Adding strict order statements (closes #353)

src/fparser/two/Fortran2003.py

@@ -563,6 +563,7 @@ def match(reader):
             [Use_Stmt, Import_Stmt, Implicit_Part, Declaration_Construct],
             None,
             reader,
+            strict_order=True,
         )
 
 
@@ -1748,6 +1749,7 @@ def match(reader):
             End_Type_Stmt,
             reader,
             match_names=True,  # C431
+            strict_order=True,
         )
 
 
@@ -2453,7 +2455,11 @@ def match(reader):
                   `Name`]) or `None`
         """
         return BlockBase.match(
-            Contains_Stmt, [Binding_Private_Stmt, Proc_Binding_Stmt], None, reader
+            Contains_Stmt,
+            [Binding_Private_Stmt, Proc_Binding_Stmt],
+            None,
+            reader,
+            strict_order=True,
         )
 
 
@@ -2865,7 +2871,10 @@ class Enum_Def(BlockBase):  # R460
     @staticmethod
     def match(reader):
         return BlockBase.match(
-            Enum_Def_Stmt, [Enumerator_Def_Stmt], End_Enum_Stmt, reader
+            Enum_Def_Stmt,
+            [Enumerator_Def_Stmt],
+            End_Enum_Stmt,
+            reader,
         )
 
 
@@ -11058,6 +11067,7 @@ def match(reader):
             reader,
             match_names=True,
             strict_order=True,
+            once_only=True,
         )
 
 
@@ -11118,6 +11128,8 @@ def match(reader):
             [Specification_Part, Execution_Part, Internal_Subprogram_Part],
             End_Program_Stmt,
             reader,
+            strict_order=True,
+            once_only=True,
         )
 
         SYMBOL_TABLES.exit_scope()
@@ -11216,6 +11228,8 @@ def match(reader):
             [Specification_Part, Module_Subprogram_Part],
             End_Module_Stmt,
             reader,
+            strict_order=True,
+            once_only=True,
         )
 
 
@@ -12723,6 +12737,8 @@ def match(reader):
             [Specification_Part, Execution_Part, Internal_Subprogram_Part],
             End_Function_Stmt,
             reader,
+            strict_order=True,
+            once_only=True,
         )
 
 
@@ -13010,6 +13026,8 @@ def match(reader):
             [Specification_Part, Execution_Part, Internal_Subprogram_Part],
             End_Subroutine_Stmt,
             reader,
+            strict_order=True,
+            once_only=True,
         )
 
 

src/fparser/two/tests/test_comments_and_directives.py

@@ -1,4 +1,4 @@
-# Copyright (c) 2017-2020 Science and Technology Facilities Council
+# Copyright (c) 2017-2022 Science and Technology Facilities Council
 # All rights reserved.
 #
 # Modifications made as part of the fparser project are distributed
@@ -35,10 +35,25 @@
 
 import pytest
 from fparser.two.Fortran2003 import Program, Comment, Directive, Subroutine_Subprogram
-from fparser.two.utils import walk, FortranSyntaxError
-from fparser.api import get_reader
 
+from fparser.api import get_reader
+from fparser.two.Fortran2003 import (
+    Program,
+    Comment,
+    Subroutine_Subprogram,
+    Execution_Part,
+    Specification_Part,
+    Block_Nonlabel_Do_Construct,
+    Main_Program,
+    Write_Stmt,
+    End_Program_Stmt,
+    If_Construct,
+    Allocate_Stmt,
+    Derived_Type_Def,
+    Function_Subprogram,
+)
 from fparser.two.parser import ParserFactory
+from fparser.two.utils import walk, get_child, FortranSyntaxError
 
 # this is required to setup the fortran2003 classes
 _ = ParserFactory().create(std="f2003")
@@ -238,24 +253,21 @@ def test_prog_comments():
     #   |--> Comment
     #   |--> Main_Program
     #   .    |--> Program_Stmt
-    #   .    |--> Specification_Part
-    #   .    .    \--> Implicit_Part
-    #   .    .         \--> Comment
+    #   .    |--> Comment
     #        |--> Execution_Part
     #        |    |--> Write_Stmt
-    #        |    \--> Comment
+    #        |    |--> Comment
     #   .    .
     #   .
     #   |--> Comment
-    from fparser.two.Fortran2003 import Main_Program, Write_Stmt, End_Program_Stmt
 
