2d7deef4e2
If we have a solution, and all that remains are generators, then feel free to remove them and win.
916 lines
31 KiB
Go
916 lines
31 KiB
Go
// Mgmt
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// Copyright (C) 2013-2021+ James Shubin and the project contributors
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// Written by James Shubin <james@shubin.ca> and the project contributors
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//
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program. If not, see <http://www.gnu.org/licenses/>.
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package unification // TODO: can we put this solver in a sub-package?
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import (
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"fmt"
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"github.com/purpleidea/mgmt/lang/interfaces"
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"github.com/purpleidea/mgmt/lang/types"
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"github.com/purpleidea/mgmt/util/errwrap"
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)
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const (
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// Name is the prefix for our solver log messages.
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Name = "solver: simple"
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// ErrAmbiguous means we couldn't find a solution, but we weren't
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// inconsistent.
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ErrAmbiguous = interfaces.Error("can't unify, no equalities were consumed, we're ambiguous")
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// AllowRecursion specifies whether we're allowed to use the recursive
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// solver or not. It uses an absurd amount of memory, and might hang
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// your system if a simple solution doesn't exist.
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AllowRecursion = false
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// RecursionDepthLimit specifies the max depth that is allowed.
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// FIXME: RecursionDepthLimit is not currently implemented
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RecursionDepthLimit = 5 // TODO: pick a better value ?
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// RecursionInvariantLimit specifies the max number of invariants we can
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// recurse into.
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RecursionInvariantLimit = 5 // TODO: pick a better value ?
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)
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// SimpleInvariantSolverLogger is a wrapper which returns a
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// SimpleInvariantSolver with the log parameter of your choice specified. The
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// result satisfies the correct signature for the solver parameter of the
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// Unification function.
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func SimpleInvariantSolverLogger(logf func(format string, v ...interface{})) func([]interfaces.Invariant, []interfaces.Expr) (*InvariantSolution, error) {
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return func(invariants []interfaces.Invariant, expected []interfaces.Expr) (*InvariantSolution, error) {
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return SimpleInvariantSolver(invariants, expected, logf)
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}
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}
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// SimpleInvariantSolver is an iterative invariant solver for AST expressions.
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// It is intended to be very simple, even if it's computationally inefficient.
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func SimpleInvariantSolver(invariants []interfaces.Invariant, expected []interfaces.Expr, logf func(format string, v ...interface{})) (*InvariantSolution, error) {
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debug := false // XXX: add to interface
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process := func(invariants []interfaces.Invariant) ([]interfaces.Invariant, []*interfaces.ExclusiveInvariant, error) {
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equalities := []interfaces.Invariant{}
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exclusives := []*interfaces.ExclusiveInvariant{}
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generators := []interfaces.Invariant{}
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for ix := 0; len(invariants) > ix; ix++ { // while
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x := invariants[ix]
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switch invariant := x.(type) {
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case *interfaces.EqualsInvariant:
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equalities = append(equalities, invariant)
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case *interfaces.EqualityInvariant:
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equalities = append(equalities, invariant)
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case *interfaces.EqualityInvariantList:
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// de-construct this list variant into a series
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// of equality variants so that our solver can
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// be implemented more simply...
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if len(invariant.Exprs) < 2 {
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return nil, nil, fmt.Errorf("list invariant needs at least two elements")
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}
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for i := 0; i < len(invariant.Exprs)-1; i++ {
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invar := &interfaces.EqualityInvariant{
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Expr1: invariant.Exprs[i],
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Expr2: invariant.Exprs[i+1],
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}
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equalities = append(equalities, invar)
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}
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case *interfaces.EqualityWrapListInvariant:
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equalities = append(equalities, invariant)
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case *interfaces.EqualityWrapMapInvariant:
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equalities = append(equalities, invariant)
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case *interfaces.EqualityWrapStructInvariant:
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equalities = append(equalities, invariant)
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case *interfaces.EqualityWrapFuncInvariant:
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equalities = append(equalities, invariant)
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case *interfaces.EqualityWrapCallInvariant:
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equalities = append(equalities, invariant)
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case *interfaces.GeneratorInvariant:
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// these are special, note the different list
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generators = append(generators, invariant)
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// contains a list of invariants which this represents
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case *interfaces.ConjunctionInvariant:
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invariants = append(invariants, invariant.Invariants...)
