# options to filter out, and why --all-warnings alias for -Wall --extra-warnings alias for -Wextra -W alias for -Wextra -Wabi this is now a no-op -Wabi-tag c++ -Wabi= c++ -Wabsolute-value enabled by -Wextra -Waddress enabled by -Wall -Waddress-of-packed-member default -Waggregate-return obsolescent -Waggressive-loop-optimizations default -Waliasing fortran -Walign-commons fortran -Waligned-new=[none|global|all] c++ -Walloc-size-larger-than= defaults to PTRDIFF_MAX -Walloc-zero Gnulib fixes this problem -Walloca we like alloca in small doses -Walloca-larger-than= FIXME: choose something sane? -Wampersand fortran -Wanalyzer-double-fclose enabled by -fanalyzer -Wanalyzer-double-free enabled by -fanalyzer -Wanalyzer-exposure-through-output-file enabled by -fanalyzer -Wanalyzer-file-leak enabled by -fanalyzer -Wanalyzer-free-of-non-heap enabled by -fanalyzer -Wanalyzer-malloc-leak enabled by -fanalyzer -Wanalyzer-mismatching-deallocation enabled by -fanalyzer -Wanalyzer-null-argument enabled by -fanalyzer -Wanalyzer-null-dereference enabled by -fanalyzer -Wanalyzer-possible-null-argument enabled by -fanalyzer -Wanalyzer-possible-null-dereference enabled by -fanalyzer -Wanalyzer-shift-count-negative enabled by -fanalyzer -Wanalyzer-shift-count-overflow enabled by -fanalyzer -Wanalyzer-stale-setjmp-buffer implied by -fanalyzer -Wanalyzer-tainted-array-index FIXME maybe? too much noise -Wanalyzer-too-complex enabled by -fanalyzer -Wanalyzer-unsafe-call-within-signal-handler enabled by -fanalyzer -Wanalyzer-use-after-free enabled by -fanalyzer -Wanalyzer-use-of-pointer-in-stale-stack-frame enabled by -fanalyzer -Wanalyzer-write-to-const enabled by -fanalyzer -Wanalyzer-write-to-string-literal enabled by -fanalyzer -Warray-bounds covered by -Warray-bounds= -Warray-bounds=<0,2> handled specially by gl_MANYWARN_ALL_GCC -Warray-parameter enabled by -Wall -Warray-parameter=<0,2> enabled by -Wall -Warray-temporaries fortran -Wassign-intercept objc/objc++ -Wattribute-alias covered by -Wattribute-alias=2 -Wattribute-alias=<0,2> handled specially by gl_MANYWARN_ALL_GCC -Wattribute-warning default -Wattributes default -Wbool-compare enabled by -Wall -Wbool-operation enabled by -Wall -Wbuiltin-declaration-mismatch default -Wbuiltin-macro-redefined default -Wc++-compat only useful for code meant to be compiled by a C++ compiler -Wc++0x-compat c++ -Wc++11-compat c++ -Wc++14-compat c++ -Wc++17-compat c++ -Wc++1z-compat c++ -Wc++20-compat c++ -Wc++2a-compat c++ -Wc-binding-type fortran -Wc11-c2x-compat c compatibility -Wc90-c99-compat c compatibility -Wc99-c11-compat c compatibility -Wcannot-profile default -Wcast-align enabled by -Wcast-align=strict -Wcast-function-type enabled by -Wextra -Wcast-qual FIXME maybe? too much noise; encourages bad changes -Wcast-result D -Wcatch-value c++ -Wcatch-value=<0,3> c++ -Wchar-subscripts enabled by -Wall -Wcharacter-truncation fortran -Wchkp deprecated -Wclass-conversion c++ and objc++ -Wclass-memaccess c++ -Wclobbered enabled by -Wextra -Wcomma-subscript c++ and objc++ -Wcomment enabled by -Wall -Wcomments alias for -Wcomment -Wcompare-reals fortran -Wconditionally-supported c++ and objc++ -Wconversion FIXME maybe? too much noise; encourages bad changes -Wconversion-extra fortran -Wconversion-null c++ and objc++ -Wcoverage-mismatch default -Wcpp default -Wctad-maybe-unsupported c++ and objc++ -Wctor-dtor-privacy c++ -Wdangling-else enabled by -Wparentheses -Wdeclaration-after-statement needed only for pre-C99, so obsolete -Wdelete-incomplete c++ and objc++ -Wdelete-non-virtual-dtor c++ -Wdeprecated default -Wdeprecated-copy c++ and objc++ -Wdeprecated-copy-dtor c++ and objc++ -Wdeprecated-declarations default -Wdeprecated-enum-enum-conversion c++ and objc++ -Wdeprecated-enum-float-conversion c++ and objc++ -Wdesignated-init default -Wdiscarded-array-qualifiers default -Wdiscarded-qualifiers default -Wdo-subscript fortran -Wdiv-by-zero default -Wduplicate-decl-specifier enabled by -Wall -Weffc++ c++ -Wempty-body enabled by -Wextra -Wenum-compare enabled by -Wall -Wenum-conversion enabled by -Wextra -Wendif-labels default -Werror-implicit-function-declaration deprecated -Wexceptions c++ and objc++ -Wexpansion-to-defined enabled by -Wextra -Wextra-semi c++ -Wfloat-conversion FIXME maybe? borderline. some will want this -Wfloat-equal FIXME maybe? borderline. some will want this -Wformat covered by -Wformat=2 -Wformat-contains-nul default -Wformat-diag enabled by -Wformat=2 -Wformat-extra-args enabled by -Wformat=2 -Wformat-nonliteral enabled by -Wformat=2 -Wformat-overflow<0,2> gcc --help=warnings artifact -Wformat-overflow=<0,2> handled specially by gl_MANYWARN_ALL_GCC -Wformat-security enabled by -Wformat=2 -Wformat-truncation covered by -Wformat-truncation=2 -Wformat-truncation=<0,2> handled specially by gl_MANYWARN_ALL_GCC -Wformat-y2k enabled by -Wformat=2 -Wformat-zero-length enabled by -Wformat=2 -Wformat=<0,2> gcc --help=warnings artifact -Wframe-address enabled by -Wall -Wframe-larger-than= FIXME: choose something sane? -Wfree-nonheap-object default -Wfunction-elimination fortran -Whsa default -Wif-not-aligned default -Wignored-attributes default -Wignored-qualifiers enabled by -Wextra -Wimplicit enabled by -Wall -Wimplicit-fallthrough covered by -Wimplicit-fallthrough=2 -Wimplicit-fallthrough=<0,5> handled specially by gl_MANYWARN_ALL_GCC -Wimplicit-function-declaration enabled by -Wimplicit -Wimplicit-int enabled by -Wimplicit -Wimplicit-interface fortran -Wimplicit-procedure fortran -Winaccessible-base c++ and objc++ -Wincompatible-pointer-types default -Winherited-variadic-ctor c++ -Winit-list-lifetime c++ and objc++ -Wint-conversion default -Wint-in-bool-context enabled by -Wall -Wint-to-pointer-cast default -Winteger-division fortran -Wintrinsic-shadow fortran -Wintrinsics-std fortran -Winvalid-imported-macros c++ and objc++ -Winvalid-memory-model default -Winvalid-offsetof c++ and objc++ -Wjump-misses-init only useful for code meant to be compiled by a C++ compiler -Wlarger-than- gcc --help=warnings artifact -Wlarger-than= FIXME: choose something sane? -Wline-truncation fortran -Wliteral-suffix c++ and objc++ -Wlogical-not-parentheses enabled by -Wall -Wlong-long obsolescent -Wlto-type-mismatch c++ and objc++ -Wmain enabled by -Wall -Wmaybe-uninitialized enabled by -Wall or -Wextra -Wmemset-elt-size enabled by -Wall -Wmemset-transposed-args enabled by -Wall -Wmisleading-indentation enabled by -Wall -Wmismatched-dealloc default -Wmismatched-new-delete default, c++ and objc++ -Wmismatched-tags c++ and objc++ -Wmissing-attributes enabled by -Wall -Wmissing-braces enabled by -Wall -Wmissing-field-initializers enabled by -Wextra -Wmissing-format-attribute obsolescent -Wmissing-noreturn obsolescent -Wmissing-parameter-type enabled by -Wextra -Wmissing-profile default -Wmultichar default -Wmultiple-inheritance c++ and objc++ -Wmultistatement-macros enabled by -Wall -Wnamespaces c++ -Wnarrowing enabled by -Wall -Wno-alloc-size-larger-than see -Walloc-size-larger-than -Wno-alloca-larger-than see -Walloca-larger-than -Wno-frame-larger-than see -Wframe-larger-than -Wno-larger-than see -Wlarger-than -Wno-stack-usage see -Wstack-usage -Wno-vla-larger-than see -Wvla-larger-than -Wnoexcept c++ -Wnoexcept-type c++ -Wnon-template-friend c++ -Wnon-virtual-dtor c++ -Wnonnull enabled by -Wall or -Wformat -Wnonnull-compare enabled by -Wall -Wnormalized default -Wnormalized=[none|id|nfc|nfkc] defaults to nfc -WNSObject-attribute objc and objc++ -Wobjc-root-class objc and objc++ -Wodr default -Wold-style-cast c++ and objc++ -Wold-style-declaration enabled by -Wextra -Woverflow default -Woverloaded-virtual c++ -Woverride-init enabled by -Wextra -Woverride-init-side-effects c++ and objc++ -Woverwrite-recursive fortran -Wpacked-bitfield-compat default -Wpacked-not-aligned enabled by -Wall -Wpadded FIXME