[rfa/dwarf-1/doco] dwarfread.c: update doco

[Michael Elizabeth Chastain]

This patch updates a big comment near the top of dwarfread.c about
the state of dwarf-1 support in gcc compilers and non-gcc compilers.

I am not suggesting that we obsolete dwarf-1 yet, but we're moving
in that direction.

Testing: I built gdb, but I didn't run any tests.

Not quite sure this is obvious, so I'll ask.  OK to commit?

Michael C

2003-12-01  Michael Chastain  <mec.gnu@mindspring.com>

	* dwarfread.c: Update documentation on the state of dwarf-1.

Index: dwarfread.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarfread.c,v
retrieving revision 1.32
diff -c -3 -p -r1.32 dwarfread.c
*** dwarfread.c	23 Nov 2003 20:41:16 -0000	1.32
--- dwarfread.c	1 Dec 2003 21:08:09 -0000
***************
*** 24,65 ****
  
  /*
     If you are looking for DWARF-2 support, you are in the wrong file.
!    Go look in dwarf2read.c.  This file is for the original DWARF.
  
!    DWARF (also known as DWARF-1) is headed for obsoletion.
  
!    In gcc 3.2.1, these targets prefer dwarf-1:
  
!      i[34567]86-sequent-ptx4*   # TD-R2
!      i[34567]86-sequent-sysv4*  # TD-R2
!      i[34567]86-dg-dgux*        # obsolete in gcc 3.2.1, to be removed in 3.3
!      m88k-dg-dgux*              # TD-R2
!      mips-sni-sysv4             # TD-R2
!      sparc-hal-solaris2*        # TD-R2
  
!     Configurations marked with "# TD-R2" are on Zach Weinberg's list
!     of "Target Deprecation, Round 2".  This is a candidate list of
!     targets to be deprecated in gcc 3.3 and removed in gcc 3.4.
  
!       http://gcc.gnu.org/ml/gcc/2002-12/msg00702.html
! 
!     gcc 2.95.3 had many configurations which prefer dwarf-1.
!     We may have to support dwarf-1 as long as we support gcc 2.95.3.
!     This could use more analysis.
! 
!     DG/UX (Data General Unix) used dwarf-1 for its native format.
!     DG/UX uses gcc for its system C compiler, but they have their
!     own linker and their own debuggers.
! 
!     Takis Psarogiannakopoulos has a complete gnu toolchain for DG/UX
!     with gcc 2.95.3, gdb 5.1, and debug formats of dwarf-2 and stabs.
!     For more info, see PR gdb/979 and PR gdb/1013; also:
! 
!       http://sources.redhat.com/ml/gdb/2003-02/msg00074.html
! 
!     There may be non-gcc compilers that still emit dwarf-1.
! 
!     -- chastain 2003-02-04
  */
  
  /*
--- 24,83 ----
  
  /*
     If you are looking for DWARF-2 support, you are in the wrong file.
!    Go look in dwarf2read.c.  This file is for the original DWARF,
!    also known as DWARF-1.
  
!    DWARF-1 is slowly headed for obsoletion.
  
!    In gcc HEAD 2003-11-29 16:28:31 UTC, no targets prefer dwarf-1.
  
!    In gcc 3.3.2, these targets prefer dwarf-1:
  
!      i[34567]86-sequent-ptx4*
!      i[34567]86-sequent-sysv4*
!      mips-sni-sysv4
!      sparc-hal-solaris2*
! 
!    In gcc 3.2.2, these targets prefer dwarf-1:
! 
!      i[34567]86-dg-dgux*
!      i[34567]86-sequent-ptx4*
!      i[34567]86-sequent-sysv4*
!      m88k-dg-dgux*
!      mips-sni-sysv4
!      sparc-hal-solaris2*
! 
!    In gcc 2.95.3, these targets prefer dwarf-1:
! 
!      i[34567]86-dg-dgux*
!      i[34567]86-ncr-sysv4*
!      i[34567]86-sequent-ptx4*
!      i[34567]86-sequent-sysv4*
!      i[34567]86-*-osf1*
!      i[34567]86-*-sco3.2v5*
!      i[34567]86-*-sysv4*
!      i860-alliant-*
!      i860-*-sysv4*
!      m68k-atari-sysv4*
!      m68k-cbm-sysv4*
!      m68k-*-sysv4*
!      m88k-dg-dgux*
!      m88k-*-sysv4*
!      mips-sni-sysv4
!      mips-*-gnu*
!      sh-*-elf*
!      sh-*-rtemself*
!      sparc-hal-solaris2*
!      sparc-*-sysv4*
! 
!    Some non-gcc compilers produce dwarf-1: 
! 
!      PR gdb/1179 was from a user with Diab C++ 4.3.
!      Other users have also reported using Diab compilers with dwarf-1.
!      On 2003-06-09 the gdb list received a report from a user
!        with Absoft ProFortran f77 which is dwarf-1.
  
!    -- chastain 2003-12-01
  */
  
  /*