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case *interfaces.ExclusiveInvariant:
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// these are special, note the different list
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if len(invariant.Invariants) > 0 {
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exclusives = append(exclusives, invariant)
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}
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case *interfaces.AnyInvariant:
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equalities = append(equalities, invariant)
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case *interfaces.ValueInvariant:
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equalities = append(equalities, invariant)
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case *interfaces.CallFuncArgsValueInvariant:
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equalities = append(equalities, invariant)
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default:
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return nil, nil, fmt.Errorf("unknown invariant type: %T", x)
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}
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}
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// optimization: if we have zero generator invariants, we can
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// discard the value invariants!
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// NOTE: if exclusives do *not* contain nested generators, then
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// we don't need to check for exclusives here, and the logic is
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// much faster and simpler and can possibly solve more cases...
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if len(generators) == 0 && len(exclusives) == 0 {
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used := []int{}
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for i, x := range equalities {
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_, ok1 := x.(*interfaces.ValueInvariant)
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_, ok2 := x.(*interfaces.CallFuncArgsValueInvariant)
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if !ok1 && !ok2 {
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continue
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}
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used = append(used, i) // mark equality as used up
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}
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logf("%s: got %d equalities left after %d used up", Name, len(equalities)-len(used), len(used))
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// delete used equalities, in reverse order to preserve indexing!
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for i := len(used) - 1; i >= 0; i-- {
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ix := used[i] // delete index that was marked as used!
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equalities = append(equalities[:ix], equalities[ix+1:]...)
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}
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}
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// append the generators at the end
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// (they can go in any order, but it's more optimal this way)
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equalities = append(equalities, generators...)
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return equalities, exclusives, nil
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}
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logf("%s: invariants:", Name)
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for i, x := range invariants {
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logf("invariant(%d): %T: %s", i, x, x)
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}
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solved := make(map[interfaces.Expr]*types.Type)
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// iterate through all invariants, flattening and sorting the list...
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equalities, exclusives, err := process(invariants)
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if err != nil {
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return nil, err
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}
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// XXX: if these partials all shared the same variable definition, would
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// it all work??? Maybe we don't even need the first map prefix...
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listPartials := make(map[interfaces.Expr]map[interfaces.Expr]*types.Type)
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mapPartials := make(map[interfaces.Expr]map[interfaces.Expr]*types.Type)
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structPartials := make(map[interfaces.Expr]map[interfaces.Expr]*types.Type)
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funcPartials := make(map[interfaces.Expr]map[interfaces.Expr]*types.Type)
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callPartials := make(map[interfaces.Expr]map[interfaces.Expr]*types.Type)
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isSolvedFn := func(solved map[interfaces.Expr]*types.Type) (map[interfaces.Expr]struct{}, bool) {
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unsolved := make(map[interfaces.Expr]struct{})
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result := true
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for _, x := range expected {
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if typ, exists := solved[x]; !exists || typ == nil {
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result = false
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unsolved[x] = struct{}{}
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}
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}
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return unsolved, result
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}
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logf("%s: starting loop with %d equalities", Name, len(equalities))
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// run until we're solved, stop consuming equalities, or type clash
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Loop:
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for {
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logf("%s: iterate...", Name)
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if len(equalities) == 0 && len(exclusives) == 0 {
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break // we're done, nothing left
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}
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used := []int{}
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for i, x := range equalities {
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logf("%s: match(%T): %+v", Name, x, x)
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// TODO: could each of these cases be implemented as a
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// method on the Invariant type to simplify this code?
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switch eq := x.(type) {
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// trivials
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case *interfaces.EqualsInvariant:
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typ, exists := solved[eq.Expr]
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if !exists {
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solved[eq.Expr] = eq.Type // yay, we learned something!
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used = append(used, i) // mark equality as used up
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logf("%s: solved trivial equality", Name)
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continue
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}
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// we already specified this, so check the repeat is consistent
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if err := typ.Cmp(eq.Type); err != nil {
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// this error shouldn't happen unless we purposefully
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// try to trick the solver, or we're in a recursive try
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return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with equals")
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}
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used = append(used, i) // mark equality as duplicate
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logf("%s: duplicate trivial equality", Name)
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continue
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// partials
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case *interfaces.EqualityWrapListInvariant:
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if _, exists := listPartials[eq.Expr1]; !exists {
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listPartials[eq.Expr1] = make(map[interfaces.Expr]*types.Type)
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}
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if typ, exists := solved[eq.Expr1]; exists {
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// wow, now known, so tell the partials!
