clang: allow to set CLANG_EXTRA_OE_VENDORS to support custom TARGET_VENDOR value

* instead of hardcoding only yoe, poky, wrs in the patch, add just placeholder
  string which gets replaced with a list based on CLANG_EXTRA_OE_VENDORS variable
  in llvm-project-source.inc:add_more_target_vendors

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/README.md b/README.md
index 1ee28ae..826b8b3 100644
--- a/README.md
+++ b/README.md
@@ -130,6 +130,40 @@ if a component does not build with libc++, you can add it to `conf/nonclangable.
 CXX_remove_pn-<recipe>_toolchain-clang = " -stdlib=libc++ "
 ```
 
+# compiler-rt failing in do_configure with custom TARGET_VENDOR
+
+If your DISTRO sets own value of TARGET_VENDOR, then it's need to be added in
+CLANG_EXTRA_OE_VENDORS, it should be done automatically, but if compiler-rt fails
+like bellow, then check the end of work-shared/llvm-project-source-12.0.0-r0/temp/log.do_patch
+is should have line like:
+NOTE: Adding support following TARGET_VENDOR values: foo in
+  /OE/build/oe-core/tmp-glibc/work-shared/llvm-project-source-12.0.0-r0/git/llvm/lib/Support/Triple.cpp and
+  /OE/build/oe-core/tmp-glibc/work-shared/llvm-project-source-12.0.0-r0/git/clang/lib/Driver/ToolChains/Gnu.cpp
+and check these files if //CLANG_EXTRA_OE_VENDORS* strings were replaced correctly.
+Read add_more_target_vendors function in recipes-devtools/clang/llvm-project-source.inc for more details.
+
+http://errors.yoctoproject.org/Errors/Details/574365/
+```shell
+-- Found assembler: TOPDIR/tmp-glibc/work/core2-64-foo-linux/compiler-rt/12.0.0-r0/recipe-sysroot-native/usr/bin/x86_64-foo-linux/x86_64-foo-linux-clang
+-- Detecting C compiler ABI info
+-- Detecting C compiler ABI info - failed
+-- Check for working C compiler: TOPDIR/tmp-glibc/work/core2-64-foo-linux/compiler-rt/12.0.0-r0/recipe-sysroot-native/usr/bin/x86_64-foo-linux/x86_64-foo-linux-clang
+-- Check for working C compiler: TOPDIR/tmp-glibc/work/core2-64-foo-linux/compiler-rt/12.0.0-r0/recipe-sysroot-native/usr/bin/x86_64-foo-linux/x86_64-foo-linux-clang - broken
+CMake Error at TOPDIR/tmp-glibc/work/core2-64-foo-linux/compiler-rt/12.0.0-r0/recipe-sysroot-native/usr/share/cmake-3.19/Modules/CMakeTestCCompiler.cmake:66 (message):
+  The C compiler
+
+    "TOPDIR/tmp-glibc/work/core2-64-foo-linux/compiler-rt/12.0.0-r0/recipe-sysroot-native/usr/bin/x86_64-foo-linux/x86_64-foo-linux-clang"
+
+  is not able to compile a simple test program.
+
+  It fails with the following output:
+
+    Change Dir: TOPDIR/tmp-glibc/work/core2-64-foo-linux/compiler-rt/12.0.0-r0/build/CMakeFiles/CMakeTmp
+
+    Run Build Command(s):ninja cmTC_928f4 && [1/2] Building C object CMakeFiles/cmTC_928f4.dir/testCCompiler.c.o
+    [2/2] Linking C executable cmTC_928f4
+```
+
 # Dependencies
 
 ```shell