Auto-generate v8 version based on tags.

BUG=chromium:446166
LOG=y

Review URL: https://codereview.chromium.org/797503007

Cr-Commit-Position: refs/heads/master@{#26062}

BUILD.gn

@@ -314,6 +314,25 @@ action("run_mksnapshot") {
   }
 }
 
+action("generate_v8_version") {
+  visibility = [ ":*" ]  # Only targets in this file can depend on this.
+
+  script = "tools/push-to-trunk/generate_version.py"
+
+  sources = [
+    "src/version.cc",
+  ]
+
+  outputs = [
+    "$target_gen_dir/version.cc"
+  ]
+
+  args = [
+    rebase_path("$target_gen_dir/version.cc", root_build_dir),
+  ]
+}
+
+
 ###############################################################################
 # Source Sets (aka static libraries)
 #
@@ -398,6 +417,7 @@ source_set("v8_base") {
   visibility = [ ":*" ]  # Only targets in this file can depend on this.
 
   sources = [
+    "$target_gen_dir/version.cc",
     "src/accessors.cc",
     "src/accessors.h",
     "src/allocation.cc",
@@ -933,7 +953,6 @@ source_set("v8_base") {
     "src/v8threads.h",
     "src/variables.cc",
     "src/variables.h",
-    "src/version.cc",
     "src/version.h",
     "src/vm-state-inl.h",
     "src/vm-state.h",
@@ -1211,6 +1230,7 @@ source_set("v8_base") {
   defines = []
   deps = [
     ":v8_libbase",
+    ":generate_v8_version",
   ]
 
   if (is_win) {

tools/gyp/v8.gyp

@@ -335,6 +335,34 @@
         }],
       ],
     },
+    {
+      'target_name': 'v8_version',
+      'type': 'none',
+      'conditions': [
+        ['want_separate_host_toolset==1', {
+          'toolsets': ['host'],
+        }, {
+          'toolsets': ['target'],
+        }],
+      ],
+      'actions': [
+        {
+          'action_name': 'generate_v8_version',
+          'inputs': [
+            '../../tools/push-to-trunk/generate_version.py',
+            '../../src/version.cc',
+          ],
+          'outputs': [
+            '<(SHARED_INTERMEDIATE_DIR)/version.cc',
+          ],
+          'action': [
+            'python',
+            '../../tools/push-to-trunk/generate_version.py',
+            '<(SHARED_INTERMEDIATE_DIR)/version.cc',
+          ],
+        },
+      ],
+    },
     {
       'target_name': 'v8_base',
       'type': 'static_library',
@@ -348,6 +376,7 @@
         '../..',
       ],
       'sources': [  ### gcmole(all) ###
+        '<(SHARED_INTERMEDIATE_DIR)/version.cc',
         '../../src/accessors.cc',
         '../../src/accessors.h',
         '../../src/allocation.cc',
@@ -886,7 +915,6 @@
         '../../src/variables.cc',
         '../../src/variables.h',
         '../../src/vector.h',
-        '../../src/version.cc',
         '../../src/version.h',
         '../../src/vm-state-inl.h',
         '../../src/vm-state.h',
@@ -898,8 +926,14 @@
       ],
       'conditions': [
         ['want_separate_host_toolset==1', {
+          'dependencies': [
+            'v8_version#host',
+          ],
           'toolsets': ['host', 'target'],
         }, {
+          'dependencies': [
+            'v8_version',
+          ],
           'toolsets': ['target'],
         }],
         ['v8_target_arch=="arm"', {

tools/push-to-trunk/generate_version.py

@@ -19,6 +19,12 @@ CWD = os.path.abspath(
 VERSION_CC = os.path.join(CWD, "src", "version.cc")
 
 def main():
+  if len(sys.argv) != 2:
+    print "Error: Specify the output file path for version.cc"
+    return 1
+  version_out = sys.argv[1]
+  assert os.path.exists(os.path.dirname(version_out))
+
   tag = subprocess.check_output(
       "git describe --tags",
       shell=True,
@@ -50,21 +56,20 @@ def main():
     patch = "0"
 
   # Modify version.cc with the new values.
-  with open(VERSION_CC, "r") as f:
-    text = f.read()
   output = []
-  for line in text.split("\n"):
-    for definition, substitute in (
-        ("MAJOR_VERSION", major),
-        ("MINOR_VERSION", minor),
-        ("BUILD_NUMBER", build),
-        ("PATCH_LEVEL", patch),
-        ("IS_CANDIDATE_VERSION", candidate)):
-      if line.startswith("#define %s" % definition):
-        line =  re.sub("\d+$", substitute, line)
-    output.append(line)
-  with open(VERSION_CC, "w") as f:
-    f.write("\n".join(output))
+  with open(VERSION_CC, "r") as f:
+    for line in f:
+      for definition, substitute in (
+          ("MAJOR_VERSION", major),
+          ("MINOR_VERSION", minor),
+          ("BUILD_NUMBER", build),
+          ("PATCH_LEVEL", patch),
+          ("IS_CANDIDATE_VERSION", candidate)):
+        if line.startswith("#define %s" % definition):
+          line =  re.sub("\d+$", substitute, line)
+      output.append(line)
+  with open(version_out, "w") as f:
+    f.write("".join(output))
 
   # Log what was done.
   candidate_txt = " (candidate)" if candidate == "1" else ""