Add support for building the JS wrappers to the Makefile

Now that we have C and C++, we need to split the compile and link steps
(because we need different flags for the C and C++ files), so this is
easier with a Makefile.

1 files changed, 45 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index a722b70..20a82a6 100644
--- a/Makefile
+++ b/Makefile
@@ -3,19 +3,38 @@
 BUILD_DIR := build
 OPTIMIZE_FLAGS ?= -g -O3
 TEST_OPTIMIZE_FLAGS ?= -g -O0
+JS_OPTIMIZE_FLAGS ?= -O3
 CC = gcc
+EMCC = emcc
 TARGET := $(BUILD_DIR)/libolm.so
+JS_TARGET := javascript/olm.js
+
+JS_EXPORTED_FUNCTIONS := javascript/exported_functions.json
+
+PUBLIC_HEADERS := include/olm/olm.hh
 
 SOURCES := $(wildcard src/*.cpp) $(wildcard src/*.c)
 OBJECTS := $(patsubst src/%,$(BUILD_DIR)/%,$(patsubst %.c,%.o,$(patsubst %.cpp,%.o,$(SOURCES))))
 TEST_SOURCES := $(wildcard tests/test_*.cpp) $(wildcard tests/test_*.c)
 TEST_BINARIES := $(patsubst tests/%,$(BUILD_DIR)/%,$(patsubst %.c,%,$(patsubst %.cpp,%,$(TEST_SOURCES))))
+JS_OBJECTS := $(patsubst %.o,%.js.bc,$(OBJECTS))
+JS_PRE := $(wildcard javascript/*pre.js)
+JS_POST := $(wildcard javascript/*post.js)
 
 CPPFLAGS += -Iinclude -Ilib
 CFLAGS += -Wall --std=c89 -fPIC
 CXXFLAGS += -Wall --std=c++11 -fPIC
 LDFLAGS += -Wall
 
+EMCCFLAGS = --closure 1 --memory-init-file 0 -s NO_FILESYSTEM=1 -s INVOKE_RUN=0
+# NO_BROWSER is kept for compatibility with emscripten 1.35.24, but is no
+# longer needed.
+EMCCFLAGS += -s NO_BROWSER=1
+
+EMCC.c = $(EMCC) $(CFLAGS) $(CPPFLAGS) -c
+EMCC.cc = $(EMCC) $(CXXFLAGS) $(CPPFLAGS) -c
+EMCC_LINK = $(EMCC) $(LDFLAGS) $(EMCCFLAGS)
+
 # generate .d files when compiling
 CPPFLAGS += -MMD
 
@@ -29,14 +48,29 @@ $(TEST_BINARIES): CPPFLAGS += -Itests/include
 $(TEST_BINARIES): LDLIBS += -lolm
 $(TEST_BINARIES): LDFLAGS += $(TEST_OPTIMIZE_FLAGS) -L$(BUILD_DIR)
 
+$(JS_OBJECTS): CFLAGS += $(JS_OPTIMIZE_FLAGS)
+$(JS_OBJECTS): CXXFLAGS += $(JS_OPTIMIZE_FLAGS)
+$(JS_TARGET): LDFLAGS += $(JS_OPTIMIZE_FLAGS)
+
 ### top-level targets
 
 $(TARGET): $(OBJECTS)
 	$(CXX) $(LDFLAGS) --shared -fPIC $^ $(OUTPUT_OPTION)
 
+js: $(JS_TARGET)
+.PHONY: js
+
+$(JS_TARGET): $(JS_OBJECTS) $(JS_PRE) $(JS_POST) $(JS_EXPORTED_FUNCTIONS)
+	$(EMCC_LINK) \
+	       --pre-js $(JS_PRE) --post-js $(JS_POST) \
+	       -s "EXPORTED_FUNCTIONS=@$(JS_EXPORTED_FUNCTIONS)" \
+               $(JS_OBJECTS) -o $@
+
 clean:;
 	rm -rf $(OBJECTS) $(OBJECTS:.o=.d) \
                $(TEST_BINARIES) $(TEST_BINARIES:=.d) \
+               $(JS_OBJECTS) $(JS_TARGET) \
+               $(JS_EXPORTED_FUNCTIONS) \
                $(TARGET)
 
 build_tests: $(TEST_BINARIES)
@@ -47,6 +81,10 @@ test: build_tests
 	    LD_LIBRARY_PATH=$(BUILD_DIR) $$i || exit $$?; \
 	done
 
+$(JS_EXPORTED_FUNCTIONS): $(PUBLIC_HEADERS)
+	perl -MJSON -ne '/(olm_[^( ]*)\(/ && push @f, "_$$1"; END { print encode_json \@f }' $^ > $@.tmp
+	mv $@.tmp $@
+
 ### rules for building objects
 $(BUILD_DIR)/%.o: src/%.c
 	$(COMPILE.c) $(OUTPUT_OPTION) $<
@@ -54,6 +92,12 @@ $(BUILD_DIR)/%.o: src/%.c
 $(BUILD_DIR)/%.o: src/%.cpp
 	$(COMPILE.cc) $(OUTPUT_OPTION) $<
 
+$(BUILD_DIR)/%.js.bc: src/%.c
+	$(EMCC.c) $(OUTPUT_OPTION) $<
+
+$(BUILD_DIR)/%.js.bc: src/%.cpp
+	$(EMCC.cc) $(OUTPUT_OPTION) $<
+
 $(BUILD_DIR)/%: tests/%.c
 	$(LINK.c) $< $(LOADLIBES) $(LDLIBS) -o $@
 
@@ -66,4 +110,5 @@ $(BUILD_DIR)/%: tests/%.cpp
 $(TEST_BINARIES): $(TARGET)
 
 -include $(OBJECTS:.o=.d)
+-include $(JS_OBJECTS:.bc=.d)
 -include $(TEST_BINARIES:=.d)