Add clang-format rules and makefile targets

Will commit the result in the next changeset.

Also, had to update to a newer version of LLVM to get some new clang-format options.
We don't necessarily have to use the same version of clang-format as the version of
llvm that we build it against, but if we can it keeps the build system simpler.

llvm_revision.txt

-205253
+205760

src/.clang-format

+BasedOnStyle: WebKit
+
+AccessModifierOffset: -4
+AlignTrailingComments: true
+AllowShortFunctionsOnASingleLine: Inline
+AllowShortIfStatementsOnASingleLine: false
+BreakBeforeBraces: Attach
+BreakConstructorInitializersBeforeComma: false
+ColumnLimit: 120
+IndentCaseLabels: true
+IndentWidth: 4
+Language: Cpp
+MaxEmptyLinesToKeep: 3
+NamespaceIndentation: None
+PointerBindsToType: true
+SpaceBeforeParens: ControlStatements
+SpacesInAngles: false
+SpacesInCStyleCastParentheses: false
+SpacesInParentheses: false
+Standard: Cpp03
+TabWidth: 4
+UseTab: Never
+
+# Unset settings are undecided

src/Makefile

@@ -305,6 +305,12 @@ define checksha
 	test "$$($1 | sha1sum)" = "$2  -"
 endef
 
+.PHONY: format check_format
+format:
+	find \( -name '*.cpp' -o -name '*.h' \) -print0 | xargs -0 $(LLVM_BIN)/clang-format -style=file -i
+check_format:
+	$(TOOLS_DIR)/check_format.sh $(LLVM_BIN)/clang-format
+
 .PHONY: test test_debug test_prof test_release
 test_debug: pyston_dbg ext
 	python ../tools/tester.py -j$(TEST_THREADS) -k $(TESTS_DIR) $(ARGS)

tools/check_format.sh

+#!/bin/bash
+set -eu
+for fn in $(find -name '*.cpp' -o -name '*.h'); do
+    $1 -style=file -output-replacements-xml $fn | grep -q "replacement offset" && { echo $fn "failed clang-format check"; exit 1; }
+done
+echo "Format checks passed"
+exit 0