Merge "Switch to prebuilt bison"

# Generic tools.

LEX := flex

YACC:= bison -d

# The default PKGDATADIR built in the prebuilt bison is a relative path

# external/bison/data.

# To run bison from elsewhere you need to set up enviromental variable

# BISON_PKGDATADIR.

BISON_PKGDATADIR := $(PWD)/external/bison/data

BISON := prebuilts/misc/$(HOST_PREBUILT_TAG)/bison/bison

YACC := $(BISON) -d

DOXYGEN:= doxygen

AAPT := $(HOST_OUT_EXECUTABLES)/aapt$(HOST_EXECUTABLE_SUFFIX)

AIDL := $(HOST_OUT_EXECUTABLES)/aidl$(HOST_EXECUTABLE_SUFFIX)