[build] Introduce an embedder version string

Sometimes, the embedder might want to merge a fix to an abandoned branch
or to a supported branch but the fix is not relevant to Chromium.
This adds a new version string that the embedder can set at compile time
and that will be appended to the official V8 version.
The separator must be provided in the string. For instance, to have a
full version string like "6.0.287.53-emb.1", the embedder must set
V8_EMBEDDER_STRING to "-emb.1".

Related Node.js issue: nodejs/node#9754

BUG=v8:5740
R=machenbach@chromium.org

Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: Ifa2d9bd213795e6d54886436f8c3787ac6162823
Reviewed-on: https://chromium-review.googlesource.com/690475
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Michaël Zasso <mic.besace@gmail.com>
Cr-Commit-Position: refs/heads/master@{#48301}

BUILD.gn

@@ -40,6 +40,9 @@ declare_args() {
   # Embeds the given script into the snapshot.
   v8_embed_script = ""
 
+  # Allows the embedder to add a custom suffix to the version string.
+  v8_embedder_string = ""
+
   # Sets -dENABLE_DISASSEMBLER.
   v8_enable_disassembler = ""
 
@@ -231,6 +234,9 @@ config("features") {
 
   defines = []
 
+  if (v8_embedder_string != "") {
+    defines += [ "V8_EMBEDDER_STRING=\"$v8_embedder_string\"" ]
+  }
   if (v8_enable_disassembler) {
     defines += [ "ENABLE_DISASSEMBLER" ]
   }

gypfiles/features.gypi

@@ -33,6 +33,9 @@
       'v8_target_arch%': '<(target_arch)',
     },
 
+    # Allows the embedder to add a custom suffix to the version string.
+    'v8_embedder_string%': '',
+
     'v8_enable_disassembler%': 0,
 
     'v8_promise_internal_field_count%': 0,
@@ -89,6 +92,9 @@
   },
   'target_defaults': {
     'conditions': [
+      ['v8_embedder_string!=""', {
+        'defines': ['V8_EMBEDDER_STRING="<(v8_embedder_string)"',],
+      }],
       ['v8_enable_disassembler==1', {
         'defines': ['ENABLE_DISASSEMBLER',],
       }],

include/v8-version-string.h

@@ -16,14 +16,18 @@
 #define V8_CANDIDATE_STRING ""
 #endif
 
+#ifndef V8_EMBEDDER_STRING
+#define V8_EMBEDDER_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
+      V8_PATCH_LEVEL) V8_EMBEDDER_STRING V8_CANDIDATE_STRING
 #else
 #define V8_VERSION_STRING \
   V8_S(V8_MAJOR_VERSION)  \

src/log-utils.cc

@@ -52,9 +52,16 @@ void Log::Initialize(const char* log_file_name) {
 
     if (output_handle_ != nullptr) {
       Log::MessageBuilder msg(this);
-      msg.Append("v8-version,%d,%d,%d,%d,%d", Version::GetMajor(),
-                 Version::GetMinor(), Version::GetBuild(), Version::GetPatch(),
-                 Version::IsCandidate());
+      if (strlen(Version::GetEmbedder()) == 0) {
+        msg.Append("v8-version,%d,%d,%d,%d,%d", Version::GetMajor(),
+                   Version::GetMinor(), Version::GetBuild(),
+                   Version::GetPatch(), Version::IsCandidate());
+      } else {
+        msg.Append("v8-version,%d,%d,%d,%d,%s,%d", Version::GetMajor(),
+                   Version::GetMinor(), Version::GetBuild(),
+                   Version::GetPatch(), Version::GetEmbedder(),
+                   Version::IsCandidate());
+      }
       msg.WriteToLogFile();
     }
   }

