Pull define for version out into v8-version.h and separate build target

This is part of removing the dependency of the Chromium browser DLL on
Windows on V8.

R=jochen@chromium.org
BUG=chromium:581766

Review-Url: https://codereview.chromium.org/2621983002
Cr-Commit-Position: refs/heads/master@{#42243}

BUILD.gn

@@ -851,6 +851,16 @@ if (v8_use_external_startup_data) {
   }
 }
 
+# This is split out to be a non-code containing target that the Chromium browser
+# DLL can depend upon to get only a version string.
+v8_source_set("v8_version") {
+  configs = [ ":internal_config" ]
+
+  sources = [
+    "include/v8-version.h",
+  ]
+}
+
 v8_source_set("v8_base") {
   visibility = [ ":*" ]  # Only targets in this file can depend on this.
 
@@ -864,7 +874,6 @@ v8_source_set("v8_base") {
     "include/v8-profiler.h",
     "include/v8-testing.h",
     "include/v8-util.h",
-    "include/v8-version.h",
     "include/v8.h",
     "include/v8config.h",
     "src/accessors.cc",
@@ -2189,6 +2198,7 @@ v8_source_set("v8_base") {
   deps = [
     ":v8_libbase",
     ":v8_libsampler",
+    ":v8_version",
   ]
 
   sources += [ v8_generated_peephole_source ]

include/v8-version.h

@@ -17,4 +17,24 @@
 // (Boolean macro values are not supported by all preprocessors.)
 #define V8_IS_CANDIDATE_VERSION 1
 
+#if V8_IS_CANDIDATE_VERSION
+#define V8_CANDIDATE_STRING " (candidate)"
+#else
+#define V8_CANDIDATE_STRING ""
+#endif
+
+#define V8_SX(x) #x
+#define V8_S(x) V8_SX(x)
+
+#if V8_PATCH_LEVEL > 0
+#define V8_VERSION_STRING                                        \
+  V8_S(V8_MAJOR_VERSION)                                         \
+  "." V8_S(V8_MINOR_VERSION) "." V8_S(V8_BUILD_NUMBER) "." V8_S( \
+      V8_PATCH_LEVEL) V8_CANDIDATE_STRING
+#else
+#define V8_VERSION_STRING \
+  V8_S(V8_MAJOR_VERSION)  \
+  "." V8_S(V8_MINOR_VERSION) "." V8_S(V8_BUILD_NUMBER) V8_CANDIDATE_STRING
+#endif
+
 #endif  // V8_INCLUDE_VERSION_H_

src/version.cc

@@ -12,25 +12,6 @@
 // number. This define is mainly used by the build system script.
 #define SONAME            ""
 
-#if V8_IS_CANDIDATE_VERSION
-#define CANDIDATE_STRING " (candidate)"
-#else
-#define CANDIDATE_STRING ""
-#endif
-
-#define SX(x) #x
-#define S(x) SX(x)
-
-#if V8_PATCH_LEVEL > 0
-#define VERSION_STRING                                                      \
-  S(V8_MAJOR_VERSION) "." S(V8_MINOR_VERSION) "." S(V8_BUILD_NUMBER) "." S( \
-      V8_PATCH_LEVEL) CANDIDATE_STRING
-#else
-#define VERSION_STRING                                               \
-  S(V8_MAJOR_VERSION) "." S(V8_MINOR_VERSION) "." S(V8_BUILD_NUMBER) \
-      CANDIDATE_STRING
-#endif
-
 namespace v8 {
 namespace internal {
 
@@ -40,7 +21,7 @@ int Version::build_ = V8_BUILD_NUMBER;
 int Version::patch_ = V8_PATCH_LEVEL;
 bool Version::candidate_ = (V8_IS_CANDIDATE_VERSION != 0);
 const char* Version::soname_ = SONAME;
-const char* Version::version_string_ = VERSION_STRING;
+const char* Version::version_string_ = V8_VERSION_STRING;
 
 // Calculate the V8 version string.
 void Version::GetString(Vector<char> str) {