refactor the C and Go wrapper build system

- moved "nimbus/api" to "wrappers"
- renamed files
- replaced the build scripts with Makefile targets
- set the rpath relative to the test binary's location so it can look
  for libnimbus.so there at runtime
- libnimbus.so.0 required on Linux, apparently
- compiled all the Nimbus code with `--app:lib`, not just one file (this
  required skipping a proc in "nimbus/config.nim" because it uses an API
  that's unavailable in libraries)
- removed static linking from the Go wrapper. It doesn't make sense at a
  global level, when using a shared Nimbus library. To selectively link
  static libraries, we should probably be specifying them as *.a. I did
  build a static libnimbus.a, as a test, but it insisted on dlopen-ing a
  shared version of itself which looked too ugly to continue.

.gitignore

@@ -1,4 +1,4 @@
-nimcache
+/nimcache
 
 # Executables shall be put in an ignored build/ directory
 /build

Makefile

@@ -49,7 +49,7 @@ TOOLS_DIRS := premix tests
 # comma-separated values for the "clean" target
 TOOLS_CSV := $(subst $(SPACE),$(COMMA),$(TOOLS))
 
-.PHONY: all $(TOOLS) deps sanity-checks github-ssh build-nim update status ntags ctags nimbus testsuite test clean mrproper fetch-dlls test-libp2p-daemon nat-libs libminiupnpc.a libnatpmp.a go-checks
+.PHONY: all $(TOOLS) deps sanity-checks github-ssh build-nim update status ntags ctags nimbus testsuite test clean mrproper fetch-dlls test-libp2p-daemon nat-libs libminiupnpc.a libnatpmp.a go-checks libnimbus.so wrappers
 
 # default target, because it's the first one that doesn't start with '.'
 all: $(TOOLS) nimbus
@@ -128,7 +128,7 @@ test-reproducibility:
 
 # usual cleaning
 clean:
-	rm -rf build/{nimbus,$(TOOLS_CSV),all_tests,test_rpc,*.exe} vendor/go/bin \
+	rm -rf build/{nimbus,$(TOOLS_CSV),all_tests,test_rpc,*.exe,*.so,*.so.0,*_wrapper_test} vendor/go/bin \
 		$(NIMBLE_DIR) $(NIM_BINARY) $(NIM_DIR)/nimcache nimcache
 	+ $(MAKE) -C vendor/nim-nat-traversal/vendor/miniupnp/miniupnpc clean $(HANDLE_OUTPUT)
 	+ $(MAKE) -C vendor/nim-nat-traversal/vendor/libnatpmp clean $(HANDLE_OUTPUT)
@@ -197,6 +197,18 @@ test-libp2p-daemon: | vendor/go/bin/p2pd deps
 		$(ENV_SCRIPT) nim c -r $(NIM_PARAMS) tests/testdaemon.nim && \
 		rm -f tests/testdaemon
 
+libnimbus.so: | build deps nat-libs
+	echo -e $(BUILD_MSG) "build/$@" && \
+		$(ENV_SCRIPT) nim c --app:lib --noMain -d:"chronicles_sinks=textlines" --debuginfo --opt:speed --lineTrace:off $(NIM_PARAMS) -o:build/$@.0 wrappers/wrapper.nim && \
+		rm -f build/$@ && \
+		ln -s $@.0 build/$@
+
+wrappers: | build deps nat-libs libnimbus.so go-checks
+	echo -e $(BUILD_MSG) "build/C_wrapper_test" && \
+		$(CC) wrappers/wrapper.c -Wl,-rpath,'$$ORIGIN' -Lbuild -lnimbus -lm -g -o build/C_wrapper_test
+	echo -e $(BUILD_MSG) "build/go_wrapper_test" && \
+		go build -o build/go_wrapper_test wrappers/wrapper.go
+
 # https://bitbucket.org/nimcontrib/ntags/ - currently fails with "out of memory"
 ntags:
 	ntags -R .

