+2003-10-20 Andrew Cagney <cagney@redhat.com>
+
+ * values.c (register_value_being_returned): Update comments. Use
+ "gdbarch_return_value" when available.
+ (using_struct_return): Ditto.
+ (set_return_value): Ditto. Use "gdbarch_return_value" when
+ available.. Print a warning, and not an error, when an unhandled
+ return type is encountered.
+ * infcmd.c: Include "gdb_assert.h".
+ (print_return_value): When gdbarch_return_value_p, and using
+ struct return, assume that the value is not available.
+ * defs.h (return_value_convention): Define.
+ * gdbarch.sh (gdbarch_return_value): New predicate method.
+ * gdbarch.h, gdbarch.c: Re-generate
+ * ppc-sysv-tdep.c (return_value_convention): Delete definition.
+
2003-10-20 Andrew Cagney <cagney@redhat.com>
* symtab.c: Replace "struct sec" with "struct bfd_section".
AUTO_BOOLEAN_AUTO
};
+/* Potential ways that a function can return a value of a given type. */
+enum return_value_convention
+{
+ /* Where the return value has been squeezed into one or more
+ registers. */
+ RETURN_VALUE_REGISTER_CONVENTION,
+ /* Commonly known as the "struct return convention". The caller
+ passes an additional hidden first parameter to the caller. That
+ parameter contains the address at which the value being returned
+ should be stored. While typically, and historically, used for
+ large structs, this is convention is applied to values of many
+ different types. */
+ RETURN_VALUE_STRUCT_CONVENTION
+};
+
/* the cleanup list records things that have to be undone
if an error happens (descriptors to be closed, memory to be freed, etc.)
Each link in the chain records a function to call and an
+2003-10-20 Andrew Cagney <cagney@redhat.com>
+
+ * gdbint.texinfo (Target Architecture Definition): Document
+ gdbarch_return_value. Add cross references from
+ USE_STRUCT_CONVENTION, EXTRACT_RETURN_VALUE, and
+ STORE_RETURN_VALUE, and from/to EXTRACT_STRUCT_VALUE_ADDRESS.
+
2003-10-18 Mark Kettenis <kettenis@gnu.org>
* gdbint.texinfo (Target Architecture Definition): Document
the raw register state @var{regbuf} and copy that, in virtual format,
into @var{valbuf}.
+This method has been deprecated in favour of @code{gdbarch_return_value}
+(@pxref{gdbarch_return_value}).
+
@item EXTRACT_STRUCT_VALUE_ADDRESS(@var{regbuf})
@findex EXTRACT_STRUCT_VALUE_ADDRESS
+@anchor{EXTRACT_STRUCT_VALUE_ADDRESS}
When defined, extract from the array @var{regbuf} (containing the raw
register state) the @code{CORE_ADDR} at which a function should return
its structure value.
-If not defined, @code{EXTRACT_RETURN_VALUE} is used.
+@xref{gdbarch_return_value}.
@item EXTRACT_STRUCT_VALUE_ADDRESS_P()
@findex EXTRACT_STRUCT_VALUE_ADDRESS_P
Define this to convert sdb register numbers into @value{GDBN} regnums. If not
defined, no conversion will be done.
+@item enum return_value_convention gdbarch_return_value (struct gdbarch *@var{gdbarch}, struct type *@var{valtype}, struct regcache *@var{regcache}, const void *@var{inval}, void *@var{outval})
+@findex gdbarch_return_value
+@anchor{gdbarch_return_value} Given a function with a return-value of
+type @var{rettype}, return which return-value convention that function
+would use.
+
+@value{GDBN} currently recognizes two function return-value conventions:
+@code{RETURN_VALUE_REGISTER_CONVENTION} where the return value is found
+in registers; and @code{RETURN_VALUE_STRUCT_CONVENTION} where the return
+value is found in memory and the address of that memory location is
+passed in as the function's first parameter.
+
+If the register convention is being used, and @var{inval} is
+non-@code{NULL}, also copy the return-value in @var{inval} into
+@var{regcache}.
