P4::DoRemoveParserControlFlow Class Reference

Converts if statements in parsers into transitions. More...

Inheritance diagram for P4::DoRemoveParserControlFlow:

Public Member Functions
	DoRemoveParserControlFlow (ReferenceMap *refMap)
Visitor::profile_t	init_apply (const IR::Node *node) override
const IR::Node *	postorder (IR::ParserState *state) override

Detailed Description

Converts if statements in parsers into transitions.

For example, this code snippet:

state s {
   statement1;
   statement2;
   if (exp)
      statement3;
   else
      statement4;
   statement5;
   transition selectExpression;
}

would be converted into the following four states:

state s {
   statement1;
   statement2;
   transition select(exp) {
      true: s_true;
      false: s_false;
   }
}
 
state s_true {
   statement3;
   transition s_join;
}
 
state s_false {
   statement4;
   transition s_join;
}
 
state s_join {
   statement5;
   transition selectExpression;
}

Precondition

Must be run after MoveDeclarations. Requires an up-to-date ReferenceMap.

Postcondition

No if statements remain in parsers.