SL-11216: Convert LLVersionInfo to an LLSingleton.

This changeset is meant to exemplify how to convert a "namespace" class whose
methods are static -- and whose data are module-static -- to an LLSingleton.
LLVersionInfo has no initClass() or cleanupClass() methods, but the general
idea is the same.

* Derive the class from LLSingleton<T>:
  class LLSomeSingleton: public LLSingleton<LLSomeSingleton> { ... };
* Add LLSINGLETON(LLSomeSingleton); in the private section of the class. This
  usage implies a separate LLSomeSingleton::LLSomeSingleton() definition, as
  described in indra/llcommon/llsingleton.h.
* Move module-scope data in the .cpp file to non-static class members. Change
  any sVariableName to mVariableName to avoid being outright misleading.
* Make static class methods non-static. Remove '//static' comments from method
  definitions as needed.
* For LLVersionInfo specifically, the 'const std::string&' return type was
  replaced with 'std::string'. Returning a reference to a static or a member,
  const or otherwise, is an anti-pattern: the interface constrains the
  implementation, prohibiting possibly later returning a temporary (an
  expression).
* For LLVersionInfo specifically, 'const S32' return type was replaced with
  simple 'S32'. 'const' is just noise in that usage.
* Simple member initialization (e.g. the original initializer expressions for
  static variables) can be done with member{ value } initializers (no examples
  here though).
* Delete initClass() method.
* LLSingleton's forté is of course lazy initialization. It might work to
  simply delete any calls to initClass(). But if there are side effects that
  must happen at that moment, replace LLSomeSingleton::initClass() with
  (void)LLSomeSingleton::instance();
* Most initClass() initialization can be done in the constructor, as would
  normally be the case.
* Initialization that might cause a circular LLSingleton reference should be
  moved to initSingleton(). Override 'void initSingleton();' should be private.
* For LLVersionInfo specifically, certain initialization that used to be
  lazily performed was made unconditional, due to its low cost.
* For LLVersionInfo specifically, certain initialization involved calling
  methods that have become non-static. This was moved to initSingleton()
  because, in a constructor body, 'this' does not yet point to the enclosing
  class.
* Delete cleanupClass() method.
* There is already a generic LLSingletonBase::deleteAll() call in
  LLAppViewer::cleanup(). It might work to let this new LLSingleton be cleaned
  up with all the rest. But if there are side effects that must happen at that
  moment, replace LLSomeSingleton::cleanupClass() with
  LLSomeSingleton::deleteSingleton(). That said, much of the benefit of
  converting to LLSingleton is deleteAll()'s guarantee that cross-LLSingleton
  dependencies will be properly honored: we're trying to migrate the code base
  away from the present fragile manual cleanup sequence.
* Most cleanupClass() cleanup can be done in the destructor, as would normally
  be the case.
* Cleanup that might throw an exception should be moved to cleanupSingleton().
  Override 'void cleanupSingleton();' should be private.
* Within LLSomeSingleton methods, remove any existing
  LLSomeSingleton::methodName() qualification: simple methodName() is better.
* In the rest of the code base, convert most LLSomeSingleton::methodName()
  references to LLSomeSingleton::instance().methodName(). (Prefer instance() to
  getInstance() because a reference does not admit the possibility of NULL.)
* Of course, LLSomeSingleton::ENUM_VALUE can remain unchanged.

In general, for many successive references to an LLSingleton instance, it
can be useful to capture the instance() as in:

auto& versionInfo{LLVersionInfo::instance()};
// ... versionInfo.getVersion() ...

We did not do that here only to simplify the code review.

The STRINGIZE(expression) macro encapsulates:
std::ostringstream out;
out << expression;
return out.str();
We used that in a couple places.

For LLVersionInfo specifically, lllogininstance_test.cpp used to dummy out a
couple specific static methods. It's harder to dummy out
LLSingleton::instance() references, so we add the real class to that test.

