/* Symbol table definitions for GDB.
Copyright 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
- 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003 Free Software
+ 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software
Foundation, Inc.
This file is part of GDB.
struct axs_value;
struct agent_expr;
-/* Don't do this; it means that if some .o's are compiled with GNU C
- and some are not (easy to do accidentally the way we configure
- things; also it is a pain to have to "make clean" every time you
- want to switch compilers), then GDB dies a horrible death. */
-/* GNU C supports enums that are bitfields. Some compilers don't. */
-#if 0 && defined(__GNUC__) && !defined(BYTE_BITFIELD)
-#define BYTE_BITFIELD :8;
-#else
-#define BYTE_BITFIELD /*nothing */
-#endif
+/* Some of the structures in this file are space critical.
+ The space-critical structures are:
+
+ struct general_symbol_info
+ struct symbol
+ struct partial_symbol
+
+ These structures are layed out to encourage good packing.
+ They use ENUM_BITFIELD and short int fields, and they order the
+ structure members so that fields less than a word are next
+ to each other so they can be packed together. */
+
+/* Rearranged: used ENUM_BITFIELD and rearranged field order in
+ all the space critical structures (plus struct minimal_symbol).
+ Memory usage dropped from 99360768 bytes to 90001408 bytes.
+ I measured this with before-and-after tests of
+ "HEAD-old-gdb -readnow HEAD-old-gdb" and
+ "HEAD-new-gdb -readnow HEAD-old-gdb" on native i686-pc-linux-gnu,
+ red hat linux 8, with LD_LIBRARY_PATH=/usr/lib/debug,
+ typing "maint space 1" at the first command prompt.
+
+ Here is another measurement (from andrew c):
+ # no /usr/lib/debug, just plain glibc, like a normal user
+ gdb HEAD-old-gdb
+ (gdb) break internal_error
+ (gdb) run
+ (gdb) maint internal-error
+ (gdb) backtrace
+ (gdb) maint space 1
+
+ gdb gdb_6_0_branch 2003-08-19 space used: 8896512
+ gdb HEAD 2003-08-19 space used: 8904704
+ gdb HEAD 2003-08-21 space used: 8396800 (+symtab.h)
+ gdb HEAD 2003-08-21 space used: 8265728 (+gdbtypes.h)
+
+ The third line shows the savings from the optimizations in symtab.h.
+ The fourth line shows the savings from the optimizations in
+ gdbtypes.h. Both optimizations are in gdb HEAD now.
+
+ --chastain 2003-08-21 */
+
+
/* Define a structure for the information that is common to all symbol types,
including minimal symbols, partial symbols, and full symbols. In a
multilanguage environment, some language specific information may need to
- be recorded along with each symbol.
+ be recorded along with each symbol. */
- These fields are ordered to encourage good packing, since we frequently
- have tens or hundreds of thousands of these. */
+/* This structure is space critical. See space comments at the top. */
struct general_symbol_info
{
/* Name of the symbol. This is a required field. Storage for the
- name is allocated on the psymbol_obstack or symbol_obstack for
- the associated objfile. For languages like C++ that make a
- distinction between the mangled name and demangled name, this is
- the mangled name. */
+ name is allocated on the objfile_obstack for the associated
+ objfile. For languages like C++ that make a distinction between
+ the mangled name and demangled name, this is the mangled
+ name. */
char *name;
This is used to select one of the fields from the language specific
union above. */
- enum language language BYTE_BITFIELD;
+ ENUM_BITFIELD(language) language : 8;
/* Which section is this symbol in? This is an index into
section_offsets for this objfile. Negative means that the symbol
#define SYMBOL_MATCHES_NATURAL_NAME(symbol, name) \
(strcmp_iw (SYMBOL_NATURAL_NAME (symbol), (name)) == 0)
+/* Classification types for a minimal symbol. These should be taken as
+ "advisory only", since if gdb can't easily figure out a
+ classification it simply selects mst_unknown. It may also have to
+ guess when it can't figure out which is a better match between two
+ types (mst_data versus mst_bss) for example. Since the minimal
+ symbol info is sometimes derived from the BFD library's view of a
+ file, we need to live with what information bfd supplies. */
+
+enum minimal_symbol_type
+{
+ mst_unknown = 0, /* Unknown type, the default */
+ mst_text, /* Generally executable instructions */
+ mst_data, /* Generally initialized data */
+ mst_bss, /* Generally uninitialized data */
+ mst_abs, /* Generally absolute (nonrelocatable) */
+ /* GDB uses mst_solib_trampoline for the start address of a shared
+ library trampoline entry. Breakpoints for shared library functions
+ are put there if the shared library is not yet loaded.
