feature: Add make style target and refactor RAJA with clang-format

.clang-format

@@ -1,27 +1,84 @@
-BasedOnStyle : google
+BasedOnStyle : LLVM
+# Indent formatting
 IndentWidth : 2
-BreakBeforeBraces : Linux
+Language: Cpp
+UseTab: Never
 KeepEmptyLinesAtTheStartOfBlocks : true
 MaxEmptyLinesToKeep : 2
 AccessModifierOffset : -2
-UseTab: Never
+# This must be off so that include order in RAJA is preserved
+SortIncludes: false
+
+# Alignment of consecutive declarations, assignments etc
+AlignConsecutiveAssignments : true
+AlignConsecutiveDeclarations : false
+AlignConsecutiveMacros : true
+AlignTrailingComments : true
+
+# Control curly brace placement
+BreakBeforeBraces : Custom
+BraceWrapping:
+  AfterCaseLabel:  true
+  AfterClass:      true
+  AfterControlStatement: true
+  AfterEnum:       true
+  AfterFunction:   true
+  AfterNamespace:  true
+  AfterObjCDeclaration: false
+  AfterStruct:     true
+  AfterUnion:      true
+  AfterExternBlock: false
+  BeforeCatch:     true
+  BeforeElse:      true
+  BeforeLambdaBody: false
+  IndentBraces:    false
+  SplitEmptyFunction: false
+  SplitEmptyRecord: false
+  SplitEmptyNamespace: false
+
+# Pointer alignment
+DerivePointerAlignment: false
+PointerAlignment: Left
+
+# Single line config
 AllowShortIfStatementsOnASingleLine : true
-ConstructorInitializerAllOnOneLineOrOnePerLine : true
 AllowShortFunctionsOnASingleLine : true
 AllowShortLoopsOnASingleLine : false
-BinPackParameters : false
+AllowShortLambdasOnASingleLine : None
+PackConstructorInitializers : CurrentLine
+AllowAllArgumentsOnNextLine : true
 AllowAllParametersOfDeclarationOnNextLine : false
-AlignTrailingComments : true
+BinPackArguments : true
+BinPackParameters : false
+ConstructorInitializerAllOnOneLineOrOnePerLine : true
 ColumnLimit : 80
-PenaltyBreakBeforeFirstCallParameter : 100
-PenaltyReturnTypeOnItsOwnLine : 65000
-PenaltyBreakString : 10
 
-# These improve formatting results but require clang 3.6/7 or higher
-BreakBeforeBinaryOperators : None
-AlignAfterOpenBracket: true
-BinPackArguments : false
+AlignAfterOpenBracket: Align
 AlignOperands : true
 AlwaysBreakTemplateDeclarations : true
-Cpp11BracedListStyle : true
+AlwaysBreakAfterDefinitionReturnType : None
+PenaltyReturnTypeOnItsOwnLine : 10000
+BreakBeforeBinaryOperators : None
+
+# Indents
+IndentCaseLabels: true
+
+# Lambda body
+LambdaBodyIndentation : Signature
+
+SeparateDefinitionBlocks : Always
 
+# Space before/after settings
+SpaceAfterTemplateKeyword: false
+SpaceBeforeCpp11BracedList: true
+SpaceBeforeCtorInitializerColon: true
+SpaceBeforeInheritanceColon: true
+SpaceBeforeRangeBasedForLoopColon: true
+SpaceInEmptyBlock: false
+SpacesBeforeTrailingComments: 2
+SpacesInAngles: false
+SpacesInCStyleCastParentheses: false
+SpacesInContainerLiterals: false
+SpacesInConditionalStatement: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false

CMakeLists.txt

@@ -41,7 +41,7 @@ project(RAJA LANGUAGES CXX C
   VERSION ${RAJA_LOADED})
 
 set(CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake/thirdparty" ${CMAKE_MODULE_PATH})
-
+set(BLT_REQUIRED_CLANGFORMAT_VERSION  "14" CACHE STRING "")
 include(cmake/SetupRajaOptions.cmake)
 
 cmake_minimum_required(VERSION 3.23)
@@ -136,6 +136,9 @@ include(cmake/SetupCompilers.cmake)
 # Macros for building executables and libraries
 include (cmake/RAJAMacros.cmake)
 
