libre2: add re2 package

RE2 is a fast, safe, thread-friendly alternative to backtracking regular
expression engines like those used in PCRE, Perl, and Python. It is a
C++ library.

Signed-off-by: Amol Bhave <ambhave@fb.com>

libs/libre2/Makefile

@@ -0,0 +1,64 @@
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=re2
+PKG_VERSION:=2018-12-01
+PKG_RELEASE:=1
+
+PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
+PKG_SOURCE_URL:=https://codeload.github.com/google/re2/tar.gz/$(PKG_VERSION)?
+PKG_HASH:=715e01685719a4ed68a353ae48249612ef4a7464755c3ecccaceae91ebd34868
+
+PKG_LICENSE:=BSD-3-Clause
+PKG_LICENSE_FILE:=LICENSE
+
+include $(INCLUDE_DIR)/package.mk
+include $(INCLUDE_DIR)/host-build.mk
+include $(INCLUDE_DIR)/cmake.mk
+
+PKG_BUILD_PARALLEL:=1
+HOST_BUILD_PARALLEL:=1
+CMAKE_OPTIONS:= \
+	-DBUILD_SHARED_LIBS=$(if $(CONFIG_RE2_SHARED),ON,OFF)
+CMAKE_INSTALL:=1
+
+define Package/re2
+	SECTION:=libs
+	CATEGORY:=Libraries
+	DEPENDS:=+libstdcpp
+	TITLE:=RE2 is a fast, safe, thread-friendly alternative to backtracking regular expression engines like those used in PCRE, Perl, and Python. It is a C++ library.
+	URL:=https://github.com/google/re2
+	MAINTAINER:=Amol Bhave <ambhave@fb.com>
+endef
+
+define Package/re2/config
+	choice
+		prompt "Compile RE2 library."
+			default RE2_SHARED
+			help
+				Choose which version to compile.
+				-> Shared:
+					- Only Shared lib will be compiled.
+				-> Static:
+					- Only Static lib will be compiled.
+
+		config RE2_SHARED
+			bool "Shared"
+
+		config RE2_STATIC
+			bool "Static"
+	endchoice
+endef
+
+define Package/re2/description
+	RE2 is a fast, safe, thread-friendly alternative to backtracking regular
+	expression engines like those used in PCRE, Perl, and Python.
+	It is a C++ library.
+endef
+
+define Package/re2/install
+	$(INSTALL_DIR) $(1)/usr/lib
+	$(INSTALL_DATA) $(PKG_INSTALL_DIR)/usr/lib/libre2.so* $(1)/usr/lib/
+endef
+
+$(eval $(call BuildPackage,re2))
+$(eval $(call HostBuild))