Added @def inside macros that takes the value of the current method. …

…Fixes #1582

CHANGELOG.md

@@ -9,6 +9,7 @@
 * Added support for AArch64 (thanks @ysbaddaden)
 * Added support for LLVM 3.9 (thanks @ysbaddaden)
 * Added `__END_LINE__` magic constant in method default arguments: will be the last line of a call (if the call has a block, it will be the last line of that block)
+* Added `@def` inside macros that takes the value of the current method
 * API docs have a nicer style now (thanks @samueleaton)
 * Slight improvement to debugging support (thanks @ggiraldez)
 * Added iteration times to `Benchmark.ips` (thanks @RX14)

spec/compiler/codegen/macro_spec.cr

@@ -1466,4 +1466,28 @@ describe "Code gen: macro" do
       Foo.x
       ), inject_primitives: false).to_i.should eq(1)
   end
+
+  it "expands @def in inline macro" do
+    run(%(
+      def foo
+        {{@def.name.stringify}}
+      end
+
+      foo
+      )).to_string.should eq("foo")
+  end
+
+  it "expands @def in macro" do
+    run(%(
+      macro foo
+        {{@def.name.stringify}}
+      end
+
+      def bar
+        foo
+      end
+
+      bar
+      )).to_string.should eq("bar")
+  end
 end

src/compiler/crystal/macros/interpreter.cr

@@ -3,7 +3,7 @@ module Crystal
     getter last : ASTNode
     property free_vars : Hash(String, TypeVar)?
 
-    def self.new(program, scope : Type, path_lookup : Type, a_macro : Macro, call)
+    def self.new(program, scope : Type, path_lookup : Type, a_macro : Macro, call, a_def : Def? = nil)
       vars = {} of String => ASTNode
       splat_index = a_macro.splat_index
       double_splat = a_macro.double_splat
@@ -68,14 +68,14 @@ module Crystal
         vars[macro_block_arg.name] = call_block || Nop.new
       end
 
-      new(program, scope, path_lookup, a_macro.location, vars, call.block)
+      new(program, scope, path_lookup, a_macro.location, vars, call.block, a_def)
     end
 
     record MacroVarKey, name : String, exps : Array(ASTNode)?
 
     def initialize(@program : Program,
                    @scope : Type, @path_lookup : Type, @location : Location?,
-                   @vars = {} of String => ASTNode, @block : Block? = nil)
+                   @vars = {} of String => ASTNode, @block : Block? = nil, @def : Def? = nil)
       @str = MemoryIO.new(512) # Can't be String::Builder because of `{{debug()}}
       @last = Nop.new
     end
@@ -397,8 +397,8 @@ module Crystal
             produce_tuple = node.names.first == "T"
           when GenericInstanceType
             produce_tuple = ((splat_index = path_lookup.splat_index) &&
-                             path_lookup.type_vars.keys.index(node.names.first) == splat_index) ||
-                            (path_lookup.double_variadic? && path_lookup.type_vars.first_key == node.names.first)
+              path_lookup.type_vars.keys.index(node.names.first) == splat_index) ||
+              (path_lookup.double_variadic? && path_lookup.type_vars.first_key == node.names.first)
           else
             produce_tuple = false
           end
@@ -444,6 +444,8 @@ module Crystal
       when "@type"
         target = @scope == @program.class_type ? @scope : @scope.instance_type
         return @last = TypeNode.new(target)
+      when "@def"
+        return @last = @def || NilLiteral.new
       end
 
       node.raise "unknown macro instance var: '#{node.name}'"

src/compiler/crystal/macros/macros.cr

@@ -32,14 +32,14 @@ class Crystal::Program
     filename
   end
 
-  def expand_macro(a_macro : Macro, call : Call, scope : Type, path_lookup : Type? = nil)
-    interpreter = MacroInterpreter.new self, scope, path_lookup || scope, a_macro, call
+  def expand_macro(a_macro : Macro, call : Call, scope : Type, path_lookup : Type? = nil, a_def : Def? = nil)
+    interpreter = MacroInterpreter.new self, scope, path_lookup || scope, a_macro, call, a_def
     a_macro.body.accept interpreter
     interpreter.to_s
   end
 
-  def expand_macro(node : ASTNode, scope : Type, path_lookup : Type? = nil, free_vars = nil)
-    interpreter = MacroInterpreter.new self, scope, path_lookup || scope, node.location
+  def expand_macro(node : ASTNode, scope : Type, path_lookup : Type? = nil, free_vars = nil, a_def : Def? = nil)
+    interpreter = MacroInterpreter.new self, scope, path_lookup || scope, node.location, def: a_def
     interpreter.free_vars = free_vars
     node.accept interpreter
     interpreter.to_s

src/compiler/crystal/semantic/semantic_visitor.cr

@@ -14,6 +14,7 @@ abstract class Crystal::SemanticVisitor < Crystal::Visitor
 
   @free_vars : Hash(String, TypeVar)?
   @path_lookup : Type?
+  @untyped_def : Def?
   @typed_def : Def?
   @block : Block?
 
@@ -263,7 +264,7 @@ abstract class Crystal::SemanticVisitor < Crystal::Visitor
     generated_nodes = expand_macro(the_macro, node) do
       old_args = node.args
       node.args = args
-      expanded = @program.expand_macro the_macro, node, expansion_scope, @path_lookup
+      expanded = @program.expand_macro the_macro, node, expansion_scope, @path_lookup, @untyped_def
       node.args = old_args
       expanded
     end
@@ -363,7 +364,7 @@ abstract class Crystal::SemanticVisitor < Crystal::Visitor
     the_macro = Macro.new("macro_#{node.object_id}", [] of Arg, node).at(node.location)
 
     generated_nodes = expand_macro(the_macro, node, mode: mode) do
-      @program.expand_macro node, (@scope || current_type), @path_lookup, @free_vars
+      @program.expand_macro node, (@scope || current_type), @path_lookup, @free_vars, @untyped_def
     end
 
     node.expanded = generated_nodes