Merge branch 'master' into core-updates

Factorize test suite support in (guix tests).

* guix/tests.scm: New file.
* Makefile.am (noinst_DATA): New variable.
  (GOBJECTS): Add guix/tests.go.
* tests/builders.scm (%store): Use 'open-connection-for-tests'
  from (guix tests).
* tests/derivations.scm: Likewise.
* tests/monads.scm: Likewise.
* tests/packages.scm: Likewise.
* tests/profiles.scm: Likewise.
* tests/union.scm: Likewise.
* tests/gexp.scm: Likewise.
  (guile-for-build): Remove.  Use (%guile-for-build) instead.
* tests/nar.scm (make-random-bytevector, %seed, random-text): Remove.
  (populate-file): Change 'make-random-bytevector' to 'random-bytevector'.
  Use (guix tests).
* tests/store.scm (%seed, random-text): Remove.
  Use (guix tests).

Merge branch 'master' into core-updates

gexp: Add 'ungexp-native' and 'ungexp-native-splicing'.

* guix/gexp.scm (<gexp>)[natives]: New field.
  (write-gexp): Use both 'gexp-references' and
  'gexp-native-references'.
  (gexp->derivation): Use both 'gexp-inputs' and 'gexp-native-inputs',
  and append them.
  (gexp-inputs): Add 'references' parameter and honor it.
  (gexp-native-inputs): New procedure.
  (gexp->sexp)[reference->sexp]: Add 'native?' parameter and honor it.
  Use it, and use 'gexp-native-references'.
  (gexp)[collect-native-escapes]: New procedure.
  [escape->ref]: Handle 'ungexp-native' and 'ungexp-native-splicing'.
  [substitute-ungexp, substitute-ungexp-splicing]: New procedures.
  [substitute-references]: Use them, and handle 'ungexp-native' and
  'ungexp-native-splicing'.
  Adjust generated 'make-gexp' call to provide both normal references
  and native references.
  [read-ungexp]: Support 'ungexp-native' and
  'ungexp-native-splicing'.
  Add reader extension for #+.
* tests/gexp.scm (gexp-native-inputs): New procedure.
  (gexp->sexp*): Add 'target' parameter.
  ("ungexp + ungexp-native",
  "input list + ungexp-native",
  "input list splicing + ungexp-native-splicing",
  "gexp->derivation, ungexp-native",
  "gexp->derivation, ungexp + ungexp-native"): New tests.
  ("sugar"): Add tests for #+ and #+@.
* doc/guix.texi (G-Expressions): Document 'ungexp-native' et al.

gexp: Add #:target parameter to 'gexp->derivation'.

* guix/gexp.scm (lower-inputs): Add #:system and #:target.  Use
  'package->cross-derivation' when TARGET is true.  Honor SYSTEM.
  (gexp->derivation): Add #:target argument.  Pass SYSTEM and TARGET to
  'lower-inputs' and 'gexp->sexp'.
  (gexp->sexp): Add #:system and #:target.  Pass them in recursive call
  and to 'package-file'.
* tests/gexp.scm (gexp->sexp*): Add 'system' and 'target' parameters.
  ("gexp->derivation, cross-compilation"): New test.

Merge branch 'master' into core-updates

build: Better reject systems where the shebang would be too long.

* tests/gexp.scm (shebang): Add "#!".

gexp: Gracefully handle printing of gexps with spliced references.

* guix/gexp.scm (write-gexp): Wrap 'write' call in
  'false-if-exception'.
* tests/gexp.scm ("printer", "printer vs. ungexp-splicing"): New tests.

gexp: Resolve the default system at '>>=' time.

Partly fixes <http://bugs.gnu.org/18002>.
Reported by David Thompson <dthompson2@worcester.edu>.

* guix/gexp.scm (gexp->derivation): Change #:system to default #f.
  Use (%current-system) from within the 'mlet*'.
* tests/gexp.scm ("gexp->derivation, default system"): New test.

Merge branch 'master' into core-updates

tests: Skip tests that would hit the shebang length limitation.

* tests/gexp.scm (shebang): New variable.
  Skip "gexp->script" when SHEBANG is longer than 127 chars.
* guix/gexp.scm (gexp->script): Add comment on the issue.

Merge branch 'master' into core-updates

gexp: Add support for 'origin?' objects in 'ungexp' forms.

* guix/gexp.scm (lower-inputs, gexp-inputs, gexp->sexp,
  canonicalize-reference): Add 'origin?' case.
* guix/monads.scm (origin->derivation): New procedure.
* tests/gexp.scm ("one input origin"): New test.

Add (guix gexp).

* guix/gexp.scm: New file.
* tests/gexp.scm: New file.
* Makefile.am (MODULES): Add guix/gexp.scm.
  (SCM_TESTS): Add tests/gexp.scm.
* doc/guix.texi (Derivations): Add #:inputs in 'derivation' example.
  Mark 'build-expression->derivation' as deprecated, refer to
  "G-Expressions".  Remove paragraph about code strata.
  (G-Expressions): New node.