joined
3299 Clear call-used registers upon function return.
3302 Common Driver RejectNegative JoinedOrMissing
3303 Generate debug information in default format.
3306 Common Driver Var(dwarf2out_as_loc_support)
3307 Assume assembler support for (DWARF2+) .loc directives.
3310 Common Driver Var(dwarf2out_as_locview_support)
3311 Assume assembler support for view in (DWARF2+) .loc directives.
3314 Common Driver WarnRemoved
3315 Does nothing. Preserved for backward compatibility.
3318 Common Driver WarnRemoved
3319 Does nothing. Preserved for backward compatibility.
3322 Common Driver WarnRemoved
3323 Does nothing. Preserved for backward compatibility.
3326 Common Driver WarnRemoved
3327 Does nothing. Preserved for backward compatibility.
3330 Common Driver Var(debug_column_info,1) Init(1)
3331 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
3333 ; The CTF generation process feeds off DWARF dies. This option implicitly
3334 ; updates the debug_info_level to DINFO_LEVEL_NORMAL.
3336 Common Driver RejectNegative JoinedOrMissing
3337 Generate CTF debug information at default level.
3340 Common Driver RejectNegative JoinedOrMissing
3341 Generate BTF debug information at default level.
3344 Common Driver JoinedOrMissing Negative(gdwarf-)
3345 Generate debug information in default version of DWARF format.
3348 Common Driver Joined UInteger Var(dwarf_version) Init(DWARF_VERSION_DEFAULT)
3349 Generate debug information in DWARF v2 (or later) format.
3352 Common Driver Var(dwarf_offset_size,4) Init(4) RejectNegative
3353 Use 32-bit DWARF format when emitting DWARF debug information.
3356 Common Driver Var(dwarf_offset_size,8) RejectNegative
3357 Use 64-bit DWARF format when emitting DWARF debug information.
3360 Common Driver JoinedOrMissing
3361 Generate debug information in default extended format.
3364 Common Driver Var(debug_inline_points)
3365 Generate extended entry point information for inlined functions.
3367 ginternal-reset-location-views
3368 Common Driver Var(debug_internal_reset_location_views) Init(2)
3369 Compute locview reset points based on insn length estimates.
3372 RejectNegative Joined Undocumented
3373 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
3376 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
3377 Don't generate DWARF pubnames and pubtypes sections.
3380 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
3381 Generate DWARF pubnames and pubtypes sections.
3384 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
3385 Generate DWARF pubnames and pubtypes sections with GNU extensions.
3387 grecord-gcc-switches
3388 Common Driver Var(dwarf_record_gcc_switches) Init(1)
3389 Record gcc command line switches in DWARF DW_AT_producer.
3392 Common Driver Var(dwarf_split_debug_info) Init(0)
3393 Generate debug information in separate .dwo files.
3396 Common Driver WarnRemoved
3397 Does nothing. Preserved for backward compatibility.
3400 Common Driver WarnRemoved
3401 Does nothing. Preserved for backward compatibility.
3403 gstatement-frontiers
3404 Common Driver Var(debug_nonbind_markers_p) PerFunction
3405 Emit progressive recommended breakpoint locations.
3408 Common Driver Var(dwarf_strict) Init(0)
3409 Don't emit DWARF additions beyond selected version.
3412 Common Driver Var(flag_describe_dies) Init(0)
3413 Add description attributes to some DWARF DIEs that have no name attribute.
3416 Common Driver Var(flag_gtoggle)
3417 Toggle debug information generation.
3419 gvariable-location-views
3420 Common Driver Var(debug_variable_location_views, 1)
3421 Augment variable location lists with progressive views.
3423 gvariable-location-views=incompat5
3424 Common Driver RejectNegative Var(debug_variable_location_views, -1) Init(2)
3427 Common Driver JoinedOrMissing
3428 Generate debug information in VMS format.
3431 Common Driver WarnRemoved
3432 Does nothing. Preserved for backward compatibility.
3435 Common Driver JoinedOrMissing WarnRemoved
3436 Does nothing. Preserved for backward compatibility.
3439 Name(compressed_debug_sections) Type(int)
3441 ; Since -gz= is completely handled in specs, the values aren't used and we
3442 ; assign arbitrary constants.
3444 Enum(compressed_debug_sections) String(none) Value(0)
3447 Enum(compressed_debug_sections) String(zlib) Value(1)
3450 Enum(compressed_debug_sections) String(zstd) Value(2)
3453 Enum(compressed_debug_sections) String(zlib-gnu) Value(3)
3457 Generate compressed debug sections.
3460 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
3461 -gz=<format> Generate compressed debug sections in format <format>.
3464 Driver Joined Separate
3467 Common Joined Var(plugindir_string) Init(0)
3468 -iplugindir=<dir> Set <dir> to be the default plugin directory.
3471 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
3472 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
3475 Driver Joined Separate
3480 no-canonical-prefixes
3499 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3500 -o <file> Place output into <file>.
3503 Common Var(profile_flag)
3504 Enable function profiling.
3507 Driver Var(pass_exit_codes)
3510 Common Alias(Wpedantic)
3513 Common Var(flag_pedantic_errors)
3514 Like -pedantic but issue them as errors.
3520 Driver Var(use_pipes)
3523 Driver JoinedOrMissing Var(print_file_name)
3525 print-libgcc-file-name
3528 print-multi-directory
3529 Driver Var(print_multi_directory)
3532 Driver Var(print_multi_lib)
3534 print-multi-os-directory
3535 Driver Var(print_multi_os_directory)
3538 Driver Var(print_multiarch)
3541 Driver JoinedOrMissing Var(print_prog_name)
3544 Driver Var(print_search_dirs)
3547 Driver Var(print_sysroot)
3549 print-sysroot-headers-suffix
3550 Driver Var(print_sysroot_headers_suffix)
3553 Common Var(quiet_flag) RejectDriver
3554 Do not display functions compiled or elapsed time.
3572 Driver Var(report_times)
3575 Driver JoinedOrMissing
3578 Driver Joined Separate
3582 ; C option, but driver must not handle as "-u ndef".
3585 Common Driver Var(verbose_flag)
3586 Enable verbose output.
3589 Common Var(version_flag) RejectDriver
3590 Display the compiler's version.
3593 Common Var(inhibit_warnings)
3597 Driver Separate Var(wrapper_string)
3600 Driver Joined Separate
3603 Driver RejectNegative Negative(static-pie)
3604 Create a shared library.
3610 Driver Separate Alias(specs=)
3623 ; Documented for Fortran, but always accepted by driver.
3627 ; Documented for D, but always accepted by driver.
3631 ; Documented for Fortran, but always accepted by driver.
3638 ; Documented for Go, but always accepted by driver.
3659 Driver RejectNegative Negative(shared)
3660 Don't create a dynamically linked position independent executable.
3663 Driver RejectNegative Negative(no-pie)
3664 Create a dynamically linked position independent executable.
3667 Driver RejectNegative Negative(pie)
3668 Create a static position independent executable.
3671 Driver Joined Separate
3674 Common Var(flag_ipa_ra) Optimization
3675 Use caller save register across calls if possible.
3677 ; This comment is to ensure we retain the blank line above.