Enable debug fission for Release build

build/common.gypi

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 820 matching lines @@
           'enable_plugins%': 0,
         }, {
           'enable_plugins%': 1,
         }],
 
         # linux_use_bundled_gold: whether to use the gold linker binary checked
         # into third_party/binutils.  Force this off via GYP_DEFINES when you
         # are using a custom toolchain and need to control -B in ldflags.
         # Do not use 32-bit gold on 32-bit hosts as it runs out address space
         # for component=static_library builds.
         ['OS=="linux" and (target_arch=="x64" or target_arch=="arm")', {

[mithro-old, 2014/09/25 04:51:09]

This is whether to use bundled gold by default.

           'linux_use_bundled_gold%': 1,
         }, {
           'linux_use_bundled_gold%': 0,
         }],
 
         # linux_use_bundled_binutils: whether to use the binary binutils
         # checked into third_party/binutils.  These are not multi-arch so cannot
         # be used except on x86 and x86-64 (the only two architectures which
         # are currently checke in).  Force this off via GYP_DEFINES when you
         # are using a custom toolchain and need to control -B in cflags.

[mithro-old, 2014/09/25 04:51:08]

This is whether to use bundled binutils by default.

         ['OS=="linux" and (target_arch=="x64")', {
           'linux_use_bundled_binutils%': 1,
         }, {
           'linux_use_bundled_binutils%': 0,
         }],
 
         # linux_use_gold_flags: whether to use build flags that rely on gold.
         # On by default for x64 Linux.

[mithro-old, 2014/09/25 04:51:08]

This is whether to use gold *flags* by default.

NFI Why this isn't just looking to see if the linker is going to be gold.....

         ['OS=="linux" and target_arch=="x64"', {
           'linux_use_gold_flags%': 1,
         }, {
           'linux_use_gold_flags%': 0,
         }],
 
         # linux_use_debug_fission: whether to use split DWARF debug info
         # files. This can reduce link time significantly, but is incompatible
         # with some utilities such as icecc and ccache. Requires gold and
         # gcc >= 4.8 or clang.
         # http://gcc.gnu.org/wiki/DebugFission

[mithro-old, 2014/09/25 04:51:08]

This is whether to enable debug fission by default.

         ['OS=="linux" and target_arch=="x64"', {
           'linux_use_debug_fission%': 1,
         }, {
           'linux_use_debug_fission%': 0,
         }],
 
         ['OS=="android" or OS=="ios"', {
           'enable_captive_portal_detection%': 0,
         }, {
           'enable_captive_portal_detection%': 1,
@@ skipping 268 matching lines @@
     'enable_plugin_installation%': '<(enable_plugin_installation)',
     'enable_plugins%': '<(enable_plugins)',
     'enable_session_service%': '<(enable_session_service)',
     'enable_themes%': '<(enable_themes)',
     'enable_autofill_dialog%': '<(enable_autofill_dialog)',
     'enable_prod_wallet_service%': '<(enable_prod_wallet_service)',
     'enable_background%': '<(enable_background)',
     'linux_use_bundled_gold%': '<(linux_use_bundled_gold)',
     'linux_use_bundled_binutils%': '<(linux_use_bundled_binutils)',
     'linux_use_gold_flags%': '<(linux_use_gold_flags)',
     'linux_use_debug_fission%': '<(linux_use_debug_fission)',

[mithro-old, 2014/09/25 04:51:09]

This is where we override the defaults from the environment.

     'use_canvas_skia%': '<(use_canvas_skia)',
     'test_isolation_mode%': '<(test_isolation_mode)',
     'test_isolation_outdir%': '<(test_isolation_outdir)',
     'test_isolation_fail_on_missing': '<(test_isolation_fail_on_missing)',
     'enable_printing%': '<(enable_printing)',
     'enable_spellcheck%': '<(enable_spellcheck)',
     'enable_google_now%': '<(enable_google_now)',
     'cld_version%': '<(cld_version)',
     'cld2_table_size%': '<(cld2_table_size)',
     'cld2_data_source%': '<(cld2_data_source)',
@@ skipping 336 matching lines @@
     'use_chromevox_next%': 0,
 
     'conditions': [
       # Enable the Syzygy optimization step for the official builds.
       ['OS=="win" and buildtype=="Official" and syzyasan!=1', {
         'syzygy_optimize%': 1,
       }, {
         'syzygy_optimize%': 0,
       }],
       # Get binutils version so we can enable debug fission if we can.
       ['os_posix==1 and OS!="mac" and OS!="ios"', {

[mithro-old, 2014/09/25 04:51:08]

This is where binutils version information is populated.

