297 temporary omp sentinel support (MetOffice#326)

source/fab/parse/fortran.py

@@ -11,6 +11,7 @@
 from pathlib import Path
 from typing import Union, Optional, Iterable, Dict, Any, Set
 
+from fparser.common.readfortran import FortranStringReader   # type: ignore
 from fparser.two.Fortran2003 import (  # type: ignore
     Entity_Decl_List, Use_Stmt, Module_Stmt, Program_Stmt, Subroutine_Stmt, Function_Stmt, Language_Binding_Spec,
     Char_Literal_Constant, Interface_Block, Name, Comment, Module, Call_Stmt, Derived_Type_Def, Derived_Type_Stmt,
@@ -284,15 +285,38 @@ def _process_comment(self, analysed_file, obj):
         # TODO: error handling in case we catch a genuine comment
         # TODO: separate this project-specific code from the generic f analyser?
         depends_str = "DEPENDS ON:"
-        if depends_str in obj.items[0]:
+        comment = obj.items[0].strip()
+        if depends_str in comment:
             self.depends_on_comment_found = True
-            dep = obj.items[0].split(depends_str)[-1].strip()
+            dep = comment.split(depends_str)[-1].strip()
             # with .o means a c file
             if dep.endswith(".o"):
                 analysed_file.mo_commented_file_deps.add(dep.replace(".o", ".c"))
             # without .o means a fortran symbol
             else:
                 analysed_file.add_symbol_dep(dep)
+        if comment[:2] == "!$":
+            # Check if it is a use statement with an OpenMP sentinel:
+            # Use fparser's string reader to discard potential comment
+            # TODO #13: once fparser supports reading the sentinels,
+            # this can be removed.
+            reader = FortranStringReader(comment[2:])
+            line = reader.next()
+            try:
+                # match returns a 5-tuple, the third one being the module name
+                module_name = Use_Stmt.match(line.strline)[2]
+                module_name = module_name.string
+            except Exception:
+                # Not a use statement in a sentinel, ignore:
+                return
+
+            # Register the module name
+            if module_name in self.ignore_mod_deps:
+                logger.debug(f"ignoring use of {module_name}")
+                return
+            if module_name.lower() not in self._intrinsic_modules:
+                # found a dependency on fortran
+                analysed_file.add_module_dep(module_name)
 
     def _process_subroutine_or_function(self, analysed_file, fpath, obj):
         # binding?

tests/unit_tests/parse/fortran/test_fortran_analyser.f90

@@ -17,6 +17,15 @@ SUBROUTINE internal_sub
         RETURN
     END SUBROUTINE internal_sub
 
+    SUBROUTINE openmp_sentinel
+!$ USE compute_chunk_size_mod, ONLY: compute_chunk_size  ! Note OpenMP sentinel
+!$ USE test that is not a sentinel with a use statement inside
+!GCC$ unroll 6
+!DIR$ assume (mod(p, 6) == 0)
+!$omp do
+!$acc parallel copyin (array, scalar).
+    END SUBROUTINE openmp_sentinel
+
     INTEGER FUNCTION internal_func()
         internal_func = 456
     END FUNCTION internal_func

tests/unit_tests/parse/fortran/test_fortran_analyser.py

@@ -18,30 +18,35 @@
 from fab.parse.fortran_common import iter_content
 from fab.tools import ToolBox
 
+'''Tests the Fortran analyser.
+'''
 
 # todo: test function binding
 
 
 @pytest.fixture
-def module_fpath():
+def module_fpath() -> Path:
+    '''Simple fixture that sets the name of the module test file.'''
     return Path(__file__).parent / "test_fortran_analyser.f90"
 
 
 @pytest.fixture
-def module_expected(module_fpath):
+def module_expected(module_fpath) -> AnalysedFortran:
+    '''Returns the expected AnalysedFortran instance for the Fortran
+    test module.'''
     return AnalysedFortran(
         fpath=module_fpath,
-        file_hash=4039845747,
+        file_hash=1757501304,
         module_defs={'foo_mod'},
         symbol_defs={'external_sub', 'external_func', 'foo_mod'},
-        module_deps={'bar_mod'},
-        symbol_deps={'monty_func', 'bar_mod'},
+        module_deps={'bar_mod', 'compute_chunk_size_mod'},
+        symbol_deps={'monty_func', 'bar_mod', 'compute_chunk_size_mod'},
         file_deps=set(),
         mo_commented_file_deps={'some_file.c'},
     )
 
