Add functions to validate OTP release in use

In the spirit of Original Rebar's "require_min_otp_vsn", this adds
rebar_utils:check_min_otp_version/1 (taking a string containing the
minimum version) and rebar_utils:check_blacklisted_otp_versions/1
(taking a list of regular expression strings), as well as tests in
rebar_utils_SUITE. They're currently only called by the tests-
how/where to best place calls to them from non-test code needs to be
determined (at which point two corresponding rebar.config keys can be
supported). For example, the version probably shouldn't be enforced when
just running "rebar3 help".

1 files changed, 45 insertions, 1 deletions

diff --git a/src/rebar_utils.erl b/src/rebar_utils.erl
index 6eb4f4b..26125a3 100644
--- a/src/rebar_utils.erl
+++ b/src/rebar_utils.erl
@@ -60,7 +60,9 @@
          set_httpc_options/0,
          escape_chars/1,
          escape_double_quotes/1,
-         escape_double_quotes_weak/1]).
+         escape_double_quotes_weak/1,
+         check_min_otp_version/1,
+         check_blacklisted_otp_versions/1]).
 
 %% for internal use only
 -export([otp_release/0]).
@@ -299,10 +301,52 @@ line_count(PatchLines) ->
     Tokenized = string:tokens(PatchLines, "\n"),
     {ok, length(Tokenized)}.
 
+check_min_otp_version(undefined) ->
+    ok;
+check_min_otp_version(MinOtpVersion) ->
+    %% Fully-qualify with ?MODULE so the function can be meck'd in rebar_utils_SUITE
+    OtpRelease = ?MODULE:otp_release(),
+    {MinMajor, MinMinor} = split_version(MinOtpVersion),
+    {OtpMajor, OtpMinor} = split_version(OtpRelease),
+
+    case {OtpMajor, OtpMinor} >= {MinMajor, MinMinor} of
+        true ->
+            ?DEBUG("~s satisfies the requirement for minimum OTP version ~s",
+                [OtpRelease, MinOtpVersion]);
+        false ->
+            ?ABORT("OTP release ~s or later is required. Verion in use: ~s",
+                [MinOtpVersion, OtpRelease])
+    end.
+
+check_blacklisted_otp_versions(undefined) ->
+    ok;
+check_blacklisted_otp_versions(BlacklistedRegexes) ->
+    %% Fully-qualify with ?MODULE so the function can be meck'd in rebar_utils_SUITE
+    OtpRelease = ?MODULE:otp_release(),
+    lists:foreach(
+        fun(BlacklistedRegex) -> abort_if_blacklisted(BlacklistedRegex, OtpRelease) end,
+        BlacklistedRegexes).
+
+abort_if_blacklisted(BlacklistedRegex, OtpRelease) ->
+    case re:run(OtpRelease, BlacklistedRegex, [{capture, none}]) of
+        match ->
+            ?ABORT("OTP release ~s matches blacklisted version ~s",
+                [OtpRelease, BlacklistedRegex]);
+            nomatch ->
+                ?DEBUG("~s does not match blacklisted OTP version ~s",
+                [OtpRelease, BlacklistedRegex])
+    end.
+
+
 %% ====================================================================
 %% Internal functions
 %% ====================================================================
 
+split_version(Version) ->
+    list_to_tuple(lists:map(
+        fun(S) -> list_to_integer(S) end,
+        string:tokens(Version, "."))).
+
 otp_release() ->
     otp_release1(erlang:system_info(otp_release)).