Makefile: add clang-format and clang-tidy lint support

These are slower and currently yield a lot of warnings to be fixed.

.clang-format

+---
+BasedOnStyle:  Google
+SortIncludes: true
+AllowShortIfStatementsOnASingleLine: false
+AllowShortLoopsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: false
+DerivePointerAlignment: true
+PointerAlignment: Left
+ColumnLimit: 80
+ForEachMacros: ['list_for_every_entry','list_for_every_entry_safe']
+IncludeBlocks: Regroup
+IncludeCategories:
+  - Regex:           '^<simbricks/.*\.h>'
+    Priority:        2
+    SortPriority:    0
+  - Regex:           '^<.*\.h>'
+    Priority:        1
+    SortPriority:    0
+  - Regex:           '^<.*'
+    Priority:        2
+    SortPriority:    0
+  - Regex:           '.*'
+    Priority:        3
+    SortPriority:    0

.clang-tidy

+---
+Checks: >
+  -*,
+  bugprone-*,
+  clang-diagnostic-*,
+  -clang-diagnostic-unused-command-line-argument,
+  google-*,
+  -google-runtime-references,
+  misc-*,
+  -misc-noexcept*,
+  -misc-unused-parameters,
+  -misc-non-private-member-variables-in-classes,
+  modernize-*,
+  -modernize-avoid-c-arrays,
+  -modernize-deprecated-headers,
+  -modernize-raw-string-literal,
+  -modernize-return-braced-init-list,
+  -modernize-use-auto,
+  -modernize-use-equals-delete,
+  -modernize-use-nodiscard,
+  -modernize-use-trailing-return-type,
+  performance-*,
+  readability-*,
+  -readability-function-cognitive-complexity,
+  -readability-implicit-bool-conversion,
+  -readability-isolate-declaration,
+  -readability-magic-numbers,
+  -readability-qualified-auto,
+  -readability-uppercase-literal-suffix,
+WarningsAsErrors: false
+AnalyzeTemporaryDtors: false
+FormatStyle:     file
+CheckOptions:
+  - key:             bugprone-assert-side-effect.AssertMacros
+    value:           'FXL_DCHECK'
+  - key:             google-readability-braces-around-statements.ShortStatementLines
+    value:           '2'
+  - key:             google-readability-function-size.StatementThreshold
+    value:           '800'
+  - key:             google-readability-namespace-comments.ShortNamespaceLines
+    value:           '10'
+  - key:             google-readability-namespace-comments.SpacesBeforeComments
+    value:           '2'
+  - key:             misc-non-private-member-variables-in-classes.IgnoreClassesWithAllMemberVariablesBeingPublic
+    value:           '1'
+  - key:             modernize-loop-convert.MaxCopySize
+    value:           '16'
+  - key:             modernize-loop-convert.MinConfidence
+    value:           reasonable
+  - key:             modernize-loop-convert.NamingStyle
+    value:           CamelCase
+  - key:             modernize-pass-by-value.IncludeStyle
+    value:           llvm
+  - key:             modernize-replace-auto-ptr.IncludeStyle
+    value:           llvm
+  - key:             modernize-use-default-member-init.UseAssignment
+    value:           '1'
+  - key:             modernize-use-emplace.IgnoreImplicitConstructors
+    value:           '1'
+  - key:             modernize-use-nullptr.NullMacros
+    value:           'NULL'
+  - key:             readability-braces-around-statements.ShortStatementLines
+    value:           '2'
+  - key: readability-identifier-naming.NamespaceCase
+    value: lower_case
+  - key: readability-identifier-naming.ClassCase
+    value: CamelCase
+  - key: readability-identifier-naming.StructCase
+    value: CamelCase
+  - key: readability-identifier-naming.TemplateParameterCase
+    value: CamelCase
+  - key: readability-identifier-naming.FunctionCase
+    value: aNy_CasE
+  - key: readability-identifier-naming.VariableCase
+    value: lower_case
+  - key: readability-identifier-naming.ClassMemberCase
+    value: lower_case
+  - key: readability-identifier-naming.ClassMemberSuffix
+    value: _
+  - key: readability-identifier-naming.PrivateMemberSuffix
+    value: _
+  - key: readability-identifier-naming.ProtectedMemberSuffix
+    value: _
+  - key: readability-identifier-naming.EnumConstantCase
+    value: CamelCase
+  - key: readability-identifier-naming.EnumConstantPrefix
+    value: k
+  - key: readability-identifier-naming.ConstexprVariableCase
+    value: CamelCase
+  - key: readability-identifier-naming.ConstexprVariablePrefix
+    value: k
+  - key: readability-identifier-naming.GlobalConstantCase
+    value: CamelCase
+  - key: readability-identifier-naming.GlobalConstantPrefix
+    value: k
+  - key: readability-identifier-naming.MemberConstantCase
+    value: CamelCase
+  - key: readability-identifier-naming.MemberConstantPrefix
+    value: k
+  - key: readability-identifier-naming.StaticConstantCase
+    value: CamelCase
+  - key: readability-identifier-naming.StaticConstantPrefix
+    value: k
+  - key: readability-implicit-bool-conversion.AllowIntegerConditions
+    value: 1
+  - key: readability-implicit-bool-conversion.AllowPointerConditions
+    value: 1
+...

