Add clang-format 14 workflow and pre-commit hook

.clang-format

@@ -1,90 +1,68 @@
 ---
+# SPDX-License-Identifier: MPL-2.0
+#
+# clang-format style for dlt-daemon
+#
+# Compatible with clang-format 14 and later.
+# Install:  sudo apt-get install clang-format-14
+# Check:    clang-format-14 --dry-run --Werror --style=file <file>
+# Fix:      clang-format-14 -i --style=file <file>
+#
 Language:        Cpp
-# BasedOnStyle:  LLVM
-AccessModifierOffset: -2
-AlignAfterOpenBracket: Align
-AlignConsecutiveAssignments: false
-AlignConsecutiveDeclarations: false
-AlignEscapedNewlinesLeft: false
+BasedOnStyle:    WebKit
+AlignAfterOpenBracket: AlwaysBreak
+AlignConsecutiveAssignments: None
+AlignConsecutiveDeclarations: None
+AlignConsecutiveMacros: None
 AlignOperands:   true
 AlignTrailingComments: true
-AllowAllParametersOfDeclarationOnNextLine: true
-AllowShortBlocksOnASingleLine: false
+AllowShortBlocksOnASingleLine: true
 AllowShortCaseLabelsOnASingleLine: false
-AllowShortFunctionsOnASingleLine: All
-AllowShortIfStatementsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: None
+AllowShortIfStatementsOnASingleLine: Never
 AllowShortLoopsOnASingleLine: false
 AlwaysBreakAfterDefinitionReturnType: None
-AlwaysBreakAfterReturnType: None
-AlwaysBreakBeforeMultilineStrings: false
-AlwaysBreakTemplateDeclarations: false
+AlwaysBreakBeforeMultilineStrings: true
+AlwaysBreakTemplateDeclarations: Yes
 BinPackArguments: true
 BinPackParameters: true
-BraceWrapping:
-  AfterClass:      false
-  AfterControlStatement: false
-  AfterEnum:       false
-  AfterFunction:   true
-  AfterNamespace:  false
-  AfterObjCDeclaration: false
-  AfterStruct:     false
-  AfterUnion:      false
-  BeforeCatch:     false
-  BeforeElse:      true
-  IndentBraces:    false
-BreakBeforeBinaryOperators: None
-BreakBeforeBraces: Custom
-BreakBeforeTernaryOperators: true
-BreakConstructorInitializersBeforeComma: false
-ColumnLimit:     80
-CommentPragmas:  '^ IWYU pragma:'
-ConstructorInitializerAllOnOneLineOrOnePerLine: false
+BreakBeforeBinaryOperators: NonAssignment
+BreakBeforeBraces: WebKit
+BreakBeforeTernaryOperators: false
+BreakConstructorInitializers: BeforeComma
+BreakStringLiterals: true
+ColumnLimit:     120
 ConstructorInitializerIndentWidth: 4
-ContinuationIndentWidth: 4
 Cpp11BracedListStyle: true
-DerivePointerAlignment: false
 DisableFormat:   false
 ExperimentalAutoDetectBinPacking: false
+FixNamespaceComments: true
 ForEachMacros:   [ foreach, Q_FOREACH, BOOST_FOREACH ]
-IncludeCategories:
-  - Regex:           '^"(llvm|llvm-c|clang|clang-c)/'
-    Priority:        2
-  - Regex:           '^(<|"(gtest|isl|json)/)'
-    Priority:        3
-  - Regex:           '.*'
-    Priority:        1
 IndentCaseLabels: false
 IndentWidth:     4
 IndentWrappedFunctionNames: false
-KeepEmptyLinesAtTheStartOfBlocks: true
+KeepEmptyLinesAtTheStartOfBlocks: false
 MacroBlockBegin: ''
 MacroBlockEnd:   ''
-MaxEmptyLinesToKeep: 1
+MaxEmptyLinesToKeep: 3
 NamespaceIndentation: None
-ObjCBlockIndentWidth: 4
-ObjCSpaceAfterProperty: false
-ObjCSpaceBeforeProtocolList: true
-PenaltyBreakBeforeFirstCallParameter: 19
-PenaltyBreakComment: 300
-PenaltyBreakFirstLessLess: 120
-PenaltyBreakString: 1000
-PenaltyExcessCharacter: 1000000
-PenaltyReturnTypeOnItsOwnLine: 60
-PointerAlignment: Right
+PackConstructorInitializers: BinPack
+PointerAlignment: Left
 ReflowComments:  true
-SortIncludes:    true
+SortIncludes:    Never
 SpaceAfterCStyleCast: false
+SpaceAfterLogicalNot: false
+SpaceAfterTemplateKeyword: false
 SpaceBeforeAssignmentOperators: true
 SpaceBeforeParens: ControlStatements
-SpaceInEmptyParentheses: false
-SpacesBeforeTrailingComments: 1
+SpaceBeforeRangeBasedForLoopColon: true
+SpacesBeforeTrailingComments: 2
 SpacesInAngles:  false
-SpacesInContainerLiterals: true
-SpacesInCStyleCastParentheses: false
-SpacesInParentheses: false
+SpacesInContainerLiterals: false
+SpacesInParens:  Never
 SpacesInSquareBrackets: false
-Standard:        Cpp11
+Standard:        c++11
 TabWidth:        4
-UseTab:          Never
+PenaltyBreakBeforeFirstCallParameter: 0
+PenaltyReturnTypeOnItsOwnLine: 10000
 ...
-

