return build_cxx_call (fn, 0, NULL, tf_warning_or_error);
}
+/* Attempt to verify that the argument, OPER, of a placement new expression
+ refers to an object sufficiently large for an object of TYPE or an array
+ of NELTS of such objects when NELTS is non-null, and issue a warning when
+ it does not. SIZE specifies the size needed to construct the object or
+ array and captures the result of NELTS * sizeof (TYPE). (SIZE could be
+ greater when the array under construction requires a cookie to store
+ NELTS. GCC's placement new expression stores the cookie when invoking
+ a user-defined placement new operator function but not the default one.
+ Placement new expressions with user-defined placement new operator are
+ not diagnosed since we don't know how they use the buffer (this could
+ be a future extension). */
+static void
+warn_placement_new_too_small (tree type, tree nelts, tree size, tree oper)
+{
+ location_t loc = EXPR_LOC_OR_LOC (oper, input_location);
+
+ /* The number of bytes to add to or subtract from the size of the provided
+ buffer based on an offset into an array or an array element reference.
+ Although intermediate results may be negative (as in a[3] - 2) the final
+ result cannot be. */
+ HOST_WIDE_INT adjust = 0;
+ /* True when the size of the entire destination object should be used
+ to compute the possibly optimistic estimate of the available space. */
+ bool use_obj_size = false;
+ /* True when the reference to the destination buffer is an ADDR_EXPR. */
+ bool addr_expr = false;
+
+ STRIP_NOPS (oper);
+
+ /* Using a function argument or a (non-array) variable as an argument
+ to placement new is not checked since it's unknown what it might
+ point to. */
+ if (TREE_CODE (oper) == PARM_DECL
+ || TREE_CODE (oper) == VAR_DECL
+ || TREE_CODE (oper) == COMPONENT_REF)
+ return;
+
+ /* Evaluate any constant expressions. */
+ size = fold_non_dependent_expr (size);
+
+ /* Handle the common case of array + offset expression when the offset
+ is a constant. */
+ if (TREE_CODE (oper) == POINTER_PLUS_EXPR)
+ {
+ /* If the offset is comple-time constant, use it to compute a more
+ accurate estimate of the size of the buffer. Otherwise, use
+ the size of the entire array as an optimistic estimate (this
+ may lead to false negatives). */
+ const_tree adj = TREE_OPERAND (oper, 1);
+ if (CONSTANT_CLASS_P (adj))
+ adjust += tree_to_uhwi (adj);
+ else
+ use_obj_size = true;
+
+ oper = TREE_OPERAND (oper, 0);
+
+ STRIP_NOPS (oper);
+ }
+
+ if (TREE_CODE (oper) == TARGET_EXPR)
+ oper = TREE_OPERAND (oper, 1);
+ else if (TREE_CODE (oper) == ADDR_EXPR)
+ {
+ addr_expr = true;
+ oper = TREE_OPERAND (oper, 0);
+ }
+
+ STRIP_NOPS (oper);
+
+ if (TREE_CODE (oper) == ARRAY_REF)
+ {
+ /* Similar to the offset computed above, see if the array index
+ is a compile-time constant. If so, and unless the offset was
+ not a compile-time constant, use the index to determine the
+ size of the buffer. Otherwise, use the entire array as
+ an optimistic estimate of the size. */
+ const_tree adj = TREE_OPERAND (oper, 1);
+ if (!use_obj_size && CONSTANT_CLASS_P (adj))
+ adjust += tree_to_shwi (adj);
+ else
+ {
+ use_obj_size = true;
+ adjust = 0;
+ }
+
+ oper = TREE_OPERAND (oper, 0);
+ }
+
+ /* Descend into a struct or union to find the member whose address
+ is being used as the agument. */
+ while (TREE_CODE (oper) == COMPONENT_REF)
+ oper = TREE_OPERAND (oper, 1);
+
+ if ((addr_expr || !POINTER_TYPE_P (TREE_TYPE (oper)))
+ && (TREE_CODE (oper) == VAR_DECL
+ || TREE_CODE (oper) == FIELD_DECL
+ || TREE_CODE (oper) == PARM_DECL))
+ {
+ /* A possibly optimistic estimate of the number of bytes available
+ in the destination buffer. */
+ unsigned HOST_WIDE_INT bytes_avail;
+ /* True when the estimate above is in fact the exact size
+ of the destination buffer rather than an estimate. */
+ bool exact_size = true;
+
+ /* Treat members of unions and members of structs uniformly, even
+ though the size of a member of a union may be viewed as extending
+ to the end of the union itself (it is by __builtin_object_size). */
+ if (TREE_CODE (oper) == VAR_DECL || use_obj_size)
+ {
+ /* Use the size of the entire array object when the expression
+ refers to a variable or its size depends on an expression
+ that's not a compile-time constant. */
+ bytes_avail = tree_to_shwi (DECL_SIZE_UNIT (oper));
+ exact_size = !use_obj_size;
+ }
+ else
+ {
+ /* Use the size of the type of the destination buffer object
+ as the optimistic estimate of the available space in it. */
+ bytes_avail = tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (oper)));
+ }
+
+ /* Avoid diagnosing flexible array members (accepted as an extension
+ and diagnosed with -Wpedantic).
