PATCH: Update _gcc as of GCC 4.8.3 for generic options and x86

[Mikael Magnusson <mikachu@xxxxxxxxx>]

I used the gcc --help=foo stuff and some mangling by _arguments as noted
in a comment I added. Because of this, I didn't add any -m stuff for other
architectures since they don't show up there. I added m to the _arguments
option that adds -xno- as aliases for -x, and maybe this causes some
wonkyness for some options that have both specified explicitly, but the
worst that should happen is that they get listed twice.

---
 Completion/Unix/Command/_gcc | 864 +++++++++++++++++++++++++++++++++++++------
 1 file changed, 754 insertions(+), 110 deletions(-)

diff --git a/Completion/Unix/Command/_gcc b/Completion/Unix/Command/_gcc
index b14c133..c6bbabb 100644
--- a/Completion/Unix/Command/_gcc
+++ b/Completion/Unix/Command/_gcc
@@ -1,6 +1,6 @@
 #compdef gcc g++ cc c++ llvm-gcc llvm-g++ clang clang++ -value-,LDFLAGS,-default- -value-,CFLAGS,-default- -value-,CPPFLAGS,-default-
 
-local curcontext="$curcontext" state line ret=1 expl args args2
+local curcontext="$curcontext" state line ret=1 expl args args2 march
 typeset -A opt_args
 
 if [[ "$service" = -value-* ]]; then
@@ -76,7 +76,7 @@ rs6000|powerpc*)
     -mpowerpc-gpopt -mno-powerpc-gpopt
     -mpowerpc-gfxopt -mno-powerpc-gfxopt
     -mnew-mnemonics -mno-new-mnemonics
-    -mfull-toc  -mminimal-toc -mno-fop-in-toc -mno-sum-in-toc
+    -mfull-toc -mminimal-toc -mno-fop-in-toc -mno-sum-in-toc
     -msoft-float -mhard-float -mmultiple -mno-multiple
     -mstring -mno-string -mbit-align -mno-bit-align
     -mstrict-align -mno-strict-align -mrelocatable -mno-relocatable
@@ -110,34 +110,118 @@ mips*)
   )
   ;;
 i[3456]86|x86_64)
+  march="native i386 i486 i586 pentium pentium-mmx pentiumpro i686 pentium2 pentium3 pentium3m pentium-m pentium4 pentium4m prescott nocona core2 corei7 corei7-avx core-avx-i core-avx2 atom k6 k6-2 k6-3 athlon athlon-tbird athlon-4 athlon-xp athlon-mp k8 opteron athlon64 athlon-fx k8-sse3 opteron-sse3 athlon64-sse3 amdfam10 barcelona bdver1 bdver2 bdver3 btver1 btver2 winchip-c6 winchip2 c3 c3-2 geode"
   args=(
-    '-mtune=:CPU type:(i386 i486 i586 pentium pentium-mmx i686 pentiumpro pentium2 pentium3 pentium3m pentium-m pentium4 pentium4m prescott nocona k6 k6-2 k6-3 athlon athlon-tbird athlon-4 athlon-xp athlon-mp k8 opteron athlon64 athlon-fx winchip-c6 winchip2 c3 c3-2)'
-    '-march=:CPU type:(i386 i486 i586 pentium pentium-mmx i686 pentiumpro pentium2 pentium3 pentium3m pentium-m pentium4 pentium4m prescott nocona k6 k6-2 k6-3 athlon athlon-tbird athlon-4 athlon-xp athlon-mp k8 opteron athlon64 athlon-fx winchip-c6 winchip2 c3 c3-2)'
-    '-mfpmath=:FPU type:(387 sse sse,387)'
-    '-masm=:asm dialect:(att intel)'
-    -mieee-fp -mno-ieee-fp -msoft-float
-    -mno-fp-ret-in-387 -mno-fancy-math-387
-    -malign-double -mno-align-double
-    -m128bit-long-double -m96bit-long-double
-    -msvr3-shlib -mno-svr3-shlib
-    -mrtd
-    '-mregparm=:number of integer argument registers:'
-    '-mpreferred-stack-boundary=:size of boundary:'
-    -mmmx  -msse  -msse2 -msse3 -m3dnow
-    -mno-mmx  -mno-sse  -mno-sse2 -mno-sse3 -mno-3dnow
-    -mpush-args -mno-push-args -maccumulate-outgoing-args
+    '-mtune=-[tune code for CPU type]:CPU type:('"$march"')'
+    '-march=-[generate instructions for CPU type]:CPU type:('"generic $march"')'
     -mthreads
-    -mno-align-stringops -minline-all-stringops
-    -momit-leaf-frame-pointer
-    -mtls-direct-seg-refs -mno-tls-direct-seg-refs
-    -m32 -m64
-    -mno-red-zone
-    '-mcmodel=:memory model:(small kernel medium large)'
-    -mno-wide-multiply
     '-mreg-alloc=:default register allocation order:' 
-    '-malign-jumps=: **2 base for jump goal alignment:'
-    '-malign-loops=: **2 base for loop alignment:'
-    '-malign-functions=: **2 base for function alignment:'
+
+    # arguments with options
+    '-mabi=-[Generate code that conforms to the given ABI]:abi:(ms sysv)'
+    '-maddress-mode=-[Use given address mode]:address mode:(short long)'
+    '-malign-functions=-[Function starts are aligned to this power of 2]: **2 base for function alignment: '
+    '-malign-jumps=-[Jump targets are aligned to this power of 2]: **2 base for jump goal alignment: '
+    '-malign-loops=-[Loop code aligned to this power of 2]: **2 base for loop alignment: '
+    '-masm=-[Use given assembler dialect]:asm dialect:(att intel)'
+    '-mbranch-cost=-[Branches are this expensive (1-5, arbitrary units)]:branch cost (1-5): '
+    '-mcmodel=-[Use given x86-64 code model]:memory model:(32 small kernel medium large)'
+    '-mfpmath=-[Generate floating point mathematics using given instruction set]:FPU type:(387 sse sse,387 both)'
+    '-mincoming-stack-boundary=-[Assume incoming stack aligned to this power of 2]:assumed size of boundary: '
+    '-mlarge-data-threshold=-[Data greater than given threshold will go into .ldata section in x86-64 medium model]:threshold: '
+    '-mpreferred-stack-boundary=-[Attempt to keep stack aligned to this power of 2]:size of boundary: '
+    '-mregparm=-[Number of registers used to pass integer arguments]:number of integer argument registers: '
+    '-mstringop-strategy=-[Chose strategy to generate stringop using]:stringop strategy:(byte_loop libcall loop rep_4byte rep_8byte rep_byte unrolled_loop)'
+    '-mtls-dialect=-[Use given thread-local storage dialect]:TLS dialect:(gnu gnu2)'
+    '-mveclibabi=-[Vector library ABI to use]:vector library ABI:(acml svml)'
+    
+    # arguments without options
+    '-m3dnow[Support 3DNow! built-in functions]'
+    '-m8bit-idiv[Expand 32bit/64bit integer divide into 8bit unsigned integer divide with run-time check]'
+    '-m32[Generate 32bit i386 code]'
+    '-m64[Generate 64bit x86-64 code]'
+    '-m96bit-long-double[sizeof(long double) is 12]'
+    '-m128bit-long-double[sizeof(long double) is 16]'
+    '-m80387[Use hardware fp]'
+    '-mabm[Support code generation of Advanced Bit Manipulation (ABM) instructions]'
+    '-maccumulate-outgoing-args[Reserve space for outgoing arguments in the function prologue]'
+    '-madx[Support flag-preserving add-carry instructions]'
+    '-maes[Support AES built-in functions and code generation]'
+    '-malign-double[Align some doubles on dword boundary]'
+    '-malign-stringops[Align destination of the string operations]'
+    '-mandroid[Generate code for the Android platform]'
+    '-mavx2[Support MMX, SSE, SSE2, SSE3, SSSE3, SSE4.1, SSE4.2, AVX and AVX2 built-in functions and code generation]'
+    '-mavx256-split-unaligned-load[Split 32-byte AVX unaligned load]'
+    '-mavx256-split-unaligned-store[Split 32-byte AVX unaligned store]'
+    '-mavx[Support MMX, SSE, SSE2, SSE3, SSSE3, SSE4.1, SSE4.2 and AVX built-in functions and code generation]'
+    '-mbionic[Use Bionic C library]'
+    '-mbmi2[Support BMI2 built-in functions and code generation]'
+    '-mbmi[Support BMI built-in functions and code generation]'
+    '-mcld[Generate cld instruction in the function prologue]'
+    '-mcrc32[Support code generation of crc32 instruction]'
+    '-mcx16[Support code generation of cmpxchg16b instruction]'
+    '-mdispatch-scheduler[Do dispatch scheduling if processor is bdver1 or bdver2 or bdver3 and Haifa scheduling is selected]'
+    '-mf16c[Support F16C built-in functions and code generation]'
+    '-mfancy-math-387[Generate sin, cos, sqrt for FPU]'
+    '-mfentry[Emit profiling counter call at function entry before prologue]'
+    '-mfma4[Support FMA4 built-in functions and code generation ]'
+    '-mfma[Support MMX, SSE, SSE2, SSE3, SSSE3, SSE4.1, SSE4.2, AVX and FMA built-in functions and code generation]'
+    '-mforce-drap[Always use Dynamic Realigned Argument Pointer (DRAP) to realign stack]'
+    '-mfp-ret-in-387[Return values of functions in FPU registers]'
+    '-mfsgsbase[Support FSGSBASE built-in functions and code generation]'
+    '-mfxsr[Support FXSAVE and FXRSTOR instructions]'
+    '-mglibc[Use GNU C library]'
+    '-mhard-float[Use hardware fp]'
+    '-mhle[Support Hardware Lock Elision prefixes]'
+    '-mieee-fp[Use IEEE math for fp comparisons]'