+ After the shared library is loaded, lookup_minimal_symbol will
+ prefer the minimal symbol from the shared library (usually
+ a mst_text symbol) over the mst_solib_trampoline symbol, and the
+ breakpoints will be moved to their true address in the shared
+ library via breakpoint_re_set. */
+ mst_solib_trampoline, /* Shared library trampoline code */
+ /* For the mst_file* types, the names are only guaranteed to be unique
+ within a given .o file. */
+ mst_file_text, /* Static version of mst_text */
+ mst_file_data, /* Static version of mst_data */
+ mst_file_bss /* Static version of mst_bss */
+};
+
/* Define a simple structure used to hold some very basic information about
all defined global symbols (text, data, bss, abs, etc). The only required
information is the general_symbol_info.
struct general_symbol_info ginfo;
- /* The info field is available for caching machine-specific information
- so it doesn't have to rederive the info constantly (over a serial line).
- It is initialized to zero and stays that way until target-dependent code
- sets it. Storage for any data pointed to by this field should be allo-
- cated on the symbol_obstack for the associated objfile.
- The type would be "void *" except for reasons of compatibility with older
+ /* The info field is available for caching machine-specific
+ information so it doesn't have to rederive the info constantly
+ (over a serial line). It is initialized to zero and stays that
+ way until target-dependent code sets it. Storage for any data
+ pointed to by this field should be allocated on the
+ objfile_obstack for the associated objfile. The type would be
+ "void *" except for reasons of compatibility with older
compilers. This field is optional.
Currently, the AMD 29000 tdep.c uses it to remember things it has decoded
char *info;
+ /* Size of this symbol. end_psymtab in dbxread.c uses this
+ information to calculate the end of the partial symtab based on the
+ address of the last symbol plus the size of the last symbol. */
+
+ unsigned long size;
+
#ifdef SOFUN_ADDRESS_MAYBE_MISSING
/* Which source file is this symbol in? Only relevant for mst_file_*. */
char *filename;
#endif
- /* Classification types for this symbol. These should be taken as "advisory
- only", since if gdb can't easily figure out a classification it simply
- selects mst_unknown. It may also have to guess when it can't figure out
- which is a better match between two types (mst_data versus mst_bss) for
- example. Since the minimal symbol info is sometimes derived from the
- BFD library's view of a file, we need to live with what information bfd
- supplies. */
+ /* Classification type for this minimal symbol. */
- enum minimal_symbol_type
- {
- mst_unknown = 0, /* Unknown type, the default */
- mst_text, /* Generally executable instructions */
- mst_data, /* Generally initialized data */
- mst_bss, /* Generally uninitialized data */
- mst_abs, /* Generally absolute (nonrelocatable) */
- /* GDB uses mst_solib_trampoline for the start address of a shared
- library trampoline entry. Breakpoints for shared library functions
- are put there if the shared library is not yet loaded.
