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[PATCH v2] Implement pahole-like 'ptype /o' option
- From: Sergio Durigan Junior <sergiodj at redhat dot com>
- To: GDB Patches <gdb-patches at sourceware dot org>
- Cc: Tom Tromey <tom at tromey dot com>, Eli Zaretskii <eliz at gnu dot org>, Sergio Durigan Junior <sergiodj at redhat dot com>
- Date: Tue, 28 Nov 2017 16:21:37 -0500
- Subject: [PATCH v2] Implement pahole-like 'ptype /o' option
- Authentication-results: sourceware.org; auth=none
- References: <20171121160709.23248-1-sergiodj@redhat.com>
Changes from v1:
- Address Tom's comments (the command now prints offset information
about unions, and the offset info is carried on for nested structs).
- Address Eli's comments.
- Extended testcase.
- A "bit" of cleanup on 'c_type_print_base'.
This commit implements the pahole-like '/o' option for 'ptype', which
prints the offsets and sizes of struct fields, reporting whenever
there is a hole found.
The output is heavily based on pahole(1), with a few modifications
here and there to adjust it to our reality. Here's an example:
(gdb) ptype /o stap_probe
/* offset | size */
struct stap_probe {
/* 0 | 40 */ struct probe {
/* 0 | 8 */ const probe_ops *pops;
/* 8 | 8 */ gdbarch *arch;
/* 16 | 8 */ const char *name;
/* 24 | 8 */ const char *provider;
/* 32 | 8 */ CORE_ADDR address;
} /* total size: 40 bytes */ p;
/* 40 | 8 */ CORE_ADDR sem_addr;
/* 48:31 | 4 */ unsigned int args_parsed : 1;
/* XXX 7-bit hole */
/* XXX 7-byte hole */
/* 56 | 8 */ union {
/* 8 */ const char *text;
/* 8 */ VEC_stap_probe_arg_s *vec;
} /* total size: 8 bytes */ args_u;
} /* total size: 64 bytes */
A big part of this patch handles the formatting logic of 'ptype',
which is a bit messy. I tried to be not very invasive, but I had to
do some cleanups here and there to make life easier.
This patch is the start of a long-term work I'll do to flush the local
patches we carry for Fedora GDB. In this specific case, I'm aiming at
upstreaming the feature implemented by the 'pahole.py' script that is
shipped with Fedora GDB:
<https://src.fedoraproject.org/rpms/gdb/blob/master/f/gdb-archer.patch#_311>
This has been regression-tested on the BuildBot. There's a new
testcase for it, along with an update to the documentation. I also
thought it was worth mentioning this feature in the NEWS file.
gdb/ChangeLog:
2017-11-28 Sergio Durigan Junior <sergiodj@redhat.com>
PR cli/16224
* NEWS (Changes since GDB 8.0): Mention new '/o' flag.
* c-typeprint.c (OFFSET_SPC_LEN): New define.
(print_spaces_filtered_with_print_options): New function.
(output_access_specifier): Take new argument FLAGS. Modify
function to call 'print_spaces_filtered_with_print_options'.
(c_print_type_union_field_offset): New function.
(c_print_type_struct_field_offset): New function.
(need_access_label_p): New function, with contents from
'c_type_print_base'.
(c_type_print_base_struct_union): Likewise.
(c_type_print_base): Print offsets and sizes for struct
fields. Struct/union handling code move to functions
mentioned above.
* typeprint.c (const struct type_print_options
type_print_raw_options): Initialize 'print_offsets' and
'offset_bitpos'.
(static struct type_print_options default_ptype_flags):
Likewise.
(whatis_exp): Handle '/o' option.
(_initialize_typeprint): Add '/o' flag to ptype's help.
* typeprint.h (struct type_print_options) <print_offsets>: New
field.
<offset_bitpos>: Likewise.
gdb/testsuite/ChangeLog:
2017-11-28 Sergio Durigan Junior <sergiodj@redhat.com>
PR cli/16224
* gdb.base/ptype-offsets.cc: New file.
* gdb.base/ptype-offsets.exp: New file.
gdb/doc/ChangeLog:
2017-11-28 Sergio Durigan Junior <sergiodj@redhat.com>
PR cli/16224
* gdb.texinfo (ptype): Add new flag '/o'.
---
gdb/NEWS | 3 +
gdb/c-typeprint.c | 1016 +++++++++++++++++-------------
gdb/doc/gdb.texinfo | 4 +
gdb/testsuite/gdb.base/ptype-offsets.cc | 113 ++++
gdb/testsuite/gdb.base/ptype-offsets.exp | 77 +++
gdb/typeprint.c | 15 +-
gdb/typeprint.h | 9 +
7 files changed, 812 insertions(+), 425 deletions(-)
create mode 100644 gdb/testsuite/gdb.base/ptype-offsets.cc
create mode 100644 gdb/testsuite/gdb.base/ptype-offsets.exp
diff --git a/gdb/NEWS b/gdb/NEWS
index 754ce103bd..1247021046 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -3,6 +3,9 @@
*** Changes since GDB 8.0
+* The 'ptype' command now accepts a '/o' flag, which prints the
+ offsets and sizes of fields in a struct, like the pahole(1) tool.
