RFA/dwarf: Fix the GCC 2.95.3 store.exp regression for multi-register variables

[Elena Zannoni]

Michael Elizabeth Chastain writes:
 > My test bed says that this is okay.  It fixes the regression in
 > store.exp with gcc 2.95.3 -gdwarf-2 (gcc 2.95.3 is the only compiler
 > that puts this particular struct into a register).  And it doesn't
 > have any regressions with any gcc v2 or v3, dwarf-2 or stabs+,
 > on my native i686-pc-linux-gnu.
 > 
 > I have another PR for this, gdb/1107, that comes with a source file
 > and an executable file.  With this patch, gdb HEAD changes from
 > 'new bad behavior' back to 'same bad behavior as 5.3'.  Specifically,
 > I have a structure which is in %ebx and %esi.  gdb 5.3 prints values
 > from %ebx and %esp (the next register in 'info registers').
 > gdb HEAD prints %ebx and something from god knows where, and
 > gdb HEAD + patch prints %ebx and %esp again.
 > 
 > (I really hate it when gdb prints the wrong numbers!)
 > 
 > With this patch gdb is better in the store.exp case and not any
 > worse in the gdb/1107 case.  What the heck, here's a table:
 > 
 >                     store.exp  gdb/1107
 >   gdb 5.3           okay       wrong
 >   gdb HEAD          wrong      wrong
 >   gdb HEAD + drow   okay       wrong
 > 
 > So ... recommended for approval.  If it goes in then we can maybe talk
 > about gdb/1107 some more.
 > 
 > Michael C

Daniel did you check this in?

elena


 > 
 > ===
 > 
 > 2003-03-12  Daniel Jacobowitz  <drow@mvista.com>
 > 
 > 	* dwarf2expr.h (struct dwarf_expr_context): Remove extra arguments
 > 	to read_reg and update its comment.  Remove regnum member.
 > 	* dwarf2expr.c (execute_stack_op): Remove memaddr and expr_lval.
 > 	Don't call read_reg when setting in_reg.  Call read_reg to get
 > 	the frame base if it's in a register.  Return the register number
 > 	on the stack instead of in the context.  Remove extra arguments
 > 	to read_reg.
 > 	* dwarf2loc.c (dwarf_expr_read_reg): Remove extra arguments.
 > 	(dwarf2_evaluate_loc_desc): Call value_from_register.  Expect
 > 	the register number on the expression stack.
 > 	(needs_frame_read_reg): Remove extra arguments.