[clang] [clang][mlibc] Predefine `__mlibc__` for mlibc targets (PR #225654)

[via cfe-commits]

llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: lzcnt (lzcunt)

<details>
<summary>Changes</summary>

Pretty much all users of mlibc targets currently vendor this or similar patches and having it upstream would be useful.

---
Full diff: https://github.com/llvm/llvm-project/pull/225654.diff


1 Files Affected:

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


``````````diff
diff --git a/clang/lib/Basic/Targets/OSTargets.h b/clang/lib/Basic/Targets/OSTargets.h
index fb5c17cefc004..36354668de69c 100644
--- a/clang/lib/Basic/Targets/OSTargets.h
+++ b/clang/lib/Basic/Targets/OSTargets.h
@@ -396,6 +396,9 @@ class LLVM_LIBRARY_VISIBILITY LinuxTargetInfo : public OSTargetInfo<Target> {
     } else {
         Builder.defineMacro("__gnu_linux__");
     }
+    if (Triple.getEnvironmentName() == "mlibc") {
+      Builder.defineMacro("__mlibc__");
+    }
     if (Opts.POSIXThreads)
       Builder.defineMacro("_REENTRANT");
     if (Opts.CPlusPlus)

``````````

</details>


https://github.com/llvm/llvm-project/pull/225654