blob: 77b1aef1d7eb92343dccd5c2262406be55fa20ce [file] [log] [blame]
#ifndef _LOCFILE_H
#define _LOCFILE_H
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include <stdarg.h>
typedef struct {
int start, end;
} location;
static const location UNKNOWN_LOCATION = {-1, -1};
struct locfile {
const char* data;
int length;
int* linemap;
int nlines;
};
static void locfile_init(struct locfile* l, const char* data, int length) {
l->data = data;
l->length = length;
l->nlines = 1;
for (int i=0; i<length; i++) {
if (data[i] == '\n') l->nlines++;
}
l->linemap = malloc(sizeof(int) * (l->nlines + 1));
l->linemap[0] = 0;
int line = 1;
for (int i=0; i<length; i++) {
if (data[i] == '\n') {
l->linemap[line] = i;
line++;
}
}
l->linemap[l->nlines] = length;
}
static void locfile_free(struct locfile* l) {
free(l->linemap);
}
static int locfile_get_line(struct locfile* l, int pos) {
assert(pos < l->length);
int line = 0;
while (l->linemap[line+1] < pos) line++;
assert(line < l->nlines);
return line;
}
static int locfile_line_length(struct locfile* l, int line) {
assert(line < l->nlines);
return l->linemap[line+1] - l->linemap[line];
}
static void locfile_locate(struct locfile* l, location loc, const char* fmt, ...) {
va_list fmtargs;
va_start(fmtargs, fmt);
vfprintf(stderr, fmt, fmtargs);
va_end(fmtargs);
fprintf(stderr, "\n");
if (loc.start == -1) {
fprintf(stderr, "<unknown location>\n");
return;
}
int startline = locfile_get_line(l, loc.start);
int offset = l->linemap[startline];
fprintf(stderr, "%.*s\n", locfile_line_length(l, startline), l->data + offset);
fprintf(stderr, "%*s", loc.start - offset, "");
for (int i = loc.start;
i < loc.end && i < offset + locfile_line_length(l, startline);
i++){
fprintf(stderr, "^");
}
fprintf(stderr, "\n");
}
#endif