+
* GDB now uses the GNU MPFR library, if available, to emulate target
floating-point arithmetic during expression evaluation when the target
uses different floating-point formats than the host. At least version
diff --git a/gdb/c-typeprint.c b/gdb/c-typeprint.c
index ed5a1a4b8a..39334ccf88 100644
--- a/gdb/c-typeprint.c
+++ b/gdb/c-typeprint.c
@@ -32,6 +32,14 @@
#include "cp-abi.h"
#include "cp-support.h"
+/* When printing the offsets of a struct and its fields (i.e., 'ptype
+ /o'; type_print_options::print_offsets), we use this many
+ characters when printing the offset information at the beginning of
+ the line. This is needed in order to generate the correct amount
+ of whitespaces when no offset info should be printed for a certain
+ field. */
+#define OFFSET_SPC_LEN 23
+
/* A list of access specifiers used for printing. */
enum access_specifier
@@ -836,21 +844,36 @@ c_type_print_template_args (const struct type_print_options *flags,
fputs_filtered (_("] "), stream);
}
+/* Use 'print_spaces_filtered', but take into consideration the
+ type_print_options FLAGS in order to determine how many whitespaces
+ will be printed. */
+
+static void
+print_spaces_filtered_with_print_options (int level, struct ui_file *stream,
+ const struct type_print_options *flags)
+{
+ if (!flags->print_offsets)
+ print_spaces_filtered (level, stream);
+ else
+ print_spaces_filtered (level + OFFSET_SPC_LEN, stream);
+}
+
/* Output an access specifier to STREAM, if needed. LAST_ACCESS is the
last access specifier output (typically returned by this function). */
static enum access_specifier
output_access_specifier (struct ui_file *stream,
enum access_specifier last_access,
- int level, bool is_protected, bool is_private)
+ int level, bool is_protected, bool is_private,
+ const struct type_print_options *flags)
{
if (is_protected)
{
if (last_access != s_protected)
{
last_access = s_protected;
- fprintfi_filtered (level + 2, stream,
- "protected:\n");
+ print_spaces_filtered_with_print_options (level + 2, stream, flags);
+ fprintf_filtered (stream, "protected:\n");
}
}
else if (is_private)
@@ -858,8 +881,8 @@ output_access_specifier (struct ui_file *stream,
if (last_access != s_private)
{
last_access = s_private;
- fprintfi_filtered (level + 2, stream,
- "private:\n");
+ print_spaces_filtered_with_print_options (level + 2, stream, flags);
+ fprintf_filtered (stream, "private:\n");
}
}
else
@@ -867,14 +890,569 @@ output_access_specifier (struct ui_file *stream,
if (last_access != s_public)
{
last_access = s_public;
- fprintfi_filtered (level + 2, stream,
- "public:\n");
+ print_spaces_filtered_with_print_options (level + 2, stream, flags);
+ fprintf_filtered (stream, "public:\n");
}
}
return last_access;
}
+/* Print information about the offset of TYPE inside its union.
+ FIELD_IDX represents the index of this TYPE inside the union. We
+ just print the type size, and nothing more.
+
+ The output is strongly based on pahole(1). */
+
+static void
+c_print_type_union_field_offset (struct type *type, unsigned int field_idx,
+ struct ui_file *stream)
+{
+ struct type *ftype = check_typedef (TYPE_FIELD_TYPE (type, field_idx));
+
+ fprintf_filtered (stream, "/* %4u */", TYPE_LENGTH (ftype));
+}
+
+/* Print information about the offset of TYPE inside its struct.
+ FIELD_IDX represents the index of this TYPE inside the struct, and
+ ENDPOS is the end position of the previous type (this is how we
+ calculate whether there are holes in the struct). At the end,
+ ENDPOS is updated.
+
+ The output is strongly based on pahole(1). */
+
+static void
+c_print_type_struct_field_offset (struct type *type, unsigned int field_idx,
+ unsigned int *endpos, struct ui_file *stream,
+ unsigned int offset_bitpos)
+{
+ struct type *ftype = check_typedef (TYPE_FIELD_TYPE (type, field_idx));
+ unsigned int bitpos = TYPE_FIELD_BITPOS (type, field_idx);
+ unsigned int fieldsize_byte = TYPE_LENGTH (ftype);
+ unsigned int fieldsize_bit;
+
+ if (*endpos > 0 && *endpos < bitpos)
+ {
+ /* If ENDPOS is smaller than the current type's bitpos, it means
+ there's a hole in the struct, so we report it here. */
+ unsigned int hole = bitpos - *endpos;
+ unsigned int hole_byte = hole / TARGET_CHAR_BIT;
+ unsigned int hole_bit = hole % TARGET_CHAR_BIT;
+
+ if (hole_bit > 0)
+ fprintf_filtered (stream, "/* XXX %2u-bit hole */\n", hole_bit);
+
+ if (hole_byte > 0)
+ fprintf_filtered (stream, "/* XXX %2u-byte hole */\n", hole_byte);
+ }
+
+ /* The position of the field, relative to the beginning of the
+ struct. Assume this number will have 4 digits. */
+ fprintf_filtered (stream, "/* %4u",
+ (bitpos + offset_bitpos) / TARGET_CHAR_BIT);
+
+ if (TYPE_FIELD_PACKED (type, field_idx))
+ {
+ /* We're dealing with a bitfield. Print how many bits are left
+ to be used. */
+ fieldsize_bit = TYPE_FIELD_BITSIZE (type, field_idx);
+ fprintf_filtered (stream, ":%u",
+ fieldsize_byte * TARGET_CHAR_BIT - fieldsize_bit);
+ }
+ else
+ {
+ fieldsize_bit = fieldsize_byte * TARGET_CHAR_BIT;
+ fprintf_filtered (stream, " ");
+ }
+
+ fprintf_filtered (stream, " | %4u */", fieldsize_byte);
+
+ *endpos = bitpos + fieldsize_bit;
+}
+
+/* Return true is an access label (i.e., "public:", "private:",
+ "protected:") needs to be printed for TYPE. */
+
+static bool
+need_access_label_p (struct type *type)
+{
+ bool need_access_label = false;
+ int i, j;
+ int len, len2;
+
+ if (TYPE_DECLARED_CLASS (type))
+ {
+ QUIT;
+ len = TYPE_NFIELDS (type);
+ for (i = TYPE_N_BASECLASSES (type); i < len; i++)
+ if (!TYPE_FIELD_PRIVATE (type, i))
+ {
+ need_access_label = true;
+ break;
+ }
+ QUIT;
+ if (!need_access_label)
+ {
+ len2 = TYPE_NFN_FIELDS (type);
+ for (j = 0; j < len2; j++)
+ {
+ len = TYPE_FN_FIELDLIST_LENGTH (type, j);
+ for (i = 0; i < len; i++)
+ if (!TYPE_FN_FIELD_PRIVATE (TYPE_FN_FIELDLIST1 (type,
+ j), i))
+ {
+ need_access_label = true;
+ break;
+ }
+ if (need_access_label)
+ break;
+ }
+ }
+ QUIT;
+ if (!need_access_label)
+ {
+ for (i = 0; i < TYPE_TYPEDEF_FIELD_COUNT (type); ++i)
+ {
+ if (!TYPE_TYPEDEF_FIELD_PRIVATE (type, i))
+ {
+ need_access_label = true;
+ break;
+ }
+ }
+ }
+ }
+ else
+ {
+ QUIT;
+ len = TYPE_NFIELDS (type);
+ for (i = TYPE_N_BASECLASSES (type); i < len; i++)
+ if (TYPE_FIELD_PRIVATE (type, i)
+ || TYPE_FIELD_PROTECTED (type, i))
+ {
+ need_access_label = true;
+ break;
+ }
+ QUIT;
+ if (!need_access_label)
+ {
+ len2 = TYPE_NFN_FIELDS (type);
+ for (j = 0; j < len2; j++)
+ {
+ QUIT;
+ len = TYPE_FN_FIELDLIST_LENGTH (type, j);
+ for (i = 0; i < len; i++)
+ if (TYPE_FN_FIELD_PROTECTED (TYPE_FN_FIELDLIST1 (type,
+ j), i)
+ || TYPE_FN_FIELD_PRIVATE (TYPE_FN_FIELDLIST1 (type,
+ j),
+ i))
+ {
+ need_access_label = true;
+ break;
+ }
+ if (need_access_label)
+ break;
+ }
+ }
+ QUIT;
+ if (!need_access_label)
+ {
+ for (i = 0; i < TYPE_TYPEDEF_FIELD_COUNT (type); ++i)
+ {
+ if (TYPE_TYPEDEF_FIELD_PROTECTED (type, i)
+ || TYPE_TYPEDEF_FIELD_PRIVATE (type, i))
+ {
+ need_access_label = true;
+ break;
+ }
+ }
+ }
+ }
+ return need_access_label;
+}
+
+/* Helper for 'c_type_print_base' that handles structs and unions.
