Revert "Implement Regex engine on PCRE2"

spec/std/regex_spec.cr

@@ -200,16 +200,12 @@ describe "Regex" do
       /foo/.matches?("foo", options: Regex::Options::ANCHORED).should be_true
     end
 
-    it "doesn't crash with a large single line string" do
-      {% if Regex::Engine.resolve.name == "Regex::PCRE" %}
-        LibPCRE.config LibPCRE::CONFIG_JIT, out jit_enabled
-        pending! "PCRE JIT mode not available." unless 1 == jit_enabled
-      {% end %}
+    it "matches a large single line string" do
+      LibPCRE.config LibPCRE::CONFIG_JIT, out jit_enabled
+      pending! "PCRE JIT mode not available." unless 1 == jit_enabled
 
       str = File.read(datapath("large_single_line_string.txt"))
-      str.matches?(/^(?:[A-Za-z0-9+\/]{4})*(?:[A-Za-z0-9+\/]{2}==|[A-Za-z0-9+\/]{3}=)?$/)
-      # We don't care whether this actually matches or not, it's just to make
-      # sure the engine does not stack overflow with a large string.
+      str.matches?(/^(?:[A-Za-z0-9+\/]{4})*(?:[A-Za-z0-9+\/]{2}==|[A-Za-z0-9+\/]{3}=)?$/).should be_false
     end
   end
 
@@ -426,12 +422,6 @@ describe "Regex" do
 
   it ".error?" do
     Regex.error?("(foo|bar)").should be_nil
-    Regex.error?("(foo|bar").should eq(
-      if Regex::Engine.to_s == "Regex::PCRE2"
-        "missing closing parenthesis at 8"
-      else
-        "missing ) at 8"
-      end
-    )
+    Regex.error?("(foo|bar").should eq "missing ) at 8"
   end
 end

src/regex/engine.cr

@@ -1,11 +1,4 @@
-{% if flag?(:use_pcre2) || (!flag?(:use_pcre) && !flag?(:win32) && `hash pkg-config 2> /dev/null && pkg-config --silence-errors --modversion libpcre2-8 || printf %s false` != "false") %}
-  require "./pcre2"
+require "./pcre"
 
-  # :nodoc:
-  alias Regex::Engine = PCRE2
-{% else %}
-  require "./pcre"
-
-  # :nodoc:
-  alias Regex::Engine = PCRE
-{% end %}
+# :nodoc:
+alias Regex::Engine = PCRE