- After the shared library is loaded, lookup_minimal_symbol will
- prefer the minimal symbol from the shared library (usually
- a mst_text symbol) over the mst_solib_trampoline symbol, and the
- breakpoints will be moved to their true address in the shared
- library via breakpoint_re_set. */
- mst_solib_trampoline, /* Shared library trampoline code */
- /* For the mst_file* types, the names are only guaranteed to be unique
- within a given .o file. */
- mst_file_text, /* Static version of mst_text */
- mst_file_data, /* Static version of mst_data */
- mst_file_bss /* Static version of mst_bss */
- }
- type BYTE_BITFIELD;
+ ENUM_BITFIELD(minimal_symbol_type) type : 8;
/* Minimal symbols with the same hash key are kept on a linked
list. This is the link. */
};
#define MSYMBOL_INFO(msymbol) (msymbol)->info
+#define MSYMBOL_SIZE(msymbol) (msymbol)->size
#define MSYMBOL_TYPE(msymbol) (msymbol)->type
\f
/* Different name domains for symbols. Looking up a symbol specifies a
domain and ignores symbol definitions in other name domains. */
-typedef enum
+typedef enum domain_enum_tag
{
/* UNDEF_DOMAIN is used when a domain has not been discovered or
none of the following apply. This usually indicates an error either
LOC_HP_THREAD_LOCAL_STATIC,
- /* Value is at a thread-specific location calculated by a
- target-specific method. SYMBOL_OBJFILE gives the object file
- in which the symbol is defined; the symbol's value is the
- offset into that objfile's thread-local storage for the current
- thread. */
-
- LOC_THREAD_LOCAL_STATIC,
-
/* The variable does not actually exist in the program.
The value is ignored. */
LOC_COMPUTED_ARG
};
-/* A structure of function pointers describing the location of a
- variable, structure member, or structure base class.
-
- These functions' BATON arguments are generic data pointers, holding
- whatever data the functions need --- the code which provides this
- structure also provides the actual contents of the baton, and
- decides its form. However, there may be other rules about where
- the baton data must be allocated; whoever is pointing to this
- `struct location_funcs' object will know the rules. For example,
- when a symbol S's location is LOC_COMPUTED, then
- SYMBOL_LOCATION_FUNCS(S) is pointing to a location_funcs structure,
- and SYMBOL_LOCATION_BATON(S) is the baton, which must be allocated
- on the same obstack as the symbol itself. */
-
-struct location_funcs
+/* The methods needed to implement a symbol class. These methods can
+ use the symbol's .aux_value for additional per-symbol information.
+
+ At present this is only used to implement location expressions. */
+
+struct symbol_ops
{
/* Return the value of the variable SYMBOL, relative to the stack
struct axs_value * value);
};
-/* Linked list of symbol's live ranges. */
-
-struct range_list
-{
- CORE_ADDR start;
- CORE_ADDR end;
- struct range_list *next;
-};
-
-/* Linked list of aliases for a particular main/primary symbol. */
-struct alias_list
-{
- struct symbol *sym;
- struct alias_list *next;
-};
+/* This structure is space critical. See space comments at the top. */
struct symbol
{
/* Domain code. */
- domain_enum domain BYTE_BITFIELD;
+ ENUM_BITFIELD(domain_enum_tag) domain : 6;
/* Address class */
+ /* NOTE: cagney/2003-11-02: The fields "aclass" and "ops" contain
+ overlapping information. By creating a per-aclass ops vector, or
+ using the aclass as an index into an ops table, the aclass and
+ ops fields can be merged. The latter, for instance, would shave
+ 32-bits from each symbol (relative to a symbol lookup, any table
+ index overhead would be in the noise). */
- enum address_class aclass BYTE_BITFIELD;
+ ENUM_BITFIELD(address_class) aclass : 6;
/* Line number of definition. FIXME: Should we really make the assumption
that nobody will try to debug files longer than 64K lines? What about
unsigned short line;
- /* Some symbols require an additional value to be recorded on a per-
- symbol basis. Stash those values here. */
+ /* Method's for symbol's of this class. */
