make unicorn a git module

.gitignore

@@ -1,8 +1,6 @@
 node_modules
 artifacts
 cache
-unicorn
-unicorn2
 .*.swp
 venv
 .idea

.gitmodules

@@ -2,3 +2,6 @@
 	branch = l2minigeth
 	path = minigeth
 	url = git@github.com:ethereum-optimism/minigeth.git
+[submodule "unicorn"]
+	path = unicorn
+	url = git@github.com:unicorn-engine/unicorn.git

Makefile

@@ -1,11 +1,11 @@
 SHELL := /bin/bash
 
-build: unicorn submodule minigeth_mips minigeth_default_arch mipsevm contracts
+build: submodules unicorn minigeth_mips minigeth_default_arch mipsevm contracts
 
 unicorn:
 	./build_unicorn.sh
 
-submodule:
+submodules:
 	# CI will checkout submodules on its own (and fails on these commands)
 	if [[ -z "$$GITHUB_ENV" ]]; then \
 		git submodule init; \
@@ -31,11 +31,16 @@ nodejs:
 		npm install; \
 	fi
 
+# Must be a definition and not a rule, otherwise it gets only called once and
+# not before each test as we wish.
 define clear_cache
 	rm -rf /tmp/cannon
 	mkdir -p /tmp/cannon
 endef
 
+clear_cache:
+	$(call clear_cache)
+
 test_challenge:
 	$(call clear_cache)
 	# Build preimage cache for block 13284469
@@ -82,5 +87,5 @@ mrproper: clean
 	rm -rf node_modules
 	rm -rf mipigo/venv
 
-.PHONY: build unicorn submodule minigeth_mips minigeth_default_arch mipsevm contracts \
-	nodejs clean mrproper test_challenge test_mipsevm test_minigeth test
+.PHONY: build unicorn submodules minigeth_mips minigeth_default_arch mipsevm contracts \
+	nodejs clean mrproper test_challenge test_mipsevm test_minigeth test clear_cache

build_unicorn.sh

@@ -1,16 +1,15 @@
-#!/usr/bin/env bash
-if [[ ! -d unicorn2 ]]; then
-    git clone https://github.com/geohot/unicorn.git -b dev unicorn2
-    #git clone https://github.com/unicorn-engine/unicorn.git -b dev unicorn2
-fi
-
-cd unicorn2
-cmake . -DUNICORN_ARCH=mips -DCMAKE_BUILD_TYPE=Release
-#cmake . -DUNICORN_ARCH=mips -DCMAKE_BUILD_TYPE=Debug
+cd unicorn
+mkdir -p build
+cd build
+cmake .. -DUNICORN_ARCH=mips -DCMAKE_BUILD_TYPE=Release
 make -j8
 
+# The Go linker / runtime expects these to be there!
+cp libunicorn.so.1 ..
+cp libunicorn.so.2 ..
+
 # export LIBUNICORN_PATH for Github CI
 # TODO: is this actually needed?
 if [[ ! -z "$GITHUB_ENV" ]]; then
-    echo "LIBUNICORN_PATH=$(pwd)/unicorn2/" >> $GITHUB_ENV
+    echo "LIBUNICORN_PATH=$(pwd)/unicorn/" >> $GITHUB_ENV
 fi

mipsevm/go.mod

@@ -4,7 +4,7 @@ go 1.17
 
 replace github.com/ethereum/go-ethereum => ../minigeth
 
-replace github.com/unicorn-engine/unicorn => ../unicorn2
+replace github.com/unicorn-engine/unicorn => ../unicorn
 
 require (
 	github.com/ethereum/go-ethereum v1.10.8