[PATCH v3 14/49] perf build: Make pylint build test opt-out (NO_PYLINT=1)

[Ian Rogers <irogers@google.com>]

Commit 8a54784e708b ("perf build: Add pylint build tests") added a
compile-time pylint check for Python files in tools/perf, but left it
opt-in via PYLINT=1.

Now that pylint issues across tools/perf/python, tools/perf/pmu-events,
and tools/perf/tests/shell/lib have been cleaned up, enable the pylint
check by default when pylint is installed on the system, with an opt-out
via NO_PYLINT=1 (matching NO_SHELLCHECK=1, NO_MYPY=1, and other perf
build feature flags).

Configure PYTHONPATH in Makefile.perf so pylint resolves perf.pyi type
stubs and pmu-events modules, enable error and warning categories
(--disable=all --enable=E,W --disable=W0123,W0311,W0511,W0603,W0622,W0718
--ignored-modules=textual,setproctitle) appropriate for perf's standalone
CLI and test scripts, and require pylint >= 2.16.0 (skipping with a
warning if an older version is installed).

Assisted-by: Antigravity:gemini-3.1-pro
Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/Build            |  2 +-
 tools/perf/Makefile.perf    | 40 +++++++++++++++++++++++++++++++++----
 tools/perf/pmu-events/Build |  2 +-
 tools/perf/tests/Build      |  2 +-
 tools/perf/util/Build       |  2 +-
 5 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/tools/perf/Build b/tools/perf/Build
index 37d603faea6d..5bd0e58d7cb0 100644
--- a/tools/perf/Build
+++ b/tools/perf/Build
@@ -101,6 +101,6 @@ endif
 
 $(OUTPUT)%.pylint_log: %
 	$(call rule_mkdir)
-	$(Q)$(call echo-cmd,test)pylint "$<" > $@ || (cat $@ && rm $@ && false)
+	$(Q)$(call echo-cmd,test)$(PYLINT) "$<" > $@ || (cat $@ && rm $@ && false)
 
 perf-y += $(PYLINT_TEST_LOGS)
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index c7cade270b23..aacaa04854c5 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -131,6 +131,8 @@ include ../scripts/utilities.mak
 # Define NO_SHELLCHECK if you do not want to run shellcheck during build
 #
 # Define NO_MYPY if you do not want to run mypy during build
+#
+# Define NO_PYLINT if you do not want to run pylint during build
 
 # As per kernel Makefile, avoid funny character set dependencies
 unexport LC_ALL
@@ -284,9 +286,39 @@ ifneq ($(force_fixdep),1)
   endif
 endif
 
-# Runs pylint on perf python files
-ifeq ($(PYLINT),1)
-  PYLINT := $(shell which pylint 2> /dev/null)
+# Runs pylint on perf python files.
+# Require pylint >= 2.16.0 (which introduced W0718 broad-exception-caught and
+# astroid .pyi stub support for perf.pyi).
+# Disabled warnings:
+#   W0123 (eval-used): Use of eval()
+#   W0311 (bad-indentation): Non-4-space indentation
+#   W0511 (fixme): Presence of FIXME/TODO comments
+#   W0603 (global-statement): Use of the global statement
+#   W0622 (redefined-builtin): Redefining a built-in name (e.g. id, type, dir)
+#   W0718 (broad-exception-caught): Catching broad Exception
+# Wait until after the fixdep bootstrap sub-make (force_fixdep != 1) before
+# resolving PYLINT and stripping PYLINT=% from MAKEOVERRIDES (substituting
+# escaped spaces so multi-word overrides are removed as a single token) so child
+# Makefile.build sub-makes inherit the PYTHONPATH- and flag-wrapped export.
+ifneq ($(force_fixdep),1)
+  MAKEOVERRIDES := $(subst __SPACE__,\ ,$(filter-out PYLINT=%,$(subst \ ,__SPACE__,$(MAKEOVERRIDES))))
+  ifeq ($(NO_PYLINT),1)
+    override PYLINT :=
+  else ifeq ($(filter-out 1,$(PYLINT)),)
+    override PYLINT := $(shell which pylint 2> /dev/null)
+  endif
+
+  ifneq ($(PYLINT),)
+    ifneq ($(shell $(PYLINT) --version 2>/dev/null | \
+          awk '/^pylint / { split($$2, v, "."); print (v[1]+0 > 2 || (v[1]+0 == 2 && v[2]+0 >= 16)) }'), 1)
+      $(warning Warning: pylint version is older than 2.16.0, skipping pylint checks.)
+      override PYLINT :=
+    else
+      override PYLINT := PYTHONPATH=$(srctree)/tools/perf/python:$(srctree)/tools/perf/pmu-events \
+        $(PYLINT) --disable=all --enable=E,W --disable=W0123,W0311,W0511,W0603,W0622,W0718 \
+        --ignored-modules=textual,setproctitle
+    endif
+  endif
 endif
 
