From bbfdfe1c572ca7710cf08607db4935e8c8db174c Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 6 Feb 2013 19:40:04 +0000 Subject: [PATCH] Allow struct 'return' on 32-bit sparc. gdb/ * sparc-tdep.c (sparc32_return_value): Handle writing return value when using RETURN_VALUE_ABI_PRESERVES_ADDRESS. * value.c (struct_return_convention): New function. (using_struct_return): Implement in terms of struct_return_convention. * value.h (struct_return_convention): Declare. * stack.c (return_command): Allow successful overriding of the return value when RETURN_VALUE_ABI_PRESERVES_ADDRESS. --- gdb/ChangeLog | 10 ++++++++++ gdb/sparc-tdep.c | 12 +++++++++--- gdb/stack.c | 25 +++++++++++++++---------- gdb/value.c | 28 +++++++++++++++++++--------- gdb/value.h | 4 ++++ 5 files changed, 57 insertions(+), 22 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 3c49f961395..32f0c49293f 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,13 @@ +2013-02-06 David S. Miller + + * sparc-tdep.c (sparc32_return_value): Handle writing return value when + using RETURN_VALUE_ABI_PRESERVES_ADDRESS. + * value.c (struct_return_convention): New function. + (using_struct_return): Implement in terms of struct_return_convention. + * value.h (struct_return_convention): Declare. + * stack.c (return_command): Allow successful overriding of the return + value when RETURN_VALUE_ABI_PRESERVES_ADDRESS. + 2013-02-06 Tom Tromey * python/py-type.c (typy_strip_typedefs): Don't call check_typedef diff --git a/gdb/sparc-tdep.c b/gdb/sparc-tdep.c index 3ae73950b09..2b38521a85f 100644 --- a/gdb/sparc-tdep.c +++ b/gdb/sparc-tdep.c @@ -1370,15 +1370,21 @@ sparc32_return_value (struct gdbarch *gdbarch, struct value *function, if (sparc_structure_or_union_p (type) || (sparc_floating_p (type) && TYPE_LENGTH (type) == 16)) { + ULONGEST sp; + CORE_ADDR addr; + if (readbuf) { - ULONGEST sp; - CORE_ADDR addr; - regcache_cooked_read_unsigned (regcache, SPARC_SP_REGNUM, &sp); addr = read_memory_unsigned_integer (sp + 64, 4, byte_order); read_memory (addr, readbuf, TYPE_LENGTH (type)); } + if (writebuf) + { + regcache_cooked_read_unsigned (regcache, SPARC_SP_REGNUM, &sp); + addr = read_memory_unsigned_integer (sp + 64, 4, byte_order); + write_memory (addr, writebuf, TYPE_LENGTH (type)); + } return RETURN_VALUE_ABI_PRESERVES_ADDRESS; } diff --git a/gdb/stack.c b/gdb/stack.c index bfec1b853b3..9f4aafc812d 100644 --- a/gdb/stack.c +++ b/gdb/stack.c @@ -2278,6 +2278,7 @@ down_command (char *count_exp, int from_tty) void return_command (char *retval_exp, int from_tty) { + enum return_value_convention rv_conv; struct frame_info *thisframe; struct gdbarch *gdbarch; struct symbol *thisfun; @@ -2331,6 +2332,7 @@ return_command (char *retval_exp, int from_tty) if (thisfun != NULL) function = read_var_value (thisfun, thisframe); + rv_conv = RETURN_VALUE_REGISTER_CONVENTION; if (TYPE_CODE (return_type) == TYPE_CODE_VOID) /* If the return-type is "void", don't try to find the return-value's location. However, do still evaluate the @@ -2338,14 +2340,18 @@ return_command (char *retval_exp, int from_tty) is discarded, side effects such as "return i++" still occur. */ return_value = NULL; - else if (thisfun != NULL - && using_struct_return (gdbarch, function, return_type)) + else if (thisfun != NULL) { - query_prefix = "The location at which to store the " - "function's return value is unknown.\n" - "If you continue, the return value " - "that you specified will be ignored.\n"; - return_value = NULL; + rv_conv = struct_return_convention (gdbarch, function, return_type); + if (rv_conv == RETURN_VALUE_STRUCT_CONVENTION + || rv_conv == RETURN_VALUE_ABI_RETURNS_ADDRESS) + { + query_prefix = "The location at which to store the " + "function's return value is unknown.\n" + "If you continue, the return value " + "that you specified will be ignored.\n"; + return_value = NULL; + } } } @@ -2375,9 +2381,8 @@ return_command (char *retval_exp, int from_tty) struct type *return_type = value_type (return_value); struct gdbarch *gdbarch = get_regcache_arch (get_current_regcache ()); - gdb_assert (gdbarch_return_value (gdbarch, function, return_type, NULL, - NULL, NULL) - == RETURN_VALUE_REGISTER_CONVENTION); + gdb_assert (rv_conv != RETURN_VALUE_STRUCT_CONVENTION + && rv_conv != RETURN_VALUE_ABI_RETURNS_ADDRESS); gdbarch_return_value (gdbarch, function, return_type, get_current_regcache (), NULL /*read*/, value_contents (return_value) /*write*/); diff --git a/gdb/value.c b/gdb/value.c index dbf1c376bed..4b70eceed9a 100644 --- a/gdb/value.c +++ b/gdb/value.c @@ -3323,6 +3323,23 @@ coerce_array (struct value *arg) } +/* Return the return value convention that will be used for the + specified type. */ + +enum return_value_convention +struct_return_convention (struct gdbarch *gdbarch, + struct value *function, struct type *value_type) +{ + enum type_code code = TYPE_CODE (value_type); + + if (code == TYPE_CODE_ERROR) + error (_("Function return type unknown.")); + + /* Probe the architecture for the return-value convention. */ + return gdbarch_return_value (gdbarch, function, value_type, + NULL, NULL, NULL); +} + /* Return true if the function returning the specified type is using the convention of returning structures in memory (passing in the address as a hidden first parameter). */ @@ -3331,19 +3348,12 @@ int using_struct_return (struct gdbarch *gdbarch, struct value *function, struct type *value_type) { - enum type_code code = TYPE_CODE (value_type); - - if (code == TYPE_CODE_ERROR) - error (_("Function return type unknown.")); - - if (code == TYPE_CODE_VOID) + if (TYPE_CODE (value_type) == TYPE_CODE_VOID) /* A void return value is never in memory. See also corresponding code in "print_return_value". */ return 0; - /* Probe the architecture for the return-value convention. */ - return (gdbarch_return_value (gdbarch, function, value_type, - NULL, NULL, NULL) + return (struct_return_convention (gdbarch, function, value_type) != RETURN_VALUE_REGISTER_CONVENTION); } diff --git a/gdb/value.h b/gdb/value.h index b9013fdf1e8..c10c3ecf163 100644 --- a/gdb/value.h +++ b/gdb/value.h @@ -696,6 +696,10 @@ extern int value_in (struct value *element, struct value *set); extern int value_bit_index (struct type *type, const gdb_byte *addr, int index); +extern enum return_value_convention +struct_return_convention (struct gdbarch *gdbarch, struct value *function, + struct type *value_type); + extern int using_struct_return (struct gdbarch *gdbarch, struct value *function, struct type *value_type); -- 2.30.2