[PATCH] rust: enable dynamic LLVM linking by default

[sunilkumar.dora@windriver.com]

From: Sunil Dora <sunilkumar.dora@windriver.com>

Fixes [YOCTO #16058]

Enable dynamic linking with LLVM (link-shared) for all rust variants
(native, nativesdk and target) via a PACKAGECONFIG option, enabled
by default. This prevents segmentation faults when reusing sstate
artifacts built with different host toolchains.

Update multilib library symlinking to include shared libraries and
adjust the rust selftest to install llvm so the dynamically linked
compiler can run correctly.

Suggested-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Sunil Dora <sunilkumar.dora@windriver.com>
---
 meta/lib/oeqa/selftest/cases/rust.py      |  2 +-
 meta/recipes-devtools/rust/rust_1.94.0.bb | 10 ++++++----
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/meta/lib/oeqa/selftest/cases/rust.py b/meta/lib/oeqa/selftest/cases/rust.py
index 3ae1946e43..7614941661 100644
--- a/meta/lib/oeqa/selftest/cases/rust.py
+++ b/meta/lib/oeqa/selftest/cases/rust.py
@@ -47,7 +47,7 @@ class RustSelfTestSystemEmulated(OESelftestTestCase, OEPTestResultTestCase):
         bitbake("{} -c test_compile".format(recipe))
         builddir = get_bb_var("RUSTSRC", "rust")
         # build core-image-minimal with required packages
-        default_installed_packages = ["libgcc", "libstdc++", "libatomic", "libgomp", "libzstd", "openssl"]
+        default_installed_packages = ["libgcc", "libstdc++", "libatomic", "libgomp", "libzstd", "llvm", "openssl"]
         features = []
         features.append('IMAGE_FEATURES += "ssh-server-dropbear"')
         features.append('CORE_IMAGE_EXTRA_INSTALL += "{0}"'.format(" ".join(default_installed_packages)))
diff --git a/meta/recipes-devtools/rust/rust_1.94.0.bb b/meta/recipes-devtools/rust/rust_1.94.0.bb
index 2be0bd8d89..0d34a312c0 100644
--- a/meta/recipes-devtools/rust/rust_1.94.0.bb
+++ b/meta/recipes-devtools/rust/rust_1.94.0.bb
@@ -15,6 +15,9 @@ DEPENDS:append:class-nativesdk = " cargo-native rust-native"
 
 RDEPENDS:${PN}:append:class-target = " gcc g++ binutils"
 
+PACKAGECONFIG ??= "llvm-shared"
+PACKAGECONFIG[llvm-shared] = ",,,"
+
 # Otherwise we'll depend on what we provide
 INHIBIT_DEFAULT_RUST_DEPS:class-native = "1"
 # We don't need to depend on gcc-native because yocto assumes it exists
@@ -124,8 +127,7 @@ python do_configure() {
 
     # [llvm]
     config.add_section("llvm")
-    if d.getVar('PN') == "rust-native":
-        config.set("llvm", "link-shared", e(True))
+    config.set("llvm", "link-shared", e(bb.utils.contains('PACKAGECONFIG', 'llvm-shared', True, False, d)))
     config.set("llvm", "static-libstdcpp", e(False))
     config.set("llvm", "download-ci-llvm", e(False))
     if "llvm" in (d.getVar('TC_CXX_RUNTIME') or ""):
@@ -190,7 +192,7 @@ python do_configure() {
     bb.build.exec_func("setup_cargo_environment", d)
 }
 
-# llvm-config expects static libraries to be in the 'lib' directory rather than 'lib64' when
+# llvm-config expects static/dynamic libraries to be in the 'lib' directory rather than 'lib64' when
 # multilibs enabled. Since we are copying the natively built llvm-config into the target sysroot
 # and executing it there, it will default to searching in 'lib', as it is unaware of the 'lib64'
 # directory. To ensure llvm-config can locate the necessary libraries, create a symlink from 'lib'
@@ -207,7 +209,7 @@ do_compile:append:class-target() {
 
         # Only do per-file symlinking if lib is a real directory (not symlink)
         if [ -d "$lib_dir" ] && [ ! -L "$lib_dir" ]; then
-            for lib64_file in "${lib64_dir}"/libLLVM*.a; do
+            for lib64_file in "${lib64_dir}"/libLLVM*.a "${lib64_dir}"/libLLVM*.so*; do
                 if [ -e "$lib64_file" ]; then
                     lib_name=$(basename "${lib64_file}")
                     target_link="${lib_dir}/${lib_name}"
-- 
2.49.0