+    '-minline-all-stringops[Inline all known string operations]'
+    '-minline-stringops-dynamically[Inline memset/memcpy string operations, but perform inline version only for small blocks]'
+    '-mlong-double-64[Use 64-bit long double]'
+    '-mlong-double-80[Use 80-bit long double]'
+    '-mlwp[Support LWP built-in functions and code generation ]'
+    '-mlzcnt[Support LZCNT built-in function and code generation]'
+    '-mmmx[Support MMX built-in functions]'
+    '-mmovbe[Support code generation of movbe instruction]'
+    '-mms-bitfields[Use native (MS) bitfield layout]'
+    '-mno-sse4[Do not support SSE4.1 and SSE4.2 built-in functions and code generation]'
+    '-momit-leaf-frame-pointer[Omit the frame pointer in leaf functions]'
+    '-mpc32[Set 80387 floating-point precision to 32-bit]'
+    '-mpc64[Set 80387 floating-point precision to 64-bit]'
+    '-mpc80[Set 80387 floating-point precision to 80-bit]'
+    '-mpclmul[Support PCLMUL built-in functions and code generation]'
+    '-mpopcnt[Support code generation of popcnt instruction]'
+    '-mprefer-avx128[Use 128-bit AVX instructions instead of 256-bit AVX instructions in the auto-vectorizer]'
+    '-mprfchw[Support PREFETCHW instruction]'
+    '-mpush-args[Use push instructions to save outgoing arguments]'
+    '-mrdrnd[Support RDRND built-in functions and code generation]'
+    '-mrdseed[Support RDSEED instruction]'
+    '-mrecip[Generate reciprocals instead of divss and sqrtss]'
+    '-mred-zone[Use red-zone in the x86-64 code]'
+    '-mrtd[Alternate calling convention]'
+    '-mrtm[Support RTM built-in functions and code generation]'
+    '-msahf[Support code generation of sahf instruction in 64bit x86-64 code]'
+    '-msoft-float[Do not use hardware fp]'
+    '-msse2[Support MMX, SSE and SSE2 built-in functions and code generation]'
+    '-msse2avx[Encode SSE instructions with VEX prefix]'
+    '-msse3[Support MMX, SSE, SSE2 and SSE3 built-in functions and code generation]'
+    '-msse4.1[Support MMX, SSE, SSE2, SSE3, SSSE3 and SSE4.1 built-in functions and code generation]'
+    '-msse4.2[Support MMX, SSE, SSE2, SSE3, SSSE3, SSE4.1 and SSE4.2 built-in functions and code generation]'
+    '-msse4[Support MMX, SSE, SSE2, SSE3, SSSE3, SSE4.1 and SSE4.2 built-in functions and code generation]'
+    '-msse4a[Support MMX, SSE, SSE2, SSE3 and SSE4A built-in functions and code generation]'
+    '-msse[Support MMX and SSE built-in functions and code generation]'
+    '-msseregparm[Use SSE register passing conventions for SF and DF mode]'
+    '-mssse3[Support MMX, SSE, SSE2, SSE3 and SSSE3 built-in functions and code generation]'
+    '-mstack-arg-probe[Enable stack probing]'
+    '-mstackrealign[Realign stack in prologue]'
+    '-mtbm[Support TBM built-in functions and code generation]'
+    '-mtls-direct-seg-refs[Use direct references against %gs when accessing tls data]'
+    '-muclibc[Use uClibc C library]'
+    '-mvect8-ret-in-mem[Return 8-byte vectors in memory]'
+    '-mvzeroupper[Generate vzeroupper instruction before a transfer of control flow out of the function]'
+    '-mx32[Generate 32bit x86-64 code]'
+    '-mxop[Support XOP built-in functions and code generation ]'
+    '-mxsave[Support XSAVE and XRSTOR instructions]'
+    '-mxsaveopt[Support XSAVEOPT instruction]'
   )
   ;;
 hppa*)
@@ -222,90 +306,635 @@ if [[ "$service" = clang* ]]; then
     )
 fi
 
+local -a languages
+languages=(
+  c  c-header  cpp-output
+  c++  c++-header  c++-cpp-output
+  objective-c  objective-c-header  objective-c-cpp-output
+  objective-c++ objective-c++-header objective-c++-cpp-output
+  assembler  assembler-with-cpp
+  ada
+  f77  f77-cpp-input f95  f95-cpp-input
+  go
+  java
+)
+
+# generic options (from --help)
+args+=(
+  -a -C -H -P -s
+  '-###[print commands to run this compilation]'
+  '-o:output file:_files -g "^*.(c|h|cc|C|cxx)(-.)"'
+  '-x[Specify the language of the following input files]:input file language:('"$languages"')'
+  '+e-:virtual function definitions in classes:((0\:only\ interface 1\:generate\ code))'
+  '-d-:dump:->dump'
+  '-g-::debugging information type or level:(0 1 2 3 gdb coff stabs stabs+ dwarf dwarf+ dwarf-2 dwarf-3 dwarf-4 xcoff xcoff+)'
+  '-O-::optimization level:((0 1 2 3 g\:optimize\ for\ debugging\ experience s\:optimize\ for\ space fast\:optimize\ for\ speed\ disregarding\ exact\ standards\ compliance))'
+  '*-M-::output dependencies:((M\:only\ user\ header\ files MD\:output\ to\ file G\:treat\ missing\ header\ files\ as\ generated))'
+  '*-A-:define assertion:'
+  '*-D-:define macro:'
+  '*-U-:undefine macro:'
+  '-E[Preprocess only; do not compile, assemble or link]'
+  '-S[Compile only; do not assemble or link]'
+  '-c[Compile and assemble, but do not link]'
+  '*-Wp,-:preprocessor option:'
+  '*-Wl,-:linker option:'
+  '*-Xpreprocessor:preprocessor option:'
+  '*-Xlinker:linker option:'
+  '*-Xassembler:assembler option:'
+  '*-u:pretend symbol to be undefined:'
+  '*-Wa,-:assembler option:'
+  '*-l:library:->library'
+  '*-L-:library search path:_files -/'
+  '*-I-:header file search path:_files -/'
+  '-B-[Add <prefix> to the compiler'\''s search paths]:executable prefix:_files -/'
+  '-b:target machine:'
+  '-V:specify compiler version:'
+  '--version[Display compiler version information]'
+  '-print-file-name=-[Display the full path to library <library>]:library:->library'
+  '-print-prog-name=-[Display the full path to compiler component <program>]:program:'
+  '*-specs=-[Override built-in specs with the contents of <file>]:file:_files'
+  '-std=-[Assume that the input sources are for <standard>]:standard:(c90 c89 c99 c11 gnu90 gnu89 gnu99 gnu11 c++98 c++03 gnu++98 gnu++03 c++11 gnu++11 c++1y gnu++1y)'
+  '*-include:include file:_files -g \*.h\(-.\)'
+  '*-imacros:macro input file:_files -g \*.h\(-.\)'
+  '*-idirafter:second include path directory:_files -/'
+  '*-iprefix:prefix:_files'
+  '*-iwithprefix:second include path directory:_files -/'
+  '*-iwithprefixbefore:main include path directory:_files -/'
+  '*-isystem:second include path directory (system):_files -/'
+  '--sysroot=-[Use <directory> as the root directory for headers and libraries]:directory:_files -/'
+  '-pass-exit-codes[Exit with highest error code from a phase]'
+  '*--help=-[Display this information]:class:->help'
+  '--target-help[Display target specific command line options]'
+  '-dumpspecs[Display all of the built in spec strings]'
+  '-dumpversion[Display the version of the compiler]'
+  '-dumpmachine[Display the compiler'\''s target processor]'
+  '-print-search-dirs[Display the directories in the compiler'\''s search path]'
+  '-print-libgcc-file-name[Display the name of the compiler'\''s companion library]'
+  '-print-multiarch[Display the target'\''s normalized GNU triplet, used as a component in the library path]'
+  '-print-multi-directory[Display the root directory for versions of libgcc]'
+  '-print-multi-lib[Display the mapping between command line options and multiple library search directories]'
+  '-print-multi-os-directory[Display the relative path to OS libraries]'
+  '-print-sysroot[Display the target libraries directory]'
+  '-print-sysroot-headers-suffix[Display the sysroot suffix used to find headers]'
+  '-save-temps[Do not delete intermediate files]'
+  '-no-canonical-prefixes[Do not canonicalize paths when building relative prefixes to other gcc components]'
+  '-pipe[Use pipes rather than intermediate files]'
+  '-pie[Create a position independent executable]'
+  '-shared[Create a shared library]'
+  '-time[Time the execution of each subprocess]'
+)
+
+# warnings (from --help=warnings), note some -W options are listed by --help=common instead
+args+=(
+# --help=warnings,^joined
+  '-W[This switch is deprecated; use -Wextra instead]'
+  '-Wabi-tag[Warn if a subobject has an abi_tag attribute that the complete object type does not have]'
+  '-Wabi[Warn about things that will change when compiling with an ABI-compliant compiler]'
+  '-Waddress[Warn about suspicious uses of memory addresses]'
+  '-Waggregate-return[Warn about returning structures, unions or arrays]'
+  '-Waggressive-loop-optimizations[Warn if a loop with constant number of iterations triggers undefined behavior]'
