re PR c/10175 (-Wunreachable-code doesn't work for single lines)

        PR c/10175
        * jump.c (never_reached_warning): Revert patch of 2002-11-02.
        Look backwards for a line note.

From-SVN: r65227

2 files changed, 18 insertions, 2 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 616b1a0..b890b9c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2003-04-03  Jason Merrill  <jason@redhat.com>
+
+	PR c/10175
+	* jump.c (never_reached_warning): Revert patch of 2002-11-02.
+	Look backwards for a line note.
+
 2003-04-03  Neil Booth  <neil@daikokuya.co.uk>
 
 	* fix-header.c (read_scan_file): Defer switch processing.
diff --git a/gcc/jump.c b/gcc/jump.c
index 6e04790..b48bc6b 100644
--- a/gcc/jump.c
+++ b/gcc/jump.c
@@ -1909,10 +1909,20 @@ never_reached_warning (avoided_insn, finish)
   if (!warn_notreached)
     return;
 
+  /* Back up to the first of any NOTEs preceding avoided_insn; flow passes
+     us the head of a block, a NOTE_INSN_BASIC_BLOCK, which often follows
+     the line note.  */
+  for (insn = PREV_INSN (avoided_insn); ; insn = PREV_INSN (insn))
+    if (GET_CODE (insn) != NOTE)
+      {
+	insn = NEXT_INSN (insn);
+	break;
+      }
+
   /* Scan forwards, looking at LINE_NUMBER notes, until we hit a LABEL
      in case FINISH is NULL, otherwise until we run out of insns.  */
 
-  for (insn = avoided_insn; insn != NULL; insn = NEXT_INSN (insn))
+  for (; insn != NULL; insn = NEXT_INSN (insn))
     {
       if ((finish == NULL && GET_CODE (insn) == CODE_LABEL)
 	  || GET_CODE (insn) == BARRIER)
@@ -1929,7 +1939,7 @@ never_reached_warning (avoided_insn, finish)
 	}
       else if (INSN_P (insn))
 	{
-	  if (reached_end || a_line_note == NULL)
+	  if (reached_end)
 	    break;
 	  contains_insn = 1;
 	}