From 7001d522d0273658d9e1fb12ca104d56bfcae34d Mon Sep 17 00:00:00 2001
From: Mark Eggleston <markeggleston@gcc.gnu.org>
Date: Fri, 22 Jan 2021 15:06:08 +0000
Subject: [PATCH 10/10] Fill in missing array dimensions using the lower bound
Use -fdec-add-missing-indexes to enable feature. Also enabled by fdec.
---
gcc/fortran/lang.opt | 8 ++++++++
gcc/fortran/options.c | 1 +
gcc/fortran/resolve.c | 24 ++++++++++++++++++++++++
gcc/testsuite/gfortran.dg/array_6.f90 | 23 +++++++++++++++++++++++
gcc/testsuite/gfortran.dg/array_7.f90 | 23 +++++++++++++++++++++++
gcc/testsuite/gfortran.dg/array_8.f90 | 23 +++++++++++++++++++++++
6 files changed, 102 insertions(+)
create mode 100644 gcc/testsuite/gfortran.dg/array_6.f90
create mode 100644 gcc/testsuite/gfortran.dg/array_7.f90
create mode 100644 gcc/testsuite/gfortran.dg/array_8.f90
diff --git a/gcc/fortran/lang.opt b/gcc/fortran/lang.opt
index 019c798cf09..f27de88ea3f 100644
--- a/gcc/fortran/lang.opt
+++ b/gcc/fortran/lang.opt
@@ -281,6 +281,10 @@ Wmissing-include-dirs
Fortran
; Documented in C/C++
+Wmissing-index
+Fortran Var(warn_missing_index) Warning LangEnabledBy(Fortran,Wall)
+Warn that the lower bound of a missing index will be used.
+
Wuse-without-only
Fortran Var(warn_use_without_only) Warning
Warn about USE statements that have no ONLY qualifier.
@@ -460,6 +464,10 @@ fdec
Fortran Var(flag_dec)
Enable all DEC language extensions.
+fdec-add-missing-indexes
+Fortran Var(flag_dec_add_missing_indexes)
+Enable the addition of missing indexes using their lower bounds.
+
fdec-blank-format-item
Fortran Var(flag_dec_blank_format_item)
Enable the use of blank format items in format strings.
diff --git a/gcc/fortran/options.c b/gcc/fortran/options.c
index 050f56fdc25..c3b2822685d 100644
--- a/gcc/fortran/options.c
+++ b/gcc/fortran/options.c
@@ -84,6 +84,7 @@ set_dec_flags (int value)
SET_BITFLAG (flag_dec_non_logical_if, value, value);
SET_BITFLAG (flag_dec_promotion, value, value);
SET_BITFLAG (flag_dec_sequence, value, value);
+ SET_BITFLAG (flag_dec_add_missing_indexes, value, value);
}
/* Finalize DEC flags. */
diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c
index fe7d0cc5944..0efeedab46e 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -4806,6 +4806,30 @@ compare_spec_to_ref (gfc_array_ref *ar)
if (ar->type == AR_FULL)
return true;
+ if (flag_dec_add_missing_indexes && as->rank > ar->dimen)
+ {
+ /* Add in the missing dimensions, assuming they are the lower bound
+ of that dimension if not specified. */
+ int j;
+ if (warn_missing_index)
+ {
+ gfc_warning (OPT_Wmissing_index, "Using the lower bound for "
+ "unspecified dimensions in array reference at %L",
+ &ar->where);
+ }
+ /* Other parts of the code iterate ar->start and ar->end from 0 to
+ ar->dimen, so it is safe to assume slots from ar->dimen upwards
+ are unused (i.e. there are no gaps; the specified indexes are
+ contiguous and start at zero. */
+ for(j = ar->dimen; j <= as->rank; j++)
+ {
+ ar->start[j] = gfc_copy_expr (as->lower[j]);
+ ar->end[j] = gfc_copy_expr (as->lower[j]);
+ ar->dimen_type[j] = DIMEN_ELEMENT;
+ }
+ ar->dimen = as->rank;
+ }
+
if (as->rank != ar->dimen)
{
gfc_error ("Rank mismatch in array reference at %L (%d/%d)",
diff --git a/gcc/testsuite/gfortran.dg/array_6.f90 b/gcc/testsuite/gfortran.dg/array_6.f90
new file mode 100644
index 00000000000..5c26e18ab3e
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/array_6.f90
@@ -0,0 +1,23 @@
+! { dg-do run }
+! { dg-options "-fdec -Wmissing-index" }!
