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, 17 insertions, 15 deletions

diff --git a/gdb/spu-tdep.c b/gdb/spu-tdep.c
index 80458ab38e0..f6ddb65f38b 100644
--- a/gdb/spu-tdep.c
+++ b/gdb/spu-tdep.c
@@ -198,7 +198,7 @@ spu_pseudo_register_read_spu (readable_regcache *regcache, const char *regname,
     return status;
   xsnprintf (annex, sizeof annex, "%d/%s", (int) id, regname);
   memset (reg, 0, sizeof reg);
-  target_read (target_stack, TARGET_OBJECT_SPU, annex,
+  target_read (current_top_target (), TARGET_OBJECT_SPU, annex,
 	       reg, 0, sizeof reg);
 
   ul = strtoulst ((char *) reg, NULL, 16);
@@ -229,7 +229,7 @@ spu_pseudo_register_read (struct gdbarch *gdbarch, readable_regcache *regcache,
       if (status != REG_VALID)
 	return status;
       xsnprintf (annex, sizeof annex, "%d/fpcr", (int) id);
-      target_read (target_stack, TARGET_OBJECT_SPU, annex, buf, 0, 16);
+      target_read (current_top_target (), TARGET_OBJECT_SPU, annex, buf, 0, 16);
       return status;
 
     case SPU_SRR0_REGNUM:
@@ -263,7 +263,7 @@ spu_pseudo_register_write_spu (struct regcache *regcache, const char *regname,
   xsnprintf (annex, sizeof annex, "%d/%s", (int) id, regname);
   xsnprintf (reg, sizeof reg, "0x%s",
 	     phex_nz (extract_unsigned_integer (buf, 4, byte_order), 4));
-  target_write (target_stack, TARGET_OBJECT_SPU, annex,
+  target_write (current_top_target (), TARGET_OBJECT_SPU, annex,
 		(gdb_byte *) reg, 0, strlen (reg));
 }
 
@@ -286,7 +286,7 @@ spu_pseudo_register_write (struct gdbarch *gdbarch, struct regcache *regcache,
     case SPU_FPSCR_REGNUM:
       regcache_raw_read_unsigned (regcache, SPU_ID_REGNUM, &id);
       xsnprintf (annex, sizeof annex, "%d/fpcr", (int) id);
-      target_write (target_stack, TARGET_OBJECT_SPU, annex, buf, 0, 16);
+      target_write (current_top_target (), TARGET_OBJECT_SPU, annex, buf, 0, 16);
       break;
 
     case SPU_SRR0_REGNUM:
@@ -2079,7 +2079,7 @@ info_spu_event_command (const char *args, int from_tty)
   id = get_frame_register_unsigned (frame, SPU_ID_REGNUM);
 
   xsnprintf (annex, sizeof annex, "%d/event_status", id);
-  len = target_read (target_stack, TARGET_OBJECT_SPU, annex,
+  len = target_read (current_top_target (), TARGET_OBJECT_SPU, annex,
 		     buf, 0, (sizeof (buf) - 1));
   if (len <= 0)
     error (_("Could not read event_status."));
@@ -2087,7 +2087,7 @@ info_spu_event_command (const char *args, int from_tty)
   event_status = strtoulst ((char *) buf, NULL, 16);
  
   xsnprintf (annex, sizeof annex, "%d/event_mask", id);
-  len = target_read (target_stack, TARGET_OBJECT_SPU, annex,
+  len = target_read (current_top_target (), TARGET_OBJECT_SPU, annex,
 		     buf, 0, (sizeof (buf) - 1));
   if (len <= 0)
     error (_("Could not read event_mask."));
@@ -2127,7 +2127,8 @@ info_spu_signal_command (const char *args, int from_tty)
   id = get_frame_register_unsigned (frame, SPU_ID_REGNUM);
 
   xsnprintf (annex, sizeof annex, "%d/signal1", id);
-  len = target_read (target_stack, TARGET_OBJECT_SPU, annex, buf, 0, 4);
+  len = target_read (current_top_target (), TARGET_OBJECT_SPU,
+		     annex, buf, 0, 4);
   if (len < 0)
     error (_("Could not read signal1."));
   else if (len == 4)
@@ -2137,7 +2138,7 @@ info_spu_signal_command (const char *args, int from_tty)
     }
     
