cmake: libc: minimal: Avoid linking against other libc implementations #79629
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The minimal libc is currently built as a zephyr_library and will be included in the final link line as such. However, the c_library property will still be set as "-lc" (for most linkers) and will be added to the link line. This effectively requires that a separate libc implementation be available in the toolchain and makes it possible to accidentally pull from the non-minimal libc. This doesn't seem desirable, so try to prevent this by clearing the c_library property if we are using the minimal libc. Signed-off-by: Jonathon Penix <jpenix@quicinc.com>
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| # SPDX-License-Identifier: Apache-2.0 | |||
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| # As minimal libc will be built as a zephyr_library, clear c_library to | |||
| # prevent accidentally requiring or linking against another libc implementation. | |||
| set_property(TARGET linker PROPERTY c_library "") | |||
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One other idea was to modify link_order_library in the various linker_libraries.cmake files to omit c if we're building with CONFIG_MINIMAL_LIBC. That did seem to work (and seems analogous to what was done for CONFIG_MINIMAL_LIBCPP), but this was a smaller change (and is somewhat similar to what is done for picolibc-as-a-module) so I ended up doing this instead--not sure if one is better than the other otherwise or if there is something entirely different that would be preferred!
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You probably need to also change math_library and c++_library to make sure we don't mix other incompatible bits. This way we'll get a build error rather than a runtime error.
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requested review from
aescolar,
cfriedt,
keith-packard,
nashif and
stephanosio
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I'm not able to add reviewers, but please take a look @tejlmand too if possible! |
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Gentle ping |
The minimal libc is currently built as a zephyr_library and will be included in the final link line as such. However, the c_library property will still be set as "-lc" (for most linkers) and will be added to the link line. This effectively requires that a separate libc implementation be available in the toolchain and makes it possible to accidentally pull from the non-minimal libc.
This doesn't seem desirable, so try to prevent this by clearing the c_library property if we are using the minimal libc.