CHANGELOG.md

@@ -26,7 +26,8 @@ Each release lists its changes in these groups, in this order:
   -Werror` and `clang-tidy` on the tracked C and C++ files, at exact versions
   (inputs `clang-format-version`, `clang-tidy-version`), with the inputs
   `working-directory`, `std`, `compile-commands-dir` and `tools-ref`. The
-  repository needs a `.clang-format`.
+  repository needs a `.clang-format`; without a `.clang-tidy` the checks
+  `clang-diagnostic-*` and `clang-analyzer-*` run.
 - Reusable workflow `quality-checks-csharp.yml` (ADR-0008): `dotnet format
   --verify-no-changes` and `dotnet build -warnaserror` on an exact .NET SDK 10
   or later (input `dotnet-sdk-version`, default `10.0.401`), with the inputs

guides/quality-checks-cpp.md

@@ -44,7 +44,9 @@ version of a tool is a new release of this repository, not a silent change.
   the top of the repository. Without one the run fails with `[configuration]`
   and no tool runs.
 - Optionally a `.clang-tidy` with the checks of the project (for example the
-  C++ Core Guidelines). Without one clang-tidy runs its default checks.
+  C++ Core Guidelines). Without one the workflow runs the compiler diagnostics
+  and the static analyzer (`clang-diagnostic-*` and `clang-analyzer-*`),
+  because clang-tidy itself enables no check when there is no configuration.
 - For precise static checks, a compile database: build it first (for example
   `cmake -S . -B build -DCMAKE_EXPORT_COMPILE_COMMANDS=ON`) and pass
   `compile-commands-dir: build`. The workflow does not build your project.
@@ -54,7 +56,7 @@ version of a tool is a new release of this repository, not a silent change.
 | Files | Tool | What it reports |
 | --- | --- | --- |
 | tracked `*.c`, `*.cc`, `*.cpp`, `*.cxx`, `*.h`, `*.hh`, `*.hpp`, `*.hxx` | `clang-format --dry-run -Werror` | formatting that differs from `.clang-format` |
-| the same files | `clang-tidy` | findings of the checks of `.clang-tidy`; `*.c` files are checked as C17, the other files as the C++ standard of `std` |
+| the same files | `clang-tidy` | findings of the checks of `.clang-tidy` (or of `clang-diagnostic-*` and `clang-analyzer-*` without one); `*.c` files are checked as C17, the other files as the C++ standard of `std` |
 
 Untracked files are not checked. A repository without these files passes with a
 notice. There is no `cppcheck`: only an old version of it is available as a

tests/test_quality_workflows_cpp_csharp.py

@@ -5,6 +5,7 @@ network, no clang and no .NET SDK are needed.
 """
 
 import os
+import re
 import shutil
 import subprocess
 from pathlib import Path
@@ -285,7 +286,69 @@ class TestCppRun:
         result, calls = self.run(repo, tmp_path, cpp_bin, COMPILE_COMMANDS_DIR="build")
         assert result.returncode == 0, result.stdout
         assert len(calls) == 2
-        assert "-p build" in calls[1] and "-std=" not in calls[1]
+        database = re.search(r"-p (\S+)", calls[1])
+        assert database is not None and database.group(1).endswith(f"/{repo.name}/build")
+        assert "-std=" not in calls[1]
+
+    def test_clang_tidy_gets_default_checks_without_a_clang_tidy_file(
+        self,
+        repo: Path,
+        tmp_path: Path,
+        cpp_bin: Path,
+    ) -> None:
+        add_files(repo, "a.cpp")
+        _, calls = self.run(repo, tmp_path, cpp_bin)
+        assert "--checks=clang-diagnostic-*,clang-analyzer-*" in calls[1]
+        assert "--checks=" not in calls[0]
+
+    def test_no_default_checks_when_a_clang_tidy_file_is_in_the_repository_root(
+        self,
+        repo: Path,
+        tmp_path: Path,
+        cpp_bin: Path,
+    ) -> None:
+        add_files(repo, "a.cpp", ".clang-tidy")
+        _, calls = self.run(repo, tmp_path, cpp_bin)
+        assert len(calls) == 2
+        assert not any("--checks=" in call for call in calls)
+
+    def test_no_default_checks_when_a_clang_tidy_file_is_above_the_working_directory(
+        self,
+        repo: Path,
+        tmp_path: Path,
+        cpp_bin: Path,
+    ) -> None:
+        add_files(repo, "service/a.cpp", ".clang-tidy")
+        _, calls = self.run(repo, tmp_path, cpp_bin, WORKING_DIRECTORY="service")
+        assert len(calls) == 2
+        assert not any("--checks=" in call for call in calls)
+
+    def test_a_compile_database_is_resolved_from_the_repository_root(
+        self,
+        repo: Path,
+        tmp_path: Path,
+        cpp_bin: Path,
+    ) -> None:
+        add_files(repo, "service/a.cpp", "build/compile_commands.json")
+        result, calls = self.run(
+            repo, tmp_path, cpp_bin, WORKING_DIRECTORY="service", COMPILE_COMMANDS_DIR="build"
+        )
+        assert result.returncode == 0, result.stdout
+        database = re.search(r"-p (\S+)", calls[1])
+        assert database is not None and database.group(1).endswith(f"/{repo.name}/build")
+
+    def test_a_compile_database_only_inside_the_working_directory_is_not_found(
+        self,
+        repo: Path,
+        tmp_path: Path,
+        cpp_bin: Path,
+    ) -> None:
+        add_files(repo, "service/a.cpp", "service/build/compile_commands.json")
+        result, calls = self.run(
+            repo, tmp_path, cpp_bin, WORKING_DIRECTORY="service", COMPILE_COMMANDS_DIR="build"
+        )
+        assert result.returncode == 1 and "[configuration]" in result.stdout
+        assert calls == []
 
