🚀 go-pugleaf

Hello,


   My name is Laurent JULLIARD, working as a Software Engineer at Hewlett
Packard Company. I'm currently in the process of writing a tool that will 
allow us to transform a GCC object file (.o) into a compatible HP_UX object 
file.

   This tool is exactly the reverse of a tool (called hpxt) distributed by 
the FSF in HP_UX implementation of GCC. Of course I didn't rewrite the all
stuff from scratch because "hpxt" was a good starting point. 

   However there are some strange things in the symbol table that I can not
explain from the information I have in hpxt. It would be very kind of you if
you could help me to sort out the following problems :

    Here is the structure of a symbol table entry (with the known value for 
the field "n_type" :


>----------------------------------------------------------<
struct gnu_nlist
  {
    union
      {
	char *n_name;		/* for use when in-core */
	long n_strx;		/* index into file string table */
      } n_un;
    unsigned char n_type;	/* type flag (N_TEXT,..)  */
    char n_other;		/* unused */
    short n_desc;		/* see <stab.h> */
    unsigned long n_value;	/* value of symbol (or sdb offset) */
  };

#define	GNU_SYMTYPE_UNDEFINED	0x0
#define	GNU_SYMTYPE_ABSOLUTE	0x2
#define	GNU_SYMTYPE_TEXT	0x4
#define	GNU_SYMTYPE_DATA	0x6
#define	GNU_SYMTYPE_BSS		0x8
#define	GNU_SYMTYPE_COMMON	0x12
#define	GNU_SYMTYPE_FILENAME	0x1F
#define	GNU_SYMTYPE_EXTERNAL	0x01
>----------------------------------------------------------<


PROBLEM #1 : Some entries have their index set to 0 (field n_strx = 0).
             What is the purpose of such entries ? (Remark : the n_desc,
             n_value and n_type fields are not null)

PROBLEM #2 : Some entries have their type flag set to "none documented"
             values such as :
                    . 0x64, 0x44, 0x24      
                    and
                    . 0x80, 0xC0, 0xE0

             What are they ? Are they (respectively) GNU_SYMTYPE_TEXT and
             GNU_SYMTYPE_UNDEFINED with an additional info into the upper
             nibble ?

NOTE : I'm using GCC 1.40.

I thank you very much for your help. 

Best regards,
Laurent JULLIARD
HP GND Lab / (Grenoble - FRANCE)
laurentj@hpgnse2.grenoble.hp.com


P.S. : GCC is really a nice piece of code !