From e4191f44c6722fa45dc4cd04e40c9291351dfdc5 Mon Sep 17 00:00:00 2001
From: Andy Wingo <wingo@igalia.com>
Date: Wed, 9 Aug 2023 22:16:03 +0200
Subject: [PATCH] First stab at an embedder's makefile snippet

---
 embed.mk | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 embed.mk

diff --git a/embed.mk b/embed.mk
new file mode 100644
index 000000000..8ce8055ce
--- /dev/null
+++ b/embed.mk
@@ -0,0 +1,78 @@
+GC_COLLECTOR ?= semi
+
+DEFAULT_BUILD := opt
+
+BUILD_CFLAGS_opt      = -O2 -g -DNDEBUG
+BUILD_CFLAGS_optdebug = -Og -g -DGC_DEBUG=1
+BUILD_CFLAGS_debug    = -O0 -g -DGC_DEBUG=1
+
+GC_BUILD_CFLAGS = $(BUILD_CFLAGS_$(or $(GC_BUILD),$(DEFAULT_BUILD)))
+
+GC_CC       = gcc
+GC_CFLAGS   = -Wall -flto -fno-strict-aliasing -fvisibility=hidden -Wno-unused $(GC_BUILD_CFLAGS)
+GC_CPPFLAGS = -I$(here)/api
+GC_LDFLAGS  = -lpthread -flto
+GC_DEPFLAGS = -MMD -MP -MF $(@:obj/%.o=.deps/%.d)
+GC_COMPILE  = $(GC_CC) $(GC_CFLAGS) $(GC_CPPFLAGS) $(GC_DEPFLAGS) -o $@
+GC_LINK     = $(CC) $(LDFLAGS) -o $@
+GC_PLATFORM = gnu-linux
+GC_OBJDIR   =
+
+$(GC_OBJDIR)gc-platform.o: src/gc-platform-$(PLATFORM).c
+	$(GC_COMPILE) -c $<
+$(GC_OBJDIR)gc-stack.o: src/gc-stack.c
+	$(GC_COMPILE) -c $<
+$(GC_OBJDIR)gc-options.o: src/gc-options.c
+	$(GC_COMPILE) -c $<
+$(GC_OBJDIR)gc-ephemeron.o: src/gc-ephemeron.c
+	$(GC_COMPILE) -include $(GC_EMBEDDER_H) -c $<
+
+GC_STEM_bdw   	   = bdw
+GC_CFLAGS_bdw 	   = -DGC_CONSERVATIVE_ROOTS=1 -DGC_CONSERVATIVE_TRACE=1
+GC_IMPL_CFLAGS_bdw = `pkg-config --cflags bdw-gc`
+GC_LIBS_bdw        = `pkg-config --libs bdw-gc`
+
+GC_STEM_semi       = semi
+GC_CFLAGS_semi     = -DGC_PRECISE_ROOTS=1
+
+define whippet_variant
+GC_STEM_$(1)       = whippet
+GC_CFLAGS_$(1)     = $(2)
+endef
+
+define generational_whippet_variants
+$(call whippet_variant,$(1)whippet,$(2))
+$(call whippet_variant,$(1)generational_whippet,$(2) -DGC_GENERATIONAL=1)
+endef
+
+define parallel_whippet_variants
+$(call generational_whippet_variants,$(1),$(2))
+$(call generational_whippet_variants,$(1)parallel_,$(2) -DGC_PARALLEL=1)
+endef
+
+define trace_whippet_variants
+$(call parallel_whippet_variants,,-DGC_PRECISE_ROOTS=1)
+$(call parallel_whippet_variants,stack_conservative_,-DGC_CONSERVATIVE_ROOTS=1)
+$(call parallel_whippet_variants,heap_conservative_,-DGC_CONSERVATIVE_ROOTS=1 -DGC_CONSERVATIVE_TRACE=1)
+endef
+
+$(eval $(call trace_whippet_variants))
+
+gc_var         = $($(1)$(subst -,_,$(2)))
+gc_impl        = $(call gc_var,GC_STEM_,$(1)).c
+gc_attrs       = $(call gc_var,GC_STEM_,$(1))-attrs.h
+gc_cflags      = $(call gc_var,GC_CFLAGS_,$(1))
+gc_impl_cflags = $(call gc_var,GC_IMPL_CFLAGS_,$(1))
+gc_libs        = $(call gc_var,GC_LIBS_,$(1))
+
+GC_IMPL        	    = $(call gc_impl,$(GC_COLLECTOR))
+GC_CFLAGS      	   += $(call gc_cflags,$(GC_COLLECTOR))
+GC_IMPL_CFLAGS 	    = $(call gc_impl_cflags,$(GC_COLLECTOR))
+GC_EMBEDDER_CFLAGS  = -include $(here)api/$(GC_IMPL)-attrs.h
+GC_ATTRS            = $(call gc_attrs,$(GC_COLLECTOR))
+GC_LIBS             = $(call gc_libs,$(GC_COLLECTOR))
+
+$(GC_OBJDIR)gc-impl.o: src/$(call gc_impl,$(GC_COLLECTOR))
+	$(GC_COMPILE) $(GC_IMPL_CFLAGS) -include $(GC_EMBEDDER_H) -c $<
+
+GC_OBJS=$(foreach O,gc-platform.o gc-stack.o gc-options.o gc-ephemeron.o gc-impl.o,$(GC_OBJDIR)/$(O))