+# Configure `style` target for enforcing code style
+raja_add_code_checks()
+
 set (raja_sources
   src/AlignedRangeIndexSetBuilders.cpp
   src/DepGraphNode.cpp

cmake/RAJAMacros.cmake

@@ -204,3 +204,62 @@ macro(raja_add_benchmark)
     NUM_OMP_THREADS ${arg_NUM_OMP_THREADS}
     COMMAND ${TEST_DRIVER} ${arg_NAME})
 endmacro(raja_add_benchmark)
+
+##------------------------------------------------------------------------------
+## raja_add_code_checks()
+##
+## Adds code checks for all source files recursively in the RAJA repository.
+##
+## This creates the following parent build targets:
+##  check - Runs a non file changing style check and CppCheck
+##  style - In-place code formatting
+##
+## Creates various child build targets that follow this pattern:
+##  raja_<check|style>
+##  raja_<cppcheck|clangformat>_<check|style>
+##------------------------------------------------------------------------------
+macro(raja_add_code_checks)
+
+  set(options)
+  set(singleValueArgs)
+  set(multiValueArgs)
+
+  # Parse the arguments to the macro
+  cmake_parse_arguments(arg
+       "${options}" "${singleValueArgs}" "${multiValueArgs}" ${ARGN})
+
+  # Only do code checks if building raja by itself and not included in
+  # another project
+  if ("${PROJECT_SOURCE_DIR}" STREQUAL "${CMAKE_SOURCE_DIR}")
+      # Create file globbing expressions that only include directories that contain source
+      # TODO(bowen) Add examples, exercises, test, and benchmark to the list below
+      set(_base_dirs "RAJA" "include" "src")
+      set(_ext_expressions "*.cpp" "*.hpp" "*.inl"
+                           "*.cxx" "*.hxx" "*.cc" "*.c" "*.h" "*.hh")
+
+      set(_glob_expressions)
+      foreach(_exp ${_ext_expressions})
+          foreach(_base_dir ${_base_dirs})
+              list(APPEND _glob_expressions "${PROJECT_SOURCE_DIR}/${_base_dir}/${_exp}")
+          endforeach()
+      endforeach()
+
+      # Glob for list of files to run code checks on
+      set(_sources)
+      file(GLOB_RECURSE _sources ${_glob_expressions})
+
+      blt_add_code_checks(PREFIX          RAJA
+                          SOURCES         ${_sources}
+                          CLANGFORMAT_CFG_FILE ${PROJECT_SOURCE_DIR}/.clang-format
+                          CPPCHECK_FLAGS  --enable=all --inconclusive)
+
+      # Set FOLDER property for code check targets
+      foreach(_suffix clangformat_check clangformat_style clang_tidy_check clang_tidy_style)
+          set(_tgt ${arg_PREFIX}_${_suffix})
+          if(TARGET ${_tgt})
+              set_target_properties(${_tgt} PROPERTIES FOLDER "RAJA/code_checks")
+          endif()
+      endforeach()
+  endif()
+
+endmacro(raja_add_code_checks)

cmake/SetupRajaOptions.cmake

@@ -28,7 +28,7 @@ option(RAJA_ENABLE_FORCEINLINE_RECURSIVE "Enable Forceinline recursive (only sup
 option(RAJA_DEPRECATED_TESTS "Test deprecated features" Off)
 option(RAJA_ENABLE_BOUNDS_CHECK "Enable bounds checking in RAJA::Views/Layouts" Off)
 option(RAJA_TEST_EXHAUSTIVE "Build RAJA exhaustive tests" Off)
-option(RAJA_TEST_OPENMP_TARGET_SUBSET "Build subset of RAJA OpenMP target tests" On)
+option(RAJA_TEST_OPENMP_TARGET_SUBSET "Build subset of RAJA OpenMP target tests when it is enabled" On)
 option(RAJA_ENABLE_RUNTIME_PLUGINS "Enable support for loading plugins at runtime" Off)
 option(RAJA_ALLOW_INCONSISTENT_OPTIONS "Enable inconsistent values for ENABLE_X and RAJA_ENABLE_X options" Off)
 

docs/sphinx/dev_guide/contributing.rst

@@ -193,6 +193,63 @@ likely the develop branch.
                **username/feature/<name-of-feature>** for a new feature, 
                **username/bugfix/<issue-fixed>** for a bugfix, etc.
 
