[llvm-branch-commits] [clang] release/21.x: opencl: Ensure printf symbol is not mangled. (#150210) (PR #150960)

[via llvm-branch-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-backend-x86

@llvm/pr-subscribers-clang

Author: None (llvmbot)

<details>
<summary>Changes</summary>

Backport a22d010002baf761f84d0a8fa5fcaaf6f3b1455f

Requested by: @<!-- -->svenvh

---
Full diff: https://github.com/llvm/llvm-project/pull/150960.diff


1 Files Affected:

- (modified) clang/lib/Headers/opencl-c-base.h (+10-1) 


``````````diff
diff --git a/clang/lib/Headers/opencl-c-base.h b/clang/lib/Headers/opencl-c-base.h
index 2b7f5043e09e4..6206a347852be 100644
--- a/clang/lib/Headers/opencl-c-base.h
+++ b/clang/lib/Headers/opencl-c-base.h
@@ -697,7 +697,16 @@ template <typename _Tp> struct __remove_address_space<__constant _Tp> {
 #if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_1_2)
 // OpenCL v1.2 s6.12.13, v2.0 s6.13.13 - printf
 
-int printf(__constant const char* st, ...) __attribute__((format(printf, 1, 2)));
+#ifdef __OPENCL_CPP_VERSION__
+#define CLINKAGE extern "C"
+#else
+#define CLINKAGE
+#endif
+
+CLINKAGE int printf(__constant const char *st, ...)
+    __attribute__((format(printf, 1, 2)));
+
+#undef CLINKAGE
 #endif
 
 #ifdef cl_intel_device_side_avc_motion_estimation

``````````

</details>


https://github.com/llvm/llvm-project/pull/150960