Parser/pgenmain.c

   1
   2 /* Parser generator main program */
   3
   4 /* This expects a filename containing the grammar as argv[1] (UNIX)
   5    or asks the console for such a file name (THINK C).
   6    It writes its output on two files in the current directory:
   7    - "graminit.c" gets the grammar as a bunch of initialized data
   8    - "graminit.h" gets the grammar's non-terminals as #defines.
   9    Error messages and status info during the generation process are
  10    written to stdout, or sometimes to stderr. */
  11
  12 /* XXX TO DO:
  13    - check for duplicate definitions of names (instead of fatal err)
  14 */
  15
  16 #include "pgenheaders.h"
  17 #include "grammar.h"
  18 #include "node.h"
  19 #include "parsetok.h"
  20 #include "pgen.h"
  21
  22 int Py_DebugFlag;
  23 int Py_VerboseFlag;
  24
  25 /* Forward */
  26 grammar *getgrammar(char *filename);
  27 #ifdef THINK_C
  28 int main(int, char **);
  29 char *askfile(void);
  30 #endif
  31
  32 void
  33 Py_Exit(int sts)
  34 {
  35         exit(sts);
  36 }
  37
  38 int
  39 main(int argc, char **argv)
  40 {
  41         grammar *g;
  42         FILE *fp;
  43         char *filename;
  44
  45 #ifdef THINK_C
  46         filename = askfile();
  47 #else
  48         if (argc != 2) {
  49                 fprintf(stderr, "usage: %s grammar\n", argv[0]);
  50                 Py_Exit(2);
  51         }
  52         filename = argv[1];
  53 #endif
  54         g = getgrammar(filename);
  55         fp = fopen("graminit.c", "w");
  56         if (fp == NULL) {
  57                 perror("graminit.c");
  58                 Py_Exit(1);
  59         }
  60         printf("Writing graminit.c ...\n");
  61         printgrammar(g, fp);
  62         fclose(fp);
  63         fp = fopen("graminit.h", "w");
  64         if (fp == NULL) {
  65                 perror("graminit.h");
  66                 Py_Exit(1);
  67         }
  68         printf("Writing graminit.h ...\n");
  69         printnonterminals(g, fp);
  70         fclose(fp);
  71         Py_Exit(0);
  72         return 0; /* Make gcc -Wall happy */
  73 }
  74
  75 grammar *
  76 getgrammar(char *filename)
  77 {
  78         FILE *fp;
  79         node *n;
  80         grammar *g0, *g;
  81         perrdetail err;
  82
  83         fp = fopen(filename, "r");
  84         if (fp == NULL) {
  85                 perror(filename);
  86                 Py_Exit(1);
  87         }
  88         g0 = meta_grammar();
  89         n = PyParser_ParseFile(fp, filename, g0, g0->g_start,
  90                       (char *)NULL, (char *)NULL, &err);
  91         fclose(fp);
  92         if (n == NULL) {
  93                 fprintf(stderr, "Parsing error %d, line %d.\n",
  94                         err.error, err.lineno);
  95                 if (err.text != NULL) {
  96                         size_t i;
  97                         fprintf(stderr, "%s", err.text);
  98                         i = strlen(err.text);
  99                         if (i == 0 || err.text[i-1] != '\n')
 100                                 fprintf(stderr, "\n");
 101                         for (i = 0; i < err.offset; i++) {
 102                                 if (err.text[i] == '\t')
 103                                         putc('\t', stderr);
 104                                 else
 105                                         putc(' ', stderr);
 106                         }
 107                         fprintf(stderr, "^\n");
 108                         PyMem_DEL(err.text);
 109                 }
 110                 Py_Exit(1);
 111         }
 112         g = pgen(n);
 113         if (g == NULL) {
 114                 printf("Bad grammar.\n");
 115                 Py_Exit(1);
 116         }
 117         return g;
 118 }
 119
 120 #ifdef THINK_C
 121 char *
 122 askfile(void)
 123 {
 124         char buf[256];
 125         static char name[256];
 126         printf("Input file name: ");
 127         if (fgets(buf, sizeof buf, stdin) == NULL) {
 128                 printf("EOF\n");
 129                 Py_Exit(1);
 130         }
 131         /* XXX The (unsigned char *) case is needed by THINK C 3.0 */
 132         if (sscanf(/*(unsigned char *)*/buf, " %s ", name) != 1) {
 133                 printf("No file\n");
 134                 Py_Exit(1);
 135         }
 136         return name;
 137 }
 138 #endif
 139
 140 void
 141 Py_FatalError(char *msg)
 142 {
 143         fprintf(stderr, "pgen: FATAL ERROR: %s\n", msg);
 144         Py_Exit(1);
 145 }
 146
 147 #ifdef macintosh
 148 /* ARGSUSED */
 149 int
 150 guesstabsize(char *path)
 151 {
 152         return 4;
 153 }
 154 #endif
 155
 156 /* No-nonsense my_readline() for tokenizer.c */
 157
 158 char *
 159 PyOS_Readline(char *prompt)
 160 {
 161         size_t n = 1000;
 162         char *p = PyMem_MALLOC(n);
 163         char *q;
 164         if (p == NULL)
 165                 return NULL;
 166         fprintf(stderr, "%s", prompt);
 167         q = fgets(p, n, stdin);
 168         if (q == NULL) {
 169                 *p = '\0';
 170                 return p;
 171         }
 172         n = strlen(p);
 173         if (n > 0 && p[n-1] != '\n')
 174                 p[n-1] = '\n';
 175         return PyMem_REALLOC(p, n+1);
 176 }
 177
 178 #include <stdarg.h>
 179
 180 void
 181 PySys_WriteStderr(const char *format, ...)
 182 {
 183         va_list va;
 184
 185         va_start(va, format);
 186         vfprintf(stderr, format, va);
 187         va_end(va);
 188 }