+ For a description of the arguments, see 'c_type_print_base'. */
+
+static void
+c_type_print_base_struct_union (struct type *type, struct ui_file *stream,
+ int show, int level,
+ const struct type_print_options *flags)
+{
+ struct type_print_options local_flags = *flags;
+ struct type_print_options semi_local_flags = *flags;
+ struct cleanup *local_cleanups = make_cleanup (null_cleanup, NULL);
+
+ local_flags.local_typedefs = NULL;
+ semi_local_flags.local_typedefs = NULL;
+
+ if (!flags->raw)
+ {
+ if (flags->local_typedefs)
+ local_flags.local_typedefs
+ = copy_typedef_hash (flags->local_typedefs);
+ else
+ local_flags.local_typedefs = create_typedef_hash ();
+
+ make_cleanup_free_typedef_hash (local_flags.local_typedefs);
+ }
+
+ c_type_print_modifier (type, stream, 0, 1);
+ if (TYPE_CODE (type) == TYPE_CODE_UNION)
+ fprintf_filtered (stream, "union ");
+ else if (TYPE_DECLARED_CLASS (type))
+ fprintf_filtered (stream, "class ");
+ else
+ fprintf_filtered (stream, "struct ");
+
+ /* Print the tag if it exists. The HP aCC compiler emits a
+ spurious "{unnamed struct}"/"{unnamed union}"/"{unnamed
+ enum}" tag for unnamed struct/union/enum's, which we don't
+ want to print. */
+ if (TYPE_TAG_NAME (type) != NULL
+ && !startswith (TYPE_TAG_NAME (type), "{unnamed"))
+ {
+ /* When printing the tag name, we are still effectively
+ printing in the outer context, hence the use of FLAGS
+ here. */
+ print_name_maybe_canonical (TYPE_TAG_NAME (type), flags, stream);
+ if (show > 0)
+ fputs_filtered (" ", stream);
+ }
+
+ if (show < 0)
+ {
+ /* If we just printed a tag name, no need to print anything
+ else. */
+ if (TYPE_TAG_NAME (type) == NULL)
+ fprintf_filtered (stream, "{...}");
+ }
+ else if (show > 0 || TYPE_TAG_NAME (type) == NULL)
+ {
+ struct type *basetype;
+
+ c_type_print_template_args (&local_flags, type, stream);
+
+ /* Add in template parameters when printing derivation info. */
+ add_template_parameters (local_flags.local_typedefs, type);
+ cp_type_print_derivation_info (stream, type, &local_flags);
+
+ /* This holds just the global typedefs and the template
+ parameters. */
+ semi_local_flags.local_typedefs
+ = copy_typedef_hash (local_flags.local_typedefs);
+ if (semi_local_flags.local_typedefs)
+ make_cleanup_free_typedef_hash (semi_local_flags.local_typedefs);
+
+ /* Now add in the local typedefs. */
+ recursively_update_typedef_hash (local_flags.local_typedefs, type);
+
+ fprintf_filtered (stream, "{\n");
+ if (TYPE_NFIELDS (type) == 0 && TYPE_NFN_FIELDS (type) == 0
+ && TYPE_TYPEDEF_FIELD_COUNT (type) == 0)
+ {
+ if (TYPE_STUB (type))
+ fprintfi_filtered (level + 4, stream,
+ _("<incomplete type>\n"));
+ else
+ fprintfi_filtered (level + 4, stream,
+ _("<no data fields>\n"));
+ }
+
+ /* Start off with no specific section type, so we can print
+ one for the first field we find, and use that section type
+ thereafter until we find another type. */
+ enum access_specifier section_type = s_none;
+
+ /* For a class, if all members are private, there's no need
+ for a "private:" label; similarly, for a struct or union
+ masquerading as a class, if all members are public, there's
+ no need for a "public:" label. */
+ bool need_access_label = need_access_label_p (type);
+
+ /* If there is a base class for this type,
+ do not print the field that it occupies. */
+
+ int len = TYPE_NFIELDS (type);
+ int vptr_fieldno = get_vptr_fieldno (type, &basetype);
+ unsigned int endpos = 0;
+
+ for (int i = TYPE_N_BASECLASSES (type); i < len; i++)
+ {
+ QUIT;
+
+ /* If we have a virtual table pointer, omit it. Even if
+ virtual table pointers are not specifically marked in
+ the debug info, they should be artificial. */
+ if ((i == vptr_fieldno && type == basetype)
+ || TYPE_FIELD_ARTIFICIAL (type, i))
+ continue;
+
+ if (need_access_label)
+ {
+ section_type = output_access_specifier
+ (stream, section_type, level,
+ TYPE_FIELD_PROTECTED (type, i),
+ TYPE_FIELD_PRIVATE (type, i),
+ flags);
+ }
+
+ bool is_static = field_is_static (&TYPE_FIELD (type, i));
+
+ if (flags->print_offsets)
+ {
+ if (!is_static)
+ {
+ if (TYPE_CODE (type) == TYPE_CODE_STRUCT)
+ c_print_type_struct_field_offset (type, i, &endpos, stream,
+ flags->offset_bitpos);
+ else if (TYPE_CODE (type) == TYPE_CODE_UNION)
