; Options for the language- and target-independent parts of the compiler. ; Copyright (C) 2003-2020 Free Software Foundation, Inc. ; ; This file is part of GCC. ; ; GCC is free software; you can redistribute it and/or modify it under ; the terms of the GNU General Public License as published by the Free ; Software Foundation; either version 3, or (at your option) any later ; version. ; ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY ; WARRANTY; without even the implied warranty of MERCHANTABILITY or ; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License ; for more details. ; ; You should have received a copy of the GNU General Public License ; along with GCC; see the file COPYING3. If not see ; . ; See the GCC internals manual (options.texi) for a description of this file's format. ; Please try to keep this file in ASCII collating order. Variable int target_flags Variable int optimize Variable int optimize_size Variable int optimize_debug ; Not used directly to control optimizations, only to save -Ofast ; setting for "optimize" attributes. Variable int optimize_fast ; True if this is the lto front end. This is used to disable gimple ; generation and lowering passes that are normally run on the output ; of a front end. These passes must be bypassed for lto since they ; have already been done before the gimple was written. Variable bool in_lto_p = false ; This variable is set to non-0 only by LTO front-end. 1 indicates that ; the output produced will be used for incrmeental linking (thus weak symbols ; can still be bound) and 2 indicates that the IL is going to be linked and ; and output to LTO object file. Variable enum incremental_link flag_incremental_link = INCREMENTAL_LINK_NONE ; 0 means straightforward implementation of complex divide acceptable. ; 1 means wide ranges of inputs must work for complex divide. ; 2 means C99-like requirements for complex multiply and divide. Variable int flag_complex_method = 1 ; Language specific warning pass for unused results. Variable bool flag_warn_unused_result = false ; Nonzero if we should write GIMPLE bytecode for link-time optimization. Variable int flag_generate_lto ; Nonzero if we should write GIMPLE bytecode for offload compilation. Variable int flag_generate_offload = 0 ; Nonzero means we should be saving declaration info into a .X file. Variable int flag_gen_aux_info = 0 ; Nonzero if we are compiling code for a shared library, zero for ; executable. Variable int flag_shlib ; These two are really VEC(char_p,heap) *. Variable void *flag_instrument_functions_exclude_functions Variable void *flag_instrument_functions_exclude_files ; Generic structs (e.g. templates not explicitly specialized) ; may not have a compilation unit associated with them, and so ; may need to be treated differently from ordinary structs. ; ; Structs only handled by reference (indirectly), will also usually ; not need as much debugging information. Variable enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY } Variable enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY } ; True if we should exit after parsing options. Variable bool exit_after_options ; Type(s) of debugging information we are producing (if any). See ; flag-types.h for the definitions of the different possible types of ; debugging information. Variable enum debug_info_type write_symbols = NO_DEBUG ; Level of debugging information we are producing. See flag-types.h ; for the definitions of the different possible levels. Variable enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE ; Nonzero means use GNU-only extensions in the generated symbolic ; debugging information. Currently, this only has an effect when ; write_symbols is set to DBX_DEBUG or XCOFF_DEBUG. Variable bool use_gnu_debug_info_extensions ; Original value of maximum field alignment in bytes, specified via ; -fpack-struct=. Variable unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT ; Type of stack check. Variable enum stack_check_type flag_stack_check = NO_STACK_CHECK ; True if stack usage information needs to be computed. Variable bool flag_stack_usage_info = false ; -dA causes debug commentary information to be produced in ; the generated assembly code (to make it more readable). This option ; is generally only of use to those who actually need to read the ; generated assembly code (perhaps while debugging the compiler itself). ; Currently, this switch is only used by dwarf2out.c; however, it is intended ; to be a catchall for printing debug information in the assembler file. Variable int flag_debug_asm ; How many NOP insns to place at each function entry by default Variable HOST_WIDE_INT function_entry_patch_area_size ; And how far the real asm entry point is into this area Variable HOST_WIDE_INT function_entry_patch_area_start ; Balance between GNAT encodings and standard DWARF to emit. Variable enum dwarf_gnat_encodings gnat_encodings = DWARF_GNAT_ENCODINGS_DEFAULT ; -dP causes the rtl to be emitted as a comment in assembly. Variable int flag_dump_rtl_in_asm ; Whether -da was passed (used only in handle_common_deferred_options). Variable bool flag_dump_all_passed ; Other flags saying which kinds of debugging dump have been requested. Variable int rtl_dump_and_exit Variable int flag_print_asm_name ; Name of top-level original source file (what was input to cpp). ; This comes from the #-command at the beginning of the actual input. ; If there isn't any there, then this is the cc1 input file name. Variable const char *main_input_filename ; Pointer to base name in main_input_filename, with directories and a ; single final extension removed, and the length of this base ; name. Variable const char *main_input_basename Variable int main_input_baselength ; Which options have been printed by --help. Variable char *help_printed ; Which enums have been printed by --help. 0 = not printed, no ; relevant options seen, 1 = relevant option seen, not yet printed, 2 ; = printed. Variable char *help_enum_printed ; The number of columns for --help output. Variable unsigned int help_columns ; Whether this options structure has been through finish_options Variable bool flag_opts_finished ; What the sanitizer should instrument Variable unsigned int flag_sanitize ; What sanitizers should recover from errors Variable unsigned int flag_sanitize_recover = (SANITIZE_UNDEFINED | SANITIZE_UNDEFINED_NONDEFAULT | SANITIZE_KERNEL_ADDRESS) & ~(SANITIZE_UNREACHABLE | SANITIZE_RETURN) ; What the coverage sanitizers should instrument Variable unsigned int flag_sanitize_coverage ; Flag whether a prefix has been added to dump_base_name Variable bool dump_base_name_prefixed = false ; Flag whether HSA generation has been explicitely disabled Variable bool flag_disable_hsa = false ### Driver -assemble Driver Alias(S) -compile Driver Alias(c) -completion= Common Driver Joined Undocumented Provide bash completion for options starting with provided string. -coverage Driver Alias(coverage) -debug Common Alias(g) -dump Common Separate Alias(d) -dump= Common Joined Alias(d) -dumpbase Common Separate Alias(dumpbase) -dumpdir Common Separate Alias(dumpdir) -entry Driver Separate Alias(e) -entry= Driver Joined Alias(e) -extra-warnings Common Warning Alias(Wextra) -for-assembler Driver Separate Alias(Xassembler) -for-assembler= Driver JoinedOrMissing Alias(Xassembler) -for-linker Driver Separate Alias(Xlinker) -for-linker= Driver JoinedOrMissing Alias(Xlinker) -force-link Driver Separate Alias(u) -force-link= Driver Joined Alias(u) -help Common Driver Var(help_flag) Display this information. -help= Common Driver Report Joined --help= Display descriptions of a specific class of options. is one or more of optimizers, target, warnings, undocumented, params. -language Driver Separate Alias(x) -language= Driver Joined Alias(x) -library-directory Driver Separate Alias(L) -library-directory= Driver Joined Alias(L) -no-canonical-prefixes Driver Alias(no-canonical-prefixes) -no-standard-libraries Driver Alias(nostdlib) -no-sysroot-suffix Driver Var(no_sysroot_suffix) -no-warnings Common Alias(w) -optimize Common Alias(O) -output Common Driver Separate Alias(o) MissingArgError(missing filename after %qs) -output= Common Driver Joined Alias(o) MissingArgError(missing filename after %qs) -pass-exit-codes Driver Alias(pass-exit-codes) -pedantic Common Alias(Wpedantic) -pedantic-errors Common Alias(pedantic-errors) -pie Driver Alias(pie) -static-pie Driver Alias(static-pie) -pipe Driver Alias(pipe) -prefix Driver Separate Alias(B) -prefix= Driver JoinedOrMissing Alias(B) -preprocess Driver Alias(E) -print-file-name Driver Separate Alias(print-file-name=) -print-file-name= Driver JoinedOrMissing Alias(print-file-name=) -print-libgcc-file-name Driver Alias(print-libgcc-file-name) -print-multi-directory Driver Alias(print-multi-directory) -print-multi-lib Driver Alias(print-multi-lib) -print-multi-os-directory Driver Alias(print-multi-os-directory) -print-multiarch Driver Alias(print-multiarch) -print-prog-name Driver Separate Alias(print-prog-name=) -print-prog-name= Driver JoinedOrMissing Alias(print-prog-name=) -print-search-dirs Driver Alias(print-search-dirs) -print-sysroot Driver Alias(print-sysroot) -print-sysroot-headers-suffix Driver Alias(print-sysroot-headers-suffix) -profile Common Alias(p) -save-temps Driver Alias(save-temps) -shared Driver Alias(shared) -specs Driver Separate Alias(specs=) -specs= Driver Joined Alias(specs=) -static Driver Alias(static) -symbolic Driver Alias(symbolic) -target-help Common Driver Alias for --help=target. -time Driver Alias(time) -verbose Driver Alias(v) ;; The driver used to convert options such as --help into forms such ;; as -fhelp; the following four entries are for compatibility with ;; any direct uses of those (undocumented) -f forms fhelp Common Driver Alias(-help) fhelp= Common Driver Joined Alias(-help=) ftarget-help Common Driver Alias(-target-help) fversion Common Driver Alias(-version) -sysroot Driver Separate Alias(-sysroot=) -sysroot= Driver JoinedOrMissing -version Common Driver B Driver Joined Separate E Driver L Driver Joined Separate N Driver O Common JoinedOrMissing Optimization -O Set optimization level to . Os Common Optimization Optimize for space rather than speed. Ofast Common Optimization Optimize for speed disregarding exact standards compliance. Og Common Optimization Optimize for debugging experience rather than speed or size. Q Driver Qn Driver Negative(Qy) Qy Driver Negative(Qn) R Driver Joined Separate S Driver T Driver Joined Separate Tbss Driver Separate Tbss= Driver Joined Tdata Driver Separate Tdata= Driver Joined Ttext Driver Separate Ttext= Driver Joined W Common RejectNegative Warning Alias(Wextra) This switch is deprecated; use -Wextra instead. Wa, Driver JoinedOrMissing RejectNegative Wl, Driver JoinedOrMissing RejectNegative Wp, Driver JoinedOrMissing RejectNegative Waggregate-return Common Var(warn_aggregate_return) Warning Warn about returning structures, unions or arrays. Waggressive-loop-optimizations Common Var(warn_aggressive_loop_optimizations) Init(1) Warning Warn if a loop with constant number of iterations triggers undefined behavior. Warray-bounds Common Var(warn_array_bounds) Warning Warn if an array is accessed out of bounds. Warray-bounds= Common Joined RejectNegative UInteger Var(warn_array_bounds) Warning IntegerRange(0, 2) Warn if an array is accessed out of bounds. Wattributes Common Var(warn_attributes) Init(1) Warning Warn about inappropriate attribute usage. Wattribute-alias Common Alias(Wattribute_alias=, 1, 0) Warning Warn about type safety and similar errors and mismatches in declarations with alias attributes. Wattribute-alias= Common Joined RejectNegative UInteger Var(warn_attribute_alias) Init(1) Warning