nrfconnect · carlescufi · Dec 4, 2024 · Dec 4, 2024 · Dec 4, 2024 · Dec 4, 2024
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -1617,10 +1617,9 @@ list(APPEND
 )
 list(APPEND post_build_byproducts ${KERNEL_MAP_NAME})
 
-if(NOT CONFIG_BUILD_NO_GAP_FILL)
-  # Use ';' as separator to get proper space in resulting command.
-  set(GAP_FILL "$<TARGET_PROPERTY:bintools,elfconvert_flag_gapfill>0xff")
-endif()
+# Use ';' as separator to get proper space in resulting command.
+set(gap_fill_prop "$<TARGET_PROPERTY:bintools,elfconvert_flag_gapfill>")
+set(gap_fill "$<$<BOOL:${gap_fill_prop}>:${gap_fill_prop}${CONFIG_BUILD_GAP_FILL_PATTERN}>")
 
 if(CONFIG_OUTPUT_PRINT_MEMORY_USAGE)
   target_link_libraries(${logical_target_for_zephyr_elf} $<TARGET_PROPERTY:linker,memusage>)
@@ -1681,7 +1680,7 @@ if(CONFIG_BUILD_OUTPUT_HEX OR BOARD_FLASH_RUNNER STREQUAL openocd)
       post_build_commands
       COMMAND $<TARGET_PROPERTY:bintools,elfconvert_command>
               $<TARGET_PROPERTY:bintools,elfconvert_flag>
-              ${GAP_FILL}
+              $<$<BOOL:${CONFIG_BUILD_OUTPUT_HEX_GAP_FILL}>:${gap_fill}>
               $<TARGET_PROPERTY:bintools,elfconvert_flag_outtarget>ihex
               ${remove_sections_argument_list}
               $<TARGET_PROPERTY:bintools,elfconvert_flag_infile>${KERNEL_ELF_NAME}
@@ -1703,7 +1702,7 @@ if(CONFIG_BUILD_OUTPUT_BIN)
       post_build_commands
       COMMAND $<TARGET_PROPERTY:bintools,elfconvert_command>
               $<TARGET_PROPERTY:bintools,elfconvert_flag>
-              ${GAP_FILL}
+              ${gap_fill}
               $<TARGET_PROPERTY:bintools,elfconvert_flag_outtarget>binary
               ${remove_sections_argument_list}
               $<TARGET_PROPERTY:bintools,elfconvert_flag_infile>${KERNEL_ELF_NAME}
@@ -1790,7 +1789,7 @@ if(CONFIG_BUILD_OUTPUT_S19)
       post_build_commands
       COMMAND $<TARGET_PROPERTY:bintools,elfconvert_command>
               $<TARGET_PROPERTY:bintools,elfconvert_flag>
-              ${GAP_FILL}
+              $<$<BOOL:${CONFIG_BUILD_OUTPUT_S19_GAP_FILL}>:${gap_fill}>
               $<TARGET_PROPERTY:bintools,elfconvert_flag_outtarget>srec
               $<TARGET_PROPERTY:bintools,elfconvert_flag_srec_len>1
               $<TARGET_PROPERTY:bintools,elfconvert_flag_infile>${KERNEL_ELF_NAME}
@@ -2233,6 +2232,8 @@ add_subdirectory_ifdef(
   cmake/makefile_exports
   )
 
+toolchain_linker_finalize()
+
 yaml_context(EXISTS NAME build_info result)
 if(result)
   build_info(zephyr version VALUE ${PROJECT_VERSION_STR})

diff --git a/Kconfig.zephyr b/Kconfig.zephyr
@@ -706,15 +706,34 @@ config CLEANUP_INTERMEDIATE_FILES
 	  from the build process. Note this breaks incremental builds, west spdx
 	  (Software Bill of Material generation), and maybe others.
 