 
-class Test_Analyser(object):
+class TestAnalyser:
 
     @pytest.fixture
     def fortran_analyser(self, tmp_path):
@@ -53,29 +58,37 @@ def fortran_analyser(self, tmp_path):
     def test_empty_file(self, fortran_analyser):
         # make sure we get back an EmptySourceFile
         with mock.patch('fab.parse.AnalysedFile.save'):
-            analysis, artefact = fortran_analyser.run(fpath=Path(Path(__file__).parent / "empty.f90"))
-        assert type(analysis) is EmptySourceFile
+            analysis, artefact = fortran_analyser.run(
+                fpath=Path(Path(__file__).parent / "empty.f90"))
+        assert isinstance(analysis, EmptySourceFile)
         assert artefact is None
 
-    def test_module_file(self, fortran_analyser, module_fpath, module_expected):
+    def test_module_file(self, fortran_analyser, module_fpath,
+                         module_expected):
         with mock.patch('fab.parse.AnalysedFile.save'):
             analysis, artefact = fortran_analyser.run(fpath=module_fpath)
         assert analysis == module_expected
-        assert artefact == fortran_analyser._config.prebuild_folder / f'test_fortran_analyser.{analysis.file_hash}.an'
+        assert artefact == (fortran_analyser._config.prebuild_folder /
+                            f'test_fortran_analyser.{analysis.file_hash}.an')
 
-    def test_program_file(self, fortran_analyser, module_fpath, module_expected):
+    def test_program_file(self, fortran_analyser, module_fpath,
+                          module_expected):
         # same as test_module_file() but replacing MODULE with PROGRAM
         with NamedTemporaryFile(mode='w+t', suffix='.f90') as tmp_file:
-            tmp_file.write(module_fpath.open().read().replace("MODULE", "PROGRAM"))
+            tmp_file.write(module_fpath.open().read().replace("MODULE",
+                                                              "PROGRAM"))
             tmp_file.flush()
             with mock.patch('fab.parse.AnalysedFile.save'):
-                analysis, artefact = fortran_analyser.run(fpath=Path(tmp_file.name))
+                analysis, artefact = fortran_analyser.run(
+                    fpath=Path(tmp_file.name))
 
             module_expected.fpath = Path(tmp_file.name)
-            module_expected._file_hash = 768896775
+            module_expected._file_hash = 3388519280
             module_expected.program_defs = {'foo_mod'}
             module_expected.module_defs = set()
-            module_expected.symbol_defs.update({'internal_sub', 'internal_func'})
+            module_expected.symbol_defs.update({'internal_func',
+                                                'internal_sub',
+                                                'openmp_sentinel'})
 
             assert analysis == module_expected
             assert artefact == fortran_analyser._config.prebuild_folder \
@@ -84,11 +97,13 @@ def test_program_file(self, fortran_analyser, module_fpath, module_expected):
 
 # todo: test more methods!
 
-class Test_process_variable_binding(object):
+class TestProcessVariableBinding:
+    '''This test class tests the variable binding.'''
 
     # todo: define and depend, with and without bind name
 
     def test_define_without_bind_name(self, tmp_path):
+        '''Test usage of bind'''
         fpath = tmp_path / 'temp.f90'
 
         open(fpath, 'wt').write("""
@@ -112,13 +127,15 @@ def test_define_without_bind_name(self, tmp_path):
         tree = f2008_parser(reader)
 
         # find the tree node representing the variable binding
-        var_decl = next(obj for obj in iter_content(tree) if isinstance(obj, Type_Declaration_Stmt))
+        var_decl = next(obj for obj in iter_content(tree)
+                        if isinstance(obj, Type_Declaration_Stmt))
 
         # run our handler
         fpath = Path('foo')
         analysed_file = AnalysedFortran(fpath=fpath, file_hash=0)
         analyser = FortranAnalyser()
-        analyser._process_variable_binding(analysed_file=analysed_file, obj=var_decl)
+        analyser._process_variable_binding(analysed_file=analysed_file,
+                                           obj=var_decl)
 
         assert analysed_file.symbol_defs == {'helloworld', }