% # -*- C -*-
% # Copyright (c) 2018 Takashi Kokubun.  All rights reserved.
% #
% # This file is a part of  the programming language Ruby.  Permission is hereby
% # granted, to either  redistribute and/or modify this file,  provided that the
% # conditions mentioned  in the  file COPYING  are met.   Consult the  file for
% # details.
%
% to_cstr = lambda do |line|
%   normalized = line.gsub(/\t/, ' ' * 8)
%   indented = normalized.sub(/\A(?!#)/, '    ') # avoid indenting preprocessor
%   rstring2cstr(indented.rstrip).sub(/"\z/, '\\n"')
% end
%
% #
% # Expand simple macro, which doesn't require dynamic C code.
% #
% expand_simple_macros = lambda do |arg_expr|
%   arg_expr.dup.tap do |expr|
%     # For `leave`. We can't proceed next ISeq in the same JIT function.
%     expr.gsub!(/^(?<indent>\s*)RESTORE_REGS\(\);\n/) do
%       indent = Regexp.last_match[:indent]
%       <<-end.gsub(/^ +/, '')
%         #if OPT_CALL_THREADED_CODE
%         #{indent}rb_ec_thread_ptr(ec)->retval = val;
%         #{indent}return 0;
%         #else
%         #{indent}return val;
%         #endif
%       end
%     end
%     expr.gsub!(/^(?<indent>\s*)NEXT_INSN\(\);\n/) do
%       indent = Regexp.last_match[:indent]
%       <<-end.gsub(/^ +/, '')
%         #{indent}UNREACHABLE_RETURN(Qundef);
%       end
%     end
%   end
% end
%
% #
% # Print a body of insn, but with macro expansion.
% #
% expand_simple_macros.call(insn.expr.expr).each_line do |line|
%   #
%   # Expand dynamic macro here (only JUMP for now)
%   #
%   # TODO: support combination of following macros in the same line
%   case line
%   when /\A\s+RUBY_VM_CHECK_INTS\(ec\);\s+\z/
%     if insn.leaf_without_check_ints? # lazily move PC and optionalize mjit_call_p here
        fprintf(f, "            if (UNLIKELY(RUBY_VM_INTERRUPTED_ANY(ec))) {\n");
        fprintf(f, "                reg_cfp->pc = original_body_iseq + %d;\n", next_pos); /* ADD_PC(INSN_ATTR(width)); */
        fprintf(f, "                rb_threadptr_execute_interrupts(rb_ec_thread_ptr(ec), 0);\n");
        fprintf(f, "                if (UNLIKELY(!mjit_call_p)) {\n");
        fprintf(f, "                    reg_cfp->sp = vm_base_ptr(reg_cfp) + %d;\n", b->stack_size);
        fprintf(f, "                    RB_DEBUG_COUNTER_INC(mjit_cancel_invalidate_all);\n");
        fprintf(f, "                    goto cancel;\n");
        fprintf(f, "                }\n");
        fprintf(f, "            }\n");
%     else
        fprintf(f, <%= to_cstr.call(line) %>);
%     end
%   when /\A\s+JUMP\((?<dest>[^)]+)\);\s+\z/
%     dest = Regexp.last_match[:dest]
%
%     if insn.name == 'opt_case_dispatch' # special case... TODO: use another macro to avoid checking name
        {
            struct case_dispatch_var arg;
            arg.f = f;
            arg.base_pos = pos + insn_len(insn);
            arg.last_value = Qundef;

            fprintf(f, "    switch (<%= dest %>) {\n");
            st_foreach(RHASH_TBL_RAW(hash), compile_case_dispatch_each, (VALUE)&arg);
            fprintf(f, "      case %lu:\n", else_offset);
            fprintf(f, "        goto label_%lu;\n", arg.base_pos + else_offset);
            fprintf(f, "    }\n");
        }
%     else
%       # Before we `goto` next insn, we need to set return values, especially for getinlinecache
%       insn.rets.reverse_each.with_index do |ret, i|
%         # TOPN(n) = ...
        fprintf(f, "            stack[%d] = <%= ret.fetch(:name) %>;\n", b->stack_size + (int)<%= insn.call_attribute('sp_inc') %> - <%= i + 1 %>);
%       end
%
        next_pos = pos + insn_len(insn) + (unsigned int)<%= dest %>;
        fprintf(f, "            goto label_%d;\n", next_pos);
%     end
%   when /\A\s+CALL_SIMPLE_METHOD\(\);\s+\z/
%     # For `opt_xxx`'s fallbacks.
        if (status->local_stack_p) {
            fprintf(f, "            reg_cfp->sp = vm_base_ptr(reg_cfp) + %d;\n", b->stack_size);
        }
        fprintf(f, "            reg_cfp->pc = original_body_iseq + %d;\n", pos);
        fprintf(f, "            RB_DEBUG_COUNTER_INC(mjit_cancel_opt_insn);\n");
        fprintf(f, "            goto cancel;\n");
%   when /\A(?<prefix>.+\b)INSN_LABEL\((?<name>[^)]+)\)(?<suffix>.+)\z/m
%     prefix, name, suffix = Regexp.last_match[:prefix], Regexp.last_match[:name], Regexp.last_match[:suffix]
        fprintf(f, "    <%= prefix.gsub(/\t/, ' ' * 8) %>INSN_LABEL(<%= name %>_%d)<%= suffix.sub(/\n/, '\n') %>", pos);
%   else
%     if insn.handles_sp?
%       # If insn.handles_sp? is true, cfp->sp might be changed inside insns (like vm_caller_setup_arg_block)
%       # and thus we need to use cfp->sp, even when local_stack_p is TRUE. When insn.handles_sp? is true,
%       # cfp->sp should be available too because _mjit_compile_pc_and_sp.erb sets it.
        fprintf(f, <%= to_cstr.call(line) %>);
%     else
%       # If local_stack_p is TRUE and insn.handles_sp? is false, stack values are only available in local variables
%       # for stack. So we need to replace those macros if local_stack_p is TRUE here.
%       case line
%       when /\bGET_SP\(\)/
%         # reg_cfp->sp
        fprintf(f, <%= to_cstr.call(line.sub(/\bGET_SP\(\)/, '%s')) %>, (status->local_stack_p ? "(stack + stack_size)" : "GET_SP()"));
%       when /\bSTACK_ADDR_FROM_TOP\((?<num>[^)]+)\)/
%         # #define STACK_ADDR_FROM_TOP(n) (GET_SP()-(n))
%         num = Regexp.last_match[:num]
        fprintf(f, <%= to_cstr.call(line.sub(/\bSTACK_ADDR_FROM_TOP\(([^)]+)\)/, '%s')) %>,
                (status->local_stack_p ? "(stack + (stack_size - (<%= num %>)))" : "STACK_ADDR_FROM_TOP(<%= num %>)"));
%       when /\bTOPN\((?<num>[^)]+)\)/
%         # #define TOPN(n) (*(GET_SP()-(n)-1))
%         num = Regexp.last_match[:num]
        fprintf(f, <%= to_cstr.call(line.sub(/\bTOPN\(([^)]+)\)/, '%s')) %>,
              (status->local_stack_p ? "*(stack + (stack_size - (<%= num %>) - 1))" : "TOPN(<%= num %>)"));
%       else
        fprintf(f, <%= to_cstr.call(line) %>);
%       end
%     end
%   end
% end