+config BUILD_GAP_FILL_PATTERN
+	hex "Gap fill pattern"
+	default 0xFF
+	help
+	  Pattern used for gap filling of output files.
+	  This value should be set to the value of a clean flash as this can
+	  significantly reduce flash write times.
+	  This setting only defines the gap fill pattern and doesn't enable gap
+	  filling.
+	  Note: binary files are always gap filled as they contain no address
+	  information.
+
 config BUILD_NO_GAP_FILL
-	bool "Don't fill gaps in generated hex/bin/s19 files."
+	bool "Don't fill gaps in generated hex/s19 files [DEPRECATED]."
+	select DEPRECATED
 
 config BUILD_OUTPUT_HEX
 	bool "Build a binary in HEX format"
 	help
 	  Build an Intel HEX binary zephyr/zephyr.hex in the build directory.
 	  The name of this file can be customized with CONFIG_KERNEL_BIN_NAME.
 
+config BUILD_OUTPUT_HEX_GAP_FILL
+	bool "Fill gaps in hex files"
+	depends on !BUILD_NO_GAP_FILL
+	help
+	  Fill gaps in hex based files.
+
 config BUILD_OUTPUT_BIN
 	bool "Build a binary in BIN format"
 	default y
@@ -749,6 +768,12 @@ config BUILD_OUTPUT_S19
 	  Build an S19 binary zephyr/zephyr.s19 in the build directory.
 	  The name of this file can be customized with CONFIG_KERNEL_BIN_NAME.
 
+config BUILD_OUTPUT_S19_GAP_FILL
+	bool "Fill gaps in s19 files"
+	depends on !BUILD_NO_GAP_FILL
+	help
+	  Fill gaps in s19 based files.
+
 config BUILD_OUTPUT_UF2
 	bool "Build a binary in UF2 format"
 	depends on BUILD_OUTPUT_BIN

diff --git a/cmake/bintools/llvm/target_bintools.cmake b/cmake/bintools/llvm/target_bintools.cmake
@@ -44,11 +44,8 @@ set_property(TARGET bintools PROPERTY elfconvert_flag_section_remove "--remove-s
 set_property(TARGET bintools PROPERTY elfconvert_flag_section_only "--only-section=")
 set_property(TARGET bintools PROPERTY elfconvert_flag_section_rename "--rename-section;")
 
-# Note, placing a ';' at the end results in the following param  to be a list,
-# and hence space separated.
-# Thus the command line argument becomes:
-# `--gap-file <value>` instead of `--gap-fill<value>` (The latter would result in an error)
-set_property(TARGET bintools PROPERTY elfconvert_flag_gapfill "--gap-fill;")
+# llvm-objcopy doesn't support gap fill argument.
+set_property(TARGET bintools PROPERTY elfconvert_flag_gapfill "")
 set_property(TARGET bintools PROPERTY elfconvert_flag_srec_len "--srec-len=")
 
 set_property(TARGET bintools PROPERTY elfconvert_flag_infile "")

diff --git a/cmake/compiler/clang/compiler_flags.cmake b/cmake/compiler/clang/compiler_flags.cmake
@@ -125,3 +125,5 @@ set_compiler_property(PROPERTY warning_error_coding_guideline
 )
 
 set_compiler_property(PROPERTY no_global_merge "-mno-global-merge")
+
+set_compiler_property(PROPERTY specs)
diff --git a/cmake/compiler/clang/target.cmake b/cmake/compiler/clang/target.cmake
@@ -64,6 +64,42 @@ if(NOT "${ARCH}" STREQUAL "posix")
     endif()
   endif()
 