+ Constructing objects that appear to overflow the C99 equivalent of
+ flexible array members (i.e., array members of size zero or one)
+ are diagnosed in C++ since their declaration cannot be diagnosed. */
+ if (bytes_avail == 0 && TREE_CODE (TREE_TYPE (oper)) == ARRAY_TYPE)
+ return;
+
+ /* The size of the buffer can only be adjusted down but not up. */
+ gcc_checking_assert (0 <= adjust);
+
+ /* Reduce the size of the buffer by the adjustment computed above
+ from the offset and/or the index into the array. */
+ if (bytes_avail < static_cast<unsigned HOST_WIDE_INT>(adjust))
+ bytes_avail = 0;
+ else
+ bytes_avail -= adjust;
+
+ /* The minimum amount of space needed for the allocation. This
+ is an optimistic estimate that makes it possible to detect
+ placement new invocation for some undersize buffers but not
+ others. */
+ unsigned HOST_WIDE_INT bytes_need;
+
+ if (CONSTANT_CLASS_P (size))
+ bytes_need = tree_to_uhwi (size);
+ else if (nelts && CONSTANT_CLASS_P (nelts))
+ bytes_need = tree_to_uhwi (nelts)
+ * tree_to_uhwi (TYPE_SIZE_UNIT (type));
+ else
+ bytes_need = tree_to_uhwi (TYPE_SIZE_UNIT (type));
+
+ if (bytes_avail < bytes_need)
+ {
+ if (nelts)
+ if (CONSTANT_CLASS_P (nelts))
+ warning_at (loc, OPT_Wplacement_new,
+ exact_size ?
+ "placement new constructing an object of type "
+ "%<%T [%wu]%> and size %qwu in a region of type %qT "
+ "and size %qwi"
+ : "placement new constructing an object of type "
+ "%<%T [%lu]%> and size %qwu in a region of type %qT "
+ "and size at most %qwu",
+ type, tree_to_uhwi (nelts), bytes_need,
+ TREE_TYPE (oper),
+ bytes_avail);
+ else
+ warning_at (loc, OPT_Wplacement_new,
+ exact_size ?
+ "placement new constructing an array of objects "
+ "of type %qT and size %qwu in a region of type %qT "
+ "and size %qwi"
+ : "placement new constructing an array of objects "
+ "of type %qT and size %qwu in a region of type %qT "
+ "and size at most %qwu",
+ type, bytes_need, TREE_TYPE (oper),
+ bytes_avail);
+ else
+ warning_at (loc, OPT_Wplacement_new,
+ exact_size ?
