Function FindPrim

cfa/cfa.go:15–52

FindPrim locates a control flow primitive in the provided control flow graph and merges its nodes into a single node.

(g graph.Directed, dom cfg.DominatorTree)

// FindPrim locates a control flow primitive in the provided control flow graph
// and merges its nodes into a single node.
func FindPrim(g graph.Directed, dom cfg.DominatorTree) (*primitive.Primitive, error) {
	// Locate pre-test loops.
	if prim, ok := FindPreLoop(g, dom); ok {
		return prim.Prim(), nil
	}

	// Locate post-test loops.
	if prim, ok := FindPostLoop(g, dom); ok {
		return prim.Prim(), nil
	}

	// Locate 1-way conditionals.
	if prim, ok := FindIf(g, dom); ok {
		return prim.Prim(), nil
	}

	// Locate 1-way conditionals with a body return statements.
	if prim, ok := FindIfReturn(g, dom); ok {
		return prim.Prim(), nil
	}

	// Locate 2-way conditionals.
	if prim, ok := FindIfElse(g, dom); ok {
		return prim.Prim(), nil
	}

	// TODO: Locate n-way conditionals.
	//if prim, ok := FindSwitch(g, dom); ok {
	//	return prim.Prim(), nil
	//}

	// Locate sequences of two statements.
	if prim, ok := FindSeq(g, dom); ok {
		return prim.Prim(), nil
	}

	return nil, errors.New("unable to locate control flow primitive")
}

// Merge merges the nodes of the primitive into a single node, which is assigned
// the basic block label of the entry node.