IntegerRange(0, 2) Warn about type safety and similar errors and mismatches in declarations with alias attributes. Wcannot-profile Common Var(warn_cannot_profile) Init(1) Warning Warn when profiling instrumentation was requested, but could not be applied to a certain function. Wcast-align Common Var(warn_cast_align) Warning Warn about pointer casts which increase alignment. Wcast-align=strict Common Var(warn_cast_align,2) Warning Warn about pointer casts which increase alignment. Wcpp Common Var(warn_cpp) Init(1) Warning Warn when a #warning directive is encountered. Wattribute-warning Common Var(warn_attribute_warning) Init(1) Warning Warn about uses of __attribute__((warning)) declarations. Wdeprecated Common Var(warn_deprecated) Init(1) Warning Warn if a deprecated compiler feature, class, method, or field is used. Wdeprecated-declarations Common Var(warn_deprecated_decl) Init(1) Warning Warn about uses of __attribute__((deprecated)) declarations. Wdisabled-optimization Common Var(warn_disabled_optimization) Warning Warn when an optimization pass is disabled. Werror Common Var(warnings_are_errors) Treat all warnings as errors. Werror= Common Joined Treat specified warning as error. Wextra Common Var(extra_warnings) Warning Print extra (possibly unwanted) warnings. Wfatal-errors Common Var(flag_fatal_errors) Exit on the first error occurred. Wframe-larger-than= Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_frame_larger_than_size) Init(HOST_WIDE_INT_MAX) -Wframe-larger-than= Warn if a function's stack frame requires in excess of . Wfree-nonheap-object Common Var(warn_free_nonheap_object) Init(1) Warning Warn when attempting to free a non-heap object. Whsa Common Var(warn_hsa) Init(1) Warning Warn when a function cannot be expanded to HSAIL. Wimplicit-fallthrough Common Alias(Wimplicit-fallthrough=,3,0) Warning Wimplicit-fallthrough= Common Var(warn_implicit_fallthrough) RejectNegative Joined UInteger Warning IntegerRange(0, 5) Warn when a switch case falls through. Winline Common Var(warn_inline) Warning Optimization Warn when an inlined function cannot be inlined. Winvalid-memory-model Common Var(warn_invalid_memory_model) Init(1) Warning Warn when an atomic memory model parameter is known to be outside the valid range. Wlarger-than- Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=) Wlarger-than= Common RejectNegative Joined Host_Wide_Int ByteSize Warning Var(warn_larger_than_size) Init(HOST_WIDE_INT_MAX) -Wlarger-than= Warn if an object's size exceeds . Wnonnull-compare Var(warn_nonnull_compare) Warning Warn if comparing pointer parameter with nonnull attribute with NULL. Wnull-dereference Common Var(warn_null_dereference) Warning Warn if dereferencing a NULL pointer may lead to erroneous or undefined behavior. Wunsafe-loop-optimizations Common Ignore Warning Does nothing. Preserved for backward compatibility. Wmissing-noreturn Common Warning Alias(Wsuggest-attribute=noreturn) Wodr Common Var(warn_odr_violations) Init(1) Warning Warn about some C++ One Definition Rule violations during link time optimization. Woverflow Common Var(warn_overflow) Init(1) Warning Warn about overflow in arithmetic expressions. Wlto-type-mismatch Common Var(warn_lto_type_mismatch) Init(1) Warning During link time optimization warn about mismatched types of global declarations. Wpacked Common Var(warn_packed) Warning Warn when the packed attribute has no effect on struct layout. Wpadded Common Var(warn_padded) Warning Warn when padding is required to align structure members. Wpedantic Common Var(pedantic) Init(0) Warning Issue warnings needed for strict compliance to the standard. Wreturn-local-addr Common Var(warn_return_local_addr) Init(1) Warning Warn about returning a pointer/reference to a local or temporary variable. Wshadow Common Var(warn_shadow) Warning Warn when one variable shadows another. Same as -Wshadow=global. Wshadow=global Common Warning Alias(Wshadow) Warn when one variable shadows another (globally). Wshadow=local Common Var(warn_shadow_local) Warning EnabledBy(Wshadow) Warn when one local variable shadows another local variable or parameter. Wshadow-local Common Warning Undocumented Alias(Wshadow=local) Wshadow=compatible-local Common Var(warn_shadow_compatible_local) Warning EnabledBy(Wshadow=local) Warn when one local variable shadows another local variable or parameter of compatible type. Wshadow-compatible-local Common Warning Undocumented Alias(Wshadow=compatible-local) Wstack-protector Common Var(warn_stack_protect) Warning Warn when not issuing stack smashing protection for some reason. Wstack-usage= Common Joined RejectNegative Host_Wide_Int ByteSize Var(warn_stack_usage) Warning Init(HOST_WIDE_INT_MAX) -Wstack-usage= Warn if stack usage might exceed . Wstrict-aliasing Common Warning Warn about code which might break strict aliasing rules. Wstrict-aliasing= Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning Warn about code which might break strict aliasing rules. Wstrict-overflow Common Warning Warn about optimizations that assume that signed overflow is undefined. Wstrict-overflow= Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning Warn about optimizations that assume that signed overflow is undefined. Wsuggest-attribute=cold Common Var(warn_suggest_attribute_cold) Warning Warn about functions which might be candidates for __attribute__((cold)). Wsuggest-attribute=const Common Var(warn_suggest_attribute_const) Warning Warn about functions which might be candidates for __attribute__((const)). Wsuggest-attribute=pure Common Var(warn_suggest_attribute_pure) Warning Warn about functions which might be candidates for __attribute__((pure)). Wsuggest-attribute=noreturn Common Var(warn_suggest_attribute_noreturn) Warning Warn about functions which might be candidates for __attribute__((noreturn)). Wsuggest-attribute=malloc Common Var(warn_suggest_attribute_malloc) Warning Warn about functions which might be candidates for __attribute__((malloc)). Wsuggest-final-types Common Var(warn_suggest_final_types) Warning Warn about C++ polymorphic types where adding final keyword would improve code quality. Wsuggest-final-methods Common Var(warn_suggest_final_methods) Warning Warn about C++ virtual methods where adding final keyword would improve code quality. Wswitch-unreachable Common Var(warn_switch_unreachable) Warning Init(1) Warn about statements between switch's controlling expression and the first case. Wsystem-headers Common Var(warn_system_headers) Warning Do not suppress warnings from system headers. Wtrampolines Common Var(warn_trampolines) Warning Warn whenever a trampoline is generated. Wtype-limits Common Var(warn_type_limits) Warning EnabledBy(Wextra) Warn if a comparison is always true or always false due to the limited range of the data type. Wuninitialized Common Var(warn_uninitialized) Warning EnabledBy(Wextra) Warn about uninitialized automatic variables. Wmaybe-uninitialized Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized) Warn about maybe uninitialized automatic variables. Wunreachable-code Common Ignore Warning Does nothing. Preserved for backward compatibility. Wunused Common Var(warn_unused) Init(0) Warning Enable all -Wunused- warnings. Wunused-but-set-parameter Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra) Warn when a function parameter is only set, otherwise unused. Wunused-but-set-variable Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused) Warn when a variable is only set, otherwise unused. Wunused-function Common Var(warn_unused_function) Warning EnabledBy(Wunused) Warn when a function is unused. Wunused-label Common Var(warn_unused_label) Warning EnabledBy(Wunused) Warn when a label is unused. Wunused-parameter Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra) Warn when a function parameter is unused. Wunused-value Common Var(warn_unused_value) Warning EnabledBy(Wunused) Warn when an expression value is unused. Wunused-variable Common Var(warn_unused_variable) Warning EnabledBy(Wunused) Warn when a variable is unused. Wcoverage-mismatch Common Var(warn_coverage_mismatch) Init(1) Warning Warn in case profiles in -fprofile-use do not match. Wmissing-profile Common Var(warn_missing_profile) Init(1) Warning Warn in case profiles in -fprofile-use do not exist. Wvector-operation-performance Common Var(warn_vector_operation_performance) Warning Warn when a vector operation is compiled outside the SIMD. Xassembler Driver Separate Xlinker Driver Separate Xpreprocessor Driver Separate Z Driver aux-info Common Separate Var(aux_info_file_name) -aux-info Emit declaration information into . aux-info= Common Joined Alias(aux-info) auxbase Common Separate RejectDriver Var(aux_base_name) auxbase-strip Common Separate RejectDriver coverage Driver c Driver d Common Joined -d Enable dumps from specific passes of the compiler. dumpbase Common Separate Var(dump_base_name) -dumpbase Set the file basename to be used for dumps. dumpdir Common Separate Var(dump_dir_name) -dumpdir Set the directory name to be used for dumps. dumpmachine Driver dumpspecs Driver dumpversion Driver dumpfullversion Driver e Driver Joined Separate ; This option has historically been passed down to the linker by an ; accident of a %{e*} spec, so ensure it continues to be passed down ; as a single option. The supported option for this purpose is ; -rdynamic. See PR 47390. export-dynamic Driver Undocumented ; The version of the C++ ABI in use. The following values are allowed: ; ; 0: The version of the ABI believed most conformant with the C++ ABI ; specification. This ABI may change as bugs are discovered and fixed. ; Therefore, 0 will not necessarily indicate the same ABI in different ; versions of G++. ; ; 1: The version of the ABI first used in G++ 3.2. No longer selectable. ; ; 2: The version of the ABI first used in G++ 3.4, and the default ; until GCC 4.9. ; ; 3: The version of the ABI that fixes the missing underscore ; in template non-type arguments of pointer type. ; ; 4: The version of the ABI that introduces unambiguous mangling of ; vector types. First selectable in G++ 4.5. ; ; 5: The version of the ABI that ignores attribute const/noreturn ; in function pointer mangling, and corrects mangling of decltype and ; function parameters used in other parameters and the return type. ; First selectable in G++ 4.6. ; ; 6: The version of the ABI that doesn't promote scoped enums to int and ; changes the mangling of template argument packs, const/static_cast, ; prefix ++ and --, and a class scope function used as a template ; argument. ; First selectable in G++ 4.7. ; ; 7: The version of the ABI that treats nullptr_t as a builtin type and ; corrects the mangling of lambdas in default argument scope. ; First selectable in G++ 4.8. ; ; 8: The version of the ABI that corrects the substitution behavior of ; function types with function-cv-qualifiers. ; First selectable in G++ 4.9 and default in G++ 5. ; ; 9: The version of the ABI that corrects the alignment of nullptr_t. ; First selectable and default in G++ 5.2. ; ; 10: The version of the ABI that mangles attributes that affect type ; identity, such as ia32 calling convention attributes (stdcall, etc.) ; Default in G++ 6 (set in c_common_post_options). ; ; 11: The version of the ABI that corrects mangling of sizeof... expressions ; and introduces new inheriting constructor handling. ; Default in G++ 7. ; ; 12: Corrects the calling convention for classes with only deleted copy/move ; constructors and changes passing/returning of empty records. ; Default in G++ 8.1. ; ; 13: Fixes the accidental change in 12 to the calling convention for classes ; with deleted copy constructor and trivial move constructor. ; Default in G++ 8.2. ; 14: Corrects the mangling of