+
+If the register convention is being used, and @var{outval} is
+non-@code{NULL}, also copy the return value from @var{regcache} into
+@var{outval} (@var{regcache} contains a copy of the registers from the
+just returned function).
+
+@xref{EXTRACT_STRUCT_VALUE_ADDRESS}, for a description of how
+return-values that use the struct convention are handled.
+
+@emph{Maintainer note: This method replaces separate predicate, extract,
+store methods. By having only one method, the logic needed to determine
+the return-value convention need only be implemented in one place. If
+@value{GDBN} were written in an @sc{oo} language, this method would
+instead return an object that knew how to perform the register
+return-value extract and store.}
+
+@emph{Maintainer note: This method does not take a @var{gcc_p}
+parameter, and such a parameter should not be added. If an architecture
+that requires per-compiler or per-function information be identified,
+then the replacement of @var{rettype} with @code{struct value}
+@var{function} should be persued.}
+
+@emph{Maintainer note: The @var{regcache} parameter limits this methods
+to the inner most frame. While replacing @var{regcache} with a
+@code{struct frame_info} @var{frame} parameter would remove that
+limitation there has yet to be a demonstrated need for such a change.}
+
@item SKIP_PERMANENT_BREAKPOINT
@findex SKIP_PERMANENT_BREAKPOINT
Advance the inferior's PC past a permanent breakpoint. @value{GDBN} normally
@var{valbuf}, into the @var{regcache}. @var{type} is the type of the
value that is to be returned.
+This method has been deprecated in favour of @code{gdbarch_return_value}
+(@pxref{gdbarch_return_value}).
+
@item SUN_FIXED_LBRAC_BUG
@findex SUN_FIXED_LBRAC_BUG
(Used only for Sun-3 and Sun-4 targets.)
for systems where GCC is known to use different calling convention than
other compilers.
+This method has been deprecated in favour of @code{gdbarch_return_value}
+(@pxref{gdbarch_return_value}).
+
@item VALUE_TO_REGISTER(@var{type}, @var{regnum}, @var{from}, @var{to})
@findex VALUE_TO_REGISTER
Convert a value of type @var{type} into the raw contents of register
gdbarch_pointer_to_address_ftype *pointer_to_address;
gdbarch_address_to_pointer_ftype *address_to_pointer;
gdbarch_integer_to_address_ftype *integer_to_address;
- gdbarch_return_value_on_stack_ftype *return_value_on_stack;
gdbarch_deprecated_pop_frame_ftype *deprecated_pop_frame;
gdbarch_deprecated_store_struct_return_ftype *deprecated_store_struct_return;
+ gdbarch_return_value_ftype *return_value;
+ gdbarch_return_value_on_stack_ftype *return_value_on_stack;
gdbarch_extract_return_value_ftype *extract_return_value;
gdbarch_store_return_value_ftype *store_return_value;
gdbarch_deprecated_extract_return_value_ftype *deprecated_extract_return_value;
gdbarch_deprecated_store_return_value_ftype *deprecated_store_return_value;
+ gdbarch_use_struct_convention_ftype *use_struct_convention;
gdbarch_extract_struct_value_address_ftype *extract_struct_value_address;
gdbarch_deprecated_extract_struct_value_address_ftype *deprecated_extract_struct_value_address;
- gdbarch_use_struct_convention_ftype *use_struct_convention;
gdbarch_deprecated_frame_init_saved_regs_ftype *deprecated_frame_init_saved_regs;
gdbarch_deprecated_init_extra_frame_info_ftype *deprecated_init_extra_frame_info;
gdbarch_skip_prologue_ftype *skip_prologue;
0, /* pointer_to_address */
0, /* address_to_pointer */
0, /* integer_to_address */
- 0, /* return_value_on_stack */
0, /* deprecated_pop_frame */
0, /* deprecated_store_struct_return */
