1 files changed, 142 insertions, 0 deletions
diff --git a/src/common.c b/src/common.c
new file mode 100644
index 0000000..b25b6a2
--- /dev/null
+++ b/src/common.c
@@ -0,0 +1,142 @@
+#include "ducky.h"
+
+vartype spec_zero(void)
+{
+    return 0;
+}
+
+vartype spec_rand(void)
+{
+    return rand();
+}
+
+vartype spec_time(void)
+{
+    return time(NULL);
+}
+
+vartype (*special_funcs[])(void) = {
+    spec_zero,
+    spec_rand,
+    spec_time,
+};
+
+void __attribute__((noreturn,format(printf,3,4))) error(jmp_buf exit_point, int current_line, const char *fmt, ...)
+{
+    char fmtbuf[256];
+
+    va_list ap;
+    va_start(ap, fmt);
+    vsnprintf(fmtbuf, sizeof(fmtbuf), fmt, ap);
+    if(current_line)
+        vid_logf("Line %d: ", current_line);
+    vid_logf("ERROR: %s",  fmtbuf);
+    va_end(ap);
+
+    longjmp(exit_point, 1);
+}
+
+vartype get_special(enum special_id special, jmp_buf exit_point, int current_line)
+{
+    if(special < ARRAYLEN(special_funcs))
+        return special_funcs[special]();
+    else
+        error(exit_point, current_line, "unknown special stream");
+}
+
+/* grabs a line from a file, -1 on error, returns # bytes read otherwise */
+int read_line(int fd, char *buf, size_t sz)
+{
+    unsigned i = 0;
+    int bytes_read = 0;
+    int status = 1;
+    while(i < sz)
+    {
+        char c;
+        status = read(fd, &c, 1);
+        if(status != 1)
+            break;
+
+        ++bytes_read;
+
+        if(c == '\r')
+            continue;
+        if(c == '\n' || c == EOF)
+        {
+            break;
+        }
+
+        buf[i++] = c;
+    }
+    buf[MIN(i, sz - 1)] = '\0';
+
+    return (status <= 0)?-1:bytes_read;
+}
+
+/* index_lines() precalculates the offset of each line for faster jumping */
+
+off_t *index_lines(int fd, unsigned *numlines, bool labels, bool (*isValidVariable)(const char*), void (*setConst)(const char*, bool), void (*setVariable)(const char*, vartype))
+{
+    size_t sz = sizeof(off_t);
+    off_t *data = malloc(sz);
+
+    /* this uses 1-indexed line numbers, so the first indice is wasted */
+    unsigned idx = 1;
+
+    while(1)
+    {
+        sz += sizeof(off_t);
+        data = realloc(data, sz);
+        data[idx] = lseek(fd, 0, SEEK_CUR);
+
+        char buf[MAX_LINE_LEN];
+
+        if(read_line(fd, buf, sizeof(buf)) < 0)
+            break;
+
+        if(labels)
+        {
+            char *save = NULL;
+            char *tok = strtok_r(buf, " \t", &save);
+            if(tok && (strcmp(tok, "LABEL") == 0 || strcmp("LBL", tok) == 0))
+            {
+                tok = strtok_r(NULL, " \t", &save);
+                if(tok && isValidVariable(tok))
+                {
+                    setVariable(tok, idx);
+                    setConst(tok, true);
+                }
+            }
+        }
+
+        ++idx;
+    }
+
+    lseek(fd, 0, SEEK_SET);
+
+    *numlines = idx - 1;
+
+    return data;
+}
+
+void __attribute__((format(printf,1,2))) vid_logf(const char *fmt, ...)
+{
+    char fmtbuf[256];
+
+    va_list ap;
+    va_start(ap, fmt);
+    vsnprintf(fmtbuf, sizeof(fmtbuf), fmt, ap);
+    printf("%s\n", fmtbuf);
+    va_end(ap);
+}
+
+void __attribute__((format(printf,2,3))) warning_real(int current_line, const char *fmt, ...)
+{
+    char fmtbuf[256];
+
+    va_list ap;
+    va_start(ap, fmt);
+    vsnprintf(fmtbuf, sizeof(fmtbuf), fmt, ap);
+    vid_logf("Line %d: WARNING: %s\n", current_line, fmtbuf);
+    va_end(ap);
+}