+-----------------------------------
+Style
+-----------------------------------
+RAJA enforces style within the ``src`` and ``include`` directories using clang-format,
+major version 14.  Formatting will be enforced on pull requests through CI.
+The contributor must guarantee that their code is in compliance with the
+clang-format settings specified within ``.clang-format``.  To make this easy,
+RAJA has provided two options for applying clang-format:
+
+* The CMake build target ``style``
+
+  *  If a ``clang-format`` executable with major version 14 is available in the ``PATH``
+     when running CMake, RAJA's build system should find that executable and set 
+     the CMake variable ``CLANGFORMAT_EXECUTABLE`` to that executable's path.  
+  *  If an invalid version exists in the ``PATH``, or no ``clang-format`` version is 
+     specified in the path, the ``CLANGFORMAT_EXECUTABLE`` variable must be set by the 
+     user.  This can be done by passing ``-DCLANGFORMAT_EXECUTABLE=<path to clang-format 14>`` 
+     to ``cmake`` during build configuration.  For example on Linux, this would look like
+
+    .. code-block:: bash
+
+      mkdir build
+      cd build
+      cmake ../ <other CMake options> -DCLANGFORMAT_EXECUTABLE=<path to clang-format 14>
+
+
+  *  If an invalid version of ``clang-format`` is supplied, the following error will be 
+     emitted at build config time:
+
+    .. code-block:: bash
+
+      blt_add_clangformat_target: clang-format '14' is required, found <incorrect version>.
+        Disabling 'style' build target.  
+
+
+  *  If no ``CLANGFORMAT_EXECUTABLE`` is supplied, ``cmake`` will print the warning 
+     ``Failed to locate CMakeFormat executable``.
+
+* Git hooks
+
+  * Follow these steps to setup githooks, from the root directory of RAJA
+
+    .. code-block:: bash
+
+     # Only necessary if clang-format 14 is not in the $PATH variable.  
+     # This line can also be placed in .zshrc
+     $ export RAJA_CLANG_FORMAT=<path to clang-format install>
+     $ scripts/setup-hooks.sh
+
+  * The ``scripts/setup-hooks.sh`` script will install a ``pre-commit`` git hook 
+    script that applies clang-format to any changes staged with git.  If a ``clang-format``
+    executable with major version 14 is available in the ``PATH``, this executable will be used.
+    If not, the user must set the environment variable ``RAJA_CLANG_FORMAT`` to a valid 
+    clang-format executable.  If the script cannot find a valid clang-format installation
+    from either the ``PATH`` or from the environment variable ``RAJA_CLANG_FORMAT``, the 
+    script will print a warning and exit, allowing the commit to continue.
+
 .. _prfromfork-label:
 
 ===========================================================

include/RAJA/RAJA.hpp

@@ -88,7 +88,7 @@
 #endif
 
 #if defined(RAJA_ENABLE_DESUL_ATOMICS)
-    #include "RAJA/policy/desul.hpp"
+#include "RAJA/policy/desul.hpp"
 #endif
 
 #include "RAJA/index/IndexSet.hpp"
@@ -197,11 +197,14 @@
 
 #include "RAJA/pattern/sort.hpp"
 
-namespace RAJA {
-namespace expt{}
+namespace RAJA
+{
+namespace expt
+{}
+
 //  // provide a RAJA::expt namespace for experimental work, but bring alias
 //  // it into RAJA so it doesn't affect user code
 //  using namespace expt;
-}
+}  // namespace RAJA
 
 #endif  // closing endif for header file include guard