Fixed #3040: Compiler crash when using responds_to? in case statement…

… switch
crystal-lang · Jul 25, 2016 · 299bbdd · 299bbdd
1 parent afff13c
commit 299bbdd
Showing 4 changed files with 46 additions and 6 deletions.
diff --git a/spec/compiler/normalize/case_spec.cr b/spec/compiler/normalize/case_spec.cr
@@ -33,6 +33,22 @@ describe "Normalize: case" do
     assert_expand "case x; when .foo(1); 2; end", "__temp_1 = x\nif __temp_1.foo(1)\n  2\nend"
   end
 
+  it "normalizes case with implicit responds_to? (#3040)" do
+    assert_expand "case x; when .responds_to?(:foo); 2; end", "__temp_1 = x\nif __temp_1.responds_to?(:foo)\n  2\nend"
+  end
+
+  it "normalizes case with implicit is_a? (#3040)" do
+    assert_expand "case x; when .is_a?(T); 2; end", "__temp_1 = x\nif __temp_1.is_a?(T)\n  2\nend"
+  end
+
+  it "normalizes case with implicit as (#3040)" do
+    assert_expand "case x; when .as(T); 2; end", "__temp_1 = x\nif __temp_1.as(T)\n  2\nend"
+  end
+
+  it "normalizes case with implicit as? (#3040)" do
+    assert_expand "case x; when .as?(T); 2; end", "__temp_1 = x\nif __temp_1.as?(T)\n  2\nend"
+  end
+
   it "normalizes case with assignment" do
     assert_expand "case x = 1; when 2; 3; end", "x = 1\nif 2 === x\n  3\nend"
   end

diff --git a/spec/compiler/parser/parser_spec.cr b/spec/compiler/parser/parser_spec.cr
@@ -888,6 +888,10 @@ describe "Parser" do
   it_parses "case\n1\nwhen 1\n2\nend\nif a\nend", [Case.new(1.int32, [When.new([1.int32] of ASTNode, 2.int32)]), If.new("a".call)]
 
   it_parses "case 1\nwhen .foo\n2\nend", Case.new(1.int32, [When.new([Call.new(ImplicitObj.new, "foo")] of ASTNode, 2.int32)])
+  it_parses "case 1\nwhen .responds_to?(:foo)\n2\nend", Case.new(1.int32, [When.new([RespondsTo.new(ImplicitObj.new, "foo")] of ASTNode, 2.int32)])
+  it_parses "case 1\nwhen .is_a?(T)\n2\nend", Case.new(1.int32, [When.new([IsA.new(ImplicitObj.new, "T".path)] of ASTNode, 2.int32)])
+  it_parses "case 1\nwhen .as(T)\n2\nend", Case.new(1.int32, [When.new([Cast.new(ImplicitObj.new, "T".path)] of ASTNode, 2.int32)])
+  it_parses "case 1\nwhen .as?(T)\n2\nend", Case.new(1.int32, [When.new([NilableCast.new(ImplicitObj.new, "T".path)] of ASTNode, 2.int32)])
   it_parses "case when 1\n2\nend", Case.new(nil, [When.new([1.int32] of ASTNode, 2.int32)])
   it_parses "case \nwhen 1\n2\nend", Case.new(nil, [When.new([1.int32] of ASTNode, 2.int32)])
   it_parses "case {1, 2}\nwhen {3, 4}\n5\nend", Case.new(TupleLiteral.new([1.int32, 2.int32] of ASTNode), [When.new([TupleLiteral.new([3.int32, 4.int32] of ASTNode)] of ASTNode, 5.int32)])

diff --git a/src/compiler/crystal/semantic/literal_expander.cr b/src/compiler/crystal/semantic/literal_expander.cr
@@ -552,6 +552,12 @@ module Crystal
 
       right_side = temp_var.clone
 
+      check_implicit_obj Call
+      check_implicit_obj RespondsTo
+      check_implicit_obj IsA
+      check_implicit_obj Cast
+      check_implicit_obj NilableCast
+
       case cond
       when NilLiteral
         return IsA.new(right_side, Path.global("Nil"))
@@ -560,10 +566,6 @@ module Crystal
       when Call
         obj = cond.obj
         case obj
-        when ImplicitObj
-          implicit_call = cond.clone.as(Call)
-          implicit_call.obj = temp_var.clone
-          return implicit_call
         when Path
           if cond.name == "class"
             return IsA.new(right_side, Metaclass.new(obj.clone).at(obj))
@@ -578,6 +580,16 @@ module Crystal
       Call.new(cond, "===", right_side)
     end
 
+    macro check_implicit_obj(type)
+      if cond.is_a?({{type}})
+        if (obj = cond.obj).is_a?(ImplicitObj)
+          implicit_call = cond.clone.as({{type}})
+          implicit_call.obj = temp_var.clone
+          return implicit_call
+        end
+      end
+    end
+
     private def regex_new_call(node, value)
       Call.new(Path.global("Regex").at(node), "new", value, regex_options(node)).at(node)
     end

diff --git a/src/compiler/crystal/syntax/parser.cr b/src/compiler/crystal/syntax/parser.cr
@@ -2479,8 +2479,16 @@ module Crystal
     def parse_when_expression(cond)
       if cond && @token.type == :"."
         next_token
-        call = parse_var_or_call(force_call: true).as(Call)
-        call.obj = ImplicitObj.new
+        call = parse_var_or_call(force_call: true)
+        case call
+        when Call        then call.obj = ImplicitObj.new
+        when RespondsTo  then call.obj = ImplicitObj.new
+        when IsA         then call.obj = ImplicitObj.new
+        when Cast        then call.obj = ImplicitObj.new
+        when NilableCast then call.obj = ImplicitObj.new
+        else
+          raise "Bug: expected Call, RespondsTo, IsA, Cast or NilableCast"
+        end
         call
       else
         parse_op_assign_no_control