tools: trim leading whitespace in documentation extract.
authorRusty Russell <rusty@rustcorp.com.au>
Thu, 16 Jun 2011 03:03:23 +0000 (12:33 +0930)
committerRusty Russell <rusty@rustcorp.com.au>
Thu, 16 Jun 2011 03:03:23 +0000 (12:33 +0930)
Take some care to preserve formatting, even with mixed tabs and spaces.

tools/doc_extract-core.c

index e7b4fcc702e2df3481756e7d5559d24991f6ccc5..8695a7e16fa2e2437c1ca1671b2eada3134f2b76 100644 (file)
@@ -129,6 +129,63 @@ static void add_line(struct doc_section *curr, const char *line)
        curr->lines[curr->num_lines++] = talloc_strdup(curr->lines, line);
 }
 
+/* We convert tabs to spaces here. */
+static void add_detabbed_line(struct doc_section *curr, const char *rawline)
+{
+       unsigned int i, eff_i, len, off = 0;
+       char *line;
+
+       /* Worst-case alloc: 8 spaces per tab. */
+       line = talloc_array(curr, char, strlen(rawline) +
+                           strcount(rawline, "\t") * 7 + 1);
+       len = 0;
+
+       /* We keep track of the *effective* offset of i. */
+       for (i = eff_i = 0; i < strlen(rawline); i++) {
+               if (rawline[i] == '\t') {
+                       do {
+                               line[len++] = ' ';
+                               eff_i++;
+                       } while (eff_i % 8 != 0);
+               } else {
+                       line[len++] = rawline[i];
+                       if (off == 0 && rawline[i] == '*')
+                               off = i + 1;
+                       eff_i++;
+               }
+       }
+       line[len] = '\0';
+
+       add_line(curr, line + off);
+       talloc_free(line);
+}
+
+/* Not very efficient: we could track prefix length while doing
+ * add_detabbed_line */
+static void trim_lines(struct doc_section *curr)
+{
+       unsigned int i, trim = -1;
+
+       /* Get minimum whitespace prefix. */
+       for (i = 0; i < curr->num_lines; i++) {
+               unsigned int prefix = strspn(curr->lines[i], " ");
+               /* Ignore blank lines */
+               if (curr->lines[i][prefix] == '\0')
+                       continue;
+               if (prefix < trim)
+                       trim = prefix;
+       }
+
+       /* Now trim it. */
+       for (i = 0; i < curr->num_lines; i++) {
+               unsigned int prefix = strspn(curr->lines[i], " ");
+               if (prefix < trim)
+                       curr->lines[i] += prefix;
+               else
+                       curr->lines[i] += trim;
+       }
+}
+
 struct list_head *extract_doc_sections(char **rawlines)
 {
        unsigned int *linemap;
@@ -161,9 +218,13 @@ struct list_head *extract_doc_sections(char **rawlines)
                        }
                } else {
                        if (curr)
-                               add_line(curr, lines[i]);
+                               add_detabbed_line(curr, rawlines[linemap[i]]);
                }
        }
+
+       list_for_each(list, curr, list)
+               trim_lines(curr);
+
        talloc_free(lines);
        return list;
 }