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Diffstat (limited to 'web/yacco2/diagrams/threadmanualcall.txt')
| -rw-r--r-- | web/yacco2/diagrams/threadmanualcall.txt | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/web/yacco2/diagrams/threadmanualcall.txt b/web/yacco2/diagrams/threadmanualcall.txt new file mode 100644 index 0000000000..ec1c574d43 --- /dev/null +++ b/web/yacco2/diagrams/threadmanualcall.txt @@ -0,0 +1,74 @@ +/* + file: /yacco2/diagrams+etc/threadmanualcall.txt + Example of a subrule calling a thread manually. + Taken from grammar pass3.lex before explicit procedure call of threads + construct invented. + The start_manually_parallel_parsing function uses the + thread's id generated from O2linker as its key to find the thread to launch. +*/ + -> "@" + /@ + \Yacco2's pre-processor include directive.\fbreak + \fbreak + This demonstrates a nested environment + where the grammar uses recursion by + calling a function which contains the |pass3| grammar sequence. + In this example, grammar |pass3| + manually calls a thread via + |start_manually_parallel_parsing| + to get its file name to process. + With the returned ``file-inclusion'' terminal, + |PROCESS_INCLUDE_FILE| is called to parse + the include file: a bom-de-bom-bom bump-and-grind sequence. + The |use_cnt_| is a global variable that protects + against the file include recursion of calling self + until a stack overflow occurs. + @/ + { + op + using namespace NS_prefile_include; + using namespace NS_yacco2_T_enum; + + Parser::parse_result result = + rule_info__.parser__-> + start_manually_parallel_parsing(ITH_prefile_include.thd_id__); + if(result == Parser::erred){ + // in this case, it will not happen: here for education + rule_info__.parser__->set_abort_parse(true); + return; + } + // process returned token + Caccept_parse& accept_parm = + *rule_info__.parser__->arbitrated_token__; + CAbs_lr1_sym* rtn_tok = accept_parm.accept_token__; + int id = rtn_tok->enumerated_id__; + accept_parm.accept_token__ = 0; + if(id == T_Enum::T_T_file_inclusion_) { + T_file_inclusion* finc = (T_file_inclusion*)(rtn_tok); + CAbs_lr1_sym* err = finc->error_sym(); + if(err != 0) { + rule_info__.parser__->set_abort_parse(true); + ADD_TOKEN_TO_ERROR_QUEUE(*finc); + ADD_TOKEN_TO_ERROR_QUEUE(*finc->error_sym()); + finc->error_sym(0); + return; + } + rule_info__.parser__-> + override_current_token(*accept_parm.la_token__ + ,accept_parm.la_token_pos__); + bool result = + PROCESS_INCLUDE_FILE + (*rule_info__.parser__ + ,*finc,*rule_info__.parser__->token_producer__); + if(result == false){ // exceeded nested file limit + rule_info__.parser__->set_abort_parse(true); + return; + } + ADD_TOKEN_TO_RECYCLE_BIN(*finc);//file name inside + return; + } + // catch all errors + rule_info__.parser__->set_abort_parse(true); + *** + } + |