IRIX Base Documentation 2002 November

home *** CD-ROM | disk | FTP | other *** search

/ IRIX Base Documentation 2002 November / SGI IRIX Base Documentation 2002 November.iso / usr / share / catman / p_man / cat3 / standard / end.z / end

Wrap

Text File | 2002-10-03 | 14.0 KB | 212 lines

END(3C) Last changed: 4-12-99 NNAAMMEE eenndd, eetteexxtt, eeddaattaa, __eenndd, __eetteexxtt, __eeddaattaa, eepprrooll, __fftteexxtt, __ffddaattaa, __ffbbssss, __rrtt__ssyymmbbooll__ttaabbllee, __rrtt__ssyymmbbooll__ttaabbllee__ssiizzee, __rrtt__ssyymmbbooll__ssttrriinngg__ttaabbllee, __pprroocceedduurree__ttaabbllee, __pprroocceedduurree__ttaabbllee__ssiizzee, __pprroocceedduurree__ssttrriinngg__ttaabbllee, __DDYYNNAAMMIICC, __DDYYNNAAMMIICC__LLNNKK, __DDYYNNAAMMIICC__LLIINNKKIINNGG, __BBAASSEE__AADDDDRREESSSS, __GGOOTT__OOFFFFSSEETT, __ggpp, __ggpp__ddiisspp, ____rrlldd__oobbjj__hheeaadd, __rrlldd__nneeww__iinntteerrffaaccee, ____eellff__hheeaaddeerr, ____pprrooggrraamm__hheeaaddeerr__ttaabbllee, ____ddssoo__ddiissppllaacceemmeenntt, __lliibb__vveerrssiioonn, ____llccllddttaa__aaddddrreessss, ____llccllddttaa__ssiizzee - Loader defined symbols in a program SSYYNNOOPPSSIISS eexxtteerrnn iinntt eenndd[[]];; eexxtteerrnn iinntt __eenndd[[]];; eexxtteerrnn iinntt eetteexxtt[[]];; eexxtteerrnn iinntt __eetteexxtt[[]];; eexxtteerrnn iinntt eeddaattaa[[]];; eexxtteerrnn iinntt __eeddaattaa[[]];; eexxtteerrnn iinntt eepprrooll[[]];; eexxtteerrnn iinntt __fftteexxtt[[]];; eexxtteerrnn iinntt __ffddaattaa[[]];; eexxtteerrnn iinntt __ffbbssss[[]];; eexxtteerrnn iinntt __pprroocceedduurree__ttaabbllee[[]];; eexxtteerrnn iinntt __pprroocceedduurree__ttaabbllee__ssiizzee[[]];; eexxtteerrnn iinntt __pprroocceedduurree__ssttrriinngg__ttaabbllee[[]];; eexxtteerrnn SSYYMMRR __rrtt__ssyymmbbooll__ttaabbllee[[]];; eexxtteerrnn cchhaarr __rrtt__ssyymmbbooll__ttaabbllee__ssiizzee[[]];; eexxtteerrnn cchhaarr __rrtt__ssyymmbbooll__ssttrriinngg__ttaabbllee[[]];; eexxtteerrnn iinntt __ggpp[[]];; eexxtteerrnn iinntt __ggpp__ddiisspp[[]];; eexxtteerrnn iinntt __DDYYNNAAMMIICC[[]];; eexxtteerrnn iinntt __DDYYNNAAMMIICC__LLIINNKK[[]];; eexxtteerrnn iinntt __DDYYNNAAMMIICC__LLIINNKKIINNGG[[]];; eexxtteerrnn iinntt __BBAASSEE__AADDDDRREESSSS[[]];; eexxtteerrnn iinntt __GGOOTT__OOFFFFSSEETT[[]];; eexxtteerrnn iinntt ____rrlldd__oobbjj__hheeaadd[[]];; eexxtteerrnn iinntt __rrlldd__nneeww__iinntteerrffaaccee[[]];; eexxtteerrnn iinntt ____eellff__hheeaaddeerr[[]];; eexxtteerrnn iinntt ____pprrooggrraamm__hheeaaddeerr__ttaabbllee[[]];; eexxtteerrnn iinntt ____ddssoo__ddiissppllaacceemmeenntt[[]];; eexxtteerrnn iinntt __lliibb__vveerrssiioonn[[]];; eexxtteerrnn iinntt ____llccllddttaa__aaddddrreessss[[]];; eexxtteerrnn iinntt ____llccllddttaa__ssiizzee[[]];; IIMMPPLLEEMMEENNTTAATTIIOONN IRIX systems DDEESSCCRRIIPPTTIIOONN For the convenience of utilities and other applications that need to access an executable in special ways, lldd(1) may create one or more of the special symbols listed in the SYNOPSIS. Of these, only the symbols __pprroocceedduurree__ttaabbllee __pprroocceedduurree__ssttrriinngg__ttaabbllee, __rrtt__ssyymmbbooll__ttaabbllee, __rrtt__ssyymmbbooll__ssttrriinngg__ttaabbllee, ____rrlldd__oobbjj__hheeaadd, ____eellff__hheeaaddeerr, ____pprrooggrraamm__hheeaaddeerr__ttaabbllee, __lliibb__vveerrssiioonn, which are described below, actually have associated data, which is specially created by lldd(1). For each of the remaining special symbols listed in the SYNOPSIS, no actual data is associated; only the address of the symbol is meaningful. lldd(1) sets the symbol's address to either the location of a particular portion of the executable (such as __eetteexxtt, or __eeddaattaa) or to the value of some other interesting parameter (such as __pprroocceedduurree__ttaabbllee__ssiizzee). NOTE: To avoid