yann@96: This patch needs to be submitted for the FSF.  Also, there may be testcases
yann@96: already in the GDB testsuite (currently disabled) that it would probably fix.
yann@96: 
yann@96: Index: gdb-6.3/gdb/infcall.c
yann@96: ===================================================================
yann@96: --- gdb-6.3.orig/gdb/infcall.c	2004-10-08 04:15:56.000000000 -0400
yann@96: +++ gdb-6.3/gdb/infcall.c	2004-11-10 12:30:07.000000000 -0500
yann@96: @@ -36,6 +36,7 @@
yann@96:  #include "gdb_string.h"
yann@96:  #include "infcall.h"
yann@96:  #include "dummy-frame.h"
yann@96: +#include "cp-abi.h"
yann@96:  
yann@96:  /* NOTE: cagney/2003-04-16: What's the future of this code?
yann@96:  
yann@96: @@ -297,8 +298,8 @@ call_function_by_hand (struct value *fun
yann@96:  {
yann@96:    CORE_ADDR sp;
yann@96:    CORE_ADDR dummy_addr;
yann@96: -  struct type *value_type;
yann@96: -  unsigned char struct_return;
yann@96: +  struct type *value_type, *target_value_type;
yann@96: +  unsigned char struct_return = 0, cp_struct_return = 0;
yann@96:    CORE_ADDR struct_addr = 0;
yann@96:    struct regcache *retbuf;
yann@96:    struct cleanup *retbuf_cleanup;
yann@96: @@ -312,6 +313,7 @@ call_function_by_hand (struct value *fun
yann@96:    struct regcache *caller_regcache;
yann@96:    struct cleanup *caller_regcache_cleanup;
yann@96:    struct frame_id dummy_id;
yann@96: +  struct cleanup *args_cleanup;
yann@96:  
yann@96:    if (!target_has_execution)
yann@96:      noprocess ();
yann@96: @@ -410,10 +412,31 @@ call_function_by_hand (struct value *fun
yann@96:      using_gcc = (b == NULL ? 2 : BLOCK_GCC_COMPILED (b));
yann@96:    }
yann@96:  
yann@96: -  /* Are we returning a value using a structure return or a normal
yann@96: -     value return? */
yann@96: +  /* Are we returning a value using a structure return (passing a
yann@96: +     hidden argument pointing to storage) or a normal value return?
yann@96: +     There are two cases: C++ ABI mandated structure return and
yann@96: +     target ABI structure return.  The variable STRUCT_RETURN only
yann@96: +     describes the latter.  The C++ version is handled by passing
yann@96: +     the return location as the first parameter to the function,
yann@96: +     even preceding "this".  This is different from the target
yann@96: +     ABI version, which is target-specific; for instance, on ia64
yann@96: +     the first argument is passed in out0 but the hidden structure
yann@96: +     return pointer would normally be passed in r8.  */
yann@96:  
yann@96: -  struct_return = using_struct_return (value_type, using_gcc);
yann@96: +  if (current_language->la_language == language_cplus
yann@96: +      && cp_pass_by_reference (value_type))
yann@96: +    {
yann@96: +      cp_struct_return = 1;
yann@96: +
yann@96: +      /* Tell the target specific argument pushing routine not to
yann@96: +	 expect a value.  */
yann@96: +      target_value_type = builtin_type_void;
yann@96: +    }
yann@96: +  else
yann@96: +    {
yann@96: +      struct_return = using_struct_return (value_type, using_gcc);
yann@96: +      target_value_type = value_type;
yann@96: +    }
yann@96:  
yann@96:    /* Determine the location of the breakpoint (and possibly other
yann@96:       stuff) that the called function will return to.  The SPARC, for a
yann@96: @@ -432,7 +455,7 @@ call_function_by_hand (struct value *fun
yann@96:        if (INNER_THAN (1, 2))
yann@96:  	{
yann@96:  	  sp = push_dummy_code (current_gdbarch, sp, funaddr,
yann@96: -				using_gcc, args, nargs, value_type,
yann@96: +				using_gcc, args, nargs, target_value_type,
yann@96:  				&real_pc, &bp_addr);
yann@96:  	  dummy_addr = sp;
yann@96:  	}
yann@96: @@ -440,7 +463,7 @@ call_function_by_hand (struct value *fun
yann@96:  	{
yann@96:  	  dummy_addr = sp;
yann@96:  	  sp = push_dummy_code (current_gdbarch, sp, funaddr,
yann@96: -				using_gcc, args, nargs, value_type,
yann@96: +				using_gcc, args, nargs, target_value_type,
yann@96:  				&real_pc, &bp_addr);
yann@96:  	}
yann@96:        break;
yann@96: @@ -507,9 +530,15 @@ call_function_by_hand (struct value *fun
yann@96:  	  param_type = TYPE_FIELD_TYPE (ftype, i);