nim.cfg

@@ -17,3 +17,7 @@
 --excessiveStackTrace:on
 -d:metrics # enable metric collection
 
+# Required to make up for the compiler's inability to invalidate the C file
+# (and object) cache on different command line arguments.
+--forceBuild
+

nimbus/api/.gitignore

@@ -1,2 +0,0 @@
-status_api_test
-libnimbus_api.so

nimbus/api/README.md

@@ -1,7 +0,0 @@
-This folder contains an experimental C API for using parts of the nimbus
-code from C/go in the status console client:
-
-https://github.com/status-im/status-console-client/
-
-It serves mainly as a proof-of-concept for now - there are several unresolved
-issues surrounding threading, inter-language communication, callbacks etc.

nimbus/api/build_go.sh

@@ -1,2 +0,0 @@
-#!/bin/sh 
-go build --ldflags '-extldflags "-static"' -o test main.go

nimbus/api/build_status_api.sh

@@ -1,12 +0,0 @@
-#!/bin/sh
-
-echo "[Cleaning up caches...]"
-rm -rf nimcache/
-rm -f libnimbus_api.so
-
-# ../env.sh nim c  --opt:speed --lineTrace:off --verbosity:2 status_api
-# gcc status_api.c ./libnimbus_api.so -lm -o xx
-
-# debug info
-../../env.sh nim c --debuginfo --opt:speed --lineTrace:off --verbosity:2 status_api
-gcc status_api.c ./libnimbus_api.so -lm -g -o status_api_test

nimbus/api/status_api.nim.cfg

@@ -1,4 +0,0 @@
--app:lib
-o:"libnimbus_api.so"
-noMain
--d:"chronicles_sinks=textlines"

nimbus/config.nim

@@ -752,6 +752,7 @@ LOGGING AND DEBUGGING OPTIONS:
     $ord(defaultNetwork)
   ]
 
+when declared(os.paramCount): # not available with `--app:lib`
   proc processArguments*(msg: var string): ConfigStatus =
     ## Process command line argument and update `NimbusConfiguration`.
     let config = getConfiguration()

wrappers/README.md

@@ -0,0 +1,21 @@
+This folder contains an experimental C wrapper for using parts of the Nimbus
+code from C/Go in the Status console client:
+
+https://github.com/status-im/status-console-client/
+
+It serves mainly as a proof-of-concept for now - there are several unresolved
+issues surrounding threading, inter-language communication, callbacks etc.
+
+To build the wrappers and the test programs, run from the top level directory:
+
+```bash
+make wrappers
+```
+
+Now you can run the test programs:
+
+```bash
+build/C_wrapper_test
+build/go_wrapper_test
+```
+

wrappers/wrapper.c

@@ -4,7 +4,7 @@
 #include <unistd.h>
 #include <time.h>
 
-#include "status_api.h"
+#include "wrapper.h"
 
 void NimMain();
 

wrappers/wrapper.go

@@ -6,8 +6,8 @@ import (
 	"time"
 )
 
-// #cgo LDFLAGS: /home/oskarth/git/nimbus/nimbus/libnimbus_api.so -lm
+// #cgo LDFLAGS: -Wl,-rpath,'$ORIGIN' -L${SRCDIR}/../build -lnimbus -lm
-// #include "libnim.h"
+// #include "wrapper.h"
 import "C"
 
 // Arrange that main.main runs on main thread.

wrappers/wrapper.nim

@@ -12,7 +12,7 @@ import
   nimcrypto/[bcmode, hmac, rijndael, pbkdf2, sha2, sysrand, utils, keccak, hash],
   eth/[keys, rlp, p2p], eth/p2p/rlpx_protocols/[whisper_protocol],
   eth/p2p/[discovery, enode, peer_pool], chronicles,
-  ../config
+  ../nimbus/config
 
 type
   CReceivedMessage* = object