[LVU] deal with md final_scan_insn

Ports call final_scan_insn with seen == NULL, and then
maybe_output_next_view crashes because it assumes it's
non-NULL.  Oops.  Fixed.

for  gcc/ChangeLog

	* final.c (final_scan_insn_1): Renamed from...
	(final_scan_insn): ... this.  New wrapper, to recover
	seen from the outermost call in recursive ones.
	* config/sparc/sparc.c (output_return): Drop seen from call.
	(output_sibcall): Likewise.
	* config/visium/visium.c (output_branch): Likewise.

From-SVN: r257562

gcc/ChangeLog

+2018-02-11  Alexandre Oliva <aoliva@redhat.com>
+
+	* final.c (final_scan_insn_1): Renamed from...
+	(final_scan_insn): ... this.  New wrapper, to recover
+	seen from the outermost call in recursive ones.
+	* config/sparc/sparc.c (output_return): Drop seen from call.
+	(output_sibcall): Likewise.
+	* config/visium/visium.c (output_branch): Likewise.
+
 2018-02-10  John David Anglin  <danglin@gcc.gnu.org>
 
 	* config/pa/pa.c (hppa_profile_hook): Mark SYMBOL_REF for _mcount as

gcc/config/sparc/sparc.c

@@ -6422,7 +6422,6 @@ output_return (rtx_insn *insn)
 	{
 	  rtx_insn *delay;
 	  rtx pat;
-	  int seen;
 
 	  delay = NEXT_INSN (insn);
 	  gcc_assert (delay);
@@ -6442,7 +6441,7 @@ output_return (rtx_insn *insn)
 		 Make sure to output its source location first.  */
 	      PATTERN (delay) = gen_blockage ();
 	      INSN_CODE (delay) = -1;
-	      final_scan_insn (delay, asm_out_file, optimize, 0, &seen);
+	      final_scan_insn (delay, asm_out_file, optimize, 0, NULL);
 	      INSN_LOCATION (delay) = UNKNOWN_LOCATION;
 
 	      output_restore (pat);
@@ -6503,7 +6502,6 @@ output_sibcall (rtx_insn *insn, rtx call_operand)
 	{
 	  rtx_insn *delay;
 	  rtx pat;
-	  int seen;
 
 	  delay = NEXT_INSN (insn);
 	  gcc_assert (delay);
@@ -6514,7 +6512,7 @@ output_sibcall (rtx_insn *insn, rtx call_operand)
 	     Make sure to output its source location first.  */
 	  PATTERN (delay) = gen_blockage ();
 	  INSN_CODE (delay) = -1;
-	  final_scan_insn (delay, asm_out_file, optimize, 0, &seen);
+	  final_scan_insn (delay, asm_out_file, optimize, 0, NULL);
 	  INSN_LOCATION (delay) = UNKNOWN_LOCATION;
 
 	  output_restore (pat);

gcc/config/visium/visium.c

@@ -3094,10 +3094,9 @@ output_branch (rtx label, const char *cond, rtx_insn *insn)
 	  if (final_sequence)
 	    {
 	      rtx_insn *delay = NEXT_INSN (insn);
-	      int seen;
 	      gcc_assert (delay);
 
-	      final_scan_insn (delay, asm_out_file, optimize, 0, &seen);
+	      final_scan_insn (delay, asm_out_file, optimize, 0, NULL);
 	      PATTERN (delay) = gen_blockage ();
 	      INSN_CODE (delay) = -1;
 	    }

gcc/final.c

@@ -2236,9 +2236,9 @@ asm_show_source (const char *filename, int linenum)
    debug information.  We force the emission of a line note after
    both NOTE_INSN_PROLOGUE_END and NOTE_INSN_FUNCTION_BEG.  */
 
-rtx_insn *
-final_scan_insn (rtx_insn *insn, FILE *file, int optimize_p ATTRIBUTE_UNUSED,
-		 int nopeepholes ATTRIBUTE_UNUSED, int *seen)
+static rtx_insn *
+final_scan_insn_1 (rtx_insn *insn, FILE *file, int optimize_p ATTRIBUTE_UNUSED,
+		   int nopeepholes ATTRIBUTE_UNUSED, int *seen)
 {
 #if HAVE_cc0
   rtx set;
@@ -3189,6 +3189,36 @@ final_scan_insn (rtx_insn *insn, FILE *file, int optimize_p ATTRIBUTE_UNUSED,
     }
   return NEXT_INSN (insn);
 }
+
+/* This is a wrapper around final_scan_insn_1 that allows ports to
+   call it recursively without a known value for SEEN.  The value is
+   saved at the outermost call, and recovered for recursive calls.
+   Recursive calls MUST pass NULL, or the same pointer if they can
+   otherwise get to it.  */
+
+rtx_insn *
+final_scan_insn (rtx_insn *insn, FILE *file, int optimize_p,
+		 int nopeepholes, int *seen)
+{
+  static int *enclosing_seen;
+  static int recursion_counter;
+
+  gcc_assert (seen || recursion_counter);
+  gcc_assert (!recursion_counter || !seen || seen == enclosing_seen);
+
+  if (!recursion_counter++)
+    enclosing_seen = seen;
+  else if (!seen)
+    seen = enclosing_seen;
+
+  rtx_insn *ret = final_scan_insn_1 (insn, file, optimize_p, nopeepholes, seen);
+
+  if (!--recursion_counter)
+    enclosing_seen = NULL;
+
+  return ret;
+}
+
 
 /* Return whether a source line note needs to be emitted before INSN.
    Sets IS_STMT to TRUE if the line should be marked as a possible