their interpretation as gp-relative data, each of these symbols must be declared as an array. Moreover, most of these arrays are declared to have elements of type iinntt though do not conclude that this imposes any restrictions on the alignment of the addresses. The symbol versions without a leading underbar may be overridden by applications. If the application defines the symbol, the symbol is no longer special and the information here is irrelevant for the symbol. NOTE: Many of the symbols mentioned here are release-specific and may change meanings or disappear across releases. The address of eetteexxtt and __eetteexxtt are the first address above the text segment, eeddaattaa and __eeddaattaa are the first address above the initialized data region, and eenndd and __eenndd are the first address above the uninitialized data region. The address of __fftteexxtt is the first address in the program text, __ffddaattaa is the first address in the initialized data region, and __ffbbssss is the first address in the uninitialized data region. Note that the __fftteexxtt, __eetteexxtt, __eeddaattaa, __fftteexxtt, __ffddaattaa, and __ffbbssss are rather questionable things to depend on for programs using dso's or having multiple text or data regions. There is no standard definition of the meanings of these symbols when there are multiple text or data regions present. For example, use of lldd options and spec files can result in the creation of multiple text and/or data regions. Most programs use dso's and that means there are multiple text, data, and bss regions in the running application. Instead of presuming that these symbols mean something specific, applications would be better off using ____eellff__hheeaaddeerr and ____pprrooggrraamm__hheeaaddeerr__ttaabbllee and ____ddssoo__ddiissppllaacceemmeenntt to determine the memory regions of whatever code refers to the symbol. That is, from within a dso (or main program), ____eellff__hheeaaddeerr refers to the ____eellff__hheeaaddeerr of that dso (or main program). One can use ddllooppeenn and ddllssyymm to access the symbols of a different dso or, from a dso, of the main program (see the ddllooppeenn man page). eepprrooll is a symbol that was once used by lliibbpprrooff but is no longer used. User code may freely define its own such symbol for any application purpose. In ISO/ANSI C, the eenndd, eeddaattaa, and eetteexxtt symbols are elements of the space of names reserved for the user. Thus, by default these symbols are not defined by the loader (lldd(1)). If, however, a reference to eenndd, eeddaattaa, or eetteexxtt is unsatisfied during the link, it will be defined by the loader. The address of the resultant symbol will be identical to the address of the symbol of the same name prefixed by an underbar. (Thus, if an unsatisfied reference to eenndd remains at the end of the link, lldd(1) will satisfy the reference by giving it the same address as __eenndd, which is always defined.) Some symbols have a dso-specific meaning. That is, a query of the value within a dso can get a dso-specific value: the values are not global, but specific to the main program or dso taking the address of the symbol. The dso-specific symbols are: __ggpp, __ggpp__ddiisspp, __pprroocceedduurree__ttaabbllee, __pprroocceedduurree__ttaabbllee__ssiizzee, __pprroocceedduurree__ssttrriinngg__ttaabbllee, __rrtt__ssyymmbbooll__ttaabbllee, __rrtt__ssyymmbbooll__ttaabbllee__ssiizzee, __rrtt__ssyymmbbooll__ssttrriinngg__ttaabbllee, __ddaattaa__iinniitt__ttaabbllee, __DDYYNNAAMMIICC__LLIINNKK, __DDYYNNAAMMIICC__LLIINNKKIINNGG, and __BBAASSEE__AADDDDRREESSSS. All the other symbols are global and therefore a single value (that of the main program) will be seen from all dsos and the main program because of the global symbol resolution rules. All of the symbols