     walk(obj.children, Comment, debug=True)
     assert type(obj.content[0]) is Comment
     assert str(obj.content[0]) == "! A troublesome comment"
     assert type(obj.content[1]) is Main_Program
     main_prog = obj.content[1]
-    assert type(main_prog.content[1].content[0].content[0]) is Comment
-    assert str(main_prog.content[1].content[0].content[0]) == "! A full comment line"
+    assert type(main_prog.content[1]) is Comment
+    assert str(main_prog.content[1]) == "! A full comment line"
     exec_part = main_prog.content[2]
     assert type(exec_part.content[0]) is Write_Stmt
     # Check that we have the in-line comment as a second statement
@@ -295,7 +307,6 @@ def test_function_comments():
   ! That was a function
 end function my_mod
 """
-    from fparser.two.Fortran2003 import Function_Subprogram
 
     reader = get_reader(source, isfree=True, ignore_comments=False)
     fn_unit = Function_Subprogram(reader)
@@ -304,17 +315,15 @@ def test_function_comments():
     #    <class 'fparser.two.Fortran2003.Name'>
     #    <type 'NoneType'>
     #    <type 'NoneType'>
-    # <class 'fparser.two.Fortran2003.Specification_Part'>
-    #   <class 'fparser.two.Fortran2003.Implicit_Part'>
-    #     <class 'fparser.two.Fortran2003.Comment'>
+    #    <class 'fparser.two.Fortran2003.Comment'>
     #       <type 'str'>, "'! This is a function'"
-    comment = fn_unit.content[1].content[0].content[0]
+    comment = fn_unit.content[1]
     assert isinstance(comment, Comment)
     assert "! This is a function" in str(comment)
-    comment = fn_unit.content[1].content[2].content[0]
+    comment = fn_unit.content[2].content[2]
     assert isinstance(comment, Comment)
     assert "! Comment1" in str(comment)
-    exec_part = fn_unit.content[2]
+    exec_part = fn_unit.content[3]
     comment = exec_part.content[1]
     assert isinstance(comment, Comment)
     assert "! Comment2" in str(comment)
@@ -338,16 +347,15 @@ def test_subroutine_comments():
     reader = get_reader(source, isfree=True, ignore_comments=False)
     fn_unit = Subroutine_Subprogram(reader)
     assert isinstance(fn_unit, Subroutine_Subprogram)
-    walk(fn_unit.children, Comment, debug=True)
-    spec_part = fn_unit.content[1]
-    comment = spec_part.content[0].content[0]
+    comment = fn_unit.content[1]
     assert isinstance(comment, Comment)
     assert "! First comment" in str(comment)
-    comment = spec_part.content[2].content[0]
+    spec_part = fn_unit.children[2]
+    comment = spec_part.children[2]
     assert isinstance(comment, Comment)
-    assert comment.parent is spec_part.content[2]
+    assert comment.parent is spec_part
     assert "! Body comment" in str(comment)
-    exec_part = fn_unit.content[2]
+    exec_part = fn_unit.content[3]
     comment = exec_part.content[1]
     assert isinstance(comment, Comment)
     assert comment.parent is exec_part
@@ -364,7 +372,6 @@ def test_derived_type():
   ! Ending comment
 end type my_type
 """
-    from fparser.two.Fortran2003 import Derived_Type_Def
 
     reader = get_reader(source, isfree=True, ignore_comments=False)
     dtype = Derived_Type_Def(reader)
@@ -395,8 +402,6 @@ def test_action_stmts():
          my_array2(size))
 end if
 """
-    from fparser.two.Fortran2003 import If_Construct, Allocate_Stmt
-    from fparser.two.utils import get_child
 
     reader = get_reader(source, isfree=True, ignore_comments=False)
     ifstmt = If_Construct(reader)
@@ -407,6 +412,31 @@ def test_action_stmts():
     assert cmt.parent is ifstmt
 
 
+def test_do_loop_coments():
+    """Check that comments around and within do loops appear in the expected
+    places in the tree."""
+    source = """\
+program test
+integer :: arg1
+integer :: iterator
+!comment_out 1
+arg1 = 10
+!comment_out 2
+do iterator = 0,arg1
+    !comment_in
+    print *, iterator
+end do
+!comment_out 3
+end program test"""
+    reader = get_reader(source, isfree=True, ignore_comments=False)
+    obj = Program(reader)
+    comments = walk(obj, Comment)
+    assert isinstance(comments[0].parent, Specification_Part)
+    assert isinstance(comments[1].parent, Execution_Part)
+    assert isinstance(comments[2].parent, Block_Nonlabel_Do_Construct)
+    assert isinstance(comments[3].parent, Execution_Part)
+
+
 def test_directive_stmts():
     """Test that directives are created instead of comments when
     appropriate."""

