linker: discard eh_frame when C++ exceptions are disabled

Discard the eh_frame section when C++ exceptions are disabled.

In principle the eh_frame may be used for other purposes such as
backtracing when linking C programs, then Zephyr compiles each source
file with '-fno-asynchronous-unwind-tables', thus keeping the eh_frame
in the elf output just takes up space.

When using gcc/ld, then the eh_frame is generally generally discarded
per default, however for clang/lld it will be included but give a
warning that the section is auto-placed.

Some platforms already discards the eh_frame, so unify this for all
targets.

As eh_frame is now discarded in linker scripts then post processing step
of removing the section during hex or bin conversion can also be
removed.

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

Author: tejlmand

CMakeLists.txt

@@ -1729,13 +1729,8 @@ if(CONFIG_BUILD_OUTPUT_ADJUST_LMA)
     )
 endif()
 
-if(NOT CONFIG_CPP_EXCEPTIONS)
-  set(eh_frame_section ".eh_frame")
-else()
-  set(eh_frame_section "")
-endif()
 set(remove_sections_argument_list "")
-foreach(section .comment COMMON ${eh_frame_section})
+foreach(section .comment COMMON)
   list(APPEND remove_sections_argument_list
     $<TARGET_PROPERTY:bintools,elfconvert_flag_section_remove>${section})
 endforeach()

include/zephyr/arch/x86/ia32/linker.ld

@@ -557,12 +557,6 @@ SECTIONS
 #include <zephyr/linker/debug-sections.ld>
 
 	/DISCARD/ : { *(.note.GNU-stack) }
-/*
- * eh_frame section won't be removed even with "--gc-sections" by LLVM lld.
- */
-#if !defined(CONFIG_CPP_EXCEPTIONS)
-	/DISCARD/ : { *(.eh_frame) }
-#endif
 
 /*
  * The sections below are still treated as warnings

include/zephyr/arch/x86/intel64/linker.ld

@@ -223,12 +223,6 @@ SECTIONS
 	*(.rel.*)
 	*(.rela.*)
 	}
-/*
- * eh_frame section won't be removed even with "--gc-sections" by LLVM lld.
- */
-#if !defined(CONFIG_CPP_EXCEPTIONS)
-	/DISCARD/ : { *(.eh_frame) }
-#endif
 
 /*
  * The sections below are still treated as warnings

include/zephyr/linker/cplusplus-rom.ld

@@ -28,3 +28,7 @@
 #endif /* CONFIG_CPP_EXCEPTIONS */
 
 #endif /* CONFIG_CPP */
+
+#if !defined(CONFIG_CPP_EXCEPTIONS)
+	/DISCARD/ : { *(.eh_frame) }
+#endif