From dc186969b5524ab768c53c2e2f226bf24d0a35f8 Mon Sep 17 00:00:00 2001
From: Tobias Burnus <burnus@net-b.de>
Date: Sat, 28 Mar 2009 14:06:30 +0100
Subject: [PATCH] re PR fortran/38432 (Add warning for loops which are never
executed)
2009-03-28 Tobias Burnus <burnus@net-b.de>
PR fortran/38432
* resolve.c (gfc_resolve_iterator): Add zero-loop warning.
2009-03-28 Tobias Burnus <burnus@net-b.de>
PR fortran/38432
* gfortran.dg/do_check_5.f90: New test.
* gfortran.dg/array_constructor_11.f90: Add dg-warning.
* gfortran.dg/array_constructor_18.f90: Ditto.
* gfortran.dg/array_constructor_22.f90: Ditto.
* gfortran.dg/do_3.F90: Ditto.
* gfortran.dg/do_1.f90: Ditto.
From-SVN: r145186
---
gcc/fortran/ChangeLog | 5 +++
gcc/fortran/resolve.c | 20 ++++++++++++
gcc/testsuite/ChangeLog | 10 ++++++
.../gfortran.dg/array_constructor_11.f90 | 10 +++---
.../gfortran.dg/array_constructor_18.f90 | 2 +-
.../gfortran.dg/array_constructor_22.f90 | 2 +-
gcc/testsuite/gfortran.dg/do_1.f90 | 6 ++--
gcc/testsuite/gfortran.dg/do_3.F90 | 28 ++++++++--------
gcc/testsuite/gfortran.dg/do_check_5.f90 | 32 +++++++++++++++++++
9 files changed, 91 insertions(+), 24 deletions(-)
create mode 100644 gcc/testsuite/gfortran.dg/do_check_5.f90
diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index 28fa7ca892da..e3bacc1aa0f6 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,8 @@
+2009-03-28 Tobias Burnus <burnus@net-b.de>
+
+ PR fortran/38432
+ * resolve.c (gfc_resolve_iterator): Add zero-loop warning.
+
2009-03-28 Francois-Xavier Coudert <fxcoudert@gcc.gnu.org>
Paul Thomas <pault@gcc.gnu.org>
Tobias Burnus <burnus@net-b.de>
diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c
index e887fb13a6f5..1d6ee852426a 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -4918,6 +4918,26 @@ gfc_resolve_iterator (gfc_iterator *iter, bool real_ok)
|| iter->step->ts.type != iter->var->ts.type)
gfc_convert_type (iter->step, &iter->var->ts, 2);
+ if (iter->start->expr_type == EXPR_CONSTANT
+ && iter->end->expr_type == EXPR_CONSTANT
+ && iter->step->expr_type == EXPR_CONSTANT)
+ {
+ int sgn, cmp;
+ if (iter->start->ts.type == BT_INTEGER)
+ {
+ sgn = mpz_cmp_ui (iter->step->value.integer, 0);
+ cmp = mpz_cmp (iter->end->value.integer, iter->start->value.integer);
+ }
+ else
+ {
+ sgn = mpfr_sgn (iter->step->value.real);
+ cmp = mpfr_cmp (iter->end->value.real, iter->start->value.real);
+ }
+ if ((sgn > 0 && cmp < 0) || (sgn < 0 && cmp > 0))
+ gfc_warning ("DO loop at %L will be executed zero times",
+ &iter->step->where);
+ }
+
return SUCCESS;
}
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index a2e329e1de3b..315f6cfc06ff 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,13 @@
+2009-03-28 Tobias Burnus <burnus@net-b.de>
+
+ PR fortran/38432
+ * gfortran.dg/do_check_5.f90: New test.
+ * gfortran.dg/array_constructor_11.f90: Add dg-warning.
+ * gfortran.dg/array_constructor_18.f90: Ditto.
+ * gfortran.dg/array_constructor_22.f90: Ditto.
+ * gfortran.dg/do_3.F90: Ditto.
+ * gfortran.dg/do_1.f90: Ditto.
