glapi: add glapi_gen.mk to help header generation

glapi_gen.mk is supposed to be included by glapi users to simplify
header generation.  This commit also makes es1api, es2api, and
shared-glapi use it.

Reviewed-by: Brian Paul <brianp@vmware.com>

[olv: updated after reviewing to prefix all variables in glapi_gen.mk by
 glapi_gen]

src/mapi/glapi/gen/glapi_gen.mk

@@ -0,0 +1,44 @@
+# Helpers for glapi header generation
+
+ifndef TOP
+$(error TOP must be defined.)
+endif
+
+glapi_gen_common_deps := \
+	$(wildcard $(TOP)/src/mapi/glapi/gen/*.xml) \
+	$(wildcard $(TOP)/src/mapi/glapi/gen/*.py)
+
+glapi_gen_mapi_script := $(TOP)/src/mapi/mapi/mapi_abi.py
+glapi_gen_mapi_deps := \
+	$(glapi_gen_mapi_script) \
+	$(glapi_gen_common_deps)
+
+# $(1): path to an XML file
+# $(2): name of the printer
+define glapi_gen_mapi
+@mkdir -p $(dir $@)
+$(PYTHON2) $(PYTHON_FLAGS) $(glapi_gen_mapi_script) \
+	--mode lib --printer $(2) $(1) > $@
+endef
+
+glapi_gen_dispatch_script := $(TOP)/src/mapi/glapi/gen/gl_table.py
+glapi_gen_dispatch_deps := $(glapi_gen_common_deps)
+
+# $(1): path to an XML file
+# $(2): empty, es1, or es2 for entry point filtering
+define glapi_gen_dispatch
+@mkdir -p $(dir $@)
+$(PYTHON2) $(PYTHON_FLAGS) $(glapi_gen_dispatch_script) \
+	-f $(1) -m remap_table $(if $(2),-c $(2),) > $@
+endef
+
+glapi_gen_remap_script := $(TOP)/src/mapi/glapi/gen/remap_helper.py
+glapi_gen_remap_deps := $(glapi_gen_common_deps)
+
+# $(1): path to an XML file
+# $(2): empty, es1, or es2 for entry point filtering
+define glapi_gen_remap
+@mkdir -p $(dir $@)
+$(PYTHON2) $(PYTHON_FLAGS) $(glapi_gen_remap_script) \
+	-f $(1) $(if $(2),-c $(2),) > $@
+endef