Macro definitions within enum declarations

closes #15

spec/headers/simple.h

@@ -52,6 +52,13 @@ enum some_enum_3 {
 };
 enum some_enum_3 just_some_enum_3();
 
+enum {
+  SOCK_STREAM = 1,
+  #define SOCK_STREAM SOCK_STREAM
+  SOCK_DGRAM = 2,
+  #define SOCK_DGRAM SOCK_DGRAM
+};
+
 typedef struct { int x; } some_struct_1;
 some_struct_1 just_some_struct_1();
 

spec/lib_body_transformer_spec.cr

@@ -119,11 +119,18 @@ describe LibBodyTransformer do
     )
 
   assert_transform "simple",
-    "fun just_some_struct_1", %(
-      struct SomeStruct1
-        x : LibC::Int
+    "fun just_some_enum_3", %(
+      enum SomeEnum3
+        NodePara = 1
+        NodeLink = 2
       end
-      fun just_some_struct_1 : SomeStruct1
+      fun just_some_enum_3 : SomeEnum3
+    )
+
+  assert_transform "simple",
+    "SOCK_STREAM = SOCK_STREAM\nSOCK_DGRAM = SOCK_DGRAM", %(
+      SOCK_STREAM = 1
+      SOCK_DGRAM = 2
     )
 
   assert_transform "simple",

src/crystal_lib/lib_body_transformer.cr

@@ -5,7 +5,7 @@ require "compiler/crystal/semantic/*"
 
 class CrystalLib::LibBodyTransformer < Crystal::Transformer
   def initialize(nodes : Array(CrystalLib::ASTNode))
-    @nodes = nodes.index_by &.name
+    @nodes = nodes
     @mapper = TypeMapper.new
   end
 
@@ -32,15 +32,33 @@ class CrystalLib::LibBodyTransformer < Crystal::Transformer
     name = node.value.to_s
     match = find_node(name)
     raise "can't find constant #{name}" unless match.is_a?(Define)
+    value = match.value
+
+    if name == match.value
+      # macro definition references an enum value
+      if enum_value = find_enum_value(name)
+        value = enum_value.value.to_s
+      end
+    end
 
     begin
-      node.value = Crystal::Parser.parse(match.value)
+      node.value = Crystal::Parser.parse(value)
     rescue ex : Crystal::Exception
-      raise "can't parse value of constant #{name}: #{match.value}"
+      raise "can't parse value of constant #{name}: #{value}"
     end
     node
   end
 
+  private def find_enum_value(name)
+    @nodes.each do |node|
+      next unless node.is_a?(CrystalLib::Enum)
+      node.values.each do |enum_value|
+        return enum_value if enum_value.name == name
+      end
+    end
+    nil
+  end
+
   def transform(node : Crystal::ExternalVar)
     name = node.real_name || node.name
 
@@ -56,7 +74,7 @@ class CrystalLib::LibBodyTransformer < Crystal::Transformer
   end
 
   def find_node(name)
-    @nodes[name]?
+    @nodes.find { |node| node.name == name }
   end
 
   def check_pending_definitions(node)