importreclassGrammar:def__init__(self,rules:Dict[str,str]):self.rules=rulesdefparse_string(grammar_source:str,_parser=None)->Grammar:rules:Dict[str,str]= {}forlineingrammar_source.splitlines():line=line.strip()ifnotlineorline.startswith("#"):continuem=re.match(r"^([A-Za-z_][A-Za-z0-9_]*)\s*:\s*(.+)$",line)ifm:name=m.group(1)rhs=m.group(2).strip()rules[name]=rhsreturnGrammar(rules)classFirstSetCalculator:TOKEN_RE=re.compile(r"'[^']*'|[A-Za-z_][A-Za-z0-9_]*|[^\s]")def__init__(self,rules:Dict[str,str]):self.rules=dict(rules)self.firsts:Dict[str,Set[str]]= {name:set()fornameinself.rules}deftokenize(self,rhs:str):return [tokfortokinself.TOKEN_RE.findall(rhs)]defis_terminal(self,tok:str)->bool:returnre.fullmatch(r"[A-Z][A-Z0-9_]*",tok)isnotNonedefis_nonterminal(self,tok:str)->bool:returnre.fullmatch(r"[a-zA-Z_][a-zA-Z0-9_]*",tok)isnotNoneandnotself.is_terminal(tok)defcalculate(self)->Dict[str,Set[str]]:changed=Truewhilechanged:forname,rhsinself.rules.items():tokens=self.tokenize(rhs)fortokintokens:ifself.is_nonterminal(tok):before=len(self.firsts[name])defcalculate_first_sets(grammar_source:str)->Dict[str,Set[str]]:grammar:Grammar=parse_string(grammar_source,None)returnFirstSetCalculator(grammar.rules).calculate()grammar="\n        start: ','.thing+ NEWLINE\n        thing: NUMBER\n        "result=calculate_first_sets(grammar)

AddressSanitizer:DEADLYSIGNAL===================================================================3246143==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000008 (pc 0x5658aaf2db85 bp 0x7fffe2be3ec0 sp 0x7fffe2be3eb0 T0)==3246143==The signal is caused by a READ memory access.==3246143==Hint: address points to the zero page.    #0 0x5658aaf2db85 in _Py_uop_sym_truthiness /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Python/optimizer_symbols.c:696:24    #1 0x5658aaf3377b in _Py_uop_sym_new_truthiness /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Python/optimizer_symbols.c:915:22    #2 0x5658aaf1f683 in optimize_uops /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Python/optimizer_cases.c.h:305:19    #3 0x5658aaf0e3d6 in _Py_uop_analyze_and_optimize /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Python/optimizer_analysis.c:705:14    #4 0x5658aaf035d7 in uop_optimize /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Python/optimizer.c:1512:18    #5 0x5658aaf035d7 in _PyOptimizer_Optimize /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Python/optimizer.c:170:15    #6 0x5658aad4ca5a in stop_tracing_and_jit /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Python/ceval.c:1110:15    #7 0x5658aad4ca5a in _PyEval_EvalFrameDefault /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Python/generated_cases.c.h:12510:23    #8 0x5658aad2cafd in _PyEval_EvalFrame /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Include/internal/pycore_ceval.h:118:16    #9 0x5658aad2cafd in _PyEval_Vector /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Python/ceval.c:2094:12    #10 0x5658aad2cafd in PyEval_EvalCode /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Python/ceval.c:673:21    #11 0x5658aaf5eefc in run_eval_code_obj /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Python/pythonrun.c:1366:12    #12 0x5658aaf5eefc in run_mod /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Python/pythonrun.c:1469:19    #13 0x5658aaf58c17 in pyrun_file /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Python/pythonrun.c:1294:15    #14 0x5658aaf58c17 in _PyRun_SimpleFileObject /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Python/pythonrun.c:518:13    #15 0x5658aaf58035 in _PyRun_AnyFileObject /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Python/pythonrun.c:81:15    #16 0x5658aafc618d in pymain_run_file_obj /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Modules/main.c:410:15    #17 0x5658aafc618d in pymain_run_file /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Modules/main.c:429:15    #18 0x5658aafc4a71 in pymain_run_python /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Modules/main.c:691:21    #19 0x5658aafc4a71 in Py_RunMain /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Modules/main.c:772:5    #20 0x5658aafc5583 in pymain_main /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Modules/main.c:802:12    #21 0x5658aafc56e2 in Py_BytesMain /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Modules/main.c:826:12    #22 0x772550968d8f in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16    #23 0x772550968e3f in __libc_start_main csu/../csu/libc-start.c:392:3    #24 0x5658aa7dce94 in _start (/home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/python+0x1fce94) (BuildId: f791960dfefd969819f59576836bc8a336f89709)==3246143==Register values:rax = 0x0000000000000008  rbx = 0x000077254fd6be00  rcx = 0x00000000ffffffff  rdx = 0x0000000000000001  rdi = 0x0000000000000000  rsi = 0x00000ee4a9fad7bf  rbp = 0x00007fffe2be3ec0  rsp = 0x00007fffe2be3eb0   r8 = 0x000000000000001d   r9 = 0x00000ee4a9fad786  r10 = 0x0000000000000000  r11 = 0x000077254fd9ea68  r12 = 0x0000000000000001  r13 = 0x000077254fd6b898  r14 = 0x000077254fd6be08  r15 = 0x00000ee4a9fad7c1  AddressSanitizer can not provide additional info.SUMMARY: AddressSanitizer: SEGV /home/fuzz/WorkSpace/FusionFuzzLoop/projects/cpython/cpython/build/../Python/optimizer_symbols.c:696:24 in _Py_uop_sym_truthiness==3246143==ABORTING