debug_macinfo buglet

["Nitin Gupta, Noida" <niting at noida dot hcltech dot com>]

Hi,
	During analysis of contents of .debug_macinfo 
	I discovered that the contents are not as per DWARF2 specifications.
	The DWARF2  spec says [section 6.3]

		Each macinfo entry consists of a "type code" and
		up to two additional operands. The series of entries for a
given compilation unit ends with an
		entry containing a type code of 0.
	
	The DWARF3 specs also retains this.

	However the last byte of the .debug_macinfo section, of the elf
binary generated by gcc3.1, 
	does not seems to be a zero. 
	
	I'm using
	$ gcc3.1 -v
	Reading specs from
/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.1/specs
	Configured with: ../3.1/gcc/configure --prefix=/usr/local
	Thread model: single
	gcc version 3.1

	$ gcc3.1 -O3 -g3 mac_bug.c
	$ readelf -S a.out    
	....
	
	  [31] .debug_line       PROGBITS        00000000 003e10 000275 00
0   0  1
	  [32] .debug_frame      PROGBITS        00000000 004088 000034 00
0   0  4
	  [33] .debug_str        PROGBITS        00000000 0040bc 00002f 00
0   0  1
	  [34] .debug_macinfo    PROGBITS        00000000 0040eb 002314 00
0   0  1
	  [35] .note             NOTE            00000000 0063ff 00003c 00
0   0  1
	  [36] .shstrtab         STRTAB          00000000 00643b 00015a 00
0   0  1
	  [37] .symtab           SYMTAB          00000000 006bb0 000530 10
38  3e  4
	  [38] .strtab           STRTAB          00000000 0070e0 00022c 00
0   0  1
	.....
	.....
	$ readelf --hex-dump=34 a.out    
	....(showing last 2 lines)
	  0x00002300 226e5c64 6c726f57 206f6c6c 65482228 ("Hello World\n"
	  0x00002310                           		    04040029 )...
	                                                                 ^
	The last byte of macinfo should be at 0x2314 and it is 04
(MACINFO_END_FILE).
	The mac_bug.c is a simple hello world programme. The program and
readelf outputs 
	are attached of your reference.
	
	However rest of the information in the section seems to be correct.

Thanks and Regards
Nitin.

.... <<mac_bug.h>>  <<mac_bug.c>>  <<readelf_hex_dump>>  <<readelf_S>>

Attachment: mac_bug.h
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Attachment: mac_bug.c
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Attachment: readelf_hex_dump
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Attachment: readelf_S
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