gdb: introduce displaced_debug_printf

Move all debug prints of the "displaced" category to use a new
displaced_debug_printf macro, like what was done for infrun and others
earlier.

The debug output for one displaced step one amd64 looks like:

    [displaced] displaced_step_prepare_throw: stepping process 3367044 now
    [displaced] displaced_step_prepare_throw: saved 0x555555555042: 1e fa 31 ed 49 89 d1 5e 48 89 e2 48 83 e4 f0 50
    [displaced] amd64_displaced_step_copy_insn: copy 0x555555555131->0x555555555042: b8 00 00 00 00 5d c3 0f 1f 84 00 00 00 00 00 f3
    [displaced] displaced_step_prepare_throw: displaced pc to 0x555555555042
    [displaced] resume_1: run 0x555555555042: b8 00 00 00
    [displaced] displaced_step_restore: restored process 3367044 0x555555555042
    [displaced] amd64_displaced_step_fixup: fixup (0x555555555131, 0x555555555042), insn = 0xb8 0x00 ...
    [displaced] amd64_displaced_step_fixup: relocated %rip from 0x555555555047 to 0x555555555136

On test case needed to be updated because it relied on the specific
formatting of the message.

gdb/ChangeLog:

	* infrun.h (displaced_debug_printf): New macro.  Replace
	displaced debug prints throughout to use it.
	(displaced_debug_printf_1): New declaration.
	(displaced_step_dump_bytes): Return string, remove ui_file
	parameter, update all callers.
	* infrun.c (displaced_debug_printf_1): New function.
	(displaced_step_dump_bytes): Return string, remove ui_file
	parameter

gdb/testsuite/ChangeLog:

	* gdb.arch/amd64-disp-step-avx.exp: Update displaced step debug
	expected output.

Change-Id: Ie78837f56431f6f98378790ba1e6051337bf6533

1 files changed, 17 insertions, 27 deletions

diff --git a/gdb/arm-linux-tdep.c b/gdb/arm-linux-tdep.c
index f60cb51..0435263 100644
--- a/gdb/arm-linux-tdep.c
+++ b/gdb/arm-linux-tdep.c
@@ -957,15 +957,11 @@ arm_linux_cleanup_svc (struct gdbarch *gdbarch,
 		    && apparent_pc < (dsc->scratch_base
 				      + ARM_DISPLACED_MODIFIED_INSNS * 4 + 4));
 
-  if (debug_displaced)
-    {
-      fprintf_unfiltered (gdb_stdlog, "displaced: PC is apparently %.8lx after "
-			  "SVC step ", (unsigned long) apparent_pc);
-      if (within_scratch)
-        fprintf_unfiltered (gdb_stdlog, "(within scratch space)\n");
-      else
-        fprintf_unfiltered (gdb_stdlog, "(outside scratch space)\n");
-    }
+  displaced_debug_printf ("PC is apparently %.8lx after SVC step %s",
+			  (unsigned long) apparent_pc,
+			  (within_scratch
+			   ? "(within scratch space)"
+			   : "(outside scratch space)"));
 
   if (within_scratch)
     displaced_write_reg (regs, dsc, ARM_PC_REGNUM,
@@ -991,16 +987,12 @@ arm_linux_copy_svc (struct gdbarch *gdbarch, struct regcache *regs,
     {
       struct symtab_and_line sal;
 
-      if (debug_displaced)
-	fprintf_unfiltered (gdb_stdlog, "displaced: found "
-			    "sigreturn/rt_sigreturn SVC call.  PC in "
-			    "frame = %lx\n",
-			    (unsigned long) get_frame_pc (frame));
+      displaced_debug_printf ("found sigreturn/rt_sigreturn SVC call.  "
+			      "PC in frame = %lx",
+			      (unsigned long) get_frame_pc (frame));
 
-      if (debug_displaced)
-	fprintf_unfiltered (gdb_stdlog, "displaced: unwind pc = %lx.  "
-			    "Setting momentary breakpoint.\n",
-			    (unsigned long) return_to);
+      displaced_debug_printf ("unwind pc = %lx.  Setting momentary breakpoint.",
+			      (unsigned long) return_to);
 
       gdb_assert (inferior_thread ()->control.step_resume_breakpoint
 		  == NULL);
@@ -1025,13 +1017,12 @@ arm_linux_copy_svc (struct gdbarch *gdbarch, struct regcache *regs,
 	     breakpoint set above.  */
 	  insert_breakpoints ();
 	}
-      else if (debug_displaced)
-	fprintf_unfiltered (gdb_stderr, "displaced: couldn't find previous "
-			    "frame to set momentary breakpoint for "
-			    "sigreturn/rt_sigreturn\n");
+      else
+	displaced_debug_printf ("couldn't find previous frame to set momentary "
+				"breakpoint for sigreturn/rt_sigreturn");
     }
-  else if (debug_displaced)
-    fprintf_unfiltered (gdb_stdlog, "displaced: found SVC call\n");
+  else
+    displaced_debug_printf ("found SVC call");
 
   /* Preparation: If we detect sigreturn, set momentary breakpoint at resume
 		  location, else nothing.
@@ -1115,9 +1106,8 @@ arm_linux_displaced_step_copy_insn (struct gdbarch *gdbarch,
      stop at the return location.  */
   if (from > 0xffff0000)
     {
-      if (debug_displaced)
-        fprintf_unfiltered (gdb_stdlog, "displaced: detected kernel helper "
-			    "at %.8lx\n", (unsigned long) from);
+      displaced_debug_printf ("detected kernel helper at %.8lx",
+			      (unsigned long) from);
 
       arm_catch_kernel_helper_return (gdbarch, from, to, regs, dsc.get ());
     }