Specify encoding for "open()" functions

platformio/builder/tools/compilation_db.py

@@ -152,7 +152,7 @@ def WriteCompilationDb(target, source, env):
         item["file"] = os.path.abspath(item["file"])
         entries.append(item)
 
-    with open(str(target[0]), "w") as target_file:
+    with open(str(target[0]), mode="w", encoding="utf8") as target_file:
         json.dump(
             entries, target_file, sort_keys=True, indent=4, separators=(",", ": ")
         )

platformio/builder/tools/piolib.py

@@ -86,7 +86,9 @@ class LibBuilderFactory(object):
                     fname, piotool.SRC_BUILD_EXT + piotool.SRC_HEADER_EXT
                 ):
                     continue
-                with io.open(os.path.join(root, fname), errors="ignore") as fp:
+                with io.open(
+                    os.path.join(root, fname), encoding="utf8", errors="ignore"
+                ) as fp:
                     content = fp.read()
                 if not content:
                     continue
@@ -671,7 +673,7 @@ class MbedLibBuilder(LibBuilderBase):
 
     def _mbed_conf_append_macros(self, mbed_config_path, macros):
         lines = []
-        with open(mbed_config_path) as fp:
+        with open(mbed_config_path, encoding="utf8") as fp:
             for line in fp.readlines():
                 line = line.strip()
                 if line == "#endif":
@@ -690,7 +692,7 @@ class MbedLibBuilder(LibBuilderBase):
                 if len(tokens) < 2 or tokens[1] not in macros:
                     lines.append(line)
         lines.append("")
-        with open(mbed_config_path, "w") as fp:
+        with open(mbed_config_path, mode="w", encoding="utf8") as fp:
             fp.write("\n".join(lines))
 
 

platformio/builder/tools/piomaxlen.py

@@ -65,7 +65,7 @@ def _file_long_data(env, data):
     )
     if os.path.isfile(tmp_file):
         return tmp_file
-    with open(tmp_file, "w") as fp:
+    with open(tmp_file, mode="w", encoding="utf8") as fp:
         fp.write(data)
     return tmp_file
 

platformio/builder/tools/piosize.py

@@ -37,7 +37,7 @@ def _run_tool(cmd, env, tool_args):
         makedirs(build_dir)
     tmp_file = join(build_dir, "size-data-longcmd.txt")
 
-    with open(tmp_file, "w") as fp:
+    with open(tmp_file, mode="w", encoding="utf8") as fp:
         fp.write("\n".join(tool_args))
 
     cmd.append("@" + tmp_file)
@@ -241,7 +241,9 @@ def DumpSizeData(_, target, source, env):  # pylint: disable=unused-argument
             file_data.update(v)
             data["memory"]["files"].append(file_data)
 
-    with open(join(env.subst("$BUILD_DIR"), "sizedata.json"), "w") as fp:
+    with open(
+        join(env.subst("$BUILD_DIR"), "sizedata.json"), mode="w", encoding="utf8"
+    ) as fp:
         fp.write(json.dumps(data))