From d49df6269975c05ab212b61bd53920fe43ca0346 Mon Sep 17 00:00:00 2001
From: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Fri, 28 Nov 1997 03:05:02 +0000
Subject: [PATCH]         * flow.c (find_basic_blocks): Handle cfg issues for
 rethrows and         nested exceptions correctly.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/egcs_1_00_branch@16811 138bc75d-0d04-0410-961f-82ee72b054a4
---
 gcc/ChangeLog |  3 +++
 gcc/flow.c    | 19 ++++++++++++++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index acaa173f91b..ea39d3810ea 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,4 +1,7 @@
 Thu Nov 27 12:20:19 1997  Jeffrey A Law  (law@cygnus.com)
+	
+	* flow.c (find_basic_blocks): Handle cfg issues for rethrows and
+	nested exceptions correctly.
 
 	* unroll.c (find_splittable_givs): Don't split givs with a dest_reg
 	that was created by loop.
diff --git a/gcc/flow.c b/gcc/flow.c
index b98008267dc..66374163e8b 100644
--- a/gcc/flow.c
+++ b/gcc/flow.c
@@ -472,10 +472,15 @@ find_basic_blocks (f, nonlocal_label_list)
       /* If we encounter a CALL_INSN, note which exception handler it
 	 might pass control to.
 
+	 Because we do rethrows by loading the address of a label into
+	 __eh_pc and throwing, we need to treat labels as potentially
+	 jumping to exception handlers.
+
 	 If doing asynchronous exceptions, record the active EH handler
 	 for every insn, since most insns can throw.  */
       else if (eh_note
 	       && (asynchronous_exceptions
+		   || code == CODE_LABEL
 		   || (GET_CODE (insn) == CALL_INSN
 		       && ! find_reg_note (insn, REG_RETVAL, NULL_RTX))))
 	active_eh_handler[INSN_UID (insn)] = XEXP (eh_note, 0);
@@ -569,7 +574,11 @@ find_basic_blocks (f, nonlocal_label_list)
 			   associated insns aren't marked dead, so we make
 			   the block in question live and create an edge from
 			   this insn to the label.  This is not strictly
-			   correct, but it is close enough for now.  */
+			   correct, but it is close enough for now.
+
+			   We also need to mark the CODE_LABEL as reaching
+			   its exception handler for nested exceptions to
+			   to work.  */
 			for (note = REG_NOTES (insn);
 			     note;
 			     note = XEXP (note, 1))
@@ -581,6 +590,14 @@ find_basic_blocks (f, nonlocal_label_list)
 				mark_label_ref (gen_rtx (LABEL_REF,
 							 VOIDmode, x),
 						insn, 0);
+
+				/* If the CODE_LABEL has an active exception
+				   handler, then make an edge to the exception
+				   handler from this insn.  */
+				if (active_eh_handler[INSN_UID (x)])
+				  mark_label_ref (gen_rtx (LABEL_REF, VOIDmode,
+							   active_eh_handler[INSN_UID (x)]),
+						  insn, 0);
 			      }
 			  }
 
-- 
2.11.4.GIT