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// TODO: this assumes typ is a list, is that guaranteed?
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listPartials[eq.Expr1][eq.Expr2Val] = typ.Val
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}
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// can we add to partials ?
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for _, y := range []interfaces.Expr{eq.Expr2Val} {
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typ, exists := solved[y]
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if !exists {
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continue
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}
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t, exists := listPartials[eq.Expr1][y]
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if !exists {
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listPartials[eq.Expr1][y] = typ // learn!
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continue
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}
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if err := t.Cmp(typ); err != nil {
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return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with partial list val")
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}
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}
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// can we solve anything?
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var ready = true // assume ready
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typ := &types.Type{
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Kind: types.KindList,
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}
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valTyp, exists := listPartials[eq.Expr1][eq.Expr2Val]
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if !exists {
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ready = false // nope!
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} else {
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typ.Val = valTyp // build up typ
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}
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if ready {
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if t, exists := solved[eq.Expr1]; exists {
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if err := t.Cmp(typ); err != nil {
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return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with list")
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}
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}
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// sub checks
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if t, exists := solved[eq.Expr2Val]; exists {
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if err := t.Cmp(typ.Val); err != nil {
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return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with list val")
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}
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}
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solved[eq.Expr1] = typ // yay, we learned something!
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solved[eq.Expr2Val] = typ.Val // yay, we learned something!
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used = append(used, i) // mark equality as used up
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logf("%s: solved list wrap partial", Name)
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continue
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}
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case *interfaces.EqualityWrapMapInvariant:
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if _, exists := mapPartials[eq.Expr1]; !exists {
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mapPartials[eq.Expr1] = make(map[interfaces.Expr]*types.Type)
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}
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if typ, exists := solved[eq.Expr1]; exists {
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// wow, now known, so tell the partials!
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// TODO: this assumes typ is a map, is that guaranteed?
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mapPartials[eq.Expr1][eq.Expr2Key] = typ.Key
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mapPartials[eq.Expr1][eq.Expr2Val] = typ.Val
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}
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// can we add to partials ?
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for _, y := range []interfaces.Expr{eq.Expr2Key, eq.Expr2Val} {
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typ, exists := solved[y]
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if !exists {
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continue
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}
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t, exists := mapPartials[eq.Expr1][y]
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if !exists {
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mapPartials[eq.Expr1][y] = typ // learn!
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continue
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}
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if err := t.Cmp(typ); err != nil {
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return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with partial map key/val")
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}
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}
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// can we solve anything?
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var ready = true // assume ready
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typ := &types.Type{
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Kind: types.KindMap,
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}
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keyTyp, exists := mapPartials[eq.Expr1][eq.Expr2Key]
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if !exists {
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ready = false // nope!
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} else {
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typ.Key = keyTyp // build up typ
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}
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valTyp, exists := mapPartials[eq.Expr1][eq.Expr2Val]
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if !exists {
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ready = false // nope!
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} else {
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typ.Val = valTyp // build up typ
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}
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if ready {
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if t, exists := solved[eq.Expr1]; exists {
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if err := t.Cmp(typ); err != nil {
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return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with map")
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}
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}
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// sub checks
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if t, exists := solved[eq.Expr2Key]; exists {
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if err := t.Cmp(typ.Key); err != nil {
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return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with map key")
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}
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}
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if t, exists := solved[eq.Expr2Val]; exists {
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if err := t.Cmp(typ.Val); err != nil {
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return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with map val")
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}
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}
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solved[eq.Expr1] = typ // yay, we learned something!
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solved[eq.Expr2Key] = typ.Key // yay, we learned something!
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solved[eq.Expr2Val] = typ.Val // yay, we learned something!
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used = append(used, i) // mark equality as used up
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logf("%s: solved map wrap partial", Name)
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continue
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}
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case *interfaces.EqualityWrapStructInvariant:
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if _, exists := structPartials[eq.Expr1]; !exists {
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structPartials[eq.Expr1] = make(map[interfaces.Expr]*types.Type)
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}
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if typ, exists := solved[eq.Expr1]; exists {
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// wow, now known, so tell the partials!
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// TODO: this assumes typ is a struct, is that guaranteed?
