From bd5406dfa9c5f952556e39eb3f0fecb4d4ee99ff Mon Sep 17 00:00:00 2001
From: normal <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Sat, 3 Feb 2018 07:25:21 +0000
Subject: [PATCH] compile.c: fix string Range optimization with FSL

The optimization in [Feature #13355] needs to be detected
differently to work with "frozen_string_literal: true"

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62177 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 compile.c                      | 29 +++++++++++++++++++++--------
 test/ruby/test_optimization.rb | 14 ++++++++------
 2 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/compile.c b/compile.c
index 315e2dc92e..c7d6a41f99 100644
--- a/compile.c
+++ b/compile.c
@@ -2454,6 +2454,20 @@ same_debug_pos_p(LINK_ELEMENT *iobj1, LINK_ELEMENT *iobj2)
     return TRUE;
 }
 
+static int
+is_frozen_putstring(INSN *insn, VALUE *op)
+{
+    if (IS_INSN_ID(insn, putstring)) {
+        *op = OPERAND_AT(insn, 0);
+        return 1;
+    }
+    else if (IS_INSN_ID(insn, putobject)) { /* frozen_string_literal */
+        *op = OPERAND_AT(insn, 0);
+        return RB_TYPE_P(*op, T_STRING);
+    }
+    return 0;
+}
+
 static int
 iseq_peephole_optimize(rb_iseq_t *iseq, LINK_ELEMENT *list, const int do_tailcallopt)
 {
@@ -2574,16 +2588,15 @@ iseq_peephole_optimize(rb_iseq_t *iseq, LINK_ELEMENT *list, const int do_tailcal
      * putobject "beg".."end"
      */
     if (IS_INSN_ID(iobj, checkmatch)) {
-	INSN *range = (INSN *)get_prev_insn(iobj);
-	INSN *beg, *end;
+        INSN *range = (INSN *)get_prev_insn(iobj);
+        INSN *beg, *end;
+        VALUE str_beg, str_end;
 
 	if (range && IS_INSN_ID(range, newrange) &&
-		(end = (INSN *)get_prev_insn(range)) != 0 &&
-		IS_INSN_ID(end, putstring) &&
-		(beg = (INSN *)get_prev_insn(end)) != 0 &&
-		IS_INSN_ID(beg, putstring)) {
-	    VALUE str_beg = OPERAND_AT(beg, 0);
-	    VALUE str_end = OPERAND_AT(end, 0);
+                (end = (INSN *)get_prev_insn(range)) != 0 &&
+                is_frozen_putstring(end, &str_end) &&
+                (beg = (INSN *)get_prev_insn(end)) != 0 &&
+                is_frozen_putstring(beg, &str_beg)) {
 	    int excl = FIX2INT(OPERAND_AT(range, 0));
 	    VALUE lit_range = rb_range_new(str_beg, str_end, excl);
 
diff --git a/test/ruby/test_optimization.rb b/test/ruby/test_optimization.rb
index e8b4f92d92..ac3440a665 100644
--- a/test/ruby/test_optimization.rb
+++ b/test/ruby/test_optimization.rb
@@ -557,12 +557,14 @@ class TestRubyOptimization < Test::Unit::TestCase
       when "1.8.0"..."1.8.8" then :bar
       end
     end;
-    iseq = RubyVM::InstructionSequence.compile(code)
-    insn = iseq.disasm
-    assert_match %r{putobject\s+#{Regexp.quote('"1.8.0"..."1.8.8"')}}, insn
-    assert_match %r{putobject\s+#{Regexp.quote('"2.0.0".."2.3.2"')}}, insn
-    assert_no_match(/putstring/, insn)
-    assert_no_match(/newrange/, insn)
+    [ nil, { frozen_string_literal: true } ].each do |opt|
+      iseq = RubyVM::InstructionSequence.compile(code, nil, nil, opt)
+      insn = iseq.disasm
+      assert_match %r{putobject\s+#{Regexp.quote('"1.8.0"..."1.8.8"')}}, insn
+      assert_match %r{putobject\s+#{Regexp.quote('"2.0.0".."2.3.2"')}}, insn
+      assert_no_match(/putstring/, insn)
+      assert_no_match(/newrange/, insn)
+    end
   end
 
   def test_branch_condition_backquote