Compiler: fixed #3314: ICE on typeof(yield) in uninitialized with ret…

…urn in block
crystal-lang · Sep 16, 2016 · f0bacbc · f0bacbc
1 parent 9bd2294
commit f0bacbc
Showing 5 changed files with 44 additions and 7 deletions.
diff --git a/spec/compiler/codegen/uninitialized_spec.cr b/spec/compiler/codegen/uninitialized_spec.cr
@@ -87,4 +87,22 @@ describe "Code gen: uninitialized" do
       a
       )).to_i.should eq(3)
   end
+
+  it "works with uninitialized NoReturn (#3314)" do
+    codegen(%(
+      def foo
+        x = uninitialized NoReturn
+        if 1
+          x = yield
+        end
+        x
+      end
+
+      def bar
+        foo { return }
+      end
+
+      bar
+      ), inject_primitives: false)
+  end
 end
diff --git a/spec/compiler/semantic/uninitialized_spec.cr b/spec/compiler/semantic/uninitialized_spec.cr
@@ -112,4 +112,18 @@ describe "Semantic: uninitialized" do
         "use a more specific type"
     end
   end
+
+  it "works with uninitialized NoReturn (#3314)" do
+    assert_type(%(
+      def foo
+        x = uninitialized typeof(yield)
+      end
+
+      def bar
+        foo { return }
+      end
+
+      bar
+      )) { nil_type }
+  end
 end
diff --git a/spec/spec_helper.cr b/spec/spec_helper.cr
@@ -273,8 +273,8 @@ def parse(string, wants_doc = false)
   parser.parse
 end
 
-def codegen(code)
-  code = inject_primitives(code)
+def codegen(code, inject_primitives = true)
+  code = inject_primitives(code) if inject_primitives
   node = parse code
   result = semantic node
   result.program.codegen result.node, single_module: false

diff --git a/src/compiler/crystal/codegen/codegen.cr b/src/compiler/crystal/codegen/codegen.cr
@@ -1032,6 +1032,8 @@ module Crystal
     def visit(node : Var)
       var = context.vars[node.name]?
       if var
+        return unreachable if var.type.no_return?
+
         # Special variables always have an extra pointer
         already_loaded = (node.special_var? ? false : var.already_loaded)
         @last = downcast var.pointer, node.type, var.type, already_loaded
@@ -1220,9 +1222,7 @@ module Crystal
     end
 
     def declare_var(var)
-      return if var.no_returns?
-
-      context.vars[var.name] ||= LLVMVar.new(alloca(llvm_type(var.type), var.name), var.type)
+      context.vars[var.name] ||= LLVMVar.new(var.no_returns? ? llvm_nil : alloca(llvm_type(var.type), var.name), var.type)
     end
 
     def declare_lib_var(name, type, thread_local)

diff --git a/src/compiler/crystal/semantic/main_visitor.cr b/src/compiler/crystal/semantic/main_visitor.cr
@@ -374,8 +374,13 @@ module Crystal
         node.declared_type.accept self
         @in_type_args -= 1
 
-        var_type = check_declare_var_type node, node.declared_type.type, "a variable"
-        var.type = var_type
+        # TOOD: should we be using a binding here to recompute the type?
+        if declared_type = node.declared_type.type?
+          var_type = check_declare_var_type node, declared_type, "a variable"
+          var.type = var_type
+        else
+          var.type = program.no_return
+        end
 
         meta_var = @meta_vars[var.name] ||= new_meta_var(var.name)
         if (existing_type = meta_var.type?) && existing_type != var_type