Modularize Compact Language Detector 2 (CLD2) data sources

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 6d356ef60e20e71bdf910671258288052e17ec95..d91e80579f3f39e669d4b3be421a4172f79a0d54 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -449,19 +449,13 @@
       #   2: Large tables, high accuracy
       'cld2_table_size%': 2,
 
-      # Set the way CLD is compiled. Only evaluated if cld_version == 2.
-      #   0: static, language scoring tables compiled into the binary
-      #   1: dynamic, language scoring tables live in a data file that must
-      #      be loaded at runtime.
-      'cld2_dynamic%': 0,
-
-      # Whether CLD2 is a component. Only evaluated if cld_version == 2 and
-      # cld2_dynamic == 1.
-      #   0: Not a component. If cld2_dynamic == 1, it is up to the distribution
-      #      to ensure that the data file is provided if desired.
-      #   1: Componentized. CLD data should be obtained via the Component
-      #      Updater.
-      'cld2_is_component%': 0,
+      # The data acquisition mode for CLD2. Possible values are:
+      #   static:     CLD2 data is statically linked to the executable.
+      #   standalone: CLD2 data is provided in a standalone file that is
+      #               bundled with the executable.
+      #   component:  CLD2 data is provided as a Chrome "component" and is
+      #               downloaded via the component updater.
+      'cld2_data_source': 'static',
 
       # Enable spell checker.
       'enable_spellcheck%': 1,
@@ -685,8 +679,6 @@
           'enable_extensions%': 0,
           'enable_google_now%': 0,
           'cld_version%': 1,
-          'cld2_dynamic%': 0,
-          'cld2_is_component%': 0,
           'enable_spellcheck%': 0,
           'enable_themes%': 0,
           'remoting%': 0,
@@ -736,7 +728,6 @@
           'enable_extensions%': 0,
           'enable_google_now%': 0,
           'cld_version%': 1,
-          'cld2_dynamic%': 0,
           'enable_printing%': 0,
           'enable_session_service%': 0,
           'enable_themes%': 0,
@@ -1091,8 +1082,7 @@
     'enable_google_now%': '<(enable_google_now)',
     'cld_version%': '<(cld_version)',
     'cld2_table_size%': '<(cld2_table_size)',
-    'cld2_dynamic%': '<(cld2_dynamic)',
-    'cld2_is_component%': '<(cld2_is_component)',
+    'cld2_data_source%': '<(cld2_data_source)',
     'enable_captive_portal_detection%': '<(enable_captive_portal_detection)',
     'disable_file_support%': '<(disable_file_support)',
     'disable_ftp_support%': '<(disable_ftp_support)',
@@ -2696,11 +2686,18 @@
       ['cld_version!=0', {
         'defines': ['CLD_VERSION=<(cld_version)'],
       }],
-      ['cld2_dynamic!=0', {
-        'defines': ['CLD2_DYNAMIC_MODE=1'],
+      ['cld2_data_source=="static"', {
+        'defines': ['CLD_DATA_FROM_STATIC'],
+      }, {
+        # This is for CLD2 itself, which uses this check to enable dynamic mode
+        # during compilation. Don't check this flag in Chromium.
+        'defines': ['CLD2_DYNAMIC_MODE'],

[Takashi Toyoshima, 2014/06/23 08:49:59]

Would it be safe to move this CLD2_DYNAMIC_MODE definition inside cld_2.gyp?

[Andrew Hayden (chromium.org), 2014/06/23 13:20:34]

Almost, but not quite. The forward declarations of "loadDataFromRawAddress" and
"isDataLoaded" methods in CLD2 header files are guarded by the preprocessor
check, and these files are included in both the cld_2 compile as well as the
translate component compile. The linker complains that it can't locate the
symbols if the define is only done in cld_2.

To fix this we'd have to expose the methods in CLD2 directly. Not necessarily a
bad idea - we could have the ifdefs inside the methods instead, and declare them
unconditionally. I'll ping Dick Sites about this, but let's skip this change for
now unless you strongly object. Agree it would be nicer to do it that way.

[Takashi Toyoshima, 2014/06/24 02:09:47]

OK. Current approach sounds reasonable.

+      }],
+      ['cld2_data_source=="standalone"', {
+        'defines': ['CLD_DATA_FROM_STANDALONE'],
       }],
-      ['cld2_is_component!=0', {
-        'defines': ['CLD2_IS_COMPONENT=1'],
+      ['cld2_data_source=="component"', {
+        'defines': ['CLD_DATA_FROM_COMPONENT'],
       }],
       ['enable_printing==1', {
         'defines': ['ENABLE_FULL_PRINTING=1', 'ENABLE_PRINTING=1'],