nullptr expression. ; Default in G++ 10. ; ; Additional positive integers will be assigned as new versions of ; the ABI become the default version of the ABI. fabi-version= Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0) The version of the C++ ABI in use. faggressive-loop-optimizations Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1) Aggressively optimize loops using language constraints. falign-functions Common Report Var(flag_align_functions) Optimization Align the start of functions. falign-functions= Common RejectNegative Joined Var(str_align_functions) Optimization flimit-function-alignment Common Report Var(flag_limit_function_alignment) Optimization Init(0) falign-jumps Common Report Var(flag_align_jumps) Optimization Align labels which are only reached by jumping. falign-jumps= Common RejectNegative Joined Var(str_align_jumps) Optimization falign-labels Common Report Var(flag_align_labels) Optimization Align all labels. falign-labels= Common RejectNegative Joined Var(str_align_labels) Optimization falign-loops Common Report Var(flag_align_loops) Optimization Align the start of loops. falign-loops= Common RejectNegative Joined Var(str_align_loops) Optimization fallow-store-data-races Common Report Var(flag_store_data_races) Optimization Allow the compiler to introduce new data races on stores. fanalyzer Common Var(flag_analyzer) Enable static analysis pass. fargument-alias Common Ignore Does nothing. Preserved for backward compatibility. fargument-noalias Common Ignore Does nothing. Preserved for backward compatibility. fargument-noalias-global Common Ignore Does nothing. Preserved for backward compatibility. fargument-noalias-anything Common Ignore Does nothing. Preserved for backward compatibility. fsanitize= Common Driver Report Joined Select what to sanitize. fsanitize-coverage= Common Report Joined Select type of coverage sanitization. fasan-shadow-offset= Common Joined RejectNegative Var(common_deferred_options) Defer -fasan-shadow-offset= Use custom shadow memory offset. fsanitize-sections= Common Joined RejectNegative Var(common_deferred_options) Defer -fsanitize-sections= Sanitize global variables in user-defined sections. fsanitize-recover= Common Report Joined After diagnosing undefined behavior attempt to continue execution. fsanitize-recover Common Report This switch is deprecated; use -fsanitize-recover= instead. fsanitize-address-use-after-scope Common Driver Report Var(flag_sanitize_address_use_after_scope) Init(0) fsanitize-undefined-trap-on-error Common Driver Report Var(flag_sanitize_undefined_trap_on_error) Init(0) Use trap instead of a library function for undefined behavior sanitization. fasynchronous-unwind-tables Common Report Var(flag_asynchronous_unwind_tables) Optimization Generate unwind tables that are exact at each instruction boundary. fauto-inc-dec Common Report Var(flag_auto_inc_dec) Init(1) Optimization Generate auto-inc/dec instructions. fauto-profile Common Report Var(flag_auto_profile) Use sample profile information for call graph node weights. The default profile file is fbdata.afdo in 'pwd'. fauto-profile= Common Joined RejectNegative Var(auto_profile_file) Use sample profile information for call graph node weights. The profile file is specified in the argument. ; -fcheck-bounds causes gcc to generate array bounds checks. ; For C, C++ and ObjC: defaults off. ; For Java: defaults to on. ; For Fortran: defaults to off. fbounds-check Common Report Var(flag_bounds_check) Generate code to check bounds before indexing arrays. fbranch-count-reg Common Report Var(flag_branch_on_count_reg) Optimization Replace add, compare, branch with branch on count register. fbranch-probabilities Common Report Var(flag_branch_probabilities) Optimization Use profiling information for branch probabilities. fbranch-target-load-optimize Common Ignore Does nothing. Preserved for backward compatibility. fbranch-target-load-optimize2 Common Ignore Does nothing. Preserved for backward compatibility. fbtr-bb-exclusive Common Ignore Does nothing. Preserved for backward compatibility. fcallgraph-info Common Report RejectNegative Var(flag_callgraph_info) Init(NO_CALLGRAPH_INFO); Output callgraph information on a per-file basis. fcallgraph-info= Common Report RejectNegative Joined Output callgraph information on a per-file basis with decorations. fcall-saved- Common Joined RejectNegative Var(common_deferred_options) Defer -fcall-saved- Mark as being preserved across functions. fcall-used- Common Joined RejectNegative Var(common_deferred_options) Defer -fcall-used- Mark as being corrupted by function calls. ; Nonzero for -fcaller-saves: allocate values in regs that need to ; be saved across function calls, if that produces overall better code. ; Optional now, so people can test it. fcaller-saves Common Report Var(flag_caller_saves) Optimization Save registers around function calls. fcheck-data-deps Common Ignore This switch is deprecated; do not use. fcheck-new Common Var(flag_check_new) Check the return value of new in C++. fchecking Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0) Perform internal consistency checkings. fchecking= Common Joined RejectNegative UInteger Var(flag_checking) Perform internal consistency checkings. fcode-hoisting Common Report Var(flag_code_hoisting) Optimization Enable code hoisting. fcombine-stack-adjustments Common Report Var(flag_combine_stack_adjustments) Optimization Looks for opportunities to reduce stack adjustments and stack references. fcommon Common Report Var(flag_no_common,0) Init(1) Put uninitialized globals in the common section. fcompare-debug Driver ; Converted by the driver to -fcompare-debug= options. fcompare-debug= Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt) -fcompare-debug[=] Compile with and without e.g. -gtoggle, and compare the final-insns dump. fcompare-debug-second Common Driver RejectNegative Var(flag_compare_debug) Run only the second compilation of -fcompare-debug. fcompare-elim Common Report Var(flag_compare_elim_after_reload) Optimization Perform comparison elimination after register allocation has finished. fconserve-stack Common Var(flag_conserve_stack) Optimization Do not perform optimizations increasing noticeably stack usage. fcprop-registers Common Report Var(flag_cprop_registers) Optimization Perform a register copy-propagation optimization pass. fcrossjumping Common Report Var(flag_crossjumping) Optimization Perform cross-jumping optimization. fcse-follow-jumps Common Report Var(flag_cse_follow_jumps) Optimization When running CSE, follow jumps to their targets. fcse-skip-blocks Common Ignore Does nothing. Preserved for backward compatibility. fcx-limited-range Common Report Var(flag_cx_limited_range) Optimization SetByCombined Omit range reduction step when performing complex division. fcx-fortran-rules Common Report Var(flag_cx_fortran_rules) Optimization Complex multiplication and division follow Fortran rules. fdata-sections Common Report Var(flag_data_sections) Place data items into their own section. fdbg-cnt-list Common Report Var(common_deferred_options) Defer List all available debugging counters with their limits and counts. fdbg-cnt= Common RejectNegative Joined Var(common_deferred_options) Defer -fdbg-cnt=[:-][:-:...][,:...] Set the debug counter limit. fdebug-prefix-map= Common Joined RejectNegative Var(common_deferred_options) Defer -fdebug-prefix-map== Map one directory name to another in debug information. ffile-prefix-map= Common Joined RejectNegative Var(common_deferred_options) Defer -ffile-prefix-map== Map one directory name to another in compilation result. fdebug-types-section Common Report Var(flag_debug_types_section) Init(0) Output .debug_types section when using DWARF v4 debuginfo. ; Nonzero for -fdefer-pop: don't pop args after each function call ; instead save them up to pop many calls' args with one insns. fdefer-pop Common Report Var(flag_defer_pop) Optimization Defer popping functions args from stack until later. fdelayed-branch Common Report Var(flag_delayed_branch) Optimization Attempt to fill delay slots of branch instructions. fdelete-dead-exceptions Common Report Var(flag_delete_dead_exceptions) Init(0) Optimization Delete dead instructions that may throw exceptions. fdelete-null-pointer-checks Common Report Var(flag_delete_null_pointer_checks) Init(-1) Optimization Delete useless null pointer checks. fdevirtualize-at-ltrans Common Report Var(flag_ltrans_devirtualize) Stream extra data to support more aggressive devirtualization in LTO local transformation mode. fdevirtualize-speculatively Common Report Var(flag_devirtualize_speculatively) Optimization Perform speculative devirtualization. fdevirtualize Common Report Var(flag_devirtualize) Optimization Try to convert virtual calls to direct ones. fdiagnostics-show-location= Common Joined RejectNegative Enum(diagnostic_prefixing_rule) -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics. ; Required for these enum values. SourceInclude pretty-print.h Enum Name(diagnostic_prefixing_rule) Type(int) EnumValue Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE) EnumValue Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE) fdiagnostics-show-caret Common Var(flag_diagnostics_show_caret) Init(1) Show the source line with a caret indicating the column. fdiagnostics-show-labels Common Var(flag_diagnostics_show_labels) Init(1) Show labels annotating ranges of source code when showing source. fdiagnostics-show-line-numbers Common Var(flag_diagnostics_show_line_numbers) Init(1) Show line numbers in the left margin when showing source. fdiagnostics-color Common Alias(fdiagnostics-color=,always,never) ; fdiagnostics-color= Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO) -fdiagnostics-color=[never|always|auto] Colorize diagnostics. ; Required for these enum values. SourceInclude diagnostic-color.h Enum Name(diagnostic_color_rule) Type(int) EnumValue Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO) EnumValue Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES) EnumValue Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO) fdiagnostics-urls= Driver Common Joined RejectNegative Var(flag_diagnostics_show_urls) Enum(diagnostic_url_rule) Init(DIAGNOSTICS_URL_AUTO) -fdiagnostics-urls=[never|always|auto] Embed URLs in diagnostics. ; Required for these enum values. SourceInclude diagnostic-url.h Enum Name(diagnostic_url_rule) Type(int) EnumValue Enum(diagnostic_url_rule) String(never) Value(DIAGNOSTICS_URL_NO) EnumValue Enum(diagnostic_url_rule) String(always) Value(DIAGNOSTICS_URL_YES) EnumValue Enum(diagnostic_url_rule) String(auto) Value(DIAGNOSTICS_URL_AUTO) fdiagnostics-format= Common Joined RejectNegative Enum(diagnostics_output_format) -fdiagnostics-format=[text|json] Select output format. ; Required for these enum values. SourceInclude diagnostic.h Enum Name(diagnostics_output_format) Type(int) EnumValue Enum(diagnostics_output_format) String(text) Value(DIAGNOSTICS_OUTPUT_FORMAT_TEXT) EnumValue Enum(diagnostics_output_format) String(json) Value(DIAGNOSTICS_OUTPUT_FORMAT_JSON) fdiagnostics-parseable-fixits Common Var(flag_diagnostics_parseable_fixits) Print fix-it hints in machine-readable form. fdiagnostics-generate-patch Common Var(flag_diagnostics_generate_patch) Print fix-it hints to stderr in unified diff format. fdiagnostics-show-option Common Var(flag_diagnostics_show_option) Init(1) Amend appropriate diagnostic messages with the command line option that controls them. fdiagnostics-show-cwe Common Var(flag_diagnostics_show_cwe) Init(1) Print CWE identifiers for diagnostic messages, where available. fdiagnostics-path-format= Common Joined RejectNegative Var(flag_diagnostics_path_format) Enum(diagnostic_path_format) Init(DPF_INLINE_EVENTS) Specify