cmake: define linker argument for undefined symbol

Specifying undefined symbol on linker invocation requests the linker to
search and include the symbol.
This ensures the symbol will be present in final output.

Signed-off-by: Torsten Rasmussen <[email protected]>

Author: tejlmand

arch/common/CMakeLists.txt

@@ -109,6 +109,9 @@ if (CONFIG_GEN_ISR_TABLES)
   add_dependencies(isr_tables zephyr_generated_headers)
   target_link_libraries(isr_tables zephyr_interface)
   zephyr_library_link_libraries(isr_tables)
+
+  zephyr_link_libraries($<TARGET_PROPERTY:linker,undefined>_sw_isr_table)
+  zephyr_link_libraries($<TARGET_PROPERTY:linker,undefined>_irq_vector_table)
 endif()
 
 if(CONFIG_COVERAGE)

cmake/linker/arcmwdt/linker_flags.cmake

@@ -41,6 +41,8 @@ check_set_linker_property(TARGET linker PROPERTY orphan_error
                           ${LINKERFLAGPREFIX},--orphan-handling=error
 )
 
+check_set_linker_property(TARGET linker PROPERTY undefined ${LINKERFLAGPREFIX},-u)
+
 set_property(TARGET linker PROPERTY partial_linking "-r")
 
 # Extra warnings options for twister run

cmake/linker/armlink/linker_flags.cmake

@@ -0,0 +1,5 @@
+# Copyright (c) 2025 Nordic Semiconductor
+#
+# SPDX-License-Identifier: Apache-2.0
+
+set_property(TARGET linker PROPERTY undefined --undefined=)

cmake/linker/iar/linker_flags.cmake

@@ -23,6 +23,7 @@ set_property(TARGET linker PROPERTY optimization_speed --entry_list_in_address_o
 set_property(TARGET linker PROPERTY optimization_size --entry_list_in_address_order)
 set_property(TARGET linker PROPERTY optimization_size_aggressive --entry_list_in_address_order)
 
+set_linker_property(TARGET linker PROPERTY undefined "--keep;")
 
 string(APPEND CMAKE_C_LINK_FLAGS --no-wrap-diagnostics)
 

cmake/linker/ld/linker_flags.cmake

@@ -22,6 +22,8 @@ check_set_linker_property(TARGET linker PROPERTY orphan_error
                           ${LINKERFLAGPREFIX},--orphan-handling=error
 )
 
+set_property(TARGET linker PROPERTY undefined ${LINKERFLAGPREFIX},--undefined=)
+
 check_set_linker_property(TARGET linker PROPERTY memusage "${LINKERFLAGPREFIX},--print-memory-usage")
 
 check_set_linker_property(TARGET linker PROPERTY sanitizer_undefined -fsanitize=undefined)

cmake/linker/xt-ld/linker_flags.cmake

@@ -34,3 +34,5 @@ check_set_linker_property(TARGET linker PROPERTY sort_alignment
                           ${LINKERFLAGPREFIX},--sort-common=descending
                           ${LINKERFLAGPREFIX},--sort-section=alignment
 )
+
+set_property(TARGET linker PROPERTY undefined ${LINKERFLAGPREFIX},--undefined=)