src/fparser/two/tests/test_fortran2003.py

@@ -137,6 +137,53 @@ def test_specification_part():
     assert isinstance(obj, tcls), repr(obj)
     assert "TYPE :: a\nEND TYPE a\nTYPE :: b\nEND TYPE b" in str(obj)
 
+    obj = tcls(
+        get_reader(
+            """\
+! comment1
+use a
+! comment2
+use b
+! comment3
+#define x
+use c
+include 'fred'
+#ifdef x
+use d
+#endif
+""",
+            ignore_comments=False,
+        )
+    )
+    assert isinstance(obj, tcls), repr(obj)
+    expected = (
+        "! comment1\nUSE a\n! comment2\nUSE b\n! comment3\n#define x\n"
+        "USE c\nINCLUDE 'fred'\n#ifdef x\nUSE d\n#endif"
+    )
+    assert expected in str(obj)
+
+    # Test a correct order of subclasses matches and then an incorrect
+    # order of subclasses fails to match (due to the strict_order flag
+    # being set). In this case Use_Stmt should precede
+    # Declaration_Construct
+    code = "USE my_mod\n" "INTEGER :: a"
+    reader = get_reader(code)
+    tcls = Specification_Part
+    obj = tcls(reader)
+    assert str(obj) == code
+
+    reader = get_reader("""
+    module mymod
+        integer :: a
+        use my_mod
+    end module
+    """)
+
+    with pytest.raises(NoMatchError) as excinfo:
+        obj = Module(reader)
+    error = str(excinfo.value)
+    assert "at line 4\n>>>        use my_mod" in error
+
 
 #
 # SECTION  3

src/fparser/two/tests/utils/test_blockbase.py

@@ -1,4 +1,4 @@
-# Copyright (c) 2019-2021, Science and Technology Facilities Council
+# Copyright (c) 2019-2022, Science and Technology Facilities Council
 
 # All rights reserved.
 
@@ -81,20 +81,22 @@ def test_include(f2003_create):
         ),
         ignore_comments=False,
     )
-    result = BlockBase.match(startcls, subclasses, endcls, reader)
+    result = BlockBase.match(
+        startcls, subclasses, endcls, reader, strict_order=True, once_only=True
+    )
     assert (
         "([Include_Stmt(Include_Filename('1')), Comment('! comment1'), "
-        "Program_Stmt('PROGRAM', Name('test')), Specification_Part("
-        "Implicit_Part(Include_Stmt(Include_Filename('2')), "
-        "Comment('! comment2')), Type_Declaration_Stmt(Intrinsic_Type_Spec("
-        "'INTEGER', None), None, Entity_Decl_List(',', (Entity_Decl(Name("
-        "'i'), None, None, None),))), Implicit_Part(Include_Stmt("
-        "Include_Filename('3')), Comment('! comment3'))), Execution_Part("
-        "Assignment_Stmt(Name('i'), '=', Int_Literal_Constant('1', None)), "
-        "Include_Stmt(Include_Filename('4')), Comment('! comment4')), "
+        "Program_Stmt('PROGRAM', Name('test')), Include_Stmt("
+        "Include_Filename('2')), Comment('! comment2'), Specification_Part"
+        "(Type_Declaration_Stmt(Intrinsic_Type_Spec('INTEGER', None), None, "
+        "Entity_Decl_List(',', (Entity_Decl(Name('i'), None, None, None),))), "
+        "Include_Stmt(Include_Filename('3')), Comment('! comment3')), "
+        "Execution_Part(Assignment_Stmt(Name('i'), '=', "
+        "Int_Literal_Constant('1', None)), Include_Stmt("
+        "Include_Filename('4')), Comment('! comment4')), "
         "Internal_Subprogram_Part(Contains_Stmt('CONTAINS'), Include_Stmt("
         "Include_Filename('5')), Comment('! comment5')), End_Program_Stmt("
-        "'PROGRAM', Name('test'))],)" in str(result).replace("u'", "'")
+        "'PROGRAM', Name('test'))],)" in str(result)
     )
     assert "should" not in str(result)