how to print any control-flow path associated with a diagnostic. Enum Name(diagnostic_path_format) Type(int) EnumValue Enum(diagnostic_path_format) String(none) Value(DPF_NONE) EnumValue Enum(diagnostic_path_format) String(separate-events) Value(DPF_SEPARATE_EVENTS) EnumValue Enum(diagnostic_path_format) String(inline-events) Value(DPF_INLINE_EVENTS) fdiagnostics-show-path-depths Common Var(flag_diagnostics_show_path_depths) Init(0) Show stack depths of events in paths. fdiagnostics-minimum-margin-width= Common Joined UInteger Var(diagnostics_minimum_margin_width) Init(6) Set minimum width of left margin of source code when showing source. fdisable- Common Joined RejectNegative Var(common_deferred_options) Defer -fdisable-[tree|rtl|ipa]-=range1+range2 disables an optimization pass. fenable- Common Joined RejectNegative Var(common_deferred_options) Defer -fenable-[tree|rtl|ipa]-=range1+range2 enables an optimization pass. fdump- Common Joined RejectNegative Var(common_deferred_options) Defer -fdump- Dump various compiler internals to a file. fdump-final-insns Driver RejectNegative fdump-final-insns= Common RejectNegative Joined Var(flag_dump_final_insns) -fdump-final-insns=filename Dump to filename the insns at the end of translation. fdump-go-spec= Common RejectNegative Joined Var(flag_dump_go_spec) -fdump-go-spec=filename Write all declarations to file as Go code. fdump-noaddr Common Report Var(flag_dump_noaddr) Suppress output of addresses in debugging dumps. freport-bug Common Driver Var(flag_report_bug) Collect and dump debug information into temporary file if ICE in C/C++ compiler occurred. fdump-internal-locations Common Var(flag_dump_locations) Init(0) Dump detailed information on GCC's internal representation of source code locations. fdump-passes Common Var(flag_dump_passes) Init(0) Dump optimization passes. fdump-unnumbered Common Report Var(flag_dump_unnumbered) Suppress output of instruction numbers, line number notes and addresses in debugging dumps. fdump-unnumbered-links Common Report Var(flag_dump_unnumbered_links) Suppress output of previous and next insn numbers in debugging dumps. fdwarf2-cfi-asm Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE) Enable CFI tables via GAS assembler directives. fearly-inlining Common Report Var(flag_early_inlining) Init(1) Optimization Perform early inlining. feliminate-dwarf2-dups Common Ignore Does nothing. Preserved for backward compatibility. fipa-sra Common Report Var(flag_ipa_sra) Init(0) Optimization Perform interprocedural reduction of aggregates. feliminate-unused-debug-symbols Common Report Var(flag_debug_only_used_symbols) Init(1) Perform unused symbol elimination in debug info. feliminate-unused-debug-types Common Report Var(flag_eliminate_unused_debug_types) Init(1) Perform unused type elimination in debug info. femit-class-debug-always Common Report Var(flag_emit_class_debug_always) Init(0) Do not suppress C++ class debug information. fexceptions Common Report Var(flag_exceptions) Optimization Enable exception handling. fexpensive-optimizations Common Report Var(flag_expensive_optimizations) Optimization Perform a number of minor, expensive optimizations. fexcess-precision= Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision) Init(EXCESS_PRECISION_DEFAULT) Optimization SetByCombined -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision. Enum Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs) EnumValue Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST) EnumValue Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD) ; Whether we permit the extended set of values for FLT_EVAL_METHOD ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11. fpermitted-flt-eval-methods= Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT) -fpermitted-flt-eval-methods=[c11|ts-18661] Specify which values of FLT_EVAL_METHOD are permitted. Enum 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) EnumValue Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11) EnumValue Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661) ffast-math Common Optimization ffat-lto-objects Common Var(flag_fat_lto_objects) Output lto objects containing both the intermediate language and binary output. ffinite-math-only Common Report Var(flag_finite_math_only) Optimization SetByCombined Assume no NaNs or infinities are generated. ffinite-loops Common Report Var(flag_finite_loops) Optimization Assume that loops with an exit will terminate and not loop indefinitely. ffixed- Common Joined RejectNegative Var(common_deferred_options) Defer -ffixed- Mark as being unavailable to the compiler. ffloat-store Common Report Var(flag_float_store) Optimization Don't allocate floats and doubles in extended-precision registers. fforce-addr Common Ignore Does nothing. Preserved for backward compatibility. fforward-propagate Common Report Var(flag_forward_propagate) Optimization Perform a forward propagation pass on RTL. ffp-contract= Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization -ffp-contract=[off|on|fast] Perform floating-point expression contraction. Enum Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs) EnumValue Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF) ; Not implemented, fall back to conservative FP_CONTRACT_OFF. EnumValue Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF) EnumValue Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST) ffp-int-builtin-inexact Common Report Var(flag_fp_int_builtin_inexact) Init(1) Optimization Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions. ; Nonzero means don't put addresses of constant functions in registers. ; Used for compiling the Unix kernel, where strange substitutions are ; done on the assembly output. ffunction-cse Common Report Var(flag_no_function_cse,0) Optimization Allow function addresses to be held in registers. ffunction-sections Common Report Var(flag_function_sections) Place each function into its own section. fgcse Common Report Var(flag_gcse) Optimization Perform global common subexpression elimination. fgcse-lm Common Report Var(flag_gcse_lm) Init(1) Optimization Perform enhanced load motion during global common subexpression elimination. fgcse-sm Common Report Var(flag_gcse_sm) Init(0) Optimization Perform store motion after global common subexpression elimination. fgcse-las Common Report Var(flag_gcse_las) Init(0) Optimization Perform redundant load after store elimination in global common subexpression elimination. fgcse-after-reload Common Report Var(flag_gcse_after_reload) Optimization Perform global common subexpression elimination after register allocation has finished. Enum Name(dwarf_gnat_encodings) Type(int) EnumValue Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL) EnumValue Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB) EnumValue Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL) fgnat-encodings= Common Enum(dwarf_gnat_encodings) Joined RejectNegative Report Undocumented Var(gnat_encodings) -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information. ; This option is not documented yet as its semantics will change. fgraphite Common Report Var(flag_graphite) Optimization Enable in and out of Graphite representation. fgraphite-identity Common Report Var(flag_graphite_identity) Optimization Enable Graphite Identity transformation. fhoist-adjacent-loads Common Report Var(flag_hoist_adjacent_loads) Optimization Enable hoisting adjacent loads to encourage generating conditional move instructions. fkeep-gc-roots-live Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization ; Always keep a pointer to a live memory block floop-parallelize-all Common Report Var(flag_loop_parallelize_all) Optimization Mark all loops as parallel. floop-strip-mine Common Alias(floop-nest-optimize) Enable loop nest transforms. Same as -floop-nest-optimize. floop-interchange Common Report Var(flag_loop_interchange) Optimization Enable loop interchange on trees. floop-block Common Alias(floop-nest-optimize) Enable loop nest transforms. Same as -floop-nest-optimize. floop-unroll-and-jam Common Report Var(flag_unroll_jam) Optimization Perform unroll-and-jam on loops. fgnu-tm Common Report Var(flag_tm) Enable support for GNU transactional memory. fgnu-unique Common Report Var(flag_gnu_unique) Init(1) Use STB_GNU_UNIQUE if supported by the assembler. floop-flatten Common Ignore Does nothing. Preserved for backward compatibility. floop-nest-optimize Common Report Var(flag_loop_nest_optimize) Optimization Enable the loop nest optimizer. fstrict-volatile-bitfields Common Report Var(flag_strict_volatile_bitfields) Init(-1) Optimization Force bitfield accesses to match their type width. fstore-merging Common Report Var(flag_store_merging) Optimization Merge adjacent stores. fguess-branch-probability Common Report Var(flag_guess_branch_prob) Optimization Enable guessing of branch probabilities. ; Nonzero means ignore `#ident' directives. 0 means handle them. ; Generate position-independent code for executables if possible ; On SVR4 targets, it also controls whether or not to emit a ; string identifying the compiler. fident Common Report Var(flag_no_ident,0) Process #ident directives. fif-conversion Common Report Var(flag_if_conversion) Optimization Perform conversion of conditional jumps to branchless equivalents. fif-conversion2 Common Report Var(flag_if_conversion2) Optimization Perform conversion of conditional jumps to conditional execution. fstack-reuse= Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables. Enum Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs) EnumValue Enum(stack_reuse_level) String(all) Value(SR_ALL) EnumValue Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS) EnumValue Enum(stack_reuse_level) String(none) Value(SR_NONE) ftree-loop-if-convert Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization Convert conditional jumps in innermost loops to branchless equivalents. ftree-loop-if-convert-stores Common Ignore Does nothing. Preserved for backward compatibility. ; -finhibit-size-directive inhibits output of .size for ELF. ; This is used only for compiling crtstuff.c, ; and it may be extended to other effects ; needed for crtstuff.c on other systems. finhibit-size-directive Common Report Var(flag_inhibit_size_directive) Do not generate .size directives. findirect-inlining Common Report Var(flag_indirect_inlining) Optimization Perform indirect inlining. ; General flag to enable inlining. Specifying -fno-inline will disable ; all inlining apart from always-inline functions. finline Common Report Var(flag_no_inline,0) Init(0) Optimization Enable inlining of function declared \"inline\", disabling disables all inlining. finline-small-functions Common Report Var(flag_inline_small_functions) Optimization Integrate functions into their callers when code size is known not to grow. finline-functions Common Report Var(flag_inline_functions) Optimization Integrate functions not declared \"inline\" into their callers when profitable. finline-functions-called-once Common Report Var(flag_inline_functions_called_once) Optimization Integrate functions only required by their single caller. finline-limit- Common RejectNegative Joined Alias(finline-limit=) finline-limit= Common RejectNegative Joined UInteger -finline-limit= Limit the size of inlined functions to . finline-atomics Common Report Var(flag_inline_atomics) Init(1) Optimization Inline __atomic operations when a lock free instruction sequence is available. fcf-protection Common RejectNegative Alias(fcf-protection=,full) fcf-protection= Common Report Joined RejectNegative Enum(cf_protection_level) Var(flag_cf_protection) Init(CF_NONE) -fcf-protection=[full|branch|return|none] Instrument functions