From 1f68002cb725c6a8fb5ca8425c1c86495a053f4f Mon Sep 17 00:00:00 2001
From: Michal Gorny <mgorny@gentoo.org>
Date: Thu, 4 Apr 2019 14:21:38 +0000
Subject: [PATCH] [llvm] [cmake] Add additional headers only if they exist

Modify the add_header_files_for_glob() function to only add files
that do exist, rather than all matches of the glob.  This fixes CMake
error when one of the include directories (which happen to include
/usr/include) contain broken symlinks.

Differential Revision: https://reviews.llvm.org/D59632

llvm-svn: 357701
---
 llvm/cmake/modules/LLVMProcessSources.cmake | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/cmake/modules/LLVMProcessSources.cmake b/cmake/modules/LLVMProcessSources.cmake
index 7cbd2863500..d0be0e8b3ba 100644
--- a/src/llvm-project/llvm/cmake/modules/LLVMProcessSources.cmake
+++ b/src/llvm-project/llvm/cmake/modules/LLVMProcessSources.cmake
@@ -30,7 +30,15 @@ endmacro(add_td_sources)

 function(add_header_files_for_glob hdrs_out glob)
   file(GLOB hds ${glob})
-  set(${hdrs_out} ${hds} PARENT_SCOPE)
+  set(filtered)
+  foreach(file ${hds})
+    # Explicit existence check is necessary to filter dangling symlinks
+    # out.  See https://bugs.gentoo.org/674662.
+    if(EXISTS ${file})
+      list(APPEND filtered ${file})
+    endif()
+  endforeach()
+  set(${hdrs_out} ${filtered} PARENT_SCOPE)
 endfunction(add_header_files_for_glob)

 function(find_all_header_files hdrs_out additional_headerdirs)
--
2.21.0