+ c_print_type_union_field_offset (type, i, stream);
+ }
+ else
+ print_spaces_filtered (OFFSET_SPC_LEN, stream);
+ }
+
+ print_spaces_filtered (level + 4, stream);
+ if (is_static)
+ fprintf_filtered (stream, "static ");
+
+ int newshow = show - 1;
+
+ if (flags->print_offsets
+ && (TYPE_CODE (TYPE_FIELD_TYPE (type, i)) == TYPE_CODE_STRUCT
+ || TYPE_CODE (TYPE_FIELD_TYPE (type, i)) == TYPE_CODE_UNION))
+ {
+ /* If we're printing offsets and this field's type is
+ either a struct or an union, then we're interested in
+ expanding it. */
+ ++newshow;
+
+ /* Make sure we carry our offset when we expand the
+ struct. */
+ local_flags.offset_bitpos
+ = flags->offset_bitpos + TYPE_FIELD_BITPOS (type, i);
+ }
+
+ c_print_type (TYPE_FIELD_TYPE (type, i),
+ TYPE_FIELD_NAME (type, i),
+ stream, newshow, level + 4,
+ &local_flags);
+ if (!is_static
+ && TYPE_FIELD_PACKED (type, i))
+ {
+ /* It is a bitfield. This code does not attempt
+ to look at the bitpos and reconstruct filler,
+ unnamed fields. This would lead to misleading
+ results if the compiler does not put out fields
+ for such things (I don't know what it does). */
+ fprintf_filtered (stream, " : %d",
+ TYPE_FIELD_BITSIZE (type, i));
+ }
+ fprintf_filtered (stream, ";\n");
+ }
+
+ /* If there are both fields and methods, put a blank line
+ between them. Make sure to count only method that we
+ will display; artificial methods will be hidden. */
+ len = TYPE_NFN_FIELDS (type);
+ if (!flags->print_methods)
+ len = 0;
+ int real_len = 0;
+ for (int i = 0; i < len; i++)
+ {
+ struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
+ int len2 = TYPE_FN_FIELDLIST_LENGTH (type, i);
+ int j;
+
+ for (j = 0; j < len2; j++)
+ if (!TYPE_FN_FIELD_ARTIFICIAL (f, j))
+ real_len++;
+ }
+ if (real_len > 0 && section_type != s_none)
+ fprintf_filtered (stream, "\n");
+
+ /* C++: print out the methods. */
+ for (int i = 0; i < len; i++)
+ {
+ struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
+ int j, len2 = TYPE_FN_FIELDLIST_LENGTH (type, i);
+ const char *method_name = TYPE_FN_FIELDLIST_NAME (type, i);
+ const char *name = type_name_no_tag (type);
+ int is_constructor = name && strcmp (method_name,
+ name) == 0;
+
+ for (j = 0; j < len2; j++)
+ {
+ const char *mangled_name;
+ gdb::unique_xmalloc_ptr<char> mangled_name_holder;
+ char *demangled_name;
+ const char *physname = TYPE_FN_FIELD_PHYSNAME (f, j);
+ int is_full_physname_constructor =
+ TYPE_FN_FIELD_CONSTRUCTOR (f, j)
+ || is_constructor_name (physname)
+ || is_destructor_name (physname)
+ || method_name[0] == '~';
+
+ /* Do not print out artificial methods. */
+ if (TYPE_FN_FIELD_ARTIFICIAL (f, j))
+ continue;
+
+ QUIT;
+ section_type = output_access_specifier
+ (stream, section_type, level,
+ TYPE_FN_FIELD_PROTECTED (f, j),
+ TYPE_FN_FIELD_PRIVATE (f, j),
+ flags);
+
+ print_spaces_filtered_with_print_options (level + 4, stream,
+ flags);
+ if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
+ fprintf_filtered (stream, "virtual ");
+ else if (TYPE_FN_FIELD_STATIC_P (f, j))
+ fprintf_filtered (stream, "static ");
+ if (TYPE_TARGET_TYPE (TYPE_FN_FIELD_TYPE (f, j)) == 0)
+ {
+ /* Keep GDB from crashing here. */
+ fprintf_filtered (stream,
+ _("<undefined type> %s;\n"),
+ TYPE_FN_FIELD_PHYSNAME (f, j));
+ break;
+ }
+ else if (!is_constructor /* Constructors don't
+ have declared
+ types. */
+ && !is_full_physname_constructor /* " " */
+ && !is_type_conversion_operator (type, i, j))
+ {
+ unsigned int old_po = local_flags.print_offsets;
+
+ /* Temporarily disable print_offsets, because it
+ would mess with indentation. */
+ local_flags.print_offsets = 0;
+ c_print_type (TYPE_TARGET_TYPE (TYPE_FN_FIELD_TYPE (f, j)),
+ "", stream, -1, 0,
+ &local_flags);
+ local_flags.print_offsets = old_po;
+ fputs_filtered (" ", stream);
+ }
+ if (TYPE_FN_FIELD_STUB (f, j))
+ {
+ /* Build something we can demangle. */
+ mangled_name_holder.reset (gdb_mangle_name (type, i, j));
+ mangled_name = mangled_name_holder.get ();
+ }
+ else
+ mangled_name = TYPE_FN_FIELD_PHYSNAME (f, j);
+
+ demangled_name =
+ gdb_demangle (mangled_name,
+ DMGL_ANSI | DMGL_PARAMS);
+ if (demangled_name == NULL)
+ {
+ /* In some cases (for instance with the HP
+ demangling), if a function has more than 10
+ arguments, the demangling will fail.
