homebrew-core/Formula/gcc@6.rb

class GccAT6 < Formula
  desc "GNU compiler collection"
  homepage "https://gcc.gnu.org"
  url "https://ftp.gnu.org/gnu/gcc/gcc-6.5.0/gcc-6.5.0.tar.xz"
  mirror "https://ftpmirror.gnu.org/gcc/gcc-6.5.0/gcc-6.5.0.tar.xz"
  sha256 "7ef1796ce497e89479183702635b14bb7a46b53249209a5e0f999bebf4740945"
  license all_of: [
    "LGPL-2.1-or-later",
    "GPL-3.0-or-later" => { with: "GCC-exception-3.1" },
  ]
  revision 7

  bottle do
    rebuild 1
    sha256                               monterey:     "6c06fbf374a3d102b63992b16c4d4af3e1631db7a6b7a73663de40abdbee276f"
    sha256                               big_sur:      "21f48173ffbe41bb31e74e5276af5c8423f740d353a9e5a553a042e296c00003"
    sha256                               catalina:     "7565805ad5e57c7c30e36b2db160279ac04b713d4fadfbdb9df4f34ad591f36f"
    sha256 cellar: :any_skip_relocation, x86_64_linux: "d5e892d3533fd82835741f2da3384e76ebc1d2c3c36e3b42e821ba8106475e19"
  end

  # The bottles are built on systems with the CLT installed, and do not work
  # out of the box on Xcode-only systems due to an incorrect sysroot.
  pour_bottle? only_if: :clt_installed

  # https://gcc.gnu.org/gcc-6/
  deprecate! date: "2022-09-09", because: :deprecated_upstream

  depends_on arch: :x86_64
  depends_on "gmp"
  depends_on "isl"
  depends_on "libmpc"
  depends_on "mpfr"

  uses_from_macos "zlib"

  on_linux do
    depends_on "binutils"
  end

  # GCC bootstraps itself, so it is OK to have an incompatible C++ stdlib
  cxxstdlib_check :skip

  def version_suffix
    version.major.to_s
  end

  # Patch for Xcode bug, taken from https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89864#c43
  # This should be removed in the next release of GCC if fixed by apple; this is an xcode bug,
  # but this patch is a work around committed to GCC trunk
  if MacOS::Xcode.version >= "10.2"
    patch do
      url "https://raw.githubusercontent.com/Homebrew/formula-patches/91d57ebe88e17255965fa88b53541335ef16f64a/gcc%406/gcc6-xcode10.2.patch"
      sha256 "0f091e8b260bcfa36a537fad76823654be3ee8462512473e0b63ed83ead18085"
    end
  end

  def install
    # Fix flat namespace use on macOS.
    configure_paths = %w[
      libatomic
      libgfortran
      libgomp
      libitm
      libobjc
      libquadmath
      libssp
      libstdc++-v3
    ]
    configure_paths.each do |path|
      inreplace buildpath/path/"configure", "${wl}-flat_namespace ${wl}-undefined ${wl}suppress",
                                            "${wl}-undefined ${wl}dynamic_lookup"
    end

    # GCC will suffer build errors if forced to use a particular linker.
    ENV.delete "LD"

    # C, C++, ObjC, Fortran compilers are always built
    languages = %w[c c++ objc obj-c++ fortran]

    # Even when suffixes are appended, the info pages conflict when
    # install-info is run so pretend we have an outdated makeinfo
    # to prevent their build.
    ENV["gcc_cv_prog_makeinfo_modern"] = "no"

    args = [
      "--prefix=#{prefix}",
      "--libdir=#{lib}/gcc/#{version_suffix}",
      "--enable-languages=#{languages.join(",")}",
      # Make most executables versioned to avoid conflicts.
      "--program-suffix=-#{version_suffix}",
      "--with-gmp=#{Formula["gmp"].opt_prefix}",
      "--with-mpfr=#{Formula["mpfr"].opt_prefix}",
      "--with-mpc=#{Formula["libmpc"].opt_prefix}",
      "--with-isl=#{Formula["isl"].opt_prefix}",
      "--enable-stage1-checking",
      "--enable-checking=release",
      "--enable-lto",
      # Use 'bootstrap-debug' build configuration to force stripping of object
      # files prior to comparison during bootstrap (broken by Xcode 6.3).
      "--with-build-config=bootstrap-debug",
      "--disable-werror",
      "--with-pkgversion=Homebrew GCC #{pkg_version} #{build.used_options*" "}".strip,
      "--with-bugurl=#{tap.issues_url}",
      "--disable-nls",
    ]

    if OS.mac?
      args << "--build=x86_64-apple-darwin#{OS.kernel_version}"
      args << "--with-system-zlib"

      # Xcode 10 dropped 32-bit support
      args << "--disable-multilib" if DevelopmentTools.clang_build_version >= 1000

      # System headers may not be in /usr/include
      sdk = MacOS.sdk_path_if_needed
      if sdk
        args << "--with-native-system-header-dir=/usr/include"
        args << "--with-sysroot=#{sdk}"
      end

      # Ensure correct install names when linking against libgcc_s;
      # see discussion in https://github.com/Homebrew/homebrew/pull/34303
      inreplace "libgcc/config/t-slibgcc-darwin", "@shlib_slibdir@", "#{HOMEBREW_PREFIX}/lib/gcc/#{version_suffix}"

      # Fix bug reported in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92061.
      inreplace "gcc/genconditions.c", "#if GCC_VERSION >= 3001", "#if GCC_VERSION >= 3001 && __clang_major__ < 9"
    else
      # Fix Linux error: gnu/stubs-32.h: No such file or directory.
      args << "--disable-multilib"