yann@96:  	else
yann@96:  	  param_type = NULL;
yann@96: -	
yann@96: +
yann@96:  	args[i] = value_arg_coerce (args[i], param_type, prototyped);
yann@96:  
yann@96: +	/* FIXME: Is current_language the right language?  */
yann@96: +	if (current_language->la_language == language_cplus
yann@96: +	    && param_type != NULL
yann@96: +	    && cp_pass_by_reference (param_type))
yann@96: +	  args[i] = value_addr (args[i]);
yann@96: +
yann@96:  	/* elz: this code is to handle the case in which the function
yann@96:  	   to be called has a pointer to function as parameter and the
yann@96:  	   corresponding actual argument is the address of a function
yann@96: @@ -607,7 +636,7 @@ You must use a pointer to function type 
yann@96:       stack, if necessary.  Make certain that the value is correctly
yann@96:       aligned. */
yann@96:  
yann@96: -  if (struct_return)
yann@96: +  if (struct_return || cp_struct_return)
yann@96:      {
yann@96:        int len = TYPE_LENGTH (value_type);
yann@96:        if (INNER_THAN (1, 2))
yann@96: @@ -632,6 +661,22 @@ You must use a pointer to function type 
yann@96:  	}
yann@96:      }
yann@96:  
yann@96: +  if (cp_struct_return)
yann@96: +    {
yann@96: +      struct value **new_args;
yann@96: +
yann@96: +      /* Add the new argument to the front of the argument list.  */
yann@96: +      new_args = xmalloc (sizeof (struct value *) * (nargs + 1));
yann@96: +      new_args[0] = value_from_pointer (lookup_pointer_type (value_type),
yann@96: +					struct_addr);
yann@96: +      memcpy (&new_args[1], &args[0], sizeof (struct value *) * nargs);
yann@96: +      args = new_args;
yann@96: +      nargs++;
yann@96: +      args_cleanup = make_cleanup (xfree, args);
yann@96: +    }
yann@96: +  else
yann@96: +    args_cleanup = make_cleanup (null_cleanup, NULL);
yann@96: +
yann@96:    /* Create the dummy stack frame.  Pass in the call dummy address as,
yann@96:       presumably, the ABI code knows where, in the call dummy, the
yann@96:       return address should be pointed.  */
yann@96: @@ -649,6 +694,8 @@ You must use a pointer to function type 
yann@96:    else
yann@96:      error ("This target does not support function calls");
yann@96:  
yann@96: +  do_cleanups (args_cleanup);
yann@96: +
yann@96:    /* Set up a frame ID for the dummy frame so we can pass it to
yann@96:       set_momentary_breakpoint.  We need to give the breakpoint a frame
yann@96:       ID so that the breakpoint code can correctly re-identify the
yann@96: @@ -839,11 +886,7 @@ the function call).", name);
yann@96:    /* Figure out the value returned by the function, return that.  */
yann@96:    {
yann@96:      struct value *retval;
yann@96: -    if (TYPE_CODE (value_type) == TYPE_CODE_VOID)
yann@96: -      /* If the function returns void, don't bother fetching the
yann@96: -	 return value.  */
yann@96: -      retval = allocate_value (value_type);
yann@96: -    else if (struct_return)
yann@96: +    if (struct_return || cp_struct_return)
yann@96:        /* NOTE: cagney/2003-09-27: This assumes that PUSH_DUMMY_CALL
yann@96:  	 has correctly stored STRUCT_ADDR in the target.  In the past
yann@96:  	 that hasn't been the case, the old MIPS PUSH_ARGUMENTS
yann@96: @@ -853,6 +896,10 @@ the function call).", name);
yann@96:  	 "struct return convention", check that PUSH_DUMMY_CALL isn't
yann@96:  	 playing tricks.  */
yann@96:        retval = value_at (value_type, struct_addr, NULL);
yann@96: +    else if (TYPE_CODE (value_type) == TYPE_CODE_VOID)
yann@96: +      /* If the function returns void, don't bother fetching the
yann@96: +	 return value.  */
yann@96: +      retval = allocate_value (value_type);
yann@96:      else
yann@96:        {
yann@96:  	/* This code only handles "register convention".  */
yann@96: Index: gdb-6.3/gdb/cp-abi.h
yann@96: ===================================================================
yann@96: --- gdb-6.3.orig/gdb/cp-abi.h	2003-04-12 13:41:25.000000000 -0400
yann@96: +++ gdb-6.3/gdb/cp-abi.h	2004-11-10 12:30:07.000000000 -0500
yann@96: @@ -1,7 +1,7 @@
yann@96:  /* Abstraction of various C++ ABI's we support, and the info we need
yann@96:     to get from them.
