From: Emil Velikov <emil.l.velikov@gmail.com>
Date: Wed, 9 Oct 2024 15:26:25 +0000 (+0100)
Subject: Add support for clang sanitizers
X-Git-Tag: v34~214
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f5b4ff82f45af668cb4d62043184829b1e9621cb;p=thirdparty%2Fkmod.git

Add support for clang sanitizers

By default clang uses static sanitizer libraries, which causes build and
test-time failures. Swap for the shared libasan which resolves both.

Note: meson tries to be helpful here, throwing a warning that we should
use -D b_lundef=false which is incorrect in our case.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://github.com/kmod-project/kmod/pull/172
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>
---

diff --git a/meson.build b/meson.build
index 9a14195d..c4eb57dd 100644
--- a/meson.build
+++ b/meson.build
@@ -159,6 +159,17 @@ add_project_link_arguments(
   language : 'c'
 )
 
+# Clang as of v18, relies on statically linking the sanitizers. This causes two
+# distinct issues:
+#  - the shared library is underlinked, so the build fails
+#  - the modules (that we dlopen/ld_preload) are underlinked so the tests fail
+#
+# Force shared libasan (GCC defaults to shared and this toggle doesn't exist),
+# which combined with the LD_PRELOAD in our wrapper makes everything happy.
+if get_option('b_sanitize') != 'none' and cc.get_id() == 'clang'
+  add_project_arguments('-shared-libasan', language : 'c')
+  add_project_link_arguments('-shared-libasan', language : 'c')
+endif
 ################################################################################
 # Options
 ################################################################################
diff --git a/scripts/sanitizer-env.sh b/scripts/sanitizer-env.sh
index 9c759a82..dc1103df 100755
--- a/scripts/sanitizer-env.sh
+++ b/scripts/sanitizer-env.sh
@@ -2,7 +2,16 @@
 
 # set -euo pipefail # don't set these, since this script is sourced
 
-OUR_PRELOAD=$(gcc -print-file-name=libasan.so)
+if [[ ${CC-} == *gcc* ]]; then
+    OUR_PRELOAD=$("$CC" -print-file-name=libasan.so)
+elif [[ ${CC-} == *clang* ]]; then
+    OUR_PRELOAD=$("$CC" -print-file-name=libclang_rt.asan-x86_64.so)
+else
+    echo "Unknown compiler CC=\"${CC-}\" - gcc and clang are supported."
+    echo "Assuming \"gcc\", manually set the variable and retry if needed."
+    echo
+    OUR_PRELOAD=$(gcc -print-file-name=libasan.so)
+fi
 
 if test -n "$OUR_PRELOAD"; then
     # In some cases, like in Fedora, the file is a script which cannot be