Added a sub-command to show if packages are relocatable (#9199)

* Added the `spack buildcache preview` sub-command

This is similar to `spack spec -I` but highlights which nodes in a DAG
are relocatable and which are not.

spec.tree has been generalized a little to accept a status function,
instead of always showing the install status

The current implementation works only for ELF, and needs to be
generalized to other platforms.

* Added a test to check if an executable is relocatable or not

This test requires a few commands to be present in the environment.
Currently it will run only under python 3.7 (which uses Xenial instead
of Trusty).

* Added tests for the 'buildcache preview' command.

* Fixed codebase after rebase

* Fixed the list of apt addons for Python 3.7 in travis.yaml

* Only check ELF executables and shared libraries. Skip checking virtual or external packages. (#229)

* Fixed flake8 issues

* Add handling for macOS mach binaries (#231)

10 files changed, 309 insertions, 25 deletions

diff --git a/lib/spack/llnl/util/lang.py b/lib/spack/llnl/util/lang.py
index 03783265dd..21eb9ee3ba 100644
--- a/lib/spack/llnl/util/lang.py
+++ b/lib/spack/llnl/util/lang.py
@@ -324,7 +324,7 @@ def check_kwargs(kwargs, fun):
     if kwargs:
         raise TypeError(
             "'%s' is an invalid keyword argument for function %s()."
-            % (next(kwargs.iterkeys()), fun.__name__))
+            % (next(iter(kwargs)), fun.__name__))
 
 
 def match_predicate(*args):
diff --git a/lib/spack/spack/cmd/buildcache.py b/lib/spack/spack/cmd/buildcache.py
index fe91312c42..9824f96cb4 100644
--- a/lib/spack/spack/cmd/buildcache.py
+++ b/lib/spack/spack/cmd/buildcache.py
@@ -8,9 +8,15 @@ import os
 import sys
 
 import llnl.util.tty as tty
-
+import spack.binary_distribution as bindist
 import spack.cmd
+import spack.cmd.common.arguments as arguments
 import spack.environment as ev
+import spack.relocate
+import spack.repo
+import spack.spec
+import spack.store
+
 from spack.error import SpecError
 import spack.config
 import spack.repo
@@ -19,8 +25,6 @@ from spack.paths import etc_path
 from spack.spec import Spec, save_dependency_spec_yamls
 from spack.spec_set import CombinatorialSpecSet
 
-import spack.binary_distribution as bindist
-import spack.cmd.common.arguments as arguments
 from spack.cmd import display_specs
 
 description = "create, download and install binary packages"
@@ -100,6 +104,15 @@ def setup_parser(subparser):
                         help="force new download of keys")
     dlkeys.set_defaults(func=getkeys)
 
+    preview_parser = subparsers.add_parser(
+        'preview',
+        help='analyzes an installed spec and reports whether '
+             'executables and libraries are relocatable'
+    )
+    preview_parser.add_argument(
+        'packages', nargs='+', help='list of installed packages'
+    )
+    preview_parser.set_defaults(func=preview)
     # Check if binaries need to be rebuilt on remote mirror
     check = subparsers.add_parser('check', help=check_binaries.__doc__)
     check.add_argument(
@@ -176,8 +189,7 @@ def setup_parser(subparser):
     saveyaml.set_defaults(func=save_spec_yamls)
 
 
-def find_matching_specs(
-        pkgs, allow_multiple_matches=False, force=False, env=None):
+def find_matching_specs(pkgs, allow_multiple_matches=False, env=None):
     """Returns a list of specs matching the not necessarily
        concretized specs given from cli
 
@@ -293,7 +305,7 @@ def createtarball(args):
     # restrict matching to current environment if one is active
     env = ev.get_env(args, 'buildcache create')
 
-    matches = find_matching_specs(pkgs, False, False, env=env)
+    matches = find_matching_specs(pkgs, env=env)
 
     if matches:
         tty.msg('Found at least one matching spec')
@@ -378,6 +390,22 @@ def getkeys(args):
     bindist.get_keys(args.install, args.trust, args.force)
 