yann@96:     Contributed by Daniel Berlin <dberlin@redhat.com>
yann@96: -   Copyright 2001 Free Software Foundation, Inc.
yann@96: +   Copyright 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
yann@96:  
yann@96:     This file is part of GDB.
yann@96:  
yann@96: @@ -145,6 +145,10 @@ extern struct type *value_rtti_type (str
yann@96:  extern int baseclass_offset (struct type *type, int index, char *valaddr,
yann@96:  			     CORE_ADDR address);
yann@96:                    
yann@96: +/* Return non-zero if an argument of type TYPE should be passed by reference
yann@96: +   instead of value.  */
yann@96: +extern int cp_pass_by_reference (struct type *type);
yann@96: +
yann@96:  struct cp_abi_ops
yann@96:  {
yann@96:    const char *shortname;
yann@96: @@ -162,6 +166,7 @@ struct cp_abi_ops
yann@96:  			     int *using_enc);
yann@96:    int (*baseclass_offset) (struct type *type, int index, char *valaddr,
yann@96:  			   CORE_ADDR address);
yann@96: +  int (*pass_by_reference) (struct type *type);
yann@96:  };
yann@96:  
yann@96:  
yann@96: Index: gdb-6.3/gdb/cp-abi.c
yann@96: ===================================================================
yann@96: --- gdb-6.3.orig/gdb/cp-abi.c	2003-11-26 17:04:00.000000000 -0500
yann@96: +++ gdb-6.3/gdb/cp-abi.c	2004-11-10 12:30:07.000000000 -0500
yann@96: @@ -1,5 +1,5 @@
yann@96:  /* Generic code for supporting multiple C++ ABI's
yann@96: -   Copyright 2001, 2002, 2003 Free Software Foundation, Inc.
yann@96: +   Copyright 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
yann@96:  
yann@96:     This file is part of GDB.
yann@96:  
yann@96: @@ -94,6 +94,14 @@ value_rtti_type (struct value *v, int *f
yann@96:    return (*current_cp_abi.rtti_type) (v, full, top, using_enc);
yann@96:  }
yann@96:  
yann@96: +int
yann@96: +cp_pass_by_reference (struct type *type)
yann@96: +{
yann@96: +  if ((current_cp_abi.pass_by_reference) == NULL)
yann@96: +    return 0;
yann@96: +  return (*current_cp_abi.pass_by_reference) (type);
yann@96: +}
yann@96: +
yann@96:  /* Set the current C++ ABI to SHORT_NAME.  */
yann@96:  
yann@96:  static int
yann@96: Index: gdb-6.3/gdb/gnu-v3-abi.c
yann@96: ===================================================================
yann@96: --- gdb-6.3.orig/gdb/gnu-v3-abi.c	2004-03-15 15:38:08.000000000 -0500
yann@96: +++ gdb-6.3/gdb/gnu-v3-abi.c	2004-11-10 12:30:07.000000000 -0500
yann@96: @@ -1,7 +1,7 @@
yann@96:  /* Abstraction of GNU v3 abi.
