[clang] [libc] [flang] [lldb] [libcxx] [llvm] [lld] [clang-tools-extra] [OpenACC] Initial commits to support OpenACC (PR #70234)

[Bruno Cardoso Lopes via cfe-commits]

================
@@ -605,6 +605,17 @@ static void InitializeStandardPredefinedMacros(const TargetInfo &TI,
       Builder.defineMacro("HIP_API_PER_THREAD_DEFAULT_STREAM");
     }
   }
+
+  if (LangOpts.OpenACC) {
+    // FIXME: When we have full support for OpenACC, we should set this to the
+    // version we support. Until then, set as '1' by default, but provide a
+    // temporary mechanism for users to override this so real-world examples can
+    // be tested against.
+    if (!LangOpts.OpenACCMacroOverride.empty())
+      Builder.defineMacro("_OPENACC", LangOpts.OpenACCMacroOverride);
+    else
+      Builder.defineMacro("_OPENACC", "1");
----------------
bcardosolopes wrote:

This probably deserves a test akin to `-E -dM` and FileCheck for the macro.

https://github.com/llvm/llvm-project/pull/70234