+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 (dwarf_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;
+}
+
+/* The engine for the expression evaluator. Using the context in this
+ object, evaluate the expression between OP_PTR and OP_END. */
+
+void
+dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr,
+ const gdb_byte *op_end)