gdb: add accessors for field (and call site) location

Add accessors for the various location values in struct field.  This
lets us assert that when we get a location value of a certain kind (say,
bitpos), the field's location indeed contains a value of that kind.

Remove the SET_FIELD_* macros, instead use the new setters directly.
Update the FIELD_* macros used to access field locations to go through
the getters.  They will be removed in a subsequent patch.

There are places where the FIELD_* macros are used on call_site_target
structures, because it contains members of the same name (loc_kind and
loc).  For now, I have replicated the getters/setters in
call_site_target.  But we could perhaps eventually factor them in a
"location" structure that can be used at both places.

Note that the field structure, being zero-initialized, defaults to a
bitpos location with value 0.  While writing this patch, I tried to make
it default to an "unset" location, to catch places where we would miss
setting a field's location.  However, I found that some places relied on
the default being "bitpos 0", so I left it as-is.  This change could
always be done as follow-up work, making these places explicitly set the
"bitpos 0" location.

I found two issues to fix:

 - I got some failures in the gdb.base/infcall-nested-structs-c++.exp
   test.  They were caused by two functions in amd64-tdep.c using
   TYPE_FIELD_BITPOS before checking if the location is of the bitpos
   kind, which they do indirectly through `field_is_static`.  Simply
   move getting the bitpos below the field_is_static call.

 - I got a failure in gdb.xml/tdesc-regs.exp.  It turns out that in
   make_gdb_type_enum, we set enum field values using SET_FIELD_BITPOS,
   and later access them through FIELD_ENUMVAL.  Fix that by using
   set_loc_enumval to set the value.

Change-Id: I53d3734916c46457576ba11dd77df4049d2fc1e8

1 files changed, 6 insertions, 6 deletions

diff --git a/gdb/cp-valprint.c b/gdb/cp-valprint.c
index f6969a5..ef7276a 100644
--- a/gdb/cp-valprint.c
+++ b/gdb/cp-valprint.c
@@ -735,13 +735,13 @@ test_print_fields (gdbarch *arch)
   if (gdbarch_byte_order (arch) == BFD_ENDIAN_LITTLE)
     {
       f = append_composite_type_field_raw (the_struct, "A", bool_type);
-      SET_FIELD_BITPOS (*f, 1);
+      f->set_loc_bitpos (1);
       FIELD_BITSIZE (*f) = 1;
       f = append_composite_type_field_raw (the_struct, "B", uint8_type);
-      SET_FIELD_BITPOS (*f, 3);
+      f->set_loc_bitpos (3);
       FIELD_BITSIZE (*f) = 3;
       f = append_composite_type_field_raw (the_struct, "C", bool_type);
-      SET_FIELD_BITPOS (*f, 7);
+      f->set_loc_bitpos (7);
       FIELD_BITSIZE (*f) = 1;
     }
   /* According to the logic commented in "make_gdb_type_struct ()" of
@@ -750,13 +750,13 @@ test_print_fields (gdbarch *arch)
   else
     {
       f = append_composite_type_field_raw (the_struct, "A", bool_type);
-      SET_FIELD_BITPOS (*f, 30);
+      f->set_loc_bitpos (30);
       FIELD_BITSIZE (*f) = 1;
       f = append_composite_type_field_raw (the_struct, "B", uint8_type);
-      SET_FIELD_BITPOS (*f, 26);
+      f->set_loc_bitpos (26);
       FIELD_BITSIZE (*f) = 3;
       f = append_composite_type_field_raw (the_struct, "C", bool_type);
-      SET_FIELD_BITPOS (*f, 24);
+      f->set_loc_bitpos (24);
       FIELD_BITSIZE (*f) = 1;
     }