@@ -1748,7 +1748,7 @@ array_to_pointer_conversion (location_t loc, tree exp)
if (!TREE_READONLY (decl) && !TREE_STATIC (decl))
warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wc___compat,
"converting an array compound literal to a pointer "
- "is ill-formed in C++");
+ "leads to a dangling pointer in C++");
}
adr = build_unary_op (loc, ADDR_EXPR, exp, true);
@@ -8578,8 +8578,6 @@ convert_like_internal (conversion *convs, tree expr, tree fn, int argnum,
array = finish_compound_literal (array, new_ctor, complain);
/* This is dubious now, should be blessed by P2752. */
DECL_MERGEABLE (TARGET_EXPR_SLOT (array)) = true;
- /* Take the address explicitly rather than via decay_conversion
- to avoid the error about taking the address of a temporary. */
array = cp_build_addr_expr (array, complain);
}
else
@@ -2534,15 +2534,6 @@ decay_conversion (tree exp,
return error_mark_node;
}
- /* Don't let an array compound literal decay to a pointer. It can
- still be used to initialize an array or bind to a reference. */
- if (TREE_CODE (exp) == TARGET_EXPR)
- {
- if (complain & tf_error)
- error_at (loc, "taking address of temporary array");
- return error_mark_node;
- }
-
ptrtype = build_pointer_type (TREE_TYPE (type));
if (VAR_P (exp))
@@ -10535,6 +10526,9 @@ maybe_warn_about_returning_address_of_local (tree retval, location_t loc)
if (TYPE_REF_P (valtype))
warning_at (loc, OPT_Wreturn_local_addr,
"returning reference to temporary");
+ else if (TYPE_PTR_P (valtype))
+ warning_at (loc, OPT_Wreturn_local_addr,
+ "returning pointer to temporary");
else if (is_std_init_list (valtype))
warning_at (loc, OPT_Winit_list_lifetime,
"returning temporary %<initializer_list%> does not extend "
@@ -1,10 +1,11 @@
/* { dg-options "-std=c99 -Wc++-compat -Werror" { target c } } */
+/* { dg-options "-Werror=dangling-pointer=1" { target c++ } } */
/* { dg-prune-output "treated as errors" } */
#include <stdio.h>
int main()
{
- for (int *p = (int[]){ 1, 2, 3, 0 }; /* { dg-error "array" } */
+ for (int *p = (int[]){ 1, 2, 3, 0 }; /* { dg-error "array|temporary" } */
*p; ++p) {
printf("%d\n", *p);
}
new file mode 100644
@@ -0,0 +1,7 @@
+// PR c++/94264
+// { dg-do compile { target c++17 } }
+
+int main() {
+ using T = int[];
+ T{1, 2} == nullptr;
+}
new file mode 100644
@@ -0,0 +1,4 @@
+// PR c++/53220
+// { dg-options "" }
+
+int* f() { return (int[]){42}; } // { dg-warning "pointer to temporary" }