+ Let's try to reconstruct the function
+ signature from the symbol information. */
+ if (!TYPE_FN_FIELD_STUB (f, j))
+ {
+ int staticp = TYPE_FN_FIELD_STATIC_P (f, j);
+ struct type *mtype = TYPE_FN_FIELD_TYPE (f, j);
+
+ cp_type_print_method_args (mtype,
+ "",
+ method_name,
+ staticp,
+ stream, &local_flags);
+ }
+ else
+ fprintf_filtered (stream,
+ _("<badly mangled name '%s'>"),
+ mangled_name);
+ }
+ else
+ {
+ char *p;
+ char *demangled_no_class
+ = remove_qualifiers (demangled_name);
+
+ /* Get rid of the `static' appended by the
+ demangler. */
+ p = strstr (demangled_no_class, " static");
+ if (p != NULL)
+ {
+ int length = p - demangled_no_class;
+ char *demangled_no_static;
+
+ demangled_no_static
+ = (char *) xmalloc (length + 1);
+ strncpy (demangled_no_static,
+ demangled_no_class, length);
+ *(demangled_no_static + length) = '\0';
+ fputs_filtered (demangled_no_static, stream);
+ xfree (demangled_no_static);
+ }
+ else
+ fputs_filtered (demangled_no_class, stream);
+ xfree (demangled_name);
+ }
+
+ fprintf_filtered (stream, ";\n");
+ }
+ }
+
+ /* Print typedefs defined in this class. */
+
+ if (TYPE_TYPEDEF_FIELD_COUNT (type) != 0 && flags->print_typedefs)
+ {
+ if (TYPE_NFIELDS (type) != 0 || TYPE_NFN_FIELDS (type) != 0)
+ fprintf_filtered (stream, "\n");
+
+ for (int i = 0; i < TYPE_TYPEDEF_FIELD_COUNT (type); i++)
+ {
+ struct type *target = TYPE_TYPEDEF_FIELD_TYPE (type, i);
+
+ /* Dereference the typedef declaration itself. */
+ gdb_assert (TYPE_CODE (target) == TYPE_CODE_TYPEDEF);
+ target = TYPE_TARGET_TYPE (target);
+
+ if (need_access_label)
+ {
+ section_type = output_access_specifier
+ (stream, section_type, level,
+ TYPE_TYPEDEF_FIELD_PROTECTED (type, i),
+ TYPE_TYPEDEF_FIELD_PRIVATE (type, i),
+ flags);
+ }
+ print_spaces_filtered_with_print_options (level + 4,
+ stream, flags);
+ fprintf_filtered (stream, "typedef ");
+
+ /* We want to print typedefs with substitutions
+ from the template parameters or globally-known
+ typedefs but not local typedefs. */
+ c_print_type (target,
+ TYPE_TYPEDEF_FIELD_NAME (type, i),
+ stream, show - 1, level + 4,
+ &semi_local_flags);
+ fprintf_filtered (stream, ";\n");
+ }
+ }
+
+ if (flags->print_offsets && level > 0)
+ print_spaces_filtered (OFFSET_SPC_LEN, stream);
+
+ fprintfi_filtered (level, stream, "}");
+ }
+
+ if (show > 0 && flags->print_offsets)
+ fprintf_filtered (stream, " /* total size: %4u bytes */",
+ TYPE_LENGTH (type));
+
+ do_cleanups (local_cleanups);
+}
+
/* Print the name of the type (or the ultimate pointer target,
function value or array element), or the description of a structure
or union.
@@ -898,10 +1476,8 @@ c_type_print_base (struct type *type, struct ui_file *stream,
int show, int level, const struct type_print_options *flags)
{
int i;
- int len, real_len;
- enum access_specifier section_type;
- int need_access_label = 0;
- int j, len2;
+ int len;
+ int j;
QUIT;
@@ -918,15 +1494,16 @@ c_type_print_base (struct type *type, struct ui_file *stream,
folk tend to expect things like "class5 *foo" rather than "struct
class5 *foo". */
- if (show <= 0
- && TYPE_NAME (type) != NULL)
+ struct type *ttype = check_typedef (type);
+
+ if (show <= 0 && TYPE_NAME (type) != NULL)
{
c_type_print_modifier (type, stream, 0, 1);
print_name_maybe_canonical (TYPE_NAME (type), flags, stream);
return;
}
- type = check_typedef (type);
+ type = ttype;
switch (TYPE_CODE (type))
{
@@ -958,416 +1535,7 @@ c_type_print_base (struct type *type, struct ui_file *stream,
case TYPE_CODE_STRUCT:
case TYPE_CODE_UNION:
- {
- struct type_print_options local_flags = *flags;
- struct type_print_options semi_local_flags = *flags;
- struct cleanup *local_cleanups = make_cleanup (null_cleanup, NULL);
-
- local_flags.local_typedefs = NULL;
- semi_local_flags.local_typedefs = NULL;
-
- if (!flags->raw)
- {
- if (flags->local_typedefs)
- local_flags.local_typedefs
- = copy_typedef_hash (flags->local_typedefs);
- else
- local_flags.local_typedefs = create_typedef_hash ();
-
- make_cleanup_free_typedef_hash (local_flags.local_typedefs);
- }
-
- c_type_print_modifier (type, stream, 0, 1);
- if (TYPE_CODE (type) == TYPE_CODE_UNION)
- fprintf_filtered (stream, "union ");
- else if (TYPE_DECLARED_CLASS (type))
- fprintf_filtered (stream, "class ");
- else
- fprintf_filtered (stream, "struct ");
-
- /* Print the tag if it exists. The HP aCC compiler emits a
- spurious "{unnamed struct}"/"{unnamed union}"/"{unnamed
- enum}" tag for unnamed struct/union/enum's, which we don't
- want to print. */
- if (TYPE_TAG_NAME (type) != NULL
- && !startswith (TYPE_TAG_NAME (type), "{unnamed"))
- {
- /* When printing the tag name, we are still effectively
- printing in the outer context, hence the use of FLAGS
- here. */
- print_name_maybe_canonical (TYPE_TAG_NAME (type), flags, stream);
- if (show > 0)
- fputs_filtered (" ", stream);
- }
-
- if (show < 0)
- {
- /* If we just printed a tag name, no need to print anything
- else. */
- if (TYPE_TAG_NAME (type) == NULL)
- fprintf_filtered (stream, "{...}");
- }
- else if (show > 0 || TYPE_TAG_NAME (type) == NULL)
- {
- struct type *basetype;
- int vptr_fieldno;
-
- c_type_print_template_args (&local_flags, type, stream);
-
- /* Add in template parameters when printing derivation info. */
- add_template_parameters (local_flags.local_typedefs, type);
- cp_type_print_derivation_info (stream, type, &local_flags);
-
- /* This holds just the global typedefs and the template
- parameters. */
- semi_local_flags.local_typedefs
- = copy_typedef_hash (local_flags.local_typedefs);
- if (semi_local_flags.local_typedefs)
- make_cleanup_free_typedef_hash (semi_local_flags.local_typedefs);
-
- /* Now add in the local typedefs. */
- recursively_update_typedef_hash (local_flags.local_typedefs, type);
-
- fprintf_filtered (stream, "{\n");
- if (TYPE_NFIELDS (type) == 0 && TYPE_NFN_FIELDS (type) == 0
- && TYPE_TYPEDEF_FIELD_COUNT (type) == 0)
- {
- if (TYPE_STUB (type))
- fprintfi_filtered (level + 4, stream,
- _("<incomplete type>\n"));
- else
- fprintfi_filtered (level + 4, stream,
- _("<no data fields>\n"));
- }
-
- /* Start off with no specific section type, so we can print