yann@96:     Contributed by Jim Blandy <jimb@redhat.com>
yann@96:  
yann@96: -   Copyright 2001, 2002, 2003 Free Software Foundation, Inc.
yann@96: +   Copyright 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
yann@96:  
yann@96:     This file is part of GDB.
yann@96:  
yann@96: @@ -419,6 +419,84 @@ gnuv3_baseclass_offset (struct type *typ
yann@96:    return base_offset;
yann@96:  }
yann@96:  
yann@96: +/* Return nonzero if a type should be passed by reference.
yann@96: +
yann@96: +   The rule in the v3 ABI document comes from section 3.1.1.  If the
yann@96: +   type has a non-trivial copy constructor or destructor, then the
yann@96: +   caller must make a copy (by calling the copy constructor if there
yann@96: +   is one or perform the copy itself otherwise), pass the address of
yann@96: +   the copy, and then destroy the temporary (if necessary).
yann@96: +
yann@96: +   For return values with non-trivial copy constructors or
yann@96: +   destructors, space will be allocated in the caller, and a pointer
yann@96: +   will be passed as the first argument (preceding "this").
yann@96: +
yann@96: +   We don't have a bulletproof mechanism for determining whether a
yann@96: +   constructor or destructor is trivial.  For GCC and DWARF2 debug
yann@96: +   information, we can check the artificial flag.
yann@96: +
yann@96: +   We don't do anything with the constructors or destructors yet,
yann@96: +   but we have to get the argument passing right anyway.  */
yann@96: +static int
yann@96: +gnuv3_pass_by_reference (struct type *type)
yann@96: +{
yann@96: +  int fieldnum, fieldelem, basenum;
yann@96: +
yann@96: +  CHECK_TYPEDEF (type);
yann@96: +
yann@96: +  /* We're only interested in things that can have methods.  */
yann@96: +  if (TYPE_CODE (type) != TYPE_CODE_STRUCT
yann@96: +      && TYPE_CODE (type) != TYPE_CODE_CLASS
yann@96: +      && TYPE_CODE (type) != TYPE_CODE_UNION)
yann@96: +    return 0;
yann@96: +
yann@96: +  for (fieldnum = 0; fieldnum < TYPE_NFN_FIELDS (type); fieldnum++)
yann@96: +    for (fieldelem = 0; fieldelem < TYPE_FN_FIELDLIST_LENGTH (type, fieldnum);
yann@96: +	 fieldelem++)
yann@96: +      {
yann@96: +	struct fn_field *fn = TYPE_FN_FIELDLIST1 (type, fieldnum);
yann@96: +	char *name = TYPE_FN_FIELDLIST_NAME (type, fieldnum);
yann@96: +	struct type *fieldtype = TYPE_FN_FIELD_TYPE (fn, fieldelem);
yann@96: +
yann@96: +	/* If this function is marked as artificial, it is compiler-generated,
yann@96: +	   and we assume it is trivial.  */
yann@96: +	if (TYPE_FN_FIELD_ARTIFICIAL (fn, fieldelem))
yann@96: +	  continue;
yann@96: +
yann@96: +	/* If we've found a destructor, we must pass this by reference.  */
yann@96: +	if (name[0] == '~')
yann@96: +	  return 1;
yann@96: +
yann@96: +	/* If the mangled name of this method doesn't indicate that it
yann@96: +	   is a constructor, we're not interested.
