builders: Added escape of 'env' parameter

There is an issue with passing the "EXT_MODULES" parameter from the
configuration moulin yaml file to the build.sh context.

The 'android_kernel' builder didn't escape double quotes, while
wrapping the 'env' parameter in additional double quotes like this:

bash -c "...env..."

As a result, an incorrect syntax was generated in the build.ninja file.

To generate a functional build.ninja file, it was necessary to take
this aspect into account in the moulin.yaml file and add additional
escaping there.

This approach is ambiguous since it requires the user to know the
implementation details of each moulin builder.

To address this issue, a simple escape function was added to all
builders that support the 'env' parameter. It escapes double quotes to
ensure proper handling of the 'env' variable.

The issue has been resolved for the following builders:
- android_kernel builder
- android builder
- zephyr builder

Signed-off-by: Mykhailo Androsiuk <[email protected]>

moulin/builders/android.py

@@ -8,6 +8,7 @@
 from typing import List
 from moulin.yaml_wrapper import YamlValue
 from moulin import ninja_syntax
+from moulin import utils
 
 
 def get_builder(conf: YamlValue, name: str, build_dir: str, src_stamps: List[str],
@@ -57,6 +58,9 @@ def gen_build(self):
         else:
             env_values = []
         env = " ".join(env_values)
+
+        env = utils.escape(env)
+
         variables = {
             "build_dir": self.build_dir,
             "env": env,

moulin/builders/android_kernel.py

@@ -8,6 +8,7 @@
 from typing import List
 from moulin.yaml_wrapper import YamlValue
 from moulin import ninja_syntax
+from moulin import utils
 
 
 def get_builder(conf: YamlValue, name: str, build_dir: str, src_stamps: List[str],
@@ -55,6 +56,9 @@ def gen_build(self):
         else:
             env_values = []
         env = " ".join(env_values)
+
+        env = utils.escape(env)
+
         variables = {
             "build_dir": self.build_dir,
             "env": env,

moulin/builders/zephyr.py

@@ -9,6 +9,7 @@
 from moulin.yaml_wrapper import YamlValue
 from moulin import ninja_syntax
 from moulin.utils import construct_fetcher_dep_cmd
+from moulin import utils
 
 
 def get_builder(conf: YamlValue, name: str, build_dir: str, src_stamps: List[str],
@@ -62,6 +63,8 @@ def gen_build(self):
             env_values = []
         env = " ".join(env_values)
 
+        env = utils.escape(env)
+
         shields_node = self.conf.get("shields", None)
         if shields_node:
             shields_vals = [x.as_str for x in shields_node]

moulin/utils.py

@@ -4,6 +4,7 @@
 
 import os.path
 import sys
+import re
 
 
 def create_stamp_name(*args):
@@ -18,3 +19,23 @@ def construct_fetcher_dep_cmd() -> str:
     this_script = os.path.abspath(sys.argv[0])
     args = " ".join(sys.argv[1:])
     return f"{this_script} {args} --fetcherdep $name"
+
+
+def escape(val: str) -> str:
+    """
+    Escape special characters in the input string.
+
+    This function takes an input string `val` and escapes special characters by adding escape
+    sequences to them. The following transformations are applied:
+    - Double quotes (") are escaped as \\".
+    - Dollar signs ($) are escaped as $$.
+    Args:
+        val (str): The input string to be escaped.
+    Returns:
+        str: The escaped string.
+    """
+    result = val
+    result = result.replace(r"\"", r"\\\"")
+    result = result.replace("$", "$$")
+    result = re.sub('(([^\\\\])"|^()")', '\\2\\"', result)
+    return result