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| <h4 class="subsection">7.2.2 Transformations on Global Variables</h4> |
| |
| <p>Stabs for global variables do not contain location information. In |
| this case, the debugger finds location information in the assembler or |
| linker symbol table entry describing the variable. The source line: |
| |
| <pre class="example"> char g_foo = 'c'; |
| </pre> |
| <p class="noindent">generates the stab: |
| |
| <pre class="example"> .stabs "g_foo:G2",32,0,0,0 |
| </pre> |
| <p>The variable is represented by two symbol table entries in the object |
| file (see below). The first one originated as a stab. The second one |
| is an external symbol. The upper case ‘<samp><span class="samp">D</span></samp>’ signifies that the |
| <code>n_type</code> field of the symbol table contains 7, <code>N_DATA</code> with |
| local linkage. The stab's value is zero since the value is not used for |
| <code>N_GSYM</code> stabs. The value of the linker symbol is the relocatable |
| address corresponding to the variable. |
| |
| <pre class="example"> 00000000 - 00 0000 GSYM g_foo:G2 |
| 00000080 D _g_foo |
| </pre> |
| <p class="noindent">These entries as transformed by the linker. The linker symbol table |
| entry now holds an absolute address: |
| |
| <pre class="example"> 00000000 - 00 0000 GSYM g_foo:G2 |
| ... |
| 0000e008 D _g_foo |
| </pre> |
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