issue #171. Removal of statement function matching.

CHANGELOG.md

@@ -12,6 +12,9 @@ Modifications by (in alphabetical order):
 * A. R. Porter, Science & Technology Facilities Council, UK
 * P. Vitt, University of Siegen, Germany
 
+03/07/2019 PR #200 for #171. Disable Statement Function support
+           in fparser2.
+
 02/07/2019 PR #205 for #204. Corrects the minimum number of arguments
            for the SELECTED_REAL_KIND intrinsic.
 

doc/fparser2.rst

@@ -160,6 +160,27 @@ number. For example:
    fparser.two.Fortran2003.FortranSyntaxError: at line 2
    >>>en
 
+Unsupported Features
+--------------------
+
+Statement Functions
++++++++++++++++++++
+
+Fparser2 is currently not able to distinguish between statement
+functions and array assignments when one or more array assignment
+statements are the first statements after a declaration section. This
+limitation leads to these particular array assignments being
+incorrectly parsed as statement functions.
+
+To avoid this incorrect behaviour, support for statement functions has
+been temporarily removed from fparser2. However, with this change,
+statement functions will be incorrectly parsed as array assignments
+when one or more statement function statements are the last statements
+in a declaration section.
+
+Whilst any incorrect behaviour should be avoided, the behaviour of
+this temporary change is considered preferable to the former case, as
+array assigments are more common than statement functions.
 
 Extensions
 ----------

src/fparser/scripts/fparser2.py

@@ -1,5 +1,5 @@
 #!/usr/bin/env python
-# Modified work Copyright (c) 2017-2018 Science and Technology
+# Modified work Copyright (c) 2017-2019 Science and Technology
 # Facilities Council
 # Original work Copyright (c) 1999-2008 Pearu Peterson
 
@@ -83,23 +83,26 @@ def runner(_, options, args):
     from fparser.two.Fortran2003 import FortranSyntaxError, InternalError
     from fparser.common.readfortran import FortranFileReader
     if not args:
-        print ("Error: No fortran files specified")
+        print("Error: No fortran files specified")
         raise SystemExit(1)
     for filename in args:
         try:
             reader = FortranFileReader(filename,
                                        ignore_comments=False)
         except IOError as error:
-            print (error)
+            print(error)
             return
         if options.mode != 'auto':
             reader.format.from_mode(options.mode)
         try:
             f2003_parser = ParserFactory().create()
             program = f2003_parser(reader)
-            print (program)
+            if options.task == "show":
+                print(program)
+            if options.task == "repr":
+                print(repr(program))
         except FortranSyntaxError as msg:
-            print ("Syntax error: {0}".format(str(msg)))
+            print("Syntax error: {0}".format(str(msg)))
             try:
                 # protect the access to fifo_item[-1] in case the fifo
                 # buffer is empty
@@ -110,7 +113,7 @@ def runner(_, options, args):
                 pass
             raise SystemExit(1)
         except InternalError as msg:
-            print ("Internal error in fparser: {0}".format(str(msg)))
+            print("Internal error in fparser: {0}".format(str(msg)))
             raise SystemExit(1)
 
 
@@ -120,7 +123,6 @@ def main():
     set_fparser_options(parser)
     options, args = parser.parse_args()
     runner(parser, options, args)
-    return
 
 
 if __name__ == "__main__":

src/fparser/scripts/script_options.py

@@ -93,15 +93,22 @@ def set_parse_options(parser):
     parser.add_option_group(get_fortran_code_group(parser))
 
 def set_fparser_options(parser):
+    ''' Command line options used by the fparser2 script.
+
+    :param parser: The OptionParser object.
+    :type parser: :py:class:`optparse.OptionParser`
+
+    '''
+
     parser.set_usage('''\
 %prog [options] <Fortran files>
 
 Description:
   %prog parses Fortran code.''')
     parser.add_option('--task',
-                      default = 'show',
-                      choices = ['show', 'none'],
-                      help = 'Specify parsing result task. Default: %default.'
+                      default='show',
+                      choices=['show', 'repr', 'none'],
+                      help='Specify parsing result task. Default: %default.'
                       )
     parser.add_option('--std',
                       default = 'f2003',

src/fparser/two/Fortran2003.py

@@ -419,23 +419,31 @@ class Implicit_Part_Stmt(Base):  # R206
 
 
 class Declaration_Construct(Base):  # R207
-    """
-:F03R:`207`::
-    <declaration-construct> = <derived-type-def>
-                              | <entry-stmt>
-                              | <enum-def>
-                              | <format-stmt>
-                              | <interface-block>
-                              | <parameter-stmt>
-                              | <procedure-declaration-stmt>
-                              | <specification-stmt>
-                              | <type-declaration-stmt>
-                              | <stmt-function-stmt>
-    """
-    subclass_names = ['Comment', 'Derived_Type_Def', 'Entry_Stmt', 'Enum_Def',
+    '''Fortran 2003 rule R207
+
+    declaration-construct is derived-type-def
+                           or entry-stmt
+                           or enum-def
+                           or format-stmt
+                           or interface-block
+                           or parameter-stmt
+                           or procedure-declaration-stmt
+                           or specification-stmt
+                           or type-declaration-stmt
+                           or stmt-function-stmt
+
+    Note, stmt-function-stmt is not currently matched.
+
+    '''
+    # Commented out Stmt_Function_Stmt as it can falsely match an
+    # access to an array or function. Reintroducing statement
+    # functions is captured in issue #202.
+
+    #                   'Type_Declaration_Stmt', 'Stmt_Function_Stmt']
+    subclass_names = ['Derived_Type_Def', 'Entry_Stmt', 'Enum_Def',
                       'Format_Stmt', 'Interface_Block', 'Parameter_Stmt',
                       'Procedure_Declaration_Stmt', 'Specification_Stmt',
-                      'Type_Declaration_Stmt', 'Stmt_Function_Stmt']
+                      'Type_Declaration_Stmt']
 