+ /* NOTE: cagney/2003-11-02: See comment above attached to "aclass". */
+
+ const struct symbol_ops *ops;
+
+ /* Some symbols require additional information to be recorded on a
+ per- symbol basis. Stash those values here. */
union
{
/* Used by LOC_BASEREG and LOC_BASEREG_ARG. */
short basereg;
-
- /* Used by LOC_THREAD_LOCAL_STATIC. The objfile in which this
- symbol is defined. To find a thread-local variable (e.g., a
- variable declared with the `__thread' storage class), we may
- need to know which object file it's in. */
- struct objfile *objfile;
-
- /* For a LOC_COMPUTED or LOC_COMPUTED_ARG symbol, this is the
- baton and location_funcs structure to find its location. For a
- LOC_BLOCK symbol for a function in a compilation unit compiled
- with DWARF 2 information, this is information used internally
- by the DWARF 2 code --- specifically, the location expression
- for the frame base for this function. */
+ /* An arbitrary data pointer. Note that this data must be
+ allocated using the same obstack as the symbol itself. */
+ /* So far it is only used by LOC_COMPUTED and LOC_COMPUTED_ARG to
+ find the location location information. For a LOC_BLOCK symbol
+ for a function in a compilation unit compiled with DWARF 2
+ information, this is information used internally by the DWARF 2
+ code --- specifically, the location expression for the frame
+ base for this function. */
/* FIXME drow/2003-02-21: For the LOC_BLOCK case, it might be better
to add a magic symbol to the block containing this information,
or to have a generic debug info annotation slot for symbols. */
- struct
- {
- void *baton;
- struct location_funcs *funcs;
- } loc;
+ void *ptr;
}
aux_value;
-
- /* Link to a list of aliases for this symbol.
- Only a "primary/main symbol may have aliases. */
- struct alias_list *aliases;
-
- /* List of ranges where this symbol is active. This is only
- used by alias symbols at the current time. */
- struct range_list *ranges;
-
struct symbol *hash_next;
};
#define SYMBOL_LINE(symbol) (symbol)->line
#define SYMBOL_BASEREG(symbol) (symbol)->aux_value.basereg
#define SYMBOL_OBJFILE(symbol) (symbol)->aux_value.objfile
-#define SYMBOL_ALIASES(symbol) (symbol)->aliases
-#define SYMBOL_RANGES(symbol) (symbol)->ranges
-#define SYMBOL_LOCATION_BATON(symbol) (symbol)->aux_value.loc.baton
-#define SYMBOL_LOCATION_FUNCS(symbol) (symbol)->aux_value.loc.funcs
+#define SYMBOL_OPS(symbol) (symbol)->ops
+#define SYMBOL_LOCATION_BATON(symbol) (symbol)->aux_value.ptr
\f
/* A partial_symbol records the name, domain, and address class of
symbols whose types we have not parsed yet. For functions, it also
on a partial symtab list and which points to the corresponding
normal symtab once the partial_symtab has been referenced. */
+/* This structure is space critical. See space comments at the top. */
+
struct partial_symbol
{
/* Name space code. */
- domain_enum domain BYTE_BITFIELD;
+ ENUM_BITFIELD(domain_enum_tag) domain : 6;
/* Address class (for info_symbols) */
- enum address_class aclass BYTE_BITFIELD;
+ ENUM_BITFIELD(address_class) aclass : 6;
};
Even after the source file has been read into a symtab, the
partial_symtab remains around. They are allocated on an obstack,
- psymbol_obstack. FIXME, this is bad for dynamic linking or VxWorks-
+ objfile_obstack. FIXME, this is bad for dynamic linking or VxWorks-
style execution of a bunch of .o's. */
struct partial_symtab
extern void reread_symbols (void);
extern struct type *lookup_transparent_type (const char *);
+extern struct type *basic_lookup_transparent_type (const char *);
/* Macro for name of symbol to indicate a file compiled with gcc. */
struct objfile *);
extern struct minimal_symbol *lookup_minimal_symbol_text (const char *,
- const char *,
struct objfile *);
struct minimal_symbol *lookup_minimal_symbol_solib_trampoline (const char *,
- const char *,
struct objfile
*);
extern int in_prologue (CORE_ADDR pc, CORE_ADDR func_start);
+extern CORE_ADDR skip_prologue_using_sal (CORE_ADDR func_addr);
+
extern struct symbol *fixup_symbol_section (struct symbol *,
struct objfile *);