crosstool-ng/config/cc/gcc.in

# GCC options

## select CC_SUPPORT_CXX
## select CC_SUPPORT_FORTRAN
## select CC_SUPPORT_JAVA if !GCC_7_or_later && OBSOLETE
## select CC_SUPPORT_ADA
## select CC_SUPPORT_OBJC
## select CC_SUPPORT_OBJCXX
## select CC_SUPPORT_GOLANG
# ISL 0.15 is the oldest release present in CTNG.
# GCC7 requires ISL 0.15+
# GCC6 requires ISL 0.14+ (it says 0.14-0.16, but accepts newer ISL as well)
# GCC5 requires ISL 0.12+ (again, it says 0.12-0.16, but also accepts newer ISL up to 0.18;
# fails to compile with 0.19+)
## select ISL_REQUIRE_0_18_or_older if ISL_NEEDED && GCC_5_or_later && !GCC_6_or_later
# GCC4.9 requires ISL 0.10..0.15
## select ISL_REQUIRE_0_15_or_older if ISL_NEEDED && GCC_4_9_or_later && !GCC_5_or_later

## help gcc is the full-blown GNU compiler. This is what most people will choose.
## help
## help gcc supports many languages, a powerful code parser, optimised binary
## help output, and lots of other features.

# Only enable gcc's support for plugins if binutils has it as well
# They are useful only when doing LTO, but it does no harm enabling
# them even without LTO.
config CC_GCC_ENABLE_PLUGINS
    def_bool y
    depends on BINUTILS_PLUGINS
    depends on ! STATIC_TOOLCHAIN

# If binutils installs gold, enable support for gold in gcc
config CC_GCC_GOLD
    def_bool y
    depends on BINUTILS_GOLD_INSTALLED

config CC_GCC_HAS_LIBMPX
    def_bool y
    depends on GCC_5_or_later

config CC_LANG_JAVA_USE_ECJ
    def_bool y
    depends on CC_LANG_JAVA

config CC_GCC_ENABLE_CXX_FLAGS
    string "Flags to pass to --enable-cxx-flags"
    default ""
    help
      Enter here the value of the gcc's ./configure option --enable-cxx-flags.
      Leave empty if you don't know better.
      
      Note: just pass in the option _value_, that is only the part that goes
      after the '=' sign.

config CC_GCC_CORE_EXTRA_CONFIG_ARRAY
    string "Core gcc extra config"
    default ""
    depends on CC_CORE_NEEDED
    help
      Extra flags to pass onto ./configure when configuring the core gcc.
      
      The core gcc is a stripped down, C-only compiler needed to build
      the C library. Kinda bootstrap gcc, if you wish.
      
      You can enter multiple arguments here, and arguments can contain spaces
      if they are properly quoted (or escaped, but prefer quotes). Eg.:
          --with-foo="1st arg with 4 spaces" --with-bar=2nd-arg-without-space

config CC_GCC_EXTRA_CONFIG_ARRAY
    string "gcc extra config"
    default ""
    help
      Extra flags to pass onto ./configure when configuring gcc.
      
      You can enter multiple arguments here, and arguments can contain spaces
      if they are properly quoted (or escaped, but prefer quotes). Eg.:
          --with-foo="1st arg with 4 spaces" --with-bar=2nd-arg-without-space

config CC_GCC_MULTILIB_LIST
    string "List of multilib variants"
    depends on MULTILIB
    default "m2,m2e,m4,m4-single,m4-single-only,m2a,m2a-single" if GCC_V_11 && ARCH_SH
    help
      Architecture-specific option of expanding or restricting the list of
      the multilib variants to be built. Refer to GCC installation manual
      for the format of this option for a particular architecture.
      Leave empty to use the default list for this architecture.

config STATIC_TOOLCHAIN
    bool
    select CC_GCC_STATIC_LIBSTDCXX

config CC_GCC_STATIC_LIBSTDCXX
    bool "Link libstdc++ statically into the gcc binary"
    default y
    depends on CONFIGURE_has_static_link || CANADIAN || CROSS_NATIVE
    select WANTS_STATIC_LINK if CROSS || NATIVE
    select WANTS_STATIC_LINK_CXX if CROSS || NATIVE
    help
      Newer gcc versions require some c++ libraries. So statically
      linking libstdc++ increases the likeliness that the gcc binary will
      run on machines other than the one which it was built on, without
      having to worry about distributing the matching version of libstdc++
      along with it.

config CC_GCC_SYSTEM_ZLIB
    bool "Use system zlib"
    help
      Do not use bundled zlib, and use the zlib already available for
      the host (eg. the system library).

