build: add a cmake target for all used linters #18543

* build: move the logic for linters to cmake
Cmake is our source of truth. We should have as much of our build
process there as possible so everyone can make use of it.

* build: remove redundant check for ninja generator
The minimum cmake version as of writing this is 3.10, which has ninja
support.

7 files changed, 62 insertions, 82 deletions

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b3949578c1..ef70fdfc3c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -107,11 +107,11 @@ jobs:
         run: ./ci/run_tests.sh build_nvim
 
       - if: "!cancelled()"
-        name: clint-full
-        run: ./ci/run_lint.sh clint-full
+        name: lintcfull
+        run: ./ci/run_lint.sh lintcfull
 
       - if: "!cancelled()"
-        name: stylua
+        name: lintstylua
         uses: JohnnyMorganz/stylua-action@1.0.0
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
@@ -124,16 +124,16 @@ jobs:
           git diff --color --exit-code
 
       - if: "!cancelled()"
-        name: lualint
-        run: ./ci/run_lint.sh lualint
+        name: lintlua
+        run: ./ci/run_lint.sh lintlua
 
       - if: "!cancelled()"
-        name: pylint
-        run: ./ci/run_lint.sh pylint
+        name: lintpy
+        run: ./ci/run_lint.sh lintpy
 
       - if: "!cancelled()"
-        name: shlint
-        run: ./ci/run_lint.sh shlint
+        name: lintsh
+        run: ./ci/run_lint.sh lintsh
 
       - if: "!cancelled()"
         name: check-single-includes
diff --git a/CMakeLists.txt b/CMakeLists.txt
index d75c1a4a6a..ee59d26a89 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -612,9 +612,6 @@ if(NOT BUSTED_OUTPUT_TYPE)
   set(BUSTED_OUTPUT_TYPE "nvim")
 endif()
 
-find_program(LUACHECK_PRG luacheck)
-find_program(FLAKE8_PRG flake8)
-
 include(InstallHelpers)
 
 file(GLOB MANPAGES
@@ -748,15 +745,13 @@ if(BUSTED_LUA_PRG)
     set_target_properties(functionaltest-lua PROPERTIES FOLDER test)
 endif()
 
-if(LUACHECK_PRG)
-  add_custom_target(lualint
-    COMMAND ${LUACHECK_PRG} -q runtime/ scripts/ src/ test/
-    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
-else()
-  add_custom_target(lualint false
-    COMMENT "lualint: LUACHECK_PRG not defined")
-endif()
-
+foreach(TARGET IN ITEMS lintlua lintsh lintpy lintuncrustify)
+  add_custom_target(${TARGET}
+    COMMAND ${CMAKE_COMMAND}
+    -DPROJECT_ROOT=${PROJECT_SOURCE_DIR}
+    -DTARGET=${TARGET}
+    -P ${PROJECT_SOURCE_DIR}/cmake/lint.cmake)
+endforeach()
 
 #add uninstall target
 if(NOT TARGET uninstall)
diff --git a/Makefile b/Makefile
index 3039d84a6b..5a5bd80763 100644
--- a/Makefile
+++ b/Makefile
@@ -47,13 +47,7 @@ endif
 
 ifeq (,$(BUILD_TOOL))
   ifeq (Ninja,$(CMAKE_GENERATOR))
-    ifneq ($(shell $(CMAKE_PRG) --help 2>/dev/null | grep Ninja),)
-      BUILD_TOOL = ninja
-    else
-      # User's version of CMake doesn't support Ninja
-      BUILD_TOOL = $(MAKE)
-      CMAKE_GENERATOR := Unix Makefiles
-    endif
+    BUILD_TOOL = ninja
   else
     BUILD_TOOL = $(MAKE)
   endif
@@ -140,51 +134,19 @@ build/runtime/doc/tags helptags: | nvim
 helphtml: | nvim build/runtime/doc/tags
 	+$(BUILD_TOOL) -C build doc_html
 
