Fix parse failures with REGEX frontend due to white space in declarations (#318)

Author: reuterbal

loki/frontend/regex.py

@@ -900,8 +900,8 @@ def __init__(self):
         super().__init__(
             r'^(((?:type|class)[ \t]*\([ \t]*(?P<typename>\w+)[ \t]*\))|' # TYPE or CLASS keyword with typename
             r'^([ \t]*(?P<basic_type>(logical|real|integer|complex|character))'
-            r'(?P<param>\((kind|len)=[a-z0-9_-]+\))?[ \t]*))'
-            r'(?:[ \t]*,[ \t]*[a-z]+(?:\((.(\(.*\))?)*?\))?)*'  # Optional attributes
+            r'[ \t]*(?P<param>\([ \t]*(kind|len)[ \t]*=[ \t]*[a-z0-9_-]+[ \t]*\))?[ \t]*))'
+            r'(?:[ \t]*,[ \t]*[a-z]+(?:[ \t]*\((.(\(.*\))?)*?\))?)*'  # Optional attributes
             r'(?:[ \t]*::)?'  # Optional `::` delimiter
             r'[ \t]*'  # Some white space
             r'(?P<variables>\w+\b.*?)$',  # Variable names

loki/frontend/tests/test_regex_frontend.py

@@ -0,0 +1,62 @@
+# (C) Copyright 2018- ECMWF.
+# This software is licensed under the terms of the Apache Licence Version 2.0
+# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+# In applying this licence, ECMWF does not waive the privileges and immunities
+# granted to it by virtue of its status as an intergovernmental organisation
+# nor does it submit to any jurisdiction.
+
+"""
+Verify correct parsing behaviour of the REGEX frontend
+"""
+
+from loki.frontend import REGEX
+from loki.types import BasicType, DerivedType
+from loki.subroutine import Subroutine
+
+def test_declaration_whitespace_attributes():
+    """
+    Test correct behaviour with/without white space inside declaration attributes
+    (reported in #318).
+    """
+    fcode = """
+subroutine my_whitespace_declaration_routine(kdim, state_t0, paux)
+    use type_header, only: dimension_type, STATE_TYPE, aux_type, jprb
+    implicit none
+    TYPE( DIMENSION_TYPE) , INTENT (IN) :: KDIM
+    type (state_type  ) , intent ( in ) :: state_t0
+    TYPE (AUX_TYPE) , InteNT( In) :: PAUX
+    CHARACTER  ( LEN=10) :: STR
+    REAL(  KIND = JPRB  ) :: VAR
+end subroutine
+    """.strip()
+
+    routine = Subroutine.from_source(fcode, frontend=REGEX)
+
+    # Verify that variables and dtype information has been extracted correctly
+    assert routine.variables == ('kdim', 'state_t0', 'paux', 'str', 'var')
+    assert isinstance(routine.variable_map['kdim'].type.dtype, DerivedType)
+    assert routine.variable_map['kdim'].type.dtype.name.lower() == 'dimension_type'
+    assert isinstance(routine.variable_map['state_t0'].type.dtype, DerivedType)
+    assert routine.variable_map['state_t0'].type.dtype.name.lower() == 'state_type'
+    assert isinstance(routine.variable_map['paux'].type.dtype, DerivedType)
+    assert routine.variable_map['paux'].type.dtype.name.lower() == 'aux_type'
+    assert routine.variable_map['str'].type.dtype == BasicType.CHARACTER
+    assert routine.variable_map['var'].type.dtype == BasicType.REAL
+
+    routine.make_complete()
+
+    # Verify that additional type attributes are correct after full parse
+    assert routine.variables == ('kdim', 'state_t0', 'paux', 'str', 'var')
+    assert isinstance(routine.variable_map['kdim'].type.dtype, DerivedType)
+    assert routine.variable_map['kdim'].type.dtype.name.lower() == 'dimension_type'
+    assert routine.variable_map['kdim'].type.intent == 'in'
+    assert isinstance(routine.variable_map['state_t0'].type.dtype, DerivedType)
+    assert routine.variable_map['state_t0'].type.dtype.name.lower() == 'state_type'
+    assert routine.variable_map['state_t0'].type.intent == 'in'
+    assert isinstance(routine.variable_map['paux'].type.dtype, DerivedType)
+    assert routine.variable_map['paux'].type.dtype.name.lower() == 'aux_type'
+    assert routine.variable_map['paux'].type.intent == 'in'
+    assert routine.variable_map['str'].type.dtype == BasicType.CHARACTER
+    assert routine.variable_map['str'].type.length == 10
+    assert routine.variable_map['var'].type.dtype == BasicType.REAL
+    assert routine.variable_map['var'].type.kind == 'jprb'