+ 0, /* return_value */
+ 0, /* return_value_on_stack */
0, /* extract_return_value */
0, /* store_return_value */
0, /* deprecated_extract_return_value */
0, /* deprecated_store_return_value */
+ 0, /* use_struct_convention */
0, /* extract_struct_value_address */
0, /* deprecated_extract_struct_value_address */
- 0, /* use_struct_convention */
0, /* deprecated_frame_init_saved_regs */
0, /* deprecated_init_extra_frame_info */
0, /* skip_prologue */
/* Skip verify of pointer_to_address, invalid_p == 0 */
/* Skip verify of address_to_pointer, invalid_p == 0 */
/* Skip verify of integer_to_address, has predicate */
- /* Skip verify of return_value_on_stack, invalid_p == 0 */
/* Skip verify of deprecated_pop_frame, has predicate */
/* Skip verify of deprecated_store_struct_return, has predicate */
+ /* Skip verify of return_value, has predicate */
+ /* Skip verify of return_value_on_stack, invalid_p == 0 */
/* Skip verify of extract_return_value, invalid_p == 0 */
/* Skip verify of store_return_value, invalid_p == 0 */
+ /* Skip verify of use_struct_convention, invalid_p == 0 */
/* Skip verify of extract_struct_value_address, has predicate */
/* Skip verify of deprecated_extract_struct_value_address, has predicate */
- /* Skip verify of use_struct_convention, invalid_p == 0 */
/* Skip verify of deprecated_frame_init_saved_regs, has predicate */
/* Skip verify of deprecated_init_extra_frame_info, has predicate */
if ((GDB_MULTI_ARCH > GDB_MULTI_ARCH_PARTIAL)
fprintf_unfiltered (file,
"gdbarch_dump: regset_from_core_section = 0x%08lx\n",
(long) current_gdbarch->regset_from_core_section);
+ fprintf_unfiltered (file,
+ "gdbarch_dump: gdbarch_return_value_p() = %d\n",
+ gdbarch_return_value_p (current_gdbarch));
+ fprintf_unfiltered (file,
+ "gdbarch_dump: return_value = 0x%08lx\n",
+ (long) current_gdbarch->return_value);
fprintf_unfiltered (file,
"gdbarch_dump: in_function_epilogue_p = 0x%08lx\n",
(long) current_gdbarch->in_function_epilogue_p);
gdbarch->integer_to_address = integer_to_address;
}
-int
-gdbarch_return_value_on_stack (struct gdbarch *gdbarch, struct type *type)
-{
- gdb_assert (gdbarch != NULL);
- gdb_assert (gdbarch->return_value_on_stack != NULL);
- if (gdbarch_debug >= 2)
- fprintf_unfiltered (gdb_stdlog, "gdbarch_return_value_on_stack called\n");
- return gdbarch->return_value_on_stack (type);
-}
-
-void
-set_gdbarch_return_value_on_stack (struct gdbarch *gdbarch,
- gdbarch_return_value_on_stack_ftype return_value_on_stack)
-{
- gdbarch->return_value_on_stack = return_value_on_stack;
-}
-
int
gdbarch_deprecated_pop_frame_p (struct gdbarch *gdbarch)
{
gdbarch->deprecated_store_struct_return = deprecated_store_struct_return;
}
+int
+gdbarch_return_value_p (struct gdbarch *gdbarch)
+{
+ gdb_assert (gdbarch != NULL);
+ return gdbarch->return_value != NULL;
+}
+
+enum return_value_convention
+gdbarch_return_value (struct gdbarch *gdbarch, struct type *valtype, struct regcache *regcache, const void *inval, void *outval)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->return_value != NULL);
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_return_value called\n");
+ return gdbarch->return_value (gdbarch, valtype, regcache, inval, outval);
+}
+
+void
+set_gdbarch_return_value (struct gdbarch *gdbarch,
+ gdbarch_return_value_ftype return_value)
+{
+ gdbarch->return_value = return_value;
+}
+
+int
+gdbarch_return_value_on_stack (struct gdbarch *gdbarch, struct type *type)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->return_value_on_stack != NULL);
