Code formatting using ClangFormat 6.0 (#230)

**Changes**
* Add `.clang-format` with configuration settings that are similar to the current codebase
* Add two custom targets:
  * `format`: format code
  * `check-format`: check code and exit 0 on success
* Setup CI to check code formatting using `check-format` target
* Format the code

Resolves #177

Author: jslee02

.ci/install_linux.sh

@@ -30,6 +30,11 @@ $SUDO apt-get -y install lcov
 $SUDO apt-get -y install python-dev python3-dev
 $SUDO apt-get -y install libpython-dev libpython3-dev
 
+# Install ClangFormat 6
+if [ $(lsb_release -sc) = "bionic" ]; then
+  $SUDO apt-get -y install clang-format-6.0
+fi
+
 # Install pybind11 from source (we need pybind11 (>=2.2.0))
 git clone https://github.com/pybind/pybind11.git
 cd pybind11

.ci/script.sh

@@ -14,6 +14,10 @@ else
   cmake "-DCMAKE_BUILD_TYPE=${BUILD_TYPE}" "-DLLVM_DIR=${LLVM_DIR}" "-DCODECOV=OFF" ..
 fi
 
+if [ "$OS_NAME" = "linux" ] && [ $(lsb_release -sc) = "bionic" ]; then
+  make check-format
+fi
+
 make -j4 binding_tests
 
 if [ $BUILD_NAME = TRUSTY_GCC_DEBUG ]; then

.clang-format

@@ -0,0 +1,89 @@
+---
+Language:        Cpp
+BasedOnStyle:   LLVM
+AccessModifierOffset: -4
+AlignAfterOpenBracket: Align
+AlignEscapedNewlinesLeft: false
+AlignOperands:   true
+AlignTrailingComments: true
+AllowAllParametersOfDeclarationOnNextLine: true
+AllowShortBlocksOnASingleLine: false
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: None
+AllowShortIfStatementsOnASingleLine: false
+AllowShortLoopsOnASingleLine: false
+AlwaysBreakAfterDefinitionReturnType: false
+AlwaysBreakBeforeMultilineStrings: true
+AlwaysBreakTemplateDeclarations: true
+BinPackArguments: true
+BinPackParameters: true
+BraceWrapping:
+  AfterClass:      true
+  AfterControlStatement: true
+  AfterEnum:       true
+  AfterFunction:   true
+  AfterNamespace:  true
+  AfterObjCDeclaration: true
+  AfterStruct:     true
+  AfterUnion:      true
+  BeforeCatch:     true
+  BeforeElse:      true
+  IndentBraces:    false
+BreakBeforeBinaryOperators: All
+BreakBeforeBraces: Custom
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializersBeforeComma: true
+ColumnLimit:     80
+CommentPragmas:  ''
+ConstructorInitializerAllOnOneLineOrOnePerLine: true
+ConstructorInitializerIndentWidth: 2
+ContinuationIndentWidth: 4
+Cpp11BracedListStyle: true
+DerivePointerAlignment: false
+DisableFormat:   false
+ExperimentalAutoDetectBinPacking: false
+FixNamespaceComments: true
+ForEachMacros:   [ foreach, Q_FOREACH, BOOST_FOREACH ]
+# Sort headers by main include file (implicit priority 0),
+# then project and private includes, then system headers
+IncludeCategories:
+  - Regex:     '^<([a-z|_]+)>'  # standard library headers
+    Priority:  1
+  - Regex:     '^(<[A-z]+)'     # dependency headers
+    Priority:  2
+  - Regex:     '^(<|")chimera/' # Chimera headers
+    Priority:  3
+  - Regex:     '^".*'           # headers relative to this project
+    Priority:  4
+IndentCaseLabels: true
+IndentFunctionDeclarationAfterType: false
+IndentWidth:     4
+IndentWrappedFunctionNames: false
+KeepEmptyLinesAtTheStartOfBlocks: true
+MacroBlockBegin: ''
+MacroBlockEnd: ''
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: None
+ObjCBlockIndentWidth: 2
+ObjCSpaceAfterProperty: false
+PenaltyBreakBeforeFirstCallParameter: 1
+PenaltyBreakComment: 300
+PenaltyBreakFirstLessLess: 120
+PenaltyBreakString: 1000
+PenaltyExcessCharacter: 1000000
+PenaltyReturnTypeOnItsOwnLine: 200
+PointerAlignment: Right
+SpaceAfterCStyleCast: false
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeParens: ControlStatements
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 1
+SpacesInAngles: false
+SpacesInContainerLiterals: true
+SpacesInCStyleCastParentheses: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+Standard:        Auto
+TabWidth:        4
+UseTab:          Never
+...

