Add Header Library support to Make

We currently use static libraries without any source files to represent
header libraries, but Soong actually has cc_library_headers. So to
export those in a separate namespace from static libraries, implement
them in Make as well.

This also adds a nice pretty-warning / pretty-error macro that can be
used to print out standard warning messages pointing to the real source
file having the problem.

Test: Use a header library exported by Soong in a Make module
Change-Id: I3486539e247524cb82a20620745fc7be03014e14
diff --git a/core/binary.mk b/core/binary.mk
index 304a72e..44f0e95 100644
--- a/core/binary.mk
+++ b/core/binary.mk
@@ -40,6 +40,7 @@
 my_static_libraries := $(LOCAL_STATIC_LIBRARIES)
 my_whole_static_libraries := $(LOCAL_WHOLE_STATIC_LIBRARIES)
 my_shared_libraries := $(LOCAL_SHARED_LIBRARIES)
+my_header_libraries := $(LOCAL_HEADER_LIBRARIES)
 my_cflags := $(LOCAL_CFLAGS)
 my_conlyflags := $(LOCAL_CONLYFLAGS)
 my_cppflags := $(LOCAL_CPPFLAGS)
@@ -320,6 +321,7 @@
 my_src_files += $(LOCAL_SRC_FILES_$($(my_prefix)OS)) $(LOCAL_SRC_FILES_$($(my_prefix)OS)_$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH))
 my_static_libraries += $(LOCAL_STATIC_LIBRARIES_$($(my_prefix)OS))
 my_shared_libraries += $(LOCAL_SHARED_LIBRARIES_$($(my_prefix)OS))
+my_header_libraries += $(LOCAL_HEADER_LIBRARIES_$($(my_prefix)OS))
 my_cflags += $(LOCAL_CFLAGS_$($(my_prefix)OS))
 my_cppflags += $(LOCAL_CPPFLAGS_$($(my_prefix)OS))
 my_ldflags += $(LOCAL_LDFLAGS_$($(my_prefix)OS))
@@ -443,6 +445,7 @@
 # arch-specific static libraries go first so that generic ones can depend on them
 my_static_libraries := $(LOCAL_STATIC_LIBRARIES_$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_STATIC_LIBRARIES_$(my_32_64_bit_suffix)) $(my_static_libraries)
 my_whole_static_libraries := $(LOCAL_WHOLE_STATIC_LIBRARIES_$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_WHOLE_STATIC_LIBRARIES_$(my_32_64_bit_suffix)) $(my_whole_static_libraries)
+my_header_libraries := $(LOCAL_HEADER_LIBRARIES_$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) $(LOCAL_HEADER_LIBRARIES_$(my_32_64_bit_suffix)) $(my_header_libraries)
 
 include $(BUILD_SYSTEM)/cxx_stl_setup.mk
 
@@ -1396,7 +1399,9 @@
     $(foreach l, $(installed_shared_library_module_names), \
       $(call intermediates-dir-for,SHARED_LIBRARIES,$(l),$(my_kind),,$(LOCAL_2ND_ARCH_VAR_PREFIX),$(my_host_cross))/export_includes) \
     $(foreach l, $(my_static_libraries) $(my_whole_static_libraries), \
-      $(call intermediates-dir-for,STATIC_LIBRARIES,$(l),$(my_kind),,$(LOCAL_2ND_ARCH_VAR_PREFIX),$(my_host_cross))/export_includes))
+      $(call intermediates-dir-for,STATIC_LIBRARIES,$(l),$(my_kind),,$(LOCAL_2ND_ARCH_VAR_PREFIX),$(my_host_cross))/export_includes) \
+    $(foreach l, $(my_header_libraries), \
+      $(call intermediates-dir-for,HEADER_LIBRARIES,$(l),$(my_kind),,$(LOCAL_2ND_ARCH_VAR_PREFIX),$(my_host_cross))/export_includes))
 $(import_includes): PRIVATE_IMPORT_EXPORT_INCLUDES := $(import_includes_deps)
 $(import_includes) : $(import_includes_deps)
 	@echo Import includes file: $@
@@ -1430,10 +1435,12 @@
    $(foreach l,$(my_whole_static_libraries) $(my_static_libraries), \
      $(call intermediates-dir-for,STATIC_LIBRARIES,$(l),$(my_kind),,$(LOCAL_2ND_ARCH_VAR_PREFIX),$(my_host_cross))/link_type))
 ifneq ($(LOCAL_MODULE_CLASS),STATIC_LIBRARIES)
+ifneq ($(LOCAL_MODULE_CLASS),HEADER_LIBRARIES)
 my_link_type_deps += $(strip \
    $(foreach l,$(my_shared_libraries), \
      $(call intermediates-dir-for,SHARED_LIBRARIES,$(l),$(my_kind),,$(LOCAL_2ND_ARCH_VAR_PREFIX),$(my_host_cross))/link_type))
 endif
+endif
 $(my_link_type): PRIVATE_DEPS := $(my_link_type_deps)
 $(my_link_type): PRIVATE_MODULE := $(LOCAL_MODULE)
 $(my_link_type): PRIVATE_MAKEFILE := $(LOCAL_MODULE_MAKEFILE)
@@ -1791,10 +1798,14 @@
 export_include_deps += $(strip \
    $(foreach l,$(LOCAL_EXPORT_STATIC_LIBRARY_HEADERS), \
      $(call intermediates-dir-for,STATIC_LIBRARIES,$(l),$(my_kind),,$(LOCAL_2ND_ARCH_VAR_PREFIX),$(my_host_cross))/export_includes))
+# Re-export requested headers from header libraries.
+export_include_deps += $(strip \
+   $(foreach l,$(LOCAL_EXPORT_HEADER_LIBRARY_HEADERS), \
+     $(call intermediates-dir-for,HEADER_LIBRARIES,$(l),$(my_kind),,$(LOCAL_2ND_ARCH_VAR_PREFIX),$(my_host_cross))/export_includes))
 $(export_includes): PRIVATE_REEXPORTED_INCLUDES := $(export_include_deps)
 # By adding $(my_generated_sources) it makes sure the headers get generated
 # before any dependent source files get compiled.
-$(export_includes) : $(my_export_c_include_deps) $(my_generated_sources) $(export_include_deps)
+$(export_includes) : $(my_export_c_include_deps) $(my_generated_sources) $(export_include_deps) $(LOCAL_EXPORT_C_INCLUDE_DEPS)
 	@echo Export includes file: $< -- $@
 	$(hide) mkdir -p $(dir $@) && rm -f $@.tmp && touch $@.tmp
 ifdef my_export_c_include_dirs