[clang] 465a3ce - [CUDA][HIP] improve error message for missing cmath (#122155)

[via cfe-commits]

Author: Yaxun (Sam) Liu
Date: 2025-01-09T10:58:06-05:00
New Revision: 465a3ce9fac1fcf49d5772f70564973a73748d57

URL: https://github.com/llvm/llvm-project/commit/465a3ce9fac1fcf49d5772f70564973a73748d57
DIFF: https://github.com/llvm/llvm-project/commit/465a3ce9fac1fcf49d5772f70564973a73748d57.diff

LOG: [CUDA][HIP] improve error message for missing cmath (#122155)

One common error seen in CUDA/HIP compilation is:

fatal error: 'cmath' file not found

which is due to inproper installation of standard C++ libraries.

Since it happens with #include_next, users may feel confusing which
cmath is not found and how to fix it.

Add an error directive to help users resolve this issue.

Added: 
    

Modified: 
    clang/lib/Headers/cuda_wrappers/cmath

Removed: 
    


################################################################################
diff  --git a/clang/lib/Headers/cuda_wrappers/cmath b/clang/lib/Headers/cuda_wrappers/cmath
index 45f89beec9b4df..7deca678bf252e 100644
--- a/clang/lib/Headers/cuda_wrappers/cmath
+++ b/clang/lib/Headers/cuda_wrappers/cmath
@@ -24,7 +24,11 @@
 #ifndef __CLANG_CUDA_WRAPPERS_CMATH
 #define __CLANG_CUDA_WRAPPERS_CMATH
 
+#if __has_include_next(<cmath>)
 #include_next <cmath>
+#else
+#error "Could not find standard C++ header 'cmath'. Add -v to your compilation command to check the include paths being searched. You may need to install the appropriate standard C++ library package corresponding to the search path."
+#endif
 
 #if defined(_LIBCPP_STD_VER)