Replace build system with port_compiler

It appears that whatever previous prevented me from using the rebar3
port_compiler is no longer an issue. This change allows rebar2 and
rebar3 compilation by relying on port_compiler for rebar3 and
reverting to standard rebar2 otherwise.

.gitignore

@@ -2,6 +2,7 @@
 .rebar
 .tool-versions
 .jiffy.dev
+.jiffy-compile-check
 *.app
 *.beam
 *.d

rebar.config

@@ -7,6 +7,10 @@
 ]}.
 
 {port_env, [
+    % Drop -lerl_interface
+    {"ERL_LDFLAGS", " -L$ERL_EI_LIBDIR -lei"},
+    {"win32", "ERL_LDFLAGS", " /LIBPATH:$ERL_EI_LIBDIR ei.lib"},
+
     {".*", "FLTO_FLAG", ""},
 
     {"(linux|solaris|freebsd|netbsd|openbsd|dragonfly|darwin|gnu)",
@@ -35,6 +39,3 @@
 {eunit_opts, [
     verbose
 ]}.
-
-{pre_hooks, [{"", compile, "escript enc compile"}]}.
-{post_hooks, [{"", clean, "escript enc clean"}]}.

rebar.config.script

@@ -17,7 +17,7 @@ Config1 = case lists:keyfind(erl_opts, 1, CONFIG) of
         CONFIG ++ [{erl_opts, ErlOpts}]
 end,
 
-case os:type() of
+Config2 = case os:type() of
     {unix, _} ->
         CC = case os:getenv("CC") of
             false -> "cc";
@@ -36,4 +36,21 @@ case os:type() of
         end;
     _ ->
         Config1
+end,
+
+IsRebar3 = code:which(rebar3) /= non_existing,
+case IsRebar3 of
+    false ->
+        Config2;
+    true ->
+        Config2 ++ [
+            {plugins, [{pc, "~> 1.0"}]},
+            {artifacts, ["priv/jiffy.so"]},
+            {provider_hooks, [
+                {post, [
+                    {compile, {pc, compile}},
+                    {clean, {pc, clean}}
+                ]}
+            ]}
+        ]
 end.

test/compile-check.py

@@ -0,0 +1,131 @@
+#!/usr/bin/env python3
+
+import os
+import shutil
+import subprocess as sp
+
+TEST_DIR = ".jiffy-compile-check"
+
+ERLANG_VMS = {
+    15: "R15B03-1",
+    16: "R16B03-1",
+    17: "17.5.6.10",
+    18: "18.3.4.11",
+    19: "19.3.6.13",
+    20: "20.3.8.26",
+    21: "21.3.8.24",
+    22: "22.3.4.24",
+    23: "23.3.4.11",
+    24: "24.2.1",
+    25: "25.0-rc1"
+}
+
+MAX_ERLANG = max(ERLANG_VMS.keys())
+
+ERLANG_COMPATIBILITY = [
+    (15, 24),
+    (22, MAX_ERLANG)
+]
+
+# The rebar3 compatibility matrix was created using the
+# ranges in this blog post:
+#   https://ferd.ca/you-ve-got-to-upgrade-rebar3.html
+REBAR_MATRIX = [
+    ("2.6.4", 15, MAX_ERLANG),
+    ("3.7.0", 17, 21),
+    ("3.13.2", 18, 22),
+    ("3.15.2", 19, 23),
+    ("3.16.0", 22, 24),
+    ("3.18.0", 24, MAX_ERLANG)
+]
+
+JTAPP2_URL = "https://github.com/davisp/jtapp2"
+REBAR2_URL = "https://github.com/rebar/rebar"
+REBAR3_URL = "https://github.com/erlang/rebar3"
+
+
+def init_test_dir():
+    if not os.path.exists(TEST_DIR):
+        os.mkdir(TEST_DIR)
+    os.chdir(TEST_DIR)
+    if not os.path.exists("jiffy"):
+        sp.check_call("git clone .. jiffy", shell=True)
+    if not os.path.exists("jtapp2"):
+        sp.check_call("git clone {}".format(JTAPP2_URL), shell=True)
+    if not os.path.exists("rebar"):
+        sp.check_call("git clone {}".format(REBAR2_URL), shell=True)
+    if not os.path.exists("rebar3"):
+        sp.check_call("git clone {}".format(REBAR3_URL), shell=True)
+
+
+def gen_tests():
+    # Check each rebar version on its last supported VM
+    for (vsn, min_erl, max_erl) in REBAR_MATRIX:
+        yield(vsn, ERLANG_VMS[max_erl], ERLANG_VMS[max_erl])
+
+    # Mixed VM tests
+    for (min_compat, max_compat) in ERLANG_COMPATIBILITY:
+        for (vsn, min_erl, max_erl) in REBAR_MATRIX:
+            if max_erl < min_compat:
+                continue
+            if min_erl > max_compat:
+                continue
+            build_vm = max(min_compat, min_erl)
+            test_vm = min(max_compat, max_erl)
+            yield (vsn, ERLANG_VMS[build_vm], ERLANG_VMS[test_vm])
+
+
+def run_test(rebar_vsn, build_vm, test_vm):
+    msg = "Checking rebar {} built with {} to compile on {}"
+    print(msg.format(rebar_vsn, build_vm, test_vm))
+
+    if rebar_vsn[:2] == "2.":
+        rebar_dir = "rebar"
+    else:
+        rebar_dir = "rebar3"
+    rebar_path = "../{}/{}".format(rebar_dir, rebar_dir)
+
+    cmds = [
+        "cd {} && git checkout -q {}".format(rebar_dir, rebar_vsn),
+        "cd {} && git clean -ffxd".format(rebar_dir),
+        "cd {} && asdf local erlang {}".format(rebar_dir, build_vm),
+        "cd {} && ./bootstrap".format(rebar_dir),
+        "cd jiffy && git clean -ffxd",
+        "cd jiffy && asdf local erlang {}".format(test_vm),
+        "cd jiffy && {} get-deps".format(rebar_path),
+        "cd jiffy && {} compile".format(rebar_path),
+        "cd jiffy && {} eunit".format(rebar_path),
+        "cd jtapp2 && git clean -ffxd",
+        "cd jtapp2 && asdf local erlang {}".format(test_vm),
+        "cd jtapp2 && {} get-deps".format(rebar_path),
+        "cd jtapp2 && {} compile".format(rebar_path),
+        "cd jtapp2 && {} eunit".format(rebar_path)
+    ]
+    for cmd in cmds:
+        sp.check_output(cmd, shell=True)
+
+    cmd = "cd jiffy && {} --version".format(rebar_path)
+    vsn = sp.check_output(cmd, shell=True).split()
+    assert vsn[1].decode("utf-8") == rebar_vsn
+
+    if rebar_vsn.startswith("2."):
+        assert build_vm.startswith(vsn[2].decode("utf-8"))
+    else:
+        # For some reason rebar3 switched to reporting the VM
+        # that is executing rebar3, not the version that was
+        # used to compile it.
+        assert test_vm.startswith(vsn[4].decode("utf-8"))
+
+    cmd = "erl -noshell -eval 'io:fwrite(erlang:system_info(otp_release)), halt().'"
+    otp = sp.check_output("cd jiffy && {}".format(cmd), shell=True).decode("utf-8")
+    assert test_vm.startswith(otp)
+
+
+def main():
+    init_test_dir()
+    for (rebar_vsn, build_vm, test_vm) in gen_tests():
+        run_test(rebar_vsn, build_vm, test_vm)
+
+
+if __name__ == "__main__":
+    main()