diff options
Diffstat (limited to 'gdb/value.c')
| -rw-r--r-- | gdb/value.c | 113 |
1 files changed, 109 insertions, 4 deletions
diff --git a/gdb/value.c b/gdb/value.c index 4d4329e..9c08a41 100644 --- a/gdb/value.c +++ b/gdb/value.c @@ -37,6 +37,7 @@ #include "dfp.h" #include "objfiles.h" #include "valprint.h" +#include "cli/cli-decode.h" #include "python/python.h" @@ -44,6 +45,23 @@ void _initialize_values (void); +/* Definition of a user function. */ +struct internal_function +{ + /* The name of the function. It is a bit odd to have this in the + function itself -- the user might use a differently-named + convenience variable to hold the function. */ + char *name; + + /* The handler. */ + internal_function_fn handler; + + /* User data for the handler. */ + void *cookie; +}; + +static struct cmd_list_element *functionlist; + struct value { /* Type of value; either not an lval, or one of the various @@ -203,6 +221,10 @@ struct value_history_chunk static struct value_history_chunk *value_history_chain; static int value_history_count; /* Abs number of last entry stored */ + +/* The type of internal functions. */ + +static struct type *internal_fn_type; /* List of all value objects currently allocated (except for those released by calls to release_value) @@ -878,7 +900,7 @@ init_if_undefined_command (char* args, int from_tty) the return value is NULL. */ struct internalvar * -lookup_only_internalvar (char *name) +lookup_only_internalvar (const char *name) { struct internalvar *var; @@ -894,7 +916,7 @@ lookup_only_internalvar (char *name) NAME should not normally include a dollar sign. */ struct internalvar * -create_internalvar (char *name) +create_internalvar (const char *name) { struct internalvar *var; var = (struct internalvar *) xmalloc (sizeof (struct internalvar)); @@ -902,6 +924,7 @@ create_internalvar (char *name) var->value = allocate_value (builtin_type_void); var->endian = gdbarch_byte_order (current_gdbarch); var->make_value = NULL; + var->canonical = 0; release_value (var->value); var->next = internalvars; internalvars = var; @@ -934,7 +957,7 @@ create_internalvar_type_lazy (char *name, internalvar_make_value fun) one is created, with a void value. */ struct internalvar * -lookup_internalvar (char *name) +lookup_internalvar (const char *name) { struct internalvar *var; @@ -1031,6 +1054,9 @@ set_internalvar (struct internalvar *var, struct value *val) { struct value *newval; + if (var->canonical) + error (_("Cannot overwrite convenience function %s"), var->name); + newval = value_copy (val); newval->modifiable = 1; @@ -1042,7 +1068,7 @@ set_internalvar (struct internalvar *var, struct value *val) /* Begin code which must not call error(). If var->value points to something free'd, an error() obviously leaves a dangling pointer. - But we also get a danling pointer if var->value points to + But we also get a dangling pointer if var->value points to something in the value chain (i.e., before release_value is called), because after the error free_all_values will get called before long. */ @@ -1059,6 +1085,76 @@ internalvar_name (struct internalvar *var) return var->name; } +static struct value * +value_create_internal_function (const char *name, + internal_function_fn handler, + void *cookie) +{ + struct value *result = allocate_value (internal_fn_type); + gdb_byte *addr = value_contents_writeable (result); + struct internal_function **fnp = (struct internal_function **) addr; + struct internal_function *ifn = XNEW (struct internal_function); + ifn->name = xstrdup (name); + ifn->handler = handler; + ifn->cookie = cookie; + *fnp = ifn; + return result; +} + +char * +value_internal_function_name (struct value *val) +{ + gdb_byte *addr = value_contents_writeable (val); + struct internal_function *ifn = * (struct internal_function **) addr; + return ifn->name; +} + +struct value * +call_internal_function (struct value *func, int argc, struct value **argv) +{ + gdb_byte *addr = value_contents_writeable (func); + struct internal_function *ifn = * (struct internal_function **) addr; + return (*ifn->handler) (ifn->cookie, argc, argv); +} + +/* The 'function' command. This does nothing -- it is just a + placeholder to let "help function NAME" work. This is also used as + the implementation of the sub-command that is created when + registering an internal function. */ +static void +function_command (char *command, int from_tty) +{ + /* Do nothing. */ +} + +/* Clean up if an internal function's command is destroyed. */ +static void +function_destroyer (struct cmd_list_element *self, void *ignore) +{ + xfree (self->name); + xfree (self->doc); +} + +/* Add a new internal function. NAME is the name of the function; DOC + is a documentation string describing the function. HANDLER is + called when the function is invoked. COOKIE is an arbitrary + pointer which is passed to HANDLER and is intended for "user + data". */ +void +add_internal_function (const char *name, const char *doc, + internal_function_fn handler, void *cookie) +{ + struct cmd_list_element *cmd; + struct internalvar *var = lookup_internalvar (name); + struct value *fnval = value_create_internal_function (name, handler, cookie); + set_internalvar (var, fnval); + var->canonical = 1; + + cmd = add_cmd (xstrdup (name), no_class, function_command, (char *) doc, + &functionlist); + cmd->destroyer = function_destroyer; +} + /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to prevent cycles / duplicates. */ @@ -1944,4 +2040,13 @@ init-if-undefined VARIABLE = EXPRESSION\n\ Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\ exist or does not contain a value. The EXPRESSION is not evaluated if the\n\ VARIABLE is already initialized.")); + + add_prefix_cmd ("function", no_class, function_command, _("\ +Placeholder command for showing help on convenience functions."), + &functionlist, "function ", 0, &cmdlist); + + internal_fn_type = alloc_type (NULL); + TYPE_CODE (internal_fn_type) = TYPE_CODE_INTERNAL_FUNCTION; + TYPE_LENGTH (internal_fn_type) = sizeof (struct internal_function *); + TYPE_NAME (internal_fn_type) = "<internal function>"; } |