+ "placement new constructing an object of type %qT "
+ "and size %qwu in a region of type %qT and size %qwi"
+ : "placement new constructing an object of type %qT"
+ "and size %qwu in a region of type %qT and size "
+ "at most %qwu",
+ type, bytes_need, TREE_TYPE (oper),
+ bytes_avail);
+ }
+ }
+}
+
/* Generate code for a new-expression, including calling the "operator
new" function, initializing the object, and, if an exception occurs
during construction, cleaning up. The arguments are as for
&& (TYPE_PTR_P (TREE_TYPE ((**placement)[0]))))
placement_first = (**placement)[0];
+ bool member_new_p = false;
+
/* Allocate the object. */
if (vec_safe_is_empty (*placement) && TYPE_FOR_JAVA (elt_type))
{
fnname = ansi_opname (array_p ? VEC_NEW_EXPR : NEW_EXPR);
- if (!globally_qualified_p
+ member_new_p = !globally_qualified_p
&& CLASS_TYPE_P (elt_type)
&& (array_p
? TYPE_HAS_ARRAY_NEW_OPERATOR (elt_type)
- : TYPE_HAS_NEW_OPERATOR (elt_type)))
+ : TYPE_HAS_NEW_OPERATOR (elt_type));
+
+ if (member_new_p)
{
/* Use a class-specific operator new. */
/* If a cookie is required, add some extra space. */
/* If we found a simple case of PLACEMENT_EXPR above, then copy it
into a temporary variable. */
if (!processing_template_decl
- && placement_first != NULL_TREE
&& TREE_CODE (alloc_call) == CALL_EXPR
&& call_expr_nargs (alloc_call) == 2
&& TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (alloc_call, 0))) == INTEGER_TYPE
&& TYPE_PTR_P (TREE_TYPE (CALL_EXPR_ARG (alloc_call, 1))))
{
- tree placement_arg = CALL_EXPR_ARG (alloc_call, 1);
+ tree placement = CALL_EXPR_ARG (alloc_call, 1);
- if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (TREE_TYPE (placement_arg)))
- || VOID_TYPE_P (TREE_TYPE (TREE_TYPE (placement_arg))))
+ if (placement_first != NULL_TREE
+ && (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (TREE_TYPE (placement)))
+ || VOID_TYPE_P (TREE_TYPE (TREE_TYPE (placement)))))
{
placement_expr = get_target_expr (placement_first);
CALL_EXPR_ARG (alloc_call, 1)
- = convert (TREE_TYPE (placement_arg), placement_expr);
+ = convert (TREE_TYPE (placement), placement_expr);
+ }
+
+ if (!member_new_p
+ && VOID_TYPE_P (TREE_TYPE (TREE_TYPE (CALL_EXPR_ARG (alloc_call, 1)))))
+ {
+ /* Attempt to make the warning point at the operator new argument. */
+ if (placement_first)
+ placement = placement_first;
+
+ warn_placement_new_too_small (orig_type, nelts, size, placement);
}
}
--- /dev/null
+/* { dg-do compile } */
+/* { dg-options "-Wplacement-new -fpermissive" } */
+
+typedef __typeof__ (sizeof 0) size_t;
+
+void* operator new (size_t, void *p) { return p; }
+void* operator new[] (size_t, void *p) { return p; }
+
+static __attribute__ ((used))char c;
+static __attribute__ ((used))char ac1 [1];
+static __attribute__ ((used))char ac2 [2];
+static __attribute__ ((used))char ac3 [3];
+static __attribute__ ((used))char ac4 [4];
+static __attribute__ ((used))char ac5 [5];
+static __attribute__ ((used))char ac6 [6];
+static __attribute__ ((used))char ac7 [7];
+static __attribute__ ((used))char ac8 [8];
+
+static __attribute__ ((used))char ac1_1 [1][1];
+static __attribute__ ((used))char ac1_2 [1][2];
+static __attribute__ ((used))char ac2_1 [2][1];
+static __attribute__ ((used))char ac2_2 [2][2];
+
+static __attribute__ ((used))short s;
+static __attribute__ ((used))short as1 [1];
+static __attribute__ ((used))short as2 [2];
+
+static __attribute__ ((used))struct SC { char c; char *pc; void *pv; } sc;
+static __attribute__ ((used))struct SAC1 { char ac [1]; } sac1;
+static __attribute__ ((used))struct SAC2 { char ac [2]; } sac2;
+static __attribute__ ((used))struct SAC3 { char ac [3]; } sac3;
+static __attribute__ ((used))struct SAC4 { char ac [4]; } sac4;
+
+static __attribute__ ((used))struct SSC { SC sc; int x; } ssc;
+static __attribute__ ((used))struct SSAC1 { SAC1 sac; } ssac1;
