gn/BUILD.gn

# Copyright 2016 Google Inc.
#
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

declare_args() {
  ar = "ar"
  cc = "cc"
  cxx = "c++"

  if (is_android) {
    ar = "$ndk/toolchains/$ndk_gccdir-4.9/prebuilt/$ndk_host/$ndk_target/bin/ar"
    cc = "$ndk/toolchains/llvm/prebuilt/$ndk_host/bin/clang"
    cxx = "$ndk/toolchains/llvm/prebuilt/$ndk_host/bin/clang++"
  }

  windk = ""

  extra_cflags = []
  extra_cflags_c = []
  extra_cflags_cc = []
  extra_ldflags = []

  cc_wrapper = ""
}

if (!is_win) {
  is_clang = exec_script("is_clang.py",
                         [
                           cc,
                           cxx,
                         ],
                         "value")
}

config("default") {
  asmflags = []
  cflags = []
  cflags_c = []
  cflags_cc = []
  defines = []
  ldflags = []

  if (is_win) {
    cflags += [
      "/FS",  # Preserve previous PDB behavior.
      "/bigobj",  # Some of our files are bigger than the regular limits.
    ]
    cflags_c += [ "/TC" ]
    cflags_cc += [ "/TP" ]
    defines += [
      "_HAS_EXCEPTIONS=0",
      "WIN32_LEAN_AND_MEAN",
      "NOMINMAX",
    ]
  } else {
    cflags += [
      "-O1",
      "-fstrict-aliasing",
      "-fPIC",
      "-fvisibility=hidden",

      "-Werror",
      "-Wall",
      "-Wextra",
      "-Winit-self",
      "-Wpointer-arith",
      "-Wsign-compare",
      "-Wvla",

      "-Wno-deprecated-declarations",
      "-Wno-unused-parameter",
    ]
    cflags_cc += [
      "-std=c++11",
      "-fno-exceptions",
      "-fno-threadsafe-statics",
      "-fvisibility-inlines-hidden",

      "-Wnon-virtual-dtor",
    ]
    if (is_clang) {
      cflags += [
        "-Weverything",
        "-Wno-unknown-warning-option",  # Let older Clangs ignore newer Clangs' warnings.
      ]

      if (is_android && target_cpu == "x86") {
        # Clang seems to think new/malloc will only be 4-byte aligned on x86 Android.
        # We're pretty sure it's actually 8-byte alignment.
        cflags += [ "-Wno-over-aligned" ]
      }

      cflags += [
        "-Wno-cast-align",
        "-Wno-conditional-uninitialized",
        "-Wno-conversion",
        "-Wno-disabled-macro-expansion",
        "-Wno-documentation",
        "-Wno-documentation-unknown-command",
        "-Wno-double-promotion",
        "-Wno-exit-time-destructors",  # TODO: OK outside libskia
        "-Wno-float-conversion",
        "-Wno-float-equal",
        "-Wno-format-nonliteral",
        "-Wno-global-constructors",  # TODO: OK outside libskia
        "-Wno-gnu-zero-variadic-macro-arguments",
        "-Wno-missing-prototypes",
        "-Wno-missing-variable-declarations",
        "-Wno-pedantic",
        "-Wno-reserved-id-macro",
        "-Wno-shadow",
        "-Wno-shift-sign-overflow",
        "-Wno-sign-conversion",
        "-Wno-switch-enum",
        "-Wno-undef",
        "-Wno-unreachable-code",
        "-Wno-unreachable-code-break",
        "-Wno-unreachable-code-return",
        "-Wno-unused-macros",
        "-Wno-unused-member-function",
      ]
      cflags_cc += [
        "-Wno-abstract-vbase-init",
        "-Wno-range-loop-analysis",
        "-Wno-weak-vtables",
      ]