     def test_a_missing_compile_database_is_a_configuration_error(
         self,

tools/quality-checks-cpp.sh

@@ -13,6 +13,7 @@
 # Every failure is printed as ::error::[category] message.
 
 C_STANDARD="${C_STANDARD:-c17}"
+DEFAULT_TIDY_CHECKS="clang-diagnostic-*,clang-analyzer-*"
 
 validate_inputs() {
   set -u
@@ -50,16 +51,19 @@ install_tools() {
     "clang-format==${CLANG_FORMAT_VERSION}" "clang-tidy==${CLANG_TIDY_VERSION}"
 }
 
-# A .clang-format must exist in the working directory or above it, up to the
-# top of the repository: clang-format finds its style the same way.
-find_clang_format_config() {
-  local top dir parent
+# Succeeds when one of the named files exists in the working directory or above
+# it, up to the top of the repository: clang-format and clang-tidy find their
+# configuration the same way.
+find_config_upwards() {
+  local top dir parent name
   top="$(cd "$(git rev-parse --show-toplevel)" && pwd -P)"
   dir="$(pwd -P)"
   while true; do
-    if [ -f "$dir/.clang-format" ] || [ -f "$dir/_clang-format" ]; then
-      return 0
-    fi
+    for name in "$@"; do
+      if [ -f "$dir/$name" ]; then
+        return 0
+      fi
+    done
     parent="$(dirname "$dir")"
     # stop at the top of the repository, or at the file system root
     if [ "$dir" = "$top" ] || [ "$parent" = "$dir" ]; then
@@ -76,6 +80,12 @@ run_checks() {
     echo "::error::[configuration] working-directory '$WORKING_DIRECTORY' does not exist."
     exit 1
   fi
+  # compile-commands-dir is relative to the repository root, not to the working directory
+  local repo_top compile_db=""
+  repo_top="$(cd "$(git rev-parse --show-toplevel)" && pwd -P)"
+  if [ -n "$COMPILE_COMMANDS_DIR" ]; then
+    compile_db="$repo_top/$COMPILE_COMMANDS_DIR"
+  fi
   cd "$WORKING_DIRECTORY"
 
   local all_files cpp_files c_files
@@ -85,11 +95,11 @@ run_checks() {
     echo "All selected checks passed."
     exit 0
   fi
-  if ! find_clang_format_config; then
+  if ! find_config_upwards .clang-format _clang-format; then
     echo "::error::[configuration] No .clang-format found in '$WORKING_DIRECTORY' or above it; add the style of the project."
     exit 1
   fi
-  if [ -n "$COMPILE_COMMANDS_DIR" ] && [ ! -f "$COMPILE_COMMANDS_DIR/compile_commands.json" ]; then
+  if [ -n "$compile_db" ] && [ ! -f "$compile_db/compile_commands.json" ]; then
     echo "::error::[configuration] compile-commands-dir '$COMPILE_COMMANDS_DIR' has no compile_commands.json; build it before the call."
     exit 1
   fi
@@ -115,14 +125,21 @@ run_checks() {
 
   run_tool "clang-format" "$QC_BIN/clang-format" --dry-run -Werror "${all_files[@]}"
 
