emit '(assertions enabled)' in the version string for a build of clang with assertions enabled

[arphaman]

Summary

This patch adds an additional '(assertions enabled)' in the version string for a build of clang with assertions enabled.

This is a useful way to differentiate between clang binaries that have assertions enabled and the ones that don't if they are based on the same version.

[dexonsmith]

I like this. Can you start a discussion on cfe-dev (if you haven't already)? This is user-visible so I want to be sure other vendors are happy with this; if not, we can hide it behind a CMake flag.

lib/Basic/Version.cpp

117

Can we just make this " (+asserts)" or " (-NDEBUG)"? If we wanted to generalize this, I'd expect to want a list of compiler features similar to CPU features.

[arphaman]

Use "(+asserts)" as suggested.

[arphaman]

In D58559#1407742, @dexonsmith wrote:

I like this. Can you start a discussion on cfe-dev (if you haven't already)? This is user-visible so I want to be sure other vendors are happy with this; if not, we can hide it behind a CMake flag.

Sure, I started a cfe-dev thread.

[dexonsmith]

Marking as "Request changes" to get this off my queue; are you still interested in pursuing this?

lib/Basic/Version.cpp

std::string getClangFullRepositoryVersion() {
   std::string LLVMRev = getLLVMRevision();
   if (!LLVMRev.empty() && LLVMRev != Revision) {
     OS << " (";
     std::string LLVMRepo = getLLVMRepositoryPath();
     if (!LLVMRepo.empty())
       OS << LLVMRepo << ' ';
     OS << LLVMRev << ')';
   }
+
+  // Differentiate between the version with and without assertions.
+#ifndef NDEBUG
+  OS << " (+asserts)";
+#endif
   return OS.str();
 }
 
 std::string getClangFullVersion() {
   return getClangToolFullVersion("clang");
 }
 
 std::string getClangToolFullVersion(StringRef ToolName) {