souffle::ast::transform::UniqueAggregationVariablesTransformer Class Reference

Transformation pass to rename aggregation variables to make them unique. More...

#include <UniqueAggregationVariables.h>

Inheritance diagram for souffle::ast::transform::UniqueAggregationVariablesTransformer:

Collaboration diagram for souffle::ast::transform::UniqueAggregationVariablesTransformer:

Public Member Functions
UniqueAggregationVariablesTransformer *	clone () const override
std::string	getName () const override
Public Member Functions inherited from souffle::ast::transform::Transformer
bool	apply (TranslationUnit &translationUnit)
virtual	~Transformer ()=default

Private Member Functions
bool	transform (TranslationUnit &translationUnit) override
	Renames all local variables of the aggregate to something unique, so that the scope of the local variable is limited to the body of the aggregate subclause. More...

Detailed Description

Transformation pass to rename aggregation variables to make them unique.

Definition at line 30 of file UniqueAggregationVariables.h.

Member Function Documentation

clone()

UniqueAggregationVariablesTransformer* souffle::ast::transform::UniqueAggregationVariablesTransformer::clone ( ) const

inlineoverridevirtual

Implements souffle::ast::transform::Transformer.

Definition at line 40 of file UniqueAggregationVariables.h.

getName()

std::string souffle::ast::transform::UniqueAggregationVariablesTransformer::getName ( ) const

inlineoverridevirtual

Implements souffle::ast::transform::Transformer.

Definition at line 36 of file UniqueAggregationVariables.h.

       :
    bool transform(TranslationUnit& translationUnit) override;
};

transform()

bool souffle::ast::transform::UniqueAggregationVariablesTransformer::transform ( TranslationUnit &  translationUnit )

overrideprivatevirtual

Renames all local variables of the aggregate to something unique, so that the scope of the local variable is limited to the body of the aggregate subclause.

This assumes that we have simplified the target expression to a target variable.

Implements souffle::ast::transform::Transformer.

Definition at line 38 of file UniqueAggregationVariables.cpp.

                                                                            {
        // find out if the target expression variable occurs elsewhere in the rule. If so, rename it
        // to avoid naming conflicts
        visitDepthFirst(clause, [&](const Aggregator& agg) {
            // get the set of local variables in this aggregate and rename
            // those that occur outside the aggregate
            std::set<std::string> localVariables = analysis::getLocalVariables(translationUnit, clause, agg);
            std::set<std::string> variablesOutsideAggregate =
                    analysis::getVariablesOutsideAggregate(clause, agg);
            for (const std::string& name : localVariables) {
                if (variablesOutsideAggregate.find(name) != variablesOutsideAggregate.end()) {
                    // then this MUST be renamed to avoid scoping issues
                    std::string uniqueName = analysis::findUniqueVariableName(clause, name);
                    visitDepthFirst(agg, [&](const Variable& var) {
                        if (var.getName() == name) {
                            const_cast<Variable&>(var).setName(uniqueName);
                            changed = true;
                        }
                    });
                }
            }
        });
    });
    return changed;
}
 
}  // namespace souffle::ast::transform

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The documentation for this class was generated from the following files:

• ast/transform/UniqueAggregationVariables.h
• ast/transform/UniqueAggregationVariables.cpp