diff mbox series

classes/cmake: unset LDFLAGS in toolchain-native.bbclass

Message ID 20250926131041.3342321-1-ross.burton@arm.com
State New
Headers show
Series classes/cmake: unset LDFLAGS in toolchain-native.bbclass | expand

Commit Message

Ross Burton Sept. 26, 2025, 1:10 p.m. UTC 
If a recipe is using toolchain-native.cmake to build native portion in a
non-native build, the target LDFLAGS from the environment will leak into
the native build.

This was noticed as building a SDK with clang means that LDFLAGS contains
a --dynamic-loader argument, so native binaries were trying to use the
target loader.

There are several variables that are set from LDFLAGS[1] so instead of
setting them all, we can simply unset the environment variable in the
toolchain.

[1] https://cmake.org/cmake/help/latest/envvar/LDFLAGS.html

Signed-off-by: Ross Burton <ross.burton@arm.com>
---
 meta/classes-recipe/cmake.bbclass | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/meta/classes-recipe/cmake.bbclass b/meta/classes-recipe/cmake.bbclass
index 2c83056273b..4f59966521e 100644
--- a/meta/classes-recipe/cmake.bbclass
+++ b/meta/classes-recipe/cmake.bbclass
@@ -212,11 +212,14 @@  set( CMAKE_LIBRARY_PATH ${STAGING_BASE_LIBDIR_NATIVE} ${STAGING_LIBDIR_NATIVE})
 list(APPEND CMAKE_C_IMPLICIT_INCLUDE_DIRECTORIES ${STAGING_INCDIR_NATIVE})
 list(APPEND CMAKE_CXX_IMPLICIT_INCLUDE_DIRECTORIES ${STAGING_INCDIR_NATIVE})
 
-# We need to be sure that the environment variables exported by bitbake.conf
-# which are for the _target_ build are not respected, as otherwise you can
-# end up mixing native and target flags.
+# The assignmens above override CFLAGS and CXXFLAGS from the environment but
+# not LDFLAGS, which ends up in CMAKE_EXE_LINKER_FLAGS. This then means our
+# native builds use target flags, and can fail.
 #
-# https://cmake.org/cmake/help/latest/manual/cmake-env-variables.7.html#environment-variables-for-languages
+# As there are a number of variables that are set from LDFLAGS,
+# clear it at source.
+#
+# https://cmake.org/cmake/help/latest/envvar/LDFLAGS.html
 unset(ENV{LDFLAGS})
 EOF
 }