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_return_value_on_stack called\n");
+ return gdbarch->return_value_on_stack (type);
+}
+
+void
+set_gdbarch_return_value_on_stack (struct gdbarch *gdbarch,
+ gdbarch_return_value_on_stack_ftype return_value_on_stack)
+{
+ gdbarch->return_value_on_stack = return_value_on_stack;
+}
+
void
gdbarch_extract_return_value (struct gdbarch *gdbarch, struct type *type, struct regcache *regcache, void *valbuf)
{
gdbarch->deprecated_store_return_value = deprecated_store_return_value;
}
+int
+gdbarch_use_struct_convention (struct gdbarch *gdbarch, int gcc_p, struct type *value_type)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->use_struct_convention != NULL);
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_use_struct_convention called\n");
+ return gdbarch->use_struct_convention (gcc_p, value_type);
+}
+
+void
+set_gdbarch_use_struct_convention (struct gdbarch *gdbarch,
+ gdbarch_use_struct_convention_ftype use_struct_convention)
+{
+ gdbarch->use_struct_convention = use_struct_convention;
+}
+
int
gdbarch_extract_struct_value_address_p (struct gdbarch *gdbarch)
{
gdbarch->deprecated_extract_struct_value_address = deprecated_extract_struct_value_address;
}
-int
-gdbarch_use_struct_convention (struct gdbarch *gdbarch, int gcc_p, struct type *value_type)
-{
- gdb_assert (gdbarch != NULL);
- gdb_assert (gdbarch->use_struct_convention != NULL);
- if (gdbarch_debug >= 2)
- fprintf_unfiltered (gdb_stdlog, "gdbarch_use_struct_convention called\n");
- return gdbarch->use_struct_convention (gcc_p, value_type);
-}
-
-void
-set_gdbarch_use_struct_convention (struct gdbarch *gdbarch,
- gdbarch_use_struct_convention_ftype use_struct_convention)
-{
- gdbarch->use_struct_convention = use_struct_convention;
-}
-
int
gdbarch_deprecated_frame_init_saved_regs_p (struct gdbarch *gdbarch)
{
#define INTEGER_TO_ADDRESS(type, buf) (gdbarch_integer_to_address (current_gdbarch, type, buf))
#endif
-typedef int (gdbarch_return_value_on_stack_ftype) (struct type *type);
-extern int gdbarch_return_value_on_stack (struct gdbarch *gdbarch, struct type *type);
-extern void set_gdbarch_return_value_on_stack (struct gdbarch *gdbarch, gdbarch_return_value_on_stack_ftype *return_value_on_stack);
-#if (GDB_MULTI_ARCH > GDB_MULTI_ARCH_PARTIAL) && defined (RETURN_VALUE_ON_STACK)
-#error "Non multi-arch definition of RETURN_VALUE_ON_STACK"
-#endif
-#if !defined (RETURN_VALUE_ON_STACK)
-#define RETURN_VALUE_ON_STACK(type) (gdbarch_return_value_on_stack (current_gdbarch, type))
-#endif
-
#if defined (DEPRECATED_POP_FRAME)
/* Legacy for systems yet to multi-arch DEPRECATED_POP_FRAME */
#if !defined (DEPRECATED_POP_FRAME_P)
#define DEPRECATED_STORE_STRUCT_RETURN(addr, sp) (gdbarch_deprecated_store_struct_return (current_gdbarch, addr, sp))
#endif
+/* It has been suggested that this, well actually its predecessor,
+ should take the type/value of the function to be called and not the
+ return type. This is left as an exercise for the reader. */
+
+extern int gdbarch_return_value_p (struct gdbarch *gdbarch);
+
+typedef enum return_value_convention (gdbarch_return_value_ftype) (struct gdbarch *gdbarch, struct type *valtype, struct regcache *regcache, const void *inval, void *outval);
+extern enum return_value_convention gdbarch_return_value (struct gdbarch *gdbarch, struct type *valtype, struct regcache *regcache, const void *inval, void *outval);
+extern void set_gdbarch_return_value (struct gdbarch *gdbarch, gdbarch_return_value_ftype *return_value);
+
+/* The deprecated methods RETURN_VALUE_ON_STACK, EXTRACT_RETURN_VALUE,