-  if [ -n "$COMPILE_COMMANDS_DIR" ]; then
-    run_tool "clang-tidy" "$QC_BIN/clang-tidy" --quiet -p "$COMPILE_COMMANDS_DIR" "${all_files[@]}"
+  # Without a .clang-tidy, clang-tidy enables no check and refuses to run, so
+  # the project gets the compiler diagnostics and the static analyzer.
+  local tidy_args=(--quiet)
+  if ! find_config_upwards .clang-tidy _clang-tidy; then
+    tidy_args+=("--checks=${DEFAULT_TIDY_CHECKS}")
+  fi
+
+  if [ -n "$compile_db" ]; then
+    run_tool "clang-tidy" "$QC_BIN/clang-tidy" "${tidy_args[@]}" -p "$compile_db" "${all_files[@]}"
   else
     if [ "${#cpp_files[@]}" -gt 0 ]; then
-      run_tool "clang-tidy (C++)" "$QC_BIN/clang-tidy" --quiet "${cpp_files[@]}" -- "-std=${STD}"
+      run_tool "clang-tidy (C++)" "$QC_BIN/clang-tidy" "${tidy_args[@]}" "${cpp_files[@]}" -- "-std=${STD}"
     fi
     if [ "${#c_files[@]}" -gt 0 ]; then
-      run_tool "clang-tidy (C)" "$QC_BIN/clang-tidy" --quiet "${c_files[@]}" -- "-std=${C_STANDARD}"
+      run_tool "clang-tidy (C)" "$QC_BIN/clang-tidy" "${tidy_args[@]}" "${c_files[@]}" -- "-std=${C_STANDARD}"
     fi
   fi
 

wiki/QualityChecksCpp.da.md

@@ -1,4 +1,4 @@
-<!-- translation of QualityChecksCpp.md, source sha256 f54f7f7dc713 -->
+<!-- translation of QualityChecksCpp.md, source sha256 fd8bb0d71906 -->
 
 > Dette er en oversættelse af [`QualityChecksCpp`](QualityChecksCpp). Den engelske side er autoritativ, og ændringer her bliver overskrevet, næste gang wikien publiceres.
 
@@ -41,7 +41,7 @@ Henvis til workflowet ved major-tagget (`@v1`) eller et præcist tag, aldrig ved
 ## Hvad repositoryet skal have
 
 - En `.clang-format` i arbejdsmappen eller i en mappe over den, op til repositoryets rod. Uden en fejler kørslen med `[configuration]`, og intet værktøj kører.
-- Eventuelt en `.clang-tidy` med projektets kontroller (for eksempel C++ Core Guidelines). Uden en kører clang-tidy sine standardkontroller.
+- Eventuelt en `.clang-tidy` med projektets kontroller (for eksempel C++ Core Guidelines). Uden en kører workflowet compilerdiagnostik og den statiske analysator (`clang-diagnostic-*` og `clang-analyzer-*`), fordi clang-tidy selv ikke aktiverer nogen kontrol uden konfiguration.
 - For præcise statiske kontroller en compile-database: byg den først (for eksempel `cmake -S . -B build -DCMAKE_EXPORT_COMPILE_COMMANDS=ON`) og angiv `compile-commands-dir: build`. Workflowet bygger ikke dit projekt.
 
 ## Hvad der kontrolleres
@@ -49,7 +49,7 @@ Henvis til workflowet ved major-tagget (`@v1`) eller et præcist tag, aldrig ved
 | Filer | Værktøj | Hvad det melder |
 | --- | --- | --- |
 | sporede `*.c`, `*.cc`, `*.cpp`, `*.cxx`, `*.h`, `*.hh`, `*.hpp`, `*.hxx` | `clang-format --dry-run -Werror` | formatering, der afviger fra `.clang-format` |
-| de samme filer | `clang-tidy` | fund fra kontrollerne i `.clang-tidy`; `*.c`-filer kontrolleres som C17, de øvrige filer som C++-standarden i `std` |
+| de samme filer | `clang-tidy` | fund fra kontrollerne i `.clang-tidy` (eller fra `clang-diagnostic-*` og `clang-analyzer-*` uden en); `*.c`-filer kontrolleres som C17, de øvrige filer som C++-standarden i `std` |
 
 Usporede filer kontrolleres ikke. Et repository uden disse filer består med en bemærkning. Der er ingen `cppcheck`: kun en gammel version findes som pakke, og gamle værktøjer køres ikke (ADR-0008).
 

