st_sym_value(3) Library Functions Manual st_sym_value(3)
NAME
st_sym_value, st_sym_type, st_sym_class, st_sym_to_file, st_sym_name, st_sym_name_copy, st_free_name, st_sym_to_outer_scope_sym,
st_end_sym, st_proc_end_sym, st_external_name_sym, st_frame_offset_to_sym, st_sym_size, st_is_sym_weak, st_is_sym_local, st_is_sym_global,
st_get_mangled_name_flag, st_set_mangled_name_flag - Access information about the symbols in an object, and access or set symbol name
demangling controls.
LIBRARY
Symbol Table and Object File Access Library (libst.a)
SYNOPSIS
#include <st.h>
st_status_t st_sym_value (
st_obj_t *obj,
st_sym_t sym,
unsigned long *value);
st_status_t st_sym_type (
st_obj_t *obj,
st_sym_t sym,
unsigned int *sym_type);
st_status_t st_sym_class (
st_obj_t *obj,
st_sym_t sym,
unsigned int *sym_class);
st_status_t st_sym_to_file (
st_obj_t *obj,
st_sym_t sym,
st_file_t *file);
st_status_t st_sym_name (
st_obj_t *obj,
st_sym_t sym,
char **name);
st_status_t st_sym_name_copy (
st_obj_t *obj,
st_sym_t sym,
char *name_buf,
int buflen,
int *truncated);
void st_free_name (
st_obj_t *obj,
char *name);
st_status_t st_sym_to_outer_scope_sym (
st_obj_t *obj,
st_sym_t sym,
st_sym_t *osym);
st_status_t st_end_sym (
st_obj_t *obj,
st_sym_t sym,
st_sym_t *esym);
st_status_t st_proc_end_sym (
st_obj_t *obj,
st_sym_t sym,
st_sym_t *esym);
st_status_t st_external_name_sym (
st_obj_t *obj,
const char *name,
st_sym_t *osym);
st_status_t st_frame_offset_to_sym (
st_obj_t *obj,
st_proc_t proc,
int frame_offset,
st_sym_t *osym,
int *byte_offset);
st_status_t st_sym_size (
st_obj_t *obj,
st_sym_t sym,
unsigned long *size);
st_status_t st_is_sym_weak (
st_obj_t *obj,
st_sym_t symbol,
st_bool_t *weak);
st_status_t st_is_sym_local (
st_obj_t *obj,
st_sym_t symbol,
st_bool_t *local);
st_status_t st_is_sym_global (
st_obj_t *obj,
st_sym_t symbol,
st_bool_t *global);
st_status_t st_set_mangled_name_flag (
st_obj_t *obj,
unsigned int flag);
st_status_t st_get_mangled_name_flag (
st_obj_t *obj,
unsigned int *flag);
PARAMETERS
Specifies an object handle, as returned by the st_obj_open function. Specifies a symbol handle. Specifies an address to which
st_sym_value returns the value of the specified symbol. The value of a symbol depends on its type and class. For procedures, data sym-
bols, or bss symbols, the value is the address. For members of structures or unions, the value is the offset to the field from the start
of the structure. For local symbols or arguments, the value is its relative offset from the procedure's frame pointer. Specifies an
address to which st_sym_type returns the type of the specified symbol. Symbol types are defined in /usr/include/symconst.h. Each symbol
type definition begins with the prefix st, for example, stProc. Specifies an address to which st_sym_class returns the class of the speci-
fied symbol. Symbol classes are defined in /usr/include/symconst.h. Each symbol class definition begins with the prefix sc, for example,
scText. Specifies an address to which st_sym_to_file returns the handle of the file that contains the given symbol. Specifies an address
to which st_sym_name returns a pointer to a null-terminated string containing the name of the given symbol. Specifies the address of a
buffer to which st_sym_name_copy returns a copy of the specified symbol's name. Specifies the length of the buffer (name_buf) to which
st_sym_name_copy returns a copy of the specified symbol's name. You should add one for the name string's null terminator to this count.
