[gcc/devel/c++-contracts] c++: use cleanup for cdtor postconditions

[gcc/devel/c++-contracts] c++: use cleanup for cdtor postconditions

[Jason Merrill]

https://gcc.gnu.org/g:99e1cabe020ca94e63008f1b5f7e0a7df11b4cfc

commit 99e1cabe020ca94e63008f1b5f7e0a7df11b4cfc
Author: Jason Merrill <jason@redhat.com>
Date:   Mon Oct 17 15:59:51 2022 -0400

    c++: use cleanup for cdtor postconditions
    
    The contracts branch used the cdtor label for emitting postconditions, but
    that's been removed on trunk, so let's use a CLEANUP_STMT instead.  And tell
    set_cleanup_locs to leave its location alone.
    
    gcc/cp/ChangeLog:
    
            * cp-tree.h (emit_postconditions): Rename...
            (emit_postconditions_cleanup): ...to this.
            * contracts.cc: Likewise.
            * decl.cc (maybe_return_this): Don't emit_postconditions.
            (begin_destructor_body): Do it here.
            * semantics.cc (finish_mem_initializers): And here.
            (set_cleanup_locs): Don't mess with POSTCONDITION_STMT.

Diff:
---
 gcc/cp/cp-tree.h    | 2 +-
 gcc/cp/contracts.cc | 7 +++++--
 gcc/cp/decl.cc      | 8 +++-----
 gcc/cp/semantics.cc | 4 +++-
 4 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index f171ebc6eba..29d49466525 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -7785,7 +7785,7 @@ extern tree get_contracts_original_fn		(tree);
 
 extern void emit_assertion			(tree);
 extern void emit_preconditions			(tree);
-extern void emit_postconditions			(tree);
+extern void emit_postconditions_cleanup		(tree);
 extern void maybe_update_postconditions		(tree);
 extern void start_function_contracts		(tree);
 extern void finish_function_contracts		(tree);
diff --git a/gcc/cp/contracts.cc b/gcc/cp/contracts.cc
index 0efbfb176c8..93048f7203d 100644
--- a/gcc/cp/contracts.cc
+++ b/gcc/cp/contracts.cc
@@ -1748,9 +1748,12 @@ emit_preconditions (tree attr)
 /* Emit statements for postcondition attributes.  */
 
 void
-emit_postconditions (tree contracts)
+emit_postconditions_cleanup (tree contracts)
 {
-  return emit_contract_conditions (contracts, POSTCONDITION_STMT);
+  tree stmts = push_stmt_list ();
+  emit_contract_conditions (contracts, POSTCONDITION_STMT);
+  stmts = pop_stmt_list (stmts);
+  push_cleanup (NULL_TREE, stmts, /*eh_only*/false);
 }
 
 /* We're compiling the pre/postcondition function CONDFN; remap any FN
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 613a715f5cf..1384358d079 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -17816,9 +17816,6 @@ store_parm_decls (tree current_function_parms)
 void
 maybe_return_this (void)
 {
-  // FIXME make this work like other functions
-  emit_postconditions (DECL_CONTRACTS (current_function_decl));
-
   if (targetm.cxx.cdtor_returns_this ())
     {
       /* Return the address of the object.  */
@@ -17840,6 +17837,9 @@ begin_destructor_body (void)
 {
   tree compound_stmt;
 
+  emit_preconditions (DECL_CONTRACTS (current_function_decl));
+  emit_postconditions_cleanup (DECL_CONTRACTS (current_function_decl));
+
   /* If the CURRENT_CLASS_TYPE is incomplete, we will have already
      issued an error message.  We still want to try to process the
      body of the function, but initialize_vtbl_ptrs will crash if
@@ -17898,8 +17898,6 @@ begin_destructor_body (void)
 	 will be properly destroyed if we throw.  */
       push_base_cleanups ();
     }
-
-  emit_preconditions (DECL_CONTRACTS (current_function_decl));
 }
 
 /* Do the necessary processing for the beginning of a function body, which
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 9174375567d..05db605a701 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -610,7 +610,8 @@ set_cleanup_locs (tree stmts, location_t loc)
   if (TREE_CODE (stmts) == CLEANUP_STMT)
     {
       tree t = CLEANUP_EXPR (stmts);
-      protected_set_expr_location (t, loc);
+      if (t && TREE_CODE (t) != POSTCONDITION_STMT)
+	protected_set_expr_location (t, loc);
       /* Avoid locus differences for C++ cdtor calls depending on whether
 	 cdtor_returns_this: a conversion to void is added to discard the return
 	 value, and this conversion ends up carrying the location, and when it
@@ -2063,6 +2064,7 @@ finish_mem_initializers (tree mem_inits)
   else
     {
       emit_preconditions (DECL_CONTRACTS (current_function_decl));
+      emit_postconditions_cleanup (DECL_CONTRACTS (current_function_decl));
       emit_mem_initializers (mem_inits);
     }
 }