- one for the first field we find, and use that section type
- thereafter until we find another type. */
-
- section_type = s_none;
-
- /* For a class, if all members are private, there's no need
- for a "private:" label; similarly, for a struct or union
- masquerading as a class, if all members are public, there's
- no need for a "public:" label. */
-
- if (TYPE_DECLARED_CLASS (type))
- {
- QUIT;
- len = TYPE_NFIELDS (type);
- for (i = TYPE_N_BASECLASSES (type); i < len; i++)
- if (!TYPE_FIELD_PRIVATE (type, i))
- {
- need_access_label = 1;
- break;
- }
- QUIT;
- if (!need_access_label)
- {
- len2 = TYPE_NFN_FIELDS (type);
- for (j = 0; j < len2; j++)
- {
- len = TYPE_FN_FIELDLIST_LENGTH (type, j);
- for (i = 0; i < len; i++)
- if (!TYPE_FN_FIELD_PRIVATE (TYPE_FN_FIELDLIST1 (type,
- j), i))
- {
- need_access_label = 1;
- break;
- }
- if (need_access_label)
- break;
- }
- }
- QUIT;
- if (!need_access_label)
- {
- for (i = 0; i < TYPE_TYPEDEF_FIELD_COUNT (type); ++i)
- {
- if (!TYPE_TYPEDEF_FIELD_PRIVATE (type, i))
- {
- need_access_label = 1;
- break;
- }
- }
- }
- }
- else
- {
- QUIT;
- len = TYPE_NFIELDS (type);
- for (i = TYPE_N_BASECLASSES (type); i < len; i++)
- if (TYPE_FIELD_PRIVATE (type, i)
- || TYPE_FIELD_PROTECTED (type, i))
- {
- need_access_label = 1;
- break;
- }
- QUIT;
- if (!need_access_label)
- {
- len2 = TYPE_NFN_FIELDS (type);
- for (j = 0; j < len2; j++)
- {
- QUIT;
- len = TYPE_FN_FIELDLIST_LENGTH (type, j);
- for (i = 0; i < len; i++)
- if (TYPE_FN_FIELD_PROTECTED (TYPE_FN_FIELDLIST1 (type,
- j), i)
- || TYPE_FN_FIELD_PRIVATE (TYPE_FN_FIELDLIST1 (type,
- j),
- i))
- {
- need_access_label = 1;
- break;
- }
- if (need_access_label)
- break;
- }
- }
- QUIT;
- if (!need_access_label)
- {
- for (i = 0; i < TYPE_TYPEDEF_FIELD_COUNT (type); ++i)
- {
- if (TYPE_TYPEDEF_FIELD_PROTECTED (type, i)
- || TYPE_TYPEDEF_FIELD_PRIVATE (type, i))
- {
- need_access_label = 1;
- break;
- }
- }
- }
- }
-
- /* If there is a base class for this type,
- do not print the field that it occupies. */
-
- len = TYPE_NFIELDS (type);
- vptr_fieldno = get_vptr_fieldno (type, &basetype);
- for (i = TYPE_N_BASECLASSES (type); i < len; i++)
- {
- QUIT;
-
- /* If we have a virtual table pointer, omit it. Even if
- virtual table pointers are not specifically marked in
- the debug info, they should be artificial. */
- if ((i == vptr_fieldno && type == basetype)
- || TYPE_FIELD_ARTIFICIAL (type, i))
- continue;
-
- if (need_access_label)
- {
- section_type = output_access_specifier
- (stream, section_type, level,
- TYPE_FIELD_PROTECTED (type, i),
- TYPE_FIELD_PRIVATE (type, i));
- }
-
- print_spaces_filtered (level + 4, stream);
- if (field_is_static (&TYPE_FIELD (type, i)))
- fprintf_filtered (stream, "static ");
- c_print_type (TYPE_FIELD_TYPE (type, i),
- TYPE_FIELD_NAME (type, i),
- stream, show - 1, level + 4,
- &local_flags);
- if (!field_is_static (&TYPE_FIELD (type, i))
- && TYPE_FIELD_PACKED (type, i))
- {
- /* It is a bitfield. This code does not attempt
- to look at the bitpos and reconstruct filler,
- unnamed fields. This would lead to misleading
- results if the compiler does not put out fields
- for such things (I don't know what it does). */
- fprintf_filtered (stream, " : %d",
- TYPE_FIELD_BITSIZE (type, i));
- }
- fprintf_filtered (stream, ";\n");
- }
-
- /* If there are both fields and methods, put a blank line
- between them. Make sure to count only method that we
- will display; artificial methods will be hidden. */
- len = TYPE_NFN_FIELDS (type);
- if (!flags->print_methods)
- len = 0;
- real_len = 0;
- for (i = 0; i < len; i++)
- {
- struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
- int len2 = TYPE_FN_FIELDLIST_LENGTH (type, i);
- int j;
-
- for (j = 0; j < len2; j++)
- if (!TYPE_FN_FIELD_ARTIFICIAL (f, j))
- real_len++;
- }
- if (real_len > 0 && section_type != s_none)
- fprintf_filtered (stream, "\n");
-
- /* C++: print out the methods. */
- for (i = 0; i < len; i++)
- {
- struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
- int j, len2 = TYPE_FN_FIELDLIST_LENGTH (type, i);
- const char *method_name = TYPE_FN_FIELDLIST_NAME (type, i);
- const char *name = type_name_no_tag (type);
- int is_constructor = name && strcmp (method_name,
- name) == 0;
-
- for (j = 0; j < len2; j++)
- {
- const char *mangled_name;
- gdb::unique_xmalloc_ptr<char> mangled_name_holder;
- char *demangled_name;
- const char *physname = TYPE_FN_FIELD_PHYSNAME (f, j);
- int is_full_physname_constructor =
- TYPE_FN_FIELD_CONSTRUCTOR (f, j)
- || is_constructor_name (physname)
- || is_destructor_name (physname)
- || method_name[0] == '~';
-
- /* Do not print out artificial methods. */
- if (TYPE_FN_FIELD_ARTIFICIAL (f, j))
- continue;
-
- QUIT;
- section_type = output_access_specifier
- (stream, section_type, level,
- TYPE_FN_FIELD_PROTECTED (f, j),
- TYPE_FN_FIELD_PRIVATE (f, j));
-
- print_spaces_filtered (level + 4, stream);
- if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
- fprintf_filtered (stream, "virtual ");
- else if (TYPE_FN_FIELD_STATIC_P (f, j))
- fprintf_filtered (stream, "static ");
- if (TYPE_TARGET_TYPE (TYPE_FN_FIELD_TYPE (f, j)) == 0)
- {
- /* Keep GDB from crashing here. */
- fprintf_filtered (stream,
- _("<undefined type> %s;\n"),
- TYPE_FN_FIELD_PHYSNAME (f, j));
- break;
- }
- else if (!is_constructor /* Constructors don't
- have declared
- types. */
- && !is_full_physname_constructor /* " " */
- && !is_type_conversion_operator (type, i, j))
- {
- c_print_type (TYPE_TARGET_TYPE (TYPE_FN_FIELD_TYPE (f, j)),
- "", stream, -1, 0,
- &local_flags);
- fputs_filtered (" ", stream);
- }
- if (TYPE_FN_FIELD_STUB (f, j))
- {
- /* Build something we can demangle. */
- mangled_name_holder.reset (gdb_mangle_name (type, i, j));
- mangled_name = mangled_name_holder.get ();
- }
- else
- mangled_name = TYPE_FN_FIELD_PHYSNAME (f, j);
-
- demangled_name =
- gdb_demangle (mangled_name,
- DMGL_ANSI | DMGL_PARAMS);
- if (demangled_name == NULL)
- {
- /* In some cases (for instance with the HP
- demangling), if a function has more than 10
- arguments, the demangling will fail.