+static __attribute__ ((used))struct SSAC2 { SAC2 sac; } ssac2;
+static __attribute__ ((used))struct SSAC3 { SAC3 sac; } ssac3;
+static __attribute__ ((used))struct SSAC4 { SAC4 sac; } ssac4;
+
+static __attribute__ ((used))struct SSAC4_2 { SSAC4 ssac4_2 [2]; } sssac4_2;
+
+static __attribute__ ((used))union UAC1 { char c; char ac [1]; } uac1;
+static __attribute__ ((used))union UAC2 { char c; char ac [2]; } uac2;
+static __attribute__ ((used))union UAC3 { char c; char ac [3]; } uac3;
+static __attribute__ ((used))union UAC4 { char c; char ac [4]; } uac4;
+
+static __attribute__ ((used))SC fsc () { return SC (); }
+static __attribute__ ((used))SAC1 fasc1 () { return SAC1 (); }
+static __attribute__ ((used))SAC2 fasc2 () { return SAC2 (); }
+static __attribute__ ((used))SAC3 fasc3 () { return SAC3 (); }
+static __attribute__ ((used))SAC4 fasc4 () { return SAC4 (); }
+
+static __attribute__ ((used))void *r;
+
+static __attribute__ ((used))void* ptr () { return 0; }
+
+static __attribute__ ((used))
+void test (void *p, int n)
+{
+ {
+ void *q = p;
+ struct { void *p; } s = { p };
+
+ // Verify that none of function arguments, local or global
+ // variables, or function return values trigger the warning.
+ new (p) char;
+ new (q) char;
+ new (r) char;
+ new (s.p) char;
+ new (ptr ()) char;
+
+ new (p) char [32];
+ new (q) char [32];
+ new (r) char [32];
+ new (s.p) char [32];
+ new (ptr ()) char [32];
+
+ new (&p) char;
+ new (&q) char;
+ new (&r) char;
+
+ // Using address of objects, however, must trigger the warning.
+ new (&p) char [32]; // { dg-warning "placement" }
+ new (&q) char [32]; // { dg-warning "placement" }
+ new (&r) char [32]; // { dg-warning "placement" }
+ }
+
+ enum { N0, N1, N2, N3 };
+
+ new (&c) char;
+
+ // Warn for the common case when constructing at an offset from
+ // the beginning of an array that doesn't leave enough space for
+ // the object.
+ new (&c + 0) char; // okay
+ new (&c + n) char; // okay (n is unknown)
+ new (&c + 1) char; // { dg-warning "placement" }
+ new (&c + N0) char;
+ new (&c + N1) char; // { dg-warning "placement" }
+
+ // No warning is issued when constructing an array in space exactly
+ // its size even though strictly speaking a compiler is allowed to
+ // add a cookie to the array (gcc does not).
+ new (&c) char [1];
+ new (&c) char [sizeof c];
+ new (&c) char [n];
+ new (&c) char [1][1];
+ new (&c) char [1][1][1];
+ new (&c + N1) char [1][1][1]; // { dg-warning "placement" }
+
+ new (&c) char [2]; // { dg-warning "placement" }
+ new (&c) char [sizeof c + 1]; // { dg-warning "placement" }
+ new (&c) char [1][2]; // { dg-warning "placement" }
+ new (&c) char [2][1]; // { dg-warning "placement" }
+ new (&c) char [n][1];
+ new (&c) char [n][2]; // { dg-warning "placement" }
+ new (&c) char [3]; // { dg-warning "placement" }
+ new (&c) char [3][1]; // { dg-warning "placement" }
+ new (&c) char [1][3]; // { dg-warning "placement" }
+ new (&c) char [4][1]; // { dg-warning "placement" }
+ new (&c) char [1][4]; // { dg-warning "placement" }
+
+ // Casts must not suppress it.
+ new ((void*)&c) char [2]; // { dg-warning "placement" }
+ new ((char*)&c) char [3]; // { dg-warning "placement" }
+
+ new (static_cast<void*>(&c)) char [4]; // { dg-warning "placement" }
+ new (reinterpret_cast<char*>(&c)) char [5]; // { dg-warning "placement" }
+
+ new (&c + 0) char [2]; // { dg-warning "placement" }
+ new (&c + 0) char [3]; // { dg-warning "placement" }
+ new (&c + 0) char [4]; // { dg-warning "placement" }
+
+ new (&c + 1) char [2]; // { dg-warning "placement" }
+ new (&c + 1) char [3]; // { dg-warning "placement" }
+ new (&c + 1) char [4]; // { dg-warning "placement" }
+
+ new (&c + N0) char [1];
+ new (&c + N1) char [2]; // { dg-warning "placement" }
+
+ // Warn even though n is unknown since c is too small for char[2]
+ // regardless of the value of n.
