When x is empty, x ## is suppressed, and when y gets expanded, the fact that it follows ## is not
available in the macro expansion result. The macro definition can be checked instead, the ## will
be available there regardless of what x expands to.
Fixes http://llvm.org/PR12767
Patch by Harald van Dijk!
llvm-svn: 182699
- This is designed to make it obvious that %clang_cc1 is a "test variable"
which is substituted. It is '%clang_cc1' instead of '%clang -cc1' because it
can be useful to redefine what gets run as 'clang -cc1' (for example, to set
a default target).
llvm-svn: 91446
Argyrios Kyrtzidis