+ STORE_RETURN_VALUE and USE_STRUCT_CONVENTION have all been folded
+ into RETURN_VALUE. For the moment do not try to fold in
+ EXTRACT_STRUCT_VALUE_ADDRESS as, dependant on the ABI, the debug
+ info, and the level of effort, it may well be possible to find the
+ address of a structure being return on the stack. Someone else can
+ make that change. */
+
+typedef int (gdbarch_return_value_on_stack_ftype) (struct type *type);
+extern int gdbarch_return_value_on_stack (struct gdbarch *gdbarch, struct type *type);
+extern void set_gdbarch_return_value_on_stack (struct gdbarch *gdbarch, gdbarch_return_value_on_stack_ftype *return_value_on_stack);
+#if (GDB_MULTI_ARCH > GDB_MULTI_ARCH_PARTIAL) && defined (RETURN_VALUE_ON_STACK)
+#error "Non multi-arch definition of RETURN_VALUE_ON_STACK"
+#endif
+#if !defined (RETURN_VALUE_ON_STACK)
+#define RETURN_VALUE_ON_STACK(type) (gdbarch_return_value_on_stack (current_gdbarch, type))
+#endif
+
typedef void (gdbarch_extract_return_value_ftype) (struct type *type, struct regcache *regcache, void *valbuf);
extern void gdbarch_extract_return_value (struct gdbarch *gdbarch, struct type *type, struct regcache *regcache, void *valbuf);
extern void set_gdbarch_extract_return_value (struct gdbarch *gdbarch, gdbarch_extract_return_value_ftype *extract_return_value);
#define DEPRECATED_STORE_RETURN_VALUE(type, valbuf) (gdbarch_deprecated_store_return_value (current_gdbarch, type, valbuf))
#endif
+typedef int (gdbarch_use_struct_convention_ftype) (int gcc_p, struct type *value_type);
+extern int gdbarch_use_struct_convention (struct gdbarch *gdbarch, int gcc_p, struct type *value_type);
+extern void set_gdbarch_use_struct_convention (struct gdbarch *gdbarch, gdbarch_use_struct_convention_ftype *use_struct_convention);
+#if (GDB_MULTI_ARCH > GDB_MULTI_ARCH_PARTIAL) && defined (USE_STRUCT_CONVENTION)
+#error "Non multi-arch definition of USE_STRUCT_CONVENTION"
+#endif
+#if !defined (USE_STRUCT_CONVENTION)
+#define USE_STRUCT_CONVENTION(gcc_p, value_type) (gdbarch_use_struct_convention (current_gdbarch, gcc_p, value_type))
+#endif
+
#if defined (EXTRACT_STRUCT_VALUE_ADDRESS)
/* Legacy for systems yet to multi-arch EXTRACT_STRUCT_VALUE_ADDRESS */
#if !defined (EXTRACT_STRUCT_VALUE_ADDRESS_P)
#define DEPRECATED_EXTRACT_STRUCT_VALUE_ADDRESS(regbuf) (gdbarch_deprecated_extract_struct_value_address (current_gdbarch, regbuf))
#endif
-typedef int (gdbarch_use_struct_convention_ftype) (int gcc_p, struct type *value_type);
-extern int gdbarch_use_struct_convention (struct gdbarch *gdbarch, int gcc_p, struct type *value_type);
-extern void set_gdbarch_use_struct_convention (struct gdbarch *gdbarch, gdbarch_use_struct_convention_ftype *use_struct_convention);
-#if (GDB_MULTI_ARCH > GDB_MULTI_ARCH_PARTIAL) && defined (USE_STRUCT_CONVENTION)
-#error "Non multi-arch definition of USE_STRUCT_CONVENTION"
-#endif
-#if !defined (USE_STRUCT_CONVENTION)
-#define USE_STRUCT_CONVENTION(gcc_p, value_type) (gdbarch_use_struct_convention (current_gdbarch, gcc_p, value_type))
-#endif
-
#if defined (DEPRECATED_FRAME_INIT_SAVED_REGS)
/* Legacy for systems yet to multi-arch DEPRECATED_FRAME_INIT_SAVED_REGS */
#if !defined (DEPRECATED_FRAME_INIT_SAVED_REGS_P)
f:2:ADDRESS_TO_POINTER:void:address_to_pointer:struct type *type, void *buf, CORE_ADDR addr:type, buf, addr:::unsigned_address_to_pointer::0
F:2:INTEGER_TO_ADDRESS:CORE_ADDR:integer_to_address:struct type *type, void *buf:type, buf
#
-f:2:RETURN_VALUE_ON_STACK:int:return_value_on_stack:struct type *type:type:::generic_return_value_on_stack_not::0