+  # LLVM will use a default sysroot for selection of the C library. The default
+  # C library sysroot was defined at built time of clang/LLVM.
+  #
+  # For example, LLVM for Arm comes pre-built with Picolibc, and thus no flags
+  # are required for selecting Picolibc.
+  #
+  # Other clang/LLVM distributions may come with other pre-built C libraries.
+  # clang/LLVM supports using an alternative C library, either by direct linking,
+  # or by specifying '--sysroot <path>'.
+  #
+  # LLVM for Arm provides a 'newlib.cfg' file for newlib C selection.
+  # Let us support this principle by looking for a dedicated 'newlib.cfg' or
+  # 'picolibc.cfg' and specify '--config <spec>.cfg' if such a file is found.
+  # If no cfg-file matching the chosen C implementation, then we assume that the
+  # chosen C implementation is identical to the default C library used be the
+  # toolchain.
+  if(CONFIG_NEWLIB_LIBC)
+    file(GLOB_RECURSE newlib_cfg ${LLVM_TOOLCHAIN_PATH}/newlib.cfg)
+    if(newlib_cfg)
+      list(GET newlib_cfg 0 newlib_cfg)
+      set_linker_property(PROPERTY c_library "--config=${newlib_cfg};-lc")
+      list(APPEND CMAKE_REQUIRED_FLAGS --config=${newlib_cfg})
+      list(APPEND TOOLCHAIN_C_FLAGS --config=${newlib_cfg})
+    endif()
+  endif()
+
+  if(CONFIG_PICOLIBC)
+    file(GLOB_RECURSE picolibc_cfg ${LLVM_TOOLCHAIN_PATH}/picolibc.cfg)
+    if(picolibc_cfg)
+      list(GET picolibc_cfg 0 picolibc_cfg)
+      set_linker_property(PROPERTY c_library "--config=${picolibc_cfg};-lc")
+      list(APPEND CMAKE_REQUIRED_FLAGS --config=${picolibc_cfg})
+      list(APPEND TOOLCHAIN_C_FLAGS --config=${picolibc_cfg})
+    endif()
+  endif()
+
   # This libgcc code is partially duplicated in compiler/*/target.cmake
   execute_process(
     COMMAND ${CMAKE_C_COMPILER} ${clang_target_flag} ${TOOLCHAIN_C_FLAGS}
@@ -76,8 +112,8 @@ if(NOT "${ARCH}" STREQUAL "posix")
   get_filename_component(RTLIB_NAME_WITH_PREFIX ${RTLIB_FILE_NAME} NAME_WLE)
   string(REPLACE lib "" RTLIB_NAME ${RTLIB_NAME_WITH_PREFIX})
 
-  list(APPEND LIB_INCLUDE_DIR -L${RTLIB_DIR})
-  list(APPEND TOOLCHAIN_LIBS ${RTLIB_NAME})
+  set_property(TARGET linker PROPERTY lib_include_dir "-L${RTLIB_DIR}")
+  set_property(TARGET linker PROPERTY rt_library "-l${RTLIB_NAME}")
 
   list(APPEND CMAKE_REQUIRED_FLAGS -nostartfiles -nostdlib ${isystem_include_flags})
   string(REPLACE ";" " " CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")

diff --git a/cmake/compiler/compiler_flags_template.cmake b/cmake/compiler/compiler_flags_template.cmake
@@ -139,3 +139,7 @@ set_compiler_property(PROPERTY warning_shadow_variables)
 # Compiler flags to avoid recognizing built-in functions
 set_compiler_property(PROPERTY no_builtin)
 set_compiler_property(PROPERTY no_builtin_malloc)
+
+# Compiler flag for defining specs. Used only by gcc, other compilers may keep
+# this undefined.
+set_compiler_property(PROPERTY specs)
diff --git a/cmake/compiler/gcc/compiler_flags.cmake b/cmake/compiler/gcc/compiler_flags.cmake
@@ -241,3 +241,5 @@ set_compiler_property(PROPERTY warning_shadow_variables -Wshadow)
 
 set_compiler_property(PROPERTY no_builtin -fno-builtin)
 set_compiler_property(PROPERTY no_builtin_malloc -fno-builtin-malloc)
+
+set_compiler_property(PROPERTY specs -specs=)
diff --git a/cmake/compiler/gcc/target.cmake b/cmake/compiler/gcc/target.cmake
@@ -109,8 +109,7 @@ get_filename_component(LIBGCC_DIR ${LIBGCC_FILE_NAME} DIRECTORY)
 
 assert_exists(LIBGCC_DIR)
 
-LIST(APPEND LIB_INCLUDE_DIR "-L\"${LIBGCC_DIR}\"")
-LIST(APPEND TOOLCHAIN_LIBS gcc)
+set_linker_property(PROPERTY lib_include_dir "-L\"${LIBGCC_DIR}\"")
 
