Thrift compiler frontend support for constants

Summary: The parser now accepts constants and adds them into the parse tree


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@664880 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/compiler/cpp/src/parse/t_const.h b/compiler/cpp/src/parse/t_const.h
new file mode 100644
index 0000000..77d7e18
--- /dev/null
+++ b/compiler/cpp/src/parse/t_const.h
@@ -0,0 +1,41 @@
+#ifndef T_CONST_H
+#define T_CONST_H
+
+#include "t_type.h"
+#include "t_const_value.h"
+
+/**
+ * A const is a constant value defined across languages that has a type and
+ * a value. The trick here is that the declared type might not match the type
+ * of the value object, since that is not determined until after parsing the
+ * whole thing out.
+ *
+ * @author Mark Slee <mcslee@facebook.com>
+ */
+class t_const {
+ public:
+  t_const(t_type* type, std::string name, t_const_value* value) :
+    type_(type),
+    name_(name),
+    value_(value) {}
+
+  t_type* get_type() const {
+    return type_;
+  }
+
+  std::string get_name() const {
+    return name_;
+  }
+
+  t_const_value* get_value() const {
+    return value_;
+  }
+
+ private:
+  t_type* type_;
+  std::string name_;
+  t_const_value* value_;
+};
+
+#endif
+
diff --git a/compiler/cpp/src/parse/t_enum.h b/compiler/cpp/src/parse/t_enum.h
index 002ca82..5fe6f89 100644
--- a/compiler/cpp/src/parse/t_enum.h
+++ b/compiler/cpp/src/parse/t_enum.h
@@ -1,11 +1,11 @@
 #ifndef T_ENUM_H
 #define T_ENUM_H
 
-#include "t_constant.h"
+#include "t_enum_value.h"
 #include <vector>
 
 /**
- * An enumerated type. A list of t_constant objects with a name for the type.
+ * An enumerated type. A list of constant objects with a name for the type.
  *
  * @author Mark Slee <mcslee@facebook.com>
  */
@@ -18,11 +18,11 @@
     name_ = name;
   }
   
-  void append(t_constant* constant) {
+  void append(t_enum_value* constant) {
     constants_.push_back(constant);
   }
 
-  const std::vector<t_constant*>& get_constants() {
+  const std::vector<t_enum_value*>& get_constants() {
     return constants_;
   }
 
@@ -31,7 +31,7 @@
   }
 
  private:
-  std::vector<t_constant*> constants_;
+  std::vector<t_enum_value*> constants_;
 };
 
 #endif
diff --git a/compiler/cpp/src/parse/t_constant.h b/compiler/cpp/src/parse/t_enum_value.h
similarity index 77%
rename from compiler/cpp/src/parse/t_constant.h
rename to compiler/cpp/src/parse/t_enum_value.h
index f502f75..65e61cb 100644
--- a/compiler/cpp/src/parse/t_constant.h
+++ b/compiler/cpp/src/parse/t_enum_value.h
@@ -1,5 +1,5 @@
-#ifndef T_CONSTANT_H
-#define T_CONSTANT_H
+#ifndef T_ENUM_VALUE_H
+#define T_ENUM_VALUE_H
 
 #include <string>
 
@@ -10,19 +10,19 @@
  *
  * @author Mark Slee <mcslee@facebook.com>
  */
-class t_constant {
+class t_enum_value {
  public:
-  t_constant(std::string name) :
+  t_enum_value(std::string name) :
     name_(name),
     has_value_(false),
     value_(0) {}
 
-  t_constant(std::string name, int value) :
+  t_enum_value(std::string name, int value) :
     name_(name),
     has_value_(true),
     value_(value) {}
 
-  ~t_constant() {}
+  ~t_enum_value() {}
 
   const std::string& get_name() {
     return name_;
diff --git a/compiler/cpp/src/parse/t_program.h b/compiler/cpp/src/parse/t_program.h
index a3270ad..b0eb60e 100644
--- a/compiler/cpp/src/parse/t_program.h
+++ b/compiler/cpp/src/parse/t_program.h
@@ -12,6 +12,7 @@
 #include "t_base_type.h"
 #include "t_typedef.h"
 #include "t_enum.h"
+#include "t_const.h"
 #include "t_struct.h"
 #include "t_service.h"
 #include "t_list.h"
@@ -24,6 +25,7 @@
  *
  *   Typedefs
  *   Enumerations
+ *   Constants
  *   Structs
  *   Exceptions
  *   Services
@@ -58,6 +60,7 @@
   // Accessors for program elements
   const std::vector<t_typedef*>& get_typedefs()  const { return typedefs_;  }
   const std::vector<t_enum*>&    get_enums()     const { return enums_;     }
+  const std::vector<t_const*>&   get_consts()    const { return consts_;    }
   const std::vector<t_struct*>&  get_structs()   const { return structs_;   }
   const std::vector<t_struct*>&  get_xceptions() const { return xceptions_; }
   const std::vector<t_service*>& get_services()  const { return services_;  }
@@ -65,6 +68,7 @@
   // Program elements
   void add_typedef  (t_typedef* td) { typedefs_.push_back(td);  }
   void add_enum     (t_enum*    te) { enums_.push_back(te);     }
+  void add_const    (t_const*   tc) { consts_.push_back(tc);    }
   void add_struct   (t_struct*  ts) { structs_.push_back(ts);   }
   void add_xception (t_struct*  tx) { xceptions_.push_back(tx); }
   void add_service  (t_service* ts) { services_.push_back(ts);  }
@@ -139,6 +143,7 @@
   // Components to generate code for
   std::vector<t_typedef*> typedefs_;
   std::vector<t_enum*>    enums_;
+  std::vector<t_const*>   consts_;
   std::vector<t_struct*>  structs_;
   std::vector<t_struct*>  xceptions_;
   std::vector<t_service*> services_;