# frozen_string_literal: true
module Bundler
class Resolver
require_relative "vendored_molinillo"
require_relative "resolver/spec_group"
include GemHelpers
# Figures out the best possible configuration of gems that satisfies
# the list of passed dependencies and any child dependencies without
# causing any gem activation errors.
#
# ==== Parameters
# *dependencies<Gem::Dependency>:: The list of dependencies to resolve
#
# ==== Returns
# <GemBundle>,nil:: If the list of dependencies can be resolved, a
# collection of gemspecs is returned. Otherwise, nil is returned.
def self.resolve(requirements, source_requirements = {}, base = [], gem_version_promoter = GemVersionPromoter.new, additional_base_requirements = [], platforms = nil)
base = SpecSet.new(base) unless base.is_a?(SpecSet)
resolver = new(source_requirements, base, gem_version_promoter, additional_base_requirements, platforms)
result = resolver.start(requirements)
SpecSet.new(SpecSet.new(result).for(requirements.reject{|dep| dep.name.end_with?("\0") }))
end
def initialize(source_requirements, base, gem_version_promoter, additional_base_requirements, platforms)
@source_requirements = source_requirements
@base = base
@resolver = Molinillo::Resolver.new(self, self)
@search_for = {}
@base_dg = Molinillo::DependencyGraph.new
@base.each do |ls|
dep = Dependency.new(ls.name, ls.version)
@base_dg.add_vertex(ls.name, DepProxy.get_proxy(dep, ls.platform), true)
end
additional_base_requirements.each {|d| @base_dg.add_vertex(d.name, d) }
@platforms = platforms.reject {|p| p != Gem::Platform::RUBY && (platforms - [p]).any? {|pl| generic(pl) == p } }
@resolving_only_for_ruby = platforms == [Gem::Platform::RUBY]
@gem_version_promoter = gem_version_promoter
@use_gvp = Bundler.feature_flag.use_gem_version_promoter_for_major_updates? || !@gem_version_promoter.major?
end
def start(requirements)
@gem_version_promoter.prerelease_specified = @prerelease_specified = {}
requirements.each {|dep| @prerelease_specified[dep.name] ||= dep.prerelease? }
verify_gemfile_dependencies_are_found!(requirements)
dg = @resolver.resolve(requirements, @base_dg)
dg.
map(&:payload).
reject {|sg| sg.name.end_with?("\0") }.
map(&:to_specs).
flatten
rescue Molinillo::VersionConflict => e
message = version_conflict_message(e)
raise VersionConflict.new(e.conflicts.keys.uniq, message)
rescue Molinillo::CircularDependencyError => e
names = e.dependencies.sort_by(&:name).map {|d| "gem '#{d.name}'" }
raise CyclicDependencyError, "Your bundle requires gems that depend" \
" on each other, creating an infinite loop. Please remove" \
" #{names.count > 1 ? "either " : ""}#{names.join(" or ")}" \
" and try again."
end
include Molinillo::UI
# Conveys debug information to the user.
#
# @param [Integer] depth the current depth of the resolution process.
# @return [void]
def debug(depth = 0)
return unless debug?
debug_info = yield
debug_info = debug_info.inspect unless debug_info.is_a?(String)
puts debug_info.split("\n").map {|s| depth == 0 ? "BUNDLER: #{s}" : "BUNDLER(#{depth}): #{s}" }
end
def debug?
return @debug_mode if defined?(@debug_mode)
@debug_mode =
ENV["BUNDLER_DEBUG_RESOLVER"] ||
ENV["BUNDLER_DEBUG_RESOLVER_TREE"] ||
ENV["DEBUG_RESOLVER"] ||
ENV["DEBUG_RESOLVER_TREE"] ||
false
end
def before_resolution
Bundler.ui.info "Resolving dependencies...", debug?
end
def after_resolution
Bundler.ui.info ""
end
def indicate_progress
Bundler.ui.info ".", false unless debug?
end
include Molinillo::SpecificationProvider
def dependencies_for(specification)
specification.dependencies_for_activated_platforms
end
def search_for(dependency_proxy)
platform = dependency_proxy.__platform
dependency = dependency_proxy.dep
name = dependency.name
@search_for[dependency_proxy] ||= begin
results = results_for(dependency, @base[name])
if vertex = @base_dg.vertex_named(name)
locked_requirement = vertex.payload.requirement
end
if !@prerelease_specified[name] && (!@use_gvp || locked_requirement.nil?)
