THRIFT-5377 Remove Erlang R16 support
Client: erl
Patch: Sergey Yelin

This closes #2357
diff --git a/compiler/cpp/src/thrift/generate/t_erl_generator.cc b/compiler/cpp/src/thrift/generate/t_erl_generator.cc
index 3d4776c..af3492a 100644
--- a/compiler/cpp/src/thrift/generate/t_erl_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_erl_generator.cc
@@ -1262,5 +1262,4 @@
     erl,
     "Erlang",
     "    legacynames:     Output files retain naming conventions of Thrift 0.9.1 and earlier.\n"
-    "    maps:            Generate maps instead of dicts.\n"
-    "    otp16:           Generate non-namespaced dict and set instead of dict:dict and sets:set.\n")
+    "    maps:            Generate maps instead of dicts.\n")
diff --git a/configure.ac b/configure.ac
index 0dd7a6d..5abfe49 100755
--- a/configure.ac
+++ b/configure.ac
@@ -220,15 +220,9 @@
   if test -n "$ERL" -a -n "$ERLC" && test "x$REBAR" != "x" ; then
     have_erlang="yes"
 
-    # otp_release is simply a number (like "17") for OTP17+ while "R16..." for OTP16 or less.
-    # OTP version is currently only used for running tests.
-    if $ERL -eval 'erlang:display(erlang:system_info(otp_release)),halt().' -noshell | grep "^\"R" >/dev/null; then
-      erlang_otp16_or_less="yes"
-    fi
   fi
 fi
 AM_CONDITIONAL(WITH_ERLANG, [test "$have_erlang" = "yes"])
-AM_CONDITIONAL(ERLANG_OTP16, [test "$erlang_otp16_or_less" = "yes"])
 
 AX_THRIFT_LIB(nodejs, [Nodejs], yes)
 have_nodejs=no
diff --git a/test/erl/Makefile.am b/test/erl/Makefile.am
index 81913ee..145a763 100644
--- a/test/erl/Makefile.am
+++ b/test/erl/Makefile.am
@@ -19,11 +19,7 @@
 
 THRIFT_FILES = $(wildcard ../*.thrift)
 
-if ERLANG_OTP16
-ERL_FLAG = erl:otp16
-else
 ERL_FLAG = erl
-endif
 # make sure ThriftTest.thrift is generated last to prevent conflicts with other *.thrift files
 .generated: $(THRIFT_FILES)
 	for f in $(THRIFT_FILES) ; do \