Fix opam build by making libff a git submodule

.gitignore

@@ -59,5 +59,6 @@ src/stdlib/*.json
 .DS_Store
 
 # external dependencies
-_deps/*
+deps/libff/build/
+deps/libff/install/
 

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "deps/libff/src"]
+	path = deps/libff/src
+	url = https://github.com/scipr-lab/libff

Makefile

@@ -75,7 +75,7 @@ clean:
 	dune clean
 # Remove remaining files/folders ignored by git as defined in .gitignore (-X)
 # but keeping a local opam switch and other dependencies built.
-	git clean -dfXq --exclude=\!_deps/** --exclude=\!_opam/**
+	git clean -dfXq --exclude=\!_opam/**
 
 # Build a standalone scilla docker
 docker:

README.md

@@ -26,6 +26,11 @@ A comprehensive documentation on Scilla, its features and constructs can be foun
 
 We suggest users to use the latest release of Scilla available [here](https://github.com/Zilliqa/scilla/releases).
 
+If you'd like to hack on Scilla, clone it with all of its submodules:
+```shell
+git clone --jobs 4 --recurse-submodules https://github.com/Zilliqa/scilla/
+```
+
 ### Build requirements
 
 Platform specific instructions for setting up your system for building Scilla can be

scilla.opam

@@ -30,8 +30,8 @@ depends: [
   "patdiff" {with-test & (>= "v0.12.1" & < "v0.13~")}
 ]
 build: [
-  [ "dune" "build" "-j" jobs "@install" ]
-  [ "dune" "runtest" "-p" name "-j" jobs ] {with-test}
+  [ "./scripts/libff.sh" ]
+  [ "dune" "build" "-p" name "-j" jobs ]
 ]
 synopsis: "Scilla: Safe-By-Design Smart Contract Language"
 description: """

scripts/libff.sh

@@ -1,11 +1,13 @@
 #!/usr/bin/env bash
+
+set -ev
+
 # This script is expected to be executed from Scilla root
 # $./scripts/libff.sh
-# The script fetches, builds and installs libff in the
+# The script builds and installs libff in the
 # _build directory of Scilla root.
 
-libffurl="https://github.com/scipr-lab/libff.git"
-libffdir="_deps/libff"
+libffdir="deps/libff"
 
 # Check if CWD has `scilla.opam`, assuring us that it's the root.
 if [[ ! -f scilla.opam ]]
@@ -21,15 +23,9 @@ then
     exit 0
 fi
 
-mkdir -p $libffdir
 cd $libffdir
 mkdir -p build install
-echo "Cloning libff into ${libffdir}/src"
-git clone $libffurl src
 cd src
-echo "Fetching submodules for libff"
-git submodule init && git submodule update
-git checkout f2067162520f91438b44e71a2cab2362f1c3cab4
 echo "Installing libff into ${libffdir}/install"
 cd ../build
 cmake ../src -DCMAKE_INSTALL_PREFIX=../install -DCMAKE_POSITION_INDEPENDENT_CODE=1 -DWITH_PROCPS=OFF

src/base/cpp/config/discover.ml

@@ -29,8 +29,8 @@ let () =
   in
 
   (* This file runs in _build/default/src/base/cpp.
-   * libff is installed in _deps/libff/install. *)
-  let libff_dir = Sys.getcwd() ^ "/../../../../../_deps/libff/install" in
+   * libff is installed in deps/libff/install. *)
+  let libff_dir = Sys.getcwd() ^ "/../../../../../deps/libff/install" in
   let libff_include_dir = libff_dir ^ "/include" in
   let libff_lib_dir = libff_dir ^ "/lib" in
   if not (Sys.file_exists libff_include_dir) || not (Sys.file_exists libff_lib_dir)