F:2:DEPRECATED_POP_FRAME:void:deprecated_pop_frame:void:-
# NOTE: cagney/2003-03-24: Replaced by PUSH_ARGUMENTS.
F:2:DEPRECATED_STORE_STRUCT_RETURN:void:deprecated_store_struct_return:CORE_ADDR addr, CORE_ADDR sp:addr, sp
-#
+
+# It has been suggested that this, well actually its predecessor,
+# should take the type/value of the function to be called and not the
+# return type. This is left as an exercise for the reader.
+
+M:::enum return_value_convention:return_value:struct type *valtype, struct regcache *regcache, const void *inval, void *outval:valtype, regcache, inval, outval
+
+# The deprecated methods RETURN_VALUE_ON_STACK, EXTRACT_RETURN_VALUE,
+# STORE_RETURN_VALUE and USE_STRUCT_CONVENTION have all been folded
+# into RETURN_VALUE. For the moment do not try to fold in
+# EXTRACT_STRUCT_VALUE_ADDRESS as, dependant on the ABI, the debug
+# info, and the level of effort, it may well be possible to find the
+# address of a structure being return on the stack. Someone else can
+# make that change.
+
+f:2:RETURN_VALUE_ON_STACK:int:return_value_on_stack:struct type *type:type:::generic_return_value_on_stack_not::0
f:2:EXTRACT_RETURN_VALUE:void:extract_return_value:struct type *type, struct regcache *regcache, void *valbuf:type, regcache, valbuf:::legacy_extract_return_value::0
f:2:STORE_RETURN_VALUE:void:store_return_value:struct type *type, struct regcache *regcache, const void *valbuf:type, regcache, valbuf:::legacy_store_return_value::0
f:2:DEPRECATED_EXTRACT_RETURN_VALUE:void:deprecated_extract_return_value:struct type *type, char *regbuf, char *valbuf:type, regbuf, valbuf
f:2:DEPRECATED_STORE_RETURN_VALUE:void:deprecated_store_return_value:struct type *type, char *valbuf:type, valbuf
-#
+f:2:USE_STRUCT_CONVENTION:int:use_struct_convention:int gcc_p, struct type *value_type:gcc_p, value_type:::generic_use_struct_convention::0
+
F:2:EXTRACT_STRUCT_VALUE_ADDRESS:CORE_ADDR:extract_struct_value_address:struct regcache *regcache:regcache
F:2:DEPRECATED_EXTRACT_STRUCT_VALUE_ADDRESS:CORE_ADDR:deprecated_extract_struct_value_address:char *regbuf:regbuf
-f:2:USE_STRUCT_CONVENTION:int:use_struct_convention:int gcc_p, struct type *value_type:gcc_p, value_type:::generic_use_struct_convention::0
#
F:2:DEPRECATED_FRAME_INIT_SAVED_REGS:void:deprecated_frame_init_saved_regs:struct frame_info *frame:frame
F:2:DEPRECATED_INIT_EXTRA_FRAME_INFO:void:deprecated_init_extra_frame_info:int fromleaf, struct frame_info *frame:fromleaf, frame
#include "reggroups.h"
#include "block.h"
#include <ctype.h>
+#include "gdb_assert.h"
/* Functions exported for general use, in inferior.h: */
ui_out_field_stream (uiout, "return-value", stb);
ui_out_text (uiout, "\n");
}
- else
- {
- /* FIXME: 2003-09-27: When returning from a nested inferior
- function call, it's possible (with no help from the
- architecture vector) to locate and return/print a "struct
- return" value. This is just a more complicated case of what
- is already being done in in the inferior function call code.