wiki/QualityChecksCpp.md

@@ -50,7 +50,9 @@ version of a tool is a new release of this repository, not a silent change.
   the top of the repository. Without one the run fails with `[configuration]`
   and no tool runs.
 - Optionally a `.clang-tidy` with the checks of the project (for example the
-  C++ Core Guidelines). Without one clang-tidy runs its default checks.
+  C++ Core Guidelines). Without one the workflow runs the compiler diagnostics
+  and the static analyzer (`clang-diagnostic-*` and `clang-analyzer-*`),
+  because clang-tidy itself enables no check when there is no configuration.
 - For precise static checks, a compile database: build it first (for example
   `cmake -S . -B build -DCMAKE_EXPORT_COMPILE_COMMANDS=ON`) and pass
   `compile-commands-dir: build`. The workflow does not build your project.
@@ -60,7 +62,7 @@ version of a tool is a new release of this repository, not a silent change.
 | Files | Tool | What it reports |
 | --- | --- | --- |
 | tracked `*.c`, `*.cc`, `*.cpp`, `*.cxx`, `*.h`, `*.hh`, `*.hpp`, `*.hxx` | `clang-format --dry-run -Werror` | formatting that differs from `.clang-format` |
-| the same files | `clang-tidy` | findings of the checks of `.clang-tidy`; `*.c` files are checked as C17, the other files as the C++ standard of `std` |
+| the same files | `clang-tidy` | findings of the checks of `.clang-tidy` (or of `clang-diagnostic-*` and `clang-analyzer-*` without one); `*.c` files are checked as C17, the other files as the C++ standard of `std` |
 
 Untracked files are not checked. A repository without these files passes with a
 notice. There is no `cppcheck`: only an old version of it is available as a

wiki/QualityChecksCpp.ms.md

@@ -1,4 +1,4 @@
-<!-- translation of QualityChecksCpp.md, source sha256 f54f7f7dc713 -->
+<!-- translation of QualityChecksCpp.md, source sha256 fd8bb0d71906 -->
 
 > Ini ialah terjemahan [`QualityChecksCpp`](QualityChecksCpp). Halaman bahasa Inggeris ialah teks yang sah, dan perubahan di sini akan ditimpa pada penerbitan wiki yang seterusnya.
 
@@ -41,7 +41,7 @@ Rujuk aliran kerja pada tag major (`@v1`) atau pada tag tepat, jangan sekali-kal
 ## Apa yang diperlukan oleh repositori
 
 - Satu `.clang-format` dalam direktori kerja atau dalam direktori di atasnya, sehingga akar repositori. Tanpanya larian gagal dengan `[configuration]` dan tiada alat dijalankan.
-- Pilihan: satu `.clang-tidy` dengan semakan projek (contohnya C++ Core Guidelines). Tanpanya clang-tidy menjalankan semakan lalainya.
+- Pilihan: satu `.clang-tidy` dengan semakan projek (contohnya C++ Core Guidelines). Tanpanya aliran kerja menjalankan diagnostik pengkompil dan penganalisis statik (`clang-diagnostic-*` dan `clang-analyzer-*`), kerana clang-tidy sendiri tidak mengaktifkan sebarang semakan tanpa konfigurasi.
 - Untuk semakan statik yang tepat, satu pangkalan data kompilasi: bina dahulu (contohnya `cmake -S . -B build -DCMAKE_EXPORT_COMPILE_COMMANDS=ON`) dan berikan `compile-commands-dir: build`. Aliran kerja tidak membina projek anda.
 
 ## Apa yang disemak
@@ -49,7 +49,7 @@ Rujuk aliran kerja pada tag major (`@v1`) atau pada tag tepat, jangan sekali-kal
 | Fail | Alat | Apa yang dilaporkan |
 | --- | --- | --- |
 | `*.c`, `*.cc`, `*.cpp`, `*.cxx`, `*.h`, `*.hh`, `*.hpp`, `*.hxx` yang dijejaki | `clang-format --dry-run -Werror` | pemformatan yang berbeza daripada `.clang-format` |
-| fail yang sama | `clang-tidy` | dapatan semakan dalam `.clang-tidy`; fail `*.c` disemak sebagai C17, fail lain sebagai piawaian C++ dalam `std` |
+| fail yang sama | `clang-tidy` | dapatan semakan dalam `.clang-tidy` (atau `clang-diagnostic-*` dan `clang-analyzer-*` tanpanya); fail `*.c` disemak sebagai C17, fail lain sebagai piawaian C++ dalam `std` |
 
 Fail yang tidak dijejaki tidak disemak. Repositori tanpa fail ini lulus dengan satu notis. Tiada `cppcheck`: hanya versi lama tersedia sebagai pakej, dan alat lama tidak dijalankan (ADR-0008).