+
2009-03-28 Richard Guenther <rguenther@suse.de>
PR tree-optimization/38180
diff --git a/gcc/testsuite/gfortran.dg/array_constructor_11.f90 b/gcc/testsuite/gfortran.dg/array_constructor_11.f90
index 395d2927b9ef..bb9f0dddb110 100644
--- a/gcc/testsuite/gfortran.dg/array_constructor_11.f90
+++ b/gcc/testsuite/gfortran.dg/array_constructor_11.f90
@@ -10,20 +10,20 @@ contains
call test (1, 11, 3, (/ (i, i = 1, 11, 3) /))
call test (3, 20, 2, (/ (i, i = 3, 20, 2) /))
- call test (4, 0, 11, (/ (i, i = 4, 0, 11) /))
+ call test (4, 0, 11, (/ (i, i = 4, 0, 11) /)) ! { dg-warning "will be executed zero times" }
call test (110, 10, -3, (/ (i, i = 110, 10, -3) /))
call test (200, 20, -12, (/ (i, i = 200, 20, -12) /))
- call test (29, 30, -6, (/ (i, i = 29, 30, -6) /))
+ call test (29, 30, -6, (/ (i, i = 29, 30, -6) /)) ! { dg-warning "will be executed zero times" }
call test (1, order, 3, (/ (i, i = 1, order, 3) /))
call test (order, 1, -3, (/ (i, i = order, 1, -3) /))
! Triggers compile-time iterator calculations in trans-array.c
call test (1, 1000, 2, (/ (i, i = 1, 1000, 2), (i, i = order, 0, 1) /))
- call test (1, 0, 3, (/ (i, i = 1, 0, 3), (i, i = order, 0, 1) /))
- call test (1, 2000, -5, (/ (i, i = 1, 2000, -5), (i, i = order, 0, 1) /))
- call test (3000, 99, 4, (/ (i, i = 3000, 99, 4), (i, i = order, 0, 1) /))
+ call test (1, 0, 3, (/ (i, i = 1, 0, 3), (i, i = order, 0, 1) /)) ! { dg-warning "will be executed zero times" }
+ call test (1, 2000, -5, (/ (i, i = 1, 2000, -5), (i, i = order, 0, 1) /)) ! { dg-warning "will be executed zero times" }
+ call test (3000, 99, 4, (/ (i, i = 3000, 99, 4), (i, i = order, 0, 1) /)) ! { dg-warning "will be executed zero times" }
call test (400, 77, -39, (/ (i, i = 400, 77, -39), (i, i = order, 0, 1) /))
do j = -10, 10
diff --git a/gcc/testsuite/gfortran.dg/array_constructor_18.f90 b/gcc/testsuite/gfortran.dg/array_constructor_18.f90
index 246f448063cb..c78976839d0d 100644
--- a/gcc/testsuite/gfortran.dg/array_constructor_18.f90
+++ b/gcc/testsuite/gfortran.dg/array_constructor_18.f90
@@ -5,7 +5,7 @@
!
! Contributed by Joost VandeVondele <jv244@cam.ac.uk>
!
- call foo ((/(S1(i),i=1,3,-1)/))
+ call foo ((/(S1(i),i=1,3,-1)/)) ! { dg-warning "will be executed zero times" }
CONTAINS
FUNCTION S1(i)
CHARACTER(LEN=1) :: S1
diff --git a/gcc/testsuite/gfortran.dg/array_constructor_22.f90 b/gcc/testsuite/gfortran.dg/array_constructor_22.f90
index d29039a80e6a..0dcdaea68c1a 100644
--- a/gcc/testsuite/gfortran.dg/array_constructor_22.f90
+++ b/gcc/testsuite/gfortran.dg/array_constructor_22.f90
@@ -7,7 +7,7 @@ module test
function my_string(x)
integer i
real, intent(in) :: x(:)
- character(0) h4(1:minval([(1,i=1,0)],1))
+ character(0) h4(1:minval([(1,i=1,0)],1)) ! { dg-warning "will be executed zero times" }
character(0) sv1(size(x,1):size(h4))
character(0) sv2(2*lbound(sv1,1):size(h4))
character(lbound(sv2,1)-3) my_string
diff --git a/gcc/testsuite/gfortran.dg/do_1.f90 b/gcc/testsuite/gfortran.dg/do_1.f90
index 20e1f31ca674..171275af3f2d 100644
--- a/gcc/testsuite/gfortran.dg/do_1.f90
+++ b/gcc/testsuite/gfortran.dg/do_1.f90
@@ -29,17 +29,17 @@ program do_1
! Zero iterations
j = 0
- do i = 1, 0, 1
+ do i = 1, 0, 1 ! { dg-warning "executed zero times" }
j = j + 1
end do
if (j .ne. 0) call abort
j = 0
- do i = 1, 0, 2
+ do i = 1, 0, 2 ! { dg-warning "executed zero times" }
j = j + 1
end do
if (j .ne. 0) call abort
j = 0
- do i = 1, 2, -1
+ do i = 1, 2, -1 ! { dg-warning "executed zero times" }
j = j + 1
end do
if (j .ne. 0) call abort