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if len(typ.Ord) != len(eq.Expr2Ord) {
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return nil, fmt.Errorf("struct field count differs")
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}
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for i, name := range eq.Expr2Ord {
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expr := eq.Expr2Map[name] // assume key exists
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structPartials[eq.Expr1][expr] = typ.Map[typ.Ord[i]] // assume key exists
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}
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}
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// can we add to partials ?
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for name, y := range eq.Expr2Map {
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typ, exists := solved[y]
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if !exists {
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continue
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}
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t, exists := structPartials[eq.Expr1][y]
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if !exists {
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structPartials[eq.Expr1][y] = typ // learn!
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continue
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}
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if err := t.Cmp(typ); err != nil {
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return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with partial struct field: %s", name)
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}
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}
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// can we solve anything?
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var ready = true // assume ready
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typ := &types.Type{
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Kind: types.KindStruct,
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}
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typ.Map = make(map[string]*types.Type)
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for name, y := range eq.Expr2Map {
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t, exists := structPartials[eq.Expr1][y]
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if !exists {
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ready = false // nope!
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break
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}
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typ.Map[name] = t // build up typ
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}
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if ready {
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typ.Ord = eq.Expr2Ord // known order
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|
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if t, exists := solved[eq.Expr1]; exists {
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if err := t.Cmp(typ); err != nil {
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return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with struct")
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}
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}
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// sub checks
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for name, y := range eq.Expr2Map {
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if t, exists := solved[y]; exists {
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if err := t.Cmp(typ.Map[name]); err != nil {
|
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return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with struct field: %s", name)
|
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}
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}
|
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}
|
|
|
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solved[eq.Expr1] = typ // yay, we learned something!
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// we should add the other expr's in too...
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for name, y := range eq.Expr2Map {
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solved[y] = typ.Map[name] // yay, we learned something!
|
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}
|
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used = append(used, i) // mark equality as used up
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logf("%s: solved struct wrap partial", Name)
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continue
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}
|
|
|
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case *interfaces.EqualityWrapFuncInvariant:
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if _, exists := funcPartials[eq.Expr1]; !exists {
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funcPartials[eq.Expr1] = make(map[interfaces.Expr]*types.Type)
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}
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|
|
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if typ, exists := solved[eq.Expr1]; exists {
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// wow, now known, so tell the partials!
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// TODO: this assumes typ is a func, is that guaranteed?
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if len(typ.Ord) != len(eq.Expr2Ord) {
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return nil, fmt.Errorf("func arg count differs")
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}
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for i, name := range eq.Expr2Ord {
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expr := eq.Expr2Map[name] // assume key exists
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funcPartials[eq.Expr1][expr] = typ.Map[typ.Ord[i]] // assume key exists
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}
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funcPartials[eq.Expr1][eq.Expr2Out] = typ.Out
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}
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|
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// can we add to partials ?
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for name, y := range eq.Expr2Map {
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typ, exists := solved[y]
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if !exists {
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continue
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}
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t, exists := funcPartials[eq.Expr1][y]
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if !exists {
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funcPartials[eq.Expr1][y] = typ // learn!
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continue
|
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}
|
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if err := t.Cmp(typ); err != nil {
|
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return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with partial func arg: %s", name)
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}
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}
|
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for _, y := range []interfaces.Expr{eq.Expr2Out} {
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typ, exists := solved[y]
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if !exists {
|
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continue
|
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}
|
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t, exists := funcPartials[eq.Expr1][y]
|
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if !exists {
|
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funcPartials[eq.Expr1][y] = typ // learn!
|
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continue
|
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}
|
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if err := t.Cmp(typ); err != nil {
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return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with partial func arg")
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}
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}
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|
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// can we solve anything?
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var ready = true // assume ready
|
|
typ := &types.Type{
|
|
Kind: types.KindFunc,
|
|
}
|
|
typ.Map = make(map[string]*types.Type)
|
|
for name, y := range eq.Expr2Map {
|
|
t, exists := funcPartials[eq.Expr1][y]
|
|
if !exists {
|
|
ready = false // nope!
|
|
break
|
|
}
|
|
typ.Map[name] = t // build up typ
|
|
}
|
|
outTyp, exists := funcPartials[eq.Expr1][eq.Expr2Out]
|
|
if !exists {
|
|
ready = false // nope!