      # We are unlikely to want to fix these.
      cflags += [
        "-Wno-covered-switch-default",
        "-Wno-deprecated",
        "-Wno-implicit-fallthrough",
        "-Wno-missing-noreturn",
        "-Wno-old-style-cast",
        "-Wno-padded",
      ]
      cflags_cc += [
        "-Wno-c++98-compat",
        "-Wno-c++98-compat-pedantic",
        "-Wno-undefined-func-template",
      ]
    }
  }

  if (current_cpu == "arm") {
    cflags += [
      "-march=armv7-a",
      "-mfpu=neon",
      "-mthumb",
    ]
  } else if (current_cpu == "mipsel") {
    cflags += [
      "-march=mips32r2",
      "-mdspr2",
    ]
  } else if (current_cpu == "x86") {
    asmflags += [ "-m32" ]
    cflags += [
      "-m32",
      "-msse2",
      "-mfpmath=sse",
    ]
    ldflags += [ "-m32" ]
  }

  if (is_android) {
    asmflags += [
      "--target=$ndk_target",
      "-B$ndk/toolchains/$ndk_gccdir-4.9/prebuilt/$ndk_host/$ndk_target/bin",
    ]
    cflags += [
      "--sysroot=$ndk/platforms/$ndk_platform",
      "--target=$ndk_target",
      "-B$ndk/toolchains/$ndk_gccdir-4.9/prebuilt/$ndk_host/$ndk_target/bin",
    ]
    cflags_cc += [
      "-isystem$ndk/sources/android/support/include",
      "-isystem$ndk/sources/cxx-stl/llvm-libc++/libcxx/include",  # Through r12b.
      "-isystem$ndk/sources/cxx-stl/llvm-libc++/include",  # Since r13.
    ]
    ldflags += [
      "--sysroot=$ndk/platforms/$ndk_platform",
      "--target=$ndk_target",
      "-B$ndk/toolchains/$ndk_gccdir-4.9/prebuilt/$ndk_host/$ndk_target/bin",
      "-pie",
    ]
    lib_dirs = [
      "$ndk/sources/cxx-stl/llvm-libc++/libs/$ndk_stdlib",
      "$ndk/toolchains/$ndk_gccdir-4.9/prebuilt/$ndk_host/lib/gcc/$ndk_target/4.9.x",
    ]

    if (current_cpu == "mips64el") {
      # The r13 NDK omits /usr/lib from the MIPS64 sysroots, but Clang searches
      # for /usr/lib64 as $PATH_TO_USR_LIB/../lib64.  If there's no /usr/lib,
      # it can't find /usr/lib64.  We must point Clang at /usr/lib64 manually.
      lib_dirs += [ "$ndk/platforms/$ndk_platform/usr/lib64" ]
      ldflags += [
        # Clang will try to link these two files, but not find them.  Again, do it manually.
        "-nostartfiles",
        "$ndk/platforms/$ndk_platform/usr/lib64/crtbegin_dynamic.o",
        "$ndk/platforms/$ndk_platform/usr/lib64/crtend_android.o",
      ]
    }

    libs = [
      # Order matters here!  Keep these three in exactly this order.
      "c++_static",
      "c++abi",
      "android_support",
    ]
    if (target_cpu == "arm") {
      libs += [ "unwind" ]
    }
  }

  if (is_linux) {
    libs = [ "pthread" ]
  }

  if (sanitize != "") {
    # You can either pass the sanitizers directly, e.g. "address,undefined",
    # or pass one of the couple common aliases used by the bots.
    sanitizers = sanitize
    if (sanitize == "ASAN") {
      sanitizers = "address,bool,function,integer-divide-by-zero,nonnull-attribute,null,object-size,return,returns-nonnull-attribute,shift,signed-integer-overflow,unreachable,vla-bound,vptr"
    } else if (sanitize == "TSAN") {
      sanitizers = "thread"
    } else if (sanitize == "MSAN") {
      sanitizers = "memory"
    }

    cflags += [
      "-fsanitize=$sanitizers",
      "-fno-sanitize-recover=$sanitizers",
      "-fsanitize-blacklist=" + rebase_path("../tools/xsan.blacklist"),
    ]
    ldflags += [ "-fsanitize=$sanitizers" ]
    if (sanitizers == "memory") {
      cflags += [ "-fsanitize-memory-track-origins" ]
      cflags_cc += [ "-stdlib=libc++" ]
      ldflags += [ "-stdlib=libc++" ]
    }
  }
}