with checks to verify jump/call/return control-flow transfer instructions have valid targets. Enum Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Control-Flow Protection Level %qs) EnumValue Enum(cf_protection_level) String(full) Value(CF_FULL) EnumValue Enum(cf_protection_level) String(branch) Value(CF_BRANCH) EnumValue Enum(cf_protection_level) String(return) Value(CF_RETURN) EnumValue Enum(cf_protection_level) String(none) Value(CF_NONE) finstrument-functions Common Report Var(flag_instrument_function_entry_exit) Instrument function entry and exit with profiling calls. finstrument-functions-exclude-function-list= Common RejectNegative Joined -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions. finstrument-functions-exclude-file-list= Common RejectNegative Joined -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files. fipa-cp Common Report Var(flag_ipa_cp) Optimization Perform interprocedural constant propagation. fipa-cp-clone Common Report Var(flag_ipa_cp_clone) Optimization Perform cloning to make Interprocedural constant propagation stronger. fipa-cp-alignment Common Ignore Does nothing. Preserved for backward compatibility. fipa-bit-cp Common Report Var(flag_ipa_bit_cp) Optimization Perform interprocedural bitwise constant propagation. fipa-profile Common Report Var(flag_ipa_profile) Init(0) Optimization Perform interprocedural profile propagation. fipa-pta Common Report Var(flag_ipa_pta) Init(0) Optimization Perform interprocedural points-to analysis. fipa-pure-const Common Report Var(flag_ipa_pure_const) Init(0) Optimization Discover pure and const functions. fipa-icf Common Report Var(flag_ipa_icf) Optimization Perform Identical Code Folding for functions and read-only variables. fipa-icf-functions Common Report Var(flag_ipa_icf_functions) Optimization Perform Identical Code Folding for functions. fipa-icf-variables Common Report Var(flag_ipa_icf_variables) Optimization Perform Identical Code Folding for variables. fipa-reference Common Report Var(flag_ipa_reference) Init(0) Optimization Discover read-only and non addressable static variables. fipa-reference-addressable Common Report Var(flag_ipa_reference_addressable) Init(0) Optimization Discover read-only, write-only and non-addressable static variables. fipa-stack-alignment Common Report Var(flag_ipa_stack_alignment) Init(1) Optimization Reduce stack alignment on call sites if possible. fipa-matrix-reorg Common Ignore Does nothing. Preserved for backward compatibility. fipa-struct-reorg Common Ignore Does nothing. Preserved for backward compatibility. fipa-vrp Common Report Var(flag_ipa_vrp) Optimization Perform IPA Value Range Propagation. fira-algorithm= Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization -fira-algorithm=[CB|priority] Set the used IRA algorithm. Enum Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs) EnumValue Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB) EnumValue Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY) fira-region= Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT) Optimization -fira-region=[one|all|mixed] Set regions for IRA. Enum Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs) EnumValue Enum(ira_region) String(one) Value(IRA_REGION_ONE) EnumValue Enum(ira_region) String(all) Value(IRA_REGION_ALL) EnumValue Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED) fira-hoist-pressure Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization Use IRA based register pressure calculation in RTL hoist optimizations. fira-loop-pressure Common Report Var(flag_ira_loop_pressure) Optimization Use IRA based register pressure calculation in RTL loop optimizations. fira-share-save-slots Common Report Var(flag_ira_share_save_slots) Init(1) Optimization Share slots for saving different hard registers. fira-share-spill-slots Common Report Var(flag_ira_share_spill_slots) Init(1) Optimization Share stack slots for spilled pseudo-registers. fira-verbose= Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5) -fira-verbose= Control IRA's level of diagnostic messages. fivopts Common Report Var(flag_ivopts) Init(1) Optimization Optimize induction variables on trees. fjump-tables Common Var(flag_jump_tables) Init(1) Optimization Use jump tables for sufficiently large switch statements. fkeep-inline-functions Common Report Var(flag_keep_inline_functions) Generate code for functions even if they are fully inlined. fkeep-static-functions Common Report Var(flag_keep_static_functions) Generate code for static functions even if they are never called. fkeep-static-consts Common Report Var(flag_keep_static_consts) Init(1) Emit static const variables even if they are not used. fleading-underscore Common Report Var(flag_leading_underscore) Init(-1) Give external symbols a leading underscore. floop-optimize Common Ignore Does nothing. Preserved for backward compatibility. flra-remat Common Report Var(flag_lra_remat) Optimization Do CFG-sensitive rematerialization in LRA. flto Common Enable link-time optimization. flto= Common RejectNegative Joined Var(flag_lto) Link-time optimization with number of parallel jobs or jobserver. Enum Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs) EnumValue Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE) EnumValue Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE) EnumValue Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED) EnumValue Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1) EnumValue Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX) flto-partition= Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED) Specify the algorithm to partition symbols and vars at linktime. ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h. flto-compression-level= Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 19) -flto-compression-level= Use zlib/zstd compression level for IL. flto-odr-type-merging Common Ignore Does nothing. Preserved for backward compatibility. flto-report Common Report Var(flag_lto_report) Init(0) Report various link-time optimization statistics. flto-report-wpa Common Report Var(flag_lto_report_wpa) Init(0) Report various link-time optimization statistics for WPA only. fmath-errno Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined Set errno after built-in math functions. fmax-errors= Common Joined RejectNegative UInteger Var(flag_max_errors) -fmax-errors= Maximum number of errors to report. fmem-report Common Report Var(mem_report) Report on permanent memory allocation. fmem-report-wpa Common Report Var(mem_report_wpa) Report on permanent memory allocation in WPA only. ; This will attempt to merge constant section constants, if 1 only ; string constants and constants from constant pool, if 2 also constant ; variables. fmerge-all-constants Common Report Var(flag_merge_constants,2) Init(1) Attempt to merge identical constants and constant variables. fmerge-constants Common Report Var(flag_merge_constants,1) Attempt to merge identical constants across compilation units. fmerge-debug-strings Common Report Var(flag_merge_debug_strings) Init(1) Attempt to merge identical debug strings across compilation units. fmessage-length= Common RejectNegative Joined UInteger -fmessage-length= Limit diagnostics to characters per line. 0 suppresses line-wrapping. fmodulo-sched Common Report Var(flag_modulo_sched) Optimization Perform SMS based modulo scheduling before the first scheduling pass. fmodulo-sched-allow-regmoves Common Report Var(flag_modulo_sched_allow_regmoves) Optimization Perform SMS based modulo scheduling with register moves allowed. fmove-loop-invariants Common Report Var(flag_move_loop_invariants) Optimization Move loop invariant computations out of loops. fdce Common Var(flag_dce) Init(1) Optimization Use the RTL dead code elimination pass. fdse Common Var(flag_dse) Init(0) Optimization Use the RTL dead store elimination pass. freschedule-modulo-scheduled-loops Common Report Var(flag_resched_modulo_sched) Optimization Enable/Disable the traditional scheduling in loops that already passed modulo scheduling. fnon-call-exceptions Common Report Var(flag_non_call_exceptions) Optimization Support synchronous non-call exceptions. foffload= Common Driver Joined MissingArgError(options or targets missing after %qs) -foffload== Specify offloading targets and options for them. foffload-abi= Common Joined RejectNegative Enum(offload_abi) Var(flag_offload_abi) Init(OFFLOAD_ABI_UNSET) -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler. Enum Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs) EnumValue Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32) EnumValue Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64) fomit-frame-pointer Common Report Var(flag_omit_frame_pointer) Optimization When possible do not generate stack frames. fopt-info Common Report Var(flag_opt_info) Optimization Enable all optimization info dumps on stderr. fopt-info- Common Joined RejectNegative Var(common_deferred_options) Defer -fopt-info[-=filename] Dump compiler optimization details. fsave-optimization-record Common Report Var(flag_save_optimization_record) Optimization Write a SRCFILE.opt-record.json file detailing what optimizations were performed. foptimize-register-move Common Ignore Does nothing. Preserved for backward compatibility. foptimize-sibling-calls Common Report Var(flag_optimize_sibling_calls) Optimization Optimize sibling and tail recursive calls. fpartial-inlining Common Report Var(flag_partial_inlining) Optimization Perform partial inlining. fpre-ipa-mem-report Common Report Var(pre_ipa_mem_report) Report on memory allocation before interprocedural optimization. fpost-ipa-mem-report Common Report Var(post_ipa_mem_report) Report on memory allocation before interprocedural optimization. fpack-struct Common Report Var(flag_pack_struct) Optimization Pack structure members together without holes. fpack-struct= Common RejectNegative Joined UInteger Optimization -fpack-struct= Set initial maximum structure member alignment. fpcc-struct-return Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN) Return small aggregates in memory, not registers. fpeel-loops Common Report Var(flag_peel_loops) Optimization Perform loop peeling. fpeephole Common Report Var(flag_no_peephole,0) Optimization Enable machine specific peephole optimizations. fpeephole2 Common Report Var(flag_peephole2) Optimization Enable an RTL peephole pass before sched2. fPIC Common Report Var(flag_pic,2) Negative(fPIE) Init(-1) Generate position-independent code if possible (large mode). fPIE Common Report Var(flag_pie,2) Negative(fpic) Init(-1) Generate position-independent code for executables if possible (large mode). fpic Common Report Var(flag_pic,1) Negative(fpie) Init(-1) Generate position-independent code if possible (small mode). fpie Common Report Var(flag_pie,1) Negative(fPIC) Init(-1) Generate position-independent code for executables if possible (small mode). fplt Common Report Var(flag_plt) Init(1) Optimization Use PLT for PIC calls (-fno-plt: load the address from GOT at call site). fplugin= Common Joined RejectNegative Var(common_deferred_options) Defer Specify a plugin to load. fplugin-arg- Common Joined RejectNegative Var(common_deferred_options) Defer -fplugin-arg--[=] Specify argument = for plugin . fpredictive-commoning Common Report Var(flag_predictive_commoning) Optimization Run predictive commoning optimization. fprefetch-loop-arrays Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization Generate prefetch instructions, if available, for arrays in loops. fprofile Common Report Var(profile_flag) Enable basic program profiling code. fprofile-abs-path Common Report Var(profile_abs_path_flag) Generate absolute source path names for gcov. fprofile-arcs