|
|
} else {
|
|
typ.Out = outTyp // build up typ
|
|
}
|
|
if ready {
|
|
typ.Ord = eq.Expr2Ord // known order
|
|
|
|
if t, exists := solved[eq.Expr1]; exists {
|
|
if err := t.Cmp(typ); err != nil {
|
|
return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with func")
|
|
}
|
|
}
|
|
// sub checks
|
|
for name, y := range eq.Expr2Map {
|
|
if t, exists := solved[y]; exists {
|
|
if err := t.Cmp(typ.Map[name]); err != nil {
|
|
return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with func arg: %s", name)
|
|
}
|
|
}
|
|
}
|
|
if t, exists := solved[eq.Expr2Out]; exists {
|
|
if err := t.Cmp(typ.Out); err != nil {
|
|
return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with func out")
|
|
}
|
|
}
|
|
|
|
solved[eq.Expr1] = typ // yay, we learned something!
|
|
// we should add the other expr's in too...
|
|
for name, y := range eq.Expr2Map {
|
|
solved[y] = typ.Map[name] // yay, we learned something!
|
|
}
|
|
solved[eq.Expr2Out] = typ.Out // yay, we learned something!
|
|
used = append(used, i) // mark equality as used up
|
|
logf("%s: solved func wrap partial", Name)
|
|
continue
|
|
}
|
|
|
|
case *interfaces.EqualityWrapCallInvariant:
|
|
// the logic is slightly different here, because
|
|
// we can only go from the func type to the call
|
|
// type as we can't do the reverse determination
|
|
if _, exists := callPartials[eq.Expr2Func]; !exists {
|
|
callPartials[eq.Expr2Func] = make(map[interfaces.Expr]*types.Type)
|
|
}
|
|
|
|
if typ, exists := solved[eq.Expr2Func]; exists {
|
|
// wow, now known, so tell the partials!
|
|
if typ.Kind != types.KindFunc {
|
|
return nil, fmt.Errorf("expected: %s, got: %s", types.KindFunc, typ.Kind)
|
|
}
|
|
callPartials[eq.Expr2Func][eq.Expr1] = typ.Out
|
|
}
|
|
|
|
typ, ready := callPartials[eq.Expr2Func][eq.Expr1]
|
|
if ready { // ready to solve
|
|
if t, exists := solved[eq.Expr1]; exists {
|
|
if err := t.Cmp(typ); err != nil {
|
|
return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with call")
|
|
}
|
|
}
|
|
// sub checks
|
|
if t, exists := solved[eq.Expr2Func]; exists {
|
|
if err := t.Out.Cmp(typ); err != nil {
|
|
return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with call out")
|
|
}
|
|
}
|
|
|
|
solved[eq.Expr1] = typ // yay, we learned something!
|
|
used = append(used, i) // mark equality as used up
|
|
logf("%s: solved call wrap partial", Name)
|
|
continue
|
|
}
|
|
|
|
// regular matching
|
|
case *interfaces.EqualityInvariant:
|
|
typ1, exists1 := solved[eq.Expr1]
|
|
typ2, exists2 := solved[eq.Expr2]
|
|
|
|
if !exists1 && !exists2 { // neither equality connects
|
|
// can't learn more from this equality yet
|
|
// nothing is known about either side of it
|
|
continue
|
|
}
|
|
if exists1 && exists2 { // both equalities already connect
|
|
// both sides are already known-- are they the same?
|
|
if err := typ1.Cmp(typ2); err != nil {
|
|
return nil, errwrap.Wrapf(err, "can't unify, invariant illogicality with equality")
|
|
}
|
|
used = append(used, i) // mark equality as used up
|
|
logf("%s: duplicate regular equality", Name)
|
|
continue
|
|
}
|
|
if exists1 && !exists2 { // first equality already connects
|
|
solved[eq.Expr2] = typ1 // yay, we learned something!
|
|
used = append(used, i) // mark equality as used up
|
|
logf("%s: solved regular equality", Name)
|
|
continue
|
|
}
|
|
if exists2 && !exists1 { // second equality already connects
|
|
solved[eq.Expr1] = typ2 // yay, we learned something!
|
|
used = append(used, i) // mark equality as used up
|
|
logf("%s: solved regular equality", Name)
|
|
continue
|
|
}
|
|
|
|
panic("reached unexpected code")
|
|
|
|
case *interfaces.GeneratorInvariant:
|
|
// this invariant can generate new ones
|
|
|
|
// optimization: we want to run the generators
|
|
// last (but before the exclusives) because
|
|
// they take longer to run. So as long as we've
|
|
// made progress this time around, don't run
|
|
// this just yet, there's still time left...