config("extra_flags") {
  cflags = extra_cflags
  cflags_c = extra_cflags_c
  cflags_cc = extra_cflags_cc
  ldflags = extra_ldflags
}

config("debug_symbols") {
  # It's annoying to wait for full debug symbols to push over
  # to Android devices.  -gline-tables-only is a lot slimmer.
  if (is_android) {
    cflags = [ "-gline-tables-only" ]
  } else if (!is_win) {
    cflags = [ "-g" ]
  }
}

config("no_rtti") {
  if (sanitize != "ASAN") {  # -fsanitize=vptr requires RTTI
    if (!is_win) {
      cflags_cc = [ "-fno-rtti" ]
    }
  }
}

config("release") {
  if (!is_win) {
    cflags = [ "-O3" ]
  }
  defines = [ "NDEBUG" ]
}

config("executable") {
  if (is_mac) {
    ldflags = [ "-Wl,-rpath,@loader_path/." ]
  } else if (is_linux) {
    ldflags = [
      "-rdynamic",
      "-Wl,-rpath,\$ORIGIN",
    ]
  }
}

toolchain("msvc") {
  vc = "$windk\VC\bin\amd64\cl.exe"
  vlink = "$windk\VC\bin\amd64\link.exe"
  vlib = "$windk\VC\bin\amd64\lib.exe"

  # TODO: add a python function that generates the includes using <VSPATH>/win_sdk/bin/SetEnv.<cpu>.json
  windk_include_dirs = "/I$windk\win_sdk\bin\..\..\win_sdk\Include\10.0.10586.0\um /I$windk\win_sdk\bin\..\..\win_sdk\Include\10.0.10586.0\shared /I$windk\win_sdk\bin\..\..\win_sdk\Include\10.0.10586.0\winrt /I$windk\win_sdk\bin\..\..\win_sdk\Include\10.0.10586.0\ucrt /I$windk\win_sdk\bin\..\..\VC\include /I$windk\win_sdk\bin\..\..\VC\atlmfc\include "

  tool("cc") {
    rspfile = "{{output}}.rsp"
    precompiled_header_type = "msvc"
    pdbname = "{{target_out_dir}}/{{label_name}}_c.pdb"

    # Label names may have spaces in them so the pdbname must be quoted. The
    # source and output don't need to be quoted because GN knows they're a
    # full file name and will quote automatically when necessary.

    command = "$vc /nologo /showIncludes /FC @$rspfile /c {{source}} /Fo{{output}} /Fd\"$pdbname\""
    depsformat = "msvc"
    description = "CC {{output}}"
    outputs = [
      "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.obj",
      # "$object_subdir/{{source_name_part}}.obj",
    ]
    rspfile_content = "$windk_include_dirs {{defines}} {{include_dirs}} {{cflags}} {{cflags_c}}"
  }

  tool("cxx") {
    rspfile = "{{output}}.rsp"
    precompiled_header_type = "msvc"
    pdbname = "{{target_out_dir}}/{{label_name}}_c.pdb"

    # Label names may have spaces in them so the pdbname must be quoted. The
    # source and output don't need to be quoted because GN knows they're a
    # full file name and will quote automatically when necessary.
    command = "$vc /nologo /showIncludes /FC @$rspfile /c {{source}} /Fo{{output}} /Fd\"$pdbname\""
    depsformat = "msvc"
    description = "C++ {{output}}"
    outputs = [
      "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.obj",
    ]
    rspfile_content = "$windk_include_dirs {{defines}} {{include_dirs}} {{cflags}} {{cflags_cc}}"
  }

  tool("alink") {
    rspfile = "{{output}}.rsp"

    # gyp_win_tool_path = rebase_path("../third_party/externals/gyp/pylib/gyp/win_tool.py")
    command = "$vlib /nologo {{arflags}} /OUT:{{output}} @$rspfile"
    description = "LIB {{output}}"
    outputs = [
      # Ignore {{output_extension}} and always use .lib, there's no reason to
      # allow targets to override this extension on Windows.
      "{{root_out_dir}}/{{target_output_name}}{{output_extension}}",
    ]
    default_output_extension = ".lib"
    default_output_dir = "{{target_out_dir}}"