src/version.cc

@@ -20,6 +20,7 @@ int Version::major_ = V8_MAJOR_VERSION;
 int Version::minor_ = V8_MINOR_VERSION;
 int Version::build_ = V8_BUILD_NUMBER;
 int Version::patch_ = V8_PATCH_LEVEL;
+const char* Version::embedder_ = V8_EMBEDDER_STRING;
 bool Version::candidate_ = (V8_IS_CANDIDATE_VERSION != 0);
 const char* Version::soname_ = SONAME;
 const char* Version::version_string_ = V8_VERSION_STRING;
@@ -28,10 +29,11 @@ const char* Version::version_string_ = V8_VERSION_STRING;
 void Version::GetString(Vector<char> str) {
   const char* candidate = IsCandidate() ? " (candidate)" : "";
   if (GetPatch() > 0) {
-    SNPrintF(str, "%d.%d.%d.%d%s", GetMajor(), GetMinor(), GetBuild(),
-             GetPatch(), candidate);
+    SNPrintF(str, "%d.%d.%d.%d%s%s", GetMajor(), GetMinor(), GetBuild(),
+             GetPatch(), GetEmbedder(), candidate);
   } else {
-    SNPrintF(str, "%d.%d.%d%s", GetMajor(), GetMinor(), GetBuild(), candidate);
+    SNPrintF(str, "%d.%d.%d%s%s", GetMajor(), GetMinor(), GetBuild(),
+             GetEmbedder(), candidate);
   }
 }
 
@@ -42,11 +44,11 @@ void Version::GetSONAME(Vector<char> str) {
     // Generate generic SONAME if no specific SONAME is defined.
     const char* candidate = IsCandidate() ? "-candidate" : "";
     if (GetPatch() > 0) {
-      SNPrintF(str, "libv8-%d.%d.%d.%d%s.so",
-               GetMajor(), GetMinor(), GetBuild(), GetPatch(), candidate);
+      SNPrintF(str, "libv8-%d.%d.%d.%d%s%s.so", GetMajor(), GetMinor(),
+               GetBuild(), GetPatch(), GetEmbedder(), candidate);
     } else {
-      SNPrintF(str, "libv8-%d.%d.%d%s.so",
-               GetMajor(), GetMinor(), GetBuild(), candidate);
+      SNPrintF(str, "libv8-%d.%d.%d%s%s.so", GetMajor(), GetMinor(), GetBuild(),
+               GetEmbedder(), candidate);
     }
   } else {
     // Use specific SONAME.

src/version.h

@@ -18,6 +18,7 @@ class Version {
   static int GetMinor() { return minor_; }
   static int GetBuild() { return build_; }
   static int GetPatch() { return patch_; }
+  static const char* GetEmbedder() { return embedder_; }
   static bool IsCandidate() { return candidate_; }
   static uint32_t Hash() {
     return static_cast<uint32_t>(
@@ -38,13 +39,15 @@ class Version {
   static int minor_;
   static int build_;
   static int patch_;
+  static const char* embedder_;
   static bool candidate_;
   static const char* soname_;
   static const char* version_string_;
 
   // In test-version.cc.
   friend void SetVersion(int major, int minor, int build, int patch,
-                         bool candidate, const char* soname);
+                         const char* embedder, bool candidate,
+                         const char* soname);
 };
 
 }  // namespace internal

test/cctest/test-version.cc

@@ -35,32 +35,33 @@ namespace v8 {
 namespace internal {
 
 void SetVersion(int major, int minor, int build, int patch,
-                bool candidate, const char* soname) {
+                const char* embedder, bool candidate, const char* soname) {
   Version::major_ = major;
   Version::minor_ = minor;
   Version::build_ = build;
   Version::patch_ = patch;
+  Version::embedder_ = embedder;
   Version::candidate_ = candidate;
   Version::soname_ = soname;
 }
 
-static void CheckVersion(int major, int minor, int build,
-                         int patch, bool candidate,
+static void CheckVersion(int major, int minor, int build, int patch,
+                         const char* embedder, bool candidate,
                          const char* expected_version_string,
                          const char* expected_generic_soname) {
   static v8::internal::EmbeddedVector<char, 128> version_str;
   static v8::internal::EmbeddedVector<char, 128> soname_str;
 
