func newOracle(iprog *loader.Program, ptalog io.Writer, needs int, reflection bool) (*Oracle, error) {
o := &Oracle{fset: iprog.Fset}
// Retain type info for all ASTs in the program.
if needs&needRetainTypeInfo != 0 {
o.typeInfo = iprog.AllPackages
}
// Create SSA package for the initial packages and their dependencies.
if needs&needSSA != 0 {
var mode ssa.BuilderMode
if needs&needSSADebug != 0 {
mode |= ssa.GlobalDebug
}
prog := ssa.Create(iprog, mode)
// For each initial package (specified on the command line),
// if it has a main function, analyze that,
// otherwise analyze its tests, if any.
var testPkgs, mains []*ssa.Package
for _, info := range iprog.InitialPackages() {
initialPkg := prog.Package(info.Pkg)
// Add package to the pointer analysis scope.
if initialPkg.Func("main") != nil {
mains = append(mains, initialPkg)
} else {
testPkgs = append(testPkgs, initialPkg)
}
}
if testPkgs != nil {
if p := prog.CreateTestMainPackage(testPkgs...); p != nil {
mains = append(mains, p)
}
}
if mains == nil {
return nil, fmt.Errorf("analysis scope has no main and no tests")
}
o.ptaConfig.Log = ptalog
o.ptaConfig.Reflection = reflection
o.ptaConfig.Mains = mains
o.prog = prog
}
return o, nil
}
// ParseQueryPos parses the source query position pos.
// If needExact, it must identify a single AST subtree;
// this is appropriate for queries that allow fairly arbitrary syntax,
// e.g. "describe".
//
func ParseQueryPos(iprog *loader.Program, posFlag string, needExact bool) (*QueryPos, error) {
filename, startOffset, endOffset, err := parsePosFlag(posFlag)
if err != nil {
return nil, err
}
start, end, err := findQueryPos(iprog.Fset, filename, startOffset, endOffset)
if err != nil {
return nil, err
}
info, path, exact := iprog.PathEnclosingInterval(start, end)
if path == nil {
return nil, fmt.Errorf("no syntax here")
}
if needExact && !exact {
return nil, fmt.Errorf("ambiguous selection within %s", astutil.NodeDescription(path[0]))
}
return &QueryPos{iprog.Fset, start, end, path, exact, info}, nil
}