yann@96: +
yann@96: +	   FIXME drow/2004-05-27: We could do this using the name of
yann@96: +	   the method and the name of the class instead of dealing
yann@96: +	   with the mangled name.  We don't have a convenient function
yann@96: +	   to strip off both leading scope qualifiers and trailing
yann@96: +	   template arguments yet.  */
yann@96: +	if (!is_constructor_name (TYPE_FN_FIELD_PHYSNAME (fn, fieldelem)))
yann@96: +	  continue;
yann@96: +
yann@96: +	/* If this method takes two arguments, and the second argument is
yann@96: +	   a reference to this class, then it is a copy constructor.  */
yann@96: +	if (TYPE_NFIELDS (fieldtype) == 2
yann@96: +	    && TYPE_CODE (TYPE_FIELD_TYPE (fieldtype, 1)) == TYPE_CODE_REF
yann@96: +	    && check_typedef (TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (fieldtype, 1))) == type)
yann@96: +	  return 1;
yann@96: +      }
yann@96: +
yann@96: +  /* Even if all the constructors and destructors were artificial, one
yann@96: +     of them may have invoked a non-artificial constructor or
yann@96: +     destructor in a base class.  If any base class needs to be passed
yann@96: +     by reference, so does this class.  */
yann@96: +  for (basenum = 0; basenum < TYPE_N_BASECLASSES (type); basenum++)
yann@96: +    if (gnuv3_pass_by_reference (TYPE_BASECLASS (type, basenum)))
yann@96: +      return 1;
yann@96: +
yann@96: +  return 0;
yann@96: +}
yann@96: +
yann@96:  static void
yann@96:  init_gnuv3_ops (void)
yann@96:  {
yann@96: @@ -434,6 +512,7 @@ init_gnuv3_ops (void)
yann@96:    gnu_v3_abi_ops.rtti_type = gnuv3_rtti_type;
yann@96:    gnu_v3_abi_ops.virtual_fn_field = gnuv3_virtual_fn_field;
yann@96:    gnu_v3_abi_ops.baseclass_offset = gnuv3_baseclass_offset;
yann@96: +  gnu_v3_abi_ops.pass_by_reference = gnuv3_pass_by_reference;
yann@96:  }
yann@96:  
yann@96:  extern initialize_file_ftype _initialize_gnu_v3_abi; /* -Wmissing-prototypes */
yann@96: Index: gdb-6.3/gdb/hpacc-abi.c
yann@96: ===================================================================
yann@96: --- gdb-6.3.orig/gdb/hpacc-abi.c	2003-06-08 14:27:13.000000000 -0400
yann@96: +++ gdb-6.3/gdb/hpacc-abi.c	2004-11-10 12:30:07.000000000 -0500
yann@96: @@ -3,7 +3,7 @@
yann@96:     Most of the real code is from HP, i've just fiddled it to fit in
yann@96:     the C++ ABI abstraction framework.
yann@96:  
yann@96: -   Copyright 2001 Free Software Foundation, Inc.
yann@96: +   Copyright 2001, 2002, 2003 Free Software Foundation, Inc.
yann@96:  
yann@96:     This file is part of GDB.
yann@96:  
yann@96: Index: gdb-6.3/gdb/Makefile.in
yann@96: ===================================================================
yann@96: --- gdb-6.3.orig/gdb/Makefile.in	2004-11-10 12:30:06.000000000 -0500
yann@96: +++ gdb-6.3/gdb/Makefile.in	2004-11-10 12:30:07.000000000 -0500
yann@96: @@ -2073,7 +2073,7 @@ ia64-tdep.o: ia64-tdep.c $(defs_h) $(inf
yann@96:  infcall.o: infcall.c $(defs_h) $(breakpoint_h) $(target_h) $(regcache_h) \
yann@96:  	$(inferior_h) $(gdb_assert_h) $(block_h) $(gdbcore_h) $(language_h) \
yann@96:  	$(objfiles_h) $(gdbcmd_h) $(command_h) $(gdb_string_h) $(infcall_h) \
yann@96: -	$(dummy_frame_h)
yann@96: +	$(dummy_frame_h) $(cp_abi_h)
yann@96:  inf-child.o: inf-child.c $(defs_h) $(regcache_h) $(memattr_h) $(symtab_h) \
yann@96:  	$(target_h) $(inferior_h) $(gdb_string_h)
yann@96:  infcmd.o: infcmd.c $(defs_h) $(gdb_string_h) $(symtab_h) $(gdbtypes_h) \
yann@96: Index: gdb-6.3/gdb/testsuite/gdb.cp/pass-by-ref.exp
yann@96: ===================================================================
yann@96: --- /dev/null	1970-01-01 00:00:00.000000000 +0000
yann@96: +++ gdb-6.3/gdb/testsuite/gdb.cp/pass-by-ref.exp	2004-11-11 09:48:00.498518899 -0500
yann@96: @@ -0,0 +1,38 @@
yann@96: +# This testcase is part of GDB, the GNU debugger.