 
+def preview(args):
+    """Print a status tree of the selected specs that shows which nodes are
+    relocatable and which might not be.
+
+    Args:
+        args: command line arguments
+    """
+    specs = find_matching_specs(args.packages, allow_multiple_matches=True)
+
+    # Cycle over the specs that match
+    for spec in specs:
+        print("Relocatable nodes")
+        print("--------------------------------")
+        print(spec.tree(status_fn=spack.relocate.is_relocatable))
+
+
 def check_binaries(args):
     """Check specs (either a single spec from --spec, or else the full set
     of release specs) against remote binary mirror(s) to see if any need
diff --git a/lib/spack/spack/cmd/spec.py b/lib/spack/spack/cmd/spec.py
index 64510df23e..f60e5f1283 100644
--- a/lib/spack/spack/cmd/spec.py
+++ b/lib/spack/spack/cmd/spec.py
@@ -13,6 +13,7 @@ import llnl.util.tty as tty
 import spack
 import spack.cmd
 import spack.cmd.common.arguments as arguments
+import spack.spec
 
 description = "show what would be installed, given a spec"
 section = "build"
@@ -42,11 +43,14 @@ def setup_parser(subparser):
 
 def spec(parser, args):
     name_fmt = '$.' if args.namespaces else '$_'
-    kwargs = {'cover': args.cover,
-              'format': name_fmt + '$@$%@+$+$=',
-              'hashlen': None if args.very_long else 7,
-              'show_types': args.types,
-              'install_status': args.install_status}
+    install_status_fn = spack.spec.Spec.install_status
+    kwargs = {
+        'cover': args.cover,
+        'format': name_fmt + '$@$%@+$+$=',
+        'hashlen': None if args.very_long else 7,
+        'show_types': args.types,
+        'status_fn': install_status_fn if args.install_status else None
+    }
 
     if not args.specs:
         tty.die("spack spec requires at least one spec")
diff --git a/lib/spack/spack/environment.py b/lib/spack/spack/environment.py
index 57a7f8c454..e9e3328bf6 100644
--- a/lib/spack/spack/environment.py
+++ b/lib/spack/spack/environment.py
@@ -595,8 +595,10 @@ class Environment(object):
 
                 # Display concretized spec to the user
                 sys.stdout.write(concrete.tree(
-                    recurse_dependencies=True, install_status=True,
-                    hashlen=7, hashes=True))
+                    recurse_dependencies=True,
+                    status_fn=spack.spec.Spec.install_status,
+                    hashlen=7, hashes=True)
+                )
 
     def install(self, user_spec, concrete_spec=None, **install_args):
         """Install a single spec into an environment.
diff --git a/lib/spack/spack/relocate.py b/lib/spack/spack/relocate.py
index 2d3bc6f837..6e508c1881 100644
--- a/lib/spack/spack/relocate.py
+++ b/lib/spack/spack/relocate.py
@@ -9,8 +9,9 @@ import platform
 import re
 import spack.repo
 import spack.cmd
+import llnl.util.lang
+import llnl.util.filesystem as fs
 from spack.util.executable import Executable, ProcessError
-from llnl.util.filesystem import filter_file
 import llnl.util.tty as tty
 
 
@@ -327,7 +328,7 @@ def relocate_binary(path_names, old_dir, new_dir, allow_root):
             if (not allow_root and
                 old_dir != new_dir and
                 strings_contains_installroot(path_name, old_dir)):
-                    raise InstallRootStringException(path_name, old_dir)
+                raise InstallRootStringException(path_name, old_dir)
 
     elif platform.system() == 'Linux':
         for path_name in path_names:
@@ -346,7 +347,7 @@ def relocate_binary(path_names, old_dir, new_dir, allow_root):
                 if (not allow_root and
                     old_dir != new_dir and
                     strings_contains_installroot(path_name, old_dir)):
-                        raise InstallRootStringException(path_name, old_dir)
+                    raise InstallRootStringException(path_name, old_dir)
     else:
         tty.die("Relocation not implemented for %s" % platform.system())
 