+ new (&c + n) char [2]; // { dg-warning "placement" }
+
+ new (ac2) char [1];
+ new (ac2) char [1][1];
+ new (ac2) char [1][2];
+ new (ac2) char [2][1];
+ new (ac2) char [1][3]; // { dg-warning "placement" }
+ new (ac2) char [2][2]; // { dg-warning "placement" }
+ new (ac2) char [3][1]; // { dg-warning "placement" }
+
+ new (ac2 + N0) char [1][1];
+ new (ac2 + N0) char [1][2];
+ new (ac2 + N1) char [1][2]; // { dg-warning "placement" }
+ new (ac2 + N1) char [2][1]; // { dg-warning "placement" }
+ new (ac2 + N2) char [1][1]; // { dg-warning "placement" }
+ new (ac2 + N2) char [1][2]; // { dg-warning "placement" }
+ new (ac2 + N2) char [2][1]; // { dg-warning "placement" }
+ new (ac2 + N2) char [2][2]; // { dg-warning "placement" }
+
+ new (ac8) char [1];
+ new (ac8) char [2][2];
+ new (ac8) char [2][3];
+ new (ac8) char [2][4];
+ new (ac8) char [2][5]; // { dg-warning "placement" }
+ new (ac8) char [2][2][2];
+ new (ac8) char [2][2][3]; // { dg-warning "placement" }
+
+ new (&c) int; // { dg-warning "placement" }
+
+ new (&ac1) int; // { dg-warning "placement" }
+ new (&ac2) int; // { dg-warning "placement" }
+ new (&ac3) int; // { dg-warning "placement" }
+ new (&ac4) int;
+
+ // Constructing at an address of an array element.
+ new (&ac1 [0]) int; // { dg-warning "placement" }
+ new (&ac2 [0]) int; // { dg-warning "placement" }
+ new (&ac3 [0]) int; // { dg-warning "placement" }
+ new (&ac4 [0]) int;
+
+ // ...plus or minus a constant offset.
+ new (&ac1 [0] + 0) int; // { dg-warning "placement" }
+ new (&ac2 [0] + 0) int; // { dg-warning "placement" }
+ new (&ac3 [0] + 0) int; // { dg-warning "placement" }
+ new (&ac4 [0] + 0) int;
+ new (&ac4 [1] + 0) int; // { dg-warning "placement" }
+ new (&ac4 [1] - 1) int;
+ new (&ac4 [2] - 1) int; // { dg-warning "placement" }
+ new (&ac4 [2] - 2) int;
+ new (&ac4 [3] - 1) int; // { dg-warning "placement" }
+ new (&ac4 [3] - 2) int; // { dg-warning "placement" }
+ new (&ac4 [3] - 3) int;
+ new (&ac4 [4] - 1) int; // { dg-warning "placement" }
+ new (&ac4 [4] - 2) int; // { dg-warning "placement" }
+ new (&ac4 [4] - 3) int; // { dg-warning "placement" }
+ new (&ac4 [4] - 4) int;
+
+ new (&ac1 [0] + 1) int; // { dg-warning "placement" }
+ new (&ac2 [0] + 1) int; // { dg-warning "placement" }
+ new (&ac3 [0] + 1) int; // { dg-warning "placement" }
+ new (&ac4 [0] + 1) int; // { dg-warning "placement" }
+
+ new (&ac3 [0] + n) int; // { dg-warning "placement" }
+ new (&ac4 [0] + n) int; // no warning (n could be zero)
+ new (&ac4 [1] + n) int; // no warning (n could be negative)
+ new (&ac4 [2] + n) int; // ditto
+ new (&ac4 [3] + n) int; // ditto
+ new (&ac4 [4] + n) int; // ditto
+ new (&ac4 [4] - n) int; // (or positive)
+
+ new (&c + 0) int; // { dg-warning "placement" }
+ new (&c + 1) int; // { dg-warning "placement" }
+
+ // Constructing at an offset into the address of an array.
