gdb: update gdb-gdb.py.in for latest changes to struct field

This commit updates uses of 'loc' and 'loc_kind' to 'm_loc' and
'm_loc_kind' respectively, in gdb-gdb.py.in, which is required after
this commit:

  commit cd3f655cc7a55437a05aa8e7b1fcc9051b5fe404
  Date:   Thu Sep 30 22:38:29 2021 -0400

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

I have also incorporated this change:

  https://sourceware.org/pipermail/gdb-patches/2021-September/182171.html

Which means we print 'm_name' instead of 'name' when displaying the
'm_name' member variable.

Finally, I have also added support for the new TYPE_SPECIFIC_INT
fields, which were added with this commit:

  commit 20a5fcbd5b28cca88511ac5a9ad5e54251e8fa6d
  Date:   Wed Sep 23 09:39:24 2020 -0600

      Handle bit offset and bit size in base types

I updated the gdb.gdb/python-helper.exp test to cover all of these
changes.

3 files changed, 191 insertions, 20 deletions

diff --git a/gdb/gdb-gdb.py.in b/gdb/gdb-gdb.py.in
index 15dbf38..a60ad01 100644
--- a/gdb/gdb-gdb.py.in
+++ b/gdb/gdb-gdb.py.in
@@ -153,8 +153,8 @@ class StructMainTypePrettyPrinter:
         """Return an image of the loc component inside the given field
         gdb.Value.
         """
-        loc_val = field_val["loc"]
-        loc_kind = str(field_val["loc_kind"])
+        loc_val = field_val["m_loc"]
+        loc_kind = str(field_val["m_loc_kind"])
         if loc_kind == "FIELD_LOC_KIND_BITPOS":
             return "bitpos = %d" % loc_val["bitpos"]
         elif loc_kind == "FIELD_LOC_KIND_ENUMVAL":
@@ -166,7 +166,7 @@ class StructMainTypePrettyPrinter:
         elif loc_kind == "FIELD_LOC_KIND_DWARF_BLOCK":
             return "dwarf_block = %s" % loc_val["dwarf_block"]
         else:
-            return "loc = ??? (unsupported loc_kind value)"
+            return "m_loc = ??? (unsupported m_loc_kind value)"
 
     def struct_field_img(self, fieldno):
         """Return an image of the main_type field number FIELDNO."""
@@ -175,9 +175,9 @@ class StructMainTypePrettyPrinter:
         if f["artificial"]:
             label += " (artificial)"
         fields = []
-        fields.append("name = %s" % f["name"])
-        fields.append("type = %s" % f["m_type"])
-        fields.append("loc_kind = %s" % f["loc_kind"])
+        fields.append("m_name = %s" % f["m_name"])
+        fields.append("m_type = %s" % f["m_type"])
+        fields.append("m_loc_kind = %s" % f["m_loc_kind"])
         fields.append("bitsize = %d" % f["bitsize"])
         fields.append(self.struct_field_location_img(f))
         return label + "\n" + "  {" + ",\n   ".join(fields) + "}"
@@ -241,9 +241,13 @@ class StructMainTypePrettyPrinter:
                 "scaling_factor: <opaque> (call __gmpz_dump with "
                 " _mp_num and _mp_den fields if needed)"
             )
+        elif type_specific_kind == "TYPE_SPECIFIC_INT":
+            img = ("int_stuff = { bit_size = %d, bit_offset = %d }"
+                   % (type_specific["int_stuff"]["bit_size"],
+                      type_specific["int_stuff"]["bit_offset"]))
         else:
             img = (
-                "type_specific = ??? (unknown type_secific_kind: %s)"
+                "type_specific = ??? (unknown type_specific_kind: %s)"
                 % type_specific_kind
             )
         return img
diff --git a/gdb/testsuite/gdb.gdb/python-helper.cc b/gdb/testsuite/gdb.gdb/python-helper.cc
new file mode 100644
index 0000000..2bacf80
--- /dev/null
+++ b/gdb/testsuite/gdb.gdb/python-helper.cc
@@ -0,0 +1,40 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2021 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+struct CC
+{
+  CC (int val)
+    : m_val (val)
+  {
+    /* Nothing.  */
+  }
+
+  int a_method ()
+  {
+    return m_val;
+  }
+
+  int m_val;
+};
+
+CC global_c (0);
+
+int
+main ()
+{
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.gdb/python-helper.exp b/gdb/testsuite/gdb.gdb/python-helper.exp
index 7013a3a..58f4338 100644
--- a/gdb/testsuite/gdb.gdb/python-helper.exp
+++ b/gdb/testsuite/gdb.gdb/python-helper.exp
@@ -24,6 +24,12 @@ if [target_info exists gdb,noinferiorio] {
     return
 }
 