@@ -379,7 +380,7 @@ def make_binary_relative(cur_path_names, orig_path_names, old_dir, allow_root):
                                 new_rpaths, new_deps, new_idpath)
             if (not allow_root and
                 strings_contains_installroot(cur_path)):
-                    raise InstallRootStringException(cur_path)
+                raise InstallRootStringException(cur_path)
     elif platform.system() == 'Linux':
         for cur_path, orig_path in zip(cur_path_names, orig_path_names):
             orig_rpaths = get_existing_elf_rpaths(cur_path)
@@ -389,7 +390,7 @@ def make_binary_relative(cur_path_names, orig_path_names, old_dir, allow_root):
                 modify_elf_object(cur_path, new_rpaths)
                 if (not allow_root and
                     strings_contains_installroot(cur_path, old_dir)):
-                        raise InstallRootStringException(cur_path, old_dir)
+                    raise InstallRootStringException(cur_path, old_dir)
     else:
         tty.die("Prelocation not implemented for %s" % platform.system())
 
@@ -466,8 +467,7 @@ def relocate_text(path_names, old_dir, new_dir):
     """
     Replace old path with new path in text file path_name
     """
-    filter_file('%s' % old_dir, '%s' % new_dir,
-                *path_names, backup=False)
+    fs.filter_file('%s' % old_dir, '%s' % new_dir, *path_names, backup=False)
 
 
 def substitute_rpath(orig_rpath, topdir, new_root_path):
@@ -479,3 +479,127 @@ def substitute_rpath(orig_rpath, topdir, new_root_path):
         new_rpath = path.replace(topdir, new_root_path)
         new_rpaths.append(new_rpath)
     return new_rpaths
+
+
+def is_relocatable(spec):
+    """Returns True if an installed spec is relocatable.
+
+    Args:
+        spec (Spec): spec to be analyzed
+
+    Returns:
+        True if the binaries of an installed spec
+        are relocatable and False otherwise.
+
+    Raises:
+        ValueError: if the spec is not installed
+    """
+    if not spec.install_status():
+        raise ValueError('spec is not installed [{0}]'.format(str(spec)))
+
+    if spec.external or spec.virtual:
+        return False
+
+    # Explore the installation prefix of the spec
+    for root, dirs, files in os.walk(spec.prefix, topdown=True):
+        dirs[:] = [d for d in dirs if d not in ('.spack', 'man')]
+        abs_files = [os.path.join(root, f) for f in files]
+        if not all(file_is_relocatable(f) for f in abs_files if is_binary(f)):
+            # If any of the file is not relocatable, the entire
+            # package is not relocatable
+            return False
+
+    return True
+
+
+def file_is_relocatable(file):
+    """Returns True if the file passed as argument is relocatable.
+
+    Args:
+        file: absolute path of the file to be analyzed
+
+    Returns:
+        True or false
+
+    Raises:
+
