Yaml spec parsing corner case (#17101)

* Catch yaml filename corner case in spec parser

* improved regex and remove redundant error checking

Co-authored-by: Gregory Becker <becker33@llnl.gov>

2 files changed, 28 insertions, 7 deletions

diff --git a/lib/spack/spack/spec.py b/lib/spack/spack/spec.py
index 03f334597a..b09d72003e 100644
--- a/lib/spack/spack/spec.py
+++ b/lib/spack/spack/spec.py
@@ -3945,7 +3945,8 @@ class SpecLexer(spack.parse.Lexer):
 
             # Filenames match before identifiers, so no initial filename
             # component is parsed as a spec (e.g., in subdir/spec.yaml)
-            (r'[/\w.-]+\.yaml[^\b]*', lambda scanner, v: self.token(FILE, v)),
+            (r'[/\w.-]*/[/\w/-]+\.yaml[^\b]*',
+             lambda scanner, v: self.token(FILE, v)),
 
             # Hash match after filename. No valid filename can be a hash
             # (files end w/.yaml), but a hash can match a filename prefix.
@@ -4096,11 +4097,6 @@ class SpecParser(spack.parse.Parser):
         """
         path = self.token.value
 
-        # don't treat builtin.yaml, builtin.yaml-cpp, etc. as filenames
-        if re.match(spec_id_re + '$', path):
-            self.push_tokens([spack.parse.Token(ID, self.token.value)])
-            return None
-
         # Special case where someone omits a space after a filename. Consider:
         #
         #     libdwarf^/some/path/to/libelf.yamllibdwarf ^../../libelf.yaml
@@ -4112,7 +4108,6 @@ class SpecParser(spack.parse.Parser):
             raise SpecFilenameError(
                 "Spec filename must end in .yaml: '{0}'".format(path))
 
-        # if we get here, we're *finally* interpreting path as a filename
         if not os.path.exists(path):
             raise NoSuchSpecFileError("No such spec file: '{0}'".format(path))
 
diff --git a/lib/spack/spack/test/spec_syntax.py b/lib/spack/spack/test/spec_syntax.py
index 688c89022c..c9a2100b09 100644
--- a/lib/spack/spack/test/spec_syntax.py
+++ b/lib/spack/spack/test/spec_syntax.py
@@ -188,6 +188,32 @@ class TestSpecSyntax(object):
             " ^_openmpi@1.2:1.4,1.6%intel@12.1~qt_4 debug=2"
             " ^stackwalker@8.1_1e arch=test-redhat6-x86")
 
+    def test_yaml_specs(self):
+        self.check_parse(
+            "yaml-cpp@0.1.8%intel@12.1"
+            " ^boost@3.1.4")
+        tempspec = r"builtin.yaml-cpp%gcc"
+        self.check_parse(
+            tempspec.strip("builtin."),
+            spec=tempspec)
+        tempspec = r"testrepo.yaml-cpp%gcc"
+        self.check_parse(
+            tempspec.strip("testrepo."),
+            spec=tempspec)
+        tempspec = r"builtin.yaml-cpp@0.1.8%gcc"
+        self.check_parse(
+            tempspec.strip("builtin."),
+            spec=tempspec)
+        tempspec = r"builtin.yaml-cpp@0.1.8%gcc@7.2.0"
+        self.check_parse(
+            tempspec.strip("builtin."),
+            spec=tempspec)
+        tempspec = r"builtin.yaml-cpp@0.1.8%gcc@7.2.0" \
+            r" ^boost@3.1.4"
+        self.check_parse(
+            tempspec.strip("builtin."),
+            spec=tempspec)
+
     def test_canonicalize(self):
         self.check_parse(
             "mvapich_foo"