|
|
if len(used) > 0 {
|
|
continue
|
|
}
|
|
|
|
// If this returns nil, we add the invariants
|
|
// it returned and we remove it from the list.
|
|
// If we error, it's because we don't have any
|
|
// new information to provide at this time...
|
|
// XXX: should we pass in `invariants` instead?
|
|
gi, err := eq.Func(equalities, solved)
|
|
if err != nil {
|
|
continue
|
|
}
|
|
|
|
eqs, exs, err := process(gi) // process like at the top
|
|
if err != nil {
|
|
// programming error?
|
|
return nil, errwrap.Wrapf(err, "processing error")
|
|
}
|
|
equalities = append(equalities, eqs...)
|
|
exclusives = append(exclusives, exs...)
|
|
|
|
used = append(used, i) // mark equality as used up
|
|
logf("%s: solved `generator` equality", Name)
|
|
continue
|
|
|
|
// wtf matching
|
|
case *interfaces.AnyInvariant:
|
|
// this basically ensures that the expr gets solved
|
|
if _, exists := solved[eq.Expr]; exists {
|
|
used = append(used, i) // mark equality as used up
|
|
logf("%s: solved `any` equality", Name)
|
|
}
|
|
continue
|
|
|
|
case *interfaces.ValueInvariant:
|
|
// don't consume these, they're stored in case
|
|
// a generator invariant wants to read them...
|
|
continue
|
|
|
|
case *interfaces.CallFuncArgsValueInvariant:
|
|
// don't consume these, they're stored in case
|
|
// a generator invariant wants to read them...
|
|
continue
|
|
|
|
default:
|
|
return nil, fmt.Errorf("unknown invariant type: %T", x)
|
|
}
|
|
} // end inner for loop
|
|
if len(used) == 0 {
|
|
// Looks like we're now ambiguous, but if we have any
|
|
// exclusives, recurse into each possibility to see if
|
|
// one of them can help solve this! first one wins. Add
|
|
// in the exclusive to the current set of equalities!
|
|
|
|
// To decrease the problem space, first check if we have
|
|
// enough solutions to solve everything. If so, then we
|
|
// don't need to solve any exclusives, and instead we
|
|
// only need to verify that they don't conflict with the
|
|
// found solution, which reduces the search space...
|
|
|
|
// Another optimization that can be done before we run
|
|
// the combinatorial exclusive solver, is we can look at
|
|
// each exclusive, and remove the ones that already
|
|
// match, because they don't tell us any new information
|
|
// that we don't already know. We can also fail early
|
|
// if anything proves we're already inconsistent.
|
|
|
|
// These two optimizations turn out to use the exact
|
|
// same algorithm and code, so they're combined here...
|
|
_, isSolved := isSolvedFn(solved)
|
|
if isSolved {
|
|
logf("%s: solved early with %d exclusives left!", Name, len(exclusives))
|
|
} else {
|
|
logf("%s: unsolved with %d exclusives left!", Name, len(exclusives))
|
|
if debug {
|
|
for i, x := range exclusives {
|
|
logf("%s: exclusive(%d) left: %s", Name, i, x)
|
|
}
|
|
}
|
|
}
|
|
|
|
// check for consistency against remaining invariants
|
|
logf("%s: checking for consistency against %d exclusives...", Name, len(exclusives))
|
|
done := []int{}
|
|
for i, invar := range exclusives {
|
|
// test each one to see if at least one works
|
|
match, err := invar.Matches(solved)
|
|
if err != nil {
|
|
logf("exclusive invar failed: %+v", invar)
|
|
return nil, errwrap.Wrapf(err, "inconsistent exclusive")
|
|
}
|
|
if !match {
|
|
continue
|
|
}
|
|
done = append(done, i)
|
|
}
|
|
logf("%s: removed %d consistent exclusives...", Name, len(done))
|
|
|
|
// Remove exclusives that matched correctly.
|
|
for i := len(done) - 1; i >= 0; i-- {
|
|
ix := done[i] // delete index that was marked as done!
|
|
exclusives = append(exclusives[:ix], exclusives[ix+1:]...)
