Previously we were always loading an AssetEnvironment when we
precompiled any executable. Now we only load that environment if some
package dependended on by some executable actually uses a transformer.
Otherwise, we precompile from disk. The new approach is substantially
faster and produces better error messages.

Closes #1473

This replaces the hidden --no-package-symlinks flag.

Closes #1340

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//2250643003 .

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//2184303002 .

We still need to verify that a Flutter SDK constraint is only
used with an appropriate Dart SDK constraint.

See #1432

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//2165423002 .

This allows PackageName equality to include description equality, and it
substantially cleans up other logic dealing with sources.

See #912

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//2079303003 .

This splits Source into two classes, Source and LiveSource. The former
is completely independent of the system cache directory, and mostly
contains source metadata and logic about manipulating descriptions.

SourceRegistry now deals strictly in Sources, with LiveSources being
handled by SystemCache. This means that classes like Pubspec and
LockFile no longer have transitive references to the system cache
directory.

This will also make it possible to clean up PackageName equality logic
by making PackageNames track their concrete Sources rather than just
their source names.

See #912

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//2044253003 .

If a path dependency had a dependency back on the root package, it
would be detected as always stale because the root package isn't in the
lockfile. This changes the check to always consider that fresh, since
all dependencies on the root package are satisfied.

Closes #1416

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1985063004 .

We had a logic error wherein we were checking dependencies only
for cached packages when we should have been checking them only
for *uncached* packages.

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1956543002 .

Closes #1396

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1809993003 .

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1585513002 .

This considers the lockfile stale if the intersection of all selected
packages' SDK constraints don't match the current SDK, or if it contains
a path dependency whose own dependencies don't match the lockfile.

Closes #1091
Closes #1101

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1534093002 .

This folds the distinction between "resolved" and "unresolved"
descriptions into the distinction between PackageIds and PackageRefs. In
other words, all PackageIds now have resolved descriptions and all
PackageRefs now have unresolved descriptions. This makes it easier to
track which descriptions are resolved and express resolution constraints
via the type system.

This also restricts the creation of PackageRefs and PackageIds to source
classes, which helps ensure that the description format—which is an
implementation detail—doesn't leak into surrounding code.

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1528523003 .

When we tried to run a global script that didn't exist, we would try to
load an AssetEnvironment, which would try to compute the transformers
for it. Because the script doesn't exist, the computation would
conservatively assume that all transformers had to run in case one of
them generated it.

To find all the scripts, it iterated through the package's dependencies.
Since it's notionally the entrypoint, it tried to include its dev
dependencies, but this broke because dev dependencies aren't installed
for globally-activated packages.

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1413713010 .

Instead of relying only on modification times, this does a more complex
compatibility check if the modification times of the pubspec, lockfile,
and .packages file aren't ordered properly. If they are up-to-date, it
updates the modification times accordingly.

This also fixes a case where "pub run" wasn't properly checking that the
dependencies were up-to-date.

Closes #1322

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1307853004 .

Previously, several commands automatically ran "pub get" implicitly before doing
their work. We've determined that this behavior is confusing, and for "pub run"
in particular, makes the executables seem much slower than they actually are.

This also allows us to make access to the entrypoint's package graph
synchronous.

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1282533003 .

The spec doesn't actually need all the data loaded from the package
graph; all it needs are the locations of packages which can be looked up
using their IDs and a SourceRegistry.

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1282083002 .

This also has it store its SourceRegistry, so that various methods don't
need to re-supply it.

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1281043004 .

It never really made sense for this to be asynchronous; most sources
didn't even do any IO to determine the directory. The only exception was
the git source, which would actually *clone a repository* if one didn't
exist yet. This heavyweight behavior wasn't a good fit for what looks
like a lightweight method anyway.

Making this synchronous has a ripple effect of making a bunch of other
methods synchronous, too. Hooray for synchrony!

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1276673006 .

This reverts commit 7fbc1040, which
reverted commit dc626af3.

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1272903002 .

Currently we don't auto-run "pub get" if there's no lockfile and also no
dependencies. We should, in order to create a self-link.

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1277633004 .

This reverts commit dc626af3.

This broke due to dart-lang/sdk#23991.

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1272833003 .

Previously this was using the packages/ directory, but that's no longer
reliable since there's now an option to not generate it.

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1269393003 .

* The package spec's reference to the entrypoint package was pointing to
  the hosted cache rather than the package's directory. This was caused
  by the package graph's instance of the entrypoint package incorrectly
  pointing to the cache; the graph now re-uses `entrypoint.root`.

* The package spec didn't contain relative paths for relative path
  dependencies. This was being missed by our tests because the package
  spec parser was automatically converting all paths to absolute at
  parse-time.

Closes #1294

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//1228093003 .

R=nweiz@google.com

Review URL: https://codereview.chromium.org//1096723002.

BUG= http://dartbug.com/23113
R=kevmoo@google.com

Review URL: https://codereview.chromium.org//1087053003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@45147 260f80e4-7a28-3924-810f-c04153c831b5

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//868463003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@43057 260f80e4-7a28-3924-810f-c04153c831b5

This fixes the "Could not find asset" issue people were seeing on "pub
upgrade".

R=rnystrom@google.com
BUG=21810

Review URL: https://codereview.chromium.org//792993004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@42273 260f80e4-7a28-3924-810f-c04153c831b5

This also makes "pub cache repair" repair activated packages, including updating
the binstub format.

R=rnystrom@google.com
BUG=21463

Review URL: https://codereview.chromium.org//745153002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@42055 260f80e4-7a28-3924-810f-c04153c831b5

This also makes pub print more detailed timing information in
--verbose mode.

R=rnystrom@google.com
BUG=20859

Review URL: https://codereview.chromium.org//600293002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41407 260f80e4-7a28-3924-810f-c04153c831b5

BUG=https://github.com/dart-lang/async_await/issues/68
R=ricow@google.com

Review URL: https://codereview.chromium.org//655703004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41126 260f80e4-7a28-3924-810f-c04153c831b5

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//655943002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41112 260f80e4-7a28-3924-810f-c04153c831b5

A package's executables may not use all of that package's transformers. This is
especially true for browser frameworks where there's a clear divide between
client-side and server-side code. This uses pub's existing dependency-sniffing
infrastructure to figure out which transformers can be omitted.

This takes "pub run polymer:new_element --help" from 1.52s to 0.96s.

R=rnystrom@google.com
BUG=20859

Review URL: https://codereview.chromium.org//599993004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@40659 260f80e4-7a28-3924-810f-c04153c831b5

BUG=20859
R=rnystrom@google.com

Review URL: https://codereview.chromium.org//583853002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@40612 260f80e4-7a28-3924-810f-c04153c831b5

R=nweiz@google.com

Review URL: https://codereview.chromium.org//586173002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@40598 260f80e4-7a28-3924-810f-c04153c831b5

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//581283003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@40559 260f80e4-7a28-3924-810f-c04153c831b5

R=rnystrom@google.com
BUG=20859

Review URL: https://codereview.chromium.org//576333002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@40477 260f80e4-7a28-3924-810f-c04153c831b5

This shaves off a pretty significant amount of time for packages that are
transformed but whose transformers never change (I saw a ~450ms gain in one of
my tests).

R=rnystrom@google.com
BUG=20859

Review URL: https://codereview.chromium.org//559833004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@40392 260f80e4-7a28-3924-810f-c04153c831b5

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//548603002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@39938 260f80e4-7a28-3924-810f-c04153c831b5