[PATCH v4 04/15] gdb/testsuite: change gdb.base/nodebug.exp to not fail with clang

[Bruno Larsen]

Clang organizes the variables differently to gcc in the original version
of this code, leading to the following differences when testing
p (int*) &dataglobal + 1

gcc:
$16 = (int *) 0x404034 <datalocal>

clang:
$16 = (int *) 0x404034 <dataglobal8>

However, since the important part of this test doesn't seem to be which
symbol is linked, but rather if GDB is correctly increasing the
address. This test was changed to actually measure address changes,
instead of assuming the ordering and naming of symbols.

Co-Authored-By: Andrew Burgess <aburgess@redhat.com>
---
 gdb/testsuite/gdb.base/nodebug.exp | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/gdb/testsuite/gdb.base/nodebug.exp b/gdb/testsuite/gdb.base/nodebug.exp
index 68a21eb07dd..1deed596095 100644
--- a/gdb/testsuite/gdb.base/nodebug.exp
+++ b/gdb/testsuite/gdb.base/nodebug.exp
@@ -170,6 +170,7 @@ if [nodebug_runto inner] then {
     set unk_type_re "has unknown type.*to its declared type"
     set ptr_math_re "Cannot perform pointer math on incomplete type \"$data_var_type\", try casting to a known type, or void \\*\\."
     set not_mem_re "Attempt to take address of value not located in memory\\."
+    set any_label_regexp "<\[^>\]+>"
 
     set dataglobal_unk_re "dataglobal.*$unk_type_re"
 
@@ -183,7 +184,7 @@ if [nodebug_runto inner] then {
 	{"dataglobal + 1"		""   $dataglobal_unk_re					$dataglobal_unk_re}
 	{"&dataglobal"			""   "\\($data_var_type \\*\\) $hex <dataglobal>"	" = $data_var_type \\*"}
 	{"&dataglobal + 1"		""   $ptr_math_re					$ptr_math_re}
-	{"(int *) &dataglobal + 1"	""   " = \\(int \\*\\) $hex <datalocal>"		"int \\*"}
+	{"(int *) &dataglobal + 1"	""   " = \\(int \\*\\) $hex $any_label_regexp"		"int \\*"}
 	{"&(int) dataglobal + 1"	""   $not_mem_re					$not_mem_re}
 	{"&dataglobal, &dataglobal"	""   "\\($data_var_type \\*\\) $hex <dataglobal>"	" = $data_var_type \\*"}
 	{"*dataglobal"			""   $dataglobal_unk_re					$dataglobal_unk_re}
@@ -214,7 +215,14 @@ if [nodebug_runto inner] then {
 	gdb_test "whatis $exp" $whatis
 	gdb_test "ptype $exp" $whatis
     }
-    
+
+    # Check that pointer arithmetic works as expected.
+    set addr1 [get_hexadecimal_valueof "&dataglobal" "*UNKNOWN*"]
+    set addr2 [get_hexadecimal_valueof "(int *) &dataglobal + 1" "*UNKNOWN*"]
+    set offset [expr $addr2 - $addr1]
+    set int_size [get_integer_valueof "sizeof (int)" "*UNKNOWN*"]
+    gdb_assert { $offset == $int_size }
+
     # The only symbol xcoff puts out for statics is for the TOC entry.
     # Possible, but hairy, for gdb to deal.  Right now it doesn't, it
     # doesn't know the variables exist at all.
-- 
2.31.1