- Let's try to reconstruct the function
- signature from the symbol information. */
- if (!TYPE_FN_FIELD_STUB (f, j))
- {
- int staticp = TYPE_FN_FIELD_STATIC_P (f, j);
- struct type *mtype = TYPE_FN_FIELD_TYPE (f, j);
-
- cp_type_print_method_args (mtype,
- "",
- method_name,
- staticp,
- stream, &local_flags);
- }
- else
- fprintf_filtered (stream,
- _("<badly mangled name '%s'>"),
- mangled_name);
- }
- else
- {
- char *p;
- char *demangled_no_class
- = remove_qualifiers (demangled_name);
-
- /* Get rid of the `static' appended by the
- demangler. */
- p = strstr (demangled_no_class, " static");
- if (p != NULL)
- {
- int length = p - demangled_no_class;
- char *demangled_no_static;
-
- demangled_no_static
- = (char *) xmalloc (length + 1);
- strncpy (demangled_no_static,
- demangled_no_class, length);
- *(demangled_no_static + length) = '\0';
- fputs_filtered (demangled_no_static, stream);
- xfree (demangled_no_static);
- }
- else
- fputs_filtered (demangled_no_class, stream);
- xfree (demangled_name);
- }
-
- fprintf_filtered (stream, ";\n");
- }
- }
-
- /* Print typedefs defined in this class. */
-
- if (TYPE_TYPEDEF_FIELD_COUNT (type) != 0 && flags->print_typedefs)
- {
- if (TYPE_NFIELDS (type) != 0 || TYPE_NFN_FIELDS (type) != 0)
- fprintf_filtered (stream, "\n");
-
- for (i = 0; i < TYPE_TYPEDEF_FIELD_COUNT (type); i++)
- {
- struct type *target = TYPE_TYPEDEF_FIELD_TYPE (type, i);
-
- /* Dereference the typedef declaration itself. */
- gdb_assert (TYPE_CODE (target) == TYPE_CODE_TYPEDEF);
- target = TYPE_TARGET_TYPE (target);
-
- if (need_access_label)
- {
- section_type = output_access_specifier
- (stream, section_type, level,
- TYPE_TYPEDEF_FIELD_PROTECTED (type, i),
- TYPE_TYPEDEF_FIELD_PRIVATE (type, i));
- }
- print_spaces_filtered (level + 4, stream);
- fprintf_filtered (stream, "typedef ");
-
- /* We want to print typedefs with substitutions
- from the template parameters or globally-known
- typedefs but not local typedefs. */
- c_print_type (target,
- TYPE_TYPEDEF_FIELD_NAME (type, i),
- stream, show - 1, level + 4,
- &semi_local_flags);
- fprintf_filtered (stream, ";\n");
- }
- }
-
- fprintfi_filtered (level, stream, "}");
- }
-
- do_cleanups (local_cleanups);
- }
+ c_type_print_base_struct_union (type, stream, show, level, flags);
break;
case TYPE_CODE_ENUM:
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 675f6e7bc8..f7a45dd5dd 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -17095,6 +17095,10 @@ names are substituted when printing other types.
@item T
Print typedefs defined in the class. This is the default, but the flag
exists in case you change the default with @command{set print type typedefs}.
+
+@item o
+Print the offsets and sizes of fields in a struct, similar to what the
+@command{pahole} tool does.
@end table
@kindex ptype
diff --git a/gdb/testsuite/gdb.base/ptype-offsets.cc b/gdb/testsuite/gdb.base/ptype-offsets.cc
new file mode 100644
index 0000000000..f9a57fd3db
--- /dev/null
+++ b/gdb/testsuite/gdb.base/ptype-offsets.cc
@@ -0,0 +1,113 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2017 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/>. */
+
+/* This file will be used to test 'ptype /o' on x86_64 only. */
+
+#include <stdint.h>
+
+/* A struct with many types of fields, in order to test 'ptype
+ /o'. */
+
+struct abc
+{
+ /* Virtual destructor. */
+ virtual ~abc ()
+ {}
+
+ /* 8-byte address. Because of the virtual destructor above, this
+ field's offset will be 8. */
+ void *field1;
+
+ /* No hole here. */
+
+ /* 4-byte int bitfield of 1-bit. */
+ unsigned int field2 : 1;
+
+ /* 31-bit hole here. */
+
+ /* 4-byte int. */
+ int field3;
+
+ /* No hole here. */
+
+ /* 1-byte char. */
+ char field4;
+
+ /* 7-byte hole here. */
+
+ /* 8-byte int. */
+ uint64_t field5;
+
+ /* We just print the offset and size of a union, ignoring its
+ fields. */
+ union
+ {
+ /* 8-byte address. */
+ void *field6;
+
+ /* 4-byte int. */
+ int field7;
+ } field8;
+
+ /* Empty constructor. */
+ abc ()
+ {}
+};
+
+/* This struct will be nested inside 'struct xyz'. */
+
+struct tuv
+{
+ int a1;
+
+ char *a2;
+
+ int a3;
+};
+
+/* This struct will be nested inside 'struct pqr'. */
+
+struct xyz
+{
+ int f1;
+
+ char f2;
+
+ void *f3;
+
+ struct tuv f4;
+};
+
+/* A struct with a nested struct. */
+
+struct pqr
+{
+ int ff1;
+
+ struct xyz ff2;
+
+ char ff3;
+};
+
+int
+main (int argc, char *argv[])
+{
+ struct abc foo;
+ struct pqr bar;
+
+ return 0;
+}
diff --git a/gdb/testsuite/gdb.base/ptype-offsets.exp b/gdb/testsuite/gdb.base/ptype-offsets.exp
new file mode 100644
index 0000000000..4f84416dc5
--- /dev/null
+++ b/gdb/testsuite/gdb.base/ptype-offsets.exp
@@ -0,0 +1,77 @@
+# This testcase is part of GDB, the GNU debugger.