+standard_testfile .cc
+
+if { [build_executable "failed to build" $testfile $srcfile {debug c++}] } {
+    return -1
+}
+
 # Find the helper script in the GDB build directory.
 set py_helper_script [file dirname $GDB]/gdb-gdb.py
 if { ![file readable $py_helper_script] \
@@ -63,16 +69,23 @@ proc test_python_helper {} {
 		  "end"] ".*" \
 	"register the type pretty printer"
 
-    # Now place a breakpoint somewhere useful.  This can be any function that:
+    # Now place breakpoints somewhere useful.  These locations can be
+    # any function that:
+    #
     # (a) is easy to reach by issuing a simple gdb command, and
     # (b) is unlikely to be modified very often within gdb, and
     # (c) has a parameter that is either a 'struct type *' or a 'struct value *'.
-    gdb_breakpoint value_print
+    gdb_breakpoint value_print qualified
+    gdb_breakpoint c_print_type qualified
+
+    # Disable all breakpoints until after we have loaded the test
+    # binary into the inner GDB.
+    gdb_test_no_output "disable breakpoints"
 
     # Adjust the prompt on the outer gdb, this just makes things a
     # little clearer when trying to unpick which GDB is active.
-    gdb_test_multiple "set prompt (xgdb) " "set xgdb prompt" {
-	-re "\[(\]xgdb\[)\].*\[(\]xgdb\[)\] $" {
+    gdb_test_multiple "set prompt (outer-gdb) " "set outer gdb prompt" {
+	-re "\[(\]outer-gdb\[)\].*\[(\]outer-gdb\[)\] $" {
 	    pass $gdb_test_name
 	}
     }
@@ -87,12 +100,45 @@ proc test_python_helper {} {
 	}
     }
 