-functionaltest: | nvim
-	+$(BUILD_TOOL) -C build functionaltest
+functionaltest functionaltest-lua unittest benchmark: | nvim
+	$(BUILD_TOOL) -C build $@
 
-functionaltest-lua: | nvim
-	+$(BUILD_TOOL) -C build functionaltest-lua
+lintlua lintsh lintpy lintuncrustify lintc lintcfull check-single-includes generated-sources: | build/.ran-cmake
+	$(CMAKE_PRG) --build build --target $@
 
-stylua:
-	stylua --check runtime/
-
-lualint: | build/.ran-cmake deps
-	$(BUILD_TOOL) -C build lualint
-
-_opt_stylua:
-	@command -v stylua && { $(MAKE) stylua; exit $$?; } \
-		|| echo "SKIP: stylua (stylua not found)"
-
-shlint:
-	@shellcheck --version | head -n 2
-	shellcheck scripts/vim-patch.sh
-
-_opt_shlint:
-	@command -v shellcheck && { $(MAKE) shlint; exit $$?; } \
-		|| echo "SKIP: shlint (shellcheck not found)"
-
-pylint:
-	flake8 contrib/ scripts/ src/ test/
-
-# Run pylint only if flake8 is installed.
-_opt_pylint:
-	@command -v flake8 && { $(MAKE) pylint; exit $$?; } \
-		|| echo "SKIP: pylint (flake8 not found)"
-
-commitlint:
+commitlint: | nvim
 	$(NVIM_PRG) -u NONE -es +"lua require('scripts.lintcommit').main({trace=false})"
 
 _opt_commitlint:
 	@test -x build/bin/nvim && { $(MAKE) commitlint; exit $$?; } \
 		|| echo "SKIP: commitlint (build/bin/nvim not found)"
 
-unittest: | nvim
-	+$(BUILD_TOOL) -C build unittest
-
-benchmark: | nvim
-	+$(BUILD_TOOL) -C build benchmark
-
 test: functionaltest unittest
 
 clean:
@@ -200,18 +162,6 @@ distclean:
 install: checkprefix nvim
 	+$(BUILD_TOOL) -C build install
 
-clint: build/.ran-cmake
-	+$(BUILD_TOOL) -C build clint
-
-clint-full: build/.ran-cmake
-	+$(BUILD_TOOL) -C build clint-full
-
-check-single-includes: build/.ran-cmake
-	+$(BUILD_TOOL) -C build check-single-includes
-
-generated-sources: build/.ran-cmake
-	+$(BUILD_TOOL) -C build generated-sources
-
 appimage:
 	bash scripts/genappimage.sh
 
@@ -221,7 +171,7 @@ appimage:
 appimage-%:
 	bash scripts/genappimage.sh $*
 
-lint: check-single-includes clint _opt_stylua lualint _opt_pylint _opt_shlint _opt_commitlint
+lint: check-single-includes lintc lintlua lintpy lintsh _opt_commitlint lintuncrustify
 
 # Generic pattern rules, allowing for `make build/bin/nvim` etc.
 # Does not work with "Unix Makefiles".
@@ -233,4 +183,4 @@ $(DEPS_BUILD_DIR)/%: phony_force
 	$(BUILD_TOOL) -C $(DEPS_BUILD_DIR) $(patsubst $(DEPS_BUILD_DIR)/%,%,$@)
 endif
 
-.PHONY: test stylua lualint pylint shlint functionaltest unittest lint clint clean distclean nvim libnvim cmake deps install appimage checkprefix commitlint
+.PHONY: test lintlua lintpy lintsh functionaltest unittest lint lintc clean distclean nvim libnvim cmake deps install appimage checkprefix commitlint
diff --git a/ci/run_lint.sh b/ci/run_lint.sh
index 3a524b4ed6..ba1a61858e 100755
--- a/ci/run_lint.sh
+++ b/ci/run_lint.sh
@@ -12,7 +12,7 @@ rm -f "$END_MARKER"
 