yann@96: +
yann@96: +# Copyright 2004 Free Software Foundation, Inc.
yann@96: +
yann@96: +# This program is free software; you can redistribute it and/or modify
yann@96: +# it under the terms of the GNU General Public License as published by
yann@96: +# the Free Software Foundation; either version 2 of the License, or
yann@96: +# (at your option) any later version.
yann@96: +#
yann@96: +# This program is distributed in the hope that it will be useful,
yann@96: +# but WITHOUT ANY WARRANTY; without even the implied warranty of
yann@96: +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
yann@96: +# GNU General Public License for more details.
yann@96: +#
yann@96: +# You should have received a copy of the GNU General Public License
yann@96: +# along with this program; if not, write to the Free Software
yann@96: +# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  
yann@96: +
yann@96: +# Check that GDB can call C++ functions whose parameters have
yann@96: +# object type, but are passed by reference.
yann@96: +
yann@96: +set testfile "pass-by-ref"
yann@96: +set srcfile ${testfile}.cc
yann@96: +set binfile ${objdir}/${subdir}/${testfile}
yann@96: +if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
yann@96: +    return -1
yann@96: +}
yann@96: +
yann@96: +gdb_exit
yann@96: +gdb_start
yann@96: +gdb_reinitialize_dir $srcdir/$subdir
yann@96: +gdb_load ${binfile}
yann@96: +
yann@96: +if ![runto_main] then {
yann@96: +    return -1
yann@96: +}
yann@96: +
yann@96: +gdb_test "print foo (global_obj)" " = 3" "call function"
yann@96: Index: gdb-6.3/gdb/testsuite/gdb.cp/pass-by-ref.cc
yann@96: ===================================================================
yann@96: --- /dev/null	1970-01-01 00:00:00.000000000 +0000
yann@96: +++ gdb-6.3/gdb/testsuite/gdb.cp/pass-by-ref.cc	2004-11-11 09:44:17.815014667 -0500
yann@96: @@ -0,0 +1,57 @@
yann@96: +/* This testcase is part of GDB, the GNU debugger.
yann@96: +
yann@96: +   Copyright 2004 Free Software Foundation, Inc.
yann@96: +
yann@96: +   This program is free software; you can redistribute it and/or modify
yann@96: +   it under the terms of the GNU General Public License as published by
yann@96: +   the Free Software Foundation; either version 2 of the License, or
yann@96: +   (at your option) any later version.
yann@96: +
yann@96: +   This program is distributed in the hope that it will be useful,
yann@96: +   but WITHOUT ANY WARRANTY; without even the implied warranty of
yann@96: +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
yann@96: +   GNU General Public License for more details.
yann@96: + 
yann@96: +   You should have received a copy of the GNU General Public License
yann@96: +   along with this program; if not, write to the Free Software
yann@96: +   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
yann@96: +   USA.  */
yann@96: +
yann@96: +class Obj {
yann@96: +public:
yann@96: +  Obj ();
yann@96: +  Obj (const Obj &);
yann@96: +  ~Obj ();
yann@96: +  int var[2];
yann@96: +};
yann@96: +
yann@96: +int foo (Obj arg)
yann@96: +{
yann@96: +  return arg.var[0] + arg.var[1];
yann@96: +}
yann@96: +
yann@96: +Obj::Obj ()
yann@96: +{
yann@96: +  var[0] = 1;
yann@96: +  var[1] = 2;
yann@96: +}
yann@96: +
yann@96: +Obj::Obj (const Obj &obj)
yann@96: +{
yann@96: +  var[0] = obj.var[0];
yann@96: +  var[1] = obj.var[1];
yann@96: +}
yann@96: +
yann@96: +Obj::~Obj ()
yann@96: +{
yann@96: +
yann@96: +}
yann@96: +
yann@96: +Obj global_obj;
yann@96: +
yann@96: +int
yann@96: +main ()
yann@96: +{
yann@96: +  int bar = foo (global_obj);
yann@96: +  return bar;
yann@96: +}