Sources
Help build the largest human-edited directory on the web.
Submit a site - Become an editor
Wikipedia. Licensed under the GNU Free Documentation License.
Are you an expert in this subject? Join the discussion and share your knowledge at Wikipedia.org.
Symbol table
From Wikipedia, the free encyclopedia
In computer science, a symbol table is a data structure used by a language translator such as a compiler or interpreter, where each identifier in a program's source code is associated with information relating to its declaration or appearance in the source, such as its type, scope level and sometimes its location.
Contents |
A common implementation technique is to use a hash table implementation. A compiler may use one large symbol table for all symbols or use separated, hierachical symbol tables for different scopes.
An object code file will contain a symbol table of the identifiers it contains that are externally visible. During the linking of different object files a linker's will use these symbol tables to resolve any unresolved references.
A symbol table may only exist during the translation process, or it may be embedded in the output of that process for later exploitation, for example, during an interactive debugging session, or as a resource for formatting a diagnostic report during or after execution of a program.
 |
This section may require cleanup to meet Wikipedia's quality standards. Please improve this article if you can (March 2007). |
This is how a symbol table of a small program generated from the GNU binutils' nm looks like, there is one data:holaamigosh (assigned by D), many functions (self defined as well as from the standard library). The first column is where the symbol is located in the memory, the second is "The symbol type" and the third is the name of the symbol. By passing suitable parameters, the symbol table was made to sort on basis of address.
| Address | Type | Name |
|---|---|---|
| 00000020 | a | T_BIT |
| 00000040 | a | F_BIT |
| 00000080 | a | I_BIT |
| 20000004 | t | irqvec |
| 20000008 | t | fiqvec |
| 2000000c | t | InitReset |
| 20000018 | T | _main |
| 20000024 | t | End |
| 20000030 | T | AT91F_US3_CfgPIO_useB |
| 2000005c | t | AT91F_PIO_CfgPeriph |
| 200000b0 | T | main |
| 20000120 | T | AT91F_DBGU_Printk |
| 20000190 | t | AT91F_US_TxReady |
| 200001c0 | t | AT91F_US_PutChar |
| 200001f8 | T | AT91F_SpuriousHandler |
| 20000214 | T | AT91F_DataAbort |
| 20000230 | T | AT91F_FetchAbort |
| 2000024c | T | AT91F_Undef |
| 20000268 | T | AT91F_UndefHandler |
| 20000284 | T | AT91F_LowLevelInit |
| 200002e0 | t | AT91F_DBGU_CfgPIO |
| 2000030c | t | AT91F_PIO_CfgPeriph |
| 20000360 | t | AT91F_US_Configure |
| 200003dc | t | AT91F_US_SetBaudrate |
| 2000041c | t | AT91F_US_Baudrate |
| 200004ec | t | AT91F_US_SetTimeguard |
| 2000051c | t | AT91F_PDC_Open |
| 2000059c | t | AT91F_PDC_DisableRx |
| 200005c8 | t | AT91F_PDC_DisableTx |
| 200005f4 | t | AT91F_PDC_SetNextTx |
| 20000638 | t | AT91F_PDC_SetNextRx |
| 2000067c | t | AT91F_PDC_SetTx |
| 200006c0 | t | AT91F_PDC_SetRx |
| 20000704 | t | AT91F_PDC_EnableRx |
| 20000730 | t | AT91F_PDC_EnableTx |
| 2000075c | t | AT91F_US_EnableTx |
| 20000788 | T | __aeabi_uidiv |
| 20000788 | T | __udivsi3 |
| 20000884 | T | __aeabi_uidivmod |
| 2000089c | T | __aeabi_idiv0 |
| 2000089c | T | __aeabi_ldiv0 |
| 2000089c | T | __div0 |
| 200009a0 | D | _data |
| 200009a0 | A | _etext |
| 200009a0 | D | holaamigosh |
| 200009a4 | A | __bss_end__ |
| 200009a4 | A | __bss_start |
| 200009a4 | A | __bss_start__ |
| 200009a4 | A | _edata |
| 200009a4 | A | _end |