Add clang-format definition, and CMake targets for formatting (#74)

The .clang-format tries to align as much as is possible with the existing
formatting, though some differences can be noted, particularly around
method parameters in declarations.

Author: bengaineyarm

.clang-format

@@ -0,0 +1,165 @@
+---
+Language: Cpp
+BasedOnStyle: Mozilla
+
+AccessModifierOffset: -4
+AlignAfterOpenBracket: Align
+AlignArrayOfStructures: None
+AlignConsecutiveAssignments: None
+AlignConsecutiveBitFields: Consecutive
+AlignConsecutiveDeclarations: None
+AlignConsecutiveMacros: Consecutive
+AlignEscapedNewlines: Right
+AlignOperands: AlignAfterOperator
+AlignTrailingComments: true
+AllowAllArgumentsOnNextLine: false
+AllowAllConstructorInitializersOnNextLine: false
+AllowAllParametersOfDeclarationOnNextLine: false
+AllowShortBlocksOnASingleLine: Never
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortEnumsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: InlineOnly
+AllowShortIfStatementsOnASingleLine: Never
+AllowShortLambdasOnASingleLine: All
+AllowShortLoopsOnASingleLine: false
+AlwaysBreakAfterDefinitionReturnType: None
+AlwaysBreakAfterReturnType: None
+AlwaysBreakBeforeMultilineStrings: false
+AlwaysBreakTemplateDeclarations: Yes
+AttributeMacros:
+BinPackArguments: false
+BinPackParameters: false
+BitFieldColonSpacing: Both
+BraceWrapping:
+  AfterCaseLabel: true
+  AfterClass: true
+  AfterControlStatement: Always
+  AfterEnum: true
+  AfterFunction: true
+  AfterNamespace: true
+  AfterStruct: true
+  AfterUnion: true
+  AfterExternBlock: true
+  BeforeCatch: true
+  BeforeElse: true
+  BeforeLambdaBody: true
+  BeforeWhile: true
+  IndentBraces: false
+  SplitEmptyFunction: true
+  SplitEmptyRecord: true
+  SplitEmptyNamespace: true
+BreakBeforeBinaryOperators: NonAssignment
+BreakBeforeBraces: Custom
+BreakBeforeConceptDeclarations: true
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializers: BeforeColon
+BreakInheritanceList: BeforeColon
+BreakStringLiterals: false
+ColumnLimit: 120
+CommentPragmas: '\(no-format\) $'
+CompactNamespaces: true
+ConstructorInitializerAllOnOneLineOrOnePerLine: false
+ConstructorInitializerIndentWidth: 4
+ContinuationIndentWidth: 4
+Cpp11BracedListStyle: true
+DeriveLineEnding: false
+DerivePointerAlignment: false
+EmptyLineAfterAccessModifier: Never
+EmptyLineBeforeAccessModifier: Always
+FixNamespaceComments: false
+ForEachMacros:
+IfMacros:
+IncludeBlocks: Regroup
+IncludeCategories:
+  - Regex:          '^"[^"]+"$'
+    Priority:       2
+    SortPriority:   2
+  - Regex:          '^<[0-9A-Za-z_/]+>$'
+    Priority:       3
+    SortPriority:   3
+  - Regex:          '^<[Ww]indows.h>$'
+    Priority:       4
+    SortPriority:   4
+  - Regex:          '^<(gtest|gmock)/[^>]+\.(h|hh|hpp)>$'
+    Priority:       7
+    SortPriority:   7
+  - Regex:          '^<[^>]+\.(h|hh|hpp)>$'
+    Priority:       8
+    SortPriority:   8
+IncludeIsMainRegex: '$'
+IncludeIsMainSourceRegex: '(_impl\.hpp)$'
+IndentAccessModifiers: false
+IndentCaseBlocks: false
+IndentCaseLabels: false
+IndentExternBlock: false
+IndentGotoLabels: false
+IndentPPDirectives: AfterHash
+IndentRequiresClause: false
+IndentWidth: 4 #
+IndentWrappedFunctionNames: true
+InsertBraces: true
+InsertNewlineAtEOF: true
+InsertTrailingCommas: Wrapped
+KeepEmptyLinesAtTheStartOfBlocks: false
+KeepEmptyLinesAtEOF: true
+LambdaBodyIndentation: Signature
+#MacroBlockBegin:
+#MacroBlockEnd:
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: Inner
+NamespaceMacros:
+PackConstructorInitializers: Never
+PenaltyBreakOpenParenthesis: 0
+PPIndentWidth: 2 #
+PointerAlignment: Left
+QualifierAlignment: Custom
+QualifierOrder:
+  - inline
+  - static
+  - constexpr
+  - friend
+  - const
+  - restrict
+  - volatile
+  - type
+RawStringFormats:
+ReferenceAlignment: Pointer
+ReflowComments: true
+RequiresClausePosition: OwnLine
+RequiresExpressionIndentation: OuterScope
+ShortNamespaceLines: 1
+SortIncludes: CaseSensitive
+SortUsingDeclarations: true
+SpaceAfterCStyleCast: true
+SpaceAfterLogicalNot: false
+SpaceAfterTemplateKeyword: false
+SpaceAroundPointerQualifiers: Default
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeCaseColon: false
+SpaceBeforeCpp11BracedList: true
+SpaceBeforeCtorInitializerColon: true
+SpaceBeforeParens: ControlStatementsExceptControlMacros
+SpaceBeforeRangeBasedForLoopColon: true
+SpaceBeforeSquareBrackets: false
+SpaceInEmptyBlock: true
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 1
+SpacesInAngles: false
+SpacesInCStyleCastParentheses: false
+SpacesInConditionalStatement: false
+SpacesInContainerLiterals: true
+SpacesInLineCommentPrefix:
+  Minimum: 1
+  Maximum: -1
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+Standard: c++20
+StatementAttributeLikeMacros:
+StatementMacros:
+  - UNUSED
+TabWidth: 4
+TypenameMacros:
+UseCRLF: false
+UseTab: Never
+WhitespaceSensitiveMacros:
+...