+        ValueError: if the file does not exist or the path is not absolute
+    """
+
+    if not (platform.system().lower() == 'darwin'
+            or platform.system().lower() == 'linux'):
+        msg = 'function currently implemented only for linux and macOS'
+        raise NotImplementedError(msg)
+
+    if not os.path.exists(file):
+        raise ValueError('{0} does not exist'.format(file))
+
+    if not os.path.isabs(file):
+        raise ValueError('{0} is not an absolute path'.format(file))
+
+    strings = Executable('strings')
+    patchelf = Executable('patchelf')
+
+    # Remove the RPATHS from the strings in the executable
+    set_of_strings = set(strings(file, output=str).split())
+
+    m_type, m_subtype = mime_type(file)
+    if m_type == 'application':
+        tty.debug('{0},{1}'.format(m_type, m_subtype))
+
+    if platform.system().lower() == 'linux':
+        if m_subtype == 'x-executable' or m_subtype == 'x-sharedlib':
+            rpaths = patchelf('--print-rpath', file, output=str).strip()
+            set_of_strings.discard(rpaths.strip())
+    if platform.system().lower() == 'darwin':
+        if m_subtype == 'x-mach-binary':
+            rpaths, deps, idpath  = macho_get_paths(file)
+            set_of_strings.discard(set(rpaths))
+            set_of_strings.discard(set(deps))
+            if idpath is not None:
+                set_of_strings.discard(idpath)
+
+    if any(spack.store.layout.root in x for x in set_of_strings):
+        # One binary has the root folder not in the RPATH,
+        # meaning that this spec is not relocatable
+        msg = 'Found "{0}" in {1} strings'
+        tty.debug(msg.format(spack.store.layout.root, file))
+        return False
+
+    return True
+
+
+def is_binary(file):
+    """Returns true if a file is binary, False otherwise
+
+    Args:
+        file: file to be tested
+
+    Returns:
+        True or False
+    """
+    m_type, _ = mime_type(file)
+
+    msg = '[{0}] -> '.format(file)
+    if m_type == 'application':
+        tty.debug(msg + 'BINARY FILE')
+        return True
+
+    tty.debug(msg + 'TEXT FILE')
+    return False
+
+
+@llnl.util.lang.memoized
+def mime_type(file):
+    """Returns the mime type and subtype of a file.
+
+    Args:
+        file: file to be analyzed
+
+    Returns:
+        Tuple containing the MIME type and subtype
+    """
+    file_cmd = Executable('file')
+    output = file_cmd('-b', '--mime-type', file, output=str, error=str)
+    tty.debug('[MIME_TYPE] {0} -> {1}'.format(file, output.strip()))
+    return tuple(output.strip().split('/'))
diff --git a/lib/spack/spack/spec.py b/lib/spack/spack/spec.py
index d37a6e402f..76c06d3fd7 100644
--- a/lib/spack/spack/spec.py
+++ b/lib/spack/spack/spec.py
@@ -3251,7 +3251,7 @@ class Spec(object):
         ret = self.format() + self.dep_string()
         return ret.strip()
 