# Move prereleases to the beginning of the list, so they're considered
# last during resolution.
pre, results = results.partition {|spec| spec.version.prerelease? }
results = pre + results
end
spec_groups = if results.any?
nested = []
results.each do |spec|
version, specs = nested.last
if version == spec.version
specs << spec
else
nested << [spec.version, [spec]]
end
end
nested.reduce([]) do |groups, (version, specs)|
next groups if locked_requirement && !locked_requirement.satisfied_by?(version)
next groups unless specs.any? {|spec| spec.match_platform(platform) }
specs_by_platform = Hash.new do |current_specs, current_platform|
current_specs[current_platform] = select_best_platform_match(specs, current_platform)
end
spec_group_ruby = SpecGroup.create_for(specs_by_platform, [Gem::Platform::RUBY], Gem::Platform::RUBY)
groups << spec_group_ruby if spec_group_ruby
next groups if @resolving_only_for_ruby
spec_group = SpecGroup.create_for(specs_by_platform, @platforms, platform)
groups << spec_group
groups
end
else
[]
end
# GVP handles major itself, but it's still a bit risky to trust it with it
# until we get it settled with new behavior. For 2.x it can take over all cases.
if !@use_gvp
spec_groups
else
@gem_version_promoter.sort_versions(dependency, spec_groups)
end
end
end
def index_for(dependency)
source_for(dependency.name).specs
end
def source_for(name)
@source_requirements[name] || @source_requirements[:default]
end
def results_for(dependency, base)
index_for(dependency).search(dependency, base)
end
def name_for(dependency)
dependency.name
end
def name_for_explicit_dependency_source
Bundler.default_gemfile.basename.to_s
rescue StandardError
"Gemfile"
end
def name_for_locking_dependency_source
Bundler.default_lockfile.basename.to_s
rescue StandardError
"Gemfile.lock"
end
def requirement_satisfied_by?(requirement, activated, spec)
requirement.matches_spec?(spec) || spec.source.is_a?(Source::Gemspec)
end
def dependencies_equal?(dependencies, other_dependencies)
dependencies.map(&:dep) == other_dependencies.map(&:dep)
end
def sort_dependencies(dependencies, activated, conflicts)
dependencies.sort_by do |dependency|
name = name_for(dependency)
vertex = activated.vertex_named(name)
[
@base_dg.vertex_named(name) ? 0 : 1,
vertex.payload ? 0 : 1,
vertex.root? ? 0 : 1,
amount_constrained(dependency),
conflicts[name] ? 0 : 1,
vertex.payload ? 0 : search_for(dependency).count,
self.class.platform_sort_key(dependency.__platform),
]
end
end
def self.platform_sort_key(platform)
# Prefer specific platform to not specific platform
return ["99-LAST", "", "", ""] if Gem::Platform::RUBY == platform
["00", *platform.to_a.map {|part| part || "" }]
end
private
# returns an integer \in (-\infty, 0]
# a number closer to 0 means the dependency is less constraining
#
# dependencies w/ 0 or 1 possibilities (ignoring version requirements)
# are given very negative values, so they _always_ sort first,
# before dependencies that are unconstrained
def amount_constrained(dependency)
@amount_constrained ||= {}
@amount_constrained[dependency.name] ||= begin
if (base = @base[dependency.name]) && !base.empty?
dependency.requirement.satisfied_by?(base.first.version) ? 0 : 1
else
all = index_for(dependency).search(dependency.name).size
if all <= 1
all - 1_000_000
else
search = search_for(dependency)
search = @prerelease_specified[dependency.name] ? search.count : search.count {|s| !s.version.prerelease? }
search - all
end
end
end
end
def verify_gemfile_dependencies_are_found!(requirements)
requirements.map! do |requirement|
name = requirement.name
next requirement if name == "bundler"
next requirement unless search_for(requirement).empty?
next unless requirement.current_platform?
if (base = @base[name]) && !base.empty?
version = base.first.version
message = "You have requested:\n" \
" #{name} #{requirement.requirement}\n\n" \
"The bundle currently has #{name} locked at #{version}.\n" \
"Try running `bundle update #{name}`\n\n" \
"If you are updating multiple gems in your Gemfile at once,\n" \
"try passing them all to `bundle update`"
else
message = gem_not_found_message(name, requirement, source_for(name))
end
raise GemNotFound, message
end.compact!
end
def gem_not_found_message(name, requirement, source, extra_message = "")
specs = source.specs.search(name)
matching_part = name
requirement_label = SharedHelpers.pretty_dependency(requirement)
cache_message = begin
" or in gems cached in #{Bundler.settings.app_cache_path}" if Bundler.app_cache.exist?
rescue GemfileNotFound
nil
end
specs_matching_requirement = specs.select {| spec| requirement.matches_spec?(spec) }
if specs_matching_requirement.any?