.clang-tidy-wrapper.sh

+#!/bin/bash
+IGNORES="sims/nic/i40e_bm/base/*.h /usr/share/verilator/include/*.h"
+
+
+
+# This is an ugly hack to exclude individual headers, until clang-tidy has a
+# proper mechanism for this (e.g. https://reviews.llvm.org/D34654)
+lf="["
+for f in $IGNORES
+do
+    lf="$lf{\"name\":\"$f\",\"lines\":[[9999999,9999999]]},"
+done
+lf="$lf{\"name\":\".c\"},{\"name\":\".cc\"},{\"name\":\".h\"}]"
+
+tidy=$1
+shift
+
+files=
+for f in `cat .lint-files`
+do
+    [ ! -f $f ] && continue
+    [ ${f: -2} == ".h" ] && continue
+    files="$files $f"
+done
+$tidy --quiet --format-style=file --header-filter='.*' --line-filter="$lf" \
+    $files -- "$@"

.lint-files

+sims/net/*/*.c
+sims/net/*/*.cc
+sims/nic/corundum/*.cc
+sims/nic/corundum/*.h
+sims/nic/corundum_bm/*.cc
+sims/nic/corundum_bm/*.c
+sims/nic/corundum_bm/*.h
+sims/nic/i40e_bm/*.cc
+sims/nic/i40e_bm/*.h
+lib/simbricks/*/*.c
+lib/simbricks/*/*.cc
+lib/simbricks/*/*.h
+trace/*.cc
+trace/*.h

Makefile

@@ -26,7 +26,9 @@ include mk/recipes.mk
 
 base_dir := $(d)./
 
-CPPLINT = cpplint
+CPPLINT ?= cpplint
+CLANG_TIDY ?= clang-tidy
+CLANG_FORMAT ?= clang-format
 CFLAGS += -Wall -Wextra -Wno-unused-parameter -O3 -fPIC
 CXXFLAGS += -Wall -Wextra -Wno-unused-parameter -O3 -fPIC
 CPPFLAGS += -I$(base_dir)/lib -iquote$(base_dir)
@@ -53,9 +55,22 @@ clean:
 distclean:
 	rm -rf $(CLEAN_ALL) $(DISTCLEAN_ALL)
 
-lint:
+lint-cpplint:
 	$(CPPLINT) --quiet --recursive .
 
+lint-clang-tidy:
+	./.clang-tidy-wrapper.sh $(CLANG_TIDY) -I$(base_dir) -I$(base_dir)lib \
+	    -I/usr/share/verilator/include
+
+clang-format:
+	$(CLANG_FORMAT) -i --style=file `cat .lint-files`
+
+lint-clang-format:
+	$(CLANG_FORMAT) --dry-run --style=file `cat .lint-files`
+
+lint: lint-cpplint lint-clang-format
+lint-all: lint lint-clang-tidy
+
 help:
 	@echo "Targets:"
 	@echo "  all: builds all the tools directly in this repo"
@@ -64,8 +79,12 @@ help:
 	@echo "  documentation: build documentation in doc/build_"
 	@echo "  external: clone and build our tools in external repos "
 	@echo "            (qemu, gem5, ns-3)"
+	@echo "  lint: run quick format and style checks"
+	@echo "  lint-all: run slow & thorough format and style checks"
+	@echo "  clang-format: reformat source (use with caution)"
 
-.PHONY: all clean distclean lint help
+.PHONY: all clean distclean lint lint-all lint-cpplint lint-clang-tidy \
+    lint-clang-format clang-format help
 
 include mk/subdir_post.mk
 -include $(DEPS_ALL)