Add build support for ppx_compare

Reviewed By: cristianoc

Differential Revision: D4232364

fbshipit-source-id: 7e62d02

infer/.merlin

@@ -5,6 +5,7 @@ PKG core
 PKG extlib
 PKG javalib
 PKG ounit
+PKG ppx_compare
 PKG ptrees
 PKG sawja
 PKG str

infer/src/Makefile

@@ -33,8 +33,9 @@ OCAMLBUILD_OPTIONS = \
   -cflags -principal \
   -cflags -strict-formats \
   -cflags -strict-sequence \
-  -cflags -w,$(OCAML_FATAL_WARNINGS)-4-9-40-41-42-45-48 \
+  -cflags -w,$(OCAML_FATAL_WARNINGS)-4-9-32-40-41-42-45-48 \
   -tag-line "<*{clang/clang_ast_*,backend/jsonbug_*,checkers/stacktree_*}>: warn(-27-32-35-39)" \
+  -tag-line "<*/{,*/}*.{ml,re}{,i}>: package(ppx_compare)" \
   -tag thread \
   -pkgs atdgen,core,ctypes.foreign,extlib,oUnit,str,unix,yojson,zip
 
@@ -172,6 +173,8 @@ INFER_CONFIG_TARGETS += $(INFERCLANG_MAIN).native
 DEPENDENCIES += clang
 endif
 
+export OCAMLFIND_IGNORE_DUPS_IN=$(shell ocamlc -where)/compiler-libs
+
 .PHONY: all
 all: infer