Support toolchain with optimization levels included in multilib configurations

CMakeLists.txt

@@ -2167,6 +2167,7 @@ if((CMAKE_BUILD_TYPE IN_LIST build_types) AND (NOT NO_BUILD_TYPE_WARNING))
       The CMake build type was set to '${CMAKE_BUILD_TYPE}', but the optimization flag was set to '${OPTIMIZATION_FLAG}'.
       This may be intentional and the warning can be turned off by setting the CMake variable 'NO_BUILD_TYPE_WARNING'"
       )
+    set(CMAKE_C_FLAGS_${CMAKE_BUILD_TYPE_uppercase} ${OPTIMIZATION_FLAG})
   endif()
 endif()
 

cmake/compiler/gcc/target.cmake

@@ -85,31 +85,19 @@ if(SYSROOT_DIR)
   list(APPEND TOOLCHAIN_C_FLAGS
     --sysroot=${SYSROOT_DIR}
     )
+endif()
 
-  # Use sysroot dir to set the libc path's
-  execute_process(
-    COMMAND ${CMAKE_C_COMPILER} ${TOOLCHAIN_C_FLAGS} --print-multi-directory
-    OUTPUT_VARIABLE NEWLIB_DIR
+# Use the compiler to find a file within the toolchain
+# This can be used to find files like crtbegin.o and crtend.o
+function(compiler_file_name file output)
+  execute_process(COMMAND ${CMAKE_C_COMPILER}
+    ${TOOLCHAIN_C_FLAGS} ${OPTIMIZATION_FLAG}
+    --print-file-name=${file}
+    OUTPUT_VARIABLE file_name
     OUTPUT_STRIP_TRAILING_WHITESPACE
     )
-
-  set(LIBC_LIBRARY_DIR "\"${SYSROOT_DIR}\"/lib/${NEWLIB_DIR}")
-endif()
-
-# This libgcc code is partially duplicated in compiler/*/target.cmake
-execute_process(
-  COMMAND ${CMAKE_C_COMPILER} ${TOOLCHAIN_C_FLAGS} --print-libgcc-file-name
-  OUTPUT_VARIABLE LIBGCC_FILE_NAME
-  OUTPUT_STRIP_TRAILING_WHITESPACE
-  )
-
-assert_exists(LIBGCC_FILE_NAME)
-
-get_filename_component(LIBGCC_DIR ${LIBGCC_FILE_NAME} DIRECTORY)
-
-assert_exists(LIBGCC_DIR)
-
-set_linker_property(PROPERTY lib_include_dir "-L\"${LIBGCC_DIR}\"")
+  set(${output} ${file_name} PARENT_SCOPE)
+endfunction()
 
 # For CMake to be able to test if a compiler flag is supported by the
 # toolchain we need to give CMake the necessary flags to compile and

cmake/linker/ld/target.cmake

@@ -155,10 +155,16 @@ macro(toolchain_linker_finalize)
 
   set(cpp_link "${common_link}")
   if(NOT "${ZEPHYR_TOOLCHAIN_VARIANT}" STREQUAL "host")
-    if(CONFIG_CPP_EXCEPTIONS AND LIBGCC_DIR)
-      # When building with C++ Exceptions, it is important that crtbegin and crtend
-      # are linked at specific locations.
-      set(cpp_link "<LINK_FLAGS> ${LIBGCC_DIR}/crtbegin.o ${link_libraries} ${LIBGCC_DIR}/crtend.o")
+    if(CONFIG_CPP_EXCEPTIONS)
+      if(LIBGCC_DIR)
+        # When building with C++ Exceptions, it is important that crtbegin and crtend
+        # are linked at specific locations.
+        set(cpp_link "<LINK_FLAGS> ${LIBGCC_DIR}/crtbegin.o ${link_libraries} ${LIBGCC_DIR}/crtend.o")
+      elseif(COMMAND compiler_file_name)
+        compiler_file_name("crtbegin.o" CRTBEGIN)
+        compiler_file_name("crtend.o" CRTEND)
+        set(cpp_link "<LINK_FLAGS> ${CRTBEGIN} ${link_libraries} ${CRTEND}")
+      endif()
     endif()
   endif()
   set(CMAKE_CXX_LINK_EXECUTABLE "<CMAKE_CXX_COMPILER> <FLAGS> <CMAKE_CXX_LINK_FLAGS> ${cpp_link}")

cmake/linker/xt-ld/target.cmake

@@ -17,8 +17,15 @@ if(CONFIG_CPP_EXCEPTIONS)
   # The location is so important that we cannot let this be controlled by normal
   # link libraries, instead we must control the link command specifically as
   # part of toolchain.
-  set(CMAKE_CXX_LINK_EXECUTABLE
+  if (LIBGCC_DIR)
+    set(CMAKE_CXX_LINK_EXECUTABLE
       "<CMAKE_CXX_COMPILER> <FLAGS> <CMAKE_CXX_LINK_FLAGS> <LINK_FLAGS> ${LIBGCC_DIR}/crtbegin.o <OBJECTS> -o <TARGET> <LINK_LIBRARIES> ${LIBGCC_DIR}/crtend.o")
+  elseif(COMMAND compiler_file_name)
+    compiler_file_name("crtbegin.o" CRTBEGIN)
+    compiler_file_name("crtend.o" CRTEND)
+    set(CMAKE_CXX_LINK_EXECUTABLE
+      "<CMAKE_CXX_COMPILER> <FLAGS> <CMAKE_CXX_LINK_FLAGS> <LINK_FLAGS> ${CRTBEGIN} <OBJECTS> -o <TARGET> <LINK_LIBRARIES> ${CRTEND}")
+  endif()
 endif()
 
 # Run $LINKER_SCRIPT file through the C preprocessor, producing ${linker_script_gen}

tests/kernel/common/testcase.yaml

@@ -47,6 +47,12 @@ tests:
     tags: picolibc
     extra_configs:
       - CONFIG_PICOLIBC=y
+  kernel.common.newlib:
+    filter: CONFIG_NEWLIB_LIBC_SUPPORTED
+    min_ram: 32
+    tags: newlib
+    extra_configs:
+      - CONFIG_NEWLIB_LIBC=y
   kernel.common.lto:
     # CONFIG_CODE_DATA_RELOCATION causes a build error (issue #69730)
     filter: CONFIG_ISR_TABLES_LOCAL_DECLARATION_SUPPORTED and not CONFIG_CODE_DATA_RELOCATION