Common Report Var(profile_arc_flag) Insert arc-based program profiling code. fprofile-dir= Common Joined RejectNegative Var(profile_data_prefix) Set the top-level directory for storing the profile data. The default is 'pwd'. fprofile-note= Common Joined RejectNegative Var(profile_note_location) Select the name for storing the profile note file. fprofile-correction Common Report Var(flag_profile_correction) Enable correction of flow inconsistent profile data input. fprofile-update= Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE) -fprofile-update=[single|atomic|prefer-atomic] Set the profile update method. fprofile-filter-files= Common Joined RejectNegative Var(flag_profile_filter_files) Instrument only functions from files where names match any regular expression (separated by a semi-colon). fprofile-exclude-files= Common Joined RejectNegative Var(flag_profile_exclude_files) Instrument only functions from files where names do not match all the regular expressions (separated by a semi-colon). Enum Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs) EnumValue Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE) EnumValue Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC) EnumValue Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC) fprofile-generate Common Enable common options for generating profile info for profile feedback directed optimizations. fprofile-generate= Common Joined RejectNegative Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=. fprofile-partial-training Common Report Var(flag_profile_partial_training) Optimization Do not assume that functions never executed during the train run are cold. fprofile-use Common Var(flag_profile_use) Enable common options for performing profile feedback directed optimizations. fprofile-use= Common Joined RejectNegative Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=. fprofile-values Common Report Var(flag_profile_values) Insert code to profile values of expressions. fprofile-report Common Report Var(profile_report) Report on consistency of profile. fprofile-reorder-functions Common Report Var(flag_profile_reorder_functions) Optimization Enable function reordering that improves code placement. fpatchable-function-entry= Common Joined Optimization Insert NOP instructions at each function entry. frandom-seed Common Var(common_deferred_options) Defer frandom-seed= Common Joined RejectNegative Var(common_deferred_options) Defer -frandom-seed= Make compile reproducible using . ; This switch causes the command line that was used to create an ; object file to be recorded into the object file. The exact format ; of this recording is target and binary file format dependent. ; It is related to the -fverbose-asm switch, but that switch only ; records information in the assembler output file as comments, so ; they never reach the object file. frecord-gcc-switches Common Report Var(flag_record_gcc_switches) Record gcc command line switches in the object file. freg-struct-return Common Report Var(flag_pcc_struct_return,0) Optimization Return small aggregates in registers. fregmove Common Ignore Does nothing. Preserved for backward compatibility. flifetime-dse Common Report Var(flag_lifetime_dse,2) Init(2) Optimization Tell DSE that the storage for a C++ object is dead when the constructor starts and when the destructor finishes. flifetime-dse= Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2) flive-patching Common RejectNegative Alias(flive-patching=,inline-clone) Optimization flive-patching= Common Report Joined RejectNegative Enum(live_patching_level) Var(flag_live_patching) Init(LIVE_PATCHING_NONE) Optimization -flive-patching=[inline-only-static|inline-clone] Control IPA optimizations to provide a safe compilation for live-patching. At the same time, provides multiple-level control on the enabled IPA optimizations. Enum Name(live_patching_level) Type(enum live_patching_level) UnknownError(unknown Live-Patching Level %qs) EnumValue Enum(live_patching_level) String(inline-only-static) Value(LIVE_PATCHING_INLINE_ONLY_STATIC) EnumValue Enum(live_patching_level) String(inline-clone) Value(LIVE_PATCHING_INLINE_CLONE) fallocation-dce Common Report Var(flag_allocation_dce) Init(1) Optimization Tell DCE to remove unused C++ allocations. flive-range-shrinkage Common Report Var(flag_live_range_shrinkage) Init(0) Optimization Relief of register pressure through live range shrinkage. frename-registers Common Report Var(flag_rename_registers) Init(2) Optimization Perform a register renaming optimization pass. fschedule-fusion Common Report Var(flag_schedule_fusion) Init(2) Optimization Perform a target dependent instruction fusion optimization pass. freorder-blocks Common Report Var(flag_reorder_blocks) Optimization Reorder basic blocks to improve code placement. freorder-blocks-algorithm= Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm. Enum Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs) EnumValue Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE) EnumValue Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC) freorder-blocks-and-partition Common Report Var(flag_reorder_blocks_and_partition) Optimization Reorder basic blocks and partition into hot and cold sections. freorder-functions Common Report Var(flag_reorder_functions) Optimization Reorder functions to improve code placement. frerun-cse-after-loop Common Report Var(flag_rerun_cse_after_loop) Optimization Add a common subexpression elimination pass after loop optimizations. frerun-loop-opt Common Ignore Does nothing. Preserved for backward compatibility. frounding-math Common Report Var(flag_rounding_math) Optimization SetByCombined Disable optimizations that assume default FP rounding behavior. fsched-interblock Common Report Var(flag_schedule_interblock) Init(1) Optimization Enable scheduling across basic blocks. fsched-pressure Common Report Var(flag_sched_pressure) Init(0) Optimization Enable register pressure sensitive insn scheduling. fsched-spec Common Report Var(flag_schedule_speculative) Init(1) Optimization Allow speculative motion of non-loads. fsched-spec-load Common Report Var(flag_schedule_speculative_load) Optimization Allow speculative motion of some loads. fsched-spec-load-dangerous Common Report Var(flag_schedule_speculative_load_dangerous) Optimization Allow speculative motion of more loads. fsched-verbose= Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1) -fsched-verbose= Set the verbosity level of the scheduler. fsched2-use-superblocks Common Report Var(flag_sched2_use_superblocks) Optimization If scheduling post reload, do superblock scheduling. fsched2-use-traces Common Ignore Does nothing. Preserved for backward compatibility. fschedule-insns Common Report Var(flag_schedule_insns) Optimization Reschedule instructions before register allocation. fschedule-insns2 Common Report Var(flag_schedule_insns_after_reload) Optimization Reschedule instructions after register allocation. ; This flag should be on when a target implements non-trivial ; scheduling hooks, maybe saving some information for its own sake. ; On IA64, for example, this is used for correct bundling. fselective-scheduling Common Report Var(flag_selective_scheduling) Optimization Schedule instructions using selective scheduling algorithm. fselective-scheduling2 Common Report Var(flag_selective_scheduling2) Optimization Run selective scheduling after reload. fself-test= Common Undocumented Joined Var(flag_self_test) Run self-tests, using the given path to locate test files. fsel-sched-pipelining Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization Perform software pipelining of inner loops during selective scheduling. fsel-sched-pipelining-outer-loops Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization Perform software pipelining of outer loops during selective scheduling. fsel-sched-reschedule-pipelined Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization Reschedule pipelined regions without pipelining. fsemantic-interposition Common Report Var(flag_semantic_interposition) Init(1) Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker. ; sched_stalled_insns means that insns can be moved prematurely from the queue ; of stalled insns into the ready list. fsched-stalled-insns Common Report Var(flag_sched_stalled_insns) Optimization UInteger Allow premature scheduling of queued insns. fsched-stalled-insns= Common RejectNegative Joined UInteger Optimization -fsched-stalled-insns= Set number of queued insns that can be prematurely scheduled. ; sched_stalled_insns_dep controls how many recently scheduled cycles will ; be examined for a dependency on a stalled insn that is candidate for ; premature removal from the queue of stalled insns into the ready list (has ; an effect only if the flag 'sched_stalled_insns' is set). fsched-stalled-insns-dep Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger Set dependence distance checking in premature scheduling of queued insns. fsched-stalled-insns-dep= Common RejectNegative Joined UInteger Optimization -fsched-stalled-insns-dep= Set dependence distance checking in premature scheduling of queued insns. fsched-group-heuristic Common Report Var(flag_sched_group_heuristic) Init(1) Optimization Enable the group heuristic in the scheduler. fsched-critical-path-heuristic Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization Enable the critical path heuristic in the scheduler. fsched-spec-insn-heuristic Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization Enable the speculative instruction heuristic in the scheduler. fsched-rank-heuristic Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization Enable the rank heuristic in the scheduler. fsched-last-insn-heuristic Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization Enable the last instruction heuristic in the scheduler. fsched-dep-count-heuristic Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization Enable the dependent count heuristic in the scheduler. fsection-anchors Common Report Var(flag_section_anchors) Optimization Access data in the same section from shared anchor points. fsee Common Ignore Does nothing. Preserved for backward compatibility. fzee Common Ignore Does nothing. Preserved for backward compatibility. free Common Report Var(flag_ree) Init(0) Optimization Turn on Redundant Extensions Elimination pass. fshow-column Common Report Var(flag_show_column) Init(1) Show column numbers in diagnostics, when available. Default on. fshrink-wrap Common Report Var(flag_shrink_wrap) Optimization Emit function prologues only before parts of the function that need it, rather than at the top of the function. fshrink-wrap-separate Common Report Var(flag_shrink_wrap_separate) Init(1) Optimization Shrink-wrap parts of the prologue and epilogue separately. fsignaling-nans Common Report Var(flag_signaling_nans) Optimization SetByCombined Disable optimizations observable by IEEE signaling NaNs. fsigned-zeros Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined Disable floating point optimizations that ignore the IEEE signedness of zero. fsingle-precision-constant Common Report Var(flag_single_precision_constant) Optimization Convert floating point constants to single precision constants. fsplit-ivs-in-unroller Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization Split lifetimes of induction variables when loops are unrolled. fsplit-stack Common Report Var(flag_split_stack) Init(-1) Generate discontiguous stack frames. fsplit-wide-types Common Report Var(flag_split_wide_types) Optimization Split wide types into independent registers. fsplit-wide-types-early Common Report Var(flag_split_wide_types_early) Optimization Split wide types into independent registers earlier. fssa-backprop