         'conditions': [
           # compiler_version doesn't work with clang
           # TODO(mithro): Land https://codereview.chromium.org/199793014/ so
           # compiler_version works with clang.
           # TODO(glider): set clang to 1 earlier for ASan and TSan builds so
           # that it takes effect here.
           ['clang==0 and asan==0 and lsan==0 and tsan==0 and msan==0 and ubsan==0 and ubsan_vptr==0', {
             'binutils_version%': '<!pymod_do_main(compiler_version target assembler)',
           }],
           # On Android we know the binutils version in the toolchain.
@@ skipping 12 matching lines @@
           }],
         ],
       }, {
         'binutils_version%': 0,
       }],
       # The version of GCC in use, set later in platforms that use GCC and have
       # not explicitly chosen to build with clang. Currently, this means all
       # platforms except Windows, Mac and iOS.
       # TODO(glider): set clang to 1 earlier for ASan and TSan builds so that
       # it takes effect here.
       ['os_posix==1 and OS!="mac" and OS!="ios" and clang==0 and asan==0 and lsan==0 and tsan==0 and msan==0 and ubsan_vptr==0', {

[mithro-old, 2014/09/25 04:51:09]

This is where gcc version information is populated.

         'conditions': [
           ['OS=="android" and android_webview_build==0', {
             'host_gcc_version%': '<!pymod_do_main(compiler_version host compiler)',
             # We directly set the gcc version since we know what we use.
             'gcc_version%': 49,
           }],
           ['OS=="android" and android_webview_build==1', {
             # Android WebView uses a hermetic clang toolchain for host builds.
             'host_gcc_version%': 0,
             # Android WebView uses the GCC toolchain from the Android build.
@@ skipping 38 matching lines @@
           ['(branding=="Chrome" and buildtype=="Official")', {
             'linux_dump_symbols%': 1,
 
             # Omit unwind support in official release builds to save space. We
             # can use breakpad for these builds.
             'release_unwind_tables%': 0,
 
             'conditions': [
               # For official builds, use a 64-bit linker to avoid running out
               # of address space. The buildbots should have a 64-bit kernel
               # and a 64-bit libc installed.

[mithro-old, 2014/09/25 04:51:09]

There seems to be some type of special override here?

               ['host_arch=="ia32" and target_arch=="ia32"', {
                 'linux_use_bundled_gold%': '1',
                 'binutils_dir%': 'third_party/binutils/Linux_x64/Release/bin',
               }],
             ],
           }],
         ],
       }],  # os_posix==1 and OS!="mac" and OS!="ios"
       ['OS=="ios"', {
         'disable_nacl%': 1,
@@ skipping 211 matching lines @@
           }],
         ],
       }],
       ['android_webview_build==1', {
         # When building the WebView in the Android tree, jarjar will remap all
         # the class names, so the JNI generator needs to know this.
         'jni_generator_jarjar_file': '../android_webview/build/jarjar-rules.txt',
       }],
       ['OS=="linux" and target_arch!="mipsel"', {
         # TODO(thakis): This is here to measure perf for a while.
         'clang%': 1,

[mithro-old, 2014/09/25 04:51:08]

Not sure what is going on here....

       }],  # OS=="mac"
       ['OS=="mac"', {
         'conditions': [
           # All Chrome builds have breakpad symbols, but only process the
           # symbols from official builds.
           ['(branding=="Chrome" and buildtype=="Official")', {
             'mac_strip_release%': 1,
           }],
         ],
       }],  # OS=="mac"
@@ skipping 1645 matching lines @@
       # enabled when not building on Chrome OS.
       # TODO(phajdan.jr): Use -fstack-protector-strong when our gcc
       # supports it.
       'target_defaults': {
         'cflags': [
           '-fstack-protector',
           '--param=ssp-buffer-size=4',
         ],
       },
     }],
     ['os_posix==1 and OS!="mac" and OS!="ios"', {

[mithro-old, 2014/09/25 04:51:09]

Check this bit here.

       'target_defaults': {
         # Enable -Werror by default, but put it in a variable so it can
         # be disabled in ~/.gyp/include.gypi on the valgrind builders.
         'variables': {
           'werror%': '-Werror',
           'libraries_for_target%': '',
         },
         'defines': [
           '_FILE_OFFSET_BITS=64',
         ],
@@ skipping 79 matching lines @@
                 ],
               }],
               ['debug_unwind_tables==1', {
                 'cflags': ['-funwind-tables'],
               }, {
                 'cflags': ['-fno-unwind-tables', '-fno-asynchronous-unwind-tables'],
               }],
               # TODO(mostynb): shuffle clang/gcc_version/binutils_version
               # definitions in to the right scope to use them when setting
               # linux_use_debug_fission, so it can be used here alone.
               ['linux_use_debug_fission==1 and linux_use_gold_flags==1 and (clang==1 or gcc_version>=48) and binutils_version>=223', {

[mithro-old, 2014/09/25 04:51:08]

Check this is working for you under debug builds.

