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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 "Python.h"
17 #include "pgenheaders.h"
18 #include "grammar.h"
19 #include "node.h"
20 #include "parsetok.h"
21 #include "pgen.h"
22 
23 int Py_DebugFlag;
24 int Py_VerboseFlag;
25 int Py_IgnoreEnvironmentFlag;
26 
27 /* Forward */
28 grammar *getgrammar(char *filename);
29 
30 void
Py_Exit(int sts)31 Py_Exit(int sts)
32 {
33     exit(sts);
34 }
35 
36 int
main(int argc,char ** argv)37 main(int argc, char **argv)
38 {
39     grammar *g;
40     FILE *fp;
41     char *filename, *graminit_h, *graminit_c;
42 
43     if (argc != 4) {
44         fprintf(stderr,
45             "usage: %s grammar graminit.h graminit.c\n", argv[0]);
46         Py_Exit(2);
47     }
48     filename = argv[1];
49     graminit_h = argv[2];
50     graminit_c = argv[3];
51     g = getgrammar(filename);
52     fp = fopen(graminit_c, "w");
53     if (fp == NULL) {
54         perror(graminit_c);
55         Py_Exit(1);
56     }
57     if (Py_DebugFlag)
58         printf("Writing %s ...\n", graminit_c);
59     printgrammar(g, fp);
60     fclose(fp);
61     fp = fopen(graminit_h, "w");
62     if (fp == NULL) {
63         perror(graminit_h);
64         Py_Exit(1);
65     }
66     if (Py_DebugFlag)
67         printf("Writing %s ...\n", graminit_h);
68     printnonterminals(g, fp);
69     fclose(fp);
70     freegrammar(g);
71     Py_Exit(0);
72     return 0; /* Make gcc -Wall happy */
73 }
74 
75 grammar *
getgrammar(char * filename)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             PyObject_FREE(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 /* Can't happen in pgen */
121 PyObject*
PyErr_Occurred()122 PyErr_Occurred()
123 {
124     return 0;
125 }
126 
127 void
Py_FatalError(const char * msg)128 Py_FatalError(const char *msg)
129 {
130     fprintf(stderr, "pgen: FATAL ERROR: %s\n", msg);
131     Py_Exit(1);
132 }
133 
134 /* No-nonsense my_readline() for tokenizer.c */
135 
136 char *
PyOS_Readline(FILE * sys_stdin,FILE * sys_stdout,char * prompt)137 PyOS_Readline(FILE *sys_stdin, FILE *sys_stdout, char *prompt)
138 {
139     size_t n = 1000;
140     char *p = (char *)PyMem_MALLOC(n);
141     char *q;
142     if (p == NULL)
143         return NULL;
144     fprintf(stderr, "%s", prompt);
145     q = fgets(p, n, sys_stdin);
146     if (q == NULL) {
147         *p = '\0';
148         return p;
149     }
150     n = strlen(p);
151     if (n > 0 && p[n-1] != '\n')
152         p[n-1] = '\n';
153     return (char *)PyMem_REALLOC(p, n+1);
154 }
155 
156 /* No-nonsense fgets */
157 char *
Py_UniversalNewlineFgets(char * buf,int n,FILE * stream,PyObject * fobj)158 Py_UniversalNewlineFgets(char *buf, int n, FILE *stream, PyObject *fobj)
159 {
160     return fgets(buf, n, stream);
161 }
162 
163 
164 #include <stdarg.h>
165 
166 void
PySys_WriteStderr(const char * format,...)167 PySys_WriteStderr(const char *format, ...)
168 {
169     va_list va;
170 
171     va_start(va, format);
172     vfprintf(stderr, format, va);
173     va_end(va);
174 }
175