|
|
}
|
|
|
|
// If we removed any exclusives, then we can start over.
|
|
if len(done) > 0 {
|
|
continue Loop
|
|
}
|
|
|
|
// If we don't have any exclusives left, then we don't
|
|
// need the Value invariants... This logic is the same
|
|
// as in process() but it's duplicated here because we
|
|
// want it to happen at this stage as well. We can try
|
|
// and clean up the duplication and improve the logic.
|
|
// NOTE: We should probably check that there aren't any
|
|
// generators left in the equalities, but since we have
|
|
// already tried to use them up, it is probably safe to
|
|
// unblock the solver if it's only ValueInvatiant left.
|
|
if len(exclusives) == 0 || isSolved { // either is okay
|
|
used := []int{}
|
|
for i, x := range equalities {
|
|
_, ok1 := x.(*interfaces.ValueInvariant)
|
|
_, ok2 := x.(*interfaces.CallFuncArgsValueInvariant)
|
|
if !ok1 && !ok2 {
|
|
continue
|
|
}
|
|
used = append(used, i) // mark equality as used up
|
|
}
|
|
logf("%s: got %d equalities left after %d value invariants used up", Name, len(equalities)-len(used), len(used))
|
|
// delete used equalities, in reverse order to preserve indexing!
|
|
for i := len(used) - 1; i >= 0; i-- {
|
|
ix := used[i] // delete index that was marked as used!
|
|
equalities = append(equalities[:ix], equalities[ix+1:]...)
|
|
}
|
|
|
|
if len(used) > 0 {
|
|
continue Loop
|
|
}
|
|
}
|
|
|
|
if len(exclusives) == 0 && isSolved { // old generators
|
|
used := []int{}
|
|
for i, x := range equalities {
|
|
_, ok := x.(*interfaces.GeneratorInvariant)
|
|
if !ok {
|
|
continue
|
|
}
|
|
used = append(used, i) // mark equality as used up
|
|
}
|
|
logf("%s: got %d equalities left after %d generators used up", Name, len(equalities)-len(used), len(used))
|
|
// delete used equalities, in reverse order to preserve indexing!
|
|
for i := len(used) - 1; i >= 0; i-- {
|
|
ix := used[i] // delete index that was marked as used!
|
|
equalities = append(equalities[:ix], equalities[ix+1:]...)
|
|
}
|
|
|
|
if len(used) > 0 {
|
|
continue Loop
|
|
}
|
|
}
|
|
|
|
// what have we learned for sure so far?
|
|
partialSolutions := []interfaces.Invariant{}
|
|
logf("%s: %d solved, %d unsolved, and %d exclusives left", Name, len(solved), len(equalities), len(exclusives))
|
|
if len(exclusives) > 0 {
|
|
// FIXME: can we do this loop in a deterministic, sorted way?
|
|
for expr, typ := range solved {
|
|
invar := &interfaces.EqualsInvariant{
|
|
Expr: expr,
|
|
Type: typ,
|
|
}
|
|
partialSolutions = append(partialSolutions, invar)
|
|
logf("%s: solved: %+v", Name, invar)
|
|
}
|
|
|
|
// also include anything that hasn't been solved yet
|
|
for _, x := range equalities {
|
|
partialSolutions = append(partialSolutions, x)
|
|
logf("%s: unsolved: %+v", Name, x)
|
|
}
|
|
}
|
|
|
|
// Lastly, we could loop through each exclusive and see
|
|
// if it only has a single, easy solution. For example,
|
|
// if we know that an exclusive is A or B or C, and that
|
|
// B and C are inconsistent, then we can replace the
|
|
// exclusive with a single invariant and then run that
|
|
// through our solver. We can do this iteratively
|
|
// (recursively for accuracy, but in our case via the
|
|
// simplify method) so that if we're lucky, we rarely
|
|
// need to run the raw exclusive combinatorial solver,
|
|
// which is slow.
|
|
logf("%s: attempting to simplify %d exclusives...", Name, len(exclusives))
|
|
|
|
done = []int{} // clear for re-use
|
|
simplified := []interfaces.Invariant{}
|
|
for i, invar := range exclusives {
|
|
// The partialSolutions don't contain any other
|
|
// exclusives... We look at each individually.
|
|
s, err := invar.Simplify(partialSolutions) // XXX: pass in the solver?