-    def _install_status(self):
+    def install_status(self):
         """Helper for tree to print DB install status."""
         if not self.concrete:
             return None
@@ -3278,7 +3278,7 @@ class Spec(object):
         depth = kwargs.pop('depth', False)
         hashes = kwargs.pop('hashes', False)
         hlen = kwargs.pop('hashlen', None)
-        install_status = kwargs.pop('install_status', False)
+        status_fn = kwargs.pop('status_fn', False)
         cover = kwargs.pop('cover', 'nodes')
         indent = kwargs.pop('indent', 0)
         fmt = kwargs.pop('format', '$_$@$%@+$+$=')
@@ -3300,8 +3300,8 @@ class Spec(object):
             if depth:
                 out += "%-4d" % d
 
-            if install_status:
-                status = node._install_status()
+            if status_fn:
+                status = status_fn(node)
                 if status is None:
                     out += colorize("@K{ - }  ", color=color)  # not installed
                 elif status:
diff --git a/lib/spack/spack/test/cmd/buildcache.py b/lib/spack/spack/test/cmd/buildcache.py
new file mode 100644
index 0000000000..329f3501d5
--- /dev/null
+++ b/lib/spack/spack/test/cmd/buildcache.py
@@ -0,0 +1,21 @@
+# Copyright 2013-2018 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+import platform
+
+import pytest
+
+import spack.main
+
+
+buildcache = spack.main.SpackCommand('buildcache')
+
+
+@pytest.mark.skipif(
+    platform.system().lower() != 'linux',
+    reason='implementation for MacOS still missing'
+)
+def test_buildcache_preview_just_runs(database):
+    buildcache('preview', 'mpileaks')
diff --git a/lib/spack/spack/test/data/templates/non_relocatable.c b/lib/spack/spack/test/data/templates/non_relocatable.c
new file mode 100644
index 0000000000..c2e3724c2c
--- /dev/null
+++ b/lib/spack/spack/test/data/templates/non_relocatable.c
@@ -0,0 +1,5 @@
+#include <stdio.h>
+
+int main(){
+    printf("Hello World from {{ prefix }} !");
+}
diff --git a/lib/spack/spack/test/data/templates/relocatable.c b/lib/spack/spack/test/data/templates/relocatable.c
new file mode 100644
index 0000000000..f3e4959692
--- /dev/null
+++ b/lib/spack/spack/test/data/templates/relocatable.c
@@ -0,0 +1,5 @@
+#include <stdio.h>
+
+int main(){
+    printf("Hello World!");
+}
diff --git a/lib/spack/spack/test/relocate.py b/lib/spack/spack/test/relocate.py
new file mode 100644
index 0000000000..083686d5e6
--- /dev/null
+++ b/lib/spack/spack/test/relocate.py
@@ -0,0 +1,95 @@
+# Copyright 2013-2018 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+import os.path
+import platform
+import shutil
+
+import pytest
+
+import llnl.util.filesystem
+import spack.paths
+import spack.relocate
+import spack.store
+import spack.tengine
+import spack.util.executable
+
+
+@pytest.fixture(autouse=True)
+def _skip_if_missing_executables(request):
+    """Permits to mark tests with 'require_executables' and skip the
+    tests if the executables passed as arguments are not found.
+    """
+    if request.node.get_marker('requires_executables'):
+        required_execs = request.node.get_marker('requires_executables').args
+        missings_execs = [
+            x for x in required_execs if spack.util.executable.which(x) is None
+        ]
+        if missings_execs:
+            msg = 'could not find executables: {0}'
+            pytest.skip(msg.format(', '.join(missings_execs)))
+
+
+@pytest.fixture(params=[True, False])
+def is_relocatable(request):
+    return request.param
+
+
+@pytest.fixture()
+def source_file(tmpdir, is_relocatable):
+    """Returns the path to a source file of a relocatable executable."""
+    if is_relocatable:
+        template_src = os.path.join(
+            spack.paths.test_path, 'data', 'templates', 'relocatable.c'
+        )
+        src = tmpdir.join('relocatable.c')
+        shutil.copy(template_src, str(src))
+    else:
+        template_dirs = [
+            os.path.join(spack.paths.test_path, 'data', 'templates')
+        ]
+        env = spack.tengine.make_environment(template_dirs)
+        template = env.get_template('non_relocatable.c')
+        text = template.render({'prefix': spack.store.layout.root})
+
+        src = tmpdir.join('non_relocatable.c')
+        src.write(text)
+
+    return src
+
+
+@pytest.mark.requires_executables(
+    '/usr/bin/gcc', 'patchelf', 'strings', 'file'
+)
+def test_file_is_relocatable(source_file, is_relocatable):
+    compiler = spack.util.executable.Executable('/usr/bin/gcc')
+    executable = str(source_file).replace('.c', '.x')
+    compiler_env = {
+        'PATH': '/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin'
+    }
+    compiler(str(source_file), '-o', executable, env=compiler_env)
+
+    assert spack.relocate.is_binary(executable)
+    assert spack.relocate.file_is_relocatable(executable) is is_relocatable
+
+
+@pytest.mark.skipif(
+    platform.system().lower() != 'linux',
+    reason='implementation for MacOS still missing'
+)
+def test_file_is_relocatable_errors(tmpdir):
+    # The file passed in as argument must exist...
+    with pytest.raises(ValueError) as exc_info:
+        spack.relocate.file_is_relocatable('/usr/bin/does_not_exist')
+    assert 'does not exist' in str(exc_info.value)
+
+    # ...and the argument must be an absolute path to it
+    file = tmpdir.join('delete.me')
+    file.write('foo')
+
+    with llnl.util.filesystem.working_dir(str(tmpdir)):
+        with pytest.raises(ValueError) as exc_info:
+            spack.relocate.file_is_relocatable('delete.me')
+        assert 'is not an absolute path' in str(exc_info.value)