.githooks/pre-commit

@@ -0,0 +1,24 @@
+#!/bin/bash
+#
+# SPDX-License-Identifier: MPL-2.0
+#
+# Pre-commit hook for dlt-daemon
+#
+# Runs clang-format on staged C/C++ files via run_lint.sh.
+# This mirrors the CI pipeline so issues are caught before push.
+#
+# To enable:
+#   ./run_lint.sh install-hook
+#
+# To bypass (emergency only):
+#   git commit --no-verify
+#
+
+set -euo pipefail
+
+# Run from repo root so relative paths resolve correctly
+REPO_ROOT=$(git rev-parse --show-toplevel)
+cd "${REPO_ROOT}"
+
+# Delegate to the shared lint script (check mode only - no auto-fix in hook)
+./run_lint.sh check

.github/workflows/clang-format.yml

@@ -0,0 +1,31 @@
+name: Clang Format
+
+# Disabled until all clang-format violations are fixed.
+# To re-enable, uncomment the on: block below.
+# on:
+#   push:
+#     branches: [ "master" ]
+#   pull_request:
+#     branches: [ "master" ]
+on:
+  workflow_dispatch:
+
+jobs:
+  clang-format:
+    name: Clang Format
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install clang-format-14
+        run: |
+          wget -qO - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
+          echo "deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-14 main" | sudo tee /etc/apt/sources.list.d/llvm.list
+          sudo apt-get update && sudo apt-get install -y clang-format-14
+
+      - name: Check formatting
+        run: CHECK_ALL=1 ./run_lint.sh check

README.md

@@ -20,7 +20,7 @@ you can [learn more](#learn-more) about advanced concepts and features.
 ## Overview
 
 COVESA DLT provides a standardized logging and tracing interface with support for two protocol versions: **V1** and **V2**.
- 
+
 - **Version 1 (V1)** is based on the AUTOSAR Classic Platform specification [AUTOSAR Classic Platform R19-11 DLT](https://www.autosar.org/fileadmin/standards/R19-11/CP/AUTOSAR_SWS_DiagnosticLogAndTrace.pdf), offering a stable and widely adopted diagnostic logging protocol.
 - **Version 2 (V2)** follows the updated AUTOSAR Classic Platform specification [AUTOSAR Classic Platform R22-11 DLT](https://www.autosar.org/fileadmin/standards/R22-11/CP/AUTOSAR_SWS_DiagnosticLogAndTrace.pdf). Currently released as a Minimum Viable Product (MVP), V2 supports a limited feature set.
 For more details, refer to [DLT Daemon V2](doc/dlt_daemon_v2.md).
@@ -198,6 +198,56 @@ make generate_man
 Start working, best practice is to commit smaller, compilable pieces during the
 work that makes it easier to handle later on.
 
+### Code Style
+
+DLT uses **clang-format 14** to enforce a consistent code style. The style is
+defined in [`.clang-format`](.clang-format) and is checked automatically by CI
+on every push and pull request.
+
+#### Install clang-format 14
+
+On Ubuntu 20.04 (focal), add the LLVM toolchain repo and install:
+
+```bash
+wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
+echo "deb http://apt.llvm.org/focal/ llvm-toolchain-focal-14 main" | sudo tee /etc/apt/sources.list.d/llvm.list
+sudo apt-get update
+sudo apt-get install clang-format-14
+```
+
+On Ubuntu 22.04 (jammy), clang-format-14 is in the default repos:
+
+```bash
+sudo apt-get install clang-format-14
+```
+
+#### Check and fix formatting
+
+Use the provided helper script:
+
+```bash
+# Install pre-commit hook and fix formatting (default)
+./run_lint.sh
+
+# Check formatting only (dry-run, fails on violations)
+./run_lint.sh check
+
+# Fix formatting only
+./run_lint.sh fix
+```
+
+Or run clang-format directly on specific files:
+
+```bash
+clang-format-14 -i --style=file src/shared/dlt_common.c
+```
+
+#### Pre-commit hook
+
+`./run_lint.sh` automatically installs the pre-commit hook (`.githooks/pre-commit`)
+and fixes formatting. The hook runs `./run_lint.sh check` on staged C/C++ files
+before each commit. To bypass it in an emergency, use `git commit --no-verify`.
+
 If you want to commit your changes, create a
 [Pull Request](https://github.com/covesa/dlt-daemon/pulls) in Github. Please
 make sure to follow the