binop_types_user_defined_p (enum exp_opcode op,
struct type *type1, struct type *type2)
{
- if (op == BINOP_ASSIGN || op == BINOP_CONCAT)
+ if (op == BINOP_ASSIGN)
return 0;
type1 = check_typedef (type1);
}
\f
-/* Concatenate two values with the following conditions:
-
- (1) Both values must be either bitstring values or character string
- values and the resulting value consists of the concatenation of
- ARG1 followed by ARG2.
-
- or
-
- One value must be an integer value and the other value must be
- either a bitstring value or character string value, which is
- to be repeated by the number of times specified by the integer
- value.
-
-
- (2) Boolean values are also allowed and are treated as bit string
- values of length 1.
-
- (3) Character values are also allowed and are treated as character
- string values of length 1. */
+/* Concatenate two values. One value must be an array; and the other
+ value must either be an array with the same element type, or be of
+ the array's element type. */
struct value *
value_concat (struct value *arg1, struct value *arg2)
{
- struct value *inval1;
- struct value *inval2;
- struct value *outval = NULL;
- int inval1len, inval2len;
- int count, idx;
- char inchar;
struct type *type1 = check_typedef (value_type (arg1));
struct type *type2 = check_typedef (value_type (arg2));
- struct type *char_type;
- /* First figure out if we are dealing with two values to be concatenated
- or a repeat count and a value to be repeated. INVAL1 is set to the
- first of two concatenated values, or the repeat count. INVAL2 is set
- to the second of the two concatenated values or the value to be
- repeated. */
+ if (type1->code () != TYPE_CODE_ARRAY && type2->code () != TYPE_CODE_ARRAY)
+ error ("no array provided to concatenation");
- if (type2->code () == TYPE_CODE_INT)
+ LONGEST low1, high1;
+ struct type *elttype1 = type1;
+ if (elttype1->code () == TYPE_CODE_ARRAY)
{
- struct type *tmp = type1;
-
- type1 = tmp;
- tmp = type2;
- inval1 = arg2;
- inval2 = arg1;
+ elttype1 = TYPE_TARGET_TYPE (elttype1);
+ if (!get_array_bounds (type1, &low1, &high1))
+ error (_("could not determine array bounds on left-hand-side of "
+ "array concatenation"));
}
else
{
- inval1 = arg1;
- inval2 = arg2;
+ low1 = 0;
+ high1 = 0;
}
- /* Now process the input values. */
-
- if (type1->code () == TYPE_CODE_INT)
- {
- /* We have a repeat count. Validate the second value and then
- construct a value repeated that many times. */
- if (type2->code () == TYPE_CODE_STRING
- || type2->code () == TYPE_CODE_CHAR)
- {
- count = longest_to_int (value_as_long (inval1));
- inval2len = TYPE_LENGTH (type2);
- std::vector<char> ptr (count * inval2len);
- if (type2->code () == TYPE_CODE_CHAR)
- {
- char_type = type2;
-
- inchar = (char) unpack_long (type2,
- value_contents (inval2).data ());
- for (idx = 0; idx < count; idx++)
- {
- ptr[idx] = inchar;
- }
- }
- else
- {
- char_type = TYPE_TARGET_TYPE (type2);
-
- for (idx = 0; idx < count; idx++)
- memcpy (&ptr[idx * inval2len], value_contents (inval2).data (),
- inval2len);
- }
- outval = value_string (ptr.data (), count * inval2len, char_type);
- }
- else if (type2->code () == TYPE_CODE_BOOL)
- {
- error (_("unimplemented support for boolean repeats"));
- }
- else
- {
- error (_("can't repeat values of that type"));
- }
- }
- else if (type1->code () == TYPE_CODE_STRING
- || type1->code () == TYPE_CODE_CHAR)
- {
- /* We have two character strings to concatenate. */
- if (type2->code () != TYPE_CODE_STRING
- && type2->code () != TYPE_CODE_CHAR)
- {
- error (_("Strings can only be concatenated with other strings."));
- }
- inval1len = TYPE_LENGTH (type1);
- inval2len = TYPE_LENGTH (type2);
- std::vector<char> ptr (inval1len + inval2len);
- if (type1->code () == TYPE_CODE_CHAR)
- {
- char_type = type1;
-
- ptr[0] = (char) unpack_long (type1, value_contents (inval1).data ());
- }
- else
- {
- char_type = TYPE_TARGET_TYPE (type1);
-
- memcpy (ptr.data (), value_contents (inval1).data (), inval1len);
- }
- if (type2->code () == TYPE_CODE_CHAR)
- {
- ptr[inval1len] =
- (char) unpack_long (type2, value_contents (inval2).data ());
- }
- else
- {
- memcpy (&ptr[inval1len], value_contents (inval2).data (), inval2len);
- }
- outval = value_string (ptr.data (), inval1len + inval2len, char_type);
- }
- else if (type1->code () == TYPE_CODE_BOOL)
+ LONGEST low2, high2;
+ struct type *elttype2 = type2;
+ if (elttype2->code () == TYPE_CODE_ARRAY)
{
- /* We have two bitstrings to concatenate. */
- if (type2->code () != TYPE_CODE_BOOL)
- {
- error (_("Booleans can only be concatenated "
- "with other bitstrings or booleans."));
- }
- error (_("unimplemented support for boolean concatenation."));