      If zlib is built as a companion library, selecting this option
      will use it.
      
      If you want to build a static toolchain, you will need to also
      install the static version of zlib for your host.
      
      If unsure, say 'n'.

config CC_GCC_CONFIG_TLS
    tristate
    prompt "Configure TLS (Thread Local Storage)"
    default m
    help
      Specify that the target supports TLS (Thread Local Storage). Usually
      configure can correctly determine if TLS is supported. In cases where
      it guesses incorrectly, TLS can be explicitly enabled or disabled.
      This can happen if the assembler supports TLS but the C library does
      not, or if the assumptions made by the configure test are incorrect.

       Option  | TLS use            | Associated ./configure switch
      ---------+--------------------+--------------------------------
         Y     | forcibly used      | --enable-tls
         M     | auto               | (none, ./configure decides)
         N     | forcibly not used  | --disable-tls
      
      If unsure, say 'M'.

#-----------------------------------------------------------------------------
# Optimisation features

comment "Optimisation features"

# Defined in config/cc/gcc.in
# For graphite: gcc needs cloog and isl
# In >= gcc-5.x, cloog is no longer needed, but isl is.
config CC_GCC_USE_GRAPHITE
    bool "Enable GRAPHITE loop optimisations"
    default y
    select CLOOG_NEEDED if !GCC_5_or_later
    select ISL_NEEDED
    help
      Enable the GRAPHITE loop optimsations.
      
      On some systems (eg. Cygwin), CLooG and ISL (required to enable
      GRAPHITE) may not build properly (yet), so you'll have to say 'N'
      here (or help debug the issues)

      TODO: Is this still true on Cygwin?

# The way LTO works is a bit twisted.
# See: http://gcc.gnu.org/wiki/LinkTimeOptimization#Requirements
# Basically:
#   - if binutils has plugins: LTO is handled by ld/gold by loading
#     the plugin when linking
#   - if binutils does not have plugins: LTO is handled by collect2
# In any case, LTO support does not depend on plugins, but takes
# advantage of it
config CC_GCC_USE_LTO
    bool "Enable LTO"
    default y
    depends on ! STATIC_TOOLCHAIN
    select ZLIB_NEEDED
    help
      Enable the Link Time Optimisations.

config CC_GCC_LTO_ZSTD
    tristate
    prompt "Support LTO compression with zstd"
    default m
    depends on CC_GCC_USE_LTO
    depends on GCC_10_or_later
    depends on ! STATIC_TOOLCHAIN
    help
      Support zstd compression for LTO object files. This will require
      libzstd to be installed when using the toolchain

       Option  | ZSTD use           | Associated ./configure switch
      ---------+--------------------+--------------------------------
         Y     | forcibly used      | --with-zstd
         M     | auto               | (none, ./configure decides)
         N     | forcibly not used  | --without-zstd

      If unsure, say 'M'

#-----------------------------------------------------------------------------
comment "Settings for libraries running on target"

config CC_GCC_ENABLE_TARGET_OPTSPACE
    bool
    prompt "Optimize gcc libs for size"
    default y
    help
      Pass --enable-target-optspace to crossgcc's configure.
      
      This will compile crossgcc's libs with -Os.

config CC_GCC_LIBMUDFLAP
    bool
    prompt "Compile libmudflap"
    help
      libmudflap is a pointer-use checking tool, which can detect
      various mis-usages of pointers in C and (to some extents) C++.
      