|
|
if err != nil {
|
|
logf("exclusive simplification failed: %+v", invar)
|
|
continue
|
|
}
|
|
done = append(done, i)
|
|
simplified = append(simplified, s...)
|
|
}
|
|
logf("%s: simplified %d exclusives...", Name, len(done))
|
|
|
|
// Remove exclusives that matched correctly.
|
|
for i := len(done) - 1; i >= 0; i-- {
|
|
ix := done[i] // delete index that was marked as done!
|
|
exclusives = append(exclusives[:ix], exclusives[ix+1:]...)
|
|
}
|
|
|
|
// Add new equalities and exclusives onto state globals.
|
|
eqs, exs, err := process(simplified) // process like at the top
|
|
if err != nil {
|
|
// programming error?
|
|
return nil, errwrap.Wrapf(err, "processing error")
|
|
}
|
|
equalities = append(equalities, eqs...)
|
|
exclusives = append(exclusives, exs...)
|
|
|
|
// If we removed any exclusives, then we can start over.
|
|
if len(done) > 0 {
|
|
continue Loop
|
|
}
|
|
|
|
// TODO: We could try and replace our combinatorial
|
|
// exclusive solver with a real SAT solver algorithm.
|
|
|
|
if !AllowRecursion || len(exclusives) > RecursionInvariantLimit {
|
|
logf("%s: %d solved, %d unsolved, and %d exclusives left", Name, len(solved), len(equalities), len(exclusives))
|
|
for i, eq := range equalities {
|
|
logf("%s: (%d) equality: %s", Name, i, eq)
|
|
}
|
|
for i, ex := range exclusives {
|
|
logf("%s: (%d) exclusive: %s", Name, i, ex)
|
|
}
|
|
|
|
// these can be very slow, so try to avoid them
|
|
return nil, fmt.Errorf("only recursive solutions left")
|
|
}
|
|
|
|
// let's try each combination, one at a time...
|
|
for i, ex := range exclusivesProduct(exclusives) { // [][]interfaces.Invariant
|
|
logf("%s: exclusive(%d):\n%+v", Name, i, ex)
|
|
// we could waste a lot of cpu, and start from
|
|
// the beginning, but instead we could use the
|
|
// list of known solutions found and continue!
|
|
// TODO: make sure none of these edit partialSolutions
|
|
recursiveInvariants := []interfaces.Invariant{}
|
|
recursiveInvariants = append(recursiveInvariants, partialSolutions...)
|
|
recursiveInvariants = append(recursiveInvariants, ex...)
|
|
// FIXME: implement RecursionDepthLimit
|
|
logf("%s: recursing...", Name)
|
|
solution, err := SimpleInvariantSolver(recursiveInvariants, expected, logf)
|
|
if err != nil {
|
|
logf("%s: recursive solution failed: %+v", Name, err)
|
|
continue // no solution found here...
|
|
}
|
|
// solution found!
|
|
logf("%s: recursive solution found!", Name)
|
|
return solution, nil
|
|
}
|
|
|
|
// TODO: print ambiguity
|
|
logf("%s: ================ ambiguity ================", Name)
|
|
unsolved, isSolved := isSolvedFn(solved)
|
|
logf("%s: isSolved: %+v", Name, isSolved)
|
|
for _, x := range equalities {
|
|
logf("%s: unsolved equality: %+v", Name, x)
|
|
}
|
|
for x := range unsolved {
|
|
logf("%s: unsolved expected: %+v", Name, x)
|
|
}
|
|
return nil, ErrAmbiguous
|
|
}
|
|
// delete used equalities, in reverse order to preserve indexing!
|
|
for i := len(used) - 1; i >= 0; i-- {
|
|
ix := used[i] // delete index that was marked as used!
|
|
equalities = append(equalities[:ix], equalities[ix+1:]...)
|
|
}
|
|
} // end giant for loop
|
|
|
|
// build final solution
|
|
solutions := []*interfaces.EqualsInvariant{}
|
|
// FIXME: can we do this loop in a deterministic, sorted way?
|
|
for expr, typ := range solved {
|
|
invar := &interfaces.EqualsInvariant{
|
|
Expr: expr,
|
|
Type: typ,
|
|
}
|
|
solutions = append(solutions, invar)
|
|
}
|
|
return &InvariantSolution{
|
|
Solutions: solutions,
|
|
}, nil
|
|
}
|