X-Git-Url: https://www.kengrimes.com/gitweb/?p=henge%2Fwebcc.git;a=blobdiff_plain;f=src%2Fapc%2Flexer.c;h=4e0a611faa06bf16bd4501dd0bed73fa850f34ce;hp=47d2c35d9bcd43d303c3b90555eb3bf0462d6d51;hb=882513ad6569a640cb5c90b83e27e742ace71b63;hpb=f8d924b76a3dfbaaa9e92dacbc4992a7ab6dc8f2 diff --git a/src/apc/lexer.c b/src/apc/lexer.c index 47d2c35..4e0a611 100644 --- a/src/apc/lexer.c +++ b/src/apc/lexer.c @@ -1,7 +1,13 @@ /*!@file \brief lexical analyzer implementation for APC - \details this lexer scans a root directory given from the command line - for subdirectories and files structured for the APC grammar. + \details The lexer manages two FIFO stacks. One for maintaining tokens, the + other for maintaining a list of files to be scanned. During + execution, the lexer will return a token from its token queue if any + are present. If not, the lexer will will pop an element from its + file queue to 'scanner' to be tokenized. If the file queue is empty, + the lexer will instead call 'parsedir' to traverse the directory tree + and tokenize the results. If 'parsedir' does not generate any new + tokens, we are done. \author Jordan Lavatai \date Aug 2016 ----------------------------------------------------------------------------*/ @@ -14,109 +20,47 @@ #include #include /* Local */ -#include "parser.tab.h" -#define TOKEN_BUF_SIZE 1024 -#define ENTITY_BUF_SIZE 512 -#define SCANDIR_ERROR -1 - -int lexer_init(void); -int lexer(void); - -extern //main.c -const char* cargs['Z']; - +//#include "parser.tab.h" +#ifndef DP_STACKSIZE +#define DP_STACKSIZE 1024 +#endif +#ifndef TK_STACKSIZE +#define TK_STACKSIZE 1024 +#endif +/* Public */ +struct tok +{ int lval; + int tok; +}; +int lexer_init(void); +int lexer(void); +inline +void lexer_pushtok(int int); +struct dirent* lexer_direntpa[DP_STACKSIZE]; +/* Private */ static inline int scan(void); static inline -int qcomp(const void*, const void*); - -/* Directory Listing Stack - FILO Stack for keeping an open DIR* at each directory depth for treewalk. - This stack is depth-safe, checking its depth during push operations, but not - during pop operations, to ensure the thread doesn't open too many files at - once (512 in c runtime), or traverse too far through symbolic links. - A directory listing includes a DIR* and all DIR-typed entity in the directory - as recognized by dirent, populated externally (and optionally). - This stack behaves abnormally by incrementing its PUSH operation prior to - evaluation, and the POP operations after evaluation. This behavior allows - the 'DL_CURDEPTH' operation to map to the current element in the 'dl_stack' - array, and it is always treated as the "current depth". This also allows us - to init the root directory to 'directory_list_stack'[0] and pop it in a safe - and explicit manner. -*/ -#define S(S)#S -#ifndef DL_DEPTHMAX -#define DL_DEPTHMAX 64 -#endif -#ifndef DL_CHILDMAX -#define DL_CHILDMAX DL_DEPTHMAX //square tree -#endif -#define DL_STACK (directory_list_stack) -#define DL_STACKP (dls) -#define DL_STACKSIZE (DL_DEPTHMAX + 1) //+1 because push increments early -#define DL_LEN (DL_STACKP - DL_STACK) -#define DL_CURDEPTH (DL_LEN) -#define DL_CD_STACK ((*DL_STACKP).child_entity_stack) -#define DL_CD_STACKP ((*DL_STACKP).cds) -#define DL_CD_STACKSIZE (DL_DEPTHMAX) //square tree -#define DL_CD_LEN (DL_CD_STACKP - DL_CD_STACK) -#define ERR_CHILD "Fatal: Maximum of " S(MAX_CHILD) \ - " child directories exceeded for directory %s at depth %i\n" \ - ,DL_STACK[DL_DEPTH()].label,DL_DEPTH() -#define ERR_DEPTH "Fatal: Maximum directory depth of " S(DL_DEPTHMAX) \ - " exceeded during directory scan\n" -#define DL_INIT() (DL_STACKP = DL_STACK) -#define DL_CD_INIT() (DL_CD_STACKP = DL_CD_STACK) -#define DL_POP() ((DIR*)(*DL_STACKP--)) -#define DL_CD_POP() (*--DL_CD_STACKP) -#define DL_PUSH(D) (*(DIR**)(++DL_STACKP) = DIRP) -#define DL_CD_PUSH(E) (*DL_CD_STACKP++ = E) -#define DL_SAFEPUSH(D) \ - do { \ - if (DL_DEPTH() >= DL_DEPTHMAX) \ - { fprintf(stderr, ERR_DEPTH); \ - exit(EXIT_FAILURE); \ - } \ - if ((*(DIR**)(++DL_STACKP) = D) == NULL) \ - { perror("DL_SAFEPUSH"); \ - exit(EXIT_FAILURE); \ - } \ - } while(0) -#define DL_CD_POPULATE() \ - do { \ - DL_CD_INIT(); \ - while ((*DL_CD_STACKP = readdir(*DL_STACKP)) != NULL) \ - { switch((*DL_CD_STACKP)->d_type) \ - { case DT_REG: \ - case DT_DIR: \ - DL_CD_STACKP++; \ - break; \ - default: \ - } \ - } \ - qsort(DL_CD_STACKP, DL_CD_LEN, sizeof *DL_CD_STACKP, qcomp); \ - } while (0) - +int dredge_current_depth(void); +static +struct dirent** dps; static -struct dirlist -{ DIR* dirp; - struct dirent** child_directory_stack[DL_CD_STACKSIZE],*** cds; - const char* label; -} directory_list_stack[DL_STACKSIZE],* dls; +struct tok token_stack[TK_STACKSIZE]; static +union tokp +{ int* i; + struct tok* t; +} tks, tkx; -/* Directory Entity Stack - Simple stack for keeping track of dirents still being processed at the - current depth. +/* Directory Entity Array/Stack + Simple array for keeping track of dirents yet to be processed by the scanner. + If this list is empty and there are no tokens, the lexer is done. */ -#define CE_STACK (child_entity_stack) -#define CE_STACKP (ces) -#define CE_STACKSIZE 1024 -static -struct dirent** child_entity_stack[CE_STACKSIZE],*** ces; -#define CE_INIT() (CE_STACKP = CE_STACK) -#define CE_POP() (*--CE_STACK) -#define CE_PUSH(E) (*CE_STACK++ = E) +#define DP_STACK (lexer_direntpa) +#define DP_STACKP (dps) +#define DP_LEN() (DP_STACKP - DP_STACK) +#define DP_INIT() (DP_STACKP = DP_STACK) +#define DP_POP() (*--DP_STACKP) /* Token Stack This is a FIFO stack whose pointers are a union of either a pointer to an @@ -127,51 +71,33 @@ struct dirent** child_entity_stack[CE_STACKSIZE],*** ces; times in a sequence! */ #define TK_STACK (token_stack) -#define TK_STACKP (tks.t) -#define TK_STACKPI (tks.i) -#define TK_STACKX (tkx.t) -#define TK_STACKXI (tkx.i) -#ifndef TK_STACKSIZE -#define TK_STACKSIZE 1024 -#endif -#define TK_EMPTY (TK_STACKP == TK_STACKX) -#define TK_INIT() (TK_STACKP = TK_STACKX = TK_STACK) -#define TK_POP() (*TK_STACKP++) -#define TK_IPOP() (*TK_STACKPI++); -#define TK_PUSH(TOK,LVAL) (*TKSTACKX++ = (struct tok){(LVAL),(TOK)}) -#define TK_IPUSH(I) (*TKSTACKXI++ = (I)) -static -struct tok -{ int lval; - int tok; -} token_stack[TK_STACKSIZE]; -static -union tokp -{ int* i; - struct tok* t; -} tks, tkx; +#define TK_STACKP (tks.t) +#define TK_STACKPI (tks.i) +#define TK_STACKX (tkx.t) +#define TK_STACKXI (tkx.i) +#define TK_LEN() (TK_STACKP - TK_STACKX) +#define TK_INIT() (TK_STACKP = TK_STACKX = TK_STACK) +#define TK_POP() (*TK_STACKP++) +#define TK_POPI() (*TK_STACKPI++); +#define TK_PUSH(T) (*TKSTACKX++ = T) +#define TK_PUSHI(I) (*TKSTACKXI++ = (I)) +extern //main.c +const char* cargs['Z']; + +extern //scanner.c +int scanner_init(void); +extern //scanner.c +int scanner(struct dirent**); /* Initializer - The initializer returns boolean true if opendir contains an error. + The initializer returns boolean true if