    # The use of inputs_newline is to work around a fixed per-line buffer
    # size in the linker.
    rspfile_content = "{{inputs_newline}}"
  }

  tool("link") {
    exename = "{{root_out_dir}}/{{target_output_name}}{{output_extension}}"
    pdbname = "$exename.pdb"
    rspfile = "$exename.rsp"

    # gyp_win_tool_path = rebase_path("../third_party/externals/gyp/pylib/gyp/win_tool.py")
    command = "$vlink /nologo /OUT:$exename /PDB:$pdbname @$rspfile"

    default_output_extension = ".exe"
    default_output_dir = "{{root_out_dir}}"
    description = "LINK {{output}}"
    outputs = [
      #"{{root_out_dir}}/{{target_output_name}}{{output_extension}}",
      exename,
    ]

    #if (symbol_level != 0) {
    #  outputs += [ pdbname ]
    #}
    #runtime_outputs = outputs

    # The use of inputs_newline is to work around a fixed per-line buffer
    # size in the linker.
    rspfile_content = "{{inputs_newline}} {{libs}} {{solibs}} {{ldflags}}"
  }

  tool("stamp") {
    win_stamp_path = rebase_path("win_stamp.py")
    command = "python $win_stamp_path {{output}}"
  }
}

toolchain("gcc_like") {
  lib_switch = "-l"
  lib_dir_switch = "-L"

  tool("cc") {
    depfile = "{{output}}.d"
    command = "$cc_wrapper $cc -MMD -MF $depfile {{defines}} {{include_dirs}} {{cflags}} {{cflags_c}} -c {{source}} -o {{output}}"
    depsformat = "gcc"
    outputs = [
      "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.o",
    ]
    description = "$cc_wrapper $cc ... -o {{output}}"
  }

  tool("cxx") {
    depfile = "{{output}}.d"
    command = "$cc_wrapper $cxx -MMD -MF $depfile {{defines}} {{include_dirs}} {{cflags}} {{cflags_cc}} -c {{source}} -o {{output}}"
    depsformat = "gcc"
    outputs = [
      "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.o",
    ]
    description = "$cc_wrapper $cxx ... -o {{output}}"
  }

  tool("asm") {
    depfile = "{{output}}.d"
    command = "$cc_wrapper $cc -MMD -MF $depfile {{defines}} {{include_dirs}} {{asmflags}} -c {{source}} -o {{output}}"
    depsformat = "gcc"
    outputs = [
      "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.o",
    ]
    description = "$cc_wrapper $cc ... -o {{output}}"
  }

  tool("alink") {
    command = "rm -f {{output}} && $ar rcs {{output}} {{inputs}}"
    outputs = [
      "{{root_out_dir}}/{{target_output_name}}{{output_extension}}",
    ]
    default_output_extension = ".a"
    output_prefix = "lib"
    description = "$ar {{output}} ..."
  }

  tool("solink") {
    soname = "{{target_output_name}}{{output_extension}}"

    rpath = "-Wl,-soname,$soname"
    if (is_mac) {
      rpath = "-Wl,-install_name,@rpath/$soname"
    }

    command = "$cc_wrapper $cxx -shared {{ldflags}} {{inputs}} {{solibs}} {{libs}} $rpath -o {{output}}"
    outputs = [
      "{{root_out_dir}}/$soname",
    ]
    output_prefix = "lib"
    default_output_extension = ".so"
    description = "$cc_wrapper $cxx -shared ... -o {{output}}"
  }

  tool("link") {
    command = "$cc_wrapper $cxx {{ldflags}} {{inputs}} {{solibs}} {{libs}} -o {{output}}"
    outputs = [
      "{{root_out_dir}}/{{target_output_name}}{{output_extension}}",
    ]
    description = "$cc_wrapper $cxx ... -o {{output}}"
  }

  tool("stamp") {
    command = "touch {{output}}"
  }

  tool("copy") {
    command = "ln -f {{source}} {{output}} 2>/dev/null || (rm -rf {{output}} && cp -af {{source}} {{output}})"
  }
}