scripts: dts: properly escape string properties

Fixed escaping of double quotes, backslashes, and new line characters
so they can be used in string properties.

Previously, double quotes and backslashes were escaped in gen_defines.py
but not in gen_dts_cmake.py, and new lines were not escaped in either,
so using any of these characters would break the build.

Signed-off-by: Joel Spadin <[email protected]>

Author: joelspadin

scripts/dts/gen_defines.py

@@ -583,7 +583,7 @@ def write_vanilla_props(node: edtlib.Node) -> None:
 
         if prop.spec.type == 'string':
             # DT_N_<node-id>_P_<prop-id>_IDX_<i>_STRING_UNQUOTED
-            macro2val[macro + "_STRING_UNQUOTED"] = prop.val
+            macro2val[macro + "_STRING_UNQUOTED"] = escape_unquoted(prop.val)
             # DT_N_<node-id>_P_<prop-id>_IDX_<i>_STRING_TOKEN
             macro2val[macro + "_STRING_TOKEN"] = prop.val_as_token
             # DT_N_<node-id>_P_<prop-id>_IDX_<i>_STRING_UPPER_TOKEN
@@ -626,7 +626,7 @@ def write_vanilla_props(node: edtlib.Node) -> None:
                     macro2val[macro + f"_IDX_{i}"] = quote_str(subval)
                     subval_as_token = edtlib.str_as_token(subval)
                     # DT_N_<node-id>_P_<prop-id>_IDX_<i>_STRING_UNQUOTED
-                    macro2val[macro + f"_IDX_{i}_STRING_UNQUOTED"] = subval
+                    macro2val[macro + f"_IDX_{i}_STRING_UNQUOTED"] = escape_unquoted(subval)
                     # DT_N_<node-id>_P_<prop-id>_IDX_<i>_STRING_TOKEN
                     macro2val[macro + f"_IDX_{i}_STRING_TOKEN"] = subval_as_token
                     # DT_N_<node-id>_P_<prop-id>_IDX_<i>_STRING_UPPER_TOKEN
@@ -1020,11 +1020,20 @@ def out_comment(s: str, blank_before=True) -> None:
         print("/* " + s + " */", file=header_file)
 
 
+ESCAPE_TABLE = str.maketrans(
+    {
+        "\n": "\\n",
+        "\r": "\\r",
+        "\\": "\\\\",
+        '"': '\\"',
+    }
+)
+
+
 def escape(s: str) -> str:
-    # Backslash-escapes any double quotes and backslashes in 's'
+    # Backslash-escapes any double quotes, backslashes, and new lines in 's'
 
-    # \ must be escaped before " to avoid double escaping
-    return s.replace("\\", "\\\\").replace('"', '\\"')
+    return s.translate(ESCAPE_TABLE)
 
 
 def quote_str(s: str) -> str:
@@ -1034,6 +1043,15 @@ def quote_str(s: str) -> str:
     return f'"{escape(s)}"'
 
 
+def escape_unquoted(s: str) -> str:
+    # C macros cannot contain line breaks, so replace them with spaces.
+    # Whitespace is used to separate preprocessor tokens, but it does not matter
+    # which whitespace characters are used, so a line break and a space are
+    # equivalent with regards to unquoted strings being used as C code.
+
+    return s.replace("\r", " ").replace("\n", " ")
+
+
 def err(s: str) -> NoReturn:
     raise Exception(s)
 

scripts/dts/gen_dts_cmake.py

@@ -48,6 +48,22 @@
 sys.path.insert(0, os.path.join(os.path.dirname(__file__), 'python-devicetree',
                                 'src'))
 
+ESCAPE_TABLE = str.maketrans(
+    {
+        "\n": "\\n",
+        "\r": "\\r",
+        '\"': '\\"',
+        "\\": "\\\\",
+    }
+)
+
+
+def escape(value):
+    if isinstance(value, str):
+        return value.translate(ESCAPE_TABLE)
+
+    return value
+
 
 def parse_args():
     # Returns parsed command-line arguments
@@ -117,7 +133,7 @@ def main():
                 # Encode node's property 'item' as a CMake target property
                 # with a name like 'DT_PROP|<path>|<property>'.
                 cmake_prop = f'DT_PROP|{node.path}|{item}'
-                cmake_props.append(f'"{cmake_prop}" "{cmake_value}"')
+                cmake_props.append(f'"{cmake_prop}" "{escape(cmake_value)}"')
 
                 if item == 'compatible':
                     # compatibles is always an array