dynasm: Switch from C-based assembler to Lua-based assembler

src/Makefile

@@ -20,7 +20,7 @@ PFLUASRC = $(shell cd ../deps/pflua/src && \
 	         find . -regex '[^\#]*\.lua' -printf '%P ')
 CSRC   = $(shell find . -regex '[^\#]*\.c' -not -regex './arch/.*' -printf '%P ')
 CHDR   = $(shell find . -regex '[^\#]*\.h' -printf '%P ')
-ASM    = $(shell find . -regex '[^\#]*\.dasc' -printf '%P ')
+ASM    = $(shell find . -regex '[^\#]*\.dasl' -printf '%P ')
 ARCHSRC= $(shell find . -regex '^./arch/[^\#]*\.c' -printf '%P ')
 RMSRC  = $(shell find . -name  README.md.src -printf '%P ')
 # regexp is to include program/foo but not program/foo/bar
@@ -32,7 +32,7 @@ PFLUAOBJ := $(patsubst %.lua,obj/%_lua.o,$(PFLUASRC))
 COBJ   := $(patsubst %.c,obj/%_c.o,    $(CSRC))
 HOBJ   := $(patsubst %.h,obj/%_h.o,    $(CHDR))
 ARCHOBJ:= $(patsubst %.c,obj/%_c.o,    $(ARCHSRC))
-ASMOBJ := $(patsubst %.dasc,obj/%_dasc.o,   $(ASM))
+ASMOBJ := $(patsubst %.dasl,obj/%_dasl.o,   $(ASM))
 JITOBJS:= $(patsubst %,obj/jit_%.o,$(JITSRC))
 EXTRAOBJS := obj/jit_tprof.o obj/jit_vmprof.o obj/strict.o
 RMOBJS := $(patsubst %.src,%,$(RMSRC))
@@ -168,10 +168,10 @@ $(HOBJ): obj/%_h.o: %.h Makefile | $(OBJDIR)
 	 echo "]=============]") > $(basename $@).luah
 	$(Q) luajit -bg -n $(subst /,.,$*)_h $(basename $@).luah $@
 
-$(ASMOBJ): obj/%_dasc.o: %.dasc $(CHDR) Makefile | $(OBJDIR)
+$(ASMOBJ): obj/%_dasl.o: %.dasl $(CHDR) Makefile | $(OBJDIR)
 	$(E) "ASM       $@"
-	$(Q) luajit ../deps/luajit/dynasm/dynasm.lua -o $@.gen $<
-	$(Q) gcc $(DEBUG) -Wl,-E -I ../deps/luajit/src -I . -I ../deps/luajit -c -Wall -Werror -x c -o $@ $@.gen
+	$(Q) luajit dynasm.lua -o $@.gen $<
+	$(Q) luajit -bg -n $(subst /,.,$*) $@.gen $@
 
 $(JITOBJS): obj/jit_%.o: ../deps/luajit/src/jit/%.lua $(OBJDIR)
 	$(E) "LUA       $@"

src/apps/example/asm.dasl

@@ -0,0 +1,62 @@
+-- Example app written in x86-64 assembly language.
+module(...,package.seeall)
+
+local ffi = require("ffi")
+local C = ffi.C
+
+local dasm = require("dasm")
+
+--
+-- Compile machine code
+--
+-- This is a really simple example. We are going to assigned 'fptr' to
+-- a machine code function that simply stores a magic number in the
+-- 'asm_status' struct so that we know it has executed.
+
+local fptr
+local asm_status = ffi.new("uint32_t[1]")
+
+|.arch x64
+|.actionlist actions
+local Dst = dasm.new(actions)
+| mov dword [asm_status], 0xdeadbeef
+| ret
+code = Dst:build() -- assign to 'code' to avoid machine code being GC'd
+fptr = ffi.cast("void(*)()", code)
+
+--
+-- Lua app
+--
+
+local config = require("core.config")
+local app = require("core.app")
+local basic_apps = require("apps.basic.basic_apps")
+
+Asm = {}
+
+function Asm:new ()
+   return setmetatable({}, {__index=Asm})
+end
+
+function Asm:pull ()
+end
+
+function Asm:push ()
+   -- Call generated code.
+   fptr()
+end
+
+function selftest ()
+   print("selftest: asm")
+   local c = config.new()
+   config.app(c, "source", basic_apps.Source)
+   config.app(c, "sink",   basic_apps.Sink)
+   config.app(c, "asm", Asm)
+   config.link(c, "source.tx -> asm.rx")
+   config.link(c, "asm.tx    -> sink.rx")
+   app.configure(c)
+   app.main({duration = 0.1})
+   print("magic number: 0x"..bit.tohex(asm_status[0]))
+   assert(asm_status[0] == 0xdeadbeef, "bad magic")
+   print("selftest: ok")
+end