Add .clang-format

Most options are configured to keep most of the current style.

Signed-off-by: Tim Crawford <tcrawford@system76.com>

.clang-format

@@ -0,0 +1,133 @@
+# https://releases.llvm.org/10.0.0/tools/clang/docs/ClangFormatStyleOptions.html
+---
+Language: Cpp
+AccessModifierOffset: -4
+AlignAfterOpenBracket: AlwaysBreak
+AlignConsecutiveAssignments: false
+AlignConsecutiveDeclarations: false
+AlignConsecutiveMacros: true
+AlignEscapedNewlines: DontAlign
+AlignOperands: true
+AlignTrailingComments: false
+AllowAllArgumentsOnNextLine: true
+AllowAllConstructorInitializersOnNextLine: true
+AllowAllParametersOfDeclarationOnNextLine: false
+AllowShortBlocksOnASingleLine: Empty
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: Inline
+AllowShortIfStatementsOnASingleLine: Never
+AllowShortLambdasOnASingleLine: All
+AllowShortLoopsOnASingleLine: false
+AlwaysBreakAfterReturnType: None
+AlwaysBreakBeforeMultilineStrings: false
+AlwaysBreakTemplateDeclarations: Yes
+BinPackArguments: false
+BinPackParameters: false
+BraceWrapping:
+  AfterCaseLabel: false
+  AfterClass: true
+  AfterControlStatement: false
+  AfterEnum: false
+  AfterFunction: false
+  AfterNamespace: true
+  AfterObjCDeclaration: false
+  AfterStruct: false
+  AfterUnion: false
+  AfterExternBlock: false
+  BeforeCatch: false
+  BeforeElse: false
+  IndentBraces: false
+  SplitEmptyFunction: false
+  SplitEmptyRecord: false
+  SplitEmptyNamespace: false
+BreakAfterJavaFieldAnnotations: false
+BreakBeforeBinaryOperators: None
+BreakBeforeBraces: Custom
+BreakBeforeTernaryOperators: false
+BreakConstructorInitializers: AfterColon
+BreakInheritanceList: AfterColon
+BreakStringLiterals: false
+ColumnLimit: 96
+CommentPragmas: '^ IWYU pragma:'
+CompactNamespaces: false
+ConstructorInitializerAllOnOneLineOrOnePerLine: false
+ConstructorInitializerIndentWidth: 4
+ContinuationIndentWidth: 4
+Cpp11BracedListStyle: false
+DeriveLineEnding: false
+DerivePointerAlignment: false
+DisableFormat: false
+ExperimentalAutoDetectBinPacking: true
+FixNamespaceComments: false
+ForEachMacros:
+  - foreach
+IncludeBlocks: Preserve
+IncludeCategories:
+  - Regex: '^"(llvm|llvm-c|clang|clang-c)/'
+    Priority: 2
+    SortPriority: 0
+  - Regex: '^(<|"(gtest|gmock|isl|json)/)'
+    Priority: 3
+    SortPriority: 0
+  - Regex: '.*'
+    Priority: 1
+    SortPriority: 0
+IncludeIsMainRegex: '(Test)?$'
+IncludeIsMainSourceRegex: ''
+IndentCaseLabels: true
+IndentGotoLabels: false
+IndentPPDirectives: BeforeHash
+IndentWidth: 4
+IndentWrappedFunctionNames: false
+JavaScriptQuotes: Leave
+JavaScriptWrapImports: true
+KeepEmptyLinesAtTheStartOfBlocks: false
+MacroBlockBegin: ''
+MacroBlockEnd: ''
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: None
+ObjCBinPackProtocolList: Auto
+ObjCBlockIndentWidth: 4
+ObjCSpaceAfterProperty: true
+ObjCSpaceBeforeProtocolList: true
+
+PenaltyBreakAssignment: 10
+PenaltyBreakBeforeFirstCallParameter: 10
+PenaltyBreakComment: 100
+PenaltyBreakFirstLessLess: 5
+PenaltyBreakString: 100
+PenaltyBreakTemplateDeclaration: 10
+PenaltyExcessCharacter: 5
+PenaltyReturnTypeOnItsOwnLine: 100
+
+PointerAlignment: Middle
+ReflowComments: false
+SortIncludes: true
+SortUsingDeclarations: true
+SpaceAfterCStyleCast: false
+SpaceAfterLogicalNot: false
+SpaceAfterTemplateKeyword: true
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeCpp11BracedList: false
+SpaceBeforeCtorInitializerColon: true
+SpaceBeforeInheritanceColon: true
+SpaceBeforeParens: ControlStatements
+SpaceBeforeRangeBasedForLoopColon: true
+SpaceBeforeSquareBrackets: false
+SpaceInEmptyBlock: false
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 1
+SpacesInAngles: false
+SpacesInCStyleCastParentheses: false
+SpacesInConditionalStatement: false
+SpacesInContainerLiterals: true
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+Standard: Latest
+StatementMacros:
+  - ARRAY_SIZE
+  - xstr
+TabWidth: 4
+UseCRLF: false
+UseTab: Never
+...

scripts/clang-format.sh

@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: GPL-3.0-only
+
+FILES=($(git ls-files '*.[ch]'))
+
+FMT_OPTS=(
+    "-style=file"
+    "--fallback-style=none"
+    "--Werror"
+)
+
+if [[ "$1" = "apply" ]]; then
+    clang-format "${FMT_OPTS[@]}" -i "${FILES[@]}"
+else
+    clang-format "${FMT_OPTS[@]}" --dry-run "${FILES[@]}"
+fi

scripts/deps.sh

@@ -19,6 +19,7 @@ if [[ "${ID}" =~ "debian" ]] || [[ "${ID_LIKE}" =~ "debian" ]]; then
         --yes \
         avr-libc \
         avrdude \
+        clang-format \
         curl \
         gcc \
         gcc-avr \
@@ -35,6 +36,7 @@ elif [[ "${ID}" =~ "fedora" ]] || [[ "${ID_LIKE}" =~ "fedora" ]]; then
         avr-gcc \
         avr-libc \
         avrdude \
+        clang-tools-extra \
         curl \
         gcc \
         make \
@@ -47,6 +49,7 @@ elif [[ "${ID}" =~ "arch" ]] || [[ "${ID_LIKE}" =~ "arch" ]]; then
         avr-gcc \
         avr-libc \
         avrdude \
+        clang \
         curl \
         gcc \
         make \