Fix issue with pointers with strides

In the simply_contiguous() function, for A_SUSCR case check whether
the object is a pointer. If so, we only want to return TRUE if the
subscripted pointer object has the CONTIGUOUS attribute.  Otherwise,
we don't know what the pointer is pointing to at compile-time.

Add pp73 test.

Author: gklimowicz

test/f90_correct/inc/pp73.mk

@@ -0,0 +1,35 @@
+#
+# Copyright (c) 2019, NVIDIA CORPORATION.  All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+#
+########## Make rule for test pp73  ########
+
+
+pp73: run
+	
+
+build:  $(SRC)/pp73.f90
+	-$(RM) pp73.$(EXESUFFIX) core *.d *.mod FOR*.DAT FTN* ftn* fort.*
+	@echo ------------------------------------ building test $@
+	-$(FC) -c $(FFLAGS) $(LDFLAGS) $(SRC)/pp73.f90 -o pp73.$(OBJX)
+	-$(FC) $(FFLAGS) $(LDFLAGS) pp73.$(OBJX) $(LIBS) -o pp73.$(EXESUFFIX)
+
+
+run: 
+	@echo ------------------------------------ executing test pp73
+	pp73.$(EXESUFFIX)
+
+verify: ;
+

test/f90_correct/lit/pp73.sh

@@ -0,0 +1,19 @@
+#
+# Copyright (c) 2017, NVIDIA CORPORATION.  All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Shared lit script for each tests. Run bash commands that run tests with make.
+
+# RUN: KEEP_FILES=%keep FLAGS=%flags TEST_SRC=%s MAKE_FILE_DIR=%S/.. bash %S/runmake | tee %t 
+# RUN: cat %t | FileCheck %S/runmake

test/f90_correct/src/pp73.f90

@@ -0,0 +1,32 @@
+! Copyright (c) 2019, NVIDIA CORPORATION.  All rights reserved.
+!
+! Licensed under the Apache License, Version 2.0 (the "License");
+! you may not use this file except in compliance with the License.
+! You may obtain a copy of the License at
+!
+!     http://www.apache.org/licenses/LICENSE-2.0
+!
+! Unless required by applicable law or agreed to in writing, software
+! distributed under the License is distributed on an "AS IS" BASIS,
+! WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+! See the License for the specific language governing permissions and
+! limitations under the License.
+!
+! 
+! Tests subscripted pointer expressions that point to non-contiguous array
+! sections.
+
+program main
+  integer, pointer :: p1(:), p2(:)
+  integer, target :: a(20)
+  integer :: expect(8) = [3, 5, 7, 9, 11, 13, 15, 17]
+  integer :: j
+  a = [(j,j=1,20)]
+  p1 => a(::2)
+  p2(1:8) => p1(2:9)
+  if (all(p2 .eq. expect)) then
+    print *, 'PASS'
+  else
+    print *, 'FAIL'
+  endif
+end program main

tools/flang1/flang1exe/ast.c

@@ -3429,6 +3429,10 @@ simply_contiguous(int arr_ast)
     }
     break;
   case A_SUBSCR:
+    sptr = memsym_of_ast(arr_ast);
+    if (POINTERG(sptr)) {
+      return CONTIGATTRG(sptr);
+    }
     return contiguous_array_section(arr_ast);
   }