+  '-Waliasing[Warn about possible aliasing of dummy arguments]'
+  '-Walign-commons[Warn about alignment of COMMON blocks]'
+  '-Wall[Enable most warning messages]'
+  '-Wampersand[Warn about missing ampersand in continued character constants]'
+  '-Warray-bounds[Warn if an array is accessed out of bounds]'
+  '-Warray-temporaries[Warn about creation of array temporaries]'
+  '-Wassign-intercept[Warn whenever an Objective-C assignment is being intercepted by the garbage collector]'
+  '-Wattributes[Warn about inappropriate attribute usage]'
+  '-Wbad-function-cast[Warn about casting functions to incompatible types]'
+  '-Wbuiltin-macro-redefined[Warn when a built-in preprocessor macro is undefined or redefined]'
+  '-Wc++-compat[Warn about C constructs that are not in the common subset of C and C++]'
+  '-Wc++0x-compat[Deprecated in favor of -Wc++11-compat]'
+  '-Wc++11-compat[Warn about C++ constructs whose meaning differs between ISO C++ 1998 and ISO C++ 2011]'
+  '-Wc-binding-type[Warn if the type of a variable might be not interoperable with C]'
+  '-Wcast-align[Warn about pointer casts which increase alignment]'
+  '-Wcast-qual[Warn about casts which discard qualifiers]'
+  '-Wchar-subscripts[Warn about subscripts whose type is "char"]'
+  '-Wcharacter-truncation[Warn about truncated character expressions]'
+  '-Wclobbered[Warn about variables that might be changed by "longjmp" or "vfork"]'
+  '-Wcomment[Warn about possibly nested block comments, and C++ comments spanning more than one physical line]'
+  '-Wcomments[Synonym for -Wcomment]'
+  '-Wcompare-reals[Warn about equality comparisons involving REAL or COMPLEX expressions]'
+  '-Wconversion-extra[Warn about most implicit conversions]'
+  '-Wconversion-null[Warn for converting NULL from/to a non-pointer type]'
+  '-Wconversion[Warn for implicit type conversions that may change a value]'
+  '-Wcoverage-mismatch[Warn in case profiles in -fprofile-use do not match]'
+  '-Wcpp[Warn when a #warning directive is encountered]'
+  '-Wctor-dtor-privacy[Warn when all constructors and destructors are private]'
+  '-Wdeclaration-after-statement[Warn when a declaration is found after a statement]'
+  '-Wdelete-non-virtual-dtor[Warn about deleting polymorphic objects with non- virtual destructors]'
+  '-Wdeprecated-declarations[Warn about uses of __attribute__((deprecated)) declarations]'
+  '-Wdeprecated[Warn if a deprecated compiler feature, class, method, or field is used]'
+  '-Wdisabled-optimization[Warn when an optimization pass is disabled]'
+  '-Wdiv-by-zero[Warn about compile-time integer division by zero]'
+  '-Wdouble-promotion[Warn about implicit conversions from "float" to "double"]'
+  '-Weffc++[Warn about violations of Effective C++ style rules]'
+  '-Wempty-body[Warn about an empty body in an if or else statement]'
+  '-Wendif-labels[Warn about stray tokens after #elif and #endif]'
+  '-Wenum-compare[Warn about comparison of different enum types]'
+#this still exists but makes completing -Werror= less convenient
+  #'-Werror-implicit-function-declaration[This switch is deprecated; use -Werror=implicit-function-declaration instead]'
+  '-Wextra[Print extra (possibly unwanted) warnings]'
+  '-Wfloat-equal[Warn if testing floating point numbers for equality]'
+  '-Wformat-contains-nul[Warn about format strings that contain NUL bytes]'
+  '-Wformat-extra-args[Warn if passing too many arguments to a function for its format string]'
+  '-Wformat-nonliteral[Warn about format strings that are not literals]'
+  '-Wformat-security[Warn about possible security problems with format functions]'
+  '-Wformat-y2k[Warn about strftime formats yielding 2-digit years]'
+  '-Wformat-zero-length[Warn about zero-length formats]'
+  '-Wformat[Warn about printf/scanf/strftime/strfmon format string anomalies]'
+  '-Wfree-nonheap-object[Warn when attempting to free a non-heap object]'
+  '-Wfunction-elimination[Warn about function call elimination]'
+  '-Wignored-qualifiers[Warn whenever type qualifiers are ignored]'
+  '-Wimplicit-function-declaration[Warn about implicit function declarations]'
+  '-Wimplicit-int[Warn when a declaration does not specify a type]'
+  '-Wimplicit-interface[Warn about calls with implicit interface]'
+  '-Wimplicit-procedure[Warn about called procedures not explicitly declared]'
+  '-Wimplicit[Warn about implicit declarations]'
+  '-Winherited-variadic-ctor[Warn about C++11 inheriting constructors when the base has a variadic constructor]'
+  '-Winit-self[Warn about variables which are initialized to themselves]'
+  '-Winline[Warn when an inlined function cannot be inlined]'
+  '-Wint-to-pointer-cast[Warn when there is a cast to a pointer from an integer of a different size]'
+  '-Wintrinsic-shadow[Warn if a user-procedure has the same name as an intrinsic]'
+  '-Wintrinsics-std[Warn on intrinsics not part of the selected standard]'
+  '-Winvalid-memory-model[Warn when an atomic memory model parameter is known to be outside the valid range]'
+  '-Winvalid-offsetof[Warn about invalid uses of the "offsetof" macro]'
+  '-Winvalid-pch[Warn about PCH files that are found but not used]'
+  '-Wjump-misses-init[Warn when a jump misses a variable initialization]'
+  '-Wline-truncation[Warn about truncated source lines]'
+  '-Wliteral-suffix[Warn when a string or character literal is followed by a ud-suffix which does not begin with an underscore]'
+  '-Wlogical-op[Warn when a logical operator is suspiciously always evaluating to true or false]'
+  '-Wlong-long[Do not warn about using "long long" when -pedantic]'
+  '-Wmain[Warn about suspicious declarations of "main"]'
+  '-Wmaybe-uninitialized[Warn about maybe uninitialized automatic variables]'
+  '-Wmissing-braces[Warn about possibly missing braces around initializers]'
+  '-Wmissing-declarations[Warn about global functions without previous declarations]'
+  '-Wmissing-field-initializers[Warn about missing fields in struct initializers]'
+  '-Wmissing-include-dirs[Warn about user-specified include directories that do not exist]'
+  '-Wmissing-parameter-type[Warn about function parameters declared without a type specifier in K&R-style functions]'
+  '-Wmissing-prototypes[Warn about global functions without prototypes]'
+  '-Wmudflap[Warn about constructs not instrumented by -fmudflap]'
+  '-Wmultichar[Warn about use of multi-character character constants]'
+  '-Wnarrowing[Warn about narrowing conversions within { } that are ill-formed in C++11]'
+  '-Wnested-externs[Warn about "extern" declarations not at file scope]'
+  '-Wnoexcept[Warn when a noexcept expression evaluates to false even though the expression can'\''t actually throw]'
+  '-Wnon-template-friend[Warn when non-templatized friend functions are declared within a template]'
+  '-Wnon-virtual-dtor[Warn about non-virtual destructors]'
+  '-Wnonnull[Warn about NULL being passed to argument slots marked as requiring non-NULL]'
+  '-Wold-style-cast[Warn if a C-style cast is used in a program]'
+  '-Wold-style-declaration[Warn for obsolescent usage in a declaration]'
+  '-Wold-style-definition[Warn if an old-style parameter definition is used]'
+  '-Woverflow[Warn about overflow in arithmetic expressions]'
+  '-Woverlength-strings[Warn if a string is longer than the maximum portable length specified by the standard]'
+  '-Woverloaded-virtual[Warn about overloaded virtual function names]'
+  '-Woverride-init[Warn about overriding initializers without side effects]'
+  '-Wpacked-bitfield-compat[Warn about packed bit-fields whose offset changed in GCC 4.4]'
+  '-Wpacked[Warn when the packed attribute has no effect on struct layout]'
+  '-Wpadded[Warn when padding is required to align structure members]'
+  '-Wparentheses[Warn about possibly missing parentheses]'
+  '-Wpedantic[Issue warnings needed for strict compliance to the standard]'
+  '-Wpmf-conversions[Warn when converting the type of pointers to member functions]'
+  '-Wpointer-arith[Warn about function pointer arithmetic]'
+  '-Wpointer-sign[Warn when a pointer differs in signedness in an assignment]'
