Add the ability to separate architecture in path scheme (#4329)

* Add format to separate target and os for path

spec format can now handle separations of target and os for setting
up the path.

* Added ${PLATFORM} et al to spec.format()

${PLATFORM}, ${OS}, ${TARGET}

* Update tests

Updated tests and got rid of unnecessary code.

* Also update documentation to reflect this new ability.

* Add default path scheme to config.yaml

Added default path scheme to config.yaml. Users can overwrite this
section if they want.

3 files changed, 67 insertions, 6 deletions

diff --git a/lib/spack/spack/spec.py b/lib/spack/spack/spec.py
index 35ab59f76a..a88cb3f62a 100644
--- a/lib/spack/spack/spec.py
+++ b/lib/spack/spack/spec.py
@@ -2905,6 +2905,9 @@ class Spec(object):
             ${COMPILERFLAGS} Compiler flags
             ${OPTIONS}       Options
             ${ARCHITECTURE}  Architecture
+            ${PLATFORM}      Platform
+            ${OS}            Operating System
+            ${TARGET}        Target
             ${SHA1}          Dependencies 8-char sha1 prefix
             ${HASH:len}      DAG hash with optional length specifier
 
@@ -3062,12 +3065,22 @@ class Spec(object):
                 elif named_str == 'OPTIONS':
                     if self.variants:
                         write(fmt % token_transform(str(self.variants)), '+')
-                elif named_str == 'ARCHITECTURE':
+                elif named_str in ["ARCHITECTURE", "PLATFORM", "TARGET", "OS"]:
                     if self.architecture and str(self.architecture):
-                        write(
-                            fmt % token_transform(str(self.architecture)),
-                            '='
-                        )
+                        if named_str == "ARCHITECTURE":
+                            write(
+                                fmt % token_transform(str(self.architecture)),
+                                '='
+                            )
+                        elif named_str == "PLATFORM":
+                            platform = str(self.architecture.platform)
+                            write(fmt % token_transform(platform), '=')
+                        elif named_str == "OS":
+                            operating_sys = str(self.architecture.platform_os)
+                            write(fmt % token_transform(operating_sys), '=')
+                        elif named_str == "TARGET":
+                            target = str(self.architecture.target)
+                            write(fmt % token_transform(target), '=')
                 elif named_str == 'SHA1':
                     if self.dependencies:
                         out.write(fmt % token_transform(str(self.dag_hash(7))))
diff --git a/lib/spack/spack/test/directory_layout.py b/lib/spack/spack/test/directory_layout.py
index b166ea4eac..e5fb8c7a29 100644
--- a/lib/spack/spack/test/directory_layout.py
+++ b/lib/spack/spack/test/directory_layout.py
@@ -74,13 +74,19 @@ def test_yaml_directory_layout_parameters(
     # Test path_scheme
     arch, compiler, package7 = path_7.split('/')
     scheme_package7 = "${PACKAGE}-${VERSION}-${HASH:7}"
-
     layout_package7 = YamlDirectoryLayout(str(tmpdir),
                                           path_scheme=scheme_package7)
     path_package7 = layout_package7.relative_path_for_spec(spec)
 
     assert(package7 == path_package7)
 
+    # Test separation of architecture
+    arch_scheme_package = "${PLATFORM}/${TARGET}/${OS}/${PACKAGE}/${VERSION}/${HASH:7}"   # NOQA: ignore=E501
+    layout_arch_package = YamlDirectoryLayout(str(tmpdir),
+                                              path_scheme=arch_scheme_package)
+    arch_path_package = layout_arch_package.relative_path_for_spec(spec)
+    assert(arch_path_package == spec.format(arch_scheme_package))
+
     # Ensure conflicting parameters caught
     with pytest.raises(InvalidDirectoryLayoutParametersError):
         YamlDirectoryLayout(str(tmpdir),
diff --git a/lib/spack/spack/test/spec_semantics.py b/lib/spack/spack/test/spec_semantics.py
index 03f77992c5..4ffb458765 100644
--- a/lib/spack/spack/test/spec_semantics.py
+++ b/lib/spack/spack/test/spec_semantics.py
@@ -720,3 +720,45 @@ class TestSpecSematics(object):
 
         with pytest.raises(ValueError):
             Spec('libelf foo')
+
+    def test_spec_formatting(self):
+        spec = Spec("libelf cflags=-O2")
+        spec.concretize()
+
+        # Since the default is the full spec see if the string rep of
+        # spec is the same as the output of spec.format()
+        # ignoring whitespace (though should we?)
+        assert str(spec) == spec.format().strip()
+
+        # Testing named strings ie ${STRING} and whether we get
+        # the correct component
+        package_segments = [("${PACKAGE}", "name"),
+                            ("${VERSION}", "versions"),
+                            ("${COMPILER}", "compiler"),
+                            ("${COMPILERFLAGS}", "compiler_flags"),
+                            ("${OPTIONS}", "variants"),
+                            ("${ARCHITECTURE}", "architecture")]
+
+        compiler_segments = [("${COMPILERNAME}", "name"),
+                             ("${COMPILERVER}", "versions")]
+
+        architecture_segments = [("${PLATFORM}", "platform"),
+                                 ("${OS}", "platform_os"),
+                                 ("${TARGET}", "target")]
+
+        for named_str, prop in package_segments:
+            expected = getattr(spec, prop, "")
+            actual = spec.format(named_str)
+            assert str(expected) == actual
+
+        compiler = spec.compiler
+        for named_str, prop in compiler_segments:
+            expected = getattr(compiler, prop, "")
+            actual = spec.format(named_str)
+            assert str(expected) == actual
+
+        arch = spec.architecture
+        for named_str, prop in architecture_segments:
+            expected = getattr(arch, prop, "")
+            actual = spec.format(named_str)
+            assert str(expected) == actual