 # Run all tests if no input argument is given
 if (($# == 0)); then
-  tests=('clint-full' 'lualint' 'pylint' 'shlint' 'check-single-includes')
+  tests=('lintcfull' 'lintlua' 'lintpy' 'lintsh' 'check-single-includes')
 else
   tests=("$@")
 fi
diff --git a/cmake/lint.cmake b/cmake/lint.cmake
new file mode 100644
index 0000000000..1fb8c749a8
--- /dev/null
+++ b/cmake/lint.cmake
@@ -0,0 +1,34 @@
+function(lint)
+  cmake_parse_arguments(LINT "QUIET" "PROGRAM" "FLAGS;FILES" ${ARGN})
+
+  if(LINT_QUIET)
+    set(OUTPUT_QUIET OUTPUT_QUIET)
+  elseif()
+    set(OUTPUT_QUIET "")
+  endif()
+
+  find_program(PROGRAM_EXISTS ${LINT_PROGRAM})
+  if(PROGRAM_EXISTS)
+    execute_process(COMMAND ${LINT_PROGRAM} ${LINT_FLAGS} ${LINT_FILES}
+      WORKING_DIRECTORY ${PROJECT_ROOT}
+      RESULT_VARIABLE ret
+      ${OUTPUT_QUIET})
+    if(ret AND NOT ret EQUAL 0)
+      message(FATAL_ERROR "FAILED: ${TARGET}")
+    endif()
+  else()
+    message(STATUS "${TARGET}: ${LINT_PROGRAM} not found. SKIP.")
+  endif()
+endfunction()
+
+if(${TARGET} STREQUAL "lintuncrustify")
+  file(GLOB_RECURSE FILES ${PROJECT_ROOT}/src/nvim/*.[c,h])
+  lint(PROGRAM uncrustify FLAGS -c src/uncrustify.cfg -q --check FILES ${FILES} QUIET)
+elseif(${TARGET} STREQUAL "lintpy")
+  lint(PROGRAM flake8 FILES contrib/ scripts/ src/ test/)
+elseif(${TARGET} STREQUAL "lintsh")
+  lint(PROGRAM shellcheck FILES scripts/vim-patch.sh)
+elseif(${TARGET} STREQUAL "lintlua")
+  lint(PROGRAM luacheck FLAGS -q FILES runtime/ scripts/ src/ test/)
+  lint(PROGRAM stylua FLAGS --color=always --check FILES runtime/)
+endif()
diff --git a/src/nvim/CMakeLists.txt b/src/nvim/CMakeLists.txt
index da74b4dc9d..c902ff6c50 100755
--- a/src/nvim/CMakeLists.txt
+++ b/src/nvim/CMakeLists.txt
@@ -800,10 +800,10 @@ foreach(sfile ${LINT_NVIM_SOURCES})
   list(APPEND LINT_TARGETS ${touch_file})
   list(APPEND LINT_NVIM_REL_SOURCES ${rsfile})
 endforeach()
-add_custom_target(clint DEPENDS ${LINT_TARGETS})
+add_custom_target(lintc DEPENDS ${LINT_TARGETS})
 
 add_custom_target(
-  clint-full
+  lintcfull
   COMMAND
     ${LINT_PRG} --suppress-errors=${LINT_SUPPRESS_FILE} ${LINT_NVIM_REL_SOURCES}
   WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
diff --git a/src/nvim/diff.c b/src/nvim/diff.c
index 8c98c1ef23..1625632842 100644
--- a/src/nvim/diff.c
+++ b/src/nvim/diff.c
@@ -2307,6 +2307,7 @@ bool diff_find_change(win_T *wp, linenr_T lnum, int *startp, int *endp)
 
   if ((dp == NULL) || (diff_check_sanity(curtab, dp) == FAIL)) {
     xfree(line_org);
+
     return false;
   }