Validate that throws clauses in Thrift contain only exceptions

Summary: Throwing non-exceptions, though allowed in some languages, is a weird concept and causes problems in many places. Disallow it in the Thrift compiler and throw an informative error.

Reviewed By: dreiss

Test Plan: Generate a file with an int or something in a throws clause. Peep the nice informative compiler error.

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665450 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/compiler/cpp/src/main.cc b/compiler/cpp/src/main.cc
index e0eb4b7..9f3eb73 100644 (file)
--- a/compiler/cpp/src/main.cc
+++ b/compiler/cpp/src/main.cc
@@ -753,6 +753,20 @@ void validate_field_value(t_field* field, t_const_value* cv) {
   validate_const_rec(field->get_name(), field->get_type(), cv);
 }
 
+/**
+ * Check that all the elements of a throws block are actually exceptions.
+ */
+bool validate_throws(t_struct* throws) {
+  const vector<t_field*>& members = throws->get_members();
+  vector<t_field*>::const_iterator m_iter;
+  for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
+    if (!(*m_iter)->get_type()->is_xception()) {
+      return false;
+    }
+  }
+  return true;
+}
+
 /**
  * Parses a program
  */

diff --git a/compiler/cpp/src/main.h b/compiler/cpp/src/main.h
index f8828af..3ab2744 100644 (file)
--- a/compiler/cpp/src/main.h
+++ b/compiler/cpp/src/main.h
@@ -49,6 +49,11 @@ void validate_const_type(t_const* c);
  */
 void validate_field_value(t_field* field, t_const_value* cv);
 
+/**
+ * Check members of a throws block
+ */
+bool validate_throws(t_struct* throws);
+
 /**
  * Converts a string filename into a thrift program name
  */

diff --git a/compiler/cpp/src/thrifty.yy b/compiler/cpp/src/thrifty.yy
index 2b09972..0b87386 100644 (file)
--- a/compiler/cpp/src/thrifty.yy
+++ b/compiler/cpp/src/thrifty.yy
@@ -766,6 +766,10 @@ Throws:
     {
       pdebug("Throws -> tok_throws ( FieldList )");
       $$ = $3;
+      if (!validate_throws($$)) {
+        yyerror("Throws clause may not contain non-exception types");
+        exit(1);
+      }
     }
 |
     {