 # 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

diff --git a/cmake/linker/armlink/linker_flags.cmake b/cmake/linker/armlink/linker_flags.cmake
diff --git a/cmake/linker/armlink/linker_libraries.cmake b/cmake/linker/armlink/linker_libraries.cmake
@@ -0,0 +1,8 @@
+# Copyright (c) 2024 Nordic Semiconductor
+#
+# SPDX-License-Identifier: Apache-2.0
+
+# Per default armclang (Arm Compiler 6) doesn't need explicit C library linking
+# so we only need to set link order linking in case a custom C library is linked
+# in, such as picolibc.
+set_property(TARGET linker APPEND PROPERTY link_order_library "c;rt")
diff --git a/cmake/linker/armlink/target.cmake b/cmake/linker/armlink/target.cmake
@@ -108,5 +108,23 @@ function(toolchain_ld_link_elf)
   )
 endfunction(toolchain_ld_link_elf)
 
+# This function will generate the correct CMAKE_C_LINK_EXECUTABLE / CMAKE_CXX_LINK_EXECUTABLE
+# rule to ensure that standard c and runtime libraries are correctly placed
+# and the end of link invocation and doesn't appear in the middle of the link
+# command invocation.
+macro(toolchain_linker_finalize)
+  set(zephyr_std_libs)
+  get_property(link_order TARGET linker PROPERTY link_order_library)
+  foreach(lib ${link_order})
+    get_property(link_flag TARGET linker PROPERTY ${lib}_library)
+    set(zephyr_std_libs "${zephyr_std_libs} ${link_flag}")
+  endforeach()
+
+  set(common_link "<LINK_FLAGS> <LINK_LIBRARIES> <OBJECTS> ${zephyr_std_libs} -o <TARGET>")
+  set(CMAKE_C_LINK_EXECUTABLE "<CMAKE_LINKER> <CMAKE_C_LINK_FLAGS> ${common_link}")
+  set(CMAKE_CXX_LINK_EXECUTABLE "<CMAKE_LINKER> <CMAKE_CXX_LINK_FLAGS> ${common_link}")
+  set(CMAKE_ASM_LINK_EXECUTABLE "<CMAKE_LINKER> <CMAKE_ASM_LINK_FLAGS> ${common_link}")
+endmacro()
+
 include(${ZEPHYR_BASE}/cmake/linker/ld/target_relocation.cmake)
 include(${ZEPHYR_BASE}/cmake/linker/ld/target_configure.cmake)
diff --git a/cmake/linker/ld/gcc/linker_flags.cmake b/cmake/linker/ld/gcc/linker_flags.cmake
@@ -15,3 +15,5 @@ add_link_options(-gdwarf-4)
 
 # Extra warnings options for twister run
 set_property(TARGET linker PROPERTY warnings_as_errors -Wl,--fatal-warnings)
+
+set_linker_property(PROPERTY specs -specs=)
diff --git a/cmake/linker/ld/linker_flags.cmake b/cmake/linker/ld/linker_flags.cmake
@@ -7,10 +7,6 @@ check_set_linker_property(TARGET linker PROPERTY base
                           ${LINKERFLAGPREFIX},--build-id=none
 )
 
-if(NOT CONFIG_MINIMAL_LIBCPP AND NOT CONFIG_NATIVE_LIBRARY AND NOT CONFIG_EXTERNAL_MODULE_LIBCPP)
-  set_property(TARGET linker PROPERTY cpp_base -lstdc++)
-endif()
-
 check_set_linker_property(TARGET linker PROPERTY baremetal
                           -nostdlib
                           -static