beginning with __ (underbar) are reserved to the implementation by ISO/ANSI C rules and it is unwise to attempt to define these as global symbols. __ggpp is the address of the region of global data accessed by offsets of the global-pointer register (its address is the run-time value of the global-pointer register.) __ggpp__ddiisspp has the same value as __ggpp. When execution begins, the program break coincides with __eenndd,, but it is reset by the routines bbrrkk(2), mmaalllloocc(3), standard input/output (ssttddiioo(3)), the profile (--pp) option of cccc(1), etc. The current value of the program break is reliably returned by ssbbrrkk((00)), see bbrrkk(2). __DDYYNNAAMMIICC__LLIINNKKIINNGG and __DDYYNNAAMMIICC__LLIINNKK are identical. If referred to, they have special value generated by the linker: 0 means this code is non-shared, 1 means the code is in a KPIC executable, and 2 means the code is in a dso. __DDYYNNAAMMIICC is a symbol which is no longer used. __BBAASSEE__AADDDDRREESSSS is the virtual address of the first loadable segment in the dso/executable. __GGOOTT__OOFFFFSSEETT is no longer used or set. __rld_obj_head is set to the virtual address of a pointer to the list of dso's in a 32-bit executable. See also <oobbjj..hh> and <oobbjj__lliisstt..hh> and rrlldd(1). __rrlldd__nneeww__iinntteerrffaaccee is set to the address of a function within rrlldd that implements various run-time linking facilities. See rrlldd for further information. ____eellff__hheeaaddeerr is set to point to the elf header of the executing object or dso. ____pprrooggrraamm__hheeaaddeerr__ttaabbllee is set to point to the program header table of the executing object or dso. ____ddssoo__ddiissppllaacceemmeenntt is set to point to a 32-bit word (in a 32-bit program) which is the amount the executable or dso has been moved by rrlldd at run-time. __lliibb__vveerrssiioonn is set to point to the address of a 32-bit integer. The value of the integer is 0 normally. It can be non-zero with applications linked -abi and -cckr which can affect slightly the behavior of abi applications calling ssccaannff, llddeexxpp, or aattooff. ____llccllddttaa__aaddddrreessss is set to the address of a special section used to keep thread-local data for MP programming. See the MP documentation for further information. This symbol is not applicable to applications compiled as 64-bit programs. ____llccllddttaa__ssiizzee is set to the size (in bytes) of the special section referred to above. This symbol is not applicable to applications compiled as 64-bit programs. The loader defined symbols __pprroocceedduurree__ttaabbllee, __pprroocceedduurree__ttaabbllee__ssiizzee, and __pprroocceedduurree__ssttrriinngg__ttaabbllee refer to data structures of the runtime procedure table. The procedure table data structures are built by lldd((11)) only if they are referenced. See the include file <ssyymm..hh> for the definition of the runtime procedure table and see the include file <eexxcceeppttiioonn..hh> for its uses. These symbols are not applicable to applications compiled as 64-bit programs. The loader defined symbols __rrtt__ssyymmbbooll__ttaabbllee, __rrtt__ssyymmbbooll__ttaabbllee__ssiizzee, and __rrtt__ssyymmbbooll__ssttrriinngg__ttaabbllee refer to data structures of the runtime symbol table. The runtime symbol table structures are built by lldd((11)) only if they are referenced. The runtime symbol table includes all stProc and stGlobal symbols and is used by the kernel for dynamically loadable kernel modules. See the <ssyymm..hh> include file for the definition of the runtime symbol table. These symbols are not applicable to applications compiled as 64-bit programs. SSEEEE AALLSSOO lldd(1), cccc(1), ff7777(1), ppcc(1), rrlldd(1) bbrrkk(2) mmaalllloocc(3C) mmllooaadd(4) This man page is available only online.