Add rule for generating lexer and implement lexer shell.

src/lexer/lexer.gyp

Index: src/lexer/lexer.gyp
diff --git a/samples/samples.gyp b/src/lexer/lexer.gyp
similarity index 62%
copy from samples/samples.gyp
copy to src/lexer/lexer.gyp
index dfc7410070b3c46edf026caa98f92fc3da64701b..7ebf3d8eb6ea14f1a76c196a5351d77fb0b8881e 100644
--- a/samples/samples.gyp
+++ b/src/lexer/lexer.gyp
@@ -30,47 +30,49 @@
     'v8_code': 1,
     'v8_enable_i18n_support%': 1,
   },
-  'includes': ['../build/toolchain.gypi', '../build/features.gypi'],
-  'target_defaults': {
-    'type': 'executable',
-    'dependencies': [
-      '../tools/gyp/v8.gyp:v8',
-    ],
-    'include_dirs': [
-      '../include',
-    ],
-    'conditions': [
-      ['v8_enable_i18n_support==1', {
-        'dependencies': [
-          '<(icu_gyp_path):icui18n',
-          '<(icu_gyp_path):icuuc',
-        ],
-      }],
-      ['OS=="win" and v8_enable_i18n_support==1', {
-        'dependencies': [
-          '<(icu_gyp_path):icudata',
-        ],
-      }],
-    ],
-  },
+  'includes': ['../../build/toolchain.gypi', '../../build/features.gypi'],
   'targets': [
     {
-      'target_name': 'shell',
-      'sources': [
-        'shell.cc',
+      'target_name': 'lexer-shell',
+      'type': 'executable',
+      'dependencies': [
+        '../../tools/gyp/v8.gyp:v8',
       ],
-    },
-    {
-      'target_name': 'process',
-      'sources': [
-        'process.cc',
+      # Generated source files need this explicitly:
+      'include_dirs+': [
+        '../../src',
       ],
-    },
-    {
-      'target_name': 'lineprocessor',
       'sources': [
-        'lineprocessor.cc',
+        'lexer-shell.cc',
+# TODO: fix compiler errors and add '<(SHARED_INTERMEDIATE_DIR)/lexer.cc',
+      ],
+      'conditions': [
+        ['v8_enable_i18n_support==1', {
+          'dependencies': [
+            '<(icu_gyp_path):icui18n',
+            '<(icu_gyp_path):icuuc',
+          ],
+        }],
       ],
-    }
+      'actions': [
+        {
+          'action_name': 're2c',
+          'inputs': [
+            '../../src/lexer/lexer.re',
+          ],
+          'outputs': [
+            '<(SHARED_INTERMEDIATE_DIR)/lexer.cc',
+          ],
+          'action': [
+            '$(RE2C)',
+            '-f',
+            '-c',
+            '--output',
+            '<(SHARED_INTERMEDIATE_DIR)/lexer.cc',
+            '../../src/lexer/lexer.re',
+          ],
+        },
+      ],
+    },
   ],
 }