 
 class Execution_Part(BlockBase):  # R208

src/fparser/two/Fortran2008.py

@@ -192,7 +192,10 @@ class Declaration_Construct_C1112(Declaration_Construct):  # C1112
     subclass_names = Declaration_Construct.subclass_names[:]
     subclass_names.remove('Format_Stmt')
     subclass_names.remove('Entry_Stmt')
-    subclass_names.remove('Stmt_Function_Stmt')
+    # Commented out Stmt_Function_Stmt as it can falsely match an
+    # access to an array or function. Reintroducing statement
+    # functions is captured in issue #202.
+    # subclass_names.remove('Stmt_Function_Stmt')
 
 
 class Submodule(BlockBase):  # R1116 [C1112,C1114]

src/fparser/two/tests/fortran2003/test_declaration_construct_r207.py

@@ -0,0 +1,173 @@
+# Copyright (c) 2019 Science and Technology Facilities Council
+
+# All rights reserved.
+
+# Modifications made as part of the fparser project are distributed
+# under the following license:
+
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+
+# 1. Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+
+# 2. Redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution.
+
+# 3. Neither the name of the copyright holder nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+'''Test Fortran 2003 rule R207 : This file tests support for the
+Declaration_Construct class.
+
+As this class just uses Base to match with a choice of subclasses we
+test that an instance of each subclass can be succesfully
+parsed. Detailed checking of the subclass rules are performed by the
+subclass tests.
+
+'''
+
+import pytest
+from fparser.two.Fortran2003 import Declaration_Construct
+from fparser.api import get_reader
+
+
+def test_derived_type_def(f2003_create):
+    '''Test a derived type definition statement is supported by the
+    declaration construct class.
+
+    '''
+    code = ("TYPE :: my_type\n"
+            "END TYPE my_type")
+    reader = get_reader(code)
+    result = Declaration_Construct(reader)
+    assert str(result) == code
+    assert "Derived_Type_Def" in repr(result)
+
+
+def test_entry_stmt(f2003_create):
+    '''Test an entry statement is supported by the declaration construct
+    class.
+
+    '''
+    code = "ENTRY my_function()"
+    reader = get_reader(code)
+    result = Declaration_Construct(reader)
+    assert str(result) == code
+    assert "Entry_Stmt" in repr(result)
+
+
+def test_enum_def(f2003_create):
+    '''Test an enum definition is supported by the declaration construct
+    class.
+
+    '''
+    code = ("ENUM, BIND(C)\n"
+            "  ENUMERATOR :: a = 1\n"
+            "END ENUM")
+    reader = get_reader(code)
+    result = Declaration_Construct(reader)
+    assert str(result) == code
+    assert "Enum_Def" in repr(result)
+
+
+def test_format_statement(f2003_create):
+    '''Test a format statement is supported by the declaration construct
+    class.
+
+    '''
+    code = "FORMAT('(x)')"
+    reader = get_reader(code)
+    result = Declaration_Construct(reader)
+    assert str(result) == code
+    assert "Format_Stmt" in repr(result)
+
+
+def test_interface_block(f2003_create):
+    '''Test an interface block statement is supported by the declaration
+    construct class.
+
+    '''
+    code = ("INTERFACE\n"
+            "END INTERFACE")
+    reader = get_reader(code)
+    result = Declaration_Construct(reader)
+    assert str(result) == code
+    assert "Interface_Block" in repr(result)
+
+
+def test_parameter_stmt(f2003_create):
+    '''Test a parameter statement is supported by the declaration
+    construct class.
+
+    '''
+    code = "PARAMETER(A = 2)"
+    reader = get_reader(code)
+    result = Declaration_Construct(reader)
+    assert str(result) == code
+    assert "Parameter_Stmt" in repr(result)
+
+
+def test_procedure_declaration_stmt(f2003_create):
+    '''Test a procedure declaration statement is supported by the
+    declaration construct class.
+
+    '''
+    code = "PROCEDURE(REAL) FUNC"
+    reader = get_reader(code)
+    result = Declaration_Construct(reader)
+    assert str(result) == code
+    assert "Procedure_Declaration_Stmt" in repr(result)
+
+
+def test_specification_stmt(f2003_create):
+    '''Test a specification statement is supported by the declaration
+    construct class. An access statement is a specification statement,
+    so check for this.
+
+    '''
+    code = "PUBLIC :: A"
+    reader = get_reader(code)
+    result = Declaration_Construct(reader)
+    assert str(result) == code
+    assert "Access_Stmt" in repr(result)
+
+
+def test_type_declaration_stmt(f2003_create):
+    '''Test a type declaration statement is supported by the declaration
+    construct class.
+
+    '''
+    code = "INTEGER :: X"
+    reader = get_reader(code)
+    result = Declaration_Construct(reader)
+    assert str(result) == code
+    assert "Type_Declaration_Stmt" in repr(result)
+
+
+@pytest.mark.xfail(reason="#202. Statement Function support removed.")
+def test_stmt_function_stmt(f2003_create):
+    '''Test a statement function statement is supported by the declaration
+    construct class.
+
+    '''
+    code = "C(F) = 5.0*(F - 32.0)/9.0"
+    reader = get_reader(code)
+    result = Declaration_Construct(reader)
+    assert str(result) == code
+    assert "Stmt_Function_Stmt" in repr(result)