1 files changed, 25 insertions, 25 deletions

diff --git a/indra/newview/llappviewer.cpp b/indra/newview/llappviewer.cpp
index ed80e7c0ce..795d14740a 100644
--- a/indra/newview/llappviewer.cpp
+++ b/indra/newview/llappviewer.cpp
@@ -1120,7 +1120,7 @@ bool LLAppViewer::init()
 
 	// Save the current version to the prefs file
 	gSavedSettings.setString("LastRunVersion",
-							 LLVersionInfo::getChannelAndVersion());
+							 LLVersionInfo::instance().getChannelAndVersion());
 
 	gSimLastTime = gRenderStartTime.getElapsedTimeF32();
 	gSimFrames = (F32)gFrameCount;
@@ -1156,7 +1156,7 @@ bool LLAppViewer::init()
 	// UpdaterServiceSettings
 	updater.args.add(stringize(gSavedSettings.getU32("UpdaterServiceSetting")));
 	// channel
-	updater.args.add(LLVersionInfo::getChannel());
+	updater.args.add(LLVersionInfo::instance().getChannel());
 	// testok
 	updater.args.add(stringize(gSavedSettings.getBOOL("UpdaterWillingToTest")));
 	// ForceAddressSize
@@ -2616,7 +2616,7 @@ bool LLAppViewer::initConfiguration()
 	std::string CmdLineChannel(gSavedSettings.getString("CmdLineChannel"));
 	if(! CmdLineChannel.empty())
     {
-		LLVersionInfo::resetChannel(CmdLineChannel);
+		LLVersionInfo::instance().resetChannel(CmdLineChannel);
 	}
 
 	// If we have specified crash on startup, set the global so we'll trigger the crash at the right time
@@ -3062,15 +3062,15 @@ LLSD LLAppViewer::getViewerInfo() const
 	// LLFloaterAbout.
 	LLSD info;
 	LLSD version;
-	version.append(LLVersionInfo::getMajor());
-	version.append(LLVersionInfo::getMinor());
-	version.append(LLVersionInfo::getPatch());
-	version.append(LLVersionInfo::getBuild());
+	version.append(LLVersionInfo::instance().getMajor());
+	version.append(LLVersionInfo::instance().getMinor());
+	version.append(LLVersionInfo::instance().getPatch());
+	version.append(LLVersionInfo::instance().getBuild());
 	info["VIEWER_VERSION"] = version;
-	info["VIEWER_VERSION_STR"] = LLVersionInfo::getVersion();
-	info["CHANNEL"] = LLVersionInfo::getChannel();
+	info["VIEWER_VERSION_STR"] = LLVersionInfo::instance().getVersion();
+	info["CHANNEL"] = LLVersionInfo::instance().getChannel();
     info["ADDRESS_SIZE"] = ADDRESS_SIZE;
-    std::string build_config = LLVersionInfo::getBuildConfig();
+    std::string build_config = LLVersionInfo::instance().getBuildConfig();
     if (build_config != "Release")
     {
         info["BUILD_CONFIG"] = build_config;
@@ -3081,7 +3081,7 @@ LLSD LLAppViewer::getViewerInfo() const
 	std::string url = LLTrans::getString("RELEASE_NOTES_BASE_URL");
 	if (! LLStringUtil::endsWith(url, "/"))
 		url += "/";
-	url += LLURI::escape(LLVersionInfo::getVersion()) + ".html";
+	url += LLURI::escape(LLVersionInfo::instance().getVersion()) + ".html";
 
 	info["VIEWER_RELEASE_NOTES_URL"] = url;
 
@@ -3372,12 +3372,12 @@ void LLAppViewer::writeSystemInfo()
     gDebugInfo["SLLog"] = gDirUtilp->getExpandedFilename(LL_PATH_LOGS,"SecondLife.old");  //LLError::logFileName();
 #endif
 
