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* [PATCH] Differentiate empty vs. opaque types
@ 2007-03-11 22:55 Jan Kratochvil
  2007-03-12  3:35 ` Daniel Jacobowitz
  0 siblings, 1 reply; 4+ messages in thread
From: Jan Kratochvil @ 2007-03-11 22:55 UTC (permalink / raw)
  To: gdb-patches

[-- Attachment #1: Type: text/plain, Size: 676 bytes --]

Hi,

attached testcase targets the difference of `struct x;' vs. `struct {} x;' by checking
the DWARF flag `DW_AT_declaration':
# DWARF3: An incomplete structure, union or class type is represented by
# a structure, union or class entry that does not have a byte size attribute
# and that has a DW_AT_declaration attribute.

The attachment then fixes GDB to make the testcase pass.

Patch goes the regression-safe way by introducing OBJF_HAVE_TYPE_STUB currently
being set only by DWARF/DWARF2.  It should be probably also set at least by
STABS but I tested the code only on DWARF2.  Unaware how feasible would be
unconditional TYPE_STUB() dependency nowadays.


Regards,
Jan

[-- Attachment #2: gdb-empty-is-not-opaque.patch --]
[-- Type: text/plain, Size: 9119 bytes --]

2007-03-11  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* gdbtypes.h (TYPE_IS_OPAQUE): Empty vs. opaque structures are now
	distinct on the OBJF_HAVE_TYPE_STUB-supported debug targets.
	* objfiles.h (OBJF_HAVE_TYPE_STUB): New flag.
	* dwarf2read.c (dwarf2_build_psymtabs): Set OBJF_HAVE_TYPE_STUB.
	* dwarfread.c (dwarf_build_psymtabs): Likewise.

2007-03-11  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* gdb.base/type-opaque-lib.c, gdb.base/type-opaque-main.c,
	gdb.base/type-opaque.exp: New files.


--- gdb/dwarf2read.c	12 Feb 2007 15:19:31 -0000	1.215
+++ gdb/dwarf2read.c	11 Mar 2007 22:35:36 -0000
@@ -1196,6 +1196,8 @@ dwarf2_build_psymtabs (struct objfile *o
 {
   /* We definitely need the .debug_info and .debug_abbrev sections */
 
+  objfile->flags |= OBJF_HAVE_TYPE_STUB;
+
   dwarf2_per_objfile->info_buffer = dwarf2_read_section (objfile, dwarf_info_section);
   dwarf2_per_objfile->abbrev_buffer = dwarf2_read_section (objfile, dwarf_abbrev_section);
 
--- gdb/dwarfread.c	12 Feb 2007 15:19:31 -0000	1.47
+++ gdb/dwarfread.c	11 Mar 2007 22:35:38 -0000
@@ -684,6 +684,8 @@ dwarf_build_psymtabs (struct objfile *ob
     }
   back_to = make_cleanup (xfree, dbbase);
 
+  objfile->flags |= OBJF_HAVE_TYPE_STUB;
+
   /* If we are reinitializing, or if we have never loaded syms yet, init.
      Since we have no idea how many DIES we are looking at, we just guess
      some arbitrary value. */
--- gdb/gdbtypes.h	29 Jan 2007 17:31:06 -0000	1.68
+++ gdb/gdbtypes.h	11 Mar 2007 22:35:38 -0000
@@ -969,7 +969,9 @@ extern void allocate_cplus_struct_type (
 #define TYPE_IS_OPAQUE(thistype) (((TYPE_CODE (thistype) == TYPE_CODE_STRUCT) ||        \
                                    (TYPE_CODE (thistype) == TYPE_CODE_UNION))        && \
                                   (TYPE_NFIELDS (thistype) == 0)                     && \
-                                  (TYPE_CPLUS_SPECIFIC (thistype) && (TYPE_NFN_FIELDS (thistype) == 0)))
+                                  (TYPE_CPLUS_SPECIFIC (thistype) && (TYPE_NFN_FIELDS (thistype) == 0)) && \
+                                  (TYPE_STUB (thistype)                                 \
+                                   || !(TYPE_OBJFILE(thistype)->flags & OBJF_HAVE_TYPE_STUB)))
 
 struct builtin_type
 {
--- gdb/objfiles.h	21 Jan 2007 16:55:49 -0000	1.44
+++ gdb/objfiles.h	11 Mar 2007 22:35:48 -0000
@@ -480,6 +480,10 @@ struct objfile
 
 #define OBJF_USERLOADED	(1 << 5)	/* User loaded */
 
+/* We can depend TYPE_STUB(t) will be set appropriately.  */
+
+#define OBJF_HAVE_TYPE_STUB	(1 << 6) /* TYPE_FLAGS_STUB supported */
+
 /* The object file that the main symbol table was loaded from (e.g. the
    argument to the "symbol-file" or "file" command).  */
 
