Driver: Run 'clang' in C++ mode based on the name it was invoked by. We match

anything that ends with ++ or ++-FOO (e.g., c++, clang++, clang++-1.1) as being
a "C++ compiler".

This allows easy testing of the C++ compiler by 'ln -s clang clang++', or by 'cp
clang clang++'.

Based on patch by Roman Divacky.

llvm-svn: 86697

1 files changed, 9 insertions, 0 deletions

diff --git a/clang/tools/driver/driver.cpp b/clang/tools/driver/driver.cpp
index 9d204ce6c0c..1947bac99b5 100644
--- a/clang/tools/driver/driver.cpp
+++ b/clang/tools/driver/driver.cpp
@@ -197,6 +197,15 @@ int main(int argc, const char **argv) {
                    llvm::sys::getHostTriple().c_str(),
                    "a.out", IsProduction, Diags);
 
+  // Check for ".*++" or ".*++-[^-]*" to determine if we are a C++
+  // compiler. This matches things like "c++", "clang++", and "clang++-1.1".
+  //
+  // Note that we intentionally want to use argv[0] here, to support "clang++"
+  // being a symlink.
+  llvm::StringRef ProgName(llvm::sys::Path(argv[0]).getBasename());
+  if (ProgName.endswith("++") || ProgName.rsplit('-').first.endswith("++"))
+    TheDriver.CCCIsCXX = true;
+
   llvm::OwningPtr<Compilation> C;
 
   // Handle QA_OVERRIDE_GCC3_OPTIONS and CCC_ADD_ARGS, used for editing a