GDB Symbol
Version
- Source code: https://sourceware.org/git/binutils-gdb.git
- GDB v13.0
Data Structures
File: gdb/symtab.h
struct symbol : public general_symbol_info, public allocate_on_obstack
{
symbol ()
/* Class-initialization of bitfields is only allowed in C++20. */
: m_domain (UNDEF_DOMAIN),
m_aclass_index (0),
m_is_objfile_owned (1),
m_is_argument (0),
m_is_inlined (0),
maybe_copied (0),
subclass (SYMBOL_NONE),
m_artificial (false)
{
/* We can't use an initializer list for members of a base class, and
general_symbol_info needs to stay a POD type. */
m_name = nullptr;
m_value.ivalue = 0;
language_specific.obstack = nullptr;
m_language = language_unknown;
ada_mangled = 0;
m_section = -1;
/* GCC 4.8.5 (on CentOS 7) does not correctly compile class-
initialization of unions, so we initialize it manually here. */
owner.symtab = nullptr;
}
...
/* Return the symtab of this symbol. It is an error to call this if
is_objfile_owned is false, which only happens for
architecture-provided types. */
struct symtab *symtab () const;
/* Set the symtab of this symbol to SYMTAB. It is an error to call
this if is_objfile_owned is false, which only happens for
architecture-provided types. */
void set_symtab (struct symtab *symtab);
...
union
{
/* The symbol table containing this symbol. This is the file associated
with LINE. It can be NULL during symbols read-in but it is never NULL
during normal operation. */
struct symtab *symtab;
/* For types defined by the architecture. */
struct gdbarch *arch;
} owner;
/* Domain code. */
ENUM_BITFIELD(domain_enum) m_domain : SYMBOL_DOMAIN_BITS;
/* Address class. This holds an index into the 'symbol_impls'
table. The actual enum address_class value is stored there,
alongside any per-class ops vectors. */
unsigned int m_aclass_index : SYMBOL_ACLASS_BITS;
/* If non-zero then symbol is objfile-owned, use owner.symtab.
Otherwise symbol is arch-owned, use owner.arch. */
unsigned int m_is_objfile_owned : 1;
...
};
/* Each source file or header is represented by a struct symtab.
The name "symtab" is historical, another name for it is "filetab".
These objects are chained through the `next' field. */
struct symtab
{
struct compunit_symtab *compunit () const
{
return m_compunit;
}
void set_compunit (struct compunit_symtab *compunit)
{
m_compunit = compunit;
}
struct linetable *linetable () const
{
return m_linetable;
}
void set_linetable (struct linetable *linetable)
{
m_linetable = linetable;
}
enum language language () const
{
return m_language;
}
void set_language (enum language language)
{
m_language = language;
}
/* Unordered chain of all filetabs in the compunit, with the exception
that the "main" source file is the first entry in the list. */
struct symtab *next;
/* Backlink to containing compunit symtab. */
struct compunit_symtab *m_compunit;
/* Table mapping core addresses to line numbers for this file.
Can be NULL if none. Never shared between different symtabs. */
struct linetable *m_linetable;
/* Name of this source file. This pointer is never NULL. */
const char *filename;
/* Language of this source file. */
enum language m_language;
/* Full name of file as found by searching the source path.
NULL if not yet known. */
char *fullname;
};
File: gdb/symtab.c
/* Check for a symtab of a specific name by searching some symtabs.
This is a helper function for callbacks of iterate_over_symtabs.
If NAME is not absolute, then REAL_PATH is NULL
If NAME is absolute, then REAL_PATH is the gdb_realpath form of NAME.
The return value, NAME, REAL_PATH and CALLBACK are identical to the
`map_symtabs_matching_filename' method of quick_symbol_functions.
FIRST and AFTER_LAST indicate the range of compunit symtabs to search.
Each symtab within the specified compunit symtab is also searched.
AFTER_LAST is one past the last compunit symtab to search; NULL means to
search until the end of the list. */
bool
iterate_over_some_symtabs (const char *name,
const char *real_path,
struct compunit_symtab *first,
struct compunit_symtab *after_last,
gdb::function_view<bool (symtab *)> callback)
{
struct compunit_symtab *cust;
const char* base_name = lbasename (name);
for (cust = first; cust != NULL && cust != after_last; cust = cust->next)
{
for (symtab *s : cust->filetabs ())
{
if (compare_filenames_for_search (s->filename, name))
{
if (callback (s))
return true;
continue;
}
/* Before we invoke realpath, which can get expensive when many
files are involved, do a quick comparison of the basenames. */
if (! basenames_may_differ
&& FILENAME_CMP (base_name, lbasename (s->filename)) != 0)
continue;
if (compare_filenames_for_search (symtab_to_fullname (s), name))
{
if (callback (s))
return true;
continue;
}
/* If the user gave us an absolute path, try to find the file in
this symtab and use its absolute path. */
if (real_path != NULL)
{
const char *fullname = symtab_to_fullname (s);
gdb_assert (IS_ABSOLUTE_PATH (real_path));
gdb_assert (IS_ABSOLUTE_PATH (name));
gdb::unique_xmalloc_ptr<char> fullname_real_path
= gdb_realpath (fullname);
fullname = fullname_real_path.get ();
if (FILENAME_CMP (real_path, fullname) == 0)
{
if (callback (s))
return true;
continue;
}
}
}
}
return false;
}
/* Check for a symtab of a specific name; first in symtabs, then in
psymtabs. *If* there is no '/' in the name, a match after a '/'
in the symtab filename will also work.
Calls CALLBACK with each symtab that is found. If CALLBACK returns
true, the search stops. */
void
iterate_over_symtabs (const char *name,
gdb::function_view<bool (symtab *)> callback)
{
gdb::unique_xmalloc_ptr<char> real_path;
/* Here we are interested in canonicalizing an absolute path, not
absolutizing a relative path. */
if (IS_ABSOLUTE_PATH (name))
{
real_path = gdb_realpath (name);
gdb_assert (IS_ABSOLUTE_PATH (real_path.get ()));
}
for (objfile *objfile : current_program_space->objfiles ())
{
if (iterate_over_some_symtabs (name, real_path.get (),
objfile->compunit_symtabs, NULL,
callback))
return;
}
/* Same search rules as above apply here, but now we look thru the
psymtabs. */
for (objfile *objfile : current_program_space->objfiles ())
{
if (objfile->map_symtabs_matching_filename (name, real_path.get (),
callback))
return;
}
}
/* A wrapper for iterate_over_symtabs that returns the first matching
symtab, or NULL. */
struct symtab *
lookup_symtab (const char *name)
{
struct symtab *result = NULL;
iterate_over_symtabs (name, [&] (symtab *symtab)
{
result = symtab;
return true;
});
return result;
}