   xsnprintf (annex, sizeof annex, "%d/signal1_type", id);
-  len = target_read (target_stack, TARGET_OBJECT_SPU, annex,
+  len = target_read (current_top_target (), TARGET_OBJECT_SPU, annex,
 		     buf, 0, (sizeof (buf) - 1));
   if (len <= 0)
     error (_("Could not read signal1_type."));
@@ -2145,7 +2146,8 @@ info_spu_signal_command (const char *args, int from_tty)
   signal1_type = strtoulst ((char *) buf, NULL, 16);
 
   xsnprintf (annex, sizeof annex, "%d/signal2", id);
-  len = target_read (target_stack, TARGET_OBJECT_SPU, annex, buf, 0, 4);
+  len = target_read (current_top_target (), TARGET_OBJECT_SPU,
+		     annex, buf, 0, 4);
   if (len < 0)
     error (_("Could not read signal2."));
   else if (len == 4)
@@ -2155,7 +2157,7 @@ info_spu_signal_command (const char *args, int from_tty)
     }
     
   xsnprintf (annex, sizeof annex, "%d/signal2_type", id);
-  len = target_read (target_stack, TARGET_OBJECT_SPU, annex,
+  len = target_read (current_top_target (), TARGET_OBJECT_SPU, annex,
 		     buf, 0, (sizeof (buf) - 1));
   if (len <= 0)
     error (_("Could not read signal2_type."));
@@ -2243,7 +2245,7 @@ info_spu_mailbox_command (const char *args, int from_tty)
   ui_out_emit_tuple tuple_emitter (current_uiout, "SPUInfoMailbox");
 
   xsnprintf (annex, sizeof annex, "%d/mbox_info", id);
-  len = target_read (target_stack, TARGET_OBJECT_SPU, annex,
+  len = target_read (current_top_target (), TARGET_OBJECT_SPU, annex,
 		     buf, 0, sizeof buf);
   if (len < 0)
     error (_("Could not read mbox_info."));
@@ -2252,7 +2254,7 @@ info_spu_mailbox_command (const char *args, int from_tty)
 			 "mbox", "SPU Outbound Mailbox");
 
   xsnprintf (annex, sizeof annex, "%d/ibox_info", id);
-  len = target_read (target_stack, TARGET_OBJECT_SPU, annex,
+  len = target_read (current_top_target (), TARGET_OBJECT_SPU, annex,
 		     buf, 0, sizeof buf);
   if (len < 0)
     error (_("Could not read ibox_info."));
@@ -2261,7 +2263,7 @@ info_spu_mailbox_command (const char *args, int from_tty)
 			 "ibox", "SPU Outbound Interrupt Mailbox");
 
   xsnprintf (annex, sizeof annex, "%d/wbox_info", id);
-  len = target_read (target_stack, TARGET_OBJECT_SPU, annex,
+  len = target_read (current_top_target (), TARGET_OBJECT_SPU, annex,
 		     buf, 0, sizeof buf);
   if (len < 0)
     error (_("Could not read wbox_info."));
@@ -2473,7 +2475,7 @@ info_spu_dma_command (const char *args, int from_tty)
   id = get_frame_register_unsigned (frame, SPU_ID_REGNUM);
 
   xsnprintf (annex, sizeof annex, "%d/dma_info", id);
-  len = target_read (target_stack, TARGET_OBJECT_SPU, annex,
+  len = target_read (current_top_target (), TARGET_OBJECT_SPU, annex,
 		     buf, 0, 40 + 16 * 32);
   if (len <= 0)
     error (_("Could not read dma_info."));
@@ -2550,7 +2552,7 @@ info_spu_proxydma_command (const char *args, int from_tty)
   id = get_frame_register_unsigned (frame, SPU_ID_REGNUM);
 
   xsnprintf (annex, sizeof annex, "%d/proxydma_info", id);
-  len = target_read (target_stack, TARGET_OBJECT_SPU, annex,
+  len = target_read (current_top_target (), TARGET_OBJECT_SPU, annex,
 		     buf, 0, 24 + 8 * 32);
   if (len <= 0)
     error (_("Could not read proxydma_info."));