- In fact, when inferior function calls are made async, this
- will likely be made the norm. */
- /* We cannot determine the contents of the structure because
- it is on the stack, and we don't know where, since we did not
- initiate the call, as opposed to the call_function_by_hand case */
+ /* FIXME: 2003-09-27: When returning from a nested inferior function
+ call, it's possible (with no help from the architecture vector)
+ to locate and return/print a "struct return" value. This is just
+ a more complicated case of what is already being done in in the
+ inferior function call code. In fact, when inferior function
+ calls are made async, this will likely be made the norm. */
#ifdef DEPRECATED_VALUE_RETURNED_FROM_STACK
- value = 0;
+#define DEPRECATED_VALUE_RETURNED_FROM_STACK_P 1
+#else
+#define DEPRECATED_VALUE_RETURNED_FROM_STACK_P 0
+#endif
+ else if (gdbarch_return_value_p (current_gdbarch)
+ || DEPRECATED_VALUE_RETURNED_FROM_STACK_P)
+ /* We cannot determine the contents of the structure because it is
+ on the stack, and we don't know where, since we did not
+ initiate the call, as opposed to the call_function_by_hand
+ case. */
+ {
+ gdb_assert (gdbarch_return_value (current_gdbarch, value_type, NULL, NULL, NULL)
+ == RETURN_VALUE_STRUCT_CONVENTION);
ui_out_text (uiout, "Value returned has type: ");
ui_out_field_string (uiout, "return-type", TYPE_NAME (value_type));
ui_out_text (uiout, ".");
ui_out_text (uiout, " Cannot determine contents\n");
-#else
+ return;
+ }
+ else
+ {
if (EXTRACT_STRUCT_VALUE_ADDRESS_P ())
{
CORE_ADDR addr = EXTRACT_STRUCT_VALUE_ADDRESS (stop_registers);
value_print (value, stb->stream, 0, Val_no_prettyprint);
ui_out_field_stream (uiout, "return-value", stb);
ui_out_text (uiout, "\n");
-#endif
}
}
return sp;
}
-/* Potential ways that a function can return a value of a given type. */
-enum return_value_convention
-{
- /* Where the return value has been squeezed into one or more
- registers. */
- RETURN_VALUE_REGISTER_CONVENTION,
- /* Commonly known as the "struct return convention". The caller
- passes an additional hidden first parameter to the caller. That
- parameter contains the address at which the value being returned
- should be stored. While typically, and historically, used for
- large structs, this is convention is applied to values of many
- different types. */
- RETURN_VALUE_STRUCT_CONVENTION
-};
-
/* Handle the return-value conventions specified by the SysV 32-bit
PowerPC ABI (including all the supplements):
return val;
}
\f
-/* Deal with the value that is "about to be returned".
+/* Deal with the return-value of a function that has "just returned".
- Return the value that a function, using the register convention,
- returning now would be returning to its caller, assuming its type
- is VALTYPE. RETBUF is where we look for what ought to be the
- contents of the registers (in raw form). This is because it is
- often desirable to restore old values to those registers after
- saving the contents of interest, and then call this function using
- the saved values. */
+ Extract the return-value (as a "struct value") that a function,
+ using register convention, has just returned to its caller. Assume
+ that the type of the function is VALTYPE, and that the "just
+ returned" register state is found in RETBUF.
+
+ The function has "just returned" because GDB halts a returning
+ function by setting a breakpoint at the return address (in the
+ caller), and not the return instruction (in the callee).