Specifies an address to which st_sym_name_copy returns the number of characters by which the symbol name returned to name_buf exceeds the
number specified in buflen. If the name exceeds buflen characters, st_sym_name_copy truncates it. Specifies an address for a symbol han-
dle. st_sym_to_outer_scope_sym returns the symbol handle of the block or procedure that contains the specified symbol. st_exter-
nal_name_sym returns the symbol handle of the named external symbol. st_frame_offset_to_sym returns the symbol handle corresponding to the
specified frame offset in the given procedure. Specifies an address to which st_end_sym or st_proc_end_sym returns the ending symbol han-
dle of the block or procedure, respectively, that contains the specified symbol. Specifies a positive number that is a relative offset
from the virtual frame pointer for a procedure (often the stack pointer) that st_frame_offset_to_sym uses to obtain a symbol handle. Spec-
ifies an address to which st_frame_offset_to_sym returns the offset into the variable to which frame_offset corresponds. Specifies an
address to which st_sym_size returns the size in bytes of the given symbol. Specify Boolean variables for return values. Specifies an
address to which st_get_mangled_name_flag returns the current state of the specified object's name-demangling flags, or an address contain-
ing the flag values that st_set_mangled_name_flag is to write to the specified object's name-demangling flags. Valid name-demangling flags
are defined in /usr/include/cmplrs/demangle_string.h.
DESCRIPTION
These functions return information about the symbols in an object. Symbols may represent files, procedures, or local or global symbols.
Return the value, type, and class of a given symbol. Returns the handle of the file that contains the given symbol. The st_sym_name func-
tion returns a pointer to a null-terminated string containing the name of the given symbol. If the symbol represents a C++ name and name-
demangling is enabled (the default), st_sym_name dynamically allocates the buffer in which it stores the name. Otherwise, it sets name to
the address of the string in the object. In either case, the caller should not modify the returned name buffer, but instead should make
modifications to a copy of the name.
To release a buffer that may have been dynamically allocated by st_sym_name, use the st_free_name function. Ensure that you specify
the same symbol handle to st_free_name that you previously specified to st_sym_name. Otherwise, you may inadvertently release mem-
ory used for some other purpose. Returns a copy of the specified symbol name to a user-supplied buffer. If the name string,
including its null terminator, exceeds buflen characters, st_sym_name_copy truncates it, returning the number of truncated charac-
ters in truncated. For C++ names, this function is useful because it avoids returning dynamically allocated buffers that must later
be released by calls to st_free_name. For non-C++ names, however, it involves more overhead. Returns the symbol handle of the
enclosing block or procedure for the specified symbol. This function is helpful when you are processing local symbols or alternate
entries. Return the ending symbol handle of the block or procedure, respectively, containing the specified symbol. Returns the
symbol handle for the named external symbol. Returns the symbol corresponding to the specified frame offset in the given procedure.
The frame offset must be a positive number and a relative offset from the virtual frame pointer for a procedure. Frequently, but
not always, this is the stack pointer. For example, if an instruction references a local variable with 20($sp), then the frame off-
set would be 20. The symbol that st_frame_offset_to_sym returns may be a parameter to the procedure or a local symbol.
st_frame_offset_to_sym sets byte-offset to the offset (always greater or equal to zero) into the variable to which the frame_offset
corresponds. The byte_offset from a variable may span compiler temporaries on the stack. To check this case, use st_sym_size to
obtain the size of the returned symbol and compare it to the byte offset. Returns the size in bytes of the specified symbol. These
routines are Boolean functions that return a flag that indicates whether a given symbol belongs to each category. Note that only
global symbols can be weak. If st_is_sym_weak is passed a local symbol handle, it returns ST_E_INVALID_SYM to indicate that the
given symbol cannot be weak. The st_get_mangled_name_flag function returns the current state of the name-demangling flags for the
specified object.
The st_set_mangled_name_flag function sets the name-demangling flags for the specified object to the value contained in the address
specified in the flag parameter.
Name demangling is enabled or disabled at the object level only for C++ files. By default, name demangling is enabled when an
object is opened. The name demangling flags have an effect on the C++ name translations that are performed when functions such as
st_sym_name are called. Valid name-demangling flags are defined in /usr/include/cmplrs/demangle_string.h.
RETURN VALUES
All functions indicate success by returning a value of 0 (zero). A positive return value is an errno value from a system call. A negative
return value is a library error or informational code. The library codes are documented in st.h.
Return parameters are set to 0 or -1 when an error occurs. Address parameters are set to 0 while file and procedure handles are set to -1.
An exception to this is if a NULL pointer for the object or other return parameter is input. In these cases, the return parameters will be
unchanged. A non-zero return status is the recommended method for detecting an error return from a libst function.
FILES
Header file that contains all definitions and function prototypes for libst.a functions Header file that controls name-demangling opera-
tions for C++ objects Header file that defines symbol types Header file that defines symbol classes
RELATED INFORMATION
Commands: atom(1)
Functions: libst_intro(3), st_addr_to_file(3), st_file_lang(3), st_obj_calls(3), st_obj_open(3), st_obj_file_start(3),
st_objlist_append(3), st_proc_addr(3)
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st_sym_value(3)