+ new (&ac1 + 0) int; // { dg-warning "placement" }
+ new (&ac1 + 1) int; // { dg-warning "placement" }
+ new (&ac1 + n) int; // { dg-warning "placement" }
+ new (&ac2 + 0) int; // { dg-warning "placement" }
+ new (&ac2 + 1) int; // { dg-warning "placement" }
+ new (&ac2 + n) int; // { dg-warning "placement" }
+ new (&ac3 + 0) int; // { dg-warning "placement" }
+ new (&ac3 + 1) int; // { dg-warning "placement" }
+
+ // Even though n below is uknown an array of 3 bytes isn't large
+ // enugh for an int.
+ new (&ac3 + n) int; // { dg-warning "placement" }
+
+ new (&ac4 + 0) int;
+ new (&ac4 + 1) int; // { dg-warning "placement" }
+ new (&ac4 + n) int; // no warning (n could be zero)
+
+ // Constructing in an array object.
+ new (ac1) int; // { dg-warning "placement" }
+ new (ac2) int; // { dg-warning "placement" }
+ new (ac3) int; // { dg-warning "placement" }
+ new (ac4) int;
+ new (ac5) int;
+ new (ac5 + 0) int;
+ new (ac5 + 1) int;
+ new (ac5 + n) int; // no warning (n could be zero)
+ new (ac5 + 2) int; // { dg-warning "placement" }
+ new (ac5 + 3) int; // { dg-warning "placement" }
+ new (ac5 + 4) int; // { dg-warning "placement" }
+ new (ac5 + 5) int; // { dg-warning "placement" }
+
+ new (ac1_1) char;
+ new (ac1_1) char[1];
+ new (ac1_1) char[n]; // no warning (n is unknown)
+ new (ac1_1) char[2]; // { dg-warning "placement" }
+ new (ac1_1) char[3]; // { dg-warning "placement" }
+
+ new (ac1_2) char;
+ new (ac1_2) char[1];
+ new (ac1_2) char[2];
+ new (ac1_2) char[3]; // { dg-warning "placement" }
+
+ new (ac2_1) char;
+ new (ac2_1) char[1];
+ new (ac2_1) char[2];
+ new (ac2_1) char[3]; // { dg-warning "placement" }
+
+ new (ac2_2) char;
+ new (ac2_2) char[1];
+ new (ac2_2) char[2];
+ new (ac2_2) char[2][2];
+
+ // Even though n below is uknown it can't meaningfully be zero
+ // (even if zero-size arrays are allowed as an extension, the size
+ // they are allocated in by placement new is zero).
+ new (ac1_1) char[n][2]; // { dg-warning "placement" }
+ new (ac2_2) char[3];
+ new (ac2_2) char[3][1];
+ new (ac2_2) char[3][2]; // { dg-warning "placement" }
+ new (ac2_2) char[4];
+ new (ac2_2) char[4][1];
+ new (ac2_2) char[4][2]; // { dg-warning "placement" }
+ new (ac2_2) char[5]; // { dg-warning "placement" }
+
+ new (&s) int; // { dg-warning "placement" }
+ new (&as1) int; // { dg-warning "placement" }
+ new (&as2) int;
+
+ new (as1) int; // { dg-warning "placement" }
+ new (as2) int;
+
+ new (&sc.c) int; // { dg-warning "placement" }
+ new (&sac1.ac) int; // { dg-warning "placement" }
+ new (&sac2.ac) int; // { dg-warning "placement" }
+ new (&sac3.ac) int; // { dg-warning "placement" }
+ new (&sac4.ac) int;
+
+ new (sc.pc) char;
+ new (sc.pc) int;
+ new (sc.pc) int[1024];
+ new (sc.pc + 0) int;
+ new (sc.pc + 0) int[2048];
+ new (sc.pv) int;
+ new (sc.pv) char[1024];
+
+ new (sac1.ac) int; // { dg-warning "placement" }
+ new (sac2.ac) int; // { dg-warning "placement" }
+ new (sac3.ac) int; // { dg-warning "placement" }
+ new (sac4.ac) int;
+
+ new (&ssc.sc) SSC; // { dg-warning "placement" }
+ new (&ssac1.sac) int; // { dg-warning "placement" }
+ new (&ssac2.sac) int; // { dg-warning "placement" }
+ new (&ssac3.sac) int; // { dg-warning "placement" }
+ new (&ssac4.sac) int;
+
+ new (&sssac4_2) char[sizeof sssac4_2];