                 'cflags': ['-gsplit-dwarf'],
               }],
             ],
           },
           'Release_Base': {
             'variables': {
               'release_optimize%': '2',
               # Binaries become big and gold is unable to perform GC
               # and remove unused sections for some of test targets
               # on 32 bit platform.
@@ skipping 15 matching lines @@
               # can be removed at link time with --gc-sections.
               '-fdata-sections',
               '-ffunction-sections',
             ],
             'ldflags': [
               # Specifically tell the linker to perform optimizations.
               # See http://lwn.net/Articles/192624/ .
               '-Wl,-O1',
               '-Wl,--as-needed',
             ],
             'conditions' : [

[mithro-old, 2014/09/25 04:51:08]

Can you test your conditions in this section rather than your current location?

               ['no_gc_sections==0', {
                 'ldflags': [
                   '-Wl,--gc-sections',
                 ],
               }],
               ['OS=="android" and target_arch!="arm64"', {
                 # We don't omit frame pointers on arm64 since they are required
                 # to correctly unwind stackframes which contain system library
                 # function frames (crbug.com/391706).
                 'cflags': [
@@ skipping 23 matching lines @@
                   }],
                 ],
               }],
               ['release_unwind_tables==1', {
                 'cflags': ['-funwind-tables'],
               }, {
                 'cflags': ['-fno-unwind-tables', '-fno-asynchronous-unwind-tables'],
               }],
             ],
           },
         },

[mithro-old, 2014/09/25 04:51:09]

This is popped up a couple of levels, there could be something to that....

         'conditions': [
+
+          ['linux_use_debug_fission==1 and linux_use_gold_flags==1 and (clang==1 or gcc_version>=48)  and binutils_version>=223', {
+           'target_conditions': [
+              ['_toolset=="target"', {
+               'cflags': ['-gsplit-dwarf'],
+             },
+           ],
+           ]
+          }],
           ['target_arch=="ia32"', {
             'target_conditions': [
               ['_toolset=="target"', {
                 'asflags': [
                   # Needed so that libs with .s files (e.g. libicudata.a)
                   # are compatible with the general 32-bit-ness.
                   '-32',
                 ],
                 # All floating-point computations on x87 happens in 80-bit
                 # precision.  Because the C and C++ language standards allow
@@ skipping 621 matching lines @@
                       # in gold which can generate crashy binaries. As
                       # a security measure, -pie takes precedence for
                       # now.
                       #'-Wl,--icf=safe',
                       '-Wl,--icf=none',
                     ],
                   }],
                 ],
               }],
             ],
           }],

[mithro-old, 2014/09/25 04:51:08]

This is a bunch of extra stuff based on the binutils flags.

           ['linux_use_bundled_binutils==1', {
             'cflags': [
               '-B<!(cd <(DEPTH) && pwd -P)/<(binutils_dir)',
             ],
           }],
           ['linux_use_bundled_gold==1', {
             # Put our binutils, which contains gold in the search path. We pass
             # the path to gold to the compiler. gyp leaves unspecified what the
             # cwd is when running the compiler, so the normal gyp path-munging
             # fails us. This hack gets the right path.
             'ldflags': [
               '-B<!(cd <(DEPTH) && pwd -P)/<(binutils_dir)',
             ],
           }],
           # Some binutils 2.23 releases may or may not have new dtags enabled,
           # but they are all compatible with --disable-new-dtags,
           # because the new dynamic tags are not created by default.
           ['binutils_version>=223', {
             # Newer binutils don't set DT_RPATH unless you disable "new" dtags
             # and the new DT_RUNPATH doesn't work without --no-as-needed flag.
             # FIXME(mithro): Figure out the --as-needed/--no-as-needed flags
             # inside this file to allow usage of --no-as-needed and removal of
             # this flag.
             'ldflags': [
               '-Wl,--disable-new-dtags',
             ],
           }],

[mithro-old, 2014/09/25 04:51:08]

This is a bunch of extra stuff based on the version information.

           ['gcc_version>=47 and clang==0', {
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags_cc': [
                   '-std=gnu++11',
                   # See comment for -Wno-c++11-narrowing.
                   '-Wno-narrowing',
                   # TODO(thakis): Remove, http://crbug.com/263960
                   '-Wno-literal-suffix',
                 ],
@@ skipping 1258 matching lines @@
     }],
     ['enable_new_npdevice_api==1', {
       'target_defaults': {
         'defines': [
           'ENABLE_NEW_NPDEVICE_API',
         ],
       },
     }],
     # Don't warn about the "typedef 'foo' locally defined but not used"
     # for gcc 4.8 and higher.
     # TODO: remove this flag once all builds work. See crbug.com/227506

[mithro-old, 2014/09/25 04:51:08]

Some more conditions based on gcc_version and similar.

     ['gcc_version>=48 and clang==0', {
       'target_defaults': {
         'cflags': [
           '-Wno-unused-local-typedefs',
         ],
       },
     }],
     ['gcc_version>=48 and clang==0 and host_clang==1', {
       'target_defaults': {
         'target_conditions': [
@@ skipping 133 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }