Since this fixes #3858

The addBuildableCondition function was added to solve the problem with
"buildable: False". The problem was that we would solve or check
dependencies on the basis of the component in question being needed, and
then at the end discover that the component is actually not buildable at
all, and if we'd known that up front we would not have solved for the
component's dependencies.

The trick that addBuildableCondition does is a syntactic transformation,
from components like:

executable blah
  buildable: False
  build-depends: foo >= 1, bar < 2
  something-else: whatever

to:

executable blah
  -- empty!

Or at least, that's the intention. In the above situation the
implementation of addBuildableCondition returns an empty CondNode:

CondNode mempty mempty []

The type at which mempty is used is important here. This transformation
is used in two places: one in the solver and the other in finalizePD.
In the solver the mempty is used at types from the PackageDescription:
Library, Executable, TestSuite etc. So in this case the transformation
works fine we end up with empty executables, test suites etc.

In finalizePD however the mempty gets used at type PDTagged (which is
sort of a union of Library, Executable etc plus none/null) and the
mempty for PDTagged is PDNull which means it does not even specify
which component we're referring to. So effectively that means instead of
ending up with an empty executable in the above example, we end up
deleting the executable entirely!

This was a change in behaviour. Prior to adding addBuildableCondition
the result of finalizePD would include non-buildable components and the
rest of the build system infrastructure was set up to skip over them
when building. The change was not noticed precisely because the rest of
the system was already set up to ignore non-buildable components.

This is not however a benign change in behaviour. In particular in
cabal-install in the install plan we end up completley forgetting about
all the non-buildable components. This means we cannot even report that
components are non-buildable when users ask to build them, because we've
completely forgotten that they exist.

So this patch keeps the original addBuildableCondition for use by the
solver since the solver uses it at sensible monoid types. The patch adds
a special version for the PDTagged type which changes the transformation
so that in the above example we end up with:

executable blah
  buildable: False
  something-else: whatever

So we've stripped out all the build-depends but we keep everything else,
including of course the "buildable: False".

Implement +nowrap verbosity flag to suppress log-msg line-wrapping

Unfortunately, propagating the `Verbosity` to the `topHandler`
proves to be more complicated.

This is mostly a problem for `die` invocations which are translated
into user-error exceptions (which in turn then cause callstacks
to be printed; are we abusing `die`?)

Improve error output when package fails to build.

Fix redundant import warning from Parsec.

Add more fields to plan.json schema

[skip ci] to reuse ci-status from PR

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

This adds the following new fields:

 - `.compiler-id`
 - `.os`
 - `.arch`
 - `.install-plan[].pkg-name`
 - `.install-plan[].pkg-version`
 - `.install-plan[].pkg-src-sha256`

Having separate "pkg-{name,version}" fields is desirable because the "id"-field
is actually a UnitId which is supposed to be an opaque id which may not
always be easily convertible into a PackageId via string operations.

The "pkg-src-sha256" is generally useful to uniquely identify a
source-tarball (when the package-id is not exact enough).

Finally, the compiler-id/os/arch information is needed to determine the
values of the respective impl()/os()/arch() predicates used in
conditionals in .cabal files.

Here's an example demonstrating the new fields:

    {
      "cabal-version": "1.25.0.0",
      "cabal-lib-version": "1.25.0.0",
      "compiler-id": "ghc-8.0.1",
      "os": "linux",
      "arch": "x86_64",
      "install-plan": [
	{
	  "type": "configured",
	  "id": "StateVar-1.1.0.4-048d5d25d5813f17f152f9e766fe3ea0ef6f5317439aa115f3fc24e53a0e3c17",
	  "pkg-name": "StateVar",
	  "pkg-version": "1.1.0.4",
	  "flags": {},
	  "style": "global",
	  "pkg-src-sha256": "7ad68decb5c9a76f83c95ece5fa13d1b053e4fb1079bd2d3538f6b05014dffb7",
	  "depends": [
	    "base-4.9.0.0",
	    "stm-2.4.4.1-2c7789312d2396a91db173e1ae8cf3a9af3dd18de42bb1021c4978fbab49c191",
	    "transformers-0.5.2.0"
	  ],
	  "exe-depends": [],
	  "component-name": "lib"
	},
        {
          "type": "pre-existing",
          "id": "rts",
          "pkg-name": "rts",
          "pkg-version": "1.0",
          "depends": []
        },
	{
	  "type": "configured",
	  "id": "hackage-matrix-builder3-0.3-inplace-matrix-lib",
	  "pkg-name": "hackage-matrix-builder3",
	  "pkg-version": "0.3",
	  "component-name": "lib:matrix-lib"
	  ...
	}
	...
    }

New error message is:

cabal: Failed to build p-1.0 (which is required by exe:e4 from p-1.0, exe:e3
from p-1.0 and others).

Fixes #4081.

TODO: Use these utility functions in other appropriate places.

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Edward Z. Yang authored 8 years ago and Edward Z. Yang committed 8 years ago

The idea is we can use Rep to get a full, structural representation
of a type, and the fingerprint it using Typeable.  This gives
us a very concise way of fingerprinting our Binary representation.

This patch is not completely correct; the fingerprint needs
to be overridable when someone writes a custom Binary instance.
But this should be "good enough" in practice; we're not using
these fingerprints to check anything security critical.

TODO: Not sure if I have tagged all the call-sites which could
profit from this.

Fixes #4059.

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Edward Z. Yang authored 8 years ago and Edward Z. Yang committed 8 years ago

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

No LambdaCase, resolve #4079

Before:

    cabal new-build               Build the package in the current
  directory or all packages in the project
    cabal new-build pkgname       Build the package named pkgname in the
  project
    cabal new-build cname       Build the component named cname in the
  project
    cabal new-build pkgname:cname       Build the component named cname
  in the package pkgname

After:

    cabal new-build               Build the package in the current
  directory or all packages in the project
    cabal new-build pkgname       Build the package named pkgname in the
  project
    cabal new-build cname         Build the component named cname in the
  project
    cabal new-build pkgname:cname Build the component named cname in the
  package pkgname

new-configure: Select the same plan subset as new-build.

Fix missing line pointed out by @abooij.

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Before:

$ cabal new-configure
Resolving dependencies...
In order, the following would be built (use -v for more details):
 - Crypto-4.2.5.1 (exe:SymmetricTest) (requires build)
 - Crypto-4.2.5.1 (exe:WordListTest) (requires build)
 - Crypto-4.2.5.1 (exe:SHA1Test) (requires build)
 - Crypto-4.2.5.1 (exe:QuickTest) (requires build)
 - Crypto-4.2.5.1 (exe:RSATest) (requires build)
 - Crypto-4.2.5.1 (exe:HMACTest) (requires build)
 - HaXml-1.25.3 (exe:Xtract) (requires build)
 - HaXml-1.25.3 (exe:Validate) (requires build)
 - HaXml-1.25.3 (exe:MkOneOf) (requires build)
 - HaXml-1.25.3 (exe:CanonicaliseLazy) (requires build)
 - HaXml-1.25.3 (exe:Canonicalise) (requires build)
 - HaXml-1.25.3 (exe:XsdToHaskell) (requires build)
 - HaXml-1.25.3 (exe:DtdToHaskell) (requires build)
 - HaXml-1.25.3 (exe:FpMLToHaskell) (requires build)
 - aeson-pretty-0.8.1 (exe:aeson-pretty) (requires build)
 - cpphs-1.20.2 (exe:cpphs) (requires build)
 - hS3-0.5.9 (exe:hs3) (requires build)
 - yaml-0.8.18 (exe:json2yaml) (requires build)
 - yaml-0.8.18 (exe:yaml2json) (requires build)

$ cabal new-build
Resolving dependencies...
Up to date

After:

$ cabal new-configure
Resolving dependencies...
Up to date

$ cabal new-build
Resolving dependencies...
Up to date

Make more dependency types

Deduplicate version checks in cabal-testsuite

    Plain `Dependency` should strictly refer to a Haskell Package, usually the
    library component of that package.

Duplication introduced by #4065.

Is this an intentional inconsistency with the old parser?

[WIP] Use UnqualComponentName newtype instead of String for component names

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Auke Booij authored 8 years ago and Edward Z. Yang committed 8 years ago

Also bump version requirements for foreign libs (ghc>=7.8)

@phadej says no code on Hackage uses this, and the new parser
already disallows it.

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Herbert Valerio Riedel authored 8 years ago and Edward Z. Yang committed 8 years ago

Construction and destruction follows the usual pattern with `mkFlagName`
& `unFlagName` functions.

Edward Z. Yang authored 8 years ago and Edward Z. Yang committed 8 years ago

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Edward Z. Yang authored 8 years ago and Edward Z. Yang committed 8 years ago

The key idea is that once we put PackageTests in its own package, we can
ensure that its Setup.hs is compiled with the same version of Cabal
library as package-tests is compiled with.  This means that LBI reading
will *always succeed* which is quite nice.

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

[skip ci] Minor reorg of profiling documentation.