+  '-Wpointer-to-int-cast[Warn when a pointer is cast to an integer of a different size]'
+  '-Wpoison-system-directories[Warn for -I and -L options using system directories if cross compiling]'
+  '-Wpragmas[Warn about misuses of pragmas]'
+  '-Wproperty-assign-default[Warn if a property for an Objective-C object has no assign semantics specified]'
+  '-Wprotocol[Warn if inherited methods are unimplemented]'
+  '-Wreal-q-constant[Warn about real-literal-constants with '\''q'\'' exponent-letter]'
+  '-Wrealloc-lhs-all[Warn when a left-hand-side variable is reallocated]'
+  '-Wrealloc-lhs[Warn when a left-hand-side array variable is reallocated]'
+  '-Wredundant-decls[Warn about multiple declarations of the same object]'
+  '-Wreorder[Warn when the compiler reorders code]'
+  '-Wreturn-local-addr[Warn about returning a pointer/reference to a local or temporary variable]'
+  '-Wreturn-type[Warn whenever a function'\''s return type defaults to "int" (C), or about inconsistent return types (C++)]'
+  '-Wselector[Warn if a selector has multiple methods]'
+  '-Wsequence-point[Warn about possible violations of sequence point rules]'
+  '-Wshadow[Warn when one local variable shadows another]'
+  '-Wsign-compare[Warn about signed-unsigned comparisons]'
+  '-Wsign-promo[Warn when overload promotes from unsigned to signed]'
+  '-Wstack-protector[Warn when not issuing stack smashing protection for some reason]'
+  '-Wstrict-null-sentinel[Warn about uncasted NULL used as sentinel]'
+  '-Wstrict-prototypes[Warn about unprototyped function declarations]'
+  '-Wstrict-selector-match[Warn if type signatures of candidate methods do not match exactly]'
+  '-Wsuggest-attribute=-[Warn about functions which might be candidates for __attribute__((const))]:const: '
+  '-Wsurprising[Warn about "suspicious" constructs]'
+  '-Wswitch-default[Warn about enumerated switches missing a "default-" statement]'
+  '-Wswitch-enum[Warn about all enumerated switches missing a specific case]'
+  '-Wswitch[Warn about enumerated switches, with no default, missing a case]'
+  '-Wsync-nand[Warn when __sync_fetch_and_nand and __sync_nand_and_fetch built-in functions are used]'
+  '-Wsynth[Deprecated. This switch has no effect]'
+  '-Wsystem-headers[Do not suppress warnings from system headers]'
+  '-Wtabs[Permit nonconforming uses of the tab character]'
+  '-Wtarget-lifetime[Warn if the pointer in a pointer assignment might outlive its target]'
+  '-Wtraditional-conversion[Warn of prototypes causing type conversions different from what would happen in the absence of prototype]'
+  '-Wtraditional[Warn about features not present in traditional C]'
+  '-Wtrampolines[Warn whenever a trampoline is generated]'
+  '-Wtrigraphs[Warn if trigraphs are encountered that might affect the meaning of the program]'
+  '-Wtype-limits[Warn if a comparison is always true or always false due to the limited range of the data type]'
+  '-Wundeclared-selector[Warn about @selector()s without previously declared methods]'
+  '-Wundef[Warn if an undefined macro is used in an #if directive]'
+  '-Wunderflow[Warn about underflow of numerical constant expressions]'
+  '-Wuninitialized[Warn about uninitialized automatic variables]'
+  '-Wunknown-pragmas[Warn about unrecognized pragmas]'
+  '-Wunsafe-loop-optimizations[Warn if the loop cannot be optimized due to nontrivial assumptions]'
+  '-Wunsuffixed-float-constants[Warn about unsuffixed float constants]'
+  '-Wunused-but-set-parameter[Warn when a function parameter is only set, otherwise unused]'
+  '-Wunused-but-set-variable[Warn when a variable is only set, otherwise unused]'
+  '-Wunused-dummy-argument[Warn about unused dummy arguments]'
+  '-Wunused-function[Warn when a function is unused]'
+  '-Wunused-label[Warn when a label is unused]'
+  '-Wunused-local-typedefs[Warn when typedefs locally defined in a function are not used]'
+  '-Wunused-macros[Warn about macros defined in the main file that are not used]'
+  '-Wunused-parameter[Warn when a function parameter is unused]'
+  '-Wunused-result[Warn if a caller of a function, marked with attribute warn_unused_result, does not use its return value]'
+  '-Wunused-value[Warn when an expression value is unused]'
+  '-Wunused-variable[Warn when a variable is unused]'
+  '-Wunused[Enable all -Wunused- warnings]'
+  '-Wuseless-cast[Warn about useless casts]'
+  '-Wvarargs[Warn about questionable usage of the macros used to retrieve variable arguments]'
+  '-Wvariadic-macros[Warn about using variadic macros]'
+  '-Wvector-operation-performance[Warn when a vector operation is compiled outside the SIMD]'
+  '-Wvirtual-move-assign[Warn if a virtual base has a non-trivial move assignment operator]'
+  '-Wvla[Warn if a variable length array is used]'
+  '-Wvolatile-register-var[Warn when a register variable is declared volatile]'
+  '-Wwrite-strings[In C++, nonzero means warn about deprecated conversion from string literals to '\''char *'\''. In C, similar warning, except that the conversion is of course not deprecated by the ISO C standard]'
+  '-Wzero-as-null-pointer-constant[Warn when a literal '\''0'\'' is used as null pointer]'
+  '-frequire-return-statement[Functions which return values must end with return statements]'
+# --help=warnings,joined
+  '-Wlarger-than=-[Warn if an object is larger than <number> bytes]:number: '
+  '-Wnormalized=-[Warn about non-normalised Unicode strings]:normalization:((id\:allow\ some\ non-nfc\ characters\ that\ are\ valid\ identifiers nfc\:only\ allow\ NFC nfkc\:only\ allow\ NFKC none\:allow\ any\ normalization)): '
+  '-Wstack-usage=-[Warn if stack usage might be larger than specified amount]:stack usage: '
+  '-Wstrict-aliasing=-[Warn about code which might break strict aliasing rules]:level of checking (higher is more accurate):(1 2 3)'
+  '-Wstrict-overflow=-[Warn about optimizations that assume that signed overflow is undefined]:level of checking (higher finds more cases):(1 2 3 4 5)'
+# -W options from --help=common
+  '-Werror=-[Treat specified warning as error (or all if none specified)]:warning:->werror'
+  '-Wfatal-errors[Exit on the first error occurred]'
+  '-Wframe-larger-than=-[Warn if a function'\'\''s stack frame requires more than <number> bytes]:number: '
+)
+# optimizers (from --help=optimizers), except for -O
+args+=(
+# --help=optimizers,^joined
+  '-faggressive-loop-optimizations[Aggressively optimize loops using language constraints]'
+  '-falign-functions=-[Align the start of functions]:function alignment'
+  '-falign-jumps=-[Align labels which are only reached by jumping]:jump alignment'
+  '-falign-labels=-[Align all labels]:label alignment'
+  '-falign-loops=-[Align the start of loops]:loop alignment'
+  '-fasynchronous-unwind-tables[Generate unwind tables that are exact at each instruction boundary]'
+  '-fbranch-count-reg[Replace add, compare, branch with branch on count register]'
+  '-fbranch-probabilities[Use profiling information for branch probabilities]'
+  '-fbranch-target-load-optimize2[Perform branch target load optimization after prologue / epilogue threading]'
+  '-fbranch-target-load-optimize[Perform branch target load optimization before prologue / epilogue threading]'
+  '-fbtr-bb-exclusive[Restrict target load migration not to re-use registers in any basic block]'
+  '-fcaller-saves[Save registers around function calls]'
+  '-fcombine-stack-adjustments[Looks for opportunities to reduce stack adjustments and stack references]'
+  '-fcommon[Do not put uninitialized globals in the common section]'
+  '-fcompare-elim[Perform comparison elimination after register allocation has finished]'
+  '-fconserve-stack[Do not perform optimizations increasing noticeably stack usage]'
+  '-fcprop-registers[Perform a register copy-propagation optimization pass]'
+  '-fcrossjumping[Perform cross-jumping optimization]'
+  '-fcse-follow-jumps[When running CSE, follow jumps to their targets]'
+  '-fcx-fortran-rules[Complex multiplication and division follow Fortran rules]'
+  '-fcx-limited-range[Omit range reduction step when performing complex division]'
+  '-fdata-sections[Place data items into their own section]'
+  '-fdce[Use the RTL dead code elimination pass]'