Common Report Var(flag_ssa_backprop) Init(1) Optimization Enable backward propagation of use properties at the SSA level. fssa-phiopt Common Report Var(flag_ssa_phiopt) Optimization Optimize conditional patterns using SSA PHI nodes. fstdarg-opt Common Report Var(flag_stdarg_opt) Init(1) Optimization Optimize amount of stdarg registers saved to stack at start of function. fvariable-expansion-in-unroller Common Report Var(flag_variable_expansion_in_unroller) Optimization Apply variable expansion when loops are unrolled. fstack-check= Common Report RejectNegative Joined Optimization -fstack-check=[no|generic|specific] Insert stack checking code into the program. fstack-check Common Alias(fstack-check=, specific, no) Insert stack checking code into the program. Same as -fstack-check=specific. fstack-clash-protection Common Report Var(flag_stack_clash_protection) Optimization Insert code to probe each page of stack space as it is allocated to protect from stack-clash style attacks. fstack-limit Common Var(common_deferred_options) Defer fstack-limit-register= Common RejectNegative Joined Var(common_deferred_options) Defer -fstack-limit-register= Trap if the stack goes past . fstack-limit-symbol= Common RejectNegative Joined Var(common_deferred_options) Defer -fstack-limit-symbol= Trap if the stack goes past symbol . fstack-protector Common Report Var(flag_stack_protect, 1) Init(-1) Optimization Use propolice as a stack protection method. fstack-protector-all Common Report RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization Use a stack protection method for every function. fstack-protector-strong Common Report RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization Use a smart stack protection method for certain functions. fstack-protector-explicit Common Report RejectNegative Var(flag_stack_protect, 4) Optimization Use stack protection method only for functions with the stack_protect attribute. fstack-usage Common RejectNegative Var(flag_stack_usage) Output stack usage information on a per-function basis. fstrength-reduce Common Ignore Does nothing. Preserved for backward compatibility. ; Nonzero if we should do (language-dependent) alias analysis. ; Typically, this analysis will assume that expressions of certain ; types do not alias expressions of certain other types. Only used ; if alias analysis (in general) is enabled. fstrict-aliasing Common Report Var(flag_strict_aliasing) Optimization Assume strict aliasing rules apply. fstrict-overflow Common Report Treat signed overflow as undefined. Negated as -fwrapv -fwrapv-pointer. fsync-libcalls Common Report Var(flag_sync_libcalls) Init(1) Implement __atomic operations via libcalls to legacy __sync functions. fsyntax-only Common Report Var(flag_syntax_only) Check for syntax errors, then stop. ftest-coverage Common Report Var(flag_test_coverage) Create data files needed by \"gcov\". fthread-jumps Common Report Var(flag_thread_jumps) Optimization Perform jump threading optimizations. ftime-report Common Report Var(time_report) Report the time taken by each compiler pass. ftime-report-details Common Report Var(time_report_details) Record times taken by sub-phases separately. ftls-model= Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC) -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model. Enum Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs) EnumValue Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC) EnumValue Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC) EnumValue Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC) EnumValue Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC) ftoplevel-reorder Common Report Var(flag_toplevel_reorder) Init(2) Optimization Reorder top level functions, variables, and asms. ftracer Common Report Var(flag_tracer) Optimization Perform superblock formation via tail duplication. ftrampolines Common Report Var(flag_trampolines) Init(0) For targets that normally need trampolines for nested functions, always generate them instead of using descriptors. ; Zero means that floating-point math operations cannot generate a ; (user-visible) trap. This is the case, for example, in nonstop ; IEEE 754 arithmetic. ftrapping-math Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined Assume floating-point operations can trap. ftrapv Common Report Var(flag_trapv) Optimization Trap for signed overflow in addition, subtraction and multiplication. ftree-ccp Common Report Var(flag_tree_ccp) Optimization Enable SSA-CCP optimization on trees. ftree-bit-ccp Common Report Var(flag_tree_bit_ccp) Optimization Enable SSA-BIT-CCP optimization on trees. ftree-store-ccp Common Ignore Does nothing. Preserved for backward compatibility. ftree-ch Common Report Var(flag_tree_ch) Optimization Enable loop header copying on trees. ftree-coalesce-inlined-vars Common Ignore RejectNegative Does nothing. Preserved for backward compatibility. ftree-coalesce-vars Common Report Var(flag_tree_coalesce_vars) Optimization Enable SSA coalescing of user variables. ftree-copyrename Common Ignore Does nothing. Preserved for backward compatibility. ftree-copy-prop Common Report Var(flag_tree_copy_prop) Optimization Enable copy propagation on trees. ftree-store-copy-prop Common Ignore Does nothing. Preserved for backward compatibility. ftree-cselim Common Report Var(flag_tree_cselim) Init(2) Optimization Transform condition stores into unconditional ones. ftree-switch-conversion Common Report Var(flag_tree_switch_conversion) Optimization Perform conversions of switch initializations. ftree-dce Common Report Var(flag_tree_dce) Optimization Enable SSA dead code elimination optimization on trees. ftree-dominator-opts Common Report Var(flag_tree_dom) Optimization Enable dominator optimizations. ftree-tail-merge Common Report Var(flag_tree_tail_merge) Optimization Enable tail merging on trees. ftree-dse Common Report Var(flag_tree_dse) Optimization Enable dead store elimination. ftree-forwprop Common Report Var(flag_tree_forwprop) Init(1) Optimization Enable forward propagation on trees. ftree-fre Common Report Var(flag_tree_fre) Optimization Enable Full Redundancy Elimination (FRE) on trees. foptimize-strlen Common Report Var(flag_optimize_strlen) Optimization Enable string length optimizations on trees. fisolate-erroneous-paths-dereference Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization Detect paths that trigger erroneous or undefined behavior due to dereferencing a null pointer. Isolate those paths from the main control flow and turn the statement with erroneous or undefined behavior into a trap. fisolate-erroneous-paths-attribute Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization Detect paths that trigger erroneous or undefined behavior due to a null value being used in a way forbidden by a returns_nonnull or nonnull attribute. Isolate those paths from the main control flow and turn the statement with erroneous or undefined behavior into a trap. ftree-loop-distribution Common Report Var(flag_tree_loop_distribution) Optimization Enable loop distribution on trees. ftree-loop-distribute-patterns Common Report Var(flag_tree_loop_distribute_patterns) Optimization Enable loop distribution for patterns transformed into a library call. ftree-loop-im Common Report Var(flag_tree_loop_im) Init(1) Optimization Enable loop invariant motion on trees. ftree-loop-linear Common Alias(floop-nest-optimize) Enable loop nest transforms. Same as -floop-nest-optimize. ftree-loop-ivcanon Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization Create canonical induction variables in loops. ftree-loop-optimize Common Report Var(flag_tree_loop_optimize) Init(1) Optimization Enable loop optimizations on tree level. ftree-parallelize-loops= Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization -ftree-parallelize-loops= Enable automatic parallelization of loops. ftree-phiprop Common Report Var(flag_tree_phiprop) Init(1) Optimization Enable hoisting loads from conditional pointers. ftree-pre Common Report Var(flag_tree_pre) Optimization Enable SSA-PRE optimization on trees. ftree-partial-pre Common Report Var(flag_tree_partial_pre) Optimization In SSA-PRE optimization on trees, enable partial-partial redundancy elimination. ftree-pta Common Report Var(flag_tree_pta) Optimization Perform function-local points-to analysis on trees. ftree-reassoc Common Report Var(flag_tree_reassoc) Init(1) Optimization Enable reassociation on tree level. ftree-salias Common Ignore Does nothing. Preserved for backward compatibility. ftree-sink Common Report Var(flag_tree_sink) Optimization Enable SSA code sinking on trees. ftree-slsr Common Report Var(flag_tree_slsr) Optimization Perform straight-line strength reduction. ftree-sra Common Report Var(flag_tree_sra) Optimization Perform scalar replacement of aggregates. ftree-ter Common Report Var(flag_tree_ter) Optimization Replace temporary expressions in the SSA->normal pass. ftree-lrs Common Report Var(flag_tree_live_range_split) Optimization Perform live range splitting during the SSA->normal pass. ftree-vrp Common Report Var(flag_tree_vrp) Init(0) Optimization Perform Value Range Propagation on trees. fsplit-paths Common Report Var(flag_split_paths) Init(0) Optimization Split paths leading to loop backedges. funconstrained-commons Common Var(flag_unconstrained_commons) Optimization Assume common declarations may be overridden with ones with a larger trailing array. funit-at-a-time Common Report Var(flag_unit_at_a_time) Init(1) Compile whole compilation unit at a time. funroll-loops Common Report Var(flag_unroll_loops) Optimization Perform loop unrolling when iteration count is known. funroll-all-loops Common Report Var(flag_unroll_all_loops) Optimization Perform loop unrolling for all loops. ; Nonzero means that loop optimizer may assume that the induction variables ; that control loops do not overflow and that the loops with nontrivial ; exit condition are not infinite funsafe-loop-optimizations Common Ignore Does nothing. Preserved for backward compatibility. fassociative-math Common Report Var(flag_associative_math) SetByCombined Optimization Allow optimization for floating-point arithmetic which may change the result of the operation due to rounding. freciprocal-math Common Report Var(flag_reciprocal_math) SetByCombined Optimization Same as -fassociative-math for expressions which include division. ; Nonzero means that unsafe floating-point math optimizations are allowed ; for the sake of speed. IEEE compliance is not guaranteed, and operations ; are allowed to assume that their arguments and results are "normal" ; (e.g., nonnegative for SQRT). funsafe-math-optimizations Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined Allow math optimizations that may violate IEEE or ISO standards. funswitch-loops Common Report Var(flag_unswitch_loops) Optimization Perform loop unswitching. fsplit-loops Common Report Var(flag_split_loops) Optimization Perform loop splitting. fversion-loops-for-strides Common Report Var(flag_version_loops_for_strides) Optimization Version loops based on whether indices have a stride of one. funwind-tables Common Report Var(flag_unwind_tables) Optimization Just generate unwind tables for exception handling. fuse-ld=bfd Common Driver Negative(fuse-ld=gold) Use the bfd linker instead of the default linker. fuse-ld=gold Common Driver Negative(fuse-ld=bfd) Use the gold linker instead of the default linker. fuse-ld=lld Common Driver Negative(fuse-ld=lld) Use the lld LLVM linker instead of the default linker. fuse-linker-plugin Common Undocumented Var(flag_use_linker_plugin) ; Positive if we should track variables, negative if we should run ; the var-tracking pass only to discard debug annotations, zero if ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it ; will be set according to optimize, debug_info_level and debug_hooks ; in process_options (). fvar-tracking Common Report Var(flag_var_tracking) Init(2) PerFunction Perform variable tracking. ; Positive if we should track variables at assignments, negative if ; we should run the var-tracking pass only to discard debug ; annotations. When flag_var_tracking_assignments == ; AUTODETECT_VALUE it will be set according to flag_var_tracking. fvar-tracking-assignments Common Report Var(flag_var_tracking_assignments) Init(2) PerFunction Perform variable tracking by annotating assignments. ; Nonzero if we should toggle flag_var_tracking_assignments after ; processing options and computing its default. */ fvar-tracking-assignments-toggle Common Report Var(flag_var_tracking_assignments_toggle) PerFunction Toggle -fvar-tracking-assignments. ; Positive if we should track uninitialized variables, negative if ; we should run the var-tracking pass only to discard debug ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it ; will be set according to flag_var_tracking. fvar-tracking-uninit Common Report Var(flag_var_tracking_uninit) PerFunction Perform variable tracking and also tag variables that are uninitialized. ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize. ftree-vectorize Common Report Optimization Enable vectorization on trees. ftree-vectorizer-verbose= Common Joined RejectNegative Ignore Does nothing. Preserved for backward compatibility. ftree-loop-vectorize Common Report Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize) Enable loop vectorization on trees. ftree-slp-vectorize Common Report Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize) Enable basic block vectorization (SLP) on trees. fvect-cost-model= Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization -fvect-cost-model=[unlimited|dynamic|cheap] Specifies the cost model for vectorization. fsimd-cost-model= Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization -fsimd-cost-model=[unlimited|dynamic|cheap] Specifies the vectorization cost model for code marked with a simd directive. Enum Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs) EnumValue Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED) EnumValue Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC) EnumValue Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP) fvect-cost-model Common Alias(fvect-cost-model=,dynamic,unlimited) Enables the dynamic vectorizer cost model. Preserved for backward compatibility. ftree-vect-loop-version Common Ignore Does nothing. Preserved for backward compatibility. ftree-scev-cprop Common Report Var(flag_tree_scev_cprop) Init(1) Optimization Enable copy propagation of scalar-evolution information. ; -fverbose-asm causes extra commentary information to be produced in ; the generated assembly code (to make it more readable). This option ; is generally only of use to those who actually need to read the ; generated assembly code (perhaps while debugging the compiler itself). ; -fno-verbose-asm, the default, causes the extra information ; to not be added and is useful when comparing two assembler files. fverbose-asm Common Report Var(flag_verbose_asm) Add extra commentary to assembler output. fvisibility= Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT) -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility. Enum Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs) EnumValue Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT) EnumValue Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL) EnumValue Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN) EnumValue Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED) fvtable-verify= Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY) Validate vtable pointers before using them. Enum Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs) EnumValue Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY) EnumValue Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY) EnumValue Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY) fvtv-counts Common Var(flag_vtv_counts) Output vtable verification counters. fvtv-debug Common Var(flag_vtv_debug) Output vtable verification pointer sets information. fvpt Common Report Var(flag_value_profile_transformations) Optimization Use expression value profiles in optimizations. fweb Common Report Var(flag_web) Init(2) Optimization Construct webs and split unrelated uses of single variable. ftree-builtin-call-dce Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization Enable conditional dead code elimination for builtin calls. fwhole-program Common Report Var(flag_whole_program) Init(0) Perform whole program optimizations. fwrapv-pointer Common Report Var(flag_wrapv_pointer) Optimization Assume pointer overflow wraps around. fwrapv Common Report Var(flag_wrapv) Optimization Assume signed arithmetic overflow wraps around. fzero-initialized-in-bss Common Report Var(flag_zero_initialized_in_bss) Init(1) Put zero initialized data in the bss section. g Common Driver RejectNegative JoinedOrMissing Generate debug information in default format. gas-loc-support Common Driver Var(dwarf2out_as_loc_support) Init(2) Assume assembler support for (DWARF2+) .loc directives. gas-locview-support Common Driver Var(dwarf2out_as_locview_support) Init(2) Assume assembler support for view in (DWARF2+) .loc directives. gcoff Common Driver WarnRemoved Does nothing. Preserved for backward compatibility. gcoff1 Common Driver WarnRemoved Does nothing. Preserved for backward compatibility. gcoff2 Common Driver WarnRemoved Does nothing. Preserved for backward compatibility. gcoff3 Common Driver WarnRemoved Does nothing. Preserved for backward compatibility. gcolumn-info Common Driver Var(debug_column_info,1) Init(1) Record DW_AT_decl_column and DW_AT_call_column in DWARF. gdwarf Common Driver JoinedOrMissing Negative(gdwarf-) Generate debug information in default version of DWARF format. gdwarf- Common Driver Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs) Generate debug information in DWARF v2 (or later) format. ggdb Common Driver JoinedOrMissing Generate debug information in default extended format. ginline-points Common Driver Var(debug_inline_points) Init(2) Generate extended entry point information for inlined functions. ginternal-reset-location-views Common Driver Var(debug_internal_reset_location_views) Init(2) Compute locview reset points based on insn length estimates. gno- RejectNegative Joined Undocumented ; Catch the gno- prefix, so it doesn't backtrack to g. gno-pubnames Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1) Don't generate DWARF pubnames and pubtypes sections. gpubnames Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1) Generate DWARF pubnames and pubtypes sections. ggnu-pubnames Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2) Generate DWARF pubnames and pubtypes sections with GNU extensions. grecord-gcc-switches Common Driver Var(dwarf_record_gcc_switches) Init(1) Record gcc command line switches in DWARF DW_AT_producer. gsplit-dwarf Common Driver Var(dwarf_split_debug_info) Init(0) Generate debug information in separate .dwo files. gstabs Common Driver JoinedOrMissing Negative(gstabs+) Generate debug information in STABS format. gstabs+ Common Driver JoinedOrMissing Negative(gvms) Generate debug information in extended STABS format. gstatement-frontiers Common Driver Var(debug_nonbind_markers_p) Init(2) Emit progressive recommended breakpoint locations. gstrict-dwarf Common Driver Report Var(dwarf_strict) Init(0) Don't emit DWARF additions beyond selected version. gdescribe-dies Common Driver Report Var(flag_describe_dies) Init(0) Add description attributes to some DWARF DIEs that have no name attribute. gtoggle Common Driver Report Var(flag_gtoggle) Toggle debug information generation. gvariable-location-views Common Driver Var(debug_variable_location_views, 1) Init(2) Augment variable location lists with progressive views. gvariable-location-views=incompat5 Common Driver RejectNegative Var(debug_variable_location_views, -1) Init(2) gvms Common Driver JoinedOrMissing Negative(gxcoff) Generate debug information in VMS format. gxcoff Common Driver JoinedOrMissing Negative(gxcoff+) Generate debug information in XCOFF format. gxcoff+ Common Driver JoinedOrMissing Negative(gdwarf) Generate debug information in extended XCOFF format. Enum Name(compressed_debug_sections) Type(int) ; Since -gz= is completely handled in specs, the values aren't used and we ; assign arbitrary constants. EnumValue Enum(compressed_debug_sections) String(none) Value(0) EnumValue Enum(compressed_debug_sections) String(zlib) Value(1) EnumValue Enum(compressed_debug_sections) String(zlib-gnu) Value(2) gz Common Driver Generate compressed debug sections. gz= Common Driver RejectNegative Joined Enum(compressed_debug_sections) -gz= Generate compressed debug sections in format . h Driver Joined Separate iplugindir= Common Joined Var(plugindir_string) Init(0) -iplugindir= Set to be the default plugin directory. imultiarch Common Joined Separate RejectDriver Var(imultiarch) Init(0) -imultiarch Set to be the multiarch include subdirectory. l Driver Joined Separate n Driver no-canonical-prefixes Driver nodefaultlibs Driver nostartfiles Driver nolibc Driver nostdlib Driver o Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs) -o Place output into . p Common Var(profile_flag) Enable function profiling. pass-exit-codes Driver Var(pass_exit_codes) pedantic Common Alias(Wpedantic) pedantic-errors Common Var(flag_pedantic_errors) Like -pedantic but issue them as errors. pg Driver pipe Driver Var(use_pipes) print-file-name= Driver JoinedOrMissing Var(print_file_name) print-libgcc-file-name Driver print-multi-directory Driver Var(print_multi_directory) print-multi-lib Driver Var(print_multi_lib) print-multi-os-directory Driver Var(print_multi_os_directory) print-multiarch Driver Var(print_multiarch) print-prog-name= Driver JoinedOrMissing Var(print_prog_name) print-search-dirs Driver Var(print_search_dirs) print-sysroot Driver Var(print_sysroot) print-sysroot-headers-suffix Driver Var(print_sysroot_headers_suffix) quiet Common Var(quiet_flag) RejectDriver Do not display functions compiled or elapsed time. r Driver s Driver save-temps Driver save-temps= Driver Joined t Driver time Driver Var(report_times) time= Driver JoinedOrMissing u Driver Joined Separate undef Driver ; C option, but driver must not handle as "-u ndef". v Common Driver Var(verbose_flag) Enable verbose output. version Common Var(version_flag) RejectDriver Display the compiler's version. w Common Var(inhibit_warnings) Suppress warnings. wrapper Driver Separate Var(wrapper_string) x Driver Joined Separate shared Driver RejectNegative Negative(static-pie) Create a shared library. shared-libgcc Driver specs Driver Separate Alias(specs=) specs= Driver Joined static Driver static-libgcc Driver static-libgfortran Driver ; Documented for Fortran, but always accepted by driver. static-libstdc++ Driver static-libgo Driver ; Documented for Go, but always accepted by driver. static-libasan Driver static-libtsan Driver static-liblsan Driver static-libubsan Driver symbolic Driver no-pie Driver RejectNegative Negative(shared) Don't create a dynamically linked position independent executable. pie Driver RejectNegative Negative(no-pie) Create a dynamically linked position independent executable. static-pie Driver RejectNegative Negative(pie) Create a static position independent executable. z Driver Joined Separate fipa-ra Common Report Var(flag_ipa_ra) Optimization Use caller save register across calls if possible. ; This comment is to ensure we retain the blank line above.