      You should say 'N' here, as libmduflap generates instrumented
      code (thus it is a bit bigger and a bit slower) and requires
      re-compilation and re-link, while it exists better run-time
      alternatives (eg. DUMA, dmalloc...) that need neither re-
      compilation nor re-link.

config CC_GCC_LIBGOMP
    bool
    prompt "Compile libgomp"
    depends on !THREADS_NONE
    help
      libgomp is "the GNU implementation of the OpenMP Application Programming
      Interface (API) for multi-platform shared-memory parallel programming in
      C/C++ and Fortran". See:
        http://gcc.gnu.org/onlinedocs/libgomp/

      GNU OpenMP support requires threading.

      The default is 'N'. Say 'Y' if you need it, and report success/failure.

config CC_GCC_LIBSSP
    tristate
    prompt "Compile libssp"
    help
      libssp is the run-time Stack-Smashing Protection library.
      
       Option  | SSP implementation  | libssp built | Associated ./configure switch
      ---------+---------------------+--------------+-------------------------------
         Y     | libssp (forced)     | yes          | --enable-libssp
         M     | libc (if available) | yes          | (none, ./configure decides)
         N     | libc (forced)       | no           | --disable-libssp
      
      The default is 'N'. Say 'Y' or 'M' if you need it, and report success/failure.

config CC_GCC_LIBQUADMATH
    bool
    prompt "Compile libquadmath"
    help
      libquadmath is a library which provides quad-precision mathematical
      functions on targets supporting the __float128 datatype. See:
        http://gcc.gnu.org/onlinedocs/libquadmath/
      
      The default is 'N'. Say 'Y' if you need it, and report success/failure.

config CC_GCC_LIBSANITIZER
    bool
    prompt "Compile libsanitizer"
    depends on THREADS_NATIVE
    depends on !LIBC_UCLIBC_NG && !LIBC_MUSL # Currently lacks required headers (like netrom.h)
    help
      libsanitizer is a library which provides run-time sanitising of either
      or both of:
        - memory access patterns (out-of-bonds, use-after-free)
        - racy data accesses (in multi-threaded programs)

      The default is 'N'. Say 'Y' if you need it, and report success/failure.

config CC_GCC_LIBMPX
    bool
    default y
    prompt "Compile libmpx"
    depends on CC_GCC_HAS_LIBMPX
    depends on ARCH_X86
    # MUSL does not define libc types that GCC requires. Mingw lacks certain headers.
    depends on !LIBC_MUSL && !LIBC_MINGW_W64
    help
      Enable GCC support for Intel Memory Protection Extensions (MPX).

#-----------------------------------------------------------------------------

comment "Misc. obscure options."

config CC_CXA_ATEXIT
    bool
    prompt "Use __cxa_atexit"
    default y
    depends on ! BARE_METAL || LIBC_PROVIDES_CXA_ATEXIT
    help
      If you get the missing symbol "__cxa_atexit" when building C++ programs,
      you might want to try disabling this option.

config CC_GCC_TM_CLONE_REGISTRY
    tristate
    prompt "Use TM clone registry"
    depends on GCC_10_or_later
    default m
    help
      Enable GCC transactional memory clone registry in libgcc.

       Option  | tm-clone-registry  | Associated ./configure switch
      ---------+--------------------+--------------------------------
         Y     | forcibly used      | --enable-tm-clone-registry
         M     | auto               | (none, ./configure decides)
         N     | forcibly not used  | --disable-tm-clone-registry

config CC_GCC_DISABLE_PCH
    bool
    prompt "Do not build PCH"
    help
      Say 'y' here to not use Pre-Compiled Headers in the resulting toolchain.
      at the expense of speed when compiling C++ code.
      
      For some configurations (most notably canadian?), PCH are broken, and
      need to be disabled. Please see:
        http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40974

config CC_GCC_SJLJ_EXCEPTIONS
    tristate
    prompt "Use sjlj for exceptions"
    depends on ! BARE_METAL
    default m
    help
      'sjlj' is short for setjmp/longjmp.
      
      On some architectures, stack unwinding during exception handling
      works perfectly well without using sjlj, while on some others,
      use of sjlj is required for proper stack unwinding.
      