+  '-fdefer-pop[Defer popping functions args from stack until later]'
+  '-fdelayed-branch[Attempt to fill delay slots of branch instructions]'
+  '-fdelete-null-pointer-checks[Delete useless null pointer checks]'
+  '-fdevirtualize[Try to convert virtual calls to direct ones]'
+  '-fdse[Use the RTL dead store elimination pass]'
+  '-fearly-inlining[Perform early inlining]'
+  '-fexceptions[Enable exception handling]'
+  '-fexpensive-optimizations[Perform a number of minor, expensive optimizations]'
+  '-ffinite-math-only[Assume no NaNs or infinities are generated]'
+  '-ffloat-store[Don'\''t allocate floats and doubles in extended- precision registers]'
+  '-fforward-propagate[Perform a forward propagation pass on RTL]'
+  '-fgcse-after-reload[Perform global common subexpression elimination after register allocation has finished]'
+  '-fgcse-las[Perform redundant load after store elimination in global common subexpression elimination]'
+  '-fgcse-lm[Perform enhanced load motion during global common subexpression elimination]'
+  '-fgcse-sm[Perform store motion after global common subexpression elimination]'
+  '-fgcse[Perform global common subexpression elimination]'
+  '-fgraphite-identity[Enable Graphite Identity transformation]'
+  '-fguess-branch-probability[Enable guessing of branch probabilities]'
+  '-fhandle-exceptions[This switch lacks documentation]'
+  '-fhoist-adjacent-loads[Enable hoisting adjacent loads to encourage generating conditional move instructions]'
+  '-fif-conversion2[Perform conversion of conditional jumps to conditional execution]'
+  '-fif-conversion[Perform conversion of conditional jumps to branchless equivalents]'
+  '-finline-atomics[Inline __atomic operations when a lock free instruction sequence is available]'
+  '-finline-functions-called-once[Integrate functions only required by their single caller]'
+  '-finline-functions[Integrate functions not declared "inline" into their callers when profitable]'
+  '-finline-small-functions[Integrate functions into their callers when code size is known not to grow]'
+  '-finline[Enable inlining of function declared "inline", disabling disables all inlining]'
+  '-fipa-cp-clone[Perform cloning to make Interprocedural constant propagation stronger]'
+  '-fipa-cp[Perform Interprocedural constant propagation]'
+  '-fipa-profile[Perform interprocedural profile propagation]'
+  '-fipa-pta[Perform interprocedural points-to analysis]'
+  '-fipa-pure-const[Discover pure and const functions]'
+  '-fipa-reference[Discover readonly and non addressable static variables]'
+  '-fipa-sra[Perform interprocedural reduction of aggregates]'
+  '-fira-hoist-pressure[Use IRA based register pressure calculation in RTL hoist optimizations]'
+  '-fivopts[Optimize induction variables on trees]'
+  '-fjump-tables[Use jump tables for sufficiently large switch statements]'
+  '-floop-block[Enable Loop Blocking transformation]'
+  '-floop-interchange[Enable Loop Interchange transformation]'
+  '-floop-nest-optimize[Enable the ISL based loop nest optimizer]'
+  '-floop-parallelize-all[Mark all loops as parallel]'
+  '-floop-strip-mine[Enable Loop Strip Mining transformation]'
+  '-fmath-errno[Set errno after built-in math functions]'
+  '-fmerge-all-constants[Attempt to merge identical constants and constant variables]'
+  '-fmerge-constants[Attempt to merge identical constants across compilation units]'
+  '-fmodulo-sched[Perform SMS based modulo scheduling before the first scheduling pass]'
+  '-fmove-loop-invariants[Move loop invariant computations out of loops]'
+  '-fno-threadsafe-statics[Do not generate thread-safe code for initializing local statics]'
+  '-fnon-call-exceptions[Support synchronous non-call exceptions]'
+  '-fnothrow-opt[Treat a throw() exception specification as noexcept to improve code size]'
+  '-fomit-frame-pointer[When possible do not generate stack frames]'
+  '-fopt-info[Enable all optimization info dumps on stderr]'
+  '-foptimize-register-move[Do the full register move optimization pass]'
+  '-foptimize-sibling-calls[Optimize sibling and tail recursive calls]'
+  '-foptimize-strlen[Enable string length optimizations on trees]'
+  '-fpack-struct[Pack structure members together without holes]'
+  '-fpeel-loops[Perform loop peeling]'
+  '-fpeephole2[Enable an RTL peephole pass before sched2]'
+  '-fpeephole[Enable machine specific peephole optimizations]'
+  '-fpredictive-commoning[Run predictive commoning optimization]'
+  '-fprefetch-loop-arrays[Generate prefetch instructions, if available, for arrays in loops]'
+  '-freg-struct-return[Return small aggregates in registers]'
+  '-fregmove[Enables a register move optimization]'
+  '-frename-registers[Perform a register renaming optimization pass]'
+  '-freorder-blocks-and-partition[Reorder basic blocks and partition into hot and cold sections]'
+  '-freorder-blocks[Reorder basic blocks to improve code placement]'
+  '-freorder-functions[Reorder functions to improve code placement]'
+  '-frerun-cse-after-loop[Add a common subexpression elimination pass after loop optimizations]'
+  '-freschedule-modulo-scheduled-loops[Enable/Disable the traditional scheduling in loops that already passed modulo scheduling]'
+  '-frounding-math[Disable optimizations that assume default FP rounding behavior]'
+  '-frtti[Generate run time type descriptor information]'
+  '-fsched-critical-path-heuristic[Enable the critical path heuristic in the scheduler]'
+  '-fsched-dep-count-heuristic[Enable the dependent count heuristic in the scheduler]'
+  '-fsched-group-heuristic[Enable the group heuristic in the scheduler]'
+  '-fsched-interblock[Enable scheduling across basic blocks]'
+  '-fsched-last-insn-heuristic[Enable the last instruction heuristic in the scheduler]'
+  '-fsched-pressure[Enable register pressure sensitive insn scheduling]'
+  '-fsched-rank-heuristic[Enable the rank heuristic in the scheduler]'
+  '-fsched-spec-insn-heuristic[Enable the speculative instruction heuristic in the scheduler]'
+  '-fsched-spec-load-dangerous[Allow speculative motion of more loads]'
+  '-fsched-spec-load[Allow speculative motion of some loads]'
+  '-fsched-spec[Allow speculative motion of non-loads]'
+  '-fsched2-use-superblocks[If scheduling post reload, do superblock scheduling]'
+  '-fschedule-insns2[Reschedule instructions after register allocation]'
+  '-fschedule-insns[Reschedule instructions before register allocation]'
+  '-fsection-anchors[Access data in the same section from shared anchor points]'
+  '-fsel-sched-pipelining-outer-loops[Perform software pipelining of outer loops during selective scheduling]'
+  '-fsel-sched-pipelining[Perform software pipelining of inner loops during selective scheduling]'
+  '-fsel-sched-reschedule-pipelined[Reschedule pipelined regions without pipelining]'
+  '-fselective-scheduling2[Run selective scheduling after reload]'
+  '-fselective-scheduling[Schedule instructions using selective scheduling algorithm]'
+  '-fshort-double[Use the same size for double as for float]'
+  '-fshort-enums[Use the narrowest integer type possible for enumeration types]'
+  '-fshort-wchar[Force the underlying type for "wchar_t" to be "unsigned short"]'
+  '-fshrink-wrap[Emit function prologues only before parts of the function that need it, rather than at the top of the function]'
+  '-fsignaling-nans[Disable optimizations observable by IEEE signaling NaNs]'
+  '-fsigned-zeros[Disable floating point optimizations that ignore the IEEE signedness of zero]'
+  '-fsingle-precision-constant[Convert floating point constants to single precision constants]'
+  '-fsplit-ivs-in-unroller[Split lifetimes of induction variables when loops are unrolled]'
+  '-fsplit-wide-types[Split wide types into independent registers]'
+  '-fstrict-aliasing[Assume strict aliasing rules apply]'
+  '-fstrict-enums[Assume that values of enumeration type are always within the minimum range of that type]'
+  '-fthread-jumps[Perform jump threading optimizations]'
+  '-ftoplevel-reorder[Reorder top level functions, variables, and asms]'
+  '-ftrapping-math[Assume floating-point operations can trap]'