an error occurs, which may be handled with standard errno. */ -int lexer_init() -#define ERR_UF "Fatal: Unknown file [%s] encountered in directory %s", \ - DL_CD_STACK[i]->d_name, DL_STACK[DL_DEPTH] -{ int i = 0; - TK_INIT(); - DL_INIT(); - DL_STACK[0].label = cargs['r'] ? cargs['r'] : "./"; - if ((DL_STACK[0].dirp = opendir(DL_STACK[0].label)) == NULL) - return -1; - errno = 0; - while ((DL_CD_STACK[i] = readdir(DL_STACK[0].dirp)) != NULL) - switch(DL_CD_STACK[i]->d_type) - { - default: - fprintf(stderr, "Fatal: Unkown File %s\n", DL_CD_STACK[i]->d_name); - } - return (errno); +int lexer_init +() +{ TK_INIT(); + DP_INIT(); + return scanner_init(); } /* Lexer @@ -181,85 +107,63 @@ int lexer_init() printing is skipped. In all other cases, 'yylval' is set, and the token's integer representation is returned. */ -int lexer() -{ if (TOK_BUF_EMPTY) - { TOK_BUF_INIT(); - switch (lexer_scan) - { case SCANDIR_ERROR: +int lexer +#define SCAN_ERROR -1 +#define TK_EMPTY (TK_STACKP == TK_STACKX) +() +{ if (TK_EMPTY) + { switch (parsedir()) + { case SCAN_ERROR: perror("lexer_scan"); case 0: yylval = 0; return 0; default: + break; } } - yylval = TOK_BUF_IPOP(); - return TOK_BUF_IPOP(); + yylval = TK_IPOP(); + return TK_IPOP(); } - -static inline -int lexer_scan() -{ static DIR* -} - -/* Scanner - Scans a filename from its alphabetically ordered list of file elements - and tokenizes the result. If the file list is empty, then the stack of - directory elements will be popped and processed as they are encountered. - - Returns the number of tokens generated. +/* Token Receiver + This receiver takes a struct tok and pushes it to the FIFO stack. */ -#define MAX_ENTITIES 256 -static -int lexer_scan() -{ static struct dirent* entity; - static struct dirent* files[MAX_ENTITIES] = {0}; - static int num_files = 0; -#define NO_FILES (num_files == 0) - - if (NO_FILES) - - - //sort out files and directories, grow directories from bottom up - while ((entity = readdir(dirp)) != NULL) - { switch (entity->d_type) - { case DT_LNK: - case DT_REG: - files[num_files++] = entity; - break; - case DT_DIR: - *(dirs - num_dirs++) = entity; - break; - case DT_UNKNOWN: - default: - printf("Ignoring unknown file: %s\n", entity->d_name); - break; - } +inline +void lexer_pushtok +#define ERR_TK "Fatal: Generated over " S(TK_STACKSIZE) " tokens in one pass." +( struct tok token ) +{ if (TK_LEN >= TK_STACKSIZE) + { fprintf(stderr, ERR_TK); + exit(EXIT_FAILURE); } - if (errno) - perror("readdir"); - qsort(&files[0], num_files, sizeof struct dirent*, qalpha); - num_ents = scandirat(dirfd, ".", &namelist, scanfilter, scancompar); - if (num_ents < 0) - { perror("scandirat"); - return -1; - } - //process files - - //recurse into directories - return tbx - tbp; + TK_PUSH(token); } -/* Quicksort comparison function - sort each dirent encountered first by its file type (regular files first) - and then by their alphabetical ordering. -*/ -static -int qcompar -( const void* a, - const void* b - ) -{ +/* Lexical Analysis + Ragel state machine for tokenizing text. + */ +void lexer_lex +(const char* str) +{ struct tok token; + token.TOK = 1; + token.LVAL = 2; + lexer_pushtok(token); + printf (str); } +/* init_file: + if (lsp != NULL) + while ((c = *lsp++) == *csp) + { switch (c) + { case DELIM: + delimeters_skipped++; + default: + csp++; //delayed to ensure csp is the start of scannable text + break; + } + } + last_string = string; + scan_text: + return scanner_tokenize(csp); +*/