+ elttype2 = TYPE_TARGET_TYPE (elttype2);
+ if (!get_array_bounds (type2, &low2, &high2))
+ error (_("could not determine array bounds on right-hand-side of "
+ "array concatenation"));
}
else
{
- /* We don't know how to concatenate these operands. */
- error (_("illegal operands for concatenation."));
+ low2 = 0;
+ high2 = 0;
}
- return (outval);
+
+ if (!types_equal (elttype1, elttype2))
+ error (_("concatenation with different element types"));
+
+ LONGEST lowbound = current_language->c_style_arrays_p () ? 0 : 1;
+ LONGEST n_elts = (high1 - low1 + 1) + (high2 - low2 + 1);
+ struct type *atype = lookup_array_range_type (elttype1,
+ lowbound,
+ lowbound + n_elts - 1);
+
+ struct value *result = allocate_value (atype);
+ gdb::array_view<gdb_byte> contents = value_contents_raw (result);
+ gdb::array_view<const gdb_byte> lhs_contents = value_contents (arg1);
+ gdb::array_view<const gdb_byte> rhs_contents = value_contents (arg2);
+ gdb::copy (lhs_contents, contents.slice (0, lhs_contents.size ()));
+ gdb::copy (rhs_contents, contents.slice (lhs_contents.size ()));
+
+ return result;
}
\f
/* Integer exponentiation: V1**V2, where both arguments are
return value_literal_complex (result_real, result_imag, result_type);
}
+/* Return the type's length in bits. */
+
+static int
+type_length_bits (type *type)
+{
+ int unit_size = gdbarch_addressable_memory_unit_size (type->arch ());
+ return unit_size * 8 * TYPE_LENGTH (type);
+}
+
+/* Check whether the RHS value of a shift is valid in C/C++ semantics.
+ SHIFT_COUNT is the shift amount, SHIFT_COUNT_TYPE is the type of
+ the shift count value, used to determine whether the type is
+ signed, and RESULT_TYPE is the result type. This is used to avoid
+ both negative and too-large shift amounts, which are undefined, and
+ would crash a GDB built with UBSan. Depending on the current
+ language, if the shift is not valid, this either warns and returns
+ false, or errors out. Returns true if valid. */
+
+static bool
+check_valid_shift_count (int op, type *result_type,
+ type *shift_count_type, ULONGEST shift_count)
+{
+ if (!shift_count_type->is_unsigned () && (LONGEST) shift_count < 0)
+ {
+ auto error_or_warning = [] (const char *msg)
+ {
+ /* Shifts by a negative amount are always an error in Go. Other
+ languages are more permissive and their compilers just warn or
+ have modes to disable the errors. */
+ if (current_language->la_language == language_go)
+ error (("%s"), msg);
+ else
+ warning (("%s"), msg);
+ };
+
+ if (op == BINOP_RSH)
+ error_or_warning (_("right shift count is negative"));
+ else
+ error_or_warning (_("left shift count is negative"));
+ return false;
+ }
+
+ if (shift_count >= type_length_bits (result_type))
+ {
+ /* In Go, shifting by large amounts is defined. Be silent and
+ still return false, as the caller's error path does the right
+ thing for Go. */
+ if (current_language->la_language != language_go)
+ {
+ if (op == BINOP_RSH)
+ warning (_("right shift count >= width of type"));
+ else
+ warning (_("left shift count >= width of type"));
+ }
+ return false;
+ }
+
+ return true;
+}
+
/* Perform a binary operation on two operands which have reasonable
representations as integers or floats. This includes booleans,
characters, integers, or floats.
break;
case BINOP_LSH:
- v = v1 << v2;
+ if (!check_valid_shift_count (op, result_type, type2, v2))
+ v = 0;
+ else
+ v = v1 << v2;
break;
case BINOP_RSH:
- v = v1 >> v2;
+ if (!check_valid_shift_count (op, result_type, type2, v2))
+ v = 0;
+ else
+ v = v1 >> v2;
break;
case BINOP_BITWISE_AND:
break;
case BINOP_LSH:
- v = v1 << v2;
+ if (!check_valid_shift_count (op, result_type, type2, v2))
+ v = 0;
+ else
+ {
+ /* Cast to unsigned to avoid undefined behavior on
+ signed shift overflow (unless C++20 or later),
+ which would crash GDB when built with UBSan.
+ Note we don't warn on left signed shift overflow,
+ because starting with C++20, that is actually
+ defined behavior. Also, note GDB assumes 2's
+ complement throughout. */
+ v = (ULONGEST) v1 << v2;
+ }
break;
case BINOP_RSH:
- v = v1 >> v2;
+ if (!check_valid_shift_count (op, result_type, type2, v2))
+ {
+ /* Pretend the too-large shift was decomposed in a
+ number of smaller shifts. An arithmetic signed
+ right shift of a negative number always yields -1
+ with such semantics. This is the right thing to
+ do for Go, and we might as well do it for
+ languages where it is undefined. Also, pretend a
+ shift by a negative number was a shift by the
+ negative number cast to unsigned, which is the
+ same as shifting by a too-large number. */
+ if (v1 < 0)
+ v = -1;
+ else
+ v = 0;
+ }
+ else
+ v = v1 >> v2;
break;
case BINOP_BITWISE_AND:
projects / binutils-gdb.git / blobdiff