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ gdb/testsuite/gdb.base/type-opaque-lib.c	11 Mar 2007 22:35:49 -0000
@@ -0,0 +1,38 @@
+/* Test resolving of an opaque type from the loaded shared library.
+
+   Copyright 2007, Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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 2 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, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+struct libtype_opaque
+{ 
+  int libfield_opaque;
+};
+struct libtype_opaque libtype_opaque_use;
+
+struct libtype_empty
+{ 
+  int libfield_empty;
+};
+struct libtype_empty libtype_empty_use;
+
+struct libtype_filled
+{ 
+  int libfield_filled;
+};
+struct libtype_filled libtype_filled_use;
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ gdb/testsuite/gdb.base/type-opaque-main.c	11 Mar 2007 22:35:49 -0000
@@ -0,0 +1,41 @@
+/* Test resolving of an opaque type from the loaded shared library.
+
+   Copyright 2007, Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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 2 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, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+struct libtype_opaque;
+
+struct libtype_empty
+  {
+  };    
+
+struct libtype_filled
+  {
+    long mainfield_filled;
+  };    
+
+int main (void)
+{
+  volatile struct libtype_opaque *pointer_opaque = (void *) 0;
+  volatile struct libtype_empty *pointer_empty = (void *) 0;
+  volatile struct libtype_filled *pointer_filled = (void *) 0;
+
+  return (int) pointer_opaque + (int) pointer_empty
+	 + (int) pointer_filled;
+}
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ gdb/testsuite/gdb.base/type-opaque.exp	11 Mar 2007 22:35:49 -0000
@@ -0,0 +1,123 @@
+# Copyright 2004, 2007 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 2 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, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+# Please email any bugs, comments, and/or additions to this file to:
+# bug-gdb@prep.ai.mit.edu
+
+# Test resolving of an opaque type from the loaded shared library.
+
+if $tracelevel then {
+    strace $tracelevel
+}
+
+set testfile type-opaque-main
+set libfile type-opaque-lib
+set srcfile ${testfile}.c
+set binfile ${objdir}/${subdir}/${testfile}
+
+set libsrc "${srcdir}/${subdir}/${libfile}.c"
+set libobj "${objdir}/${subdir}/${libfile}.so"
+set execsrc "${srcdir}/${subdir}/${srcfile}"
+
+remote_exec build "rm -f ${binfile}"
+
+# Are we on a target board?  No support for downloading shared libraries
+# to a target yet.
+if ![isnative] then {
+    return 0
+}
+
+# get the value of gcc_compiled
+if [get_compiler_info ${binfile}] {
+    return -1
+}
+
+if { [gdb_compile_shlib $libsrc $libobj {debug}] != ""
+     || [gdb_compile $execsrc ${binfile} executable \
+	     [list debug shlib=${libobj}]] != "" } {
+    return -1
+}
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfile}
+
+if ![runto_main] then {
+    fail "Can't run to main"
+    return 0
+}
+
+
+# DWARF3: An incomplete structure, union or class type is represented by
+# a structure, union or class entry that does not have a byte size attribute
+# and that has a DW_AT_declaration attribute.
+
+
+# <1><15f>: Abbrev Number: 8 (DW_TAG_structure_type)
+#     DW_AT_name        : libtype_opaque
+#     DW_AT_declaration : 1
+
+set name "opaque type resolving"
+gdb_test_multiple "ptype pointer_opaque" $name \
+{
+    -re "libfield_opaque.*$gdb_prompt $"  {
+	pass $name
+    }
+}
+
+
+# <1><9e>: Abbrev Number: 2 (DW_TAG_structure_type)
+#     DW_AT_name        : libtype_empty
+#     DW_AT_byte_size   : 0
+#     DW_AT_decl_file   : 1
+#     DW_AT_decl_line   : 25
+
+set name "empty type resolving"
+gdb_test_multiple "ptype pointer_empty" $name \
+{
+    -re "\\{\[ \t\r\n\]*<no data fields>\[ \t\r\n\]*\\}.*$gdb_prompt $"  {
+	pass $name
+    }
+    -re "libfield_empty.*$gdb_prompt $"  {
+	fail $name
+    }
+}
+
+
+# <1><b0>: Abbrev Number: 3 (DW_TAG_structure_type)
+#     DW_AT_sibling     : <e3>
+#     DW_AT_name        : libtype_filled
+#     DW_AT_byte_size   : 4
+#     DW_AT_decl_file   : 1
+#     DW_AT_decl_line   : 29
+# <2><c7>: Abbrev Number: 4 (DW_TAG_member)
+#     DW_AT_name        : mainfield_filled
+#     DW_AT_decl_file   : 1
+#     DW_AT_decl_line   : 30
+#     DW_AT_type        : <e3>
+#     DW_AT_data_member_location: 2 byte block: 23 0     (DW_OP_plus_uconst: 0)
+
+set name "filled type resolving"
+gdb_test_multiple "ptype pointer_filled" $name \
+{
+    -re "mainfield_filled.*$gdb_prompt $"  {
+	pass $name
+    }
+    -re "libfield_filled.*$gdb_prompt $"  {
+	fail $name
+    }
+}

^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2007-04-10 21:19 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2007-03-11 22:55 [PATCH] Differentiate empty vs. opaque types Jan Kratochvil
2007-03-12  3:35 ` Daniel Jacobowitz
2007-03-12 21:36   ` Jan Kratochvil
2007-04-10 21:19     ` Daniel Jacobowitz

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