Editing Symbol table (section)

==Example: SysV ABI==

{| class="wikitable floatright"
|+Example table: SysV ABI
|- 
! Address !! Type !! Name
|- style="font-size:105%;font-family:monospace;;"
|00000020 || style="text-align:center;" | a || T_BIT
|- style="font-size:105%;font-family:monospace;;"
|00000040 || style="text-align:center;" | a || F_BIT
|- style="font-size:105%;font-family:monospace;;"
|00000080 || style="text-align:center;" | a || I_BIT
|- style="font-size:105%;font-family:monospace;;"
|20000004 || style="text-align:center;" | t || irqvec
|- style="font-size:105%;font-family:monospace;;"
|20000008 || style="text-align:center;" | t || fiqvec
|- style="font-size:105%;font-family:monospace;;"
|2000000c || style="text-align:center;" | t || InitReset
|- style="font-size:105%;font-family:monospace;;"
|20000018 || style="text-align:center;" | T || _main
|- style="font-size:105%;font-family:monospace;;"
|20000024 || style="text-align:center;" | t || End
|- style="font-size:105%;font-family:monospace;;"
|20000030 || style="text-align:center;" | T || AT91F_US3_CfgPIO_useB
|- style="font-size:105%;font-family:monospace;;"
|2000005c || style="text-align:center;" | t || AT91F_PIO_CfgPeriph
|- style="font-size:105%;font-family:monospace;;"
|200000b0 || style="text-align:center;" | T || [[Entry point|main]]
|- style="font-size:105%;font-family:monospace;;"
|20000120 || style="text-align:center;" | T || AT91F_DBGU_Printk
|- style="font-size:105%;font-family:monospace;;"
|20000190 || style="text-align:center;" | t || AT91F_US_TxReady
|- style="font-size:105%;font-family:monospace;;"
|200001c0 || style="text-align:center;" | t || AT91F_US_PutChar
|- style="font-size:105%;font-family:monospace;;"
|200001f8 || style="text-align:center;" | T || AT91F_SpuriousHandler
|- style="font-size:105%;font-family:monospace;;"
|20000214 || style="text-align:center;" | T || AT91F_DataAbort
|- style="font-size:105%;font-family:monospace;;"
|20000230 || style="text-align:center;" | T || AT91F_FetchAbort
|- style="font-size:105%;font-family:monospace;;"
|2000024c || style="text-align:center;" | T || AT91F_Undef
|- style="font-size:105%;font-family:monospace;;"
|20000268 || style="text-align:center;" | T || AT91F_UndefHandler
|- style="font-size:105%;font-family:monospace;;"
|20000284 || style="text-align:center;" | T || AT91F_LowLevelInit
|- style="font-size:105%;font-family:monospace;;"
|200002e0 || style="text-align:center;" | t || AT91F_DBGU_CfgPIO
|- style="font-size:105%;font-family:monospace;;"
|2000030c || style="text-align:center;" | t || AT91F_PIO_CfgPeriph
|- style="font-size:105%;font-family:monospace;;"
|20000360 || style="text-align:center;" | t || AT91F_US_Configure
|- style="font-size:105%;font-family:monospace;;"
|200003dc || style="text-align:center;" | t || AT91F_US_SetBaudrate
|- style="font-size:105%;font-family:monospace;;"
|2000041c || style="text-align:center;" | t || AT91F_US_Baudrate
|- style="font-size:105%;font-family:monospace;;"
|200004ec || style="text-align:center;" | t || AT91F_US_SetTimeguard
|- style="font-size:105%;font-family:monospace;;"
|2000051c || style="text-align:center;" | t || AT91F_PDC_Open
|- style="font-size:105%;font-family:monospace;;"
|2000059c || style="text-align:center;" | t || AT91F_PDC_DisableRx
|- style="font-size:105%;font-family:monospace;;"
|200005c8 || style="text-align:center;" | t || AT91F_PDC_DisableTx
|- style="font-size:105%;font-family:monospace;;"
|200005f4 || style="text-align:center;" | t || AT91F_PDC_SetNextTx
|- style="font-size:105%;font-family:monospace;;"
|20000638 || style="text-align:center;" | t || AT91F_PDC_SetNextRx
|- style="font-size:105%;font-family:monospace;;"
|2000067c || style="text-align:center;" | t || AT91F_PDC_SetTx
|- style="font-size:105%;font-family:monospace;;"
|200006c0 || style="text-align:center;" | t || AT91F_PDC_SetRx
|- style="font-size:105%;font-family:monospace;;"
|20000704 || style="text-align:center;" | t || AT91F_PDC_EnableRx
|- style="font-size:105%;font-family:monospace;;"
|20000730 || style="text-align:center;" | t || AT91F_PDC_EnableTx
|- style="font-size:105%;font-family:monospace;;"
|2000075c || style="text-align:center;" | t || AT91F_US_EnableTx
|- style="font-size:105%;font-family:monospace;;"
|20000788 || style="text-align:center;" | T || __aeabi_uidiv
|- style="font-size:105%;font-family:monospace;;"
|20000788 || style="text-align:center;" | T || __udivsi3
|- style="font-size:105%;font-family:monospace;;"
|20000884 || style="text-align:center;" | T || __aeabi_uidivmod
|- style="font-size:105%;font-family:monospace;;"
|2000089c || style="text-align:center;" | T || __aeabi_idiv0
|- style="font-size:105%;font-family:monospace;;"
|2000089c || style="text-align:center;" | T || __aeabi_ldiv0
|- style="font-size:105%;font-family:monospace;;"
|2000089c || style="text-align:center;" | T || __div0
|- style="font-size:105%;font-family:monospace;;"
|200009a0 || style="text-align:center;" | D || _data
|- style="font-size:105%;font-family:monospace;;"
|200009a0 || style="text-align:center;" | A || _etext
|- style="font-size:105%;font-family:monospace;;"
|200009a4 || style="text-align:center;" | A || __bss_end__
|- style="font-size:105%;font-family:monospace;;"
|200009a4 || style="text-align:center;" | A || __bss_start
|- style="font-size:105%;font-family:monospace;;"
|200009a4 || style="text-align:center;" | A || __bss_start__
|- style="font-size:105%;font-family:monospace;;"
|200009a4 || style="text-align:center;" | A || _edata
|- style="font-size:105%;font-family:monospace;;"
|200009a4 || style="text-align:center;" | A || _end
|}

An example of a symbol table can be found in the [[SysV]] [[Application Binary Interface]] (ABI) specification, which mandates how [[Symbol (programming)|symbols]] are to be laid out in a binary file, so that different compilers, linkers and loaders can all consistently find and work with the symbols in a compiled object.

The SysV ABI is implemented in the [[GNU Binary Utilities|GNU binutils']] [[nm (Unix)|nm]] utility.  This format uses a sorted [[memory address]] field, a "symbol type" field, and a symbol identifier (called "Name").<ref>{{cite web |title=nm |url=http://sourceware.org/binutils/docs-2.17/binutils/nm.html#nm|website=sourceware.org |accessdate=May 30, 2020}}</ref>

The symbol types in the SysV ABI (and nm's output) indicate the nature of each entry in the symbol table. Each symbol type is represented by a single character. For example, symbol table entries representing initialized data are denoted by the character "d" and symbol table entries for functions have the symbol type "t" (because executable code is located in the ''text'' section of an object file). Additionally, the capitalization of the symbol type indicates the type of linkage: lower-case letters indicate the symbol is local and upper-case indicates external (global) linkage.