Why not remove entry for stripped function in ELF .debug_info section

[Terry Guo]

Hi,

I have following code which will be built with options
"-ffunction-sections -fdata-sections -Wl,--gc-sections
-Wl,-Map=test.map":

#include <stdlib.h>

static int unusedint=5;

static int usedint=1;

int unused(void) {
    return 1;
}

int foo(void)  {
    return usedint;
}

int main(void) {

    if (foo())
        exit(0);
    else
        abort();
}

According to the generated map file, the function named "unused" is
discarded in final .out file.

Discarded input sections

.text.unused   0x00000000       0x10 gcsec-1.o

But when check .debug_info section of .out file, I can still see entry
for this deadstripped function:

 <0><b>: Abbrev Number: 1 (DW_TAG_compile_unit)
    < c>   DW_AT_producer    : (indirect string, offset: 0xe): GNU C
4.8.0 20120612 (experimental) -fpreprocessed -mthumb -mcpu=cortex-m3
-g2 -ffunction-sections -fdata-sections -fno-inline
............

 <1><79>: Abbrev Number: 4 (DW_TAG_subprogram)
    <7a>   DW_AT_external    : 1
    <7a>   DW_AT_name        : (indirect string, offset: 0x8d): unused
    <7e>   DW_AT_decl_file   : 1
    <7f>   DW_AT_decl_line   : 16
    <80>   DW_AT_prototyped  : 1
    <80>   DW_AT_type        : <0x48>
    <84>   DW_AT_low_pc      : 0x0
    <88>   DW_AT_high_pc     : 0x0
    <8c>   DW_AT_frame_base  : 1 byte block: 9c         (DW_OP_call_frame_cfa)
    <8e>   Unknown AT value: 2117: 1

Is this expected behavior? Why not remove this entry? Thanks in
advance for any help.

BR,
Terry