Refactor language detection logic to allow non-static CLD data sources.

third_party/cld_2/cld_2.gyp

Index: third_party/cld_2/cld_2.gyp
diff --git a/third_party/cld_2/cld_2.gyp b/third_party/cld_2/cld_2.gyp
index cde2bd3ac43a244d4cb734d71298c87a72874c3b..eff7ab47d66aa760735e42570c1d1e5caac06b3b 100644
--- a/third_party/cld_2/cld_2.gyp
+++ b/third_party/cld_2/cld_2.gyp
@@ -34,7 +34,8 @@
       'src/internal/compact_lang_det.cc',
       'src/internal/compact_lang_det_hint_code.cc',
       'src/internal/compact_lang_det_hint_code.h',
-      'src/internal/compact_lang_det_impl.cc',
+      # Omitted intentionally: compact_lang_det_impl.cc, which has IFDEFs that
+      # depend upon build flags. See cld2_core_impl_sources, below.
       'src/internal/compact_lang_det_impl.h',
       'src/internal/debug.h',
       'src/internal/debug_empty.cc',
@@ -68,6 +69,10 @@
       'src/public/compact_lang_det.h',
       'src/public/encodings.h',
     ],
+    'cld2_core_impl_sources': [
+      # Compilation is dependent upon flags.
+      'src/internal/compact_lang_det_impl.cc',
+    ],
     'cld2_dynamic_data_loader_sources': [
       'src/internal/cld2_dynamic_data.h',
       'src/internal/cld2_dynamic_data.cc',
@@ -108,26 +113,26 @@
       'sources': [
         # Note: sources list duplicated in GN build.
         '<@(cld2_core_sources)',
+        '<@(cld2_core_impl_sources)',
         '<@(cld2_data_sources)',
         '<@(cld2_dynamic_data_loader_sources)',
         'src/internal/cld2_dynamic_data_extractor.h',
         'src/internal/cld2_dynamic_data_extractor.cc',
         'src/internal/cld2_dynamic_data_tool.cc',
       ],
+      'defines': ['CLD2_DYNAMIC_MODE'],
     },
 
     {
       # GN version: //third_party/cld_2
+      # Depending upon cld_2 will provide core headers and function definitions,
+      # but no data. You must also declare on one of the following two targets:
+      # cld2_static - for a statically-linked data set built into the executable
+      # cld2_dynamic - for a dynamic data set loaded at runtime
       'target_name': 'cld_2',
       'type': 'static_library',
-      'sources': [],
+      'sources': ['<@(cld2_core_sources)'],
       'dependencies': [],
-      'conditions': [
-        ['cld2_data_source=="static"',
-          {'dependencies': ['cld2_static']},
-          {'dependencies': ['cld2_dynamic']}
-        ],
-      ],
     },
 
     {
@@ -140,6 +145,7 @@
       ],
       'sources': [
         '<@(cld2_core_sources)',
+        '<@(cld2_core_impl_sources)',
         '<@(cld2_data_sources)',
       ],
     },
@@ -154,12 +160,10 @@
       ],
       'sources': [
         '<@(cld2_core_sources)',
+        '<@(cld2_core_impl_sources)',
         '<@(cld2_dynamic_data_loader_sources)',
       ],
       'defines': ['CLD2_DYNAMIC_MODE'],
-      'all_dependent_settings': {
-        'defines': ['CLD2_DYNAMIC_MODE'],
-      },
     },
   ],
 }