CMakeLists.txt

@@ -9,6 +9,10 @@ set(SHARE_INSTALL_DIR "share/${PROJECT_NAME}")
 ## SETUP ##
 ###########
 
+# Preset for code formatting
+include(ClangFormat)
+clang_format_setup()
+
 ## Find necessary packages.
 find_package(LLVM REQUIRED CONFIG)
 include_directories(SYSTEM ${LLVM_INCLUDE_DIRS})
@@ -124,6 +128,12 @@ target_link_libraries("${PROJECT_NAME}"
 add_subdirectory(bindings)
 target_link_libraries(chimera chimera_bindings)
 
+# Add main sources for code formatting
+clang_format_add_sources(
+  ${${PROJECT_NAME}_HEADERS}
+  ${${PROJECT_NAME}_SOURCES}
+)
+
 #############
 ## INSTALL ##
 #############
@@ -154,3 +164,10 @@ install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake"
 # Enable unit testing by including the `test` subdirectory.
 enable_testing()
 add_subdirectory(test EXCLUDE_FROM_ALL)
+
+#####################
+## CODE FORMATTING ##
+#####################
+
+# Define 'format' target that runs ClangFormat
+clang_format_add_targets()

cmake/ClangFormat.cmake

@@ -0,0 +1,67 @@
+function(clang_format_setup)
+  find_program(CLANG_FORMAT_EXECUTABLE NAMES clang-format-6.0)
+  if(NOT CLANG_FORMAT_EXECUTABLE)
+    message(STATUS "Looking for clang-format - NOT found, please install "
+      "clang-format to enable automatic code formatting."
+    )
+    return()
+  endif()
+
+  message(STATUS "Found clang-format.")
+endfunction()
+
+#===============================================================================
+function(_property_add property_name)
+  get_property(is_defined GLOBAL PROPERTY ${property_name} DEFINED)
+  if(NOT is_defined)
+    define_property(GLOBAL PROPERTY ${property_name}
+      BRIEF_DOCS "${property_name}"
+      FULL_DOCS "Global properties for ${property_name}"
+    )
+  endif()
+  foreach(item ${ARGN})
+    set_property(GLOBAL APPEND PROPERTY ${property_name} "${item}")
+  endforeach()
+endfunction()
+
+#===============================================================================
+function(clang_format_add_sources)
+  foreach(source ${ARGN})
+    if(IS_ABSOLUTE "${source}")
+      set(source_abs "${source}")
+    else()
+      get_filename_component(source_abs
+        "${CMAKE_CURRENT_LIST_DIR}/${source}" ABSOLUTE)
+    endif()
+    if(EXISTS "${source_abs}")
+      _property_add(CLANG_FORMAT_FORMAT_FILES "${source_abs}")
+    else()
+      message(FATAL_ERROR
+        "Source file '${source}' does not exist at absolute path"
+        " '${source_abs}'. This should never happen. Did you recently delete"
+        " this file or modify 'CMAKE_CURRENT_LIST_DIR'")
+    endif()
+  endforeach()
+endfunction()
+
+#===============================================================================
+function(clang_format_add_targets)
+  get_property(formatting_files GLOBAL PROPERTY CLANG_FORMAT_FORMAT_FILES)
+  list(LENGTH formatting_files formatting_files_length)
+  message(STATUS "Formatting on ${formatting_files_length} source files.")
+
+  add_custom_target(format
+    COMMAND ${CMAKE_COMMAND} -E echo "Formatting ${formatting_files_length} files..."
+    COMMAND ${CLANG_FORMAT_EXECUTABLE} -style=file -i ${formatting_files}
+    COMMAND ${CMAKE_COMMAND} -E echo "Done."
+    DEPENDS ${CLANG_FORMAT_EXECUTABLE}
+    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+  )
+  add_custom_target(check-format
+    COMMAND ${CMAKE_COMMAND} -E echo "Checking ${formatting_files_length} files..."
+    COMMAND ${CMAKE_SOURCE_DIR}/tools/check_format.sh ${CLANG_FORMAT_EXECUTABLE} ${formatting_files}
+    COMMAND ${CMAKE_COMMAND} -E echo "Done."
+    DEPENDS ${CLANG_FORMAT_EXECUTABLE}
+    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+  )
+endfunction()

include/chimera/binding.h

@@ -1,8 +1,8 @@
 #ifndef __CHIMERA_BINDING_H__
 #define __CHIMERA_BINDING_H__
 
-#include <string>
 #include <map>
+#include <string>
 
 namespace chimera
 {
@@ -12,7 +12,8 @@ namespace binding
 /**
  * Interface for defining a built-in language binding.
  */
-struct Definition {
+struct Definition
+{
     std::string class_cpp;
     std::string enum_cpp;
     std::string function_cpp;

include/chimera/configuration.h

@@ -3,13 +3,13 @@
 
 #include "chimera/binding.h"
 
+#include <map>
+#include <memory>
+#include <set>
 #include <clang/AST/DeclBase.h>
 #include <clang/AST/Mangle.h>
 #include <clang/Frontend/CompilerInstance.h>
-#include <map>
-#include <memory>
 #include <mstch/mstch.hpp>
-#include <set>
 #include <yaml-cpp/yaml.h>
 
 namespace chimera
@@ -23,9 +23,8 @@ class Function;
 class Variable;
 class Namespace;
 