-	gDebugInfo["ClientInfo"]["Name"] = LLVersionInfo::getChannel();
-	gDebugInfo["ClientInfo"]["MajorVersion"] = LLVersionInfo::getMajor();
-	gDebugInfo["ClientInfo"]["MinorVersion"] = LLVersionInfo::getMinor();
-	gDebugInfo["ClientInfo"]["PatchVersion"] = LLVersionInfo::getPatch();
-	gDebugInfo["ClientInfo"]["BuildVersion"] = LLVersionInfo::getBuild();
-	gDebugInfo["ClientInfo"]["AddressSize"] = LLVersionInfo::getAddressSize();
+	gDebugInfo["ClientInfo"]["Name"] = LLVersionInfo::instance().getChannel();
+	gDebugInfo["ClientInfo"]["MajorVersion"] = LLVersionInfo::instance().getMajor();
+	gDebugInfo["ClientInfo"]["MinorVersion"] = LLVersionInfo::instance().getMinor();
+	gDebugInfo["ClientInfo"]["PatchVersion"] = LLVersionInfo::instance().getPatch();
+	gDebugInfo["ClientInfo"]["BuildVersion"] = LLVersionInfo::instance().getBuild();
+	gDebugInfo["ClientInfo"]["AddressSize"] = LLVersionInfo::instance().getAddressSize();
 
 	gDebugInfo["CAFilename"] = gDirUtilp->getCAFile();
 
@@ -3420,7 +3420,7 @@ void LLAppViewer::writeSystemInfo()
 
 	// Dump some debugging info
 	LL_INFOS("SystemInfo") << "Application: " << LLTrans::getString("APP_NAME") << LL_ENDL;
-	LL_INFOS("SystemInfo") << "Version: " << LLVersionInfo::getChannelAndVersion() << LL_ENDL;
+	LL_INFOS("SystemInfo") << "Version: " << LLVersionInfo::instance().getChannelAndVersion() << LL_ENDL;
 
 	// Dump the local time and time zone
 	time_t now;
@@ -3642,7 +3642,7 @@ void LLAppViewer::handleViewerCrash()
 // static
 void LLAppViewer::recordMarkerVersion(LLAPRFile& marker_file)
 {
-	std::string marker_version(LLVersionInfo::getChannelAndVersion());
+	std::string marker_version(LLVersionInfo::instance().getChannelAndVersion());
 	if ( marker_version.length() > MAX_MARKER_LENGTH )
 	{
 		LL_WARNS_ONCE("MarkerFile") << "Version length ("<< marker_version.length()<< ")"
@@ -3659,7 +3659,7 @@ bool LLAppViewer::markerIsSameVersion(const std::string& marker_name) const
 {
 	bool sameVersion = false;
 
-	std::string my_version(LLVersionInfo::getChannelAndVersion());
+	std::string my_version(LLVersionInfo::instance().getChannelAndVersion());
 	char marker_version[MAX_MARKER_LENGTH];
 	S32  marker_version_length;
 
@@ -5517,12 +5517,12 @@ void LLAppViewer::handleLoginComplete()
 	initMainloopTimeout("Mainloop Init");
 
 	// Store some data to DebugInfo in case of a freeze.
-	gDebugInfo["ClientInfo"]["Name"] = LLVersionInfo::getChannel();
+	gDebugInfo["ClientInfo"]["Name"] = LLVersionInfo::instance().getChannel();
 
-	gDebugInfo["ClientInfo"]["MajorVersion"] = LLVersionInfo::getMajor();
-	gDebugInfo["ClientInfo"]["MinorVersion"] = LLVersionInfo::getMinor();
-	gDebugInfo["ClientInfo"]["PatchVersion"] = LLVersionInfo::getPatch();
-	gDebugInfo["ClientInfo"]["BuildVersion"] = LLVersionInfo::getBuild();
+	gDebugInfo["ClientInfo"]["MajorVersion"] = LLVersionInfo::instance().getMajor();
+	gDebugInfo["ClientInfo"]["MinorVersion"] = LLVersionInfo::instance().getMinor();
+	gDebugInfo["ClientInfo"]["PatchVersion"] = LLVersionInfo::instance().getPatch();
+	gDebugInfo["ClientInfo"]["BuildVersion"] = LLVersionInfo::instance().getBuild();
 
 	LLParcel* parcel = LLViewerParcelMgr::getInstance()->getAgentParcel();
 	if ( parcel && parcel->getMusicURL()[0])