 export srctree OUTPUT RM CC CXX RUSTC CLANG LD AR CFLAGS CXXFLAGS RUST_FLAGS V BISON FLEX AWK LIBBPF READELF
@@ -966,7 +998,7 @@ clean:: $(LIBAPI)-clean $(LIBBPF)-clean $(LIBSUBCMD)-clean $(LIBSYMBOL)-clean $(
 		$(OUTPUT)perf-iostat $(LANG_BINDINGS)
 	$(Q)find $(or $(OUTPUT),.) -name '*.o' -delete -o -name '*.a' -delete -o \
 		-name '\.*.cmd' -delete -o -name '\.*.d' -delete -o -name '*.shellcheck_log' -delete -o \
-		-name '*.mypy_log' -delete
+		-name '*.mypy_log' -delete -o -name '*.pylint_log' -delete
 	$(Q)$(RM) $(OUTPUT).config-detected
 	$(call QUIET_CLEAN, core-progs) $(RM) $(ALL_PROGRAMS) perf perf-read-vdso32 \
 		perf-read-vdsox32 $(OUTPUT)$(LIBJVMTI).so
diff --git a/tools/perf/pmu-events/Build b/tools/perf/pmu-events/Build
index c3542e5ae46f..1ac067be9d34 100644
--- a/tools/perf/pmu-events/Build
+++ b/tools/perf/pmu-events/Build
@@ -203,7 +203,7 @@ endif
 ifdef PYLINT
 define PYLINT_RULE
 $(2): $(1)
-	$$(Q)$$(call echo-cmd,test)pylint $(1) > $(2) || (cat $(2) && rm $(2) && false)
+	$$(Q)$$(call echo-cmd,test)$$(PYLINT) $(1) > $(2) || (cat $(2) && rm $(2) && false)
 endef
 $(foreach src,$(wildcard pmu-events/*.py), \
     $(eval dest := $(patsubst pmu-events/%,$(OUTPUT)pmu-events/%.pylint_log,$(src))) \
diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build
index 98b05b68fc14..f88e9a55c4f5 100644
--- a/tools/perf/tests/Build
+++ b/tools/perf/tests/Build
@@ -117,6 +117,6 @@ endif
 
 $(OUTPUT)%.pylint_log: %
 	$(call rule_mkdir)
-	$(Q)$(call echo-cmd,test)pylint "$<" > $@ || (cat $@ && rm $@ && false)
+	$(Q)$(call echo-cmd,test)$(PYLINT) "$<" > $@ || (cat $@ && rm $@ && false)
 
 perf-test-y += $(PYLINT_TEST_LOGS)
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 71d1f7289d03..3ea888f4210a 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -438,7 +438,7 @@ endif
 
 $(OUTPUT)%.pylint_log: %
 	$(call rule_mkdir)
-	$(Q)$(call echo-cmd,test)pylint "$<" > $@ || (cat $@ && rm $@ && false)
+	$(Q)$(call echo-cmd,test)$(PYLINT) "$<" > $@ || (cat $@ && rm $@ && false)
 
 perf-util-y += $(PYLINT_TEST_LOGS)
 
-- 
2.56.0.rc1.310.g51773c2048-goog