-    # Send a command to the inner GDB (hence send_inferior), this
-    # should result in the outer GDB stopping at the breakpoint we
-    # just created.
+    # Load the test executable into the inner GDB.  The output here is
+    # being read from the inner GDB, hence the use of -i here.
+    send_inferior "file -readnow $::binfile\n"
+    gdb_test_multiple "" "loading test binary into inner GDB" {
+	-i "$inferior_spawn_id"
+	-re "Reading symbols from.*\r\n$gdb_prompt $" {
+	    pass $gdb_test_name
+	}
+    }
+
+    # Send Ctrl-C to the inner GDB, this should kick us back to the
+    # prompt of the outer GDB.
+    send_inferior "\003"
+    gdb_test_multiple "" "interrupted the inner" {
+	-re ".*\\(outer-gdb\\) $" {
+	    pass $gdb_test_name
+	}
+    }
+
+    # Now enable all breakpoints within the outer GDB.
+    gdb_test_multiple "enable breakpoints" "" {
+	-re "\\(outer-gdb\\) $" {
+	    pass $gdb_test_name
+	}
+    }
+
+    # We need to resume the inner GDB after interrupting it, this is
+    # done by sending 'continue'.  However, GDB will not redisplay the
+    # prompt in this case, so we have nothing that we can detect in
+    # order to know this continue was successful.  Still, if this
+    # didn't work, then later tests should fail.
+    send_gdb "continue\n"
+
+    # Control is back with the inner GDB.  Send a command to the inner
+    # GDB, this should result in the outer GDB stopping at one of the
+    # breakpoints we created..
     send_inferior "print 1\n"
-    gdb_test_multiple "" "hit breakpoint in inner gdb" {
-	-re "Breakpoint $decimal, value_print.*\\(xgdb\\) $" {
+    gdb_test_multiple "" "hit breakpoint in outer gdb" {
+	-re "Breakpoint $decimal, value_print.*\\(outer-gdb\\) $" {
 	    pass $gdb_test_name
 	}
     }
@@ -107,12 +153,12 @@ proc test_python_helper {} {
 		    " instance_flags = 0," \
 		    " length = $decimal," \
 		    " main_type = $hex}" \
-		    "\\(xgdb\\) $"]
+		    "\\(outer-gdb\\) $"]
     gdb_test_multiple "print *val->type" "pretty print type" {
 	-re "$answer" {
 	    pass $gdb_test_name
 	}
-	-re "There is no member named.*\r\n\\(xgdb\\) $" {
+	-re "There is no member named.*\r\n\\(outer-gdb\\) $" {
 	    fail $gdb_test_name
 	}
     }
@@ -125,12 +171,93 @@ proc test_python_helper {} {
 		    " owner = $hex \\(gdbarch\\)," \
 		    " target_type = 0x0," \
 		    " type_specific_field = TYPE_SPECIFIC_NONE}" \
-		    "\\(xgdb\\) $"]
+		    "\\(outer-gdb\\) $"]
     gdb_test_multiple "print *val->type->main_type" "pretty print type->main_type" {
 	-re "$answer" {
 	    pass $gdb_test_name
 	}
-	-re "There is no member named.*\r\n\\(xgdb\\) $" {
+	-re "There is no member named.*\r\n\\(outer-gdb\\) $" {
+	    fail $gdb_test_name
+	}
+    }
+
+    # Send the continue to the outer GDB, which resumes the inner GDB,
+    # we then detect the prompt from the inner GDB, hence the use of
+    # -i here.
+    gdb_test_multiple "continue" "resume inner gdb" {
+	-i $inferior_spawn_id
+	-re "\r\n$gdb_prompt $" {
+	    pass $gdb_test_name
+	}
+    }
+
+    # Now print an integer that was created from the DWARF
+    # information, this will include the TYPE_SPECIFIC_INT
+    # information.
+    send_inferior "print global_c.m_val\n"
+    gdb_test_multiple "" "print integer from DWARF info" {
+	-re "Breakpoint $decimal, value_print.*\\(outer-gdb\\) $" {
+	    pass $gdb_test_name
+	}
+    }
+
+    set answer [multi_line \
+		    "$decimal = " \
+		    "{name = $hex \"int\"," \
+		    " code = TYPE_CODE_INT," \
+		    " flags = \[^\r\n\]+," \
+		    " owner = $hex \\(objfile\\)," \
+		    " target_type = 0x0," \
+		    " int_stuff = { bit_size = $decimal, bit_offset = $decimal }}" \
+		    "\\(outer-gdb\\) $"]
+    gdb_test_multiple "print *val->type->main_type" "pretty print type->main_type for DWARF type" {
+	-re "$answer" {
+	    pass $gdb_test_name
+	}
+	-re "There is no member named.*\r\n\\(outer-gdb\\) $" {
+	    fail $gdb_test_name
+	}
+    }
+
+    # Send the continue to the outer GDB, which resumes the inner GDB,
+    # we then detect the prompt from the inner GDB, hence the use of
+    # -i here.
+    gdb_test_multiple "continue" "resume inner gdb again" {
+	-i $inferior_spawn_id
+	-re "\r\n$gdb_prompt $" {
+	    pass $gdb_test_name
+	}
+    }
+
+    # Send a command to the inner GDB, this should result in the outer
+    # GDB stopping at the value_print breakpoint again.
+    send_inferior "ptype global_c\n"
+    gdb_test_multiple "" "hit breakpoint in outer gdb again" {
+	-re "Breakpoint $decimal, c_print_type .*\\(outer-gdb\\) $" {
+	    pass $gdb_test_name
+	}
+    }
+
+    set answer [multi_line \
+		    "$decimal = " \
+		    "{name = $hex \"CC\"," \
+		    " code = TYPE_CODE_STRUCT," \
+		    " flags = \[^\r\n\]+," \
+		    " owner = $hex \\(objfile\\)," \
+		    " target_type = 0x0," \
+		    " flds_bnds\\.fields\\\[0\\\]:" \
+		    "  {m_name = $hex \"m_val\"," \
+		    "   m_type = $hex," \
+		    "   m_loc_kind = FIELD_LOC_KIND_BITPOS," \
+		    "   bitsize = 0," \
+		    "   bitpos = 0}," \
+		    " cplus_stuff = $hex}" \
+		    "\\(outer-gdb\\) $"]
+    gdb_test_multiple "print *type->main_type" "" {
+	-re "$answer" {
+	    pass $gdb_test_name
+	}
+	-re "\r\n\\(outer-gdb\\) $" {
 	    fail $gdb_test_name
 	}
     }