+! Checks that under-specified arrays (referencing arrays with fewer
+! dimensions than the array spec) generates a warning.
+!
+! Contributed by Jim MacArthur <jim.macarthur@codethink.co.uk>
+! Updated by Mark Eggleston <mark.eggleston@codethink.co.uk>
+!
+
+program under_specified_array
+ integer chessboard(8,8)
+ integer chessboard3d(8,8,3:5)
+ chessboard(3,1) = 5
+ chessboard(3,2) = 55
+ chessboard3d(4,1,3) = 6
+ chessboard3d(4,1,4) = 66
+ chessboard3d(4,4,3) = 7
+ chessboard3d(4,4,4) = 77
+
+ if (chessboard(3).ne.5) stop 1 ! { dg-warning "Using the lower bound for unspecified dimensions in array reference" }
+ if (chessboard3d(4).ne.6) stop 2 ! { dg-warning "Using the lower bound for unspecified dimensions in array reference" }
+ if (chessboard3d(4,4).ne.7) stop 3 ! { dg-warning "Using the lower bound for unspecified dimensions in array reference" }
+end program
diff --git a/gcc/testsuite/gfortran.dg/array_7.f90 b/gcc/testsuite/gfortran.dg/array_7.f90
new file mode 100644
index 00000000000..5588a5bd02d
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/array_7.f90
@@ -0,0 +1,23 @@
+! { dg-do run }
+! { dg-options "-fdec-add-missing-indexes -Wmissing-index" }!
+! Checks that under-specified arrays (referencing arrays with fewer
+! dimensions than the array spec) generates a warning.
+!
+! Contributed by Jim MacArthur <jim.macarthur@codethink.co.uk>
+! Updated by Mark Eggleston <mark.eggleston@codethink.co.uk>
+!
+
+program under_specified_array
+ integer chessboard(8,8)
+ integer chessboard3d(8,8,3:5)
+ chessboard(3,1) = 5
+ chessboard(3,2) = 55
+ chessboard3d(4,1,3) = 6
+ chessboard3d(4,1,4) = 66
+ chessboard3d(4,4,3) = 7
+ chessboard3d(4,4,4) = 77
+
+ if (chessboard(3).ne.5) stop 1 ! { dg-warning "Using the lower bound for unspecified dimensions in array reference" }
+ if (chessboard3d(4).ne.6) stop 2 ! { dg-warning "Using the lower bound for unspecified dimensions in array reference" }
+ if (chessboard3d(4,4).ne.7) stop 3 ! { dg-warning "Using the lower bound for unspecified dimensions in array reference" }
+end program
diff --git a/gcc/testsuite/gfortran.dg/array_8.f90 b/gcc/testsuite/gfortran.dg/array_8.f90
new file mode 100644
index 00000000000..f0d2ef5e37d
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/array_8.f90
@@ -0,0 +1,23 @@
+! { dg-do compile }
+! { dg-options "-fdec -fno-dec-add-missing-indexes" }!
+! Checks that under-specified arrays (referencing arrays with fewer
+! dimensions than the array spec) generates a warning.
+!
+! Contributed by Jim MacArthur <jim.macarthur@codethink.co.uk>
+! Updated by Mark Eggleston <mark.eggleston@codethink.co.uk>
+!
+
+program under_specified_array
+ integer chessboard(8,8)
+ integer chessboard3d(8,8,3:5)
+ chessboard(3,1) = 5
+ chessboard(3,2) = 55
+ chessboard3d(4,1,3) = 6
+ chessboard3d(4,1,4) = 66
+ chessboard3d(4,4,3) = 7
+ chessboard3d(4,4,4) = 77
+
+ if (chessboard(3).ne.5) stop 1 ! { dg-error "Rank mismatch" }
+ if (chessboard3d(4).ne.6) stop 2 ! { dg-error "Rank mismatch" }
+ if (chessboard3d(4,4).ne.7) stop 3 ! { dg-error "Rank mismatch" }
+end program
--
2.27.0