https://gcc.gnu.org/g:ed63cd2aa5b114565fe5499c3a6bf8da5e8e48ba
commit r15-796-ged63cd2aa5b114565fe5499c3a6bf8da5e8e48ba
Author: Jason Merrill <ja...@redhat.com>
Date: Wed May 22 18:41:27 2024 -0400
c++: deleting array temporary [PR115187]
Decaying the array temporary to a pointer and then deleting that crashes in
verify_gimple_stmt, because the TARGET_EXPR is first evaluated inside the
TRY_FINALLY_EXPR, but the cleanup point is outside. Fixed by using
get_target_expr instead of save_expr.
I also adjust the stabilize_expr comment to prevent me from again thinking
it's a suitable replacement.
PR c++/115187
gcc/cp/ChangeLog:
* init.cc (build_delete): Use get_target_expr instead of save_expr.
* tree.cc (stabilize_expr): Update comment.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1z/array-prvalue3.C: New test.
Diff:
---
gcc/cp/init.cc | 9 ++++++++-
gcc/cp/tree.cc | 6 +++++-
gcc/testsuite/g++.dg/cpp1z/array-prvalue3.C | 8 ++++++++
3 files changed, 21 insertions(+), 2 deletions(-)
diff --git a/gcc/cp/init.cc b/gcc/cp/init.cc
index 906e401974c..52396d87a8c 100644
--- a/gcc/cp/init.cc
+++ b/gcc/cp/init.cc
@@ -5228,9 +5228,13 @@ build_delete (location_t loc, tree otype, tree addr,
addr = convert_force (build_pointer_type (type), addr, 0, complain);
}
+ tree addr_expr = NULL_TREE;
if (deleting)
/* We will use ADDR multiple times so we must save it. */
- addr = save_expr (addr);
+ {
+ addr_expr = get_target_expr (addr);
+ addr = TARGET_EXPR_SLOT (addr_expr);
+ }
bool virtual_p = false;
if (type_build_dtor_call (type))
@@ -5349,6 +5353,9 @@ build_delete (location_t loc, tree otype, tree addr,
if (!integer_nonzerop (ifexp))
expr = build3 (COND_EXPR, void_type_node, ifexp, expr, void_node);
+ if (addr_expr)
+ expr = cp_build_compound_expr (addr_expr, expr, tf_none);
+
protected_set_expr_location (expr, loc);
return expr;
}
diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc
index 4d87661b4ad..0485a618c6c 100644
--- a/gcc/cp/tree.cc
+++ b/gcc/cp/tree.cc
@@ -5924,7 +5924,11 @@ decl_storage_duration (tree decl)
*INITP) an expression that will perform the pre-evaluation. The
value returned by this function is a side-effect free expression
equivalent to the pre-evaluated expression. Callers must ensure
- that *INITP is evaluated before EXP. */
+ that *INITP is evaluated before EXP.
+
+ Note that if EXPR is a glvalue, the return value is a glvalue denoting the
+ same address; this function does not guard against modification of the
+ stored value like save_expr or get_target_expr do. */
tree
stabilize_expr (tree exp, tree* initp)
diff --git a/gcc/testsuite/g++.dg/cpp1z/array-prvalue3.C
b/gcc/testsuite/g++.dg/cpp1z/array-prvalue3.C
new file mode 100644
index 00000000000..f264e46084a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/array-prvalue3.C
@@ -0,0 +1,8 @@
+// PR c++/115187
+// { dg-do compile { target c++17 } }
+
+void f() {
+ using T = int[2];
+ delete T{}; // { dg-warning "deleting array" }
+ // { dg-warning "unallocated object" "" { target *-*-* } .-1 }
+}