maybe? warns about "stabil" member in /usr/include/bits/timex.h -Wparentheses enabled by -Wall -Wpedantic FIXME: too strict? -Wpessimizing-move c++ and objc++ -Wplacement-new c++ -Wplacement-new=<0,2> c++ -Wpmf-conversions c++ and objc++ -Wpointer-compare default -Wpointer-sign enabled by -Wall -Wpointer-to-int-cast default -Wpragmas default -Wprio-ctor-dtor c++ -Wproperty-assign-default objc++ -Wprotocol objc++ -Wpsabi default -Wrange-loop-construct c++ and objc++ -Wreal-q-constant fortran -Wrealloc-lhs fortran -Wrealloc-lhs-all fortran -Wredundant-decls FIXME maybe? many _gl_cxxalias_dummy FPs -Wredundant-move c++ and objc++ -Wredundant-tags c++ and objc++ -Wregister c++ and objc++ -Wreorder c++ and objc++ -Wrestrict enabled by -Wall -Wreturn-local-addr default -Wreturn-type enabled by -Wall -Wscalar-storage-order default -Wselector objc and objc++ -Wsequence-point enabled by -Wall -Wshadow-compatible-local covered by -Wshadow -Wshadow-ivar objc -Wshadow-local covered by -Wshadow -Wshadow=compatible-local covered by -Wshadow -Wshadow=global covered by -Wshadow -Wshadow=local covered by -Wshadow -Wshift-count-negative default -Wshift-count-overflow default -Wshift-negative-value enabled by -Wextra -Wshift-overflow covered by -Wshift-overflow=2 -Wshift-overflow=<0,2> gcc --help=warnings artifact -Wsign-compare enabled by -Wextra -Wsign-conversion FIXME maybe? borderline. some will want this -Wsign-promo c++ and objc++ -Wsized-deallocation c++ and objc++ -Wsizeof-array-argument default -Wsizeof-array-div enabled by -Wall -Wsizeof-pointer-div enabled by -Wall -Wsizeof-pointer-memaccess enabled by -Wall -Wstack-usage= FIXME: choose something sane? -Wstrict-aliasing enabled by -Wall -Wstrict-aliasing=<0,3> FIXME: choose something sane? -Wstrict-null-sentinel c++ and objc++ -Wstrict-overflow=<0,5> FIXME: choose something sane? -Wstrict-selector-match objc and objc++ -Wstring-compare enabled by -Wextra -Wstringop-overflow covered by -Wstringop-overflow=2 -Wstringop-overflow=<0,4> defaults to 2 -Wstringop-overread default -Wstringop-truncation default -Wsubobject-linkage c++ and objc++ -Wsuggest-override c++ and objc++ -Wsurprising fortran -Wswitch enabled by -Wall -Wswitch-bool default -Wswitch-default https://lists.gnu.org/r/bug-gnulib/2018-05/msg00179.html -Wswitch-enum FIXME maybe? borderline. some will want this -Wswitch-outside-range default -Wswitch-unreachable default -Wsynth deprecated -Wtabs fortran -Wtarget-lifetime fortran -Wtautological-compare enabled by -Wall -Wtemplates c++ and objc++ -Wterminate c++ and objc++ -Wtraditional obsolescent -Wtraditional-conversion obsolescent -Wtrigraphs enabled by -Wall -Wtsan default -Wtype-limits enabled by -Wextra -Wundeclared-selector objc and objc++ -Wundef FIXME maybe? too many false positives -Wundefined-do-loop fortran -Wunderflow fortran -Wunreachable-code obsolescent no-op -Wunsuffixed-float-constants triggers warning in gnulib's timespec.h -Wunused enabled by -Wall -Wunused-but-set-parameter enabled by -Wunused -Wunused-but-set-variable enabled by -Wunused -Wunused-const-variable covered by -Wunused-const-variable=2 -Wunused-const-variable=<0,2> gcc --help=warnings artifact -Wunused-dummy-argument fortran -Wunused-function enabled by -Wunused -Wunused-label enabled by -Wunused -Wunused-local-typedefs enabled by -Wunused -Wunused-parameter enabled by -Wunused -Wunused-result enabled by -Wunused -Wunused-value enabled by -Wunused -Wunused-variable enabled by -Wunused -Wuse-without-only fortran -Wuseless-cast c++ and objc++ -Wvarargs default -Wvexing-parse c++ and objc++ -Wvirtual-inheritance c++ -Wvirtual-move-assign c++ -Wvla-larger-than= handled specially by gl_MANYWARN_ALL_GCC -Wvla-parameter enabled by -Wall -Wvolatile c++ and objc++ -Wvolatile-register-var enabled by -Wall -Wzero-as-null-pointer-constant c++ and objc++ -Wzero-length-bounds enabled by -Wall -Wzerotrip fortran -frequire-return-statement go