Add support for generating a compile_commands.json for c-dependencies/js-compute-runtime (#91)

* Add support for generating a compile_commands.json for c-dependencies/js-compute-runtime

* Move gitignore patterns to c-dependencies/js-compute-runtime

* Fix assignment of `MODE` and `CARGO_FLAG` in `else` branch

* Use a separate command for invoking `WASM_STRIP`

* Mark the `compile_commands.json` target as `.PHONY`

* The default WASM_STRIP definition is no longer needed

Author: elliottt

c-dependencies/js-compute-runtime/.gitignore

@@ -0,0 +1,9 @@
+# clangd state
+/compile_commands.json
+/.cache
+
+/rusturl
+/compiler_flags
+/*.o
+/*.d
+/*.wasm

c-dependencies/js-compute-runtime/Makefile

@@ -3,36 +3,40 @@ WIZER ?= wizer
 
 CXX_OPT ?= -O2
 
-MODE=release
-CARGO_FLAG=--release
 ifdef DEBUG
-  MODE=debug
-  CARGO_FLAG=
+  MODE := debug
+  CARGO_FLAG :=
   CXX_OPT := $(CXX_OPT) -DDEBUG -DJS_DEBUG
+  Q :=
+else
+  MODE := release
+  CARGO_FLAG := --release
+  Q := @
 endif
 
-ROOT_SRC?=$(shell dirname $(realpath $(firstword $(MAKEFILE_LIST))))/..
-SM_SRC=$(ROOT_SRC)/spidermonkey/$(MODE)/
-SM_OBJ=$(SM_SRC)lib/*.o
-SM_OBJ+=$(SM_SRC)lib/*.a
-FSM_SRC=$(ROOT_SRC)/js-compute-runtime/
+ROOT_SRC ?= $(shell dirname $(realpath $(firstword $(MAKEFILE_LIST))))/..
+SM_SRC := $(ROOT_SRC)/spidermonkey/$(MODE)/
+SM_OBJ := $(SM_SRC)lib/*.o
+SM_OBJ += $(SM_SRC)lib/*.a
+FSM_SRC := $(ROOT_SRC)/js-compute-runtime/
 
 WASI_CXX ?= /opt/wasi-sdk/bin/clang++
 
 
 CXX_FLAGS := -std=gnu++17 -Wall -Werror -Qunused-arguments -fno-sized-deallocation -fno-aligned-new -mthread-model single -fPIC -fno-rtti -fno-exceptions -fno-math-errno -pipe -fno-omit-frame-pointer -funwind-tables
+DEFINES ?=
 LD_FLAGS := -Wl,-z,noexecstack -Wl,-z,text -Wl,-z,relro -Wl,-z,nocopyreloc -Wl,-z,stack-size=1048576 -Wl,--stack-first
 
-.PHONY: all
+.PHONY: all clean compile_commands.json
 
 all: js-compute-runtime.wasm
 
 compiler_flags:
-	echo '$(CXX_OPT)' | cmp -s - $@ || echo '$(CXX_OPT)' > $@
+	echo '$(CXX_OPT) $(CXX_FLAGS)' | cmp -s - $@ || echo '$(CXX_OPT) $(CXX_FLAGS)' > $@
 
 ifeq (,$(findstring g,$(CXX_OPT)))
 ifneq (,$(shell which wasm-opt))
-WASM_STRIP = wasm-opt --strip-debug -o $@ $@
+WASM_STRIP = wasm-opt --strip-debug -o $1 $1
 endif
 endif
 
@@ -54,7 +58,32 @@ $(RUST_URL_LIB): $(RUST_URL_RS_FILES) $(RUST_URL_SRC)/Cargo.toml $(RUST_URL_SRC)
 
 js-compute-runtime.wasm: $(FSM_OBJ) $(SM_OBJ) $(RUST_URL_LIB)
 	$(WASI_CXX) $(CXX_FLAGS) $(CXX_OPT) $(DEFINES) $(LD_FLAGS) -o $@ $^
-	$(WASM_STRIP)
+	$(call WASM_STRIP,$@)
 
 initialized-js-compute-runtime.wasm: js-compute-runtime.wasm $(INIT_JS)
 	cat $(INIT_JS) | $(WIZER) --allow-wasi --dir=. -r _start=wizer.resume -o $@ $<
+
+clean:
+	$(RM) compile_commands.json $(FSM_OBJ)
+
+distclean: clean
+	$(RM) $(FSM_DEP) compiler_flags
+
+.PHONY: compile_commands.json
+compile_commands.json:
+	$Q ( \
+		sep="["; \
+		for file in $(FSM_CPP); do \
+			echo "$$sep"; \
+			sep=","; \
+			echo "{ \"directory\": \"$(FSM_SRC)\","; \
+			echo "  \"command\": \"$(WASI_CXX) $(CXX_FLAGS) $(DEFINES) -I $(SM_SRC)include\","; \
+			echo -n "  \"file\": \"$$(basename $$file)\"}"; \
+		done; \
+		echo; \
+		echo ']' \
+	) > "$@"
+
+# Useful for debugging, try `make print-FSM_CPP`
+print-%:
+	$Q echo "$($*)"