From: Peter Collingbourne <peter@pcc.me.uk>
Date: Thu, 27 Apr 2017 17:04:05 +0000 (+0000)
Subject: cmake: Touch $GIT_DIR/logs/HEAD if it does not already exist.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=5cb8f643275d9766cbeac525e2dafda672ec7c3f;p=llvm

cmake: Touch $GIT_DIR/logs/HEAD if it does not already exist.

Apparently some git tools (such as "repo") may not create this file.
Patch by Quentin Neill.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301565 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/Support/CMakeLists.txt b/include/llvm/Support/CMakeLists.txt
index b4b99370574..825052171cd 100644
--- a/include/llvm/Support/CMakeLists.txt
+++ b/include/llvm/Support/CMakeLists.txt
@@ -18,6 +18,10 @@ macro(find_first_existing_vc_file out_var path)
   if(git_result EQUAL 0)
     string(STRIP "${git_dir}" git_dir)
     set(${out_var} "${git_dir}/logs/HEAD")
+    # some branchless cases (e.g. 'repo') may not yet have .git/logs/HEAD
+    if (NOT EXISTS "${git_dir}/logs/HEAD")
+      file(WRITE "${git_dir}/logs/HEAD" "")
+    endif()
   else()
     find_first_existing_file(${out_var}
       "${path}/.svn/wc.db"   # SVN 1.7