   // Test version without specific SONAME.
-  SetVersion(major, minor, build, patch, candidate, "");
+  SetVersion(major, minor, build, patch, embedder, candidate, "");
   Version::GetString(version_str);
   CHECK_EQ(0, strcmp(expected_version_string, version_str.start()));
   Version::GetSONAME(soname_str);
   CHECK_EQ(0, strcmp(expected_generic_soname, soname_str.start()));
 
   // Test version with specific SONAME.
   const char* soname = "libv8.so.1";
-  SetVersion(major, minor, build, patch, candidate, soname);
+  SetVersion(major, minor, build, patch, embedder, candidate, soname);
   Version::GetString(version_str);
   CHECK_EQ(0, strcmp(expected_version_string, version_str.start()));
   Version::GetSONAME(soname_str);
@@ -69,18 +70,26 @@ static void CheckVersion(int major, int minor, int build,
 
 
 TEST(VersionString) {
-  CheckVersion(0, 0, 0, 0, false, "0.0.0", "libv8-0.0.0.so");
-  CheckVersion(0, 0, 0, 0, true,
-               "0.0.0 (candidate)", "libv8-0.0.0-candidate.so");
-  CheckVersion(1, 0, 0, 0, false, "1.0.0", "libv8-1.0.0.so");
-  CheckVersion(1, 0, 0, 0, true,
-               "1.0.0 (candidate)", "libv8-1.0.0-candidate.so");
-  CheckVersion(1, 0, 0, 1, false, "1.0.0.1", "libv8-1.0.0.1.so");
-  CheckVersion(1, 0, 0, 1, true,
-               "1.0.0.1 (candidate)", "libv8-1.0.0.1-candidate.so");
-  CheckVersion(2, 5, 10, 7, false, "2.5.10.7", "libv8-2.5.10.7.so");
-  CheckVersion(2, 5, 10, 7, true,
-               "2.5.10.7 (candidate)", "libv8-2.5.10.7-candidate.so");
+  CheckVersion(0, 0, 0, 0, "", false, "0.0.0", "libv8-0.0.0.so");
+  CheckVersion(0, 0, 0, 0, "", true, "0.0.0 (candidate)",
+               "libv8-0.0.0-candidate.so");
+  CheckVersion(1, 0, 0, 0, "", false, "1.0.0", "libv8-1.0.0.so");
+  CheckVersion(1, 0, 0, 0, "", true, "1.0.0 (candidate)",
+               "libv8-1.0.0-candidate.so");
+  CheckVersion(1, 0, 0, 1, "", false, "1.0.0.1", "libv8-1.0.0.1.so");
+  CheckVersion(1, 0, 0, 1, "", true, "1.0.0.1 (candidate)",
+               "libv8-1.0.0.1-candidate.so");
+  CheckVersion(2, 5, 10, 7, "", false, "2.5.10.7", "libv8-2.5.10.7.so");
+  CheckVersion(2, 5, 10, 7, "", true, "2.5.10.7 (candidate)",
+               "libv8-2.5.10.7-candidate.so");
+  CheckVersion(6, 0, 287, 0, "-emb.1", false, "6.0.287-emb.1",
+               "libv8-6.0.287-emb.1.so");
+  CheckVersion(6, 0, 287, 0, "-emb.1", true, "6.0.287-emb.1 (candidate)",
+               "libv8-6.0.287-emb.1-candidate.so");
+  CheckVersion(6, 0, 287, 53, "-emb.1", false, "6.0.287.53-emb.1",
+               "libv8-6.0.287.53-emb.1.so");
+  CheckVersion(6, 0, 287, 53, "-emb.1", true, "6.0.287.53-emb.1 (candidate)",
+               "libv8-6.0.287.53-emb.1-candidate.so");
 }
 
 }  // namespace internal