+  '-ftrapv[Trap for signed overflow in addition, subtraction and multiplication]'
+  '-ftree-bit-ccp[Enable SSA-BIT-CCP optimization on trees]'
+  '-ftree-builtin-call-dce[Enable conditional dead code elimination for builtin calls]'
+  '-ftree-ccp[Enable SSA-CCP optimization on trees]'
+  '-ftree-ch[Enable loop header copying on trees]'
+  '-ftree-coalesce-inlined-vars[Enable coalescing of copy-related user variables that are inlined]'
+  '-ftree-coalesce-vars[Enable coalescing of all copy-related user variables]'
+  '-ftree-copy-prop[Enable copy propagation on trees]'
+  '-ftree-copyrename[Replace SSA temporaries with better names in copies]'
+  '-ftree-cselim[Transform condition stores into unconditional ones]'
+  '-ftree-dce[Enable SSA dead code elimination optimization on trees]'
+  '-ftree-dominator-opts[Enable dominator optimizations]'
+  '-ftree-dse[Enable dead store elimination]'
+  '-ftree-forwprop[Enable forward propagation on trees]'
+  '-ftree-fre[Enable Full Redundancy Elimination (FRE) on trees]'
+  '-ftree-loop-distribute-patterns[Enable loop distribution for patterns transformed into a library call]'
+  '-ftree-loop-distribution[Enable loop distribution on trees]'
+  '-ftree-loop-if-convert-stores[Also if-convert conditional jumps containing memory writes]'
+  '-ftree-loop-if-convert[Convert conditional jumps in innermost loops to branchless equivalents]'
+  '-ftree-loop-im[Enable loop invariant motion on trees]'
+  '-ftree-loop-ivcanon[Create canonical induction variables in loops]'
+  '-ftree-loop-optimize[Enable loop optimizations on tree level]'
+  '-ftree-lrs[Perform live range splitting during the SSA- >normal pass]'
+  '-ftree-partial-pre[In SSA-PRE optimization on trees, enable partial- partial redundancy elimination]'
+  '-ftree-phiprop[Enable hoisting loads from conditional pointers]'
+  '-ftree-pre[Enable SSA-PRE optimization on trees]'
+  '-ftree-pta[Perform function-local points-to analysis on trees]'
+  '-ftree-reassoc[Enable reassociation on tree level]'
+  '-ftree-scev-cprop[Enable copy propagation of scalar-evolution information]'
+  '-ftree-sink[Enable SSA code sinking on trees]'
+  '-ftree-slp-vectorize[Enable basic block vectorization (SLP) on trees]'
+  '-ftree-slsr[Perform straight-line strength reduction]'
+  '-ftree-sra[Perform scalar replacement of aggregates]'
+  '-ftree-switch-conversion[Perform conversions of switch initializations]'
+  '-ftree-tail-merge[Enable tail merging on trees]'
+  '-ftree-ter[Replace temporary expressions in the SSA->normal pass]'
+  '-ftree-vect-loop-version[Enable loop versioning when doing loop vectorization on trees]'
+  '-ftree-vectorize[Enable loop vectorization on trees]'
+  '-ftree-vrp[Perform Value Range Propagation on trees]'
+  '-funit-at-a-time[Compile whole compilation unit at a time]'
+  '-funroll-all-loops[Perform loop unrolling for all loops]'
+  '-funroll-loops[Perform loop unrolling when iteration count is known]'
+  '-funsafe-loop-optimizations[Allow loop optimizations to assume that the loops behave in normal way]'
+  '-funsafe-math-optimizations[Allow math optimizations that may violate IEEE or ISO standards]'
+  '-funswitch-loops[Perform loop unswitching]'
+  '-funwind-tables[Just generate unwind tables for exception handling]'
+  '-fvar-tracking-assignments-toggle[Toggle -fvar-tracking-assignments]'
+  '-fvar-tracking-assignments[Perform variable tracking by annotating assignments]'
+  '-fvar-tracking-uninit[Perform variable tracking and also tag variables that are uninitialized]'
+  '-fvar-tracking[Perform variable tracking]'
+  '-fvariable-expansion-in-unroller[Apply variable expansion when loops are unrolled]'
+  '-fvect-cost-model[Enable use of cost model in vectorization]'
+  '-fvpt[Use expression value profiles in optimizations]'
+  '-fweb[Construct webs and split unrelated uses of single variable]'
+  '-fwhole-program[Perform whole program optimizations]'
+  '-fwrapv[Assume signed arithmetic overflow wraps around]'
+# --help=optimizers,joined
+  '-fpack-struct=-[Set initial maximum structure member alignment]:alignment: '
+)
 
-_arguments -C -M 'L:|-{fW}no-=-{fW} r:|[_-]=* r:|=*' \
+# other common options, gcc --help=warnings --help=optimizers --help=common|sed 1,/language-independent/d
+args+=(
+# | grep -v ::
+  '--debug[This switch lacks documentation]'
+  '--dump[This switch lacks documentation]'
+  '--dumpbase[This switch lacks documentation]'
+  '--dumpdir[This switch lacks documentation]'
+  '--help[Display this information]'
+  '--no-warnings[This switch lacks documentation]'
+  '--optimize[This switch lacks documentation]'
+  '--output[This switch lacks documentation]'
+  '--param[Set parameter <param> to value.  See manpage for a complete list of parameters]:name=value'
+  '--pedantic-errors[This switch lacks documentation]'
+  '--pedantic[This switch lacks documentation]'
+  '--profile[This switch lacks documentation]'
+  '--verbose[This switch lacks documentation]'
+  '--version[This switch lacks documentation]'
+  '-aux-info[Emit declaration information into <file>]:file:_files'
+  '-dumpbase[Set the file basename to be used for dumps]'
+  '-dumpdir[Set the directory name to be used for dumps]'
+  '-fPIC[Generate position-independent code if possible (large mode)]'
+  '-fPIE[Generate position-independent code for executables if possible (large mode)]'
+  '-fassociative-math[Allow optimization for floating-point arithmetic which may change the result of the operation due to rounding]'
+  '-fauto-inc-dec[Generate auto-inc/dec instructions]'
+  '-fbounds-check[Generate code to check bounds before indexing arrays]'
+  '-fcall-saved--[Mark <register> as being preserved across functions]:register'
+  '-fcall-used--[Mark <register> as being corrupted by function calls]:register'
+  '-fcheck-data-deps[Compare the results of several data dependence analyzers]'
+  '-fcompare-debug-second[Run only the second compilation of -fcompare-debug]'
+  '-fcompare-debug=[Compile with and without e.g. -gtoggle, and compare the final-insns dump]:opts:' #TODO: complete gcc options here
+  '-fdbg-cnt-list[List all available debugging counters with their limits and counts]'
+  '-fdbg-cnt=[,<counter>-<limit>,...) Set the debug counter limit]:counter\:limit,...: ' #TODO: gcc -fdbg-cnt-list -x c /dev/null -o /dev/null -c
+  '-fdebug-types-section[Output .debug_types section when using DWARF v4 debuginfo]'
+  '-fdelete-dead-exceptions[Delete dead instructions that may throw exceptions]'
+  '-fdiagnostics-show-caret[Show the source line with a caret indicating the column]'
+  '-fdiagnostics-show-location=-[How often to emit source location at the beginning of line-wrapped diagnostics]:source location:(once every-line)'
+  '-fdiagnostics-show-option[Amend appropriate diagnostic messages with the command line option that controls them]'
+  #not meant for end users
+  #'-fdisable--pass=[disables an optimization pass]:range1+range2: '
+  #'-fdisable-[disables an optimization pass]'
+  #'-fenable--pass=[enables an optimization pass]:range1+range2: '
+  #'-fenable-[enables an optimization pass]'
+  #'-fdump-<type>[Dump various compiler internals to a file]'
+  '-fdump-final-insns=-[Dump to filename the insns at the end of translation]:filename:_files'
+  '-fdump-go-spec=-[Write all declarations to file as Go code]:filename:_files'
+  '-fdump-noaddr[Suppress output of addresses in debugging dumps]'
+  '-fdump-passes[Dump optimization passes]'
+  '-fdump-unnumbered-links[Suppress output of previous and next insn numbers in debugging dumps]'
+  '-fdump-unnumbered[Suppress output of instruction numbers, line number notes and addresses in debugging dumps]'
+  '-fdwarf2-cfi-asm[Enable CFI tables via GAS assembler directives]'
+  '-feliminate-dwarf2-dups[Perform DWARF2 duplicate elimination]'
+  '-feliminate-unused-debug-symbols[Perform unused type elimination in debug info]'
+  '-feliminate-unused-debug-types[Perform unused type elimination in debug info]'
+  '-femit-class-debug-always[Do not suppress C++ class debug information]'
+  '-fexcess-precision=-[Specify handling of excess floating-point precision]:precision handling:(fast standard)'
