[ocamlformat] Support passing args to ocamlformat

Summary: Useful for testing / debugging ocamlformat updates

Reviewed By: skcho

Differential Revision: D21395971

fbshipit-source-id: d4f2f2dcb

Makefile

@@ -218,19 +218,19 @@ fb-setup:
 
 .PHONY: fmt
 fmt:
-	parallel $(OCAMLFORMAT_EXE) -i ::: $$(git diff --name-only --diff-filter=ACMRU $$(git merge-base origin/master HEAD) | grep "\.mli\?$$")
+	parallel $(OCAMLFORMAT_EXE) $(OCAMLFORMAT_ARGS) -i ::: $$(git diff --name-only --diff-filter=ACMRU $$(git merge-base origin/master HEAD) | grep "\.mli\?$$")
 
 DUNE_ML:=$(shell find * -name 'dune*.in' | grep -v workspace | grep -v infer-source)
 
 .PHONY: fmt_dune
 fmt_dune:
-	parallel $(OCAMLFORMAT_EXE) -i ::: $(DUNE_ML)
+	parallel $(OCAMLFORMAT_EXE) $(OCAMLFORMAT_ARGS) -i ::: $(DUNE_ML)
 
 SRC_ML:=$(shell find * \( -name _build -or -name facebook-clang-plugins -or -path facebook/dependencies -or -path sledge/llvm -or -path sledge/.llvm_build \) -not -prune -or -type f -and -name '*'.ml -or -name '*'.mli 2>/dev/null)
 
 .PHONY: fmt_all
 fmt_all:
-	parallel $(OCAMLFORMAT_EXE) -i ::: $(SRC_ML) $(DUNE_ML)
+	parallel $(OCAMLFORMAT_EXE) $(OCAMLFORMAT_ARGS) -i ::: $(SRC_ML) $(DUNE_ML)
 
 # pre-building these avoids race conditions when building, eg src_build and test_build in parallel
 .PHONY: src_build_common