Fine-grained dependencies #2514
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
It turns out not to be the right solution for general private dependencies and is just complicated. However we keep qualified goals, just much simpler. Now dependencies simply inherit the qualification of their parent goal. This gets us closer to the intended behaviour for the --independent-goals feature, and for the simpler case of private dependencies for setup scripts. When not using --independent-goals, the solver behaves exactly as before (tested by comparing solver logs for a hard hackage goal). When using --independent-goals, now every dep of each independent goal is qualified, so the dependencies are solved completely independently (which is actually too much still).
POption annotates a package choice with a "linked to" field. This commit just introduces the datatype and deals with the immediate fallout, it doesn't actually use the field for anything.
This is implemented as a separate pass so that it can be understood independently of the rest of the solver.
In particular, in the definition of dependencyInconsistencies. One slightly annoying thing is that in order to validate an install plan, we need to know if the goals are to be considered independent. This means we need to pass an additional Bool to a few functions; to limit the number of functions where this is necessary, also recorded whether or not goals are independent as part of the InstallPlan itself.
Since we didn't really have a unit test setup for the solver yet, this introduces some basic tests for solver, as well as tests for independent goals specifically.
This address @23Skidoo's comment #2500 (comment)
I don't know why we we constructed this graph manually here rather than calling `graphFromEdges`; it doesn't really matter except that we will want to change the structure of this graph somewhat once we have more fine-grained dependencies, and then the manual construction becomes a bit more painful; easier to use the standard construction.
This commit does nothing but rearrange the Modular.Dependency module into a number of separate sections, so that's a bit clearer to see what's what. No actual code changes here whatsoever.
The ComponentDeps datatype will give us fine-grained information about the dependencies of a package's components. This commit just introduces the datatype, we don't use it anywhere yet.
The modular solver has its own representation for a package (PInfo). In this commit we modify PInfo to keep track of the different kinds of dependencies. This is a bit intricate because the solver also regards top-level goals as dependencies, but of course those dependencies are not part of any 'component' as such, unlike "real" dependencies. We model this by adding a type parameter to FlaggedDeps and go which indicates whether or not we have component information; crucially, underneath flag choices we _always_ have component information available. Consequently, the modular solver itself will not make use of the ComponentDeps datatype (but only using the Component type, classifying components); we will use ComponentDeps when we translate out of the results from the modular solver into cabal-install's main datatypes. We don't yet _return_ fine-grained dependencies from the solver; this will be the subject of the next commit.
In this commit we modify the _output_ of the modular solver (CP, the modular's solver internal version of ConfiguredPackage) to have fine-grained dependency. This doesn't yet modify the rest of cabal-install, so once we translate from CP to ConfiguredPackage we still lose the distinctions between different kinds of dependencies; this will be the topic of the next commit. In the modular solver (and elsewhere) we use Data.Graph to represent the dependency graph (and the reverse dependency graph). However, now that we have more fine-grained dependencies, we really want an _edge-labeled_ graph, which unfortunately it not available in the `containers` package. Therefore I've written a very simple wrapper around Data.Graph that supports edge labels; we don't need many fancy graph algorithms, and can still use Data.Graph on these edged graphs when we want (by calling them on the underlying unlabeled graph), so adding a dependency on `fgl` does not seem worth it.
The crucial change in this commit is the change to PackageFixedDeps to return a
ComponentDeps structure, rather than a flat list of dependencies, as long with
corresponding changes in ConfiguredPackage and ReadyPackage to accomodate this.
We don't actually take _advantage_ of these more fine-grained dependencies yet;
any use of
depends
is now a use of
CD.flatDeps . depends
but we will :)
Note that I have not updated the top-down solver, so in the output of the
top-down solver we cheat and pretend that all dependencies are library
dependencies.
|
Tests fail on Travis for some reason. |
|
Something strange is going on here.. I tried to reproduce this (checked out this branch, compiled, ran the tests), tests pass. Ran |
|
Ok, I'm not sure where my false positives where coming from, but i suspect something to do with the fact that I override |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This PR depends on #2500 and #2504, and it is the last PR before the introduction of setup dependencies proper.
Although we have fine grained dependencies in the
.cabalfile, and correspondingly in thePackageDescription(andGenericPackageDescription), the distinction between the various kinds of dependencies (dependencies of the library proper as well as the dependencies of the various executables, test-suites and benchmarks) was lost after the solver. In this PR I modify the solver so that it keeps these distinctions, and correspondingly modifyConfiguredPackage,ReadyPackage, and thePackageFixedDepsclass to use a new data-structure calledComponentDepswhich records dependencies per component.This distinction will be crucial in the next PR where we want to treat setup dependencies as independent, but will also be very important in subsequent related features, such as treating the dependencies of the test suites as independent.
/cc @kosmikus