cmake/clang-tools.cmake

@@ -0,0 +1,73 @@
+# Copyright (C) 2025 by Arm Limited (or its affiliates). All rights reserved.
+include_guard(GLOBAL)
+
+# ###
+# Find various optional tools
+# ###
+find_file(CLANG_FORMAT NAMES "clang-format${CMAKE_EXECUTABLE_SUFFIX}"
+    NO_CMAKE_FIND_ROOT_PATH)
+
+if(EXISTS ${CLANG_FORMAT})
+    execute_process(
+        COMMAND "${CLANG_FORMAT}" --version
+        WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
+        RESULT_VARIABLE _cf_res
+        OUTPUT_VARIABLE _cf_out
+        ERROR_QUIET)
+    string(REGEX REPLACE "[\n\r\t]" " " _cf_out "${_cf_out}")
+    string(STRIP "${_cf_out}" _cf_out)
+
+    if(NOT "${_cf_res}" EQUAL 0)
+        message(STATUS "Failed to execute '${CLANG_FORMAT} --version'")
+        unset(CLANG_FORMAT)
+    elseif(NOT "${_cf_out}" MATCHES ".*clang-format version ([^ ]+).*")
+        message(STATUS "Failed to understand '${CLANG_FORMAT} --version' output")
+        unset(CLANG_FORMAT)
+    else()
+        string(REGEX REPLACE ".*clang-format version ([^ ]+).*" "\\1" _cf_ver "${_cf_out}")
+        message(STATUS "Detected clang-format version '${_cf_ver}'")
+
+        if("${_cf_ver}" VERSION_LESS "18.0.0")
+            message(STATUS "The version of clang-format is too old")
+            unset(CLANG_FORMAT)
+        endif()
+    endif()
+
+    unset(_cf_res)
+    unset(_cf_out)
+    unset(_cf_ver)
+endif()
+
+# ###
+# Add a custom targets for running clang-format
+# ###
+if(EXISTS ${CLANG_FORMAT})
+    add_custom_target(clang-format
+        COMMENT "Run clang-format on all targets")
+endif()
+
+# used to get the root project directory
+file(REAL_PATH "${CMAKE_CURRENT_LIST_DIR}/.." _cf_root)
+
+function(add_clang_tools)
+    if(EXISTS ${CLANG_FORMAT})
+        # Determine the name to give the custom target; base it on the folder path relative to the repo root
+        file(RELATIVE_PATH _cf_relpath "${_cf_root}" "${CMAKE_CURRENT_SOURCE_DIR}")
+        string(REGEX REPLACE "[^0-9A-Za-z_\-]" "-" _cf_name "${_cf_relpath}")
+
+        # find the sources
+        file(
+            GLOB_RECURSE _cf_srcs
+            LIST_DIRECTORIES false
+            RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}"
+            CONFIGURE_DEPENDS "*.cpp" "*.hpp")
+
+        # add the task
+        add_custom_target(clang-format-${_cf_name}
+            COMMAND ${CLANG_FORMAT} -i ${_cf_srcs}
+            WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+            SOURCES ${_cf_srcs}
+            COMMENT "Run clang-format on the sources in ${CMAKE_CURRENT_SOURCE_DIR} for ${_cf_name}")
+        add_dependencies(clang-format clang-format-${_cf_name})
+    endif()
+endfunction()

