Revert "clang: Do not provide llvm-native implicitly"

This reverts commit 384e8d169a2c408e2cef03ea2deb88fb82058011.

The original commit removed the implicit PROVIDES declarations for llvm,
llvm-native, and nativesdk-llvm from the clang recipe.

However, this change breaks builds in kirkstone-clang18 environments, where
mesa and lib32-llvm expect these to be provided by clang:

- Mesa fails due to missing providers for llvm18.1.6 and nativesdk-llvm18.1.6.
- lib32-llvm 13.0.1 fails on ARM BSPs with the following error, falling back to
  the core layer's outdated LLVM:

    error: 'RegVT' was not declared in this scope

This commit was backported from scarthgap, but it is incompatible with oe-core
expectations in the kirkstone branch. Reverting it restores compatibility.

Signed-off-by: Haixiao Yan <haixiao.yan.cn@windriver.com>

3 files changed, 6 insertions, 14 deletions

diff --git a/README.md b/README.md
index 599237c..3683fe5 100644
--- a/README.md
+++ b/README.md
@@ -57,20 +57,6 @@ TOOLCHAIN = "clang"
 also look at `conf/nonclangable.conf` for list of recipes which do not yet fully
 build with clang.
 
-# Providing LLVM
-
-clang recipes can provide llvm and related packages too, it might be worth using single
-provider for llvm and clang to save some compile time and space, select the knobs
-to point to clang, default is to use the version provided by core layer.
-
-```shell
-PREFERRED_PROVIDER_llvm = "clang"
-PREFERRED_PROVIDER_llvm-native = "clang-native"
-PREFERRED_PROVIDER_nativesdk-llvm = "nativesdk-clang"
-PROVIDES:pn-clang = "llvm"
-PROVIDES:pn-clang-native = "llvm-native"
-PROVIDES:pn-nativesdk-clang = "nativesdk-llvm"
-```
 # Default Compiler Runtime
 
 Default is to use GNU runtime `TC_CXX_RUNTIME = "gnu"` which consists of libgcc, libstdc++ to provide C/C++
diff --git a/conf/layer.conf b/conf/layer.conf
index 3cf7fc3..0e2caec 100644
--- a/conf/layer.conf
+++ b/conf/layer.conf
@@ -27,6 +27,9 @@ BBFILES_DYNAMIC += " \
 
 PREFERRED_PROVIDER_libgcc-initial = "libgcc-initial"
 #PREFERRED_PROVIDER_virtual/${TARGET_PREFIX}compilerlibs_forcevariable = "libcxx"
+PREFERRED_PROVIDER_llvm = "clang"
+PREFERRED_PROVIDER_llvm-native = "clang-native"
+PREFERRED_PROVIDER_nativesdk-llvm = "nativesdk-clang"
 PREFERRED_PROVIDER_libunwind = "${@bb.utils.contains_any("TC_CXX_RUNTIME", "llvm android", "libcxx", "libunwind", d)}"
 INHERIT += "clang"
 
diff --git a/recipes-devtools/clang/clang_git.bb b/recipes-devtools/clang/clang_git.bb
index cf4456c..096b11a 100644
--- a/recipes-devtools/clang/clang_git.bb
+++ b/recipes-devtools/clang/clang_git.bb
@@ -287,6 +287,9 @@ do_install:append:class-nativesdk () {
 PACKAGES =+ "${PN}-libllvm ${PN}-lldb-python ${PN}-libclang-cpp ${PN}-tidy ${PN}-format ${PN}-tools \
              libclang lldb lldb-server liblldb llvm-linker-tools"
 
+PROVIDES += "llvm llvm${PV}"
+PROVIDES:append:class-native = " llvm-native"
+
 BBCLASSEXTEND = "native nativesdk"
 
 RDEPENDS:lldb += "${PN}-lldb-python lldb-server"