+ new (&sssac4_2) char[sizeof sssac4_2 + 1]; // { dg-warning "placement" }
+
+ // taking the address of a temporary is allowed with -fpermissive
+ new (&fsc ().c) int; // { dg-warning "address|placement" }
+ new (&fasc1 ().ac) int; // { dg-warning "address|placement" }
+ new (&fasc2 ().ac) int; // { dg-warning "address|placement" }
+ new (&fasc3 ().ac) int; // { dg-warning "address|placement" }
+ new (&fasc4 ().ac) int; // { dg-warning "address|placement" }
+
+ new (&uac1) int; // { dg-warning "placement" }
+ new (&uac2) int; // { dg-warning "placement" }
+ new (&uac3) int; // { dg-warning "placement" }
+ new (&uac4) int;
+ new (&uac4 + 1) int; // { dg-warning "placement" }
+
+ new (&uac1.c) int; // { dg-warning "placement" }
+ new (&uac2.c) int; // { dg-warning "placement" }
+ new (&uac3.c) int; // { dg-warning "placement" }
+
+ // Diagnose the following even though the size of uac4.c could be
+ // expected to extend to the end of the union (as it is by Built-in
+ // Object Size and so isn't diagnosed in calls to functions like
+ // memset(&uac4.c, 0, sizeof(int)) when _FORTIFY_SOURCE is non-zero. */
+ new (&uac4.c) int; // { dg-warning "placement" }
+
+ new (&uac4.c + 1) int; // { dg-warning "placement" }
+}
+
+
+struct S { char c [2]; };
+
+// Verify the full text of the warning message.
+static __attribute__ ((used))
+void test_message (int i)
+{
+ char a [2];
+
+ // The exact sizes of both the buffer and the type are known.
+ new (a + 1) S; // { dg-warning "placement new constructing an object of type .S. and size .2. in a region of type .char \\\[2\\\]. and size .1." }
+
+ // The buffer size is known but only the size of the type whose
+ // objects are being constructed is known, not their number. While
+ // in theory it could be zero, it practice likely never will be so
+ // the potential false positive is acceptable.
+ new (a + 1) S [i]; // { dg-warning "placement new constructing an array of objects of type .S. and size .2. in a region of type .char \\\[2\\\]. and size .1." }
+
+ // The exact amount of space in the buffer isn't known, only its
+ // maximum is. The exact size of the array being created is known.
+ new (a + i) S [2]; // { dg-warning "placement new constructing an object of type .S \\\[2\\\]. and size .4. in a region of type .char \\\[2\\\]. and size at most .2." }
+}
+
+
+struct ClassWithMemberNew {
+ struct Object { int i; } *pobj;
+ unsigned nobj;
+
+ ClassWithMemberNew ();
+ void foo ();
+
+ void* operator new (size_t, void*);
+ void* operator new[] (size_t, void*);
+};
+
+void ClassWithMemberNew::foo()
+{
+ for (unsigned i = 0; i != nobj; ++i)
+ new (pobj + i) Object ();
+}
+
+
+struct ClassWithGlobalNew {
+ int a [4];
+ ClassWithGlobalNew ();
+};
+
+void* operator new (size_t, ClassWithGlobalNew*);
+void* operator new[] (size_t, ClassWithGlobalNew*);
+
+void test_user_defined_placement_new ()
+{
+ {
+ ClassWithMemberNew x;
+
+ // Expect no diagnostics for placement new expressions with types
+ // with their own placement operator new since the semantics of
+ // the operator aren't known.
+ new (&c) ClassWithMemberNew;
+ new (&x) ClassWithMemberNew[2];
+ }
+
+ {
+ ClassWithGlobalNew x;
+
+ new (&c) ClassWithGlobalNew; // { dg-warning "placement" }
+ new (&x) ClassWithGlobalNew[2];
+ }
+}
projects / gcc.git / commitdiff