From 2fffde08916a0b1ca74075ab0d482fafcf83245f Mon Sep 17 00:00:00 2001
From: Rubidium <rubidium@openttd.org>
Date: Thu, 2 Mar 2023 22:02:37 +0100
Subject: [PATCH] Add: workflow and script for checking missing mode
 enforcements

---
 .github/script-missing-mode-enforcement.py    | 71 +++++++++++++++++++
 .github/unused-strings.py                     |  7 +-
 .../script-missing-mode-enforcement.yml       | 22 ++++++
 3 files changed, 96 insertions(+), 4 deletions(-)
 create mode 100644 .github/script-missing-mode-enforcement.py
 create mode 100644 .github/workflows/script-missing-mode-enforcement.yml

diff --git a/.github/script-missing-mode-enforcement.py b/.github/script-missing-mode-enforcement.py
new file mode 100644
index 0000000000..5903b5f0a0
--- /dev/null
+++ b/.github/script-missing-mode-enforcement.py
@@ -0,0 +1,71 @@
+"""
+Script to scan the OpenTTD's script API for functions that miss checks for the
+function being called from the right mode (deity or company mode).
+
+When a function calls either ScriptObject::Command or ScriptObject::GetCompany
+then the function is considered dangerous. When one of the mode enforcement
+macros from script_error.hpp, i.e. EnforceDeityMode, EnforceCompanyModeValid or
+EnforceDeityOrCompanyModeValid, are called in the function, then we consider
+that the function has mode enforcement.
+
+Any dangerous function for which no enforcement is found are emitted as errors.
+"""
+
+import glob
+import re
+import sys
+
+
+def check_mode_enforcement(path):
+    errors = []
+    with open(path, "r") as reader:
+        mode_enforcement_found = False
+        dangerous_function = False
+        for line in reader:
+            # Line does not start with a tab and have <word>::<word>. That looks like the begin of a function, so reset the state.
+            if re.match(r"^[^\t].*\w::\w", line):
+                mode_enforcement_found = False
+                dangerous_function = False
+                currentFunction = line
+                continue
+
+            if re.match(
+                r"\t(EnforceDeityMode|EnforceCompanyModeValid|EnforceDeityOrCompanyModeValid|EnforceDeityOrCompanyModeValid_Void)\(",
+                line,
+            ):
+                # Mode enforcement macro found
+                mode_enforcement_found = True
+                continue
+
+            if re.match(r".*(ScriptObject::Command|ScriptObject::GetCompany).*", line):
+                # Dangerous function found
+                dangerous_function = True
+                continue
+
+            # Line with only a closing bracket. That looks like the end of a function, so check for the dangerous function without mode enforcement
+            if re.match(r"^}$", line) and dangerous_function and not mode_enforcement_found:
+                function_name = currentFunction.rstrip("\n").replace("/* static */ ", "")
+                errors.append(f"{path}: {function_name}")
+
+    return errors
+
+
+def main():
+    errors = []
+    for path in sorted(glob.glob("src/script/api/*.cpp")):
+        # Skip a number of files that yield only false positives
+        if path.endswith(("script_object.cpp", "script_companymode.cpp", "script_controller.cpp", "script_game.cpp")):
+            continue
+
+        errors.extend(check_mode_enforcement(path))
+
+    if errors:
+        print("Mode enforcement was expected in the following files/functions:")
+        print("\n".join(errors))
+        sys.exit(1)
+
+    print("OK")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/.github/unused-strings.py b/.github/unused-strings.py
index 210212c397..527a938dc5 100644
--- a/.github/unused-strings.py
+++ b/.github/unused-strings.py
@@ -210,11 +210,10 @@ def main():
             errors.append(f"ERROR: {string} is (possibly) no longer needed.")
 
     if errors:
-        for error in errors:
-            print(error)
+        print("\n".join(errors))
         sys.exit(1)
-    else:
-        print("OK")
+
+    print("OK")
 
 
 if __name__ == "__main__":
diff --git a/.github/workflows/script-missing-mode-enforcement.yml b/.github/workflows/script-missing-mode-enforcement.yml
new file mode 100644
index 0000000000..9b9e8e7efa
--- /dev/null
+++ b/.github/workflows/script-missing-mode-enforcement.yml
@@ -0,0 +1,22 @@
+name: Script missing mode enforcement
+
+on:
+  pull_request:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.ref != 'refs/heads/master' }}
+
+jobs:
+  script-missing-mode-enforcement:
+    name: Script missing mode enforcement
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v3
+
+    - name: Check for finding script functions that require company/deity mode enforcement/checks
+      run: |
+        set -ex
+        python3 .github/script-missing-mode-enforcement.py