chore: Add custom clang-tidy plugin for isEmpty() checks

scripts/clang-tidy-plugin/CMakeLists.txt

@@ -0,0 +1,61 @@
+# Custom clang-tidy plugin for GeneralsGameCode
+# This plugin provides checks for custom types like AsciiString and UnicodeString
+
+cmake_minimum_required(VERSION 3.20)
+project(GeneralsGameCodeClangTidyPlugin)
+
+# Find LLVM and Clang
+find_package(LLVM REQUIRED CONFIG)
+find_package(Clang REQUIRED CONFIG)
+
+message(STATUS "Found LLVM ${LLVM_PACKAGE_VERSION}")
+message(STATUS "Using LLVMConfig.cmake in: ${LLVM_DIR}")
+message(STATUS "Using ClangConfig.cmake in: ${Clang_DIR}")
+
+# Set up include directories
+include_directories(${LLVM_INCLUDE_DIRS})
+include_directories(${CLANG_INCLUDE_DIRS})
+
+# Add definitions
+add_definitions(${LLVM_DEFINITIONS})
+add_definitions(${CLANG_DEFINITIONS})
+
+# Set C++ standard
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+# Source files
+set(SOURCES
+  GeneralsGameCodeTidyModule.cpp
+  readability/UseIsEmptyCheck.cpp
+)
+
+# Header files
+set(HEADERS
+  GeneralsGameCodeTidyModule.h
+  readability/UseIsEmptyCheck.h
+)
+
+# Create the module library
+add_library(GeneralsGameCodeClangTidyPlugin MODULE ${SOURCES} ${HEADERS})
+
+# Link against required libraries
+target_link_libraries(GeneralsGameCodeClangTidyPlugin
+  PRIVATE
+  clangTidy
+  clangTidyReadabilityModule
+  clangAST
+  clangASTMatchers
+  clangBasic
+  clangFrontend
+  clangLex
+  clangTooling
+  LLVMSupport
+)
+
+# Set output directory
+set_target_properties(GeneralsGameCodeClangTidyPlugin PROPERTIES
+  LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib
+  RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin
+)
+

scripts/clang-tidy-plugin/GeneralsGameCodeTidyModule.cpp

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+//===--- GeneralsGameCodeTidyModule.cpp - GeneralsGameCode Tidy Module ---===//
+//
+// Custom clang-tidy module for GeneralsGameCode
+// Provides checks for custom types like AsciiString and UnicodeString
+//
+//===----------------------------------------------------------------------===//
+
+#include "GeneralsGameCodeTidyModule.h"
+#include "readability/UseIsEmptyCheck.h"
+#include "llvm/Support/Registry.h"
+
+namespace clang::tidy::generalsgamecode {
+
+void GeneralsGameCodeTidyModule::addCheckFactories(
+    ClangTidyCheckFactories &CheckFactories) {
+  CheckFactories.registerCheck<readability::UseIsEmptyCheck>(
+      "generals-use-is-empty");
+}
+
+} // namespace clang::tidy::generalsgamecode
+
+static llvm::Registry<::clang::tidy::ClangTidyModule>::Add<
+    ::clang::tidy::generalsgamecode::GeneralsGameCodeTidyModule>
+    X("generalsgamecode", "GeneralsGameCode-specific checks");
+
+volatile int GeneralsGameCodeTidyModuleAnchorSource = 0;
+

scripts/clang-tidy-plugin/GeneralsGameCodeTidyModule.h

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+//===--- GeneralsGameCodeTidyModule.h - GeneralsGameCode Tidy Module -----===//
+//
+// Custom clang-tidy module for GeneralsGameCode
+// Provides checks for custom types like AsciiString and UnicodeString
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_GENERALSGAMECODE_GENERALSGAMECODETIDYMODULE_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_GENERALSGAMECODE_GENERALSGAMECODETIDYMODULE_H
+
+#include "clang-tidy/ClangTidyModule.h"
+
+namespace clang::tidy::generalsgamecode {
+
+/// This module is for GeneralsGameCode-specific checks.
+class GeneralsGameCodeTidyModule : public ClangTidyModule {
+public:
+  void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override;
+};
+
+} // namespace clang::tidy::generalsgamecode
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_GENERALSGAMECODE_GENERALSGAMECODETIDYMODULE_H
+

scripts/clang-tidy-plugin/README.md

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+# GeneralsGameCode Clang-Tidy Plugin
+
+This is a custom clang-tidy plugin that provides checks specific to the GeneralsGameCode codebase.
+
+## Checks
+
+### `generals-use-is-empty`
+
+Finds uses of `getLength() == 0` or `getLength() > 0` on `AsciiString` and `UnicodeString`, and `Get_Length() == 0` on `StringClass` and `WideStringClass`, and suggests using `isEmpty()`/`Is_Empty()` or `!isEmpty()`/`!Is_Empty()` instead.
+
+Also finds uses of `compare("") == 0`, `compare(TheEmptyString) == 0`, `compareNoCase("") == 0`, and similar patterns, suggesting `isEmpty()` instead.
+
+**Examples:**
+
+```cpp
+// Before (AsciiString/UnicodeString)
+if (str.getLength() == 0) { ... }
+if (str.getLength() > 0) { ... }
+if (str.compare("") == 0) { ... }
+if (str.compare(AsciiString::TheEmptyString) == 0) { ... }
+if (str.compareNoCase("") == 0) { ... }
+
+// After (AsciiString/UnicodeString)
+if (str.isEmpty()) { ... }
+if (!str.isEmpty()) { ... }
+if (str.isEmpty()) { ... }
+if (str.isEmpty()) { ... }
+if (str.isEmpty()) { ... }
+
+// Before (StringClass/WideStringClass)
+if (str.Get_Length() == 0) { ... }
+if (str.Get_Length() > 0) { ... }
+
+// After (StringClass/WideStringClass)
+if (str.Is_Empty()) { ... }
+if (!str.Is_Empty()) { ... }
+```
+
+## Building
+
+This plugin requires LLVM and Clang to be installed. Build it with CMake:
+
+```bash
+cd scripts/clang-tidy-plugin
+mkdir build && cd build
+cmake .. -DLLVM_DIR=/path/to/llvm/lib/cmake/llvm -DClang_DIR=/path/to/clang/lib/cmake/clang
+make
+```
+
+The plugin will be built as a shared library (`.so` on Linux, `.dylib` on macOS, `.dll` on Windows) in the `build/lib/` directory.
+
+## Prerequisites
+
+Before using the plugin, you need to generate a compile commands database:
+
+```bash
+cmake -B build/clang-tidy -DCMAKE_DISABLE_PRECOMPILE_HEADERS=ON -G Ninja
+```
+
+This creates `build/clang-tidy/compile_commands.json` which tells clang-tidy how to compile each file.
+
+## Usage
+
+### Basic Usage
+
+```bash
+clang-tidy -p build/clang-tidy \
+  --checks='-*,generals-use-is-empty' \
+  -load scripts/clang-tidy-plugin/build/lib/libGeneralsGameCodeClangTidyPlugin.so \
+  file.cpp
+```
+
+### With Automatic Fixes
+
+```bash
+clang-tidy -p build/clang-tidy \
+  --checks='-*,generals-use-is-empty' \
+  -load scripts/clang-tidy-plugin/build/lib/libGeneralsGameCodeClangTidyPlugin.so \
+  -fix-errors \
+  file.cpp
+```
+
+### On Multiple Files
+
+```bash
+find Core -name "*.cpp" -type f -exec clang-tidy \
+  -p build/clang-tidy \
+  --checks='-*,generals-use-is-empty' \
+  -load scripts/clang-tidy-plugin/build/lib/libGeneralsGameCodeClangTidyPlugin.so \
+  -fix-errors {} \;
+```
+
+The `-p build/clang-tidy` flag tells clang-tidy to use the compile commands database to understand how to parse each file.
+