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<title>13.1.4 Tentative variables </title>
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<a name="1204986"> </a><font color="#003366" face="Verdana, Arial, Helvetica, sans-serif">13.1.4 Tentative variables</font>
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<a name="1204987"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">Where variables are defined tentatively in file scope the linker "commons" them up, that is treats them as a single variable. For example, the linker treats variables in the following manner:
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<caption><b><i><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1208001"> </a><font face="Helvetica">Table 43: Linker variables treatment</font></font></i></b></caption>
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<th><font face="Verdana, Arial, Helvetica, sans-serif" color="#003366"><a name="1204990"> </a><font face="Verdana, Arial, Helvetica, sans-serif">File 1</font></font></th>
<th><font face="Verdana, Arial, Helvetica, sans-serif" color="#003366"><a name="1204992"> </a><font face="Verdana, Arial, Helvetica, sans-serif">File 2 </font></font></th>
<th><font face="Verdana, Arial, Helvetica, sans-serif" color="#003366"><a name="1204994"> </a><font face="Verdana, Arial, Helvetica, sans-serif">Linker action</font></font></th>
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<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204996"> </a><div ><font size=2><font size=2 face=Courier><strong>int i;</strong></font></font></div></font></td>
<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204998"> </a><div ><font size=2><font size=2 face=Courier><strong>int i;</strong></font></font></div></font></td>
<td colspan="1" rowspan="4"><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1205000"> </a><div ><font size=2>Treats as the same variable</font></div></font></td>
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<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1205002"> </a><div ><font size=2><font size=2 face=Courier><strong>int i;</strong></font></font></div></font></td>
<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1205004"> </a><div ><font size=2><font size=2 face=Courier><strong>char i;</strong></font></font></div></font></td>
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<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1205008"> </a><div ><font size=2><font size=2 face=Courier><strong>double i;</strong></font></font></div></font></td>
<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1205010"> </a><div ><font size=2><font size=2 face=Courier><strong>int i;</strong></font></font></div></font></td>
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<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1205014"> </a><div ><font size=2><font size=2 face=Courier><strong>int i; </strong></font></font></div></font></td>
<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1205016"> </a><div ><font size=2><font size=2 face=Courier><strong>int i=1;</strong></font></font></div></font></td>
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<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1205020"> </a><div ><font size=2><font size=2 face=Courier><strong>int i=1;</strong></font></font></div></font></td>
<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1205022"> </a><div ><font size=2><font size=2 face=Courier><strong>int i=1;</strong></font></font></div></font></td>
<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1205024"> </a><div ><font size=2>Gives an error - multiply defined</font></div></font></td>
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<a name="1205025"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">The linker uses the size of the first variable encountered and so the user should make sure such variables are the same size.</font>
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<a name="1205026"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">Where a variable has been defined in two places to have a value, even if this is the same value, the linker generates a "<font size=2 face=Courier><strong>multiply defined</strong></font>" error.</font>
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