diff --git a/cmake/linker/ld/linker_libraries.cmake b/cmake/linker/ld/linker_libraries.cmake
@@ -0,0 +1,38 @@
+# Copyright (c) 2024 Nordic Semiconductor
+#
+# SPDX-License-Identifier: Apache-2.0
+
+# Do not specify default link libraries when targeting host (native build).
+if(NOT CONFIG_NATIVE_BUILD)
+  set_linker_property(NO_CREATE PROPERTY c_library    "-lc")
+  set_linker_property(NO_CREATE PROPERTY rt_library   "-lgcc")
+  set_linker_property(NO_CREATE PROPERTY c++_library  "-lstdc++")
+  set_linker_property(NO_CREATE PROPERTY math_library "-lm")
+  # Keeping default include dir empty. The linker will then select libraries
+  # from its default search path. The toolchain may adjust the value to a
+  # specific location, for example gcc infrastructure will set the value based
+  # on output from --print-libgcc-file-name.
+  set_linker_property(NO_CREATE PROPERTY lib_include_dir "")
+endif()
+
+if(CONFIG_CPP
+   AND NOT CONFIG_MINIMAL_LIBCPP
+   AND NOT CONFIG_NATIVE_LIBRARY
+   # When new link principle is fully introduced, then the below condition can
+   # be removed, and instead the external module c++ should use:
+   # set_property(TARGET linker PROPERTY c++_library  "<external_c++_lib>")
+   AND NOT CONFIG_EXTERNAL_MODULE_LIBCPP
+)
+  set_property(TARGET linker PROPERTY link_order_library "c++")
+endif()
+
+
+if(CONFIG_NEWLIB_LIBC AND CMAKE_C_COMPILER_ID STREQUAL "GNU")
+  # We are using c;rt;c (expands to '-lc -lgcc -lc') in code below.
+  # This is needed because when linking with newlib on aarch64, then libgcc has a
+  # link dependency to libc (strchr), but libc also has dependencies to libgcc.
+  # Lib C depends on libgcc. e.g. libc.a(lib_a-fvwrite.o) references __aeabi_idiv
+  set_property(TARGET linker APPEND PROPERTY link_order_library "math;c;rt;c")
+else()
+  set_property(TARGET linker APPEND PROPERTY link_order_library "c;rt")
+endif()
diff --git a/cmake/linker/ld/target.cmake b/cmake/linker/ld/target.cmake
@@ -6,16 +6,12 @@ set(CMAKE_LINKER ${GNULD_LINKER})
 
 set_ifndef(LINKERFLAGPREFIX -Wl)
 
-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.
-    # 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
-        "<CMAKE_CXX_COMPILER> <FLAGS> <CMAKE_CXX_LINK_FLAGS> <LINK_FLAGS> ${LIBGCC_DIR}/crtbegin.o <OBJECTS> -o <TARGET> <LINK_LIBRARIES> ${LIBGCC_DIR}/crtend.o")
-  endif()
+if((${CMAKE_LINKER} STREQUAL "${CROSS_COMPILE}ld.bfd") OR
+   ${GNULD_LINKER_IS_BFD})
+  # ld.bfd was found so let's explicitly use that for linking, see #32237
+  list(APPEND TOOLCHAIN_LD_FLAGS -fuse-ld=bfd)
+  list(APPEND CMAKE_REQUIRED_FLAGS -fuse-ld=bfd)
+  string(REPLACE ";" " " CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
 endif()
 
 # Run $LINKER_SCRIPT file through the C preprocessor, producing ${linker_script_gen}
@@ -118,16 +114,9 @@ function(toolchain_ld_link_elf)
     ${ARGN}                                                   # input args to parse
   )
 
-  if((${CMAKE_LINKER} STREQUAL "${CROSS_COMPILE}ld.bfd") OR
-     ${GNULD_LINKER_IS_BFD})
-    # ld.bfd was found so let's explicitly use that for linking, see #32237
-    set(use_linker "-fuse-ld=bfd")
-  endif()
-
   target_link_libraries(
     ${TOOLCHAIN_LD_LINK_ELF_TARGET_ELF}
     ${TOOLCHAIN_LD_LINK_ELF_LIBRARIES_PRE_SCRIPT}
-    ${use_linker}
     ${TOPT}
     ${TOOLCHAIN_LD_LINK_ELF_LINKER_SCRIPT}
     ${TOOLCHAIN_LD_LINK_ELF_LIBRARIES_POST_SCRIPT}
@@ -138,14 +127,44 @@ function(toolchain_ld_link_elf)
     ${LINKERFLAGPREFIX},--no-whole-archive
     ${NO_WHOLE_ARCHIVE_LIBS}
     $<TARGET_OBJECTS:${OFFSETS_LIB}>
-    ${LIB_INCLUDE_DIR}
     -L${PROJECT_BINARY_DIR}
-    ${TOOLCHAIN_LIBS}
 
