cmake: linker: separate toolchain_ld_options() calls for grouped flags

Fixes #91045

Adding NO_SPLIT in the TOOLCHAIN_LD_FLAGS list caused every flags in the
list to be checked together by the linker. This caused issues where
incompatible flags was passed together, and the result was that none was
propagated to the linker.

By using separate variables, we can achieve the initial goal of NO_SPLIT to
only group a sub-set of flags.

Signed-off-by: Pierrick Guillaume <pguillaume@fymyte.com>

Author: Fymyte

CMakeLists.txt

@@ -403,6 +403,12 @@ if(DEFINED TOOLCHAIN_LD_FLAGS)
   zephyr_ld_options(${TOOLCHAIN_LD_FLAGS})
 endif()
 
+if(DEFINED TOOLCHAIN_GROUPED_LD_FLAGS)
+  foreach(GROUPED_FLAGS IN LISTS TOOLCHAIN_GROUPED_LD_FLAGS)
+    zephyr_ld_options(NO_SPLIT ${${GROUPED_FLAGS}})
+  endforeach()
+endif()
+
 zephyr_link_libraries(PROPERTY base)
 
 zephyr_link_libraries_ifndef(CONFIG_LINKER_USE_RELAX PROPERTY no_relax)

cmake/compiler/clang/target_arm.cmake

@@ -39,4 +39,4 @@ if(CONFIG_FP16)
   endif()
 endif()
 list(APPEND TOOLCHAIN_C_FLAGS ${ARM_C_FLAGS})
-list(APPEND TOOLCHAIN_LD_FLAGS NO_SPLIT ${ARM_C_FLAGS})
+list(APPEND TOOLCHAIN_GROUPED_LD_FLAGS ARM_C_FLAGS)

cmake/compiler/gcc/target_arm.cmake

@@ -45,7 +45,7 @@ if(CONFIG_THREAD_LOCAL_STORAGE)
 endif()
 
 list(APPEND TOOLCHAIN_C_FLAGS ${ARM_C_FLAGS})
-list(APPEND TOOLCHAIN_LD_FLAGS NO_SPLIT ${ARM_C_FLAGS})
+list(APPEND TOOLCHAIN_GROUPED_LD_FLAGS ARM_C_FLAGS)
 
 # Flags not supported by llext linker
 # (regexps are supported and match whole word)

cmake/compiler/gcc/target_riscv.cmake

@@ -87,7 +87,8 @@ if(CONFIG_RISCV_ISA_EXT_ZMMUL AND
 endif()
 
 list(APPEND TOOLCHAIN_C_FLAGS -mabi=${riscv_mabi} -march=${riscv_march})
-list(APPEND TOOLCHAIN_LD_FLAGS NO_SPLIT -mabi=${riscv_mabi} -march=${riscv_march})
+list(APPEND RISCV_LD_FLAGS -mabi=${riscv_mabi} -march=${riscv_march})
+list(APPEND TOOLCHAIN_GROUPED_LD_FLAGS RISCV_LD_FLAGS)
 
 # Flags not supported by llext linker
 # (regexps are supported and match whole word)