generator/generate_vulkan_common.py

@@ -502,6 +502,9 @@ def generate_instance_decls(
     file.write('#pragma once\n')
     file.write('\n')
 
+    file.write('// clang-format off\n')
+    file.write('\n')
+
     file.write('#include <vulkan/vulkan.h>\n')
     file.write('\n')
 
@@ -558,6 +561,8 @@ def generate_instance_decls(
         file.write('\n'.join(lines))
         file.write('\n')
 
+    file.write('// clang-format on\n')
+
 
 def generate_instance_defs(
         file: TextIO, mapping: VersionInfo, commands: list[Command]) -> None:
@@ -695,6 +700,9 @@ def generate_device_decls(
     file.write('#pragma once\n')
     file.write('\n')
 
+    file.write('// clang-format off\n')
+    file.write('\n')
+
     file.write('#include <vulkan/vulkan.h>\n')
     file.write('\n')
 
@@ -750,6 +758,8 @@ def generate_device_decls(
         file.write('\n'.join(lines))
         file.write('\n')
 
+    file.write('// clang-format on\n')
+
 
 def generate_device_defs(
         file: TextIO, mapping: VersionInfo, commands: list[Command]) -> None:

generator/vk_codegen/device_defs.txt

@@ -1,3 +1,5 @@
+// clang-format off
+
 #include <mutex>
 
 // Include from per-layer code
@@ -10,3 +12,4 @@
 extern std::mutex g_vulkanLock;
 
 {FUNCTION_DEFS}
+// clang-format on

generator/vk_codegen/device_dispatch_table.txt

@@ -1,5 +1,7 @@
 #pragma once
 
+// clang-format off
+
 #include <vulkan/vulkan.h>
 
 #include "framework/device_functions.hpp"
@@ -64,3 +66,5 @@ static inline void initDriverDeviceDispatchTable(
 }
 
 #undef ENTRY
+
+// clang-format on

generator/vk_codegen/instance_defs.txt

@@ -1,3 +1,5 @@
+// clang-format off
+
 #include <mutex>
 
 // Include from per-layer code
@@ -12,3 +14,4 @@
 extern std::mutex g_vulkanLock;
 
 {FUNCTION_DEFS}
+// clang-format on

generator/vk_codegen/instance_dispatch_table.txt

@@ -1,5 +1,7 @@
 #pragma once
 
+// clang-format off
+
 #include <vulkan/vulkan.h>
 
 #include "framework/device_functions.hpp"
@@ -67,3 +69,5 @@ static inline void initDriverInstanceDispatchTable(
 }
 
 #undef ENTRY
+
+// clang-format on

generator/vk_codegen/root_CMakeLists.txt

@@ -33,6 +33,7 @@ set(LGL_CONFIG_TRACE 0)
 set(LGL_CONFIG_LOG 1)
 
 include(../source_common/compiler_helper.cmake)
+include(../cmake/clang-tools.cmake)
 
 # Build steps
 add_subdirectory(source)

generator/vk_codegen/source_CMakeLists.txt

@@ -70,3 +70,5 @@ if (CMAKE_BUILD_TYPE STREQUAL "Release")
         ARGS --strip-all -o ${VK_LAYER_STRIP} $<TARGET_FILE:${VK_LAYER}>
         COMMENT "Stripped lib${VK_LAYER}.so to ${VK_LAYER_STRIP}")
 endif()
+
+add_clang_tools()

layer_example/CMakeLists.txt

@@ -33,6 +33,7 @@ set(LGL_CONFIG_TRACE 0)
 set(LGL_CONFIG_LOG 1)
 
 include(../source_common/compiler_helper.cmake)
+include(../cmake/clang-tools.cmake)
 
 # Build steps
 add_subdirectory(source)