-} // mstch
-} // chimera
-
+} // namespace mstch
+} // namespace chimera
 
 namespace chimera
 {
@@ -35,13 +34,13 @@ class CompiledConfiguration;
 class Configuration
 {
 public:
-    Configuration(const Configuration&) = delete;
-    Configuration &operator=(const Configuration&) = delete;
+    Configuration(const Configuration &) = delete;
+    Configuration &operator=(const Configuration &) = delete;
 
     /**
      * Get the chimera configuration singleton for this process.
      */
-    static Configuration& GetInstance();
+    static Configuration &GetInstance();
 
     /**
      * Load the specified file to use as the YAML configuration.
@@ -81,28 +80,28 @@ class Configuration
     /**
      * Process the configuration settings against the current AST.
      */
-    std::unique_ptr<CompiledConfiguration>
-    Process(clang::CompilerInstance *ci) const;
+    std::unique_ptr<CompiledConfiguration> Process(
+        clang::CompilerInstance *ci) const;
 
     /**
      * Get the root node of the YAML configuration structure.
      */
-    const YAML::Node& GetRoot() const;
+    const YAML::Node &GetRoot() const;
 
     /**
      * Get the filename of the loaded YAML configuration file, if it exists.
      */
-    const std::string& GetConfigFilename() const;
+    const std::string &GetConfigFilename() const;
 
     /**
      * Get the desired output path for bindings.
      */
-    const std::string& GetOutputPath() const;
+    const std::string &GetOutputPath() const;
 
     /**
      * Get the desired output python module name for top-level binding.
      */
-    const std::string& GetOutputModuleName() const;
+    const std::string &GetOutputModuleName() const;
 
 private:
     Configuration();
@@ -123,14 +122,14 @@ class CompiledConfiguration
 {
 public:
     virtual ~CompiledConfiguration();
-    CompiledConfiguration(const CompiledConfiguration&) = delete;
-    CompiledConfiguration &operator=(const CompiledConfiguration&) = delete;
+    CompiledConfiguration(const CompiledConfiguration &) = delete;
+    CompiledConfiguration &operator=(const CompiledConfiguration &) = delete;
 
     /**
      * Adds a namespace to an ordered set of traversed namespaces.
      * This set can later be rendered in a template.
      */
-    void AddTraversedNamespace(const clang::NamespaceDecl* decl);
+    void AddTraversedNamespace(const clang::NamespaceDecl *decl);
 
     /**
      * Return list of namespace declarations that should be included.
@@ -139,24 +138,25 @@ class CompiledConfiguration
      * is desirable since parent namespaces will naturally be lexically
      * ordered before their children.
      */
-    const std::set<const clang::NamespaceDecl*>& GetNamespacesIncluded() const;
+    const std::set<const clang::NamespaceDecl *> &GetNamespacesIncluded() const;
 
     /**
      * Returns list of namespace declarations that should be skipped.
      */
-    const std::set<const clang::NamespaceDecl*>& GetNamespacesSuppressed() const;
+    const std::set<const clang::NamespaceDecl *> &GetNamespacesSuppressed()
+        const;
 
     /**
      * Get the YAML configuration associated with a specific declaration,
      * or return an empty YAML node if no configuration was found.
      */
-    const YAML::Node& GetDeclaration(const clang::Decl *decl) const;
+    const YAML::Node &GetDeclaration(const clang::Decl *decl) const;
 
     /**
      * Get the YAML configuration associated with a specific qualified type,
      * or return an empty YAML node if no configuration was found.
      */
-    const YAML::Node& GetType(const clang::QualType type) const;
+    const YAML::Node &GetType(const clang::QualType type) const;
 
     /**
      * Gets the compiler instance used by this configuration.
@@ -198,7 +198,8 @@ class CompiledConfiguration
 
     /**
      * Render a particular mstch template based on some declaration.
-     * This context must contain a "mangled_name" from which to create the filename.
+     * This context must contain a "mangled_name" from which to create the
+     * filename.
      */
     bool Render(const std::shared_ptr<chimera::mstch::CXXRecord> context);
     bool Render(const std::shared_ptr<chimera::mstch::Enum> context);
@@ -220,13 +221,13 @@ class CompiledConfiguration
     chimera::binding::Definition bindingDefinition_;
     clang::CompilerInstance *ci_;
     std::vector<std::pair<const clang::QualType, YAML::Node>> types_;
-    std::map<const clang::Decl*, YAML::Node> declarations_;
-    std::set<const clang::NamespaceDecl*> namespacesIncluded_;
-    std::set<const clang::NamespaceDecl*> namespacesSuppressed_;
+    std::map<const clang::Decl *, YAML::Node> declarations_;
+    std::set<const clang::NamespaceDecl *> namespacesIncluded_;
+    std::set<const clang::NamespaceDecl *> namespacesSuppressed_;
 
     std::vector<std::string> binding_names_;
     std::vector<std::shared_ptr<chimera::mstch::Namespace>> binding_namespaces_;
-    std::set<const clang::NamespaceDecl*> binding_namespace_decls_;
+    std::set<const clang::NamespaceDecl *> binding_namespace_decls_;
 
     friend class Configuration;
 };