      # Change the default directory name for 64-bit libraries to `lib`
      # https://www.linuxfromscratch.org/lfs/view/development/chapter06/gcc-pass2.html
      inreplace "gcc/config/i386/t-linux64", "m64=../lib64", "m64="
    end

    mkdir "build" do
      system "../configure", *args
      system "make", "bootstrap"

      if OS.mac?
        system "make", "install"
      else
        system "make", "install-strip"
      end
    end

    # Handle conflicts between GCC formulae and avoid interfering
    # with system compilers.
    # Rename man7.
    Dir.glob(man7/"*.7") { |file| add_suffix file, version_suffix }
    # Even when we disable building info pages some are still installed.
    info.rmtree
  end

  def add_suffix(file, suffix)
    dir = File.dirname(file)
    ext = File.extname(file)
    base = File.basename(file, ext)
    File.rename file, "#{dir}/#{base}-#{suffix}#{ext}"
  end

  def post_install
    if OS.linux?
      gcc = bin/"gcc-#{version_suffix}"
      libgcc = Pathname.new(Utils.safe_popen_read(gcc, "-print-libgcc-file-name")).parent
      raise "command failed: #{gcc} -print-libgcc-file-name" if $CHILD_STATUS.exitstatus.nonzero?

      glibc = Formula["glibc"]
      glibc_installed = glibc.any_version_installed?

      # Symlink crt1.o and friends where gcc can find it.
      crtdir = if glibc_installed
        glibc.opt_lib
      else
        Pathname.new(Utils.safe_popen_read("/usr/bin/cc", "-print-file-name=crti.o")).parent
      end
      ln_sf Dir[crtdir/"*crt?.o"], libgcc

      # Create the GCC specs file
      # See https://gcc.gnu.org/onlinedocs/gcc/Spec-Files.html

      # Locate the specs file
      specs = libgcc/"specs"
      ohai "Creating the GCC specs file: #{specs}"
      specs_orig = Pathname.new("#{specs}.orig")
      rm_f [specs_orig, specs]

      system_header_dirs = ["#{HOMEBREW_PREFIX}/include"]

      if glibc_installed
        # https://github.com/Linuxbrew/brew/issues/724
        system_header_dirs << glibc.opt_include
      else
        # Locate the native system header dirs if user uses system glibc
        target = Utils.safe_popen_read(gcc, "-print-multiarch").chomp
        raise "command failed: #{gcc} -print-multiarch" if $CHILD_STATUS.exitstatus.nonzero?

        system_header_dirs += ["/usr/include/#{target}", "/usr/include"]
      end

      # Save a backup of the default specs file
      specs_string = Utils.safe_popen_read(gcc, "-dumpspecs")
      raise "command failed: #{gcc} -dumpspecs" if $CHILD_STATUS.exitstatus.nonzero?

      specs_orig.write specs_string

      # Set the library search path
      # For include path:
      #   * `-isysroot #{HOMEBREW_PREFIX}/nonexistent` prevents gcc searching built-in
      #     system header files.
      #   * `-idirafter <dir>` instructs gcc to search system header
      #     files after gcc internal header files.
      # For libraries:
      #   * `-nostdlib -L#{libgcc}` instructs gcc to use brewed glibc
      #     if applied.
      #   * `-L#{libdir}` instructs gcc to find the corresponding gcc
      #     libraries. It is essential if there are multiple brewed gcc
      #     with different versions installed.
      #     Noted that it should only be passed for the `gcc@*` formulae.
      #   * `-L#{HOMEBREW_PREFIX}/lib` instructs gcc to find the rest
      #     brew libraries.
      libdir = HOMEBREW_PREFIX/"lib/gcc/#{version_suffix}"
      specs.write specs_string + <<~EOS
        *cpp_unique_options:
        + -isysroot #{HOMEBREW_PREFIX}/nonexistent #{system_header_dirs.map { |p| "-idirafter #{p}" }.join(" ")}

        *link_libgcc:
        #{glibc_installed ? "-nostdlib -L#{libgcc}" : "+"} -L#{libdir} -L#{HOMEBREW_PREFIX}/lib

        *link:
        + --dynamic-linker #{HOMEBREW_PREFIX}/lib/ld.so -rpath #{libdir} -rpath #{HOMEBREW_PREFIX}/lib

      EOS
    end
  end

  test do
    (testpath/"hello-c.c").write <<~EOS
      #include <stdio.h>
      int main()
      {
        puts("Hello, world!");
        return 0;
      }
    EOS
    system "#{bin}/gcc-#{version.major}", "-o", "hello-c", "hello-c.c"
    assert_equal "Hello, world!\n", `./hello-c`

    (testpath/"hello-cc.cc").write <<~EOS
      #include <iostream>
      int main()
      {
        std::cout << "Hello, world!" << std::endl;
        return 0;
      }
    EOS
    system "#{bin}/g++-#{version.major}", "-o", "hello-cc", "hello-cc.cc"
    assert_equal "Hello, world!\n", `./hello-cc`

    fixture = <<~EOS
      integer,parameter::m=10000
      real::a(m), b(m)
      real::fact=0.5

      do concurrent (i=1:m)
        a(i) = a(i) + fact*b(i)
      end do
      print *, "done"
      end
    EOS
    (testpath/"in.f90").write(fixture)
    system "#{bin}/gfortran-#{version.major}", "-o", "test", "in.f90"
    assert_equal "done", `./test`.strip
  end
end