       Option  | sjlj use           | Associated ./configure switch
      ---------+--------------------+--------------------------------
         Y     | forcibly used      | --enable-sjlj-exceptions
         M     | auto               | (none, ./configure decides)
         N     | forcibly not used  | --disable-sjlj-exceptions
      
      It should be safe to say 'M' or 'N'.
      
      It can happen that ./configure is wrong in some cases. Known
      case is for ARM big endian, where you should say 'N'.

config CC_GCC_LDBL_128
    tristate
    prompt "Enable 128-bit long doubles"
    default m
    help
      Saying 'Y' will force gcc to use 128-bit wide long doubles
      Saying 'N' will force gcc to use 64-bit wide long doubles
      Saying 'M' will let gcc choose (default is 128-bit for
                 glibc >= 2.4, 64-bit otherwise)
      
      If in doubt, keep the default, ie. 'M'.

config CC_GCC_BUILD_ID
    bool
    prompt "Enable build-id"
    help
      Tells GCC to pass --build-id option to the linker for all final
      links (links performed without the -r or --relocatable option),
      if the linker supports it. If you say 'y' here, but your linker
      does not support --build-id option, a warning is issued and this
      option is ignored.
      
      The default is off.

choice CC_GCC_LNK_HASH_STYLE_CHOICE
    bool
    prompt "linker hash style"

config CC_GCC_LNK_HASH_STYLE_DEFAULT
    bool
    prompt "Default"
    help
      Do not specify any value, and use the default value (sysv).

config CC_GCC_LNK_HASH_STYLE_SYSV
    bool
    prompt "sysv"
    help
      Force use of the SYSV hash style.

config CC_GCC_LNK_HASH_STYLE_GNU
    bool
    prompt "gnu"
    help
      Force use of the GNU hash style.

config CC_GCC_LNK_HASH_STYLE_BOTH
    bool
    prompt "both"
    help
      Force use of both hash styles.

endchoice # CC_GCC_LNK_HASH_STYLE_CHOICE

config CC_GCC_LNK_HASH_STYLE
    string
    default ""      if CC_GCC_LNK_HASH_STYLE_DEFAULT
    default "sysv"  if CC_GCC_LNK_HASH_STYLE_SYSV
    default "gnu"   if CC_GCC_LNK_HASH_STYLE_GNU
    default "both"  if CC_GCC_LNK_HASH_STYLE_BOTH

choice CC_GCC_DEC_FLOATS_CHOICE
    bool "Decimal floats"
    default CC_GCC_DEC_FLOATS_AUTO
    help
      Choose what type of decimal floats to support.
      
      Note that using decimal floats requires a C library that provides
      support for fenv (namely, the fenv.h header).  This is the case
      for (e)glibc, and uClibc on x86/32.  For other C libraries, or
      uClibc on other archs, this might not be the case, so you should
      disable support for decimal floats.
      
      The default is to let ./configure decide.

config CC_GCC_DEC_FLOATS_AUTO
    bool "auto"
    help
      Let ./configure decide. If you say 'y' here, gcc will default to:
        - 'bid' for x86 (32- and 64-bit)
        - 'dpd' for powerpc
        - 'no' for the other architectures

config CC_GCC_DEC_FLOATS_BID
    bool "bid"
    help
      Use the 'binary integer decimal' format for decimal floats.

config CC_GCC_DEC_FLOATS_DPD
    bool "dpd"
    help
      Use the 'densely packed decimal' for decimal floats.

config CC_GCC_DEC_FLOATS_NO
    bool "no"
    help
      Do not support decimal floats. The default.

endchoice # CC_GCC_DEC_FLOATS_CHOICE

config CC_GCC_DEC_FLOATS
    string
    default ""      if CC_GCC_DEC_FLOATS_AUTO
    default "bid"   if CC_GCC_DEC_FLOATS_BID
    default "dpd"   if CC_GCC_DEC_FLOATS_DPD
    default "no"    if CC_GCC_DEC_FLOATS_NO

#-----------------------------------------------------------------------------

config CC_GCC_HAS_ARCH_OPTIONS
    bool

comment "archictecture-specific options"
    depends on CC_GCC_HAS_ARCH_OPTIONS

if ARCH_MIPS
source "config/cc/gcc.in.mips"
endif # ARCH_MIPS