Don't depend on unspecified ordering.

Thanks to Matthew O'Connor for reporting this bug.
zauberzeug · Dec 4, 2021 · 0622ab1 · 0622ab1
1 parent 01087f1
commit 0622ab1
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Showing 2 changed files with 8 additions and 4 deletions.
diff --git a/src/1-parse.h b/src/1-parse.h
@@ -888,23 +888,26 @@ static size_t finish_token(uint32_t rule, size_t next_sibling, void *info) {
         if (offset == 0)
             abort();
         write_tree(tree, offset);
-        tree->next_identifier_token_offset = offset - read_tree(&offset, tree);
+        tree->next_identifier_token_offset = offset;
+        tree->next_identifier_token_offset -= read_tree(&offset, tree);
         break;
     }
     case 14: {
         size_t offset = tree->next_string_token_offset;
         if (offset == 0)
             abort();
         write_tree(tree, offset);
-        tree->next_string_token_offset = offset - read_tree(&offset, tree);
+        tree->next_string_token_offset = offset;
+        tree->next_string_token_offset -= read_tree(&offset, tree);
         break;
     }
     case 15: {
         size_t offset = tree->next_integer_token_offset;
         if (offset == 0)
             abort();
         write_tree(tree, offset);
-        tree->next_integer_token_offset = offset - read_tree(&offset, tree);
+        tree->next_integer_token_offset = offset;
+        tree->next_integer_token_offset -= read_tree(&offset, tree);
         break;
     }
     default:

diff --git a/src/6a-generate.c b/src/6a-generate.c
@@ -619,7 +619,8 @@ void generate(struct generator *gen)
         output_line(out, "        if (offset == 0)");
         output_line(out, "            abort();");
         output_line(out, "        write_tree(tree, offset);");
-        output_line(out, "        tree->next_%%rule_token_offset = offset - read_tree(&offset, tree);");
+        output_line(out, "        tree->next_%%rule_token_offset = offset;");
+        output_line(out, "        tree->next_%%rule_token_offset -= read_tree(&offset, tree);");
         output_line(out, "        break;");
         output_line(out, "    }");
     }