+
+ Because, in the case of a return from an inferior function call,
+ GDB needs to restore the inferiors registers, RETBUF is normally a
+ copy of the inferior's registers. */
struct value *
register_value_being_returned (struct type *valtype, struct regcache *retbuf)
{
struct value *val = allocate_value (valtype);
- CHECK_TYPEDEF (valtype);
+
/* If the function returns void, don't bother fetching the return
value. */
- if (TYPE_CODE (valtype) != TYPE_CODE_VOID)
- EXTRACT_RETURN_VALUE (valtype, retbuf, VALUE_CONTENTS_RAW (val));
+ if (TYPE_CODE (valtype) == TYPE_CODE_VOID)
+ return val;
+
+ if (!gdbarch_return_value_p (current_gdbarch))
+ {
+ /* NOTE: cagney/2003-10-20: Unlike "gdbarch_return_value", the
+ EXTRACT_RETURN_VALUE and USE_STRUCT_CONVENTION methods do not
+ handle the edge case of a function returning a small
+ structure / union in registers. */
+ CHECK_TYPEDEF (valtype);
+ EXTRACT_RETURN_VALUE (valtype, retbuf, VALUE_CONTENTS_RAW (val));
+ return val;
+ }
+
+ /* This function only handles "register convention". */
+ gdb_assert (gdbarch_return_value (current_gdbarch, valtype,
+ NULL, NULL, NULL)
+ == RETURN_VALUE_REGISTER_CONVENTION);
+ gdbarch_return_value (current_gdbarch, valtype, retbuf,
+ NULL, VALUE_CONTENTS_RAW (val));
return val;
}
if (code == TYPE_CODE_ERROR)
error ("Function return type unknown.");
- if (code == TYPE_CODE_STRUCT
- || code == TYPE_CODE_UNION
- || code == TYPE_CODE_ARRAY
- || RETURN_VALUE_ON_STACK (value_type))
- return USE_STRUCT_CONVENTION (gcc_p, value_type);
+ if (!gdbarch_return_value_p (current_gdbarch))
+ {
+ /* FIXME: cagney/2003-10-01: The below is dead. Instead an
+ architecture should implement "gdbarch_return_value". Using
+ that new function it is possible to exactly specify the ABIs
+ "struct return" vs "register return" conventions. */
+ if (code == TYPE_CODE_STRUCT
+ || code == TYPE_CODE_UNION
+ || code == TYPE_CODE_ARRAY
+ || RETURN_VALUE_ON_STACK (value_type))
+ return USE_STRUCT_CONVENTION (gcc_p, value_type);
+ else
+ return 0;
+ }
- return 0;
+ /* Probe the architecture for the return-value convention. */
+ return (gdbarch_return_value (current_gdbarch, value_type,
+ NULL, NULL, NULL)
+ == RETURN_VALUE_STRUCT_CONVENTION);
}
/* Store VAL so it will be returned if a function returns now.
if (code == TYPE_CODE_ERROR)
error ("Function return type unknown.");
+ if (gdbarch_return_value_p (current_gdbarch))
+ {
+ switch (gdbarch_return_value (current_gdbarch, type, NULL, NULL, NULL))
+ {
+ case RETURN_VALUE_REGISTER_CONVENTION:
+ /* Success. The architecture can deal with it, write it to
+ the regcache. */
+ gdbarch_return_value (current_gdbarch, type, current_regcache,
+ VALUE_CONTENTS (val), NULL);
+ return;
+ case RETURN_VALUE_STRUCT_CONVENTION:
+ /* Failure. For the moment, assume that it is not possible
+ to find the location, on the stack, at which the "struct
+ return" value should be stored. Only a warning because
+ an error aborts the "return" command leaving GDB in a
+ weird state. */
+ warning ("Location of return value unknown");
+ return;
+ }
+ }
+
+
if (code == TYPE_CODE_STRUCT
|| code == TYPE_CODE_UNION) /* FIXME, implement struct return. */
- error ("GDB does not support specifying a struct or union return value.");
+ /* FIXME: cagney/2003-10-20: This should be an internal-warning.
+ The problem is that while GDB's core supports "struct return"
+ using "register convention", many architectures haven't been
+ updated to implement the mechanisms needed to make it work.
+ It's a warning, and not an error, as otherwize it will jump out
+ of the "return" command leaving both GDB and the user in a very
+ confused state. */
+ {
+ warning ("This architecture does not support specifying a struct or union return-value.");
+ return;
+ }
STORE_RETURN_VALUE (type, current_regcache, VALUE_CONTENTS (val));
}
projects / deliverable / binutils-gdb.git / commitdiff