diff --git a/gcc/testsuite/gfortran.dg/do_3.F90 b/gcc/testsuite/gfortran.dg/do_3.F90
index 3cada5a00516..67723a508f43 100644
--- a/gcc/testsuite/gfortran.dg/do_3.F90
+++ b/gcc/testsuite/gfortran.dg/do_3.F90
@@ -21,16 +21,16 @@ program test
TEST_LOOP(i, 0, 1, 2, 1, test_i, 2)
TEST_LOOP(i, 0, 1, 3, 1, test_i, 3)
TEST_LOOP(i, 0, 1, huge(0), 1, test_i, huge(0))
- TEST_LOOP(i, 0, 1, -1, 0, test_i, 0)
- TEST_LOOP(i, 0, 1, -2, 0, test_i, 0)
- TEST_LOOP(i, 0, 1, -3, 0, test_i, 0)
- TEST_LOOP(i, 0, 1, -huge(0), 0, test_i, 0)
- TEST_LOOP(i, 0, 1, -huge(0)-1, 0, test_i, 0)
-
- TEST_LOOP(i, 1, 0, 1, 0, test_i, 1)
- TEST_LOOP(i, 1, 0, 2, 0, test_i, 1)
- TEST_LOOP(i, 1, 0, 3, 0, test_i, 1)
- TEST_LOOP(i, 1, 0, huge(0), 0, test_i, 1)
+ TEST_LOOP(i, 0, 1, -1, 0, test_i, 0) ! { dg-warning "executed zero times" }
+ TEST_LOOP(i, 0, 1, -2, 0, test_i, 0) ! { dg-warning "executed zero times" }
+ TEST_LOOP(i, 0, 1, -3, 0, test_i, 0) ! { dg-warning "executed zero times" }
+ TEST_LOOP(i, 0, 1, -huge(0), 0, test_i, 0) ! { dg-warning "executed zero times" }
+ TEST_LOOP(i, 0, 1, -huge(0)-1, 0, test_i, 0) ! { dg-warning "executed zero times" }
+
+ TEST_LOOP(i, 1, 0, 1, 0, test_i, 1) ! { dg-warning "executed zero times" }
+ TEST_LOOP(i, 1, 0, 2, 0, test_i, 1) ! { dg-warning "executed zero times" }
+ TEST_LOOP(i, 1, 0, 3, 0, test_i, 1) ! { dg-warning "executed zero times" }
+ TEST_LOOP(i, 1, 0, huge(0), 0, test_i, 1) ! { dg-warning "executed zero times" }
TEST_LOOP(i, 1, 0, -1, 2, test_i, -1)
TEST_LOOP(i, 1, 0, -2, 1, test_i, -1)
TEST_LOOP(i, 1, 0, -3, 1, test_i, -2)
@@ -58,14 +58,14 @@ program test
TEST_LOOP(i1, huge(i1), -huge(i1)-1_1, -huge(i1)-1_1, 2, test_i1, -huge(i1)-2_1)
TEST_LOOP(i1, -2_1, 3_1, huge(i1), 1, test_i1, huge(i1)-2_1)
- TEST_LOOP(i1, -2_1, 3_1, -huge(i1), 0, test_i1, -2_1)
+ TEST_LOOP(i1, -2_1, 3_1, -huge(i1), 0, test_i1, -2_1) ! { dg-warning "executed zero times" }
TEST_LOOP(i1, 2_1, -3_1, -huge(i1), 1, test_i1, 2_1-huge(i1))
- TEST_LOOP(i1, 2_1, -3_1, huge(i1), 0, test_i1, 2_1)
+ TEST_LOOP(i1, 2_1, -3_1, huge(i1), 0, test_i1, 2_1) ! { dg-warning "executed zero times" }
! Real loops
TEST_LOOP(r, 0.0, 1.0, 0.11, 1 + int(1.0/0.11), test_r, 0.0)
- TEST_LOOP(r, 0.0, 1.0, -0.11, 0, test_r, 0.0)
- TEST_LOOP(r, 0.0, -1.0, 0.11, 0, test_r, 0.0)
+ TEST_LOOP(r, 0.0, 1.0, -0.11, 0, test_r, 0.0) ! { dg-warning "executed zero times" }
+ TEST_LOOP(r, 0.0, -1.0, 0.11, 0, test_r, 0.0) ! { dg-warning "executed zero times" }
TEST_LOOP(r, 0.0, -1.0, -0.11, 1 + int(1.0/0.11), test_r, 0.0)
TEST_LOOP(r, 0.0, 0.0, 0.11, 1, test_r, 0.0)
TEST_LOOP(r, 0.0, 0.0, -0.11, 1, test_r, 0.0)
diff --git a/gcc/testsuite/gfortran.dg/do_check_5.f90 b/gcc/testsuite/gfortran.dg/do_check_5.f90
new file mode 100644
index 000000000000..081a228cfc78
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/do_check_5.f90
@@ -0,0 +1,32 @@
+! { dg-do compile }
+!
+! PR/fortran 38432
+! DO-loop compile-time checks
+!
+implicit none
+integer :: i
+real :: r
+do i = 1, 0 ! { dg-warning "executed zero times" }
+end do
+
+do i = 1, -1, 1 ! { dg-warning "executed zero times" }
+end do
+
+do i = 1, 2, -1 ! { dg-warning "executed zero times" }
+end do
+
+do i = 1, 2, 0 ! { dg-error "cannot be zero" }
+end do
+
+do r = 1, 0 ! { dg-warning "must be integer|executed zero times" }
+end do
+
+do r = 1, -1, 1 ! { dg-warning "must be integer|executed zero times" }
+end do
+
+do r = 1, 2, -1 ! { dg-warning "must be integer|executed zero times" }
+end do
+
+do r = 1, 2, 0 ! { dg-error "must be integer|cannot be zero" }
+end do
+end
--
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