[gcc r13-1766] Avoid registering __builtin_setjmp_receiver label twice [PR101347]

[gcc r13-1766] Avoid registering __builtin_setjmp_receiver label twice [PR101347]

[Alexander Monakov]

https://gcc.gnu.org/g:daa36cfc2fc2538810db071b81d250f4d621f7ea

commit r13-1766-gdaa36cfc2fc2538810db071b81d250f4d621f7ea
Author: Alexander Monakov <amonakov@ispras.ru>
Date:   Tue Jul 19 18:04:30 2022 +0300

    Avoid registering __builtin_setjmp_receiver label twice [PR101347]
    
    The testcase in the PR demonstrates how it is possible for one
    __builtin_setjmp_receiver label to appear in
    nonlocal_goto_handler_labels list twice (after the block with
    __builtin_setjmp_setup referring to it was duplicated).
    
    remove_node_from_insn_list did not account for this possibility and
    removed only the first copy from the list. Add an assert verifying that
    duplicates are not present.
    
    To avoid adding a label to the list twice, move registration of the
    label from __builtin_setjmp_setup handling to __builtin_setjmp_receiver.
    
    gcc/ChangeLog:
    
            PR rtl-optimization/101347
            * builtins.cc (expand_builtin) [BUILT_IN_SETJMP_SETUP]: Move
            population of nonlocal_goto_handler_labels from here ...
            (expand_builtin) [BUILT_IN_SETJMP_RECEIVER]: ... to here.
            * rtlanal.cc (remove_node_from_insn_list): Verify that a
            duplicate is not present in the remainder of the list.

Diff:
---
 gcc/builtins.cc | 15 +++++++--------
 gcc/rtlanal.cc  |  1 +
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/gcc/builtins.cc b/gcc/builtins.cc
index 0d13197703d..b08b4365da3 100644
--- a/gcc/builtins.cc
+++ b/gcc/builtins.cc
@@ -7472,15 +7472,7 @@ expand_builtin (tree exp, rtx target, rtx subtarget, machine_mode mode,
 	  tree label = TREE_OPERAND (CALL_EXPR_ARG (exp, 1), 0);
 	  rtx_insn *label_r = label_rtx (label);
 
-	  /* This is copied from the handling of non-local gotos.  */
 	  expand_builtin_setjmp_setup (buf_addr, label_r);
-	  nonlocal_goto_handler_labels
-	    = gen_rtx_INSN_LIST (VOIDmode, label_r,
-				 nonlocal_goto_handler_labels);
-	  /* ??? Do not let expand_label treat us as such since we would
-	     not want to be both on the list of non-local labels and on
-	     the list of forced labels.  */
-	  FORCED_LABEL (label) = 0;
 	  return const0_rtx;
 	}
       break;
@@ -7493,6 +7485,13 @@ expand_builtin (tree exp, rtx target, rtx subtarget, machine_mode mode,
 	  rtx_insn *label_r = label_rtx (label);
 
 	  expand_builtin_setjmp_receiver (label_r);
+	  nonlocal_goto_handler_labels
+	    = gen_rtx_INSN_LIST (VOIDmode, label_r,
+				 nonlocal_goto_handler_labels);
+	  /* ??? Do not let expand_label treat us as such since we would
+	     not want to be both on the list of non-local labels and on
+	     the list of forced labels.  */
+	  FORCED_LABEL (label) = 0;
 	  return const0_rtx;
 	}
       break;
diff --git a/gcc/rtlanal.cc b/gcc/rtlanal.cc
index ec95ecd6cf9..56da7435a28 100644
--- a/gcc/rtlanal.cc
+++ b/gcc/rtlanal.cc
@@ -2899,6 +2899,7 @@ remove_node_from_insn_list (const rtx_insn *node, rtx_insn_list **listp)
 	  else
 	    *listp = temp->next ();
 
+	  gcc_checking_assert (!in_insn_list_p (temp->next (), node));
 	  return;
 	}