specs = specs_matching_requirement
matching_part = requirement_label
requirement_label = "#{requirement_label} #{requirement.__platform}"
end
message = String.new("Could not find gem '#{requirement_label}'#{extra_message} in #{source}#{cache_message}.\n")
if specs.any?
message << "\nThe source contains the following gems matching '#{matching_part}':\n"
message << specs.map {|s| " * #{s.full_name}" }.join("\n")
end
message
end
def version_conflict_message(e)
# only show essential conflicts, if possible
conflicts = e.conflicts.dup
if conflicts["bundler"]
conflicts.replace("bundler" => conflicts["bundler"])
else
conflicts.delete_if do |_name, conflict|
deps = conflict.requirement_trees.map(&:last).flatten(1)
!Bundler::VersionRanges.empty?(*Bundler::VersionRanges.for_many(deps.map(&:requirement)))
end
end
e = Molinillo::VersionConflict.new(conflicts, e.specification_provider) unless conflicts.empty?
e.message_with_trees(
:full_message_for_conflict => lambda do |name, conflict|
o = if name.end_with?("\0")
String.new("Bundler found conflicting requirements for the #{name} version:")
else
String.new("Bundler could not find compatible versions for gem \"#{name}\":")
end
o << %(\n)
if conflict.locked_requirement
o << %( In snapshot (#{name_for_locking_dependency_source}):\n)
o << %( #{SharedHelpers.pretty_dependency(conflict.locked_requirement)}\n)
o << %(\n)
end
o << %( In #{name_for_explicit_dependency_source}:\n)
trees = conflict.requirement_trees
# called first, because we want to reduce the amount of work required to find maximal empty sets
trees = trees.uniq {|t| t.flatten.map {|dep| [dep.name, dep.requirement] } }
# bail out if tree size is too big for Array#combination to make any sense
if trees.size <= 15
maximal = 1.upto(trees.size).map do |size|
trees.map(&:last).flatten(1).combination(size).to_a
end.flatten(1).select do |deps|
Bundler::VersionRanges.empty?(*Bundler::VersionRanges.for_many(deps.map(&:requirement)))
end.min_by(&:size)
trees.reject! {|t| !maximal.include?(t.last) } if maximal
trees.sort_by! {|t| t.reverse.map(&:name) }
end
metadata_requirements = {}
o << trees.map do |tree|
t = "".dup
depth = 2
base_tree = tree.first
base_tree_name = base_tree.name
if base_tree_name.end_with?("\0")
metadata_requirements[base_tree_name] = base_tree
t = nil
else
tree.each do |req|
t << " " * depth << SharedHelpers.pretty_dependency(req)
unless tree.last == req
if spec = conflict.activated_by_name[req.name]
t << %( was resolved to #{spec.version}, which)
end
t << %( depends on)
end
t << %(\n)
depth += 1
end
end
t
end.compact.join("\n")
if name == "bundler"
o << %(\n Current Bundler version:\n bundler (#{Bundler::VERSION}))
conflict_dependency = conflict.requirement
conflict_requirement = conflict_dependency.requirement
other_bundler_required = !conflict_requirement.satisfied_by?(Gem::Version.new(Bundler::VERSION))
if other_bundler_required
o << "\n\n"
candidate_specs = source_for(:default_bundler).specs.search(conflict_dependency)
if candidate_specs.any?
target_version = candidate_specs.last.version
new_command = [File.basename($PROGRAM_NAME), "_#{target_version}_", *ARGV].join(" ")
o << "Your bundle requires a different version of Bundler than the one you're running.\n"
o << "Install the necessary version with `gem install bundler:#{target_version}` and rerun bundler using `#{new_command}`\n"
else
o << "Your bundle requires a different version of Bundler than the one you're running, and that version could not be found.\n"
end
end
elsif name.end_with?("\0")
o << %(\n Current #{name} version:\n #{SharedHelpers.pretty_dependency(metadata_requirements[name])}\n\n)
elsif conflict.locked_requirement
o << "\n"
o << %(Running `bundle update` will rebuild your snapshot from scratch, using only\n)
o << %(the gems in your Gemfile, which may resolve the conflict.\n)
elsif !conflict.existing
o << "\n"
relevant_source = conflict.requirement.source || source_for(name)
extra_message = if conflict.requirement_trees.first.size > 1
", which is required by gem '#{SharedHelpers.pretty_dependency(conflict.requirement_trees.first[-2])}',"
else
""
end
o << gem_not_found_message(name, conflict.requirement, relevant_source, extra_message)
end
o
end
)
end
end
end