[cmake] Use separate doctrees to prevent races between Sphinx instances

Use separate doctrees between different Sphinx builders in order to
prevent race condition issues due to multiple Sphinx instances accessing
the same doctree cache in parallel.

Bug: https://llvm.org/bugs/show_bug.cgi?id=23781

Differential Revision: https://reviews.llvm.org/D23755

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283188 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/cmake/modules/AddSphinxTarget.cmake b/cmake/modules/AddSphinxTarget.cmake
index a968555aa06c1f8040c006585e69ea506544e6d9..ca9f4c38ffdb513b148a07a5890e6c7a99a18738 100644 (file)
--- a/cmake/modules/AddSphinxTarget.cmake
+++ b/cmake/modules/AddSphinxTarget.cmake
@@ -6,7 +6,7 @@
 # ``project`` should be the project name
 function (add_sphinx_target builder project)
   set(SPHINX_BUILD_DIR "${CMAKE_CURRENT_BINARY_DIR}/${builder}")
-  set(SPHINX_DOC_TREE_DIR "${CMAKE_CURRENT_BINARY_DIR}/_doctrees")
+  set(SPHINX_DOC_TREE_DIR "${CMAKE_CURRENT_BINARY_DIR}/_doctrees-${builder}")
   set(SPHINX_TARGET_NAME docs-${project}-${builder})
 
   if (SPHINX_WARNINGS_AS_ERRORS)