Stephen Dolan
95dd64b0f0
Getting proper locations through flex/bison was more effort than was advertised.
63 lines
1.4 KiB
C
63 lines
1.4 KiB
C
#include <stdlib.h>
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#include <stdio.h>
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#include <assert.h>
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typedef struct {
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int start, end;
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} location;
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struct locfile {
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const char* data;
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int length;
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int* linemap;
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int nlines;
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};
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static void locfile_init(struct locfile* l, const char* data, int length) {
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l->data = data;
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l->length = length;
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l->nlines = 1;
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for (int i=0; i<length; i++) {
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if (data[i] == '\n') l->nlines++;
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}
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l->linemap = malloc(sizeof(int) * (l->nlines + 1));
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l->linemap[0] = 0;
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int line = 1;
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for (int i=0; i<length; i++) {
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if (data[i] == '\n') {
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l->linemap[line] = i;
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line++;
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}
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}
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l->linemap[l->nlines] = length;
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}
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static void locfile_free(struct locfile* l) {
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free(l->linemap);
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}
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static int locfile_get_line(struct locfile* l, int pos) {
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assert(pos < l->length);
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int line = 0;
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while (l->linemap[line+1] < pos) line++;
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assert(line < l->nlines);
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return line;
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}
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static int locfile_line_length(struct locfile* l, int line) {
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assert(line < l->nlines);
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return l->linemap[line+1] - l->linemap[line];
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}
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static void locfile_locate(struct locfile* l, location loc) {
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int startline = locfile_get_line(l, loc.start);
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int offset = l->linemap[startline];
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printf("%.*s\n", locfile_line_length(l, startline), l->data + offset);
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printf("%*s", loc.start - offset, "");
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for (int i = loc.start;
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i < loc.end && i < offset + locfile_line_length(l, startline);
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i++){
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printf("^");
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}
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printf("\n");
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}
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