target_stack -> current_top_target() throughout

The recent C++ification of target_ops replaced references to the old
"current_target" squashed target throughout with references to a
"target_stack" pointer.  I had picked the "target_stack" name very
early in the multi-target work, and managed to stick with it, even
though it's a bit of a misnomer, since it isn't really a "target
stack" object, but a pointer into the current top target in the stack.
As I'm splitting more pieces off of the multi-target branch, I've come
to think that it's better to rename it now.  A following patch will
introduce a new class to represent a target stack, and "target_stack"
would be _its_ ideal name.  (In the branch, the class is called
a_target_stack to work around the clash.)

Thus this commit renames target_stack to current_top_target and
replaces all references throughout.  Also, while at it,
current_top_target is made a function instead of a pointer, to make it
possible to change its internal implementation without leaking
implementation details out.  In a couple patches, the implementation
of the function will change to refer to a target stack object, and
then further down the multi-target work, it'll change again to find
the right target stack for the current inferior.

gdb/ChangeLog:
2018-06-07  Pedro Alves  <palves@redhat.com>

	* target.h (target_stack): Delete.
	(current_top_target): Declare function.
	* target.c (target_stack): Delete.
	(g_current_top_target): New.
	(current_top_target): New function.
	* auxv.c: Use current_top_target instead of target_stack
	throughout.
	* avr-tdep.c: Likewise.
	* breakpoint.c: Likewise.
	* corefile.c: Likewise.
	* elfread.c: Likewise.
	* eval.c: Likewise.
	* exceptions.c: Likewise.
	* frame.c: Likewise.
	* gdbarch-selftests.c: Likewise.
	* gnu-v3-abi.c: Likewise.
	* ia64-tdep.c: Likewise.
	* ia64-vms-tdep.c: Likewise.
	* infcall.c: Likewise.
	* infcmd.c: Likewise.
	* infrun.c: Likewise.
	* linespec.c: Likewise.
	* linux-tdep.c: Likewise.
	* minsyms.c: Likewise.
	* ppc-linux-nat.c: Likewise.
	* ppc-linux-tdep.c: Likewise.
	* procfs.c: Likewise.
	* regcache.c: Likewise.
	* remote.c: Likewise.
	* rs6000-tdep.c: Likewise.
	* s390-linux-nat.c: Likewise.
	* s390-tdep.c: Likewise.
	* solib-aix.c: Likewise.
	* solib-darwin.c: Likewise.
	* solib-dsbt.c: Likewise.
	* solib-spu.c: Likewise.
	* solib-svr4.c: Likewise.
	* solib-target.c: Likewise.
	* sparc-tdep.c: Likewise.
	* sparc64-tdep.c: Likewise.
	* spu-tdep.c: Likewise.
	* symfile.c: Likewise.
	* symtab.c: Likewise.
	* target-descriptions.c: Likewise.
	* target-memory.c: Likewise.
	* target.c: Likewise.
	* target.h: Likewise.
	* tracefile-tfile.c: Likewise.
	* tracepoint.c: Likewise.
	* valops.c: Likewise.
	* valprint.c: Likewise.
	* value.c: Likewise.
	* windows-tdep.c: Likewise.
	* mi/mi-main.c: Likewise.

1 files changed, 4 insertions, 3 deletions

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 00c538e989e..f20bc500f5f 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -3489,7 +3489,8 @@ create_exception_master_breakpoint (void)
 	}
 
       addr = BMSYMBOL_VALUE_ADDRESS (bp_objfile_data->exception_msym);
-      addr = gdbarch_convert_from_func_ptr_addr (gdbarch, addr, target_stack);
+      addr = gdbarch_convert_from_func_ptr_addr (gdbarch, addr,
+						 current_top_target ());
       b = create_internal_breakpoint (gdbarch, addr, bp_exception_master,
 				      &internal_breakpoint_ops);
       initialize_explicit_location (&explicit_loc);
@@ -4743,7 +4744,7 @@ watchpoints_triggered (struct target_waitstatus *ws)
       return 0;
     }
 
-  if (!target_stopped_data_address (target_stack, &addr))
+  if (!target_stopped_data_address (current_top_target (), &addr))
     {
       /* We were stopped by a watchpoint, but we don't know where.
 	 Mark all watchpoints as unknown.  */
@@ -4783,7 +4784,7 @@ watchpoints_triggered (struct target_waitstatus *ws)
 		  }
 	      }
 	    /* Exact match not required.  Within range is sufficient.  */
-	    else if (target_watchpoint_addr_within_range (target_stack,
+	    else if (target_watchpoint_addr_within_range (current_top_target (),
 							 addr, loc->address,
 							 loc->length))
 	      {