     ${TOOLCHAIN_LD_LINK_ELF_DEPENDENCIES}
   )
 endfunction(toolchain_ld_link_elf)
 
+# Function for finalizing link setup after Zephyr configuration has completed.
+#
+# This function will generate the correct CMAKE_C_LINK_EXECUTABLE / CMAKE_CXX_LINK_EXECUTABLE
+# rule to ensure that standard c and runtime libraries are correctly placed
+# and the end of link invocation and doesn't appear in the middle of the link
+# command invocation.
+macro(toolchain_linker_finalize)
+  get_property(zephyr_std_libs TARGET linker PROPERTY lib_include_dir)
+  get_property(link_order TARGET linker PROPERTY link_order_library)
+  foreach(lib ${link_order})
+    get_property(link_flag TARGET linker PROPERTY ${lib}_library)
+    list(APPEND zephyr_std_libs "${link_flag}")
+  endforeach()
+  string(REPLACE ";" " " zephyr_std_libs "${zephyr_std_libs}")
+
+  set(link_libraries "<LINK_FLAGS> <OBJECTS> -o <TARGET> <LINK_LIBRARIES> ${zephyr_std_libs}")
+  set(common_link "<LINK_FLAGS> ${link_libraries}")
+
+  set(CMAKE_ASM_LINK_EXECUTABLE "<CMAKE_ASM_COMPILER> <FLAGS> <CMAKE_ASM_LINK_FLAGS> ${common_link}")
+  set(CMAKE_C_LINK_EXECUTABLE   "<CMAKE_C_COMPILER> <FLAGS> <CMAKE_C_LINK_FLAGS> ${common_link}")
+
+  set(cpp_link "${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")
+    endif()
+  endif()
+  set(CMAKE_CXX_LINK_EXECUTABLE "<CMAKE_CXX_COMPILER> <FLAGS> <CMAKE_CXX_LINK_FLAGS> ${cpp_link}")
+endmacro()
+
 # Load toolchain_ld-family macros
 include(${ZEPHYR_BASE}/cmake/linker/${LINKER}/target_relocation.cmake)
 include(${ZEPHYR_BASE}/cmake/linker/${LINKER}/target_configure.cmake)
diff --git a/cmake/linker/linker_flags_template.cmake b/cmake/linker/linker_flags_template.cmake
@@ -49,3 +49,7 @@ set_property(TARGET linker PROPERTY no_relax)
 
 # Linker flag for enabling relaxation of address optimization for jump calls.
 set_property(TARGET linker PROPERTY relax)
+
+# Linker flag for defining specs. Defined only by gcc, when gcc is used as
+# front-end for ld.
+set_compiler_property(PROPERTY specs)
Original file line number	Diff line number	Diff line change
Expand Up		@@ -125,3 +125,5 @@ set_compiler_property(PROPERTY warning_error_coding_guideline
		)

		set_compiler_property(PROPERTY no_global_merge "-mno-global-merge")

		set_compiler_property(PROPERTY specs)
Original file line number	Diff line number	Diff line change
Expand Up		@@ -241,3 +241,5 @@ set_compiler_property(PROPERTY warning_shadow_variables -Wshadow)

		set_compiler_property(PROPERTY no_builtin -fno-builtin)
		set_compiler_property(PROPERTY no_builtin_malloc -fno-builtin-malloc)

		set_compiler_property(PROPERTY specs -specs=)
Original file line number	Diff line number	Diff line change
Expand Up		@@ -15,3 +15,5 @@ add_link_options(-gdwarf-4)

		# Extra warnings options for twister run
		set_property(TARGET linker PROPERTY warnings_as_errors -Wl,--fatal-warnings)

		set_linker_property(PROPERTY specs -specs=)