[gdb/testsuite] Fix gdb.fortran/array-slices.exp with -m32

When running test-case gdb.fortran/array-slices.exp with target board
unix/-m32, we run into:
...
(gdb) print /x &array4d^M
$69 = 0xffffb620^M
(gdb) print /x (&array4d) + sizeof (array4d)^M
$70 = 0x95c620^M
(gdb) FAIL: gdb.fortran/array-slices.exp: repack=on: test 9: check sizes match
...
The expressions calculate the start and end of an array, but the calculation
of the end expression has an unexpected result (given that it lies before the
start of the array).  By printing "sizeof (array4d)" as a separate
expression:
...
(gdb) print /x sizeof (array4d)
$1 = 0xc40
...
it becomes clear we expected to get 0xffffb620 + 0xc40 == 0xffffc260 instead.

The problem is that using the '&' returns a pointer type:
...
(gdb) p &array4d
$5 = (PTR TO -> ( integer(kind=4) (-3:3,7:10,-3:3,-10:-7) )) 0xffffbe00
...
which has the consequence that the addition is done as pointer arithmetic.

Fix this by using the result of "print /x &array4d" instead of &array4d in the
addition.

Tested on x86_64-linux.

gdb/testsuite/ChangeLog:

2021-01-15  Tom de Vries  <tdevries@suse.de>

	PR testsuite/26997
	* gdb.fortran/array-slices.exp (run_test): Avoid pointer arithmetic
	when adding sizeof.

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index b8c9010d28f022caf09ca02643f54866f6605fcc..49623b59acc728e0eb8a1e84300faabaf7de3494 100644 (file)
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2021-01-15  Tom de Vries  <tdevries@suse.de>
+
+       PR testsuite/26997
+       * gdb.fortran/array-slices.exp (run_test): Avoid pointer arithmetic
+       when adding sizeof.
+
 2021-01-14  Tom de Vries  <tdevries@suse.de>
 
        PR testsuite/24590

diff --git a/gdb/testsuite/gdb.fortran/array-slices.exp b/gdb/testsuite/gdb.fortran/array-slices.exp
index f45a299b26843e1837c29023c3056b5bea3098e4..45753d9baea70b8e8b9518e6bda2a2b4bc5ed65f 100644 (file)
--- a/gdb/testsuite/gdb.fortran/array-slices.exp
+++ b/gdb/testsuite/gdb.fortran/array-slices.exp
@@ -208,7 +208,7 @@ proc run_test { repack } {
            set start_addr [get_hexadecimal_valueof "&${full_var_name}" \
                                "start unknown"]
            set end_addr [get_hexadecimal_valueof \
-                             "(&${full_var_name}) + sizeof (${full_var_name})" \
+                             "$start_addr + sizeof (${full_var_name})" \
                              "end unknown"]
 
            # The Fortran compiler can choose to either send a descriptor that