[ci]: use cppcheck and clang-tidy for static analysis

.woodpecker/analysis.yml

@@ -0,0 +1,27 @@
+pipeline:
+  analysis:
+    image: alpine
+    when:
+      branch: master
+    commands: |
+      apk add --no-cache build-base cppcheck clang-extra-tools \
+          imlib2-dev xorgproto \
+          libxft-dev libexif-dev giflib-dev libwebp-dev >/dev/null
+      make config.h version.h
+      std="c99"
+      run_cppcheck() {
+        cppcheck --std="$std" --enable=performance,portability \
+          --force --quiet --inline-suppr --error-exitcode=1 \
+          --max-ctu-depth=8 -j"$(nproc)" \
+          $(make OPT_DEP_DEFAULT="$1" dump_cppflags) \
+          *.c
+      }
+      run_tidy() {
+        checks="$(sed '/^#/d' .woodpecker/clang-tidy-checks | paste -d ',' -s)"
+        clang-tidy --warnings-as-errors="*" --checks="$checks" --quiet *.c \
+                   -- -std="$std" $(make OPT_DEP_DEFAULT="$1" dump_cppflags)
+      }
+      run_cppcheck "0"
+      run_cppcheck "1"
+      run_tidy "0"
+      run_tidy "1"

.woodpecker/clang-tidy-checks

@@ -0,0 +1,16 @@
+# checks
+clang-analyzer-*,clang-diagnostic-*,bugprone-*,performance-*,modernize-*
+misc-*,readability-*,android-cloexec-*,cert-*
+
+# silence
+-misc-unused-parameters
+-bugprone-easily-swappable-parameters,-bugprone-narrowing-conversions,-bugprone-incorrect-roundings
+-bugprone-implicit-widening-of-multiplication-result,-bugprone-integer-division
+-readability-braces-around-statements,-readability-magic-numbers,-readability-isolate-declaration
+-readability-function-cognitive-complexity,-readability-else-after-return
+-readability-uppercase-literal-suffix,-readability-avoid-const-params-in-decls
+-android-cloexec-fopen,-android-cloexec-pipe
+
+# false positive warnings
+-clang-analyzer-valist.Uninitialized
+-misc-no-recursion

Makefile

@@ -55,6 +55,9 @@ version.h: config.mk .git/index
 
 .git/index:
 
+dump_cppflags:
+	@echo $(nsxiv_cppflags)
+
 clean:
 	rm -f *.o nsxiv version.h