From dcf167e612f8497166401070ecea3e2b9d2971f8 Mon Sep 17 00:00:00 2001
From: Petr Bred <bredpetr@gmail.com>
Date: Mon, 5 Feb 2018 12:23:33 +0300
Subject: [PATCH] [Linux] Auto-detect clang version 	- Auto-detect if there
 is clang symlink and version is not specified 	- Remove hardcode clang
 version from msbuild file

Signed-off-by: Petr Bred <bredpetr@gmail.com>
---
 buildscripts/buildvars-setup.sh               | 22 +++++++++++++++++++
 .../Microsoft.NETCore.Native.Unix.props       |  2 ++
 2 files changed, 24 insertions(+)

diff --git a/buildscripts/buildvars-setup.sh b/buildscripts/buildvars-setup.sh
index 4b2fd8f12b8..835c03ebca9 100755
--- a/buildscripts/buildvars-setup.sh
+++ b/buildscripts/buildvars-setup.sh
@@ -109,6 +109,12 @@ export __CrossBuild=0
 
 __BuildArch=$__HostArch
 
+# Checking for any clang versions, if there is a symlink
+if [ -x "$(command -v clang)" ]; then
+    __ClangMajorVersion="$(echo | clang -dM -E - | grep __clang_major__ | cut -f3 -d ' ')"
+    __ClangMinorVersion="$(echo | clang -dM -E - | grep __clang_minor__ | cut -f3 -d ' ')"
+fi
+
 while [ "$1" != "" ]; do
         lowerI="$(echo $1 | awk '{print tolower($0)}')"
         case $lowerI in
@@ -171,6 +177,22 @@ while [ "$1" != "" ]; do
             export __ClangMajorVersion=3
             export __ClangMinorVersion=9
             ;;
+        clang4.0)
+            export __ClangMajorVersion=4
+            export __ClangMinorVersion=0
+            ;;
+        clang5.0)
+            export __ClangMajorVersion=5
+            export __ClangMinorVersion=0
+            ;;
+        clang6.0)
+            export __ClangMajorVersion=6
+            export __ClangMinorVersion=0
+            ;;
+        clang7.0)
+            export __ClangMajorVersion=7
+            export __ClangMinorVersion=0
+            ;;
         cross)
             export __CrossBuild=1
             ;;
diff --git a/src/BuildIntegration/Microsoft.NETCore.Native.Unix.props b/src/BuildIntegration/Microsoft.NETCore.Native.Unix.props
index 441f4754c40..20f76484753 100644
--- a/src/BuildIntegration/Microsoft.NETCore.Native.Unix.props
+++ b/src/BuildIntegration/Microsoft.NETCore.Native.Unix.props
@@ -16,6 +16,7 @@ See the LICENSE file in the project root for more information.
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
     <CppCompilerAndLinker Condition="'$(CppCompilerAndLinker)' == '' and '$(TargetOS)' == 'OSX'">clang</CppCompilerAndLinker>
+    <CppCompilerAndLinker Condition="'$(CppCompilerAndLinker)' == '' and '$(TargetOS)' == 'Linux' and '$(__ClangMajorVersion)' != '' and $(__ClangMinorVersion) != ''">clang-$(__ClangMajorVersion).$(__ClangMinorVersion)</CppCompilerAndLinker>
     <CppCompilerAndLinker Condition="'$(CppCompilerAndLinker)' == ''">clang-3.9</CppCompilerAndLinker>
     <CppCompiler>$(CppCompilerAndLinker)</CppCompiler>
     <CppLinker>$(CppCompilerAndLinker)</CppLinker>
@@ -26,6 +27,7 @@ See the LICENSE file in the project root for more information.
   <!-- Ensure that runtime-specific paths have already been set -->
   <PropertyGroup>
     <CppCompilerAndLinker Condition="'$(CppCompilerAndLinker)' == '' and '$(TargetOS)' == 'OSX'">clang</CppCompilerAndLinker>
+    <CppCompilerAndLinker Condition="'$(CppCompilerAndLinker)' == '' and '$(TargetOS)' == 'Linux' and '$(__ClangMajorVersion)' != '' and $(__ClangMinorVersion) != ''">clang-$(__ClangMajorVersion).$(__ClangMinorVersion)</CppCompilerAndLinker>
     <CppCompilerAndLinker Condition="'$(CppCompilerAndLinker)' == ''">clang-3.9</CppCompilerAndLinker>
     <CppCompiler>$(CppCompilerAndLinker)</CppCompiler>
     <CppLinker>$(CppCompilerAndLinker)</CppLinker>