BUILD.gn (4387B)
1 # Copyright 2014 The Chromium Authors 2 # Use of this source code is governed by a BSD-style license that can be 3 # found in the LICENSE file. 4 5 import("//chromium/build/config/c++/c++.gni") 6 import("//chromium/build/config/compiler/compiler.gni") 7 import("//chromium/build/config/sanitizers/sanitizers.gni") 8 import("//chromium/build/config/sysroot.gni") 9 import("//chromium/build/toolchain/toolchain.gni") 10 11 declare_args() { 12 # When non empty, overrides the target rpath value. This allows a user to 13 # make a Chromium build where binaries and shared libraries are meant to be 14 # installed into separate directories, like /usr/bin/chromium and 15 # /usr/lib/chromium for instance. It is useful when a build system that 16 # generates a whole target root filesystem (like Yocto) is used on top of gn, 17 # especially when cross-compiling. 18 # Note: this gn arg is similar to gyp target_rpath generator flag. 19 gcc_target_rpath = "" 20 ldso_path = "" 21 } 22 23 # This config causes functions not to be automatically exported from shared 24 # libraries. By default, all symbols are exported but this means there are 25 # lots of exports that slow everything down. In general we explicitly mark 26 # which functions we want to export from components. 27 # 28 # Some third_party code assumes all functions are exported so this is separated 29 # into its own config so such libraries can remove this config to make symbols 30 # public again. 31 # 32 # See http://gcc.gnu.org/wiki/Visibility 33 config("symbol_visibility_hidden") { 34 cflags = [ "-fvisibility=hidden" ] 35 rustflags = [ "-Zdefault-visibility=hidden" ] 36 37 # Visibility attribute is not supported on AIX. 38 if (current_os != "aix") { 39 cflags_cc = [ "-fvisibility-inlines-hidden" ] 40 cflags_objcc = cflags_cc 41 } 42 } 43 44 # This config is usually set when :symbol_visibility_hidden is removed. 45 # It's often a good idea to set visibility explicitly, as there're flags 46 # which would error out otherwise (e.g. -fsanitize=cfi-unrelated-cast) 47 config("symbol_visibility_default") { 48 cflags = [ "-fvisibility=default" ] 49 } 50 51 # The rpath is the dynamic library search path. Setting this config on a link 52 # step will put the directory where the build generates shared libraries into 53 # the rpath. 54 # 55 # This is required for component builds since the build generates many shared 56 # libraries in the build directory that we expect to be automatically loaded. 57 # It will be automatically applied in this case by :executable_config. 58 # 59 # In non-component builds, certain test binaries may expect to load dynamic 60 # libraries from the current directory. As long as these aren't distributed, 61 # this is OK. For these cases use something like this: 62 # 63 # if ((is_linux || is_chromeos) && !is_component_build) { 64 # configs += [ "//chromium/build/config/gcc:rpath_for_built_shared_libraries" ] 65 # } 66 config("rpath_for_built_shared_libraries") { 67 if (!is_android && current_os != "aix" && !is_castos) { 68 # Note: Android, Aix don't support rpath. Chromecast has its own logic for 69 # setting the rpath in //build/config/chromecast. 70 if (current_toolchain != default_toolchain || gcc_target_rpath == "") { 71 ldflags = [ 72 # Want to pass "\$". GN will re-escape as required for ninja. 73 "-Wl,-rpath=\$ORIGIN", 74 ] 75 } else { 76 ldflags = [ "-Wl,-rpath=${gcc_target_rpath}" ] 77 } 78 if (current_toolchain == default_toolchain && ldso_path != "") { 79 ldflags += [ "-Wl,--dynamic-linker=${ldso_path}" ] 80 } 81 } 82 } 83 84 if (is_component_build && !is_android) { 85 # See the rpath_for... config above for why this is necessary for component 86 # builds. 87 executable_and_shared_library_configs_ = 88 [ ":rpath_for_built_shared_libraries" ] 89 } else { 90 executable_and_shared_library_configs_ = [] 91 } 92 93 # Settings for executables. 94 config("executable_config") { 95 configs = executable_and_shared_library_configs_ 96 ldflags = [ "-pie" ] 97 if (is_android) { 98 ldflags += [ 99 "-Bdynamic", 100 "-Wl,-z,nocopyreloc", 101 ] 102 } 103 104 if (!is_android && current_os != "aix") { 105 ldflags += [ 106 # TODO(GYP): Do we need a check on the binutils version here? 107 # 108 # Newer binutils don't set DT_RPATH unless you disable "new" dtags 109 # and the new DT_RUNPATH doesn't work without --no-as-needed flag. 110 "-Wl,--disable-new-dtags", 111 ] 112 } 113 } 114 115 # Settings for shared libraries. 116 config("shared_library_config") { 117 configs = executable_and_shared_library_configs_ 118 }