+  '-ffast-math[Sets -fno-math-errno, -funsafe-math-optimizations, -ffinite-math-only, -fno-rounding-math, -fno-signaling-nans and -fcx-limited-range]'
+  '-ffat-lto-objects[Output lto objects containing both the intermediate language and binary output]'
+  '-ffixed--[Mark <register> as being unavailable to the compiler]:register'
+  '-ffunction-cse[Allow function addresses to be held in registers]'
+  '-ffunction-sections[Place each function into its own section]'
+  '-fgnu-tm[Enable support for GNU transactional memory]'
+  '-fgraphite[Enable in and out of Graphite representation]'
+  '-fident[Process #ident directives]'
+  '-findirect-inlining[Perform indirect inlining]'
+  '-finhibit-size-directive[Do not generate .size directives]'
+  '-finline-limit=[Limit the size of inlined functions to <number>]:number: '
+  '-finstrument-functions[Instrument function entry and exit with profiling calls]'
+  '-fira-loop-pressure[Use IRA based register pressure calculation in RTL loop optimizations]'
+  '-fira-share-save-slots[Share slots for saving different hard registers]'
+  '-fira-share-spill-slots[Share stack slots for spilled pseudo-registers]'
+  '-fira-verbose=[Control IRA'\''s level of diagnostic messages]:verbosity: '
+  '-fkeep-inline-functions[Generate code for functions even if they are fully inlined]'
+  '-fkeep-static-consts[Emit static const variables even if they are not used]'
+  '-fleading-underscore[Give external symbols a leading underscore]'
+  '-flto-compression-level=[Use zlib compression level <number> for IL]:compression level: '
+  '-flto-partition=[Partition symbols and vars at linktime based on object files they originate from]:partitioning algorithm:(1to1 balanced max)'
+  '-flto-report[Report various link-time optimization statistics]'
+  '-flto[Enable link-time optimization]'
+  '-fmax-errors=-[Maximum number of errors to report]:errors: '
+  '-fmem-report-wpa[Report on permanent memory allocation in WPA only]'
+  '-fmem-report[Report on permanent memory allocation]'
+  '-fmerge-debug-strings[Attempt to merge identical debug strings across compilation units]'
+  '-fmessage-length=-[Limit diagnostics to <number> characters per line.  0 suppresses line-wrapping]:length: '
+  '-fmodulo-sched-allow-regmoves[Perform SMS based modulo scheduling with register moves allowed]'
+  '-fopt-info-type=-[Dump compiler optimization details]:filename:_files'
+  '-fopt-info[Dump compiler optimization details]'
+  '-fpartial-inlining[Perform partial inlining]'
+  '-fpcc-struct-return[Return small aggregates in memory, not registers]'
+  '-fpic[Generate position-independent code if possible (small mode)]'
+  '-fpie[Generate position-independent code for executables if possible (small mode)]'
+  '-fplugin-arg--[Specify argument <key>=<value> for plugin <name>]:-fplugin-arg-name-key=value: ' #TODO
+  '-fpost-ipa-mem-report[Report on memory allocation before interprocedural optimization]'
+  '-fpre-ipa-mem-report[Report on memory allocation before interprocedural optimization]'
+  '-fprofile-arcs[Insert arc-based program profiling code]'
+  '-fprofile-correction[Enable correction of flow inconsistent profile data input]'
+  '-fprofile-generate[Enable common options for generating profile info for profile feedback directed optimizations]'
+  '-fprofile-report[Report on consistency of profile]'
+  '-fprofile-use[Enable common options for performing profile feedback directed optimizations]'
+  '-fprofile-values[Insert code to profile values of expressions]'
+  '-fprofile[Enable basic program profiling code]'
+  '-frandom-seed=-[Use <string> as random seed]:seed: '
+  '-freciprocal-math[Same as -fassociative-math for expressions which include division]'
+  '-frecord-gcc-switches[Record gcc command line switches in the object file]'
+  '-free[Turn on Redundant Extensions Elimination pass]'
+  '-fsanitize=-[Enable AddressSanitizer, a memory error detector]:style:(address thread)'
+  '-fsched-stalled-insns-dep=-[Set dependence distance checking in premature scheduling of queued insns]:instructions: '
+  '-fsched-stalled-insns=-[Set number of queued insns that can be prematurely scheduled]:instructions: '
+  '-fsched-verbose=-[Set the verbosity level of the scheduler]:verbosity: '
+  '-fshow-column[Show column numbers in diagnostics, when available]'
+  '-fsplit-stack[Generate discontiguous stack frames]'
+  '-fstack-check=-[Insert stack checking code into the program.  -fstack-check=specific if to argument given]:type:(none generic specific)'
+  '-fstack-limit-register=-[Trap if the stack goes past <register>]:register: '
+  '-fstack-limit-symbol=-[Trap if the stack goes past symbol <name>]:name: '
+  '-fno-stack-limit'
+  '-fstack-protector-all[Use a stack protection method for every function]'
+  '-fstack-protector[Use propolice as a stack protection method]'
+  '-fstack-usage[Output stack usage information on a per-function basis]'
+  '-fstrict-overflow[Treat signed overflow as undefined]'
+  '-fstrict-volatile-bitfields[Force bitfield accesses to match their type width]'
+  '-fsync-libcalls[Implement __atomic operations via libcalls to legacy __sync functions]'
+  '-fsyntax-only[Check for syntax errors, then stop]'
+  '-ftest-coverage[Create data files needed by "gcov"]'
+  '-ftime-report[Report the time taken by each compiler pass]'
+  '-ftls-model=-[Set the default thread-local storage code generation model]:TLS model:(global-dynamic local-dynamic initial-exec local-exec)'
+  '-ftracer[Perform superblock formation via tail duplication]'
+  '-ftree-loop-linear[Enable loop interchange transforms.  Same as  -floop-interchange]'
+  '-fuse-ld=[Use the specified linker instead of the default linker]:linker:(bfd gold)'
+  '-fuse-linker-plugin[Use linker plugin during link-time optimization]'
+  '-fverbose-asm[Add extra commentary to assembler output]'
+  '-fvisibility=[Set the default symbol visibility]:visibility:(default internal hidden protected)'
+  '-fzero-initialized-in-bss[Put zero initialized data in the bss section]'
+  '-gno-pubnames[Don'\''t generate DWARF pubnames and pubtypes sections]'
+  '-gno-record-gcc-switches[Don'\''t record gcc command line switches in DWARF DW_AT_producer]'
+  '-gno-split-dwarf[Don'\''t generate debug information in separate .dwo files]'
+  '-gno-strict-dwarf[Emit DWARF additions beyond selected version]'
+  '-gpubnames[Generate DWARF pubnames and pubtypes sections]'
+  '-grecord-gcc-switches[Record gcc command line switches in DWARF DW_AT_producer]'
+  '-gsplit-dwarf[Generate debug information in separate .dwo files]'
+  '-gstrict-dwarf[Don'\''t emit DWARF additions beyond selected version]'
+  '-gtoggle[Toggle debug information generation]'
+  '-gvms[Generate debug information in VMS format]'
+  '-imultiarch[Set <dir> to be the multiarch include subdirectory]:directory:_files -/' #XXX not in manpage
+  '-iplugindir=[Set <dir> to be the default plugin directory]:directory:_files -/'
+  '(-pg)-p[Enable function profiling for prof]'
+  '(-p)-pg[Enable function profiling for gprof]'
+  '-pedantic-errors[Like -pedantic but issue them as errors]'
+  '-pedantic[Issue all mandatory diagnostics in the C standard]'
+  '-quiet[Do not display functions compiled or elapsed time]'
+  '-v[Enable verbose output]'
+  '-version[Display the compiler'\''s version]'
+  '-w[Suppress warnings]'
+# | grep ::
+  '-fabi-version=-[Use version <n> of the C++ ABI (default: 2)]:ABI version:(1 2 3 4 5 6)'
+  '-fdebug-prefix-map=-[Map one directory name to another in debug information]:/old/dir=/new/dir:->dirtodir'
+  '-ffp-contract=-[Perform floating- point expression contraction (default: fast)]:style:(on off fast)'
+  '-finstrument-functions-exclude-file-list=-[Do not instrument functions listed in files]:comma-separated file list:->commafiles'
+  '-finstrument-functions-exclude-function-list=-[Do not instrument listed functions]:comma-separated list of syms: '
+  '-fira-algorithm=-[Set the used IRA algorithm]:algorithm:(priority CB)'
+  '-fira-region=-[Set regions for IRA]:region:(all mixed one)'
+  '-fplugin=-[Specify a plugin to load]:plugin: ' # TODO: complete plugins?
