[clang] Introduce a new UEFI target predefine.

[Prabhuk]

Add a __UEFI__ predefine for UEFI target.

Co-authored-by: RossComputerGuy

[jhuber6]

Didn't know this existed, but we have #120632 tracking it now.

[llvmbot]

@llvm/pr-subscribers-clang-driver

@llvm/pr-subscribers-clang

Author: Prabhuk (Prabhuk)

Changes

Add a __UEFI__ predefine for UEFI target.

---

Full diff: https://github.com/llvm/llvm-project/pull/111719.diff

1 Files Affected:

• (modified) clang/lib/Basic/Targets/OSTargets.h (+3-1)

diff --git a/clang/lib/Basic/Targets/OSTargets.h b/clang/lib/Basic/Targets/OSTargets.h
index a83d6464e789d6..5a23eef0117294 100644
--- a/clang/lib/Basic/Targets/OSTargets.h
+++ b/clang/lib/Basic/Targets/OSTargets.h
@@ -783,7 +783,9 @@ template <typename Target>
 class LLVM_LIBRARY_VISIBILITY UEFITargetInfo : public OSTargetInfo<Target> {
 protected:
   void getOSDefines(const LangOptions &Opts, const llvm::Triple &Triple,
-                    MacroBuilder &Builder) const override {}
+                    MacroBuilder &Builder) const override {
+    Builder.defineMacro("__UEFI__");
+  }
 
 public:
   UEFITargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)

[petrhosek]

Can you include a test for this change?

[Prabhuk]

Can you include a test for this change?

I'll add the test.

[Prabhuk]

Didn't know this existed, but we have #120632 tracking it now.

Thanks. I left another comment there for @RossComputerGuy to decide on whether to land this patch or not.