Re-use the parse tree generated during error detection for execution

Prior to this fix, read_ni would use parse_util_detect_errors
to lint the script to run, and then parser_t::eval() to execute it.
Both functions would parse the script into a parse tree. This allows
us to re-use the parse tree, improving perfomance.

1 files changed, 7 insertions, 2 deletions

diff --git a/src/parse_util.cpp b/src/parse_util.cpp
index a528c898..628e86c5 100644
--- a/src/parse_util.cpp
+++ b/src/parse_util.cpp
@@ -1287,7 +1287,7 @@ parser_test_error_bits_t parse_util_detect_errors_in_argument(const parse_node_t
     return err;
 }
 
-parser_test_error_bits_t parse_util_detect_errors(const wcstring &buff_src, parse_error_list_t *out_errors, bool allow_incomplete)
+parser_test_error_bits_t parse_util_detect_errors(const wcstring &buff_src, parse_error_list_t *out_errors, bool allow_incomplete, parse_node_tree_t *out_tree)
 {
     parse_node_tree_t node_tree;
     parse_error_list_t parse_errors;
@@ -1546,10 +1546,15 @@ parser_test_error_bits_t parse_util_detect_errors(const wcstring &buff_src, pars
     if (has_unclosed_block || has_unclosed_quote)
         res |= PARSER_TEST_INCOMPLETE;
 
-    if (out_errors)
+    if (out_errors != NULL)
     {
         out_errors->swap(parse_errors);
     }
+    
+    if (out_tree != NULL)
+    {
+        out_tree->swap(node_tree);
+    }
 
     return res;