| rsc | 7f11104 | 2003-12-11 18:15:57 +0000 | [diff] [blame] | 1 | |
| 2 | #include <u.h> |
| 3 | #include <libc.h> |
| 4 | #include <bio.h> |
| 5 | #include "libString.h" |
| 6 | |
| 7 | struct Sinstack{ |
| 8 | int depth; |
| 9 | Biobuf *fp[32]; /* hard limit to avoid infinite recursion */ |
| 10 | }; |
| 11 | |
| 12 | /* initialize */ |
| 13 | extern Sinstack * |
| 14 | s_allocinstack(char *file) |
| 15 | { |
| 16 | Sinstack *sp; |
| 17 | Biobuf *fp; |
| 18 | |
| 19 | fp = Bopen(file, OREAD); |
| 20 | if(fp == nil) |
| 21 | return nil; |
| 22 | |
| 23 | sp = malloc(sizeof *sp); |
| 24 | sp->depth = 0; |
| 25 | sp->fp[0] = fp; |
| 26 | return sp; |
| 27 | } |
| 28 | |
| 29 | extern void |
| 30 | s_freeinstack(Sinstack *sp) |
| 31 | { |
| 32 | while(sp->depth >= 0) |
| 33 | Bterm(sp->fp[sp->depth--]); |
| 34 | free(sp); |
| 35 | } |
| 36 | |
| 37 | /* Append an input line to a String. |
| 38 | * |
| 39 | * Empty lines and leading whitespace are removed. |
| 40 | */ |
| 41 | static char * |
| 42 | rdline(Biobuf *fp, String *to) |
| 43 | { |
| 44 | int c; |
| 45 | int len = 0; |
| 46 | |
| 47 | c = Bgetc(fp); |
| 48 | |
| 49 | /* eat leading white */ |
| 50 | while(c==' ' || c=='\t' || c=='\n' || c=='\r') |
| 51 | c = Bgetc(fp); |
| 52 | |
| 53 | if(c < 0) |
| 54 | return 0; |
| 55 | |
| 56 | for(;;){ |
| 57 | switch(c) { |
| 58 | case -1: |
| 59 | goto out; |
| 60 | case '\\': |
| 61 | c = Bgetc(fp); |
| 62 | if (c != '\n') { |
| 63 | s_putc(to, '\\'); |
| 64 | s_putc(to, c); |
| 65 | len += 2; |
| 66 | } |
| 67 | break; |
| 68 | case '\r': |
| 69 | break; |
| 70 | case '\n': |
| 71 | if(len != 0) |
| 72 | goto out; |
| 73 | break; |
| 74 | default: |
| 75 | s_putc(to, c); |
| 76 | len++; |
| 77 | break; |
| 78 | } |
| 79 | c = Bgetc(fp); |
| 80 | } |
| 81 | out: |
| 82 | s_terminate(to); |
| 83 | return to->ptr - len; |
| 84 | } |
| 85 | |
| 86 | /* Append an input line to a String. |
| 87 | * |
| 88 | * Returns a pointer to the character string (or 0). |
| 89 | * Leading whitespace and newlines are removed. |
| 90 | * Lines starting with #include cause us to descend into the new file. |
| 91 | * Empty lines and other lines starting with '#' are ignored. |
| 92 | */ |
| 93 | extern char * |
| 94 | s_rdinstack(Sinstack *sp, String *to) |
| 95 | { |
| 96 | char *p; |
| 97 | Biobuf *fp, *nfp; |
| 98 | |
| 99 | s_terminate(to); |
| 100 | fp = sp->fp[sp->depth]; |
| 101 | |
| 102 | for(;;){ |
| 103 | p = rdline(fp, to); |
| 104 | if(p == nil){ |
| 105 | if(sp->depth == 0) |
| 106 | break; |
| 107 | Bterm(fp); |
| 108 | sp->depth--; |
| 109 | return s_rdinstack(sp, to); |
| 110 | } |
| 111 | |
| 112 | if(strncmp(p, "#include", 8) == 0 && (p[8] == ' ' || p[8] == '\t')){ |
| 113 | to->ptr = p; |
| 114 | p += 8; |
| 115 | |
| 116 | /* sanity (and looping) */ |
| 117 | if(sp->depth >= nelem(sp->fp)) |
| rsc | 834469a | 2005-01-04 22:19:46 +0000 | [diff] [blame] | 118 | sysfatal("s_rdinstack: includes too deep"); |
| rsc | 7f11104 | 2003-12-11 18:15:57 +0000 | [diff] [blame] | 119 | |
| 120 | /* skip white */ |
| 121 | while(*p == ' ' || *p == '\t') |
| 122 | p++; |
| 123 | |
| 124 | nfp = Bopen(p, OREAD); |
| 125 | if(nfp == nil) |
| 126 | continue; |
| 127 | sp->depth++; |
| 128 | sp->fp[sp->depth] = nfp; |
| 129 | return s_rdinstack(sp, to); |
| 130 | } |
| 131 | |
| 132 | /* got milk? */ |
| 133 | if(*p != '#') |
| 134 | break; |
| 135 | |
| 136 | /* take care of comments */ |
| 137 | to->ptr = p; |
| 138 | s_terminate(to); |
| 139 | } |
| 140 | return p; |
| 141 | } |