+
+# Copyright 2017 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/>.
+
+standard_testfile .cc ptype-offsets.cc
+
+# Test only works on x86_64 LP64 targets. That's how we guarantee
+# that the expected holes will be present in the struct.
+if { !([istarget "x86_64-*-*"] && [is_lp64_target]) } {
+ untested "test work only on x86_64 lp64"
+ return 0
+}
+
+if { [prepare_for_testing "failed to prepare" $testfile $srcfile \
+ { debug c++ optimize=-O0 }] } {
+ return -1
+}
+
+# Test general offset printing, ctor/dtor printing, union, formatting.
+gdb_test "ptype /o struct abc" \
+ [multi_line \
+"type = struct abc {" \
+"/\\\* offset | size \\\*/" \
+" public:" \
+"/\\\* 8 | 8 \\\*/ void \\\*field1;" \
+"/\\\* 16:31 | 4 \\\*/ unsigned int field2 : 1;" \
+"/\\\* XXX 7-bit hole \\\*/" \
+"/\\\* XXX 3-byte hole \\\*/" \
+"/\\\* 20 | 4 \\\*/ int field3;" \
+"/\\\* 24 | 1 \\\*/ char field4;" \
+"/\\\* XXX 7-byte hole \\\*/" \
+"/\\\* 32 | 8 \\\*/ uint64_t field5;" \
+"/\\\* 40 | 8 \\\*/ union {" \
+"/\\\* 8 \\\*/ void \\\*field6;" \
+"/\\\* 4 \\\*/ int field7;" \
+" } /\\\* total size: 8 bytes \\\*/ field8;" \
+"" \
+" abc\\(void\\);" \
+" ~abc\\(\\);" \
+"} /\\\* total size: 48 bytes \\\*/"] \
+ "ptype offset struct abc"
+
+# Test nested structs.
+gdb_test "ptype /o struct pqr" \
+ [multi_line \
+"type = struct pqr {" \
+"/\\\* offset | size \\\*/" \
+"/\\\* 0 | 4 \\\*/ int f1;" \
+"/\\\* XXX 4-byte hole \\\*/" \
+"/\\\* 8 | 16 \\\*/ struct xyz {" \
+"/\\\* 8 | 4 \\\*/ int f1;" \
+"/\\\* 12 | 1 \\\*/ char f2;" \
+"/\\\* XXX 3-byte hole \\\*/" \
+"/\\\* 16 | 8 \\\*/ void \\\*f3;" \
+"/\\\* 24 | 24 \\\*/ struct tuv {" \
+"/\\\* 24 | 4 \\\*/ int a1;" \
+"/\\\* XXX 4-byte hole \\\*/" \
+"/\\\* 32 | 8 \\\*/ char *a2;" \
+"/\\\* 40 | 4 \\\*/ int a3;" \
+" } /\\\* total size: 24 bytes \\\*/ f4;" \
+" } /\\\* total size: 40 bytes \\\*/ ff2;" \
+"/\\\* 48 | 1 \\\*/ char ff3;" \
+"} /\\\* total size: 56 bytes \\\*/"] \
+ "ptype offset struct pqr"
diff --git a/gdb/typeprint.c b/gdb/typeprint.c
index 427af17ad7..1463e802ad 100644
--- a/gdb/typeprint.c
+++ b/gdb/typeprint.c
@@ -42,6 +42,8 @@ const struct type_print_options type_print_raw_options =
1, /* raw */
1, /* print_methods */
1, /* print_typedefs */
+ 0, /* print_offsets */
+ 0, /* offset_bitpos */
NULL, /* local_typedefs */
NULL, /* global_table */
NULL /* global_printers */
@@ -54,6 +56,8 @@ static struct type_print_options default_ptype_flags =
0, /* raw */
1, /* print_methods */
1, /* print_typedefs */
+ 0, /* print_offsets */
+ 0, /* offset_bitpos */
NULL, /* local_typedefs */
NULL, /* global_table */
NULL /* global_printers */
@@ -438,6 +442,9 @@ whatis_exp (const char *exp, int show)
case 'T':
flags.print_typedefs = 1;
break;
+ case 'o':
+ flags.print_offsets = 1;
+ break;
default:
error (_("unrecognized flag '%c'"), *exp);
}
@@ -497,6 +504,11 @@ whatis_exp (const char *exp, int show)
real_type = value_rtti_type (val, &full, &top, &using_enc);
}
+ if (flags.print_offsets &&
+ (TYPE_CODE (type) == TYPE_CODE_STRUCT
+ || TYPE_CODE (type) == TYPE_CODE_UNION))
+ fprintf_filtered (gdb_stdout, "/* offset | size */\n");
+
printf_filtered ("type = ");
if (!flags.raw)
@@ -722,7 +734,8 @@ Available FLAGS are:\n\
/m do not print methods defined in a class\n\
/M print methods defined in a class\n\
/t do not print typedefs defined in a class\n\
- /T print typedefs defined in a class"));
+ /T print typedefs defined in a class\n\
+ /o print offsets and sizes of fields in a struct (like pahole)\n"));
set_cmd_completer (c, expression_completer);
c = add_com ("whatis", class_vars, whatis_command,
diff --git a/gdb/typeprint.h b/gdb/typeprint.h
index a458aa4e2f..a2a5285012 100644
--- a/gdb/typeprint.h
+++ b/gdb/typeprint.h
@@ -35,6 +35,15 @@ struct type_print_options
/* True means print typedefs in a class. */
unsigned int print_typedefs : 1;
+ /* True means to print offsets, a la 'pahole'. */
+ unsigned int print_offsets : 1;
+
+ /* The offset to be applied to bitpos when PRINT_OFFSETS is true.
+ This is needed for when we are printing nested structs and want
+ to make sure that the printed offset for each field carries off
+ the offset of the outter struct. */
+ unsigned int offset_bitpos;
+
/* If not NULL, a local typedef hash table used when printing a
type. */
struct typedef_hash_table *local_typedefs;
--
2.13.3