[clang] Replace BACKEND_PACKAGE_STRING with LLVM_VERSION_STRING

420d7ccbac0f499a6ff9595bdbfa99cd3376df22 introduced BACKEND_PACKAGE_STRING to
replace `PACKAGE_VERSION` (llvm/Config/config.h) to support standalone builds.
This is used in the output of `clang -cc1 -v`.

Since llvm-config.h is available for both standalone and non-standalone builds,
we can just use `LLVM_VERSION_STRING` from llvm-config.h.

clang/cmake/modules/AddClang.cmake uses `VERSION_STRING "${CLANG_VERSION} (${BACKEND_PACKAGE_STRING})"`.
Just simplify it to `"${CLANG_VERSION}"` so that we can remove the CMake
variable BACKEND_PACKAGE_STRING.

Reviewed By: tstellar

Differential Revision: https://reviews.llvm.org/D136660

1 files changed, 4 insertions, 3 deletions

diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 46f97e0..c28eaba8 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -41,6 +41,7 @@
 #include "clang/Serialization/InMemoryModuleCache.h"
 #include "llvm/ADT/ScopeExit.h"
 #include "llvm/ADT/Statistic.h"
+#include "llvm/Config/llvm-config.h"
 #include "llvm/Support/BuryPointer.h"
 #include "llvm/Support/CrashRecoveryContext.h"
 #include "llvm/Support/Errc.h"
@@ -1023,9 +1024,9 @@ bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
 
   // Validate/process some options.
   if (getHeaderSearchOpts().Verbose)
-    OS << "clang -cc1 version " CLANG_VERSION_STRING
-       << " based upon " << BACKEND_PACKAGE_STRING
-       << " default target " << llvm::sys::getDefaultTargetTriple() << "\n";
+    OS << "clang -cc1 version " CLANG_VERSION_STRING << " based upon LLVM "
+       << LLVM_VERSION_STRING << " default target "
+       << llvm::sys::getDefaultTargetTriple() << "\n";
 
   if (getCodeGenOpts().TimePasses)
     createFrontendTimer();