From 9e7fc1915b388704e5fd8c45004486bd91999fce Mon Sep 17 00:00:00 2001
From: Andrew Johnson <anj@aps.anl.gov>
Date: Tue, 3 Mar 2020 01:00:42 -0600
Subject: [PATCH] Add build rules to generate and install *API.h header files

---
 configure/CONFIG_COMMON |  2 +-
 configure/RULES_BUILD   | 16 ++++++++++++++++
 configure/RULES_TARGET  | 13 +++++++++++++
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/configure/CONFIG_COMMON b/configure/CONFIG_COMMON
index b79e15cf5..6c0e11e0d 100644
--- a/configure/CONFIG_COMMON
+++ b/configure/CONFIG_COMMON
@@ -306,7 +306,7 @@ LDLIBS = $(POSIX_LDLIBS) $(ARCH_DEP_LDLIBS) $(DEBUG_LDLIBS) $(OP_SYS_LDLIBS)\
 CPPFLAGS = $($(BUILD_CLASS)_CPPFLAGS) $(POSIX_CPPFLAGS) $(OPT_CPPFLAGS)\
  $(DEBUG_CPPFLAGS) $(WARN_CPPFLAGS) $(BASE_CPPFLAGS) $(TARGET_CPPFLAGS)\
  $(USR_CPPFLAGS) $(CMD_CPPFLAGS) $(ARCH_DEP_CPPFLAGS) $(OP_SYS_CPPFLAGS)\
- $(OP_SYS_INCLUDE_CPPFLAGS) $(CODE_CPPFLAGS)
+ $(OP_SYS_INCLUDE_CPPFLAGS) $(CODE_CPPFLAGS) $(API_CPPFLAGS)
 
 #--------------------------------------------------
 # ar definition default
diff --git a/configure/RULES_BUILD b/configure/RULES_BUILD
index 3df3052b4..99bbb0726 100644
--- a/configure/RULES_BUILD
+++ b/configure/RULES_BUILD
@@ -409,6 +409,22 @@ endif
 	$(PERL) $(TOOLS)/makeTestfile.pl $(T_A) $(EPICS_HOST_ARCH) $@ $<
 
 #---------------------------------------------------------------
+# Generate an $(API_HEADER) file on request (%API.h)
+
+ifdef API_HEADER
+# Install it
+INC += $(API_HEADER)
+
+# Ensure we generate it early enough
+$(filter-out $(INSTALL_INCLUDE)/$(API_HEADER), $(INSTALL_INC)) $(HDEPENDS_FILES): \
+    | $(INSTALL_INCLUDE)/$(API_HEADER)
+
+# How to make it
+$(COMMON_DIR)/$(API_HEADER):
+	@$(RM) $@
+	$(PERL) $(TOOLS)/makeAPIheader.pl -o $@ $(API_HEADER:API.h=)
+endif
+
 # Generate header with version number from VCS
 
 ifneq ($(GENVERSION),)
diff --git a/configure/RULES_TARGET b/configure/RULES_TARGET
index e96232876..5d77b105e 100644
--- a/configure/RULES_TARGET
+++ b/configure/RULES_TARGET
@@ -95,12 +95,20 @@ $(1)_DLL_DEPLIBS=$$(foreach lib, $$($(1)_DLL_LIBS), \
 $$(LIB_PREFIX)$(1)$$(LIB_SUFFIX):$$($(1)_OBJSNAME) $$($(1)_RESS)
 $$(LIB_PREFIX)$(1)$$(LIB_SUFFIX):$$($(1)_DEPLIBS)
 
+ifneq ($$($(1)_API),)
+$$(LIB_PREFIX)$(1)$$(LIB_SUFFIX): API_CPPFLAGS += -DBUILDING_$$($(1)_API)_API
+endif
+
 ifeq ($$(SHARED_LIBRARIES),YES)
 
 ifdef SHRLIB_SUFFIX
 $$(SHRLIB_PREFIX)$(1)$$(SHRLIB_SUFFIX):$$($(1)_OBJSNAME) $$($(1)_RESS)
 $$(SHRLIB_PREFIX)$(1)$$(SHRLIB_SUFFIX):$$($(1)_DEPLIBS)
 $$(SHRLIB_PREFIX)$(1)$$(SHRLIB_SUFFIX):$$($(1)_DLL_DEPLIBS)
+
+ifneq ($$($(1)_API),)
+$$(SHRLIB_PREFIX)$(1)$$(SHRLIB_SUFFIX): API_CPPFLAGS += -DBUILDING_$$($(1)_API)_API
+endif
 endif
 
 endif
@@ -141,6 +149,11 @@ $(1)_DLL_DEPLIBS=$$(foreach lib, $$($(1)_DLL_LIBS),\
 $$(LOADABLE_SHRLIB_PREFIX)$(1)$$(LOADABLE_SHRLIB_SUFFIX):$$($(1)_OBJSNAME) $$($(1)_RESS)
 $$(LOADABLE_SHRLIB_PREFIX)$(1)$$(LOADABLE_SHRLIB_SUFFIX):$$($(1)_DEPLIBS)
 $$(LOADABLE_SHRLIB_PREFIX)$(1)$$(LOADABLE_SHRLIB_SUFFIX):$$($(1)_DLL_DEPLIBS)
+
+ifneq ($$($(1)_API),)
+$$(LOADABLE_SHRLIB_PREFIX)$(1)$$(LOADABLE_SHRLIB_SUFFIX): \
+    API_CPPFLAGS += -DBUILDING_$$($(1)_API)_API
+endif
 endef
 
 $(foreach target, $(LOADABLE_LIBRARY), \