update configure.py to handle new bootstrap.example.toml

Author: lolbinarycat

bootstrap.example.toml

@@ -385,7 +385,7 @@
 #
 # The default value for the `features` array is `[]`. However, please note that other flags in
 # `bootstrap.toml` might influence the features enabled for some tools.
-#tool.TOOL_NAME.features = [FEATURE1, FEATURE2]
+#build.tool.TOOL_NAME.features = [FEATURE1, FEATURE2]
 
 # Verbosity level: 0 == not verbose, 1 == verbose, 2 == very verbose, 3 == print environment variables on each rustc invocation
 #build.verbose = 0

src/bootstrap/configure.py

@@ -6,6 +6,7 @@
 import shlex
 import sys
 import os
+import re
 
 rust_dir = os.path.dirname(os.path.abspath(__file__))
 rust_dir = os.path.dirname(rust_dir)
@@ -585,16 +586,31 @@ def parse_example_config(known_args, config):
     section_order = [None]
     targets = {}
     top_level_keys = []
+    comment_lines = []
 
     with open(rust_dir + "/bootstrap.example.toml") as example_config:
         example_lines = example_config.read().split("\n")
     for line in example_lines:
-        if cur_section is None:
-            if line.count("=") == 1:
-                top_level_key = line.split("=")[0]
-                top_level_key = top_level_key.strip(" #")
-                top_level_keys.append(top_level_key)
-        if line.startswith("["):
+        if line.count("=") == 1 and not line.startswith("# "):
+            key = line.split("=")[0]
+            key = key.strip(" #")
+            parts = key.split(".")
+            if len(parts) > 1:
+                cur_section = parts[0]
+                if cur_section not in sections:
+                    sections[cur_section] = ["[" + cur_section + "]"]
+                    section_order.append(cur_section)
+            elif cur_section is None:
+                top_level_keys.append(key)
+            # put the comment lines within the start of
+            # a new section, not outside it.
+            sections[cur_section] += comment_lines
+            comment_lines = []
+            # remove just the `section.` part from the line, if present.
+            sections[cur_section].append(
+                re.sub("(#?)([a-zA-Z_-]+\\.)?(.*)", "\\1\\3", line)
+            )
+        elif line.startswith("["):
             cur_section = line[1:-1]
             if cur_section.startswith("target"):
                 cur_section = "target"
@@ -605,8 +621,9 @@ def parse_example_config(known_args, config):
             sections[cur_section] = [line]
             section_order.append(cur_section)
         else:
-            sections[cur_section].append(line)
+            comment_lines.append(line)
 
+    sections[cur_section] += comment_lines
     # Fill out the `targets` array by giving all configured targets a copy of the
     # `target` section we just loaded from the example config
     configured_targets = [build(known_args)]