+/* Return true iff the types T1 and T2 are "the same". This only does
+ checks that might reasonably be needed to compare DWARF base
+ types. */
+
+static int
+base_types_equal_p (struct type *t1, struct type *t2)
+{
+ if (TYPE_CODE (t1) != TYPE_CODE (t2))
+ return 0;
+ if (TYPE_UNSIGNED (t1) != TYPE_UNSIGNED (t2))
+ return 0;
+ return TYPE_LENGTH (t1) == TYPE_LENGTH (t2);
+}
+
+/* A convenience function to call get_base_type on CTX and return the
+ result. DIE is the DIE whose type we need. SIZE is non-zero if
+ this function should verify that the resulting type has the correct
+ size. */
+
+static struct type *
+dwarf_get_base_type (struct dwarf_expr_context *ctx, cu_offset die, int size)
+{
+ struct type *result;
+
+ if (ctx->funcs->get_base_type)
+ {
+ result = ctx->funcs->get_base_type (ctx, die);
+ if (result == NULL)
+ error (_("Could not find type for DW_OP_GNU_const_type"));
+ if (size != 0 && TYPE_LENGTH (result) != size)
+ error (_("DW_OP_GNU_const_type has different sizes for type and data"));
+ }
+ else
+ /* Anything will do. */
+ result = builtin_type (ctx->gdbarch)->builtin_int;
+
+ return result;
+}
+
+/* If <BUF..BUF_END] contains DW_FORM_block* with single DW_OP_reg* return the
+ DWARF register number. Otherwise return -1. */
+
+int
+dwarf_block_to_dwarf_reg (const gdb_byte *buf, const gdb_byte *buf_end)
+{
+ uint64_t dwarf_reg;
+
+ if (buf_end <= buf)
+ return -1;
+ if (*buf >= DW_OP_reg0 && *buf <= DW_OP_reg31)
+ {
+ if (buf_end - buf != 1)
+ return -1;
+ return *buf - DW_OP_reg0;
+ }
+
+ if (*buf == DW_OP_GNU_regval_type)
+ {
+ buf++;
+ buf = gdb_read_uleb128 (buf, buf_end, &dwarf_reg);
+ if (buf == NULL)
+ return -1;
+ buf = gdb_skip_leb128 (buf, buf_end);
+ if (buf == NULL)
+ return -1;
+ }
+ else if (*buf == DW_OP_regx)
+ {
+ buf++;
+ buf = gdb_read_uleb128 (buf, buf_end, &dwarf_reg);
+ if (buf == NULL)
+ return -1;
+ }
+ else
+ return -1;
+ if (buf != buf_end || (int) dwarf_reg != dwarf_reg)
+ return -1;
+ return dwarf_reg;
+}
+
+/* If <BUF..BUF_END] contains DW_FORM_block* with just DW_OP_breg*(0) and
+ DW_OP_deref* return the DWARF register number. Otherwise return -1.
+ DEREF_SIZE_RETURN contains -1 for DW_OP_deref; otherwise it contains the
+ size from DW_OP_deref_size. */
+
+int
+dwarf_block_to_dwarf_reg_deref (const gdb_byte *buf, const gdb_byte *buf_end,
+ CORE_ADDR *deref_size_return)
+{
+ uint64_t dwarf_reg;
+ int64_t offset;
+
+ if (buf_end <= buf)
+ return -1;
+
+ if (*buf >= DW_OP_breg0 && *buf <= DW_OP_breg31)
+ {
+ dwarf_reg = *buf - DW_OP_breg0;
+ buf++;
+ if (buf >= buf_end)
+ return -1;
+ }
+ else if (*buf == DW_OP_bregx)
+ {
+ buf++;
+ buf = gdb_read_uleb128 (buf, buf_end, &dwarf_reg);
+ if (buf == NULL)
+ return -1;
+ if ((int) dwarf_reg != dwarf_reg)
+ return -1;
+ }
+ else
+ return -1;
+
+ buf = gdb_read_sleb128 (buf, buf_end, &offset);
+ if (buf == NULL)
+ return -1;
+ if (offset != 0)
+ return -1;
+
+ if (*buf == DW_OP_deref)
+ {
+ buf++;
+ *deref_size_return = -1;
+ }
+ else if (*buf == DW_OP_deref_size)
+ {
+ buf++;
+ if (buf >= buf_end)
+ return -1;
+ *deref_size_return = *buf++;
+ }
+ else
+ return -1;
+
+ if (buf != buf_end)
+ return -1;
+
+ return dwarf_reg;
+}
+
+/* If <BUF..BUF_END] contains DW_FORM_block* with single DW_OP_fbreg(X) fill
+ in FB_OFFSET_RETURN with the X offset and return 1. Otherwise return 0. */
+
+int
+dwarf_block_to_fb_offset (const gdb_byte *buf, const gdb_byte *buf_end,
+ CORE_ADDR *fb_offset_return)
+{
+ int64_t fb_offset;
+
+ if (buf_end <= buf)
+ return 0;
+
+ if (*buf != DW_OP_fbreg)
+ return 0;
+ buf++;
+
+ buf = gdb_read_sleb128 (buf, buf_end, &fb_offset);
+ if (buf == NULL)
+ return 0;
+ *fb_offset_return = fb_offset;
+ if (buf != buf_end || fb_offset != (LONGEST) *fb_offset_return)
+ return 0;
+
+ return 1;
+}
+
+/* If <BUF..BUF_END] contains DW_FORM_block* with single DW_OP_bregSP(X) fill
+ in SP_OFFSET_RETURN with the X offset and return 1. Otherwise return 0.
+ The matched SP register number depends on GDBARCH. */
+
+int
+dwarf_block_to_sp_offset (struct gdbarch *gdbarch, const gdb_byte *buf,
+ const gdb_byte *buf_end, CORE_ADDR *sp_offset_return)
+{
+ uint64_t dwarf_reg;
+ int64_t sp_offset;
+
+ if (buf_end <= buf)
+ return 0;
+ if (*buf >= DW_OP_breg0 && *buf <= DW_OP_breg31)
+ {
+ dwarf_reg = *buf - DW_OP_breg0;
+ buf++;
+ }
+ else
+ {
+ if (*buf != DW_OP_bregx)
+ return 0;
+ buf++;
+ buf = gdb_read_uleb128 (buf, buf_end, &dwarf_reg);
+ if (buf == NULL)
+ return 0;
+ }
+
+ if (gdbarch_dwarf2_reg_to_regnum (gdbarch, dwarf_reg)
+ != gdbarch_sp_regnum (gdbarch))
+ return 0;
+
+ buf = gdb_read_sleb128 (buf, buf_end, &sp_offset);
+ if (buf == NULL)
+ return 0;
+ *sp_offset_return = sp_offset;
+ if (buf != buf_end || sp_offset != (LONGEST) *sp_offset_return)
+ return 0;
+
+ return 1;
+}
+