+  '-fprofile-dir=-[Set the top-level directory for storing the profile data]:profile directory:_files -/'
+  '-fstack-reuse=-[Set stack reuse level for local variables]:reuse-level:(all named_vars none)'
+  '-ftree-parallelize-loops=-[Enable automatic parallelization of loops]:threads: '
+)
+
+# How to mostly autogenerate the above stuff:
+# joinhelplines() { sed '$!N;s/^\(  -.*\)\n  \s*\([^-]\)/\1 \2/;P;D' }
+# gcc-x86() { gcc --help=target,\^undocumented | joinhelplines | joinhelplines }
+# compdef _gnu_generic gcc-x86
+# printf '%s\n' ${(onq-)_args_cache_gcc_x86}
+_arguments -C -M 'L:|-{fWm}no-=-{fWm} r:|[_-]=* r:|=*' \
   "$args[@]" \
-  -c -S -E -v -a -w -C -H -P -s '(-pg)-p' '(-p)-pg' \
-  '-###[print commands to run this compilation]' \
-  '-o:output file:_files -g "^*.(c|h|cc|C|cxx)(-.)"' \
-  '-x:input file language:(c objective-c c++ c-header cpp-output c++-cpp-output assembler assembler-with-cpp none)' \
-  '+e-:virtual function definitions in classes:((0\:only\ interface 1\:generate\ code))' \
-  '-d-:dump:->dump' \
-  '-g-::debugging information type:(gdb coff stabs stabs+ dwarf dwarf+ xcoff xcoff+)' \
-  '-O-::optimization level:(0 1 2 3)' \
-  '*-M-::output dependencies:((M\:only\ user\ header\ files MD\:output\ to\ file G\:treat\ missing\ header\ files\ as\ generated))' \
-  '*-A-:define assertion:' \
-  '*-D-:define macro:' \
-  '*-U-:undefine macro:' \
-  '*-Wp,-:preprocessor option:' \
-  '*-Wl,-:linker option:' \
-  '*-Xpreprocessor:preprocessor option:' \
-  '*-Xlinker:linker option:' \
-  '*-u:pretend symbol to be undefined:' \
-  '*-Wa,-:assembler option:' \
-  '*-l:library:->library' \
-  '*-L-:library search path:_files -/' \
-  '*-I-:header file search path:_files -/' \
-  '-B-:executable prefix:_files -/' \
-  '-b:target machine:' \
-  '-V:specify compiler version:' \
-  '--version' \
-  '-print-file-name=:library:->library' \
-  '-print-prog-name=:program:' \
-  '*-include:include file:_files -g \*.h\(-.\)' \
-  '*-imacros:macro input file:_files -g \*.h\(-.\)' \
-  '*-idirafter:second include path directory:_files -/' \
-  '*-iprefix:prefix:_files' \
-  '*-iwithprefix:second include path directory:_files -/' \
-  '*-iwithprefixbefore:main include path directory:_files -/' \
-  '*-isystem:second include path directory (system):_files -/' \
-  -nostdinc -trigraphs -undef -pipe -ansi \
-  -fallow-single-precision -fcond-mismatch -fasm \
-  -fbuiltin -fsigned-bitfields -fsigned-char \
-  -funsigned-bitfields -funsigned-char -fwritable-strings \
-  -traditional -traditional-cpp -trigraphs \
-  -fall-virtual -fdollars-in-identifiers -felide-constructors \
-  -fenum-int-equiv -fexternal-templates -ffor-scope \
-  -fhandle-signatures -fmemoize-lookups -fdefault-inline -fgnu-keywords \
-  -fnonnull-objects -foperator-names -fstrict-prototype \
-  -fthis-is-variable -nostdinc++ -traditional \
-  -fsyntax-only -pedantic -pedantic-errors \
-  -Wall -Waggregate-return -Wbad-function-cast \
-  -Wcast-align -Wcast-qual -Wchar-subscript -Wcomment \
-  -Wconversion -Wenum-clash -Werror -Wformat \
-  '-Wid-clash--:minimum identifier difference length:' \
-  -Wimplicit -Wimport -Winline \
-  '-Wlarger-than--:maximum object length:' \
-  -Wmissing-declarations \
-  -Wmissing-prototypes -Wnested-externs \
-  -Wimport -Woverloaded-virtual -Wparentheses \
-  -Wpointer-arith -Wredundant-decls -Wreorder -Wreturn-type -Wshadow \
-  -Wstrict-prototypes -Wswitch -Wsynth -Wtemplate-debugging \
-  -Wtraditional -Wtrigraphs -Wuninitialized -Wunused \
-  -Wwrite-strings \
-  -fpretend-float \
-  -print-libgcc-file-name \
-  -print-search-dirs -save-temps \
-  -fcaller-saves -fcse-follow-jumps -fcse-skip-blocks \
-  -fdelayed-branch  -fexpensive-optimizations \
-  -ffast-math -ffloat-store -fforce-addr -fforce-mem \
-  -finline-functions -fkeep-inline-functions \
-  -fdefault-inline -fdefer-pop -ffunction-cse \
-  -finline -fpeephole -fomit-frame-pointer \
-  -frerun-cse-after-loop -fschedule-insns \
-  -fschedule-insns2 -fstrength-reduce -fthread-jumps \
-  -funroll-all-loops -funroll-loops \
-  -nostartfiles -nodefaultlibs -nostdlib \
-  -static -shared -symbolic \
-  '*-fcall-saved--:register saved by function call:' \
-  '*-fcall-used--:register clobbered by function call:' \
-  '*-ffixed--:fixed register:' \
-  -finhibit-size-directive \
-  -fno-common -fno-ident -fno-gnu-linker \
-  -fpcc-struct-return -fpic -fPIC \
-  -freg-struct-return -fshared-data -fshort-enums \
-  -fshort-double -fvolatile -fvolatile-global \
-  -fverbose-asm -fpack-struct \
   "$args2[@]" && ret=0
 
 
@@ -342,7 +971,22 @@ library)
 rundir)
   compset -P '*:'
   compset -S ':*'
-  _files -/ -S/ -r '\n\t\- /:' "$@"
+  _files -/ -S/ -r '\n\t\- /:' "$@" && ret=0
+  ;;
+help)
+  _values -s , 'help' \
+    optimizers warnings target params common \
+    c c++ objc objc++ lto ada adascil adawhy fortran go java \
+    {\^,}undocumented {\^,}joined {\^,}separate \
+  && ret=0
+  ;;
+dirtodir)
+  compset -P '*='
+  _files -/ && ret=0
+  ;;
+commafiles)
+  compset -P '*,'
+  _files && ret=0
   ;;
 esac
 
-- 
1.9.0